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Biomedical subjects

H Jiborn

Publications and source records attributed to H Jiborn.

53 records · Page 3Linked to original sources
PubMed1984

The effect of relative bowel rest on collagen metabolism and suture holding capacity in the colonic wall. Studies in the rat.

In a previous experimental study it was shown that bowel rest with low residue diet led to a reduction of the non-collagenous substances in the intact, unoperated colon, while the collagen content remained unchanged. In the cecum, both the collagen content and the non-collagenous substances were markedly increased. In the present investigation the effect of relative bowel rest on collagen synthesis in the colonic wall was studied. Further, a possible influence on mechanical properties was evaluated. It was found out that bowel rest led to a marked decrease of collagen and protein synthesis in the colon. In the cecum, there was an unchanged collagen synthesis but an increased protein synthesis. It can be deduced that lysis of collagen is decreased in all parts of the colon. The depression of collagen turnover in the colonic wall was not accompanied by measurable changes in mechanical strength. It remains to be studied whether the observed changes in collagen metabolism do affect colonic healing.

Animals↗
PubMed1984

The effect of relative bowel rest on collagen in the colonic wall. Studies in the rat.

In previous studies it was shown that diminished colonic content pre- and postoperatively, obtained by feeding rats low residue diet, results in less marked postoperative disturbances in collagen metabolism than in animals fed standard laboratory diet. In the present investigation the effect of relative bowel rest on collagen content and collagen concentration in the intact colonic wall was studied by feeding unoperated rats low residue diet. It was found that the colonic and cecal contents were reduced significantly and that this primarily affected the non-collagenous substances in the colon with a marked decrease, while the collagen content was unchanged. In the cecum, both the collagen and the non-collagenous contents were significantly increased. Thus, the pattern of change in biochemical response varied in different parts of the large intestine after institution of bowel rest. Further, the present data imply that collagen concentration can be misleading as a measure of the actual collagen amount.

Animals↗
PubMed1984

The effect of relative bowel rest on healing of colonic anastomoses. Breaking strength and collagen in the colonic wall following left colon resection and anastomosis in the rat.

The breaking strength of anastomoses in the left colon in the early phase of healing was studied in rats fed low residue diet (Biosorbin MCT) and the results were compared to those from rats fed standard laboratory diet. Further, eventual correlation between mechanical strength development and collagen content in the colonic wall around the anastomosis was evaluated. The anastomotic strength with sutures in place decreased by approximately 30% of the immediate postoperative value during the first two days in both groups of animals. There was no correlation between changes in anastomotic strength and collagen content at that time. After the second day there was a gradual increase of anastomotic strength, reaching the strength at day 0 after 7 days. The regain of strength was mainly due to collagen deposition in the anastomosis. Despite more collagen deposition in animals on standard laboratory diet the anastomoses had comparable strength development in the two groups. It was concluded that low residue diet does not impair the suture holding capacity or the anastomotic strength. Instead there was some evidence for a more uncomplicated healing when the bowel content was diminished.

Animals↗
PubMed1984

The effect of relative bowel rest on healing of colonic anastomoses. Collagen synthesis and content in the colonic wall after left colon resection and anastomosis in the rat.

Collagen metabolism was studied in the colonic wall of rats after standardized resection and anastomosis. Diminished faecal loading was obtained by feeding rats low-residue diet (Bisorbin MCT). The postoperative increase of collagen synthesis and collagen content was on a lower level in these rats than in rats on standard laboratory diet. The increase was confined to the immediate anastomotic region and presumably represented changes in collagen caused by the operative trauma per se. It was concluded that the intraluminal content is an important factor in stimulating collagen turnover. The findings of lower collagen turnover in the anastomotic area in animals on low-residue diet may have positive significance, but could also imply impairment of healing. For elucidation of this question, studies on mechanical strength of the anastomosis are necessary.

Animals↗
PubMed1983

Breaking strength of small intestinal anastomoses.

The breaking strength of standardized small bowel anastomoses at different times after surgery was studied in the rat. The anastomotic strength with sutures in place successively decreased during the first 3 postoperative days to approximately 15 percent of the immediate postoperative value. This indicates a rapid decrease in the suture holding capacity of the gut wall in the early postoperative course. From the fourth day onward a rapid increase in strength was recorded. This could be due not only to deposition of collagen in the tissue bridging the anastomosis but also to the regained capacity of the gut wall to withstand tearing forces. After 14 days the strength of the anastomosis was due mainly to healing, and the relative contribution from the sutures was negligible. It may be that tearing of sutures through the tissue is more important than defective healing for anastomotic complications.

Animals↗
PubMed1983

Connective tissue changes and collagen metabolism in syngeneic vena caval grafts in rats.

An attempt was made to determine if changes occurring in connective tissue and collagen metabolism of vein-to-artery grafts arose from the trauma of transplantation as such or from the higher pulsatile pressure. Segments of the supradiaphragmatic inferior vena cava were therefore transplanted to the infrarenal vena cava in syngeneic pairs of rats. The sequential changes in hydroxyproline concentration, 3H-proline incorporation and the histologic appearance of collagen, elastic fibres and fibronectin were noted. Comparisons were made with previously reported changes in syngeneic venoartery grafts in rats. The initial changes, probably resulting from the transplantation trauma, were similar in the veno-vein and veno-artery grafts. Subsequent changes, however, were less pronounced in veno-vein than in veno-artery grafts. The study thus suggests that these changes in vein-to-artery grafts are due partly to the transplantation trauma, but mainly to the increased pressure in the new environment.

