Health
What is a chromosome DNA and genes
What is a chromosome? Everything we need to know about chromosomes . Our genetic information is stored in 23 pairs of chromosomes that vary greatly in size and shape. Join us to learn more about chromosomes.
What is a chromosome?
Chromosomes are string-like structures located in the nucleus of plant and animal cells. Each chromosome consists of a protein and a molecule of deoxyribonucleic acid (DNA). DNA is passed from parent to offspring and contains specific instructions that make each living thing unique.
The term chromosome (colored body) comes from the Greek words color (chroma) and body (soma). Scientists gave this name to chromosomes because they are structures or cell bodies that are strongly colored by special dyes used in research. What do chromosomes do?
The unique structure of chromosomes keeps DNA tightly wrapped around coil-like proteins called histones. Without such packaging, DNA molecules are too long to fit inside cells. For example, if all the DNA molecules in a human cell were separated from their histones and strung together, they would be 6 feet (1.8 meters) long.
For an organism to grow and function properly, cells must constantly divide to produce new cells to replace old cells. During cell division, it is essential that DNA remains intact and is equally distributed between cells. Chromosomes are a key part of the process that ensures that DNA is accurately copied and distributed during cell division. However, in rare cases, mistakes also occur.
Changes in the number or structure of chromosomes in new cells can lead to serious problems. For example, in humans, some types of leukemia and some other cancers are caused by defective chromosomes, which are made up of joined pieces of broken chromosomes.
It is also very important that reproductive cells such as eggs and sperm contain the correct number of chromosomes and that their chromosome structure is correct. Otherwise, the growth and development of the resulting children may be disturbed. For example, people with Down syndrome have 3 copies of chromosome 21 instead of the two copies that other people have.
Chromosome DNA and genes
Do all living things have the same type of chromosomes?
The number and shape of chromosomes vary among living organisms. Most bacteria have one or two circular chromosomes. Humans, along with other animals and plants, have linear chromosomes that are located in pairs in the nucleus of cells.
The only human cells that do not contain a pair of chromosomes are the reproductive cells, or gametes, which carry only one copy of each chromosome. When two gametes fuse, they become a single cell that contains two copies of each chromosome. This cell then divides and the resulting cells divide many times, eventually forming an adult that has a complete set of chromosome pairs in almost all of its cells.
In addition to the linear chromosomes found in the cell nucleus, human cells, and other complex organisms have a much smaller type of chromosome that resembles what is found in bacteria. This circular chromosome is found in mitochondria, which are structures outside the nucleus that act as the powerhouse of the cell.
Scientists think that in the past, mitochondria were independent bacteria with the ability to convert oxygen into energy. When these bacteria attacked cells that could not use oxygen, the cells kept them, and over time, the bacteria evolved into today’s mitochondria.
Chromosome structure
What is a centromere?
The compact region of linear chromosomes is called the centromere. Although this compaction is called a centromere (which refers to the center), it is usually not located exactly in the center of the chromosome, and in some cases, it is located almost at the end of the chromosome. The regions on both sides of the centromere are called chromosome arms.
The centromere helps to place the chromosomes in the right position in the cell during the complex process of cell division. Chromosomes are copied before a new cell is produced, and the centromere serves as the junction for the two halves of each replicated chromosome, known as sister chromatids.
What is chromatid?
A chromatid is one of the two identical halves of a replicated chromosome. During cell division, first, the chromosomes go through the replication process so that each daughter cell receives a complete set of chromosomes. Following DNA replication, the chromosome consists of two identical structures called sister chromatids, which are joined together at the centromere.
Chromosome structure
In simpler terms, during DNA division, when a cell divides, the cell must copy its DNA and then transfer half of it to one cell and half to another cell. As you know, DNA is arranged in chromosomes, so when a chromosome replicates or makes a copy of itself, the resulting genetic material is put together as two chromosomes, called chromatids. Then in the next stage of cell division, when the DNA is transferred to two daughter cells, one of the chromatids is transferred to each of the two cells; Therefore, a chromatid is a copy of a chromosome after DNA replication.
What is a telomere?
Telomeres are repetitive segments of DNA located at the ends of linear chromosomes. They protect the ends of chromosomes the way a shoelace protects a shoelace from unraveling.
In many types of cells, telomeres lose a portion of their DNA each time the cell divides. Eventually, when all the telomeric DNA is gone, the cell can no longer reproduce and dies. White blood cells and other cells that have a very high rate of cell division have a special enzyme that prevents their chromosomes from losing their telomeres. Because they maintain their telomeres, they usually live longer than other cells. Telomeres also play a role in cancer. Chromosomes in malignant cells usually do not lose their telomeres, contributing to the uncontrolled growth that makes cancer so devastating.
Read More: Why was the human genome never completed?
The number of human chromosomes
Humans have 23 pairs of chromosomes and a total of 46 chromosomes. All plants and animals have a specific number of chromosomes. For example, a fruit fly has four pairs of chromosomes, while a rice plant has 12 and a dog has 39.
What is a karyotype?
