Mercury concentrations in hair exposed in vitro to mercury vapor

Hair is often used as an index of environmental and industrial exposure to different metals. The interpretation of metal levels in hair is difficult because of the risk of external contamination. The aim of this study was to define the degree of external contamination of hair exposed in vitro to mercury vapor. Specimens of hair were exposed to concentration: 0.026, 0.21, and 2.7 mg Hg/m³ for 2–28 d. Mercury levels in hair increased during 28 d of exposure 2, 3 and 13, times, respectively, when compared to initial values. Mercury levels in hair exposed to the first and second (but not third) concentration of mercury vapor attained a steady state on the 21st d of exposure. The contamination of hair with mercury could not be removed by washing with water, solvent, and detergent. Hair may be used as an index of internal uptake of mercury provided that it was not externally exposed to mercury vapor. In cases of occupational exposure to mercury vapor, hair could become a useful tool for monitoring exposures.     

Distribution of inositol 1,4,5-trisphosphate receptor isoforms, SERCA isoforms and Ca binding proteins in RBLm2H3 rat basophilic leukemia cells

RBL-2H3 rat basophilic leukemia cells were homogenized and fractionated. A fraction F3 obtained by differential centrifugation was 6-fold enriched in [3H]-inositol 1,4,5-trisphosphate (InsP3) binding activity, while the NADH-cytochrome c oxidoreductase and sulphatase-C activities were only 3.8- and 2.9-fold enriched, respectively. Furthermore, the three InsP3 receptor (InsP3R) isoforms, two sarco/endoplasmic reticulum Ca ²⁺ ATPase (SERCA) isoforms (2b and 3) as well as four Ca ²⁺ binding proteins (calreticulin, calnexin, protein disulfide isomerase (PDI) and BiP), were present in this fraction. Fraction F3 was, therefore, further purified on a discontinuous sucrose density gradient, and the 3 resulting fractions were analyzed. The InsP₃ binding sites were distributed over the gradient and did not co-migrate with the RNA. We examined the relative content of the three InsP3R isoforms, of both SERCA2b and 3, as well as that of the four Ca ²⁺ binding proteins in fraction F3 and the sucrose density gradient fractions. Ins P₃R-1 and InsP3R-2 showed a similar distribution, with the highest level in the light and intermediate density fractions. InsP₃R-3 distributed differently, with the highest level in the intermediate density fraction. Both SERCA isoforms distributed similarly to InsP₃R-1 and InsP₃R-2. SERCA3 was present at a very low level in the high density fraction. Calreticulin and BiP showed a pattern similar to that of InsP₃R-1 and InsP₃R-2 and the SERCs. PDI was clearly enriched in the light density fraction while calnexin was broadly distributed. These results indicate a heterogeneous distribution of the three InsP₃R isoforms, the two SERCA isoforms and the four Ca²⁺ binding proteins investigated. This heterogeneity may underlie specialization of the Ca²⁺ stores and the subsequent initiation of intracellular Ca²⁺ signals.     

Isoforms of the inositol 1,4,5-trisphosphate receptor are expressed in bovine oocytes and ovaries: the type-1 isoform is down-regulated by fertilization and by injection of adenophostin A.

Mammalian fertilization is characterized by the presence of long-lasting intracellular calcium ([Ca2+]i) oscillations that are required to induce oocyte activation. One of the Ca2+ channels that may mediate this Ca2+ release is the inositol 1,4, 5-trisphosphate receptor (IP(3)R). Three isoforms of the receptor have been described, but their expression in oocytes and possible roles in mammalian fertilization are not well known. Using isoform-specific antibodies against IP(3)R types 1, 2, and 3 and Western analysis, we determined the isoforms that are expressed in bovine metaphase II oocytes and ovaries. In oocytes, all isoforms are expressed, but type 1 is present in overwhelmingly larger amounts and is likely responsible for the majority of Ca2+ release at fertilization. In ovarian microsomes, all three isoforms appear well expressed, suggesting the participation of all IP(3)R isoforms in ovarian Ca2+ signaling. We then investigated whether the reported cessation/reduction in amplitude of fertilization-associated [Ca2+]i oscillations, which is observed as pronuclear formation approaches, corresponded with down-regulation of the IP(3)R-1 isoform. Fertilization resulted in approximately 40% reduction in the amount of receptor by 16 h postinsemination. In addition, injection of adenophostin A, a potent IP(3)R agonist that elicits high-frequency [Ca2+]i oscillations in mammalian oocytes, induced similar reduction in receptor numbers. Together, these data show that 1) the three IP(3)R isoforms are expressed in bovine oocytes; 2) IP(3)R-1 is likely to mediate most of the Ca2+ release during fertilization; 3) its down-regulation may explain the decline in amplitude of sperm-induced [Ca2+]i rises as fertilization progresses toward pronuclear formation; and 4) agonists of the IP(3)R induce down-regulation of the type-1 receptor in oocytes similar to that evoked by fertilization.     

