Showing papers in "Journal of Investigative Surgery in 2004"
TL;DR: An inexpensive, reproducible murine pressure ulcer model was developed, which results in graded injury without long-term immobilization of the animals, and will facilitate the development of new prevention and management strategies.
Abstract: The formation of pressure ulcers and other skin wounds is considered to be a multifactorial process. Cycles of ischemia–reperfusion have been considered to be significant contributing factors in the pathogenesis of pressure ulcers. This study reports the development of a reproducible murine model of ischemia–reperfusion injury by the external application of magnets. Mice were sedated with 50% CO2:50% O2 for 50–60 s. Dorsal hair was shaved and the area cleaned. The skin was gently pulled and placed between two round ceramic magnetic plates (5 × 12 mm diameter, 2.4 g weight, 1000 G magnetic force). The resultant “pinch” procedure was designed to leave a 5-mm skin bridge between the magnets, creating 50 mm Hg pressure between the plates. Three 12-h ischemia–reperfusion cycles were employed to cause pressure ulcer formation. Animals tolerated the procedure well. They returned to normal activity a few minutes after magnet placement. The lesions reached their maximum at 10 days postinjury. Full-thickness skin l...
141 citations
TL;DR: The results demonstrate the feasibility of vitrification as a storage method for cartilaginous tissues and demonstrate the ability of ice-free vitrification to be used as a cryopreservation method foricular cartilage.
Abstract: Articular cartilage has proved refractory to satisfactory cryopreservation using conventional freezing methods. Therefore, an ice-free cryopreservation method by vitrification was tested. Osteochondral plugs from New Zealand White rabbits were preserved using either a freezing method or an ice-free vitrification method of cryopreservation. Preserved and fresh control plugs were implanted in the tibial plateau of allogeneic recipients. A modified O'Driscoll grading scale, based on gross pathology, histopathology, and histochemistry, was used to evaluate the explants.The histology of fresh and vitrified explants was essentially the same, while the frozen cryopreserved explants were devoid of chondrocytes and only fibroblastlike cells were observed. The O'Driscoll grading indicated that both fresh and vitrified plugs performed significantly better than frozen plugs (p≤ .05). The results demonstrate the feasibility of vitrification as a storage method for cartilaginous tissues.
62 citations
TL;DR: It is suggested that direct injection of scolicidal agents into the cyst should be avoided particulary in case of biliary communication, and hypertonic saline should be preferred as aScolicidal agent.
Abstract: Hydatid disease of the liver is a parasitic infection. Surgery still remains as the primary choice of treatment. Caustic sclerosing cholangitis is reported following surgical treatment. Hypertonic saline (20%), povidone iodine (1%), and silver nitrate (0.5%) are extensively used as scolicidal solutions. The effects of these scolicidal agents on liver and biliary tree are investigated by direct injection into the common bile duct of rats. At the end of 15 wk, liver function tests, cholangiography, and histopathological examination of the liver and biliary tree were performed. Liver function tests were within normal limits, except elevation of alkaline phosphatase in 2 and 1 rats of the silver nitrate and povidone iodine groups, respectively. Differences were not statistically significant (p >. 05). Cholangiograms of the rats in all groups were normal. Histopathologic changes comprising low-grade inflammatory changes were induced in all study groups. The intensity of the lesions were more remarkable with si...
47 citations
TL;DR: Partial hepatectomy can be performed safely and rapidly in mice using haemostatic clip ligation of hepatic lobes, with no impairment to the subsequent process of liver regeneration.
Abstract: A versatile, simple, and reproducible model of hepatectomy is essential for the study of liver regeneration and its effects on various pathological processes. A murine model of liver resection and regeneration suitable for research is described. Male inbred CBA mice 6-8 wk old were used in all experiments. The contribution of the hepatic lobes to the total liver mass was determined by wet weight measurements. Resection of 37% (n = 10) and 70% (n = 10) liver volume was performed using hemostatic clips to ligate the hepatic lobe pedicles. Animals were recovered and subsequently killed 21 days postoperatively Liver mass was determined and compared to control animals (n = 17) to assess the completeness of liver regeneration. There were no operative deaths in animals undergoing either 37% or 70% hepatectomy. The procedures could be performed expediently, and animal recovery was complete. Liver mass (grams) assessed 21 days postoperatively [mean (SE)] in both the 37% resection, 1.76 g (0.07), and 70% resection, 1.56 g (0.05), groups was not significantly different from control animals, 1.64 g (0.07) (p =.265). Thus, partial hepatectomy can be performed safely and rapidly in mice using haemostatic clip ligation of hepatic lobes, with no impairment to the subsequent process of liver regeneration.
