Antigens of Streptococcus sanguis

An antigenic analysis of the alpha-hemolytic streptococci isolated from dental plaque was performed by use of antisera against a strain of Streptococcus sanguis (M-5) which was isolated from dental plaque. Immunoelectrophoretic and Ouchterlony tests of Rantz and Randall extracts of 45 strains gave positive reactions with the M-5 antisera. These strains represented 60% of the strains tested. The number of antigens which could be identified in these extracts varied from one to five and were designated a to e. The a antigen was found in 36 of the strains tested, including reference strains of S. sanguis and the group H streptococci. The strains reacting with the M-5 antisera were divided into two majors types: type I consisted of 23 strains in which the a antigen was found alone or with one or more of the c, d, and e antigens; type II consisted of 13 strains in which both the a and b antigens were found with or without one or more of the c, d, and e antigens. The remaining strains contained, either singly or in combination, the b, c, d, and e antigens but not the a antigen. Biochemical tests of representatives of each serotype and reference strains indicated that strains reacting with M-5 antisera were S. sanguis. These findings suggest that S. sanguis strains share common physiological and serological properties.     

Brain responses associated with the Valsalva maneuver revealed by functional magnetic resonance imaging

The Valsalva maneuver, a test frequently used to evaluate autonomic function, recruits discrete neural sites. The time courses of neural recruitment relative to accompanying cardiovascular and breathing patterns are unknown. We examined functional magnetic resonance imaging signal changes within the brain to repeated Valsalva maneuvers and correlated these changes with physiological trends. In 12 healthy subjects (age, 30-58 yr), a series of 25 volumes (20 gradient echo echo-planar image slices per volume) was collected using a 1.5-Tesla scanner during a 60-s baseline and 90-s challenge period consisting of three Valsalva maneuvers. Regions of interest were examined for signal intensity changes over baseline and challenge conditions in cardiorespiratory-related regions. In addition, whole brain correlations between signal intensity and heart rate and airway load pressure were performed on a voxel-by-voxel basis. Significant signal changes, correlated with the time course of load pressure and heart rate, emerged within multiple areas, including the amygdala and hippocampus, insular and lateral frontal cortices, dorsal pons, dorsal medulla, lentiform nucleus, and fastigial and dentate nuclei of the cerebellum. Signal intensities peaked early in the Valsalva maneuver within the hippocampus and amygdala, later within the dorsal medulla, pons and midbrain, and deep cerebellar nuclei, and last within the lentiform nuclei and the lateral prefrontal cortex. The ventral pontine signals increased during the challenge, but not in a fashion correlated to load pressure or heart rate. Sites showing little or no correlation included the vermis and medial prefrontal cortex. These data suggest an initiating component arising in rostral brain areas, a later contribution from cerebellar nuclei, basal ganglia, and lateral prefrontal cortex, and a role for the ventral pons in mediating longer term processes.     

Projections from the paratrigeminal nucleus and the medullary and spinal dorsal horns to the peribrachial area in the cat

