Sub-chronic (13-week) oral toxicity study, preceded by an in utero exposure phase and genotoxicity studies with fish source phosphatidylserine in rats.

The safety of fish phosphatidylserine (PS) conjugated to DHA (InCog™) was examined in a series of toxicology studies as first step to support future use in infants and general population using in vitro genotoxicity tests and in a sub-chronic toxicity study with an in-utero exposure phase. PS is a major lipid in the cell membrane, active in various membrane-mediated processes. PS-DHA, present in human milk, has been suggested to be important for early brain development. Rats were exposed to diets containing 1.5%, 3% or 4.5% InCog or two control diets. Parental (F0) animals were fed throughout mating, gestation and lactation. Subsequently, a subchronic, 13-week study was conducted on the F1 animals followed by 4 weeks of recovery. The genotoxicity tests showed no mutagenicity potential. No significant toxicological findings were found in the F0 rats or the F1 pups. In the 13-weeks study, an increase in the presence of renal minimal-mild multifocal corticomedullary mineralization was noted in nine females of the high-dose group. This change was not associated with any inflammatory or degenerative changes in the kidneys. The no-observed-adverse-effect level (NOAEL) in the present study was placed at 3% in the diet (mid-dose group), equivalent to an overall intake of at least 2.1 g InCog/kg bw/day in the F1 generation.

Reduction of glial glutamate transporters in the parietal cortex and hippocampus of the EL mouse.

There is extensive experimental evidence indicating a crucial role for glutamate in epileptogenesis and epileptic activity. The glial glutamate transporters GLT1 and GLAST are proposed to account for the majority of extracellular glutamate re-uptake. In the present study, polyclonal antibodies specific to GLT1 and GLAST were generated and characterized, revealing distribution patterns for the two transporters confirming those previously reported. In situ hybridization and immunoblotting were then used to compare levels of these two transporters in the parietal cortex and hippocampus of unstimulated and stimulated EL mice with DDY control mice. Additionally, HPLC determined tissue glutamate concentrations in the same regions of these animals. These experiments revealed reductions in GLT1 mRNA and protein in the parietal cortex of unstimulated and stimulated EL mice compared with DDY controls, accompanied by an increase in tissue glutamate concentration in the stimulated EL mice group. GLT1 mRNA was also reduced in the CA3 hippocampal subfield of both unstimulated and stimulated EL mice. GLAST protein was reduced in the hippocampus of the stimulated EL mice group, while no changes in GLAST mRNA or protein were detected in the parietal cortex of EL mice when compared with DDY controls. The glial glutamate transporter down-regulation reported here may play a role in seizure initiation, spread and maintenance in the EL mouse.

Acute gastrointestinal bleeding in the intensive care unit. The intensivist's perspective.

Gastrointestinal (GI) hemorrhage is a common and potentially lethal medical emergency that is a common cause for intensive care unit admission. The intensivist plays an important role as a member of the medical team managing the patient with GI bleeding who is at high risk because of severe bleeding, comorbidity, or the presence of endoscopic stigmata of recent hemorrhage. This article presents the intensivist's approach to GI hemorrhage in initial patient assessment, triage, resuscitation, specialist consultation, diagnostic evaluation, and medical therapy. This article focuses on types of GI bleeding of particular concern to the intensivist, including esophageal variceal bleeding, stress-related GI bleeding, and GI bleeding associated with myocardial infarcation.

Glial glutamate transporter mRNAs in the genetically absence epilepsy rat from Strasbourg.

Recent studies support a critical role for the glutamatergic system and glutamate transporters in the pathogenesis of epilepsy. The glial glutamate transporters GLT-1 (L-glutamate transporter) and GLAST (L-glutamate/L-aspartate transporter) are known to be responsible for the majority of glutamate reuptake from the synaptic cleft and constitute one mechanism by which extracellular glutamate levels may be controlled. The present study therefore compared GLT-1 and GLAST mRNA levels in the genetically absence epilepsy rat from Strasbourg (GAERS) with those of age-matched non-epileptic controls. The GAERS rat has been proposed as an animal model of inherited human absence epilepsy, displaying recurrent, generalised, non-convulsive seizures that originate from thalamic and cortical structures. In situ hybridisation with 35S-labelled oligonucleotide probes demonstrated substantial and significant increases in GLT-1 mRNA levels in the ventromedial nucleus of the thalamus (VM) and the subthalamic nucleus (STN) of GAERS rats. Increases in GLAST mRNA were found in the primary somatosensory cortex (SS1) and temporal cortex (Te) of GAERS. These data, along with previous studies, suggest that regional imbalances in GABAergic and glutamatergic systems may be associated with the pathogenesis of absence seizures in GAERS.

