Effect of growth hormone treatment on the healing of left colonic anastomoses in protein-malnourished rats

BACKGROUND: Malnutrition is known to affect wound healing but it is not known with certainty whether or not postoperative hyperalimentation can reverse this defect. The present study was designed to examine the effects of recombinant human growth hormone (hGH) on left colonic anastomoses in malnourished rats. METHODS: Experimental animals were allocated randomly into four groups. In groups 1 and 2 animals were fed with normal diet for 10 days before surgery. In groups 3 and 4 animals were fed with a low-protein diet. Left colonic anastomoses were performed in all animals. Following surgery, rats in groups 1 and 3 received hGH whereas rats in groups 2 and 4 were injected with saline as control. Bursting pressure and hydroxyproline levels on day 4 after operation were used to determine anastomotic healing. Results: Bursting pressure was lower in the malnourished rats than those fed with normal diet (P< 0.05). Bursting pressure was higher in normally fed rats which were given hGH. No significant differences could be noted between malnourished control rats and those receiving hGH. CONCLUSION: These results suggest that hGH strengthened the left colonic anastomoses in rats fed a normal diet, but could not reverse the negative effects of malnutrition on colonic anastomoses.     

Influence of intraperitoneal 5-fluorouracil plus folinic acid on the healing of colonic anastomoses in rats

We studied the effects of intraperitoneal 5-fluorouracil (5-FU) administration with or without the addition of folinic acid (FA) on the healing of colonic anastomoses in rats immediately after surgery. Sixty-three male Wistar rats were subjected to colonic anastomosis. During surgery, the rats were randomized into one of three groups. Therapy was administered as an intraoperative intraperitoneal injection which was repeated once daily for the first 2 postoperative days. A 0.9% NaCl solution was administered to the rats in the control group. In group 2, we injected 5-FU (20 mg/kg/day) and in group 3 5-FU (20 mg/kg/day) plus FA (2 mg/kg/day). The rats were sacrificed on postoperative days 3, 5 or 8. Rupture of the anastomosis was significantly higher in the rats of groups 2 and 3, compared with the control group (p < 0.05). There were, however, no differences between groups 2 and 3. Formation of adhesions and abscesses was more common in groups 2 and 3 than in the control group for all study days. A significant difference in the anastomotic bursting pressure was measured for the control group in comparison to groups 2 and 3 on days 5 and 8 (p < 0.05). Histologic evaluation also showed a more profound inflammatory reaction and delayed healing of the anastomoses in groups 2 and 3, compared to the control group. Therefore, the perioperative intraperitoneal administration of 5-FU can inhibit the healing of colonic anastomoses in rats. The addition of an intraperitoneal injection of FA does not aggravate this negative effect.     

Comparison of catgut and polyglycolic acid sutures in colonic anastomoses

Microfibrillar collagen, a recently introduced topical hemostatic agent, was used to obtain hemostasis in suction-evacuation lesions of canine cortex. Gelatin foam was used as a control in identical lesions on the opposite side. Microfibrillar collagen was found to be faster acting and more effective than gelatin foam. Histological evaluation of the lesions at 2,4, and 6 months postoperatively showed no significant difference in the amount or type of tissue reaction to the two agents.     

Effect of dry fibrin sealant dressings versus gauze packing on blood loss in grade V liver injuries in resuscitated swine

