Twin Birth Considering the Current Results of the "Twin Birth Study"

The rate of caesarean sections in multiple births has grown sharply worldwide. The reason for this may be the results of large retrospective cohort studies from the 1990s, which displayed an increased risk of mortality and morbidity, especially for the second twin, in the case of vaginal births. Multiple monocentric analyses have not been able to confirm this. As a prospective, multi-centre randomised study, the Twin Birth Study published in 2013, in which 105 clinics in 25 countries took part, showed that, under optimum conditions, there was no difference in neonatal and maternal mortality and morbidity if the birth was planned to be vaginal or via caesarean. Detailed analyses, which would be helpful in choosing the type of birth method and obstetric management in the event of vaginal birth, have not previously been published. Retrospective studies must be referred to for this.

HIV-1 seroprevalence among pregnant women in rural Uganda: a longitudinal study over fifteen years.

INTRODUCTION: In order to determine the development of the prevalence of HIV infection in rural Western Uganda, data of epidemiological studies conducted in 2001 and 2007 were compared to study data from 1993. METHODS: In 2001 (n = 466) and in 2007 (n = 486), one group each of clinically healthy pregnant women of a local prenatal care department were enrolled in the study and anonymously screened for HIV-1. For both groups, informed consent was obtained prior to enrolment. Testing for HIV was done by enzyme-linked immunosorbent assay (ELISA) and confirmed by Western blot. In addition, age and antibodies against syphilis were determined as risk factors of HIV infection. RESULTS: The seroprevalence of HIV-1 infection did not decrease significantly over this time period, dropping from 28.3 to 25.1% between 2001 and 2007, but the prevalence of syphilis antibodies decreased from 27.9 to 11.1%. The data of 2001 and 2007 were compared to a third cohort from 1993, in which 21.5% of pregnant women were HIV-1-positive and 31.1% were Treponema pallidum hemagglutination assay (TPHA)-positive. CONCLUSION: The current prevalence of HIV-1 infection in Uganda is still high and there is a need for further promotion of HIV prevention and control services.

Antibiotic Therapy for Premature Rupture of Membranes and Preterm Labor and Effect on Fetal Outcome.

In Germany almost 10 % of children are born before the end of 37th week of gestation. In at least one quarter of these cases, ascending infection of the vagina plays a causative role, particularly during the early weeks of gestation. If, in addition to the decidua, the amniotic membrane, amniotic fluid and the umbilical cord are also affected, infection not only triggers uterine contractions and premature rupture of membranes but also initiates a systemic inflammatory reaction on the part of the fetus, which can increase neonatal morbidity. Numerous studies and meta-analyses have found that antibiotic therapy prolongs pregnancy and reduces neonatal morbidity. No general benefit of antibiotic treatment was found for premature uterine contractions. But it is conceivable that a subgroup of pregnant women would benefit from antibiotic treatment. It is important to identify this subgroup of women and offer them targeted treatment. This overview summarizes the current body of evidence on antibiotic treatment for impending preterm birth and the effect on neonatal outcomes.

Altered red blood cell distribution width in overweight adolescents and its association with markers of inflammation.

BACKGROUND: Obesity and the metabolic syndrome are dramatically increasing problems. Red blood cell distribution width (RDW), the variability in size of circulating red blood cells, has been demonstrated to be altered in different clinical settings. This analysis aimed to investigate the relationship between RDW and obesity in adolescents and in an animal model of diet-induced obesity (DIO). METHODS: Seventy-nine male adolescents (aged 13-17 years) were studied. Thirty-seven of them were overweight (body mass index ≥ 90th percentile). RDW, markers of inflammation and stem cell factor (SCF) were determined. In an animal study, mice were fed with different diets for 15 weeks. RDW was determined using an animal blood count machine. RESULTS: RDW differed significantly between normal-weight adolescents (13.07 ± 0.09) and overweight adolescents (13.39 ± 0.10, P = 0.015), whereas erythrocyte counts and haematocrit did not differ. RDW correlated to markers of inflammation and inversely to SCF. In the mice animal model, nutritional changes increased RDW, whereas overweight per se did not change RDW. CONCLUSIONS: RDW is elevated in overweight and reflects the inflammatory state. RDW potentially represents an additional and cost-effective tool to indicate inflammation. Future studies are needed to understand the differential influences of nutrition and overweight on RDW.

Preparing Taft-Hartleys for the 21st century: health care leads list of challenges for plan administrators.

