BIOCHEMISTRY, BIOMEDICINE & PHARMACEUTICS

                                                  MCQs and answers on Spirochetes 1) Which of the following is not the common morphological characteristics of spirochetes? a) They are gram-negative helical bacteria b) They are motile and have periplasmic flagella ( endo flagella ) c) They reproduce by transverse binary fusion d) They are obligate aerobes 2) Which of the following subspecies of Treponema pallidum causes endemic syphilis? a) Treponema carateum b) Treponema endemicum c) Treponema pertenue d) None of the above 3) The RPR   test  ( Rapid Plasma Reagin test ) is a nontreponemal test method that is a common screening test for syphilis, which of the following statement correctly describes the test? a) A screening test used for the detection of syphilis antibodies in the urine b) A screening test used for the detection of syp...

                                                            MCQ on Microorganisms Associated With Cancer 1 .  Epstein Barr virus is most commonly associated with all of the following types of cancer in humans, Except ? a) Burkitt's lymphoma b) Hodgkin's disease c) Kaposi's sarcoma          d) Nasopharyngeal carcinoma 2 . All of the following regarding the Rous sarcoma virus (RSV) are correct, Except ? a) The first described oncogenic RNA virus b) Belongs to family Retrovirus c) First oncovirus to cause tumor in chickens d) Consists of the extra oncogene causing sarcoma  3 .  A 47 year old woman suffering from gastritis for more than 3 years and has been taking medication for gastritis, pain killers for episodes of abdominal pain. Since the diagnosis she lost more than 15 pounds and had a problem gai...

Introduction to Anti Drug-Antibody Assay The total anti-drug antibody(TAb) assays detect the antibodies that are specific to the therapeutic molecules. These assays do not distinguish specific isotypes and detect all classes of antibodies present in the samples. The different platforms have been used for the detection of total antibodies such as bridging antibody assays, indirect ELISA assays, SPR assays, Immuno-PCR assay and most recently mass spectrometric assay.  Although the detection system varies with different platforms, the detection still relies on the ADA and therapeutic molecules binding and interactions. A tier-based approach is utilized for detection of ADA that includes a) Screening Assay b) Confirmation Assay c) Titer Assay a) Screening Assay : The screening assay is designed to detect and distinguish the presence or absence of anti-drug antibodies in the samples. The screening assays involve the incubation of samples with capture and detection reagents. Th...

Case Presentation A 62-year-old man with a 10-year history of type 2 diabetes mellitus visited the hospital with complaints of swelling in his lower extremities. The patients' had a co-incidence of diabetes mellitus and hypertension. The clinical laboratory report showed the following observations: Biochemical Parameters Results Serum Glucose 250 mg/dL Serum Albumin 2.5g/dL Serum Creatinine 1.5 mg/dL Blood Urea itrogen 25mg/dL Serum Sodium 130 mEq/L Serum Potassium 4.3 mEq/L Serum Total Cholesterol 275 mg/dL Serum Anti-ANA antibodies Negative Serum Rheumatoid factors Negative Serum Cryoglobulins Negative Urine examinations Urinary proteins: 5.0 gm/dL Urinary glucose: ++ Provisional diagnosis: Diabetic kidney disease with hypoalbuminemia, massive protein loss( nephrotic syndrome), hypercholesterolemia. Nephroti...

Anti-drug antibody (ADA) assays are developed to detect and characterize an antibody response generated against bio-therapeutic products. The total antibody (TAb) assay (TAb) detects the total antibodies generated against the therapeutic proteins. The total antibody assay positive samples that are positive for total ADA are tested for the neutralizing capacity. These TAb-positive samples may be subjected to isotype characterization as necessary. These assays are performed in three tiers : a) screening assay, b) confirmation assay, c) titer assay  Assay cut points are established with three basic assumptions The cut points are usually a statistically determined cut off value above which the samples are considered positive. During pre-study validation, the cut points are established by analyzing a set of approximately fifty drug-naïve healthy individual samples. The cut points are established with the following basic assumptions: a) No prior exposure to the drug b) No preexisting...

                                              Highlights of Vosoritide Program - Vosoritide is the FDA approved drug for the treatment of Achondroplasia  - Developed by Biomarin, and received orphan designation from FDA and EMA - New Drug Application Under Review by FDA with Set PDUFA August 2020 - EMA validated the marketing authorization application - Publication of positive outcome data from Phase 3 study in Lancet Achondroplasia is   the most common form of disproportionate short stature in humans, it is characterized by slowing of endochondral ossification, which results in disproportionate short stature and disordered architecture in the long bones, spine, face, and base of the skull.  This condition is caused by a mutation in the fibroblast growth factor receptor 3 gene (FGFR3), a negative regulator of bone growth. Beyond disproportionate short stature...

  Metabolic Pathway for Phenylalanine and Tyrosine  ( For MCQ Practice click here ) Conversion of Phenylalanine to Tyrosine  - Phenylalanine hydroxylase (PAH) converts phenylalanine to tyrosine  - PAH is encoded by the PAH gene located in Chromosome 12 and consist of 13 exons  - Tetrameters with each monomer consisting of the catalytic site, regulator site, and subunit binding domain  - Phenylalanine hydroxylase is tetrahydrobiopterin (BH4) requiring enzyme  - Dihydrobioteridine reductase catalyzes the conversion of dihydrobiopteridine to tetrahydrobiopterin  - Deficiency of enzyme caused phenylketonuria  Figure- Overview of Phenylalanine and Tyrosine Metabolism   Transamination of Tyrosine  - Tyrosine aminotransferase catalyzes the conversion to tyrosine to p-hydroxyphenylpyruvate  - Tyrosine aminotransferase is a Pyridoxal-5-phosphate requiring enzyme  - In the process, alpha-ketoglutarate is converted into glutama...