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Biomedical subjects

P C Rath

Publications and source records attributed to P C Rath.

At least 19 recordsLinked to original sources
PubMed2005

Bilateral carotid angioplasty and stenting.

Bilateral carotid stenosis is generally treated by staged stenting procedure and rarely simultaneously due to concerns about hemodynamic impairment from stimulation of the carotid sinus baroreflex (severe bradycardia, hypotension) and the risk of cerebral hyperperfusion syndrome. Most of the accounts of bilateral carotid stenting are of small series. The aim of this study was to evaluate the feasibility and safety of simultaneous bilateral carotid angioplasty and stenting (CAS) in comparison with staged procedure. We retrospectively analyzed the procedural outcome and complications of bilateral CAS done between February 1995 and June 2004 in a consecutive series of 57 high-risk patients. Mean age was 64 +/- 9 years (male, 43; female 14). One hundred fifteen arteries were treated (one patient had bilateral internal carotid artery stenosis associated to an ostial common carotid artery stenosis). Thirty-nine patients were symptomatic (70%). Thirty-six patients had severe coronary artery disease. Seventeen patients underwent a simultaneous bilateral CAS (group 1), 40 in a staged manner (group 2). Among these 40 patients 10 were treated with a time interval of 24 hr, while the 30 other ones were treated with a time interval of 2 days to 2 months. A neuroprotection device was used in the last 42 patients. There was technical success in all patients and transient bradycardia and/or hypotension in 25 patients (44%). There was no prolonged bradycardia or hypotension. At 30 days, we observed in group 1 (simultaneous bilateral CAS) no transient ischemic attack (TIA), no minor stroke, one (5.8%) major stroke (hyperperfusion syndrome with brain hemorrhage leading to death in a patient under IIb/IIIa inhibitors), one myocardial infarction leading to death, and two (11.7%) death/stroke/myocardial infarction; in group 2 (staged procedure), two (5%) TIAs, no minor stroke, no major stroke, and one (2.5%) hyperperfusion syndrome with rapid recovery. Among the 10 patients treated with a time interval of 24 hr, we observed one TIA. Among carefully selected patients, bilateral CAS is feasible simultaneously or the day after, with a safety and complication rate comparable to that of large published series of CAS or endarterectomies in high-risk patients. Nevertheless, careful monitoring of the patient, blood pressure, and heart rate is mandatory to avoid complications related to hyperperfusion syndrome. Routine use of neuroprotection device and meticulous technique should improve the outcomes of bilateral CAS.

Aged↗
PubMed2004

Percutaneous transluminal angioplasty using a new peripheral cutting balloon for stenosis of arch vessels in aorto arteritis.

Percutaneous transluminal angioplasty (PTA) with or without stenting of steno-occlusions in the supra-aortic arch vessels in aortoarteritis is associated with higher residual stenosis and restenosis, particularly in those with diffuse disease. The use of the new peripheral cutting balloon (Boston Scientific Interventional Technologies, San Diego, CA, USA) in these lesions in aortoarteritis has not been described. We report here the first 2 cases of stand alone cutting angioplasty for 2 patients (3 arteries). One patient presented with a critical stenosis of the common carotid artery. We obtained a good immediate result but a restenosis appeared at 6 months, easily treated by a new angioplasty with cutting balloon and stent implantation. The second patient had an occlusion of the subclavian artery associated with a severe ostial vertebral artery stenosis. The immediate result was excellent and the 6-month clinical and angiographic control showed no restenosis.

Adult↗
PubMed2002

Renal artery involvement in patients of coronary artery disease undergoing coronary angiography--a prospective study.

METHODS: We prospectively studied the angiographic incidence of renal artery stenosis in 1000 consecutive patients who underwent coronary angiography for clinically suspected coronary artery disease since December, 1998. Selective renal arteriography was performed in all the patients (mean age 57 years, 74.6% males) after coronary angiography. RESULTS: Systemic arterial hypertension was present in 52%, 29.1% were smokers, 21% had diabetes and 31.2% had hypercholesterolemia. Significant coronary artery diseases was found in 849 (84.9%) patients. Of the total patient cohort, 103 (10.3%) patients had renal artery disease; 78 (7.8%) had insignificant stenosis (> 50%) and significant renal artery stenosis (< 50%) was identified in 25 (2.5%) patients. Three had bilateral renal artery stenosis. Comparisons were made between renal artery stenosis and risk factor profile. There was no statistically significant association between renal artery stenosis and parameters like diabetes mellitus, hypertension, smoking, lipid levels and serum creatinine. CONCLUSION: In our study, the absolute number of cases with significant renal artery stenosis is small, so no statistical analysis could be performed to demonstrate the relationship of presence of renal artery stenosis with severity of CAD. However patients with severe coronary artery disease or having multiple risk factor showed a trend towards increased prevalence of renal artery stenosis, hence renal angiography should be done for this subset of patients.

