126
|
Peitgen K, Walz MK, Krause U, Eigler FW. [Laparoscopic gastrostomy--advantages in comparison with percutaneous endoscopic gastrostomy (PEG)]. LANGENBECKS ARCHIV FUR CHIRURGIE. SUPPLEMENT. KONGRESSBAND. DEUTSCHE GESELLSCHAFT FUR CHIRURGIE. KONGRESS 1998; 114:1180-1. [PMID: 9574370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Laparoscopic gastrostomy was performed on 70 patients with contraindications to PEG. All procedures were performed successfully, even in patients with gastric resections, after gallbladder surgery, and in patients with liver cirrhosis and ascites. Long-term results comprise a low complication rate of 0.12 in 100 application days. Laparoscopic gastrostomy is a highly effective procedure with low morbidity and good long-term results in patients with contraindications to PEG requiring enteral feeding.
Collapse
|
127
|
Friedrich J, Krause U, Saller B, Eigler FW. [Unilateral neck exploration in primary hyperparathyroidism]. LANGENBECKS ARCHIV FUR CHIRURGIE. SUPPLEMENT. KONGRESSBAND. DEUTSCHE GESELLSCHAFT FUR CHIRURGIE. KONGRESS 1998; 114:1157-60. [PMID: 9574364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Within a prospective case control study from 1993 to 1996, in 85 first operations for primary hyperparathyroidism the neck exploration was ended unilaterally when an adenoma (also histologically proven) and one normally small parathyroid gland were found. Otherwise or in case of simultaneous surgery of the thyroid gland, a bilateral exploration was performed. The primary success rate with this strategy, additionally based on 69.4% correct results of cervical ultrasound, was 95.3%, with a significant saving of an average of 30 min. operating time.
Collapse
|
128
|
Hellinger A, Lange R, Peitgen K, Stephan V, Krause U, Erhard J. [Bile duct lesions in laparoscopic cholecystectomy--methods of reconstruction and results]. Zentralbl Chir 1998; 122:1092-8. [PMID: 9499533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
From 1/1991 to 1/1997 a total of 18 patients with major biliary lesions after laparoscopic cholecystectomy were treated. Besides 4 biliary strictures (Bismuth III, Siewert II), which were found between 20 and 180 days after laparoscopic cholecystectomy, large defects (Siewert III, IV) of the proximal parts of the hepatic duct (Bismuth III, IV) occurred in the majority of cases (n = 14). Except for 3 intraoperatively realized lesions, diagnosis was made during the first 3 weeks. Subsequent reinterventions resulted in a high morbidity rate and the need of further procedures to establish definitive biliary reconstruction. Selection criteria of the technique used for repair were the extension of the biliary lesion and the exposure of the distal stump of the common bile duct. A small defect was treated by direct suturing protected by a t-tube (n = 1). Large defects and biliary strictures were reconstructed using either a Roux-en-Y bilio-digestive anastomosis (n = 7) or jejunal interposition (n = 10). The results suggest, that early repair of biliary lesions after laparoscopic cholecystectomy should be achieved. Besides the standard procedure of bilio-digestive anastomosis, reconstruction of major biliary lesions should be performed by jejunal interposition in selected cases.
Collapse
|
129
|
Gsell W, Strein I, Krause U, Riederer P. Neurochemical abnormalities in Alzheimer's disease and Parkinson's disease--a comparative review. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 1998; 51:145-59. [PMID: 9470135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We report a meta-analysis of the brain neurochemical abnormalities in Alzheimer's (AD) and Parkinson's disease (PD). Evidence for oxidative stress, and disorders of energy metabolism and excitatory amino acids is presented for both disorders. However, limited data and conflicting findings preclude any definitive statement relating to differences and overlap between the two conditions.
