Showing papers in "Journal of Investigative Surgery in 2002"
TL;DR: This work reviews the literature for each type of flap to determine the kind, incidence, and consequences of flap associated morbidity and suggests that tissue-engineered prefabricated free flaps might play an important role.
Abstract: Microvascular osteocutaneous free flaps have given reconstructive surgeons a powerful tool in the reconstruction of composite defects in head and neck surgery. Radial forearm, scapula, iliac crest, and fibula flaps have been used extensively in mandibular reconstruction. The inevitable donor-site morbidity of these osteocutaneous flaps has received less attention than the reconstructive advantages. We have reviewed the literature for each type of flap to determine the kind, incidence, and consequences of flap associated morbidity. In the future, tissue-engineered prefabricated free flaps might play an important role.
108 citations
TL;DR: The quality of theECM deposition as determined by collagen type I/III ratio is impaired in general, whereas the quantity of ECM deposition is markedly influenced by the kind of mesh material.
Abstract: Alterations of the extracellular matrix (ECM) with its major component collagen are increasingly discussed as possible risk factors implicated in the development of abdominal-wall herniation. Because of the widespread use of alloplastic meshes for the surgical repair of hernias, an animal study was performed to analyze the influence of various mesh materials on the quantity and quality of collagen deposition. In 60 male Sprague-Dawley rats an abdominal replacement was performed using three different kinds of mesh materials: polyester (PE), a pure polypropylene (PP), and a composite mesh made of polypropylene and polyglactin (PG). A simple fascia suture repair served as control. The count of fibroblasts, the collagen/protein ratio, the type I/III collagen ratio, and the ex-pression of basic fibroblast growth factor (b-FGF) at the interface were analyzed after 7, 21, and 90 days. The ratio of collagen to overall protein ( w g/mg) showed significant differences comparing different mesh materials (sham co...
63 citations
44 citations
TL;DR: The new proposed technique is a valid alternative to the classic one that used single portal stenosing ligation and the variability in the obtained weights, particularly in the liver weight, stands out.
Abstract: A surgical technique based on the development of a triple stenosing ligation is used to worsen the complications inherent to the prehepatic chronic portal hypertension. The results have been compared with those obtained in rats with a single-portal stenosing ligation. An increase ( p < .05) in the body, liver, spleen, and kidney weights as well as a decrease ( p < .001) in the testes weight to body weight ratio were produced in both groups of animals. In addition, the variability in the obtained weights, particularly in the liver weight, stands out. The incidence of portosystemic and portohepatic collateral circulation and of the mesenteric venous vasculopathy increases in the animals with triple-portal stenosing ligation. The new proposed technique is a valid alternative to the classic one that used single portal stenosing ligation.
39 citations
TL;DR: The use of osteoinductive implants may provide an alternative to autologous and allogeneic bone tissue in the therapeutic approach to bone defects and promotion of fusion by eliminating the donor site morbidity associated with autogenous bone and the decreased efficacy and potential for disease transmission associated with allogeneIC bone.
Abstract: Twelve African green monkeys were implanted with recombinant human osteogenic protein-1 (rhOP-1) placed on a bovine bone-derived Type I collagen carrier to characterize healing in an ulna segmental bone defect model at 1, 3, 12, and 20 weeks postoperative. Defect healing was evaluated by plain film radiography, computed tomography (CT), magnetic resonance imaging (MRI), bone mineral density (BMD), and histologic analysis. Radiographically, new bone formation was observed as early as 3 weeks postoperative. By 6 weeks, new bone was visible in five of six defects. Increased quantity and mineralization of the new bone were apparent by 12 weeks. Reformation of the medullary cavity with appearance of marrow elements was demonstrated by CT and MRI at 20 weeks. BMD studies revealed a significant increase in the presence of bone with time. Histology at 1 week demonstrated that the implant material was well contained in the defect, and a proliferation of cells occurred at the defect borders. At 3 weeks cell proliferation continued and cell phenotype differentiation was recognized. By 12 weeks substantially less residual carrier was found in the defects, and calcifying tissues with plump chondrocytes, osteoblasts, and immature woven bone were observed. Areas of lamellar and woven bone were identified at 12 weeks, with advanced remodeling and revascularization observed at 20 weeks. The use of osteoinductive implants may provide an alternative to autologous and allogeneic bone tissue in the therapeutic approach to bone defects and promotion of fusion by eliminating the donor site morbidity associated with autogenous bone and the decreased efficacy and potential for disease transmission associated with allogeneic bone.
