A case of Conn's syndrome presenting with painfull muscular weakness.

We present a case of 30-year-old lady presenting with gradual difficulty in standing up from sitting position for 6 months, pain in arms and thighs, tingling sensation and numbness in palms and soles, increased fluid intake and increased frequency of micturition for the same duration. She was hypertensive for 12 years. On general examination patient seemed depressed and on nervous system examination her power of muscles in both upper and lower limb of both side was 3/5. Plasma sodium at the upper normal range 144mmol/l (normal range 135-146), lower level of serum potassium 1.7mmol/L (normal range 3.5-5.0), high urinary potassium 26.7mmol/l (normal range 1-10), very high serum CPK 4269U/L (for female normal range 10-79), low normal plasma rennin 1.58mg/ml/hr (normal range standing 0.40-8.80, supine 0.30-3.0), high serum aldosterone 1326.39pg/ml (normal range 25-315), high pH 7.45 (normal range 7.36-7.44) and on imaging evidence of an adrenal adenoma on left side was found and the patient was diagnosed as a case of Conn's syndrome.

Distribution and characterization of Borrelia burgdorferi isolates from Ixodes scapularis and presence in mammalian hosts in Ontario, Canada.

The blacklegged tick, Ixodes scapularis Say (Acari: Ixodidae), has a wide geographical distribution in Ontario, Canada, with a detected range extending at least as far north as the 50th parallel. Our data of 591 adult I. scapularis submissions collected from domestic animals (canines, felines, and equines) and humans during a 10-yr period (1993-2002) discloses a monthly questing activity in Ontario that peaks in May and October. The Lyme disease spirochete Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwalt & Brenner was detected in 12.9% of I. scapularis adults collected from domestic hosts with no history of out-of-province travel or exposure at a Lyme disease endemic area. Fifty-three isolates of B. burgdorferi were confirmed positive with polymerase chain reaction by targeting the rrf (5S)-rrl (23S) gene. Using DNA sequencing of the ribosomal species-specific rrf (5S) -rrl (23S) intergenic spacer region, all isolates belong to the pathogenic genospecies B. burgdorferi sensu stricto (s.s.). Nucleotide sequence analysis of a 218- to 220-bp amplicon fragment exhibits six cluster patterns and, collectively, these isolates branch into four phylogenetic cluster groups for both untraveled, mammalian hosts and those with travel to the northeastern United States (New Jersey and New York). Four of five geographic regions in Ontario had strain variants consisting of three different genomic cluster groups. Overall, our molecular characterization of B. burgdorferi s.s. shows genetic heterogeneity within Ontario and displays a connecting link to common strains from Lyme disease endemic areas in the northeastern United States. Moreover, our findings of B. burgdorferi in I. scapularis reveal that people and domestic animals may be exposed to Lyme disease vector ticks, which have wide-ranging distribution in eastern and central Canada.

Investigation of ground level and remote-sensed data for habitat classification and prediction of survival of Ixodes scapularis in habitats of southeastern Canada.

In southeastern Canada, most populations of Ixodes scapularis Say, the Lyme disease vector, occur in Carolinian forests. Climate change projections suggest a northward range expansion of I. scapularis this century, but it is unclear whether more northerly habitats are suitable for I. scapularis survival. In this study, we assessed the suitability of woodlands of the Lower Great Lakes/St. Lawrence Plain region for I. scapularis by comparing tick egg survival in four different woodlands. Woodlands where I. scapularis are established, and sand dune where I. scapularis do not survive, served as positive and negative control sites, respectively. At two woodland sites, egg survival was the same as at the positive control site, but at two of the sites survival was significantly less than either the positive control site, or one of the other test sites. Egg survival in all woodland sites was significantly higher than in the sand dune site. Ground level habitat classification discriminated among woodlands in which tick survival differed. The likelihood that I. scapularis populations could persist in the different habitats, as deduced using a population model of I. scapularis, was significantly associated with variations in Landsat 7 ETM+ data (normalized difference vegetation index [NDVI] and Tasselled Cap indices). The NDVI index predicted habitat suitability at Long Point, Ontario, with high sensitivity but moderate specificity. Our study suggests that I. scapularis populations could establish in more northerly woodland types than those in which they currently exist. Suitable habitats may be detected by ground-level habitat classification, and remote-sensed data may assist this process.

A conceptual model of water's role as a reservoir in Helicobacter pylori transmission: a review of the evidence.

