Observations on the breeding habitat of Aedes species in the steel township, Rourkela

Prompted by report of large number of dengue fever cases in township of Rourkela steel plant, entomological surveys were carried out to know the distribution and extent of Aedes breeding in and around the dengue fever affected areas. Out of 2062 water containers searched, 819 were positive for Aedes larvae. The house index (HI), container index (CI) and Breteau index (BI) were 53.4, 39.7 and 118.5 respectively. 27.9% of the houses had single breeding habitats. The breateau index of single storeyed houses and double storeyed buildings was 149.8 and 54.6 respectively, showing that the single storeyed houses have more potential for Aedes breeding. The breeding preference ratio (BPR) was highest for plastic containers. Three species of Aedes were found breeding in different habitats and Aedes aegypti was found breeding in coolers, cement tanks, tyres and miscellaneous containers with a prevalence rate of 13.2%. The role of entomological surveillance and health education has been highlighted for the control of disease through community participation.

RNase activity of a DNA minor groove binder with a minimalist catalytic motif from RNase A

Imidazole and compounds containing imidazole residues have been shown to cleave RNA in an RNase A-mimicking manner. Di-imidazole lexitropsin is a compound which is derived from the polyamide drugs distamycin and netropsin essentially by the replacement of two pyrrole heterocycles with N-methyl-imidazole residues. This enables it to bind to the minor groove of B-DNA in a sequence-specific manner. We demonstrate here that this lexitropsin derivative has RNA cleavage activity, as tested on model RNAs. Optimal cleavage conditions and cleavage specificity resemble those known from other imidazole conjugates and are thus consistent with an RNase A type cleavage mechanism. The optimum concentration of the compound for cleavage is similar to previously investigated imidazole-based RNase mimics. As a whole new class of chemical compounds capable of interacting with nucleic acids through extensive hydrogen bonding, these imidazole containing compounds constitute promising scaffolds and ligands, for the construction of novel RNase mimics with high affinity.

Sandfly survey in Nainital and Almora districts of Uttaranchal with particular reference to Phlebotomus argentipes, vector of kala-azar

Kala-azar continues to pose a major public health problem in Bihar, West Bengal and parts of eastern Uttar Pradesh in India causing great deal of morbidity and mortality. During 1998, several kala-azar cases from Sub-Himalayan region were treated in Delhi hospitals. And a suspected focus of kala-azar was subsequently reported from this area. Therefore a preliminary sandfly survey was carried out during October, 1999 in 18 randomly selected villages at different altitudes in Nainital & Almora districts of Kumaon region Uttaranchal. The surveys revealed relative preponderance of vector sandfly Ph. argentipes as 77%; mainly confined to cattlesheds and mixed dwellings in the villages at an altitude ranging from 350-960 metres main sea level. The other sandfly species encountered were: Ph. papatasi 6.9%, Ph. major 2.9% and 13.2% Sergentomyia spp. 17.4% Ph. argentipes reacted positive with human antisera and 82.6% with bovine but none reacted with goat, pig dog and bird antisera indicating that Ph. argentipes in the area is mainly zoophilic. Ph. argentipes was found to be highly susceptible to DDT; mortality ranging from 98-100%.

Unstable angina pectoris and non-Q-wave myocardial infarction

Unstable angina pectoris and non-Q-wave myocardial infarction are clinical syndromes that share many pathophysiologic and clinical features. In the spectrum of coronary artery disease, these syndromes lie between chronic stable angina and Q-wave myocardial infarction. Although both conditions are associated with significant morbidity and mortality, patients presenting with these syndromes can be further risk stratified into higher and lower risk based on a number of readily available clinical features and biochemical parameters. Such risk stratification can allow for more tailored treatment and better resource allocation. Although routine early coronary angiography and revascularization has not been shown to be superior to conservative management, certain high-risk patients may benefit from a more aggressive strategy. Medical therapy with the use of antiplatelet, anticoagulant, and antiischemic agents remains the cornerstone of emergent treatment for patients presenting with these syndromes. The recent demonstration of a reduction in both morbidity and mortality with the glycoprotein IIb/IIIa antagonists has further expanded the armamentarium of available agents. Following initial stabilization, risk stratification with stress testing can help identify patients with a large residual ischemic burden who may benefit from coronary angiography with revascularization if feasible.