34 citations
TL;DR: It is concluded that exogenous NO had a temporal protective effect in organ function and histology and exerted a downregulating response in the production of MIP-2 and Mip-1 f chemokines and the activation of MAPK p44/42 following I/R.
Abstract: The mechanisms by which nitric oxide (NO) exerts its protective effect in the ischemia/reperfusion (I/R) injury of the kidney have not been fully determined. The hypothesis of this study was based on the assumption that I/R upregulates some chemokines (MIP-2 and MIP-1alpha) as well as certain protein kinases (MAPK p44/42), and therefore we aimed in this work at recognizing if an exogenous NO donor would downregulate these effects in rat ischemic kidneys at the same time that it would offer functional protection as measured by serum creatinine. Sprague-Dawley rats were subjected to renal warm ischemia (75 min) and contralateral nephrectomy. Animals were divided into 3 groups (n = 8 per group): sham, ischemic control, and ischemic group treated with sodium nitroprusside (NaNP 5 mg/kg) given 15 min prior to reperfusion. Serum creatinine (SCr), serum chemokines (MIP-2 and MIP-1alpha), kidney tissue MAPK p44/42, kidney neutrophil infiltration determined by myeloperoxidase (MPO), and light histology were evaluated 4 h after reperfusion began. There were significant improvements in SCr and better histopathological features in the I/R-NaNP group compared with the I/R group. Similarly, the I/R-NaNP kidneys exhibited a downregulating effect of serum chemokines (MIP-2 and MIP-1alpha) and kidney tissue MAPK p44/42 that was not observed in the I/R group alone. The MPO levels were lower in the I/R-NaNP group compared with the I/R untreated group. We can conclude from these experiments that I/R of the rat kidney upregulated the production of MIP-2 and MIP-1alpha chemokines and the activation of MAPKp44/42. It also had a detrimental effect on the function and structure of the ischemic kidney. Exogenous NO had a temporal protective effect in organ function and histology and exerted a downregulating response in the production of MIP-2 and MIP-1alpha chemokines and the activation of MAPK p44/42 following I/R.
27 citations
TL;DR: It is suggested that pulmonary vascular resistance is more dramatically affected by inhaled nitric oxide in cardiac surgery patients with a greater degree of pulmonary hypertension.
Abstract: Pulmonary hypertension is associated with significant morbidity and mortality in adult cardiac surgery patients. Inhaled nitric oxide is known to be a selective pulmonary vasodilator in this setting. However, it is not known which cardiac surgery patients benefit most from nitric oxide therapy. This study sought to prospectively determine whether a patient's baseline pulmonary vascular resistance could be used to predict responsiveness to inhaled nitric oxide therapy. Subjects were 30 consecutive cardiac surgery patients with pulmonary hypertension immediately prior to induction of anesthesia. There were 2 study groups: Group 1 ( n = 15) had an initial pulmonary vascular resistance between 125 and 300 dyn-s/cm 5 , while group 2 ( n = 15) had an initial pulmonary vascular resistance of greater than 300 dyn-s/cm 5 . Both groups were empirically treated with inhaled nitric oxide (30 ppm) upon separation from bypass. The conduct of anesthesia, surgery, and cardiopulmonary bypass were controlled. A therapeutic...
21 citations
TL;DR: Tissue engineering is an attractive concept for facilitating the transplantation of different tissue types with a low immunogeneity and a well-preserved tissue structure but tissue preparation with trypsin/EDTA does not seem to be a suitable method of preparatory treatment of tracheae intended for transplantation.
Abstract: Tissue engineering is an attractive concept for facilitating the transplantation of different tissue types with a low immunogeneity and a well-preserved tissue structure. We examined the influence of treatment with trypsin/ethylenediamine tetraacetic acid (EDTA) on the mechanical properties of tracheae. Fresh sheep tracheae were stored in a trypsin/EDTA solution for various periods of time (24, 46, and 72 h) and their breaking strength was subsequently examined. The results were compared with native trachea. The treatment with trypsin/EDTA results in a considerable reduction of the mechanical stability under load, in this case compared with the tensile strength, that does not correlate with the results obtained from light-optical microscopy. The results from this study reveal that tissue preparation with trypsin/EDTA does not seem to be a suitable method of preparatory treatment of tracheae intended for transplantation.
