Modulation of cytokine production from an EpiOcular corneal cell culture model in response to Staphylococcus aureus superantigen

The present study investigated the hypothesis that Staphylococcus aureus enterotoxin B (SEB) produces epithelial cell death and releases inflammatory cytokines that produce stromal infiltration during contact lens induced peripheral ulceration. Epithelial cells were incubated with different doses of SEB for various time periods. Culture supernatants were assayed for cytokines IL-1 beta, IL-6 and chemotactic agents IL-8 and LTB4 SEB induced the production of IL-1 beta and IL-8. Epithelial cells exposed for longer periods (48 h) with low concentrations of SEB produced significantly higher levels (P < 0.02) of IL-1 beta and IL-8 (P < 0.05) compared to a 24 h exposure. SEB did not induce the production of IL-6 and LTB4.

High rates of genital mycoplasma infection in the highlands of Papua New Guinea determined both by culture and by a commercial detection kit

Duplicate vaginal swabs were collected from 100 women, and comparisons were made between an in-house broth-agar culture system and a commercially available kit, the Mycoplasma IST kit (bioMérieux), for the detection of Mycoplasma hominis and Ureaplasma urealyticum. There was good agreement between the two systems for detection of the genital mycoplasmas in terms of sensitivity, with values of > 92% being obtained. In terms of specificity, the mutual comparisons were less favorable, though specificity values of > 72% were obtained. Statistically there was no significant difference in the performance of the two tests (P < 0.1 for both M. hominis and U. urealyticum). While the broth-agar culture system was considerably less expensive than the kit, the Mycoplasma IST kit provided additional information on antibiotic susceptibilities and had the advantages of a shelf life of up to 12 months and not requiring the preparation of culture media. The prevalences of colonization obtained for M. hominis and U. urealyticum were extremely high in this randomly selected group of women from periurban and rural settlements in the Eastern Highlands of Papua New Guinea, being > or = 70% for M. hominis and > or = 78% for U. urealyticum. colonization with both genital mycoplasmas simultaneously was also very common, with > or = 60% of women being colonized by both M. hominis and U. urealyticum.

High prevalence of trichomonal vaginitis and chlamydial cervicitis among a rural population in the highlands of Papua New Guinea

We conducted a community-based study of the prevalence of sexually transmitted diseases in rural and periurban communities in Eastern Highlands Province. We interviewed a stratified random sample of women and men, examined the women for evidence of sexually transmitted diseases (STDs) and collected specimens for diagnosis of syphilis, by serology and dark-field microscopy, gonorrhoea, by Gram stain and culture, chlamydial infection, by polymerase chain reaction (PCR) and direct immunofluorescence (DIF), trichomoniasis, by wet mount, and bacterial vaginosis, by wet mount and Gram stain. The men were tested for chlamydial infection only (first void urine tested by PCR and DIF). 201 women and 169 men were tested. Additionally, adults in the same communities who had not been randomly selected were offered the same services. An extra 243 women and 85 men were tested in this way. The laboratory results confirmed the clinical impression of an extremely high prevalence of STDs in this population. Among those randomly selected, 46% of the women had trichomonal vaginal infections and 26% had Chlamydia trachomatis infections detected by PCR, while 25% of the men had chlamydial infections. Other infections were much less common. 58% had one or more STDs. The prevalence of infection in self-selected adults was similar to that found in those randomly selected.

Molecular analysis of isolates of Salmonella typhi obtained from patients with fatal and nonfatal typhoid fever

Molecular characterization of a total of 52 human isolates of Salmonella typhi from Papua New Guinea was performed by using pulsed-field gel electrophoresis (PFGE) after digestion of chromosomal DNA with three restriction endonucleases, XbaI (5'-TCTAGA-3'), AvrII (5'-CCTAGG-3'), and SpeI (5'-ACTAGT-3'). Of the 52 isolates tested, 11 were obtained from patients with fatal typhoid fever and 41 were obtained from patients with nonfatal disease. The 52 isolates showed limited genetic diversity as evidenced by only three different PFGE patterns detected following digestion with XbaI (patterns X1 to X3; F [coefficient of similarity] = 0.86 to 1.0), four patterns detected following digestion with AvrII (patterns A1 to A4; F =0.78 to 1.0), and two patterns detected following digestion with SpeI (patterns S1 and S2; F = 0.97 to 1.0). Of the 52 isolates, 37 were phage typed, and all belonged to phage type D2. All 11 isolates obtained from patients with fatal typhoid fever were identical (F = 1.0) and possessed the PFGE pattern combination X1S1A1, whereas the 41 isolates from patients with nonfatal typhoid fever had various PFGE pattern combinations, the most common being X2S1A2 (39%), X1S1A1 (24%), and X1S1A2 (15%). Thus, all the isolates from patients with the fatal disease had the X1 and A1 patterns, whereas the majority of the isolates from patients with nonfatal typhoid fever possessed the X2 and A2 patterns. The data suggest that there is an association among strains of S. typhi between genotype, as assessed by PFGE patterns, and the capability to cause fatal illness. Analysis of blood and fecal isolates of S. typhi from the same patient also indicated that some genetic changes occur in vivo during the course of infection.