Collapse
|
130
|
Kock HJ, Krause U, Albrecht KH, van der Laan E, Rudofsky G, Eigler FW. [Crossectomy in ascending superficial thrombophlebitis of the leg veins]. Zentralbl Chir 1998; 122:795-800. [PMID: 9454490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ascending thrombophlebitis of the superficial leg veins is known to propagate into the deep leg veins and to embolize. In a prospective study we followed up 44 patients with sonographically diagnosed ascending thrombophlebitis into the deep veins (V. saphena magna n = 40, V. saphena parva n = 4). In 15 of 44 cases (34%) thrombosis of the crossing veins was found intraoperatively and 6 of 44 crossings were filled with floating thrombi into the deep vein lumina (14%). Among complications of treatment (11.4%) recurrence of thrombi in the ligated superficial residual vein stump was seen in 2 of 44 cases. One of these patients suffered a symptomatic, non-fulminant pulmonary embolism. The other patient developed a femoral vein thrombosis. 1 patient had an abscess and 1 a seroma of the groin. In 11% of all cases ascending thrombophlebitis diagnosed duplex sonographically was not effective in preventing propagation of thrombi into the deep veins thromboembolism remains a complication of ascending thrombophlebitis.
Collapse
|
131
|
Krause U, Kock HJ, Kröger K, Albrecht K, Rudofsky G. Prevention of deep venous thrombosis associated with superficial thrombophlebitis of the leg by early saphenous vein ligation. VASA 1998; 27:34-8. [PMID: 9540431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Thrombophlebitis of the superficial veins of the leg used to be regarded as a mild and uncomplicated disease, particularly in German speaking countries. PATIENTS AND METHODS In a retrospective clinical study from 6/91 until 12/96 we followed the progress of all patients (n = 398) with thrombophlebitis of the vena saphena magna or parva. Parameters of interest were: the incidence of concomitant deep vein thrombosis and subsequent pulmonary embolism. All patients underwent colour duplex scanning, most of them repeatedly. In cases of proven ascending superficial thrombosis, or involvement of the saphenofemoral junction, proximal saphenous vein ligation was performed (n = 56, 49 vena saphena magna and 7 vena saphena parva). Among these groups, there were 10 patients with malignant disease (18%), ten with a history of thrombosis (18%), another five comprised diabetes, recent major surgery and organ transplantation. RESULTS In 56 operations we found free-floating thrombi 6x (11%), 19x the sapheno-femoral junction was involved (33%), 24x the saphenous vein close to the junction (43%). Three patients develop deep vein thrombosis, despite surgery (0.75% of all and 5% of the operated cases). 2 patients suffered from (non-lethal) pulmonary embolism (0.5% and 3.5%, respectively). One embolism occurred before vein ligation. Perioperative morbidity amounted to 8.5% (superficial wound infection, hematoma). CONCLUSION Venous ligation is probably effective in reducing the rate of fatal pulmonary embolism.
Collapse
|
132
|
Kock HJ, Pietsch M, Krause U, Wilke H, Eigler FW. Implantable vascular access systems: experience in 1500 patients with totally implanted central venous port systems. World J Surg 1998; 22:12-6. [PMID: 9465755 DOI: 10.1007/s002689900342] [Citation(s) in RCA: 254] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Totally implantable venous access systems are widely used, but large-scale studies evaluating these systems are lacking. In this study 1500 patients (719 male, 781 female) with an average age of 49 years (15-86 years) were fitted with subcutaneously implanted venous access systems, in most cases for long-term chemotherapy. All patients were observed until removal of the system, death, or the end of treatment. A retrospective analysis showed an average catheter life of 284 patient-days. A total of 1308 (87%) of the patients had no implant-related complications. Catheter infections occurred in 3.2% of the patients and catheter thromboses in 2.5%. Rarer complications, such as catheter malfunction, migration of the catheter, skin necrosis, catheter fracture, catheter disconnection, and pneumothorax, occurred in another 4.3% of the patients. The complications led to explantation of 178 access systems (11.9%). There was a significant difference (p < 0.05) between the low rate of infections and other complications in the group of patients with solid tumors (2% and 4%, respectively) and the rate in patients with hematologic diseases (6% and 8%, respectively). This study confirms the safety and convenience of using totally implantable venous access systems in patients on long-term chemotherapy.
Collapse
|
133
|
Peitgen K, Schlensak M, Krause U, Hellinger A, Walz MK. [Experiences with a vent button system in endoscopic and surgical gastrostomy]. Zentralbl Chir 1997; 122:344-8. [PMID: 9334095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
INTRODUCTION In all variants of surgical or endoscopic gastrostomies, the abdominal wall is penetrated by a catheter. This reduces life-quality and often induces complications in gastrostomies. METHOD In a prospective trial, an anti-refluxive replacement button was applied as a catheter-substitute in 45 patients after conventional, laparoscopic and percutaneous-endoscopic gastrostomies. RESULTS In 1 of 45 patients the button was falsely inserted, only two patients experienced minor local infections of the stoma. No further major complications were noted. The average usage-time is 6.3 +/- 4.9 [1-17] months, the rate of complications in 100 days is 0.06. CONCLUSIONS The gastrostomy replacement button is safely applicable and improves clearly the comfort of gastrostomies with a low complication rate.
