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S Benz

Publications and source records attributed to S Benz.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Successful catheter-guided local thrombolysis in acute pulmonary embolism in the early postoperative period after pancreatic head resection].

Pulmonary embolism in the early postoperative period is characterized by high morbidity and mortality. Systemic application of thrombolytic agents during this time is contraindicated; operative thrombectomy also has a high mortality rate. We report a case of successful local lysis in combination with catheter fragmentation of a massive two-sided pulmonary embolism diagnosed on the 4th postoperative day after pylorus-preserving duodenopancreatectomy for distal carcinoma of the common bile duct. Thrombolysis was performed in three sessions by a combination of catheter-supported interventional fragmentation of the thrombus with local rt-PA lysis. There were no bleeding complications or disturbances of anastomotic healing. The patient was discharged from the hospital on the 23rd postoperative day after changing anticoagulation to a vitamin K antagonist. The case presented demonstrates the possibility of local lysis in combination with interventional methods as a therapeutic option for pulmonary embolism in the early postoperative period as an alternative to surgical strategies.

Adenocarcinoma↗
PubMed2002

Quantification of the dopaminergic response in Parkinson's disease.

BACKGROUND: Various investigators have developed complex quantitative procedures for objective assessment of parkinsonian motor impairment, since drawbacks of rating scales are interrater variability, subjective impression, insensitivity to subtle modifications. OBJECTIVES: To determine whether standardized performance of inserting pegs (i) differentiates between parkinsonian subjects and healthy controls and (ii) reflects quantification of the dopaminergic response with rating scales within a levodopa challenge test design. SUBJECTS AND METHODS: We used an easy-to-operate Purdue Pegboard-like apparatus, which measures the total time taken to insert 25 pegs from a rack into a series of appropriate holes by a computer to 100 ms accuracy, and simultaneous rating with part III of the Unified Parkinson's Disease Rating Scale for assessment of motor impairment in 28 idiopathic parkinsonian patients before and during a levodopa challenge test. Additionally we compared data of the instrumental task to age- and sex-matched healthy controls. RESULTS: We found significant differences between parkinsonian subjects and controls and significant correlations to the rated severity of Parkinson's disease. Within-subject comparisons and correlation analysis demonstrated the ability of this tool to reflect scored motor improvement after intake of levodopa. CONCLUSION: Inserting pegs provides an objective quantitative estimation of changes in motor impairment within a typical levodopa challenge test design.

Adult↗
PubMed2002

Characterization of microcirculatory disturbance in a novel model of pancreatic ischemia-reperfusion using intravital fluorescence-microscopy.

INTRODUCTION: Microcirculatory disturbances caused by ischemia-reperfusion injury (IRI) are the crucial hallmarks of pancreatitis following pancreas transplantation. AIMS: To develop a novel rodent model of normothermic in situ ischemia of a pancreatic tail-segment that simulates the clinical situation of pancreas transplantation by flushing the organ via an inserted microcatheter and thus enables selective treatment of the organ via this access. METHODOLOGY: Four experimental groups were investigated (n = 7 Wistar rats/group): sham animals without ischemia and dissection of the pancreas; control animals with dissection of a pancreatic tail segment pedunculated on the splenic vessels and flushing od this segment with saline via a microcatheter; and two groups of animals treated like controls with a pancreatic ischemia time of 1 hour or 2 hours. With use of intravital epifluorescence microscopy, the microcirculatory damage was characterized by investigation of functional capillary density (FCD) and leukocyte adherence in postcapillary venules (LAV) before ischemia and during a reperfusion time of 2 hours. Dry:wet ratio determinations, light microscopy, and electron microscopic investigations were performed to characterize the histologic organ damage. RESULTS: FCD decreased significantly (p < 0.05) 2 hours after reperfusion in the groups of 1-hour (-29.21%) and 2-hour ischemia (-42.73%), in comparison with baseline values. LAV increased significantly (p < 0.05), 4.3- and 5.8-fold, after 1-hour and 2-hour ischemia during the observation time. The histologic damage was similar to posttransplantation pancreatitis in humans 1 hour after reperfusion. In sham and control animals these alterations were not significant. CONCLUSIONS: The rodent in situ model of pancreatic IRI showed standardized microcirculatory damage dependent on the ischemia time. Offering the possibility of selective treatment by the direct artery access to the ischemic pancreatic area, the model enables investigations of questions related to human pancreas transplantation.