Rising health care costs are a major challenge facing administrators of Taft-Hartley health and welfare plans. Managing costs while continuing to provide coverage that meets members' expectations and needs will require a delicate balancing act. Among areas that require close scrutiny are legislative activity, retiree medical benefits, prescription drugs, funding and cost-control methods.

Maturation of near-field and far-field somatosensory evoked potentials after median nerve stimulation in children under 4 years of age.

OBJECTIVES: The maturation of subcortical SEPs in young children. METHODS: Median nerve SEPs were recorded during sleep in 42 subjects aged 0-48 months. Active electrodes were at the ipsilateral Erb's point, the lower and upper dorsal neck, and the frontal and contralateral centroparietal scalp; reference electrodes were at the contralateral Erb's point, the ipsilateral earlobe and the frontal scalp; bandpass was 10-3000 Hz. The peaks were labelled by their latencies in adults. RESULTS: The peak latencies of N9 (brachial plexus potential) decreased exponentially with age during the first year, but increased with height thereafter. The interpeak latencies (IPLs) N9-N11, which measure conduction between brachial plexus and dorsal column, decreased with age (linear regression). The IPLs N11-P13 and N11-N13b, which measure conduction between the dorsal column and approximately the cervico-medullary junction, did not change across this age range. The IPLs N13a-N20, N13b-N20 and P13-N20, which measure central conduction, showed negative exponential regressions with rapidly decreasing latencies during the first year of life and slowly decreasing latencies thereafter. CONCLUSIONS: Maturation of the peripheral segments of the somatosensory pathway progresses more rapidly than that of the central segments. The maturation of central conduction is not completed within the first 4 years of age. Our maturational data may serve as a reference source for subsequent developmental and clinical studies.

Ramiprilat prevents the development of acute coronary endothelial dysfunction in the dog.

We investigated the effect of an infusion of ramiprilat on the development of coronary endothelial dysfunction. In anesthetized dogs, the endothelium-dependent vasodilators acetylcholine (ACh, 5 and 10 microg x min(-1) for 1 min) and serotonin (5-HT, 50 and 100 microg x min(-1) for 1 min) and the endothelium-independent vasodilator nitroglycerin (NTG, 50 and 100 microg x min(-1) for 1 min) were given intracoronarily (i.c.) both prior to and after 60 min of ischemia (I) and 180 min of reperfusion (R) of a coronary artery. During I/R the dogs received i.c. either saline (N = 22) or ramiprilat (40 ng/kg x min(-1), N = 14). At the end of the experiment, a biopsy of the most distal coronary bed was processed for scanning electron microscopy (SEM). Prior to I/R all vasodilators induced a similar dose-related increase in coronary flow in both groups. Following I/R, in controls the responses to ACh and 5-HT were significantly blunted (ACh: -39% and -34%; 5-HT: -48% and -49%); those to NTG were unchanged. Ramiprilat significantly prevented the blunting of the responses to ACh (-5%, and -10%) and 5-HT (-11%, and -19%). SEM of control subepicardial arterioles showed adhesion of leukocytes to the endothelium and crater formation. No craters were seen in the ramiprilat-treated dogs. Thus, an acute infusion of ramiprilat significantly prevents the development of coronary endothelial dysfunction. Additionally, the appearance of crater-like changes on the endothelial surface can be taken as a morphological marker of endothelial dysfunction.

HPV 16 antibody prevalence in Jamaica and the United States reflects differences in cervical cancer rates.

Human papillomavirus (HPV) is widely accepted as the primary etiologic agent in the development of cervical cancer. DNA of a particular HPV type, HPV 16, is found in about half of tumors tested. Inconsistent with this causal relationship, however, population-based studies of HPV DNA prevalence have often failed to find high rates of anogenital HPV infection in countries with high cervical cancer rates. To examine this issue, we used serology to compare HPV 16 exposure in healthy volunteer blood donors in the United States (n = 278) and similar subjects from a country with 3-fold higher cervical cancer rates, Jamaica (n = 257). Jamaican sexually transmitted disease (STD) patients (n = 831) were also studied to examine in detail the relation of HPV 16 antibodies with sexual history. Serology was conducted using an ELISA employing HPV 16 virus-like particles (VLPs). Age-adjusted seroprevalence rates were greatest among male (29%) and female (42%) STD patients, intermediate in male (19%) and female (24%) Jamaican blood donors and lowest among male (3%) and female (12%) U.S. blood donors. The higher seroprevalence in women was significant, and prevalence tended to increase with age. In multivariate logistic regression, controlling for age and gender, Jamaican blood donors were 4.2-fold (95% CI 2.4-7.2) and STD patients 8.1-fold (95% CI 5.0-13.2) more likely to have HPV 16 VLP antibodies than U.S. blood donors. Among STD patients, HPV 16 antibodies were associated with lifetime number of sex partners and years of sexual activity, as well as other factors. Our data suggest that HPV 16 VLP antibodies are strongly associated with sexual behavior. Moreover, exposure to HPV 16 appears to be much greater in Jamaica than in the United States, consistent with the high rate of cervical cancer in Jamaica.

