Biotype traits and antibiotic susceptibility of Vibrio cholerae serogroup O1 before, during and after the emergence of the O139 serogroup.

Sixty-nine strains of Vibrio cholerae O1 isolated at different times were analysed to investigate if there were any differences among the O1 strains isolated before, during and after the advent of the O139 serogroup. Of the 69 O1 strains examined, 68 belonged to the Ogawa serotype while one belonged to the Inaba serotype. With the exception of one strain all other strains of V. cholerae O1 belonged to the eltor biotype. A single O1 strain isolated before the emergence of the O139 serogroup could not be classified as either eltor or classical biotype because it was resistant to both classical and eltor specific bacteriophages. Marked variations in the susceptibility to antibiotics of V. cholerae O1 isolated during the different periods were observed. In addition, strains of V. cholerae isolated after the epidemic of serogroup O139 in Calcutta showed an expanding R-type with resistance to a variety of drugs as compared to the O1 strains isolated before the advent of the O139 serogroup. From this study, it is clear that there is a substantial mobility in genetic elements of V. cholerae O1 which necessitates a continuous monitoring to keep abreast of the changing traits of the etiologic agent of cholera.     

Subchronic rat inhalation study with Skydrol 500B-4 fire resistant hydraulic fluid.

Skydrol 500B-4 fire resistant hydraulic fluid, a proprietary phosphate ester mixture composed principally of dibutyl phenyl phosphate (DBPP) and tributyl phosphate (TBP) and used as a commercial airline hydraulic fluid, was evaluated in an inhalation toxicity study of Sprague-Dawley rats. Target exposure levels used in the study were 0, 5, 100, and 300 mg/m3, and exposures were maintained for 6 hr/day, 5 days/week. Mass median aerodynamic diameters determined for particles in the mid- and high-exposure inhalation chambers were 2.85 microns and 3.31 microns, with geometric standard deviations of 1.99 microns and 1.92 microns, respectively. The percentage of particles less than 10 microns in diameter were 96.4% in the mid-exposure chamber and 95.5% in the high-exposure chamber. After 6 weeks of Skydrol exposure, 10 rats/sex/group were euthanized and then assessed for indications of possible chemical toxicity. Another 15 rats/sex/group were studied for a total of 13 weeks of exposure. The only clinical sign of chemical toxicity was the observation of a reddish nasal discharge with accompanying oral salivation in mid- and high-exposure animals of both sexes, indicative of an irritant response. Statistically significant reduced body weights; increased absolute and relative liver weights; and decreased erythrocyte counts, hemoglobin levels, and hematocrit values were observed in high-exposure female rats euthanized after 13 weeks of Skydrol exposure. High-exposure male rats also had increased absolute and relative liver weights and decreased hematocrit values after 13 weeks. Plasma cholinesterase levels were decreased in high-exposure female rats both 6 and 13 weeks after the study was initiated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Heroin-Induces Differential Protein Expression by Normal Human Astrocytes (NHA)

Heroin use is postulated to act as a cofactor in the neuropathogenesis of human immunodeficiency virus (HIV-1) infection. Astrocytes, integral components of the CNS, are reported to be susceptible to HIV-1 infection. Upon activation, astrocytes release a number of immunoregulatory products or modulate the expression of a number of proteins that foster the immunopathogenesis of HIV-1 infection. However, the role of heroin on HIV-1 infectivity and the expression of the proteome of normal human astrocytes (NHA) have not been elucidated. We hypothesize that heroin modulates the expression of a number of proteins by NHA that foster the neuoropathogenesis of HIV-1 infection. We utilized LTR amplification and the p24 antigen assay to quantitate the effect of heroin on HIV-1 infectivity while difference gel electrophoresis (DIGE) combined with protein identification through high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to analyze the effects of heroin on the proteomic profile of NHA. Results demonstrate that heroin potentiates HIV-1 replication in NHA. Furthermore, heroin significantly increased protein expression levels for protein kinase C (PKC), reticulocalbin 1 precursor, reticulocalbin 1, tyrosine 3-monooxgenase/tryptophan 5-monooxgenase activation protein, chloride intracellular channel 1, cathepsin D preproprotein, galectin 1 and myosin light chain alkali. Heroin also significantly decreased protein expression for proliferating cell nuclear antigen, proteasome beta 6 subunit, tropomyosin 3, laminin receptor 1, tubulin alpha 6, vimentin, EF hand domain family member D2, Tumor protein D54 (hD54), ATP synthase, H+ transporting, mitochondrial F1 complex and ribosomal protein S14. Identification of unique, heroin-induced proteins may help to develop novel markers for diagnostic, preventative and therapeutic targeting in heroin using subjects.     