43 citations
TL;DR: This preliminary study to evaluate the integrity of sciatic nerve repair was conducted over a period of 90 d andDistally directed growth of the proximal nerve was demonstrated histologically and the extent and integrity of this regeneration are underway.
Abstract: The goal of peripheral nerve repair is to successfully direct the regenerating fibers into the environment of the distal terminus with minimal loss of fibers at the suture line. Successful nerve repair is dependent on sensory, motor, and autonomic axons making appropriate connection with their distal terminus. The subsequent results are dependent on parameters such as the location and extent of the injury, appropriateness of realignment of the injured nerve, and the surgical technique. Peripheral nerve repair using autograft material has several shortcomings, including donor site morbidity, inadequate return of function, and aberrant regeneration. Recent peripheral nerve research has focused on the generation of synthetic conduits for nerve guidance. Small intestine submucosa (SIS) is a biological material that might better address those outcomes and improve regeneration. Its unique properties appear to offer several advantages. The SIS graft acts as a natural conduit between the proximal and distal nerves, provides a favorable growth environment, and appears to lack antigenicity. This preliminary study to evaluate the integrity of sciatic nerve repair was conducted over a period of 90 d. Distally directed growth of the proximal nerve was demonstrated histologically. Further investigations to demonstrate the extent and integrity of this regeneration are underway.
39 citations
TL;DR: The same potentials characterizing zinc as a promising tool of prophylactic therapy in sepsis seem to ban its use during the acute phase of endotoxemia.
Abstract: By antiapoptotic effects and the induction of the heat-shock response, zinc is supposed to be a promising means of therapy during sepsis. As zinc also stimulates the expression of proinflammatory cytokines, its administration during the proinflammatory stage of septic shock might have adverse effects. Therefore, this study analyzes the influence of zinc during the acute phase of endotoxemia. In a pig model of acute endotoxemia, animals were divided into two groups: group I (n = 5) with saline treatment and group II (n = 5) with zinc treatment in close succession to lipopolysaccharide (LPS) (1.0 μ g/kg Escherichia coli endotoxin WO 111:B4). Hemodynamic and pulmonary monitoring was followed by combined reflection photometry, pulse oxymetry, blood gas samples, and temperature measurement. Plasma concentrations of tumor necrosis factor (TNF)α and interleukin (IL)-6 were analyzed by enzyme-linked immunosorbent assay (ELISA). Morphology included the weight of the lungs, the width of the alveolar septae, and the...
34 citations
TL;DR: It was demonstrated that the small molecule multi-selectin inhibitor (TBC-1269) offered the most significant protection for the ischemic liver when given at 40 mg/kg at the time of reperfusion.
Abstract: Tissue damage after ischemia and reperfusion (I/R) is largely caused by the sequelae of neutrophil infiltration. This inflammatory process can be initiated as the result of stroke, coronary ischemia, trauma, and other related conditions. The infiltration of neutrophils is facilitated by the expression of adhesion molecules on the surface of endothelial cells. Particularly important are the selectin family of adhesion molecules at the onset of neutrophil-mediated injury. The aim of this study was to determine the role of selectin inhibition in the modulation of chemokine expression and Akt/MAPK signaling after liver I/R. In addition, we evaluated the optimal dose and time of administration of a small molecule selectin inhibitor, TBC-1269. Mice subjected to 90 min of partial (70-80%) hepatic ischemia followed by 3 h of reperfusion were divided into 15 groups (n = 4/group); sham, ischemic control, and 10, 20, and 40 mg/kg dose groups for the antiselectin molecule were studied at 3 times of drug administration: 1 h before reperfusion (but after ischemia), at the time of reperfusion, and at 15 min after reperfusion. The parameters measured after 3 h of reperfusion included liver function tests (ALT and AST), histopathology, and tissue myeloperoxidase (MPO). Chemokine expression (MIP-1alpha, MIP-1beta, MIP-2 and KC), Akt, MAPK (p44/p42), and RSK expressions were also measured in liver tissue by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis, respectively. It was demonstrated that the small molecule multi-selectin inhibitor (TBC-1269) offered the most significant protection for the ischemic liver when given at 40 mg/kg at the time ofreperfusion. AST significantly differed between the control group and the group receiving 40 mg/kg at the time of reperfusion (p = .01). MPO levels in the liver tissue of the ischemic controls were significantly increased when compared to the levels of this enzyme in the TBC-1269 group at 40 mg/kg. Histological examination reflected the same results, with a significant difference (p = .02) between these same two groups. The chemokine profile also showed that the same treatment group had a downregulation of MIP-lalpha, MIP-1beta, MIP-2, and KC, as well as a lower expression of Akt, MAPK(p44/42), and RSK when compared to the control group. Thus, we demonstrated that the small molecule selectin inhibitor, TBC-1269, offered significant functional and structural protection of the ischemic liver when given at 40 mg/kg at the time of reperfusion. Lower doses and different times of administration did not show as prominent a drug effect. This selectin inhibition modulated the expression of Akt, MAPK (p44/42), and RSK, as well as MIP-1alpha, MIP-1beta, MIP-2, and KC chemokines. These alterations in cellular signaling and chemokine expression represent potential mechanisms or pathways of inflammatory response in I/R.
