French maritime pine bark treatment decelerates plaque development and improves spatial memory in Alzheimer's disease mice.

BACKGROUND: Plant extracts are increasingly investigated as potential drugs against Alzheimer's disease (AD) and dementia in general. Pycnogenol is an extract from the bark of the French maritime pine (Pinus pinaster Aiton subsp. atlantica) with known anti-oxidative and neuroprotective effects. HYPOTHESIS/PURPOSE: Pycnogenol is thought to improve cognitive functions in elderly. We wanted to investigate and quantify these effects in a model system of cerebral ß-amyloidosis/AD. STUDY DESIGN/METHODS: This study experimentally assessed the effects of Pycnogenol on AD-related pathology in a ß-amyloidosis mouse model. APP-transgenic mice and controls were treated orally in a pre-onset and post-onset treatment paradigm. The effects of Pycnogenol were characterized by analysing ß-amyloid (Aß) plaques, number of neurons, glia coverage, myelination pattern, and cortical coverage with axons using immunohistochemistry. Aß levels were quantified using ELISA and gene expression levels of APP-processing enzymes ADAM10, BACE1 and IDE protein levels were determined by Western blot. Behavioural changes in circadian rhythm were monitored and spatial memory / cognition was assessed using a water maze test. RESULTS: Pycnogenol significantly decreased the number of plaques in both treatment paradigms but did not alter levels of soluble Aß or the gene expression of APP-processing enzymes. The morphological analyses revealed no changes in the number of neurons, astrocytes, microglia, the myelination pattern, or the morphology of axons. Behavioural testing revealed an improvement of the spatial memory in the pre-onset treatment paradigm only. CONCLUSION: Our results suggest to evaluate clinically a potential use of Pycnogenol in the prevention or in early stages of mild cognitive impairment (MCI) and AD.

Human cell-based taste perception - a bittersweet job for industry.

Covering: 2000 to 2016On the molecular level humans sense food by a variety of specialized tissues which express sensory receptors to handle nutritive value. In general, this means the interplay of gustatory, olfactory, trigeminal and haptic sensation is translated into perception and leads, in terms of taste, to descriptions like sweet, bitter, salty, sour and umami. Further perceptions include astringent, cool, hot, prickle, lingering, kokumi and fatty to name predominant characterizations. It is still not fully understood how this plethora of impressions can be perceived by quite a limited number of receptors obviously being the initial compilers to judge palatability. However, since the discovery of mammalian taste receptors (TASRs) almost 30 years ago the use of taste receptors in cell-based screening campaigns is advancing in industrial approaches. The article will highlight the impacts and the limits of cell-based guided identification of taste modulators for food applications with an emphasis on sweet, bitter and savory taste as well as implications emerging from natural products.

Identifying microRNAs regulating B7-H3 in breast cancer: the clinical impact of microRNA-29c.

BACKGROUND: B7-H3, an immunoregulatory protein, is overexpressed in several cancers and is often associated with metastasis and poor prognosis. Here, our aim was to identify microRNAs (miRNAs) regulating B7-H3 and assess their potential prognostic implications in breast cancer. METHODS: MicroRNAs targeting B7-H3 were identified by transfecting two breast cancer cell lines with a library of 810 miRNA mimics and quantifying changes of B7-H3 protein levels using protein lysate microarrays. For validations we used western immunoblotting and 3'-UTR luciferase assays. Clinical significance of the miRNAs was assayed by analysing whether their expression levels correlated with outcome in two cohorts of breast cancer patients (142 and 81 patients). RESULTS: We identified nearly 50 miRNAs that downregulated B7-H3 protein levels. Western immunoblotting validated the impact of the 20 most effective miRNAs. Thirteen miRNAs (miR-214, miR-363*, miR-326, miR-940, miR-29c, miR-665, miR-34b*, miR-708, miR-601, miR-124a, miR-380-5p, miR-885-3p, and miR-593) targeted B7-H3 directly by binding to its 3'-UTR region. Finally, high expression of miR-29c was associated with a significant reduced risk of dying from breast cancer in both cohorts. CONCLUSIONS: We identified miRNAs efficiently downregulating B7-H3 expression. The expression of miR-29c correlated with survival in breast cancer patients, suggesting a tumour suppressive role for this miRNA.