17 citations
TL;DR: It is demonstrated that the percutaneous DLC is the preferable method for apheresis in the dog model, which is more efficient and cost-effective, and is associated with a lower complication rate.
Abstract: The dog model has been used extensively for preclinical hematopoietic stem-cell transplantation (HSCT) research. Apheresis of granulocyte colony-stimulating factor mobilized peripheral blood donor stem cells is increasingly being used for transplantation. We investigated the use of a percutaneous dual-lumen central venous catheter (DLC) for large-volume apheresis in the dog model. Fifteen dogs undergoing apheresis for HSCT had catheters placed percutaneously. Apheresis was performed in all 15 dogs without complications. In comparison to the previous techniques of arteriovenous shunts for apheresis, the DLC demonstrates comparable efficacy, is more efficient and cost-effective, and is associated with a lower complication rate. We demonstrate that the percutaneous DLC is the preferable method for apheresis in the dog model.
15 citations
TL;DR: This chapter discusses Galen, the revered physician and surgeon, who returned to Pergamon fully qualified to practice medicine and having completed a well-outlined and comprehensive postgraduate course (even better than contemporary postgraduate programs).
Abstract: (2002). Claudius Galenus of Pergamum: Surgeon of Gladiators. Father of Experimental Physiology. Journal of Investigative Surgery: Vol. 15, No. 6, pp. 299-301.
15 citations
TL;DR: It is concluded that TBC-1269, multisectin blocker, was effective in reducing liver damage even with the addition of a second inflammatory insult as the nonlethal LPS challenge used in this study.
Abstract: The effects of anti-adhesion molecule antibodies on the blockade of leukocyte-endothelial interactions have the potential of decreasing survival through possibly increased infection vulnerability. The aim of this study was to determine the effect of a small-molecule selectin inhibitor (TBC-1269) on both liver response and survival to a nonlethal lipopolysaccharide (LPS) challenge after hemorrhagic shock. Ninety-six Sprague-Dawley rats were subjected to a model of uncontrolled hemorrhagic shock. Six groups of animals were included in this study (n = 16 per group): sham/saline, sham/LPS, shock/saline, shock/LPS, shock/TBC1269, and shock/TBC-1269/LPS. Experimental design consisted of the development of hemorrhagick shock (3 mL/100 g) in a 15-min period, tail amputation and drug administration at 30 min, and subsequent resuscitation to maintain mean arterial pressure at 70mm Hg. A septic challenge was produced with 0.1 mg/kg of LPS (Escherichia coli type 78H4086; Sigma Chemical, St. Louis, MO) given intravenously via penile vein at 20 h. Liver injury tests (alanine aminotransferase, ALT), liver myeloperoxidase, liver histology, and 21-day survival were evaluated. Statistical analysis included the Bartlett test for equality of variance, a two-way analysis of variance (ANOVA), and overall followed by pairwise log-rank test for survival. Significant improvements in liver function and histology were observed in animals treated with TBC-1269 with or without a nonlethal septic challenge. Neutrophil infiltration, as evidenced by liver myeloperoxidase (MPO) was significantly decreased in animals treated with TBC-1269 alone and those having LPS administration after TBC-1269 treatment. We conclude that TBC-1269, multisectin blocker, was effective in reducing liver damage even with the addition of a second inflammatory insult as the nonlethal LPS challenge used in this study.
TL;DR: P pig hearts from an abattoir with 25 min of warm ischemic time can be resuscitated by whole blood reperfusion and continuous machine perfusion with UW solution is superior to cold storage on ice.
Abstract: A non-heart-beating donor model was considered to examine whether pig hearts from the abattoir could be resuscitated by whole blood reperfusion. For preservation, machine perfusion using University of Wisconsin (UW) solution was compared with storage on ice. Nineteen hearts from abattoir pigs, harvested 25 - 3 min after exsanguination, were harvested and transported to the laboratory. Controls ( n = 7) were immediately reperfused with homologous whole pig blood in an isolated heart model for 60 min with monitoring of left ventricular developed pressure (LVDP), contractility, and coronary flow. UW solution hearts (UW, n = 6) were perfused for 4 h with 10°C cold UW solution before blood reperfusion. In the cold storage group (CS, n = 6), the organs were stored for an additional 4 h on ice before blood reperfusion. In all hearts, histology was performed after 60 min of blood reperfusion to evaluate myocardial reperfusion injury. All three groups showed significant increases in LVDP ( p < .001), although t...
