Clinical trial of two antivenoms for the treatment of Bothrops and Lachesis bites in the north eastern Amazon region of Brazil

The efficacies of specific Bothrops atrox-Lachesis and standard Bothrops-Lachesis antivenoms were compared in the north eastern Amazon region of Brazil. The main aim was to investigate whether a specific antivenom raised against the venom of B. atrox, the most important Amazon snake species from a medical point of view, was necessary for the treatment of patients in this region. Seventy-four patients with local and systemic effects of envenoming by Bothrops or Lachesis snakes were randomly allocated to receive either specific (n = 38) or standard (n = 36) antivenoms. In 46 cases (24 in the standard antivenom group, 22 in the other) the snake was identified either by enzyme immunoassay or by examination of the dead snake, as B. atrox in 45, L. muta in one. Patients were similar in all clinical and epidemiological respects before treatment. Results indicated that both antivenoms were equally effective in reversing all signs of envenoming detected both clinically and in the laboratory. Venom-induced haemostatic abnormalities were resolved within 24 h after the start of antivenom therapy in most patients. The extent of local complications, such as local skin necrosis and secondary infection, was similar in both groups. There were no deaths. The incidence of early anaphylactic reactions was 18% and 19%, respectively for specific and standard antivenoms; none was life-threatening. Measurement of serum venom concentrations by enzyme immunoassay (EIA) confirmed that both antivenoms cleared venom antigenaemia effectively. EIA also revealed that one patient had been bitten by Lachesis muta, although the clinical features in this case were not distinctive.     

Glycinergic and GABAergic calcium responses in the developing lateral superior olive

The lateral superior olive (LSO), a binaural nucleus involved in sound localization, receives tonotopically organized inhibitory inputs from the medial nucleus of the trapezoid body (MNTB). During development, the tonotopic organization of this glycinergic/GABAergic MNTB-LSO pathway is established by activity-dependent axonal reorganization. However, the underlying mechanisms by which this reorganization takes place have remained largely unknown. As cytosolic calcium is one of the most important second messengers responsible for inducing synaptic plasticity and reorganization, we examined whether and how activity in the MNTB-LSO pathway changes the intracellular calcium concentration ([Ca2+]i) in developing LSO neurons. By applying calcium imaging techniques to Fura-2-labelled slices from neonatal rats and mice, we found that glycine and GABA (gamma-aminobutyric acid) affect [Ca2+]i in LSO neurons in an age-dependent manner; during the first postnatal week, the period at which glycine and GABA are depolarizing in the LSO, glycine and GABA always increased [Ca2+]i. However, in 2-week-old animals, the time around hearing onset when glycine and GABA are hyperpolarizing, glycine and GABA slightly decreased [Ca2+]i. Calcium responses could also be elicited by stimulation of afferent fibres from the MNTB, and these synaptic responses were mediated by glycine and GABA(A) receptors. Furthermore, GABA, which is a neurotransmitter only in the immature MNTB-LSO pathway, played a major role in generating MNTB-elicited Ca2+ responses. The direct link of glycinergic/GABAergic synaptic activity to intracellular calcium signalling during the period of inhibitory synaptic plasticity could be one of the mechanisms by which tonotopic MNTB-LSO connections become established.     

Use of simvastatin treatment in patients with combined hyperlipidemia in clinical practice. For the Simvastatin Combined Hyperlipidemia Registry Group

OBJECTIVE: To describe and understand current care of simvastatin-treated patients with combined hyperlipidemia in routine clinical practice. DESIGN: A 6-month prospective observational study. Demographics, simvastatin dosage, cardiac risk factors, and lipid profile were collected from August 1997 to December 1998 at 20 sites (230 patients) across the United States. RESULTS: Overall mean percentage of reduction in total cholesterol levels was 27% (P<.001), low-density lipoprotein cholesterol (LDL-C) was 35% (P<.001), and triglyceride values was 28% (P<.001). Among those patients with low baseline high-density lipoprotein cholesterol (HDL-C) values (<0.91 mmol/L [<35 mg/dL]) (N = 49), there was a 17% increase in HDL-C (P< or =.001); 35% of these patients achieved National Cholesterol Education Program HDL-C goal (ie, < or =0.91 mmol/L [> or =35 mg/dL]). Coronary heart disease (CHD) patients were given significantly higher initial doses (mean, 15.1 mg) compared with non-CHD patients (mean, 11.5 mg) (P< or =.001). Overall, 74% of patients achieved LDL-C goal (52% on starting dose, 22% after 1 titration). Among those patients who were not at goal and had a follow-up lipid profile result available, only 1 patient (2%) was at the maximum dose (80 mg); 69% were receiving 20 mg or less. Approximately 63% of patients with CHD, 80% of patients with 2 or more risk factors, and 91% of patients with fewer than 2 risk factors achieved LDL-C goal. CONCLUSIONS: Multiple factors contribute to LDL-C goal achievement in a usual care setting. A significant opportunity exists to increase the number of patients who achieve LDL-C goal by appropriate dose titration and/or give patients a higher initial dose of simvastatin.     

