[Robot-assisted surgery - Progress or expensive toy? : Matched-pair comparative analysis of robot-assisted cholecystectomy vs. laparoscopic cholecystectomy]. / Roboterassistierte Chirurgie ­ Fortschritt oder teures Spielzeug? : Matched-Pair-Vergleichsanalyse der roboterassistierten Cholezystektomie vs. der laparoskopischen Cholezystektomie.

AIM AND METHODS: By means of a matched-pair analysis comparing data obtained from laparoscopic cholecystectomy (LC) and robot-assisted laparoscopic cholecystectomy (RAC), the value of both methods as well as the advantages and disadvantages of both approaches were elucidated. The consideration was carried out by evaluation of postoperative surgical results, a cost analysis and a subjective survey of the patients using a questionnaire. Thus, from the 35 consecutive RAC, 35 (parallel) retrospectively matched pairs were established. RESULTS: Postoperative surgical results did not show any significant differences between LC and RAC. In the individual assessment by each patient, there were also no significant differences; however, there was a tendency towards the assessment of the RAC to be slightly worse. A striking difference was found with respect to the cost analysis at the time of surgery. CONCLUSION: The RAC operation alone is significantly more expensive compared to LC with respect to maintenance and acquisition costs. In addition, RAC can at present not be completely reimbursed under the current German diagnosis-related system. The postulated advantages of RAC comprise mainly the precise preparation within narrow confinements and the favorable ergonomic handling for the surgeon. The basic prerequisites are control of the costs and a reasonable reflection in the current reimbursement system.

Mutant Huntingtin induces activation of the Bcl-2/adenovirus E1B 19-kDa interacting protein (BNip3).

Huntington's disease (HD) is a neurodegenerative disorder characterized by progressive neuronal death in the basal ganglia and cortex. Although increasing evidence supports a pivotal role of mitochondrial dysfunction in the death of patients' neurons, the molecular bases for mitochondrial impairment have not been elucidated. We provide the first evidence of an abnormal activation of the Bcl-2/adenovirus E1B 19-kDa interacting protein 3 (BNip3) in cells expressing mutant Huntingtin. In this study, we show an abnormal accumulation and dimerization of BNip3 in the mitochondria extracted from human HD muscle cells, HD model cell cultures and brain tissues from HD model mice. Importantly, we have shown that blocking BNip3 expression and dimerization restores normal mitochondrial potential in human HD muscle cells. Our data shed light on the molecular mechanisms underlying mitochondrial dysfunction in HD and point to BNip3 as a new potential target for neuroprotective therapy in HD.

Healing characteristics of a new silver-coated, gelatine impregnated vascular prosthesis in the porcine model.

OBJECTIVES: To investigate the intraluminal and extraluminal healing behaviour of a new metallic silver coated, gelatine impregnated vascular graft. DESIGN: Comparative animal experimental investigation with randomisation of the animals to control and experimental groups. MATERIAL AND METHODS: 24 pigs were assigned to two control and two experimental groups. The prostheses were interposed in the pigs' infrarenal aorta. For the evaluation, macroscopic, histological and immunohistochemical criteria were applied. RESULTS: The macroscopic evaluation after explantation of the prosthesis revealed similar healing characteristics in the control and experimental groups. The microscopic determination of neo-intimal thickness showed no significant differences between the groups; nor did the immunohistochemical investigations show any significant difference between the control group and the silver-coated prosthesis group. CONCLUSIONS: No disadvantage of the silver coating in terms of healing and graft patency was found. A possible advantage in terms of the antibacterial effect of the silver coating must be investigated in the clinical setting.

Antibody response to collagen after functional implantation of different polyester vascular prostheses in pigs.

