Studies on nest construction and nest microclimate of the Baya weaver, Ploceus philippinus (Linn.).

The nest construction pattern at different stages of nest and variations in the nest microclimate, i.e., temperature and light intensity were assessed in different nests of Baya weaver (Ploceus philippinus) between November 2002 and March 2003 in Nagapattinam and Tiruvarur District of Tamil Nadu, India. The Baya weaver constructed nests in palm (Borassus flabellifer), coconut (Cocos nucifera) and date palm trees (Phoneix psuilla) and majority of the nests were found in the solitary palm. The male bird only involved in the construction and took 18 days to construct a single nest. The birds spent different amount of working hours (in terms of days) for completing various stages of nests viz., wad, ring and helmet stage and in which the 'helmet stage took a maximum of eight days. Furthermore, totally eight active nests were selected and once in a week the variations in the nest microclimate was investigated with reference to atmospheric temperature and light intensity (two active nests) across day throughout the study period. The mean temperature of the nests ranged from 25 degrees C to 29 degrees C and light intensity varied between 25 Lux and 625 Lux. The analysis of variance (ANOVA and ANCOVA) indicated that the nest microclimate varied among the nests in different hr of a day

Transcatheter closure of perimembranous ventricular septal defect with amplatzer membranous occluder.

BACKGROUND: Use of trancatheter device closure for membranous ventricular septal defect is still in evolving phase. We report the early and mid-term results of our experience with the new asymmetric Amplatzer membranous ventricular septal defect occluder. METHODS AND RESULTS: We attempted, transcatheter closure of perimembranous ventricular septal defect using asymmetric Amplatzer occluder in 26 patients. The patients were selected on the basis of transthoracic and transesophageal echocardiographic assessment of the ventricular septal defect. The procedure was successful in 21 (81%) patients. The age ranged from 3 to 23 years, weight from 10 to 59 kg and defect size ranged from 3 to 9 mm (mean: 5 +/- 1.8 mm). One patient had situs inversus with dextrocardia: 11 had aneurysmal tissue partly occluding the defect and the device was deployed either across (n=6) or within the aneurysmal sac (n=5). Three patients developed high degree atrioventricular block on attempts to cross the defect with the sheath and the procedure was discontinued. In two patients it was not possible to place the sheath in left ventricle despite repeated attempts. There was a residual flow in 4 (19%) patients at 24 hours. Two patients developed bundle branch block and none had complete heart block. At follow-up (1-9 months, n=20), residual flow was seen in two patients. None developed late conduction defect, aortic regurgitation, infective endocarditis or hemolysis. CONCLUSIONS: Transcatheter closure of perimembranous ventricular septal defect can be performed safely and effectively with the new asymmetric Amplatzer occluder device in selected patients with good short- and midterm results. These devices can be deployed safely in and across and the aneurysmal sacs. In selected cases, this procedure is a satisfactory alternative to surgery.

Studies on Merops orientalis Latham 1801 with special reference to its population in Mayiladuthurai, Tamil Nadu.

Role of habitat-structure and climatic factors in the population dynamics of the small green bee-eater Merops orientalis was evaluated in three habitats viz., agricultural lands, river banks and human habitations during 1991-1993. The river banks supported relatively high population of bee-eaters (157/Km2) followed by the agricultural lands (101/Km2) and human habitations (58/Km2). Bee-eater populations showed year-wise variations in river banks and human habitations having high values during 1992 (123/Km2) and 1993 (43/Km2) respectively. Agricultural lands showed a significantly low mean density in 1991 than other years. Seasonal variations in the bee-eater densities among the habitats were also recorded. Vegetation structure, food (insects) availability, climatic conditions and human disturbance were the casual factors for variations in bee-eater populations.

Optic disc size in ocular hypertension.

PURPOSE: To study the optic disc size in eyes with ocular hypertension (OHT) in comparison to primary open-angle glaucoma (POAG) and normals. METHODS: Optic disc photographs obtained with the Nidek 3dx NM camera were digitized (Nikon coolscan) and disc area calculated using Littmann correction in a randomly chosen eye of 28 OHT, 42 POAG and 30 normal subjects. OHT was defined as increased intraocular pressure with no disc or field changes suggestive of glaucoma with open angles. RESULTS: The optic disc area in OHT was 9.47 +/- 1.09 mm2; 12.27 +/- 2.87 mm2 in POAG; and 12.11 +/- 2.83 mm2 in normal individuals. CONCLUSION: Using magnification corrected morphometry and the criteria for OHT diagnosis, the optic disc area in OHT was significantly smaller (p < 0.0001) in POAG and normals.

Ocular toxicity of tamoxifen.

Tamoxifen is an antioestrogen drug used widely in the management of oestrogen-dependent metastatic breast carcinoma. A number of ocular complications have been described secondary to tamoxifen therapy. We report two patients, one of whom had superior ophthalmic vein thrombosis and the other who had painful proptosis and acute angle-closure glaucoma with choroidal detachment secondary to tamoxifen therapy, both of which have not been reported earlier. In both patients the signs and symptoms resolved rapidly after the discontinuation of tamoxifen therapy. Awareness of the ocular toxicity of tamoxifen is essential as prompt withdrawal can result in resolution of most of the complications.

Post-penetrating keratoplasty glaucoma.

To study the risk factors in the development of glaucoma following penetrating keratoplasty, we retrospectively analysed 190 eyes of 185 consecutive patients who had undergone surgery during 1990. The donor button was larger by 0.2 mm and 0.5 mm in phakia and aphakia/pseudophakia patients, respectively. Over a mean follow-up period of 14.5 months, 52 of the 190 eyes (27.4%) either developed glaucoma de novo or had worsening of preexisting glaucoma. Of these 52 eyes, 38 were managed medically and 14 required surgery. From our study, aphakia (37%), pseudophakia (24%), preexisting glaucoma (81.8%), and regrafting (43.18%) were found to be the significant risk factors in the development of glaucoma following penetrating keratoplasty.

Isoproterenol infusion--an alternative to exercise testing.

Isoproterenol, as an exercise simulating agent, was evaluated in twenty subjects, ten normal volunteers and ten with Coronary Artery Disease (CAD). Both groups were evaluated using 0.5 ug increments of intravenous infusion of isoproterenol every 3 minutes with computerised ECG (Marquette Electronics--MAC PC) monitoring. The normal volunteers did not have significant ST segment depression even at heart rates of 130 BPM. The CAD groups showed diagnostic ischaemic ST segment depression at heart rates below 130 BPM. None of the subjects had any serious complications during or after the test. Isoproterenol infusion is a better alternative to exercise testing.