In mammalian fertilization, inositol 1,4,5-trisphosphate receptor (IP3R)-dependent Ca2+ release is a crucial signaling event that originates from the vicinity of sperm-egg interaction and spreads as a wave throughout the egg cytoplasm. While it is known that Ca2+ is released by the type 1 IP3R in the egg cortex, the potential involvement of other isoform types responsible for the Ca2+ rise in the mouse egg (interior) and their spatial distribution are not known. In addition, the biochemical basis has not been definitively established for the development of increased sensitivity to inositol 1,4,5-trisphosphate (IP3) during meiotic maturation. Using specific antibodies to the type 1, 2, and 3 IP3R, we tested the hypotheses that different IP3R isoforms are responsible for the internal Ca2+ elevation and that they contribute to the maturation-associated acquisition of IP3 sensitivity. In both preovulatory oocytes and ovulated eggs of CF-1 mice, immunofluorescence revealed that types 1 and 2 isoforms were present in the cell cortex and interior. Type 1 was observed throughout the cytoplasm, and Western analysis indicated a 1.9-fold maturation-associated increase. In contrast, the signals detected for the type 2 (high-affinity) isoform and type 3 were present to a lesser extent, with type 2 restricted to isolated islands (similar to aggregates of vesicles detected by electron microscopy), which, in the cortex, may amplify early sperm-egg signaling events. The cortical-to-perinuclear localization of the receptor and cortical vesicle aggregates imply an efficient mechanism for propagating Ca2+ release from the cortex into the interior of the egg to activate development, and the isoform localization analysis indicates a clear spatial and biochemical heterogeneity. Types 1 and 2 isoforms were also present in granulosa cells.     

Healing of colonic ischemic anastomoses in the rat: role of superoxide radicals

PURPOSE: The aim of this study was to evaluate the role of superoxide radicals in the healing of ischemic colonic anastomoses in the rat. METHODS: Adult male Wistar rats were used in a factorial design with two factors (normal or ischemic colonic anastomoses) each having two levels (treatment with saline or allopurinol). Colonic anastomoses were performed either in normal or previously devascularized colons (ischemic anastomoses) at identical locations, using the same technique. On the fourth postoperative day, animals were killed, and specimens were taken for determinations. RESULTS: Ischemic anastomoses displayed significant increases in superoxide radical (assayed as superoxide anion), superoxide dismutase, and glutathione peroxidase concentrations. Bursting strength and hydroxyproline levels were also significantly lower in these anastomoses. Allopurinol administration elicited a significant decrease in superoxide anions and raised both bursting strength and hydroxyproline levels only in ischemic anastomoses. CONCLUSIONS: Superoxide radicals are involved in the delay in healing of ischemic anastomoses. Allopurinol lowers superoxide anion production and has beneficial effects on the cicatrization of ischemic anastomoses.     

Hemostatic efficacy of a fibrin sealant dressing in an animal model of kidney injury

Arterial spin tagging techniques have been used to image tissue perfusion in MR without contrast injection or ionizing radiation. Currently, spin tagging studies are performed primarily using single-slice imaging sequences, which are time consuming. This note reports a multislice echo-planar arterial spin tagging technique (Simultaneous Multislice Acquisition with aRterial-flow Tagging, or "SMART"). Multiband RF encoding (Hadamard) is used to provide simultaneous multislice acquisition capability for spin tagging techniques (such as echo planar imaging signal targeting with alternating radio frequency and flow-sensitive alternative inversion recovery). The method is illustrated with a two-slice pulse sequence that was implemented using the FAIR technique to generate two perfusion weighted images simultaneously. Compared with single-slice sequences, this two-slice sequence provided similar image quality, signal-to-noise ratio, and twice the spatial coverage compared with the single-slice technique within the same scan time.     

The effect of intravenous amino acids in total parenteral nutrition on the healing of experimental colonic anastomoses in the rat]

Elderly patients are particularly sensitive to the development of various electrolyte abnormalities, since they commonly exhibit some derangements in the physiologic homeostasis of acid-base status and electrolyte balance. Our study was undertaken to assess the prevalence, as well as the pathophysiologic mechanisms involved in the development of electrolyte abnormalities in 248 elderly patients admitted to our clinic for a variety of causes. Fifty-five out of these patients (22.2%) had at least one electrolyte abnormality. In such cases a thorough laboratory investigation was performed in an attempt to delineate the pathophysiologic mechanisms involved in relation to age.     