33 citations
TL;DR: This review studies the role of MAPKs in trauma and/or I/R, because these pathways may be a possible target for anti-inflammatory drug intervention.
Abstract: Mitogen-activated protein kinases (MAPKs) have been the focus of a number of studies, as these compounds are involved in a number of important inflammatory cell signaling mechanisms. Recent studies have further elucidated the role of MAPKs in the inflammatory response, as a result of trauma and/or ischemia–reperfusion (I/R) injury. There are three major classes of MAPKs that may be involved in the inflammatory response: extracellular signal-regulated kinases (ERKs), stress-activated protein kinases (SAPKs)/c-Jun NH2-terminal kinases (JNKs), and p38 MAPKs (p38). This is clinically relevant, because these pathways may be a possible target for anti-inflammatory drug intervention. This review studies the role of MAPKs in trauma and/or I/R.
31 citations
TL;DR: It is determined that SIS facilitates successful regeneration of uterine horn morphology in a manner similar to that observed in other tissues and species.
Abstract: Tubal factor infertility may be reversed using porcine small-intestinal submucosa (SIS). The method uses as a model the New Zealand White rabbit uerine horn. In surgery, SIS grafts were prepared from porcine jejunum; the uterine horn segment was resected and a graft was placed; then the contralateral adnexa was resected. Fecundability was tested with natural mating. Three out of six rabbits became pregnant. Gross and microscopic examination confirmed regeneration of all tissue layers. Thus, this study determined that SIS facilitates successful regeneration of uterine horn morphology in a manner similar to that observed in other tissues and species.
23 citations
TL;DR: Results indicate a correlation between the electromechanical impedance spectrum of the bio-PWAS and the state of implantation, and it seems that the shear and pressure wave interactions have specificity in detecting the different stages of the body's reaction response to implants.
Abstract: A novel sensor for in situ monitoring of the body reaction to implants has been developed. A piezoelectric wafer active sensor was adapted for biomedical applications (bio-PWAS). A number of bio-PWAS sensors have been implanted in rats and left in place up to 64 days. The bio-PWAS were able to oscillate in several resonance modes, radial-wise (in-plane) and thickness-wise (out-of-plane). The electromechanical impedance was measured over a wide frequency band, covering several radial vibration modes and the first thickness mode. The recorded data was processed with impedance spectroscopy methods. Preliminary results indicate a correlation between the electromechanical impedance spectrum of the bio-PWAS and the state of implantation. Quantitative studies have shown that the first radial mode amplitude seems to correlate with the short-time inflammatory and immune response, while the thickness mode amplitude seems to correlate with both the short-term inflammatory response and long-term encapsulation and fib...
22 citations
TL;DR: Tests performed by four surgeons on cadaveric knees showed that the variability in identifying the ankle center using two out of the three methods presented introduced an inaccuracy in the mechanical axis identification of around 1°.
Abstract: Many surgical computer-assisted systems use mechanical axis identification as a reference for their computations. The goal of this study was to compare three methods to determine the location of the distal point of the tibial mechanical axis, based on percutaneous digitization of definite anatomical landmarks. In particular, we evaluated the accuracy of the identified tibial mechanical axis and the repeatability of the obtained results. Tests performed by four surgeons on cadaveric knees showed that the variability in identifying the ankle center using two out of the three methods presented introduced an inaccuracy in the mechanical axis identification of around 1°. This makes their use suitable for computer-assisted systems.
