Introducing misoprostol for the management of postpartum hemorrhage in Zimbabwe: final report on operational research.

Postpartum Haemorrhage (PPH) is the most common cause of maternal mortality globally, leading to a woman's death every seven minutes. In Zimbabwe, there has been a 300% increase in the Maternal Mortality Ratio (MMR) between 1994 and 2010 and the MMR was estimated at 960 maternal deaths per 100,000 live births in 2012.2-3 Overall, 14% of all maternal deaths in Zimbabwe are due to PPH. Ensuring prompt access to high-quality prevention and treatment of PPH for all women who deliver is an essential strategy to combat PPH-related morbidity and mortality and to make progress toward reaching Millennium Development Goal 5, the reduction of maternal mortality by three-quarters by 2015.

Behavioral characterization of striatal-enriched protein tyrosine phosphatase (STEP) knockout mice.

Striatal-enriched protein tyrosine phosphatase (STEP) has been described as a regulator of multiple kinases and glutamate receptor subunits critical for synaptic plasticity. Published behavioral and biochemical characterization from the founder line of STEP knockout (KO) mice revealed superior cognitive performance, with enhanced phosphorylation of substrates such as ERK, Fyn and GluN2B; suggesting that inhibitors of STEP may have potential as therapeutic agents for the treatment of neuropsychiatric disorders. The objectives of this work aimed to replicate and extend the previously reported behavioral consequences of STEP knockout. Consistent with previous reported data, STEP KO mice demonstrated exploratory activity levels and similar motor coordination relative to WT littermate controls as well as intact memory in a Y-maze spatial novelty test. Interestingly, KO mice demonstrated deficits in pre-pulse inhibition as well as reduced seizure threshold relative to WT controls. Immunohistochemical staining of brains revealed the expected gene-dependent reduction in STEP protein confirming knockout in the mice. The present data confirm expression and localization of STEP and the absence in KO mice, and describe functional downstream implications of reducing STEP levels in vivo.

Broad-band conductivity and dielectric spectroscopy of composites of multiwalled carbon nanotubes and poly(ethylene terephthalate) around their low percolation threshold.

Composites of multiwalled carbon nanotubes with poly(ethylene terephthalate) (PET-MWCNT) with up to 3 vol% MWCNTs were prepared and characterized by broad-band AC conductivity and dielectric spectroscopy up to the infrared range using several techniques. A very low electrical percolation threshold of 0.07 vol% MWCNTs was revealed from the low-frequency conductivity plateau as well as from DC conductivity, whose values show the same critical power dependence on MWCNT concentration with the exponent t = 4.3. Above the plateau, the AC conductivity increases with frequency up to the THz range, where it becomes overlapped with the absorption of vibrational modes. The temperature dependence down to ~5 K has shown semiconductor behaviour with a concentration-independent but weakly temperature-dependent small activation energy of ~3 meV. The behaviour is compatible with the previously suggested fluctuation-induced tunnelling conductivity model through a thin (~1 nm) polymer contact layer among the adjacent MWCNTs within percolated clusters. At higher frequencies, deviations from the simple universal conductivity behaviour are observed, indicating some distribution of energy barriers for an electron hopping mechanism.

Eosinophil activation and preschool viral wheeze.

BACKGROUND: A study was undertaken to ascertain whether systemic eosinophil activation is associated with preschool viral wheeze (PVW). METHODS: Urinary eosinophil protein X (uEPX) and serum total IgE (IgE) levels were measured in children admitted to hospital with PVW, and uEPX was measured 6 weeks after discharge. Two years after admission, current wheeze in children aged > or =5 years was determined by questionnaire. Controls were recruited from children undergoing elective surgery (normal controls) and from those with skin prick test reactivity to foods (atopic controls). RESULTS: There was no difference in uEPX levels between normal controls (n=15) and atopic controls (n=8). uEPX levels were increased in children with acute PVW (n=84; p<0.001 v normal controls, p<0.01 v atopic controls) and fell on convalescence (n=20, 95% CI -217 to -31 microg/mmol creatinine, p<0.05). In children with acute PVW there was no association between uEPX and serum IgE levels or markers of clinical severity. Respiratory questionnaires were returned for 25/55 eligible children. There was no difference in uEPX level during acute PVW when stratified by "current wheeze" (n=18) or "no wheeze" (n=7) 2 years later. CONCLUSIONS: Systemic eosinophil activation is associated with PVW but is not associated with serum IgE, clinical severity, or persistence of wheeze into the early school age period.

