Role of Animal Danders as Inhalant Allergens in Bronchial Asthma in India

The etiological significance of animal danders in Indian patients with nasobronchial disorders has not yet been investigated. In the present study, the role of animal danders in the etiology of bronchial asthma was studied. Extracts of danders from 6 animals along with guinea pig whole pelt were prepared. Intradermal and bronchial provocation tests with these extracts were performed on (i) 68 asthmatics and (ii) 20 nonallergic healthy volunteers. In patients, significant positive skin reactions (2+ to 4+) ranged from 1.4% each with guinea pig whole pelt and ox dander to 8.8% with dog dander extracts. None of the healthy volunteers elicited such a response. On bronchial provocation, 20% and 53.8% of the tests were positive in asthmatics showing 1 +and 2+skin reactivity, respectively. All the patients as well as controls eliciting negative intradermal responses demonstrated uniformly negative bronchial provocation tests to different dander extracts. Analysis of various clinical features of asthmatics with respect to skin positivity to dander/pelt extract was also carried out. Radioallergosorbent tests (RASTs) were performed to estimate dander-specific IgE levels in the sera of patients showing different grades of skin response to dander extracts of dog, horse, and goat. Sixty percent of sera from the patients showing 2+ to 4+ skin reactivity to various animal dander extracts showed positive RASTs. RAST positivity as well as RAST ratio increased with increase in the intensity of skin response. All the patients with positive cutaneous as well as positive bronchial responses also showed positive RASTs. Similarly, all the patients with positive skin and positive RASTs showed positive bronchoprovocation tests. These results suggested that animal danders play an important role in the etiology of bronchial asthma. Some of the clinical characteristics of asthmatics, such as (i) early age at onset of asthma, (ii) positive family history, and (iii) asthma with associated allergies, have significant bearing on the cutaneous response to various dander extracts.     

Redo mitral valve surgery using the port-access system

Redo mitral valve surgery is hazardous, hence we explored an alternative approach using a port-access system that avoids reentry. Between October 1997 and December 2000, 32 patients underwent mitral reoperation using the system. All patients had previous cardiac operations. This procedure consisted of a right anterolateral minithoracotomy and femorofemoral cannulation using special port-access instruments and endoaortic clamping in 24 patients or direct transthoracic sliding-rod aortic clamping in 8. The valve disease was of rheumatic etiology in 28 patients and degenerative in 4. The valve was replaced in 31 cases and a paravalvular leak after mitral valve replacement was closed in 1. In 2 cases, the tricuspid valve was repaired along with mitral valve replacement. Mean total operating time was 4.5 +/- 1.2 hours, cardiopulmonary bypass time 162 +/- 72 minutes, and aortic crossclamp time 62 +/- 21 minutes. There was no mortality, and mean stay in the intensive care unit was 22 +/- 7 hours and hospital stay 6.4 +/- 1.2 days. Postoperative blood transfusion was required in 12 patients. In view of the favorable results, we recommend using the port-access system as a standard approach for mitral reoperation.     

A 2-D/3-D model-based method to quantify the complexity of microvasculature imaged by in vivo multiphoton microscopy

This paper presents model-based information-theoretic methods to quantify the complexity of tumor microvasculature, taking into account shape, textural, and structural irregularities. The proposed techniques are completely automated, and are applicable to optical slices (3-D) or projection images (2-D). Improvements upon the prior literature include: (i) measuring local (vessel segment) as well as global (entire image) vascular complexity without requiring explicit segmentation or tracing; (ii) focusing on the vessel boundaries in the complexity estimate; and (iii) added robustness to image artifacts common to tumor microvasculature images. Vessels are modeled using a family of super-Gaussian functions that are based on the superquadric modeling primitive common in computer vision. The superquadric generalizes a simple ellipsoid by including shape parameters that allow it to approximate a cylinder with elliptical cross-sections (generalized cylinder). The super-Gaussian is obtained by composing a superquadric with an exponential function giving a form that is similar to a standard Gaussian function but with the ability to produce level sets that approximate generalized cylinders. Importantly, the super-Gaussian is continuous and differentiable so it can be fit to image data using robust non-linear regression. This fitting enables quantification of the intrinsic complexity of vessel data vis-a-vis the super-Gaussian model within a minimum message length (MML) framework. The resulting measures are expressed in units of information (bits). Synthetic and real-data examples are provided to illustrate the proposed measures.     

Association of HLA phenotype with primary non-response to recombinant hepatitis B vaccine: a study from north India.

