Sequence analysis of cloned dengue virus type 2 genome (New Guinea-C strain)

Sequences totalling 5472 nucleotides (nt) from four complementary DNA (cDNA) clones of the dengue virus type 2 (DEN-2) RNA (New Guinea strain, NGS-C) have been reported previously [Yaegashi et al., Gene 46 (1986) 257-267; Putnak et al., Virology 163 (1988) 93-103]. This report describes the complete nucleotide sequence, with the exception of about 7 nt at the 5'-noncoding region, of this RNA genome derived from several cDNA clones. It is 10,723 nt in length and contains a single long open reading frame of 10,173 nt, encoding a polyprotein of 3391 amino acids. The genomic organization is similar to that of other flaviviruses that have recently been reported. Among the three DEN-2 strains - the Jamaica genotype (DEN-2JAM), the DEN-2NGS-C, and the S1 candidate vaccine strain derived from Puerto Rico (PR)-159 isolate (DEN-2S1) - which have been sequenced to date, the amino acid sequences of the polyproteins bear 94%-99% similarity. When the amino acid sequences of DEN-2NGS-C are compared with those of the other two strains, the variations are greater in the DEN-2S1 than in the DEN-2JAM. When DEN-2 and DEN-4 are compared, the overall amino acid identities range from 30% to 80% in both the structural and nonstructural proteins; whereas between DEN-2 and DEN-1, they range from 68% to 79% in the region encoding the structural proteins and the nonstructural protein NS1.     

Erythrocyte insulin binding abnormalities in fibro calculous pancreatic diabetes

Insulin binding to erythrocyte insulin receptors was studied in 17 patients (13 men and 4 women) with fibrocalculous pancreatic diabetes mellitus (FCPD) and compared with that of 14 newly diagnosed NIDDM patients matched for age, sex and severity of hyperglycemia, and 14 age and sex-matched non-diabetic control subjects. In the uncompensated diabetic state, mean (+/- S.D.) specific binding of insulin was lower in both FCPD and NIDDM patients, compared with non-diabetic controls (P less than 0.001). Control of diabetes with short term therapy (2-6 weeks) resulted in a significant improvement in the mean specific insulin binding in both FCPD and NIDDM patients (P less than 0.001) due to increased binding affinity in the former, and increased affinity and the number of binding sites in the latter. As compared to short term therapy, chronic therapy (5-8 months) in FCPD patients resulted in a marginal decrease in specific insulin binding. However, this was still significantly higher than the basal value (P less than 0.05). FCPD patients had an initial low mean basal plasma IRI and a much lower mean stimulated IRI response as compared to NIDDM and non-diabetic controls.     

Insulin resistance in Fibrocalculous (tropical) pancreatic diabetes

Insulin resistance was assessed by Insulin Tolerance Test (ITT) in 12 patients with FCPD, 10 with NIDDM and 12 age and sex matched control subjects. The mean BMI of the FCPD was lower than the NIDDM and control groups (P less than 0.001). There was no significant difference between the mean fasting plasma glucose or HbA1 between the FCPD and NIDDM patients. The mean fasting C-peptide of the FCPD group was significantly lower than the NIDDM and control groups (P less than 0.001). The mean glucose disposal rate (KITT) was 5.57 +/- 2.28 in the control group, 2.15 +/- 2.00 in the FCPD and 1.77 +/- 0.91 in the NiDDM group (P less than 0.001, control vs FCPD and NIDDM). The difference in KITT between FCPD and NIDDM groups was not significant statistically. The data suggests that patients with FCPD have evidence of insulin resistance and this is similar to that seen in NIDDM patients.     

Population Explosions of Tiger Moth Lead to Lepidopterism Mimicking Infectious Fever Outbreaks

