Hydroxyproline Levels In Group Research Articles

THE PREVENTIVE EFFECT OF SIROLIMUS ON URETERAL STRICTURE FORMATION

Introduction: Stricture of the transplant kidney ureter occurs in approximately 3% of transplant recipients. Risk factors for ureteral stricture include kidneys coming from marginal donors with advanced age and multiple comorbidities. Additionally, delayed graft function, presence of multiple renal arteries and direct injury during retrieval may increase the risk of this complication. Its clinical presentation is typical with elevated serum creatinine accompanied by hydronephrosis. Although several open and endoscopic techniques have been described to manage this condition, ureteral stricture still increases short and long-term graft loss significantly. An M-TOR inhibitor Sirolimus has been shown to reduce fibrosis. Since the mechanism of stricture formation is also through fibrosis, we analyzed the effect of this immunosuppressive drug on the prevention of ureteral strictures. Methods: 32 New Zealand White rabbits (2500-3000grams) were used in the study. The rabbits were randomly assigned into four groups (n=8). Group 1: A unilateral nephrectomy and subsequent full transection of the contralateral ureter was performed. The transected ureter was reconstructed over a double J ureteral stent by using interrupted 7/0 PDS stitches. Group 2: Same procedure with group 1 with Sirolimus- impregnated (1mg) stent placement Group 3: A unilateral nephrectomy and subsequent full transection of the contralateral ureter was performed. The transected ureter was reconstructed without a stent and 1 ml of saline was instilled over the anastomosis. Group 4: Same with group 3 with 1ml (1mg/ml) of Sirolimus solution instilled over the ureteric anastomosis (Figure 1). On postoperative day 3, serum creatinine levels were measured. On postoperative day 7, an ultrasound of the kidney was performed to evaluate hydronephrosis. On postoperative day 21, all rabbits were explored to evaluate the ureteral anastomosis. Subsequently, all subjects were terminated, and full segment of the ureter was removed for histopathology assessments and tissue hydroxyproline level measurements. Results: Severe hydronephrosis and creatinine elevation were observed in group 3 compared to other groups (Figure 2). Histopathological evaluation of the specimens showed increased fibrosis scores in groups 1 and 3 (Figures 3&4). Tissue hydroxyproline levels in group 4 were found to be lower compared to other groups. Conclusion: Sirolimus-impregnated double J stents may decrease ureteric stricture formation. This effect can be beneficial both in both kidney transplant and endourology practice.Fig. 1.Fig. 2.Fig. 3.

Adhesion Prevention to Polypropylene Meshes Using Combined Icodextrin Four Percent and Dimetindene Maleate

BackgroundThe use of surgical meshes in ventral hernia repair has significantly reduced hernia recurrence rates. However, when placed intraperitoneally prosthetic materials can trigger the development of peritoneal adhesions. The present experimental study evaluated the combined icodextrin 4% and dimetindene maleate treatment in preventing peritoneal adhesion formation to polypropylene and titanium-coated polypropylene meshes. Materials and methodsSixty female white rabbits were divided into four groups. A 2 × 2 cm piece of mesh was fixed to intact peritoneum in all animals through a midline laparotomy. A lightweight polypropylene mesh was implanted in groups 1 and 2 and a titanium-coated polypropylene mesh in groups 3 and 4. Groups 2 and 4 were treated, intraoperatively, with intravenous dimetindene maleate (0.1 mg/kg) and intraperitoneal solution of icodextrin 4% (20 mL/kg) and for the next 6 d with dimetindene maleate intramuscularly. The observation period lasted 15 d. Adhesion scores, percentage of mesh affected surface, tissue hydroxyproline levels, and tissue histopathology were examined. ResultsAll animals in group 1 and 57% of animals in group 3 presented postoperative adhesions. The combination of antiadhesives significantly reduced the extent and severity of adhesions as well as the hydroxyproline levels in groups 2 and 4 compared with groups 1 and 3. On microscopic evaluation, animals in group 1 exhibited higher inflammation scores compared with group 2, whereas animals in groups 2 and 4 had better mesotheliazation compared with groups 1 and 3. ConclusionsThe combined administration of icodextrin 4% and dimetindene maleate reduces the extent and severity of adhesions and may be successfully used to prevent adhesion formation after mesh intraperitoneal placement.