TL;DR: The microsurgical cholestasis technique is a valid alternative to other techniques and can be an adequate experimental model for the study of etiopathogenic mechanisms of obstructive jaundice and especially to study extrahepatic biliary atresia.
Abstract: An experimental model of microsurgical cholestasis is studied as an alternative to the most frequently used surgical techniques, based on the section of the common bile duct. This microsurgical technique consists of the resection of the extrahepatic biliary tract, that is, of the common bile duct in continuity with the bile ducts that drain the four lobes of the rat liver. At 30 days of evolution, rats with microsurgical cholestasis do not develop biliary pseudocysts or intraperitoneal hilar hepatopulmonary abscesses and show an increase (p< 0.001) in total bilirubin (9.50 ± 1.50 mg/dL vs. 1.60 ± 0.35 mg/dL), bile acids (225 ± 87 μmol/L vs. 12.5 ± 14.50 μmol/L), gamma-glutamyltranspeptidase (375 ± 143 U/L vs. 8 ± 11 U/L), and alkaline phosphatase (73 ± 25 U/L vs. 23 ± 4 U/L) levels. The histological study shows fibrosis with biliary proliferation. The microsurgical cholestasis technique is a valid alternative to other techniques and can be an adequate experimental model for the study of etiopathogenic mec...
TL;DR: The results of this study suggest that encapsulating foreign substances with these types of biodegradable materials will not significantly hinder capsule formation and a more direct attack on the wound healing mechanism may provide a definitive solution for capsule problems with implanted materials.
Abstract: The insertion of a foreign substance, such as a breast implant into mammalian soft tissues, evokes a wound healing response that culminates in a dense connective-tissue envelope or capsule surrounding the implant. Several biodegradable products, such as Seprafilm (carboxymethylcellulose and hyaluronic acid) and Interceed (oxidized regenerated cellulose), have been demonstrated to inhibit adhesions in abdominal and gynecologic surgery. The ability of these cellulose compounds to inhibit capsule formation was addressed in this investigation. Twenty-eight rats were implanted intermuscularly with either plain silicone discs (10 animals), discs wrapped in Seprafilm (10 animals), or discs covered with Interceed (8 animals). Additional control animals (6 animals) consisted of two that had sham operations, two animals implanted with Seprafilm only, and two more implanted with Interceed only. Animals were sacrificed in pairs at varying time intervals after implantation (2, 4, 8, 12, and 16 wk), and the tissues around the silicone discs were analyzed with light microscopy. Control animals were sacrificed at 8 wk. Both Interceed and Seprafilm slowed the formation of a capsule around the implanted silicone discs as both products were degraded. Evidence of residual material, presumably Seprafilm and Interceed, was seen intracellularly in animals 3 to 4 mo, respectively, after implantation. However, neither material prevented the eventual formation of a fibrous capsule around the silicone discs. The results of this study suggest that encapsulating foreign substances with these types of biodegradable materials will not significantly hinder capsule formation. A more direct attack on the wound healing mechanism may provide a definitive solution for capsule problems with implanted materials.
TL;DR: The two most promising surgical animal models of fulminant hepatic failure (FHF) for investigation of the safety and efficacy of new treatment modalities were analyzed in a porcine study.
Abstract: The two most promising surgical animal models of fulminant hepatic failure (FHF) for investigation of the safety and efficacy of new treatment modalities were analyzed in a porcine study. Animals underwent total hepatectomy or devascularization of hepatic artery and portal vein followed by portocaval (PC) shunting. Survival time, technical feasibility, safety, and reproducibility of the models were investigated. Devascularization seems to be most useful for studying the development and treatment of FHF caused by ischemia and its side effects. Total hepatectomy is superior for investigation of the anhepatic status and treatment of FHF by bioartifical liver support systems.
TL;DR: It is concluded that mucosal structure is partly maintained by administration of P GE1 and PGE2 during intestinal obstruction; PGE1 is more effective than P GE2 for ameliorating mucosal injury.