Coronary endothelial dysfunction after ischemia and reperfusion in the dog: a functional and morphological investigation.

Coronary endothelial dysfunction is characterized by a lower response to endothelium-dependent vasodilators such as acetylcholine (ACh) and serotonin (5HT), but by an unaltered response to endothelium-independent vasodilators such as nitroglycerin (NTG). In the present study, we investigated the vasoreactivity of the coronary bed in vivo, in a dog model of ischemia and reperfusion (I/R). We also assessed the morphology of the subepicardial arterioles and capillary bed by means of scanning electron microscopy (SEM). Anesthetized, instrumented dogs were divided in two groups. One group (N = 27) was submitted to ischemia (60 min) and reperfusion (180 min) of the left circumflex coronary artery, the second group (N = 8) was sham-operated. Prior to and following I/R, ACh, 5-HT, and NTG were given intracoronarily. At the end of the experiment a 1 cm3 myocardial biopsy was processed for SEM. The sham-operated dogs showed a reduction of basal coronary flow of 11%, but the vasoreactivity to ACh and 5-HT remained constant. In the I/R group, basal coronary flow was reduced by 35% (p < 0.05), and the vasoreactivity to ACh and 5-HT, but not to NTG, was significantly blunted. At SEM the arterioles of the dogs submitted to I/R showed a marked adhesion of leukocytes associated with holes on the endothelial surface, while the capillary bed was free of changes and patient. Thus, following I/R, coronary endothelial dysfunction could be demonstrated in vivo by the blunting of the vasoreactive responses to two different endothelium-dependent vasodilators. The responses to NTG were not affected, probably because the function of the smooth muscle cell was preserved, and the capillary bed was patent.

Specific ribosomal DNA sequences from diverse environmental settings correlate with experimental contaminants.

Phylogenetic analysis of 16S ribosomal DNA (rDNA) clones obtained by PCR from uncultured bacteria inhabiting a wide range of environments has increased our knowledge of bacterial diversity. One possible problem in the assessment of bacterial diversity based on sequence information is that PCR is exquisitely sensitive to contaminating 16S rDNA. This raises the possibility that some putative environmental rRNA sequences in fact correspond to contaminant sequences. To document potential contaminants, we cloned and sequenced PCR-amplified 16S rDNA fragments obtained at low levels in the absence of added template DNA. 16S rDNA sequences closely related to the genera Duganella (formerly Zoogloea), Acinetobacter, Stenotrophomonas, Escherichia, Leptothrix, and Herbaspirillum were identified in contaminant libraries and in clone libraries from diverse, generally low-biomass habitats. The rRNA sequences detected possibly are common contaminants in reagents used to prepare genomic DNA. Consequently, their detection in processed environmental samples may not reflect environmentally relevant organisms.

Lymphadenopathy: differentiation of benign from malignant disease--color Doppler US assessment of intranodal angioarchitecture.

PURPOSE: To differentiate reactive from malignant lymphadenopathy by using color Doppler ultrasonographic (US) findings of intranodal blood vessels. MATERIALS AND METHODS: Color Doppler US was performed in 117 lymph nodes in 100 consecutive patients before performance of surgical biopsy (47 nodes), neck dissection (62 nodes), or high-speed core biopsy (eight nodes). The presence of malignant changes in intranodal angioarchitecture (focal perfusion defects, aberrant course of central vessels, displacement of intranodal vessels, subcapsular vessels) was evaluated in each node. Inter- and intraobserver variability were evaluated. RESULTS: Histopathologic examination demonstrated 48 reactive lymph nodes (longest diameter +/- standard deviation, 13.5 mm +/- 6.0), 56 nodal metastases (longest diameter, 19.2 mm +/- 8.8), 12 malignant lymphomas (longest diameter, 23.2 mm +/- 10.5), and one node infiltrated by Langerhans cell histiocytosis. At color Doppler US, 103 (88%) nodes were classified correctly, with a specificity of 77% and a sensitivity of 96%. Reproducibility was 90%-96% (kappa = 0.79-0.91, P < .001). CONCLUSION: Color Doppler US is a reliable and reproducible method for help in the differentiation between reactive and malignant alterations of superficial lymph nodes by using findings of intranodal angioarchitecture.

