Brain scans of more than 100 mammalian species, including humans, reveal that the efficiency of information transfer in the brain is the same in all mammals, regardless of size.
The mammalian brain consists of two sides, or hemispheres, which nerve tracts, also known as axons, connect. The two hemispheres share information along these axons.
How rapidly information spreads in the brain depends on the number of synapses — the junctions between nerve cells — it has to pass through.
An ideal system would have a multitude of long connections to enable the rapid transfer of information between all parts of the brain. However, producing this many neuronal connections comes at a cost to the animal. The evolution of the brain, therefore, represents a compromise.
People commonly believe that human beings, due to our advanced evolution, have higher levels of brain connectivity than other animals, enabling the more efficient and rapid transfer of information throughout the brain.
A new study that researchers from Tel Aviv University in Israel led challenges this assumption. They scanned the brains of more than 120 different mammals and found that brain connectivity is neither higher in humans nor dependent on the size of the brain.
Their findings, which suggest that all mammals have equal levels of brain connectivity, appear in the journal Nature Neuroscience.
The idea that brain connectivity — and, therefore, efficiency — is greater in the human brain has been around for a long time.
“Many scientists have assumed that connectivity in the human brain is significantly higher compared to other animals, as a possible explanation for the superior functioning of the ‘human animal,'” explains the study’s first author, Prof. Yaniv Assaf.
To test this assumption, Prof. Assaf and his team used a type of brain scan called diffusion MRI to scan the brains of 123 different species of mammal, including humans. It was the first time that researchers had placed the majority of these animals’ brains inside an MRI scanner.
The animals in the study included rodents, monkeys, and even dolphins. The brain volumes of the species ranged from 0.1 milliliters (ml) to more than 1,000 ml.
The researchers also scanned the brains of 32 people. They used a scanning program to reconstruct the neural network of each species, including the neurons that transfer information and the synapses where they meet.
To estimate the brain connectivity of each species, the researchers applied a mathematical approach based on the number of synapses that information must cross to get from two points inside the brain.
Prof. Assaf explains, “For every brain we scanned, we measured four connectivity gages: connectivity in each hemisphere (intrahemispheric connections), connectivity between the two hemispheres (interhemispheric), and overall connectivity.”
The team derived a value called the mean-short path, or MSP, which indicates the minimum number of connections that information needs to pass to get between two parts of the network. A high MSP indicates low brain connectivity.
Comparing these values among species, the researchers found that brain connectivity is independent of the size and structure of a mammal’s brain.
“In other words, the brains of all mammals, from tiny mice through humans to large bulls and dolphins, exhibit equal connectivity, and information travels with the same efficiency within them,” explains Prof. Assaf.
The team also identified a mechanism by which the brain balances the number of connections that it uses for transferring information. When there were many connections between the two hemispheres of the brain, connections within the individual hemispheres remained low, and vice versa.
This mechanism ensures that high connectivity in one part of the brain is always countered by low connectivity in another part.
Unlike overall brain connectivity, there were variations in this process among different species.
“[T]he brains of some rats, bats, or humans exhibit higher interhemispheric connectivity at the expense of connectivity within the hemispheres, and the other way around — compared to others of the same species,” says the study’s senior author, Prof. Yossi Yovel.
The team also found variations in this “connectivity compensation” among different members of the same species.
In humans, these differences could underlie differing cognitive abilities or even aptitude in certain fields, such as mathematics or music. Future research by the team will map this in more detail.
Other mammals' brains are efficient more than human brain
By Raphael Hans
Bacterial vaginosis, also known as vaginal bacteriosis, is the most common cause of vaginal infection for women of childbearing age.
It frequently develops after sexual intercourse with a new partner, and it is rare for a woman to have it if she has never had sexual intercourse.
Bacterial vaginosis (BV) also increases the risk of developing a sexually transmitted infection (STI). However, BV is not considered an STI.
BV is the vaginal infection most likely to affect women between the ages of 15 and 44 years.
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Fast facts about bacterial vaginitis
- Bacterial vaginitis (BV) is the most common vaginal infection among women aged 15 to 44 years.
- Symptoms, if they appear, may include itching and a gray, watery discharge with a “fishy” smell.