Gene expression of metabotropic glutamate receptor 5 and excitatory amino acid transporter 2 in the schizophrenic hippocampus.

A disturbance in glutamatergic transmission has been suggested to contribute to the pathophysiology of schizophrenia and recent studies on ionotropic glutamate receptors are consistent with altered glutamatergic function in the hippocampus of schizophrenics. In order to investigate this hypothesis further, the expression of two 'glutamatergic' markers, the mRNAs of metabotropic glutamate receptor 5 (mGluR5) and human excitatory amino acid transporter (EAAT2) were compared in the hippocampus of control subjects and schizophrenics. We examined the regional/cellular mRNA expression of mGluR5 and EAAT2 in postmortem hippocampal sections from schizophrenics and control subjects, using in situ hybridization. Regions of interests were dentate gyrus, cornu ammonis 4, 3, 1 and parahippocampal gyrus. The regional/cellular mGluR5 mRNA content was not different between the two groups. The cellular EAAT2 mRNA content was significantly decreased in schizophrenic parahippocampal gyrus, but not in other hippocampal regions. Furthermore, only in the parahippocampal gyrus, schizophrenics had a significantly increased mGluR5/EAAT2 ratio at both the regional and cellular mRNA level. The results suggest that a disturbance of glutamatergic neurotransmission in schizophrenia was not apparent using these indices in the hippocampus, but 'hypo-glutamatergic' neurotransmission may be present in the schizophrenic parahippocampal gyrus.

Changes in sex hormone-binding globulin, insulin, and serum lipids in postmenopausal women on a low-fat, high-fiber diet combined with exercise.

Dietary factors including fat and fiber have been reported to play a role in the development of breast cancer, possibly mediated by changes in estradiol. Diet and exercise have been shown to affect levels of sex hormone-binding globulin (SHBG), which in turn regulate the bioavailability of estradiol. Diet and exercise also affect insulin levels, which play a role in the synthesis of SHBG, and the hormone itself is a potent mitogen for many cancer cell lines. This study was designed to measure the effects of a low-fat, high-fiber diet, combined with regular aerobic exercise, on the levels of SHBG, insulin, and serum lipids in postmenopausal women with or without hormone replacement therapy (HRT). Two groups of postmenopausal women, 11 on HRT and 11 not on HRT, underwent a low-fat (1O% fat calories), high-fiber (65-70 g/day) diet-and-exercise intervention for three weeks. Serum SHBG, insulin, and lipids were measured before and after the regimen. After the intervention, SHBG levels were significantly increased for the women on HRT (44.5 +/- 3.4 vs. 62 +/- 6.4 nmol/l) and the women not on HRT (32.1 +/- 4.6 vs. 45.5 +/- 6.1 nmol/l, both changes p < 0.01). Also after the intervention, insulin levels were significantly reduced for the women on HRT (196 +/- 44.4 vs. 119.8 +/- 28.7 pmol/l) and the women not on HRT (144.2 +/- 17.9 vs. 115.5 +/- 20.8 pmol/l, both changes p < 0.01). Body mass index and total cholesterol were significantly reduced for both groups of women (all changes p < 0.01). Although the exact mechanism for the change in SHBG is not known, the increases in SHBG and reductions in insulin as a result of this lifestyle intervention should reduce the risk for breast cancer in postmenopausal women.

Expression of the glutamate transporters in human temporal lobe epilepsy.