A karyotype is a picture of a person’s chromosomes. To produce this image, the chromosomes are separated, stained, and examined under a microscope. This is usually done using the chromosomes in the white blood cells. The chromosomes are imaged under a microscope and then cut, and the chromosomes are sorted by size from largest to smallest. An experienced cytogeneticist can identify missing or extra parts of chromosomes. The karyotype of a male is shown in the figure below.
How are chromosomes numbered?
Each chromosome is assigned a specific number based on its size. The largest chromosome is chromosome number one. For example, in humans, chromosome number 18 is one of the smallest chromosomes.
How are chromosomes inherited?
In humans and most other complex organisms, one copy of each chromosome is inherited from the female parent and the other from the male parent. This explains why children inherit some traits from the mother and others from the father. The inheritance pattern of the small circular chromosome present in mitochondria is different. Only egg cells (and not sperm cells) retain their mitochondria during fertilization; Therefore, mitochondrial DNA is always inherited from the female parent. In humans, a few diseases, including some forms of hearing impairment and diabetes, have been linked to mitochondrial DNA.
Are male chromosomes different from female chromosomes?
Yes, they differ in a pair of chromosomes known as sex chromosomes. Females have two X chromosomes in their cells, while males have one X chromosome and one Y chromosome. Inheriting extra or fewer copies of sex chromosomes can lead to serious problems. For example, women with extra copies of the X chromosome tend to be taller than average, and some have mental retardation. Men with more than one X chromosome have Klinefelter syndrome, a condition characterized by tall stature and often impaired fertility. Another syndrome caused by an imbalance in the number of sex chromosomes is Turner’s syndrome. Women with Turner syndrome have only one X chromosome. They are very short, usually do not reach puberty, and some may have heart or kidney problems.
Facts about X chromosome and Y chromosome
1. In the nucleus of each cell, DNA is packaged in string-like structures called chromosomes.
2. Most human cells have 23 pairs of chromosomes. One set of chromosomes comes from the mother, while the other set is inherited from the father. The 23rd pair are sex chromosomes, while the other 22 pairs are called autosomes.
3. Normally, people who are biologically female have two X chromosomes, while people who are biologically male have one X chromosome and one Y chromosome. Although there are exceptions to this rule.
4. From the point of view of female biology, people inherit one X chromosome from their father and another X chromosome from their mother. Biologically male people always get their X chromosome from their mother.
5. In terms of size, the X chromosome is about three times the size of the Y chromosome and contains about 900 genes, while the Y chromosome has about 55 genes.
6. Female mammals have two X chromosomes in each cell. However, one of the X chromosomes is inactive. This inactivation prevents transcription so that the amount of X-linked genes does not double, which can be potentially dangerous. An inactive X chromosome is compacted in the nucleus as a small compact structure called a cargo body. Objects are usually used to determine gender.
7. Changes in the structure or number of X chromosomes can lead to disease. For example, trisomy X syndrome is caused by having three X chromosomes instead of two X chromosomes. Turner syndrome occurs when women inherit only one copy of the X chromosome.
8. Some women have excellent color vision. This condition is very rare and is called tetrachromacy and is linked to the X chromosome. These women can see up to 100 million shades of color because they have four types of cone cells in their eyes instead of the usual three.
9. Contrary to popular belief, the calico is not a breed of cat, but a distinct coat color pattern that is linked to the X chromosome. More than 95% of calico cats are female. The patches of fur on a calico cat are orange and black, and the color depends on which X chromosome is inactive within each patch of the coat.
10. In genealogy, male descent is often traced using the Y chromosome, as it is only passed down from the father.
11. All people who carry a Y chromosome are related through a common XY ancestor who lived (probably) about 300,000 years ago.
12. The Y chromosome contains a gene called SRY, which causes the testicles to form in the embryo and leads to the development of the internal and external reproductive organs of the male sex. If a mutation occurs in the SRY gene, the embryo will develop female reproductive organs despite having XY chromosomes.
13. Variation in the number of sex chromosomes in a cell is quite normal. Some men have more than two X chromosomes in all their cells (the XXY condition is called Klinefelter syndrome), and many men lose the Y chromosome as they age. Smoking may accelerate this process.
14. Some genes that were thought to be lost on the Y chromosome have actually been moved and transferred to other chromosomes.
15. Most of the Y chromosome consists of repetitive DNA fragments, and special techniques are needed to sequence and determine the order of these very similar fragments.
What are chromosomal abnormalities?
Different types of chromosomal abnormalities can be divided into two main groups: numerical abnormalities and structural abnormalities.
Numerical anomalies
The condition in which a person loses one of his pairs of chromosomes are called monosomy, and the condition in which a person has more than two chromosomes instead of one pair is called trisomy. An example of a disease caused by numerical abnormalities is Down syndrome, which is characterized by mental retardation, learning problems, specific facial features, and weak muscle tone (hypotonia) in infancy. A person with Down syndrome has three copies of chromosome 21 instead of two. For this reason, Down syndrome is also called trisomy 21. An example of monosomy, in which a person lacks one chromosome, is Turner syndrome. In Turner syndrome, the female sex is born with only one sex chromosome, an X, and is usually shorter than usual and is unable to have children, and has other problems.
