Functional Effects of Adiponectin on Endothelial Progenitor Cells

Adiponectin is an adipokine whose plasma levels are inversely correlated to metabolic syndrome components. Adiponectin protects against atherosclerosis and decreases risks in myocardial infarction. Endothelial progenitor cells (EPCs) are a heterogeneous population of circulating cells involved in vascular repair and neovascularization. EPCs number is reduced in patients with cardiovascular disease. We hypothesize that the positive effects of adiponectin against atherosclerosis are explained in part by its interactions with EPCs. Cells were obtained from healthy volunteers' blood by mononuclear cell isolation and plating on collagen‐coated dishes. Three sub‐populations of EPCs were identified and characterized using flow cytometry. EPCs' expression of adiponectin receptors, AdipoR1, and AdipoR2 was evaluated by quantitative PCR. The effects of recombinant adiponectin on EPCs' susceptibility to apoptosis were assessed. Finally, expression of neutrophil elastase by EPCs and activity of this enzyme on adiponectin processing were assessed. Quantitative PCR analysis of EPCs mRNAs showed that AdipoR1 mRNA is expressed at higher levels than AdipoR2. Expression of AdipoR1 protein was confirmed by western blot. Adiponectin significantly increased survival of two sub‐populations of EPCs in conditions of serum deprivation. Such effect could not be demonstrated in the third EPCs sub‐population. We also demonstrated that EPCs, particularly one sub‐population, express neutrophil elastase. Neutrophil elastase activity was confirmed in EPCs' conditioned media. Adiponectin protects some EPCs sub‐populations against apoptosis and therefore could modulate EPCs ability to induce repair of vascular damage. Neutrophil elastase activity of EPCs could locally modulate adiponectin activity by its involvement in the generation of the globular form of adiponectin.     

Pharmacologic profile of BN 50739, a new PAF antagonist in vitro and in vivo

The effect of a new PAF antagonist BN 50739 was studied on PAF-induced [3H]-serotonin release from washed rabbit platelets in vitro and on PAF-induced hypotension in vivo. BN 50739 competitively inhibited PAF-induced [3H]-serotonin release from the platelets in a dose-dependent manner. In the presence of 4, 10 and 50 nM of BN 50739, the concentration of PAF inducing 50% maximal [3H]-serotonin release from the platelets (EC50) increased from 2.15 nM to 5.10, 45.10 and 900 nM, respectively. The IC50 of BN 50739 for PAF (10 nM) induced [3H]-serotonin release was 3.67 nM. Under the same experimental condition, the IC50s of BN 50726, BN 50730, BN 50741, WEB 2086, SRI 63-441 and BN 52021 were 5.40, 4.61, 6.88, 5.98, 40.90 nM and 14.90 microM, respectively. PAF-induced hypotension in conscious rats was also inhibited dose-dependently by i.p. pretreatment of BN 50739 (3 and 10 mg/kg). PAF-induced hypotension was diminished both in magnitude and duration in rats pretreated with BN 50739. These data taken together indicate that BN 50739 is a most potent PAF antagonist in vitro and in vivo.     

Thermotolerant varieties of Bacillus licheniformis isolated from desert environments

One hundred and nineteen thermotolerant and thermophilic Bacillus strains isolated from solar-heated and non-heated environments in Jordan were classified by numerical techniques. Some strains were classified into thermophilic taxa which did not equate with established species. However, most of the isolates were identified phenotypically as Bacillus licheniformis, a conclusion supported by the high DNA hybridization which was detected between these strains and a reference strain of this species (gt64% at optimal renaturation temperature). Several of the B. licheniformis isolates had a higher ratio of iso-C₁₅ and iso-C₁₇ fatty acids to the anteiso equivalents in their membranes than the reference strain of B. licheniformis and they grew more strongly at high temperature than the reference strain. This suggests that the B. licheniformis isolates represent thermotolerant variants of this species.     