Administration of abciximab to patients receiving tirofiban or eptifibatide: effect on platelet function

OBJECTIVES

The goal of this study was to evaluate platelet function and to preliminarily assess the clinical safety of sequential treatment with tirofiban or eptifibatide followed by abciximab in patients undergoing percutaneous coronary intervention (PCI).

BACKGROUND

An increasing number of acute coronary syndrome (ACS) patients are treated early with tirofiban or eptifibatide. Some later require PCI and may benefit from switching to abciximab, for which long-term benefits have been reported.

METHODS

Fifty ACS patients planned for PCI were enrolled. Twenty-five patients received tirofiban followed by abciximab. Ten patients received eptifibatide followed by abciximab. Fifteen patients received only abciximab. All patients had blood samples drawn six times during the therapeutic course. Platelet function was evaluated by ADP- and TRAP-induced aggregation, flow cytometry analysis of fibrinogen binding and the cone and plate(let) analyzer, which tests shear rate-dependent platelet activation.

RESULTS

Administered after tirofiban, abciximab caused a significant further decline in platelet function, as evidenced by all methods. Administered after eptifibatide, abciximab caused a significant further reduction in platelet function, as assessed by the cone and plate(let) analyzer and fibrinogen binding methods. The platelet inhibition achieved by the combination therapy was always greater than or equal to that achieved by abciximab alone. There were no major bleeding or severe thrombocytopenia episodes. Three of the 35 combination therapy patients and one of the 15 who received abciximab alone had minor bleeding.

CONCLUSIONS

This is the first in vivo study of combination intravenous platelet glycoprotein IIb/IIIa inhibitor therapy. Administration of abciximab immediately after tirofiban or eptifibatide therapy effectively inhibits platelet function and appears to be safe.

Transient neurologic symptoms after spinal anesthesia with lidocaine in obstetric patients

We investigated the relationship between intrathecal lidocaine and transient neurologic symptoms in the obstetric population because lidocaine spinal anesthetics are commonly used for various obstetric procedures, and little has been reported in this regard from within this population. In this study, 58 ASA physical status I patients presenting for postpartum bilateral tubal ligation under spinal anesthesia were randomized to receive either hyperbaric 5% lidocaine or 0.75% bupivacaine in a double-blinded manner. All patients were in the supine position for their surgery. Postoperatively, all patients were followed by a blinded investigator using a standardized symptom checklist. The incidence of transient neurologic symptoms with lidocaine was 3% (95% confidence interval = 0.1%--17.8%) and that with bupivacaine was 7% (95% confidence interval = 0.9%--23.5%), (P = not significant). Symptoms consistent with this syndrome occurred within 24 h without any associated sensory or motor deficits or functional impairment, and resolved within 48 h without any intervention.

Characterization of the in vitro phosphorylation of human tau by tau protein kinase II (cdk5/p20) using mass spectrometry

Hyperphosphorylated tau is an integral part of the neurofibrillary tangles that form within neuronal cell bodies, and tau protein kinase II is reported to play a role in the pathogenesis of Alzheimer's disease. Recently, we reported that tau protein kinase II (cdk5/p20)-phosphorylated human tau inhibits microtubule assembly, and tau protein kinase II (cdk5/p20) phosphorylation of microtubule-associated tau results in dissociation of phosphorylated tau from the microtubules and tubulin depolymerization. In the studies reported here, a combination of mass spectrometric techniques was used to study the phosphorylation of human recombinant tau by recombinant tau protein kinase II (cdk5/p20) in vitro. The extent of phosphorylation was determined by measuring the molecular mass of phosphorylated tau using mass spectrometry. Reaction of human recombinant tau with tau protein kinase II (cdk5/p20) resulted in the formation of two major species containing either five or six phosphate groups. The specific amino acid residues phosphorylated were determined by analyzing tryptic peptides by tandem mass spectrometry via either MALDI/TOF post-source decay or by electrospray tandem mass spectrometry. Based on these experiments, we conclude that tau protein kinase II (cdk5/p20) can phosphorylate human tau at Thr(181), Thr(205), Thr(212), Thr(217), Ser(396) and Ser(404).

