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Biomedical subjects

P Klever

Publications and source records attributed to P Klever.

16 recordsLinked to original sources
PubMed2002

[Modification of human osteoblasts by various analgesics].

Analgesia plays a major role in the therapy of fractures. This raises the question whether frequently used analgetics as Tramadol and Diclofenac have negative effects on the healing of fractures. Human osteoblasts were isolated from human spongiosa and incubated with Diclofenac, Tramadol and without analgetic substance in an in vitro experiment. After 9 days the absolute number of cells as a marker for proliferation and their mitochondrial activity were quantified. The mitochondrial activity was measured using the metabolisation of XTT (sodium-3'-(1-[phenylamino-carbonyl]-3,4-tetrazolium)-bis(4- methoxy-6-nitro) benzene-sulfonic acid hydrate). Both drugs led to a concentration-dependent decrease of cell proliferation. Tramadol showed a significant effect at a concentration of 20 micrograms/ml, which is much higher than the therapeutical concentration of 0.25 microgram/ml in serum. Diclofenac decreased cell proliferation at a concentration of 6 micrograms/ml, having a therapeutical concentration of 1.5 micrograms/ml in serum. Vitality of cells had constant correlation to absolute number of cells (R = 0.95). Our results don't suggest any negative effects of Tramadol on the osteoblast activities in vitro. Diclofenac significantly decreased the proliferation of human osteoblasts at concentrations probably reachable in vivo. A prolonged healing of fractures under treatment with Diclofenac may be possible in critical situations (pseudarthrosis revision, callus distraction).

Cell Count↗
PubMed2002

[Heparin facilities proliferation of human osteoblasts in vitro].

It is a well-known fact that long-term application of heparin can lead to osteoporosis. To learn more about the mechanisms of heparin-induced osteoporosis, we exposed human osteoblasts in vitro to heparin in various concentrations. We found an increased proliferation rate, especially in concentrations used therapeutically in humans (0.1-0.2 IU/ml). In our experiments fetal calf serum (FCS) was able to heighten the positive effect of heparin, showing a synergism between heparin and FCS.

Cell Count↗
PubMed1997

Fluorine-18 fluorodeoxyglucose positron emission tomography in the differential diagnosis of pancreatic carcinoma: a report of 106 cases.

The aim of this study was to evaluate fluorine-18 fluorodeoxyglucose positron emission tomography ([18F]FDG PET) as a tool for the differential diagnosis of pancreatic carcinoma while taking into account serum glucose level. A group of 106 patients with unclear pancreatic masses were recruited for the study. PET was performed following intravenous administration of an average of 190 MBq [18F]FDG. Focally increased glucose utilisation was used as the criterion of malignancy. In addition, the "standardised uptake value" (SUV) was determined 45 min after injection. Carcinoma of the pancreas was demonstrated histologically in 74 cases, and chronic pancreatitis in 32 cases. Employing visual evaluation, 63 of the 74 (85%) pancreatic carcinomas were identified by PET. In 27 of the 32 cases (84%) of chronic pancreatitis it was possible to exclude malignancy. False-negative results (n=11) were obtained mostly in patients with raised serum glucose levels (10 out of 11), and false-positives (n=5) in patients with inflammatory processes of the pancreas. Thus PET showed an overall sensitivity of 85%, a specificity of 84%, a negative predictive value of 71%, and a positive predictive value of 93%. In a subgroup of patients with normal serum glucose levels (n=72), the results were 98%, 84%, 96% and 93%, respectively. Quantitative assessment yielded a mean SUV of 6.4+/-3.6 for pancreatic carcinoma as against a value of 3.6+/-1.7 for chronic pancreatitis (P<0.001), without increasing the diagnostic accuracy. This shows PET to be of value in assessing unclear pancreatic masses. The diagnostic accuracy of PET examinations is very dependent on serum glucose levels.

Adenocarcinoma↗
PubMed1997

[Role of sonography as primary diagnostic method in acute abdomen--a prospective study].

A prospective study of 584 consecutive patients presenting with acute abdominal pain was conducted to evaluate the role of ultrasonography as a first-line diagnostic tool for differentiating between surgical and nonsurgical diseases. The study reveals a high sensitivity and specificity for the diagnosis of diverticulitis, cholecystitis, and bowel obstruction. In acute appendicitis the method is highly specific, but the sensitivity is rather low. Taking into account the high rate of specific results, routine ultrasonography can be recommended as a screening method in patients suffering from acute abdominal pain.

Abdomen, Acute↗
PubMed1996

[Benefits and risk of resection of liver metastases in elderly patients].

Between 1986 und 1995 we performed 60 hepatic resections in 52 patients aged over 70 years for liver metastases of different primary tumours. The results were comparable regarding morbidity, mortality and long-term prognosis to the group of 176 patients under the age of 70 undergoing a total of 210 hepatic resections for metastases during the same time period. Thus liver resections for metastases can be performed with tolerable risks even in aged patients; postoperative mortality is independent of the patients' age and is due to the extent of resection; the survival rate is mainly influenced by radical resection.

Aged↗
PubMed1995

Intraoperative radiotherapy for pancreatic carcinoma.