Abstract: The aim of this experimental study was to investigate effects of prostaglandin E1 and E2 analogues on mucosal structure and bacterial translocation during small bowel obstruction. The study was carried out on 40 Wistar rats equally divided into four groups; group 1 = control, group 2 = intestinal obstruction by ligation of distal ileum, and groups 3 and 4 = obstruction and administration of PGE2 and PGE1, respectively. Intestinal bacterial content and translocation to mesenteric lymph nodes and to the blood were determined by microbiological analysis. Mucosal structural changes were assessed by histopathological examination and expressed as a structural damage score and as the thickness of the mucosal layer. Bacterial overgrowth was determined in all obstruction groups. Mucosal thickness was 39.7 μm in group 1 and 26.8 μm in group 2 (p< .001). The thickness was significantly preserved by administration of PGE1 and PGE2 (p< .001). Mean structural damage score was 0.4 in group 1 and 6.7 in group 2 (p< .001)...
TL;DR: This study showed that preoperative use of iv tenoxicam is safe, simple, and effective for postoperative pain relief after laparoscopic cholecystectomy or inguinal hernia repair.
Abstract: In this study, we aimed to investigate the postoperative pain relief effect of preoperative tenoxicam usage in patients who undergo elective laparoscopic cholecystectomy or groin hernia repair. Eighty patients undergoing laparoscopic cholecystectomy or groin hernia repair procedures were randomized to receive either physiologic serum at 100 mL (group I, n = 40) or 20 mg iv tenoxicam (group II, n = 40) immediately before induction. Postoperative analgesic requirement, peroperative side effects and complications of drugs, operating time, postoperative mobilization time and pain score, hospitalization time, and patient pleasure were recorded. Postoperative pain was assessed by the visual analogue scale (VAS) on the recovery unit (RU), at 4, 8, and 24 h and every day at the same times in the morning. The RU median VAS score was also not different when Group 1 was compared with Group 2 (p =. 97). However, the postoperative 4-h and 8-h median VAS score was significantly less (p =. 01 and p =. 03, respectively);...
TL;DR: A case of severe GVHD resembling HPS in clinical features that occurred after living-related liver transplantation is described, with demonstration of remarkable anti-self response and undetectable anti-donor response in a mixed lymphocyte reaction assay using carboxyfluorescein diacetate succinimidyl ester.
Abstract: Graft-versus-host disease (GVHD) after liver transplantation is uncommon but is a serious complication that can be fatal. Hemophagocytic syndrome (HPS), which is caused by activation of autologous T lymphocytes, is also a serious complication that can occur after liver transplantation. Because these complications share the clinical triad of skin rash, marrow failure, and diarrhea, differential diagnosis is difficult. We describe a case of severe GVHD resembling HPS in clinical features that occurred after living-related liver transplantation. The patient who had undergone the transplantation had high fever, pancytopenia, and skin rash 3 wk after the operation. Examination of a bone-marrow biopsy sample revealed the presence of abundant monocytes with phagocytosis, suggesting either GVHD or HPS. Donor human leukocyte antigens were detected in the peripheral blood of the patient by polymerase chain reaction, but this finding is not specific for GVHD. A definitive diagnosis was made by demonstration of remarkable anti-self response and undetectable anti-donor response in a mixed lymphocyte reaction assay using carboxyfluorescein diacetate succinimidyl ester.
TL;DR: In the presence of obstructive jaundice, endotoxemia primes a more vigorous inflammatory response despite cellular immune depression in common bile duct ligated rats.
Abstract: The aim of this study was to investigate the relationship between the obstructive jaundice-induced cellular immune suppression and endotoxin challenge with respect to the levels of tumor necrosis factor (TNF), interleukin-10 (IL-10), and interleukin-2 (IL-2). Rats underwent either bile duct ligation or sham operation. At 21 days, all rats were challenged either with lipopolysaccharide (LPS) or saline. In the sham-operated group LPS injection significantly increased TNF levels at 90 min. The common bile duct ligated group showed a significant increase in TNF levels compared with all other groups, including the sham-operated, LPS-injected group, at 90 min. At 180 min following LPS challenge, TNF levels decreased, and there was no difference between any of the LPS-challenged groups at 180 min and any of the saline groups at either 90 or 180 min. In the sham-operated group, LPS injection significantly increased IL-10 levels at both 90 and 180 min. In the bile duct ligated group, LPS injection significantly increased IL-10 levels compared with saline injection at both 90 and 180 min. On the other hand, bile duct ligated animals had significantly less increase in IL-10 levels following LPS challenge at 90 min but not at 180 min. In common bile duct ligated rats, LPS challenge induced a significantly greater increase in IL-2 levels compared with all other groups. In conclusion, in the presence of obstructive jaundice, endotoxemia primes a more vigorous inflammatory response despite cellular immune depression.
