Relationship Between Insulin-Receptor Substrate 1 and Langerhans' Islet in a Rat Model of Type 2 Diabetes Mellitus.

BACKGROUND/AIM: In vivo studies on pathogenesis of type 2 diabetes mellitus (T2DM) have been reported, however, the relationship between insulin-receptor substrate 1 (IRS1) and the area of Langerhans' islets was unknown. Therefore, a correlation between both parameters was assessed. MATERIALS AND METHODS: Diabetic groups were fed with a high-fat diet (HFD) and injected with three different doses of streptozotocin, namely 25, 35 and 45 mg/kg, and compared to a control group after 9 weeks. RESULTS: Administration of HFD/streptozotocin increased the level of fasting blood glucose but reduced the level of IRS1 and the area of Langerhans' islets in diabetic groups. The coefficient of correlation between IRS1 and area of Langerhans' islets was 0.259 (p=0.232). In addition, the coefficient of correlation for fasting blood glucose with the area of Langerhans' islets and IRS1 was -0.520 (p=0.011) and -0.603 (p=0.002), respectively. CONCLUSION: The reduction of IRS1 was weakly correlated with the destruction of Langerhans' islets, suggesting there is an intermediate step between both parameters.

Rickettsial infections of fleas collected from small mammals on four islands in Indonesia.

Ectoparasites were sampled from small mammals collected in West Java, West Sumatra, North Sulawesi, and East Kalimantan, Indonesia, in 2007-2008 and were screened for evidence of infection from bacteria in the Rickettsaceae family. During eight trap nights at eight sites, 208 fleas were collected from 96 of 507 small mammals trapped from four orders (379 Rodentia; 123 Soricomorpha; two Carnivora; three Scandentia). Two species of fleas were collected: Xenopsylla cheopis (n = 204) and Nosopsyllus spp. (n = 4). Among the 208 fleas collected, 171 X. cheopis were removed from rats (Rattus spp.) and 33 X. cheopis from shrews (Suncus murinus). X. cheopis were pooled and tested for DNA from rickettsial agents Rickettsia typhi, Rickettsia felis, and spotted fever group rickettsiae. R. typhi, the agent of murine typhus, was detected in X. cheopis collected from small mammals in West Java and East Kalimantan. R. felis was detected in X. cheopis collected from small mammals in Manado, North Sulawesi. R. felis and spotted fever group rickettsiae were detected in a pool of X. cheopis collected from an animal in East Kalimantan. Sixteen percent of the X. cheopis pools were found positive for Rickettsia spp.; four (10.8%) R. typhi, one (2.7%) R. felis, and one (2.7%) codetection of R. felis and a spotted fever group rickettsia. These data suggest that rickettsial infections remain a threat to human health across Indonesia.

Abundance and distribution of Xenopsylla cheopis on small mammals collected in West Java, Indonesia during rodent-borne disease surveys.

During February 2004 and September 2005, Xenopsylla cheopis were collected from small mammal hosts during rodent-bone disease surveys in Jakarta and Bandung, Indonesia. During 4 trap nights in Jakarta, 4 rodent species (Rattus exulans, Rattus norvegicus, Rattus tanezumi and Mus musculus) and one shrew species (Suncus murinus) were collected. Rattus tanezumi had the highest X. cheopis load (128 X. cheopis from 84 R. tanezumi) but R. norvegicus had the highest flea index, 1.8. In Bandung, over 6 trap nights 3 rodent species were collected (R. norvegicus, R. tanezumi and M. musculus) and the shrew, S. murinus, were collected. Rattus norvegicus had the highest number of X. cheopis collected (407 X. cheopis from 181 R. norvegicus) but R. tanezumi had the highest flea index, 3.5. During both surveys, X. cheopis was the species of flea collected.

Geographical Assessment of Rickettsioses in Indonesia.

To expand the documentation of rickettsioses in Indonesia, we conducted an ectoparasite and small mammal investigation involving four major islands: Java, Sumatra, Sulawesi, and Kalimantan. Coastal and highland regions on each island surveyed were chosen to represent different ecologies in Indonesia. Indication of the presence of Rickettsia spp. was evident in all areas sampled. Typhus group rickettsiae-specific antibodies had significantly higher prevalence among small mammals captured in Java compared to the other islands surveyed (78% in coastal and 50% in highland regions) and the prevalence of spotted fever group rickettsiae-specific antibodies was significantly higher in Kalimantan than the other islands investigated. Hosts and vectors were restricted by Rickettsia spp. but not by coastal or highland regions. Our findings expand the range in which rickettsial pathogens have been documented within the Indonesian archipelago and point to a significant risk to human health.

Bartonella species in rodents and shrews in the greater Jakarta area.

In February 2004, we captured 221 rodents and shrews in the Greater Jakarta area as part of a study to determine the prevalence of rodent-associated vector-borne infections. Microscopic examination of blood smears revealed 6% (13/218) to be positive for Bartonella spp. The corresponding DNA samples, either from blood blots or frozen spleen pieces and from fleas collected on these animals, were tested for evidence of Bartonella infection by PCR, targeting the portions: 378bp and 930bp of the citrate synthase gene (g/tA). The sequences from our sample clusters with a Peruvian entity, B. phoceensis, B. rattimassiliensis and B. elizabethae, the latter species has been associated with endocarditis and neuroretinitis in humans. As previous analyses have shown, there appears to be little geographic or host consistency with phylogenetic placement. The public health significance of these findings remains to be determined.

Evidence of human hantavirus infection and zoonotic investigation of hantavirus prevalence in rodents in western Java, Indonesia.

During febrile surveillance in the western Java City of Bandung, Indonesia, a patient with clinical symptoms consistent with hantavirus infection was found to have elevated titers of hantavirus-specific immunoglobulin M (IgM) and IgG antibodies. A subsequent epizoological investigation demonstrated a higher prevalence of hantavirus IgG antibodies in rodents trapped in the vicinity of the patient's home compared with rodents from a control area (13.2% vs. 4.7%, p = 0.036). The Old World Seoul hantavirus was detected by reverse transcriptase-polymerase chain reaction in the organs of 71% of the seropositive rodents tested. This is the first report of a Seoul virus infection in Indonesia supported by clinical, serological, and epizoological evidences. These findings suggest that hantavirus infection should be on the clinical differential diagnosis when acutely ill febrile patients report for care in western Java.

Identification of Seoul hantavirus in Rattus norvegicus in Indonesia.

The first genetic evidence for the presence of Seoul hantavirus (SEOV) in Indonesia is presented. Partial M segment sequence was recovered from the lung tissue of Rattus norvegicus trapped in central Jakarta. The sequence belongs to SEOV genotype and is most closely related to the strain B-1 from Japan.