Collapse
|
134
|
Meier K, Krause U, Holtmann G, Eigler FW. [Upper gastrointestinal hemorrhage caused by necrotizing cholecystitis with gallstone perforation into the duodenum]. Chirurg 1997; 68:1035-6. [PMID: 9453897 DOI: 10.1007/s001040050317] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A 68-year-old woman suffering from severe upper gastrointestinal bleeding underwent an urgent laparotomy. A necrotizing cholecystitis was found. The source of the bleeding was the eroded cystic artery. Perforation of a giant gallstone led to a fistula into the duodenum. The gallstone was removed from the distal jejunum. The patient's postoperative course was uneventful. Later on a choledochal stenosis had to be treated by stenting. One year after the procedure the patient is alive and well.
Collapse
|
135
|
Pfeiffer T, Krause U, Thome U, Rajewski A, Skorzek M, Scheulen ME. Tissue toxicity of doxorubicin in first and second hyperthermic isolated limb perfusion--an experimental study in dogs. EUROPEAN JOURNAL OF SURGICAL ONCOLOGY 1997; 23:439-44. [PMID: 9393575 DOI: 10.1016/s0748-7983(97)93727-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The aim of this experimental study in dogs was to assess the tissue toxicity of doxorubicin (DOX) and the impact of dose and pharmacokinetics after double isolated limb perfusion (ILP). Fifteen beagle dogs were assigned to three groups of five animals each. In the first ILP 0.75 mg/kg bodyweight (bw) DOX was given to all animals. In the second perfusion after an interval of 6 to 8 weeks the dosage was 0.5 mg/kg bw in group I, 0.75 mg/kg bw in group II, and 1.0 mg/kg bw in group III. At the same dosage tissue toxicity increased in comparison to the first ILP. At the second ILP there was a dose-toxicity relationship. At a dose of 0.75 mg/kg bw pharmacokinetics of DOX in the perfusate showed no significant differences between first and second perfusion. The mean muscle tissue levels during the second ILP were lower than during the first perfusion. However, in contrast to the first perfusion, they showed a further increase after perfusate eluation. A disturbed microcirculation caused by intima proliferations in arteries and arterioles fter the first ILP may impair the removal of DOX from the intravasal and interstitial compartment and can be assumed as a reason for increased tissue toxicity. Therefore, we recommend a reduction of DOX dose in the second ILP for clinical use.
Collapse
|
136
|
Gimm O, Krause U, Wessel H, Finke R, Dralle H. Ectopic intrathyroidal thymus diagnosed as a solid thyroid lesion: case report and review of the literature. J Pediatr Surg 1997; 32:1241-3. [PMID: 9269979 DOI: 10.1016/s0022-3468(97)90691-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The authors report a case of a 6-year-old boy in whom aberrant thymic tissue was misdiagnosed as an intrathyroidal solid lesion. The patient underwent hemithyroidectomy and did well. Because cervical ectopic thymus rarely produces symptoms, the true incidence in children is unclear. Surgeons need to consider this rare entity, not to mistake it as a thyroid neoplasm, and not to perform extensive thyroid resection.
