Bioassay and molecular study for detection of insecticide resistance dengue causing mosquito vectors

Nowadays, dengue infection creates a major problem across the country. The vector species carrying dengue infection has progressively started to developed resistance against most of the currently used insecticides. Hence, a study was carried out in dengue-endemic areas of Assam and Arunachal Pradesh to find the current situation of insecticide susceptibility status of dengue vectors. Based on the previous history of dengue incidence, Aedes mosquitoes were collected from Dibrugarh, Kamrup, Sivasagar, Tezpur and Tinsukia districts in Assam and Pasighat district in Arunachal Pradesh to test the insecticide resistance status through bioassay and molecular methods. The WHO standard bioassay test kits were used to detect insecticide susceptibility status among dengue vectors. In molecular study, allele-specific polymerase chain reaction (PCR) method was done for the detection of mutations in paratype voltage-gated sodium channel gene of Aedes aegypti and Aedes albopictus mosquitoes. In bioassay method, 100% A. aegypti mosquitoes were found to be resistant towards dichlorodiphenyltrichloroethane (DDT), 8% towards pyrethroid and 4% towards malathion. Similarly, 92% A. albopictus mosquitoes have shown resistance competency towards DDT, 12% towards pyrethroid and 8% towards malathion. In allele-specific PCR methods, V1016G heterozygous mutations were detected from the field collected A. aegypti and A. albopictus mosquitoes of Tinsukia, Dibrugarh and Sivasagar district. Similarly, F1534C heterozygous mutations were observed from A. aegypti mosquitoes of Tezpur, Tinsukia and Sivasagar district and A. albopictus mosquitoes of Tinsukia, Dibrugarh and Sivasagar district. From the study, it was concluded that the Aedes mosquitoes have progressively started to developed resistance towards commonly used insecticides.

Population genetic study of Plasmodium falciparum parasites pertaining to dhps gene sequence in malaria endemic areas of Assam.

Plasmodium falciparum malaria parasite had developed resistance to almost all the currently used antimalarial drugs. The purpose of the study was to come across the genetic distances in P. falciparum dhps gene sequences circulating in Assam. A partial fragment of P. falciparum dhps gene containing major single nucleotide polymorphisms associated with sulphadoxine resistance were amplified and sequenced. Thereafter specific bioinformatics tools like BioEdit v7.0.9, ClustalW in Mega 5, DnaSP version v.5.10.01 etc were used for the analysis. A total of 100 P. falciparum positive cases in different malaria endemic areas of Assam were included for the study. Based upon the mutation analysis, a total of seven different P. falciparum dhps genotypes were observed with five variable sites. Maximum five haplotypes were found in the P. falciparum isolates from Jorhat district of Assam. Four polymorphic sites were observed in the P. falciparum dhps gene sequences in Karbi Anglong, NC Hills, Chirang and Jorhat whereas the isolates from other study areas had three polymorphic sites. A statistically significant positive value of Tajima’s D were observed among the P. falciparum field isolates in Assam indicating that there is an excess of intermediate frequency alleles and can result from population bottlenecks, structure and/or balancing selection. Extensive gene flow took place among the P. falciparum population of Jorhat with Sivasagar, Chirang with Sivasagar and Chirang with Karbi Anglong. However, large genetic differentiation was observed among the P. falciparum isolates of NC Hills with Lakhimpur, Tinsukia, Dibrugarh and Golaghat and also the parasite population of Karbi Anglong with Lakhimpur and Tinsukia signifying little gene flow among the population. This finding has shown that mutant Pfdhps gene associated with sulphadoxine resistance is circulating in Assam. It is believed that, the parasite population may have undergone high level of breeding.

Biological Activity of Essential Oils of two Variant of Cinnamomum Verum Presl. From North East India on Callosobruchus Chinensis (L.).

Callosobruchus chinensis (L.) (Coleoptera: Bruchidae) is one of the major insect pest infesting stored pulses in India. Recourse of synthetic insecticides to protect stored pulses often lead to dangers of the development of resistant strains, toxic residue and users safety. Locally available and less toxic pest management alternatives such as the use of effective botanicals are important. Essential oils of two variants of Cinnamomum verum Presl. Syn. C. zelanicum Blume from North East India (RRL J 1620 and RRL J 1622) were characterized and tested for their biological activity in vapour form against Callosobruchus chinensis (L.). Choice and no-choice tests showed that leaf and bark oil of two variants of C. verum Presl. had significant repellent action and reduced the fecundity and decreased egg hatchability of C. chinenisis (L.). However, leaf oil with higher percentage of eugenol exhibited better activity than the bark oil in both the tests. Hence, the volatile essential oils of both the variants of C. verum Presl. can be used safely as fumigants.