Glutamate is the major excitatory neurotransmitter in the central nervous system and is implicated in the pathogenesis of neurodegenerative diseases. Five human glutamate transporters have been cloned and are responsible for the removal of potentially excitotoxic excess glutamate from the extracellular space. In this study we consider whether there are selective changes in the expression of the glutamate transporters in the medial temporal cortex and hippocampus from temporal lobe epilepsy patients, which might contribute to the development or maintenance of seizures. Since disruption of the glial transporter excitatory amino acid transporter 2 in mice results in lethal spontaneous seizures, we were interested primarily in studying changes in this transporter. Using in situ hybridization we show that there was no reduction in the level of excitatory amino acid transporter 2 encoding messenger RNA in the temporal lobe epilepsy cases compared to post mortem controls and indeed there was a relative increase in content of excitatory amino acid transporter 2 messenger RNA per cell in temporal lobe epilepsy cases. Western blotting showed that there was no change in the excitatory amino acid transporter 2 protein content in temporal lobe epilepsy cases as compared to post mortem controls. A small reduction in the level of the second astroglial transporter protein, excitatory amino acid transporter 1, was observed in temporal lobe epilepsy cases. Surprisingly, immunohistochemical experiments using a polyclonal antiexcitatory amino acid transporter 2 antibody, showed a different localization of this protein in epilepsy derived tissue as compared to post mortem controls although glial markers such as glial fibrillary acidic protein and glutamine synthase showed similar patterns of staining. However, repeating this experiment using control tissue from non-temporal lobe epilepsy biopsies demonstrated that this change in the excitatory amino acid transporter 2 transporter localization occurred post mortem. These data suggest that major changes in the level of expression of the glutamate transporters do not play an important role in the development of human temporal lobe epilepsy but may be implicated the aetiology of other types of epilepsy.

Effects of diet and exercise on insulin, sex hormone-binding globulin, and prostate-specific antigen.

A diet high in fat has been linked to prostate cancer, possibly through an influence on hormones. Sex hormone-binding globulin (SHBG) binds androgens and is regulated in part by insulin. Diet and exercise can modify insulin levels, potentially affecting SHBG and the biologically available levels of androgens. To determine the effects of a low-fat (< 10% of calories), high-fiber diet plus daily exercise on insulin, SHBG, prostate-specific antigen (PSA), and serum lipids, we measured the levels of these factors in the serum of 27 obese men undergoing a three-week diet-and-exercise program. Insulin decreased from 222 +/- 30 to 126 +/- 21 pmol/l (p < 0.01), and SHBG increased from 18 +/- 2 to 25 +/- 3 nmol/l (p < 0.01). Body mass index decreased from 35 +/- 1.9 to 33.4 +/- 1.8 kg/m2 (p < 0.01). PSA levels were normal and did not change significantly, although in a small subset of men (n = 3) with slightly elevated PSA levels (> 2.5 ng/ml) all showed a decrease. The three-week diet-and-exercise intervention decreased insulin and lipid levels while increasing SHBG. The increase in SHBG would result in more testosterone being bound and, therefore, less of the androgen available to act on the prostate. The decrease in insulin might also decrease mitogenic activity in the prostate. The diet-and-exercise regimen did not have a significant impact on normal PSA levels. Although modest, these changes may be protective against the development of prostate cancer.

Double-blind randomised controlled trial of monoclonal antibody to human tumour necrosis factor in treatment of septic shock. NORASEPT II Study Group.

BACKGROUND: Despite the availability of potent antibiotics and intensive care, mortality rates from septic shock are 40-70%. We assessed the safety and efficacy of murine monoclonal antibody to human tumour necrosis factor alpha (TNF alpha MAb) in the treatment of septic shock. METHODS: In a randomised, multicentre, double-blind, placebo-controlled clinical trial in 105 hospitals in the USA and Canada, we randomly assigned 1879 patients a single infusion of 7.5 mg/kg TNF alpha MAb (n=949) or placebo (0.25% human serum albumin n=930). Our main outcome measurement was the rate of all-cause mortality at 28 days. FINDINGS: 382 (40.3%) of 948 patients who received TNF alpha MAb and 398 (42.8%) of 930 who received placebo had died at 28 days (95% CI -0.02 to 0.07, p=0.27). We found no association between therapy with TNF alpha MAb and increased rapidity in reversal of initial shock or prevention of subsequent shock. Similarly, baseline plasma interleukin-6 concentrations of more than 1000 pg/mL or detectable circulating TNF concentrations were not associated with improvement in survival after TNF alpha MAb therapy. Coagulopathy but not other organ or system failures, was significantly decreased in the TNF alpha MAb group compared with placebo (day 7, p<0.001; day 28, p=0.005). Serious adverse events were reported in 55.2% of patients given placebo and 54.1% in the TNF alpha MAb group. INTERPRETATION: We did not find an improvement in survival after septic shock with TNF alpha MAb. Therapy not solely dependent on TNF alpha blockade may be required to improve survival.