Immunological properties of Hn-33 purified from type A Clostridium botulinum

Type A botulinum neurotoxin is produced along with 6-7 neurotoxin associated proteins to form a complex in addition to the neurotoxin. Immunological reactivity of type A botulinum complex and purified hemagglutinin (Fu et al., 1998) to polyclonal antibody raised against the complex have been investigated using ELISA. In competitive ELISA, 50% inhibition of the binding of IgG antibody against complex A is observed at 78 ng/ml of complex and hemagglutinin-33, suggesting that the hemagglutinin-33 accounts for most of the immunogenic response of the complex. Considering the fact that the complex consists of a group of proteins with a cumulative molecular weight of 900 kDa, hemagglutinin-33 may be one of the major immunoreactive proteins present in the type A neurotoxin complex.

Recombinant anti-carcinoembryonic antigen antibodies for targeting cancer

Antibodies can be used to target cancer therapies to malignant tissue; the approach is attractive because conventional treatments such as chemo- and radiotherapy are dose limited due to toxicity in normal tissues. Effective targeting relies on appropriate pharmacokinetics of antibody-based therapeutics, ideally showing maximum uptake and retention in tumor and rapid clearance from normal tissue. We have studied the factors influencing these dynamics for antibodies against carcinoembryonic antigen (CEA). Protein engineering of anti-CEA antibodies, in vivo biodistribution models, and mathematical models have been employed to improve understanding of targeting parameters, define optimal characteristics for the antibody-based molecules employed, and develop new therapies for the clinic. Engineering antibodies to obtain the desired therapeutic characteristics is most readily achieved using recombinant antibody technology, and we have taken the approach of immunizing mice to provide high-affinity anti-CEA single-chain Fv antibodies (sFvs) from filamentous bacteriophage libraries. MFE-23, the most characterized of these sFvs, has been expressed in bacteria and purified in our laboratory for two clinical trials: a gamma camera imaging trial using 123I-MFE-23 and a radioimmunoguided surgery trial using 125I-MFE-23, where tumor deposits are detected by a hand-held probe during surgery. Both these trials showed that MFE-23 is safe and effective in localizing tumor deposits in patients with cancer. We are now developing fusion proteins that use the MFE-23 antibody to deliver a therapeutic moiety; MFE-23:: carboxypeptidase G2 (CPG2) targets the enzyme CPG2 for use in the antibody-directed enzyme prodrug therapy system and MFE::tumor necrosis factor alpha (TNFalpha) aims to reduce sequestration and increase tumor concentrations of systemically administered TNFalpha.

Nephron-sparing surgery in a case of giant renal hydatid cyst

We report a case of a centrally located giant renal hydatid cyst managed successfully by excision of the cyst alone and preserving the renal parenchyma after clamping the main renal artery. Follow-up IVP showed good function.

Tau phosphorylation at serine 396 and serine 404 by human recombinant tau protein kinase II inhibits tau's ability to promote microtubule assembly