Animals↗
PubMed2001

Impairment of microcirculation in the early reperfusion period predicts the degree of graft pancreatitis in clinical pancreas transplantation.

BACKGROUND: Graft pancreatitis is thought to be induced by ischemia/reperfusion. Animal experiments have suggested that an impaired microcirculation is crucial in this process. We have therefore studied the relevance of microcirculation in clinical pancreas transplantation. METHODS: In 17 patients undergoing pancreas transplantation, tissue pO2 was monitored continuously by an electrode implanted into the pancreatic tail. A catheter was inserted in the distal part of the splenic vein of the pancreas graft. After reperfusion blood samples were taken from this catheter and blood flow was measured by the venous outflow method. The degree of graft pancreatitis was assessed by peak-C-reactive protein (CRP) defined as highest CRP within 3 days after transplantation. RESULTS: Tissue pO2 increased within 5 min after reperfusion. Thereafter, in most patients a transient decrease was noted, indicating impairment of nutritive perfusion. During this period there was an increasing negative correlation between peak-CRP and tissue pO2 which was highly significant at 60 min after reperfusion (r=-0.70, P<0.002). Also donor age correlated significantly with peak-CRP (r=0.64, P<0.005) and to a somewhat lesser extend with tissue pO2 60 min after reperfusion (r= -0.55, P<0.03). CONCLUSION: These data show that the degree of organ damage in clinical pancreas transplantation is directly related to an impairment of microcirculation in the early reperfusion period. These data also support the idea that grafts from older donors have a higher probability to develop graft pancreatitis and that this might be due to an increased incidence of microcirculatory disturbances in these organs.

Adult↗
PubMed2001

Ischemia/reperfusion-induced pancreatitis in rats: a new model of complete normothermic in situ ischemia of a pancreatic tail-segment.

Ischemia/reperfusion injury plays an important role in the development of graft pancreatitis and thrombosis after pancreas transplantation. Up to now there are few therapeutic options for this severe complication because very little is known about pancreatic ischemia/reperfusion injury. The same pathomechanisms may also be involved in the induction and determination of the course of acute pancreatitis. We observed the effect of 2 h of warm in situ ischemia on the postischemic tissue oxygenation, histological organ damage, and pancreatic enzymes. Experiments were performed in 21 male Wistar rats. In sham-operated animals without ischemia, the pancreas was not dissected. In the ischemia/reperfusion group a pancreatic tail-segment was carefully separated from the head, and ischemia was induced by clamping the splenic vessels for 2 h, after flushing the pancreatic tail-segment with heparinized saline. Animals treated similarly, but with opening of the clamps some seconds after induction of ischemia, served as controls. The animals were observed for 2 h after reperfusion. Tissue oxygenation was monitored by a PO2-sensitive probe (LICOX, GMS, Kiel, Germany) which was implanted into the pancreatic tissue. Blood samples were taken before, 5 min, 60 min, and 120 min after reperfusion. At the end of the experiment the pancreatic tail was excised for histological examination; biopsies froin the non-ischemic pancreatic head served as intraindividual control to exclude side effects on the nonischemic pancreatic head. In the ischemia/reperfusion group, PO2ti was significantly lower 1 h (18.0+/-1.7 mmHg) and 2 h (16.4+/-1.6 mmHg) after reperfusion compared with baseline conditions (32.8+/-5.2 mmHg) and the control group (1 h 30.6+/-1.9 mmHg, 2 h 32.4+/-2.4 mmHg). Histological injury score and plasma lipase activity were significantly higher in the ischemia/reperfusion group compared with the control group. Thus we describe a new experimental model of complete normothermic in situ ischemia of a pancreatic tail-segment with the possibility of flushing the pancreatic tail-segment and selective local application of drugs to the pancreas.