Structural abnormalities
Chromosome structure can be changed in several ways:
Deletion: A part of the chromosome is lost or deleted.
Duplication: Part of the chromosome is duplicated, resulting in extra genetic material.
Translocation: A part of a chromosome is transferred to another chromosome. There are two main types of chromosomal translocations. In reciprocal translocation, parts of two different chromosomes are exchanged. In Robertson translocation, a complete chromosome is attached to another chromosome at the centromere.
Inversion: A part of the broken chromosome turns upside down and then rejoins. As a result of this phenomenon, the genetic material is reversed.
Rings: A part of the chromosome breaks and forms a ring or circle. This phenomenon can be associated with the loss of genetic material or the genetic material does not change.
Most chromosomal abnormalities occur randomly in the egg or sperm. In these cases, there is an abnormality in every cell of the body. However, some abnormalities occur after fertilization, so some cells are abnormal and others are not.
Chromosomal abnormalities can be inherited from one parent (such as a translocation) or present in a new individual. This is why when it is determined that a child has some kind of abnormality, chromosomal studies are often done on the parents.
How do chromosomal abnormalities occur?
Chromosomal abnormalities usually occur when an error occurs in cell division. There are two types of cell division: mitosis and meiosis.
Mitosis results in two cells that are copies of the original cell. A cell with 46 chromosomes divides and becomes two cells, each of which has 46 chromosomes. This type of cell division occurs throughout the body except for the reproductive organs. This is how most of the cells that make up our body are made and replaced.
Meiosis leads to the production of cells that have half the number of chromosomes, i.e. 23 chromosomes, instead of 46 chromosomes. Meiosis occurs in the reproductive organs and leads to the formation of eggs and sperm.
In both processes, the correct number of chromosomes is supposed to be established in the resulting cells. Of course, errors in cell division can lead to the formation of cells that have fewer or more copies of chromosomes. Errors can also occur when chromosomes are duplicated.
Other factors that can increase the risk of chromosomal abnormalities are:
Maternal age: Women are born with all the eggs they will have in their lifetime. Some researchers believe that with age, errors appear in the egg’s genetic material. Older women are at higher risk of giving birth to babies with chromosomal abnormalities than younger women. Because men produce new sperm throughout their lives, paternal age does not increase the risk of chromosomal abnormalities.
Environment: Although there is no conclusive evidence that certain environmental factors cause chromosomal abnormalities, the environment may play a role in the occurrence of genetic errors.
Skin cancer: symptoms, prevention and treatment
Skin cancer is the abnormal growth of skin cells. This problem generally occurs in areas of the skin that are exposed to sunlight, but sometimes it occurs in areas of the skin that are not normally exposed to light.
Brief anatomy of the skin
The skin is the largest organ of the body and consists of three main layers:
- Epidermis: It is a very thin outer layer of the skin that acts as a barrier to environmental infections and controls the amount of water that evaporates from the body.
- Dermis: The middle and thicker layer of the skin that contains hair follicles as well as nerves and a large number of blood and lymph vessels embedded in a framework of collagen.
- Hypodermis: the deepest layer of the skin, which is rich in fat and collagen and has many blood and lymphatic vessels.
Most skin cancers appear from the cells in the epidermis layer. Keratinocytes are the main cells in this layer of the skin. Deep in the epidermis and near the dermis layer, these cells grow and actively produce new skin cells. This layer is the basal cell layer. Over time, these cells migrate to the surface of the skin and become squamous cells. Among the basal cells, there are brown pigments called melanin that make up the melanocyte cells. These are located close to other cells that remove foreign substances such as bacteria or cancer cells from the skin and deliver them to the lymph nodes through the lymphatic vessels (ie Langerhans cells of the skin).
The lymphatic vessels of the skin reach the lymph nodes of the groin, armpit, and neck. These vessels carry lymph fluid and are one of the fluid circulation systems in the body. This system is considered part of the body’s immune system, but at the same time, it is a pathway that skin cancer cells can use to spread throughout the body. Lymph nodes act as a filter and trap these cells. The proliferation of these cells in the lymph nodes causes the lymph nodes to enlarge.
Types of skin cancer
There are two types of skin cancer based on the type of cells involved:
Keratinocyte cancer
This type of skin cancer includes basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). These are the most common forms of skin cancer. These are more likely to develop in areas of the body that are exposed to sunlight more, i.e. the head and neck. In this form of skin cancer, the probability of the spread of cancer cells and the death of the patient is less than in other types, but if it is not treated, it may grow and spread to other parts of the body.
Squamous cell cancer: This type of cancer occurs in the outer layer of the skin and is usually more aggressive than basal cell cancer. This disease may appear as red and scaly lesions on the skin.
Squamous cell skin cancer
Basal cell cancer: The most common form of skin cancer is basal cell cancer, which accounts for 90% of all skin cancer cases. These are slow-growing lumps that often appear in the head and neck area.