In Alzheimer's disease, hyperphosphorylated tau is an integral part of the neurofibrillary tangles that form within neuronal cell bodies and fails to promote microtubule assembly. Dysregulation of the brain-specific tau protein kinase II is reported to play an important role in the pathogenesis of Alzheimer's disease (Patrick, G. N., Zukerberg, L., Nikolic, M., De La Monte, S., Dikkes, P., and Tsai, L.-H. (1999) Nature 402, 615-622). We report here that in vitro phosphorylation of human tau by human recombinant tau protein kinase II severely inhibits the ability of tau to promote microtubule assembly as monitored by tubulin polymerization. The ultrastructure of tau-mediated polymerized tubulin was visualized by electron microscopy and compared with phosphorylated tau. Consistent with the observed slower kinetics of tubulin polymerization, phosphorylated tau is compromised in its ability to generate microtubules. Moreover, we show that phosphorylation of microtubule-associated tau results in tau's dissociation from the microtubules and tubulin depolymerization. Mutational studies with human tau indicate that phosphorylation by tau protein kinase II at serine 396 and serine 404 is primarily responsible for the functional loss of tau-mediated tubulin polymerization. These in vitro results suggest a possible role for tau protein kinase II-mediated tau phosphorylation in initiating the destabilization of microtubules.

Noninvasive in vivo human coronary artery lumen and wall imaging using black-blood magnetic resonance imaging

BACKGROUND

High-resolution MRI has the potential to noninvasively image the human coronary artery wall and define the degree and nature of coronary artery disease. Coronary artery imaging by MR has been limited by artifacts related to blood flow and motion and by low spatial resolution.

METHODS AND RESULTS

We used a noninvasive black-blood (BB) MRI (BB-MR) method, free of motion and blood-flow artifacts, for high-resolution (down to 0.46 mm in-plane resolution and 3-mm slice thickness) imaging of the coronary artery lumen and wall. In vivo BB-MR of both normal and atherosclerotic human coronary arteries was performed in 13 subjects: 8 normal subjects and 5 patients with coronary artery disease. The average coronary wall thickness for each cross-sectional image was 0.75+/-0.17 mm (range, 0.55 to 1.0 mm) in the normal subjects. MR images of coronary arteries in patients with >/=40% stenosis as assessed by x-ray angiography showed localized wall thickness of 4.38+/-0.71 mm (range, 3.30 to 5.73 mm). The difference in maximum wall thickness between the normal subjects and patients was statistically significant (P<0.0001).

CONCLUSIONS

In vivo high-spatial-resolution BB-MR provides a unique new method to noninvasively image and assess the morphological features of human coronary arteries. This may allow the identification of atherosclerotic disease before it is symptomatic. Further studies are necessary to identify the different plaque components and to assess lesions in asymptomatic patients and their outcomes.

Anti-microbial activity of a new vaginal contraceptive NIM-76 from neem oil (Azadirachta indica)

Efficacy of NIM-76, a spermicidal fraction from neem oil, was investigated for its antimicrobial action against certain bacteria, fungi and Polio virus as compared to whole neem oil. The NIM-76 preparation showed stronger anti-microbial activity than the whole neem oil. It inhibited growth of various pathogens tested including Escherichia coli and Kleibsiella pneumoniae which were not affected by the whole neem oil. NIM-76 also exhibited antifungal activity against Candida albicans and antiviral activity against Polio virus replication in vero cell lines. It also protected mice from systemic candidiasis as revealed by enhanced % survival and reduced colony forming units of C. albicans in various tissues. This shows that NIM-76 has a potent broad spectrum anti-microbial activity.

Cardioprotective effect of prior beta-blocker therapy in reducing creatine kinase-MB elevation after coronary intervention: benefit is extended to improvement in intermediate-term survival

BACKGROUND

Both retrospective studies and prospective randomized trials have shown that beta-blockers improve survival and reduce the risk of reinfarction in patients with myocardial infarction. To evaluate whether beta-blockers exert similar protective benefits during and after coronary intervention, we studied the incidence of postprocedure creatine kinase (CK)-MB elevation in patients with or without prior beta-blocker therapy and its effect on intermediate-term ( approximately 1 year) survival.

