BIOCHEMISTRY, BIOMEDICINE & PHARMACEUTICS

Case study: A 65-year-old man with a history of diabetes and hypertension presents to his primary care physician with complaints of fatigue and malaise. His physical exam is unremarkable except for mild hypertension. Laboratory tests reveal an elevated serum creatinine level of 2.5 mg/dL (normal range 0.7-1.3 mg/dL) and a creatinine clearance of 35 mL/min (normal range >60 mL/min). A diagnosis of chronic kidney disease (CKD) is made. Discussion: This case highlights the importance of measuring creatinine clearance in the diagnosis and management of CKD. Creatinine clearance is a measure of kidney function and is used to estimate the glomerular filtration rate (GFR), which is the rate at which blood is filtered by the kidneys. In this case, the patient's serum creatinine level is elevated, indicating impaired kidney function. The creatinine clearance value of 35 mL/min is significantly lower than the normal range, confirming the presence of CKD. CKD is a progressive condition tha...

       Lesch Nyhan Syndrome: Clinical Presentation and Biochemical Diagnosis A 3-year-old child was brought to the hospital with a complaint of self-mutilation. He had a chronic ulcer on the buccal surface of his lips, and self-inflicted trauma by biting his finger. History revealed that severe motor retardation was apparent at the age 6 months old and he has never been able to lift or support his trunk.  The growth chart showed that he has growth retardation. Biochemical analysis was performed which is represented below : Serum Uric acid: 9.0 mg/dL Blood Urea : 32 mg/dL Serum Sodium : 139 mmol/l Potassium: 5.1 mmol/l Calcium 39 mmol/l Total Protein: 70 g/L Albumin: 23 g/L Urinary Uric acid: 160mg/100 ml Urinary Glucose: Absent Urinary Protein: Absent Microscopic urine examination: triphosphate crystals Diagnosis? Provisional Diagnosis : Based on the behavioral pattern of self-mutilation, growth retardation, dystonia, and increased serum and ...

                                       Multiple Choice Questions on Foodborne and waterborne pathogens 1. Which of the following tapeworms parasite is usually found in raw pork? a) Taenia saginata b) Taenia solium      c) Ascaris lumbricoides d) Trichuris trichiura 2. Name the common waterborne illness that is most prevalent in the nations like Haiti, India, Nepal, and other poor regions with lack of clean drinking water and good sanitation practices. a) Cholera       b) Hand, Foot and mouth disease c) Chagas disease d) Kala-azar / Leishmaniasis 3. Which of the following gram positive bacteria is a common pathogen that can adulterate dairy, and frozen products? a) Staphylococcus saprophyticus b) Listeria monocytogenes      c) Giardia lamblia d) Bacillus cereus 4. Canned food poisoning is commonly linked to which of the following microorga...

The circulating drug binds to the anti-drug antibodies (ADA) in the samples and interferes with the detection of ADA. The circulating drug severely reduces the sensitivity of the assay and increases the false-negative rate during clinical bioanalysis.  Drugs can interfere with ADA detection by two mechanisms;  a) Circulating drugs form immune complexes with ADA b) Circulating drugs compete with the detection reagents in the assay  Biotin-Drug Extraction and Acid Dissociation (BEAD)  procedure: BEAD method has shown to effectively remove the circulating drugs from the serum samples and reduce the drug interference in the assay. The BEAD method utilizes acetic acid to dissociate the drug-ADA complex. The sample is rapidly neutralized in the Tris-HCl containing an excess of biotinylated drug and allow binding to ADA to biotinylated drugs.  The streptavidin-coated magnetic Bead is used to capture the biotinylated drug-ADA complex and remove any free circul...

Pharmacological agents that directly or indirectly inhibit purine and pyrimidine synthesis have been used as anti-bacterial agents and anti-tumor drugs. These classes of drugs inhibit purine / pyrimidine synthesis and availability in the cells thereby decreasing cell replication. The inhibitors of the purine degradation pathway are used for the treatment of Gout. The pharmacological agents / inhibitors are as follows: i) Fluorouracil (anti-tumor agents) ii) Sulfonamides and Trimethoprim (antibacterial agents) iii) Allopurinol (for 'Gout' management) Anti-tumor agents: Fluorouracil is a mechanism-based drug that inhibits the enzyme Thymidylate synthetase (TS). Thymidylate synthetase is an enzyme that catalyzes the synthesis of deoxyuridine monophosphate to deoxythymidine monophosphate, a building block of DNA. The inhibitor of the enzyme led to decreased production of dTMP and reduced substrate for DNA replication and cell cycle.  5-Fluorouracil competes with uracil ...

