In the United States, public health priorities and development of strategies to address health concerns are identified by the Centers for Disease Control and Prevention or CDC. Five parasitic diseases have been officially considered by CDC to have been neglected or not adequately studied. The list of neglected parasitic diseases include trichomoniasis, cysticercosis, toxocariasis, Chagas disease, and toxoplasmosis.
These diseases were recognized as neglected and CDC will commit resources towards better awareness and improving diagnostic testing and treatment through research studies. CDC may also help on the treatment and distributing medications that are difficult to obtain for these diseases.
Since CDC’s resources are limited, giving study priority for these five diseases effectively deprioritizing others. Many people never heard of these five diseases and asked CDC what criteria they used in prioritizing diseases. CDC said that the criteria includes the population of infected individual, severity of the disease, or if the disease is treatable or preventable. Several of these neglected diseases are uncommon in the United States, but many of these cases in the U.S. were not diagnosed nor treated due to the lack of knowledge for these diseases.
Should this call for a major overhaul on the system of prioritizing diseases? What criteria should be considered? Are the identified diseases reasonable? Are there any ethical implications of deprioritizing other neglected diseases?
OpenStax Microbiology. Neglected Parasites. Eye on Ethics. Accessed November 19, 2019
An organism is formed based from an architectural blueprint called DNA. In eukaryotes including human cell, the nucleus holds the DNA. Humans contain 46 chromosomes and for each chromosome, DNA is organized into a strand. Each shorter segment of the DNA strand is called genes. This is analogous to organizing a long paragraph into a different clear sentences. Each gene is an instruction to make a protein. Analogically speaking, DNA in eukaryotic cells are like the apps (application software) in mobile phone. If you want to know the current date, you would only access the calendar app and not run the other programs. The same idea applies in eukaryotic DNA. A cell does not express all the gene stored in the nucleus and only express gene that are needed depending on the type of cell. For example, each cell in the human body regardless of where it is located contains the gene to make the hair, skin, teeth, liver, and ovary, but these genes are turned off in the stomach cells. If genes for making the teeth were turned on in the stomach cells, you will have teeth forming in the stomach.
Blankenship-Williams, L. (2015). What You Really Need To Know Before Anatomy, Physiology, and Microbiology. Carbohydrates and Nucleic Acids. Accessed November 18, 2019.
Zona reticularis is the deepest part of the adrenal cortex. It produces androgen (a steroid sex hormones) in a small quantity. Usually, androgens are produced in the gonads and are supplemented by the androgens produced in the zona reticularis. Adrenal androgens are produced in response to adrenocorticotropic hormone from the anterior pituitary and are converted to testosterone or estrogen. One possible function of andrenal androgens is to help the sex drive in adult female, but it is not well understood in adult men. After menopause when the activity of ovaries decline, androgens from zona reticularis will take place as the main source of estrogens.
Extraction of DNA or RNA must be done first before we can study and manipulate nucleic acids. There are many ways to extract different types of DNA. Most extraction techniques involve breaking the cell and destroying all unwanted macromolecules. Cells can be broken using a detergent solution called lysis buffer which can disrupt nuclear and cell membranes. Unwanted proteins are broken down using an enzyme called proteases and unwanted RNA are broken down using ribonucleases. The test tube used in performing the process is centrifuged to separate the DNA from the unwanted cell debris. Alcohol is then added to precipitate the DNA and forms into a visible white gelatinous mass. DNA samples can be stored in ultra-freezers (–80°C ) for many years.
The world produces more than 300 billion pounds of plastic from petroleum. Plastic is a material used to make bottles, containers, toys, and many other common items. Products made from plastic degrade at a much slower rate creating problems in the environment. Fortunately, natural plastic exists and bacteria are the main source. Polyhydroxyalkanoate or PHA is a natural polyesters synthesize by many microorganisms as a form of chemical energy storage. PHA can be removed from a bacteria and form into pellets which then used to produce biodegradable plastic. Bacteria that are involved in biosynthesizing PHA include Cupriavidus necator, Bacillus subtilis, and Alcaligenes latus. The photo shows bacteria producing and storing PHA that can be used to make durable and environmental friendly plastic.
Flagellum is a structure in bacteria that gives them the ability to move. The motor of flagellum comprise of a system of rings planted in the plasma membrane and cell wall. Protons are pumped out of the bacterial cell by the electron transport chain but diffuses back into the cell providing the force to rotate the filament and move the cell. The photo shows a diagram of the structure of flagellum in gram negative bacteria and a close-up electron microscope image of the motor system of flagellum.
The Hox gene Ubx is fully expressed in crustaceans (region shaded in green) including the expression of the legs. The Hox gene Ubx is partially expressed in modern-day insect (region shaded in pink) resulting in formation of the homologous body segment similar with the crustacean but with the absence of legs.
Biological transmission occurs when the infectious microbes reproduce within a vector such as insects (arthropods) and the microbes are being transmitted between hosts. Most insects transmit the infectious microbes by biting the host. Below is a list of common insects and the pathogen/disease they may carry.
Pediculus humanus humanus
Aedes spp., Haemagogus spp.
Yellow fever virus
West Nile virus
West Nile disease
Rocky Mountain Spotted Fever
OpenStax Microbiology. Common Arthropod Vectors and Select Pathogens. Accessed November 15, 2019