PubMed Health⌕ Search

Biomedical subjects

J Winston

Publications and source records attributed to J Winston.

26 records · Page 2Linked to original sources
PubMed1995

Use of a mesh for musculoaponeurotic defects of the abdominal wall in cancer surgery and the risk of bowel fistulas.

BACKGROUND: Enterocutaneous fistulas resulting from mesh reconstruction of full-thickness musculoaponeurotic abdominal defects in benign conditions is a relatively infrequent, but serious complication. STUDY DESIGN: In the period 1977 to 1986, 26 patients with abdominal wall defects due to ablative surgery for carcinoma had repair with prosthetic material without any special effort to interpose tissue between bowel loops and the mesh. In the period 1986 to 1992, 30 patients with similar defects had tissue interposition between the bowel loops and the mesh (four patients had a free peritoneal patch). In an experimental study, 11 rabbits had an abdominal wall defect repaired with mesh alone, and 14 other rabbits had the abdominal wall defect repaired with the mesh plus a free peritoneal patch sutured underneath. RESULTS: In the first group of patients, six (23 percent) of 26 had enterocutaneous fistulas develop, in the second group zero (zero percent) of 30 had a fistula develop (p = 0.007). In the experimental study, the first group (ten of 11 rabbits) had dense adhesions develop between bowel loops and the mesh. In the second group, none of the 14 rabbits had adhesions develop (p < 0.0001). CONCLUSIONS: In full-thickness abdominal wall defects, omentum, muscle flap, or a peritoneal patch sewn under a mesh prevent fistula formation.

Abdominal Muscles↗
PubMed1987

Cisplatin nephrotoxicity: insights into mechanism.

Cis-dichlorodiammine platinum (II), or cisplatin, is currently among the most widely used agents in the chemotherapy of cancer. The chief limit to its greater efficacy is its nephrotoxicity. Acute and chronic nephrotoxicity of cisplatin occurs in man and animals especially after repeated administration. Morphological damage is restricted to the P3 segment of the proximal tubule. Abnormalities of water and solute reclamation and transglomerular passage of fluid are commonly associated with cisplatin nephrotoxicity. The vulnerability of the kidney to cisplatin may be related to its function as the primary excretory organ for platinum. Platinum binds to multiple cellular organelles and macromolecules, yet the precise mechanism of its cytotoxicity has not been delineated. Because abnormalities in renal function are preceded by a period where gross renal function appears normal, it is an ideal model to study the early physiological and biochemical determinants of metal induced acute renal failure.

Acute Kidney Injury↗
PubMed1986

Cisplatin nephrotoxicity.

Cis-dichlorodiammine platinum (II), or cisplatin, has emerged as a principal chemotherapeutic agent in the treatment of otherwise resistant solid tumors and is currently among the most widely used agents in the chemotherapy of cancer. The chief limit to its greater efficacy is its nephrotoxicity, which has made it necessary both to lower its dosage and actively hydrate patients to reduce it. The vulnerability of the kidney to cisplatin is almost certainly related to its primary role in the excretion of cisplatin. Cisplatin enters renal cells by a process that depends on normal oxygen utilization and is specifically inhibited by organic bases. Greater localization of platinum to the S3 segment of the proximal tubules suggests that the vulnerability of this segment may depend on its specific uptake of the drug. The majority of intracellular platinum is bound to macromolecules, including protein and DNA, yet a significant portion of cell platinum is biotransformed to a nonmutagenic and possibly nontoxic compound. Polyuria and hypomagnesemia, which are commonly associated with cisplatin nephrotoxicity, may be due to defects in deep nephron or collecting duct fluid and solute transport. Low single nephron glomerular filtration rates (SNGFR) during early cisplatinum-induced acute renal failure is accompanied by reduced renal blood flow and transglomerular hydrostatic pressure without elevated intratubular hydrostatic pressure, suggesting preglomerular vasoconstriction as an important determinant of renal failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Localization of current dipole within a sphere by magnetic measurements.

The principal objective of this study is the development of computer programs to determine the location and strength of neural electric activity within the brain from noninvasive magnetic field measurements at the surface of the head. This report presents theoretical calculations and computer programs derived from the method described by Williamson and Kaufman to determine the depth and strength of a current dipole in a sphere. From the location of the magnetic field radial component extremes, Br maximum and Br minimum, the orientation and location of the current dipole can be determined. The accuracy of the solution is dependent on precise location of of the magnetic field extremes as measured from the surface of a sphere, e.g. the head. To validate the program for locating the dipole, theoretical calculations and computer programs related to the total magnetic field vector resulting from a hypothetical current source within a homogeneous sphere were generated. The errors in calculations of the current dipole depth and strength are presented.

Brain↗