The Best Gastric Site for Obtaining a Positive Rapid Urease Test

Background Rapid urease tests (RUTs) provide a simple, sensitive method of detecting Helicobacter pylori infection.
Objectives. Our aim, therefore, was to determine whether the yield of detecting H. pylori infection by RUT varied depending on the site of gastric biopsy.
Materials and Methods. Gastric biopsies were obtained from 50 patients for RUT by use of hp fast (GI Supply, Camp Hill, PA). Biopsies were taken from the prepyloric greater curve antrum, from the gastric angle, and from the greater curve in mid-corpus. One biopsy specimen was placed in the RUT gel, and the biopsy from the adjacent mucosa was placed in formalin for subsequent histological evaluation by using the Genta stain. RUTs were examined and scored at intervals of 5, 10, 15, 30, and 45 minutes and after 1, 2, 4, and 24 hours.
Results. Fifty patients were entered in the test (150 RUTs), 32 having H. pylori infection. There were no false-positive RUTs (specificity, 100%). The gastric angle site was positive in 100%. The prepyloric site was positive in 87%, and the corpus site was positive in 84.4% ( p < .052 for angle or prepyloric antrum versus corpus). The most common pattern was for all to be positive (74%). The median time to positivity was similar with angle and prepyloric sites (37.5 and 60 minutes, respectively, p = not significant) and shorter than the corpus biopsy (180 minutes); ( p < .05 for angle or prepyloric antrum versus corpus).
Conclusion. The maximum probability for detecting H. pylori infection using a RUT is to obtain a biopsy from the gastric angle. To prevent missing a positive result when intestinal metaplasia is present, we recommend that (at a minimum) biopsies be taken from both the angle and the corpus.     

Virtual assessment,training, and evaluation of clinical laboratory technologists amidst peak Covid-19 pandemic: An observational study

Medical technologists are considered a neglected group when it comes to academic interventions. We developed and implemented an educational intervention and assessment for the technologists based on an online questionnaire as a pre-test consisting of questions related to knowledge (n=5), attitude (n=3), and practices (n=4) of daily internal quality control (QC) monitoring via Google Docs survey tool. This study served multiple purposes. It allowed keeping the technologists engaged during the peak of the COVID-19 pandemic while also improving the knowledge, attitude, and practices about the internal quality control using Bio-Rad Unity Real Time (URT) QC software. Subjects were graded based on the scores they received out of 100 (0-60 = poor; 61-79 = good; 80-100 = excellent). Training materials, i.e., a set of 5 videos every week via e-mail, were circulated. A voice-over PowerPoint presentation was also shared for easy comprehension. This activity was repeated after one month. A post-test was administered to assess the improvement. The study results show significant improvement in the technologists'' performance after the intervention.     

Aluminum-Induced Cholinergic Deficits in Different Brain Parts and Its Implications on Sociability and Cognitive Functions in Mouse

Aluminum is associated with etiology of many neurodegenerative diseases specially Alzheimer’s disease. Chronic exposure to aluminum via drinking water results in aluminum deposition in the brain that leads to cognitive deficits. The study aimed to determine the effects of aluminum on cholinergic biomarkers, i.e., acetylcholine level, free choline level, and choline acetyltransferase gene expression, and how cholinergic deficit affects novel object recognition and sociability in mice. Mice were treated with AlCl₃ (250 mg/kg). Acetylcholine level, free choline level, and choline acetyltransferase gene expression were determined in cortex, hippocampus, and amygdala. The mice were subjected to behavior tests (novel object recognition and social novelty preference) to assess memory deficits. The acetylcholine level in cortex and hippocampus was significantly reduced in aluminum-treated animals, as compared to cortex and hippocampus of control animals. Acetylcholine level in amygdala of aluminum-treated animals remained unchanged. Free choline level in all the three brain parts was found unaltered in aluminum-treated mice. The novel object recognition memory was severely impaired in aluminum-treated mice, as compared to the control group. Similarly, animals treated with aluminum showed reduced sociability compared to the control mice group. Our study demonstrates that aluminum exposure via drinking water causes reduced acetylcholine synthesis in spite of normal free choline availability. This deficit is caused by reduced recycling of acetylcholine due to lower choline acetyltransferase level. This cholinergic hypofunction leads to cognitive and memory deficits. Moreover, hippocampus is the most affected brain part after aluminum intoxication.     

DAPK plays an important role in panobinostat-induced autophagy and commits cells to apoptosis under autophagy deficient conditions

The histone deacetylase inhibitor (HDACi) LBH589 has been verified as an effective anticancer agent. The identification and characterization of new targets for LBH589 action would further enhance our understanding of the molecular mechanisms involved in HDACi therapy. The role of the tumor suppressor death-associated protein kinase (DAPK) in LBH589-induced cytotoxicity has not been investigated to date. Stable DAPK knockdown (shRNA) and DAPK overexpressing (DAPK+++) cell lines were generated from HCT116 wildtype colon cancer cells. LBH589 inhibited cell proliferation, reduced the long-term survival, and up-regulated and activated DAPK in colorectal cancer cells. Moreover, LBH589 significantly suppressed the growth of colon tumor xenografts and in accordance with the in vitro studies, increased DAPK levels were detected immunohistochemically. LBH589 induced a DAPK-dependent autophagy as assessed by punctuate accumulation of LC3-II, the formation of acidic vesicular organelles, and degradation of p62 protein. LBH589-induced autophagy seems to be predominantly caused by DAPK protein interactions than by its kinase activity. Caspase inhibitor zVAD increased autophagosome formation, decreased the cleavage of caspase 3 and PARP but didn’t rescue the cells from LBH589-induced cell death in crystal violet staining suggesting both caspase-dependent as well as caspase-independent apoptosis pathways. Pre-treatment with the autophagy inhibitor Bafilomycin A1 caused caspase 3-mediated apoptosis in a DAPK-dependent manner. Altogether our data suggest that DAPK induces autophagy in response to HDACi-treatment. In autophagy deficient cells, DAPK plays an essential role in committing cells to HDACi-induced apoptosis.     