Mitochondrial and liver oxidative stress alterations induced by N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine: relevance for hepatotoxicity

The most significant toxicological effect of nitrosamines like N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine (BBN) is their carcinogenic activity, which may result from exposure to a single large dose or from chronic exposure to relatively small doses. However, its effects on mitochondrial liver bioenergetics were never investigated. Liver is the principal organ responsible for BBN metabolic activation, and mitochondria have a central function in cellular energy production, participating in multiple metabolic pathways. Therefore any negative effect on mitochondrial function may affect cell viability. In the present work, ICR male mice were given 0.05% of BBN in drinking water for a period of 12 weeks and were sacrificed one week later. Mitochondrial physiology was characterized in BBN‐ and control‐treated mice. Transmembrane electric potential developed by mitochondria was significantly affected when pyruvate–malate was used, with an increase in state 4 respiration observed for pyruvate–malate (46%) and succinate (38%). A decrease in the contents of one subunit of mitochondrial complex I and in one subunit of mitochondrial complex IV was also observed. In addition, the activity of both complexes I and II was also decreased by BBN treatment. The treatment with BBN increases the susceptibility of liver mitochondria to the opening of the mitochondrial permeability transition pore. This susceptibility could be related with the increase in the production of H₂O₂ by mitochondria and increased oxidative stress confirmed by augmented susceptibility to lipid peroxidation. These results lead to the conclusion that hepatic mitochondria are one primary target for BBN toxic action during liver metabolism. Copyright © 2011 John Wiley & Sons, Ltd.     

Why did patients with cardiovascular disease in the Netherlands accept Q fever vaccination?

This study examines patient's reasons for accepting Q fever vaccination, including risk perception, feelings of doubt, social influence, information-seeking behavior, preventive measures taken, and perceptions regarding received information and governmental action. Data was obtained from exit interviews conducted after Q fever vaccination, between January and April 2011. A total of 413 patients with specific cardiovascular conditions in the Netherlands participated in exit interviews; 70% were older than 60 years. Most reported reasons for accepting Q fever vaccination were: "I am at an increased risk for developing (chronic) Q fever" (69%) and "my general practitioner recommends Q fever vaccination for me" (34%). The majority (86%) reported a high perceived severity of Q fever, and only 6% felt vulnerable to Q fever after vaccination. One-third had doubts about getting vaccinated, primarily related to fears of side effects and practical barriers. Fifty-two percent solicited advice from their social networks; of these, 67% reported influence on their vaccination decision. General practitioners and family were the most reported sources of advice. Thirty percent actively sought information about Q fever vaccination. Twenty-two percent of all respondents had taken other preventive measures, such as avoiding contact with goats and sheep (74%), and cancelling or postponing visits to Q fever-affected areas (36%). Almost one-half of all respondents reported negative feelings regarding governmental action to control Q fever. Significant differences were observed regarding feelings of doubt, information-seeking behavior, perceived vulnerability, preventive measures taken, and perceptions regarding received information and governmental action regarding gender, age, educational level, and/or employment status. Vaccination decision-making may differ among socio-demographic subgroups. When preparing future vaccination campaigns, it is important to obtain greater insight into these differences and take these aspects into account in risk communication strategies by tailoring information to specific target groups.     

