Evidence that cytokine-mediated immune interactions induced by Schistosoma mansoni alter disease outcome in mice concurrently infected with Trichuris muris.

In murine models of Schistosoma mansoni infection, egg production is associated with a switch from T helper cell (Th)1- to Th2-type responses to both schistosome-specific and unrelated antigens. Polyparasitism is common in human populations within S. mansoni endemic areas. We have, therefore, examined whether coinfection with S. mansoni could affect the outcome of a second parasitic infection, through Th2 cytokine-dependent modifications to the host immune response. We find that when mice susceptible to infection with the gut nematode Trichuris muris are coinfected with S. mansoni, they acquire the capacity to resolve T. muris infection, thus demonstrating a resistant phenotype. This ability to expel T. muris is associated with the production of Th2-associated cytokines, and corresponding antibody isotypes, in response to S. mansoni egg antigens. The Th2 response shows that there is no compartmentalization between spleen and mesenteric lymph nodes, and that the expulsion of T. muris is not caused by any changes in the host intestine associated with excretion of schistosome eggs. This influence of schistosome infections may be important, not only for the outcome of infections with unrelated pathogens in endemic areas, but also for the efficacy of vaccines in such areas.

Molecular cloning and sequence analysis of the Chlamydomonas gene coding for radial spoke protein 3: flagellar mutation pf-14 is an ochre allele.

Chlamydomonas reinhardtii flagellar motility mutant pf-14 fails to assemble radial spokes because of a deficiency for assembly-competent radial spoke protein 3 (Huang, B., G. Piperno, Z. Ramanis, and D. J. L. Luck. 1981. J. Cell Biol. 88:80-88). Here, we raise an antiserum to protein 3 and use it to isolate the corresponding structural gene from an expression library. Southern blot analysis indicates that the gene is single copy and has not undergone major rearrangement in mutant pf-14 cells. Northern blot analysis suggests that wild-type amounts of an apparently normal 2.3-kb transcript accumulate in mutant cells during flagellar regeneration. When this mutant RNA is hybrid selected and translated in vitro, however, it produces a slightly truncated polypeptide 3 with an altered charge. The mutant protein 3 fails to assemble into pf-14 flagella and is maintained within a cytoplasmic pool of unassembled radial spoke polypeptides, as indicated by immunoblot analysis of proteins from whole cells and isolated axonemes using antisera to several radial spoke polypeptides. Interestingly, amounts of the mutant protein are greatly diminished relative to other spoke components. Complete genomic and cDNA nucleotide sequences were determined, and the pf-14 mutation was identified. It is a C-to-T transition near the 5' end of the protein coding region, which changes codon 21 to the ochre termination signal UAA. The size and charge of the mutant protein, and its reduced levels in cells, suggest that it is produced by relatively inefficient translational initiation as codon 42. The unphosphorylated isoform of radial spoke protein 3 is identified, and the sequence similarities between intervening sequences of the radial spoke protein 3 gene and a conserved intervening sequence of the two Chlamydomonas beta-tubulin genes (Youngblom, J., J. A. Schloss, and C. D. Silflow. 1984. Mol. Cell. Biol. 4:2686-2696) are reported.

Maternal plasma cytokines in early- and mid-gestation of normal human pregnancy and their association with maternal factors.