METHODS AND RESULTS

We prospectively analyzed 1675 consecutive patients undergoing coronary intervention; of these patients, 643 (38.4%) were on beta-blocker therapy before the intervention. The incidence of CK-MB elevation after coronary intervention was 13.2% in patients on beta-blocker therapy before intervention and 22.1% in patients who were not on beta-blockers (P<0.001). Patients with prior beta-blocker therapy had lower persistent/recurrent postprocedure chest pain and lower preprocedure and postprocedure heart rates and mean blood pressures compared with patients who were not on beta-blockers (P<0.001). Multiple linear regression analysis revealed prior beta-blocker therapy as the sole independent factor for lower CK-MB release after coronary intervention. During intermediate-term follow-up at 15+/-3 months, patients on beta-blocker therapy before intervention had lower mortality rates compared with those not on beta-blockers (0.78% versus 1.96%; P=0. 04), although the benefit was independent of the reduction in CK-MB release.

CONCLUSIONS

Our nonrandomized, prospective analysis suggests that prior beta-blocker therapy has a cardioprotective effect in limiting CK-MB release after coronary intervention and that it is associated with a lower mortality at intermediate-term follow-up.

Mechanism of biochemical action of substituted 4-methylbenzopyran-2-ones. Part 7: Assay and characterization of 7,8-diacetoxy-4-methylcoumarin:protein transacetylase from rat liver microsomes based on the irreversible inhibition of cytosolic glutathione S-transferase

The enzymatic transfer of acetyl groups from acetylated xenobiotics to specific proteins is a relatively grey area in the evergreen field of biotransformation of foreign compounds. In this paper, we have documented evidence for the existence of a transacetylase in liver microsomes that catalyses the transfer of acetyl groups from 7,8-diacetoxy-4-methylcoumarin (DAMC) to glutathione S-transferase (GST), either purified or present in cytosol leading to the irreversible inhibition of GST. A simple procedure is described for the assay of transacetylase by preincubation of DAMC with liver microsomes and pure GST/liver cytosol, followed by the addition of 1-chloro-2,4-dinitrobenzene (CDNB) and reduced glutathione (GSH) in order to quantify GST activity by the conventional procedure. The extent of inhibition of GST by DAMC under the conditions of the assay is indicative of DAMC:protein transacetylase activity. Following the assay procedure described here, the transacetylase was shown to exhibit hyperbolic kinetics. The bimolecular nature of the transacetylase reaction was apparent by the demonstration of Km and vmax values. 7,8-Dihydroxy-4-methylcoumarin (DHMC), one of the products of transacetylase reaction was identified and quantified using the partially purified enzyme. The fact that p-hydroxymercuribenzoate (PHMB) and iodoacetamide abolished irreversible inhibition of GST upon the action of transacetylase on DAMC strongly characterized transacetylase as a protein containing thiol group at the active site. In addition, the relative specificities of acetoxy 4-methylcoumarins to transacetylase have been demonstrated.

AETIOLOGY OF UPPER GASTROINTESTINAL HAEMORRHAGEAN ENDOSCOPIC STUDY

610 patients of upper gastrointestinal haemorrhage were endoscoped over a period of eleven years from July 1985 to June 1996. Average age of the patients was 39.2 years. 82.6% were males and 17.4% were females. Duodenal ulcer (31.5%), erosive mucosal disease (30.8%), oesophageal varices (31.5%) and gastric ulcer (6.2%) were the major causes. Other causes included Mallory Weiss syndrome (10 patients), gastric polyp (3 patients), stomal ulcer (5 patients) and self-induced bleeding (3 patients). Multiple lesions responsible for bleeding were detectable in 6.6% of patients. Endoscopy was non-contributory in 50 (11.2%) patients. Haemorrhage was the first presentation in 8.5% patients of duodenal ulcer. A known ulcerogenic agent in 21% of duodenal ulcer cases precipitated the bleeding. 77.4% of duodenal ulcer patients responded to conservative management. Erosive gastritis (57.5%) was the commonest finding in the erosive mucosal group. Alcohol and analgesics were the major precipitating factors in these patients. Majority of oesophageal varices were treated by sclerotherapy. Mortality (20%) were highest in the oesophageal varices group.

