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Biomedical subjects

A Saxena

Publications and source records attributed to A Saxena.

At least 235 records · Page 13Linked to original sources
PubMed1992

Renal artery stenosis caused by nonspecific arteritis (Takayasu disease): results of treatment with percutaneous transluminal angioplasty.

Renovascular hypertension is common in nonspecific aortoarteritis (Takayasu disease). The utility of percutaneous transluminal renal angioplasty in managing this disease has been reported infrequently, and technical problems in using this treatment method have not been described. We retrospectively evaluated the results of renal angioplasty in treating 33 stenoses in 20 patients. Each patient's diagnosis was based on the criteria established by the Aortitis Syndrome Research Committee of Japan. Criteria for selection of patients for angioplasty were (1) severe hypertension uncontrolled by single-drug therapy, (2) angiographic evidence of at least 70% stenosis of the renal artery with a pressure gradient of more than 20 mm Hg, and (3) a normal sedimentation rate. The transfemoral route was used to treat all 33 stenoses. Follow-up examinations included blood pressure and medication evaluation 1 day, 1 week, and 4-6 weeks after treatment, and thereafter at 6-month intervals. Technical success was obtained in 28 lesions (85%) in 17 patients (85%). All failures occurred in the presence of coexistent abdominal aortic disease and tight, proximal stenosis of the renal artery. Technical difficulties were attributed to the tough, noncompliant nature of the stenoses, which were difficult to cross and resisted repeated, prolonged balloon inflations. These patients experienced backache and a fall in systemic blood pressure during balloon inflation. In one patient, the ipsilateral renal vein was injured during angioplasty and required surgery. Clinical success was obtained in 14 (82%) of the 17 patients in whom technical success was achieved and included cure in six patients and improvement in eight others. Follow-up 1-18 months (mean, 8 months) after treatment showed restenosis in six (21%) of 28 lesions. We conclude that renal angioplasty in nonspecific arteritis is associated with technical difficulties; however, the short-term results are good and the complication rate is acceptable.

Adolescent↗
PubMed1992

Clonal composition of glioblastoma multiforme.

Glioblastoma multiforme, the most common and most lethal primary central nervous system neoplasm, is noted for its phenotypic and biological heterogeneity. This heterogeneity may result from genetic alterations accumulated by a single transformed astrocyte as it evolves into a monoclonal tumor. Alternatively, it may be attributed to the presence of multiple biologically and genetically distinct astrocytic populations within a polyclonal tumor. To address the issue of clonal composition of glioblastoma multiforme the authors used two independent approaches: analysis of X-chromosome inactivation and analysis of chromosomes 10 and 17 for tumor-specific somatic deletions. The analysis included 10 tumors from nine female patients with glioblastoma multiforme (eight primary and two recurrent tumors), who were heterozygous at either of two X-chromosome genes (hypoxanthine phosphoribosyl-transferase or phosphoglycerate kinase). Nine glioblastomas multiforme demonstrated a monoclonal pattern on X-chromosome analysis; contamination with normal tissue obscured the analysis in one tumor. Somatic deletions on chromosomes 10 and/or 17 occurred in nine tumors, supporting a monoclonal composition for these tumors. These data suggest that glioblastoma multiforme is a monoclonal neoplasm, derived from the clonal expansion of a single transformed astrocyte that has, as a fundamental step in tumorigenesis, sustained a critical genetic alteration on chromosome 10 and/or 17.

Brain Neoplasms↗
PubMed1992

Postoperative physical therapy for podiatric surgery.

The authors discuss several rehabilitation protocols for different surgical procedures on the foot. These are designed to be used as a reference for the podiatrist and therapist. In addition, various modalities are highlighted to familiarize the practitioner with their uses. Physical therapy can aid in decreasing the recovery period from foot surgery, which is particularly advantageous for the athlete.

Foot↗
PubMed1992

Study on the physico-chemical characteristics of breeding grounds in relation to the population density of Anopheles stephensi.