Expression patterns of sarco/endoplasmic reticulum Ca(2+)-ATPase and inositol 1,4,5-trisphosphate receptor isoforms in vascular endothelial cells.

Expression patterns of sarcoplasmic/endoplasmic-reticulum Ca(2+)-ATPase (SERCA) and inositol 1,4,5-trisphosphate receptor (IP3R) isoforms were studied in endothelial cells at the mRNA level by ratio RT-PCR technique and subsequent restriction-enzyme analysis. Three types of cells have been used in the present study: rat adrenal medulla microvascular endothelial cells (RAMEC), rat aortic endothelial cells (RAEC), and human umbilical vein endothelial cells (HUVEC). Our data show the presence of multiple SERCA and IP3R isoforms in each type of endothelial cells. Freshly isolated HUVEC were an exception in this respect since they contained only SERCA3 without SERCA2b messengers. The expression patterns changed upon cell proliferation: SERCA3 and IP3R-1 messengers decreased, while IP3R-3 increased with culturing. Upon cell differentiation, induced by culturing the cells on Matrigel, the expression pattern of the IP3R changed even further in all endothelial cell types: IP3R-1 was reduced in all three cell kinds, while IP3R-3 raised significantly in RAEC and RAMEC. In HUVEC the expression of SERCA returned, upon differentiation, to the levels observed in the freshly isolated cells. Thus, the plasticity of expression of various SERCA and IP3R isoforms shows that possibly different Ca2+ pools may play distinct roles in cell proliferation and differentiation.     

IFN-gamma promoter gene polymorphism in psoriasis vulgaris.

This study was performed to investigate the association between interferon (IFN)-gamma single nucleotide polymorphism (SNP) and susceptibility for psoriasis vulgaris. DNA from 78 patients with psoriasis vulgaris (54 patients with type I psoriasis, 24 with type II psoriasis) and 74 healthy volunteers was investigated. IFN-gamma promoter gene SNP in position 874 was evaluated by polymerase chain reaction with sequence-specific primers (PCR-SSP) and the results were compared between a group of psoriatic patients, divided into early onset of psoriasis (type I) and late onset of psoriasis (type II) subgroups, and healthy control subjects. A significant difference in the genotype frequencies between psoriasis patients and healthy controls was found (p < 0.02) and no significant differences were observed analyzing subsets of psoriatic patients (gender, type of disease) also in carriage and allele frequencies. The results suggest that IFN-gamma polymorphism is associated with susceptibility to psoriasis vulgaris.     

Regulation of inositol 1,4,5-trisphosphate receptor type 1 function during oocyte maturation by MPM-2 phosphorylation

Egg activation and further embryo development require a sperm-induced intracellular Ca²⁺ signal at the time of fertilization. Prior to fertilization, the egg's Ca²⁺ machinery is therefore optimized. To this end, during oocyte maturation, the sensitivity, i.e. the Ca²⁺ releasing ability, of the inositol 1,4,5-trisphosphate receptor type 1 (IP₃R1), which is responsible for most of this Ca²⁺ release, markedly increases. In this study, the recently discovered specific Polo-like kinase (Plk) inhibitor BI2536 was used to investigate the role of Plk1 in this process. BI2536 inactivates Plk1 in oocytes at the early stages of maturation and significantly decreases IP₃R1 phosphorylation at an MPM-2 epitope at this stage. Moreover, this decrease in Plk1-dependent MPM-2 phosphorylation significantly lowers IP₃R1 sensitivity. Finally, using in vitro phosphorylation techniques we identified T²⁶⁵⁶ as a major Plk1 site on IP₃R1. We therefore propose that the initial increase in IP₃R1 sensitivity during oocyte maturation is underpinned by IP₃R1 phosphorylation at an MPM-2 epitope(s).     

