Induction of programmed cell death in a dorsal root ganglia × neuroblastoma cell line

Growth factor-dependent neurons die when they are deproved of their specific growth factor. This “programmed” cell death (PCD) requires macromolecular synthesis and is distinct from necrotic cell death. To investigate the mechanisms involved in neuronal PCD, we have studied the sequence of events that occur when a neuronal cell line (F-11: Mouse neuroblastoma X rat dorsal root ganglia) is deprived of serum in a manner analogous to growth factor deprivation from neurons. Protein synthesis was inhibited within the first 8 h of serum deprivation, while DNA cleavage into nucleosome ladders was prominent by 24 h. The DNA cleavage could be inhibited by cycloheximide, consistent with a requirement for protein synthesis. In contrast, mitochondrial function was not compromised by serum deprivation. Rather, the cells appeared to be metabolically activated after serum removal as shown by an increased reduction of MTT by mitochondrial dehydrogenases and an increase in cellular autofluorescence, which is thought to be due to elevated levels of NADH and flavoproteins. Assessment of cell viability by propidium iodide staining showed no indication of cell death within 24 h. After 48 h of serum deprivation, cells decreased in size and increased propidium iodide uptake. Thus, serum deprivation activates PCD in F-11 cells and may be a useful model to study the intracellular events responsible for PCD. © 1993 John Wiley & Sons, Inc.     

MRSA Clonal Complex 22 Strains Harboring Toxic Shock Syndrome Toxin (TSST-1) Are Endemic in the Primary Hospital in Gaza,Palestine

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen in both community and healthcare-related settings worldwide. Current knowledge regarding the epidemiology of S. aureus and MRSA in Gaza is based on a single community-based carriage study. Here we describe a cross-sectional analysis of 215 clinical isolates collected from Al-Shifa Hospital in Gaza during 2008 and 2012.

Methods

All isolates were characterized by spa typing, SCCmec typing, and detection of genes encoding Panton-Valentine leukocidin (PVL) and toxic shock syndrome toxin (TSST-1). Representative genotypes were also subjected to multilocus sequence typing (MLST). Antibiotic susceptibility testing was performed using VITEK2 and MicroScan.

Results

MRSA represented 56.3% of all S. aureus strains, and increased in frequency from 2008 (54.8%) to 2012 (58.4%). Aside from beta-lactams, resistance was observed to tetracycline, erythromycin, clindamycin, gentamicin, and fluoroquinolones. Molecular typing identified 35 spa types representing 17 MLST clonal complexes (CC), with spa 998 (Ridom t223, CC22) and spa 70 (Ridom t044, CC80) being the most prevalent. SCCmec types I, III, IV, V and VI were identified among MRSA isolates, while type II was not detected. PVL genes (lukF/S-PV) were detected in 40.0% of all isolates, while the TSST-1 gene (tst) was detected in 27.4% of all isolates, with surprisingly high frequency within CC22 (70.4%). Both PVL and TSST-1 genes were found in several isolates from 2012.

Conclusions

Molecular typing of clinical isolates from Gaza hospitals revealed unusually high prevalence of TSST-1 genes among CC22 MRSA, which is noteworthy given a recent community study describing widespread carriage of a CC22 MRSA clone known as the ‘Gaza strain’. While the latter did not address TSST-1, tst-positive spa 998 (Ridom t223) has been detected in several neighboring countries, and described as endemic in an Italian NICU, suggesting international spread of a ‘Middle Eastern variant’ of pandemic CC22 strain EMRSA-15.     

Synthesis of new 9-glycosyl-4,9-dihydropyrano [3,4-b]indole-1(3H)-ones as antibacterial agents

A series of new 9-glycosyl-4,9-dihydropyrano[3,4-b]indole-1(3H)-ones 3 was synthesized in moderate to low yields. 4,9-Dihydropyrano[3,4-b]indole-1(3H)-ones (1) were coupled with different acetobromoglycopyranoses 2 in refluxing toluene in the presence of silver oxide to afford one coupling product of the respective N-glycosides. α-L-Arabinopyranosides 3j and 3m were the most active glycosides among the tested compounds against certain Gram positive and Gram negative bacterial strains.     

Craniectomy for malignant cerebral infarction: prevalence and outcomes in US hospitals

Object

Randomized trials have demonstrated the efficacy of craniectomy for the treatment of malignant cerebral edema following ischemic stroke. We sought to determine the prevalence and outcomes related to this by using a national database.

Methods

Patient discharges with ischemic stroke as the primary diagnosis undergoing craniectomy were queried from the US Nationwide Inpatient Sample from 1999 to 2008. A subpopulation of patients was identified that underwent thrombolysis. Two primary end points were examined: in-hospital mortality and discharge to home/routine care. To facilitate interpretations, adjusted prevalence was calculated from the overall prevalence and two age-specific logistic regression models. The predictive margin was then generated using a multivariate logistic regression model to estimate the probability of in-hospital mortality after adjustment for admission type, admission source, length of stay, total hospital charges, chronic comorbidities, and medical complications.