Comparison of individual and combination DNA vaccines for B. anthracis,Ebola virus,Marburg virus and Venezuelan equine encephalitis virus

Multiagent DNA vaccines for highly pathogenic organisms offer an attractive approach for preventing naturally occurring or deliberately introduced diseases. Few animal studies have compared the feasibility of combining unrelated gene vaccines. Here, we demonstrate that DNA vaccines to four dissimilar pathogens that are known biowarfare agents, Bacillus anthracis, Ebola (EBOV), Marburg (MARV), and Venezuelan equine encephalitis virus (VEEV), can elicit protective immunity in relevant animal models. In addition, a combination of all four vaccines is shown to be equally as effective as the individual vaccines for eliciting immune responses in a single animal species. These results demonstrate for the first time the potential of combined DNA vaccines for these agents and point to a possible method of rapid development of multiagent vaccines for disparate pathogens such as those that might be encountered in a biological attack.     

Platelets as targets of snake venom metalloproteinases

For centuries snake venoms have been known to interfere with haemostasis and this is now known basically due either to toxins activating/inhibiting clotting factors, having effects on blood vessels or interfering with platelet function. In this short review, the interaction of one major group of toxins, the snake venom metalloproteinases, with platelets is considered. This is relevant for understanding the mechanism of haemorrhage induced by these toxins.     

Factors affecting the sensitivity and specificity of the Heidelberg Retina Tomograph parameters to glaucomatous progression in disc photographs

Purpose: To evaluate the factors affecting the sensitivity and specificity of the stereometric optic nerve head (ONH) parameters of the Heidelberg Retina Tomograph (HRT) to glaucomatous progression in stereoscopic ONH photographs. Methods: The factors affecting the sensitivity and specificity of the vertical cup : disc ratio, the cup : disc area ratio, the cup volume, the rim area and a linear discriminant function to progression were analysed. These parameters were the best indicators of progression in a retrospective study of 476 eyes. The reference standard for progression was the masked evaluation of stereoscopic ONH photographs. Results: The factors having the most significant effect on the sensitivity and specificity of the stereometric ONH parameters were the reference height difference and the mean topography standard deviation (TSD), indicating image quality. Also, the change in the TSD and age showed consistent, but variably significant, influence on all parameters tested. The sensitivity and specificity improved when there was little change in the reference height, the image quality was good and stable, and the patients were younger. The sensitivity and specificity of the vertical cup : disc ratio was improved by a large disc area and high baseline cup : disc area ratio. The rim area showed a better sensitivity and specificity for progression with a small disc area and low baseline cup : disc area ratio. Conclusion: The factors affecting the sensitivity and specificity of the stereometric ONH parameters to glaucomatous progression in disc photographs are essentially the same as those affecting the measurement variability of the HRT.     

Rapid interrogation of cancer cell of origin through CRISPR editing

The increasing complexity of different cell types revealed by single-cell analysis of tissues presents challenges in efficiently elucidating their functions. Here we show, using prostate as a model tissue, that primary organoids and freshly isolated epithelial cells can be CRISPR edited ex vivo using Cas9–sgRNA (guide RNA) ribotnucleoprotein complex technology, then orthotopically transferred in vivo into immunocompetent or immunodeficient mice to generate cancer models with phenotypes resembling those seen in traditional genetically engineered mouse models. Large intrachromosomal (∼2 Mb) or multigenic deletions can be engineered efficiently without the need for selection, including in isolated subpopulations to address cell-of-origin questions.

Models to study the earliest stages in cancer progression must, by definition, start with normal cells to assess the consequences of a suspected oncogenic perturbation. Inbred mouse strains and genetically engineered mouse models (GEMMs) have, for decades, served as gold standards for such studies but require significant time (years) to generate, breed, and age mice. CRISPR technology has greatly accelerated the pace of generating GEMMs through delivery of sgRNAs (guide RNAs) and/or Cas9 to tissues such as lung and liver (1–3). The ability to grow primary tissues ex vivo as organoids and introduce precise genetic changes into these cultures provides an alternative platform to model genomic alterations with speed and efficiency, as reported for intestine and prostate (4–7). Here we demonstrate highly efficient (50 to 90%) editing of primary prostate epithelial organoid cultures, including multigenic or intrachromosomal (>2 Mb) deletions, through transient electroporation of Cas9–sgRNA ribonucleoprotein (cRNP) complexes. We also show cRNP-based CRISPR editing can be performed on freshly isolated prostate epithelial cells and then transplanted orthotopically into the prostates of recipient mice in a single day, enabling extremely rapid generation of in vivo cancer models in immunodeficient as well as immunocompetent settings. Finally, we show that this approach can be used to address cancer cell-of-origin questions by multigenic editing selectively in luminal versus basal epithelial cells.