Biomedical subjects

T Hendriks

Publications and source records attributed to T Hendriks.

At least 91 records · Page 5Linked to original sources

PubMed1992

Blood transfusion impairs the healing of experimental intestinal anastomoses.

Blood transfusions are reported to impair the cell-mediated immune response. Because both T lymphocyte and macrophage function are important for wound repair, the authors investigated the effect of blood transfusions on anastomotic repair. Lewis rats underwent resection of both ileum and colon, followed by the construction of either an everted or an inverted end-to-end anastomosis. Immediately after operation, they received either 3 mL saline intravenously, or 3 mL heparinized blood from Lewis or Brown Norway donors. The animals were killed 3 or 7 days after operation, and anastomotic strength was assessed by measuring the bursting pressure. Anastomotic abscesses and generalized peritonitis were not found in the control group. Blood transfusions, particularly allogeneic, significantly increased the incidence of these septic complications. Three days after operation, anastomotic strength was significantly reduced in both Lewis and Brown Norway transfused groups. For instance, average bursting pressures (+/- standard deviation [SD]) of inverted ileal anastomoses were 79 +/- 13 mmHg in the control group and 46 +/- 14 and 21 +/- 12 mmHg in the Lewis and Brown Norway transfused groups, respectively. Seven days after operation, the rupture site was found significantly more often within the anastomotic line in the animals that had received blood transfusions. The authors conclude that blood transfusions impair the healing of experimental intestinal anastomoses and increase susceptibility to intra-abdominal sepsis.

Abscess↗

PubMed1992

Collagen synthesis in fibroblasts from human colon: regulatory aspects and differences with skin fibroblasts.

The purpose of this study was to examine regulation of collagen synthesis in human colon fibroblasts and compare the results from colon fibroblasts with those obtained in fibroblasts from human skin. The effects of interleukin-1 beta, tumour necrosis factor alpha, interferon gamma, transforming growth factor-beta, dexamethasone, and the calcium ionophore A23187 were investigated. All compounds were tested both in the absence and in the presence of fetal calf serum in the culture medium. The process of collagen synthesis in fibroblasts from colon and skin appears to be affected differently by these regulatory compounds. The most pronounced differences were that the relative collagen synthesis increased in dermal fibroblasts and decreased in colon fibroblasts upon addition of serum. In the presence of serum, interleukin-1 beta inhibited collagen synthesis in skin fibroblasts but not in colon fibroblasts. Dexamethasone suppressed the relative collagen synthesis in skin fibroblasts but not in colon fibroblasts. Transforming growth factor-beta stimulated the collagen synthesis in dermal fibroblasts in the presence of serum, but inhibited the process in colon fibroblasts. Because fibroblasts are the primary sources of collagen needed during wound repair, these results may offer (part of) the explanation why wounds in skin and intestine appear to behave differently under certain conditions.

Calcimycin↗

PubMed1992

Cytostatics and anastomotic healing in the intestine: an experimental study on the effect of parenteral nutrition.

The effects of parenteral nutrition on the healing of experimental ileal and colonic anastomoses constructed on the 3rd day of a 5-day cytostatics course were investigated. Intravenous saline alone already reduced weight loss induced by cytostatics while parenteral nutrition almost completely prevented postoperative loss of weight. A negative effect of cytostatics on anastomotic bursting strength was found in the ileum 7 days after operation. Parenteral feeding negated this effect but had no positive effect on anastomotic hydroxyproline content. Thus, parenteral nutrition increases the strength of intestinal anastomoses, constructed during a cytostatics regimen, but intravenous saline alone also appears to have a similar effect.

Anastomosis, Surgical↗

PubMed1991

Petunia peroxidase a: isolation, purification and characteristics.