Animals↗
PubMed2001

Delay of simple reaction time after levodopa intake.

BACKGROUND: Parkinsonian patients (PP) have deficits in the preparation and execution of movements. It is generally accepted that PP show delayed performance of simple reaction time (SRT) paradigms due to impaired response preprogramming. To date, no trial considered putative effects of dopaminergic substitution on SRT performance in PP. OBJECTIVES: To determine short-term effects of acute levodopa intake and impact of long-term dopaminergic substitution on the results of a SRT task. METHODS: We repeatedly performed a SRT paradigm in previously untreated- and treated PP, taken off medication for at least 12 h, before and after intake of levodopa/benserazide and in PP, who received placebo. RESULTS: Reaction time significantly increased and movement time did not change after levodopa intake. Placebo application showed no effects. CONCLUSIONS: Levodopa delayed cognitive processing and/or behaviour. Sedative effects of levodopa and/or dopamine overflow in prefrontal regions with subsequent cholinergic dysfunction hypothetically caused this phenomenon.

Adult↗
PubMed2001

[Distal pancreatic resection--indications, techniques and complications].

AIM: Description of the indications, surgical technique and postoperative complications of distal pancreatic resection. METHODS: We analyzed the prospectively documented perioperative data of 41 patients undergoing distal pancreatectomy between 1994 and 2001. Indications for resection were chronic pancreatitis (n = 21), malignant or benign tumors (n = 19) and others (n = 1). RESULTS: Median operation time was 4.5 hours, a Y-Roux-pancreaticojejunostomy was performed in 66 %. Further organs were resected in 93 %, most frequently in form of splenectomy. A malignant vascular invasion led to positive resection margins in three patients. Mortality was 2 %. Postoperative complications occurred in 41 % with 15 % revealing pancreatic leakage. A relaparotomy was carried out in 20 %. Pancreatic leakage was more frequently seen in the first part of the study period and after oversewing of the pancreatic stump. A new onset diabetes occurred postoperatively in 6 % of the patients. CONCLUSIONS: Distal pancreatectomy can be carried out with low mortality, despite a high complication rate. The probability of postoperative diabetes is low. The frequency of pancreatic leakage may be reduced significantly by increasing hospital experience. The management of the pancreatic stump by pancreatojejunostomy should be considered in patients with a high risk of pancreatic leakage.

Adenocarcinoma↗
PubMed2000

Choice reaction time after levodopa challenge in parkinsonian patients.

Various types of choice reaction time paradigms demonstrated deficits in the preparation and execution of movements in parkinsonian subjects. These studies showed controversial results, since they included parkinsonian individuals being: (i) previously untreated; (ii) off; or (iii) on anti-parkinsonian medication. Moreover, these trials do not take into consideration the acute effects of levodopa administration. Objective of this study was to determine the effect of long-term dopaminergic substitution therapy within a standardized levodopa challenge test in combination with a repeatedly performed choice reaction time task in parkinsonian individuals. Parkinsonian participants consisted of previously untreated, so-called "de-novo" patients and of individuals, who were chronically substituted with dopaminergic drugs, but were taken off medication for at least 12 h. All participants took 250 mg levodopa/benserazide after assessment of baseline data. Then we repeatedly measured choice reaction- and movement time within the next 90 min. No significant change of the assessed task data appeared in the "de-novo" group, but reaction- and movement time significantly shortened in previously treated subjects. Sedative effects of levodopa and/or dopaminergic overstimulation hypothetically explain the results of the previously untreated patients, whereas long-term dopaminergic substitution therapy hypothetically causes tolerance to these phenomena in treated parkinsonian individuals. Future studies on parkinsonian subjects should discuss their results on the basic pathophysiology or basal ganglia dysfunction in the light of a putative impact of long-term anti-parkinsonian drug therapy.

Adult↗
PubMed2000

Does glucagon stimulation predict oral glucose tolerance in patients after simultaneous pancreas-kidney transplantation?

