Cisplatin nephrotoxicity and protection by milk thistle extract in rats

The protective effect of methanolic extract of milk thistle seeds and silymarin against cisplatin-induced renal toxicity in male rats after a single intraperitoneal injection of 3 mg kg cisplatin were studied. Over 5 days, cisplatin-treated rats showed tubular necrosis and elevation in blood urea nitrogen (BUN) and serum creatinine (Scr). Pretreatment of animals with silymarin (50 mg kg) or extract (0.6 g kg) 2 h before cisplatin prevented the tubular damage. Rats treated with silymarin or extract 2 h after cisplatin had BUN and Scr significantly lower than those receiving cisplatin, but mild to moderate necrosis was observed. These results suggested that milk thistle may protect against cisplatin-induced renal toxicity and might serve as a novel combination agent with cisplatin to limit renal injury.     

Clinical Characteristics,Treatment, and Outcomes of Critically Ill Patients With COVID-19: A Scoping Review

A growing number of studies on coronavirus disease 2019 (COVID-19) are becoming available, but a synthesis of available data focusing on the critically ill population has not been conducted. We performed a scoping review to synthesize clinical characteristics, treatment, and clinical outcomes among critically ill patients with COVID-19. Between January 1, 2020, and May 15, 2020, we identified high-quality clinical studies describing critically ill patients with a sample size of greater than 20 patients by performing daily searches of the World Health Organization and LitCovid databases on COVID-19. Two reviewers independently reviewed all abstracts (2785 unique articles), full text (218 articles), and abstracted data (92 studies). The 92 studies included 61 from Asia, 16 from Europe, 10 from North and South America, and 5 multinational studies. Notable similarities among critically ill populations across all regions included a higher proportion of older males infected and with severe illness, high frequency of comorbidities (hypertension, diabetes, and cardiovascular disease), abnormal chest imaging findings, and death secondary to respiratory failure. Differences in regions included newly identified complications (eg, pulmonary embolism) and epidemiological risk factors (eg, obesity), less chest computed tomography performed, and increased use of invasive mechanical ventilation (70% to 100% vs 15% to 47% of intensive care unit patients) in Europe and the United States compared with Asia. Future research directions should include proof-of-mechanism studies to better understand organ injuries and large-scale collaborative clinical studies to evaluate the efficacy and safety of antivirals, antibiotics, interleukin 6 receptor blockers, and interferon. The current established predictive models require further verification in other regions outside China.     

Stoichiometry of Na+-HCO-3 cotransport in basolateral membrane vesicles isolated from rabbit renal cortex.

The major pathway for HCO3- transport across the basolateral membrane of the proximal tubule cell is electrogenic Na+-HCO3- cotransport. In this study, we have determined the stoichiometry of the Na+-HCO3- cotransport system in basolateral membrane vesicles that were isolated from rabbit renal cortex by Percoll gradient centrifugation. When the membrane potential is approximated by the Nernst potential for K+, as in the presence of the K+ ionophore valinomycin, equilibrium thermodynamics predicts that the Na+-HCO3- cotransport system should come to equilibrium and mediate no net flux when (Na)i/(Na)o = [(HCO3)o/(HCO3)i]n[(K)o/(K)i]n-1, where n is the HCO3-:Na+ stoichiometry. Our experimental approach was to impose transmembrane Na+, HCO3-, and K+ gradients of varying magnitude and direction, and then to measure the net flux of Na+ over the subsequent 3-s period. In this way, we could determine the conditions for equilibrium of the transport system and thereby calculate n. The results of these experiments indicate that the value of n is greater than 2.6 and less than 3.5, consistent with a stoichiometry of 3 HCO3-:1 Na+, or a thermodynamically equivalent process. Based on reported intracellular potentials and ion activities, this value for the stoichiometry indicates that the inside-negative membrane potential is sufficient to drive HCO3- exit against the inward concentration gradients of HCO3- and Na+ that are present across the basolateral membrane of the intact proximal tubule cell under physiologic conditions.     

Sagittal back contour and craniofacial morphology in preadolescents

The aim of this study was to analyze the correlation ratios between the sagittal back contour (flèche cervicale and lombaire, trunk inclination) and selected parameters of craniofacial morphology in children. The patient sample consisted of 66 healthy children with a mean age of 11.2 years (SD 1.6 years), of which 34 were male (mean age 11.5 years, SD 1.3 years) and 32 were females (mean age 10.9 years, SD 1.9 years). The children were recruited during the preparation of the initial orthodontic treatment records. Craniofacial morphology was analyzed by six angular measurements: facial axis, mandibular plane angle, inner gonial angle, lower facial height, facial depth and maxilla position. Rasterstereography was used for reconstruction of the spinal back sagittal profile. From the profile flèche cervicale, flèche lombaire and trunk inclination were determined and the correlations with the craniofacial morphology were calculated (Pearson and Mann–Whitney U test). Significant correlations were found with respect to the inner gonial angle and the flèche cervicale, the mandibular plane angle and the flèche lombaire, the inner gonial angle and the flèche lombaire, and the angular lower facial height and the flèche lombaire, as well as the inner gonial angle and the trunk inclination. The craniofacial vertical growth pattern, presented by mandibular plane angle, inner gonial angle and the angular lower facial height, and the correlation to flèche cervicale and lombaire as well as trunk inclination reveal correlations between growth pattern and sagittal back contour.     

