PubMed Health⌕ Search

Biomedical subjects

S Mehta

Publications and source records attributed to S Mehta.

At least 19 recordsLinked to original sources
PubMed1992

Excimer laser coronary angioplasty.

Recent experience with excimer laser coronary angioplasty (ELCA) has shown the safety and efficacy of the technique in the treatment of coronary stenosis, with results similar to percutaneous transluminal coronary angioplasty (PTCA). Several advantages of the excimer laser for intravascular use have been identified by the ELCA Registry, a group of 15 institutions nationally that have pooled data on their cooperative experience with ELCA. Advantages include the ability of the laser to ablate atheroma with microscopic precision without thermal injury and the ability of vessel surfaces to heal without scarring. The initial results of the multicenter investigation of ELCA in 958 patients indicate that ELCA may be indicated particularly for long, diffuse lesions. With the advent of larger diameter catheters, ELCA is a viable alternative to PTCA. Restenosis was seen as a significant problem, and it remained problematic at 6-month follow-up. In comparison with conventional balloon angioplasty, ELCA may eliminate that component of restenosis due to inadequate dilation or elastic recoil, but it does not appear to affect restenosis caused by smooth muscle proliferation. Catheter design and energy delivery continue to evolve and may affect future results of laser coronary angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1992

ACS RX flow support catheter as a temporary stent for dissection or occlusion during balloon angioplasty: initial experience.

The ACS RX flow support catheter, which functions as a temporary stent, was placed successfully during four procedures in three patients who had suboptimal results following angioplasty. This investigational device allowed prolonged perfusion and supported the vessel wall when coronary blood flow was compromised, avoiding emergent coronary artery bypass graft surgery during two procedures. In the remaining procedures the device was used as a bridge to surgery. These early applications of the flow support catheter following failed balloon angioplasty suggest a rapid, effective alternative to the autoperfusion balloon when it fails or is contraindicated because of the lesion location.

Aged↗
PubMed1992

Incidence of thrombosis during central venous catheterization of newborns: a prospective study.

Forty-two newborns were studied prospectively to determine the incidence of thrombosis due to central venous catheterization. Following Broviac catheter placement, the catheter tip, distal superior vena cava, and right atrium were evaluated by weekly two-dimensional echocardiograms. The presence of thrombosis was examined in relation to birth weight, gestational age, age and weight at the time of catheter placement, antithrombin III levels, and platelet counts. Six newborns (14%) were noted to have a thrombus by echocardiographic examination after the catheter had been in place for a median duration of 7 weeks. The infants with thrombus formation had significantly lower birth weights (887 +/- 231 v 1,409 +/- 766 g; P = .003) and gestational ages (27 +/- 2.4 v 30.3 +/- 4.3 weeks; P = .018) than those without thrombus. Their weights (757 +/- 203 v 1,832 +/- 1,098 g; P = .000) and ages (2.75 +/- 0.76 v 7.24 +/- 7.8 weeks; P = .002) at the time of catheter placement were also lower; the antithrombin III levels were lower at the time of catheter placement (0.32 +/- 0.08 v 0.06 +/- 0.31 U/mL; P = .001), but were normal for gestational and postnatal age. The presence of thrombosis was not related to the sex of the baby, the platelet count, or the duration of catheterization.

Age Factors↗
PubMed1992

The use of antibiotic-impregnated polymethylmethacrylate beads to prevent the evolution of localized infection.

The effect of antibiotic bead chains on the evolution of infection cannot be studied entirely in man due to the ethical problems of obtaining valid controls. Therefore, a model of musculoskeletal injury was devised in rabbits by making a paraspinal wound, fracturing a spinous process, and contaminating the wound with 1 x 10(4) colony-forming units/ml of Staphylococcus aureus. These contaminated wounds were treated with tobramycin-containing polymethylmethacrylate (PMMA) beads. Control rabbits were either treated with PMMA beads that did not contain antibiotic, treated with IM tobramycin, or left untreated. At 5 days, six of eight animals treated with antibiotic-impregnated beads had no recoverable organisms. Six of eight rabbits receiving IM tobramycin had wound infections, and five of five in whom non-antibiotic-containing beads had been implanted had significant wound infections, with one of the five dying of sepsis on the 3rd day of the experiment. The clinical course of infected controls was the same as the course of those animals receiving IM antibiotics and the same as those in whom beads without antibiotics were implanted. That is, the rabbits had grossly infected wounds and the organisms recovered were of the same type as those implanted. This research shows a highly statistically significant effect of tobramycin-containing antibiotic beads in retarding the evolution of an experimental Staphylococcus infection in rabbits.

Animals↗
PubMed1992

Maxillary antrum involvement in multibacillary leprosy: a radiologic, sinuscopic, and histologic assessment.

Thirty patients having lepromatous leprosy (22 males, 8 females) and showing radiological involvement of the maxillary antrum were subjected to sinuscopy, biopsy, and histopathological examination. Radiological observations showed diffuse opacity in 33.3% of the sinuses, localized mucosal thickening in 28.6%, and generalized thickened mucosa in 38.1%. Sinuscopy revealed inflamed mucosa as the most common finding (40%), followed by ulcerative (26.7%) and granulomatous (10%) lesions of the mucosal lining. The mucosal thickening (localized or generalized) evident on radiology was always associated with granuloma formation and acid-fast bacilli in the histology. The presence of an external nasal deformity indicated a statistically significant chance of encountering mucosal involvement on sinuscopy and histopathology (p < 0.05). There was more chance of finding positive sinuscopic lesions in those patients with a bacterial index above 3+.