Can Human Recombinant Epidermal Growth Factor Improve Ischemia and Induce Healing of Anastomosis in an Experimental Study in a Rabbit Model?

ABSTRACTPurpose: Anastomotic leaks following intestinal operations may cause devastating effects on patients. Ischemia may also occur at the intestinal walls in the presence of strangulations. In this study, we examined the effects of human recombinant (Hr)-epidermal growth factor (EGF) given at a single intramural dose into the intestinal walls and daily intraperitoneal cavity on ischemia and the healing process of anastomosis. Materials and Methods: Sixteen male New Zeland white rabbits were randomly divided into four groups (n = 4 in each group). In Group 1, two different segments of ileum were identified and, then, transected and the free ends were sutured each other. In the other groups, ischemia was induced by ligating the mesenteric vascular arcade. After the ischemic induction, Group 2 received intramural injections of %0.9 saline, Group 3 received intramural injections of a single dose of EGF, and Group 4 received intramural and intraperitoneal injections of EGF. Bursting pressures and tissue hydroxyproline levels were analyzed. Necrosis, fibroblastic activity, collagen deposition and neovascularization were also studied. Results: The mean levels of bursting pressures in Group 4 (148.6 ± 25.3 mmHg) were higher than Group 2 (70 ± 21.5 mmHg) (p = 0.001). The mean level of bursting pressures was not statistically significant between Group 1 (170.1 ± 35 mmHg) and Group 4 (p = 0.073). Hydroxyproline levels in Group 2 were lower than Groups 3 and 4. There was a statistically significant difference in the mucosal ischemia, mucosal healing and degree of adhesion, but not in the mural anastomotic healing among the groups. Conclusions: Intramural injection with daily intraperitoneal administration of low-dose EGF enhances the bursting pressure and collagen accumulation in ischemic anastomosis, improving many histological variables associated with ischemic intestinal anastomosis.

Effects of preoperative nutritional support on colonic anastomotic healing in malnourished rats.

It has been proven that malnutrition increases postoperative morbidity and mortality, and it may also negatively affect wound healing in the gastrointestinal tract. In the literature, there is only one study evaluating the effects of preoperative nutritional support on colonic anastomotic healing under malnourished conditions. In order to improve the data on this topic, an experimental study was planned to evaluate the effects of preoperative nutritional support on colonic anastomotic healing in malnourished rats. The study included 18 male Wistar albino rats divided into 3 groups. The control (C) group was fed ad libitum for 21 days. The malnutrition (M) group and preoperative nutrition (P) group were given 50% of the daily food consumed by the rats in Group C for 21 days to induce malnutrition. At the end of 21 days, Group P was fed ad libitum for 7 days (preoperative nutritional support). Colonic transection and end-to-end anastomosis was performed at 21 days in Group C and Group M and at 28 days in Group P. The rats were sacrificed at postoperative 4 days, anastomotic bursting pressure was measured, and samples were taken to analyze tissue hydroxyproline levels. Anastomotic bursting pressure was significantly higher in Group C than in Group M and Group P (p<0.05), and it was significantly higher in Group P than in Group M (p<0.05). Tissue hydroxyproline levels in Group P were found to be significantly higher than those in Group M and Group C (p<0.05). One week of preoperative nutritional support increases collagen synthesis in the colon and positively affects anastomotic healing under malnourished conditions.

Biochemical and biomechanical assessment of effects of L-carnitine on oral mucosal wounds.

The present study aimed to investigate the oral mucosal wound healing potential of L-carnitine in a rat model. Twenty-four Wistar-albino rats were divided into 4 groups: control group (group I), L-carnitine groups (100 and 200 mg/kg/day, intraperitoneally) (groups II and III), and vitamin E group (100 mg/kg/day, intraperitoneally) (group IV). A 1.5-cm linear incision was created on the buccal mucosa of each rat and was left to heal by secondary intention. On the tenth day, rats were anesthetized and sacrificed. The tensile strength of wound was measured with a tensiometer. Hydroxyproline (HYP) and malondialdehyde (MDA) levels in wound were assayed by spectrophotometry. Results were statistically analyzed using a one-way ANOVA analysis (p ≤ 0.001). In the analysis of tissue samples, there was a statistically significant decrease in MDA levels in group II (p < 0.01) and group IV (p < 0.001). Wound tension strength that was seen in groups II (57.88 %) and IV (48.71 %) was better than group III (33.39 %). Hydroxyproline levels in group II (46.98 ± 1.37) was higher than groups III (29.40 ± 1.64) and IV (38.83 ± 1.41). Although there was a tendency toward faster healing in the groups receiving L-carnitine, it may have a dose-related positive effect for wound healing. With the advantages of having positive effects on wound healing, being a natural substance in the body, being easy to procure, and having a practical usage, L-carnitine may be clinically feasible for human oral mucosal wounds.