Few studies have assessed longitudinal changes in circulating cytokine levels during normal pregnancy. We have examined the natural history of maternal plasma cytokines from early- to mid-pregnancy in a large, longitudinal cohort. Multiplex flow cytometry was used to measure interleukin (IL)-2, IL-6, IL-12, tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma and granulocyte-macrophage colony-stimulating factor (GM-CSF) in early- (median [IQR]: 8.5 weeks [7.1, 10.0]) and mid-pregnancy (25.0 [24.1, 26.1]) from 1274 Danish women delivering singleton term infants. GM-CSF decreased from early- to mid-pregnancy (median percent change [95% CI]: -51.3% [-59.1%, -41.8%]), while increases were observed in IL-6 (24.3% [4.6%, 43.9%]), IL-12 (21.3% [8.9%, 35.7%]) and IFN-gamma (131.7% [100.2%, 171.6%]); IL-2 (-2.8% [-11.5%, 0.0%]) and TNF-alpha (0% [-5.9%, 25.6%]) remained stable. Positive correlations were found between all cytokines, both in early- and mid-pregnancy (all p<0.001). Early- and mid-pregnancy levels were rank-correlated for IL-2, IL-12, TNF-alpha and GM-CSF, but not IL-6 and IFN-gamma; these correlations were generally weaker than correlations between different cytokines at a single time point in pregnancy. Women with a pre-pregnancy BMI <18.5 had reduced levels of IFN-gamma and GM-CSF compared to women in other BMI categories, while women aged >or=35 years had elevated IL-2, IL-6, TNF-alpha and IFN-gamma. Early-pregnancy levels of TNF-alpha were higher in women with a prior preterm delivery. Cytokine levels were not associated with gravidity. In conclusion, cytokines were detected in plasma during early- and mid-pregnancy, with IL-6, IL-12, IFN-gamma and GM-CSF concentrations varying over pregnancy. Concentrations may depend on BMI, maternal age and prior preterm delivery.

DefibViz: a visualization tool for the assessment of electrode parameters on transthoracic defibrillation thresholds.

DefibViz is a software application developed for defibrillation simulation and visualization. It exploits both surface techniques and methods for the interactive exploration of volumetric datasets for the analysis of transthoracic defibrillation simulation results. DefibViz\ has a graphical user interface for the specification of the shape, size, position, and applied voltage of a defibrillator's electrodes. An option is provided for using 3-D slice plane widgets, which operate on the volumetric datasets, such that the distribution of the voltage gradient induced by an electric shock can be visually inspected in various tissues throughout the myocardium and torso. One goal of DefibViz is to enhance understanding of how electrode parameters relate to the change of the voltage gradient distribution throughout the heart, which may help lead to optimal defibrillator design. DefibViz; is significant, in that, it is built by using an open-source graphics and visualization framework providing a platform for subsequent modifiability and extensibility. Moreover, it integrates simulation and visualization techniques, which previously required the running of several independent software executables, into an enhanced, seamless, and comprehensive software application.

Evaluation of hibergene loop-mediated isothermal amplification assay for detection of group B streptococcus in recto-vaginal swabs: a prospective diagnostic accuracy study.

OBJECTIVES: To prospectively evaluate HiberGene's loop-mediated isothermal amplification (LAMP) assay for detection of group B streptococcus (GBS) in maternal recto-vaginal swabs and compare it with enrichment culture. METHODS: Following ethical approval and informed written consent, two low vaginal and rectal swabs were obtained from 400 pregnant women. One swab was tested for GBS using the rapid LAMP assay (index test), the second swab was tested using enrichment culture (reference standard). Antimicrobial susceptibility testing was performed according to EUCAST guidelines. RESULTS: There were 376 concordant results, 20 discordant and four invalid LAMP results. Among discordant results, six were LAMP negative/culture positive and 14 were LAMP positive/culture negative. The sensitivity was 92.2%, specificity 95.6%, positive predictive value 83.5% and negative predictive value 98.1%. The prevalence of GBS carriage was 19.25% (77/400). Forty-eight of 77 GBS-positive women were colonized vaginally (62.3%) and 70 were colonized rectally (90.9%). Erythromycin resistance was 22.4% (17/76) and clindamycin resistance was 17.1% (13/76). CONCLUSIONS: The LAMP assay is a rapid and simple test with results available in approximately 1 h compared with 48 h for culture. The test has good sensitivity and specificity compared with enrichment culture. This test can be used for rapid antenatal GBS screening.

Sequence analysis reveals homology between two proteins of the flagellar radial spoke.

Flagellar radial spokes contribute to the regulation of dynein arm activity and thus the pattern of flagellar bending. We have sequenced the genes for radial spoke protein 4 (RSP4) and RSP6, two of the five proteins that make up the radial spoke head in Chlamydomonas reinhardtii. The two genes, which are tightly linked genetically (B. Huang, G. Piperno, Z. Ramanis, and D.J.L. Luck, J. Cell Biol. 88:80-88, 1981), are separated by only 435 bp. They encode proline-rich polypeptides of 49.8 kDa (RSP4) and 48.8 kDa (RSP6), which are 48% identical to each other but do not resemble any previously sequenced proteins. The transcription start sites of these genes and an additional radial spoke protein gene, that for RSP3, were determined, and patterns of mRNA accumulation during flagellar regeneration were examined for the three radial spoke protein genes. These studies provide the molecular tools for a detailed analysis of radial spoke head function and assembly and for a determination of the mechanism by which the genes required to build a complex organelle are regulated.

