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Biomedical subjects

P Venugopal

Publications and source records attributed to P Venugopal.

At least 73 records · Page 4Linked to original sources
PubMed1998

Total correction of tetralogy of Fallot in adults--surgical experience.

A total of 100 patients of tetralogy of Fallot aged 13 years and over were operated upon at the All India Institute of Medical Sciences, New Delhi, India between January 1991 and December 1996. There were 69 males (69%) and 31 females (31%). Age ranged from 13 years to 43 years (mean 19.66 years). Twenty % of patients had preoperative complications like haemoptysis, cerebrovascular accidents, brain abscess and infective endocarditis. Twenty-two patients had previous palliative shunts. Fifteen patients had coil embolisation of major collaterals prior to surgery. In hospital mortality rate was 4%. Follow-up ranged from 1 month to 5 years (mean 3.4 years). There was one late death due to infective endocarditis. Postoperatively 93.6% patients were in NYHA class I. Significant residual defects warranting re-operation were present in three patients. Total correction of tetralogy of Fallot in older patients can be performed with acceptable results.

Adolescent↗
PubMed1998

Aneurysm of sinus of Valsalva dissecting into interventricular septum.

BACKGROUND: Dissection of interventricular septum by aneurysm of the sinus of Valsalva is extremely rare. We present our experience with the management of 10 patients with this condition. METHODS: Ten patients with aneurysm of the sinus of Valsalva dissecting into the interventricular septum were managed at All India Institute of Medical Sciences, New Delhi, between May 1987 and September 1996. Conduction abnormalities and aortic insufficiency dominated the clinical picture. Eight patients underwent surgical repair. Two patients refused operation, and only permanent pacemaker implantation was done for complete heart block in both these patients. RESULTS: There was no hospital mortality. Follow-up ranged from 1 to 9 years. There was one late death due to carcinoma of the larynx, and 1 patient required reoperation for persistent aortic insufficiency. All other patients who underwent operation are in New York Heart Association functional class I. CONCLUSIONS: We recommend surgical repair of this condition to deal with aortic regurgitation and to avoid the potential risk of rupture, thromboembolism, and infective endocarditis. However, surgical repair offers no guarantee against arrhythmias and conduction abnormalities.

Adolescent↗
PubMed1998

Surgical experience with intracardiac myxomas: long-term follow-up.

BACKGROUND: Myxomas are the most common benign intracardiac tumors. This report summarizes our 20-year experience with these tumors. METHODS: Sixty-six patients (25 male) with a median age of 39 years (range, 6 to 70 years) underwent surgical excision of primary or recurrent intracardiac myxomas during the years 1976 to 1996. Symptom duration ranged from 2 to 8 months. There were 55 left atrial myxomas, 10 right atrial myxomas, and 1 biatrial myxoma. Three of the patients were in one family. The surgical approach comprised complete wide excision. RESULTS: There were two early deaths. Late follow-up is 89% (57/64) complete. There was one late death, which was not due to a cardiac cause. Echocardiography at a mean follow-up of 66.9 months (range, 7 to 241 months) showed no recurrence of sporadic myxomas. However, 2 of the 3 patients with familial myxomas had recurrence. CONCLUSIONS: Surgical excision of atrial myxoma gives excellent short-term and long-term results leading to eventual cure of nonfamilial myxomas. However, familial myxomas retain a strong tendency to recur even 20 years after excision.

Adolescent↗
PubMed1998

Cytokine gene activity in AML cells in vivo in patients.

The proliferation of acute myelogenous leukemia cells is dependent upon cytokine stimulation. Additionally, there is a body of literature which reports that leukemia cells produce GMCSF, IL6, and other cytokines. The study reported here, using an rt-multiplex polymerase method, determined the presence or absence of transcripts in freshly obtained AML cells for the following cytokine or cytokine-related genes: IL 1beta, IL1ra, TNF alpha, GMCSF, IL6, flt 3, and hSCF. This demonstrated that leukemia cell populations usually contain transcripts for IL1beta, TNF alpha, flt 3 and flt 3 ligand in vivo and that transcripts for the other cytokines only appear after the leukemia cells are processed in vitro. The presence of TNF alpha transcripts appears to be associated with resistance to remission induction therapy. Furthermore, the transcript profile of the leukemia cells can change during remission induction therapy. The data also demonstrate the assessment of cytokine production by leukemia cells after in vitro manipulation should not be extrapolated to the in vivo situation.