Besides inflammation, specific immune responses are seen also after implantation of biomaterials. The aim was to investigate the humoral response to bovine collagen type I following implantation of various polyester (Dacron) prostheses into pigs. In 24 randomized pigs, the infrarenal aorta was replaced with a segment of collagen-impregnated, woven polyester prosthesis of low, medium, or high porosity. IgG antibodies were detected by immunoassay using native and denatured collagen type I as a target for blood samples taken on day 1 (implantation), 10, 17, 24, 62, and 116. As generally observed, antibodies to native and denatured collagen are of low titer and were significantly correlated with enhanced binding to the denatured form (p < 0.001). The highest overall antibody prevalence to native and denatured collagen was obtained on day 116 with 68% and on day 62 with 59%, respectively. Prostheses with high porosity induced an early immune response on day 10; those with low and medium porosity induced the highest antibody levels later after 2 months. Collagen antibodies neither correlated with serum IgG contents nor with antibodies to the prosthesis polyester matrix. Thus, humoral immune response against implant components may provide a further parameter in describing biocompatibility but also a potential marker that may facilitate monitoring of individual perigraft reaction.

Immunogenicity of polymeric implants: long-term antibody response against polyester (Dacron) following the implantation of vascular prostheses into LEW.1A rats.

Implanted biomaterials trigger acute and chronic inflammatory responses directly correlated to the central role of phagocytic cells at the host-implant interface. This study was designed to evaluate specific humoral immune responses following repeated intraperitoneal implantations of collagen-impregnated polyester (Dacron) prosthetic segments into LEWIS rats. Serum antibody detection was performed by enzyme immunoassay with the prosthetic segments as a target. Cutoff values for antibody positivity were greater than or equal to the 99th percentile for control rats. Polymer immunoglobiulin G (IgG) antibodies were significantly increased (p < 0.05) by repeated implantation and were subsequently followed until experimental day 293. Antibody formation was significantly enhanced through the application of complete Freund's adjuvant in combination with the first implantation. All rats within this group were antibody-positive on day 53, but only 6 of 10 animals that received the prosthesis without the adjuvant were. After preincubation of sera with bovine collagen type I (solid phase adsorbed or in solution), polymer antibody binding was discovered not to be diminished, indicating that the IgG antibodies detected were not directed against the prosthesis impregnation. Furthermore, a significant correlation was obtained between polymer antibody binding to collagen-impregnated and nonimpregnated prostheses (r(s) = 0.797, p < 0.001). There was no substantiated correlation between antibody binding to polyester and to an irrelevant polymer (Tecoflex EG 80). We conclude that specific polymer antibodies may indeed provide an additional parameter for biocompatibility testing as well as a possible serological marker of an inflammatory response to implants.

[Which factors are responsible for postoperative mortality in colorectal cancer patients?]. / Welche Faktoren beeinflussen die postoperative Letalität beim kolorektalen Karzinom?

INTRODUCTION: The postoperative decease is the most severe complication in surgery. PATIENTS AND METHOD: Within the framework of a multicentre study between January 1 (st) and December 31, 1999, 3,756 patients, 1,463 of them suffering from rectal cancer and 2 293 from colon carcinoma, from 75 clinics were documented with the help of a standardized questionnaire. We compared data of 211 patients who died postoperatively with data of 3,484 patients who survived after surgical treatment of colorectal cancer. Logistical regressions, under inclusion and exclusion of intra- and postoperative complications, show independent influence factors on the postoperative decease and provide models for the prediction of the postoperative death. RESULTS: Compared to the patients who survived, the postoperative deceased patients were significantly older. They had a poorer risk profile and therefore a higher ASA-score (p < 0.001). 20.4 % of the patients underwent an emergency operation. General and specific postoperative complications occurred significantly more frequently. The model of a logistical regression allowed the prediction of postoperative decease with a sensitivity and specificity of 91 %. General postoperative complications such as pulmonary embolism (relative risk: 30.3), cardiac (relative risk: 24.1), renal (relative risk: 22.1), and pulmonary complications (relative risk: 12.0) are crucial for lethality. DISCUSSION: The postoperative decease is influenced by several factors. It is impossible to reduce the number of influence factors for the prediction of outcome. The general postoperative complications, however, represent a crucial problem. It is important to avoid these problems in order to reduce postoperative lethality.

[The importance of laparoscopy in blunt abdominal trauma]. / Der Stellenwert der Laparoskopie beim Abdominaltrauma.