TL;DR: It is concluded that thermal injury causes both bacterial overgrowth within intestinal lumen and bacterial translocation across the intestinal wall and HBO 2 administration prevents bothacterial overgrowth and translocation.
Abstract: This study was designed to evaluate the effects of hyperbaric oxygen (HBO2) on intestinal microflora and bacterial translocation (BT) caused by experimentally induced thermal injury in rats. Rats were separated into four groups, namely, HBO2 group, thermal injury (TI) group, TI + HBO2 group, and control group. All groups were further separated into short-term (2 days) and long-term (7 days) treatment or injury groups. Control group was neither exposed to thermal injury nor was given any treatment. Thirty percent second-degree thermal burn was induced on the dorsal body part of the rats in TI groups. In the HBO2 groups, rats received HBO2 treatment either without TI or following TI induction, for 2 and 7 days, respectively. Sampling from tissues and portal vein was performed on day 3 in the short-term groups and on day 8 in the long-term groups. Samples were cultured for identification of bacteria and colony counts. HBO2 treatment significantly reduced the colony counts of endogenous microflora in distal ileum of healthy rats (p < .05), while TI significantly increased the colony counts of endogenous microflora in distal ileum in short and long-term TI groups (p < .05). Presence of bacterial translocation was proven by bacterial isolation in mesenteric lymph nodes, liver, spleen and blood. Both short- and long-term HBO2 treatment following TI significantly reduced the colony counts of intestinal microflora (p < .05) and prevented bacterial translocation almost completely. It is concluded that thermal injury causes both bacterial overgrowth within intestinal lumen and bacterial translocation across the intestinal wall. HBO2 administration prevents both bacterial overgrowth and translocation.
TL;DR: The goal of this review is to address the basic principles of the technology and methodology employed in gene expression profiling with DNA microarrays, and then to highlight recent studies with particular importance for clinical medicine, focusing on cancer.
Abstract: DNA microarrays are capable of measuring the expression of thousands of genes in a single assay. This technology has led to an explosion in global gene expression profiling studies, allowing researchers to more fully explore a multitude of complex biological systems ranging from the yeast cell cycle to the progression of cancer. By analyzing collections of these global profiles, the molecular underpinnings of biological phenomena are being unraveled. It is the goal of this review to address the basic principles of the technology and methodology employed in gene expression profiling with DNA microarrays, and then to highlight recent studies with particular importance for clinical medicine, focusing on cancer.
TL;DR: It is demonstrated that MMP-i administration during the inflammatory phase significantly affects several characteristics of wound healing, and it is postulate that these effects may be attributed to decreased degradation of ECM components, increased concentrations of endogenous growth factors, and a shortened inflammatory phase.
Abstract: This study investigates the effects of a broad-spectrum matrix metalloproteinase inhibitor (MMP-i) on the rate of closure, hydroxyproline deposition, and macrophage infiltration in healing wounds. Full-thickness excisional wounds were created on the dorsal surface of hairless mice. Two experimental groups were used to measure rates of wound closure: (a) MMP-i administration (0.03, 0.3, 3.0, and 30 microg/mL) on days 0-1 postwounding (inflammatory phase) and (b) MMP-i administration (0.03, 0.3, 3.0, and 30 microg/mL) on days 6-8 postwounding (proliferative phase). Additionally, hydroxyproline deposition and percent macrophage infiltration were measured in skin wound margins on days 2, 8, and 16 postwounding. MMP-i administration at concentrations of 0.03, 0.3, and 3.0 microg/mL on days 0-1 postwounding significantly (p <.05) increased the rate of wound closure. No significant effect on the rate of wound closure was observed with MMP-i administration on days 6-8 postwounding. Hydroxyproline deposition was significantly (p <.05) increased on day 8 postwounding, and the percent macrophage infiltration was significantly (p <.05) decreased on day 2 postwounding by MMP-i administration on days 0-1 postwounding. These experiments demonstrate that MMP-i administration during the inflammatory phase significantly affects several characteristics of wound healing. We postulate that these effects may be attributed to decreased degradation of ECM components, increased concentrations of endogenous growth factors, and a shortened inflammatory phase.