Lepidopterism is a disease caused by the urticating scales and toxic fluids of adult moths, butterflies or its caterpillars. The resulting cutaneous eruptions and systemic problems progress to clinical complications sometimes leading to death. High incidence of fever epidemics were associated with massive outbreaks of tiger moth Asota caricae adult populations during monsoon in Kerala, India. A significant number of monsoon related fever characteristic to lepidopterism was erroneously treated as infectious fevers due to lookalike symptoms. To diagnose tiger moth lepidopterism, we conducted immunoblots for tiger moth specific IgE in fever patients’ sera. We selected a cohort of patients (n = 155) with hallmark symptoms of infectious fevers but were tested negative to infectious fevers. In these cases, the total IgE was elevated and was detected positive (78.6%) for tiger moth specific IgE allergens. Chemical characterization of caterpillar and adult moth fluids was performed by HPLC and GC-MS analysis and structural identification of moth scales was performed by SEM analysis. The body fluids and chitinous scales were found to be highly toxic and inflammatory in nature. To replicate the disease in experimental model, wistar rats were exposed to live tiger moths in a dose dependant manner and observed similar clinico-pathological complications reported during the fever epidemics. Further, to link larval abundance and fever epidemics we conducted cointegration test for the period 2009 to 2012 and physical presence of the tiger moths were found to be cointegrated with fever epidemics. In conclusion, our experiments demonstrate that inhalation of aerosols containing tiger moth fluids, scales and hairs cause systemic reactions that can be fatal to human. All these evidences points to the possible involvement of tiger moth disease as a major cause to the massive and fatal fever epidemics observed in Kerala.     

Alterations in cardiac adrenergic terminal function and beta-adrenoceptor density in pacing-induced heart failure

Congestive heart failure is associated with cardiac adrenergic nerve terminal changes and beta-adrenoceptor density downregulation. To study the temporal sequence of these changes, we performed studies in rabbits at 2, 4, and 8 wk of cardiac pacing (360 beats/min) and at 1, 2, and 4 wk after cessation of pacing. Rapid pacing produced left ventricular (LV) dysfunction and an increase in plasma norepinephrine (NE) in 1-2 wk. At week 2, NE uptake activity, NE uptake-1 density, and adenylyl cyclase responses to isoproterenol, 5'-guanylyl imidodiphosphate [Gpp(NH)p], and forskolin reduced. However, immunostained tyrosine hydroxylase profile, beta-adrenoceptor density, and NE histofluorescence did not reduce until 4-8 wk of pacing. After cessation of cardiac pacing, LV function normalized quickly, followed by return of tyrosine hydroxylase and NE profiles in 1 wk and adenylyl cyclase responses to agonists and NE uptake activity in 2 wk. Myocardial beta-adrenoceptor density returned to normal by 4 wk after cessation of pacing. Our results suggest that there is no permanent structural neuronal damage in the myocardium within the first 8 wk of rapid cardiac pacing. Abnormal myocardial NE reuptake mechanism may play an important pathophysiological role in heart failure.     

Hedgehog signaling: networking to nurture a promalignant tumor microenvironment

In addition to its role in embryonic development, the Hedgehog pathway has been shown to be an active participant in cancer development, progression, and metastasis. Although this pathway is activated by autocrine signaling by Hedgehog ligands, it can also initiate paracrine signaling with cells in the microenvironment. This creates a network of Hedgehog signaling that determines the malignant behavior of the tumor cells. As a result of paracrine signal transmission, the effects of Hedgehog signaling most profoundly influence the stromal cells that constitute the tumor microenvironment. The stromal cells in turn produce factors that nurture the tumor. Thus, such a resonating cross-talk can amplify Hedgehog signaling, resulting in molecular chatter that overall promotes tumor progression. Inhibitors of Hedgehog signaling have been the subject of intense research. Several of these inhibitors are currently being evaluated in clinical trials. Here, we review the role of the Hedgehog pathway in the signature characteristics of cancer cells that determine tumor development, progression, and metastasis. This review condenses the latest findings on the signaling pathways that are activated and/or regulated by molecules generated from Hedgehog signaling in cancer and cites promising clinical interventions. Finally, we discuss future directions for identifying the appropriate patients for therapy, developing reliable markers of efficacy of treatment, and combating resistance to Hedgehog pathway inhibitors.     

Role of septins and the exocyst complex in the function of hydrolytic enzymes responsible for fission yeast cell separation

Cell separation in Schizosaccharomyces pombe is achieved by the concerted action of the Eng1 endo-beta-1,3-glucanase and the Agn1 endo-alpha-1,3-glucanase, which are transported to the septum and localize to a ringlike structure that surrounds the septum. The requirements for the correct localization of both hydrolases as a ring were analyzed using green fluorescent protein fusion proteins. Targeting to the septum required a functional exocyst, because both proteins failed to localize correctly in sec8-1 or exo70delta mutants, suggesting that Agn1 and Eng1 might be two of the cargo proteins present in the vesicles that accumulate in exocyst mutants. Septins and Mid2 were also required for correct formation of a ring. In their absence, Eng1 and Agn1 were found in a disk-like structure that spanned the septum, rather than in a ring. Even though septin and mid2delta mutants have a cell separation defect, the septum and the distribution of linear beta-1,3-glucans were normal in these cells, suggesting that mislocalization of Eng1 and Agn1 might be the reason underlying the failure to separate efficiently. Thus, one of the functions of the septin ring would be to act as a positional marker for the localization of hydrolytic proteins to the medial region.     

