Tag Archives: Immunosuppression

INFECTION: OPPORTUNISTIC INVASIVE FUNGI EXPLAINED

Fungi are in the outside air, the inside air, and even the air of isolation units In hospitals. The normal human respiratory tract is able to breathe these fungi in, have them deposited on the mucous membrane surfaces and have no problem. The normal respiratory membranes, with their associated cleansing cilia and normal mucus production are able to sweep the invaders out without sustaining any harm.

Problems arise when the respiratory tract is functionally or structurally abnormal, such as in cystic fibrosis, bronchiectasis and COPD. Immunocompromised conditions have been increasing in frequency with the improvement in medical care in recent years. Intravascular catheters and sensors can provide a resting place for pathogens including fungi, as can cavities, scars and other damage to the lung. The immune system may require suppression to accommodate an organ transplants or ameliorate autoimmune conditions.

Cancers, especially of the hematologic or lymphatic system, such as lymphomas, pose a definite problem. Severe burns and  malnutrition may weaken the immune system, as may Viral infections, especially AIDS, and more recently COVID-19. More subtle immune problems may arise with diabetes, Obesity, or even a lack of sleep and exercise.

These and other conditions give the fungal infections the OPPORTUNITY to invade the body, and a few dozen of the thousands of species of fungi proceed to do just that. Opportunistic fungi often have special features, depending upon the species. Most prefer the respiratory tract, and if they get in to the bloodstream can go to their favored spots.

Aspergillus, and coccidiomycosis , for instance, prefer the lung. Mucormycosis often involves the sinuses and eyes. Blastomycosis can involve bone. Sporothrix is often found infecting the skin.

Symptoms depend upon the area involved. Of course if it’s a respiratory tract, you have coughing, mucus production, sometimes shortness of breath. With the central nervous system you have headache and confusion. You can see the involvement in the skin.

The number of drugs available to fight fungal infection is fairly limited, and currently involves only three different classes. Many fungi are resistant to one or two of these classes, and can be problematic.
However, fungi do not as a rule spread through the air from person to person, and a true epidemic would be unlikely.

—Dr. C.

STANFORD: RESEARCHERS FIND WAY TO “REGROW” NEW CARTILAGE IN JOINTS

The Stanford researchers figured out how to regrow articular cartilage by first causing slight injury to the joint tissue, then using chemical signals to steer the growth of skeletal stem cells as the injuries heal. The work was published Aug. 17 in the journal Nature Medicine.

“Cartilage has practically zero regenerative potential in adulthood, so once it’s injured or gone, what we can do for patients has been very limited,” said assistant professor of surgery Charles K.F. Chan, PhD. “It’s extremely gratifying to find a way to help the body regrow this important tissue.”

STANFORD MEDICINE (Aug 17, 2020): Researchers at the Stanford University School of Medicine have discovered a way to regenerate, in mice and human tissue, the cushion of cartilage found in joints.

Loss of this slippery and shock-absorbing tissue layer, called articular cartilage, is responsible for many cases of joint pain and arthritis, which afflicts more than 55 million Americans. Nearly 1 in 4 adult Americans suffer from arthritis, and far more are burdened by joint pain and inflammation generally.

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COMMENTARY

Stanford has come up with a Promising new approach to the surgical treatment of osteoarthritis. Unfortunately for the suffering public, this approach is still in the rodent experimental stage.

The pain of osteoarthritis is caused by the LOSS of the CARTILAGE which insulates the bone of the joints. The wonderful cartilage coating prevents the pain which would result from the rubbing of bone on bone. The best solution in osteoarthritis would be to replace the cartilage, and I have no doubt that this will be possible some day.

STEM CELLS is the theoretical method most commonly imagined when it comes to replacing lost tissue.. Brain cells, cardiac muscle cells, and pancreatic islet cells are some of the research areas. The development of stem cells from the cells of the Patient herself (iSCs) obviates the need for immunosuppression, which plagues allographs ( stem cells or organs from other humans).

Recently, in situ transformation of neighboring cells has been described, which sidesteps the need to introduce any cells. For instance the transformation of astrocytes (a type of brain cell) into neuronal stem cells of the dopamine lineage would be a great boon to Parkinson’s disease.

The Stanford method somewhat resembles this last-mentioned technique. An injury is created where the cartilage is desired. Like any injury, bleeding, clotting, and cell infiltration follows, destined to form a scar. However, the researchers added BMP-2, which in this milieu causes the pro-fibroblasts to head toward the bone (osteoblast) lineage. Since cartilage forms first in a tissue destined to be bone, they then added a VEGF antagonist, which interrupts the transformation in the desired cartilage stage. Both BMP-2 and anti-VEGF have already been approved for use, facilitating the development of this attractive therapy.

The researchers have even identified an excellent potential Patient Population: Osteoarthritis patients scheduled for surgical removal of the first metacarpal articulation with the wrist. They could do their procedure on this area, and if there is no benefit, They could just go ahead with the original plan of removal. The thumb happens to be one of my most painful arthritic areas.

I will most interestedly follow their research.

–Dr. C.