- Untreated BV can lead to serious complications.
- Treatment is normally with antibiotics.
- Some home remedies are suggested, but anyone with symptoms should see a doctor.
Symptoms
BV may be present without symptoms, but if symptoms occur, they include vaginal discharge, burning, and itching.
Vaginal discharge may:
- be watery and thin
- be gray or white in color
- have a strong and unpleasant smell, often described as fishy
Less commonly, there may be:
- a burning sensation during urination
- itching around the outside of the vagina
Between 50 and 75 percent of women with BV have no symptoms. BV alone is not considered harmful, but complications can arise.
Complications
Complications that have been linked to BV include a higher risk of:
- HIV infection, as BV increases susceptibility to the virus
- STIs, such as the herpes simplex virus, chlamydia, gonorrhea, and human papilloma virus (HPV)
- post-surgical infection, for example, after a termination or a hysterectomy
Possible complications of BV during pregnancy include:
- early, or preterm, delivery
- loss of pregnancy
- the amniotic sac breaking open too early
- postpartum endometritis, an irritation or inflammation of the lining of the uterus after delivery
- tubal factor infertility, caused by damage to the fallopian tubes, which connect the ovaries to the uterus
- chorioamnionitis, an inflammation of the membranes surrounding the fetus, known as the chorion and the amnion
Chorioamnionitis significantly increases the chance of an early delivery. If the newborn survives, they have a higher risk of cerebral palsy.
In-vitro fertilization (IVF) may be less likely to succeed if a woman has BV.
BV also increases the risk of pelvic inflammatory disease (PID), an infection and inflammation of the upper female genital tract that can have severe consequences, including infertility.
READ MORE:How often should a man release sperm?
Causes
BV is caused by an imbalance of naturally occurring bacterial flora, the usual bacteria found in a woman’s vagina. Why this happens is not clear.
It is different from candidiasis, a yeast infection, or Trichomonas vaginalis (T. vaginalis), or trichomoniasis, also known as trich. These are not caused by bacteria
The role of bacteria
All parts of the body have bacteria, but some are beneficial while others are harmful. When there are too many harmful bacteria, problems can arise.
The vagina contains mostly “good” bacteria and some harmful bacteria. BV occurs when the harmful bacteria grow in numbers.
A vagina should contain bacteria called lactobacilli. These bacteria produce lactic acid, making the vagina slightly acidic. This prevents other bacteria from growing there.
Lower levels of lactobacilli may cause the vagina to become less acidic. If the vagina is not as acidic as it should be, this can give other bacteria the chance to grow and thrive. However, exactly how these harmful bacteria are linked with BV is not known.
Risk factors
Any woman can develop BV, but some behaviors or activities can increase the risk.
These include:
- douching, or using water or a medicated solution to clean the vagina
- having a bath with antiseptic liquids
- having a new sex partner
- having multiple sex partners
- using perfumed bubble baths, vaginal deodorants, and some scented soaps
- smoking
- washing underwear with strong detergents
BV cannot be caught from toilet seats, bedding, swimming pools, or touching objects.
Treatment
BV often clears up without treatment, but women with signs and symptoms should seek treatment to avoid complications.
Treatment may not be needed if there are no symptoms. Sometimes BV can appear and disappear for no apparent reason.
If there is an abnormal vaginal discharge, it is important to see a doctor as soon as possible. A doctor can diagnose BV and rule out other infections, such as gonorrhea or trich.
Untreated BV can also lead to complications, especially during pregnancy.
Some doctors recommend giving BV treatment to all women who will be undergoing a hysterectomy or termination, before the procedure, regardless of symptoms.
Male partners do not usually need treatment, but they can spread BV between female sex partners.
Antibiotic medication
Antibiotics are effective in up to 90 percent of cases, but BV often comes back again within a few weeks.
Metronidazole is the most common antibiotic for BV.
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It is available in the following forms:
- Tablets: Taken orally, twice daily for 7 days. It is seen as the most effective treatment, and the preferred treatment if the woman is breastfeeding or pregnant.
- A single tablet: Taken orally as a one-time dose. BV is more likely to return with this treatment, compared with the 7-day tablet course.
- Gel: Applied to the vagina once daily, for 5 days.