Contrast-enhanced spectral mammography versus MRI: Initial results in the detection of breast cancer and assessment of tumour size.

OBJECTIVES: To compare mammography (MG), contrast-enhanced spectral mammography (CESM), and magnetic resonance imaging (MRI) in the detection and size estimation of histologically proven breast cancers using postoperative histology as the gold standard. METHODS: After ethical approval, 80 women with newly diagnosed breast cancer underwent MG, CESM, and MRI examinations. CESM was reviewed by an independent experienced radiologist, and the maximum dimension of suspicious lesions was measured. For MG and MRI, routine clinical reports of breast specialists, with judgment based on the BI-RADS lexicon, were used. Results of each imaging technique were correlated to define the index cancer. Fifty-nine cases could be compared to postoperative histology for size estimation. RESULTS: Breast cancer was visible in 66/80 MG, 80/80 CESM, and 77/79 MRI examinations. Average lesion largest dimension was 27.31 mm (SD 22.18) in MG, 31.62 mm (SD 24.41) in CESM, and 27.72 mm (SD 21.51) in MRI versus 32.51 mm (SD 29.03) in postoperative histology. No significant difference was found between lesion size measurement on MRI and CESM compared with histopathology. CONCLUSION: Our initial results show a better sensitivity of CESM and MRI in breast cancer detection than MG and a good correlation with postoperative histology in size assessment. KEY POINTS: • Contrast-enhanced spectral mammography (CESM) is slowly being introduced into clinical practice. • Access to breast MRI is limited by availability and lack of reimbursement. • Initial results show a better sensitivity of CESM and MRI than conventional mammography. • CESM showed a good correlation with postoperative histology in size assessment. • Contrast-enhanced spectral mammography offers promise, seemingly providing information comparable to MRI.

Depressive symptoms in women seeking surgery for pelvic organ prolapse.

INTRODUCTION AND HYPOTHESIS: To compare depressive symptoms in women with and without prolapse and evaluate impact on quality of life. METHODS: This is a secondary analysis of a case-control study assessing the effect of prolapse on body image. Cases had prolapse and sought surgery (Pelvic Organ Prolapse Quantification stage > or = 2). Controls had stage < or = 1. Subjects completed the Pelvic Floor Impact Questionnaire (PFIQ), Pelvic Floor Distress Inventory, and the Patient Health Questionnaire-9 (PHQ-9) at baseline. Cases completed measures 6 months post-operatively. We report: (1) the comparison of cases and controls at baseline and (2) comparison of baseline and post-operative scores in cases. RESULTS: Baseline questionnaires were completed by 75 cases and 65 controls; 57 cases completed post-operative measures. Cases were 5-fold more likely than controls to have depressive symptoms. Cases with depressive symptoms had higher PFIQ scores than cases without symptoms. PHQ-9 scores improved post-operatively. CONCLUSIONS: Depressive symptoms are common in women with prolapse and a decrease following surgical treatment.

[The role of blood-brain barrier in the pathogenesis of Alzheimer dementia--implications for immunological therapies for plaque dissolution]. / Die Funktion der Blut-Hirn-Schranke für die Pathogenese der Alzheimer-Demenz--Implikationen für immunologische Therapien zur Plaqueauflösung.

Alzheimer's disease (AD) is a devastating neurodegenerative disorder affecting more than 27 million people worldwide and leading to severe social-economic problems. One characteristic hallmark of AD--the amyloid plaques--are still being discussed to be one important triggering factor. However, current animal and autopsy studies refer to soluble and highly toxic A block oligomers as the deadly agent for the neurons. Current therapies mainly rely on the abatement of symptoms without antagonizing the etiology of the disease. Potential new approaches address reduced production, increased degradation and/or evacuation of toxic A block peptides from the brain. Among others one important group of target-proteins are the ABC transporters of the blood-brain barrier which contribute importantly to the detoxification of the brain. Changes of specific transport functions evoke important alterations for the known pathogenesis and future therapies of AD, especially approaches that target plaque dissolution and plaque reduction.

