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Biomedical subjects

D Shah

Publications and source records attributed to D Shah.

At least 145 records · Page 8Linked to original sources
PubMed1980

Pathologic interactions between prosthetic aortic grafts and the gastrointestinal tract. Clinical problems and a new experimental approach.

Twenty-one patients presented with pathologic interactions between the gastrointestinal tract and aortic grafts. Seventeen patients were managed by excision of the graft and axillobifemoral bypass. Six patients died. four deaths were due to disruption of the proximal aortic stump after initial therapy that appeared successful. An experimental model of a seromuscular jejunal patch is presented that may be beneficial for closure of the proximal aortic stump.

Animals↗
PubMed1980

Glaucoma in a case of Hurler disease.

The electron microscopic appearances of the corneoscleral and iris tissue removed at operation from a child with Hurler disease and glaucoma showed distinctive swollen cells with intracellular inclusions similar to those which are observed in other tissues in these patients and which are due to abnormal lysosomal storages of mucopolysaccharides. Some recent observations on the possible relationship between mucopolysaccharides and the drainage of fluid from the anterior chamber are briefly reviewed and correlated with the present observations. The development of glaucoma in this patient is thought to be associated with the presence of the mucopolysaccharide-containing cells in the region of the aqueous drainage channels.

Child↗
PubMed1979

Nonresective treatment of abdominal aortic aneurysms. Use of acute thrombosis and axillofemoral bypass.

In good-risk patients, abdominal aortic aneurysmectomy can be accomplished with a mortality of 2% to 5%. However, in poor-risk patients, ie, those with severe reduction of cardiac, respiratory, and/or renal function, the mortality of this procedure has been reported to be as high as 60%. Fifteen poor-risk patients with abdominal aortic aneurysms have been treated with acute, induced thrombosis and simultaneous axillobilateral femoral bypass. Each patient had preoperative ultrasound and radionucleide flow studies and the runoff from the aneurysm was determined angiographically. Thrombosis, induced by interruption of the iliac outflow vessels, occurred in 12 patients within 72 hours. Flow persisted in three patients, and thrombosis was induced by transaxillary catheter deposition of bucrylate in the residual outflow vessels. There were two operative deaths (less than 30 days), both due to myocardial infarctions, and four late deaths, three of which were caused by the problems that initially contraindicated direct graft replacement of the aneurysm. Preliminary experience with this approach indicates that this is a simple and potentially effective method of treatment of abdominal aortic aneurysm where direct graft replacement is contraindicated.

Aorta, Abdominal↗
PubMed1979

Partial regeneration of the above-elbow amputated rat forelimb. I. Innate responses.

Although a number of recent studies describe the facilitation of limb regeneration by electrical and other forms of stimulation, little is known of innate regenerative capacity in the mammalian limb. The present report describes spontaneous regenerative responses following subtotal forelimb amputation in the young white rat. In one group of animals the forelimb was amputated through the lower humerus and the skin sutured closed. In a second group, adjacent muscle tissue still attached to bone at its origin(s) was interposed between the cut surface of the humerus and the skin. Among animals of the first group (skin closure only) bone growth and limb regenerative responses were generally not observed. Animals of the second group displayed significant elaborations of cartilage and bone at the limb terminus. The appearance and subsequent modification of these tissues suggest that some capacity for limb regeneration exists innately in the young rat and can be more readily evoked than has been recognized heretofore. It is concluded that extant and forthcoming reports of electrically stimulated skeletal tissue growth, repair and regeneration among eutherial mammals should be examined to determine whether reported responses to stimulation represent advances beyond what might be expected from innate replacement processes alone.

Amputation, Surgical↗
PubMed1979

Partial regeneration of the above-elbow amputated rat forelimb. II. Electrical and mechanical facilitation.

This investigation was undertaken to examine the observations of Becker ('72) pertaining to the electrical facilitation of partial limb regenerative responses by means of Ag-Pt wire couples applied to the limb stumps of young, forelimb-amputated white rats. Additionally, in order to examine the possible role of mechanical effects of such device implantations, we have employed uncoupled devices delivering no current or potential difference. In the present experiments, in response to coupled device implantation, cartilage and bone were actively formed in the vicinity of the Pt electrode tip. These tissues contributed to the lengthwise extension of the limb and to the partial restoration of the distal humeral extremity. In limbs bearing the uncoupled electrical devices, qualitatively similar responses were noted, but osteogenesis was diminished in extent compared to that seen in limbs bearing the active or coupled devices. It is therefore necessary to consider the role of mechanical factors in the elicitation of the observed regenerative responses. Myogenesis was enhanced in electrically stimulated limbs, but not in those rats bearing uncoupled devices.

Amputation, Surgical↗
PubMed1977

Hypertonic mannitol in the therapy of the acute respiratory distress syndrome.

Increased pulmonary artery pressure, an increase in pulmonary vascular resistance and an increase in physiologic dead space are consistent findings in patients with post-traumatic respiratory distress. Since mannitol has been shown to decrease renal vascular resistance following trauma, the effect of a bolus injection of 100 ml of 25% solution of this drug on pulmonary hemodynamics and physiologic dead space was investigated in 11 patients who had suffered multiple trauma. Five minutes after the injection, pulmonary vascular resistance fell (p less than .01), cardiac index increased (p less than .001) and physiologic dead space decreased (p less than .05). In contrast, the administration of 40 mg of furosemide produced no significant change in any of these parameters. Mannitol rapidly equilibrates in the extracellular space and exerts an osmotic effect across cell membranes. We postulate that the beneficial response to mannitol on the pulmonary vascular resistance and the improved perfusion of ventilated regions of the lung is due to a reduction in cell swelling and is not explainable by its diuretic effect. Improvement in the distribution of perfusion of pulmonary blood flow by mannitol may be a useful aid in the treatment of the post-traumatic form of the respiratory distress syndrome.