TL;DR: There appears to exist a temporal correlation between number of mast cells, their degranulation, and the release of bFGF during angiogenesis in vivo, as well as the appearance of the growth factor in the wound fluid.
Abstract: Basic fibroblast growth factor (bFGF) is a potent angiogenic factor produced by cells of mesodermal and neuroectodermal origin. Despite numerous advances, the precise mechanism of bFGF release from cells still remains unknown. Upon release from cells, the protein is stored and protected in the extracellular matrix by binding to heparan sulfate proteoglycans. A number of reports suggest that degrading enzymes secreted by mast cells may play a role in the release of bFGF from connective tissue stores. Additionally, mast cells are believed to play a role in the formation of new blood vessels. In this report, we studied the events involved in neovascularization using a well-characterized model of angiogenesis in rabbits where neovascularization is induced by transfer of a well-perfused rectus abdominis muscle flap to an ischemic limb. Using this model, we demonstrate that bFGF expression is induced in normal myofibers and bFGF is released in the wound fluid at the ischemic/nonischemic interface. The highest c...
TL;DR: Results from this study suggest that hyperthermic preconditioning 4 h prior to the onset of septic events may improve the adverse outcome in sepsis.
Abstract: The impact of immune parameters in the mechanism of hyperthermia is yet to be explained. In this study, the optimal timing and temperature of thermal treatment for reversing the abnormal immunologic parameters obtained in a rat model of peritonitis were planned to be determined. Male Sprague-Dawley rats were grouped as sham, control peritonitis, and thermally treated rats at the time of peritonitis or 4 h prior to induction of peritonitis both at 40 and 42°C. Peritonitis was induced by the cecal ligation and perforation model. Eight hours after the induction of peritonitis, rats were sacrified and samples were taken for measurements of CD 4 + , CD 8 + , CD 11b , B cells, NK cells, and tumor necrosis factor f (TNF f ) and thiobarbituric acid-reactive substances (TBARS) levels. CD 4 + expression and B cell amount were decreased whereas TNF f levels, CD 8 + and CD 11b expression, and NK cell amount were found to be increased in the control peritonitis group when compared to the sham group. Perito...
TL;DR: In pursuing surgical research, the surgical investigator needs to build up, encourage, and maintain all the important characteristics of passion, and remember that passion can be learned through daily exposure and the continuous example of surgeon masters.
Abstract: Luis H. Toledo-Pereyra Editor-in-Chief W ithout passion, a successful career in surgical research is almost unimaginable. As a good dictionary would indicate, passion is intense desire, dedicated fervor, and powerful ardor to conquer a particular activity in life. Passion is also great enthusiasm and uncontrollable zeal to excel. Passion suffuses accomplishment, success, improvement, advancement, and all the other attributes of progress. Passion demands our full giving but returns fruits in plenty. In many ways, the discipline of surgical research is not different from regular life. The surgical investigator needs to build up, encourage, and maintain all the important characteristics of passion. Without passion, surgical research loses its focus on the highest standards of academics and scholarship. As researchers, we need to teach students and colleagues the enormous bene ts of a passionate life, the noble mission of discovering with oriented purpose. Time in the surgical research laboratory should represent the nest time of each day. Entering a laboratory without passion is like diagnosing without a history and physical, performing surgery without a knife, or writing a novel without a plot. Passion drives experimentation, planning, and the pursuit of truth. And passion perpetuates more passion. Passion has been the immediate source of discipline and methodical exploration in the lives of great scienti c surgeons [1]. Consider the contributions of these renowned surgeon researchers: John Hunter (1728–1793) to experimental surgery, Joseph Lister (1827–1912) to antiseptic surgery, William Halsted (1852–1922) to surgical residency, Harvey Cushing (1869–1939) to brain surgery, Evarts Graham (1882– 1957) to pulmonary oncology, and C. Walton Lillehei (1918–1999) to open-heart surgery. Could they have succeeded without their intense passion? In pursuing surgical research, we should ask, “Is it possible to teach passion to our young residents and faculty?” At rst the answer may not be evident. Yet we can reply in the af rmative by remembering that passion can be learned through daily exposure and the continuous example of surgeon masters. Passion grows in the research laboratory that exudes passion and exemplary work. Passion reaches others when there are tangible bene ts from its practice. Passion translates into practice when the
TL;DR: The absence of anesthesia-related complications allows model development for outcomes studies for ARDS in general and AVCO 2 R specifically.
