Craniosynostosis is a condition which the suture lines in the skull closed prematurely. This results in the deformity and abnormal growth of the skull. The usual cause is either bone ossification defects or failure of the brain to grow normally. Genetic factors are considered but the cause is still unknown. Craniosynostosis is a common condition which happens approximately once every 2000 births. Males have a higher risk than females. There are two types of the condition namely primary craniosynostosis which involves early fusion of one cranial suture and complex craniosynostosis which involves early fusion of several sutures.
Primary craniosynostosis prevents the growth of the cranial bone and skull along that one suture line. As the brain and skull grow, some parts are diverted to the other regions of the head resulting in the abnormal enlargement of these areas. One of the type of craniosynostosis is called scaphocephaly where the head becomes long, narrow, and wedge-shaped and accounts to about 50 percent of craniosynostosis. Despite the fact of the abnormal head shape, the brain still has enough room to grow and will not cause any neurological issues.
In complex craniosynostosis, there are several suture lines prematurely close. The severity of the head deformity depends on the location and the number of associated suture lines. This type of craniosynostosis is more severe because it restricts the normal growth and development of the brain.
Surgery is the usual treatment for craniosynostosis. The treatment involves opening the fused suture which allow the cranial bones to recommence growth in this region. Some treatments require the removal of a skull part and replaced with an artificial plate. Performing the surgery right after birth gives the best outcome. Most children grow normally and do not exhibit neurological problems after treatment.
OpenStax Anatomy and Physiology. Homeostatic Imbalances. Craniosynostosis. Accessed November 9, 2019
In 1976, the Ebola virus was identified in central Africa and is currently one of the many emerging viruses that cause hemorrhagic fever. This type of fever has symptoms that include fever, massive bleeding, bruising, red eyes, headache, internal bleeding, bleeding from the nose, red spots on skin, diarrhea, and vomiting with blood. Hemorrhagic fever is fatal because it collapses the circulatory system. The photo above shows Ebola viruses budding out from a monkey cells.
Bacteria are found everywhere and they can be either good or pathogenic. It may be a good time to know which ones are the adversaries and understand what disease they cause. Below is a list of common bacteria that cause illness in humans. Ladies and gentlemen, meet your pathogens.
Bordetella pertussis: Bacteria that causes pertussis or whooping cough. Complication can lead to brain damage and death in children. Its virulence factors are fimbrae, exotoxins, and capsule.
Borrelia burgdorferi: Gram negative bacteria in the spirochete class. This bacteria is known to cause Lyme disease. Symptoms include bulls eye rash and flu-like symptoms. Its virulence factor is the shape which allows to burrow into tissues.
Chlamydia trachomatis: Bacteria that cause sexually transmitted infection chlamydia. Its symptoms include painful urination, puss-filled discharge, and vaginal discharge with foul odor.
Clostridium botulinum: Bacteria that cause botulism. Its symptoms include blurry vision, respiratory paralysis, inhibition of muscle relaxation, and flaccid paralysis.
Clostridium tetani: Common soil bacteria and the causative agent of tetanus. Port of entry is through puncture wound. Symptoms include lock jaw, muscle spasm, difficulty swallowing, and fever.
E.coli O157:H7: Type of Escherichia coli bacteria that is extremely virulent. It produces several potent enterotoxins that cause organ damage. This bacteria also cause hemolytic uremic syndrome or damages to the kidney blood vessels.
Escherichia coli: Bacteria that usual cause urinary tract infection. Virulence factors include fimbrae and flagella. Its symptoms include cloudy urine, foul odor smell, and urine blood.
Haemophilus influenzae: Bacteria that cause a type of pneumonia. It cause an opportunistic secondary infection in people who may be infected with a virus-like flu or virus. This bacteria also cause meningitis or inflammation of the meninges.
Helicobacter pylori: Bacteria that infects and colonizes the stomach. It cause stomach or gastric ulcer. Its virulence factor is flagella.
Klebsiella pneumoniae: Bacteria that cause the most severe pneumonia. Its symptoms include coughing with bloody sputum.
Mycobacterium tuberculosis: Bacteria that cause tuberculosis, a disease identified by the growth of nodules called tubercles in the lung tissues. Its virulence factor is mycolic acid which makes the bacteria resistant to chemical damages.
Mycoplasma pneumoniae: Bacteria that lacks a cell wall and cause mild form of pneumonia or walking pneumonia.
Neisseria gonorrhoeae: Bacteria that cause sexually transmitted infection gonorrhea. Symptoms include pain when urinating, genital discharge, and swollen testicles.
