DSpace Collection: 61 - 142

The significance of teaching human biochemistry to dental students

Fri, 01 Jan 2021 00:00:00 GMT

Title: The significance of teaching human biochemistry to dental students Authors: Ahsan, Haseeb Abstract: Objectives: Biochemistry instructions in dental studies should highlight the fact that the basic biochemical processes occurring in the oral cavity are the same as those that take place in other tissues and organs of the body. Saliva is a complex fluid that plays an essential role in the maintenance of oral health and contains a wide range of proteins, enzymes (lysozyme, lactoferrin, peroxidases) and secretory immunoglobulins. Salivary cationic peptides and defense proteins, such as lysozyme, salivary amylase, cystatins, mucins, peroxidases, and statherin, are primarily responsible for innate immunity. The role of collagen, which forms a large part of the organic material of dentin, should be given prominence in the study of proteins. The study of carbohydrates and lipids is also an important topic, since the digestion of starch and lipids begins in the oral cavity due to the presence of various enzymes, e.g., amylase and lipase. The biochemistry syllabus for dental sciences should also include the role of weak acids and bases and buffers to help students understand the buffering capacity of saliva and its implications for oral health. Patients with poor glycemic control are more prone to oral manifestations of diabetes, including periodontal disease, salivary gland dysfunction, halitosis, burning mouth sensation, delayed wound healing, and increased susceptibility to infection. Diabetic patients are also at greater risk of an intraoperative diabetic emergency in the dental clinic. Therefore, dentists must appreciate and implement important dental management considerations when providing care to diabetic patients. Strategies to investigate bleeding disorders can help guide stepwise, rational testing for inherited and acquired causes of bleeding. It is clear that biochemistry is becoming increasingly important in the field of dentistry, and this should be reflected in both teaching and research.

Data to assist in the determination of biochemistry test ranges to assess hemodialysis efficacy in patients with chronic renal failure

Fri, 01 Jan 2021 00:00:00 GMT

Title: Data to assist in the determination of biochemistry test ranges to assess hemodialysis efficacy in patients with chronic renal failure Authors: Ilardo, Claudio; Ehrhard, Yoann; Calas, Olivier; Barthes, Joel Abstract: Objectives: Reference intervals are usually defined based on blood samples from healthy subjects and specific reference ranges for patients on hemodialysis (HD) are not currently available. The aim of the study was to establish expected ranges of biochemical analytes before and after HD for patients with chronic renal failure (CRF). Methods: The findings of the 4 most recent quarterly check-ups of 684 patients (233 women and 451 men; age 18-95 years) treated with HD in several dialysis units attached to a single laboratory were studied. Biochemical analytes were measured using fully automated Roche Cobas C 501 or C 701 analyzers (Roche Diagnostics, Basel, Switzerland). Expected ranges were set according to International Federation of Clinical Chemistry and Clinical and Laboratory Standards Institute guidelines using the nonparametric method. Results: Compared with pre-HD values, beta-2 microglobulin (β2m), chloride, creatinine, phosphate, potassium, and urea concentrations were lower post-HD (p<0.001), while bicarbonate, calcium, protein, and sodium concentrations were higher (p<0.001). Comparison with healthy subjects revealed that the levels of β2m, creatinine, and urea were higher before and after HD. Other analyte ranges were either lower, higher, or equivalent to healthy subjects in pre- and post-dialysis measurements. Differences between sexes were not significant, with the exception of creatinine, as well as a significant difference (>10%) in the creatinine level between individuals under and over 60 years of age (p<0.0001). Conclusion: The establishment of specific ranges for dialysis patients could contribute to finding specific thresholds to monitor the effectiveness of HD.