The importance of laparoscopy in the management of blunt abdominal trauma should be evaluated. Therefore we retrospectively analysed all patients with blunt abdominal trauma treated in the Department of Surgery at the Carl-Thiem-Hospital Cottbus between 1998 and 2000. Within this period a total number of 53 patients with blunt abdominal trauma underwent operative treatment, 20 (37.7 %) of them had primary laparoscopy. Of the 11 cases where laparoscopic operation could be completed without conversion to exploratory laparotomy, 8 patients had intra-abdominal injuries and underwent sufficient laparoscopic treatment. The percentage of so called "negative" exploratory laparotomies within this study was 13.2 %. Our analysis suggests that laparoscopy should become firmly established in the diagnostic management and, if indicated, in the treatment of blunt abdominal trauma as well.

[Laparoscopic treatment of iatrogenic perforations of the colon]. / Laparoskopische Versorgung iatrogener Kolonperforationen.

Iatrogenic perforations of the colon are serious complications that have been observed in association with both diagnostic and therapeutic colonoscopies, and are not always avoidable, even in the hands of an experienced investigator. Patients suffering from a perforation during elective colonoscopy are starving, and have a clean bowel. If the perforation is quickly diagnosed with only local mild peritonitis, laparoscopic treatment is often possible. The therapeutic options available are: oversewing, wedge resection and, in the individual case, tubular resection, as well as laparoscopic-assisted reconstruction, if indicated including a protective stoma. The decision to perform a laparoscopic procedure should depend on the time of detection of the lesion, and on the skills of the existing surgical team; otherwise, a laparotomy is indicated. We describe four cases that reflect the relevance of the laparoscopic approach.

["Colon-/rectal carcinoma" prospective studies as comprehensive surgical quality assurance]. / Prospektive Multizenterstudien "Kolon-/Rektumkarzinome" als flächendeckende chirurgische Qualitätssicherung.

INTRODUCTION: Currently, only a small percentage of the diagnostic and therapeutic data on colonic carcinomas has been confirmed by data obtained in randomized controlled studies. For this reason, the results of prospective multicentre observational studies are extremely important. METHOD: Within a multicentre observational study involving 75 surgical departments carried out between 01.01. and 31.12.1999, 3,756 patients with a colorectal carcinoma (2,293 carcinoma of the colon; 1,463 carcinomas or the rectum) were investigated prospectively using a standardised questionnaire. RESULTS: The OP rate was 98.4%, the resection rate 92.5% (colon 94.1%, rectum 89.9%). The rate of rectal extirpations was relatively high at 30.3%. General postoperative morbidity was 27.4% (colon 27.0%, rectum 27.9%); the specific postoperative morbidity was 24.6% (colon 21.8%, rectum 29.1%). The anastomotic insufficiency rate was 5.2% (colon 3.7%, rectum 9.5%). The 30-day mortality rate was 4.7%, and the postoperative mortality rate 5.7%. CONCLUSIONS: Surgical quality control in the form of prospective multicentre observational studies make possible the analysis of the therapeutic situation of a surgical disease under quality assurance aspects. At the same time, the comprehensive data material available will serve the specific planning of prospective randomized studies. With the aid of the present study, a basis for a thorough and complete evaluation of colorectal carcinoma has been created.

Routine use of transrectal ultrasound in rectal carcinoma: results of a prospective multicenter study.

BACKGROUND AND STUDY AIMS: Preoperative transrectal ultrasound (TRUS) can establish the depth of penetration of a tumor, and thus provide important information for decisions about further management. In the literature, this method is reported to have a high level of sensitivity and specificity. Our investigation aimed at establishing the quality of the diagnostic procedure and treatment of colorectal carcinoma. PATIENTS AND METHODS: This investigation, which covered a 1-year period, and involved 75 hospitals, was conducted in the form of a prospective multicenter study and included a total of 3756 patients. For rectal carcinomas, all endosonographically determined uT categories were compared with histologically established T categories (pT). RESULTS: At 49 hospitals a total of 499 TRUS examinations in 1463 rectal carcinomas (34.1 %) were performed. A comparison of uT with pT category was possible for 422 TRUS examinations. Agreement between the preoperative endosonographic diagnosis with the histological diagnosis was found in 63.3 % (n = 267) of cases (95 % confidence interval 58.5 % - 67.9 %). The diagnostic accuracy was 50.8 % for pT1 carcinomas, 58.3 % for pT2 lesions, 73.5 % for pT3 tumors, and 44.4 % for pT4 carcinomas. Overstaging was observed in 23.9 %, overall, and understaging in 12.8 %. Understaging was significantly less common than overstaging (P < 0.05, s.). CONCLUSION: The accuracy of transrectal ultrasound used as a routine clinical examination in rectal carcinoma patients was clearly lower than that reported in the literature. We conclude that TRUS may aid decisions relevant to treatment only when used by well-trained investigators with a large case load of rectal carcinoma patients. Centralization of transrectal ultrasonography service is mandatory if a high level of quality is to be achieved with this method.

