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Biomedical subjects

D Reddy

Publications and source records attributed to D Reddy.

32 records · Page 2Linked to original sources
PubMed1993

A reevaluation of the role of crystalloid preload in the prevention of hypotension associated with spinal anesthesia for elective cesarean section.

BACKGROUND: Hypotension after spinal anesthesia for cesarean section remains a common and serious complication despite the use of uterine displacement and volume preloading. The current study revaluated the role of crystalloid volume preloading in this context. METHODS: In a two-stage open sequential design, patients presenting for elective repeat cesarean section were allocated to receive either no preload or 20 ml/kg crystalloid administered over 15-20 min before spinal anesthesia. Hypotension was defined as a decrease in systolic pressure to less than 100 mmHg and to less than 80% of baseline value, and the study was designed to detect a 20% difference in the incidence of hypotension between the groups, with statistical significance at the 10% (alpha = 0.1) level, one-tailed. RESULTS: One hundred forty patients were studied. Hypotension occurred in 43 (55%, 95% CI 43.4-66.4) preloaded and 44 (71%, 95% CI 58-81.8) unpreloaded subjects, a difference in incidence of 16% (95% CI 0.04-31.6), which was statistically significant. There were no significant differences in the severity, timing, or duration of hypotension; the dose requirement for ephedrine; or the clinical and biochemical status of neonates between the groups. The only difference seen was a lower mean base excess (-3.4, SD 2.81 mM-1) in the neonates of hypotensive mothers compared to neonates of nonhypotensive mothers (-2.4, SD 1.99 mM-1). CONCLUSIONS: The study confirms that hypotension associated with spinal anesthesia for cesarean section cannot be eliminated by volume preloading in the supine wedged patient. The relatively small reduction in incidence of hypotension challenges our perception of the value of crystalloid preload. Though volume preload in the elective cesarean section is advocated, the requirement for a mandatory administration of a fixed volume before spinal anesthesia for urgent cases has been abandoned.

Adult↗
PubMed1992

Vaccinia-rotavirus VP7 recombinants protect mice against rotavirus-induced diarrhoea.

Recombinant vaccinia viruses expressing wild type intracellular VP7 (VP7wt) from rotavirus SA11 or VP7sc, a cell surface-anchored variant, boosted antibody titres in SA11-immune mice. Pups born to these mice were protected from diarrhoea following challenge with SA11. In rotavirus-naive mice, two immunizations with recombinant vaccinia virus expressing VP7sc stimulated protective immunity that could be transferred to pups, whereas viruses expressing VP7wt did not stimulate protective immunity. Recombinant vaccinia viruses expressing intracellular or cell surface-anchored VP6, the rotavirus group-reactive antigen from the inner capsid, did not stimulate protective immunity. These experiments demonstrate that a live viral vector expressing cell surface anchored VP7 may represent a strategy for the development of safe, effective vaccines against rotavirus-induced diarrhoea.

Animals↗
PubMed1990

Cholesterol embolization: clinical findings and implications.

The clinical characteristics of 13 patients with cholesterol embolization are described. Embolization occurred spontaneously in 2 patients and after a vascular procedure in 11. Acute but vague symptoms were reported by 11 of the 13 patients; skin findings of purple toes or livedo reticularis and renal dysfunction were present in 12 patients, 5 of whom required dialysis. Blood pressure elevation occurred in all 13 patients, eosinophilia in 9 of 10 and elevated sediment rate in 5 of 6. Death occurred within 6 months in three patients. Two distinct patterns were observed: mild (five patients) and severe (eight patients). Compared with the severe pattern, patients with mild cholesterol embolization had early symptoms less frequently (two of five versus eight of eight), less severe renal insufficiency (serum creatinine 1.7 versus 7.4 mg/100 ml), less of an increase in blood pressure (22 versus 34 mm Hg) and later development of skin lesions (14 versus 6 weeks). Baseline blood pressure and development of eosinophilia were comparable in both groups. The presentation of cholesterol embolization is often subtle and may go unrecognized, particularly in its mild form. As vascular interventions increase in elderly atherosclerotic and hypertensive patients, so too will the incidence of this disorder.

Aged↗
PubMed1989

Pancoast syndrome in a patient with malignant lymphoma.

Pancoast syndrome is usually secondary to lung cancer. We report a patient with Pancoast syndrome in whom a biopsy specimen of a cervical mass at first thought to be anaplastic carcinoma was found to stain positively for leukocyte common antigen and negatively for keratin, epithelial membrane antigen, and alpha-fetoprotein. A diagnosis of malignant lymphoma associated with Pancoast syndrome was made, and a salutary response was observed after combination chemotherapy. To our knowledge, this is the first reported case of Pancoast syndrome associated with malignant lymphoma. We emphasize the importance of using immunohistochemical stains to define the pathologic condition in difficult cases.

Aged↗
PubMed1987

Absence of HTLV I from New Zealand.

Sera from 1,943 individuals from Auckland, New Zealand, were tested for the presence of serum antibodies to human T cell lymphotropic virus I (HTLV I), mainly with an enzyme-linked immunosorbent assay (ELISA) with cell extracts as target antigen. The individuals tested were blood donors and mostly Caucasian, but included indigenous Maoris and representatives of several groups of Pacific islanders now resident in New Zealand. Also included were 37 patients with various hematological malignancies, including seven with T cell leukemias. Although 1% of samples were positive by ELISA, none of these were confirmed as positives by Western blotting. On the basis of these results we consider that it is unlikely that HTLV I infection occurs in Auckland; however, we cannot exclude the possibility that pockets of virus infection may occur in other parts of New Zealand or the South Pacific.

