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Biomedical subjects

K Desai

Publications and source records attributed to K Desai.

At least 55 records · Page 3Linked to original sources
PubMed1998

Patterns of coordination and clinical outcomes: a study of surgical services.

OBJECTIVE: To test the hypothesis that surgical services combining relatively high levels of feedback and programming approaches to the coordination of surgical staff would have better quality of care than surgical services using low levels of both coordination approaches as well as those surgical service using low levels of either coordination approach. STUDY SETTING: A study sample of 44 academically affiliated surgical services that are part of the Department of Veterans Affairs. STUDY DESIGN: In a cross-sectional analysis, surgical services were assigned to one of three groups based on their scores on feedback and programming coordination measures: high on both measures; high on one measure, low on the other; and low on both. Univariate and multivariate analyses were used to assess differences among these groups with respect to three quality indicators: risk-adjusted mortality, risk-adjusted morbidity, and staff perceptions of quality. DATA COLLECTION/EXTRACTION METHODS: Risk-adjusted mortality and morbidity came from an outcomes reporting program within the Department of Veterans Affairs that entails the prospective collection of clinical data from patient charts. Data on coordination practices and perceived quality came from a survey of surgical staff at each of the 44 participating surgical services. PRINCIPAL FINDINGS: The group of surgical services using high feedback and high programming had the best perceived quality. This group also had the lowest morbidity, but the difference was statistically significant with respect to only one of the two other groups: the group with low feedback and low programming. No significant group differences were found for mortality. CONCLUSIONS: Study results provide partial support for the hypothesis that high levels of feedback and programming should be combined for optimal quality of care. Study results also suggest that staff coordination is more important for improving morbidity than mortality in surgical services.

Cross-Sectional Studies↗
PubMed1997

Improving the diagnostic accuracy of cytologic cerebrospinal fluid examinations in acute lymphoblastic leukemia using high-power microscopy and terminal deoxynucleotidyl transferase determinations.

In patients with acute lymphoblastic leukemia (ALL), cytologic examination of cerebrospinal fluid (CSF) is becoming increasingly important for clinical management. In order to enhance the diagnostic accuracy of CSF cytology results, the value of using terminal deoxynucleotidyl transferase (Tdt) and high-power (1,000x) light microscopy, together with conventional cytologic examination was assessed. In 33 CSF samples from ten multiply examined Tdt-positive ALL patients, original cytologic interpretations were compared to Tdt results. Cytology samples were reviewed by two pathologists (one with hematopathologic expertise). The cases in which cytologic interpretation did not correlate with Tdt result were first reviewed via 1,000x microscopy without knowledge of Tdt result, then re-reviewed with knowledge of Tdt result. Conventional cytology alone diagnosed 64% of cases accurately (Tdt representing the comparative standard). High-power microscopy increased the correlation to 82%. Use of high-power microscopy and knowledge of Tdt result together produced a total of 85% of cases with correlation of results. High-power microscopic examination therefore contributes significantly to the accurate diagnosis of ALL, and knowledge of the Tdt result at the time of cytologic examination produces an additional advantage in providing an objective measure for CSF involvement by leukemia. Using all three methods in conjunction is recommended in order to increase the overall accuracy of CSF examination for the detection of leukemic involvement in ALL patients.

Adolescent↗
PubMed1997

Ossified glomus jugulare tumour: case report.

A huge, ossified and highly vascular glomus jugulare tumour in a 19-year-old boy was radically and successfully resected. External carotid artery embolization and intermittent internal carotid artery trapping during surgery were the principle methods employed to control the operative blood loss. Extensive petrous bone resection, and adequate and wide exposure were necessary. The case and the operative steps in this unusual and difficult surgical problem are discussed.

Adult↗
PubMed1996

Cardiovascular regulation in mice lacking alpha2-adrenergic receptor subtypes b and c.

alpha2-Adrenergic receptors (alpha2ARs) are essential components of the neural circuitry regulating cardiovascular function. The role of specific alpha2AR subtypes (alpha2a, alpha2b, and alpha2c) was characterized with hemodynamic measurements obtained from strains of genetically engineered mice deficient in either alpha2b or alpha2c receptors. Stimulation of alpha2b receptors in vascular smooth muscle produced hypertension and counteracted the clinically beneficial hypotensive effect of stimulating alpha2a receptors in the central nervous system. There were no hemodynamic effects produced by disruption of the alpha2c subtype. These results provide evidence for the clinical efficacy of more subtype-selective alpha2AR drugs.

Adrenergic alpha-Agonists↗
PubMed1996

The AO unreamed nail: friend or foe.