Reactions of superoxide radicals with curcumin: probable mechanisms by optical spectroscopy and EPR

Reactions of superoxide-crown ether complex with curcumin have been studied in acetonitrile. Optical absorption spectra showed that curcumin on reaction with superoxide forms a blue color intermediate absorbing at 560 nm, which subsequently decayed in a few hours with the development of the absorption band corresponding to the parent curcumin. The regeneration was 100% at low superoxide concentrations (1:1, or 1:2 or 1:3 of curcumin:superoxide) but reduced to 60% at high superoxide concentration (>1:5). The regeneration of curcumin is confirmed by HPLC analysis. Stopped-flow studies in acetonitrile following either the decay of parent curcumin at 420 nm or formation of 560 nm absorption have been used to determine the rate constant for the reaction of superoxide with curcumin. EPR studies confirmed the disappearance of characteristic superoxide signal in presence of curcumin with the formation of new featureless signal with g = 2.0067. Based on these studies it is concluded that at low superoxide concentrations curcumin effectively causes superoxide dismutation without itself undergoing any chemical change. At higher concentrations of superoxide, curcumin inhibits superoxide activity by reacting with it.     

Effect of corticosteroids and eicosapentaenoic acid/docosahexaenoic acid on pro-oxidant and anti-oxidant status and metabolism of essential fatty acids in patients with glomerular disorders.

It is known that the concentrations of essential fatty acids and their metabolites including eicosanoids, free radicals and anti-oxidants are altered in glomerular disorders. Both corticosteroids and n-3 fatty acids--eicosapentaenoic acid and docosahexaenoic acid (EPA and DHA respectively)--are useful in the management of glomerular disorders. In the present study, the altered plasma concentrations of lipid peroxides, nitric oxide and the metabolites of essential fatty acids and anti-oxidants--superoxide dismutase, glutathione peroxidase and vitamin E--in the RBC membranes of patients with glomerular disorders (nephrotic syndrome) reverted to normalcy following corticosteroids or EPA/DHA administration. This suggests that the beneficial actions of corticosteroids and EPA/DHA in glomerular disorders can be attributed to their action on the pro-oxidant and anti-oxidant concentrations and metabolism of essential fatty acids.     

The burden of scrub typhus in India: A systematic review

BackgroundScrub typhus, a vector-borne zoonotic infection caused by the bacteria Orientia tsutsugamushi, is one of the most common and clinically important rickettsial infections worldwide. An estimated one million cases occur annually with a high case fatality rate. Although scrub typhus is a major public health threat in India, the burden and distribution remains unclear. We aimed to estimate the burden of scrub typhus in India.MethodologyWe performed a systematic review of published literature on scrub typhus from India to extract information on epidemiology, morbidity, and mortality. Important databases were searched using keywords and appropriate combinations. We identified observational, interventional, and population-based studies and extracted the data to evaluate the number of cases diagnosed using serology or PCR and the number of deaths due to scrub typhus. We conducted a systematic narrative synthesis to summarize included studies.Principal findingsIn the last decade, there were 18,781 confirmed scrub typhus cases reported in 138 hospital-based studies and two community-based studies. IgM ELISA was used in 122 studies to confirm the cases in majority (89%). The proportion of scrub typhus among acute undifferentiated febrile illness (AUFI) studies was 25.3%, and community seroprevalence was 34.2%. Ninety studies had data published on multiple organ involvement out of which 17.4% of cases had multiple organ dysfunction syndromes, 20.4% patients required ICU admission, and 19.1% needed ventilation. The overall case-fatality rate was 6.3%, and the mortality among those with multi-organ dysfunction syndrome was as high as 38.9%.Conclusion/significanceScrub typhus, a common acute febrile illness in India causing severe morbidity, accounts for a large number of deaths. The burden of the disease has been underappreciated. Early diagnosis and prompt treatment can significantly reduce complications and mortality. Establishing good surveillance and instituting appropriate control measures are urgently needed.