Neisseria meningitidis: Bacteria that cause meningitis in adults. Symptoms include fever, headache, stiff neck, sensitive to light, muscle pain, and rashes that do not fade under pressure.
Pseudomonas aeruginosa: Bacteria that cause various acute and chronic infection at different parts of the body. Can cause ear infection.
Rickettsia rickettsii: Bacteria that cause Rocky Mountain Spotted Fever. Symptoms include non-itchy spotted rash on trunk and appendages including palms and soles. Other symptoms include muscles aches and nausea.
Salmonella typhimurium: Causative agent of bacterial gastroenteritis. Usually found in poultry products. Symptoms include diarrhea, abdominal pain, nausea, and fever.
Salmonella typhi: Bacteria that cause typhoid fever and can be asymptomatic.
Staphylococcus aureus: Causative agent of bacterial gastroenteritis. Also causes ear infection.
Streptococcus mutans: Bacteria that cause dental caries. It produce lactic acid that degrades tooth enamel.
Streptococcus pneumoniae: Common cause of pneumonia and can also cause meningitis. Its virulence factor is capsule.
Streptococcus pyogenes: Bacteria can cause ear infection. It can also cause necrotizing fascitis or flesh-eating disease, strep throat, scarlet fever, and strawberry red tongue.
Group B Streptococcus: An opportunistic bacteria that becomes pathogenic to fetus/newborns and cause blindness, pneumonia, and brain damage.
Treponema pallidum: Bacteria that cause sexually transmitted disease syphilis. It is a type spirochete bacteria and can burrow in the tissues.
Vibrio cholerae: Bacteria that cause cholera, an infectious disease that causes severe watery diarrhea which can lead to dehydration and even death if untreated.
Yersinia pestis: Bacteria that cause plague. Its virulence factor is endotoxin that causes septic shock.
Cystic fibrosis is a genetic disease that damages the lungs causing difficulty in breathing and chronic pulmonary infections. The disease also affects other organs such as liver, pancreas, and intestines. Half a century ago, the outcome for children with cystic fibrosis was very depressing. These children do not live for more than 10 years, but with medical treatment advancement, cystic fibrosis patients can live for 30 years.
In normal people, an integral membrane protein called CFTR (cystic fibrosis transmembrane conductance regulator) transports Cl- ions out of the cell. A person with cystic fibrosis has a mutated CFTR gene and assembles a defective membrane protein that do not integrate into the cell membrane but instead, destroyed by the cell.
In health lungs, CFTR maintains a negatively charged environment outside the cell by moving out Cl- ions. This negatively charged environment attracts positive ions such as Na+ forming a concentration of Na+ and Cl- in the extracellular space. At the same time, respiratory epithelial cells secrete mucus in the extracellular space that helps trap dust and bacteria. Cilia in the respiratory linings then moves the trapped dust and bacteria out of the respiratory tract. The concentration of Na+ and Cl- helps create a solute-rich mucus that draws water by osmosis from the cell making the mucus thinner and not too viscous. These characteristics make the mucus more effective in protecting the respiratory tissues and help cilia move debris out of the airways.
People with cystic fibrosis lack the CFTR channels and Cl- ions cannot be transported out of the cell in sufficient amount. Consequently, there is a deficiency of Na+ and Cl- ions in the mucus which hinders the movement of water from the cell that should make the mucus thin and watery. The resulting mucus is very thick and sticky making it ineffective in protecting the lungs. Respiratory tracts become blocked by the thick mucus and infection may likely occur due to the cilia not able to move and get rid of bacteria in the airways.
Acidosis is a condition of the body where the acidity in the blood is excessive. One of the common causes of acidosis is the reduced effectiveness of breathing especially when exhaling because it builds up carbon dioxide in the bloodstream. Metabolic problems that reduces the level of buffers and the promotion of acids in blood can also cause acidosis. An example where the acids can build up is by having a severe diarrhea because the condition promotes the loss of bicarbonate, a substance that helps regulate the acid in the body. In poorly managed diabetes, ketones are acids that the body produced as a form of fuel. Ketones can accumulate in the blood and cause a condition known as diabetic ketoacidosis. Other conditions such as heart failure, liver failure, kidney failure, and cancer can give rise to metabolic acidosis.
In some circumstances, the blood becomes too alkaline or basic and the condition is known as alkalosis. With this condition, carbon dioxide level and the concentration of hydrogen proton is very low. Respiratory alkalosis can be caused by lung disease, aspirin overdose, shock, and anxiety.