Genetic association of Toll-like receptor 4 with cervical cytokine concentrations during pregnancy.

Toll-like receptors (TLRs) are critical components of innate immunity, recognizing bacterial microorganisms and initiating local inflammatory responses. In this study, we assessed the impact of genetic variation in TLR genes on cervical concentrations of pro- and anti-inflammatory cytokines, and determined whether this relationship is influenced by bacterial vaginosis (BV). A total of 4 single nucleotide polymorphisms (SNPs) in TLR2 and 12 in TLR4 were examined for associations with 10 cervical pro- and anti-inflammatory cytokine concentrations in 91 African-American (AA) and 97 European-American (EA) women in the first trimester of pregnancy. In EAs, individuals with the TT genotype at rs1554973 (TLR4) had higher cervical concentrations of interleukin-1 beta (IL-1b) compared with those with the CT or TT genotypes (P=1.5 x 10(-5)), which remains significant after correction for multiple testing. This association was more significant in women with BV (P=5 x 10(-3)) than those without BV (P=0.02). This SNP was also associated with cervical concentrations of IL-1a, IL-6, IL-8 and IP10 (interferon-gamma-inducible protein 10) (P=6 x 10(-3), 0.03, 0.05, 6 x 10(-3), respectively). Our study demonstrates that TLR4 is an important mediator of pro-inflammatory cervical immune responses, particularly in EA women and especially in those with microbial disorders such as BV.

Predicting risk of bacterial vaginosis: the role of race, smoking and corticotropin-releasing hormone-related genes.

Bacterial vaginosis (BV) is one of the most prevalent vaginal disorders in adult women and is associated with adverse pregnancy outcomes such as pre-term birth. Genetic factors, particularly in genes involved in inflammation and infection, are associated with this condition. Additionally, environmental risk factors including stress and smoking are associated with BV. The purpose of this study was to identify genetic variants in stress-related genes such as corticotropin-releasing hormone (CRH), receptor 1, receptor 2 and binding protein (CRH-BP) that associate with BV. Also gene-environment effects with smoking are determined. BV was quantified using the Nugent score in 82 white and 65 black women in the first trimester of pregnancy. Associations between Nugent score, genotype and smoking were analyzed using Kruskal-Wallis and Wilcoxon rank sum non-parametric tests. In white women, non-smokers with the CT genotype at CRH-BP + 17487 have lower Nugent scores (median: 0, range: 0-0) than non-smokers with the TT genotype (median: 2, range: 0-8) (P = 0.002); whereas smokers with the CT genotype have higher Nugent scores (median: 6, range: 0-10) than smokers with the TT genotype (median: 1, range: 0-10) (P = 0.021). In black women, the AG genotype at CRH + 3362 or CRH - 1667 is associated with lower Nugent scores (median for both: 3, range: 0-10) compared with the homozygous genotypes (median for each homozygous genotype: 8, range: 0-10). Also, in black women, models remain significant after adjusting for smoking (P = 0.04 for both). These data indicate that susceptibility to BV is affected by patterns of genetic variation in stress-related genes and smoking plays an important role.

Use of polymerase chain reaction as a diagnostic tool for neonatal sepsis can result in a decrease in use of antibiotics and total neonatal intensive care unit length of stay.