BACKGROUND: Exogenous glucagon rapidly stimulates insulin secretion. This test has been used to estimate insulin secretory capacity, which may predict oral glucose tolerance in patients after pancreas transplantation. METHODS: In 32 pancreas-kidney transplant recipients, in 10 nondiabetic kidney transplant recipients, and in 9 healthy control subjects, a glucagon stimulation test (1 mg i.v.) and a 75-g oral glucose tolerance test were performed with determination of glucose, insulin, and C-peptide profiles. RESULTS: Of 16 pancreas transplant recipients with the lowest insulin responses after glucagon, 7 had an impaired oral glucose tolerance, in contrast to 1 of 16 with high insulin responses (P=0.037). A low insulin response after glucagon was associated with significantly lower 120-min glucose concentrations (P=0.043) and a lower integrated incremental insulin response after oral glucose (P=0.006). CONCLUSIONS: In pancreas-kidney transplant recipients, a low insulin response after intravenous glucagon predicts a reduced insulin response after oral glucose and an impaired oral glucose tolerance. This simple test may be helpful in the follow-up of pancreas transplant recipients.

Adult↗
PubMed1999

Identification of three cysteines as targets for the Zn2+ blockade of the human skeletal muscle chloride channel.

Currents through the human skeletal muscle chloride channel hClC-1 can be blocked by external application of 1 mM Zn2+ or the histidine-reactive compound diethyl pyrocarbonate (DEPC). The current block by Zn2+ strongly depends on the external pH (pKa near 6.9), whereas the block by DEPC is rather independent of the pH in the range of 5.5 to 8.5. To identify the target sites of these reagents, we constructed a total of twelve cysteine- and/or histidine-replacement mutants, transfected tsA201 cells with them, and investigated the resulting whole-cell chloride currents. The majority of the mutants exhibited a similar sensitivity toward Zn2+ or DEPC as wild type (WT) channels. Block by 1 mM Zn2+ was nearly absent only with the mutant C546A. Four mutants (C242A, C254A, H180A, and H451A) were slightly less sensitive to Zn2+ than WT. Tests with double, triple, and quadruple mutants yielded that, in addition to C546, C242 and C254 are also most likely participating in Zn2+-binding.

Cell Line↗
PubMed1999

Electrical myotonia in heterozygous carriers of recessive myotonia congenita.

We investigated electrophysiologically the unaffected parents of patients with recessive myotonia congenita. We studied 18 families, in nine of which the diagnosis was confirmed by molecular genetics. Brief myotonic discharges were present in at least one parent in 67% of the families. Fathers were more likely than mothers to show these discharges. The difficulty in distinguishing very mildly affected parents with dominant myotonia congenita from the heterozygous carriers of recessive myotonia congenita is stressed.

Action Potentials↗
PubMed1999

First clinical application of a newly developed device for intragastric surgery for the treatment of pancreatic pseudocysts.

BACKGROUND: Instruments that have been used during GI endoscopy have always been confined to the accessory channel of the endoscope. We have therefore developed a device that allows transabdominal manipulation in the stomach under gastroscopic control. Here we report the first clinical application of this device, which was used for the drainage of pancreatic pseudocysts. METHODS: The device is similar to a PEG tube and consists of a 7 mm polyethylene tube that is inserted by the "thread pull through" method. A trocar valve is mounted at the external tip of the tube. Four pseudocysts were treated in three patients. The retrogastric pseudocysts were punctured through the device under endoscopic (n = 2) and CT (n = 2) guidance. External drainage was used for 3 to 5 days; thereafter the drain was cut and internalized. The device was also cut and sealed. After 10 days it was removed as with a standard PEG tube. RESULTS: No complications related to the device occurred. In two patients the pseudocysts resolved completely. One patient had to undergo pseudocystojejunostomy for an infected pseudocyst containing large amounts of necrotic material. CONCLUSIONS: We believe that our new device is valuable to the further development of intragastric surgery and can be used to safely perform pseudocystogastrostomy.

Adult↗
PubMed1999

[Secondary diabetes in pancreatic carcinoma and after pancreatectomy: pathophysiology, therapeutic peculiarities and prognosis].