Regulation of P-selectin binding to the neutrophil P-selectin counter-receptor P-selectin glycoprotein ligand-1 by neutrophil elastase and cathepsin G.

In the inflammatory response, leukocyte rolling before adhesion and transmigration through the blood vessel wall is mediated by specific cell surface adhesion receptors. Neutrophil rolling involves the interaction of P-selectin expressed on activated endothelium and its counter-receptor on neutrophils, P-selectin glycoprotein ligand-1 (PSGL-1). Here, it is reported that P-selectin binding to neutrophils is lost under conditions that cause the release of proteinases from neutrophil primary granules. Treatment of neutrophils with the purified neutrophil granule proteinases, cathepsin G and elastase, rapidly abolished their capacity to bind P-selectin. This inactivation corresponded to loss of the N-terminal domain of PSGL-1, as assessed by Western blot analysis. A loss of intact PSGL-1 protein from the surfaces of neutrophils after the induction of degranulation was also detected by Western blot analysis. Cathepsin G initially cleaved near the PSGL-1 N-terminus, whereas neutrophil elastase predominantly cleaved at a more C-terminal site within the protein mucin core. Consistent with this, cathepsin G cleaved a synthetic peptide based on the PSGL-1 N-terminus between Tyr-7/Leu-8. Under conditions producing neutrophil degranulation in incubations containing mixtures of platelets and neutrophils, the loss of PSGL-1, but not P-selectin, from platelet-neutrophil lysates was detected. Cathepsin G- or neutrophil elastase-mediated PSGL-1 proteolysis may constitute a potential autocrine mechanism for down-regulation of neutrophil adhesion to P-selectin.

Molecular characterization of human SUR2-containing K(ATP) channels.

The distribution of human sulfonylurea receptor-2 (SUR2)-containing K(ATP) channels was investigated using reverse transcriptase-polymerase chain reaction (RT-PCR). mRNA for SUR2B was detected in a variety of tissues including brain, skeletal, cardiac and smooth muscle, whereas SUR2A message was restricted to cardiac and skeletal muscle. An additional splice variant of SUR2 that lacked exon 17 was also identified by RT-PCR in tissues expressing both SUR2A and SUR2B or SUR2B alone. Quantification of RNA for SUR2 exon 17+ and SUR2 exon 17- splice variants using real-time Taqman PCR indicated differential levels of expression in brain, kidney, skeletal muscle, heart and small intestine. Interestingly, the SUR2 exon 17+ variant is the major species expressed in all tissues examined in this study. Each of the SUR2 splice variants transiently expressed with the inward rectifier Kir 6.2 formed functional K(ATP) channels in HEK 293 cells as assessed either by changes in DiBAC(4)(3) fluorescence responses or glyburide-sensitive whole cell currents. Collectively, our findings demonstrate that various SUR2 splice variants have distinct expression patterns and can form functional K(ATP) channels.

In vitro biomechanical evaluation of the double loop suture for flexor tendon repair.

Fifty-one fresh frozen human anatomic specimen flexor superficialis and profundus tendons that had been transected completely were repaired using the double loop, the single loop, and the modified Kessler techniques, and the resistances to mechanical distraction at 1, 2, and 3 mm and the ultimate load to failure were compared. The mechanical distraction at 1, 2, and 3 mm created nearly identical gaps at the tendon repair sites. There was no significant difference among the three repair techniques to resisting distraction at 1 and 2 mm. However, the double loop technique presented a mean resistance force of 22.0 N to distraction at 3 mm and 45.8 N in load to failure, which was significantly greater than the single loop (18.8 N at 3 mm distraction and 31.5 N failure load) and the modified Kessler (19.0 N at 3 mm distraction and 26.0 N failure load). This suggests the double loop technique may be superior to the single loop and the modified Kessler techniques in resisting gap in the range of forces generated in the early rehabilitation protocol.

Biomechanics of the coracoclavicular ligament complex and augmentations used in its repair and reconstruction.