Metronidazole reacts with alcohol. The combination can make the patient feel very ill. Individuals taking metronidazole should not consume alcohol for at least 48 hours afterward.
Clindamycin is an alternative antibiotic. It may be used if metronidazole is not effective, or if the infection recurs.
When taking clindamycin, barrier contraception methods, such as latex condoms, diaphragms, and caps may be less effective.
Tinidazole is another antibiotic that is sometimes used to treat BV if metronidazole does not work or if BV recurs. It is taken by mouth as a single dose. Alcohol must be avoided when taking this medication.
If the following happens, further tests will be needed:
- symptoms persist
- symptoms go away but come back
- the patient is pregnant
If symptoms resolve after completing a course of antibiotics, the woman will not have to be tested for BV again.
Recurring symptoms
Around 30 percent of women whose symptoms disappear with treatment will have a recurrence within 3 months, and 50 percent will have a recurrence within 6 months.
This may be treated with a 7-day course of oral or vaginal metronidazole or clindamycin. If the previous treatment was by mouth, vaginal treatment might work better the second time, and if the first treatment was vaginal, the follow-up treatment should be by mouth.
If more than three episodes occur within 12 months, the doctor may prescribe a vaginal metronidazole gel to use twice a week for 3 to 6 months.
Diagnosis
The doctor may be able to diagnose BV from a description of symptoms and a physical examination. They will look out for an unpleasant smell and a thin, white or gray discharge.
If the patient is sexually active and there is a chance that an STI is present, the doctor may order some diagnostic tests.
A swab or small plastic loop can be used to collect sample cells from the vaginal wall. The pH balance of the vagina may also be measured, to assess acidity levels.
Home remedies
No over-the-counter medication is approved for BV, but there is anecdotal evidence that probiotics can help treat BV.
A review of studies, published in January 2014, concludes:
“Although the results of different studies are controversial, most studies have been in favor of the probiotics in the prevention or treatment of BV, and no adverse effects have been reported. Therefore, it may be helpful to recommend daily consumption of probiotic products to improve public health among women.”
However, more research is needed to confirm its effectiveness.
Some other home remedies have been suggested, but, since BV can lead to serious complications, anyone with symptoms should see a doctor.
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Bacterial vaginosis well explained
By Raphael Hans
What you should know!!!
Kidney, or renal, cancer refers to any type of cancer that involves the kidney. Older age, obesity, smoking, and high blood pressure increase the risk of developing kidney cancer.
The kidneys are part of the urinary system, which eliminates waste and excess fluid and electrolytes from the blood. They also control the production of red blood cells and regulate blood pressure.
Kidney cancers mainly originate in two parts of the kidney, the renal tubule and the renal pelvis. A cancer that starts outside the kidney and metastasizes to the kidney is not normally called kidney cancer.
Kidney cancer is one of the 10 most common cancers, affecting about 1 in every 63 people over a lifetime. It occurs more frequently among adults aged between 50 and 80 years.
Worldwide, North America has the highest rate of kidney cancer, but in developing countries, the incidence has been steadily increasing over the last three decades. This increase may be linked to a parallel rise in obesity rates, or it could be due to improved detection and diagnosis.
Symptoms
Growing rates of kidney cancer may be linked to a rise in obesity.
Symptoms do not usually appear in the early stages of kidney cancer.
In the later stages, the person may experience:
Ø blood in the urine
Ø a lump or mass in the back, near the kidneys
Less often, there may be:
Ø a continuous pain in the side, near the kidneys
Ø a lump in the abdomen
Ø anemia
Ø constant fever and night sweats
Ø tiredness or fatigue
Ø weight loss and loss of appetite
Other conditions can lead to similar symptoms, so it is important to see a physician if any of these occur.
Managment
Treatment options depend on several factors, including the patient's general health, the type and stage of kidney cancer, and the patient's own preferences.
Most kidney cancers are treated first by surgery. A person can function with just one kidney, so removing a kidney is an option.
Nephrectomy involves removing the kidney, the nearby adrenal gland, a border of healthy tissue, and the adjacent lymph nodes. The surgery can be done laparoscopically, through small incisions.
If the tumor is less than 1.5 inches, or 4 centimetres across, the surgeon may remove only part of the kidney in a partial nephrectomy.