Effect of intravesical capsaicin and vehicle on bladder integrity control and spinal cord injured rats

PURPOSE: To determine the acute effect of intravesical capsaicin on bladder mucosal integrity in normal and spinal cord injured (SCI) rats. MATERIALS AND METHODS: Intravesical reagents were instilled in 5 groups of age and weight matched female rats: 1) control + normal saline solution (NSS), 2) control + ethanol (EtOH), 3) control + capsaicin/EtOH, 4) SCI + NSS, 5) SCI + capsaicin/EtOH. Intravesical instillations were performed 4 weeks after a standard T10 SCI. Intravesical capsaicin (1 mM.) was dissolved in 30% EtOH/NSS. The animals (n = 3 each group) were sacrificed at 30 minutes, 24 hours, 72 hours, and 7 days after intravesical instillation. Whole bladders were harvested, fixed in 10% buffered formalin, and paraffin embedded. Tissue blocks were blind coded and sectioned (5 microns thickness) for histopathological analysis. All sections were initially stained with hematoxylin and eosin (H & E). Specific staining for mucin carbohydrate moieties included periodic acid-Schiff (PAS) and alcian blue. Also, immunohistochemical staining for GP51 (a urinary glycoprotein) was performed. RESULTS: Control and SCI rats exhibited similar bladder mucosal histology by H & E and mucin specific stains. Instillation of saline demonstrated no effect on bladder histology, whereas instillation of intravesical capsaicin induced a profound acute effect of thinning of the epithelium, submucosal edema, and diminished presence of GP51. EtOH produced similar pathological findings, but to a lesser degree than capsaicin. Intravesical capsaicin demonstrated a similar effect in both control and SCI animals. The peak effect was seen after 30 minutes and continued for 24 hours. Partial recovery was noted after 72 hours and complete recovery was evident by 1 week. CONCLUSIONS: The control and SCI rats demonstrated a histologically similar mucosa and glycosaminoglycan layer. The effect of saline instillation on the mucosa was negligible. Intravesical capsaicin dissolved in 30% ethanol/NSS had a profound effect on the bladder urothelium submucosa that was more pronounced than that seen with the ethanol vehicle alone in normal animals.     

SEM evaluation of endothelial changes following end-to-side microvascular anastomoses in rats

A scanning electron microscopic (SEM) study was carried out to evaluate the endothelial changes in carotid end-to-side microsurgical anastomoses. This procedure, associated with occlusion of the brachiocephalic trunk, was performed in 24 Sprague-Dawley rats. The animals were sacrificed at time intervals ranging between 15 minutes and 14 days after surgery. The specimens were collected after perfusion-fixation in vivo and treated for SEM observations. The findings show that the first 45 minutes are the most critical time for thrombus formation. Reendothelialization could be detected at 3 days after the microsurgical procedure. Endothelial regeneration occurred earlier on the suture line than on the stitches, documented by the migration and morphological changes of the endothelial cells advancing from the normal endothelium to cover the defect and the suture material. The repair was usually completed within 14 days. Damage of the inner vascular wall, related to minor failures of the microsurgical technique, appears to be a cause of delayed reendothelialization.     

Effect of zinc ions on fibrin network structure

In addition to calcium, other physiologically important divalent cations (magnesium and zinc) are known to influence fibrin formation and structure. We have studied the effect of different concentrations (0-20 micromol/l) of zinc ions (Zn2+) in the absence and presence of calcium on the gel structure formed in purified fibrinogen-enzyme systems. For that purpose, we used turbidity measurement, liquid permeation and confocal three-dimensional microscopy of the gel as well as sodium dodecyl sulphate (SDS)-gel electrophoresis. The results of turbidity measurements indicated that the clotting time decreased with increasing concentrations of Zn2+. The fiber mass: length ratio (mu) values showed that the porosity of the gels increased in a concentration-dependent manner, i.e. at higher concentrations of Zn2+, larger pores with thicker fibrin fibers were formed. Three-dimensional microscopy data of the gels were in good agreement with the mu data. On SDS-gel electrophores of reduced fibrin, no cross-linking was observed in the presence of zinc ions only (without the addition of calcium ions), nor were D-D dimer bands observed in non-reduced plasmin digested fibrin samples in the presence of zinc ions only. The above results show that zinc changes the fibrin gel structure and that this effect appears to be independent of calcium.     

Endoscopic visualization of induced colonic tumors in rats

The visualization of induced colonic tumors in rats was investigated using either a rigid or flexible endoscope. There was 89% agreement between presence or absence of at least one tumor as visualized at endoscopy and necropsy. The agreement was 83% (p < 0.01) when the exact number of tumors was compared. Neither carcinogens (1,2-dimethylhydrazine or N-methylnitrosourea) nor dietary supplements affected the results.     