TL;DR: The results of this model indicate that chronic intestinal obstruction induced different degrees of enteric nervous system Dysplasia, including histological features of neuronal intestinal dysplasia.
Abstract: The etiology of neuronal intestinal dysplasia remains largely unknown. There is, however, supporting evidence of the existence of Hirschprung's disease or chronic intestinal obstruction associated with neuronal intestinal dysplasia. With the aim of investigating the possible development of neuronal intestinal dysplasia linked to chronic intestinal obstruction, we have examined the enteric nervous system response to long-term obstruction in a rat model. Three different surgical techniques were tested in Wistar male rats. In animals that survived longer than the cutoff chronic intestinal obstruction point (6 weeks), full-thickness biopsies and acetylcholinesterase (AChE), NADH, hematoxylin-eosin, and anti-S100 protein stainings were performed. The results of our model indicate that chronic intestinal obstruction induced different degrees of enteric nervous system dysplasia, including histological features of neuronal intestinal dysplasia. The relationship between chronic intestinal obstruction and anomalies of the enteric nervous system, including neuronal intestinal dysplasia, needs to be further studied.
TL;DR: In the 1960s, the world of orthopedic surgery turned its full attention to the small town of Wrightington, Lancashire, England, as John Charnley mesmerized his colleagues with advances as discussed by the authors.
Abstract: In the 1960s, the world of orthopedic surgery turned its full attention to the small town of Wrightington, Lancashire, England, as John Charnley (1911–1982) mesmerized his colleagues with advances ...
TL;DR: The issues that the authors consider important in the management of intracranial meningiomas can be discussed under the headings of diagnosis, surgery, multiplicity, pathology, and recurrence.
Abstract: Meningiomas account for approximately 15–20% of all brain tumors, and are the most common benign intracranial tumor. These neoplasms develop from cap cells in the arachnoidea; thus, they can be found anywhere that dura mater exists. Meningiomas are usually diagnosed in middle age, and are significantly more frequent in females than in males. Atypical and anaplastic malignant forms also exist. Some types of meningiomas are difficult to manage and require special considerations. The first-line therapy for meningioma is surgery aimed at total excision; however, limitations of surgery must be fully evaluated in order to achieve better results. Conventional radiotherapy and gamma-knife radiosurgery can be used as adjuvant therapeutic modalities under certain conditions. The issues that we consider important in the management of intracranial meningiomas can be discussed under the headings of diagnosis, surgery, multiplicity, pathology, and recurrence.
TL;DR: It was concluded that undiluted and 1% diluted octenidine might be used for scolicidal purpose in the treatment of hydatid disease.
Abstract: Hydatid disease is still endemic in many devoloping countries and continues to be an important cause of morbidity. The objective of this study was to determine the in vitro scolicidal effects of octenidine hydrochloride in different concentrations using different exposure times. After hydatid cyst liquid was left to precipitate for 1 h to obtain cystic sand, various concentrations of octenidine (undiluted, 1% and 0.1% diluted) were added to concentrated hydatid cyst sediments for 5, 10, 15, 20, 25, 30, 45, and 60 min, and scolicidal effects of octenidine were compared with 20% saline and control group for the same times. It was found that undiluted octenidine had a strong scolicidal effect at 15 min compared to saline at 20%. One percent octenidine had a scolicidal effect at 30 min. However, 0.1% octenidine did not have enough scolicidal effect in 1 h. It was concluded that undiluted and 1% diluted octenidine might be used for scolicidal purpose in the treatment of hydatid disease.
TL;DR: The effects of a lathyrogen, beta-aminopropionitrile (BAPN), on the healing of colonic anastomosis and the prevention of gastrointestinal stricture formation are suggested.
Abstract: Wound contraction is a clinically important biological process because it frequently results in contractures, strictures, and stenosis. If collagen synthesis could be altered to minimize the contracture, then the outcome could be improved. Lathyrism produces poorly cross-linked collagen in healing anastomosis, keeping a larger portion of the synthesized collagen soluble. Ultimately, the amount of contracting collagen is reduced, lowering the bulk and lessening the contracture. The aim of this study was to observe the effects of a lathyrogen, beta-aminopropionitrile (BAPN), on the healing of colonic anastomosis. Thirty rats were divided into three groups. Colostomy and anastomosis were performed on all rats. Intraperitoneal saline solution (control) and either intraperitoneal (ip) or oral (po) BAPN were administered. The rats were killed 1 week later. Anastomotic healing was assessed by bursting pressure and the hydroxyproline content of the anastomotic tissues. Granulation tissue thickness, number of fibr...