During severe vomiting, metabolic alkalosis may trigger due to the loss of hydrogen and chloride ions which are the components of the acid HCl. Some medications which include diuretics and antacids taken in excessive amounts can also cause alkalosis.
A human DNA gene for making the blood protein antithrombin was introduced into a goat shown in the photo. Antithrombin is an enzyme that inhibits blood clotting. The goat can secrete milk that contains the protein which can help patients suffering from a rare hereditary disorder that causes thrombophilia, a high tendency to form blood clot in the blood vessels.
Fecal microbiota transplantation or FMT is an emerging medical procedure which a stool from a healthy donor is transferred into the digestive tract of a patient suffering Clostridium difficile colitis, an infection of the colon caused by Clostridium difficile bacteria. When an antibiotic (usually broad-spectrum), eliminates bacteria including the microbiome (the good bacteria) in the gut, opportunistic bacteria such as C. diff overtake and becomes pathogenic causing an illness. FMT can help restore the microbiome and reduce the number of C. diff bacteria in the gut.
Unfortunately, two patients received FMT from the same stool source that led them to have bacteremia, the presence of bacteria in the circulatory system. The type of bacteria found in their bloodstream is Escherichia coli with the ability to produce extended-spectrum beta-lactamase or ESBL. This type of bacteria is resistant to many antibiotics such as penicillin prescribed by many doctors. These cases were announced by the Food and Drug Administration in June 2019 safety alert because one case ended in the death of the patient.
The patient who died was a 73-year-old man who was undergoing treatment for myelodysplastic syndrome, a type of cancer in which immature blood cells do not fully mature. He received FMT through oral capsule with the donor stool.
After few days, the man developed fever, chills, febrile neutropenia (low neutrophil count), and change in mental status. He was treated with the antibiotic cefepime but developed hypoxia and labored respiration. Further blood culture test detected gram negative bacilli and was given another type of antibiotic called meropenem. Despite the loads of antibiotics given, the patient’s condition worsened and died of severe sepsis.
Further investigation revealed that each lot of three stool capsules, all coming from the same donor, contain ESBL-producing E. coli. More than 20 patients have taken the capsule from this donor and was contacted for stool screening and five were positive of the ESBL-producing E. coli
To limit the transmission of infectious bacteria and explain the benefits and risks of fecal microbiota transplantation across various patients, improved donor screening and continued surveillance was implemented.
A condition known as decompression sickness (DCS) occurs when there is a decrease in pressure on the body and gases are no longer dissolved in blood. The condition affects divers who dives at a very deep high pressure waters and surfaces quickly to a low pressure area. This is similar to the bubbles of gases escaping from a bottle of soda that has just been opened. One of the symptoms includes joint pain which is why the condition is often called “the bends.”
DCS mostly occurs when there is a decrease in barometric pressure. In deep waters, the pressure of the water pressing on the body of a diver is so high. When the diver moves back to the surface where the pressure is low, DCS may occur due to the rapid change in pressure. Lake surfaces in higher mountains have barometric pressure lower than sea level surfaces. It is not surprising that diving in these mountain lakes will result in decompression sickness far more likely than diving in water bodies at sea level.
Similar to the bottled soda concept, DCS causes the gases in blood and other body tissues to come out rapidly in the form of bubbles. The constant air pressure is the one keeping the gases in the blood dissolved. When the air pressure on the body changes from high to low rapidly, dissolved gases may escape and less gas is dissolved in the blood.
Joint pain is the most common symptoms of decompression sickness. Headache and vision problems may also occur. DCS is a serious condition that may lead to death and needs immediate treatment. The main treatment for DCS is putting the patient in a hyperbaric chamber which introduces oxygen to the patient’s body at a very high pressure. The treatment increases the concentration of oxygen in the blood. Most of the time, DCS responds well with a single hyperbaric treatment.
Who are at risk for DCS?
Person with congenital heart defects
30 years old and older
Person with sedentary lifestyle
People who lack sleep
Cold water divers
Person with lung disease
Difficulty thinking clearly
Tingling or numbness
Weakness in arms or legs
A skin rash
Slowly dive and rise in the water
Do not stay in your deepest depth longer than the recommended time
Wait 24 hours before flying after diving
Do not consume alcohol before diving
Avoid hot baths after diving
Get well hydrated and rested before a scuba dive
Talk to your doctor before diving if you have recent serious illness or injuries