The present study which was based on the quarterly sampling and estimation of various physico-chemical factors throw light on the three significant points with regard to the population build up of Anopheles stephensi. Slightly alkaline pH is essential for higher population density, lower the salinity, higher the population density and higher amount of free ammonia in the water is accounted for the higher population density of A. stephensi.

Ammonia↗
PubMed1992

Increased expression of genes from growth factor signaling pathways in glioblastoma cell lines.

The concept of autocrine stimulation of cell proliferation postulates growth autonomy by acquisition of the ability to produce and respond to growth factors. Overproduction of several growth factors in a variety of human tumors and cell lines derived from these tumors has been reported. We have screened several cell lines derived from glioblastomas for anomalies in the expression of genes encoding transforming growth factor alpha (TGF-alpha), TGF-beta, basic fibroblast growth factor (bFGF) and its high-affinity receptor, flg. Compared with normal human brain tissue, we observed a generalized elevation in the levels of expression of these genes in glioblastoma cell lines and an SV40-transformed human astroglial cell line. Overexpression of these genes does not appear to be merely a reflection of the proliferative state of transformed cells since some other human tumor cell lines, when analysed for the expression of TGF-beta and bFGF, did not show a significant increase in these transcripts. The specificity of the elevated transcription of TGF-alpha, TGF-beta, bFGF and flg in glioblastoma cell lines is further suggested by the fact that the transcription of the proto-oncogene c-erbB2, which is overproduced in breast tumor cell lines, was not elevated in glioblastoma cell lines. Increased expression of growth factors, which are potent mitogens and angiogens, and/or their receptors may have critical roles in autonomous proliferation as well as neovascularization of glioblastomas.

Fibroblast Growth Factor 2↗
PubMed1992

Comparison of immediate hemodynamic response to closed mitral commissurotomy, single-balloon, and double-balloon mitral valvuloplasty in rheumatic mitral stenosis.

The hemodynamic response to closed mitral commissurotomy, single-balloon, and double-balloon mitral valvuloplasty was compared using 20 patients in each group. All patients had symptomatic rheumatic mitral stenosis with a mitral valve area < 1 cm2, without any left atrial clot, mitral valve calcification, or mitral regurgitation. There was a significant improvement in hemodynamics following intervention in all three groups. The mean pulmonary artery pressure decreased from 49.1 +/- 17.5 to 28.6 +/- 8.3 mm Hg (p < 0.001), 48.8 +/- 12.3 to 34.0 +/- 13.9 mm Hg (p < 0.001), and 46.7 +/- 18.0 to 26.3 +/- 13.7 mm Hg (p < 0.001) in the closed mitral commissurotomy, single-balloon, and double-balloon mitral valvuloplasty groups, respectively. The mitral valve area increased from 0.62 +/- 0.27 to 1.5 +/- 0.5 cm2 (p < 0.001), 0.68 +/- 0.24 to 1.5 +/- 0.4 cm2 (p < 0.001), and 0.68 +/- 0.25 to 1.9 +/- 0.8 cm2 (p < 0.001) in the closed mitral commissurotomy, single-balloon, and double-balloon mitral valvuloplasty groups, respectively. The increase in the mitral valve area was maximum in the group with double-balloon mitral valvuloplasty. In the closed mitral commissurotomy group there was a significant rise in left ventricular end-diastolic pressure, from 6.8 +/- 3.9 to 9.3 +/- 3.1 mm Hg (p < 0.001), but this remained unchanged in the single-balloon and double-balloon mitral valvuloplasty groups. Our study shows that single-balloon and double-balloon mitral valvuloplasty are comparable to closed mitral commissurotomy in the immediate hemodynamic response, with a larger valve area in the double-balloon mitral valvuloplasty group.

Adolescent↗
PubMed1992

Significance of cord problems at birth.

