A comparison of a bovine albumin/glutaraldehyde glue versus fibrin sealant for hernia mesh fixation in experimental onlay and IPOM repair in rats.

BACKGROUND: Research in hernia repair has targeted new atraumatic mesh fixation to reduce major complications such as chronic pain and adhesion formation. The efficacy and safety of two surgical adhesives, viz. Artiss® (FS, fibrin sealant containing 4 IU thrombin) and Bioglue® (AGG, bovine serum albumin/glutaraldehyde glue), were evaluated in this study. Primary study endpoints were tissue integration, dislocation, and adhesion formation. Foreign-body reaction formed the secondary study endpoint. METHODS: Twenty-four polypropylene meshes (VM, Vitamesh®) were randomized to four groups (n = 6): two groups of onlay hernia repair (two meshes per animal) with mesh fixation by FS (O-FS) or by AGG (O-AGG), and two groups of IPOM repair (one mesh per animal) with mesh fixation by four sutures and FS (I-FS) or AGG (I-AGG). Eighteen rats underwent surgery. Follow-up was 30 days. Tissue integration, dislocation, seroma formation, inflammation, adhesion formation, and foreign-body reaction were assessed. RESULTS: Meshes fixed with FS (O-FS, I-FS) showed good tissue integration. No dislocation, seroma formation, or macroscopic signs of inflammation were detectable. Adhesion formation of I-FS was significantly milder compared with I-AGG (P = 0.024). A moderate foreign-body reaction without active inflammation was seen histologically in O-FS and I-FS groups. Samples fixed with AGG (O-AGG, I-AGG) showed extensive scar formation. No dislocation and no seroma formation were observed. All of these samples showed moderate to severe signs of inflammation with abscess formation in the six meshes of O-AGG. Histology underlined these findings. CONCLUSIONS: The fibrin sealant adhesive showed very good overall results of the primary and secondary outcome parameters. FS is a recommendable atraumatic fixation tool for the surgical onlay technique. AGG provides high adhesive strength, but shows low biocompatibility. Persisting active inflammation was seen in both the O-AGG and I-AGG groups, not favoring its use for these indications.

Efficient calculation of heats of formation.

An efficient procedure has been devised for calculating heats of formation of uncharged, closed-shell molecules comprising H, C, N, O, F, S, Cl, and Br. Known as T1, it follows the G3(MP2) recipe, by substituting an HF/6-31G* for the MP2/6-31G* geometry, eliminating both the HF/6-31G* frequency and QCISD(T)/6-31G* energy and approximating the MP2/G3MP2large energy using dual basis set RI-MP2 techniques. Taken together, these changes reduce computation time by 2-3 orders of magnitude. Atom counts, Mulliken bond orders, and HF/6-31G* and RI-MP2 energies are introduced as variables in a linear regression fit to a set of 1126 G3(MP2) heats of formation. The T1 procedure reproduces these values with mean absolute and rms errors of 1.8 and 2.5 kJ/mol, respectively. It reproduces experimental heats of formation for a set of 1805 diverse organic molecules from the NIST thermochemical database with mean absolute and rms errors of 8.5 and 11.5 kJ/mol, respectively. Heats of formation of flexible molecules have been approximated by the heats of formation of their lowest-energy conformer as given by the T1 recipe. This has been identified by examining all conformers for molecules with fewer than 100 conformers and by examining a random sample of 100 conformers for molecules with more than 100 conformers. While this approximation necessarily yields heats of formation that are too negative, the error for typical organic molecules with less than 10 degrees of conformational freedom (several thousand conformers) is <2-3 kJ/mol. T1 heats of formation have been used to calculate energy differences for a variety of structural, positional, and stereoisomers, as well as energy differences between conformers in a variety of simple acyclic and cyclic molecules for which reliable experimental data are available. In terms of both overall error and errors for individual systems, T1 provides a better account of the experimental thermochemistry than any practical quantum chemical method that we have previously examined. A database of approximately 40,000 T1 calculations for both rigid and flexible organic molecules has been produced and is available as part of the Spartan Molecular Database (SMD) in the current version of the Spartan electronic structure program (Spartan'08). (A subset of approximately 5000 molecules is provided as part of the standard release, and the full T1 database can be licensed.). This collection differs from the other components of SMD in that the lowest-energy conformation for each molecule has been assigned using a high-level quantum chemical method and not molecular mechanics. Thus, it is not only a source of "high-quality" calculated heats of formation for organic molecules but also a source of conformational preferences.