Basal cell skin cancer
Melanoma cancer
The second type of skin cancer is melanoma. This type of cancer is related to melanocytes. Benign moles created by melanocytes can become cancerous. These moles can form anywhere on the body, but they are more likely to develop on the chest and back. In women, the possibility of forming these moles on the legs is more. Most melanomas are curable if diagnosed and treated promptly. If left untreated, they can spread to other areas of the body and become more difficult to treat. This type of skin cancer is more likely to spread than basal cell cancer and squamous cell cancer. This type of skin cancer is less common, but it is considered the most dangerous type of skin cancer. In fact, melanoma only accounts for one percent of skin cancers, but the majority of skin cancer-related deaths each year are related to this disease.
Melanoma cancer
There are types of skin lesions that are a subset of skin cancer. All of these are not skin cancers, but they can become cancerous. One of these cases is actinic keratosis: these red or pink lesions on the skin are not cancerous but are considered a precancerous condition. If left untreated, it can turn into squamous cell carcinoma.
Actinic keratosis is a precancerous condition that can develop into squamous cell carcinoma if left untreated.
Symptoms of skin cancer
All skin cancers are not the same and may cause different symptoms. However, abnormal changes in the skin can be a warning sign for different types of skin cancer. Awareness of the condition of the skin can help diagnose the disease faster.
- Skin lesions: A new mole, abnormal growth, bump, sore, skin patch, or dark spot that appears and does not go away.
- Asymmetry: both sides of skin lesions or moles are not the same.
- Edges: The edges of the skin lesions are jagged and the edges are not equal.
- Color: The stain has an unusual color such as white, black, blue or red.
- Diameter: The thickness of the stain is more than half a centimeter.
- Change: A visible change in the size, color, or shape of a mole.
Moles and skin lesions that can be related to skin cancer often look like moles and skin spots that are not cancerous at all, so you must see a doctor for diagnosis.
Causes of skin cancer
Both types of skin cancer occur when mutations occur in the DNA of skin cells. These mutations cause the skin cells to grow out of control and create a mass of cancer cells in the skin. Basal cell skin cancer is caused by ultraviolet (UV) rays from the sun or tanning devices. UV rays can damage the DNA in skin cells, which will result in abnormal cell growth. Squamous cell cancer is also caused by ultraviolet radiation. In addition, squamous cell cancer may also occur as a result of long-term exposure to cancer-causing chemical agents. This condition can manifest itself in wounds from burns or other injuries, and viruses such as the human papillomavirus (HPV) may cause it.
The cause of melanoma is not clear. Most moles don’t turn into melanoma, and researchers aren’t sure why in some cases they do become cancerous. Like basal cell cancer and squamous cell cancer, melanoma may be caused by UV radiation. However, melanoma can also develop in parts of the body that are not normally exposed to sunlight.
When is a mole dangerous or at high risk of becoming skin cancer?
Moles are usually harmless and rarely turn into skin cancer. If a mole becomes cancerous, it becomes melanoma. There is a precancerous stage called a dysplastic mole where the mole is no longer normal. An early sign of melanoma is a change in a mole: asymmetry, abnormal edges, changes in color, increased diameter, or other changes in condition can indicate that the mole has turned into melanoma. Moles never develop into basal cell carcinoma or squamous cell carcinoma. In the figure below, a normal mole (top row) is compared to a cancerous mole (bottom row).
Skin cancer diagnosis
If a person notices suspicious spots and lumps on their skin or if they notice a change in spots that were already there, they should see a doctor. The specialist doctor examines the shape, size, color, and texture of the suspicious area on the skin, and if he suspects that the area is cancerous, he may perform a biopsy (tissue sampling). During this simple and safe procedure, a sample of suspicious tissue is isolated and examined. With this examination, it is determined whether a person has skin cancer or not. If a person is diagnosed with skin cancer, other tests may be needed to determine how far the disease has progressed. The patient’s treatment plan depends on the type, stage of the disease, and other factors.
Skin cancer screening
Screening for skin cancer by a dermatologist is quick and easy. The patient is asked to remove his clothes and the doctor looks all over his skin for unusual spots and moles. Early detection is the best way to ensure successful skin cancer treatment. Unlike other organs, the skin is always visible so that anyone can notice unusual changes or changes in the condition of their skin.
Stages of skin cancer
To determine the stage or severity of skin cancer, the doctor pays attention to the size of the tumor, and its status in terms of spreading to the lymph nodes and other parts of the body. Skin cancers are divided into two main groups in terms of stage of development: non-melanoma skin cancer and melanoma skin cancer.
Non-melanoma skin cancers include basal and squamous cell cancers, which have the following stages:
- Stage zero: Abnormal cells have not spread beyond the outer layer of the skin, the epidermis.
- Stage one: The cancer may have reached the next layer of the skin, the dermis, but its thickness is not more than two centimeters.
- Stage two: In this stage, the tumor has a size of more than two centimeters, but it has not yet reached the surrounding areas or lymph nodes.
- Stage three: The cancer has spread from the primary site to the adjacent tissue or bone and its size is more than three centimeters.
- Stage four: The cancer has spread to more distant areas than the primary tumor and has entered the lymph nodes, bone, and tissue. The size of the tumor is more than three centimeters.