The projections from the medullary and spinal dorsal horns to the dorsolateral pons were investigated in the cat utilizing both the retrograde and anterograde transport of a wheat germ agglutinin-horseradish peroxidase complex and the retrograde transport of the fluorescent dyes Fast Blue and Nuclear Yellow. After injections of wheat germ agglutinin-horseradish peroxidase into the area surrounding the brachium conjunctivum, numerous neurons were labeled ipsilaterally near levels of the obex in the paratrigeminal nucleus. Such neurons were located in connected pockets of neuropil located within the spinal trigeminal tract and along its medial edge. Most of the neurons labeled in the dorsal horns after such injections were found in lamina I. Those found in the medullary dorsal horn were mostly ipsilateral to the injection while those in the spinal dorsal horn were found bilaterally. Some labeled neurons were also found in lamina V of both the medullary and spinal dorsal horns bilaterally. When the injection was centered in either the medial parabrachial nucleus or the Kolliker-Fuse nucleus, a greater number of neurons were labeled ipsilaterally in lamina V of the medullary dorsal horn. Since neurons in lamina I of the medullary dorsal horn also project to the medial thalamus, fluorescent dyes were used to determine if the same neuron might project to both targets. Fast Blue was first injected into either the peribrachial area or the medial thalamus. After an appropriate period, Nuclear Yellow was injected into that target not injected first with Fast Blue. The injection of Nuclear Yellow was always placed on the side of the brain opposite to the first injection. Both dyes were transported retrogradely and were found in neurons located in lamina I of the medullary dorsal horn. However, no double-labeled neurons were seen. In general those labeled after injections of the medial thalamus were more superficial than those labeled after injections of the dorsolateral pons. The anterograde transport of wheat germ agglutinin-horseradish peroxidase was used to determine the termination of the projections from neurons in the medulary dorsal horn and the cervical spinal cord to the peribrachial area. After injections into these areas a moderate to sparse labeling of the lateral parabrachial nucleus and the Kolliker-Fuse nucleus was seen. It was mostly ipsilateral in cases with injections of the medullary dorsal horn but was bilateral following injections into the cervical enlargement.(ABSTRACT TRUNCATED AT 400 WORDS)     

Attenuation of ethanol tolerance by a novel stimulus

A Pavlovian conditioning model of tolerance emphasizes that an association between predrug cues and the systemic effects of the drug contributes to tolerance. On the basis of this model, established tolerance should be attenuated by external inhibition, i.e., by presentation of a novel, extraneous stimulus. This prediction was evaluated in the present experiment. Rats that were so tolerant to the hypothermic effect of ethanol that they evidenced no drug-induced decrease in temperature were presented with a bright strobe light following ethanol administration. The light precipitated a large decrease in temperature in these rats. These results provide further evidence that tolerance to the hypothermic effect of ethanol is, in part, mediated by learning.     

Evaluating the Impact of a Novel Peer-to-Peer Educational Modality on Knowledge and Attitudes About Perinatal Mood and Anxiety Disorders

Maternal and Child Health Journal - This study assessed whether the use of a peer-to-peer educational book, written and illustrated by women who experienced common mental disorders (CMDs) in the...     

The Development of a Multilevel Intervention to Optimise Participant Engagement with an Obesity Prevention Programme Delivered in UK children’s Centres

Prevention Science - Poor participant engagement threatens the potential impact and cost-effectiveness of public health programmes preventing meaningful evaluation and wider application. Although...     

Effect of Condoms on Reducing the Transmission of Herpes Simplex Virus Type 2 From Men to Women

Context  Herpes simplex virus type 2 (HSV-2) is one of the most common sexually transmitted infections in the United States. No prospective study has shown the ability of condoms to reduce transmission of HSV-2. Objective  To evaluate risk factors for HSV-2 acquisition and efficacy of condoms in prevention of HSV-2 transmission. Design  Analysis of data from a randomized, double-blind, placebo-controlled trial conducted December 13, 1993, to June 28, 1996, of an ineffective candidate HSV-2 vaccine with 18 months of follow-up. Setting  Eighteen clinical trial centers in the United States. Participants  A total of 528 monogamous couples discordant for HSV-2 infection, including an HSV-2–susceptible population of 261 men and 267 women. Main Outcome Measure  Acquisition of HSV-2 infection by susceptible partners, compared with those remaining free of HSV-2 with regard to demographic characteristics, sexual activity, and condom use. Results  Twenty-six women (9.7%) vs 5 men (1.9%) acquired HSV-2, for a rate per 10 000 sex acts (episodes of sexual intercourse) of 8.9 vs 1.5, respectively (P<.001). In multivariable analysis, younger age (adjusted hazard ratio [HR] per 5 years, 1.57; 95% confidence interval [CI], 1.22-2.04), seropositivity for HSV-1 and HSV-2 vs HSV-2 alone in the source partner (adjusted HR, 2.34; 95% CI, 1.14-4.82), and more frequent sexual activity (adjusted HR per additional sex act per week, 1.10; 95% CI, 1.01-1.19) were associated with higher risk of HSV-2 acquisition. Condom use during more than 25% of sex acts was associated with protection against HSV-2 acquisition for women (adjusted HR, 0.085; 95% CI, 0.01-0.67) but not for men (adjusted HR, 2.02; 95% CI, 0.32-12.50). Risk of HSV-2 transmission declined from 8.5 per 100 person-years in the initial 150-day interval to 0.9 per 100 person-years in the final 150-day interval (P = .002 for trend), concurrent with a decrease in sexual activity and proportion of sex acts occurring when the source partner had genital lesions. Conclusions  Condom use offers significant protection against HSV-2 infection in susceptible women. Changes in sexual behavior, correlated with counseling about avoiding sex when a partner has lesions, were associated with reduction in HSV-2 acquisition over time. These data suggest that identification of discordant couples can reduce transmission of HSV-2, especially for heterosexual couples in which the male partner has HSV-2 infection.      

