Biochemistry

The paper proposes an automatic measurement system for monitoring of biological processes using amperometric biosensors in flow injection analysis. Whereas this kind of measurement usually requires the intervention of human experts, the proposed system allows a fully automation of the measurement process. Both the flow injection and the analyte concentration measurements are managed without human interactions. The first experimental results

Inherited thrombophilia has recently been identified as a major cause of thrombembolism, but it may also contribute to adverse pregnancy outcomes and recurrent pregnancy loss. Three gene mutations namely leiden (FV G1691A), prothrombin (FII G20210A), and methylenetetrahydrofolate reductase (MTHFR C677T) are the most common types of hereditary thrombophilias in women with RPL, which in turn can result in placentation. These are usually undiagnosed, because most carriers are asymptomatic. The aim of this study was to determine the association of specific inherited thrombophilias and recurrent pregnant loss (RPL) among Saudi women. The study included 142 females were 72 had a history of 2 or more events of fetal loss in any of the 3 trimesters of pregnancy. The remaining 70 were clinically healthy women with a good obstetric history and have designated as a control group. Detection of inherited thrombophilia genes mutations was confirmed using different PCR screening protocols. The frequencies of FV & FII mutations related to the pregnancy loss stages showed that FV mutation ratio was similar among cases with early or late stage pregnancy loss (25%-26%) but significantly higher than that of controls (1.4%). On the other hand FII mutation ratio was high among cases with late pregnancy loss (50%) followed by early pregnancy loss (38%) and was significant higher than that of controls (1.4%). MTHFR C677T mutation was more common in group of women with fetal loss in first trimester compared to the controls. We have reported that the combinations of two or more thrombophilic polymorphism risk factors were observed in 10.8% healthy Saudi women with unexplained RPL while no more than one risk factor was observed in any of the controls. We concluded that there is a strong association between the combined inherited thrombophilic mutations related to FV G1691A, FII G20210A, and MTHFR C677T genes among Saudi women. Our data confirm the hypothesis that inherited thrombophilia is indeed a significant abnormality in the RPL subjects.

Obesity is a significant public health concern that predisposes individuals to a high risk of premature mortality. Previous studies also reported that low serum concentrations of AMY1 have been associated with obesity. The aimed of the study to assess the relationship between salivary amylase (AMY1) activity and body mass index (BMI) in Saudi male and female adults in Riyadh. This study included a total of 200 (100 individuals who were overweight and obese and 100 who had normal body weight [control individuals]) Saudi participants aged 20 to 50 years old. They were recruited from physical fitness clubs and were school employees in Riyadh City. The dietary food intake was assessed using a 24-hour dietary recall. The activity of the AMY1 was measured using a microplate fluorescence reader. A significant (P .05) increase was observed in the incidence of hypertension, dyslipidemia, diabetes mellitus (DM), and family history of overweight and obesity in overweight and obese individuals than in the control individuals, and these were in parallel to the significant increase in weight, waist circumference (WC), hip circumference (HC), systolic blood pressure (SBP), diastolic blood pressure (DBP), and BMI. A significant (P .05) increase was also observed in the carbohydrate and total fat dietary intake of overweight and obese individuals in relation to the respective dietary reference intake (DRI) values. AMY1 activity was significantly lower than the reference values in the overweight and obese group. Furthermore, AMY1 activity was significantly (P .05) reverse with weight, WC, HC, and BMI in both males and females in the overweight and obese group. In conclusion, the Saudi overweight and obese population seems to be at risk of low AMY1, which correlates with their obesity. Abbreviations: AMY1 = salivary amylase, AMY2 = pancreatic amylase, BMI = body mass index, CNVs = copy number variations, DBP = diastolic blood pressure, DM = diabetes mellitus, DQ = quenching starch, DRI = dietary reference intake, HC = hip circumference, SBP = systolic blood pressure, SPSS = Statistical Package for the Social Sciences, T2DM = type 2 diabetes mellitus, WC = waist circumference, WHO = World Health Organization.

Date Fruits are consumed in Arab areas for a long time as a part of essential diet. Phoenix dactylifera belongs to family Arecaceae and its leaves, barks, pits, fruits and pollens have anticancer, antioxidant, hepatoprotective, antidiabetic, antihypertensive, antiulcertavie, anti-inflammatory, antiproliferative, antimutagenic, antidiarheal, antibacterial, antifungal and antiviral potential. Besides these, Dates also increase level of estrogen, testosterone, RBCs, Hb, PCV, reticulocytes and platelet counts. It can also cure lead induced heamotoxicity, side effects of methylprednisolon, male and female infertility. It has also cerebroprotective, neuroprotective and haemopoietic activity. Phoenix dactylifera can be used for number of complications if further evaluated and isolated. The present paper is an overview of pharmacological properties of Phoenix dactylifera reported in literature.