Adult↗
PubMed1998

Aortic valve replacement with biological substitute.

In the quest for an ideal aortic valve substitute, homografts and autografts are well-established options. We reviewed our results with homografts and autografts for aortic valve replacement during the last 5 years. From March 1992 through July 1997, 189 patients (138 male and 51 female), age 8 months to 68 years (mean 31.0+/-4.2 years), underwent aortic valve replacement with a human biological substitute. Of these, 93 patients received a cryopreserved or antibiotic-preserved aortic/pulmonary homograft, whereas 96 patients underwent a Ross procedure. Etiology was rheumatic in 143 (75.6%) patients, bicuspid aortic valve in 40 (21.2%), Marfan's disease in 5 (2.6%), and myxomatous aortitis in 1 (0.5%). Among the homograft group, a scalloped subcoronary implantation technique was used in 54 patients, whereas 32 patients underwent root replacement. Five patients required aortic root and ascending aortia replacement for annuloaortic ectasia. In all patients undergoing the Ross procedure, a root replacement technique was used. Operative mortality was 7.4% (14 patients). Late mortality was 5.3% (10 patients). Follow-up ranged from 1 to 46 months postoperatively. In patients with homograft aortic valve replacement, 76 patients (91.5%) had trivial to mild aortic regurgitation, while 7 patients (8.4%) had important aortic regurgitation. In patients with the Ross procedure, 78 patients (89.6%) had trivial to mild regurgitation. Moderate to severe aortic regurgitation was present in 9 patients (10.3%), all of whom had rheumatic heart disease and were young (< 30 years at surgery). We conclude that homografts and autografts provide an excellent substitute for the diseased aortic valve. Young age (< 30 years) with rheumatic etiology is a major risk factor for early progressive aortic regurgitation in patients undergoing the Ross procedure.

Adult↗
PubMed1998

Prostaglandin E1 in infants with congenital heart disease: Indian experience.

BACKGROUND: E-type prostaglandins (PGE1) can effectively maintain the patency of the ductus arteriosus in neonates. Its use, therefore and be life saving in infants born with ductus dependent congenital heart disease. Although PGE1 is available for over two decade in western world, it has been introduced in India only since April, 1995. OBJECTIVE: To assess the efficacy of PGE1 at our center. SETTING: Hospital based. METHOD: 65 infants with ductus dependent congenital heart disease were included. Age at time of starting PGE1 infusion ranged from 18 hours to 39 days. Forty two of these were more than a week of age, 19 were more than 14 days, and two were above one month. PGE1 was started in an initial dose of 0.05 microgram/kg/min, decreased to 0.005-0.01 microgram/kg/min for maintenance. The indications for use of PGE1 were to increase pulmonary blood flow in 33 cases with pulmonary atresia, tricuspid atresia or critical pulmonic stenosis (Group I); to increase systemic blood flow in 15 cases with coarctation of aorta, hypoplastic left heart and interruption of aortic arch (Group II); to improve mixing in 13 cases of transposition of great arteries (Group III) and for improving the left ventricular volumes by keeping the duct open in 4 cases of transposition of great arteries with intact ventricular septum (Group IV). The efficacy of the drug was assessed by a rise on PaO2 and SaO2% determined for Group I & III, and by appearance of lower limbs pulses in Group II. Left ventricular volumes were serially measured by echocardiography in Group IV cases. RESULTS: The drug was successful in 62 of the 65 cases. There were two failures. One was a 39 days old baby with Ebstein's anomaly of tricuspid valve and pulmonary atresia and other was an eight days old baby with coarctation of aorta and renal failure. In addition, PGE1 could not be continued in another baby due to development of a linear skin rash locally. Side effects included apnea in 5 (9%) of 56 spontaneously breathing patients. Necrotizing enterocolitis, hyperpyrexia and jitteriness was sent in one case each. Six patients died. Two were related to PGE1, one due to failure, another due to its side effects. Definitive procedure were performed in 51 cases electively. PGE1 was used upto 13 days with sustained benefit. CONCLUSIONS: PGE1 is an effective drug for keeping the ductus open in infants with ductus dependent congenital heart disease. It can be used for neonates beyond the first week of life with efficacy. Apnea is a major side effect and close monitoring is essential.