Involvement of CDC25Mm/Ras-GRF1-dependent signaling in the control of neuronal excitability.

Ras-GRF1 is a neuron-specific guanine nucleotide exchange factor for Ras proteins. Mice lacking Ras-GRF1 (-/-) are severely impaired in amygdala-dependent long-term synaptic plasticity and show higher basal synaptic activity at both amygdala and hippocampal synapses (Brambilla et al., 1997). In the present study we investigated the effects of Ras-GRF1 deletion on hippocampal neuronal excitability. Electrophysiological analysis of both primary cultured neurons and adult hippocampal slices indicated that Ras-GRF1-/- mice displayed neuronal hyperexcitability. Ras-GRF1-/- hippocampal neurons showed increased spontaneous activity and depolarized resting membrane potential, together with a higher firing rate in response to injected current. Changes in the intrinsic excitability of Ras-GRF1-/- neurons can entail these phenomena, suggesting that Ras-GRF1 deficiency might alter the balance between ionic conductances. In addition, we showed that mice lacking Ras-GRF1 displayed a higher seizure susceptibility following acute administration of convulsant drugs. Taken together, these results demonstrated a role for Ras-GRF1 in neuronal excitability.

Laparoscopy of a traumatic rupture of a dysontogenetic splenic cyst. A case report.

The role of laparoscopy in the stepped approach to the diagnosis and treatment of blunt abdominal trauma has not yet been fully elucidated. Despite the use of a variety of imaging modalities, it can still be difficult to make a proper evaluation in cases where there are questionable abdominal injuries. In particular, when there is a discrepancy between a bland clinical picture and the results of diagnostic imaging procedures, laparoscopy should be given preference over laparotomy, provided the patient's circulatory situation is stable. Herein we describe a case in which laparoscopy allowed the detection and treatment of a traumatic rupture of a dysontogenetic splenic cyst that had mimicked a rupture of the spleen on both the ultrasound (US) and computed tomography (CT) images.

Cloning and characterization of mouse UBPy, a deubiquitinating enzyme that interacts with the ras guanine nucleotide exchange factor CDC25(Mm)/Ras-GRF1.

We used yeast "two-hybrid" screening to isolate cDNA-encoding proteins interacting with the N-terminal domain of the Ras nucleotide exchange factor CDC25(Mm). Three independent overlapping clones were isolated from a mouse embryo cDNA library. The full-length cDNA was cloned by RACE-polymerase chain reaction. It encodes a large protein (1080 amino acids) highly homologous to the human deubiquitinating enzyme hUBPy and contains a well conserved domain typical of ubiquitin isopeptidases. Therefore we called this new protein mouse UBPy (mUBPy). Northern blot analysis revealed a 4-kilobase mRNA present in several mouse tissues and highly expressed in testis; a good level of expression was also found in brain, where CDC25(Mm) is exclusively expressed. Using a glutathione S-transferase fusion protein, we demonstrated an "in vitro" interaction between mUBPy and the N-terminal half (amino acids 1-625) of CDC25(Mm). In addition "in vivo" interaction was demonstrated after cotransfection in mammalian cells. We also showed that CDC25(Mm), expressed in HEK293 cells, is ubiquitinated and that the coexpression of mUBPy decreases its ubiquitination. In addition the half-life of CDC25Mm protein was considerably increased in the presence of mUBPy. The specific function of the human homolog hUBPy is not defined, although its expression was correlated with cell proliferation. Our results suggest that mUBPy may play a role in controlling degradation of CDC25(Mm), thus regulating the level of this Ras-guanine nucleotide exchange factor.