OBJECTIVE: To retrospectively determine if a negative 16S ribosomal RNA (rRNA) polymerase chain reaction (PCR) (PCR(-)) could lead to a decrease in the number of antibiotic doses and neonatal intensive care unit (NICU) length of stay (LOS) for infants admitted to the NICU for presumed early-onset sepsis (EOS) with negative blood culture results (BC(-)). STUDY DESIGN: Analysis included 419 infants, greater than 35 weeks gestational age, with PCR(-), BC(-) and LOS > 48 h. Both the investigators and clinical care team were unaware of the PCR results. The actual number of antibiotic doses (AAD) administered was compared to an estimated number of antibiotics doses (EAD) that would have been given until PCR(-) results were available by 18 h. The number of antibiotic doses saved was calculated as (AAD-EAD). The actual NICU LOS in hours (aLOS) for a subset of infants who remained in the hospital primarily for antibiotic therapy was compared to an estimated LOS (eLOS) if infants with PCR(-) were discharged from the NICU when clinically stable. The number of hours saved was calculated as (aLOS-eLOS). RESULTS: Approximately eight antibiotic doses and 85 NICU hours per infant could be saved using PCR(-) results available at 18 h. CONCLUSIONS: Use of 16S rRNA PCR could decrease the number of antibiotics doses and NICU LOS for infants admitted for EOS. This may facilitate: (1) earlier NICU discharge; (2) parental satisfaction; and (3) decreased health care costs.

Characterization of vaginal & rectal colonization with multiple serotypes of group B streptococci using multiple colony picks.

BACKGROUND & OBJECTIVES: There is paucity of information on vaginal and rectal colonization with multiple serotypes of group B streptococci (GBS). As part of an ongoing cohort study evaluating the natural history of vaginal and rectal colonization by GBS, the colonization with multiple serotypes was studied in 102 non-pregnant women aged 18-30 yr. METHODS: Up to ten separate colony picks of beta-haemolytic streptococci (total 1515 isolates) were selected from vaginal and rectal primary culture plates. The colonies were identified as GBS, and their capsular polysaccharides (CPS) serotypes determined using monospecific rabbit antisera for types Ia-VIII by double immunodiffusion in agarose (DID). A colony dot immunoblot (DB) assay, using monospecific rabbit antisera to purified type polysaccharides conjugated to tetanus toxoid, was developed to serotype efficiently the multiple colony picks of GBS. RESULTS: The CPS serotype distribution, examining only the 177 "a" or first colony picks from the 102 patients, was 30.5 per cent for Ia; 28.2 per cent for type III; 15.3 per cent for type II; and 13.6 per cent for type V. Only 2.8 per cent were nontypeable. Eighty of the 102 patients (78.4%) were colonized with only one serotype; 20 (19.6%) had two serotypes and two patients (2%) had three serotypes in their vaginal and/or rectal paired cultures. Overall, 91.9 per cent of the culture sites colonized with one to three CPS types (from the total number of colonies picked) were identified with a minimum of three colony picks. In 75 patients with vaginal/rectal pairs the GBS serotype concordance of only the "a" colony was 89.3 per cent and concordance decreased to 80 per cent when the serotype concordance of the total colony picks was analyzed. INTERPRETATION & CONCLUSION: In conclusion, there was a relatively high prevalence of serotype nonconcordance in this population, and 21.6 per cent of patients had multiple GBS serotypes.

Cross-talk of phosphoinositide- and cyclic nucleotide-dependent signaling pathways in differentiating avian nasal gland cells.

In many bird species, the nasal glands secrete excess salt ingested with drinking water or food. In ducks ( Anas platyrhynchos), osmotic stress results in adaptive cell proliferation and differentiation in the gland. Using 'naive' nasal gland cells isolated from animals that had never ingested excess salt or 'differentiated' cells from animals fed with a 1% NaCl solution for 48 h, we investigated the allocation of metabolic energy to salt excretory processes and to other cellular activities. Activation of muscarinic acetylcholine receptors (carbachol) or beta-adrenergic receptors (isoproterenol) in nasal gland cells resulted in a transient peak in metabolic rate followed by an elevated plateau level that was maintained throughout the activation period. Activation of cells using vasoactive intestinal peptide, however, had only marginal effects on metabolic rate. In differentiated cells, sequential stimulation with carbachol and isoproterenol resulted in additive changes in metabolic rate during the plateau phase. Naive cells, however, developed supra-additive plateau levels in metabolic rates indicating cross-talk of both signaling pathways. Using bumetanide, TEA or barium ions to block different components of the ion transport machinery necessary for salt secretion, the relative proportion of energy needed for processes related to ion transport or other cellular processes was determined. While differentiated cells in the activated state allocated virtually all metabolic energy to processes related to salt secretion, naive cells reserved a significant amount of energy for other processes, possibly sustaining cellular signaling and regulating biosynthetic mechanisms related to adaptive growth and differentiation.