Induction of G1 cell cycle arrest and cyclin D1 down-regulation in response to pericarp extract of Baneh in human breast cancer T47D cells

Background and the purpose of the study

Natural products from plants have an important role in the development and production of new drugs mainly for cancer therapy. More recently, we have shown that the pericarp methanolic extract of Pistacia atlantica sub kurdica (with local name of Baneh) as a rich source of active biological components with high antioxidant and radical scavenging activities, has ability to cease proliferation and induce apoptosis in T47D human breast cancer cells. The present study aimed to clarify whether Baneh extract able to alter cell cycle progression of T47D cells or not.

Methods

In order to study the possible effect of Baneh extract on cell cycle of T47D cells, we evaluated cell cycle distribution and its regulatory proteins by flow cytometry and western blot analysis respectively.

Results

Baneh extract induced G₀/G₁ cell cycle arrest in conjunction with a marked decrease in expression of cyclin D1 and cdk4 that was strongly dependent on time of exposure. In parallel, Dox-treated T47D cells in early time points were accumulated on S phase, but after 48 h cell cycle progression was inhibited on G₂/M. Dox promoted striking accumulation of cyclin B1 rapidly and enhanced cyclin A abundance.

Conclusion

Taken together, our results establish that the antitumor activity of the pericarp extract of Baneh partly is mediated via cell cycle arrest and downregulation of cyclin D1 and cdk4 expression. These findings warrant further evaluation regarding the mechanism(s) of action of this promising anticancer agent.     

A simple quantitative affinity capturing assay of poliovirus antigens and subviral particles by single-domain antibodies using magnetic beads

Recently, single-domain recombinant antibody fragments (VHHs or nanobodies) against poliovirus type 1 were isolated. To examine the antigenicity of poliovirus using these recombinant VHHs, an alternative technique mimicking protein A immunoprecipitation had to be developed that was designed specifically for VHHs. The current study validated an affinity capturing assay that is based on the magnetic separation of unbound antigen and antigen-VHH complexes. The technique is simple, fast, reliable, quantitative and inexpensive and was employed to assess the reactivity of 15 VHHs for native infectious poliovirus (N antigen), heat-denatured virus (H antigen) and 14S subviral particles. Three distinct subsets of VHHs were tentatively distinguished based on their specificity for the antigens: one that binds only to 14S precursors, another that binds to the H antigen and a third that binds to the N antigen. Some VHHs of the latter two subsets bound 14S subviral particles with equal affinity but others had at least 100-fold less affinity for the precursors. All neutralizing VHHs were demonstrated to recognize N antigen and all N-specific VHHs were shown to be neutralizing. This study corroborates the findings that VHHs mainly target conformational epitopes and that they target additional epitopes as compared to classical antibodies. The described technique may be useful for epitope mapping and tracking conformational changes of proteins.     

Induction of apoptosis and cell cycle arrest by pericarp polyphenol-rich extract of Baneh in human colon carcinoma HT29 cells

Plants as important source of natural active components with anticancer effects commonly are different in structure and biological properties. The pericarp of Pistacia atlantica sub kurdica with local name of Baneh, a rich source of active phytochemicals, contains noticeable amounts of polyphenolic compounds, flavonoids and anthocyanins. Therefore, the antiproliferative, apoptosis induction and cell cycle alterations of Baneh were evaluated in human colon carcinoma HT29 cells. The Baneh extract (0.7 mg/ml) resulted in 50% growth inhibition similar to 500 nM of Doxorubicin (Dox) in HT29 cells after 72 h. The down-regulation of cyclin A protein by Baneh extract induced S phase delay in cell cycle progression of HT29 cells. Unlike the Baneh extract, Dox showed G2/M accumulation of HT29 cells which was associated with an increase in cyclin A and cyclin B1 protein expression. Furthermore, the induction of apoptosis following Baneh extract and Dox treatment in HT29 cells was confirmed by DNA fragmentation and translocation of phosphatidylserine. The morphological characteristics of apoptosis were also observed in HT29 cells exposed to the Baneh extract and Dox. These results suggest that due to the existence of bioactive components, methanolic extract of the Baneh has significant cytotoxic effects against human colon carcinoma HT29 cells.