88 research outputs found

    Can the outcome of induction of labour with oral misoprostol be predicted?

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    Objective. To determine predictors of outcome for induction of labour using oral misoprostol.Setting. Labour ward at Kalafong Hospital in Atteridgeville, Pretoria, that serves an indigent South African urban population.Methods. Data were collected prospectively on all women undergoing induction of  labour with oral misoprostol from 1 March  2004 to 28 February 2005. Patients with contraindications to misoprostol induction were excluded. Univariate analysis and  logistical regression analysis were performed to determine the significant predictors of success of induction of labour. Successful induction was defined as a vaginal delivery achieved within 24 hours.Results. Five hundred and fifty-eight patients were included. There were three major  indications for induction of labour, namely hypertension (45%), postdates (22.1%)  and prelabour rupture of membranes (20.6%). Vaginal delivery was achieved within 24 hours in 52.4% of patients. The caesarean section rate was 42.1 %. Fetal heart rate changes occurred in 25.6% and    hyperstimulation in 1.4% of patients.  Logistical regression analysis identified the following parameters as independent  predictors of vaginal delivery achieved within 24 hours: primiparity (p < 0.001), Bishop score< 3 (p < 0.001), Bishop score 4- 6 (p = 0.029), ruptured membranes (p < 0.001) and preeclampsia (p = 0.006). A method of scoring (Mbele score) has been developed making use of the results of this analysis in order to predict the successful outcome of induction.Conclusions. Primigravidity, intact membranes, pre-eclampsia and a low Bishop  score were indicators of an unsuccessful  outcome for induction of labour. It is thought that the Mbele score will be helpful in counselling patients on methods of delivery when they are admitted for induction of labour

    Basic and comprehensive emergency obstetric and neonatal care in 12 South African health districts

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    Aim. To assess the functionality of healthcare facilities with respect to providing the signal functions of basic and comprehensive emergency obstetric care in 12 districts. Setting. Twelve districts were selected from the 52 districts in South Africa, based on the number of maternal deaths, the institutional maternal mortality ratio and the stillbirth rate for the district. Methods. All community health centres (CHCs) and district, regional and tertiary hospitals were visited and detailed information was obtained on the ability of the facility to perform the basic (BEmONC) and comprehensive (CEmONC) emergency obstetric and neonatal care signal functions. Results. Fifty-three CHCs, 63 district hospitals (DHs), 13 regional hospitals and 4 tertiary hospitals were assessed. None of the CHCs could perform all seven BEmONC signal functions; the majority could not give parenteral antibiotics (68%), perform manual removal of the placenta (58%), do an assisted delivery (98%) or perform manual vacuum aspiration of the uterus in a woman with an uncomplicated incomplete miscarriage (96%). Seventeen per cent of CHCs could not bag-and-mask ventilate a neonate. Less than half (48%) of the DHs could perform all nine CEmONC signal functions (81% could perform eight of the nine functions), 24% could not perform caesarean sections, and 30% could not perform assisted deliveries. Conclusions. The ability of the CHCs and district hospitals to perform the signal functions (lifesaving services) of basic and comprehensive emergency obstetric care was poor in many of the districts studied. This implies that safe maternity care was not consistently available at many facilities conducting births

    Generic Mechanism of Emergence of Amyloid Protofilaments from Disordered Oligomeric aggregates

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    The presence of oligomeric aggregates, which is often observed during the process of amyloid formation, has recently attracted much attention since it has been associated with neurodegenerative conditions such as Alzheimer's and Parkinson's diseases. We provide a description of a sequence-indepedent mechanism by which polypeptide chains aggregate by forming metastable oligomeric intermediate states prior to converting into fibrillar structures. Our results illustrate how the formation of ordered arrays of hydrogen bonds drives the formation of beta-sheets within the disordered oligomeric aggregates that form early under the effect of hydrophobic forces. Initially individual beta-sheets form with random orientations, which subsequently tend to align into protofilaments as their lengths increases. Our results suggest that amyloid aggregation represents an example of the Ostwald step rule of first order phase transitions by showing that ordered cross-beta structures emerge preferentially from disordered compact dynamical intermediate assemblies.Comment: 14 pages, 4 figure

    Dislocation Loop Formation and Growth under In Situ Laser and/or Electron Irradiation

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    Vacancies and interstitial atoms are primary lattice (point) defects that cause observable microstructural changes, such as the formation of dislocation loops and voids in crystalline solids. These defects' diffusion properties determine the phase stability and environmental resistibility of macroscopic materials under ambient conditions. Although in situ methods have been proposed for measuring the diffusion energy of point defects, direct measurement has been limited. In this study, we propose an alternative in situ method to measure the activation energy for vacancy migration under laser irradiation using a pulsed laser beam from a laser-equipped high-voltage electron microscope (laser-HVEM). We made in situ observations that revealed the formation and growth of vacancy dislocation loops in an austenitic stainless steel during laser irradiation. These loops continued to grow when thermal annealing was performed after laser irradiation at the same temperature. We anticipate that laser-HVEM will provide a new method for investigating lattice defects

    Predictors of HIV Serostatus Disclosure to Partners among HIV-Positive Pregnant women in Morogoro, Tanzania.