HIV seropositivity among adult tuberculosis patients in Delhi

We report HIV seropositivity among tuberculosis patients from our hospital between 1994-99. Of the 500 patients with various forms of tuberculosis, two were found to be seropositive (0.4%). This report contrasts with the HIV seropositivity reports from other parts of India where increasing HIV seropositivity has been reported. As the HIV infection is making rapid in-roads in India, it is suggested that continuous HIV sero-surveillance should be done in patients with tuberculosis.

Evaluation of myocardial viability in asymptomatic patients early after infarction with perfusion/metabolism single-photon-emission computed tomographic imaging and dobutamine echocardiography

OBJECTIVE

To study the impact of detection of viability of myocardium in asymptomatic patients early (3-10 days) after Q-wave myocardial infarction on segmental recovery of left ventricular function after elective revascularization.

METHODS

Patients were studied with low-dose dobutamine echocardiography (LDDE) and single photon-emission computed tomography with 99mTc sestamibi and [18F]-fluorodeoxyglucose (FDG) imaging. Viability of myocardium was defined as detection of improvement in segmental thickening of left ventricle by LDDE (versus baseline echocardiographic data), uptake of 99mTc sestamibi > 50% of maximum counts, uptake of [18F]-FDG > 50% of maximum normal, combined uptake of 99mTc sestamibi or [18F]-FDG > 50% of normal maximum, uptake of [18F]-FDG > 50% or mismatched pattern (uptake of [18F]-FDG greater than that of 99mTc sestamibi). Functional recovery was defined as improvement of segmental thickening of left ventricle detected at follow-up 8 weeks after infarction (versus baseline resting echocardiographic data). Interpretation of the tests was blinded with respect to the angiographic data and the results of the alternative method.

RESULTS

In total 18 patients with 133 left-ventricle segments with abnormal contractile function at baseline were analysed; 29% were hypocontractile and 71% were noncontractile. Examination with LDDE showed that 18% of the segments had normal contractility and 26% were hypocontractile; the respective percentages were 29 and 28% according to follow-up resting echocardiography. Radionuclide tests for viability of myocardium gave positive results in 57% (uptake of [18F]-FDG > 50%) and 62% (uptake of 99mTc sestamibi > 50%) of cases. With respect to segmental analysis, there was a 25-27% positive concordance, a 24-27% negative concordance, and a 48-50% discordance between the LDDE and the radionuclide definitions of viability of myocardium. Additionally, there was no significant difference among sensitivities and specificities for the definitions of viability. The sensitivity was 69% for the uptake of 99mTc sestamibi > 50% criterion, and the highest specificity was 66% for the LDDE. Incorporation of imaging with [18F]-FDG into the analysis yielded a marginally higher sensitivity of 71% for the criterion of uptake of [18F]-FDG or 99mTc sestamibi > 50%, versus imaging with the 99mTc sestamibi alone.

CONCLUSION

LDDE was more specific and radionuclide imaging more sensitive for detection of viability of myocardium in asymptomatic patients early after infarction. Possibly defective myocardial metabolization of glucose in the period early after infarction and the specific LDDE protocol applied account for the limited benefit of these studies in terms of facilitating prediction of segmental functional recovery after revascularization in this clinical setting.

Effect of Kombucha tea on chromate(VI)-induced oxidative stress in albino rats

The effect of Kombucha tea (KT) on oxidative stress induced changes in rats subjected to chromate treatment are reported. KT feeding alone did not show any significant change in malondialdehyde (MDA) and reduced glutathione (GSH) levels, but did enhance humoral response and delayed type of hypersensitivity (DTH) response appreciably over control animals. Chromate treatment significantly enhanced plasma and tissue MDA levels, decreased DTH response considerably, enhanced glutathione peroxidase and catalase activities; however, no change in GSH, superoxide dismutase and antibody titres was noticed. KT feeding completely reversed the chromate-induced changes. These results show that Kombucha tea has potent anti-oxidant and immunopotentiating activities.