Augmentation is a well-accepted and common component of coracoclavicular ligament repairs and reconstructions. The purpose of this study was to examine and compare the strength, stiffness, and mode of failure of the coracoclavicular ligament complex and four different augmentation techniques in cadaveric shoulders. There was no significant difference in the mean failure load between the intact ligament complex (724.9+/-230.9 N) and augmentations performed with braided polydioxanone (PDS) (676.7+/-115.4 N) or braided polyethylene placed through (986.1+/-391.1 N) or around (762.7+/-218.2 N) the clavicle. The mean failure load for augmentations using a 6.5-mm cancellous screw through the clavicle and into a single cortex of the coracoid (390.1+/-253.6 N) was significantly lower than that for the intact coracoclavicular ligaments. There was no difference in mean stiffness between the intact coracoclavicular ligament complex (115.9+/-36.2 N/mm) and the braided polyethylene augmentations placed through (99.8+/-22.2 N/mm) or around (90.0+/-25.5 N/mm) the clavicle. Polydioxanone augmentations were significantly less stiff (27.4+/-3.3 N/mm) than the intact complex, while screw augmentations were significantly stiffer (250.4+/-88.2 N/mm). There were no significant differences in strength or stiffness of braided polyethylene reconstructions placed around or through a drill hole in the clavicle.

Coping with technological disaster: an application of the conservation of resources model to the Exxon Valdez oil spill.

One hundred twenty-five commercial fishers in Cordova, Alaska, completed a mailed survey regarding current mental health functioning 6 years after the Exxon Valdez oil spill. Economic and social impacts of the oil spill and coping and psychological functioning (modified Coping Strategies Scales, Symptom Checklist 90-R) were measured. Multiple regression was used to test the utility of the Conservation of Resources stress model for explaining observed psychological symptoms. Current symptoms of depression, anxiety, and Posttraumatic Stress Disorder were associated with conditions resource loss and avoidant coping strategies. The Conservation of Resources model provided a framework for explaining psychological impacts of the oil spill. Future research is needed to identify factors related to recovery.

Confusing extrication with immobilization: the inappropriate use of hard spine boards for interhospital transfers.

INTRODUCTION: To determine if air medical interhospital transport of patients with spinal injuries is done with techniques that minimize ischemic skin damage. METHODS: A formal telephone survey instrument was given to all U.S. flight services accredited by the Commission on Accreditation of Medical Transport Systems (CAMTS). RESULTS: Thirty-seven active services were listed by CAMTS; the author's service was excluded from the survey. One service did only scene responses; one was unreachable by phone; four were unwilling to complete the form, leaving 30 services for evaluation. Twenty-nine services used metal, plywood, or plastic "spine" boards for immobilization during interhospital transport. Eight services padded boards with blankets or cloth for patients immobilized for "extended periods." Eighteen services routinely reimmobilized all major trauma patients even if cleared by the sending physician, and four others reimmobilized patients not "cleared" by a radiologist. No service moved patients with known spinal injuries to softer, more conforming devices before transport. Only three services followed patients for complications throughout hospitalization. Two services reported cases of skin breakdown thought to be a result of prolonged immobilization. CONCLUSION: Air medical services often transport patients several hours after injury. Patients, particularly those unable to move because of their injuries, medication, or paralysis, are at risk for ischemic necroses of their skin. Decubitus ulcers are a major cause of morbidity and mortality, and preventing ulcers requires a very soft, conforming surface. Despite these facts, the highly select services surveyed continue to use hard, slippery boards designed for extrication at trauma scenes to immobilize patients for transport.

Structure and function of the von Willebrand factor A1 domain: analysis with monoclonal antibodies reveals distinct binding sites involved in recognition of the platelet membrane glycoprotein Ib-IX-V complex and ristocetin-dependent activation.