Adrenomedulline improves ischemic left colonic anastomotic healing in an experimental rodent model

BACKGROUND:Leakage from colonic anastomosis is a major complication causing increased mortality and morbidity. Ischemia is a well-known cause of this event. This study was designed to investigate the effects of adrenomedullin on the healing of ischemic colon anastomosis in a rat model.METHODSStandardized left colon resection 3 cm above the peritoneal reflection and colonic anastomosis were performed in 40 Wistar rats that were divided into four groups. To mimic ischemia, the mesocolon was ligated 2 cm from either side of the anastomosis in all of the groups. The control groups (1 and 2) received no further treatment. The experimental groups (3 and 4) received adrenomedullin treatment. Adrenomedullin therapy was started in the perioperative period in group 3 and 4 rats (the therapeutic groups). Group 1 and group 3 rats were sacrificed on postoperative day 3. Group 2 and group 4 rats were sacrificed on postoperative day 7. After careful relaparotomy, bursting pressure, hydroxyproline, malondialdehyde, interleukin 6, nitric oxide, vascular endothelial growth factor, and tumor necrosis factor alpha levels were measured. Histopathological characteristics of the anastomosis were analyzed.RESULTSThe group 3 animals had a significantly higher bursting pressure than group 1 (p<0.05). Hydroxyproline levels in group 1 were significantly lower than in group 3 (p<0.05). The mean bursting pressure was significantly different between group 2 and group 4 (p<0.05). Hydroxyproline levels in groups 3 and 4 were significantly increased by adrenomedullin therapy relative to the control groups (p<0.05). When all groups were compared, malondialdehyde and nitric oxide were significantly lower in the control groups (p<0.05). When vascular endothelial growth factor levels were compared, no statistically significant difference between groups was observed. Interleukin 6 and tumor necrosis factor alpha were significantly decreased by adrenomedullin therapy (p<0.05). The healing parameters and inflammatory changes (e.g., granulocytic cell infiltration, necrosis, and exudate) were significantly different among all groups (p<0.05).CONCLUSIONAdrenomedullin had positive effects on histopathologic anastomotic healing in this experimental model of ischemic colon anastomosis.

Hydroxyproline levels in nasal polyps

The aim of this study was to evaluate hydroxyproline levels in nasal specimens from patients with nasal polyps, and to examine hydroxyproline levels after nasal steroid spray and oral steroid treatments. This study was performed on 41 patients. The subjects were divided into four groups: no medication group (group A, n 11), oral methylprednisolone group (group B, n 8), topical steroid spray group (group C, n 8) and control group (group D, n 14). Nasal polyp samples were collected endoscopically. Healthy subjects were studied as a control group, and their nasal samples were taken during turbine reduction surgery. All samples were analyzed using the immunocytochemistry method. Hydroxyproline levels were investigated and compared with the control group. Mean hydroxyproline levels in groups A-D were 98.48, 24.20, 8.97 and 4.52, respectively. The hydroxyproline levels were significantly higher in group A compared with that of group D. The treatment that revealed significant decreases in hydroxyproline levels was group C. Although there was also a noticeable reduction in group B, there were no statistically significant differences between group B and group A. Our study revealed a significant correlation between nasal polyp and hydroxyproline levels. The hydroxyproline levels were significantly higher in nasal polyps. Both oral and topical steroid treatments decrease hydroxyproline levels in nasal polyps. Thus, in theory, steroid treatment can directly decrease hydroxyproline levels by inhibiting proline hydroxylase and indirectly by lowering the inflammatory process.