Cyanoacrylate tissue sealant impairs tissue integration of macroporous mesh in experimental hernia repair.

BACKGROUND: Tissue sealants have been proposed as an alternative to permanent fixation devices in hernia repair with the aim of reducing perforation-associated complications and chronic pain. Sealants can be divided into three main categories: synthetic glues (e.g., cyanoacrylate based), biologic products (e.g., fibrin sealant), and genetically engineered polymer protein glues. The beneficial effects of fibrin sealant have been reported in both experimental and clinical hernia repair. However, data on cyanoacrylate glues for mesh sealing are limited. METHODS: In 20 Sprague-Dawley rats, two hernia defects (1.5 cm in diameter) per animal were created bilaterally in the midline of the abdominal wall. The peritoneum was spared. The lesions were left untreated for 10 days to achieve a chronic condition. Defects then were covered with TI-Mesh xl (2 x 2 cm), which was glued with Glubran-II. The time points of sacrifice were 17 days, 28 days, and 3 months. At autopsy, meshes were biomechanically tested, and histology was performed. RESULTS: Tissue integration of the meshes was impaired at all time points by impenetrable glue plaques. At application sites, the elasticity of the abdominal wall was significantly reduced because of nonresorbed, rigid glue residues. CONCLUSIONS: Mesh fixation by Glubran-II impairs tissue integration, elicits inflammation, and unfavorably alters the biomechanics of macroporous mesh and the abdominal wall.

Adverse effects of porcine small intestine submucosa implants in experimental ventral hernia repair.

BACKGROUND: Biomeshes made of porcine small intestine submucosa (SIS) have recently been suggested for repair of ventral hernia. A fully biodegradable combination of implant and fibrin sealant fixation was assessed in a new rat model with sutures serving as control. METHODS: In 10 Sprague-Dawley rats, two defects per animal were created in the abdominal wall left and right of the linea alba (1 cm in diameter), and the peritoneum was spared. The lesions were left untreated for 10 days to achieve a chronic condition and were then covered with SIS (2 x 2 cm), sealed or sutured (n = 10 per group). Randomization allowed sealant and sutures in one animal. Animals were killed on postoperative day 17, and implant sites were analyzed macroscopically, histologically, and microbiologically. RESULTS: Abscedation, encapsulation, and putrid seroma were observed in all samples, regardless of fixation technique. Histology revealed lytic necrosis and extensive inflammatory response of the surrounding tissue. Tissue samples obtained from three implant sites were positive for beta-hemolytic Streptococcus. SIS was not detectable after 17 days. CONCLUSIONS: Adverse effects were observed using SIS in an experimental model of ventral hernia and were not linked to fixation method or study design. Further experimental investigations on SIS are necessary before its clinical use in hernia repair.

NON-activated protein C as post-treatment after spinal cord compression injury in rats.

