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Biomedical subjects

V Dev

Publications and source records attributed to V Dev.

At least 37 records · Page 2Linked to original sources
PubMed1995

Deltamethrin impregnated bednets against Anopheles minimus transmitted malaria in Assam, India.

Of the 20 Anopheles species caught in villages in Sonapur, Assam, only An. minimus was incriminated as a malaria vector by finding sporozoites in the salivary glands. It was found to be endophagic and endophilic in Assam and because its biting peaked after midnight it was a suitable target for insecticide impregnated bednets. After the withdrawal of DDT spraying and collecting a year's baseline data, deltamethrin impregnated nets were distributed in 3 villages, untreated nets were distributed in 6 villages and 3 were held as untreated controls. The population of each of these groups of villages was about 1700. The nets were well received by the local tribal population. Human landing catches with baits unprotected or under partially lifted nets showed that the nets provided a high degree of personal protection against all the local species of human biting mosquito. In addition, there was evidence for suppression of the An. minimus population in a village with treated nets. Malaria was monitored by weekly active surveillance in all the villages. In the untreated control villages the slide positivity rate and monthly parasite index rose significantly during the trial. In the villages with untreated nets, these parameters showed no significant change, but in the villages with treated nets they declined significantly. On the basis of these results, the widespread distribution of impregnated nets was recommended to the state health authorities.

Animals↗
PubMed1995

Susceptibility of Plasmodium falciparum to chloroquine in tea garden tribes of Assam, India.

P. falciparum was the predominant parasite ( > 80%) species in malaria ridden tea estates of Assam. A simplified 3 day in vivo test to determine chloroquine sensitivity in tea garden tribes revealed that the majority of the cases (85%) were S/RI, 7% were RI, and 3% were RII and 5% were RIII, respectively. Early case detection and treatment were deemed necessary to reduce morbidity and mortality due to P. falciparum in these tea estates.

Adolescent↗
PubMed1994

Current status and prospects for the use of temporary stents.

Temporary stenting appears to be an attractive potential therapy that combines some of the benefits of permanent stenting without the need for permanent endovascular prostheses and oral anticoagulation. The devices used for temporary stenting are still evolving. The Flow Support Catheter showed promise in the early clinical trial phase but is not being pursued by the original manufacturer because the device was associated with a high rate of thrombosis and suboptimal overall success rate. The experience with the Instent is limited and the removal of its unattached version relies upon catching the end of the stent in the retrieval device (a wire loop); also, its safety and reliability still need to be proved. The HARTS device is currently in the preclinical phase, but available data from animal studies show it to be a feasible device for coronary use. Its potential applications include use as a permanent stent, a temporary stent, a repositionable stent, a primary lesion-dilating device, or a local drug-delivery vehicle. Clinical trials are likely to commence in the foreseeable future for one or more of these applications.

Administration, Oral↗
PubMed1994

Localized arterial wall drug delivery from a polymer-coated removable metallic stent. Kinetics, distribution, and bioactivity of forskolin.

BACKGROUND: Coronary stenting is associated with two major complications: subacute thrombosis and neointimal proliferation resulting in restenosis. Our hypothesis is that the biocompatibility of metallic stents can be improved by coating with a polymer membrane that delivers agents that favorably modify the local arterial microenvironment. This study evaluates the kinetics, distribution, and bioactivity of the model drug forskolin delivered to the local arterial wall by a polyurethane-coated removable metallic stent. METHODS AND RESULTS: Stents were used in rabbit carotid arteries (n = 20) for as long as 24 hours. The quantity of forskolin bound to the stent decreased exponentially with a half-life of 5.8 hours. Blood concentrations peaked at 140 +/- 39 pg/microL at 4 hours. The adjacent arterial media contained 60 +/- 39 ng/mg, which was 380- and 460-fold greater than the contralateral carotid media and the systemic blood, respectively (P < .0001). Media forskolin concentrations declined exponentially over time with a tissue half-life of 5.0 hours. Drug distributed throughout the vessel wall with decreasing gradients in the radial and axial dimensions consistent with a diffusion process. Removal of the stent was associated with a 100-fold decline in media forskolin concentration within 2 hours. Forskolin release was associated with a sustained 92% increase in carotid blood flow and a 60% decrease in local arterial resistance compared with coated control stents (P < .005). In another set of rabbits (n = 14) using a carotid crush injury, flow-reduction model, forskolin prolonged the time to flow variation and occlusion by 12-fold compared with the use of bare metal stents and 5-fold compared with the use of polyurethane-coated stents (P < .0001). CONCLUSIONS: A polymer-coated metallic stent can deliver forskolin to the local arterial wall in high concentrations relative to the blood or other tissues. High local drug concentrations are dependent on maintaining stent-to-tissue gradients. The delivered drug is biologically active, demonstrating vasodilating and antiplatelet properties.