                                           MCQ on Pathology of Vascular System    1) Vasculitis is a term referred to a vessel wall inflammation. Which of the following is the mechanism of non-infectious vasculitis? a) Immune complex deposition b) Antineutrophilic cytoplasmic antibodies c) Autoreactive cells d) All of the above 2) Based on the location, vasculitis may be classified into large, medium, and small-vessel vasculitis. Identify the disease associated with large vessel vasculitis. a) Kawasaki disease b) Takayasu arteritis c) Wergener granulomatosis d) Chrug Strauss Syndrome 3) Identify the disease associated with small vessel vasculitis a) Kawasaki disease b) Takayasu arteritis c) Wergener granulomatosis d) Chrug Strauss Syndrome 4) Identify the condition associated with medium vessel vasculitis: a) Kawasaki disease b) Takayasu arteritis c) Wergener granulom...

FDA guidance for Immunogenicity Testing Assays:   Development & Validation of Anti-drug Antibody Assays The FDA has finalized its guidance for the development and validation of assays for immunogenicity testing. The new guidance supersedes other previous guidance for related to bioanalytical assay validation for immunogenicity testing. The objective of this guidance is to facilitate the industry’s development and validation of assays for assessment of the immunogenicity of therapeutic protein products during clinical trials. More specifically the guidance provides a stepwise approach to develop, validate the anti-drug antibody assay, it helps to answer the following questions: a) Why it is important to assess immunogenicity? b) What is the ADA assay? c) When is it appropriate to develop ADA assays and assess immunogenicity? d) How to develop reliable, sensitive and specific ADA assays? a) Why it is important to assess immunogenicity? Immunogenicity is defined a...

1. Simple microscopes      Procedure : a) Set up the microscope Simple microscopes come with 4x, 10x, 25x and 40x objective lenses, use the desired magnifying lenses to observe and examine the microorganisms. Avoid touching the lenses on the objectives and the eyepieces. Plug in the microscope to turn the unit on. With both eyes open, look into the eyepieces. Adjust the interpupillary distance by holding the eyepiece tubes and rotate the eyepiece tubes either towards or away from each other until only one circle of light is seen by both eyes. Place the specimen to be studied onto the stage of the microscope (slide, flask, vial, etc). Using the mechanical stage’s slide controls, center the specimen over the stage opening, lining it up with the light and the objective lens. To adjust the illumination, turn the dimmer knob on the left side of the body until the desired intensity of light is achieved. Adjust the iris on the light source itself by r...

Metabolic Pathway of Methionine and Cysteine Conversion of Methionine to S-Adenosyl Methionine  - Methionine is a nutritionally essential amino acid, therefore, the dietary source is generally proteins.  - S-adenosyl methionine synthase catalyzes the conversion of methionine to S-adenosyl methionine - Require ATP, the ATP is hydrolyzed to AMP and PPi, therefore two energy equivalent of ATP is consumed in the reaction Figure 1: Metabolic Pathway for the methionine metabolism Formation of S-Adenosyl homocysteine from S-Adenosyl methionine  - S-adenosyl methionine serves as an active methyl group donor in various metabolic pathways including amino acid metabolism, hormones/neurotransmitter synthesis, etc. - Once the methyl group is transferred to the methyl acceptor, the S-Adenosyl methionine is formed  - Generally transferred by specific methyltransferase Hydrolysis of S-Adenosyl homocysteine to form homocysteine  -The hydrolysis of S-Adenosyl homocysteine form...

A 54- year old female was brought to the Emergency Department with complaints of sweating, palpitations, and dizziness. Her random blood glucose is 25 mg/dl. After the infusion of glucose, the symptoms were relieved. Upon clinical chemistry analysis, her plasma insulin level was higher with a low level of C-peptide. What is the diagnosis for this patient? Provisional Diagnosis : Hypoglycemia , due to hyperinsulinemia Answer and Explanation: First, the case presentation suggests that the female subject may have been suffering from hypoglycemia based on a classical feature of Whipple Triad which includes :  a) the decreased blood glucose level below normal reference level ( 60-110 mg/dL),  b) the subject is also presented with classical symptoms of hypoglycemia such as sweating, palpitation, and dizziness. c) the symptoms were immediately relieved with the infusion of glucose. Second, the blood chemistry analysis revealed the insulin level in the subject wa...