Age Factors↗
PubMed1998

Coronary artery bypass grafting without cardiopulmonary bypass.

Coronary artery bypass surgery on a beating heart is now an accepted modality to treat selected patients of ischaemic heart disease. From June '92 through Sep '97, 162 patients underwent this procedure. There was no mortality and none of the patients had any respiratory or neurological morbidity, though 24% of the patients form a high risk group for conventional coronary bypass surgery. It is definitely cost effective in comparison to any other modalities for treatment of ischaemic heart disease. We conclude that continous use of this technique is justified and all cardiac surgeons should have exposure to this procedure.

Adult↗
PubMed1998

Recurrent pseudoaneurysm of the left ventricle with subcutaneous herniation into the chest wall. A case report.

Pseudoaneurysm of the left ventricle is rare, and recurrence is extremely rare. We report the case of a 62-year-old man who presented at our hospital with a painless pulsatile swelling in the left breast. He had undergone coronary artery bypass grafting and left-ventricular aneurysmectomy 14 years earlier. On investigation, the swelling was diagnosed to be a pseudoaneurysm of the left ventricle with subcutaneous herniation. The extreme rarity of this condition prompted us to report the case. The investigative techniques and the surgical strategy are discussed.

Aneurysm, False↗
PubMed1997

Severe hypoxic biventricular dysfunction in tetralogy of Fallot: is Blalock shunt the answer?

In a 4-year-old boy with tetralogy of Fallot, a right modified Blalock-Taussig anastomosis was created because of severe myocardial dysfunction and repeated hypercyanotic spells. Post-operatively, systemic oxygen saturation improved and also myocardial function. It is postulated that hypoxia was responsible for myocardial dysfunction previously, and its elimination has resulted in markedly improved cardiac performance.

Child, Preschool↗
PubMed1997

Aortic atherosclerosis and perioperative stroke in patients undergoing coronary artery bypass: role of intra-operative transesophageal echocardiography.

Intra-operative transesophageal echocardiography was performed in 126 patients undergoing coronary artery bypass grafting. Significant protruding atheromas (grade IV and V; Katz et al., 1992) were present in 12 patients (9.5%). Protruding atheromas had significantly higher incidence in patients above 60 years in age. Preoperative assessment with chest roentgenography and angiography, as well as intra-operative assessment by surgical palpation proved to be insensitive in detecting aortic atheromas. Out of four patients with grade V atheromas, two (50%) developed right hemiplegia postoperatively. For the rest, patients with grade V atheromas and eight patients with grade IV atheromas, surgical technique was modified and that helped in preventing occurrence of perioperative stroke.

Adult↗
PubMed1997

Cytokines, molecular biological abnormalities, and acute myelogenous leukemia.

Leukemia cell proliferation is dependent upon cytokines produced by the leukemia cells or by the microenvironment under stimulation by leukemia cells. Abnormal expression of the p53, rb, and ras genes is associated with cytokine production, suggesting that abnormal expression can affect leukemia cells by affecting intracellular growth controls and by stimulating cytokine production. While these observations suggest that cytokines can be used to stimulate leukemia proliferation during cytotoxic therapy increasing the sensitivity to treatment, they also suggest that inhibition of cytokine affects could increase clinical responses by reducing leukemia cell regrowth between courses of therapy.