Human Golgi Antiapoptotic Protein Modulates Intracellular Calcium Fluxes

Golgi antiapoptotic protein (GAAP) is a novel regulator of cell death that is highly conserved in eukaryotes and present in some poxviruses, but its molecular mechanism is unknown. Given that alterations in intracellular Ca²⁺ homeostasis play an important role in determining cell sensitivity to apoptosis, we investigated if GAAP affected Ca²⁺ signaling. Overexpression of human (h)-GAAP suppressed staurosporine-induced, capacitative Ca²⁺ influx from the extracellular space. In addition, it reduced histamine-induced Ca²⁺ release from intracellular stores through inositol trisphosphate receptors. h-GAAP not only decreased the magnitude of the histamine-induced Ca²⁺ fluxes from stores to cytosol and mitochondrial matrices, but it also reduced the induction and frequency of oscillatory changes in cytosolic Ca²⁺. Overexpression of h-GAAP lowered the Ca²⁺ content of the intracellular stores and decreased the efficacy of IP₃, providing possible explanations for the observed results. Opposite effects were obtained when h-GAAP was knocked down by siRNA. Thus, our data demonstrate that h-GAAP modulates intracellular Ca²⁺ fluxes induced by both physiological and apoptotic stimuli.     

Refined anaesthesia for implantation of engineered experimental aortic valves in the pulmonary artery using a right heart bypass in sheep

The feasibility of an anaesthetic protocol developed for surgery during right heart bypass in sheep is reported. Seven female Suffolk sheep, weighing 25-35 kg, were selected for the study. Premedication consisted of midazolam and methadone (both 0.1 mg kg(-1) intravenously). Anaesthesia was induced with propofol (2-4 mg kg(-1)) and maintained with isoflurane in oxygen and continuous rate infusions of propofol (5-7 mg kg(-1 )h(-1)) and fentanyl (5 microg kg(-1) bolus, 5 microg kg(-1) h(-1)). Cisatracurium (0.2 mg kg(-1)) provided muscle relaxation. A standard roller pump was used for the extracorporeal circulation. Drugs administered to maintain blood pressure and heart rate within acceptable levels included phenylephrine (3-4 microg kg(-1)), ephedrine (0.1-0.2 mg kg(-1)), nitroglycerine (50-150 microg kg(-1) h(-1)) and metoprolol succinate (30-80 microg kg(-1)). Electrolytes were infused as needed. Postoperative analgesia was provided by an intercostal block (15 mL 0.5% bupivacaine + epinephrine), carprofen (4 mg kg(-1)) and an opioid (methadone 0.1 mg kg(-1) or buprenorphine 0.01 mg kg(-1)). One sheep became hypoxic during the bypass (PaO(2) 47.7 mmHg). Irregularities of the electrocardiogram were observed during manipulation of the heart in all animals. During the initial phase of the bypass, blood pressure decreased in all sheep, accompanied by dilatation of the heart and large intrathoracic veins in five sheep. With appropriate treatment, blood pressure was restored and easily maintained until the end of the bypass. Weaning from the bypass, using an infusion of nitrates, was smooth. One sheep required a blood transfusion because of severe blood loss and another sheep died postoperatively from respiratory complications. Minor irregularities of the electrocardiogram observed during manipulation of the heart were not life threatening and required no treatment. Decreases in blood pressure at the beginning of the bypass can be expected and require treatment. Nitrates are useful in avoiding volume overload during weaning. The anaesthetic protocol is acceptable for surgery under right heart bypass in sheep.     

Intimate Partner Violence and Pregnancy: A Systematic Review of Interventions

Background

Intimate partner violence (IPV) around the time of pregnancy is a widespread global health problem with many negative consequences. Nevertheless, a lot remains unclear about which interventions are effective and might be adopted in the perinatal care context.

Objective

The objective is to provide a clear overview of the existing evidence on effectiveness of interventions for IPV around the time of pregnancy.

Methods

Following databases PubMed, Web of Science, CINAHL and the Cochrane Library were systematically searched and expanded by hand search. The search was limited to English peer-reviewed randomized controlled trials published from 2000 to 2013. This review includes all types of interventions aiming to reduce IPV around the time of pregnancy as a primary outcome, and as secondary outcomes to enhance physical and/or mental health, quality of life, safety behavior, help seeking behavior, and/or social support.

Results

We found few randomized controlled trials evaluating interventions for IPV around the time of pregnancy. Moreover, the nine studies identified did not produce strong evidence that certain interventions are effective. Nonetheless, home visitation programs and some multifaceted counseling interventions did produce promising results. Five studies reported a statistically significant decrease in physical, sexual and/or psychological partner violence (odds ratios from 0.47 to 0.92). Limited evidence was found for improved mental health, less postnatal depression, improved quality of life, fewer subsequent miscarriages, and less low birth weight/prematurity. None of the studies reported any evidence of a negative or harmful effect of the interventions.

Conclusions and implications

Strong evidence of effective interventions for IPV during the perinatal period is lacking, but some interventions show promising results. Additional large-scale, high-quality research is essential to provide further evidence about the effect of certain interventions and clarify which interventions should be adopted in the perinatal care context.