Binding of the adhesive glycoprotein, von Willebrand factor (vWf), to the platelet membrane glycoprotein (GP) Ib-IX-V complex initiates platelet adhesion and aggregation at high shear stress in hemostasis and thrombosis. In this study, the GP Ib-IX-V binding site within the vWf A1 domain was analyzed using a panel of murine monoclonal antibodies raised against a 39/34-kd vWf fragment (Leu-480/Val-481-Gly-718) encompassing the A1 domain. One antibody, 6G1, strongly inhibited ristocetin-dependent vWf binding to platelets, but had no effect on botrocetin- or jaracetin-dependent binding, or asialo-vWf-dependent platelet aggregation. The 6G1 epitope was mapped to Glu-700-Asp-709, confirming the importance of this region for modulation of vWf by ristocetin. Like ristocetin, 6G1 activated the vWf A1 domain, because it enhanced binding of the 39/34-kd fragment to platelets. In contrast, 5D2 and CR1 completely inhibited asialo-vWf-induced platelet aggregation and ristocetin-induced vWf binding to GP Ib-IX-V. However, only 5D2 blocked botrocetin- and jaracetin-induced vWf binding to platelets and binding of vWf to botrocetin- and jaracetin-coated beads. Epitopes for 5D2 and CR1 were conformationally dependent, but not congruent. Other antibodies mapped to epitopes within the A1 domain (CR2 and CR15, Leu-494-Leu-512; CR2, Phe-536-Ala-554; CR3, Arg-578-Glu-596; CR11 and CR15, Ala-564-Ser-582) were not functional, identifying regions of the vWf A1 domain not directly involved in vWf-GP Ib-IX-V interaction. The combined results provide evidence that the proline-rich sequence Glu-700-Asp-709 constitutes a regulatory site for ristocetin, and that ristocetin and botrocetin induce, at least in part, separate receptor-recognition sites on vWf. (Blood. 2000;95:164-172)

Elbow ligament strain under valgus load: a biomechanical study.

This study assessed the importance of the anterior and posterior bundles of the medial collateral ligament in the elbow by measuring in situ strain in response to valgus loads at three positions of forearm rotation throughout a full arc of motion. Strain in the anterior bundle was significantly greater than in the posterior bundle and increased with more flexion. The anterior bundle developed strain at a lower flexion angle (30 degrees) than the posterior bundle (60 degrees). Strain ratio increased with load increase for all flexion angles. Forearm position minimally affected strain. These results indicate that the anterior bundle is important in resisting a valgus load, particularly in mid-flexion, while the importance of the posterior bundle increases as the elbow approaches full flexion.

Binding of purified 14-3-3 zeta signaling protein to discrete amino acid sequences within the cytoplasmic domain of the platelet membrane glycoprotein Ib-IX-V complex.

The glycoprotein (GP) Ib-IX-V complex constitutively expressed on the platelet plasma membrane mediates initial adhesion of circulating platelets to vessel wall matrix at high shear, and shear-induced platelet aggregation. In both cases, this involves binding of GP Ib-IX-V to the adhesive glycoprotein, von Willebrand Factor (vWF). vWF binding to GP Ib-IX-V rapidly induces platelet activation, leading to cytoskeletal rearrangement, shape change, and secretion that enables alphaIIbbeta3 integrin (GP IIb-IIIa)-dependent platelet aggregation. All these events are critical in (patho)physiological thrombus formation. The recent discovery that the signaling protein, 14-3-3 zeta, copurifies with the GP Ib-IX complex (minus GP V) [Du, X., Harris, S. J., Tetaz, T. J., Ginsberg, M. H., & Berndt, M. C. (1994) J. Biol. Chem. 269, 18287-18290] indicated a potential mechanism for vWF-dependent signaling. The aim of the present study was to identify discrete amino acid sequences that bind 14-3-3 zeta within the cytoplasmic domain of the receptor. As an initial screening assay, overlapping synthetic peptides based on the cytoplasmic domains of GP Ibalpha (100 residues), GP Ibbeta (34 residues), GP IX (5 residues), and GP V (16 residues) were immobilized and assessed for the ability to bind purified 14-3-3 zeta. The C-terminal sequence GHSL of GP Ibalpha was identified as one 14-3-3 zeta interactive sequence, consistent with previous results [Du, X., Fox, J. E., & Pei, S. (1996) J. Biol. Chem. 271, 7362-7367]. Binding of 125I-labeled 14-3-3 zeta to GHSL-containing peptides was inhibitable by unlabeled 14-3-3 zeta and by anti-14-3-3 zeta IgG. Ala-walking through the GHSL sequence suggested all residues were necessary for optimal binding. In addition, 14-3-3 zeta bound with lower affinity to a peptide based on the central region of the GP Ibalpha cytoplasmic domain (Arg-557-Gly-575), whereas peptide sequences within the cytoplasmic domains of GP Ibbeta (Arg-160-Arg-175) and GP V (Lys-529-Gly-544) bound 14-3-3 zeta with comparable affinity to the GHSL-containing peptide. Soluble GHSL-containing peptides, GP Ibbeta- and GP V-based peptides semidissociated 14-3-3 zeta from GP Ib-IX-V or GP Ib-IX in platelet extracts as analyzed by immunoprecipitation, suggesting these sequences, at least partially, mediate the GP Ib-IX-V-14-3-3 zeta interaction in cells. Further, phosphorylation of the GP Ibbeta peptide at a site corresponding to a protein kinase A phosphorylation site (Ser-166) enhanced the affinity of 14-3-3 zeta binding by approximately 8-fold, suggesting phosphorylation as a potential mechanism for regulating 14-3-3 zeta association with the GP Ib-IX-V complex.