The fast-moving anionic peroxidase isoenzyme variant PRXa was purified from leaves of petunia (Petunia hybrida). Over 1300-fold purification was achieved by subjecting extracellular extracts to two sequential acetone precipitations and resuspending the pellets at pH 5.0 and pH 8.0, respectively, followed by gel filtration and chromatofocusing. The purified enzyme had an absorbance ratio (A405 nm/A280 nm) of 3.6, a molecular mass of about 37 kDa and a pI of 3.8. Three molecular forms with slightly different molecular masses were separated by concanavalin-A--Sepharose affinity chromatography, indicating that these three forms differ in their carbohydrate moieties. The absorption spectrum of PRXa had maxima at 496 and 636 nm and a Soret band at 405 nm. Spectra of compounds I and IV were obtained by titrating a batch of PRXa stored for several months at -20 degrees C with H2O2. The addition of 1 mol H2O2/mol freshly purified PRXa caused the formation of compound II, indicating that freshly isolated PRXa contains a bound hydrogen donor which is lost upon storage. Compound III was obtained from both preparations in the presence of excess H2O2. The pH optimum of PRXa for the reaction with H2O2 and guaiacol was 5.0 and its specific activity 61 mkat/g protein. Among various aromatic compounds, coniferyl alcohol was polymerized by PRXa to presumed lignin-like material. The extracellular localization and high affinity of PRXa for the cinnamic acid derivatives suggest that this isoenzyme functions in the polymerization or cross-linking of lignin in the plant cell wall.

Catalysis↗

PubMed1991

Influence of methylprednisolone on the healing of intestinal anastomoses in rats.

Although steroids are generally thought to impair intestinal anastomotic healing, this effect has never been proven unequivocally in either clinical or experimental studies. We have investigated the influence of methylprednisolone (2.5 or 10.0 mg kg-1 day-1) given from 2 days before operation onwards, on 3-day-old and 7-day-old ileal and colonic anastomoses in rats. Anastomotic abscesses occurred more frequently in the ileum, but not in the colon, after steroid medication. However, methylprednisolone did not lower anastomotic bursting pressures in either of the bowel segments. Comparison of the hydroxyproline content of the anastomotic segment yielded no significant difference between control and methylprednisolone groups in either small or large bowel. Thus, healing of experimental colonic anastomoses remains unaffected by short-term administration of this corticosteroid.

Anastomosis, Surgical↗

PubMed1991

Patatin and four serine proteinase inhibitor genes are differentially expressed during potato tuber development.

A highly efficient and synchronous in vitro tuberization system is described. One-node stem pieces from potato (Solanum tuberosum cv. Bintje) plants grown under short day-light conditions containing an axillary bud were cultured in the dark on a tuber-inducing medium. After 5 or 6 days all axillary buds started to develop tubers. To study gene expression during tuber development, RNA isolated from tuberizing axillary buds was used for both in vitro translation and northern blot hybridizations. The genes encoding the proteinase inhibitors I and II (PI-I and PI-II), a Kunitz- and a Bowman-Birk-type proteinase inhibitor were already expressed in uninduced axillary buds. The length of the day-light conditions differently influenced the expression level of the individual genes. In addition, the expression of each of these genes changed specifically during the development of the axillary bud to tuber. In contrast to the expression of these proteinase inhibitor genes, patatin gene expression was only detectable from the day tuberization was manifested as a radial expansion of the axillary bud. These results are discussed with respect to the regulation of the expression of the genes studied in relation to the regulation of tuber development.

Blotting, Northern↗

PubMed1991

Intestinal anastomotic healing in the absence of suture material: an experimental study in rats.

In order to investigate the influence of sutures on intestinal anastomotic healing, 48 rats underwent both ileal and colonic resection. In 24 rats all intestinal sutures were removed 30 min after anastomotic construction (group 1), while in the remaining animals (group 2) the sutures were left in place. Bursting pressures and collagen (hydroxyproline) levels in anastomotic segments were measured 1, 3, and 7 days after operation. Two lethal ileal dehiscences and 9 anastomotic abscesses (5 ileal and 4 colonic) occurred in group 1, while in group 2 there were 3 ileal anastomotic abscesses. On the first day after operation, bursting pressures were significantly lower in sutureless ileal and colonic than in sutured anastomoses. During the post-operative course, changes in collagen concentrations in ileal and colonic segments did not differ between the groups. Thus, sutures are only essential in providing anastomotic strength during the immediate post-operative period, but do not seem to affect post-operative collagen metabolism.

Anastomosis, Surgical↗

PubMed1991

The influence of NSAIDs on experimental intestinal anastomoses.