Effect of YNS-15P, a new alpha-2 adrenoceptor antagonist, on stress-stimulated colonic propulsion in rats

We studied effects of a novel alpha-2 adrenoceptor antagonist, YNS-15P (N-[(2R,11bS)-9-methoxy-1,3,4,6,7, 11b-hexahydro-2H-benzoquinolizin-2-yl]-N-methylmethanesulfonami de hydrochloride), on colonic propulsion stimulated by wrap-restraint stress (WRS) or bethanechol, on normal colonic propulsion and on diarrhea induced by castor oil in rats. Alpha-2 adrenoceptor antagonists, rauwolscine and RX821002, decreased the increase in the number and weight of fecal pellets induced by WRS. YNS-15P also inhibited WRS-stimulated fecal excretion in a dose-dependent manner. A 5-hydroxytryptamine3 receptor antagonist, granisetron, trimebutine and diazepam, but not a 5-hydroxytryptamine4 receptor antagonist, GR113808, significantly inhibited WRS-stimulated fecal excretion. YNS-15P inhibited WRS-stimulated colonic transit in a dose-dependent manner. However, YNS-15P had no significant effect on normal fecal excretion and colonic transit or on bethanechol-stimulated fecal excretion. YNS-15P also failed to inhibit castor-oil-induced diarrhea. These results indicate that YNS-15P selectively inhibits WRS-stimulated colonic propulsion, and that alpha-2 adrenoceptors may be involved in stress-induced colonic motor dysfunction in fed rats.     

Effect of platelet antiserum on the precipitation of soluble fibrin by endotoxin

Rabbits were injected with a platelet antiserum to examine the role of thrombocytopenia of the precipitation of soluble fibrin by endotoxin.dotoxin. Platelet antiserum removed more than 98% of the circulating platelets, and the resulting thrombocytopenia with platelet counts below 10,000 per mul persisted during the entire 10 hr-period of the experiment. Leukocyte counts were not significantly influenced by the platelet antiserum. Since the rabbits were treated with high doses of heparin, activation of intravascular coagulation by the antiserum did not occur. Precipitation of soluble fibrin was achieved by injection of endotoxin into rabbits with ancrod-induced circulating soluble fibrin. Thrombocytopenia did not prevent the occurrence of glomerular microclots after ancrod and endotoxin administration. On the contrary, if endotoxin was injected into antiserum- and heparin-treated rabbits with circulating soluble fibrin, glomerular microclot formation occurred even in a higher percentage than in control rabbits treated with absorbed platelet antiserum. This investigation indicates that platelet antiserum-induced thrombocytopenia does not protect against precipitation of soluble fibrin by en     

Effect of lumenal contents on colonic cell replacement

Recent studies have shown that the rate of colonic cell renewal can be altered through fasting and refeeding, which produces a marked depression and transient stimulation, respectively. In the present study, the role of physical versus nutritional stimulation in the colonic fasting-refeeding response and the renewal of the functional colonic compartment were evaluated via a nondestructive colonic ligation procedure. The results reported herein suggest that physical stimulation by lumenal factors is in part required to initiate the colonic hyperplasia seen after refeeding. Blood-borne nutritional factors, in the absence of physical stimulation, cannot alone stimulate colonic cell production. Additional evidence is presented which suggests that this physical stimulation may be manifested through the lumenal distension produced by the newly ingested food materials. The results are discussed from the viewpoint of influencing the functional colonic compartment and physiological capacity.     