Coronary Angiography↗
PubMed2001

Radiation induced oxidative stress: I. Studies in Ehrlich solid tumor in mice.

Understanding the response of tumors to ionizing radiation might potentially lead to improvement in tumor control and patient morbidity. Since the antioxidant status is likely to be linked to radioresponse, its modulation needs to be examined. Therefore, Swiss albino male mice (7-8 weeks old) with Ehrlich solid tumors were irradiated with different doses of gamma rays (0-9 Gy) at a dose rate of 0.0153 Gy/s; and enzymes involved in antioxidant functions were determined in the tumors. Radiation effects in terms of oxidative damage, LDH, nitric oxide and DNA fragmentation were also examined. In tumors, the specific activity of SOD was increased with dose but declined 6 Gy onwards. GST, DTD and GSH showed an almost progressive increase. These enhanced activities might have resulted from the increased protein expression. This possibility was supported by the Western Blot analysis for GST protein. These changes might be closely linked to the radiation-induced oxidative stress as reflected by the enhanced levels of peroxidative damage, DNA fragmentation, LDH activity and nitric oxide levels. These findings may have relevance to radiation therapy of cancer as the elevated antioxidant status of irradiated tumors is likely to limit the effectiveness of radiation dose and adversely affect the therapeutic gain.

Animals↗
PubMed2001

Antiproliferative effects of IFN-alpha correlate with the downregulation of nuclear factor-kappa B in human Burkitt lymphoma Daudi cells.

Interferon-alpha (IFN-alpha) is known to exhibit antiviral, antiproliferative, and immunomodulatory properties through mechanisms still not fully understood. Nuclear transcription factor-kappaB (NF-kappaB) plays a major role in viral replication, cell proliferation, and immune response. Whether antiproliferative effects of IFN are mediated through suppression of NF-kappaB is not known. We, therefore, examined the relationship between the antiproliferative effects of IFN-alpha and NF-kappaB activity in a human Burkitt lymphoma Daudi cell line. These cells were found to constitutively express high levels of active NF-kappaB that cannot be further activated by tumor necrosis factor (TNF). Treatment of cells with IFN-alpha suppressed the activated NF-kappaB in a dose-dependent manner, with an optimum effect at 10 U/ml in 72 h. Suppression of NF-kappaB correlated with a concomitant decrease in the cytoplasmic levels of IkappaBalpha, the inhibitory protein of NF-kappaB, known to be regulated by NF-kappaB. Downregulation of constitutive NF-kappaB activity correlated with a decrease in cell proliferation by IFN-alpha. Overall, our results suggest that IFN-alpha is a potent suppressor of constitutive NF-kappaB, which may contribute to the inhibition of cell proliferation.

Burkitt Lymphoma↗
PubMed2000

Percutaneous transluminal myocardial revascularisation: current status and future perspectives.

Percutaneous transluminal myocardial revascularisation presently appears to be a potential palliative treatment for coronary artery disease, neither controlled with drugs nor amenable to available coronary revascularisation techniques. Ongoing trials will provide answer to short and long term efficacy. Recent developments using angiogenic growth factors appear very promising, and the role of growth factors as an adjunct to percutaneous transmyocardial revascularisation with laser remains to be seen.

Angioplasty, Balloon, Coronary↗
PubMed1999

Percutaneous mechanical mitral commissurotomy with a newly designed metallic valvulotome: immediate results of the initial experience in 153 patients.

BACKGROUND: Percutaneous balloon valvotomy has become a common treatment of mitral stenosis, but the cost of the procedure remains a limitation in countries with restricted financial resources, leading to a frequent reuse of the disposable catheters. To overcome this limitation, a reusable metallic valvotomy device has been developed with the goals of both improving the mitral valvotomy results and decreasing the cost of the procedure. METHODS AND RESULTS: The device consists of a detachable metallic cylinder with 2 articulated bars screwed onto the distal end of a disposable catheter whose proximal end is connected to an activating pliers. By the transseptal route, the device is advanced across the valve over a traction guidewire. Squeezing the pliers opens the bars up to a maximum extent of 40 mm. The clinical experience consisted of 153 patients with a broad spectrum of mitral valve deformities. The procedure was successful in 92% of cases and resulted in a significant increase in mitral valve area, from 0.95+/-0.2 to 2. 16+/-0.4 cm2. No increase in mitral regurgitation was noted in 80% of cases. Bilateral splitting of the commissures was observed in 87%. Complications were 2 cases of severe mitral regurgitation (1 requiring surgery), 1 pericardial tamponade, and 1 transient cerebrovascular embolic event. In this series, the maximum number of consecutive patients treated with the same device was 35. CONCLUSIONS: The results obtained with this new device are encouraging and at least comparable to those of current balloon techniques. Multiple uses after sterilization should markedly decrease the procedural cost, a major advantage in countries with limited resources and high incidence of mitral stenosis.