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    Prevention of mother to child transmission of HIV (PMTCT) has been scaled, to more than 90% of health facilities in Tanzania. Disclosure of HIV results to partners and their participation is encouraged in the program. This study aimed to determine the prevalence, patterns and predictors of HIV sero-status disclosure to partners among HIV positive pregnant women in Morogoro municipality, Tanzania. A cross sectional study was conducted in March to May 2010 among HIV-positive pregnant women who were attending for routine antenatal care in primary health care facilities of the municipality and had been tested for HIV at least one month prior to the study. Questionnaires were used to collect information on possible predictors of HIV disclosure to partners. A total of 250 HIV-positive pregnant women were enrolled. Forty one percent (102) had disclosed their HIV sero-status to their partners. HIV-disclosure to partners was more likely among pregnant women who were < 25 years old [Adjusted odds ratio (AOR) = 2.2; 95% CI: 1.2--4.1], who knew their HIV status before the current pregnancy [AOR = 3.7; 95% CI: 1.7--8.3], and discussed with their partner before testing [AOR = 6.9; 95% CI: 2.4--20.1]. Dependency on the partner for food/rent/school fees, led to lower odds of disclosure to partners [AOR = 0.4; 95% CI: 0.1--0.7]. Nine out of ten women reported to have been counseled on importance of disclosure and partner participation. Six in ten HIV positive pregnant women in this setting had not disclosed their results of the HIV test to their partners. Empowering pregnant women to have an individualized HIV-disclosure plan, strengthening of the HIV provider initiated counseling and testing and addressing economic development, may be some of the strategies in improving HIV disclosure and partner involvement in this setting

    Heparin Induces Harmless Fibril Formation in Amyloidogenic W7FW14F Apomyoglobin and Amyloid Aggregation in Wild-Type Protein In Vitro

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    Glycosaminoglycans (GAGs) are frequently associated with amyloid deposits in most amyloid diseases, and there is evidence to support their active role in amyloid fibril formation. The purpose of this study was to obtain structural insight into GAG-protein interactions and to better elucidate the molecular mechanism underlying the effect of GAGs on the amyloid aggregation process and on the related cytotoxicity. To this aim, using Fourier transform infrared and circular diochroism spectroscopy, electron microscopy and thioflavin fluorescence dye we examined the effect of heparin and other GAGs on the fibrillogenesis and cytotoxicity of aggregates formed by the amyloidogenic W7FW14 apomyoglobin mutant. Although this protein is unrelated to human disease, it is a suitable model for in vitro studies because it forms amyloid-like fibrils under physiological conditions of pH and temperature. Heparin strongly stimulated aggregation into amyloid fibrils, thereby abolishing the lag-phase normally detected following the kinetics of the process, and increasing the yield of fibrils. Moreover, the protein aggregates were harmless when assayed for cytotoxicity in vitro. Neutral or positive compounds did not affect the aggregation rate, and the early aggregates were highly cytotoxic. The surprising result that heparin induced amyloid fibril formation in wild-type apomyoglobin and in the partially folded intermediate state of the mutant, i.e., proteins that normally do not show any tendency to aggregate, suggested that the interaction of heparin with apomyoglobin is highly specific because of the presence, in protein turn regions, of consensus sequences consisting of alternating basic and non-basic residues that are capable of binding heparin molecules. Our data suggest that GAGs play a dual role in amyloidosis, namely, they promote beneficial fibril formation, but they also function as pathological chaperones by inducing amyloid aggregation

    Amelioration of galactosamine-induced nephrotoxicity by a protein isolated from the leaves of the herb, Cajanus indicus L

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    <p>Abstract</p> <p>Background</p> <p>Galactosamine (GalN), an established experimental toxin, mainly causes liver injury via the generation of free radicals and depletion of UTP nucleotides. Renal failure is often associated with end stage liver damage. GalN intoxication also induces renal dysfunction in connection with hepatic disorders. Present study was designed to find out the effect of a protein isolated from the leaves of the herb <it>Cajanus indicus </it>against GalN induced renal damage.</p> <p>Methods</p> <p>Both preventive as well as curative effect of the protein was investigated in the study. GalN was administered intraperitoneally at a dose of 800 mg/kg body weight for 3 days pre and post to protein treatment at an intraperitoneal dose of 2 mg/kg body weight for 4 days. The activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and glutathione-S-transferase (GST), levels of cellular metabolites, reduced glutathione (GSH), total thiols, oxidized glutathione (GSSG) and lipid peroxidation end products were determined to estimate the status of the antioxidative defense system. In addition, serum creatinine and urea nitrogen (UN) levels were also measured as a marker of nephrotoxicity.</p> <p>Results</p> <p>Results showed that GalN treatment significantly increased the serum creatinine and UN levels compared to the normal group of mice. The extent of lipid peroxidation and the level of GSSG were also enhanced by the GalN intoxication whereas the activities of antioxidant enzymes SOD, CAT, GR and GST as well as the levels of total thiols and GSH were decreased in the kidney tissue homogenates. Protein treatment both prior and post to the toxin administration successfully altered the effects in the experimental mice.</p> <p>Conclusion</p> <p>Our study revealed that GalN caused a severe oxidative insult in the kidney. Protein treatment both pre and post to the GalN intoxication could protect the kidney tissue against GalN induced oxidative stress. As GalN induced severe hepatotoxicity followed by renal failure, the protective role of the protein against GalN induced renal damages is likely to be an indirect effect. Since the protein possess hepatoprotective activity, it may first ameliorate GalN-induced liver damage and consequently the renal disorders are reduced. To the best of our knowledge, this is probably the first report describing GalN-induced oxidative stress in renal damages and the protective role of a plant protein molecule against it.</p