Melanoma includes the following stages:
- Stage zero: This non-invasive type of skin cancer has not yet penetrated the lower part of the epidermis.
- Stage one: The cancer may have penetrated the second layer of the skin, the dermis, but its size is small.
- Stage two: The cancer has not spread beyond the primary tumor, but it is larger and thicker, and other signs and symptoms such as bleeding or scaling may also be seen.
- Stage three: The cancer has spread and entered the lymph nodes or adjacent tissue and skin.
- Stage four: It is the most advanced form of melanoma. In stage four, the cancer has spread beyond the primary tumor and is seen in lymph nodes, organs, or tissues far from the original cancer site.
If the cancer comes back after treatment, it is called recurrent skin cancer. There is a possibility of cancer returning in any person whose skin cancer has been diagnosed and treated, so it is necessary to conduct investigations in this field on these patients.
Skin cancer treatment methods
The treatment method for this disease depends on various factors such as the size, location, type, and stage of the disease. After considering these factors, the medical team may recommend one or more of the following treatments:
Micrographic Maze surgery: the desired area is locally numbed and the surgeon removes the tumor along with a small amount of surrounding healthy tissue. The tissue is quickly examined under a microscope and areas that still contain microscopic remnants of the tumor are removed and reexamined until no trace of tumor-related cells is seen (figure below). This complex and expensive treatment option is the treatment of choice in cases where it is critical to preserve the healthy tissues around the tumor, as well as in the cases where the borders of the tumor are not well defined, as well as in the cases of tumors that have been treated before but have recurred.
Tumor destruction by curettage and electrocautery (EDC): The tumor area is numbed using a local anesthetic and scraped repeatedly using a sharp blade, and then the edges of the wound are cauterized using an electric needle (electrode). The advantage of this method is that it is fast, easy, and relatively cheap. The problem with this method is that the scar is usually unpleasant and the probability of recurrence is 15%.
In the EDC method, first, the infected area is repeatedly scraped using a sharp blade to remove abnormal tissues.
The edges of the wound are cauterized with an electric needle to remove the remnants of cancer cells.
Surgical tumor removal: First, the tumor area is numbed using a local anesthetic. A ball-like section of skin, which includes the tumor, is removed from the skin, and then the edges of the wound are sutured. In the case of large tumors, a skin graft may be needed to close the wound. The advantage of this method of treatment is that its success rate is more than 90% and the surgeon can simultaneously check whether the entire tumor has been removed or not. The wound created in this way is better than the wound produced by the EDC method, but it has more complexity and cost.
Radiation therapy: In this method, during 10 to 15 sessions, the tumor and a small amount of the surrounding skin area are exposed to high radiation. This form of treatment is useful in cases where patients cannot undergo surgery. The advantage of this method is that no cutting is done. One of the disadvantages of this expensive method is that the treated area cannot be examined at the same time to determine whether the entire tumor is gone or not, and the wounds caused by this method may worsen over time. This method is usually used for elderly people.
Drug therapy: In the case of superficial basal cell cancer, some creams, gels, and solutions such as Imiquimod (Aldara) can be used. The way these drugs work is to stimulate the patient’s immune system to produce interferon. Interferons are proteins that attack cancer cells. Another effective drug in this field is fluorouracil (5-FU), which is a chemotherapy drug. Some patients do not experience any side effects from these topical treatments, but some may experience redness, inflammation, and skin irritation. One of the disadvantages of topical drugs is that because no tissue is available for examination, it is not possible to determine whether the tumor has been completely removed or not.
Cryotherapy: In this method, the tissue is frozen and destroyed using liquid nitrogen. The doctor sprays liquid nitrogen on the infected area and some of the surrounding areas. This causes a burning or stinging sensation in the person, which disappears within a few minutes. Liquid nitrogen freezes and kills the abnormal cells, creating a sore that will be red for several days and may blister and ooze. The area may be swollen for a few days, and in some cases this may need to be repeated. A crust will form over the wound and the dead tissue will fall off within one to four weeks, depending on the size of the treated area. After that, healthy skin cells grow and a scar may remain. Healing may take several weeks, and the healed skin will likely be paler than the surrounding area.
In the cryotherapy method, liquid nitrogen is used to freeze and destroy tissue
Photodynamic therapy (PDT): In this method of treatment, a drug and a special type of light are used. The drug is a chemical that sensitizes the skin to light. This drug is called a photosensitizing agent. The light can be a laser or another type of light. The drug can be used as a cream on the skin or injected into the bloodstream. By absorbing the drug, the cells become sensitive to light. Then the doctor shines light on the desired area and destroys the cancer cells.
Prevention of skin cancer
To reduce the risk of skin cancer, long-term exposure to sunlight and other sources of ultraviolet radiation should be avoided. for example:
- Avoiding tanning devices and solar lamps
- Avoid exposure to sunlight when the intensity of the radiation is high, otherwise you should use an umbrella.
- Using face and lip sunscreens with SPF of 30 or more
- Using a brimmed hat and protective clothing in the sun
- Use sunglasses that have 100% protection against UVB and UVA.
It is also important to check your skin regularly to see if there are any lesions on the skin or if the previous spots and moles have changed.