Predictive agreement between the fetal arterial oxygen saturation and fetal scalp pH: results of the German multicenter study.

OBJECTIVE: To discuss and substantiate the 30% critical threshold of fetal arterial oxygen saturation and to complete the puzzle with low fetal arterial oxygen saturation and low scalp pH data, scalp samples have been performed while fetal arterial oxygen saturation registration during labor was in place and while the saturation was < or = 30%. STUDY DESIGN: Between 1993 and 1996, 46 term fetuses during active labor had parallel arterial oxygen saturation registration by pulse oximetry combined with cardiotocograph. They include patients in whom the saturation was < or = 30% for at least 10 minutes. In these cases scalp pH sample values have been obtained simultaneously. Outcome data, Apgar scores, cord gases, and whether the infants were transferred to the neonatal intensive care unit have been examined. Compared with this, there were other cases during labor that had also parallel fetal arterial oxygen saturation and cardiotocographic registration, where the saturation was > 30%. Also in these cases scalp pH was determined to support and demonstrate the predictive value of fetal arterial oxygen saturation for scalp pH, especially in the low ranges. All 46 fetuses were evaluated during periods of nonreassuring cardiotocograph with Nellcor N-400 Fetal Oxygen Saturation Monitoring Systems and FS 14 B sensors in a multicenter study involving three German obstetric centers. Receiver operating characteristic analysis was done on all raw data, as well as the receiver operating characteristic curve from the preceding analysis. RESULTS: These data validate the critical threshold of 30% fetal arterial oxygen saturation and show an extremely good separation of "good" versus "bad" at a fetal arterial oxygen saturation of 30%, especially when seen in conjunction with data points that are > 7.20. Data at < or = 7.20 scalp pH and < 30% fetal arterial oxygen saturation can be a big help in calculating the sensitivity and specificity of fetal arterial oxygen saturation in predicting neonatal outcome (e.g., Apgar score, cord pH). CONCLUSION: Low fetal arterial oxygen saturation data of < 30% for at least 10 minutes or longer correlate significantly with low scalp pH values and have a predictive value concerning fetal outcome.

Subcortical somatosensory evoked potentials after median nerve stimulation in children.

We report our normative data of subcortical somatosensory evoked potentials (SEPs) after median nerve stimulation from a group of 55 children 4-15 years of age and 18 young adults 18-29 years of age. We recorded near-field potentials from the brachial plexus, the cervical cord and the somatosensory cortex. The far-field potentials P13, P14 and N18 from the brainstem were recorded from the scalp electrodes, when a non-cephalic reference at the contralateral Erb's point or an ear reference was used. The N9 (brachial plexus), N13a (dorsal horn), P13 (caudal medulla oblongata), N18 (medulla oblongata) and N20 (somatosensory cortex) were present in all subjects. The N13b (dorsal column near the foramen magnum or cuneate nucleus) was observed in all children and in 16 adults, P14 (medial lemniscus) in 52 children and 17 adults. The median nerve SEPs provide reliable information about the function of the somatosensory pathway from the upper limb. The subcortical median nerve SEPs should be particularly useful to detect lesions of the upper cervical cord and the cervicomedullary junction. The subcortical SEPs remain unchanged during sleep and facilitate reliable SEP recordings, when sedation is necessary in infants and children.

Somatosensory evoked potentials after posterior tibial nerve stimulation--normative data in children.

We report normative data of somatosensory evoked potentials to posterior tibial nerve stimulation from 47 children 4-15 years of age. We recorded near-field potentials from the peripheral nerve, the cauda equina, the lumbar spinal cord and the somatosensory cortex. Far-field potentials were recorded from the scalp electrodes with a reference at Erb's point and on the earlobe. The near-field potentials N8 (peripheral nerve) and P40 (cortex) were present in all children. N20 (near-field from the cauda equina) was recorded in 38 subjects. N22 (near-field from the lumbar spinal cord), P30 and N37 ( both far-field waveforms probably generated in the brainstem) were recorded in 46 subjects each. The latencies and the peripheral conduction time (N8-N22) increased with age, while the central conduction time (N22-P40) and the intracranial conduction time (P30-P40) both decreased with age (up to about 10 years of age). The spinal conduction time (N22-P30) was relatively independent of age. The interpeak latencies allow the assessment of specific portions of this pathway. The subcortical posterior tibial nerve-somatosensory evoked potentials are of particular interest in children when the cortical peaks are influenced by sedation and sleep, or by anaesthesia.