TL;DR: This technique provides a simple method of harvesting large segments of periosteum in a single procedure and may facilitate better exploitation of pero-cartilage in tissue engineering.
Abstract: Periosteum has been promoted as a potential substrate for tissue engineering. Its principal virtues are that it has a source of pluripotential mesenchymal cells and chondrogenic growth factors located in the cambium layer, and it can serve as a template for directional evolution of neo-tissue. The clinical use and in vitro study of periosteum-derived neo-tissue has been limited by the level of surgical skill required for harvest. Precise surgical technique, task-specific experience, adequate volume of procedures, and general surgical expertise are required for optimal harvest using the traditional periosteal elevator method. This report describes an easily mastered technique that preserves viability while providing the harvest of relatively large amounts of periosteum. Skeletally mature New Zealand white rabbits (11 males/20 tibias; 4 females/8 tibias; approximate weight 3.5 kg) and one Yucatan miniature pig were used for harvest of periosteum from the tibia using the traditional periosteal elevator and t...
TL;DR: Coughing and straining effected an increase of the LES EMG activity and pressure, an action presumably mediated through a reflex that is called the “straining-esophageal reflex” that seems to be evoked during increased intra-abdominal pressure and to effect LES contraction, thus, sharing with other factors in prevention of gastroesophagal reflux.
Abstract: The lower esophagus is intra-abdominal and exposed to intra-abdominal pressure (IAP) variations that may lead to gastroesophageal reflux (GER). We investigated the hypothesis that the lower esophageal sphincter (LES) undergoes phasic contraction on IAP increase, with a resulting inhibition of the stress GER. The study comprised 17 subjects (age 42.3 ± 8.7 SD yr, 10 men, 7 women) who were scheduled for surgical repair of abdominal hernia. The patients had no swallowing problems. The electromyographic (EMG) activity of the LES and pressure within the LES were recorded at rest and during increased IAP (coughing, straining). The recording was repeated after LES anesthetization or saline infiltration. The LES EMG at rest showed regular slow waves (SWs), superimposed on or followed by random action potentials (APs). Coughing or straining induced increase of the SWs parameters and also of the APs; although the increase with straining was less than with coughing, the difference was insignificant. Coughing or stra...
TL;DR: Under ideal conditions, the resistance to pressure of a mechnical suture is equal to, if not better than, that of the manual suture.
Abstract: The objective of this study was to determine the resistance to pressure of a bronchial stump depending upon the closure technique For the experimental study, 30 pig tracheae were alternatively closed either by a double-layer running suture at 90° to the cartilaginous rings or with an automatic stapling device Sutures were placed under pressure until air leakage was observed The air leakage pressure was digitally recorded A statistically significant difference existed between the two groups The mechanical suture proved more resistant to pressure (p= 011) Thus, under ideal conditions, the resistance to pressure of a mechnical suture is equal to, if not better than, that of the manual suture
TL;DR: In this paper, domestic white pigs were divided into two groups: one group received electrolysis using two electrode catheters, and in the other group a concurrent intermittent Pringle maneuver was performed to induce intermittent ischemia.
Abstract: Several methods of liver tumor ablation have been investigated, and these include the novel technique of electrolysis. Electrolysis is slower than other forms of ablative therapy. This study determined methods of increasing the ablative effect of electrolysis. Domestic white pigs were divided. One group received electrolysis using two electrode catheters, and in the other group a concurrent intermittent Pringle maneuver was performed to induce intermittent ischemia. The effect of two electrode catheters versus a single electrode catheter was compared, and the effect of the Pringle maneuver versus no Pringle was examined with two electrode catheters. The livers were harvested, and the volume of each lesion was calculated. There was a linear relationship between the volume of hepatic necrosis and the electrolytic dose in (p< .005) in both the single-electrode-catheter and two-electrode-catheter groups. Comparison between the single- and multiple-electrode groups showed a highly significant difference in the...
TL;DR: Valerio Cigaina’s initial animal studies began in 1992 in the porcine model, and the results show that this concept of utilizing electrical stimulation of the stomach was effective in moderating weight gain in growing swine.