Collapse
|
137
|
Knelles D, Barthel T, Karrer A, Krause U, Eulert J, Kölbl O. PREVENTION OF HETEROTOPIC OSSIFICATION AFTER TOTAL HIP REPLACEMENT. ACTA ACUST UNITED AC 1997. [DOI: 10.1302/0301-620x.79b4.0790596] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We have carried out a prospective, randomised study of prophylaxis for heterotopic ossification (HO) comparing indomethacin for 7 and 14 days, acetylsalicylic acid, and fractional (4 × 3 Gy) or single exposure of 5 or 7 Gy irradiation after operation. We initially had 723 patients (733 hip replacements), but after withdrawals there were 685 hips of which 18.4% developed HO; 14% were grade I, 2.9% grade II and 1.5% grade III of the Brooker classification. We compared the results between these groups with those of a matched control series and found that indomethacin, 2 × 50 mg for 7 and 14 days, and postoperative irradiation of 4 × 3 Gy or 1 × 7 Gy, significantly reduced the development of HO compared with the control group. Patients in the acetylsalicylic acid group and those with a single irradiation of 5 Gy after operation developed significantly more ossification than those in the indomethacin and other irradiation groups. We suggest the use of 2 × 50 mg of indomethacin with mucoprotection for seven days as prophylaxis against HO after total hip replacement for all patients. A single irradiation of 7 Gy is recommended for patients who have developed HO after previous operations or to whom administration of indomethacin is contraindicated.
Collapse
|
138
|
Dimitriadis G, Parry-Billings M, Bevan S, Leighton B, Krause U, Piva T, Tegos K, Challiss RA, Wegener G, Newsholme EA. The effects of insulin on transport and metabolism of glucose in skeletal muscle from hyperthyroid and hypothyroid rats. Eur J Clin Invest 1997; 27:475-83. [PMID: 9229227 DOI: 10.1046/j.1365-2362.1997.1380688.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effects of insulin on the rates of glucose disposal were studied in soleus muscles isolated from hyper- or hypothyroid rats. Treatment with triiodothyronine for 5 or 10 days decreased the sensitivity of glycogen synthesis but increased the sensitivity of lactate formation to insulin. The sensitivity of 3-O methylglucose to insulin was increased only after 10 days of treatment and was accompanied by an increase in the sensitivity of 2-deoxyglucose phosphorylation; however, 2-deoxyglucose and glucose 6-phosphate in response to insulin remained unaltered. In hypothyroidism, insulin-stimulated rates of 3-O-methylglucose transport and 2-deoxyglucose phosphorylation were decreased; however, at basal levels of insulin, 3-O-methylglucose transport was increased, while 2-deoxyglucose phosphorylation was normal. In these muscles, the sensitivity of lactate formation to insulin was decreased; this defect was improved after incubation of the muscles with prostaglandin E2. The results suggest: (a) in hyperthyroidism, insulin-stimulated rates of glucose utilization in muscle to form lactate are increased mainly because of a decrease in glycogen synthesis; when hyperthyroidism progresses in severity, increases in the sensitivity of glucose transport to insulin and in the activity of hexokinase may also be involved; (b) in hypothyroidism, the decrease in insulin-stimulated rates of glucose utilization is caused by decreased rates of glycolysis; (c) prostaglandins may be involved in the changes in sensitivity of glucose utilization to insulin observed in muscle in altered thyroid states.
Collapse
|
139
|
Abstract
BACKGROUND Laparoscopic gastrostomy as an alternative to open gastrostomy was introduced with various technical variants 5 years ago. However, long-term results of these new methods are still lacking. METHODS From 4/1993 to 2/1996, laparoscopic gastrostomies were performed on 42 patients (50.9 +/- 15.6 [24-71] years) with esophageal stenosis in locally advanced hypopharyngeal (17 patients) or oropharyngeal (nine patients) carcinoma, incurable esophageal carcinoma (13 patients) and cerebral dyspagia (three patients). Operating time was 38 +/- 11 min [15-65 min]. Procedure-related mortality was 0%. Major complications occurred in 2/42 (4.7%) patients; minor complications were found in 4/42 (9.4%) patients. During a total usage time of 427 months, 14 stoma infections occurred (0.11 infections/100 days). CONCLUSION Laparoscopic gastrostomy allows a safe, fast, and cheap reestablishment of enteral nutrition. The procedure is minimally invasive and can also be performed under local anesthesia. It has become our method of choice in patients with malignant, nonresectable subtotal stenosis of the hypopharynx or esophagus.