BACKGROUND: Neuroprotective effects of recombinant human activated Protein C (rhAPC) in models of Spinal Cord Injury (SCI) and ischemic stroke have been reported in rodents. To rule out immunogenicity of rhAPC and to possibly maintain the physiological PC/thrombin balance the use of zymogen PC in SCI might be preferable. Although activation of Protein C (PC) has been demonstrated in rats, the efficacy and drug safety of NON activated PC has not been previously tested in experimental SCI. METHODS: Twelve rats were subjected to 40 g compression of the spinal cord at TH11 for 20 minutes and randomly allocated to either the NON activated PC (25 IU/kg) or the Placebo group (saline).Results. 25 IU treatment yielded improved recovery from SCI compared to placebo and the triple fold dose of PC (75 IU/kg) was subsequently tested to detect treatment associated complications (TAC). Treatment was administered as a single shot via the right vena jugularis forty minutes after onset of compression. The observation period was 5 weeks in 25 IU treated and 1 week in the 75 IU treated rats. Improvement of motor function recovery was measured with behaviour tests and electrophysiology. FINDINGS: Single shot treatment with 25 IU/kg of NON activated PC led to improved recovery in terms of behaviour and electrophysiology. TACs neither occurred in the 25 IU nor in the 75 IU group within one week. CONCLUSION: NON activated PC is a potent and safe drug in experimental SCI and should be considered for treatment in neurotrauma.

Fibrin sealing versus stapling of hernia meshes in an onlay model in the rat.

Incisional and inguinal hernia repair are among the most common procedures of general surgery. Mesh fixation by means of staples or sutures may lead to severe complications. The use of fibrin sealant (FS) has been suggested as alternative, but data on biocompatibility and adhesive strength of FS in combination with macroporous meshes is limited. Ventral hernia (n = 8 per group) was treated in rats in onlay technique with two types of meshes, fibrin sealed or stapled. TI-Mesh (TMxl) extralight and VYPROII (VPII) were tested 17 days post op. No failure in mechanical tests (tensile and burst strength) occurred in sealed or stapled meshes. Histology revealed equally good tissue integration and neovascularization in all groups. Fibrin sealant yields excellent fixation in experimental hernia repair. This rat model is suitable for testing meshes and fixation techniques.

Primary gastric B-cell lymphoma: results of a prospective multicenter study. The German-Austrian Gastrointestinal Lymphoma Study Group.

BACKGROUND & AIMS: Appropriate management of primary gastric lymphoma is controversial. This prospective, multicenter study aimed to evaluate the accuracy of endoscopic biopsy diagnosis and clinical staging procedures and assess a treatment strategy based on Helicobacter pylori status and tumor stage and grade. METHODS: Of 266 patients with primary gastric B-cell lymphoma, 236 with stages EI (n = 151) or EII (n = 85) were included in an intention-to-treat analysis. Patients with H. pylori-positive stage EI low-grade lymphoma underwent eradication therapy. Nonresponders and patients with stage EII low-grade lymphoma underwent gastric surgery. Depending on the residual tumor status and predefined risk factors, patients received either radiotherapy or no further treatment. Patients with high-grade lymphoma underwent surgery and chemotherapy at stages EI/EII, complemented by radiation in case of incomplete resection. RESULTS: Endoscopic-bioptic typing and grading and clinical staging were accurate to 73% and 70%, respectively, based on the histopathology of resected specimens. The overall 2-year survival rates for low-grade lymphoma did not differ in the risk-adjusted treatment groups, ranging from 89% to 96%. In high-grade lymphoma, patients with complete resection or microscopic tumor residuals had significantly better survival rates (88% for EI and 83% for EII) than those with macroscopic tumor residues (53%; P < 0.001). CONCLUSIONS: There is a considerable need for improvement in clinical diagnostic and staging procedures, especially with a view toward nonsurgical treatment. With the exception of eradication therapy in H. pylori-positive low-grade lymphoma of stage EI and the subgroup of locally advanced high-grade lymphoma, resection remains the treatment of choice. However, because there is an increasing trend toward stomach-conserving therapy, a randomized trial comparing cure of disease and quality of life with surgical and conservative treatment is needed.

Kinetics of endotoxin and tumor necrosis factor appearance in portal and systemic circulation after hemorrhagic shock in rats.