The effects of preconditioning with IFN-γ, IL-4, and IL-10 on costimulatory ligand expressions of mesenchymal stem cells

Fri, 01 Jan 2021 00:00:00 GMT

Title: The effects of preconditioning with IFN-γ, IL-4, and IL-10 on costimulatory ligand expressions of mesenchymal stem cells Authors: Ozdemir, Alper Tunga; Oztatlici, Mustafa; Ozdemir, Rabia Bilge Ozgul; dkk. Abstract: Objectives: Mesenchymal stem cells (MSCs) are strong immunomodulatory cells, and co-stimulation may play an important role in increasing the effects of MSCs on adaptive immune cells. Preconditioning may add to the effectiveness of MSCs. The aim of this study was to investigate alterations in the costimulatory ligand expressions of MSCs preconditioned with inflammatory cytokines. Methods: MSCs were preconditioned with interferon gamma (IFN-γ), interleukin (IL) 4 (IL-4), and IL-10, and changes in CD80, CD86, CD137L, CD252, CD274, CD275, and human leukocyte antigen (HLA) class I and II expressions were analyzed using flow cytometry and quantitative polymerase chain reaction methods. Human acute monocytic leukemia cell line (THP-1) macrophages preconditioned under the same conditions served as a control for comparison. Results: The frequencies of CD80 (p=0.0003), CD86 (p<0.0001), CD137L (p<0.0001), CD252 (p=0.0003), CD274 (p=0.0077), CD275 (p<0.0001), and HLA-II (p<0.0001) -positive MSCs was significantly lower than that of the THP-1 macrophages with either method, but there was no significant difference in the HLA-I (p=0.1506) cells. Comparison of the expression of the costimulatory ligands revealed that the expression of MSCs was significantly lower than that of THP-1 cells, and was not affected by cytokine stimuli. Conclusion: The study data indicated that although MSCs are strong immunomodulatory cells, the costimulatory ligand expression required for an effective antigen presentation was extremely low compared with that of professional antigen presenting cells. In addition, preconditioning with IFN-γ, IL-4, and IL-10 failed to increase the expression of important costimulatory ligands, such as CD80 and CD86, in MSCs. The stability of costimulatory ligand expression suggests that MSCs may be an effective source for HLA-I-mediated peripheral tolerance.

Biosafety risk assessment of a clinical biochemistry laboratory for SARS-CoV2 infection

Fri, 01 Jan 2021 00:00:00 GMT

Title: Biosafety risk assessment of a clinical biochemistry laboratory for SARS-CoV2 infection Authors: Zorbozan, Nergiz; Zorbozan, Orcun Abstract: Objectives: Clinical laboratories are a transfer point for infected patient samples. According to the World Health Organization (WHO) Laboratory Biosafety Guideline, a risk assessment approach is the backbone of laboratory biosafety. In laboratories, risk assessment is recommended at predetermined periods and in the event of new circumstances. On February 12, 2020, the WHO published an interim guidance document, "Laboratory biosafety guidance related to the novel coronavirus (2019-nCoV)" and it was highly recommended that all coronavirus 2019 (COVID-19) testing procedures be performed based on a local risk assessment. This study was designed to evaluate the biosafety risk in a biochemistry laboratory where routine testing of patients diagnosed with COVID-19 is performed. Methods: Risk assessment for tests performed on analyzers and a complete urinalysis was performed using the risk assessment template included in the subsequent WHO interim guidance document, “Laboratory biosafety guidance related to coronavirus disease (COVID-19).” Results: The overall initial risk for tests performed on analyzers and a complete urinalysis test was determined to be very high. Processes such as pipetting a sample and checking a sample tube by scanning the barcode during tests performed on analyzers were suspended until additional risk control measures could be implemented. The manual microscopic urinalysis process was also discontinued. To reduce the risk, surgical masks, surgical caps, eye protection, and disposable laboratory coats were added to the previously mandated personal protective equipment. After implementing additional risk control measures, the total residual risk of both processes was graded medium. Conclusion: Since there is as yet no effective treatment for COVID-19, exposure risk is considered severe. Therefore, the probability of exposure is important in determining the level of risk. Measures put in place reduced the total residual risk.