Antigenicity of polyester (Dacron) vascular prostheses in an animal model.

Objectives to investigate the specific humoral immune response to three different polyester (Dacron) prostheses in pigs. Design, materials and methods twenty-four growing pigs were randomly divided into three groups. The infrarenal aorta was replaced by a segment of collagen-impregnated woven polyester prosthesis (low, medium and high porosity). Serum antibodies were detected by modified enzyme immunoassay using non-impregnated prosthesis as the target for the blood samples taken on experimental days 1, 10, 17, 24, 62 and 116 of the 22 pigs followed over the whole observation period. Results significantly enhanced (p <0.05) mean IgG antibody binding against polyester was detected on experimental days 10, 17, 24 and 62 with antibody prevalences of 41%, 41%, 32% and 37%, respectively. Antibody positive pigs were divided into early responders (n =9) and late responders ( n =5) with antibody detection on day 10 and/or 17 vs day 62 and/or 116. No significant differences between the three different prostheses were found. The formation of specific IgG antibodies against polyester in the animals investigated demonstrates a broad individual variability. Conclusions polyester is an antigenic polymer. Specific antibodies, reflecting the inflammatory response, might be not only a parameter for testing biomaterials but also for determining individual bio(in)compatibility for long-term biomaterial function.

Sites of phosphorylation by protein kinase A in CDC25Mm/GRF1, a guanine nucleotide exchange factor for Ras.

Activation of the neuronal Ras GDP/GTP exchange factor (GEF) CDC25Mm/GRF1 is known to be associated with phosphorylation of serine/threonine. To increase our knowledge of the mechanism involved, we have analyzed the ability of several serine/threonine kinases to phosphorylate CDC25Mm in vivo and in vitro. We could demonstrate the involvement of cAMP-dependent protein kinase (PKA) in the phosphorylation of CDC25Mm in fibroblasts overexpressing this RasGEF as well as in mouse brain synaptosomal membranes. In vitro, PKA was found to phosphorylate multiple sites on purified CDC25Mm, in contrast to protein kinase C, calmodulin kinase II, and casein kinase II, which were virtually inactive. Eight phosphorylated serines and one threonine were identified by mass spectrometry and Edman degradation. Most of them were clustered around the Ras exchanger motif/PEST motifs situated in the C-terminal moiety (residues 631-978) preceding the catalytic domain. Ser745 and Ser822 were the most heavily phosphorylated residues and the only ones coinciding with PKA consensus sequences. Substitutions S745D and S822D showed that the latter mutation strongly inhibited the exchange activity of CDC25Mm on Ha-Ras. The multiple PKA-dependent phosphorylation sites on CDC25Mm suggest a complex regulatory picture of this RasGEF. The results are discussed in the light of structural and/or functional similarities with other members of this RasGEF family.

[Elective surgical treatment of a giant scrotal hernia]. / Die elektiv-chirurgische Therapie einer monströsen Skrotalhernie.

We report on a 69-year-old man presenting with a giant scrotal hernia, who failed to tolerate a pre-operative pneumoperitoneum applied with the intention to increase his intra-abdominal capacity. After enlarging the hernial orifice, the hernia contents - comprising the entire small bowel, the right colon and the greater omentum - were replaced into the abdominal cavity. Closure of the abdominal wound with mesh support was possible only after extensive resection of the small bowel, together with the voluminous mesentery and greater omentum. In a second operation performed later on revision of the scrotum and penis was undertaken. It is not always possible to achieve the required increase in intra-abdominal capacity through the use of a pneumoperitoneum. In such cases, extensive bowel resections and the use of biomaterials for tension-free abdominal wall repair must form an integral part of the treatment concept. Surgical management of such giant hernias has to be adapted to the individual situation of the patient using all therapeutic options.

Effect of caseload on the short-term outcome of colon surgery: results of a multicenter study.