Limiting degradation of collagen during the initial phase of wound healing is expected to improve postoperative intestinal strength and thereby decrease chances for anastomotic dehiscence. We studied the influence of four nonsteroid anti-inflammatory drugs on the healing of intestinal anastomoses in rats, with special regard to changes of collagen levels around the anastomoses. Four experimental groups of 20 rats each received daily oral doses of piroxicam, ibuprofen, aspirin, or indomethacin and were compared with a control group. Animals were sacrificed 3 or 7 days after operation. Both morbidity and mortality rate in the experimental groups were high. Collagen, measured as hydroxyproline, levels in anastomotic and adjoining 1-cm intestinal segments were compared with concentrations in control segments resected during operation. After an initial decrease on day 3, hydroxyproline concentrations increased on day 7. In the colon the lowering of hydroxyproline concentrations, which was more pronounced than in the ileum, was significantly reduced by administration of piroxicam and ibuprofen, both in the anastomosis and its proximal segment. On day 7, the increase of hydroxyproline concentrations in the ileum was inhibited by administration of anti-inflammatory drugs. It is concluded that nonsteroidal anti-inflammatory drugs may limit postoperative degradation of collagen in colonic anastomoses, but at the same time may increase the rat's susceptibility to surgical infections.

Analysis of Variance↗

PubMed1991

Intraperitoneal cytostatics impair healing of experimental intestinal anastomoses.

We investigated the effect of two doses of cytostatics, administered intraperitoneally during 5 consecutive days, on the healing of ileal and colonic anastomoses constructed on the third day. The cytostatics regimen consisted of a combination of 5-fluorouracil, bleomycin and cisplatin at 10, 2 and 0.35 mg kg-1d-1, respectively, or at twice higher doses. The lower dose was similar to that given intravenously in previous experiments. Rats were sacrificed 3 or 7 days after operation. No effects of cytostatics were observed after 3 days, neither on anastomotic bursting pressure nor on hydroxyproline concentration (microgram/mg dry weight) or content (microgram cm-1). Profound effects were seen at 7 days. In the high dose group, bursting pressures in both anastomoses were greatly reduced with respect to the control group. Concurrently, collagen synthesis was severely impaired, as indicated by sustained decreased hydroxyproline concentrations and content. The lower dose of cytostatics showed essentially similar effects on hydroxyproline parameters, but affected anastomotic strength less dramatically. The data indicate that, while intraperitoneal chemotherapy may show less detrimental systemic toxicity and thus allow higher doses, its application as an adjunct to gastrointestinal surgery may be limited because of its severe effects on anastomotic repair.

Anastomosis, Surgical↗

PubMed1991

Postoperative changes in collagen synthesis in intestinal anastomoses of the rat: differences between small and large bowel.

Collagen synthesis is an essential feature of anastomotic healing in the intestine. Postoperative collagen synthesis, measured in vitro in intestinal anastomoses was studied from three hours to 28 days after operation. For this purpose, an ileal and a colonic anastomosis were constructed within the same animal and the results in both intestinal segments were compared. In the ileum, collagen synthesis was significantly increased, with respect to unoperated controls, three hours after operation. It remained raised during the period of study, with a maximal 10-fold stimulation four days after operation, and had nearly returned to the preoperative level after four weeks. The general pattern was the same in the colon, although quantitatively different: the increase in synthetic activity was delayed in comparison with the ileum. Maximal stimulation was approximately six-fold. In addition, we calculated the ratio for each rat between anastomotic collagen synthesis and the average value found in non-operated control animals. Postoperative stimulation in the ileum was higher than in the colon in almost every animal examined. The results show that the ileum responds more quickly and strongly to wounding than the colon, at least as far as the production of new collagen is concerned. Possibly, this phenomenon contributes to the lower failure rate apparent for anastomoses in the small bowel.

Anastomosis, Surgical↗

PubMed1990

Correlation between collagenolytic activity and grade of histological differentiation in colorectal tumors.