Adult↗
PubMed1992

Ingestion of strong corrosive alkalis: spectrum of injury to upper gastrointestinal tract and natural history.

We have prospectively studied 31 patients who ingested strong alkalis for location, extent, severity, and outcome of the injury to the upper gastrointestinal tract. Alkalis ingested were sodium hydroxide (n = 28) and potassium hydroxide (n = 3). The injury was assessed within 36 h of alkali intake by endoscopy or surgery, or at autopsy. Symptoms and signs did not give a reliable forecast of the extent and severity of injury. The corrosive burns were classified as grade 2a in six patients, grade 2b in eight, and grade 3 in 17. The esophagus was injured in all patients, the stomach in 93.5%, and the duodenum in 29.6%. Acute complications occurred in 32.3% of the patients and death in 12.9%; all but one of such patients had grade 3 burns. All patients with 2a injury recovered without sequelae. Four of the eight patients with grade 2b injury and all survivors of grade 3 injury developed esophageal or gastric cicatrization, or both, which needed endoscopic or surgical treatment. We find endoscopy is not only a safe and reliable tool for diagnosis in such patients, but also is of importance in treatment and prognosis. We conclude that ingestion of strong alkalis is a very serious condition that inflicts severe contiguous injury to the esophagus and stomach and results in high morbidity and mortality.

Adolescent↗
PubMed1992

Niemann-Pick disease presenting as hepatic disorder.

A 2 year old female child with Niemann-Pick disease was referred as case of chronic liver disease; clinically, she had neurological involvement. Liver biopsy showed Niemann-Pick cells. Hepatic manifestations of Niemann-Pick disease as seen in nine cases reported from India are discussed.

Child, Preschool↗
PubMed1992

Lymphokine-activated effector cells: modulation of activity by cytokines.

Interleukin 2 (IL-2) has been demonstrated to generate lymphokine-activated killer (LAK) cells from normal human peripheral blood lymphocytes (PBL). Such LAK cells have demonstrated lytic activities on certain tumor cell targets including melanoma, renal carcinoma, and other tumor targets. B lymphoblastoid cell lines such as Raji cells are routinely employed to assess functional LAK cell activity. In our studies we have assessed the effect of various cytokines that affect lymphocyte cell growth and differentiation, including rIL-2, interleukin 4 (rIL-4), interleukin 6 (rIL-6), interferon alpha and gamma (rIFN-alpha and -gamma) and tumor necrosis factors alpha and beta (rTNF-alpha, rTNF-beta), for their ability to generate functional LAK cell activity. Our data confirm that rIFN-alpha and -gamma singularly are capable of inducing LAK cell activity (55 +/- 21 and 40 +/- 10, respectively, in comparison to rIL-2 at 1000 units/ml) whereas rIL-4, rIL-6, BCGF, rTNF-alpha, or rTNF-beta failed to generate the functional LAK cell activity from human PBL. Interferon alpha, itself capable of generating LAK cell activity, was augmentative in its effect with rIL-2 for the generation of functional LAK cell activity. Conversely, rIL-4 inhibited LAK cell activity induced by either rIL-2 alone or the combination of rIL-2 and rIFN-alpha. Furthermore, the increased effects of rIFN-alpha with rIL-2 on LAK cell activity are partly abrogated by as much as 30 or 52% by delaying the addition of either rIL-2 or rIFN-alpha, respectively, for more than 24 h. These results suggest a regulatory role for certain cytokines on LAK cell functions.

Cell Line↗
PubMed1992

A prospective randomized study of the injurious effects of aspirin and naproxen on the gastroduodenal mucosa in patients with rheumatoid arthritis.

A prospective double-blind randomized placebo-controlled study was conducted to compare the injurious effects of aspirin and naproxen on the gastroduodenal mucosa. Patients with rheumatoid arthritis attending the immunology clinic of a tertiary care center were included in the study. Ninety consecutive patients were randomized to receive aspirin, naproxen, or placebo. Clinical evaluation was done every 2 wk. Upper gastrointestinal endoscopy, biopsies from the gastric antrum and duodenum for histological examination, and Helicobacter pylori studies were done at entry and after 2 months. The number of patients with dyspeptic symptoms was similar in the aspirin (12) and naproxen (9) groups. In both cases, however, it was higher (p less than 0.01) than in the placebo group (none). Naproxen was associated with a higher score of endoscopic abnormalities in the gastric body (0.6 +/- 1.3) than aspirin (0.2 +/- 0.6) or placebo (0.03 +/- 0.18). H. pylori was present in a similar proportion of patients in the three groups (33-43%). A greater fall in hemoglobin was observed with aspirin (0.35 +/- 0.48 g%) and naproxen (0.44 +/- 0.53 g%) than with placebo (0.09 +/- 0.4 g%). The present study suggests that aspirin and naproxen produce a similar degree of injury to the gastroduodenal mucosa.

Adult↗