Abstract: Alan A. Saber, MD, MS Department of Surgery, Michigan State University, Kalamazoo Center for Medical Studies, Kalamazoo, Michigan, USA Obesity is becoming a more pronounced global epidemic and a major health care problem in most developed countries. It has the greatest prevalence in the United States, where more than 55% of Americans are overweight and over one-third of the adult population is obese [1]. Obesity is not primarily a cosmetic problem; it is a medical, physical, social, psychological, and economic problem. Consequences of being obese include increased morbidity and early death. Morbid obesity is the second leading cause of preventable death in the United States, with 300,000 fatalities yearly [2]. It has been estimated that the cost for management of comorbidities associated with obesity in the United States is $100 billion annually [3]. There are multiple obesity treatment options available, with various degrees of effectiveness. These include diet, exercise, appetite-suppressant medications, and surgery. Given the limited success of diet, exercise, and drug therapy for morbid obesity, in 1991 the U.S. National Institutes of Health concluded that surgery is the only effective long-term treatment for patients with morbid obesity [4]. However, all currently performed operations for weight loss alter the anatomy and function of the gastrointestinal tract to some degree. This can be associated with an appreciable mortality as well as morbidity. Therefore, a novel, less invasive, and safe alternative procedure for obesity would be welcome. Valerio Cigaina, from Italy, conceptualized a treatment of obesity that utilizes electrical stimulation of the stomach. He hypothesized that electrical impulses could be used to dysregulate normal gastric electromotor activity, slowing gastric emptying with early satiety. The intention was to induce weight loss with minimal derangement of physiology and less side effects than those that are associated with conventional bariatric procedures. Cigaina’s initial animal studies began in 1992 in the porcine model [5, 6]. He found that long-term antral pacing could reduce feed intake in young growing swine. The results show that this concept of utilizing electrical stimulation was effective in moderating weight gain in growing
TL;DR: An experimental model of short bowel syndrome in rats is presented and it is believed this experimental model could be a very useful tool for studying the enterohormonal changes related to an abnormal blood flow of nutrients.
Abstract: The short bowel syndrome is a well-known human clinical entity that produces serious metabolic disorders. This syndrome arises after a massive resection of more than 50% of the small intestine, when the intestine attempts to minimize the consequent irregularities by means of compensatory mechanisms. Many reports suggest that an exocrine and endocrine pancreatic dysfunction is associated with enterohormones and an abnormal altered nutrient flow. In this report, we present an experimental model of short bowel syndrome in rats. A massive intestine resection was performed in rats, followed by a histological study of the small intestine. We report the histological changes related to the compensatory changes that occurred in the remaining intestine. The residual intestine produces a hyperplasic response, and hypertrophy was seen in the portion proximal to the anastomosis. We believe this experimental model of short bowel syndrome could be a very useful tool for studying the enterohormonal changes related to an abnormal blood flow of nutrients.
TL;DR: Polyunsaturated phospatidylcholine protected against wound contraction and modulated wound healing in the rat model of skin burn injury, and wound contraction was measured by planimetry weekly.
Abstract: Polyunsaturated phosphatidylcholine (PP) is a soybean lecithin, whose oral supplementation prevents fibrosis and strictures in animal models. The purpose of the present study was to investigate the effect of PP on wound contraction using a model of skin burn injury. Thirty male Sprague-Dawley rats were randomly divided into three groups: control (C), just burn (JB), and burn treated with PP (BPP). Burns were induced on the dorsum of the rats by a metal plate with a 4-cm(2) contact surface. Ten percent emulsion of PP was given orally for 21 days in BPP group. The effects of PP on burns were evaluated histologically on day 21, and wound contraction was measured by planimetry weekly. Microscopic evaluation included the amount and density of myofibroblasts and collgen type III, the existence of mature collagen fibers in the regenerated dermis, and thickness measurements of the regenerated tissue. There was a significant decrease in mean wound size index in group JB when compared to BPP on days 14 and 21 (p <.05 and p <.01, respectively). After 3 weeks, the granulation tissue was more cell dense, containing high numbers of myofibroblasts in group JB when compared to BPP (p <.05). The wounds had more mature collagen bundles, but less collagen type III in group BPP when compared to JB. Thus, polyunsaturated phospatidylcholine protected against wound contraction and modulated wound healing in the rat model of skin burn injury.