Tag: doctor

Anemia Study Guide Notes: Vocabulary, Types of Anemia, Heme Breakdown, and Anemia of Chronic Disease [Biology, MCAT, USMLE]

In this study guide, we review anemia, types of anemia, formulas, vocabulary, heme breakdown, and anemia of chronic diseases.

Immunology 101: Stages of B-cell Development [Biology, MCAT, USMLE Medicine]

B-Cell Development Stages. stem cell –> early pro-B cell –> late pro-B cell –> large pre-B cell –> [1st checkpoint – selects for functional heavy chains] –> small pre-B cell –> [2nd checkpoint – select for functional light chains] –> Immature B cell (has surface IgM, no surface IgD). Somatic recombination is the process in which different individual gene segments of the H (heavy) chain combine with rearranged gene segments of the L (light) chain. The enzymes responsible for somatic recombination are the recombinase enzymes (RAG-1 and RAG-2) that recognize specific sequences (RSS) or recombination signal sequences. RAG-1 and RAG-2 are only expressed in B or T lymphocytes. These specific sequences recognized by the RAG-1 or RAG-2 enzymes are either a 1) heptamer or 2) nonamer. The heptamer literally contains 7 nucleotides, and the nonamer literally contains 9 nucleotides. There are typically 12 or 23 nucleotides in between the heptamer and nonamer to separate them.

Top 15 Activities to do During Quarantine

In the midst of the COVID-19 pandemic, many people have been forced to quarantine themselves in their homes. Although countries are starting to open and people are exiting quarantine, social distancing is still common  and previously planned summer activities such as trips, internships and summer jobs have been postponed or cancelled. With summer having arrived, students will no longer be distracted by their classes. This raises the question, what can we do over a quarantined summer?

Gastrointestinal System: Pathophysiology of Diseases and Cancers [Biology, MCAT, USMLE]

In this quick and easy guide, learn about Gastrointestinal System: Pathophysiology of Diseases and Cancers [Biology, MCAT, USMLE]. Topics include heptobiliary disease, understanding liver functions and cirrhosis, liver function tests, causes of liver injury, alcoholic hepatitis, NAFLD, NASH, viral hepatitis, autoimmune hepatitis, durg-induced liver injury, hereditary hemochromatosis, Wilson’s disease, Alpha-1 Antitrypsin Deficiency, PSC, PBC, cholelithiasis, cholecystitis, cholangitis, hepatocellular carcinoma, and more.

Biology 101: Gel Electrophoresis

In this educational lesson, we learn about the purpose of gel electrophoresis and how gel electrophoresis works. Gel electrophoresis in a method of separating DNA. It can be used to separate the size of DNA, RNA, and protein. You first start with a variety of different fragments of DNA all mixed together. The gel is a porous matrix like a sponge and separates the DNA based on two main things: 1) size and 2) charge. The charge on DNA is what makes it move through the gel. DNA is a negatively charged molecule, so it will move towards a positive charge.

The Collapsed Lung: Types of Pneumothorax

Pneumothorax also known as collapsed lung occurs when air is trapped in the pleural space. Trapped air causes a loss of negative pressure in the pleural cavity, reduces surface tension, and induces the lungs to collapse. There are 3 types of Pneumothorax or collapsed lungs: 1) Spontaneous 2) Traumatic, and 3) Tension Pneumothorax.

In this lesson, we learn the different types of pneumothorax (collapsed lung) and important terminology. USMLE