Why adolescents delay with presentation to hospital with acute testicular pain: A qualitative study

Background/purposeAdolescents have poor outcomes following testicular torsion directly attributable to delay from onset of symptoms to presentation to hospital. The aim of this study was to investigate the barriers to urgent presentation in young men.MethodsSemistructured interviews were undertaken with young men (11–19 years), using a topic guide exploring issues surrounding testicular pain and health. Thematic analysis was undertaken using a framework approach.ResultsTwenty-seven adolescents were recruited, data saturation was reached at sixteen participants, and median age was 13.5 years (range 11–18). The process by which an adolescent gets to hospital with testicular pain is slow. They must recognize the problem and alert their parents, who then use a ‘watch and wait’ policy to assess need for medical review, often leaving it ‘a day’ or overnight. Adolescent males do not engage with healthcare services independently of their parents. Additional factors preventing early presentation include: absence of knowledge about testicular pathology from adolescents and their parents; concern from the young people about raising a false alarm and family concerns about burdening healthcare services.ConclusionsRecommendations include designing a testicular health education campaign for young men and educating parents regarding the medical conditions where a ‘watch and wait’ policy may be harmful to their child.Level of evidenceVI     

Association of hospital and surgeon operative volumes and surgeon pediatric subspecialization with pediatric laparoscopic cholecystectomy outcomes: A population-based cohort study

BackgroundMost pediatric cholecystectomies are performed by adult general surgeons, but it is unclear whether outcomes differ by surgeon pediatric subspecialization, hospital procedure volume, or surgeon procedure volume. We aimed to determine whether higher hospital or surgeon laparoscopic cholecystectomy (LC) volume or surgeon pediatric subspecialization is associated with better outcomes after LC in children.MethodsWe performed a retrospective cohort study using statewide hospital discharge databases from the states of Florida, Georgia, and Iowa. We included children aged 4–18 years who underwent inpatient or outpatient LC for acute or chronic gallbladder disease in January 2010–August 2015.Propensity score weighting was used to estimate relationships between operative volumes or surgeon pediatric subspecialization and rates of readmission or emergency department (ED) visit within 30 days.ResultsA total of 5391 children were included (mean age 15.9 years, 81.6% female). Children operated on by surgeons with high LC volumes in hospitals with high LC volumes were less likely to experience a readmission or ED visit within 30 days (10.8% vs. 13.7%, p = 0.04). Additionally, children operated on by adult general surgeons in hospitals with high LC volumes were less likely to experience a readmission or ED visit within 30 days (10.9% vs. 13.8%, p = 0.03).ConclusionsChildren are less likely to be readmitted to the hospital or present to the ED after laparoscopic cholecystectomy if they receive their care from adult general surgeons at hospitals that frequently perform this procedure in both adults and children.Level of evidenceIII