Neuropilin-1 is a placenta growth factor-2 receptor.

Placenta growth factor (PlGF) belongs to the family of vascular endothelial growth factors (VEGFs). It binds to the flt-1 VEGF receptor but not to the KDR/flk-1 receptor which is thought to mediate most of the angiogenic and proliferative effects of VEGF. Three PlGF isoforms are produced by alternative splicing. PlGF-1 and PlGF-3 differ from PlGF-2 since they lack the exon 6 encoded peptide which bestows upon PlGF-2 its heparin binding properties. Cross-linking experiments revealed that 125I-PlGF-2 binds to two endothelial cell surface receptors in a heparin dependent fashion. The binding of 125I-PlGF-2 to these receptors was inhibited by an excess of PlGF-2 and by the 165-amino acid form of VEGF (VEGF165), but not at all by VEGF121 and very marginally if at all by PlGF-1. The apparent molecular weight and the binding characteristics of these receptors correspond to those of the recently identified VEGF165 specific receptor neuropilin-1, and we therefore conclude that neuropilin-1 is a receptor for PlGF-2. The binding of 125I-PlGF-2 as well as the binding of 125I-VEGF165 to these receptors was inhibited by a synthetic peptide derived from exon 6 of PlGF. Furthermore, the binding of 125I-PlGF-2, but not that of 125I-VEGF165, was also inhibited by a synthetic peptide derived from exon 7 of PlGF. These observations indicate that the peptides encoded by these exons probably participate in the formation of the domain which mediates the binding of PlGF-2 to these receptors. We have also determined, using chemically modified heparin species, that the presence of sulfate moieties on the glucosamine-O-6 and on the iduronic acid-O-2 groups of heparin was required for the potentiation of 125I-PlGF-2 binding to these receptors. To determine if PlGF-2 is able to induce biological responses that are not induced by PlGF-1, we compared the effects of PlGF-1 and PlGF-2 on the migration and proliferation of endothelial cells. Both PlGF forms induced migration of endothelial cells. However, there was no quantitative difference between the response to PlGF-2 and the response to PlGF-1. Furthermore, neither PlGF-1 nor PlGF-2 had any effect upon the proliferation of the endothelial cells.

Perceptions of contraceptive effectiveness and health effects of oral contraception.

PIP: The hypothesis that misperceptions about the effectiveness of contraceptive methods and the risks and benefits of oral contraceptive (OC) use are widespread in the US, even among the most educated population groups, was investigated in 147 women presenting to the Brown University (Providence, Rhode Island) health service and 189 students solicited by female volunteers on the campus. 90% of respondents correctly estimated the effectiveness of OCs in preventing pregnancy, but 32-34% inflated the pregnancy rates associated with subdermal implants and Depo-Provera. 60% overestimated the failure rate of the IUD. On the other hand, a majority underestimated the failure rates of barrier methods and spermicides. 41% believed OCs increase the risk of breast cancer and 33% thought the pill increases cervical cancer risk. 66% knew that OCs reduce dysmenorrhea and 50% were aware the pill decreases menstrual bleeding. However, the majority were unaware OCs reduce the risk of benign breast disease (95%), ectopic pregnancy (91%), pelvic inflammatory disease (90%), and anemia (89%). 81% were unaware of the protective effects of OCs against uterine cancer and 77% did not know they have a protective effect against ovarian cancer. In general, OC users were more aware of the health benefits of OCs than condom users. Finally, respondents were asked to rate their satisfaction with their current birth control method on a scale of 1-12. Mean satisfaction scores were significantly higher among OC users (10.3) than condom users (7.1). These findings indicate that, even among highly educated US women, misperceptions persist about the reliability of birth control, the risks of pregnancy, and the health effects of OCs.^ieng

Gas gangrene of the arm due to Enterobacter cloacae in a neutropenic patient.

Gas gangrene is a life-threatening emergency. Most cases are caused by clostridial infections, but nonclostridial causes are being increasingly recognized. Nonclostridial gas gangrene is most often due to polymicrobial organisms. Early diagnosis and therapy are required, since the disease may rapidly progress to fatal toxemia. We report a case of gangrenous, atraumatic, nonclostridial myonecrosis of the arm due to Enterobacter cloacae in a nondiabetic patient with neutropenia.