The effect of erythropoietin on healing of obstructive vs nonobstructive left colonic anastomosis: an experimental study

BackgroundAnastomotic leakage is an important problem following primary resection in the left colon and is even more prominent when obstruction is present. We aimed to evaluate the possible effects of erythropoietin on the healing of anastomosis under both obstructive and non-obstructive states.MethodsForty male Wistar albino rats were divided into four groups. In group I, two cm left colonic resection and primary anastomosis were done. In group II, left colon were completely ligated and 24 hours later animals were re-operated for segmental resection. The same procedures were performed for rats in group III and IV in respect to group I and II and, 500 IU/kg a day erythropoietin were given in the latter two groups for seven days. For the quantative description of anastomotic healing mechanical, biochemical and histopathological parameters were employed on the seventh day and the animals were sacrificied.ResultsAlthough erythropoietin had positive effects on bursting pressure in group IV when compared to group II, it has no effect in group III. Despite the increased tissue hydroxyproline levels in group IV, erythropoietin failed to show any effects in group III.Erythropoietin had positive effects on neovascularization, fibroblast proliferiation and storage of collagen in group IV.ConclusionWe failed to find any direct and evident effects of erythropoietin on healing of left colonic anastomosis. On the other hand, erythropoietin might prevent negative effects of obstruction on healing.

The effects of hyperbaric oxygen on normal and ischemic colon anastomoses

BACKGROUND: Leakage from colonic anastomoses is a major complication causing increased mortality and morbidity, and ischemia is a well-known cause of this event. Inadequate tissue oxygenation could be reversed by using hyperbaric oxygen. This study was designed to investigate the effects of hyperbaric oxygen on the healing of ischemic and normal colon anastomoses in the rat model. METHODS: Standardized left colon resection 3 cm above the peritoneal reflection and colonic anastomosis were performed in 40 Wistar rats divided into four groups. The control group (I) received no further treatment. To mimic ischemia, 2 cm mesocolon was ligated on either site of the anastomosis in group II and IV rats. Hyperbaric oxygen therapy was started immediately after surgery in group III and IV rats (therapeutic groups). All animals were sacrificed on the fourth postoperative day. After careful relaparotomy, in situ bursting pressure was measured. The hydroxyproline contents of the anastomotic segments in equal length were determined. RESULTS: The hydroxyproline assay revealed that rats in group II with ischemic colonic anastomosis have significantly lower levels ( P <0.05). The highest levels are in the group III rats with normal colonic anastomosis treated by hyperbaric oxygen ( P <0.05). There was no significant difference in hydroxyproline levels between group II and group IV animals ( P >0.05). Group III animals had significantly higher bursting pressures than any other group ( P <0.05). Group II rats had lowest bursting pressures ( P <0.05). Group IV animals had significantly higher levels than group II ( P <0.05). Mean bursting pressure values both in groups III and IV and hydroxyproline levels in group III were significantly increased by hyperbaric oxygen therapy ( P <0.05). CONCLUSIONS: Ischemia impairs anastomotic healing. Hyperbaric oxygen increases anastomotic healing of both normal and ischemic colonic anastomosis and reverses ischemic damage. This study demonstrated that hyperbaric oxygen improves anastomotic healing.

Effects of antifibrotic substances on pancreatic fibrosis following acute necrotizing pancreatitis.

This study was designed to search for a way to inhibit pancreatic fibrosis following acute pancreatitis. Experimental necrotizing pancreatitis was induced by a freezing procedure in the pancreas of male Wistar rats. After the freezing procedure, the rats were divided into 3 groups: nothing addition was done to the control group, while the other 2 groups received daily intraperitoneal administration of antifibrotic substances (colchicine or L-azetidine-2-carboxylic acid (AZC)) for 6 weeks. Pancreatic enzymes in the serum were not markedly influenced by administration of antifibrotic substances, and there were no differences in the ratios of dry to wet weights of the pancreas between groups with and without these drugs. After freezing, the hydroxyproline levels in the pancreas of the control group increased from 1 to 4 weeks and then decreased during the 5th and 6th weeks. All groups receiving colchicine or AZC exhibited a significant decrease in the hydroxyproline levels at 2 to 4 weeks compared with the control group (P less than 0.01). Histological examination also showed the inhibition of pancreatic fibrosis, agreeing with changes in the hydroxyproline levels in groups receiving colchicine or AZC. These results suggest that administration of antifibrotic substances, colchicine and AZC, have the possibility of inhibiting pancreatic fibrosis following acute pancreatitis.