Interactions between HIV and hepatitis B virus in homosexual men: effects on the natural history of infection.

OBJECTIVES: Hepatitis B virus (HBV) and HIV infections share risk-factors; therefore coinfection is common. Interactions have been reported but controlled studies have been limited. Our objective was to study the effect of HIV infection on the natural history of chronic HBV infection and the reverse effect of the HBV carrier state on HIV infection. DESIGN: Prospective observational cohort study. SETTING: Open-access outpatient HIV/genitourinary medicine clinic at a Central London hospital. PATIENTS: Total of 152 untreated homosexual male HBV carriers and 212 HBV surface antigen-negative controls (41.4 and 70.3% HIV-seropositive, respectively). OUTCOME MEASURES: The rate of loss of serum HBV e antigen (HBeAg) and its reappearance in HIV-infected and HIV-uninfected HBV carriers; serum HBV DNA levels measured by dot-blot hybridization assay), HBV DNA polymerase activity and liver transaminase activities, the progression of HIV infection to symptomatic disease or AIDS in HIV-infected compared with HBV-HIV coinfected patients. RESULTS: In HIV-infected HBV carriers, serum HBV DNA polymerase activity was higher, alanine aminotransferase was lower and loss of serum HBeAg (mean follow-up, 2.8 years) occurred at a lower rate when compared with HIV-uninfected HBV carriers (estimated relative hazard, 0.39; 95% confidence interval, 0.161-0.942) Concomitant chronic HBV infection had no detectable effect on the rate of progression of HIV disease after correction for lead-time bias. CONCLUSION: This study strengthens the evidence for a significant effect of HIV infection on the natural history of chronic HBV infection, which by prolonging the period of infectivity could have an important impact on the epidemiology of HBV infection in regions, or patient groups, with high HIV seroprevalence. There was no evidence of an important effect of HBV carriage on HIV disease progression.

Cloning and expression of the adenosine kinase gene from rat and human tissues.

Adenosine kinase is ubiquitous in eukaryotes and is a key enzyme in the regulation of the intracellular levels of adenosine, an important physiological effector of many cells and tissues. In this paper we report the cloning of cDNAs encoding adenosine kinase from both rat and human tissues. Two distinct forms of adenosine kinase mRNA were identified in human tissues. Sequence variation between the two forms is restricted to the extreme 5'-end of the adenosine kinase mRNA, including a portion of the coding region, and is consistent with differential splicing of a single transcriptional product. We have expressed both forms in E. coli and produced soluble active enzyme which catalyzes the phosphorylation of adenosine with high specific activity in vitro and is susceptible to known adenosine kinase inhibitors.

The production, binding characteristics and sequence analysis of four human IgG monoclonal antiphospholipid antibodies.

Antiphospholid antibodies (APL) have a notable association with recurrent miscarriages, arterial and venous thrombosis and thrombocytopenia. Analysis of the potential pathogenic effects of such human antibodies has been hampered by the considerable difficulty in producing IgG as opposed to IgM monoclonal immunoglobulins. We have developed four human monoclonal IgG APL (LJ1, AH2, DA3 and UK4) by fusing the peripheral blood lymphocytes of three patients with SLE with a mouse human heteromyeloma cell line, CB-F7. These antibodies bind to a variety of anionic phospholipids, two (LJ1 and AH2) bind total histones but none binds to ssDNA or dsDNA. Binding to beta 2 GPI is non-specific. UK4 alone demonstrates lupus anticoagulant activity. All four have lambda light chains, two are IgG1 (AH2 and UK4) and two are IgG3 (LJ1 and DA3). These APL utilize VH genes present in the fetally restricted repertoire and multiple somatic mutations in the CDR suggest an antigen-driven process. In contrast, there is no restriction in V lambda gene usage and only one lambda chain is extensively mutated. Two clonally related hybridomas were isolated from a single patients. This supports the theory that clonal expansion is the mechanism whereby antigen selects high affinity mutations.