Collapse
|
140
|
Eigler FW, Krause U. [Isolated hyperthermic extremity perfusion in soft tissue sarcoma]. Chirurg 1997; 68:649. [PMID: 9324449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
141
|
Dimitriadis G, Leighton B, Parry-Billings M, Sasson S, Young M, Krause U, Bevan S, Piva T, Wegener G, Newsholme EA. Effects of glucocorticoid excess on the sensitivity of glucose transport and metabolism to insulin in rat skeletal muscle. Biochem J 1997; 321 ( Pt 3):707-12. [PMID: 9032457 PMCID: PMC1218126 DOI: 10.1042/bj3210707] [Citation(s) in RCA: 179] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
GENBANK/dy examines the mechanisms of glucocorticoid-induced insulin resistance in rat soleus muscle. Glucocorticoid excess was induced by administration of dexamethasone to rats for 5 days. Dexamethasone decreased the sensitivity of 3-O-methylglucose transport, 2-deoxyglucose phosphorylation, glycogen synthesis and glucose oxidation to insulin. The total content of GLUT4 glucose transporters was not decreased by dexamethasone; however, the increase in these transporters in the plasma membrane in response to insulin (100 m-units/litre) was lessened. In contrast, the sensitivity of lactate formation to insulin was normal. The content of 2-deoxyglucose in the dexamethasone-treated muscle was decreased at 100 m-units/litre insulin, while the contents of glucose 6-phosphate and fructose 2,6-bisphosphate were normal at all concentrations of insulin studied. The maximal activity of hexokinase in the soleus muscle was not affected by dexamethasone; however, inhibition of this enzyme by glucose 6-phosphate was decreased. These results suggest the following. (1) Glucocorticoid excess causes insulin resistance in skeletal muscle by directly inhibiting the translocation of the GLUT4 glucose transporters to the plasma membrane in response to insulin; since the activity of hexokinase is not affected, the changes in the sensitivity of glucose phosphorylation to insulin seen under these conditions are secondary to those in glucose transport. (2) The sensitivity of glycogen synthesis and glucose oxidation to insulin is decreased, but that of glycolysis is not affected: a redistribution of glucose away from the pathway of glycogen synthesis and glucose oxidation could maintain a normal rate of lactate formation although the rate of glucose transport is decreased.
Collapse
|
142
|
Blommaart EF, Krause U, Schellens JP, Vreeling-Sindelárová H, Meijer AJ. The phosphatidylinositol 3-kinase inhibitors wortmannin and LY294002 inhibit autophagy in isolated rat hepatocytes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 243:240-6. [PMID: 9030745 DOI: 10.1111/j.1432-1033.1997.0240a.x] [Citation(s) in RCA: 669] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Recent studies indicate that phosphatidylinositol 3-kinase is essential in the regulation of many processes dependent on membrane flow. Autophagy is a complex pathway in which cell material, including proteins, can be degraded. Membrane flow plays a pivotal role in this process. To find out whether phosphatidylinositol 3-kinase is also required for autophagy, we tested the effects on autophagy of two structurally unrelated phosphatidylinositol 3-kinase inhibitors, wortmannin and 2-(4-morpholinyl)-8-phenylchromone (LY294002). The addition of low concentrations of each of these inhibitors to incubations of hepatocytes in the absence of amino acids resulted in a strong inhibition of proteolysis. The antiproteolytic effect of wortmannin (IC50 30 nM) and LY294002 (IC50 10 microM) was accompanied by inhibition of autophagic sequestration and not by an increase in lysosomal pH or a decrease in intracellular ATP. No further inhibition of proteolysis by the two compounds was observed when autophagy was already maximally inhibited by high concentrations of amino acids. 3-Methyladenine, which is commonly used as a specific inhibitor of autophagic sequestration, was an inhibitor of phosphatidylinositol 3-kinase, thus providing a target for its action. It is proposed that phosphatidylinositol 3-kinase activity is required for autophagy. 3-Methyladenine inhibits autophagy by inhibition of this enzyme.