Abstract: Percutaneous arteriovenous CO2 removal (AVCO2R) uses a simple arteriovenous (A-V) shunt for near-total CO2 removal that allows significant reductions in minute ventilation. We critically reviewed our algorithm-directed perioperative anesthesia management in our LD40 ovine smoke-burn injury model of acute respiratory distress syndrome (ARDS) treated with AVCO2R. General anesthesia is required for: (1) Vascular access followed by ARDS model development by smoke insufflation (36 breaths) plus 40% TBSA III degrees burn with mechanical ventilation. Induction: 12.5 mg/kg im ketamine and 4% halothane by mask, then intubation. Maintenance: 1.0-2.5% halothane in 100% O2; (2) When PaO2/FiO2 300 s), fluid, and analgesia management. All sheep met criteria for ARDS, survived anesthesia, and were standing by 0.5-5 h. There were no complications attributable to anesthesia. The absence of anesthesia-related complications allows model development for outcomes studies for ARDS in general and AVCO2R specifically.
TL;DR: Evaluating the influence of early drainage of the administered fluid volume on the control of adhesion formation proves the efficacy of phospholipids after a limited contact period of 30 min and proves the frequent use of drains in abdominal surgery will not impair the beneficial effect of phosphoripids on prevention of adhesions.
Abstract: Postoperative peritoneal adhesions impose a long-term risk of morbidity and mortality. Adjunctive means are needed to prevent these complications. In previous studies we could demonstrate the efficacy and safety of intraperitoneally applied phospholipids with regard to adhesion prevention and wound healing, respectively. The assumption is that phospholipids rapidly adhere to the peritoneal surface and to the mesothelial lesions. This study was designed to evaluate the influence of early drainage of the administered fluid volume on the control of adhesion formation. Forty chinchilla rabbits underwent median laparotomy and standardized abrasion of circumscript areas of the ventral abdominal wall, the cecum, and the ileum. The animals randomly received either 75 mg/kg body weight of phospholipids in a volume of 5.0 mL/kg body weight ( n = 20) or the same volume of Ringer's lactate solution ( n = 20) prior to closing the laparotomy wounds. In 50% of the rabbits with either medication, 80% of the volume was re...
TL;DR: The results show that APTE is associated with pulmonary hypertension and deterioration of gas exchange but not with the systemic release of TNF- f, IL-1 g , or IL-8, and it is concluded that these cytokines have minimal impact on the systemic circulation during APTE.
Abstract: Histological examination of acute lung injury associated with sepsis often revealed thromboembolic lesions in the pulmonary microcirculation. Several inflammatory mediators such as platelet activating factor, thromboxane, and endothelins have also been implicated in the pathogenesis of acute pulmonary thromboembolism (APTE). In the present study we examined the roles of three proinflammatory cytokines, tumor necrosis factor- f (TNF- f ), interleukin 1 g (IL-1 g ), and IL-8, in the early phase of APTE. APTE was induced in 13 anesthetized piglets (22 - 4 kg) by injecting thrombin-induced blood clots directly into the left lower lobar pulmonary artery. Five animals that received only warm sterile saline served as controls. Arterial plasma samples were collected regularly over 8 h so that cytokine levels could be measured later by enzyme-linked immunosorbent assay (ELISA). Administration of clots doubled the mean pulmonary arterial pressure (from 13 - 5 to 26 - 7 mm Hg) and caused sig...
TL;DR: Polyurethane caused the least adhesion formation among the four materials evaluated, and can be used more extensively for the construction of catheters for prolonged intraperitoneal use.
Abstract: To compare the adhesion formation, in a rat model, of commercially available materials used as intraperitoneal catheters in clinical practice, pieces of polyurethane, Teflon, silicone, and polyvinyl chloride (PVC) were placed intraperitoneally in 36 female Wistar rats randomly assigned into four groups. Adhesion development was quantitated according to Nair's classification system (NCS). According to NCS, polyurethane showed the least adhesion formation, while the highest scores were found in the PVC group. Comparing the thickness and the firmness of adhesions in the four groups, significant differences were found, with the polyurethane group developing none or filmy and mild adhesions. In contrast, almost all the rats in the Teflon group developed thick and dense adhesions. Thus, polyurethane caused the least adhesion formation among the four materials evaluated, and can be used more extensively for the construction of catheters for prolonged intraperitoneal use.