MR cholangiography in the examination of patients with biliary-enteric anastomoses

OBJECTIVE: The aim of our study was to determine the role of MR cholangiography in the noninvasive examination of patients with biliary-enteric anastomoses. SUBJECTS AND METHODS: Twenty-four patients (nine men and 15 women; mean age, 68.9 years old) with biliary-enteric anastomoses underwent MR cholangiography. We used a fat-suppressed three-dimensional turbo spin-echo sequence (3000/700 [TR/TE]; echo train length, 128) with no breath-hold, optimized with a 0.5-T magnet. Imaging studies were performed because of scheduled follow-up (five patients), persistent jaundice (six patients), cholangitis and abnormal liver function (eight patients), and a combination of transient jaundice, epigastric pain, and abnormal liver function (five patients). RESULTS: Image quality was graded from optimal to good in 21 (88%) of 24 cases and poor in three (13%) of 24 cases. The degree of bile duct dilatation was correctly assessed, with complete agreement between the two observers in all cases. MR cholangiography correctly showed bile duct irregularities in six of the eight patients with cholangitis (kappa = .59), anastomotic strictures in all 19 patients with strictures (kappa = .86), and 3- to 15-mm stones in nine of 10 patients (kappa = .95). A slight overestimation of the strictures occurred in four of the 19 cases with strictures. CONCLUSION: MR cholangiography is a reliable imaging technique for the examination of patients with biliary-enteric anastomoses.     

Effects of perorally applied endotoxin on colonic mucins of germfree rats

BACKGROUND: The intestinal epithelium, with the potential to restrict luminal noxae from the host, secretes a mucous layer with various protective functions. Microbial colonization of germfree (GF) rats stimulates this mucin-secreting tissue. The present study determined the effect of bacterial lipopolysaccharides (LPS) on this process. METHODS: One, 3, and 5 days after peroral application of 35 micrograms LPS/100 g body weight (from Escherichia coli O55:B5), LPS concentrations were monitored in ingesta, intestinal tissue, and liver. Mucin high molecular weight glycoproteins (HMG), released in response to LPS, were isolated and separated into mucins, i) attached to the colonic epithelium (EM) and ii) mixed to the luminal content (LM), respectively. Subsequently, the binding capacity of both mucin fractions for various lectins and for type-1 pili expressing E. coli was determined. RESULTS: Ingesta and tissue had maximal LPS concentrations on days 3 (jejunum) and 5 (colon). Maximal EM secretion was found on day 3, release of LM further increased to day 5. Both mucin fractions had altered glycosylation patterns: augmentation of beta-galactose, alpha-N-acetyl galactosamine, and mannose coincided with a decrease in alpha-fucose. Compared with the controls, attachment of E. coli to EM increased slightly on day 1 only; the binding capacity of LM increased continuously up to day 5. CONCLUSION: Results suggest that mucins, released in response to LPS, in addition to the epithelial protection, support the gut microbial clearance system.     

Expression of colonic antigens by goblet and columnar epithelial cells in ileal pouch mucosa: their association with inflammatory change and faecal stasis

AIMS: To investigate colonic metaplasia of goblet and columnar epithelial cells in ileal pouch mucosa; to correlate this with the degree of morphological and inflammatory change; and to assess whether such changes are related to the presence of faecal stasis. METHODS: Biopsy specimens of ileal pouch mucosa were taken from 31 patients (30 with ulcerative colitis, one with familial adenomatous polyposis) either before (eight patients) or after (23 patients) ileostomy closure. A simple morphological technique was used to assess changes in villous height. Inflammatory change was estimated using an established scoring system for pouchitis, and acquisition of colonic antigens was determined by immunohistochemistry using three monoclonal antibodies which recognise components of the two major epithelial cell types in the colorectum. The degree of staining with the monoclonal antibodies was graded and the grades correlated with an index of villous atrophy and with the inflammatory scores. RESULTS: Five of eight (63%) pre-closure and 15 of 23 (65%) post-closure biopsy specimens showed increased staining with an antibody against components of columnar epithelial cells. One of eight (12%) pre-closure and 15 of 23 (65%) post-closure biopsy specimens stained with an antibody for colonic mucin. Although both types of staining showed a positive correlation with the pouchitis score, they also occurred in the absence of inflammation. CONCLUSIONS: Both goblet and columnar cells acquire colonic characteristics which are incomplete, but may represent a true adaptive response as they can develop in the absence of inflammation. As the change in goblet cells occurs after ileostomy closure, faecal stasis is likely to be a major contributory factor. Changes in columnar cells may occur before ileostomy closure in the absence of faecal stasis.