Collapse
|
143
|
Thomsen H, Haeckel O, Krause U, Preetz W. Darstellung und spektroskopische Charakterisierung der Monofluorohydro-closo-Borate [B6H5F]2? und [B12H11F]2? Z Anorg Allg Chem 1996. [DOI: 10.1002/zaac.19966221211] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
144
|
Linnola RJ, Happonen RP, Andersson OH, Vedel E, Yli-Urpo AU, Krause U, Laatikainen L. Titanium and bioactive glass-ceramic coated titanium as materials for keratoprosthesis. Exp Eye Res 1996; 63:471-8. [PMID: 8944554 DOI: 10.1006/exer.1996.0137] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The current problem with keratoprosthesis is the ingrowth of corneal or conjunctival epithelium into the anterior chamber. This may lead to infections and extrusion of the prosthesis as well as to the development of retroprosthetic membrane and secondary glaucoma. Glass-ceramic coated and uncoated titanium has been tested as material for the keratoprosthesis to prevent epithelial ingrowth. Twenty-two Supra-Descemet's membrane keratoprostheses were inserted in the eyes of 22 rabbits for 1, 2, 4, 8, or 12 months. The prosthesis had an optic part made of polymethylmetacrylate (PMMA). The support for the optic part and the flange of the prosthesis were made of titanium. Eleven of the prostheses were coated with glass-ceramic. The histological sections of the enucleated eyes were prepared through the central part of the cornea and the prosthesis using a cutting-grinding method. The histological analysis was made on both halves of the implants separately giving two analysis areas in each eye. All 11 titanium prostheses were retained for the time period planned. Two glass-ceramic coated prostheses were lost at 2 and 4 weeks, respectively. This was caused by difficulties at surgery due to a thick coating. These eyes were excluded from the histological analysis. No significant ingrowth of epithelium was seen in 15/18 (83%) and in 16/22 (73%) of the analysed areas of the glass-ceramic coated and titanium prostheses, respectively. Titanium appears to be a suitable material for the keratoprosthesis. The ingrowth of the epithelium may be hindered further by coating the titanium with bioactive glass-ceramic.
Collapse
|
145
|
Krause U, Rider MH, Hue L. Protein kinase signaling pathway triggered by cell swelling and involved in the activation of glycogen synthase and acetyl-CoA carboxylase in isolated rat hepatocytes. J Biol Chem 1996; 271:16668-73. [PMID: 8663301 DOI: 10.1074/jbc.271.28.16668] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Incubation of isolated hepatocytes with glutamine or proline or in hypotonic media is known to activate glycogen synthase and acetyl-CoA carboxylase as a result of cell swelling. We report here that the same experimental conditions caused an activation of phosphatidylinositol 3-kinase and p70 ribosomal protein S6 kinase (p70 S6 kinase) but did not modify the activity of p42 mitogen-activated protein kinase. In addition, rapamycin, an inhibitor of p70 S6 kinase activation, prevented the amino acid- and hypotonicity-induced activation of p70 S6 kinase but did not block the activation of glycogen synthase and acetyl-CoA carboxylase, thus ruling out p70 S6 kinase as a necessary component in the activation pathway. By contrast, wortmannin or LY294002, inhibitors of phosphatidylinositol 3-kinase, completely blocked the activation of phosphatidylinositol 3-kinase and p70 S6 kinase and partly blocked the activation of glycogen synthase and acetyl-CoA carboxylase. Therefore, phosphatidylinositol 3-kinase might be a component of the signaling pathway that is triggered by cell swelling and is responsible, at least in part, for the activation of glycogen synthase and acetyl-CoA carboxylase. Incubation of hepatocytes with 0.1 microM epidermal growth factor doubled the activity of p42 mitogen-activated protein kinase without activating glycogen synthase.
Collapse
|
146
|
Wegener G, Krause U, Newsholme EA. Metabolic regulation--physiological and medical aspects. EXPERIENTIA 1996; 52:391-5. [PMID: 8641373 DOI: 10.1007/bf01919305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
|
147
|
Krause U, Wegener G. Control of adenine nucleotide metabolism and glycolysis in vertebrate skeletal muscle during exercise. EXPERIENTIA 1996; 52:396-403. [PMID: 8641374 DOI: 10.1007/bf01919306] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The turnover of adenosine triphosphate (ATP) in vertebrate skeletal muscle can increase more than a hundredfold during high-intensity exercise, while the content of ATP in muscle may remain virtually unchanged. This requires that the rates of ATP hydrolysis and ATP synthesis are exactly balanced despite large fluctuations in reaction rates. ATP is regenerated initially at the expense of phosphocreatine (PCr) and then mainly through glycolysis from muscle glycogen. The increased ATP turnover in contracting muscle will cause an increase in the contents of adenosine diphosphate (ADP), adenosine monophosphate (AMP) and inorganic phosphate (P(i)), metabolites that are substrates and activators of regulatory enzymes such as glycogen phosphorylase and phosphofructokinase. An intracellular metabolic feedback mechanism is thus activated by muscle contraction. How muscle metabolism is integrated in the intact body under physiological conditions is not fully understood. Common frogs are suitable experimental animals for the study of this problem because they can readily be induced to change from rest to high-intensity exercise, in the form of swimming. The changes in metabolites and effectors in gastrocnemius muscle were followed during exercise, post-exercise recovery and repeated exercise. The results suggest that glycolytic flux in muscle is modulated by signals from outside the muscle and that fructose 2,6-bisphosphate is a key signal in this process.