Adolescent↗
PubMed1999

TNF-induced signaling in apoptosis.

Out of the almost 17 members of the TNF superfamily, TNF is probably the most potent inducer of apoptosis. TNF activates both cell-survival and cell-death mechanisms simultaneously. Activation of NF-kB-dependent genes regulates the survival and proliferative effects pf TNF, whereas activation of caspases regulates the apoptotic effects. TNF-induced apoptosis is mediated primarily through the activation of type I receptors, the death domain of which recruits more than a dozen different signaling proteins, which together are considered part of an apoptotic cascade. This cascade does not, however, account for the role of reactive oxygen intermediates, ceramide, phospholipases, and serine proteases which are also implicated in TNF-induced apoptosis. This cascade also does not explain how type II TNF receptors which lack the death domain, induce apoptosis. Nevertheless, this review of apoptosis signaling will be limited to those proteins that makeup the cascade.

Animals↗
PubMed1999

Coil embolization of a giant atherosclerotic coronary artery aneurysm.

The incidence of the coronary artery aneurysm varies from 1.5-5%. Atherosclerosis is the most common cause of coronary artery aneurysm in adults. A discrete, giant, saccular atherosclerotic coronary artery aneurysm in an artery without significant proximal stenosis is rare. We report the first such case of a giant atherosclerotic coronary artery aneurysm successfully treated with coil embolization.

Adult↗
PubMed1998

Balloon mitral valvuloplasty with bifoil catheter: immediate and long-term follow-up results.

This report documents clinical and hemodynamic benefits of balloon mitral valvuloplasty (BMV) using a bifoil balloon catheter from a single center in 415 consecutive cases of rheumatic mitral stenosis (MS). The procedure was successful in 396 (95.2%) patients, with an increase in mitral valve area (MVA) from 0.82+/-0.35 cm2 to 2.21+/-0.24 cm2 (P < 0.001). There were 2 (0.48%) in-hospital deaths, and 6 (1.44%) patients developed acute mitral regurgitation. The procedural and fluroscopy time was reduced significantly from 52+/-11 and 38+/-6 min to 33+/-7 and 19+/-5 min, respectively, after modifications of technique in our last 326 cases. The bifoil balloon catheter technique is safe and effective, and provides excellent hemodynamic benefits which are sustained at long-term follow-up. This technique should be considered as an addition to the existing armamentarium of interventional cardiologists performing mitral balloon valvuloplasty.

Adolescent↗
PubMed1998

Elective coronary artery stenting--immediate and follow up results.

Elective coronary artery stenting was performed in 242 consecutive patients in our centre for complex lesions (Type B, C), proximal lesions, restenotic lesions, total occlusion and venous grafts. The procedural success rate was 94.21%. Three patients (1.23%) required emergency coronary artery bypass surgery. Acute and sub-acute thrombosis rate was 1.26% and 4.13%, respectively. There was one in-hospital death (0.41%). 164 patients were followed up clinically for a mean period of 11 +/- 6 months (range 1 month to 30 months). Angiographic follow up was done in 68 patients with a restenosis rate of 16.17%.

Adult↗
PubMed1989

Methylation of repetitive DNA sequences in the brain during aging of the rat.

Methylation of repetitive DNA sequences (RDS) of the genomic DNA of the brain of 15- and 88-week old rats was analysed by digestion with HpaII, MspI, EcoRI + HpaII and EcoRI + MspI followed by end-labelling. mCpG doublets are present in two RDS of approximately 5 and 0.4 kb, and are also randomly distributed throughout the genome. Hemimethylated mCpC doublets also occur. Both mCpG and mCpC doublets are found more in the old than in the young. This age-related increase in DNA methylation occurs both at CCGG sites of the RDS and in the entire genome. Such increase in DNA methylation may alter chromatin conformation and gene expression in the brain as the rat ages.

Aging↗
PubMed1989

Electrocardiographic left atrial enlargement--correlation with echo.

To assess the utility of electrocardiogram in identifying left atrial enlargement, electrocardiogram of 600 consecutive patients were correlated with their M-mode echocardiographic findings. Left atrial enlargement, as reflected by P terminal force in V1 had sensitivity of 79%, specificity 91%, predictive value 85% and accuracy of 86%. Patients older than 30 years with large left atrium (greater than 5.0 cm) had atrial fibrillation more frequently than younger patients (P less than 0.001). It is concluded that P terminal force in V1 is a reliable indicator of left atrial enlargement.

Adult↗