Novel alterations in CDK1/cyclin B1 kinase complex formation occur during the acquisition of a polyploid DNA content.

The pathways that regulate the S-phase events associated with the control of DNA replication are poorly understood. The bone marrow megakaryocytes are unique in that they leave the diploid (2C) state to differentiate, synthesizing 4 to 64 times the normal DNA content within a single nucleus, a process known as endomitosis. Human erythroleukemia (HEL) cells model this process, becoming polyploid during phorbol diester-induced megakaryocyte differentiation. The mitotic arrest occurring in these polyploid cells involves novel alterations in the cdk1/cyclin B1 complex: a marked reduction in cdk1 protein levels, and an elevated and sustained expression of cyclin B1. Endomitotic cells thus lack cdk1/cyclin B1-associated H1-histone kinase activity. Constitutive over-expression of cdk1 in endomitotic cells failed to re-initiate normal mitotic events even though cdk1 was present in a 10-fold excess. This was due to an inability of cyclin-B1 to physically associate with cdk1. Nonetheless, endomitotic cyclin B1 possesses immunoprecipitable H1-histone kinase activity, and specifically translocates to the nucleus. We conclude that mitosis is abrogated during endomitosis due to the absence of cdk1 and the failure to form M-phase promoting factor, resulting in a disassociation of mitosis from the completion of S-phase. Further studies on cyclin and its interacting proteins should be informative in understanding endomitosis and cell cycle control.

Detection of pigeon circovirus in cloacal swabs: implications for diagnosis, epidemiology and control.

Pigeon circovirus (picv) was detected in cloacal swab samples by means of a newly-developed, sensitive pcr. An initial investigation of 17 Belgian racing pigeons aged up to eight months showed that rates of detection of 88 per cent and above were achieved using samples of cloacal swab, blood and bursa of Fabricius. The sampling of 15 caged pigeons six times when they were from three to 31 weeks of age indicated that picv infections were more readily detected in cloacal swabs than in blood, and that the virus could be detected in cloacal swabs for longer periods after infection than in blood. picv infections were detected in cloacal swabs from 38 of 47 young pigeons aged from two to 31 weeks, from 12 racing lofts, which had clinical signs including diarrhoea and weight loss, regurgitation and respiratory signs. Samples from birds from two infected lofts indicated that picv could be detected in some birds for at least 27 weeks. Although nine of 14 pigeons aged from 32 to 45 weeks were virus-positive, picv was detected in only one of 18 adult pigeons that originated from four infected lofts.

Substrate effect on refractive index dependence of plasmon resonance for individual silver nanoparticles observed using darkfield microspectroscopy.

We use optical darkfield micro-spectroscopy to characterize the plasmon resonance of individual silver nanoparticles in the presence of a substrate. The optical system permits multiple individual nanoparticles to be identified visually for simultaneous spectroscopic study. For silver particles bound to a silanated glass substrate, we observe changes in the Plasmon resonance due to induced variations in the local refractive index. The shifts in the plasmon resonance are investigated using a simple analytical theory in which the contributions from the substrate and environment are weighted with distance from the nanoparticle. The theory is compared with experimental results to determine a weighting factor which facilitates modeling of environmental refractive index changes using standard Mie code. Use of the optical system for characterizing nanoparticles attached to substrates for biosensing applications is discussed.

New data on the transmission of pigeon circovirus.

Nineteen racing pigeons aged from one to five years were examined postmortem. pcr tests showed that the spleens of 16 of them were positive for pigeon circovirus, the livers of six were positive, and blood from one of them was positive for the virus. Five of 44 embryos in embryonated eggs collected from three lofts were positive by pcr, but swabs taken from the crops of 64 adult birds which were feeding one- to 10-day-old squabs in these three lofts were negative for the viral dna.