Helicobacter pylori infection plays a role in the development of chronic gastritis, peptic ulcer and gastric cancer, yet the route of transmission into susceptible hosts remains unknown. Studies employing microbiological techniques have demonstrated that H. pylori has the ability to survive when introduced into water and that H. pylori is present in water and other environmental samples all over the world. Epidemiological studies have shown that water source and exposures related to water supply, including factors related to sewage disposal and exposure to animals, are risk factors for infection. This review describes the microbiological and epidemiological evidence for, and proposes a model of, waterborne H. pylori transmission outlining important features in the transmission cycle. In the model, humans and animals shed the bacteria in their faeces and the mechanisms for entry into water, and for survival, ingestion and infection are dependent upon a range of environmental influences. Verification of the proposed model pathways has important implications for public-health prevention strategies.

Chemotaxis between Vibrio cholerae O1 and a blue-green alga, Anabaena sp.

The chemotactic response of Vibrio cholerae O1 towards the mucilaginous sheath of Anabaena sp. was investigated by capillary tube method using a virulent strain of V. cholerae O1, El Tor, Ogawa (3083-T) and its isogenic mutant (HAP-1-T) that lacks the hap gene, which codes for mucinase (HA/protease). Homogenates of Anabaena sp. and purified mucin were used in this study as chemoattractants. Results showed 5.7% bacterial accumulation of wild-type V. cholerae O1 towards 4% homogenates of Anabaena sp. whereas, its mutant (hap-) showed 2.9% accumulation after 90 min. The higher percentage of attraction of wild-type V. cholerae O1 than the mutant (hap-) towards mucin and the homogenates of Anabaena sp. might be due to the activity of mucinase. These results indicate the role of mucinase in the chemotactic motility of V. cholerae O1 towards Anabaena sp.

Climate change and the potential for range expansion of the Lyme disease vector Ixodes scapularis in Canada.

We used an Ixodes scapularis population model to investigate potential northward spread of the tick associated with climate change. Annual degree-days >0 degrees C limits for I. scapularis establishment, obtained from tick population model simulations, were mapped using temperatures projected for the 2020s, 2050s and 2080s by two Global Climate Models (the Canadian CGCM2 and the UK HadCM3) for two greenhouse gas emission scenario enforcings 'A2'and 'B2' of the Intergovernmental Panel on Climate Change. Under scenario 'A2' using either climate model, the theoretical range for I. scapularis establishment moved northwards by approximately 200 km by the 2020s and 1000 km by the 2080s. Reductions in emissions (scenario 'B2') had little effect on projected range expansion up to the 2050s, but the range expansion projected to occur between the 2050s and 2080s was less than that under scenario 'A2'. When the tick population model was driven by projected annual temperature cycles (obtained using CGCM2 under scenario 'A2'), tick abundance almost doubled by the 2020s at the current northern limit of I. scapularis, suggesting that the threshold numbers of immigrating ticks needed to establish new populations will fall during the coming decades. The projected degrees of theoretical range expansion and increased tick survival by the 2020s, suggest that actual range expansion of I. scapularis may be detectable within the next two decades. Seasonal tick activity under climate change scenarios was consistent with maintenance of endemic cycles of the Lyme disease agent in newly established tick populations. The geographic range of I. scapularis-borne zoonoses may, therefore, expand significantly northwards as a consequence of climate change this century.

Role of cyanobacteria in the persistence of Vibrio cholerae O139 in saline microcosms.

Recently, a new strain of cholera, Vibrio cholerae O139, has emerged as an epidemic strain, but there is little information about its environmental reservoir. The present investigation was aimed to determine the role of cyanobacteria in the persistence of V. cholerae O139 in microcosms. An environmental isolate of V. cholerae O139 and three cyanobacteria (Anabaena sp., Nostoc sp., and Hapalosiphon sp.) were used in this study. Survival of culturable V. cholerae O139 in microcosms was monitored using taurocholate-tellurite gelatin agar medium. Viable but nonculturable V. cholerae O139 were detected using a fluorescent antibody technique. Vibrio cholerae O139 could be isolated for up to 12 days in a culturable form in association with cyanobacteria but could not be isolated in the culturable form after 2 days from control water without cyanobacteria. The viable but nonculturable V. cholerae O139 could be detected in association with cyanobacteria for up to 15 months. These results, therefore, suggest that cyanobacteria can act as a long-term reservoir of V. cholerae O139 in an aquatic environment.

Involvement of the hap gene (mucinase) in the survival of Vibrio cholerae O1 in association with the blue-green alga, Anabaena sp.