The role of the laboratory in the diagnosis and management of typhoid fever

In typhoid-endemic areas the results obtained from the laboratory are important in confirming the clinical diagnosis of typhoid and may also contribute to decisions made on the management and treatment of typhoid cases. Isolation of Salmonella typhi remains the gold standard, with culture from bone marrow aspirate or a combination of specimens from other body sites resulting in the greatest sensitivity. Antibody detection techniques may still provide valuable information, but only if the results are interpreted in the context of the background antibody levels in the local population. None of the available antigen detection techniques have been consistently demonstrated to be of diagnostic value and a recently developed polymerase chain reaction (PCR) for the detection of Salmonella typhi has yet to undergo a full-scale clinical evaluation. The initial identification of chronic typhoid carriers relies upon the detection of elevated Vi capsular antibody levels, but seeking out chronic carriers will be of limited value in controlling the spread of typhoid in areas where transmission is principally mediated by convalescent excretors. Whilst resistance of Salmonella typhi to antibiotics has emerged as an increasing problem in some areas of the world, it is still uncommon in isolates from Papua New Guinea. However, monitoring of antibiotic susceptibility patterns will ensure that signs of developing resistance are detected early and that the appropriate action is taken.

Re-evaluation of the Widal agglutination test in response to the changing pattern of typhoid fever in the highlands of Papua New Guinea

In 1992 it was decided to re-evaluate the Widal slide agglutination test as a rapid diagnostic test for typhoid fever in Papua New Guinea. This was in response to an apparent increase in the number of false positive Widal slide agglutinations occurring using an O cut-off titre greater than or equal to 40 which was previously shown to be appropriate in 1987. The results of the re-evaluation indicated that the Widal test using a diagnostic cut-off titre of > or = 40 lacked specificity and was no longer appropriate for this population. A new O antibody titre of > or = 160 was recommended as a diagnostic titre for typhoid fever in PNG. The fall in the specificity of the Widal slide agglutination test over the five-year period between the initial assessment and the re-evaluation is due to an increase in general population antibody levels caused by the changing pattern of typhoid in the community. Before 1987 typhoid fever occurred as sporadic, isolated outbreaks and most people living in the highlands of PNG were immunologically naive. By 1992 typhoid fever had become a well-established endemic disease and many more people had been exposed to Salmonella typhi and as a result developed antibodies. We have been able to demonstrate clearly a remarkable change in the immune status of the community, in which the proportion of healthy individuals with a Widal tube O agglutination titre of 40 or more rose from 0 to 56% in the short span of five years.(ABSTRACT TRUNCATED AT 250 WORDS)

The inhibitory effect of spermicidal agents on replication of HSV-2 and HIV-1 in-vitro

Five spermicides including nonoxynol-9 were assessed under in-vitro conditions, for their inhibitory activity against two viruses capable of spread by sexual intercourse, herpes simplex virus type-2 (HSV-2) and the human immunodeficiency virus type-1. A further eight commercially-available spermicidal preparations containing varying concentrations of either nonoxynol-9 or nonoxynol-11 were also assessed for activity against HSV-2. All spermicides and spermicidal preparations tested showed inhibitory activity against both viruses over periods of time ranging from 30 sec to 5 min. This activity was dependent on the concentration of spermicide to which the viruses were exposed.

The carriage of Streptococcus suis type 2 by pigs in Papua New Guinea

An indirect fluorescent antibody test was used to detect the presence of Streptococcus suis type 2 in nasal and pharyngeal swabs taken from pigs in Papua New Guinea. The rate of carriage for the two sites in domesticated indigenous village pigs was 0.5 and 2.5% respectively, compared to 39 and 43% for intensively reared pigs. These findings were supported by the results of a serological survey, using an enzyme linked immunosorbent assay, in which 87% of intensively reared pigs but only 8% of village pigs were seropositive to S. suis type 2. It is proposed that in intensive piggeries S. suis type 2 is continually cycled between pigs. In village pigs, the low population density and harsh environmental conditions prevents this cycle of infection.