Geometric approach to the pressure tensor and the elastic constants.

Expressions are obtained for the pressure tensor in the canonical and the microcanonical ensemble for both isolated and periodic systems, using the same geometric approach to thermodynamic derivatives as has been used previously to define the configurational temperature. The inherent freedom of the method leads to a straightforward proof of the equivalence of atomic and molecular pressures, for short molecules and for molecules exceeding the dimensions of a periodic simulation box. The effect of holonomic constraints on the pressure is discussed. Expressions for the elastic constants are derived in the same manner.

Self-collection of vaginal swabs for the detection of Chlamydia, gonorrhea, and trichomoniasis: opportunity to encourage sexually transmitted disease testing among adolescents.

BACKGROUND: Many sexually transmitted diseases (STDs) are prevalent among adolescents, yet compliance to undergo STD testing by this population is suboptimal. Efforts to enhance compliance with testing among at-risk youth are needed. GOAL: To determine the feasibility and acceptability of self-collection of vaginal swabs for the detection of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis among high-school students attending a school health clinic. STUDY DESIGN: Enrolled in the study were 228 female students between the ages of 15 and 19 years. Each student self-collected a single vaginal swab that was tested for C trachomatis, N gonorrhoeae, and T vaginalis by polymerase chain reaction amplification. Acceptability of self-collection of vaginal swabs was assessed. RESULTS: The prevalence of any STD was 18%. Trichomoniasis, chlamydia, and gonorrhea were diagnosed in 10%, 8%, and 2% of students, respectively. Nearly 13% of females who had never previously had a gynecologic examination tested positive for an STD, and 51% of infected students would not have pursued testing by traditional gynecologic examination if self-collection was not offered. Self-collection of vaginal swabs was almost uniformly reported as easy to perform (99%) and preferable to a gynecologic examination (84%). Nearly all (97%) stated that they would undergo testing at frequent intervals if self-testing were available. CONCLUSIONS: Self-collected vaginal swabs for STD testing can be easily implemented in a high-school setting with high acceptability among students, enabling the detection of many STDs that would otherwise remain undetected and untreated.

Barriers to screening sexually active adolescent women for chlamydia: a survey of primary care physicians.

PURPOSE: To determine the proportion of primary care physicians who screen sexually active teenage women for chlamydia and to determine demographic factors, practice characteristics, and attitudes associated with chlamydia screening. METHODS: We obtained a random sample of 1600 Pennsylvania physicians from the American Medical Association masterfile, stratified to include at least 40% women and equal numbers of family physicians, internists, obstetricians/gynecologists, and pediatricians. In January 1998, physicians received mailed questionnaires; nonrespondents received two follow-up mailings. Physician characteristics associated with chlamydia screening were determined using bivariate and logistic regression analyses. RESULTS: Only one-third of physicians responded that they would screen asymptomatic, sexually active teenage women for chlamydia during a routine gynecologic examination. In multivariate analysis, physicians were significantly (p <.05) more likely to screen if they were female (43% vs. 24%), worked in a clinic versus solo practice (60% vs. 18%), worked in a metropolitan location (46% vs. 26%), or had a patient population > or = 20% African-American (54% vs. 25%). Attitudes associated with screening included the belief that most 18-year-old women in their practice were sexually active (36% vs. 12%), feeling responsible for providing information about the prevention of sexually transmitted diseases to their patients (42% vs. 21%), or knowing that screening for chlamydia prevents pelvic inflammatory disease (37% vs. 13%). Physicians were less likely to screen if they believed that the prevalence of chlamydia was low (10% vs. 41%). CONCLUSIONS: A majority of physicians do not adhere to recommended chlamydia screening practices for teenage women. Interventions to improve chlamydia screening might target physicians who are male, in private practice, or who practice in rural areas, and should focus on increasing awareness of the prevalence of chlamydia and benefits of screening.