Results

After excluding 71,996 patients with the diagnosis of intracranial hemorrhage and posterior intracranial circulation occlusion, we identified 4,248,955 adult hospitalizations with ischemic stroke as a primary diagnosis. The estimated rates of hospitalizations in craniectomy per 10,000 hospitalizations with ischemic stroke increased from 3.9 in 1999–2000 to 14.46 in 2007–2008 (p for linear trend<0.001). Patients 60+ years of age had in-hospital mortality of 44% while the 18–59 year old group was found to be 24%(p = 0.14). Outcomes were comparable if recombinant tissue plasminogen activator had been administered.

Conclusions

Craniectomy is being increasingly performed for malignant cerebral edema following large territory cerebral ischemia. We suspect that the increase in the annual incidence of DC for malignant cerebral edema is directly related to the expanding collection of evidence in randomized trials that the operation is efficacious when performed in the correct patient population. In hospital mortality is high for all patients undergoing this procedure.     

Constituents of Chrysothamnus viscidiflorus

A phytochemical investigation of the aerial parts of Chrysothamnus viscidiflorus var. viscidiflorus afforded three new [chrysothol (1), 2 and 4] and seven known compounds, including five sesquiterpenes, two cinnamic acid derivatives, two ketoalcohol derivatives and one coumarin glucoside. The structures of two previously reported compounds, 1b and 1c, were revised on the basis of chemical reaction. Structures of the compounds were determined by extensive NMR studies, including DEPT, COSY, NOE, HMQC, HMBC and X-ray analysis. The unpublished X-ray data of the known compounds 6 and 7 are reported. Compounds chrysothol (1), and 8-10 showed anti-cancer activity against human breast cancer cells.     

Anticancer effect of atorvastatin nanostructured polymeric micelles based on stearyl-grafted chitosan

The purpose of this study was to develop a new therapeutic approach for atorvastatin (ATV) adopting nanostructured polymeric micelles for its controlled delivery to the cancer cells. Amphiphilic block copolymers of stearyl chitosan (SC) and sulfated stearyl chitosan (S-SC) that could self assemble to form polymeric micelles with different degree of substitution (DS) were synthesized and characterized. The synthesized chitosan derivatives were able to self assemble and form micelles encapsulating ATV with critical micellar concentrations ranging from 6.9 to 21μg/ml, drug-loading ranging from 40% to 84.1% and encapsulation efficiency ranging from 10.4% to 35%. ATV caused a significant decrease in particle size and zeta potential of both SC and S-SC micelles. Micelles encapsulating ATV exhibited a sustained release and more cytotoxic activity against MCF 7 and HCT 116 cell lines than ATV alone. The 50% cellular growth inhibition (IC50%) of the drug decreased from 10.4 to 3.7 in case of MCF 7 and from 9.4 to 3.4 in case of HCT 116 after its loading in micelles. These results indicate that SC ATV polymeric micelles can be considered as a promising system for site specific controlled delivery of ATV to tumor cells.     

Increased Levels of Sphingosylphosphorylcholine (SPC) in Plasma of Metabolic Syndrome Patients

Recent developments in lipid mass spectrometry enable extensive lipid class and species analysis in metabolic disorders such as diabesity and metabolic syndrome. The minor plasma lipid class sphingosylphosphorylcholine (SPC) was identified as a ligand for lipid sensitive G-protein coupled receptors playing a key role in cell growth, differentiation, motility, calcium signaling, tissue remodeling, vascular diseases and cancer. However, information about its role in diabesity patients is sparse. In this study, we analyzed plasma lipid species in patients at risk for diabesity and the metabolic syndrome and compared them with healthy controls. Our data show that SPC is significantly increased in plasma samples from metabolic syndrome patients but not in plasma from patients at risk for diabesity. Detailed SPC species analysis showed that the observed increase is due to a significant increase in all detected SPC subspecies. Moreover, a strong positive correlation is observed between total SPC and individual SPC species with both body mass index and the acute phase low grade inflammation marker soluble CD163 (sCD163). Collectively, our study provides new information on SPC plasma levels in metabolic syndrome and suggests new avenues for investigation.     

Progesterone-induced Acrosome Exocytosis Requires Sequential Involvement of Calcium-independent Phospholipase A2β (iPLA2β) and Group X Secreted Phospholipase A2 (sPLA2)

Phospholipase A₂ (PLA₂) activity has been shown to be involved in the sperm acrosome reaction (AR), but the molecular identity of PLA₂ isoforms has remained elusive. Here, we have tested the role of two intracellular (iPLA₂β and cytosolic PLA₂α) and one secreted (group X) PLA₂s in spontaneous and progesterone (P4)-induced AR by using a set of specific inhibitors and knock-out mice. iPLA₂β is critical for spontaneous AR, whereas both iPLA₂β and group X secreted PLA₂ are involved in P4-induced AR. Cytosolic PLA₂α is dispensable in both types of AR. P4-induced AR spreads over 30 min in the mouse, and kinetic analyses suggest the presence of different sperm subpopulations, using distinct PLA₂ pathways to achieve AR. At low P4 concentration (2 μm), sperm undergoing early AR (0–5 min post-P4) rely on iPLA₂β, whereas sperm undergoing late AR (20–30 min post-P4) rely on group X secreted PLA₂. Moreover, the role of PLA₂s in AR depends on P4 concentration, with the PLA₂s being key actors at low physiological P4 concentrations (≤2 μm) but not at higher P4 concentrations (∼10 μm).