The ability of human immunodeficiency virus (HIV-1) to persist and cause AIDS is dependent on its avoidance of antibody-mediated neutralization. The virus elicits abundant, envelope-directed antibodies that have little neutralization capacity. This lack of neutralization is paradoxical, given the functional conservation and exposure of receptor-binding sites on the gp120 envelope glycoprotein, which are larger than the typical antibody footprint and should therefore be accessible for antibody binding. Because gp120-receptor interactions involve conformational reorganization, we measured the entropies of binding for 20 gp120-reactive antibodies. Here we show that recognition by receptor-binding-site antibodies induces conformational change. Correlation with neutralization potency and analysis of receptor-antibody thermodynamic cycles suggested a receptor-binding-site 'conformational masking' mechanism of neutralization escape. To understand how such an escape mechanism would be compatible with virus-receptor interactions, we tested a soluble dodecameric receptor molecule and found that it neutralized primary HIV-1 isolates with great potency, showing that simultaneous binding of viral envelope glycoproteins by multiple receptors creates sufficient avidity to compensate for such masking. Because this solution is available for cell-surface receptors but not for most antibodies, conformational masking enables HIV-1 to…

We have developed a microfluidic cell culture method that allows for the formation of linear isolated myotubes organized in a parallel microarray. Attachment and spreading of cells are confined within microtracks of cell-adherent proteins separated by a protein-repellent coating. Signaling molecules or other molecules of interest can be focally delivered to the myotubes using heterogeneous microfluidic streams. We have used the method to focally deliver agrin (a molecule implicated as a postsynaptic organizer), which leads to localized acetylcholine receptor clustering. These techniques can be modified to accommodate other cell types and can be adapted to virtually any bioactive molecule such as signaling factors or drugs. This protocol features two major techniques that can be utilized simultaneously or independently to (i) micropattern cells using surface chemical modification and (ii) use a microfluidic platform for culturing and focal stimulation of cells with molecules of interest. Device design, fabrication and assembly can be completed in 3 days.

1. Among the digestive enzymes synthesized by pancreas, lipase is the principle lipolytic enzyme which hydrolyses dietary glycerides. 2. For its action it requires a coenzyme, colipase. 3. The molecular mechanisms of the interaction of these two are not fully understood. 4. Further, molecular events that regulate and influence lipid absorption are ill defined. 5. The rabbit is the conventional animal model for the study of lipid absorption. We have undertaken the molecular cloning, and characterization of rabbit pancreatic colipase, the coenzyme for pancreatic lipase. 6. Colipase has been cloned from a gt 11 library of an adult rabbit pancreatic cDNA by probing with an oligonucleotide derived from human colipase sequence. 7. The total reading frame consists of 321 nucleotides coding for 90 amino acids of the functional protein and 17 nucleotides of the leader peptide. 8. Northern blot analysis revealed a distinct band around 0.5 kb. Comparison with other species revealed an over all homology of 75% at the nucleotide level. 9. At the amino acid level highest conservation is observed at the lipase-binding region (AA 53-73). 10. Rabbit enzyme also retained the N-terminal pentapeptide of its preform. 11. The regions of homology and conservation may aid to define the sites of interaction of colipase with lipase.

We previously isolated a monoclonal antithrombin IgG from a patient with multiple myeloma [Colwell et al. (1997) Br. J. Haematol. 97, 219-226]. Using a panel of 55 surface mutants of recombinant thrombin, we now show that the epitope for the IgG most likely includes Arg-101, Arg-233, and Lys-236 in exosite II. The IgG affects the rate at which thrombin cleaves various peptide p-nitroanilide substrates with arginine in the P1 position, increasing the kcat for substrates with a P2 glycine residue but generally decreasing the kcat for substrates with a P2 proline. The allosteric effect of the IgG is altered by deletion of Pro-60b, Pro-60c, and Trp-60d from the 60-loop of thrombin, which lies between exosite II and the catalytic triad. The effect of the IgG, however, does not depend on the presence or absence of sodium ions, a known allosteric regulator of thrombin. The IgG does not affect the conformation of thrombin exosite I as determined by binding of a fluorescent derivative of hirudin54-65. These results provide evidence for a direct allosteric linkage between exosite II and the catalytic site of thrombin.

Hall, SS, Doweyko, AM, & Jordan, F. (1976) J. Am. ... Kang, U., Nolan, L., & Frey, P. (1975) J. Biol. Chem. 250, ... Kermack, W. O., & Matheson, NA (1 957) Biochem. J. 65, ... Knowles, JR, & Albery, WJ (1 977) Acc. Chem. Res. 10, ... Kozarich, JW, & Chari, RVJ (1982) J. Am. ...