Interlaboratory agreement among results of human papillomavirus type 16 enzyme-linked immunosorbent assays.

Serological assays for measuring antibodies to human papillomavirus type 16 (HPV-16) virus-like particles (VLPs) have become important epidemiologic tools in recent years. However, the interlaboratory replicability of these assays has not been assessed. In this investigation, three laboratories tested a panel of specimens obtained from two different groups: 265 subjects in a vulvar cancer case-control study and 107 healthy volunteer blood donors. Each laboratory used an enzyme-linked immunosorbent assay (ELISA), but no attempt was made to standardize assay procedures among the three laboratories. The data showed good day-to-day intralaboratory replicability in laboratory 1 (correlation coefficient, > or = 0.88) and good intra-assay variability in laboratory 3 (correlation coefficient, > or = 0.93). Interlaboratory correlations, likewise, ranged between 0.61 and 0.80 in both case-control study subjects and healthy blood donors, indicating that ELISA optical density (OD) values between laboratories were linearly related regardless of the population. Kappa coefficients (kappa), based on each laboratory's categorical interpretation of its results (as positive or negative), showed good agreement (kappa, > 0.6) in case-control study subjects and moderate agreement (kappa, > or = 0.4) in blood donors, a population that had few strongly positive sera. When OD values near seropositive cutoffs were treated as indeterminates, there was little discordance between laboratories in either population. The data suggest that each laboratory measured the same humoral immune response and that their HPV-16 VLP ELISAs performed similarly (Pearson correlations). Interlaboratory differences, however, probably due to reagents and procedures, were considerably greater than intralaboratory day-to-day variability. Interlaboratory agreement in determining seropositivity (kappa) could be improved by sharing positive and negative serum controls and by treating marginal results as indeterminate. As part of continuing cooperation to improve interlaboratory agreement, we are preparing bulk serum control specimens to be shared and made available to interested researchers.

Multilayer technology for diffractive optical elements.

The proposed multilayer technology makes it possible to approximate a continuous phase distribution by discrete phase steps. Compared with binary techniques, a higher diffraction efficiency can be achieved. In most known processes a bulk substrate is used and etched directly; therefore it is difficult to control the height of the phase steps. We propose applying layers of a well-known thickness and structuring them with a selective etching process. In this new multilayer process for reflecting elements a system of metal and dielectric layers is used that can easily be produced by standard methods.

Cultural and phylogenetic analysis of mixed microbial populations found in natural and commercial bioleaching environments.

A range of autotrophic and heterotrophic enrichment cultures were established to determine the cultural bacterial diversity present in samples obtained from the acidic runoff of a chalcocite overburden heap and from laboratory-scale (1- to 4-liter) batch and continuous bioreactors which were being used for the commercial assessment of the bioleachability of zinc sulfide ore concentrates. Strains identified as Thiobacillus ferrooxidans, Thiobacillus thiooxidans, "Leptospirillum ferrooxidans," and Acidiphilium cryptum were isolated from both the natural site and the batch bioreactor, but only "L. ferrooxidans," a moderately thermophilic strain of T. thiooxidans, and a moderately thermophilic iron-oxidizing bacterium could be recovered from the continuous bioreactor running under steady-state conditions. Sequence analysis of the 16S rRNA genes of 33 representative strains revealed that all of the strains were closely related to strains which have been sequenced previously and also confirmed the phylogenetic diversity of bacteria present in bioleaching environments.

The phylogeny of the genus Yersinia based on 16S rDNA sequences.

The inter- and intrageneric relationships of the genus Yersinia were investigated by sequence analysis of the 16S rRNA gene. A stretch of approximately 1450 nucleotides was sequenced from representatives of ten of the eleven validly described species. Phylogenetic analysis revealed that yersinae form a coherent cluster within the gamma subgroup of Proteobacteria. The intrageneric relationship was characterized by five sublines with Y. enterocolitica, Y. rohdei, and Y. ruckeri forming separate sublines each represented by a single species. A separate subline was formed by Y. pestis, Y pseudotuberculosis and Y. kristensenii, while Y. mollaretii, Y. intermedia, Y. bercovieri, Y. aldovae, and Y. kristensenii formed a fifth subline. The phylogenetic distinctness of the yersiniae sublines is compared to published phenotypic properties and results of DNA-DNA similarity studies.