Animals↗
PubMed1997

Cell cycle kinetic studies in 68 patients with myelodysplastic syndromes following intravenous iodo- and/or bromodeoxyuridine.

Sixty-eight patients with myelodysplastic syndromes (MDS) received sequential infusions of iodo- and/or bromodeoxyuridine for cell kinetic analysis. Bone marrow biopsy sections were treated by appropriate antibodies and a labeling index (LI), duration of S-phase (Ts), and total cell cycle time (Tc) of myeloid cells were determined. The mean LI was 28.4%, Ts was 11.8 hours and Tc was 40.7 hours. The %LI decreased as the disease evolved from refractory anemia toward transformation to acute leukemia (p = 0.04). Double-labeling of biopsy sections for apoptosis and proliferation showed that 30-90% of S-phase cells in MDS patients were simultaneously apoptotic or "antonymous." We conclude that MDS are highly proliferative disorders in which the ineffective hematopoiesis is probably the result of excessive apoptosis rather than slow proliferation.

Apoptosis↗
PubMed1997

Aortic valve replacement with a homovital valve.

"Homovital" allografts (viable homografts) are a good substitute for native aortic valves. A case of aortic valve replacement with a homovital aortic allograft is reported along with the results of immunologic investigations. Postoperatively, there was no clinical or echocardiographic evidence of valve dysfunction, and immunologic tests did not show evidence of graft versus host reaction.

Aortic Valve↗
PubMed1996

Indication of an involvement of interleukin-1 beta converting enzyme-like protease in intramedullary apoptotic cell death in the bone marrow of patients with myelodysplastic syndromes.

Our previous studies using in situ end labeling (ISEL) of fragmented DNA revealed extensive apoptotic cell death in the bone marrows (BM) of patients with myelodysplastic syndromes (MDS) involving both stromal and hematopoietic cells. In the present report we show greater synthesis of interleukin-1 beta (IL-1 beta) in 4 hour cultures of density separated BM aspirate mononuclear (BMAM) cells from MDS patients as compared to the cultures of normal BM from healthy donors or lymphoma patients (1.7 +/- 0.37 pg/10(5) cells, n = 29 v 0.42 +/- 0.24 pg/10(5) cells, n = 11, respectively, P = .049). Further, these amounts of IL-1 beta in MDS showed a significant correlation with the extent of apoptosis detected by ISEL in corresponding plastic embedded BM biopsies (r = .480, n = 30, P = .007). In contrast normal BMs did not show any correlation between the two (r = .091, n = 12, P = .779). No significant correlation was found between the amounts of IL-1 beta and % S-phase cells (labeling index; LI%) in MDS determined in BM biopsies using immunohistochemistry following in vivo infusions of iodo- and/or bromodeoxyuridine. Neither anti-IL-1 beta antibody nor IL-1 receptor antagonist blocked the apoptotic death of BMAM cells in 4 hour cultures (n = 5) determined by ISEL (apoptotic index; AI%), although the latter led to a dose-dependent accumulation of active IL-1 beta in the culture supernatants. On the other hand, a specific tetrapetide-aldehyde inhibitor of ICE significantly retarded the apoptotic death of BMAM cells at 1 mumol/L in 5/6 MDS cases studied (AI% = 2.99 +/- 0.30 in controls v 1.58 +/- 0.40 with ICE-inhibitor, P = .05) and also reduced the levels of active IL-1 beta synthesized (5.59 +/- 2.63 v 2.24 +/- 0.93 pg/10(6) cells, respectively). In normal cells, neither IL-1 blockers nor the ICE inhibitor showed any effect on the marginal increase in apoptosis observed in 4 hour cultures. Our data thus suggest a possible involvement of an ICE-like protease in the intramedullary apoptotic cell death in the BMs of MDS patients.

Antibodies, Monoclonal↗
PubMed1996

Surgical experience with total correction of tetralogy of Fallot in infancy.