The hepatitis B vaccine is considered to be highly immunogenic and has a good safety profile. In adults, it has a primary non-response rate of 5%-10%. Causes of nonresponse to hepatitis B vaccine include age, sex, obesity smoking. Certain human leucocyte antigen (HLA) phenotypes have been known to be associated with responsiveness to the vaccine, and found to be different in different ethnic groups, such as Caucasians and Orientals. The study was designed to identify the HLA phenotypes that are associated with non-responsiveness to hepatitis B virus (HBV) vaccination amongst a cohort of Indian subjects who agreed to participate in the vaccination programme. The study was offered to 107 volunteers, of whom 102 were found to be negative for HBV markers (hepatitis B surface antigen [HBsAg], anti-HBc, anti-HBe, anti-HBs, hepatitis Be antigen [HBeAg]) . All 102 volunteers were offered recombinant hepatitis B vaccine (20 microg) at 0, 1, and 6 months. Anti-HBs antibody titres were tested on days 90 and 210 of the first vaccine dose. HLA typing was done using standard microlymphotoxicity tests. The seroconversion rate of the hepatitis B vaccine was 86.3% (88/102). Fifteen nonresponders (15/102) and 15 of the 88 responders were randomly selected after age and sex matching for the purpose of studying the HLA phenotypes. HLA subtypes A1, B15, B40, A10 and DQ2 were found to be increased among nonresponders while HLA- A11, C3, DR10, DR51 (p>0.05) were the most common phenotypes amongst the responders. Further studies are needed to characterize the HLA phenotypes amongst the responders in different ethnic groups in India with respect to HBV vaccination.     

A clinical trial of 7 alpha-methyl-19-nortestosterone implants for possible use as a long-acting contraceptive for men

Several preparations of testosterone and its esters are being investigated alone or in combination with other gonadotropin-suppressing agents as possible antifertility agents for men. We studied the effectiveness of 7 alpha-methyl-19-nortestosterone (MENT) as an antispermatogenic agent in men. MENT has been shown to be more potent than testosterone and to be resistant to 5 alpha-reduction. For sustained delivery of MENT, we used a system consisting of ethylene vinyl acetate implants containing MENT acetate (Ac), administered subdermally. Thirty-five normal volunteers were recruited in 3 clinics and were randomly assigned to 1 of 3 doses: 1 (12 men), 2 (11 men), or 4 (12 men) MENT Ac implants. The initial average in vitro release rate of MENT Ac from each implant was approximately 400 micro g/day. Implants were inserted subdermally in the medial aspect of the upper arm under local anesthesia. The duration of treatment was initially designed to be 6 months. However, in 2 clinics the duration of treatment was extended to 9 months for the 2-implant group and to 12 months for the 4-implant group. Dose-related increases in serum MENT levels and decreases in testosterone, LH, and FSH levels were observed. Effects on sperm counts were also dose related. None of the subjects in the 1-implant group exhibited oligozoospermia (sperm count, <3 million/ml). Four subjects in the 2-implant group became oligozoospermic, 2 of whom reached azoospermia. Eight subjects in the 4-implant group reached azoospermia, with 1 exhibiting oligozoospermia, whereas 2 were nonresponders. Side effects generally seen with androgen administration, such as increases in erythrocyte count, hematocrit, and hemoglobin and a decrease in SHBG, were also seen in this study and were reversible. Changes in lipid parameters were moderate and transient. Liver enzymes showed small changes. This study demonstrates that MENT Ac, when administered in a sustained release fashion via subdermal implants, can inhibit spermatogenesis over a prolonged period after a single administration and has the potential to be used as a male contraceptive.     

Variations in the insecticide-resistance spectrum of Anopheles stephensi after selection with deltamethrin or a deltamethrin-piperonyl-butoxide combination

When the larvae of Anopheles stephensi, a malaria vector, were selected with deltamethrin for 40 successive generations, there was a 60-fold increase in larval resistance to deltamethrin but no increase in the resistance of the adult mosquitoes. This result, and the observation that deltamethrin selection of adults for 40 generations resulted in only a six-fold increase in adult resistance to deltamethrin, indicated some stage specificity. When F(24) deltamethrin-resistant larvae were selected with 1:5 deltamethrin-piperonyl butoxide (deltamethrin-PBO), instead of deltamethrin alone, for 16 generations, the level of resistance to deltamethrin in the F(40) larvae was reduced by 6%-21%. Similarly, selection with deltamethrin-PBO of adults of the parental strain for 20 generations reduced the speed of the development of resistance to deltamethrin, compared with that seen using selection with deltamethrin alone. Deltamethrin selection appears to select initially a monooxygenase-based mechanism. When the monooxygenase-based mechanism is blocked, by treatment with PBO, selection of a kdr-type mechanism is accelerated, as is evident from increased cross-resistance to 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) in the adults selected with deltamethrin-PBO. The implications of these results are discussed in terms of the management of the larval and adult stages of An. stephensi .     

Left Main Myocardial Infarction in a Healthy Young Male—A Case Report

Acute left main coronary artery occlusion is a catastrophic and mostly fatal event. Patients may present with sudden death or cardiogenic shock. Intra-aortic balloon pump support and emergency revascularization is indicated to preserve the left ventricular function. We describe a case of left main thrombus in a health 24-year-old young male with no risk factors for coronary atherosclerosis.