OBJECTIVE: This study was performed to investigate gut-derived bacterial translocation and the time course of endotoxin (lipopolysaccharide [LPS]) and tumor necrosis factor (TNF) appearance, both in portal and systemic circulation. SUMMARY BACKGROUND DATA: The significance of intestinal bacteria/endotoxin translocation or TNF formation in the development of systemic sepsis has been disputed. METHODS: A rat model of hemorrhagic shock (30-35 mm Hg for 90 min) and resuscitation was used. RESULTS: Bacterial translocation was histologically observed in the small intestinal wall 30 minutes after resuscitation. A significant increase in LPS concentrations was found in the portal vein (91.7 +/- 30.6 pg/mL) at 90 minutes, which remained steady until 150 minutes after shock. Lipopolysaccharide increased in the systemic circulation, the levels became significant at 120 minutes, and peaked (66.5 +/- 39.2 pg/mL) 150 minutes after shock. Tumor necrosis factor concentrations were found to be significantly elevated in both portal and systemic circulation (75.6 +/- 22.1 vs. 58.4 +/- 14.1 pg/mL) at 90 minutes post-shock. Although there was no further increase in TNF concentration in the portal blood. TNF peaked (83.5 +/- 17.7 pg/mL) in systemic circulation at 120 minutes and still was markedly increased at 150 minutes post-shock. In addition, higher LPS and TNF concentrations in systemic circulation were found in the nonsurvivors than in the surviving animals at the end of resuscitation. CONCLUSIONS: These results suggest that hemorrhagic shock may lead to early bacterial translocation in the intestinal wall and transient access of gut-derived LPS and LPS-induced mediators into the circulation predominantly via the portal circulation.

Bridging of peripheral nerve defects with exogenous laminin-fibrin matrix in silicone tubes in a rat model.

Fibrin matrix (FM) is a biological substance involved in the comprehensive wound healing process, and has been used in local applications as a carrier of nerve growth factor (NGF) to achieve an effective local neurotrophic concentration by slow release of the factor. In the present experiment, an exogenous fibrin matrix enriched with laminin (LM) and tubulized by a silicone conduit was used to improve the bridging effect of a peripheral nerve defect in a rat model. A 10 mm nerve defect was bridged with a 14 mm silicone conduit which was prefilled either with 25 µl fibrin matrix enriched without or with laminin (0.1 µg/ml), serving as groups FM and LM-FM, or with the same amount of saline solution for control (CTR group) (n = 10). After 12 weeks, the nerve conduction velocity and the distal latency were calculated from the electromyographic recordings. In addition, morphological semi-quantitative evaluations in longitudinal and transversal sections were carried out by immuno-histochemical staining with a monoclonal antibody against neurofilament. An improvement in nerve conduction velocity and distal latency, and a better orientation of the regenerated nerve fibers in the gap area were achieved in the LM-FM group than in the CTR and FM groups. These results indicate that the bridging of peripheral nerve defect in a rat model may be improved by the use of exogenous fibrin matrix enriched with laminin (as a filling material) in a silicone conduit.

Familial haemophagocytic lymphohistiocytosis. A report of three cases with unusual lung involvement.

Three cases of familial haemophagocytic lymphohistiocytosis are presented with lung infiltration by haemophagocytic histiocytes. In all patients the diagnosis was based on hepatosplenomegaly, thrombocytopenia and anaemia, abnormal increase in triglycerides, ferritin and LDH, hypofibrinogenaemia and lymphohistiocytosis with haemophagocytosis in bone marrow. Two patients died of respiratory failure due to interstitial pneumonia. In these two patients the pneumonia was obscured and misinterpreted by the pathologists. A careful re-examination revealed lymphohistiocytosis and haemophagocytic cells within the lung parenchyma. The third patient showed alveolar wall infiltration by haemophagocytic histiocytes and lymphocytes. In early childhood acute or recurrent interstitial pneumonia should prompt a search for haemophagocytic histiocytes, and familial haemophagocytic lymphohistiocytosis should be included in the differential diagnosis.

Response of the endothelium to trauma and sepsis. Adherence, cytokine effects and procoagulatory response.