Effects of systematic variation of the minimal Escherichia coli met consensus operator site: in vivo and in vitro met repressor binding.

We have produced a set of sequence variants based upon the idealized, minimal Escherichia coli met operator in which each position within the basic recognition unit, the 8 bp met box (dAGACGTCT), has been changed to all other possible sequences containing single symmetrical base substitutions. The effects of these sequence variations have been assayed in vivo by monitoring the production of beta-galactosidase from a standard promoter regulated by the operator variants, and in vitro by gel-retardation assay. The two sets of data are consistent and correlate well with expectations based on the three-dimensional structure of the holorepressor bound to a minimal idealized operator and the results of in vitro evolution experiments. Comparison with two natural operators, metA and metC, suggests that in vivo, with non-consensus operators, the repressor binds to at least four consecutive met boxes.

beta 2 glycoprotein-I inhibits factor XII activation on triglyceride rich lipoproteins: the effect of antibodies from plasma of patients with antiphospholipid syndrome.

It is now well recognised that antiphospholipid antibodies are associated with thrombosis and recurrent fetal loss. Some antiphospholipid antibodies (aPAs) have been shown to require a cofactor, beta 2 glycoprotein-I (beta 2 GPI), for binding to phospholipids, and recently beta 2 GPI has been identified as the antigenic target for some aPAs. beta 2 GPI possesses in vitro anticoagulant properties and modulation of beta 2 GPI function may therefore result in altered haemostatic regulation. In the present study, the influence of plasma derived aPAs and beta 2 GPI on factor XII activation on the surface of very low density lipoprotein (VLDL) was investigated. Factor XIIa generation was dependent on lipoprotein lipase treatment of VLDL and beta 2 GPI inhibited the factor XIIa generation in a concentration dependent manner. No consistent effects on factor XIIa generation were demonstrated with the IgG fractions from patients with aPAs. Inhibition of the beta 2 GPI activity was demonstrated by some antibodies, and study with cardiolipin affinity purified antibody indicated that antibody concentration is critical. These results suggest that perturbation of beta 2 GPI function may contribute to the pathogenic mechanism for thrombosis in some patients with aPAs.

Increased levels of beta 2 glycoprotein-I antigen and beta 2 glycoprotein-I binding antibodies are associated with a history of thromboembolic complications in patients with SLE and primary antiphospholipid syndrome.

beta 2 Glycoprotein-I (beta 2GPI), a plasma component with in vitro anticoagulant properties, has been identified as a cofactor for the binding of some antiphospholipid antibodies (aPAs). In order to determine whether beta 2GPI changes were associated with the thromboembolic complications of aPAs, we measured beta 2GPI antigen (beta 2GPI:Ag), beta 2GPI aPA cofactor activity (beta 2GPI:Cof) and antibodies to beta 2GPI (alpha beta 2GPI) in 44 systemic lupus erythematosus (SLE) patients, of whom 19 had evidence of aPAs (SLE-aPA+) and 17 patients with primary antiphospholipid syndrome (PaPS). beta 2GPI:Ag levels were significantly increased in SLE-aPA+ patients and PaPS patients compared with SLE-aPA- patients and normal healthy controls. The ratio of beta 2GPI:Cof/Ag was significantly reduced in SLE-aPA+ patients compared with SLE-aPA- patients, indicating functional modification of beta 2GPI in SLE-aPA+ patients. Eighty per cent of patients with anticardiolipin (aCL) IgG also had alpha beta 2GPI, and 13% patients with no detectable aCL IgG had alpha beta 2GPI. Increased beta 2GPI:Ag and alpha beta 2GPI were associated with a clinical history of thrombosis or recurrent fetal loss. The results of these investigations suggest that beta 2GPI may play a role in the pathogenic mechanism of thrombosis associated with aPAs.