Mucinase is a soluble haemagglutinin protease, which may be important for the survival of Vibrio cholerae in association with mucilaginous blue-green algae (cyanobacteria). A comparative survival study was carried out with an Anabaena sp. and a wild-type V. cholerae O1 strain hap+ gene (haemagglutinin-protease), together with its isogenic mutant hap (hap-deleted gene). A simple spread plate technique was followed to count culturable V. cholerae O1 on taurocholate tellurite gelatin agar plate. The fluorescent antibody technique of Kogure et al. (1979) was used for the microscopical viable count of V. cholerae O1. Polymerase chain reaction (PCR) and Southern blot hybridization were carried out to detect a lower number of viable but nonculturable (VBNC) V. cholerae O1 from the laboratory-based experiments. The wild and mutant V. cholerae O1 strains survived in culturable form for 22 and 10 days. respectively, in association with the Anabaena sp., with the difference being statistically significant (P < 0.01). The fluorescent antibody technique, PCR, and hybridization results also showed that the wild strain survived better in the VBNC state than did the mutant VBNC strain in association with an Anabaena sp. These results indicate that the enzyme mucinase may play an important role in the association and long-term survival of V. cholerae O1 with a mucilaginous blue-green alga, Anabaena sp.

Birds disperse ixodid (Acari: Ixodidae) and Borrelia burgdorferi-infected ticks in Canada.

A total of 152 ixodid ticks (Acari: Ixodidae) consisting of nine species was collected from 82 passerine birds (33 species) in 14 locations in Canada from 1996 to 2000. The Lyme disease spirochete Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwaldt & Brenner was cultured from the nymph of a blacklegged tick, Ixodes scapularis Say, that had been removed from a common yellowthroat, Geothlypis trichas L., from Bon Portage Island, Nova Scotia. As a result of bird movement, a nymphal I. scapularis removed from a Swainson's thrush, Catharus ustulatus incanus (Godfrey), at Slave Lake, Alberta, during spring migration becomes the new, most western and northern record of this tick species in Canada. Amblyomma longirostre Koch, Amblyomma sabanerae Stoll, and Ixodes baergi Cooley & Kohls are reported for the first time in Canada. Similarly, Amblyomma americanum L., Arnblyomma maculatum Koch, and ixodes muris Bishopp & Smith are reported for the first time on birds in Canada. After removal of an I. muris gravid female from a song sparrow, Melospiza melodia Wilson, at St. Andrews, New Brunswick, eggs were laid, which developed into larvae, and this new tick-host record demonstrates that birds have the potential to start a new tick population. We conclude that passerine birds disperse several species of ixodid ticks in Canada, and during spring migration translocate ticks from the United States, and Central and South America, some of which are infected with B. burgdorferi.

Evaluation of Teknaf Enteric Agar (TEA): A modified MacConkey's Agar for the isolation of Shigella dysenteriae type 1 and Shigella flexneri.

To develop a better and selective medium for the isolation of Shigella spp., MacConkey's Agar (MAC) was modified by adding potassium tellurite (K2TeO3) at a concentration of 1 microgram/ml. The formulation designated Teknaf Enteric Agar (TEA) was studied for the inhibitory effect of potassium tellurite on the growth of different enteric bacteria, and as a medium for isolating Shigella spp. from clinical stool samples (n = 3125). We observed that the growth of E. coli was effectively inhibited on TEA with no effect on the growth of S. dysenteriae type 1 and S. flexneri. A total of 2019 Shigellae were isolated through the combined use of TEA, MAC, and Salmonella-Shigella Agar (SS). On TEA, 1921 S. dysenteriae type 1 and S. flexneri were isolated as compared to 1765 from the combined use of MAC and SS. A total of 194 of S. dysenteriae type 1 and S. flexneri were exclusively isolated from TEA as compared to 38 which were only made from MAC and SS. We conclude that TEA significantly increased the overall isolation rate of Shigella spp. as compared to the combined use of MAC and SS (P < 0.0001), although it is not suitable for the isolation of S. sonnei.

Protective activity of Borrelia duttonii-specific immunoglobulin subclasses in mice.

To analyse the immune response of mice to Borrelia duttonii infection, BALB/c mice were inoculated intraperitoneally with B. duttonii strain 406K, and the titres of B. duttonii-specific immunoglobulins - IgM, IgG1, IgG2a, IgG2b and IgG3 - were determined by ELISA. IgM antibodies appeared first, followed by IgG2a and IgG3, and then IgG1 and IgG2b. The protective activity of individual classes and subclasses of B. duttonii-specific immunoglobulins was then determined by passive immunisation of BALB/c mice with immunoglobulin preparations purified by affinity chromatography. The mice were then challenged by intraperitoneal inoculation of B. duttonii. The study demonstrated that B. duttonii-specific IgM and IgG3 protected against the development of spirochaetaemia and death after borrelial infection, whereas B. duttonii-specific IgG1, IgG2a and IgG2b had low protective activities.