Cord problems at birth were prospectively studied in 12,000 singleton deliveries, of which 258 (2.15%) babies had cord abnormalities. Nearly 32% of these cases had fetal distress and 20.5% had 1 minute Apgar score less than 6. Of the various cord problems nuchal cord was noted in 79.1%, cord prolapse in 12.4% and true knots in 3.9% cases. Perinatal mortality rate with cord problems was 85.27/1000 births. Neonatal problems noted were septicemia (4.56%), aspiration syndromes (13.48%), hypoxic ischemic encephalopathy (7.30%), neonatal convulsions (2.14%) and hyperbilirubinemia (2.14%). Although mean Hb and PCV were lower in those with cord round the neck as compared to normal controls, this difference was not significant. Seven babies had Hb less than 13 g/dl with nuchal cords. Neonates born with cord around the neck or with other cord abnormalities should be carefully followed up for morbidity.

Apgar Score↗
PubMed1991

Experience with a third-generation implantable cardioverter-defibrillator.

A Medtronic 7216A pacemaker cardioverter-defibrillator was implanted in 16 patients (mean age 56 years) with sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) and organic heart disease with a mean left ventricular ejection fraction of 33%. Endocardial and epicardial defibrillation shock efficacy was evaluated before or at implant using 1 to 3 shock patterns, i.e., monophasic single, sequential or simultaneous shocks with dual and triple electrode configurations. Endocardial leads used a common right ventricular cathode and dual anodes, whereas epicardial leads used 2 or 3 helical coil patches. VT termination was evaluated using pacing or shock therapy, or both, whereas only shocks were used in VF. Programmable bradycardia pacing, individual zones for VT and VF detection and individualized pacing and shock therapy for VT and VF were used. Monophasic shocks had epicardial defibrillation thresholds ranging from 3 to 18 (mean 10) J and were comparable for sequential and simultaneous shocks (p greater than 0.2). VT detection rates ranged from 340 to 470 ms and VF detection rates from 270 to 330 ms. VT or VF induction, or both, was performed noninvasively in 13 patients after implant and was reproducibly terminated by rapid pacing alone (5 patients), low-energy shocks (2 patients), high-energy shocks (3 patients) and combined therapy (3 patients). Intermediate or high-energy shocks terminated all induced VF episodes. During follow-up (2 to 12 months), there have been 2 noncardiac deaths. Electrical therapy was delivered in 7 patients, for VT (3 patients), VT and VF (3 patients) and indeterminate tachyarrhythmia (1 patient). All VT/VF episodes were successfully terminated, with 78 of 96 (81%) spontaneous VT episodes terminated by pacing. Follow-up reprogramming was required in 5 patients. It is concluded that successful application of individualized electrical therapy prescriptions in patients with VT/VF is feasible. Pacing therapies, which are effective for induced VT, can be reliably used for effective long-term spontaneous VT termination in conjunction with shock therapy and can permit reduced patient exposure to shock therapy. Thus, a programmable hybrid pacemaker cardioverter-defibrillator system provides nonthoracotomy implantation, effective VT/VF termination, demand ventricular pacing and noninvasive modes for arrhythmia induction, event monitoring and clinical trouble-shooting.

Adult↗
PubMed1991

Cardiac arrhythmias after surgical correction of total anomalous pulmonary venous connection: late follow-up.

Sixteen patients (10 males and six females) aged 7 months to 20 years, who had undergone surgical repair in the first year of life for total anomalous pulmonary venous connection (TAPVC), underwent assessment of cardiac rhythm by 24-h electrocardiogram (ECG) monitoring, nine of them also had maximal exercise treadmill tests, 3 months to 19.5 years after surgical repair. No patient had symptoms of an arrhythmia and the resting ECG was normal in all except one who had occasional single supraventricular ectopic beats. But on 24-h ECG monitoring significant arrhythmias were recorded in six of the 16 patients, including supraventricular tachycardia (three patients), bradyarrhythmia (two patients), sick sinus syndrome (two patients), and multiform supraventricular and ventricular ectopic beats (two patients). Five of these six patients were assessed more than 6 years after surgery. An inappropriate chronotropic response was seen on maximal exercise treadmill testing in four patients; three of them had arrhythmias previously recorded by 24-h ECG monitoring. Our observations show that significant arrhythmias may occur in asymptomatic patients long after TAPVC correction, and we therefore recommend long-term follow-up of these patients, even if they are asymptomatic.