TL;DR: Used as an adjunct to conventional laparoscopy, laparoscopic fluorometry brought significant gains in sensitivity and specificity in the distinction between reversible and irreversible intestinal ischemia.
Abstract: The aim of this study was to develop and establish a new system of laparoscopic fluorometry for the purpose of investigating the intestinal microcirculation. In 25 pigs (German Landrace, 16-25 kg body weight), ischemia was established in two segments (A, irreversible; B, reversible ischemia; C, internal control) of the small intestine by a laparoscopic technique. Microcirculation in the segments was assessed by laparoscopy at a second-look operation 24 h later by means of the fluorescence system Endoscan. The fluorescence of the three bowel segments was measured by arbitrary dye fluorescence units (DFU) 15 min after starting reperfusion, before and after injection of sodium fluorescein (NaFlu, 0.25 mg/kg body weight). The dividing line between viable and nonviable bowel tissue was established from the inflow and outflow rates of NaFlu with the aid of ROC (receiver operating characteristic) curves. The specificity and sensitivity of the new method were evaluated by correlating the results with the viabilit...
TL;DR: Inhibition of the classic complement cascade may be a promising therapeutic approach for myocardial protection in reperfusion injury as assessed by albumin permeability.
Abstract: Acute myocardial injury has been demonstrated as a remote sequela of severe lower torso ischemia-reperfusion (I/R) due to proinflammatory events. In a model of I/R injury, administration of C1 esterase inhibitor (C1-Inh) reduces myocardial necrosis. We investigated the susceptibility of the left (LV) versus right ventricle (RV) and the protective effect of transgenic C1-Inh-overexpressing mice. Two groups of mice (n = 6) underwent a 2-h lower torso ischemia followed by 3 h of reperfusion: transgenic and wild type with sham-operated controls. Animals were then injected with (125)I bovine albumin. Heart was removed and samples from right and left ventricular free wall were harvested, weighted, and radioactivity was determined. Permeability index for wild-type animals in the RV was 0.22 +/- 0.04, compared to 0.17 +/- 0.07 in controls (NS), and in the LV 0.36 +/- 0.08, compared to 0.21 +/- 0.05 in controls (p <.01). The LV showed a significantly higher value compared to the right (0.22 +/- 0.04 vs. 0.36 +/- 0.08, p <.01). No difference was seen in the RV between transgenic and wild-type mice; however, in the LV the values decreased significantly in transgenic animals (p <.015). Thus, remote myocardial injury after lower torso I/R is present in both ventricles; however, the LV seems to be more susceptible as assessed by albumin permeability. Inhibition of the classic complement cascade may be a promising therapeutic approach for myocardial protection in reperfusion injury.
TL;DR: This surgery involves the removal of the gallbladder and cannulation of the proximal and distal aspects of the common bile duct using a 40 cm flexible surgical-grade cannula and has been used in 18 rabbits for up to 1 month without clinical complications.
Abstract: In the development of novel pharmaceutical compounds, pharmacokinetic parameters, such as the extent of biliary excretion, must be characterized. Pharmacokinetic studies in nonrodent species, typically dogs, are generally required for new drug approvals. However, in some cases, rabbits may be a more desirable model. We developed a surgical procedure for the intermittent or continuous collection of bile for long-term use. This surgery involves the removal of the gallbladder and cannulation of the proximal and distal aspects of the common bile duct using a 40 cm flexible surgical-grade cannula. The cannula loop is passed subcutaneously and exteriorized between the scapulae to divert bile flow. During use, the proximal cannula segment is attached to a collection container placed in a nylon torso jacket worn by the animal, and the distal segment of catheter is sealed with a stainless-steel adapter. An auricular catheter, secured by ligatures, is placed aseptically into the lateral ear vein and the tip is adva...
TL;DR: It was concluded that pinealectomy has no effect on the healing of colonic anastomoses and hydroxyproline levels were observed.
