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Biomedical subjects

K Köhler

Publications and source records attributed to K Köhler.

At least 37 records · Page 2Linked to original sources

Analysis of subjective, objective and functional examination tests after anterior cruciate ligament reconstruction. A follow-up of 527 patients.

This study included 527 patients (178 female and 349 male) with unilateral anterior cruciate ligament (ACL) rupture who underwent arthroscopic ACL reconstruction using bone-patellar tendon-bone autograft and interference screw fixation. The follow-up examination was performed by independent observers at a median of 38 (21-68) months after the index operation. At the follow-up, the Lysholm score was 86 (14-100) points, the Lysholm instability subscore was 22 (0-25) points and the Lysholm pain subscore was 19 (0-25) points. The Tegner activity level was 6 (1-10). The one-leg-hop test was 91 (0-167)% of the non-injured knee. The difference in the anterior side-to-side laxity as measured with the KT-1000 arthrometer at 89 Newton (N) was 1.5 (-5-13) mm and the total KT-1000 side-to-side difference at 89 N was 2 (-7-11) mm. Using the International Knee Documentation Committee (IKDC) evaluation system, 177 (33.6%) patients were classified as normal (group A), 211 (40%) as nearly normal (group B), 109 (20.7%) as abnormal (group C) and 30 (5.7%) as severely abnormal (group D). The highest correlation coefficients were recorded between the IKDC evaluation system and the Lysholm score (p = 0.66), the patients' subjective evaluation (p = 0.53), the Tegner activity level (p = 0.34), all the laxity tests (p > or = 0.34) and the one-leg-hop test (p = 0.28). The resumption of sporting activities and work as evaluated by the Tegner activity level correlated with the patients' subjective evaluation (p = 0.34) but did not correlate with the laxity tests, i.e., the manual Lachman test (p = -0.06) and the total and anterior KT-1000 tests (p = -0.06). Furthermore, none of the laxity tests correlated with the functional tests or the patients' subjective evaluation. We conclude that the IKDC evaluation system is a reliable and useful tool for evaluating the post-operative outcome after an ACL reconstruction.

Adolescent↗

Cellular composition, coronavirus antigen expression and production of specific antibodies in lesions in feline infectious peritonitis.

Twenty-three cats with spontaneous feline infectious peritonitis (FIP) were examined by light microscopy including immunohistology and histochemistry in order to determine the cellular composition and the expression of viral antigen in lesions in FIP. Furthermore, the presence of plasma-cells producing coronavirus-specific antibodies was evaluated in situ. Macrophages and neutrophils were demonstrated by an antibody against calprotectin (leukocyte protein L1, myeloid/histiocyte antigen), neutrophils were recognized due to their chloroacetate esterase activity, and B- and T-lymphocytes were identified by antibodies against the CD3 antigen and the CD45R antigen, respectively. Expression of viral antigen was immunohistologically demonstrated by a monoclonal antibody (mAb) against coronavirus while coronavirus-specific antibodies in situ were identified by the application of feline coronavirus prior to the coronavirus antibody. Lesions were classified as diffuse alterations at serosal surfaces, granulomas with areas of necrosis, granulomas without extended necrosis, focal and perivascular lymphoplasmocytic infiltrates, and granulomatous-necrotizing vasculitis. Diffuse alterations on serosal surfaces were represented either by activated mesothelial cells with single coronavirus antigen-bearing macrophages or by layers of precipitated exudate containing single to numerous granulomas with areas of necrosis. In liver and spleen, the exudate was often underlaid by a small band of subcapsular B-cells with an occasional plasma-cell producing coronavirus-specific antibodies. In other locations, a variably broad band of B-cells and plasma-cells, often infiltrating between underlying muscle fibers, separated the exudate from the unaltered tissue. Some of these plasma-cells were positive for coronavirus-specific antibodies. In granulomas with areas of necrosis, the central necrosis was surrounded by macrophages usually expressing considerable amounts of viral antigen. Few B-cells and plasma-cells were found in the periphery. In granulomas without extended necrosis, the number of macrophages were lower. Only few macrophages expressing low amounts of viral antigen were present. B-cells and plasma-cells formed a broad rim. Few plasma-cells stained positive for coronavirus-specific antibodies. In both types of granulomas, few neutrophils were found between macrophages. Few T-cells were seen scattered throughout the lesions. Focal and perivascular lymphoplasmocytic infiltrates were mainlyseen in omentum and leptomeninx. B-cells were the predominant cells; some plasma-cells were positive for coronavirus-specific antibodies. Viral antigen was not readily detected in these alterations. Granulomatous-necrotizing vasculitis was occasionally found in kidneys and leptomeninx. It was dominated by macrophages which often stained strongly positive for coronavirus antigen. Different types of alteration were often seen in the same animal and even the same tissue. There was no obvious correlation between the cat's age, gross pathological changes, and the histological types of alteration. Single plasma-cells positive for coronavirus-specific antibodies were found around blood vessels distant from inflammatory alterations, within the lung parenchyma, as infiltrating cells in the mucosa of the small intestine, and in spleen and mesenteric lymph node. Results show that alterations in FIP are heterogeneous concerning cellular composition and expression of viral antigen. The dominance of B-cells in part of the lesions together with the presence of plasma-cells positive for coronavirus-specific antibodies indicate that these cells may play a role in the maintenance of inflammatory processes in FIP.