Adolescent↗
PubMed1991

Echocardiographic determinants of outcome after percutaneous transluminal balloon dilatation of discrete subaortic stenosis.

Eleven patients (seven females and four males; age 4 to 24 years) with discrete subaortic stenosis (DSS) diagnosed on echocardiography were subjected to balloon dilatation. The site of the obstruction was 1 to 8 mm below the aortic valve. On the basis of echocardiographic appearance, the patients could be divided into three groups. Group I patients had a uniformly thin (1 to 3 mm) obstructing "membrane" (n = 7). Group II patients had a thin obstructing "membrane" present at the tip of a thick bulge from the interventricular septum (n = 2) (intermediate form). Group III patients had an obstruction caused by a thick ridge of tissue (6 to 8 mm thick, n = 2). Maximum inflatable diameter of the balloon used was less than or equal to the aortic valve anulus. After balloon dilatation in group I, the gradients across the obstruction fell from 86.6 +/- 16.9 mm Hg to 24.0 +/- 13.1 mm Hg. Relief of obstruction persisted on follow-up of 3 to 24 months (gradient 28.8 +/- 15.7 mm Hg). In group II patients gradients fell from 116 and 40 mm Hg to 58 and 20 mm Hg, respectively immediately after balloon dilatation. On follow-up of 6 and 9 months the gradients have increased to 76 and 32 mm Hg, respectively. In group III the gradients fell from 64 and 70 mm Hg to 15 and 16 mm Hg, respectively, immediately after balloon dilatation, which increased to 58 and 60 mm Hg, respectively, within 24 hours and persisted around that level at 3 months' follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Identity of BCA200 and c-erbB-2 indicated by reactivity of monoclonal antibodies with recombinant c-erbB-2.

BCA200 has been described as a 200,000 Mr monomeric cell surface glycoprotein associated with human breast cancer. Since the physical properties and cellular distribution of BCA200 resemble those of c-erbB-2, antibodies to BCA200 were tested for the ability to bind a recombinant protein containing the c-erbB-2 extracellular domain (erbB-2 ECD). Three antibodies to distinct epitopes of BCA200 reacted with erbB-2 ECD but not with a control protein expressed in a similar baculovirus lysate. Control myeloma proteins and antibodies to four other antigens did not react with erbB-2 ECD. A protein with the expected molecular weight for erbB-2 ECD was also immunoprecipitated by anti-BCA200 antibody 520C9. We conclude that BCA200 is another synonym for c-erbB-2.

Antibodies, Monoclonal↗
PubMed1991

Lone atrial fibrillation with complete heart block in a child.

An asymptomatic 9-year-old boy presented with a slow heart rate and a structurally normal heart. He was detected to have complete atrioventricular block and fine atrial fibrillation that was not evident on the surface electrocardiogram. This case appears to be an unusual example of a disease of the cardiac conduction system presenting in childhood.

Atrial Fibrillation↗
PubMed1991

Factors affecting alkaline nature of rain water in Agra (India).

Rain water was collected and analysed from a reference site, Dayalbagh and Taj Ganj, near the Taj Mahal in Agra. The ionic components Ca, Mg, Na, K, NH(4), Pb, Fe, Zn, SO(4), HCO(3), Cl and F were analysed along with pH, alkalinity and conductance. The average pH of rain water at both sites is 7.05. There is a dominance of alkaline components, particularly Ca. The rain water chemistry shows the importance of calcareous soil-derived materials in controlling the pH of rain water.

Journal Article↗