Abstract: Gastrointestinal system anastomoses, especially colonic anastomoses, have significant morbidity and mortality despite recent technical improvements. Besides regulating the circadian rhythm, the pineal gland and its main neurohormone product melatonin have widespread actions in the organism. The purpose of this study was to investigate the effects of pinealectomy on the healing of colonic anastomoses. One hundred male albino Wistar rats were used in this study. The rats were separated into three groups: control, pinealectomy, and sham groups. In the control group, only colonic resection and anastomoses were performed. Following pinealectomy, colonic anastomosis was performed 2 weeks later on one half and 2 months later on the other half of the pinealectomy group. Only craniotomy was performed on the sham group, and the rats were separated and evaluated like the pinealectomy group. Colonic anastomoses were evaluated on postanastomotic day 3 and 7 by measuring the bursting pressure and the hydroxyproline lev...
TL;DR: A multiple in vivo liver biopsy technique was developed to measure labile metabolites (creative phosphate, ATP, lactate) without interfering with normal perfusion and metabolism and it allows for large multiple biopsies, which give reliable metabolic data and can be consistently taught.
Abstract: A multiple in vivo liver biopsy technique was developed to measure labile metabolites (creative phosphate [CP], ATP, lactate) without interfering with normal perfusion and metabolism. Anesthetized rats ( n = 7) had a midline abdominal incision done to expose the liver. Four biopsies were taken across 20 min. Bleeding was controlled by a small, nontraumatic clamp proximal to the biopsy. Prefrozen dressing forceps grasped the liver and scissors cut the biopsy, which was frozen in liquid nitrogen. Bleeding was minimal and hemodynamic stability was preserved. This technique has few complications, bleeding is easily controlled, and it allows for large multiple biopsies, which give reliable metabolic data and can be consistently taught.
TL;DR: Harvey Cushing lived when surgery began its extraordinary development and should be considered the father of American neurosurgery.
Abstract: (2002). Harvey Cushing: Father of American Neurosurgery. Journal of Investigative Surgery: Vol. 15, No. 3, pp. 115-116.
TL;DR: Leonardo da Vinci: The Hidden Father of Modern Anatomy is described as the "hidden father of modern Anatomy".
Abstract: (2002). Leonardo da Vinci: The Hidden Father of Modern Anatomy. Journal of Investigative Surgery: Vol. 15, No. 5, pp. 247-249.
TL;DR: It is shown that the rate of incorporation of glucosamine is decreased in the PHT gastric mucosa and that EGF significantly stimulated glycoprotein synthesis in the H2O-binding group of rats, which may be helpful to explain the protective effect of EGF on the P HT gastrics mucosa via increased glycoproteins biosynthesis in the stomach.
Abstract: The aim of this study was to assess the influence of epidermal growth factor (EGF) on glycoprotein biosynthesis in portal hypertensive (PHT) gastric mucosa. Portal-vein ligation (PVL) for a period of 4 weeks was applied to 40 male Wistar rats to produce experimental portal hypertension. The rats were subdivided into four groups. Human EGF was administrated to these four groups of animals at a does of 0, 10, 25, and 50 microg/kg/day for 7 days. An additional group of 10 rats without PVL and EGF pretreatment was employed as a control. The severity of gross gastric mucosal lesions was evaluated macroscopically by a gross ulcer index. Glycoprotein biosynthesis of the gastric mucosa was determined by the incorporation rate of [(3)H]glucosamine. Quantitative changes of gastric mucosal hexosamines were also used for mucosal glycoproteins analyses. The gross mucosal damage was considerably greater in the PVL group without EGF pretreatment than in the EGF-pretreated groups (p <.05). The incorporation rate of [(3)H]glucosamine was significantly higher in the control group and the EGF-pretreated groups than in the PVL group without EGF pretreatment (p <.05). Moreover, the incorporation rate of [(3)H]glucosamine and the gastric mucosal hexosamine content were closely relevant to administration does of human EGF (p <.001). In addition, the reduction of glycoprotein biosynthesis was closely related to the increase in portal pressure (p =.001) and the severity of portal hypertensive gastropathy (p <.001). Our current study shows that the rate of incorporation of glucosamine is decreased in the PHT gastric mucosa and that EGF significantly stimulated glycoprotein synthesis in the PHT gastric mucosa. Accordingly, these findings may be helpful to explain the protective effect of EGF on the PHT gastric mucosa via increased glycoprotein biosynthesis in the stomach.