Coronavirus is most pandemic virus and it is challenging too for the scholars and scientists to discover its vaccine. Like every organism in nature struggling for survival, they evolve or mutate. Similarly, the coronavirus has changed its genome sequence to adapt to the new species. In fact, research has shown COVID-19 has mutated repeatedly in ways to boost its survival which results in more difficulties to discover its vaccine. We can't hit the coronavirus directly and neither our immune system is capable enough to fight with it, but by killing the infected cells, we can kill the corona virus too.

Were it not for the textbook Clinical Chemistry in Diagnosis and Treatment by Joan Zilva and Peter Pannall, I would not be a chemical pathologist. As a medical student, I was so struck by its clarity, depth and clinical relevance that I decided that theirs was the medical field I wished to work in.
Over the years, the fi eld of clinical biochemistry has changed radically. Confusingly, there is no consensus on the name for this fi eld of medicine, which is known variously as clinical chemistry, chemical pathology or clinical biochemistry, to name but a few. Additionally, the fi eld now overlaps with that of metabolic medicine, a clinical specialty involved with the management and treatment of patients with disorders of metabolism. Clinical biochemistry laboratories have become further automated, molecular biology technologies have entered the diagnostic arena, and chemical pathologists have become more clinically orientated towards running out-patient clinics for a variety of biochemical disturbances. This book aims to address these new changes. Indeed, it is diffi cult to imagine a branch of medicine that does not at some time require clinical biochemistry tests, which may not be too surprising, given the fact that every body cell is composed of chemicals!
Unfortunately, there have been some diffi culties in recent times, with a relative shortage of graduates entering the specialty, which has not been helped by some people’s attitude that clinical biochemistry is merely a laboratory factory churning out results that anyone can interpret. There are also concerns that medical student clinical biochemistry teaching may become ‘diluted’ as part of an expanding curriculum. It is hoped that this book will excite a new generation to enter this fascinating and essential fi eld, as well as benefi t patients as their doctors learn more about their biochemical and metabolic problems.

Colonel Michael J. Ainscough, M.D., M.P.H., is an Air Force flight surgeon and a diplomat of the American Board of Preventive Medicine in Aerospace Medicine. Prior to attending Air War College in residence, he was the 92d Aeromedical-Dental Squadron Commander at Fairchild AFB, Washington. Other assignments included tours as Chief of Aerospace Medicine at the 343d Medical Group, Eielson AFB, Alaska; Chief of Operations Branch, Hyperbaric Medicine Division, Armstrong Laboratory, Brooks AFB, TX; Chief, Aeromedical Evacuation Branch, Professional Services Directorate, Office of the Air Mobility Command Surgeon; and then Chief, Clinical Aeromedical Evacuation for the Global Patient Movement Requirements Center of USTRANSCOM at Scott AFB, IL. Colonel Ainscough completed USAF Squadron Officers School in residence and was an outstanding graduate of the Air Command and Staff and Air War College seminar programs. He earned his Bachelor’s degree from the St. Louis College of Pharmacy and his Doctorate of Medicine from the Southern Illinois University School of Medicine. He completed a USAF Residency in Aerospace Medicine and a Fellowship in Hyperbaric Medicine at Brooks AFB, TX. He also completed a Masters in Public Health degree at the University of Texas. Colonel Ainscough’s military decorations include the Defense Meritorious Service Medal, the Meritorious Service Medal with three Oak Leaf Clusters, the Air Force Commendation Medal, the Air Force Achievement Medal, and the Humanitarian Service Medal. In 1989, he was named the Alaskan Air Command Flight Surgeon of the Year, and in 2001 he was nominated by Air Mobility Command for the Paul Myers Award. He is a Senior Flight Surgeon with 1,100 total flying hours in over 20 types of military aircraft.

Antibiotic-producing polyketide synthases (PKSs) are enzymes responsible for the biosynthesis in Streptomyces and related filamentous bacteria of a remarkably broad range of bioactive metabolites, including antitumour aromatic compounds such as mithramycin and macrolide antibiotics such as erythromycin. The molecular basis for the selection of the starter unit on aromatic PKSs is unknown. Here we show that a component of aromatic PKS, previously named 'chain-length factor', is a factor required for polyketide chain initiation and that this factor has decarboxylase activity towards malonyl-ACP (acyl carrier protein). We have re-examined the mechanism of initiation on modular PKSs and have identified as a specific initiation factor a domain of previously unknown function named KSQ, which operates like chain-length factor. Both KSQ and chain-length factor are similar to the ketosynthase domains that catalyse polyketide chain extension in modular multifunctional PKSs and in arom...