Twenty-nine tibial shaft fractures were stabilized with the AO unreamed tibial nail. These included 13 type A fractures, 11 type B fractures and five type C injuries. Fourteen of the fractures were open. The AO unreamed tibial nail was the primary device used in all cases. Our series suggests that this is an easy device to insert and that its multiple locking options confer an advantage for the management of distal fractures. It also has a low soft-tissue complication rate. There was a delay in full patient mobilization and in the progression to fracture union. There was also a significant degree of implant failure with screw breakage in 21 per cent. This necessitated a high rate of secondary operative intervention. The high incidence (55 per cent) of anterior knee pain was also worrying and frequently necessitated nail removal. We feel that this implant may still have a role for distal fractures and in the multiply injured patient but do not feel that, in its current form, it is the ideal implant for the majority of tibial shaft fractures.

Adolescent↗
PubMed1996

Creating health with chronic illness.

Within the current context of health care, health promotion for individuals with chronic illness often reflects the priorities of disease-specific preventive care needs and related physical, social, emotional, and spiritual well-being. This article reports a phenomenological study of how older people with chronic illness experience health and health promotion and illuminates a different perspective of health resources and strategies. The findings have profound implications for nursing practice and theory, suggesting the need for restructuring work assignments and refocusing nursing care more clearly away from the medical model.

Adaptation, Psychological↗
PubMed1995

Molecular cloning and characterization of a cellular protein that interacts with the human immunodeficiency virus type 1 Tat transactivator and encodes a strong transcriptional activation domain.

The mechanism by which human immunodeficiency virus type 1 Tat transactivates the long terminal repeat promoter is not understood. It is generally believed that Tat has one or more transcription factors as its cellular target. One might expect a cellular target for Tat to possess several properties, including (i) the ability to bind to the Tat activation region, (ii) the possession of a transcriptional activation domain, and (iii) the ability to contact the cellular transcription machinery. Here we describe the cloning, expression, and characterization of a human protein, termed TAP (Tat-associated protein), which possesses some of these properties. TAP is highly conserved in eukaryotes and is expressed in a variety of human tissues. The major intracellular species of TAP is a highly acidic 209-amino-acid protein that likely is formed by removal of a highly basic 70-amino-acid N-terminal segment from a primary translation product. By deletion analysis, we have identified a TAP C-terminal region rich in acidic amino acids and leucine residues which acts as a strong transcriptional activator when bound through GAL4 sites upstream of the core long terminal repeat promoter, as well as flanking sequences that mask the activation function. Amino acid substitution of two leucine residues within the core activation region results in loss of the TAP activation function. Two lines of evidence suggest that Tat interacts with TAP in vivo. First, promoter-bound Tat can recruit a TAP/VP16 fusion protein to the promoter. Second, transiently expressed Tat is found associated with endogenous TAP, as demonstrated by coimmuno-precipitation analysis. As shown in an accompanying report, the TAP activation region binds the Tat core activation region and general transcription factor TFIIB (L. Yu, P.M. Loewenstein, Z. Zhang, and M. Green, J. Virol. 69:3017-3023, 1995). These combined results suggest the hypothesis that TAP may function as a coactivator that bridges Tat to the general transcription machinery of the cell via TFIIB.

3T3 Cells↗
PubMed1995

Fatal postoperative 'pituitary apoplexy': its cause and management.

Two cases of giant pituitary tumours are reported. The patients underwent transcranial operation, one by the pterional and one by the subfrontal route. Only partial resection of the tumour was possible in each instance for various reasons. Acute worsening of the clinical condition in the immediate postoperative phase led to reoperation in both patients. In one case the reoperation was carried out within 45 min of the closure of the wound and in the other after 12 h. Massive swelling of the tumour with evidence of haemorrhagic infarction was a surprise finding. After a turbulent postoperative phase, both patients died. We postulate that these patients developed pituitary apoplexy of the residual tumours.

Adolescent↗
PubMed1993

Identification of a novel cell attachment domain in the HIV-1 Tat protein and its 90-kDa cell surface binding protein.

The HIV-1 transactivator protein Tat is essential for viral gene expression and replication. Tat is taken up by cells and transactivates the HIV-LTR promoter in the cell nucleus. The present studies show that cells adhere to both synthetic and recombinant Tat, and, using synthetic peptides, we localize the binding site to a region spanning amino acid residues 49-57 (peptide Tat49-57). Tat49-57 also inhibited cell attachment to solid phase full-length Tat peptide and to recombinant Tat protein. Using Tat peptide affinity chromatography, we identified a 90-kDa cell surface protein that binds to Tat. The 90-kDa protein could be eluted from the Tat column using the Tat49-57 peptide. A 90-kDa cell surface Tat binding protein was also identified by coprecipitation with Tat after incubation with radiolabeled cell membrane preparations. Co-precipitation of the 90-kDa protein was inhibited by competition with a Tat49-65 peptide, but not with Tat55-86. Our findings suggest that cellular attachment to Tat is mediated through a 90-kDa cell surface protein that binds to a Tat domain between amino acids 49 and 57.