Left pulmonary artery agenesis with pulmonary hypoplasia in an elderly patient: a rare case report.

Proximal interruption of the unilateral pulmonary artery is a rare congenital anomaly, which is often associated with other cardiovascular abnormalities. It is usually diagnosed in children but rarely discovered in adulthood as an isolated phenomenon, occurring more frequently on the right side and is often associated with a contralateral aortic arch. We are presenting a rare case of a sixty year old male who was diagnosed with left lung hypoplasia due to proximal interruption of left pulmonary artery with left sided aortic arch without any associated cardiovascular anomalies.

Survey of new mosquito species of Meghalaya, India .

A study on mosquitoes in parts of Meghalaya revealed the presence of 64 species of mosquitoes under 10 genera. In monsoon (June to October) and post-monsoon (November to May) survey, 42 and 48 species of mosquitoes were detected, respectivily. Higher species diversity was found at lower elevations (up to 1050 m). Anopheles peditaeniatus, An. sinensis, Aedes vexans, Ae. nigrostriatus, Ae. annandalei, Culex. fuscocephala, Cx. pseudovishnui, Cx. murrelli, Cx. brevipalpis, Coquillettidia novochracea, Lutzia halifaxii, Malaya genurostris, Ml. jacobsoni, Tripteroides aranoides, Toxorhynchites minimus, Uranotaenia campestris, Ur. edwardsi and Ur. testaceae which were never reported earlier from Meghalaya state were detected in the present study and the findings were discussed with previously published reports from the state.

Pulmonary Lymphangitis Carcinomatosis In Primary Oesophagogastric Carcinoma.

Pulmonary Lymphangitis carcinomatosis is an unusual metastatic manifestation of Oesophagogastric carcinoma and it occurs due to diffuse spread of the tumour to the pulmonary lymphatic system. We described a case of a 28 year old woman, presenting with gradually progressive dyspnoea and cough where results of Chest X-ray and HRCT thorax were consistent with features of Lymphangitis carcinomatosis. Upper GI endoscopic evaluation showed a tumour originating from oesophagogastric junction and extending to cardia of stomach. Biopsy from tumour revealed adenocarcinoma. As there is no definitive therapy to this condition, patient was managed conservatively only to succumb few days after hospitalisation.

Survey of mosquito species in Nagaland, a hilly state of north east region of India.

In an entomological study conducted during monsoon and post- monsoon season in the hilly state of Nagaland, a total number of 58 mosquito species under 11 genera were recorded. Out of these, 21 species viz., Aedes aegypti, Ae. nigrostriatus, Ae. annandalei, Ae. vittatus, Ae.caecus, Ae. vexans, Armigeres kuchingensis, Culex fuscocephala, Cx. pseudovishnui, Cx. murrelli, Cx. brevipalpis, Cx. epidesmus, Cx. minor, Cx. whitmorei, Coquilittidae crassipes, Malaya jacobsoni, Ml. genurostris, Toxorhynchites splendens, Uranotaenia campestris, Mansonia dives and Ma. annulifera were recorded for the first time from this state. Eleven mosquito species recorded earlier were not detected in the present study. Thus, with the addition these 11 species, the total mosquito fauna of the state goes up to 69. All the recognized vectors of malaria in the northeast and the vectors of Japanese encephalitis and dengue are recorded in the present study.

Mosquito biodiversity of Dibru-Saikhowa biosphere reserve in Assam, India.

Entomological surveys were conducted for three consecutive years in core and buffer zone of the Dibru-Saikhowa biosphere reserve in pre monsoon, monsoon and post-monsoon seasons. A total of 52 species of mosquitoes under eleven genera have been detected. The genus Anopheles (18 species) was the predominant followed by Culex, Aedes, Mansonia, Armigeres, Mimomyia, Ochlerostatus, Malaya, Toxorhynchites, Ficalbia and Aedeomyia. The buffer zone of the forest reserve where human habitations are there exhibited the presence of maximum number of species (49 species under 10 genera) in comparison to core zone (42 species under 10 genera). In buffer zone, maximum numbers of species (38) were recorded in monsoon season followed by post- monsoon (35 species) and Pre-monsoon season (34 species). Whereas in core zone, maximum number of species were collected in post monsoon season followed by pre monsoon season and monsoon season. In Core and buffer zone, the maximum species were recorded from the ground pool habitat and slow flowing stream respectively. Among the disease vectors, the potential Japanese encephalitis vectors incriminated in India were very much prevalent. This study provides the list of available mosquito species recorded for the first time in the Dibru-Saikhowa biosphere reserve.