Prevalence of gonococcal conjunctivitis in adults and neonates.

PURPOSE: To report the prevalence of gonococcal conjunctivitis (GC) presenting to a tertiary referral maternity hospital (NMH) and a tertiary referral ophthalmic hospital (RVEEH) from 2011 to 2013 and describe the demographics, clinical presentation, and antibiotic susceptibility of Neisseria gonorrhoeae ocular infections. METHODS: Demographic, clinical, and microbiological data were collected from patients with laboratory confirmed GC. RESULTS: There were 27 556 live births at NMH during the study period, and no case of neonatal GC was identified. Fourteen cases of GC were identified at RVEEH in this period, representing a prevalence of 0.19 cases per 1000 eye emergency attendees. Antibiotic susceptibility data were available on nine cases, of which, all were ceftriaxone- and ciprofloxacin sensitive. 64.3% of patients were male, with a mean age of 18 years. The mean duration of symptoms was 3 days. All patients presented with unilateral conjunctival injection and purulent discharge. Eight cases had visual impairment at presentation and their mean visual acuity was 6/15. Corneal involvement was present in 25% of patients. Uveitis was not detected. On receipt of positive culture and/or PCR results, treatment was altered in two thirds of patients. All patients were referred for full STI screening and all patients showed a full clinical recovery 1 week posttreatment. CONCLUSION: We observed that GC presented in young adults with a male predominance and was rare in neonates. In cases of unilateral purulent conjunctivitis, there should be a high clinical suspicion of GC, early swab for PCR and culture, and knowledge of current CDC-recommended antibiotic guidelines.

Threshold duration of ischemia for myogenic tone in middle cerebral arteries: effect on vascular smooth muscle actin.

BACKGROUND AND PURPOSE: We investigated the effect of different periods of ischemia on the myogenic tone of middle cerebral arteries (MCAs) and tested the hypothesis that ischemia disrupts the actin cytoskeleton in vascular smooth muscle. METHODS: The MCA occlusion model was used in male Wistar rats (n=27) to induce different periods of ischemia (15, 30, and 120 minutes) with 24 hours of reperfusion. Successful occlusion was determined by laser-Doppler flowmetry. MCAs were then studied in vitro with a specialized arteriograph system that allowed control of transmural pressure and measurement of lumen diameter. After equilibration for 1 hour at transmural pressure of 75 mm Hg, lumen diameter was measured, and the amount of spontaneous myogenic tone was determined. Arteries were then fixed with 10% formalin while still pressurized in the arteriograph bath and stained for filamentous (F-) actin with fluorescently labeled phalloidin, a specific probe for F-actin. The amount of F-actin was quantified by confocal microscopy. RESULTS: The amount of tone was similar between control and 15 minutes of ischemia (27.0+/-2.0% and 25.3+/-1.7%, respectively; P>0.05) but was significantly diminished after 30 and 120 minutes (11.7+/-2.0% and 8.5+/-2.0%, respectively; P<0.01 versus control). F-actin content also decreased at the longer ischemic periods and correlated significantly with vascular tone (P=0.04) such that the lesser the tone, the lesser was the F-actin content. Fluorescence intensity for control and 15, 30, and 120 minutes of ischemia was (x10(7)) 3.21+/-0.25, 2.54+/-0.32 (P>0.05), 2.32+/-0.15 (P<0.01), and 2.22+/-0.16 (P<0.01), respectively. CONCLUSIONS: These results demonstrate that ischemia disrupts the actin cytoskeleton in smooth muscle and diminishes vascular tone of MCAs in a threshold-dependent manner. This effect likely exacerbates brain tissue damage during stroke, including infarction and edema formation.

The reliability of activated partial thromboplastin time methods and the relationship to lipid composition and ultrastructure.