Ecological and individual effects in childhood immunisation uptake: a multi-level approach

Analyses of childhood immunisation uptake have traditionally been conducted at either the ecological or the individual scale. In this paper the problems stemming from these distinct strategies are explored and the potential of a multi-level modelling approach taking simultaneous account of processes at both levels is discussed. This discussion is set in the context of a case-study of pertussis immunisation uptake using data gathered from routine child health surveillance and immunisation uptake monitoring. The role of multi-level modelling in medical geographic research is briefly evaluated.

Retrospective study of temperature rhythms of intensive care patients

The hourly rectal temperature record of 15 patients who spent greater than or equal to 8 days in the ICU were analyzed for circadian rhythmicity. Using cosinor analysis, a statistically significant rhythm in a period of 24 h was present on 80% of the patient days studied. The position of the acrophase, or peak, of the rhythm varied markedly both between patients and within patients, with changes of several hours from day to day. There was a tendency for the amplitude of the rhythm to be greater when the patients were unconscious than when they were conscious and in those patients who died compared with those who survived.

Suppression of natural and activated human antitumour cytotoxicity by human seminal plasma

The influence of human seminal plasma (SP) and whole semen (S) on the expression of natural cytotoxicity by human peripheral blood mononuclear cells (PBMNC) was examined. Marked suppression of natural cytotoxicity against K562 targets was observed when effectors were pre-treated for 1 h with SP or S diluted up to 1:400. Abrogation of cytolytic activity by SP was not the result of direct lymphotoxicity, although a reduction of approximately 50% in the number of target binding cells was observed. In addition, the cytotoxicity of interferon (alpha-IFN, beta-IFN, gamma-IFN) and interleukin 2 (IL-2) activated human PBMNC was suppressed by components present in human SP, although IL-2 activated human PBMC were relatively resistant to suppression compared with other effector (spontaneous or activated) populations. Following 1 h exposure to SP, PBMNC failed to recover more than 25% of their initial cytotoxic potential upon further in vitro incubation (18 h) in the absence of SP. However, both interferon and IL-2 caused an increase in the cytotoxicity of these populations, in some instances to the level obtained with control, IFN or IL-2 activated PBMNC. The biological significance of SP as an inhibitor of immune function under experimentally defined conditions is discussed in relation to its possible role in vivo.

The calmodulin content of normal and leukaemic lymphocytes

Normal human peripheral blood mononuclear cells (PBMC) and leukaemic cell lines (three of human and one of gibbon origin) were found to contain similar levels of calmodulin (CaM) when expressed relative to the total cell protein. Two of the cell lines examined further were found to contain much higher amounts of CaM per cell (up to 5-fold) than PBMC but this was readily explained by their much greater cell size. Variations in CaM levels were noted during culture of both PBMC and leukaemic cells which were apparently independent of the percentage of cells undergoing active division in these cultures. These results do not support the contention that transformed cells contain a higher proportion of CaM than normal cells.

Natural killer cell activity and response to phytohaemagglutinin compared with the histological diagnosis of patients with transitional cell carcinoma of the bladder

In vitro tests of immune reactivity in patients with transitional cell carcinoma (TCC) of the urinary bladder were compared with the clinical and histological diagnosis. Response of peripheral blood lymphocytes to the mitogen phytohaemagglutinin (PHA) tended to be reduced in patients with more advanced disease, although the difference between patients with advanced disease and those with early disease or controls was not statistically significant (P greater than 0.05). Assessment of natural killer (NK) cell activity in the same patients showed no change in levels of reactivity at any stage of the disease. There was no difference between the NK cell activity of patients with TCC of the bladder and normal controls.

Studies on the antitumour effects of N-137

The antitumour properties of the drug N-137 were assessed in vivo in two murine T lymphoma models and two naturally metastatic hamster fibrosarcomas of Herpesvirus hominis aetiology. N-137 therapy caused a significant delay in the subcutaneous growth rate of both lymphomas (EL4 and TLX9) and in many cases completely prevented tumour appearance when administered at high doses. The antitumour effect observed in both systems was shown to be dose dependent. In contrast, N-137 therapy failed to influence the growth of two hamster fibrosarcomas (HSV-333-2-26 Met A and Met B lines), and drug administration prior to or following resection of Met B tumours failed to influence the development of natural metastases as measured by monitoring animal survival.

Standards of cleansing and sterilization of infant feeding utensils in the home

Microbiological standards achieved by mothers when sterilizing babies' feeding utensils in the home were studied in the Slough area in England. Results indicated a marked improvement in this aspect of baby hygiene when compared to results of a similar survey conducted in the town of Reading, England, in 1970. Previously, 78% of bottles and 70% of the teats were recorded as being satisfactorily sterilized. During this study the number of sterile bottles had risen to 98.1%, sterile teats to 90-6%. These improved standards may be an indication of better education of mothers.