Animals↗

Arthroscopic and open shoulder stabilization using absorbable implants. A clinical and radiographic comparison of two methods.

The aim of this study was to compare the clinical and radiographic results in patients with recurrent unidirectional, post-traumatic shoulder instability (dislocations/subluxations). All the patients had a Bankart lesion and underwent reconstruction using either an open or an arthroscopic technique and absorbable implants. Thirty-three consecutive patients (36 shoulders) were operated on by one surgeon. Group A comprised 18 shoulders which underwent an open Bankart reconstruction using absorbable 3.7-mm TAG suture anchors. Group B comprised 18 shoulders which underwent a combination of an intra- and extra-articular arthroscopic stabilization using 8-mm Suretac fixators. The median number of dislocations before the reconstruction was 5(0-45) in group A and 4 (0-30) in group B (NS). The follow-up examination was performed by an independent observer after a median of 31 (range 25-38) months in group A and 28 (range 18-46) months in group B (NS). An independent radiologist without any knowledge of the surgical procedure evaluated all the radiographs. There were no re-dislocations in either group. In group A, the Rowe and Constant scores were 86 (range 61-98) and 89 (range 73-99), respectively. The corresponding values in group B were 92 (range 83-98; P = 0.05) and 96 (range 75-100; NS). The external rotation in abduction was 65 degrees (range 20 degrees-90 degrees) in group A and 83 degrees (range 65 degrees-105 degrees) in group B (P = 0.0017). The radiographs revealed that 10/18 (56%) in group A and 4/18 (23%) in group B had visible drill-holes or cystic formations in conjunction with the drill-holes (P = 0.002). In this study the open procedure resulted in a restriction in external rotation more frequently than the arthroscopic procedure. The radiographs revealed visible drill-holes or cystic formations in conjunction with the drill-holes more frequently when TAG suture anchors were used than when Suretac fixators were used. The radiographic changes did, not appear to affect the clinical outcome, however.

Adolescent↗

Lipid peroxidation and cardiac troponin T release during routine cardiac surgery.