Wide variations in procoagulant properties, lipid composition and ultrastructure of five commonly used APTT methods have been demonstrated. Performance of the methods with a range of coagulation abnormalities has been ranked. Most of the reagents obtained a high score with one or more defects, but a low score with others. A consistent good ranking throughout was only observed with one reagent. The number of significant correlations between the reagents' procoagulant activities and lipid content confirms the view that the performance of an APTT method is largely dependent upon its lipid composition. Marked differences in concentration and distribution of phospholipids, fatty acids and neutral lipids were evident. The importance of the concentration of phosphatidyl serine in regulating the procoagulant activity of an APTT method has been demonstrated. Electron microscopy provides evidence of the contrasting composition of the reagents from the more discrete uniform liposomes present in the more reliable reagents, to more ill-defined components present in those reagents which performed less well. The study highlights the need for standardisation of the APTT.

Illicit drug use in one's social network and in one's neighborhood predicts individual heroin and cocaine use.

PURPOSE: The nature of competing social environmental factors' influence on substance abuse is unclear. A longitudinal study was undertaken to determine the relative power of social network and neighborhood characteristics to predict continuing illicit drug use. METHODS: Three hundred forty-two inner-city adults with a history of injection drug use were followed for 1 year; their heroin and cocaine use were assessed semiannually. Multiple logistic regression models were fit to determine the degree to which social network and neighborhood characteristics, assessed at baseline, predicted continuing heroin and/or cocaine use throughout the study period. RESULTS: Two hundred thirty-six (69%) participants reported continuing heroin and/or cocaine use. Drug use by members of the social network was a stronger predictor of participants' continuing drug use (OR = 4.31, 95% CI 2.51 to 7.40) than was a high level of drug-related arrests in the participant's neighborhood (OR = 2.41, 95% CI 1.24 to 4.71), after adjusting for drug treatment and demographic variables. Both seemed to have independent effects on study participants' drug use. CONCLUSIONS: These findings reiterate the importance of breaking ties with drug-using associates, even for those who reside in high-risk environments. Further work is needed to develop interventions that increase drug users' success in altering social network composition or also treat drug-using network members.

Evaluation of a commercial ELISA for detecting Norwalk-like virus antigen in faeces.

A commercially available enzyme immunoassay, the IDEIA Norwalk-like virus (NLV) enzyme linked immunosorbent assay (ELISA; Dako Cytomation, Ely, UK) for detecting NLV antigen in faecal samples and determining the NLV genogroup was evaluated. The performance of the ELISA was compared with that of electron microscopy and the reverse transcription polymerase chain reaction by testing a panel of faecal samples collected from patients involved in outbreaks of gastroenteritis. When compared with reverse transcription-polymerase chain reaction (RT-PCR), the ELISA had a sensitivity and specificity of 55.5 and 98.3%, respectively. This compares with a sensitivity and specificity for EM of 23.9 and 99.2%, respectively. The sensitivity and specificity of the ELISA for determining the aetiology of a Norwalk virus-like outbreak, based on two or more positive samples within an outbreak, were 52.2 and 100% when two samples were collected from an outbreak and 71.4 and 100% when six or more samples were collected. The ELISA correctly identified the NLV genogroups of viruses previously characterised by partial DNA sequencing. The ELISA is a suitable alternative to the preliminary screening by EM for investigating outbreaks of gastroenteritis. Outbreaks, negative by ELISA should be examined by RT-PCR in order to detect strains non-reactive in the assay and virus strains from representative ELISA positive outbreaks should be characterised fully to allow the genetic diversity of NLVs co-circulating in the population to be described.

National epidemic of Lordsdale Norovirus in the UK.

BACKGROUND: In early 2002 reports of outbreaks of gastroenteritis reached unprecedented levels in the UK. Forty five Norovirus outbreaks were reported in January 2002. OBJECTIVES: The objective of the study was to determine whether the outbreaks were Noroviral in origin and if so whether they represented a homogeneous or heterogeneous collection of Noroviruses by applying EIA and sequence analysis to representative faecal samples. STUDY DESIGN: Faecal specimens were collected during the week of highest incidence from 21 outbreaks in a variety of health care settings including hospitals and nursing homes. The outbreaks occurred in geographically distinct regions of the UK and samples were collected by reference laboratories in Glasgow, Manchester, Bristol and Southampton. RESULTS: The samples were all positive for Noroviruses by negative stain electron microscopy (EM) and Lordsdale virus (LV) EIA, therefore reverse transcriptase polymerase chain reaction (RT-PCR) amplification and nucleotide sequencing of the Norovirus RNA polymerase gene was performed on amplicons from samples of each of the 21 outbreaks to investigate the nature and extent of diversity. All samples were very closely related to the reference Lordsdale virus genome sequence. LV was first discovered during an hospital outbreak of gastroenteritis in Southampton General Hospital in March 1993. CONCLUSIONS: Noroviruses are a major cause of outbreaks of gastroenteritis in health care settings. LV is the predominant Norovirus in the UK and was detected in outbreaks that occurred during the national peak of gastroenteritis reports in January 2002.