Collapse
|
148
|
Krause U, Thomson-Carter FM, Pennington TH. Molecular epidemiology of Escherichia coli O157:H7 by pulsed-field gel electrophoresis and comparison with that by bacteriophage typing. J Clin Microbiol 1996; 34:959-61. [PMID: 8815116 PMCID: PMC228925 DOI: 10.1128/jcm.34.4.959-961.1996] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
One hundred twenty-four Escherichia coli O157:H7 isolates were characterized by pulse-field gel electrophoresis, bacteriophage typing, and PCR of verotoxin genes. Diversity indices obtained--0.786 for phage types and 0.987 for pulsed-field gel electrophoresis types--demonstrated that phage typing falls below the critical value (0.9) required for confident interpretation of results.
Collapse
|
149
|
Krause U, Wegener G. Control of glycolysis in vertebrate skeletal muscle during exercise. THE AMERICAN JOURNAL OF PHYSIOLOGY 1996; 270:R821-9. [PMID: 8967412 DOI: 10.1152/ajpregu.1996.270.4.r821] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The gastrocnemius muscle of the frog (Rana temporaria) has a high capacity for anaerobic glycolysis from glycogen. Glycolytic metabolites and effectors of phosphofructokinase, particularly the hexose bisphosphates, were followed in muscle during exercise (swimming between 5 s and 5 min), recovery (rest for up to 2 h after 5 min of swimming), and repeated exercise (swimming for up to 60 s after 2 h of recovery). Glycogen phosphorylase and phosphofructokinase were swiftly activated with exercise. The hexose bisphosphates followed markedly different time courses. Fructose 1,6-bisphosphate was transiently increased in both exercise and repeated exercise. This appears to be an effect rather than a cause of phosphofructokinase activation. Glucose 1,6-biphosphate was accumulated only while phosphofructokinase was active and was unchanged at other times. Fructose 2,6-biphosphate showed a 10-fold transient increase on exercise in rested frogs, almost disappeared from the muscle during recovery, and did not change during repeated exercise. Fructose 2,6-biphosphate is a potent activator of phosphofructokinase in vitro under near physiological assay conditions, and it may serve this function also in vivo during exercise. Glucose 1,6-biphosphate could be an activator of phosphofructokinase in repeated exercise when fructose 2,6-biphosphate is not available.
Collapse
|
150
|
Krause U, Wegener G. Exercise and recovery in frog muscle: metabolism of PCr, adenine nucleotides, and related compounds. THE AMERICAN JOURNAL OF PHYSIOLOGY 1996; 270:R811-20. [PMID: 8967411 DOI: 10.1152/ajpregu.1996.270.4.r811] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The effects of exercise (swimming), fatigue, and recovery on the intracellular pH (pHi), energy-rich phosphates, and related metabolites were studied in the gastrocnemius muscle of common frogs (Rana temporaria) at 20 degrees C. Exercise caused a rapid decrease in the content of phosphocreatine (PCr) and a corresponding increase in that of Pi. The ATP level remained virtually constant for 1 min; its precipitous decrease during the following minute was associated with a rise in the contents of inosine 5'-monophosphate (IMP) and NH4+, indicating a marked activation of AMP deaminase. Five minutes of swimming caused severe fatigue, which was correlated with decreases in muscle PCr (-85%), ATP (-42%), and pHi (-0.8 units). Recovery appeared almost complete within 2 h, and the frogs were then induced to swim again. During the initial 10 s of this second exercise, ATP synthesis was as high as in the first exercise, but the rate decreased more rapidly between 10 and 60 s, thus indicating that repeated exercise caused increased metabolic stress. IMP formation in working muscle was not strictly correlated with the pHi or the tissue contents of Pi, AMP and ADP, although from studies in vitro AMP deaminase is known to be modulated by these parameters.
Collapse
|