Skin cancer risk factors
Certain factors increase the risk of skin cancer. For example, a person is more likely to develop skin cancer if:
- Have a family history of skin cancer.
- exposed to certain substances such as arsenic compounds, radium, bitumen, and creosote.
- exposed to radiation, for example, during special treatments for acne and eczema.
- exposed to excessive sunlight, tanning lamps, and other similar factors.
- Live in sunny, hot climates or high altitudes.
- Be constantly engaged in outdoor work.
- Have a history of severe burns.
- They have many large and abnormal moles.
- The skin is pale and has freckles.
- Have skin that gets sunburned easily.
- Have natural blonde or red hair.
- Have blue or green eyes.
- Have precancerous skin lesions.
- Have a weak immune system, for example, have HIV infection.
- Have a history of organ transplantation and taking immunosuppressive drugs.
The use of sunglasses with 100% UVB and UVA protection is recommended to prevent skin cancer.
Doctors who treat skin cancer
If a person is diagnosed with skin cancer, a group of doctors may help the patient with different aspects of the condition. for example:
- A dermatologist who treats skin diseases.
- A cancer surgeon who treats cancer through surgery.
- A radiation therapy specialist who treats cancer using radiation therapy.
- A cancer drug treatment specialist who treats cancer using targeted drug therapies, immunotherapy, chemotherapy, or other drugs.
Complications and complications related to skin cancer
Side effects of skin cancer include the following:
- Disease recurrence means the return of cancer after treatment
- Local recurrence means the spread of cancer to nearby tissues
- Cancer progression in which cancer cells spread to the muscles, nerves, or other organs of the body.
If a person has skin cancer, there is a high risk that the disease will reappear in another part of his body.
Is skin cancer hereditary?
Since most types of skin cancer are caused by exposure to ultraviolet light, they are generally not considered hereditary skin cancers. But the fact that skin cancer is more common among people with less skin pigmentation, and skin color trait is an inherited trait, so it can be said that the role of genetics is important. There are several rare genetic syndromes that lead to an increased frequency of skin cancer cases among those with these syndromes. There is a type of hereditary melanoma called FAM-M syndrome, which is caused by a mutation in the CDKN2A gene located on chromosome 9. This mutation is also called the p16 mutation.
What is the prognosis and longevity of skin cancer?
In general, the prognosis for non-melanoma skin cancer is excellent. Both basal cell carcinoma and squamous cell carcinoma are highly treatable. Almost no death occurs from basal cell cancer, and rarely, death can occur from squamous cell cancer, which is mainly in people who are immunosuppressed. Depending on the treatment method and the location and type of skin cancer, the probability of recurrence of a skin cancer treated in the maze surgery method is 1-2% and in the electric burning and curettage method it is about 10-15%. Early detection of skin cancers can lead to better treatment outcomes.
The results of new research related to effective factors on skin cancer
Statistics show strong evidence that drinking water contaminated with arsenic compounds increases the risk of skin cancer. Arsenic contamination is common in underground water and arsenic contamination of drinking water is significant in some areas. At least 140 million people in 50 countries of the world are consuming drinking water whose concentration of arsenic compounds exceeds the set limit (10 micrograms per liter). Arsenic is one of the natural compounds of the earth’s crust and is widely present in the air, water, and soil. This substance is very toxic in its inorganic form. People are exposed to high levels of inorganic arsenic through drinking contaminated water, using contaminated water to prepare food and irrigate agricultural crops, industrial activities, eating contaminated food, and using tobacco. Long-term exposure to inorganic arsenic, mainly through consumption of contaminated food and water, can lead to chronic arsenic poisoning. Skin lesions and skin cancer are some of the undesirable effects of this substance. In Iran, few researches have been conducted in the field of arsenic contamination of drinking water in different regions. In a study conducted in Ardabil City in 2017, it was found that the concentration of arsenic in the drinking water of this region is higher than the standard (with an average of 15 micrograms per liter). In a similar study in Kashmir city, the presence of high concentrations of arsenic compounds in drinking water was confirmed.
Skin lesions and skin cancer are the main characteristics of arsenic pollution
Being taller at puberty also increases the risk of developing malignant melanoma. Beta-carotene supplementation has no significant effect on increasing the risk of non-melanoma skin cancer. Drinking coffee may reduce the risk of malignant melanoma in women and may reduce the risk of basal cell carcinoma in men and women. There is also evidence that drinking alcoholic beverages may increase the risk of malignant melanoma and basal cell carcinoma.
How common is skin cancer?
In general, melanoma skin cancer is the 15th most common cancer among men and women. The prevalence of both melanoma and non-melanoma skin cancer has increased in recent decades. Currently, about 2 to 3 million cases of non-melanoma skin cancer and 132,000 cases of melanoma skin cancer occur worldwide every year. One out of every three cancers diagnosed is skin cancer, and one in five Americans will develop skin cancer in their lifetime. In 2018, 300,000 new cases of this cancer have been diagnosed. Australia, New Zealand, Norway, Denmark, and the Netherlands are among the countries in the world with the highest prevalence of this disease.