Alloys↗
PubMed1993

Management of hepatic venous outflow obstruction.

Hepatic venous outflow obstruction (HVOO) is a rare cause of portal hypertension and conservative treatment is usually ineffective. A large series of patients gave us an opportunity to devise a management protocol for this disorder. Between 1978 and 1992, we prospectively studied 75 patients with HVOO. The obstruction was in the hepatic vein in 24, in the inferior vena cava (IVC) in 44, and in both in 7. For hepatic vein obstruction proximal splenorenal shunts were done in 7 (2 died postoperatively); 4 shunts blocked and only 1 patient became completely symptom free. In 2 patients with partial obstruction we performed balloon dilatation of the right hepatic veins but within 6 months the obstruction recurred. In the next 6 patients we constructed a side-to-side portocaval shunt; 2 died of encephalopathy after discharge and 4 are alive and well. For IVC obstruction, after surgical procedures had yielded poor results in 14 patients, we changed to balloon angioplasty which was successful in 28 of the 30 other patients; restenosis occurred in 4. Of the 7 patients with a combined block, 3 have had balloon angioplasty followed by a side-to-side portocaval shunt; 1 died, 2 are well, and the remainder have not completed treatment. Of our 75 patients, 22 have died (5 in hospital and 17 after discharge), 7 have not completed treatment, and 2 have been lost to follow-up. However, 44 are symptom free. We did not encounter any case of hepatocellular carcinoma. We suggest that patients with HVOO should be actively managed with a side-to-side portocaval shunt for hepatic vein obstruction, balloon angioplasty for inferior vena caval obstruction, and perhaps both procedures for those with combined obstructions.

Adolescent↗
PubMed1993

Left ventricular diastolic function in end-stage renal disease and the impact of hemodialysis.

Twenty-one patients (17 men and 4 women, aged 20 to 40 years) with end-stage renal disease (creatinine clearance persistently < 5 ml/min for > 3 months) were evaluated for left ventricular (LV) diastolic function by Doppler echocardiography before and after hemodialysis. Fifteen patients were on maintenance hemodialysis (group A) and 6 were studied before and after their first hemodialysis (group B). The following indexes of LV diastolic function were studied: (1) isovolumic relaxation time; and (2) Doppler indexes from mitral inflow signal--peak early velocity, peak late velocity (atrial), deceleration of early filling phase, and deceleration time of early filling phase. LV systolic function in groups A and B (LV ejection fraction 68 +/- 6 and 77 +/- 5%, fractional shortening 0.39 +/- 0.06 and 0.46 +/- 0.05%) was normal and did not change after hemodialysis. Group A had a prolonged isovolumic relaxation time of 80 +/- 22 ms, which decreased to 57 +/- 14 ms (p < 0.005). Deceleration time decreased from 248 +/- 58 to 184 +/- 38 ms (p < 0.00005) and the deceleration slope increased from 4.3 +/- 1.8 to 5.1 +/- 1.6 m/s2 (p < 0.005) after hemodialysis. In group B, isovolumic relaxation time decreased from 87 +/- 21 to 73 +/- 15 ms (p < 0.05), deceleration time decreased from 256 +/- 43 to 185 +/- 34 ms (p < 0.05), and deceleration slope increased from 3.5 +/- 0.8 to 4.2 +/- 1.1 m/s2 (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Pulmonary balloon valvotomy for severe valvular pulmonic stenosis with congestive heart failure beyond infancy.