Collagenolytic activity, extracted from 55 tumor and healthy corresponding intestinal control samples, was determined by 3 different assays using soluble type I and fibrillar type I and III collagen, respectively, as substrate. The enzyme extracted from tumor-digested collagen type I reconstituted fibrils and yielded the three-quarter segments characteristic for the action of one of the matrix metalloproteinases: MMP-I or mammalian collagenase. Metal-chelating agents such as EDTA and O-phenanthrolin indeed inhibited this activity. Collagenolytic activities were calculated on the basis of wet weight, total DNA and total extracted protein. Correlations were sought between levels of activity and both clinicopathological stage (Dukes' staging) and grade of histological differentiation. In all the assays applied, significant correlations were found between grade of histological differentiation and collagenolytic activity expressed as the tumor/control ratios: poorly differentiated tumors exhibited a higher tumor/control ratio than well-differentiated tumors. Also, tumors penetrating into the serosa showed a higher tumor/control ratio than tumors invading the muscularis propria only. A relation between collagenolytic activity and clinico-pathological stage was observed only if activities were calculated on a DNA basis. These results confirm a relationship between the histological appearance of a tumor and its enzymatic potential to degrade interstitial collagens.

Adenocarcinoma↗

PubMed1990

Healing of experimental intestinal anastomoses. Parameters for repair.

Anastomotic dehiscence remains a major complication in surgery of the large bowel, and studies on the healing sequence of experimental anastomoses are necessary to define underlying mechanisms and find ways to improve surgical outcome, particularly in high-risk situations. For the quantitative description of anastomotic repair, both mechanical and biochemical parameters are employed, each with their own limitations. Mechanical parameters, either bursting pressure or breaking strength, only reflect growing anastomotic strength as long as disruption occurs within the anastomotic area, which is less than one week after surgery for the bursting pressure and probably up to two weeks for the breaking strength. The biochemical description of anastomotic repair has been limited to behavior of collagen, as represented by its rather unique constituent amino acid hydroxyproline. Conclusions based on collagen concentrations--per unit weight--should be considered with caution since they may change as a consequence of changes in noncollagenous substances. In this respect, collagen content, per unit length, is probably a better parameter to describe anastomotic collagen levels. Few investigations have addressed the quality of collagen (e.g., crosslinking or type). Since, at this time, no distinct correlations have been demonstrated between development of mechanical strength or occurrence of leakage and collagen levels in the healing anastomosis, attention should not be restricted to a description of the quantity of collagen present: the quality of anastomotic collagen should be investigated, perhaps even more so.

Anastomosis, Surgical↗

PubMed1990

The effects of lathyrogens on intestinal anastomoses in the rat.

Submucosal collagen provides strength to the intestinal wall. In order to assess the importance of collagen fibers for the developing strength of intestinal anastomoses we have sought to prevent postoperative collagen crosslinking by administration of lathyrogens. Rats, receiving both an ileal and a colonic anastomosis, were treated with either D-penicillamine or beta-aminopropionitrile from 1 day before operation. Animals were sacrificed 7 days postoperatively and bursting pressures, bursting sites, and anastomotic collagen (hydroxyproline) content and solubility were determined. D-Penicillamine, in a dose of 500 mg/kg/day and administered orally, had no effect at all. beta-Aminopropionitrile, in a dose of 625 mg/kg/day and given orally or intraperitoneally, significantly increased the acid solubility of anastomotic hydroxyproline in both ileum and colon without affecting total hydroxyproline content or concentration. Bursting pressures of the anastomotic segments were lowered, more significantly in colon than in ileum. Also, the bursting site was found more frequently in the anastomotic area in these animals. By inhibiting the formation of crosslinks in intestinal wounds with beta-aminopropionitrile, the anastomotic strength was reduced. These results demonstrate the importance of collagen in maintaining anastomotic integrity and at the same time emphasize that not only the quantity but also, and perhaps even more so, the quality of the collagen should be taken as an index of healing.

Aminopropionitrile↗

PubMed1990

Spectrophotometric correction for bile pigments in the thiobarbituric acid test for malondialdehyde-like substances in plasma.

A simple method is proposed to improve specificity when estimating malondialdehyde-like components of plasma thiobarbituric acid-reactivity, especially with regard to the considerable contribution of bilirubin. The spectrophotometric method comprises measurement of A485, A532 and A560 instead of only A532. A correction formula is then applied to calculate the portion of the A532 which originates from malondialdehyde-like substances. Using this method, normal values for malondialdehyde average 0.84 mumol/l.