Cross-neutralisation of Australian brown and tiger snake venoms with commercial antivenoms: Cross-reactivity or antivenom mixtures?

Recently it has been suggested that the Australian snake antivenoms made by CSL Ltd. are in fact not truly monovalent and may contain antibodies to other snake venoms because the horses are injected with multiple snake venoms. It is unclear to what extent various monovalent antivenoms can neutralise the effect of other venoms, whether this is due to a mixture of antibodies or true cross-reactivity, and whether this has any clinical significance. We aimed to study the immunological and functional properties of brown snake (Pseudonaja spp.) antivenom (BSAV) and tiger snake (Notechis spp.) antivenom (TSAV) against their respective venoms using enzyme immunoassays (EIA) and in vitro clotting studies. There was significant overlap between the two antivenoms with both TSAV and BSAV being detected by EIA on brown snake venom (BSV)-coated and tiger snake venom (TSV)-coated wells, respectively. In a competition EIA, increasing amounts of immunoaffinity-purified hen anti-brown antibodies (IgYp) mixed with TSAV reduced TSAV measured on TSV-coated wells. Both BSAV and TSAV prevented the clotting activity of both venoms. IgYp also prevented the clotting activity of TSV, suggesting true cross-reactivity. The cross-reactivity of TSAV and BSAV with BSV and TSV, respectively, was likely due to each being a mixture of anti-brown and anti-tiger antibodies, but there was partial cross-reactivity demonstrated by the effect of IgYp. Single-polyvalent antivenom for brown snake and tiger snake may be feasible in the future.     

Anovaginal and rectovaginal fistula in patients with Crohn's disease.

Between 1971 and 1991, details of 67 women with perianal Crohn's disease were recorded prospectively using the Cardiff classification. Two groups were identified according to the presence (n = 29) or absence (n = 38) of anorectal Crohn's fistula involving the vagina. Patients in both groups were of a similar age and had had Crohn's disease for a similar period before diagnosis of perianal involvement. The incidence of associated perianal lesions, superficial ulcers, cavitating ulcers, other fistulas and strictures was not significantly different between the two groups. A greater proportion of patients with anorectal-vaginal fistulation (n = 15) had distal intestinal Crohn's disease (rectal or contiguous colorectal) compared with women with no vaginal fistulation (n = 14). A range of therapies was used to manage women with perianal Crohn's disease, from local surgery to a defunctioning stoma and/or proctectomy. Only 13 of 38 women with perianal Crohn's disease but no vaginal fistula required a defunctioning stoma or proctectomy, whereas 18 of 29 with anorectal-vaginal fistulation underwent these procedures (P < 0.05). A vaginal fistula has a considerable adverse effect on the outcome of perianal Crohn's disease.     

Oligoastrocytoma presenting with intractable epilepsy.

OBJECTIVE: Oligoastrocytomas (OA) are mixed gliomas with distinct oligodendroglial and astrocytic neoplastic components. Very little about OA has been reported in the intractable epilepsy population. METHODS: We undertook a retrospective review of 923 patients who underwent resective surgery for intractable epilepsy between 1996 and 2004. RESULTS: 6/923 (0.7%) patients were diagnosed with OA. Five patients were female, one was male. Median age at diagnosis was 25 years (range 19-44 years). Tumors arose from the left side in all patients and from the temporal lobe in five patients. Three patients had complex partial seizures. Median length of refractory epilepsy prior to surgery was 10.5 years (range 1-28 years), and the median number of antiepileptic drugs used was 2 (range 1-10). Preoperative WADA testing for language and memory localization was done for three patients; preoperative stereotactical localization was done for three patients. Surgical pathology revealed low-grade OA (WHO II) in five patients, and anaplastic OA in one. There were no surgical complications, clinical or radiographic tumor recurrence at a mean follow up period of 3.2 years (range 2-8). Excellent seizure freedom was achieved in 5/6 patients. CONCLUSION: As a result of our small sample size, general conclusions may be imprecise, but this review suggests that OA behave similar to other tumors related to intractable epilepsy: they usually have a preoperative seizure course of many years, an excellent rate of seizure-freedom following surgery, and are in general, low-grade tumors with an indolent course for which serial imaging is sufficient follow-up.