    Structural Elements Regulating Amyloidogenesis: A Cholinesterase Model System

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    Polymerization into amyloid fibrils is a crucial step in the pathogenesis of neurodegenerative syndromes. Amyloid assembly is governed by properties of the sequence backbone and specific side-chain interactions, since fibrils from unrelated sequences possess similar structures and morphologies. Therefore, characterization of the structural determinants driving amyloid aggregation is of fundamental importance. We investigated the forces involved in the amyloid assembly of a model peptide derived from the oligomerization domain of acetylcholinesterase (AChE), AChE586-599, through the effect of single point mutations on β-sheet propensity, conformation, fibrilization, surfactant activity, oligomerization and fibril morphology. AChE586-599 was chosen due to its fibrilization tractability and AChE involvement in Alzheimer's disease. The results revealed how specific regions and residues can control AChE586-599 assembly. Hydrophobic and/or aromatic residues were crucial for maintaining a high β-strand propensity, for the conformational transition to β-sheet, and for the first stage of aggregation. We also demonstrated that positively charged side-chains might be involved in electrostatic interactions, which could control the transition to β-sheet, the oligomerization and assembly stability. Further interactions were also found to participate in the assembly. We showed that some residues were important for AChE586-599 surfactant activity and that amyloid assembly might preferentially occur at an air-water interface. Consistently with the experimental observations and assembly models for other amyloid systems, we propose a model for AChE586-599 assembly in which a steric-zipper formed through specific interactions (hydrophobic, electrostatic, cation-π, SH-aromatic, metal chelation and polar-polar) would maintain the β-sheets together. We also propose that the stacking between the strands in the β-sheets along the fiber axis could be stabilized through π-π interactions and metal chelation. The dissection of the specific molecular recognition driving AChE586-599 amyloid assembly has provided further knowledge on such poorly understood and complicated process, which could be applied to protein folding and the targeting of amyloid diseases

    Chemosensory Cues to Conspecific Emotional Stress Activate Amygdala in Humans

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    Alarm substances are airborne chemical signals, released by an individual into the environment, which communicate emotional stress between conspecifics. Here we tested whether humans, like other mammals, are able to detect emotional stress in others by chemosensory cues. Sweat samples collected from individuals undergoing an acute emotional stressor, with exercise as a control, were pooled and presented to a separate group of participants (blind to condition) during four experiments. In an fMRI experiment and its replication, we showed that scanned participants showed amygdala activation in response to samples obtained from donors undergoing an emotional, but not physical, stressor. An odor-discrimination experiment suggested the effect was primarily due to emotional, and not odor, differences between the two stimuli. A fourth experiment investigated behavioral effects, demonstrating that stress samples sharpened emotion-perception of ambiguous facial stimuli. Together, our findings suggest human chemosensory signaling of emotional stress, with neurobiological and behavioral effects

    From proteomic analysis to potential therapeutic targets: functional profile of two lung cancer cell lines, A549 and SW900, widely studied in pre-clinical research

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    Lung cancer is a serious health problem and the leading cause of cancer death worldwide. The standard use of cell lines as in vitro pre-clinical models to study the molecular mechanisms that drive tumorigenesis and access drug sensitivity/effectiveness is of undisputable importance. Label-free mass spectrometry and bioinformatics were employed to study the proteomic profiles of two representative lung cancer cell lines and to unravel the specific biological processes. Adenocarcinoma A549 cells were enriched in proteins related to cellular respiration, ubiquitination, apoptosis and response to drug/hypoxia/oxidative stress. In turn, squamous carcinoma SW900 cells were enriched in proteins related to translation, apoptosis, response to inorganic/organic substances and cytoskeleton organization. Several proteins with differential expression were related to cancer transformation, tumor resistance, proliferation, migration, invasion and metastasis. Combined analysis of proteome and interactome data highlighted key proteins and suggested that adenocarcinoma might be more prone to PI3K/Akt/mTOR and topoisomerase IIα inhibitors, and squamous carcinoma to Ck2 inhibitors. Moreover, ILF3 overexpression in adenocarcinoma, and PCNA and NEDD8 in squamous carcinoma shows them as promising candidates for therapeutic purposes. This study highlights the functional proteomic differences of two main subtypes of lung cancer models and hints several targeted therapies that might assist in this type of cancer.publishe
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