With the process of destroying the ozone layer, the atmosphere loses its protective layer and more ultraviolet rays reach the earth’s surface. It is estimated that a ten percent decrease in the ozone layer will lead to the occurrence of 300,000 cases of non-melanoma skin cancer and 4,500 cases of melanoma skin cancer. The global prevalence of melanoma is increasing, although the main predisposing factors for the development of melanoma appear to be related to recreational exposure to sunlight and having a history of sunburn. The responsibility for these factors lies with the people themselves.
The strange ways skin affects our health
Worn-out or unhealthy skin is a major contributor to every age-related disease, from Parkinson’s to type 2 diabetes. BBC journalist Zarya Gorot explains how skin affects health and how to protect it.
I am boating in the Ardèche Strait in the south of France when I notice people’s strange looks. It is early afternoon on a scorching July day and the sky is blue and clear. Although there are high cliffs on both sides of the river, I have never felt the sun’s rays so strongly.
The sun’s rays have turned the surface of the water into a squiggly path of brilliant light that is impossible to look at. I have chosen my outfit with the seriousness of an explorer who is going to walk in the African desert. My clothes cover my whole body and protect me from the sun. I used a wide-brimmed fishing hat as well as plenty of high SPF sunscreen and I didn’t forget my sunglasses. I am determined to prevent further aging from the sun. But are there other hidden benefits to these extreme measures of mine?
The latest research shows that our skin is not just a mirror of our lifestyle that reflects the effects of years of smoking, drinking alcohol, and stress. According to the new view, the skin as the largest organ of the body is an active participant in our physical health, and wrinkled and dry skin itself causes aging.
Weird theory
In 1958, the Baltimore Longitudinal Study began, which was supposed to be a scientific study of aging with a bold and rather unorthodox hypothesis. Before that, scientists used to study donated cadavers to understand the physiology of living people. But this time the subjects were examined while their hearts were still beating and their bodies were fully alive. Researchers have followed thousands of men and women for decades to study how genes and environment affect their health.
Wrinkled and dry skin causes aging
In the two decades since the Baltimore study began, scientists have made interesting advances: from the discovery that men who were emotionally unstable were more likely to develop heart disease to the discovery that our problem-solving abilities decline slightly as we age. .
One of the most striking findings of the Baltimore study confirms what researchers have long suspected: how young you look is an accurate measure of how healthy you are inside. In 1982, researchers found that men who looked much older than their age at the start of the study were more likely to die.
In more recent studies, 99% of patients who looked at least 10 years older than their actual age had health problems. It appears that skin health can be used to predict a number of seemingly unrelated factors, from bone density to the risk of developing neurodegenerative diseases or death from cardiovascular disease. But is the skin merely a sign of damage that has accumulated in us, or is it something more complex: can it preserve the health of the healthy and worsen the condition of the unhealthy?
Chronological age and biological age
There are two main ways to measure people’s age. The first method is the standard method known as chronological age. But there is also biological age, which shows the speed of aging of the body. Biological age may vary between different people and even within the same body.
As we age, our chronological age eventually affects our appearance: skin becomes thinner and more uneven, and its elasticity decreases; Because the cells responsible for the production of pigment and collagen die or get old. But usually, the environment causes real damage to the skin.
Although UVB rays can damage our DNA and cause sunburns, mutations, and skin cancer, 95% of all UV radiation reaching the Earth’s surface is UVA. This part of the sun’s rays has a longer wavelength and can penetrate deep into the skin, break down collagen, and stimulate cells to produce melanin.
At the microscopic level, skin that has aged due to exposure to sunlight is thicker and has malformed collagen and elastin fibers. On the visible surface, such skin has an uneven color and is significantly more wrinkled.
Even the darkest skin can burn and is susceptible to photoaging, although it takes longer for wrinkles to appear.
While UVB rays usually damage the surface of the skin, UVA penetrates deep into the skin and both can cause systemic inflammation.
Internal factors are thought to be responsible for a small part of skin aging, while UV light is responsible for more than 80% of visible skin changes.
Along with the physical effects described, the skin also undergoes a chemical transformation, and this is something that may have a profound effect on our general health.
Inflammatory aging
In 2000, a group of scientists from the University of Bologna in Italy proposed a new way of thinking about aging by observing how organisms react to stress.
In a healthy young person, the immune system normally functions to maintain order, that is, to repair damage and fight off infections. But when we age or when our health is not good, these inflammatory responses can cross a certain threshold and trigger the release of a cascade of powerful chemicals that travel throughout the body, destroying healthy cells and breaking DNA.
Even the darkest skin is susceptible to sun aging and can burn
The term inflammatory aging is used to describe the global inflammation that accompanies the aging process. Research shows that wrinkled, diseased, or damaged skin becomes part of the inflammatory system and releases chemicals that cause further damage and inflammation.
Higher levels of inflammatory cytokines and chemokines are observed in aged skin. These chemicals destroy collagen and elastin and cause thinning, wrinkling, and loss of skin elasticity. They also disrupt the skin barrier, increasing water loss and susceptibility to stressors. This feedback loop combines with aging cells in the skin, which in turn release their own inflammatory chemicals. Chemicals released by unhealthy skin enter the bloodstream and from there reach different tissues and damage them. The result of this is accelerated aging and a higher risk of various diseases.
