Larval habitats and species composition of mosquitoes in Darjeeling Himalayas, India

BACKGROUND & OBJECTIVES: A preliminary survey of larval mosquito habitats and temporal variation in mosquito diversity in the hill town of Darjeeling, India was made during 2003, for a qualitative and quantitative assessment of mosquito distribution. METHODS: The possible larval habitats of mosquitoes were surveyed and the species diversity in the sites positive for mosquito larvae was noted. Bi-weekly sampling from a particular habitat was carried out to reveal the temporal variation in mosquito species. RESULTS: A good number of lentic aquatic habitats were found to be hosting mosquito immatures, though difference in the physical and biological features of these habitats was prominent. Altogether, immatures of six mosquito species, belonging to four genera--Aedes, Armigeres, Culex and Toxorhynchites were noted with significant difference in temporal variation in their relative and absolute numbers. A positive correlation (r = + 0.707) was found between population of the prey mosquito immatures and the population of immatures of Tx. splendens. The species diversity index (H') for the mosquitoes remained between 0.87 and 1.53. The evenness components ranged between 54.03 and 95.03% and differed significantly. INTERPRETATION & CONCLUSION: In the present study, the aquatic bodies could be categorised into six types depending on the size and structural complexity that may account for the observed variation in the species composition of the larval habitats. In addition to this, other factors like temperature, rainfall and other related climatic attributes may be responsible for the observed species variation, which needs to be confirmed through further studies.     

Cyclic intermittent hypoxia enhances renal sympathetic response to ICV ET-1 in conscious rats

To test the hypothesis that central changes in sympathoregulation might contribute to sympathoexcitation after cyclic intermittent hypoxia (CIH) we exposed male Sprague–Dawley rats to CIH or to room air sham (Sham) for 8 h/d for 3 weeks. After completion of the exposure we assessed heart rate, mean arterial pressure and renal sympathetic nerve activity in conscious animals before and after intracerebroventricular (i.c.v.) administration of endothelin-1 (ET-1, 3 pmol). CIH-exposed animals had a significantly greater sympathetic response to ET-1 than did Sham-exposed animals (CIH 137.8 ± 15.6% of baseline; Sham 112.2 ± 10.0% of baseline; CIH vs. Sham, P = 0.0373). This enhanced sympathetic response to i.c.v. ET-1 was associated with greater expression of endothelin receptor A (ETA) protein in the subfornical organs of CIH-exposed relative to Sham-exposed rats. We conclude that 3-week CIH exposure enhances central ET-1 receptor expression and the sympathetic response to i.c.v. ET-1 suggesting central endothelin may contribute to the sympathetic and hemodynamic response to cyclic intermittent hypoxia.     

Exploring the false discovery rate in multichannel NIRS

Near infrared spectroscopy (NIRS), an emerging non-invasive tool for functional neuroimaging, has evolved as a multichannel technique allowing simultaneous measurements through many channels ranging from below ten to above hundred. Simultaneous testing of such a large number of channels escalates the risk of Type I error, therefore multiplicity correction is unavoidable. To date, only a few studies have considered this issue using Bonferroni correction, which is an effective conservative solution, but may be too severe for neuroimaging. Its power varies in inverse proportion of the number of channels, which varies among NIRS studies depending on selected region of interest (ROI), thereby leading to a subjective inference. This problem may be well circumvented by a more contemporary approach, called false discovery rate (FDR) that is widely being adopted in functional neuroimaging. An FDR-based procedure controls the expected proportion of erroneously rejected hypotheses among the rejected hypotheses, which offers a more objective, powerful, and consistent measure of Type I error than Bonferroni correction and maintains a better balance between power and specificity. In this technical note, we examine FDR approach using examples from simulated and real NIRS data. The FDR-based procedure could yield 52% more power than Bonferroni correction in a 172-channel real NIRS study and proved to be more robust against the changing number of channels.     