Efficacy of cabergoline on rapid escalation of dose in men with macroprolactinomas.

Background & objectives: Since cabergoline has a long half-life and sustained occupancy of dopamine (D2) receptors in lactotrophs, its doses are slowly built up either monthly or two monthly. This possibly results in delayed normalization of serum prolactin and slow reduction in tumour size. This study was planned to assess the efficacy and safety of rapid escalation of cabergoline doses in men with macroprolactinomas. Materials: Fifteen consecutive men with macroprolactinomas underwent evaluation for anterior pituitary functions, visual fields, quality of life (QOL) score and magnetic resonance imaging (MRI), at baseline and after 6 months of cabergoline therapy. Serum prolactin and testosterone levels were assessed at monthly intervals. Cabergoline was started at a dosage of 0.5 mg twice per week and increased to 1.5 mg twice per week (3 mg ) by the third week, as 3 mg is usually considered as effective dose. Subsequent increase in doses was done as per protocol. Results: The mean age of patients at presentation was 31.7 ± 3.3 yr and duration of symptoms was 25.0 ± 3.6 months. Serum prolactin at baseline was 6249.3 ± 3259.2 μg/l with a tumour volume of 28.9 ± 8.3 cm3. Eighty six per cent of the patients had visual field defects while 53 per cent had decreased visual acuity. The mean dose of cabergoline required was 3.2 mg/wk. Symptoms improved in majority (93%) of patients after four weeks of cabergoline therapy with a dramatic fall in serum prolactin by 99 per cent from 6249.3 ± 3259.2 to 46.9 ± 14.9 μg/l and it was normalized in 93 per cent of the patients by 8.2 wk. Improvement in visual field defects was noted in all but one, after one month and there was further improvement at 6 months. All patients had >25 per cent reduction in tumour size, and 73 per cent had > 50 per cent reduction after six months of cabergoline therapy. Basal circulating testosterone levels were low in 11 (73%) patients and started improving from first month of cabergoline therapy and became normal in around half of the patients after 6 months. No major side effects were observed requiring discontinuation of cabergoline therapy. Interpretation & conclusions: Our preliminary findings show that rapid build-up of cabergoline doses increases its efficacy as well as rapidity of response in terms clinical improvement, normalization of serum prolactin and gonadal functions and reduction in tumour size, without compromising its safety in men with macroprolactinomas. Further studies with a larger sample size and control group for comparison need to be done to confirm these findings.

Hypophosphataemic rickets/osteomalacia: A descriptive analysis.

Background & objectives: Hypophosphataemic rickets/osteomalacia (HRO) is an uncommon metabolic bone disorder which affects all ages and either sex. It is characterized by low concentration of serum phosphate levels leading to impairment of mineralization of bone matrix with variable aetiology. We present clinical profile and treatment outcome of 17 patients of HRO. Methods: Seventeen consecutive patients (8 were < 18 yr of age, with median age of presentation being 27.5 yr) of HRO who came to the department of Endocrinology in a tertiary care hospital in north India from January 2000 to December 2006 were included in the present study. Their aetiology, clinical features, biochemical parameters, radiographic features, treatment and outcome were analyzed. Results: HRO was commoner in females (70.5%) with positive family history observed in 6 (35.3%) patients. Common presenting features were short stature (58.8%), backache (58.8%), bony deformities (58.8%), joint pain (52.9%), fractures (29.4%) and dental abnormalities (23.5%). Radiological abnormalities noted were generalized bony deformities (58.8%), fractures (29.4%), and pseudo fractures (17.6%). Mesenchymal tumours were localized in the pelvis in one patient and in the right jaw in another. The patients were treated with calcium (elemental calcium 1 g/d) and oral phosphate supplements (dose 30 – 50mg/kg/day in divided doses) along with active vitamin D supplements (dose 1- 3 μg/day) and followed up for a mean of 2 yr. Two patients also received growth hormone (GH) therapy in the dose of 2U/day for 6 and 18 months respectively. Symptomatic well being was reported by all the patients and improvement was noted in the levels of phosphate (P<0.005) and alkaline phosphatase (P<0.05) after treatment. Interpretation & Conclusions: A diagnosis of HRO should be considered in all patients presenting with short stature, deformities or musculoskeletal pains along with low serum phosphate with normal iPTH and 25 – hydroxy vitamin D.

