LC/MS analysis of brevetoxin metabolites in the Eastern oyster (Crassostrea virginica).

Brevetoxin (PbTx) metabolism was examined in the Eastern oyster (Crassostrea virginica) following exposure to a Karenia brevis red tide, by using LC/MS(/MS) and cytotoxicity assay. Metabolites observed in field-exposed oysters were confirmed in oysters exposed to K. brevis cultures in the laboratory. Previously, we identified a cysteine conjugate and its sulfoxide (MH(+): m/z 1018 and 1034) as metabolites of the brevetoxin congener PbTx-2. In the present study, we found a cysteine conjugate and its sulfoxide with A-type brevetoxin backbone structure (MH(+): m/z 990 and 1006), as probable derivatives of PbTx-1. We also found glycine-cysteine-PbTx (m/z 1047 and 1075), gamma-glutamyl-cysteine-PbTx (m/z 1147), and glutathione-PbTx (m/z 1176 and 1204) conjugates with A- and B-type backbone structures. Amino acid-PbTx conjugates react with fatty acids through amide linkage to form a series of fatty acid-amino acid-PbTx conjugates. These fatty acid conjugates are major contributors to the composite cytototoxic responses obtained in extracts of brevetoxin-contaminated oysters. Other brevetoxin derivatives found in oysters are consistent with hydrolytic ring-opening and oxidation/reduction reactions.     

Large Electrocaloric Responsivity and Energy Storage Response in the Lead-Free Ba(GexTi1−x)O3 Ceramics

Ferroelectric property that induces electrocaloric effect was investigated in Ba(Ge_xTi_1−x)O₃ ceramics, known as BTGx. X-ray diffraction analysis shows pure perovskite phases in tetragonal symmetry compatible with the P4mm (No. 99) space group. Dielectric permittivity exhibits first-order ferroelectric-paraelectric phase transition, confirmed by specific heat measurements, similar to that observed in BaTiO₃ (BTO) crystal. Curie temperature varies weakly as a function of Ge-content. Using the direct and indirect method, we confirmed that the adiabatic temperature change ΔT reached its higher value of 0.9 K under 8 kV/cm for the composition BTG6, corresponding to an electrocaloric responsivity ΔT/ΔE of 1.13 × 10⁻⁶ K.m/V. Such electrocaloric responsivity significantly exceeds those obtained so far in other barium titanate-based lead-free electrocaloric ceramic materials. Energy storage investigations show promising results: stored energy density of ~17 mJ/cm³ and an energy efficiency of ~88% in the composition BTG5. These results classify the studied materials as candidates for cooling devices and energy storage applications.     

Race, insurance status, and tubal sterilization

OBJECTIVE: To examine the independent effects of race or ethnicity and insurance status on use of tubal sterilization rates. METHODS: This study used cross-sectional data collected by the 2002 National Survey of Family Growth. The survey is designed to represent women and men aged 15-44 years in the household population of the United States. Our main outcome measure was tubal sterilization at any time before interview. A multivariable logistic regression model was used to estimate the effects of race or ethnicity and insurance status on rates of tubal sterilization after adjusting for important confounders. RESULTS: The sample consisted of 7,643 women: 66% were white, 15% were Hispanic, and 14% were African American; 68% had private insurance and 32% had public or no insurance. After adjusting for age, insurance status, parity, income, education, marital status, and religion, African-American women were more likely than white women to undergo tubal sterilization (adjusted odds ratio 1.43, 95% confidence interval 1.08-1.88). After adjusting for age, race or ethnicity, parity, income, education, marital status, and religion, women with public or no insurance were more likely to undergo sterilization compared with women with private insurance (adjusted odds ratio 1.38, 95% confidence interval 1.09-1.74). CONCLUSION: African-American women and women with no or public insurance were more likely to have undergone tubal sterilization compared with white women and women with private insurance, respectively. Additional research to identify factors that influence women's decision to undergo sterilization is warranted. LEVEL OF EVIDENCE: II.     

Arboviral causes of non-specific fever and myalgia in a fever hospital patient population in Cairo, Egypt

Fever and myalgia are non-specific clinical manifestations of illness which commonly occur in patients with arboviral disease. In Egypt, such illness is often mis-diagnosed as "influenza". To determine arboviral aetiology in patients admitted with fever and myalgia, acute and convalescent sera samples were obtained from 55 patients admitted with these clinical manifestations to the Imbaba Fever Hospital, Giza, Egypt, during October and November 1984. Based on viral isolation, and a comparison of acute and convalescent sera, 4 patients (7%) had acute arboviral infections. Haemagglutination inhibition and indirect immunofluorescence tests showed that one had West Nile virus (WNV) infection, 2 had sandfly fever virus-Naples (SFN), and 1 had sandfly fever virus-Sicilian (SFS) infection. SFN was isolated from the acute serum sample of 1 of the 2 patients with SFN infection.     

Surface-engineered liposomes for dual-drug delivery targeting strategy against methicillin-resistant Staphylococcus aureus (MRSA)

This study focused on the encapsulation of vancomycin(VAN) into liposomes coated with a red blood cell membrane with a targeting ligand, daptomycin–polyethylene glycol–1,2-distearoyl-sn-glycero-3-phosphoethanolamine, formed by conjugation of DAPT and Nhydroxysuccinimidyl-polyethylene glycol-1,2-distearoyl-sn-glycero-3-phosphoethanolamine.This formulation is capable of providing controlled and targeted drug delivery to the bacterial cytoplasm. We performed MALDI-TOF, NMR and FTIR analyses to conf...     

The Role of Streptococcal Cell-Envelope Proteases in Bacterial Evasion of the Innate Immune System

Bacteria possess the ability to evolve varied and ingenious strategies to outwit the host immune system, instigating an evolutionary arms race. Proteases are amongst the many weapons employed by bacteria, which specifically cleave and neutralize key signalling molecules required for a coordinated immune response. In this article, we focus on a family of S8 subtilisin-like serine proteases expressed as cell-envelope proteases (CEPs) by group A and group B streptococci. Two of these proteases known as Streptococcus pyogenes CEP (SpyCEP) and C5a peptidase cleave the chemokine CXCL8 and the complement fragment C5a, respectively. Both CXCL8 and C5a are potent neutrophil-recruiting chemokines, and by neutralizing their activity, streptococci evade a key defence mechanism of innate immunity. We review the mechanisms by which CXCL8 and C5a recruit neutrophils and the characterization of SpyCEP and C5a peptidase, including both in vitro and in vivo studies. Recently described structural insights into the function of this CEP family are also discussed. We conclude by examining the progress of prototypic vaccines incorporating SpyCEP and C5a peptidase in their preparation. Since streptococci-producing SpyCEP and C5a peptidase are responsible for a considerable global disease burden, targeting these proteases by vaccination strategies or by small-molecule antagonists should provide protection from and promote the resolution of streptococcal infections.     

Adult presentation of ALCAPA: Echo and CT diagnosis

A healthy 20‐year‐old male presented with aborted sudden death. Both thoracic echocardiography and cardiac computed tomographic angiography demonstrated the characteristic findings of ALCAPA noting a dilated and tortuous right coronary artery, dilated coronary collateral arteries within the interventricular septum or along the surface of the heart, and visualization of the left coronary artery origin from the posterior aspect of the main pulmonary artery. Both imaging modalities demonstrated all three characteristic findings of this rare coronary anomaly and served as complementary imaging studies for surgical correction.