This prospective multicenter study investigated the effect of hospital caseload on early postoperative outcome of surgery for carcinoma of the colon in 75 German hospitals and included 2293 patients. The hospitals were divided into those with a caseload of 1-30 (group A), 31-60 (group B), and more than 60 (group C) operations. Increasing caseload was associated only with fewer general postoperative complications. It was also associated with significantly greater use of antibiotic prophylaxis. No significant differences between the groups were found in resection rates, intraoperative complications, specific postoperative complications, overall postoperative morbidity, hospital mortality, or 30-day mortality. The significance of hospital caseload for the short-term postoperative outcome following surgery on the colon should not be overestimated. Basing conclusions about the results to be expected simply on the case volume is impermissible. On the basis of the available data it is not possible to establish a threshold value, that is, a minimum number of required operations.

Prospective multicenter study of antibiotic prophylaxis in operative treatment of appendicitis.

BACKGROUND/AIMS: A prospective, multicenter observation study was conducted to investigate the effectiveness of antibiotic prophylaxis in the operative treatment of appendicitis. METHODS: Between June 1996 and May 1997, a total of 4,968 patients underwent an operation for appendicitis at 34 East German hospitals. 41.4% (n = 2,424) received perioperative antibiotic prophylaxis whereas in 58.9% of the cases this was not given. The patients who received antibiotic prophylaxis constituted a negative selection, both with regard to risk factors and to the stage of inflammation. RESULTS: In the total test group, the rate for septic disorders of wound healing amounted to 2.5% (n = 120). The use of antibiotic prophylaxis makes it possible to significant lower the incidence of postoperative septic disorders of wound healing (p < 0.001). In both conventional (0.7% with prophylaxis vs. 3.8% without) and in laparoscopic appendectomy (0 vs. 1.0%) the rate for septic disorders of wound healing can be reduced (p < 0.001). The global comparison irrespective of possible antibiotic prophylaxis shows a significant advantage for appendectomies which started with laparoscopy (p = 0.008), but in the subgroups with prophylaxis this advantage is completely neutralized (p = 0.78). CONCLUSION: From this one can deduce that conventional appendectomy with antibiotic prophylaxis comprises no higher risk of wound infection than laparoscopy, since the risk of conversion exists for every operation begun by laparoscopy. These results would lead to the conclusion that antibiotic prophylaxis should be given before every appendectomy, whether by laparoscopy or conventional methods.

Calcium and calmodulin are essential for Ras-GRF1-mediated activation of the Ras pathway by lysophosphatidic acid.

The exchange factor Ras-GRF1, also called CDC25Mm, couples calcium signaling and G-protein-coupled receptors to Ras and downstream effectors. Here we show that when expressed in different cell lines Ras-GRF1 strongly enhances the level of active Ras (Ras-GTP) and the activity of mitogen-activated protein kinases (MAPK). Moreover, in NIH 3T3 fibroblasts it potentiates the effect of lysophosphatidic acid (LPA) on Ras protein and MAPK activity. Calmodulin and cytosolic free calcium are essential for Ras and MAPK activation induced by LPA and mediated by Ras-GRF1, as shown by the finding that BAPTA-AM, an intracellular calcium chelator, and calmodulin inhibitors completely abolished this effect. This report demonstrates the relevance of calmodulin in addition to calcium for the response of Ras-GRF1 to LPA.

cAMP cascade leads to Ras activation in cortical neurons.

Monoaminergic G protein-coupled receptors (GPCRs) are highly expressed in the CNS at the cerebrocortical level, where they support a variety of behavioural responses. To elucidate possible intracellular signalling pathways coupled to these receptors, we have studied their ability to activate extracellular signal-regulated kinases (ERKs) in cultured cortical neurons. An increase in ERK activity was observed after stimulation of neurons with dopamine or serotonin, and with agonists selective for various GPCRs. In addition, ERK activation was also observed following treatment with phorbol dibutyrate (PdBu) and forskolin, activators of protein kinase C (PKC) and protein kinase A (PKA), respectively. Concomitant with ERK activation, all the monoaminergic agonists tested also increased the level of active Ras (Ras-GTP). Surprisingly, Ras activation was also observed after activation of cAMP pathway, and this effect was at least in part mediated by PKA. Ras activation by cAMP was unique for neurons, since in PC12 cells forskolin caused activation of ERK but did not increase Ras-GTP level. These results highlight the relevance of Ras as a target for multiple signalling cascades leading to activation of the ERK pathway in neurons.