Trauma and sepsis induced organ dysfunction is the result of an overwhelming inflammatory response, in which the endothelium plays a central role. Within the mediator cascade reactions involve thrombin, histamine induced endothelial "stimulation" and endotoxin/cytokine induced endothelial "activation" in the endothelial/leukocyte interactions. Adherence events beyond the physiological degree lead to endothelial damage, increase of permeability and result in organ dysfunction. Activated endothelial cells are further involved in cytokine production and they are important actors in the procoagulatory/anticoagulatory balance. The homeostasis is disturbed in the systemic inflammatory response, which leads to a procoagulant state of the endothelium and severe coagulation disorders.

Immunohistochemical detection of tumor necrosis factor-alpha, other cytokines and adhesion molecules in human livers with alcoholic hepatitis.

This immunohistochemical study was designed to investigate the possible contribution to and topographical distribution of some important cytokines, such as tumour necrosis factor alpha (TNF alpha) and interleukins, in acute alcoholic hepatitis. The well-known inductive capacity of these cytokines with respect to the expression and/or up-regulation of adhesion molecules, such as intercellular adhesion molecule-1 (ICAM-1) and endothelial leukocyte adhesion molecule-1 (ELAM-1), was a further point to be studied. Moreover, the proposed induction of adhesion molecules might also be associated with the activation and attraction of a special population of inflammatory cells characteristic for alcoholic hepatitis. Frozen liver samples from patients who died with signs of acute alcoholic hepatitis were evaluated using the alkaline phosphatase anti-alkaline phosphatase immunostaining technique and also single and double indirect immunofluorescence. In acute alcoholic hepatitis TNF alpha could be detected predominantly in ballooned hepatocytes, which often contained alcoholic hyalin (Mallory bodies). Moreover, TNF alpha showed a co-distribution with ICAM-1 expressed in the membranes of hepatocytes and with the occurrence of CD11b positive polymorphonuclear leukocytes (neutrophils) suggesting a possible major role of the beta 2-integrin Mac-1 as a ligand for ICAM-1. No induction of ELAM-1 could be found. In alcoholic hepatitis cytokines may be responsible for the induction of the adhesion molecule ICAM-1 on hepatocytic membranes and activate a defined population of inflammatory cells, thus contributing to the characteristic histological picture of acute alcoholic hepatitis with its concentration of neutrophils especially in areas with ballooned Mallory body-containing hepatocytes. Our results are in line with clinical findings showing high levels of TNF alpha and interleukin-1 in sera of patients with alcoholic hepatitis and with the already reported expression of ICAM-1 on hepatocytes.

Successful treatment of primary adrenal insufficiency due to malignant non-Hodgkin's lymphoma.

Although the adrenal glands are frequently the site of tumor metastases, adrenal insufficiency is exceedingly rare. We report on a patient with high-grade B-cell centroblastic lymphoma who initially presented with right axillary lymphadenopathy and bilateral adrenal masses. Four months after axillary lymphadenectomy the patient developed overt signs of Addison's disease. He recovered promptly after initiation of hormone replacement therapy and bilateral adrenalectomy. At present, 16 months after additional chemo- and radiation therapy the patient is considered free of tumor. To our knowledge this is the first report on a patient who presented with adrenal insufficiency in the course of non-Hodgkin's lymphoma and who was successfully treated. Demonstrating this case, we would also like to stress that the development of adrenal insufficiency does not necessarily indicate widespread tumor manifestation in patients with non-Hodgkin's lymphoma.

Peripheral T-cell lymphomas: a clinicopathologic study of 75 cases.