Standard measures of right ventricular function assessment in adult patients with acute sickle cell crises

Chronic sickle cell (SC) disease is known to cause pulmonary hypertension (PH) which eventually affects right as well as left ventricular function. However, the acute effects of SC crisis on right ventricular (RV) function in adults have not been well described. Our echocardiography database was queried for patients followed in the outpatient hematology clinic, who were admitted with SC crises, and had an inpatient echocardiogram. Comparisons of RV fractional area change (RVFAC) and tricuspid annular peak systolic excursion (TAPSE) were then made to a group of healthy patients and a group with mild PH. TAPSE was normal in patients with SC disease (3.05+/-0.56). However, the SC patients had significantly larger RV's compared to controls and mild PH patients (31.33+/-7.23 cm(2) vs. 19.07+/-4.49 cm(2) and 21.51+/-6.07 cm(2), respectively, P<0.0001). RVFAC was reduced in SC patients, and was comparable to patients with mild PH (46+/-9% vs. 49 +/-14%, P=0.4). We found no correlation between hemoglobin level (8.1+/-2.5 g) and RVFAC, TAPSE, or PH severity. We found that adult patients admitted with SC crises have frequent dilatation of the RV with an abnormal reduction in RVFAC, despite normal TAPSE values. Therefore, caution should be exercised in using TAPSE to estimate RV function in this patient population.     

Isonicotinic acid hydrazide induced anagen effluvium and associated lichenoid eruption.

A 32 year-old woman developed generalised lichenoid eruptions on her body followed by diffuse loss of scalp hair of the anagen effluvium type. She was receiving several anti-tubercular drugs, including rifampicin, isonicotinic acid hydrazide (INH), pyrazinamide, and ethambutol, for abdominal tuberculosis. INH, which is a leading cause of drug eruptions in the above group of drugs was withdrawn. However, the other antitubercular drugs were continued along with 40 mg of prednisolone in a single daily morning dose. The latter was discontinued slowly over a period of 10 weeks. There was complete recovery of hair loss and the regrowth started after 12 weeks of alopecia. Such anagen effluvium with lichenoid eruption following INH therapy has not been observed previously. The complete recovery from anagen effluvium is difficult to explain, but it could have been because of the early initiation of corticosteroid.     

Changing author counts in five major general medicine journals: effect of author contribution forms

ObjectivesObjective and indirect evidence was used to determine whether required author contribution forms were associated with a decrease in author counts in four major general medicine journals (British Medical Journal [BMJ], Journal of the American Medical Association [JAMA], Canadian Medical Association Journal [CMAJ], and the Lancet). The number of authors listed per article before and after the introduction of explicit author contribution requirements were counted and compared with that found for the New England Journal of Medicine (NEJM) that did not require such disclosure. The primary hypothesis was that author counts decreased more in the BMJ, CMAJ, JAMA, and the Lancet after introduction of the rules than they did in the NEJM.Study Design and SettingThe number of authors listed per original research article published in the five general medical journals with the greatest 2004 Impact Factors in the first issue of each month in the years before and after introduction of required author contribution forms was compared.ResultsIntroduction of the required author contribution forms by the four leading general medical journals did not result in a drop in the rate of increasing authors per article per year, or in the number of authors per article compared with the control. Overall, there was a trend of an increasing number of authors listed per article.ConclusionBased on the presented objective and indirect evidence, required author contribution forms were not associated with a decrease in author counts.     

Multiple myeloma presenting as bilateral orbital proptosis

A 58-year-old-man presented with painful rapidly progressive bilateral proptosis with restricted ocular movements of 15 days duration. There was history of significant weight loss in the recent past. Computed tomography scan of the head and orbit revealed bilateral multiple, well-defined, round, soft tissue masses, isointense with muscles in intraconal and extraconal space. Fine needle aspiration cytology and incision biopsy from the lesion, urine for Bence-Jones proteins and immunofixation clinched the diagnosis of multiple myeloma. Skeletal survey did not reveal any bony involvement.The diagnosis of multiple myeloma should be kept in mind in cases of bilateral proptosis. Bony involvement is not universal in cases of orbital myeloma. Early diagnosis can be established with extensive biochemical and histopathological investigations and timely treatment is life saving for these patients.