Animals↗
PubMed1981

Bursting strength of syngeneic aortic vein grafts in the rat.

Mechanical strength of the supradiaphragmatic part of the vena cava transplanted from one rat into the abdominal aorta of another rat of the same inbred strain was studied before transplantation, as well as 3 days and 1, 2, 3 and 4 weeks after transplantation. Bursting pressure was determined by distending the specimens with water at a constant infusion rate. The diameter of the specimens was measured at the moment of burst by a shadow technique, and the wall thickness by a micrometer on formalin-fixed and paraffin-embedded transverse sections, thus enabling calculation of bursting wall tangential and circular tension. No significant changes in bursting pressure were observed within 2 weeks after transplantation. Three and 4 weeks after transplantation a significant increase in bursting strength was observed. This increase coincided with the increase in collagen concentration previously reported. The previously reported initial decrease in collagen concentration did not, however, result in significant changes in the bursting strength. It is suggested that the increase in the thickness of the vein wall due to the increase of components other than collagen compensates for the loss of collagen.

Animals↗
PubMed1979

Cardiac output distribution after left colon anastomosis in the rat.

Resection and anastomosis of the left colon result in an aysmmetric breakdown of preexisting collagen in the colonic wall during the first days of healing. Suture technique influences this reaction. To study the regional blood flow in the colon after resection and anastomosis a tracer microsphere technique was used for determination of the cardiac output distribution in four groups of rats: unoperated and sham-operated controls and rats with left colon anastomosis sutured either by continuous or interrupted sutures. There were no differences in the organ distribution of caridac output between unoperated and sham-operated controls. Left colon resection and anastomosis led to an increased regional blood flow in the colon, which was most marked proximal to the anastomosis and furthermore more pronounced in animals with anastomosis made of continuous suture than in those made of interrupted sutures. Further, resection and anastomosis resulted in an increased cardiac output distribution to the visceral organs. The visceral increase was most pronounced in animals with continuous suture. This increase was predominantly observed in the kidneys and in the colon. The latter is interpreted as being due to an increased metabolic demand induced by resection and anastomosis.

Animals↗
PubMed1979

Protective effect of hypoxia against radiation induced fibrosis in the rat gut.

The protective effect of hypoxia, induced by degradable microspheres, against the development of fibrosis was investigated after single-dose irradiation of exteriorized rat ileum. Evaluation, based upon microscopy and analysis of hydroxyproline in protected and nonprotected gut segments, demonstrated an evident protective effect at doses of 15 to 25 Gy.

Animals↗
PubMed1978

Healing of experimental colonic anastomoses. The effect of suture technic on collagen concentration in the colonic wall.

The present experimental study in rats has demonstrated a marked difference in the healing process of anastomoses in the left colon following two different suture technics: continuous and interrupted sutures. Rats having anastomoses constructed of continuous suture showed a high incidence of complications and a marked decrease of collagen concentration in the anastomosis and in the colonic wall proximal to the anastomosis during the first week of healing. In animals with anastomoses made of interrupted sutures there were fewer complications, the decrease in collagen concentration was confined to the anastomotic region, and the recovery of collagen concentration occurred earlier. The findings indicate that the interrupted suture technic is preferable for anastomosis in the left colon.

Animals↗
PubMedDate not supplied

The effect of stenosis on collagen metabolism in the colonic wall. Studies in the rat.

The influence of colonic stenosis resulting in faecal loading was investigated in regard to collagen metabolism in the intact colonic wall. The collagen content was increased in the left colon proximal to the stenosis, due to enhanced collagen synthesis. The collagen concentration fell significantly, however, as noncollagenous substances increased more than collagen. Collagen concentration clearly can be misleading as an indication of the actual amount of collagen. The enhanced rate of collagen turnover with collagen accumulation proximal to stenosis requires further analysis in regard to its importance for healing capacity.

Anastomosis, Surgical↗
PubMedDate not supplied

Bronchobiliary fistula in chronic pancreatitis. Case report.

Bronchobiliary fistulas are rare. One aetiological cause is biliary obstruction with secondary suppuration and subsequent hepatic and subphrenic abscesses. Only a few cases of bronchobiliary fistulas in patients with chronic pancreatitis have been reported and we record another case. A 47-year-old white male, with chronic alcohol-induced pancreatitis who had earlier undergone several laparotomies related to this disease, was admitted with a hepatic abscess. Drainage was not successful. The patient developed bilioptysis and a bronchobiliary fistula was diagnosed. The fistulous tract was demonstrated using PTC as well as bronchography. Laparotomy was performed and the fistulous tract was excised. The hepaticoduodenal ligament was completely obstructed by the inflamed pancreatic gland. An earlier but now obstructed cholecystojejunostomy was revised. This case was complicated by episodes of severe gastrointestinal bleeding probably caused by thrombosis of the portal vein and local varices around the gallbladder and common duct.

Alcoholism↗