Osteogenesis imperfecta.

Background: Osteogenesis imperfecta (OI) is a rare metabolic bone disorder characterized by increased bone fragility, low bone mass, recurrent fractures and numerous extra-osseus features. Many patients remain undiagnosed and unattended particularly in developed countries. Presently, medical management with bisphosphonates has changed the scenario. Materials and Methods: Twenty consecutive patients of OI were enrolled over a period of four years. Their clinical features, radiology, and biochemical parameters and treatment outcome were analysed. Results: Of the 20 patients, 16 (80%) were male and 4 (20%) were female. Mean age (SD) of the patients was 20.8 (13.8) years. All the patients had presented with fractures, the number of fractures per person varying from 1 to 20. Long bones were predominantly involved and thirteen (65%) had deformities of long bones. Ten (50%) had a positive family history of fractures after trivial traum. Eleven (55%) patients had dentiginous imperfecta (DI) and ten (50%) had blue sclerae at presentation. Impaired hearing was present in 1 patient only. Calcium profile was normal. Nine patients received pamidronate. Fracture frequency and pain decreased remarkably in these patients. Conclusion: Patients with OI presented late, predominantly with fracture of long bones, deformities and blue sclerae. Pamidronate therapy remarkably decreased fractures and pain in these patients. ©

Proliferative glomerulonephritis with acute renal failure-a rare manifestation in seronegative rheumatoid arthritis.

A 55 years old lady with advanced rheumatoid arthritis (RA) presented with severe acute renal failure with significant proteinuria preceded by fever for 14 days. She had no history of taking drugs usually responsible for glomerulonephritis, neither had she any clinico-biochemical evidence of peri-infectious glomerulonephritis. Acute interstitial nephritis (AIN) was excluded by absence of eosinophilia and eosinophils in urine. Renal biopsy reveled absence of amyloidosis and showed Focal segmental proliferative glomerulonephritis (FSGN). Patient was successfully managed with methyl-prednisolone followed by steroid and immunosuppressive and patient came over renal failure. So FSGN should be considered as one of the causes of acute renal failure in a patient with seronegative RA which may respond to immune-therapy like rapidly progressive glomerulonephritis.

Ectopic Cushing's syndrome: experience from a tertiary care centre.

BACKGROUND & OBJECTIVE: Ectopic secretion of adrenocorticotropic hormone (ACTH) is rare, contributing to 10 per cent cases of endogenous Cushing's syndrome. We describe our experience of about two decades of patients with ectopic Cushing's syndrome (ECS) seen at a tertiary care centre from north India. METHODS: Records of patients with ECS from 1985 to 2006 were retrospectively reviewed that included the presenting manifestations, clinical symptoms and signs, biochemical investigations including plasma cortisol, ACTH and high dose dexamethasone suppression test (HDDST), imaging modalities to localize the non pituitary source of ACTH production, management and follow up of these patients. RESULTS: The study group included 12 patients (7 men) with mean (+/-SD) age at presentation 27.6 +/- 9.5 yr (range 13 to 48 yr) and the mean lag period between onset of symptoms and the diagnosis was 18.3 +/- 12.9 months with a range of 3 to 48 months. The weight loss (41.7%) followed by hyperpigmentation (25%) and infections (16.7%) were the common presenting manifestations. Cuticular atrophy (100%), hypertension (100%), bruise (92%) and proximal myopathy (83%) were the commonest signs. Plasma cortisol at 0800 h was 1267.3 +/- 483.3 nmol/l and at 2200 h was 1214.9 +/- 442.6 nmol/l indicating loss of circadian rhythm. The mean plasma ACTH was 221.1 +/- 55.9 (range 21.7 to 950 pg/ml). All but 2 patients had non-suppressibility of 0800 h plasma cortisol with HDDST. Five patients had thymic carcinoid, 3 had bronchial and one each had islet, hepatic and gut carcinoid and one had medullary thyroid carcinoma as a cause of ectopic ACTH secretion. The mean duration of follow up of these patients was 42.6 months and only two could sustain cure while remaining had either residual or recurrence. INTERPRETATION & CONCLUSION: Ectopic Cushing's syndrome is a rare disease with varied manifestations and associated with increased morbidity and mortality. It presents with clinical features quite similar to classical Cushing's. Surgery with removal of primary tumour was found to be treatment of choice.

Eradicating Polio: It's Feasibility in Near Future.