Bile Pigments↗

PubMed1989

Collagen synthesis in explants from rat intestine.

Collagen is the major structural component of the intestinal wall and its metabolism is of special interest for intestinal strength. We describe collagen synthesis in short-term (3 h) incubations of rat intestinal tissue, as measured in terms of incorporation of [3H]proline in collagenase-digestible protein and percentage relative collagen synthesis. In this time span, incorporation of [3H]proline in collagen increases linearly with time and tissue weight. Addition of unlabeled proline during incubation, in excess of the 0.1 microM [3H]proline always present, strongly increases both total protein and collagen synthesis, suggesting that proline transport is rate limiting. Further experiments have been performed in the presence of labeled proline alone and with the addition of 0.35 mM unlabeled proline. Collagen synthesis is significantly higher in colon than in ileum, comprising 0.37 and 0.21%, respectively, of total protein synthesis. Also, collagen synthesis decreases considerably with age, both in ileum and colon. The results presented here demonstrate that rat intestinal explants synthesize measurable amounts of collagen in vitro and that the system used is able to detect changes in in vivo synthetic capability such as those induced by ageing.

Aging↗

PubMed1989

Collagen changes around intestinal anastomoses in germ-free rats.

The changes in collagen, measured as hydroxyproline, concentration around both ileal and colonic anastomoses in germ-free and control rats have been investigated and compared with each other. The germ-free rats were raised, operated on and maintained under completely pyrogen-free conditions. Animals were killed 2, 3 or 7 days after operation. There was a significant reduction in the lowering of hydroxyproline concentrations around the colonic anastomosis of germ-free rats compared with control rats both in the anastomosis at days 2 and 3 (P = 0.04 and P = 0.006 respectively) and in the proximal segment at day 3 (P = 0.03). In ileal anastomoses, significant differences between control and germ-free rats were only found at 7 days. Here, the increase in hydroxyproline concentration observed in control rats was significantly reduced in germ-free rats. These data are taken to support the hypothesis that bacteria affect colonic anastomotic healing by contributing to postoperative collagen degradation.

Anastomosis, Surgical↗

PubMed1989

Collagenolytic activity extracted from intestinal anastomoses of the rat.

The post-operative degradation of collagen has been postulated to play an important role in the development of anastomotic leakage in the intestine. However, collagenolytic activity in intestinal anastomoses has hardly been studied so far. We have measured collagenolytic activity, after extraction in an urea-containing medium, in both ileal and colonic anastomoses in the rat, from 12 hours to 31 days after operation. In ileum collagenolytic activity increased significantly, from 2 to 4 (average 2.7) times the control value, at 12 hours post-operatively followed by a steady decline to original levels. Four weeks after surgery the activity was still slightly, but significantly, enhanced. In colon collagenolytic activity also increased up to 4 times the pre-operative level (average 3.0) 12 hours after operation. Return to original levels was delayed in colon compared to ileum but here activities were similar to control values after one month. In both parts of the intestine there was only a small increase in activity at a segment proximal to the anastomosis during the first 24 hours after operation. The amount of protein extracted did not vary significantly between control and anastomotic samples. These data are the first to show a transiently increased extractable collagenolytic activity in intestinal anastomoses.

Anastomosis, Surgical↗

PubMed1989

Piroxicam affects collagen changes around experimental intestinal anastomoses.

The effects of piroxicam on postoperative changes of collagen--measured as hydroxyproline--concentrations were measured around intestinal anastomoses in rats. Piroxicam, in a dose of 2 mg/kg/day, significantly reduced the decrease of hydroxyproline concentrations around colonic anastomoses during the first 3 days after the operation but also reduced the increase of hydroxyproline concentrations observed at day 7 around ileal anastomoses in the control group. 10 mg piroxicam/kg/day resulted in a 100% lethal peritonitis after the 5th postoperative day. We suggest that piroxicam affects collagen metabolism by inhibiting granulocyte functions.

Anastomosis, Surgical↗