Acute Disease↗
PubMedDate not supplied

Placental lesions associated with abnormal growth in twins.

Abnormal growth in one or both twins may contribute to the increased morbidity and mortality observed in twin gestation. Our objective in this retrospective study of all twin pregnancies delivered at our hospital (n = 240) over a 2-year period was to study the relationship between placental lesions and abnormal growth. Standardized placental examinations were performed in 192 cases (80%), which constituted the study population. Two growth abnormalities were studied: discordant growth as defined by > 15% difference in birth weight and small-for-gestational-age (SGA) birth as defined by birth weight less-than the 10th percentile for gestational age. The majority of twin pregnancies with either discordant growth (41/57 cases) or SGA birth (26/35 cases) had dichorionic placentas. In monochorionic placentas studied by injection there was no significant relationship between vascular anastomoses and discordant growth. Placental weight for small discordant and SGA twins was equivalent or increased relative to infant weight, a pattern not suggestive of maternal vascular underperfusion. Eight lesions, five considered to represent chronic placental disease and three considered to represent intrauterine adaptation, were studied as possible predictors of abnormal growth. The overall prevalence of these lesions in twin placentas was less than that seen in singleton births. Concordance between twin placentas for most lesions was higher than would be expected, based on their prevalence in singleton placentas. Two lesions were associated with discordant growth in both univariate and multivariate analyses: peripheral cord insertion (OR 3.6, 95% CI 1.7-7.6) and avascular villi (AV; OR 3.2, 95% CI 1.0-10.3). Three placental lesions were associated with SGA infants at the univariate level: peripheral cord insertion, avascular villi, and maternal vascular underperfusion. Only peripheral cord insertion (OR 9.8, 95% CI 4.1-23.4) and AV (OR 3.7, CI 1.0-13.7) were significant in the multivariate analysis. The relative increase in peripheral cord insertion and AV with abnormal growth was observed for both monochorionic and dichorionic placentas. Subgroups of discordant infants with and without SGA were both associated with peripheral cord insertion while only those with SGA had an increase in AV. Both peripheral cord insertion and AV were increased in the subgroup with SGA but no discordancy. In summary, two placental lesions, peripheral cord insertion indicating a spatially limited intrauterine compartment and AV indicating occlusion of fetal vessels in the placenta, were associated with abnormal growth in twins.

Adult↗
PubMedDate not supplied

Signs and symptoms of patients with brain tumors presenting to the emergency department.

This retrospective chart review was conducted to determine the presenting signs and symptoms of patients with primary brain tumors diagnosed in the emergency department. There were 101 patients (65 males and 36 females) identified with a hospital discharge diagnosis of primary brain tumor who were admitted through the emergency department. The presenting symptoms included headache (56 patients), altered mental status (51 patients), ataxia (41 patients), nausea or vomiting (37 patients), weakness (27 patients), speech deficits (21 patients), and sensory abnormalities (18 patients). The presenting signs included motor weakness (37 patients), ataxia (37 patients), papilledema (28 patients), cranial nerve palsies (26 patients), visual deficits (20 patients), and speech deficits (12 patients). The average age was 42.8 years, with a range of 3 days to 88 years. The majority of tumors were malignant astrocytomas. Tumor location was cortical in 68 patients, subcortical in 9 patients, and brainstem or cerebellum in 24 patients. In conclusion, patients of all ages may present to the emergency department with a variety of symptoms resulting from a primary brain tumor. Headache and altered mental status were common in our series of patients, but symptoms will depend on the size, location, and type of tumor. A complete neurologic examination is essential, including evaluation for papilledema.

Adolescent↗
PubMedDate not supplied

Improved serologic detection of hepatitis C virus with a paramagnetic microparticle assay using multiple antigenic sequences.

A paramagnetic microparticle (MP) assay for antibody to hepatitis C virus (anti-HCV) was developed, in which the probe for antibody consisted of synthetic peptides corresponding to HCV capsid and nonstructural c-100 regions, as well as a recombinant protein corresponding to the nonstructural c33c region. Assay performance was evaluated by testing serum from 108 geographically diverse patients with non-A, non-B hepatitis (NANBH). The frequency of anti-HCV reactivity detected with the MP assay and with an enzyme-linked immunosorbent assay (ELISA) for c-100 was 91 and 70 percent, respectively. All c-100 HCV ELISA-reactive specimens also reacted on the MP assay. In addition, anti-HCV seroconversion in three plasma donors was detected one to two blood collection dates earlier by the MP assay than by the c-100 HCV ELISA and at similar blood collection dates by the MP assay and a second-generation anti-HCV ELISA. Serologic responses to the three distinct antigenic regions of HCV in NANBH patients varied: reactivity to all three antigens was most common (49%), reactivity to both capsid and c33c (40%) was next most common, and single-antigen reactivity was rare (4%). MP assay reactivity of 825 volunteer donors was 0.1 percent. These results demonstrate both the utility of additional HCV antigens for an effective anti-HCV screening assay and the application of paramagnetic MP technology to serologic testing for HCV infection.

Antibody Specificity↗