Myocardial injury after cardiac surgery with cardiopulmonary bypass may be related to free oxygen radical-induced lipid peroxidation. The purpose of this study was to monitor perioperative changes of cardiac troponin t and malondialdehyde as an indicator of lipid peroxidation in patients who underwent routine cardiac operation and had no signs of perioperative myocardial infarction. Patients with thoracic surgery alone served as controls. We studied 20 patients with cardiopulmonary bypass (CPB) and 9 patients with other thoracic operations. Serum troponin t, malondialdehyde, myoglobin, creatine kinase (CK) including CK-MB isoenzyme levels were monitored before CPB, immediately after cessation of CPB, 20 and 44 h after CPB. Patients with signs of myocardial infarction before or up to 44 h after surgery were excluded. Of 20 patients with CBP, 18 patients showed a significant increase of troponin t and 16 patients had elevated malondialdehyde serum levels following CPB. Troponin t serum values were raised immediately after CPB to 0.60 +/- 0.12 microg/l and increased further to 0.90 +/- 0.17 microg/l after 44 h (p < 0.005, in comparison to preoperative: 0.08 +/- 0.02 microg/l). Patients undergoing the other thoracic operations showed neither any detectable troponin t serum values nor significant changes of serum malondialdehyde during the observed period. In the CPB group serum malondialdehyde peaked immediately after CPB to 98 +/- 9 nmol/g albumin (p < 0.005) and returned to preoperative levels (63 +/- 3 nmol/g albumin) within 20 h (60 +/- 3 nmol/g albumin). Individual maximal troponin t serum levels did not correlate with individual maximal serum malondialdehyde levels. The observed increase of troponin t levels had no influence on patients' outcome followed up for 18 months. The results demonstrate that troponin t and lipid peroxidation increase during uncomplicated cardiac surgery in patients without signs of myocardial infarction. Following uncomplicated cardiac surgery, a moderate increase of cardiac troponin t may not reflect severe cardiac injury.

Cardiac Surgical Procedures↗

Transient transcriptional activation of gastrin during sodium butyrate-induced differentiation of islet cells.

Transient expression of pancreatic gastrin corresponds to a period of rapid islet cell development. After birth gastrin expression silencing is coincidental with islet cell terminal differentiation, while persistent expression is accompanied with nesidioblastosis and reexpression observed in islet cell tumors. Experiments with transgenic animals suggested that gastrin might act synergistically with growth factors to stimulate islet cell development. The present study intended to establish an in vitro cell culture model to analyse the molecular events controlling gastrin gene activation and repression dependent on islet cell differentiation. Sodium butyrate, a proliferation-arresting compound has previously been shown to differentiate insulinoma cells while increasing insulin production. The present paper demonstrates concomitant transient increase in gastrin mRNA, intracellular and secreted gastrin during sodium butyrate treatment. Increased gastrin expression was due to activation or derepression of gastrin promoter activity as revealed by promoter analyses. This in vitro model mimics the expression pattern of gastrin and insulin observed during fetal islet cell development and provides an excellent tool to analyse the molecular mechanisms controlling gastrin gene activation and selective repression during islet cell differentiation.

Animals↗

[Peripheral aneurysm of the hepatic artery as the etiology of acute upper gastrointestinal hemorrhage].

We report the case of a 64-year-old female with an intrahepatic aneurysm of the right hepatic artery. Initially uncharacteristic upper abdominal symptoms were followed by repeated upper gastrointestinal bleeding and, eventually, hemorrhagic shock. Finding the cause of severe hematemesis was challenging due to a previous Billroth-II gastric resection. Delayed diagnosis of hemobilia necessitated coeliacography, whereby an intrahepatic aneurysm of the right hepatic artery was found and, during the same session, super-selective embolization was achieved. If the cause of upper abdominal complaints remains unknown after routine diagnostic measures and the origin of bleeding in the upper gastrointestinal tract cannot be identified, aneurysms of abdominal arteries should be considered. Hemobilia of unknown etiology should always be an indication for coeliacography. The superselective angiographic embolization of intrahepatic aneurysms is a promising form of treatment with low risk.

Angiography↗

Is bracing after anterior cruciate ligament reconstruction necessary? A 2-year follow-up of 78 consecutive patients rehabilitated with or without a brace.