Isolated valvular pulmonic stenosis (PS) in association with tricuspid regurgitation and congestive heart failure (CHF) is rarely encountered after infancy, and there is very little information available regarding the application of pulmonary balloon valvotomy (PBV) for this subset of patients. Since 1985, 10 patients (5 males, 5 females; mean age: 12.4 +/- 7.5 years, range 4-25 years) underwent PBV for severe valvular PS with CHF in our institution. All patients had associated tricuspid regurgitation and cardiomegaly. Before PBV, the mean peak systolic gradient across the right ventricular outflow was 131 +/- 36 mmHg and the mean right atrial pressure was 14.4 +/- 5.4 mmHg. Specific modifications in the PBV technique included the sequential use of progressively larger balloon catheters and the use of an extra stiff guidewire to support the dilatation assembly. One patient underwent PBV via the right internal jugular vein. Problems encountered during PBV included hypotension and bradycardia (2 patients) and respiratory arrest, which was transient in one patient, and prolonged and eventually fatal in one patient. A successful outcome was achieved in 8 patients (4 of these required 2 PBV attempts) with a final residual gradient of 40 mmHg or less, mean 28 +/- 7; range: 21-38 mmHg) and complete resolution of CHF. One patient has had no significant change in gradients and awaits repeat dilatation. Patients with isolated severe valvular PS with TR and CHF represent a relatively high risk group for PBV. A successful outcome is, however, feasible if a carefully planned and cautious approach is used.

Catheterization↗
PubMed1993

Determinants of immediate and follow-up results of pulmonary balloon valvuloplasty.

The data of 93 patients (age 11.4 +/- 9.4 years, range 8 months-56 years) who underwent pulmonary balloon valvuloplasty (PBV) for valvular pulmonic stenosis (PS) in our institution are reviewed. The patients were classified into three groups: Group I (34 patients) had a right ventricular (RV) to aortic systolic pressure ratio of < 1, Group II (39 patients) had suprasystemic RV systolic pressures, and Group III (20 patients) included patients with elevated mean right atrial (RA) pressures irrespective of the RV systolic pressures. The percentage drop in immediate postdilatation peak systolic gradients (PSG) and the follow-up PSG were similar in the three groups and were not influenced by any predilatation patient characteristics. A balloon-annulus ratio < 1 predicted a poorer follow-up outcome. Nine patients, eight of Group III and one of Group II, experienced difficult procedures requiring sequential use of progressively larger balloon catheters. Eleven patients, six of Group II and five of Group III, experienced procedure-related events (hypotension, bradycardia/asystole, hypoxia, apnea, tachyarrhythmias, and seizures) and one patient (Group II) died. Although changes in immediate and follow-up gradients after PBV are not influenced by the severity of PS, difficult procedures and procedure-related events are particularly common in patients with severe PS and elevated RA pressures. A cautious and planned approach is therefore indicated in these patients.

Adolescent↗
PubMed1993

Percutaneous balloon mitral valvuloplasty: analysis of echocardiographic and other variables related to outcome.

To determine whether mitral valve (MV) morphology influences the result of balloon mitral valvuloplasty (BMV) for mitral stenosis, two-dimensional echocardiography was performed before BMV in 53 patients and in 25 normal controls. The two-dimensional echocardiographic features of MV leaflets: thickness, length and motion, diastolic MV excursion, chordal length, MV annular diameter (MVAnD), subvalvular distance ratio (SDR), and effective balloon dilating area (EBDA) and diameter (EBDD) were then correlated to the immediate post-BMV mitral valve area (MVA). For the total patient population, post-BMV MVA increased from 0.76 +/- 0.24 to 1.91 +/- 0.59 cm2 (p < 0.0001) and mean diastolic transmitral gradient decreased from 20.1 +/- 6.15 to 5.8 +/- 3.29 mm (p < 0.0001). The patients were divided into two groups on the basis of post-BMV MVA. Group I had post-BMV MVA < 2.0 cm2 and group II had post-BMV MVA > or = 2.0 cm2. A statistically significant difference was noted in SDR (0.33 +/- 0.057 vs 0.45 +/- 0.042, p < 0.0001); mid-MV anulus to tip of papillary muscle (PM) distance (20.0 +/- 3.8 vs 27.9 +/- 4.54 mm, p < 0.0001); chordal length (4.3 +/- 3.6 vs 9.8 +/- 3.9 mm, p < 0.0001); diastolic MV excursion (15.5 +/- 2.6 vs 18.2 +/- 4.2 mm, p < 0.01); leaflet mobility (p < 0.05); and EBDA (4.4 +/- 0.6 vs 4.9 +/- 0.5 cm2, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Echocardiographic diagnosis of aneurysm of the sinus of Valsalva.