Continuous wild poliovirus transmission despite 12 years of intensive surveillance has raised serious questions about the feasibility of polio eradication programme with current strategy in near future. At present most of the cases are confined to four endemic countries, which are causing sporadic outbreaks in non-endemic areas. India has experienced a significant increase in number of cases reported in 2006 compared to previous year. Outbreaks originated in western UP which was due to the accumulation of susceptibles between the last outbreak in 2002 and early 2006. Substantial improvement has been observed in strategies of polio eradication but still there are gaps in the programme implementation which needs immediate attention so that goal of polio eradication can be achieved at the earliest opportunity. Even though there are many issues but there are also many factors, which favour polio eradication. These factors include new tool in form of m OPV, natural immunity due to recent outbreak, limiting international spread of polio, new researches to guide programme in right direction, political commitments from endemic countries, etc. 2008 presents the best opportunity ever to interrupt wild polio virus transmission which will lead to global eradication of Polio. Since global eradication is within sight, it is scientifically possible to eradicate the disease in near future.

Disseminated Langerhans cell histiocytosis-an interesting case report with concise review of literature.

A 2-year-old boy presented with fever, recurrent infections and multiple skin lesions. He had anemia, eczematous skin lesions, cervical lymph node enlargement, hepatomegaly and lytic lesions on skull x-ray. The skin infiltrates were CD 68, CD 1a positive and S100 positive. He was diagnosed as disseminated langerhans cell histiocytosis. The occurrence of histiocytosis is reviewed and possible treatment is discussed.

Angiogenesis in myelodysplastic syndromes (MDS) in Indian patients.

Angiogenesis plays an important role in the pathogenesis of haematological neoplasms and may be correlated with the prognosis. We recently evaluated the microvessel densities in trephine biopsy sections of seventeen patients of myelodysplastic syndromes (MDS). Of the 17 cases, 2 were RAEB-t, 3 were RAEB, one was RARS and 11 were of the subtype RA (FAB subtyping). The microvessel counts were measured in the bone marrow biopsy sections by immunohistochemical staining, using CD34 reactive monoclonal antibodies. MVD was significantly higher in the cases of RAEB and RAEB-t as compared to the cases of RA. The average MVD per x400 in the cases of RA was 5.7 +/- 4.7 with a median value of 4.65 (range 19) whereas it was 45.4 +/- 10.0 and 44.0 (range 27.3) respectively in RAEB and RAEB-t (p <.001), the 95% confidence interval being (2.94, 8.5) and (36.6, 54.3), for the two groups respectively. This finding may imply that subtypes of MDS with a higher tendency for converting to acute leukaemia are associated with increased angiogenesis as compared to other subtypes where the risk of progression to acute leukaemia is much lower.

Histopathological changes in experimental cholera with a non toxigenic non- O1 non-O139 Vibrio cholerae strain isolated from Kolkata, India.

This study was conducted to understand the pathophysiological changes in experimental rabbit ileal loop model using the Vibrio cholerae strain non-O1non-O139, isolated as sole pathogen from clinically diagnosed cholera patients in Kolkata. Significant amount of haemorrhagic fluid accumulation was observed in all the test loops of rabbit model where the strain of V.cholerae was inoculated as compared to control loops. Microscopic examination of the accumulated fluid showed the presence of erythrocytes and pus cells. Histology revealed structural alteration of the villous epithelium with inflammatory cells infiltration in all the layers of the gut mucosa including the nerve plexus region. Preliminary observation with a haemagglutinin protease extracted from the non-O1 non-O139 strain, was also studied in different concentrations in the same animal model which showed similar type of macroscopic and microscopic response in the ileal loops as seen with the original strain. The results highlight that along with other pathways, inflammatory cells and the enteric neurons have an important role in the pathophysiology of diarrhoea and the isolated protease may be the probable virulence factor in initiating the disease process in this non-O1non-O139 strain induced cholera.

Pathophysiology of prediabetes.

Type 2 diabetic patients pass through a phase of impaired glucose tolerence and/or impaired fasting glucose known as 'prediabetic state'. Prediabetic state form a part of syndrome X, other components being obesity, hypertension, dyslipidaemia, hyperinsulinaemia and insulin resistance. The pathophysiology of prediabetes is similar to type 2 diabetes mellitus, two basic defects are insulin resistance and early beta cell failure. In prediabetes, the rapid oscillations of insulin secretion are lost and amplitude of large pulses are decreased. When insulin is delivered in a pulsatile fashion that mimics the normal rapid oscillation, its hypoglycaemic effects are greater. In prediabetes, the glycaemic excursions after each meal are high and early insulin responses to meals tend to be lower than normal but the second phase of insulin secretion is delayed and prolonged.