Fifty two patients less than one year old with tetralogy of Fallot underwent primary repair between January 1991 and December 1994. Age range was three to twelve months (mean 10.09 +/- 2.01 months) and body weight ranged from 4.5 to 9 kg (mean 8.38 +/- 2.79 kg). Transatrial-transpulmonary repair was performed in 36 patients and the classical transventricular approach was used in 16 patients. Six patients underwent emergency surgery for severe cyanosis and spells. Five patients had left pulmonary artery plasty for pulmonary artery bifurcation stenosis and two out of the five patients who had anomalous coronary arteries needed a right ventricle to pulmonary artery conduit. Mean post repair peak right ventricular/systemic pressure ratio was 0.74 +/- 0.18 in the transventricular group and 0.71 +/- 0.26 in the transatrial-transpulmonary group. There were three hospital deaths. Follow-up ranged from 3 to 46 months (mean 21.18 months). Forty patients underwent echocardiography and twenty patients underwent cardiac catheterisation six to eighteen months after surgery. Mean right ventricular outflow tract gradient on echocardiography was 20.35 +/- 10.12 and, at cardiac catheterisation, 17.51 +/- 13.49 mmHg with mean post repair peak right ventricle/left ventricle pressure ratio of 0.44 +/- 0.11. These were significantly less than the values obtained in the operating room. Only one patient had residual ventricular septal defect with left to right shunt of 1.6:1 at cardiac recatheterisation. There was one late death after reoperation for residual obstruction. Encouraging results with primary repair of tetralogy of Fallot in infancy prompt us to continue this policy in suitable cases.

Body Weight↗
PubMed1996

Novel insights into the biology of myelodysplastic syndromes: excessive apoptosis and the role of cytokines.

The paradox of myelodysplastic syndromes (MDS) which present with pancytopenias despite cellular bone marrows (BM) was investigated by conducting detailed studies of proliferation and apoptosis in 89 MDS patients. Our results demonstrated a rapid rate of both proliferation as well as apoptosis. Levels of three cytokines, tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta) and interleukin-1 beta (IL-1 beta) were measured in the same patients. High levels of TNF-alpha were found to correlate with high levels of apoptosis in 83 MDS patients (P = 0.0045). We propose a dual role for TNF-alpha (or other cytokines) in the pathogenesis of MDS. On the one hand, TNF-alpha induces apoptosis in the maturing cells causing pancytopenia while on the other, it stimulates the proliferation of the primitive progenitors accounting for the hypercellular BM frequently seen in MDS. A new model for MDS is presented. The initial abnormality probably affects a primitive hemopoietic progenitor which acquires a growth advantage leading to monoclonal hemopoiesis, which in turn makes these cells susceptible towards acquiring additional mutations and appearance of cytogenetically marked (or unmarked) clones. Cytokines such as TNF-alpha whose source is presently unknown, then contribute towards the clinical syndrome of pancytopenia and hypercellularity.

Antigens, CD34↗
PubMed1996

Phenotypic characterization of cellular components of cardiac myxoma: a light microscopy and immunohistochemistry study.

Cardiac myxoma is the most common primary tumor of the heart. A detailed evaluation of cell types in 41 cardiac myxomas by light microscopy and in 30 cases by immunohistochemistry was made. Reactivity to the various antisera were observed in the surface lining cells, the stromal myxoma cells and the cells in the perivascular location. Factor VIII-related antigen (FVIIIR-Ag) and Ulex europaeus agglutinin (UEA-1), both endothelial markers, were positive in 23 cases each. UEA-1 was found to be a more sensitive marker than factor VIII. Desmin and myoglobin were positive in 16 and 24 cases, respectively. Reactivity for cytokeratin was noted in ten cases, one of which showed glandular differentiation. Vimentin and S-100 positivity was obtained in 16 and 14 cases respectively. Thus, cardiac myxoma appears to arise from multipotent cells which have the potential to differentiate along several mesenchymal cells or epithelial cells and may also concurrently exhibit reactivity for both mesenchymal and epithelial markers.

Adolescent↗