The aim of this study was to evaluate the effect of a standard postoperative rehabilitation knee brace on function, stability and postoperative complications at the 2-year follow-up after anterior cruciate ligament (ACL) reconstructive surgery. Seventy-eight consecutive patients with a unilateral chronic ACL rupture reconstructed by the same surgeon using the endoscopic "all-inside" technique, patellar tendon autograft and interference screw fixation were included in the study. The rehabilitation followed a standard protocol. Group A included 39 patients who were supplied postoperatively with a knee brace for 4 (range 3-6) weeks. Group B included 39 patients for whom a brace was not used. The median age was 27 (range 16-48) years in group A and 26 (range 14-51) years in group B. The median time period between the injury and the index operation was 24 (range 3-150) months in group A and 18 (range 3-360) months in group B. All 78 patients were re-examined by two independent observers after a median follow-up period of 25 (range 23-28) months in group A and 24 (range 22-27) months in group B. The median KT-1000 total side-to-side difference between the reconstructed and the uninjured knees at 89 N was 3 (range -5.5-11) mm in group A and 3 (range -7-10) mm in group B (NS). When the anterior translation was tested separately at 89 N, the corresponding values were 3 (range -4-13) mm in group A and 3 (range -5-10) mm in group B (NS). The median one-leg hop quotient was 95% (range 50%-167%) of the uninjured leg in group A and 92% (range 64%-119%) in group B (NS). The median Lysholm score was 89 (range 39-100) points in group A and 85 (range 37-100) points in group B (NS). In group A, 27/39 (69%) patients and in group B 21/39 (54%) patients were classified as excellent or good (NS). The median Tegner activity level was 7 (range 3-9) in group A and 6 (range 3-9) in group B (NS). Using the IKDC scale, 27/39 (69%) in group A and 24/39 (62%) in group B were classified as normal or nearly normal (NS). The median sick leave in group A was 62 (range 0-357) days and 59 (range 0-243) days in group B (NS). No serious complications occurred during the first 6 postoperative weeks. Two serious complications were, however, registered after the 6th postoperative week. One patient in group A sustained a rupture of the reconstructed ACL 8 weeks postoperatively (3 weeks after removing the brace), and one patient in group B sustained an undislocated patellar fracture during the 7th postoperative week after a fall. This study indicates that the use of a postoperative rehabilitation brace after an arthroscopic ACL reconstruction did not appear to influence either objective stability or subjective function by the 2-year follow-up.

Adolescent↗

Amphiphysin heterodimers: potential role in clathrin-mediated endocytosis.

Amphiphysin (Amph) is a src homology 3 domain-containing protein that has been implicated in synaptic vesicle endocytosis as a result of its interaction with dynamin. In a screen for novel members of the amphiphysin family, we identified Amph2, an isoform 49% identical to the previously characterized Amph1 protein. The subcellular distribution of this isoform parallels Amph1, both being enriched in nerve terminals. Like Amph1, a role in endocytosis at the nerve terminal is supported by the rapid dephosphorylation of Amph2 on depolarization. Importantly, the two isoforms can be coimmunoprecipitated from the brain as an equimolar complex, suggesting that the two isoforms act in concert. As determined by cross-linking of brain extracts, the Amph1-Amph2 complex is a 220- to 250-kDa heterodimer. COS cells transfected with either Amph1 or Amph2 show greatly reduced transferrin uptake, but coexpression of the two proteins rescues this defect, supporting a role for the heterodimer in clathrin-mediated endocytosis. Although the src homology 3 domains of both isoforms interact with dynamin, the heterodimer can associate with multiple dynamin molecules in vitro and activates dynamin's GTPase activity. We propose that it is an amphiphysin heterodimer that drives the recruitment of dynamin to clathrin-coated pits in endocytosing nerve terminals.

Amino Acid Sequence↗