Echocardiographic and Doppler data of 62 patients with ASOV are presented. Catheterization and angiography were performed in 38 cases and surgery in 25 of the 38. The origin of these aneurysms was the RCS in 56 cases, NCS in 5, and LCS in 1 case. Seven had unruptured aneurysms, 6 rising from RCS dissected into the ventricular septum, producing heart block in 4, AR in 5, mitral regurgitation in 1; 1 aneurysm rising from the LCS was asymptomatic. In other cases (n = 55) the aneurysm had ruptured into one of the cardiac chambers. Thirty-two of the 50 RCS aneurysms ruptured into the RVOT, 13 into the RV cavity, 2 into the RA, and 3 into the LV. Of the 5 NCS aneurysms, (3 ruptured into the RA, 1 into the RV, and 1 into both the RA and RV. Associated VSD was identified in 16 (25.8%) of 62 cases. All of these patients had RCS aneurysms that ruptured into the RVOT. Echocardiography missed VSD in three cases that at surgery were found to have VSD. AR was found in 34 of 62 cases. Echocardiography picked up discrete subaortic stenosis in two cases but missed subvalvar PS in 2 of the 3 cases. A detailed echocardiographic study (two-dimensional, Doppler, and color flow imaging) is accurate in the diagnosis of ASOV, in the identification of its site of origin and rupture, and in the evaluation of the associated defects; in the vast majority of cases, it can totally supplant the need for angiography.

Adolescent↗
PubMed1993

Echocardiographic diagnosis of total anomalous pulmonary venous connection.

Over a 7-year period, 110 of 35,000 echocardiographic cases were diagnosed to have total anomalous pulmonary venous connection (TAPVC). Ages ranged from 7 days to 38 years (male 62, female, 48). In 60 cases the diagnosis was confirmed by angiography (n = 47) and/or surgery (n = 50). In 13 cases angiography was not performed; surgery was performed on the basis of echocardiographic diagnosis. Diagnosis of TAPVC was correctly made in all of the 60 confirmed cases. Drainage sites were correctly identified by echocardiography in 58 (96.7%) of these 60 cases. Of the five cases of mixed TAPVC, the second drainage site was missed by echocardiography in two cases. Of the 110 cases the drainage sites were as follows: supracardiac 70, cardiac 30, infracardiac 5, and mixed variety 5. Seventeen cases had Doppler echocardiographic evidence of obstruction along the course of the anomalous vein. The continuous wave Doppler signal for tricuspid regurgitation was present in 14 of 47 catheterized patients, and catheterization-measured peak pulmonary artery systolic pressure correlated well with that derived by Doppler study (r = 0.96, p = 0.001). Additionally, 17 patients had other cardiac anomalies that were correctly diagnosed by echocardiography. Combined two-dimensional and Doppler echocardiography is accurate in the diagnosis of TAPVC, identification of the site of drainage, presence of obstruction, and assessment of pulmonary arterial hypertension and other associated anomalies.

Adolescent↗
PubMed1993

Concurrent percutaneous balloon valvotomy for combined rheumatic tricuspid and aortic stenosis.

Concurrent percutaneous balloon valvotomy of aortic and tricuspid valve was successfully performed in a 20-year-old male with severe rheumatic aortic and tricuspid stenosis. Balloon valvotomy was done using a 18-mm single balloon for aortic and 20 + 20-mm double balloon for the tricuspid valve. Immediately after valvotomy the peak transaortic systolic gradient decreased from 120 to 32 mmHg and the aortic valve area increased from 0.27 to 1.1 cm2, the mean and end-diastolic trans-tricuspid gradient decreased from 14 and 18 to 1.5 and 2 mmHg, respectively, the tricuspid valve area increased from 0.8 to 3.6 cm2 and the cardiac-index increased from 2 to 2.9 l/mt/m2. At 1 year of follow-up the clinical (NYHA class 1) and hemodynamic improvement was maintained.

Adult↗
PubMed1993

Anopheline fauna and malaria incidence in Changlang District (Arunachal Pradesh).

Data on malaria incidence and prevalence as well as on abundance of anopheline species collected in Jairampur, Arunachal Pradesh, show that P. falciparum contributed 27.59% of the total positive cases, most of these being recorded during July to September. Of the twelve anopheline species recorded, Anopheles maculatus was the most predominant comprising 54.32% of the total collection. Other common species were An. peditaeniatus, An. philippinensis and An. kochi in order of decreasing proportion. An. dirus, the known vector, was collected in the whole-night human bait catches (indoor) but in low numbers. An. philippinensis is implicated as another potential vector, and changes in anopheline/vector fauna are attributed to ecological succession.

Animals↗