So far, old or diseased skin has been associated with the onset of cardiovascular disease, type 2 diabetes and cognitive disorders, as well as Alzheimer’s and Parkinson’s disease.
The importance of skin protection
The first step to protecting your skin is to avoid the sun. In order to protect the skin, observe the following:
- Wear protective clothing against sunlight.
- Use sunscreen with a high protection factor.
- Wear a brimmed hat.
- Use sunglasses.
- Do not stay in the sun as much as possible.
Protecting the skin from the sun is very effective in preventing the visible signs of aging. In a preliminary study, those who used a broad-spectrum sunscreen with an SPF of 15 every day for four and a half years showed no signs of further skin aging.
Moisturizing the skin reduces inflammation.
The important thing in choosing a sunscreen is to choose a product that is broad-spectrum. Broad-spectrum sunscreen not only absorbs or reflects UVB (indicated by SPF) but also protects against UVA. Dermatologists recommend that you always check the product label for UVA protection. Protection against UVA is usually indicated by UV-PF or PPD.
Sunscreen can prevent inflammation that occurs when the skin is exposed to the sun, and as previously mentioned, inflammation is the first step toward aging-related diseases. But using sunscreen is not the only way to maintain skin health.
The easiest way to improve skin health is to moisturize it. Moisturizing the skin reduces inflammation and may even help prevent dementia.
In addition to uneven color and wrinkling, skin that has aged due to exposure to sunlight and age is drier. The moisture level of human skin reaches its peak at the age of 40, and after that, it decreases drastically and produces less amounts of natural moisturizers, namely lipids, filaggrin, sebum, and glycerol.
Dry skin is problematic because when the skin is dry, its function as a barrier between the inside and the outside of the body is weakened. When our skin is dry and scaly, its natural functions (keeping out infectious agents, environmental toxins, and allergens while maintaining moisture) become more difficult.
Sun-damaged skin releases chemicals that contribute to systemic inflammation and increase the risk of age-related diseases.
Adding moisture to the skin is not a complicated task, and this simple intervention produces significant results.
A group of researchers asked elderly volunteers to use a topical moisturizer twice a day for a month. Compared to older participants who did not use moisturizer, their skin was significantly repaired and their skin levels of inflammatory chemicals were lower.
Even the simplest moisturizers can help prevent inflammatory aging
The promising results of the above study were followed by another study in which people over the age of 65 used a moisturizing cream twice a day for three years. The cognitive performance of the participants was measured at the beginning and at the end of the study. After three years, the cognitive performance of the participants in the control group had declined significantly, but the cognitive performance of the group that hydrated their skin had not.
Read more: Inventing a new drug to treat influenza
Dry skin usually has a higher level of inflammation and is often itchy. A decrease in the level of hydration of the stratum corneum (the outer layer of the epidermis) probably plays a major role in inflammatory aging. On the other hand, scratching the skin intensifies the inflammation.
Natural ingredients include glycerol, petroleum, hyaluronic acid, and lipids that are normally found in the outer layer of the skin and are also the natural components of the most basic moisturizers. Drinking more water may also help hydrate the skin, although the evidence is unclear.
To visualize how much skin can affect the rest of your body, think about how much skin you have. There is as much skin on the inside of your body as there is on the outside of your body. When skin is damaged, every inch of it can release toxic chemicals. Therefore, protecting the skin from the sun is a very effective solution, but don’t forget to use moisturizer as well.
Conclusion
The skin not only indicates the internal state of our body and our lifestyle but also plays a role in age-related diseases. When the skin is exposed to environmental factors, especially sunlight, in addition to changes in appearance, it undergoes chemical changes and contributes to various diseases by participating in global inflammation.
Use a broad-spectrum sunscreen to protect your skin from the sun. Using a moisturizer also helps prevent and reduce inflammation and prevent skin damage.
What are the obstacles on the way for humans to reach Mars?
Unveiling of OpenAI new artificial intelligence capabilities
Samsung S95B OLED TV review
Discovery of the brain circuit that manages inflammation
History of the world; From the Big Bang to the creation of the planet Earth
Xiaomi Pad 6S Pro review
AI PC; revolutionary technology of the future?
Black holes may be the source of mysterious dark energy
Motorola Edge 50 Pro review, technical specifications
Can humans endure the psychological torment of living on Mars?
-
Technology10 months agoWho has checked our Whatsapp profile viewed my Whatsapp August 2023
-
Technology11 months ago
How to use ChatGPT on Android and iOS
-
Technology10 months ago
Second WhatsApp , how to install and download dual WhatsApp August 2023
-
Technology11 months ago
The best Android tablets 2023, buying guide
-
AI1 year ago
Uber replaces human drivers with robots
-
Humans1 year ago
Cell Rover analyzes the inside of cells without destroying them
-
Technology11 months ago
The best photography cameras 2023, buying guide and price
-
Technology11 months ago
How to prevent automatic download of applications on Samsung phones