Evaluation of culture, histological examination, serology and the rapid urease test for diagnosis of Helicobacter pylori in patients with dyspepsia in Bangladesh.

Helicobacter pylori, a gram-negative, microaerophilic bacterium, has been established to have a causal association with chronic gastritis, peptic ulcer, gastric adenocarcinoma, and low-grade lymphoma. The present study was undertaken to evaluate the efficacy of culture, histological examination, the rapid urease test, and serology for the diagnosis of H. pylori infection. A total of 45 consecutive subjects with various upper gastrointestinal symptoms were included in this study. The rates of diagnosis of H. pylori infection were 51.1%, 55.6%, 82.2%, and 93.3%, by culture, rapid urease test (RUT), histological examination, and serology, respectively. The sensitivity, specificity, and positive and negative predictive values were 95.5%, 82.6%, 84.0%, and 95.0%, respectively for RUT; 95.5%, 30.4%, 56.8%, and 87.5% for histological examination; 100%, 13.6%, 54.8% and 100% for serology.

Prevalence of Helicobacter pylori in asymptomatic population--a pilot serological study in Bangladesh.

Epidemiological reports reveal that H. pylori is distributed among all population in the world. The present cross-sectional study was undertaken to see the H. pylori seroprevalence rates among the asymptomatic adults, as yet reportedly no such data available in Bangladesh. Serum samples were collected from 181 consecutive subjects who attended at the health check-up centre of Bangladesh Institute of Diabeties, Endocrine and Metabolic Disorders (BIRDEM), Dhaka, during the period of August to November 1995 for medical check up. The mean age of these subjects was 30.33 years (range 20-44 yrs). Incidentally all were male and belonged to average socioeconomic class. H. pylori specific IgG antibody level was assayed by an enzyme immunoassay kit ElAgen (Clone system). Among the 181 subjects, 166 (92%) had H. pylori specific antibodies and 15 (8%) were seronegative. No significant difference (p < 0.90) in seroprevalence rates was observed among different age groups. However, the results of higher seroprevalence rates of H. pylori infection in these asymptomatic adult population of Bangladesh are consistent with that of Africa and India.

Drug sensitivity pattern of E. coli causing urinary tract infection in diabetic and non-diabetic patients.

Escherichia coli was isolated from 65 urine samples out of 300 specimens collected from diabetic and non-diabetic patients with urinary tract infections. All isolates were screened for susceptibility to commonly used antibiotics. No remarkable difference in sensitivity pattern was observed between the E. coli isolates from diabetic and non-diabetic out-patients. However, the isolates from hospitalized diabetic patients showed a clear difference in sensitivity; E. coli from this group was more resistant to commonly used antibiotics compared with those from non-hospitalized diabetic and non-diabetic patients.

Essential role of Helicobacter pylori urease in gastric colonization: definite proof using a urease-negative mutant constructed by gene replacement.

OBJECTIVE: To investigate the involvement of urease in Helicobacter pylori colonization in the nude mouse stomach by using a genetically defined urease-negative mutant. METHODS AND RESULTS: Through electroporation-mediated gene replacement, one of the urease genes of an H. pylori strain, CYP3401, was disrupted by insertion of a kanamycin-resistance determinant to construct a stable urease-negative mutant, HPT73. Southern analysis confirmed that gene replacement was achieved. The two isogenic strains were introduced into the stomachs of nude mice, and the number of H. pylori and the histological changes in the stomachs were investigated 1 or 4 weeks after the challenge. Gastritis was present in the CPY3401-challenged stomach, from which bacteria indistinguishable from CPY3401 were successfully recovered. In contrast, no gastritis was found in the HPT73-challenged stomach, and H. pylori was not recovered from these stomachs. CONCLUSION: H. pylori urease is essential for colonization of the nude mouse stomach.

A urease-negative mutant of Helicobacter pylori constructed by allelic exchange mutagenesis lacks the ability to colonize the nude mouse stomach.

The urease of Helicobacter pylori has been proposed to be one of its pathogenic factors. A kanamycin resistance determinant was inserted in a cloned urease gene, and transformation-mediated allelic exchange mutagenesis was carried out to introduce the disrupted gene into the corresponding wild-type chromosomal region of a clinical isolate of H. pylori, CPY3401. The resulting mutant, HPT73, had the null activity of urease. Nude mouse stomachs were challenged with these two isogenic strains to examine the role of urease in pathogenesis. Gastritis was found in the CPY3401-challenged stomachs, from which bacteria indistinguishable from CPY3401 were recovered. There was no gastritis in the HPT73-challenged stomachs, and we could not recover H. pylori from them. These results indicated that H. pylori urease is essential for colonizing the nude mouse stomach.