If the cancer has spread outside the kidney, surgery may not cure it, but it can ease pain and make other non-surgical treatments more effective.
In nephron-sparing surgery, the tumor, but not the kidney, is surgically removed. This may be an option during the early stage of kidney cancer, or if the patient has only one kidney.
A patient who is unwell or frail may not be able to undergo surgery. In this case, a number of nonsurgical treatment options are possible.
It is important to get as much information as possible and to talk to a doctor or counselor about what to expect.
Embolization aims to block the flow of blood to the tumor. The surgeon inserts a small tube known as a catheter into the groin. X-ray images guide the catheter into the blood supply for the kidney. A special material passes through the catheter into the blood vessel, blocking the blood supply to the kidney and starving the tumor of oxygen and nutrients. This causes the tumor to shrink.
Cryoablation involves inserting one or more special needles, known as cryoprobes, through small incisions into the tumor. An imaging scan guides the process. A gas in the needles freezes the cells around the tip of each needle. Another gas warms thaws the tissue, and then the cells are refrozen. This freeze-thaw cycle kills the cancer cells.
Some pain may occur after the procedure, and, rarely, some bleeding, infection, and damage to the tissue close to the tumor.
Advanced or recurrent kidney cancer treatment is for kidney cancer that comes back, or kidney cancer that has spread out of the kidney.
Surgery aims to remove as much of the tumor as possible.
In biological therapy, or immunotherapy, drugs use the body's own immune system to fight cancer. Examples are interferon and interleukin-2. Both are synthetic versions of chemicals that our bodies make. Side effects include nausea, vomiting, chills, elevated body temperature, and loss of appetite.
In targeted therapy, medicines interrupt the functions that cancer needs to survive, such as the blood supply.
Targeted therapies include:
Ø Sunitinib, or Sutent
Ø Sorafenib, or Nexavar
Ø Bevacizumab
Ø Temsirolimus
Radiation therapy cannot usually cure kidney cancer, but it may help reduce the spread and the severity of symptoms. Patients typically undergo a few minutes of treatment daily for a number of days. Radiation therapy that is used to control rather than to cure a cancer tends to have less severe side effects.
Side effects can include fatigue, nausea, and vomiting.
Complementary treatments may include taking certain vitamins alongside regular treatment. This should first be discussed with a physician. Some people have found that alternative treatments can relieve symptoms, but these can be unhelpful or hazardous, and should first be discussed with the medical team.
Stages
One way of staging kidney cancer is a four-stage system:
Stage 1: The tumor is under 2.8 inches, or 7 centimeters in diameter and it is limited to the kidney.
Stage 2: The tumor is greater than 2.8 inches, or 7 centimeters, in diameter, and it is still limited to the kidney.
Stage 3: The cancer is any size but has spread beyond the kidney to at least one other location. It may have reached the adrenal gland, nearby blood vessels, a lymph node, or the fat that surrounds the kidney.
Stage 4: The cancer has spread beyond the fatty tissue around the kidney, it affects at least one lymph node, or it has spread to other organs.
Some causes
Cancer starts when there is a change in the structure of DNA in cells. A genetic mutation causes cells to grow uncontrollably eventually producing tumor cells.
Untreated, cancer grows and spreads, usually through the lymphatic system, a series of nodes or glands that exist throughout the body.
Renal cell carcinoma typically starts in the cells that line the tiny tubes of the nephron. Tumors normally grow as a single mass, but sometimes, more than one tumor can grow in one kidney, and sometimes in both kidneys.
Transitional cell carcinoma develops in the tissue that forms the tubes that connect the kidneys to the bladder. This type of cancer can begin in the ureters and also in the bladder itself.
Wilms' tumor is a childhood kidney cancer caused by the loss or inactivation of a tumor suppressor gene called QT1 on chromosome 11. Tumor suppressor genes generally suppress tumor growth and control cell growth.
Putting up kidney cancer
When a person finds out they have cancer or another serious illness, they may experience feelings of grief, stress, anxiety and depression. Talking to a well-qualified counselor may help.
It is important to get as much information as possible. Members of the medical team will provide details about the diagnosis, available options, and their effectiveness.