Evidence for in vivo mitosis by granule-containing mast cells from canine mastocytomas.

Mast cell accumulations are generally considered to arise almost exclusively from the recruitment of non-granulated, bone-marrow-derived, precursor cells, with the stem cell factor (SCF) reported to play a crucial role in the growth, development and maturation of granulated mast cells within specific tissue sites. In this study dog mastocytoma specimens have been examined by both immunohistochemical and ultrastructural techniques, to demonstrate that fully granulated mast cells are capable of mitotic activity. Observations showing the formation of mitotic spindles, chromosome separation and cytokinesis all support the concept that granulated mast cells are capable of proliferative activity. The ability of mature granulated mast cells to replicate provides an alternative process for local increases in mast cell numbers, at least in canine mast cell tumours. Such observations suggest the possibility that normal or neoplastic human mast cells, fully granulated, have the potential to proliferate in specific tissue sites.

Pneumocystis carinii pneumonia: a light microscopical and ultrastructural study.

A case of Pneumocystis carinii pneumonia developing a patient with treated diffuse lymphocytic lymphoma is described. The electron microscopic features and life cycle of the organism are illustrated. The patient died twenty-four hours after the biopsy had been taken. Septrin appeared to have affected the trophozoite stage. Pneumocystis carinii appears to induce interstitial pulmonary oedema and fibrosis. A discussion of the role of electron microscopy in early diagnosis of the disease is presented.

Cryptosporidium species a "new" human pathogen.

Publications describing aspects of the coccidian protozoan parasite Cryptosporidium, increased greatly during 1983 and 1984 as a result of not only increasing veterinary interest but also in the role of the parasite in the newly recognised acquired immune deficiency syndrome (AIDS). The reports reflected widespread collaboration, not only between clinicians, microbiologists, and histopathologists, but also between veterinary and human health care workers. Cryptosporidium was first described in mice in 1907 and subsequently in various other species; it was not described in man until 1976. Several likely putative species have been described, but there is probably little host specificity. Experimental and clinical studies have greatly increased the knowledge about the organism's biology. The parasite undergoes its complete life cycle within the intestine, although it may occasionally occur in other sites. The main symptom produced is a non-inflammatory diarrhoea, which, in patients with AIDS and children in Third World countries, may be life threatening: even in immunocompetent subjects this symptom is usually protracted. Attempts to find effective chemotherapeutic agents have been unsuccessful. Epidemiologically the infection was thought to be zoonotic in origin, but there is increasing evidence of person to person transmission. Diagnosis has depended upon histological examination, but simple methods of detection have now been described: more invasive methods need no longer be used. The parasite, which is found more commonly in children, occurs in about 2% of faecal specimens examined and seems to be closely associated with production of symptoms. A serological response has been shown. Much remains to be learned about its epidemiology and pathogenic mechanisms, while the expected increase in incidence of AIDS makes an effective form of treatment essential.

Spinous injury caused by a sea urchin.

A bather on holiday in Kenya injured a finger on a spiny marine creature living on the sea bed. A skin biopsy specimen from the injured finger contained several black spines about 0.5 mm in diameter and up to 1.5 cm in length. Spines removed from the specimen were embedded in plastic resin to facilitate transverse sectioning. Light microscopical examination using crossed polarisers showed an ornate symmetrical structure brightly illuminated against a dark background. These features are characteristic of sea urchin (Echinoderm) spines which are composed of ornately formed calcite crystals covered by an epithelium. The spines of sea mice, on the other hand, are chitinous in nature; they are also much finer and lack the ornate symmetry of sea urchin spines.