Adolescent↗
PubMed1987

An estimation and correction scheme for system imperfections in multiple-echo magnetic resonance imaging.

Multiecho sequences are widely used in MRI because they are an efficient means of acquiring data and they can be used to quantitatively estimate T2. However, the uniformity of each image and the accuracy of each T2 estimate may be corrupted by several instrumental factors such as rf pulse imperfections and static field inhomogeneities. We propose a scheme based on our prior knowledge of the effects of such factors and using the Levenberg-Marquardt method of nonlinear estimation that produces accurate estimates of T2 even in the presence of substantial system imperfections and improves the image quality of later echo images in a multiecho sequence. A further extension of this scheme permits mapping the distribution of the static magnetic field from a single multiecho imaging study of a uniform object. Simulations have been performed to test the efficacy of this scheme and the results are substantiated with experiments performed on a whole-body imager operating at 6.35 MHz.

Algorithms↗
PubMed1984

A simplified method for computerized densitometry of complex shapes in 2-deoxyglucose autoradiographs.

A simple, computerized densitometer is described which can be used to measure densities of photographic prints by means of a fiber-optic reflectance densitometric probe coupled to the movable cursor of a digitizing tablet. The cursor, with its attached probe, is moved by hand along a scan trajectory determined by the operator. In its configuration for use with 2-deoxyglucose autoradiographs, the histological section from which the autoradiograph was derived provides architectonic landmarks for guiding the path of the scan. The X, Y and density values taken along a scan line are sequentially stored in the computer memory. Algorithms are presented for plotting densities along unfolded scan lines within layers of structures with complicated shapes, for normalizing non-linearities introduced during photographic processing, for standardizing the data sets with reference to the density of average gray matter in different animals, for calculating total integrated density within defined boundaries along the scan line, for generating averages of multiple scans, and for stacking sequential scans to form pseudo-3-dimensional plots. This system allows densitometric measures to be made from autoradiographs in anatomically defined regions, thereby permitting precise correlation between isotope concentration and histological structure.

Animals↗
PubMed1984

Behavioral and biochemical effects of job loss and unemployment stress.

Previous research on the effects of unemployment has focused upon both anticipation of job loss and long-term unemployment, typically using self-report and some biochemical measures of response to unemployment stress. The present study was concerned with behavioral and biochemical responses to unemployment. It was also designed to examine a somewhat different time course of unemployment than has been used in previous work. Results indicated that stress accompanies unemployment; looking at people who had been unemployed for up to four months, those who had been unemployed for greater lengths of time performed more poorly on a behavioral task and exhibited higher levels of urinary norepinephrine and epinephrine than did persons unemployed for shorter time periods or subjects who were employed.

Adult↗
PubMed1983

Nitrite inhibition of Clostridium botulinum: electron spin resonance detection of iron-nitric oxide complexes.

Vegetative cells of Clostridium botulinum were shown to contain iron-sulfur proteins that react with added nitrite to form iron-nitric oxide complexes, with resultant destruction of the iron-sulfur cluster. Inactivation of iron-sulfur enzymes (especially ferredoxin) by binding of nitric oxide would almost certainly inhibit growth, and thus is probably the mechanism of botulinal inhibition by nitrite in foods.

Clostridium botulinum↗
PubMedDate not supplied

Infected false aneurysms of the femoral artery in intravenous drug addicts.

The evaluation and treatment of 60 intravenous drug addicts with infected false aneurysms of the femoral artery seen at Henry Ford Hospital (Detroit) from 1977 to 1988 were retrospectively reviewed. The most common presenting signs and symptoms were groin swelling and/or mass in 56 (93%) of the patients and pain and/or tenderness in 48 (80%) of the patients. Digital subtraction angiography and standard arteriography showed sensitivities of 92% and 96%, respectively, in the detection of aneurysms. Twenty-three (39%) of the 60 patients had polymicrobial infections. Staphylococcus aureus was isolated in 50 (83%) of 60 cases; 21 (42%) of the isolates were beta-lactam-resistant strains. Anaerobes and aerobic gram-negative bacilli were observed in 12 (20%) and seven (12%) of 60 patients, respectively. Thirty-six (60%) of the patients were bacteremic. All patients received parenteral antibiotics and had surgical resection of their false aneurysm(s). Bacteriologic treatment failures occurred in five of 13 patients who received less than or equal to 15 days of parenteral antibiotics following surgical ligation, as compared with one of 47 who received longer courses (P = .002). Six of 12 grafting procedures were successful, and six of the 60 patients required amputations. There were no deaths. Previously reported cases from the United States medical and surgical literature are reviewed.

Aneurysm↗
PubMedDate not supplied

Physician decision-making in antiretroviral use.

The results of a survey of physicians treating HIV are reported. The survey aimed to determine physicians' attitudes to and practices in antiretroviral prescribing and to assess the factors they use for decision-making regarding initiation and change of therapy.

Antiviral Agents↗