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Biomedical subjects

K Krishna

Publications and source records attributed to K Krishna.

15 recordsLinked to original sources
PubMed2006

Randomized clinical trial of the effect of quilting latissimus dorsi flap donor site on seroma formation.

BACKGROUND: Latissimus dorsi (LD) flap breast reconstruction is associated with a high incidence of donor site seromas, despite the use of surgical drains. The aim of this study was to evaluate the use of donor site quilting sutures, as well as drains, on the incidence, volume and frequency of seroma aspiration. METHODS: The trial randomized 108 women undergoing LD breast reconstruction to quilting procedures (54) or control group (52) for intention-to-treat analysis; two were excluded. Outcome measures were the incidence and volume of postoperative seroma. Secondary outcome measures included postoperative back pain, analgesic consumption, shoulder movement and duration of hospital stay. RESULTS: Quilting significantly reduced the overall incidence of seroma from 46 of 48 (96 per cent) to 43 of 52 (83 per cent) (P = 0.036), including the 38 women who had extended LD flap (with or without implants). There were further significant reductions in seroma volume (P = 0.004), frequency of aspiration (P = 0.001) and overall seroma volumes, including surgical drainage and symptomatic seromas (P = 0.013). Subset analyses for LD-implant (60 women) and extended LD (with or without implant) showed similar significance. Quilting did not affect back pain or compromise shoulder mobility. CONCLUSION: Quilting significantly reduced overall seroma volumes after LD breast reconstruction including extended LD, and is recommended in combination with surgical drains.

Adult↗
PubMed2005

QSAR studies of N(1)-(5-chloro-2-pyridyl)-2-{[4-(alkyl methyl)benzoyl]amino}-5-chlorobenzamide analogs.

Factor X(a) has materialized as a key enzyme for the intervention of blood coagulation cascade and for the development of new antithrombotic agents. It is the lone enzyme that is responsible for the production of thrombin and is therefore an attractive target for the control of thrombus formation. The biological activities (log1/IC(50)) of anthranilamide-based factor X(a) inhibitors were quantitatively analyzed in terms of physicochemical parameters by the regression analysis. Structural requirements for maximal potency were derived from the results of a quantitative structure activity relationship analysis. The leave-one-out cross-validation method was used to judge the predictive power of final equations.

Benzamides↗
PubMed1992

Zervamicins, a structurally characterised peptide model for membrane ion channels.

Voltage dependent membrane channels are formed by the zervamicins, a group of alpha-aminoisobutyric acid containing peptides. The role of polar residues like Thr, Gln and Hyp in promoting helical bundle formation is established by dramatically reduced channel lifetimes for a synthetic apolar analog. Crystal structures of Leu1-zervamicin reveal association of bent helices. Polar contacts between convex faces result in an 'hour glass' like arrangement of an aqueous channel with a central constriction. The structure suggests that gating mechanisms may involve movement of the Gln11 carboxamide group. Gln3 may play a role in modulating the size of the channel mouth.

Amino Acid Sequence↗
PubMed1992

The properties of ion channels formed by zervamicins.

The zervamicins (Zrv) are a family of 16 residue peptaibol channel formers, related to the 20 residue peptaibol alamethicin (Alm), but containing a higher proportion of polar sidechains. Zrv-IIB forms multi-level channels in planar lipid (diphytanoyl phosphatidylcholine) bilayers in response to cis positive voltages. Analysis of the voltage and concentration dependence of macroscopic conductances induced by Zrv-IIB suggests that, on average, channels contain ca. 13 peptide monomers. Analysis of single channel conductance levels suggests a similar value. The pattern of successive conductance levels is consistent with a modified helix bundle model in which the higher order bundle are distorted within the plane of the bilayer towards a "torpedo" shaped cross-section. The kinetics of intra-burst switching between adjacent conductance levels are shown to be approximately an order of magnitude faster for Zrv-IIB than for Alm. The channel forming properties of the related naturally occurring peptaibols, Zrv-Leu and Zrv-IC, have also been demonstrated, as have those of the synthetic apolar analogue Zrv-Al-16. The experimental studies on channel formation are combined with the known crystallographic structures of Zrv-Al-16 and Zrv-Leu to develop a molecular model of Zrv-IIB channels.

Alamethicin↗
PubMed1978

Tobacco chewing in pregnancy.

The effects of tobacco chewing by pregnant women were investigated. When compared with those who did not do so, tobacco-chewing mothers had a greatly increased stillbirth rate, a low male : female infant sex ratio and a major reduction in birth weight which was due in large part to early delivery.

Birth Weight↗