Sulla carnosa modulates root invertase activity in response to the inhibition of long‐distance sucrose transport under magnesium deficiency

• Being the principal product of photosynthesis, sucrose is involved in many metabolic processes in plants. As magnesium (Mg) is phloem mobile, an inverse relationship between Mg shortage and sugar accumulation in leaves is often observed.
• Mg deficiency effects on carbohydrate contents and invertase activities were determined in Sulla carnosa Desf. Plants were grown hydroponically at different Mg concentrations (0.00, 0.01, 0.05 and 1.50 mM Mg) for one month.
• Mineral analysis showed that Mg contents were drastically diminished in shoots and roots mainly at 0.01 and 0.00 mM Mg. This decline was adversely associated with a significant increase of sucrose, fructose and mainly glucose in shoots of plants exposed to severe deficiency. By contrast, sugar contents were severely reduced in roots of these plants indicating an alteration of carbohydrate partitioning between shoots and roots of Mg‐deficient plants. Cell wall invertase activity was highly enhanced in roots of Mg‐deficient plants, while the vacuolar invertase activity was reduced at 0.00 mM Mg. This decrease of vacuolar invertase activity may indicate the sensibility of roots to Mg starvation resulting from sucrose transport inhibition. ¹⁴CO₂ labeling experiments were in accordance with these findings showing an inhibition of sucrose transport from source leaves to sink tissues (roots) under Mg depletion.
• The obtained results confirm previous findings about Mg involvement in photosynthate loading into phloem and add new insights into mechanisms evolved by S. carnosa to cope with Mg shortage in particular the increase of the activity of cell wall invertase.

     

Apolipoprotein E gene polymorphism and the risk of left ventricular dysfunction among Egyptian β-thalassemia major

In Egypt, β-thalassemia is the most common hereditary hemolytic anemia. Cardiac dysfunction, secondary to iron overload with formation of oxygen free radicals, is the most common cause of death in β-thalassemia patients. This study was designed to determine whether the allelic genotype of apolipoprotein E (Apo E), which exhibits antioxidant properties, could represent a genetic risk factor for the development of left ventricular (LV) dysfunction in β-thalassemia major. Fifty Egyptian β-thalassemia major patients were subjected to echocardiography to assess LV function. Apo E genotyping by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was done for all patients in addition to 50 age and sex matched healthy control subjects. Patients were classified into three groups. Group I and II were clinically asymptomatic. Group II subjects had evidence of LV dilatation, while Group III patients had clinical and echocardiographic findings of LV failure. Apo E4 allele was significantly higher among Group II and III than in controls. In conclusion, Apo E4 allele can be considered as a genetic risk factor for LV dysfunctions in β-thalassemic patients. It could be used as predictive indicator for additional risk of LV failure, particularly in asymptomatic patients with LV dilatation, requiring a closer follow-up, to prevent further disease progression.     

Spectrofluorimetric determination of eptifibatide in human plasma and dosage form

A spectrofluorimetric method for the determination of eptifibatide is presented based on its native fluorescence. The type of solvent and the wavelength of maximum excitation and emission were carefully selected to optimize the experimental conditions. Under the specified experimental conditions, the linearities obtained between the emission intensity and the corresponding concentrations of eptifibatide were in the range 0.1–2.5 μg/ml for the calibration curve constructed for direct determination of eptifibatide in dosage form and 0.05–2.2 μg/ml for the calibration curve constructed in spiked human plasma with a good correlation coefficient (r > 0.99). The lower limit of quantification for the calibration curve constructed in human plasma was 0.05 μg/ml. Recovery results for eptifibatide in spiked plasma samples and in dosage form, represented as mean ± % RSD, were 95.17 ± 1.94 and 100.29 ± 1.33 respectively. The suggested procedures were validated according to the International Conference on Harmonization (ICH) guidelines for the direct determination of eptifibatide in its pure form and dosage form and United States Food and Drug Administration (US FDA) Guidance for Industry, Bioanalytical Method Validation for the assay of eptifibatide in human plasma.