The patient should eat a healthy diet with plenty of fruits and vegetables, sleep at least 7.5 hours each day, and get enough exercise, within the limits set by the physician. This will maximize the benefits of any treatment.
Allow friends and family to help. They can provide practical assistance and support the patient's mental, emotional, spiritual, and, ultimately, physical health.
How you could avoid it
Measures to reduce the risk of developing kidney and other cancers include:
A healthy lifestyle can help reduce the risk of kidney cancer.
not smoking
eating plenty of fruit and vegetables
exercising regularly
keeping the body weight within normal limits for your height, sex, and age
getting at least 7 hours good quality continuous sleep every 24 hours
maintaining a healthy blood pressure
avoiding toxic chemicals
Kinds of kidney cancer
Renal cell carcinoma the most common,
Other types are:
Ø urothelial cell carcinoma of the renal pelvis
Ø squamous cell carcinoma
Ø juxtaglomerular cell tumor, or reninoma
Ø angiomyolipoma
Ø renal oncocytoma
Ø Bellini duct carcinoma
Ø clear-cell sarcoma of the kidney
Ø mesoblastic nephroma
Ø Wilms' tumor, usually diagnosed in children under 5 years of age
Ø mixed epithelial stromal tumor
Rarely, potentially cancerous tumors that usually originate in other parts of the body can start off in the kidneys. These include clear cell adenocarcinoma, transitional cell carcinoma, inverted papilloma, renal lymphoma, teratoma, carcinosarcoma, and carcinoid tumor of the renal pelvis.
Most cancers that originate in the renal tubule are renal cell carcinoma and clear cell adenocarcinoma. Those that originate in the renal pelvis are transitional cell carcinoma.
Risk factors
Risk factors for renal cell carcinoma, the most common type of kidney cancers, include:
Kidney disease that needs dialysis may increase the risk of renal cancer.
Ø Age: The risk increases significantly after the age of 60 years
Ø Sex: For every two women who get kidney cancer, 3 men will do so
Ø Obesity: People with obesity have a significantly higher risk
Ø Smoking: Regular tobacco smokers have a much higher risk, but the risk drops when the person quits
Ø Hypertension, or high blood pressure: The higher risk may be due to the hypertension itself, or it may be due to anti-hypertensive medications
Ø Smoking, obesity, and hypertension account for around 50 percent of all renal cell carcinomas
Ø Workers who are exposed to chemicals, such as asbestos, trichloroethylene, and cadmium, are more likely to develop renal cell carcinoma
Asbestos was widely used in the past in construction. Cadmium is a metal used in batteries. Trichloroethylene is an industrial solvent used to strip paint from metals.
Patients receiving long-term dialysis for chronic kidney failure are more likely to develop renal cell carcinoma. This may be due to kidney disease rather than the dialysis itself.
Patients who have received a kidney transplant and are taking immunosuppressant medications have a higher risk of developing renal cell carcinoma. The use of medications such as phenacetin, a pain reliever, has been linked to a higher risk of kidney cancer, and the use of diuretics may contribute.
Von Hippel-Lindau disease is a genetic condition that increases the risk of several kinds of tumors, including renal cell carcinoma. In hereditary papillary renal cell carcinoma, multiple papillary tumors develop in both kidneys. Other diseases that increase the risk include Birt-Hogg-Dube syndrome and hereditary leiomyoma-renal cell carcinoma.
Diagnosis
The doctor will look at the patient's symptoms and order some tests.
Ø Blood and urine tests can rule out other possible causes of symptoms such as kidney stones or an infection
Ø An ultrasound scan can help the doctor identify any change in the shape of the kidney that could be caused by a tumor
Ø A CT scan normally involves the patient drinking a dye first
Ø An image-guided biopsy involves using a needle to remove a small sample of kidney tissue for examination under a microscope for cancer cells
Additional tests for transitional cell cancer include:
Excretory urogram: A dye is injected into a vein in the patient's arm. The kidneys and urinary system process the dye, and this may enable any signs of cancer to show up on an X-ray.
Cystoscopy: A long narrow tube with a special lens and light at the end is inserted into the urethra, to provide an image inside the patient's bladder. A biopsy may be taken at the same time.
Kidney cancer well explained (2020 updated)
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