Seventy-five peripheral T-cell lymphomas (PTLs) were classified according to the recently proposed "Updated Kiel Classification of Non-Hodgkin's Lymphomas" (mycosis fungoides and Sezary's syndrome excluded). Thirty-seven PTLs belonged to the low-grade category (T-cell chronic lymphocytic leukemia [T-CLL], 3; lymphoepithelioid, 4; angioimmunoblastic, 22; T-zone, 6; pleomorphic small cell, 2) and 38 belonged to the high-grade category (pleomorphic medium and large cell, 24; immunoblastic, 1; large-cell anaplastic Ki-1-positive, 13). Loss of pan-T antigens occurred exclusively in high-grade PTLs; on paraffin sections UCHL 1 was slightly more sensitive than MT 1. Sixty patients presented with lymphadenopathy and 15 patients (20%) presented with extranodal disease most frequently affecting the skin and upper aerodigestive tract. B-cell lymphoma symptoms were found in 43 cases (57%) and bone marrow involvement (T-CLL excluded) was found in 12 cases (17%). Staging (T-CLL excluded) revealed stage I in 13%, stage II in 15%, and stages III and IV in 72% of the cases. Among the intensively treated patients, 37% achieved complete remission and 15 are still in complete remission after 4 to 79 months (median: 24 months). The overall median survival (MS) rate was 23 months. Peripheral T-cell lymphoma of pleomorphic medium and large-cell type was the most aggressive lymphoma (MS: 8 months). B-cell lymphoma symptoms, bone marrow involvement, and Ki-67 positivity 60% or greater significantly shortened survival times, whereas age (under 60 versus over 60 years), stage (I and II versus III and IV), and grade had no significant influence. Ki-67 reactivity was found to be a prognostic factor which allows prediction of probable poor outcome, especially in cases with limited stage of disease.

[Sonographically guided percutaneous fine needle puncture of space occupying processes of the abdomen and retroperitoneum]. / Sonographisch gesteuerte perkutane Feinnadelpunktion raumfordernder prozesse des Abdomens und Retroperitoneums.

In the past four years percutaneous ultrasonically guided fine needle aspiration biopsies of space occupying lesions of the abdomen and retroperitoneum wee performed on 180 patients. There were 71 aspirations of cystic and 169 aspirations of solid lesions. Amongst the latter pancreas was first with 67 followed by the liver with 58, the kidney with 31 and other organs of the abdomen with 13 aspirations. No diagnostic material was obtained in 27 percent of aspirations of the pancreas and in 18 percent of kidney aspirations. The cytological diagnoses were right positive in 88 percent and false negative in 12 percent. There was no false positive result. 5 pseudocysts of the pancreas wee aspirated therapeutically, in one case 8 times subsequently. The only complication of all aspirations was a pancreatitis which healed under conservative treatment. There were 4 therapeutic aspirations of kidney cysts. 860 ml urine was drained from the largest cyst. We conclude that percutaneous ultrasonically guided fine needle aspiration biopsy is an easy, safe and painless method of diagnosis of space occupying lesions of the abdomen and retroperitoneum. The same applies to therapeutic aspirations of cysts of the pancreas and kidney.

Endocarditis due to a penicillin-tolerant streptococcus bovis: microbiological findings and echocardiographic follow-up.

We are presenting a case of endocarditis due to a penicillin-tolerant Streptococcus bovis in a 65-year-old patient. The minimal bactericidal concentration of penicillin (40 mg/l) was more than 100-fold the minimal inhibitory concentration (0.08 mg/l). The MBC of penicillin was 0.31 mg/l in the presence of 1.25 mg/l gentamicin. Cross-sectional echocardiography revealed endocarditis of the anterior leaflet of the tricuspid valve and a vegetation on the aortic valve which appeared to be pedunculated and which prolapsed into the left ventricular outflow tract during diastole. During therapy, the pedunculated part of the vegetation disappeared without signs of embolization. After initial clinical improvement, the patient died of cerebral bleeding caused by a mycotic aneurysm of the left median cerebral artery. The patient's final outcome suggested an asymptomatic embolus. Cross-sectional echocardiography was distinctly superior to M-mode echocardiography in estimating changes in the size and shape of the valve vegetation. The results of the post-mortem examination of the aortic and tricuspid valves corresponded to the echocardiographic findings.