Vaginal indicators of amniotic fluid infection in preterm labor.

OBJECTIVE: To determine whether vaginal interleukin-6, interleukin-8, neutrophils, bacterial vaginosis, and selected vaginal bacteria are predictors of amniotic fluid (AF) infection among women in preterm labor. METHODS: One hundred ninety-seven afebrile women in preterm labor with intact membranes had vaginal and AF samples collected for Gram stain, culture, and interleukin-8 and interleukin-6 determinations. Vaginal interleukin-6, interleukin-8, neutrophils, and vaginal flora were compared in women with positive and negative AF cultures. The negative AF culture group was subdivided according to AF interleukin-6 concentration. Logistic regression was used to examine the associations between vaginal cytokines and flora and AF infection or elevated AF interleukin-6. RESULTS: The vaginal interleukin-8 concentration and neutrophil count were significantly higher with both AF infection and elevated concentrations of AF interleukin-6 and interleukin-8. The vaginal interleukin-6 concentration was not associated with AF infection or high concentration of AF cytokines. Amniotic fluid infection was associated with bacterial vaginosis or intermediate vaginal flora by Gram stain, absence of hydrogen peroxide-producing Lactobacillus, and presence of vaginal Bacteroides ureolyticus and Fusobacterium. Vaginal interleukin-8 levels greater than 30 ng/mL had 80% sensitivity and a positive predictive value of 35%, and an abnormal vaginal Gram stain (more than five neutrophils per 400x field, bacterial vaginosis species, or intermediate flora) had 90% sensitivity and a positive predictive value of 27% to detect AF infection or elevated AF interleukin-6. CONCLUSION: A high vaginal interleukin-8 concentration, abnormal vaginal Gram stain, absent hydrogen peroxide-producing Lactobacillus, and anaerobic vaginal flora were strongly associated with AF infection among women in preterm labor.

Variation of HMGB1 expression in breast cancer.

The amount of steroid hormone receptor proteins does not always correlate with the response of breast cancers to endocrine therapy. This may partly be due to the fact that binding of the estrogen receptor (ER) to estrogen responsive elements (ERE) of its target genes is mediated by additional cellular proteins. One of these is the high mobility group protein HMGB1, known to interact with ER thus dramatically increasing its binding to ERE. This is the first report analysing the expression patterns of HMGB1 in breast cancer cells. Northern blot analyses of the 1.4 kb and the 2.4 kb transcripts of HMGB1 in 13 breast cancer samples revealed a strong intertumoural variation by a factor of 8.5 and 14.5, respectively. This variation may contribute to the different response, of estrogen receptor-positive breast tumours to endocrine therapy, making HMGB1 a marker of considerable clinical interest.

Predicting cesarean delivery with decision tree models.

OBJECTIVE: The purpose of this study was to determine whether decision tree-based methods can be used to predict cesarean delivery. STUDY DESIGN: This was a historical cohort study of women delivered of live-born singleton neonates in 1995 through 1997 (22,157). The frequency of cesarean delivery was 17%; 78 variables were used for analysis. Decision tree rule-based methods and logistic regression models were each applied to the same 50% of the sample to develop the predictive training models and these models were tested on the remaining 50%. RESULTS: Decision tree receiver operating characteristic curve areas were as follows: nulliparous, 0.82; parous, 0.93. Logistic receiver operating characteristic curve areas were as follows: nulliparous, 0.86; parous, 0.93. Decision tree methods and logistic regression methods used similar predictive variables; however, logistic methods required more variables and yielded less intelligible models. Among the 6 decision tree building methods tested, the strict minimum message length criterion yielded decision trees that were small yet accurate. Risk factor variables were identified in 676 nulliparous cesarean deliveries (69%) and 419 parous cesarean deliveries (47.6%). CONCLUSION: Decision tree models can be used to predict cesarean delivery. Models built with strict minimum message length decision trees have the following attributes: Their performance is comparable to that of logistic regression; they are small enough to be intelligible to physicians; they reveal causal dependencies among variables not detected by logistic regression; they can handle missing values more easily than can logistic methods; they predict cesarean deliveries that lack a categorized risk factor variable.