Diabetes and pancreatic cancer are known to be associated. The relative risk for pancreatic carcinoma is dependent on the time after onset of diabetes. Diabetes in patients with pancreatic carcinoma is frequently of recent onset and partially caused by the tumor. Diabetes in a patient without obesity, no family history and unusual requirement for aggressive management including a rapid start of insulin treatment, may be early symptoms of pancreatic cancer. Recognition of atypical diabetes as an early symptom of pancreatic cancer may lead to earlier diagnosis and improved survival in these patients. Pancreatic carcinoma and chronic pancreatitis with untractable, incapacitating pain are the main reasons for (partial) pancreas resection. Pancreas resection may lead to a deterioration of pancreatic endocrine function. In healthy humans, hemipancreatectomy leads to impaired glucose tolerance after oral stimulation in 25% of the patients. To reduce morbidity resulting from operation, several operation techniques have been developed. Postoperative glucose metabolism is primarily dependent on the degree of preexisting endocrine function and on the amount of pancreatic tissue being resected. Early surgical intervention may, on the other hand, prevent the progression of endocrine insufficiency in the course of chronic pancreatitis. Good results of resective procedures now allow earlier operation. Any operative technique should aim on stopping the inflammatory process while preserving as much pancreatic tissue as possible. The choice of operation to be performed is dependent of morphological changes and individual local complications of the patient.

Diabetes Mellitus, Type 1↗
PubMed1998

The nitric oxide donor sodium nitroprusside is protective in ischemia/reperfusion injury of the pancreas.

BACKGROUND: The role of nitric oxide in the ischemia/reperfusion injury of the pancreas is still unclear. In other organs, protective as well as aggravating effects have been described. We have, therefore, investigated the effect of the nitric oxide donor sodium nitroprusside on pancreatic ischemia/reperfusion injury. METHODS: In Landrace pigs, after transsection of the pancreas, complete vascular isolation of the pancreatic tail was performed. The tail was subjected to 3 hr of warm ischemia and thereafter reperfusion (6 hr). The animals were divided into a control group (n=7) and a treatment group (n=7) that received 15 mg of sodium nitroprusside after reperfusion intra-arterially into the splenic artery. RESULTS: The morphological tissue damage and lipase activity in the venous effluent of the pancreas were significantly lower in the treatment group. Partial oxygen tension in the tissue after reperfusion was markedly reduced in the control group, indicating an impairment of microcirculation. In the treatment group, however, partial oxygen tension in the tissue was significantly higher (43 vs. 20 mmHg; P<0.014). Furthermore, total blood flow through the pancreatic tail in the treatment group was found to be significantly higher in the late reperfusion period (14 vs. 9.5 ml/min at 5 hr after reperfusion; P<0.05). CONCLUSION: There is a marked impairment of pancreatic microcirculation after reperfusion. Sodium nitroprusside counteracts this impairment and has a protective effect on ischemia/reperfusion injury of the pancreas.

Adenosine Triphosphate↗
PubMed1998

The dominant chloride channel mutant G200R causing fluctuating myotonia: clinical findings, electrophysiology, and channel pathology.

Clinical, electrophysiological, and molecular findings are reported for a family with dominant myotonia congenita in which all affected members have experienced long-term fluctuations of the symptom of myotonia. In some patients myotonia is combined with myalgia. The myotonia-causing mutation in this family is in the gene encoding the muscular chloride channel, hCIC-1, predicting the amino acid exchange G200R. We have constructed recombinant DNA vectors for expression of the mutant protein in tsA201 cells and investigation of the properties of the mutant channel. The most prominent alteration was a +100-mV shift of the midpoint of the activation curve. Therefore, within the physiological range the open probability of the mutant channel is markedly smaller than in wild-type. This shift is likely to be responsible for the myotonia in the patients. The fluctuating symptoms of this chloride channelopathy are discussed with respect to short-term fluctuations of myotonia in the sodium channelopathy of potassium-aggravated myotonia.

Adolescent↗