Amino Acid Sequence↗
PubMed1991

Isolation of a cellular protein that binds to the human immunodeficiency virus Tat protein and can potentiate transactivation of the viral promoter.

The human immunodeficiency virus type 1 Tat protein is a powerful transactivator of the viral long terminal repeat (LTR). We have identified a cellular protein that strongly binds to Tat and can complement Tat transactivation in rodent cells. The cellular protein of about 36 kDa was isolated from extracts of human cells by Tat peptide-affinity chromatography and can form a complex with Tat in vitro. Tat transactivation is inefficient in rodent cells microinjected or transfected with the reporter plasmid pHIV-LTRCAT plus the Tat-expressing plasmid pCV-1. Remarkably, coinjection of purified 36-kDa protein with pHIV-LTRCAT plus pCV-1 stimulated Tat transactivation 2.7- to 4.9-fold. Taken together, our findings suggest that the 36-kDa protein may be a transcription factor or modulator that is important for efficient Tat transactivation.

3T3 Cells↗
PubMed1991

Bipolar hemiarthroplasty for subcapital fracture of the femoral neck. A prospective randomised trial of cemented Thompson and uncemented Moore stems.

We performed a randomised prospective trial to compare the results of 27 cemented and 26 uncemented bipolar hemiarthroplasties in active patients with displaced subcapital fractures of the femoral neck. After a mean follow-up of 17 months, significantly more of the uncemented group were experiencing pain in the hip and using more walking aids than the patients in the cemented group. The incidence of postoperative complications, the early mortality rate and the operating time and blood loss were not significantly different. Using otherwise identical prostheses the early results were much better with a cemented Thompson stem than with an uncemented Austin Moore stem.

Aged↗
PubMed1991

Osteochondritis dissecans of the knee. A long-term study.

Twenty-two knees with osteochondritis dissecans diagnosed before skeletal maturity were followed prospectively into middle age: 32% had radiographic evidence of moderate or severe osteoarthritis at an average follow-up of 33.6 years; only half had a good or excellent functional result. We found that osteoarthritis was more likely to occur if the defect was large or affected the lateral femoral condyle.

Adolescent↗
PubMed1989

Inhibition of platelet aggregation by abnormal high density lipoprotein particles in plasma from patients with hepatic cirrhosis.

ADP-induced aggregation of normal washed platelets was measured by nephelometry in the presence of plasma high density lipoprotein (HDL) from normal subjects and from 30 patients with hepatic cirrhosis. HDL, at one-eighth of its plasma concentration, inhibited platelet aggregation; the effect of cirrhotic HDL (40% [SD 29%] inhibition) was significantly greater than that of normal HDL (16% [11%]). The mean apolipoprotein E content of cirrhotic HDL was significantly higher than that of normal HDL, and strongly inhibitory HDL contained twice as many apolipoprotein-E-rich particles as weakly inhibitory HDL. Inhibition of platelet aggregation was correlated with the apolipoprotein E content of HDL from patients with cirrhosis.

Adenosine Diphosphate↗
PubMed1989

Rat pancreatic interlobular duct epithelium: isolation and culture in collagen gel.

Interlobular duct fragments from the pancreas of the rat were isolated by collagenase digestion and filtration, embedded in a matrix of rat-tail collagen, and cultured in a 1:1 mixture of Dulbecco's minimal essential and Ham's F12 media supplemented with cholera toxin (CT, 100 ng/ml) and epidermal growth factor (EGF, 10 ng/ml) in addition to supplements used previously, thereby improving the yield of ducts by a factor of two compared with previous results. The ducts were harvested by digestion of the collagen matrix with collagenase and were then dissociated by treatment with EDTA in divalent cation-free salt suspended in collagen and cultured as were the ducts. Numerous cysts appeared as a function of time and some of these enlarged dramatically. Some of the larger cysts exhibited secondary tubular processes extending into the surrounding collagen. The addition of bovine pituitary extract (BPE, 50 micrograms/ml) doubled the number of cysts, whereas omission of serum or CT + EGF reduced the number. BPE or forskolin could substitute effectively for CT. Agents that stimulate (secretin) or inhibit (e.g., ouabain or acetazolamide) fluid-electrolyte secretion in vivo had no effect on the number or average diameter of the cysts. The cysts were 83 to 88% epithelial with the balance of the cells being fibroblastic in appearance. Some cysts consisted only of epithelium. The proliferative capacity of the cystic epithelium was shown by the presence of mitotic figures and by an autoradiographic labeling index of 22 to 30% after a 24-h exposure to [3H]thymidine. The labeling index was reduced by the omission of CT + EGF. Transmission electron microscopy showed that the cysts exhibited morphologic features of duct epithelium in vivo, including apical microvilli, lateral interdigitations of the plasma membrane, and typical cytoplasmic organelles.

Animals↗