Levels of vaginal secretory leukocyte protease inhibitor are decreased in women with lower reproductive tract infections.

OBJECTIVE: Secretory leukocyte protease inhibitor contributes resistance to primary human immunodeficiency virus infection in the oral cavity. However, the levels of this inhibitor in the genital tract of women with sexually transmitted diseases or vaginitis are not well described. The objective was to determine vaginal inhibitor levels in women with symptomatic and asymptomatic genital infections. STUDY DESIGN: We tested 207 nonpregnant women for Neisseria gonorrhoeae, Trichomonas vaginalis, Chlamydia trachomatis, Candida species, and bacterial vaginosis by standard methods. A second group of symptom-free pregnant women (N = 231) was also studied. Secretory leukocyte protease inhibitor was measured by enzyme-linked immunosorbent assay, and results were compared by nonparametric methods. RESULTS: Vaginal levels of secretory leukocyte protease inhibitor in both groups were significantly lower in women with any sexually transmitted disease than in those without infection (P<.0001). Patients with bacterial vaginosis and those with bacterial vaginosis with yeast vaginitis also had decreased levels (P<.025). CONCLUSIONS: Levels of secretory leukocyte protease inhibitor in vaginal fluid are decreased in women with lower genital tract infection. This may represent a common mechanism of increasing susceptibility to infection with human immunodeficiency virus.

Group B streptococcal colonization and serotype-specific immunity in pregnant women at delivery.

OBJECTIVE: To describe the relationship between serum concentration of group B streptococcal capsular polysaccharide-specific immunoglobulin (Ig) G, colonization status, race or ethnicity, and age in pregnant women. METHODS: Pregnant women (n = 3307) were enrolled from geographically and ethnically diverse populations. At the time of admission for delivery, swabs of the lower vagina and rectum were obtained for isolation of group B streptococci. In a subset of women whose sera were available, capsular polysaccharide-specific IgG concentrations were quantified by serotype-specific (Ia, Ib, II, III, and V) enzyme-linked immunosorbent assay and compared by group B streptococcal colonization status. RESULTS: Group B streptococcal colonization was detected in 856 women (26%), and the rate was significantly higher among black women (37%) than in other racial or ethnic groups (odds ratio 1.7, 95% confidence interval 1.4, 2.1). Colonization status did not differ by study site or age. Colonization with serotypes Ia, II, III, or V was associated with significantly higher serum concentrations of IgG specific for the capsular polysaccharide of the colonizing serotype compared with noncolonization. However, 48% of colonized women had low capsular polysaccharide-specific IgG levels (less than 0.5 microg/mL) in their delivery sera. Colonized teenagers had the lowest median concentration. CONCLUSION: Colonization with group B streptococcus can elicit a systemic immune response, with a cumulative increase in the prevalence of capsular polysaccharide-specific IgG with increasing age. Conversely, low antibody levels in colonized teenagers might account in part for the reported increased risk of group B streptococcal disease in neonates born to these patients.

The amniotic fluid index in normal twin pregnancies.

OBJECTIVE: We sought to investigate the amniotic fluid index for individual gestational sacs of twin pregnancies. STUDY DESIGN: Four hundred eighty-eight patients with normal diamniotic twins were examined between 14 and 40 weeks' gestation. The dividing membrane between twin fetuses was identified. An amniotic fluid index was then obtained for each gestational sac. RESULTS: The median amniotic fluid index in individual twin gestational sacs rises slowly from 14 to 16 weeks' gestation to 23 to 28 weeks' gestation and then gradually declines. The median amniotic fluid index values by gestational age for twin A and twin B are not statistically different. Although twin pregnancies have a slightly lower median amniotic fluid index value than singleton pregnancies, the difference is also not statistically significant. CONCLUSION: Individual amniotic fluid indices can be obtained in twin pregnancies, and the values are comparable with those of singleton gestations.