Intraoperative radiotherapy (IORT) with an electron beam is a therapeutic modality employed predominantly in tumours with a high risk of local recurrence. In this department 35 patients with proven adenocarcinoma of the pancreas underwent surgery and IORT, while 41 patients underwent surgery only. Irradiated patients suffered more serious postoperative complications (21 per cent versus 7 per cent), spent more time in hospital (32 days versus 26 days) and did not show a survival advantage (median of 326 days versus 366 days for two patients with curative resection). Anastomotic breakdown (twp patients), abscess formation (two patients) and pancreatitis in the pancreatic remnant (one patient) occurred only in this group. It is concluded that IORT may increase the risk of postoperative complications. As, on the basis of experimental data, an additional serious long-term risk is to be expected, application of IORT should be limited to well controlled study conditions.

Aged↗
PubMed1995

[Injuries in horseback riding--incidence and causes].

This article presents the examination of 78 accidents in horseback riding, referring to their origin and kind of injury. It was found that 76% of all injuries did not occur during the active phase of riding, but in the time just before and right after it. Children without any experience in horseback riding were most susceptible to injuries. Referring to lesions occurring before and after the active phase, the longer extremity was predominantly involved (40%); furthermore, the skull was injured in 18% and the hand in 14% of all lesions. During the active phase of horseback riding, skull injuries increased to 34%. Thoracic and spinal lesions occurred in 15% each. The frequency of all lesions shows a reversed proportional dependence on the amount of experience in this sport. Severity of the accidents increases significantly with increasing demand on performance. In consideration of these studies the thesis can be advanced that coordinated prevention directly before and after the active riding phase can decrease the frequency of all accidents and especially the involvement of the lower extremity and the skull.

Adolescent↗
PubMed1995

[Intraoperative risks and early postoperative complications in surgery of chronic pancreatitis].

69 patients (1986-1991) who underwent conventional surgery for chronic pancreatitis (n = 42) or related pseudocysts (n = 27) were analyzed retrospectively. 17 patients underwent partial duodenopancreatectomy (pDPE), 13 pancreaticojejunostomy (PJ), 20 cystojejunostomy (CJ), 9 resection of the left pancreas and 10 other procedures. We evaluated especially time spent in hospital (pDPE:28,5d (mean), PJ:29d, CJ:22,3d, others:28,8d), duration of operation (pDPE:6h, PJ:4,6h, CJ:2,6h, others:2,6h), requirement for blood substitution (pDPE:3,2 units, PJ:3, CJ:0,8, others:1,9), postoperative surgical (pDPE:6%, PJ:15%, CJ:5%, others:29%) and nonsurgical (pDPE:0, PJ:0, CJ:15%, others:14%) complications, and operative mortality (0 in all groups). Conventional surgery for chronic pancreatitis and pseudocysts carries a very low mortality risk but may cause prolonged morbidity in a minority of cases.

Adult↗
PubMed1994

F-18 fluorodeoxyglucose PET in vivo evaluation of pancreatic glucose metabolism for detection of pancreatic cancer.

PURPOSE: To evaluate positron emission tomography (PET) with fluorine-18-labeled fluorodeoxyglucose (FDG) for detection of pancreatic cancer compared with computed tomography (CT) and ultrasonography (US). MATERIALS AND METHODS: Forty patients with suspected pancreatic cancer underwent static PET after intravenous injection of 150-300 MBq FDG. Focal FDG accumulation was regarded as a sign of malignancy and was quantitated by calculating differential uptake ratios (DURs) and tumor-liver ratios (TLRs). RESULTS: Malignancy was histologically proved in 27 patients. PET helped correctly classify 25 of 27 malignant conditions and 11 of 13 benign disorders. DUR and TLR were statistically significantly higher in malignant compared with benign disease (P < .01). False-negative findings were obtained in patients with insulin-dependent diabetes. False-positive findings were noted in a patient with retroperitoneal fibrosis and in one with pancreas divisum with chronic pancreatitis. PET was superior to CT and US in detection of lymph node metastases (13 of 17 vs three of 17 or one of 15, respectively. CONCLUSION: FDG PET has the potential to improve the detection of lymphadenopathy and the differential diagnosis of pancreatic masses.

Adenocarcinoma↗
PubMed1993

[Manganese dipyridoxal diphosphate as a new contrast medium in the MRT of benign and malignant pancreatic tumors: initial clinical findings].

MnDPDP is a new intracellular contrast medium of which 50% is excreted through the bile; its acceptability and effect on MR images was studied in 21 patients, 18 of whom had malignant and three benign tumours of the pancreas. Spin echo T1 images (SE-T1: TR = 500 ms; TE = 15 ms) showed a 20% increase in signal to noise ratio (S/N) (p = 0.059) and a 90% increase in contrast to noise ratio (C/N) (p = 0.0027). In gradient T1 images (GE-T1: TR = 100 ms; TE = 6 ms; flip angle = 70 degrees) there was an increase of S/N of 70% (p < 0.0001) and of the C/N of 200% (p < 0.0001). T2 weighted SE sequences were inferior to plain SE-T1 weighted sequences with regard to their S/N and C/N ratios. There were no significant clinical complications or biochemical changes in the blood or urine. A subjective side effect in three patients was a feeling of heat. MnDPDP is a well tolerated and effective contrast medium for MRT of pancreatic tumours.

Adenocarcinoma↗
PubMed1993

Pancreatic cancer detected by positron emission tomography with 18F-labelled deoxyglucose: method and first results.

In order to evaluate the utility of positron emission tomography (PET) with 18F-labelled deoxyglucose (FDG) for detection of pancreatic cancer 15 patients with pancreatic masses shown by computed tomography were investigated. Static PET scans covering an axial field of view of 15 cm were obtained 45 min after intravenous injection of 150-300 MBq FDG. Focally increased FDG accumulation was present in 12 out of 13 patients with histologically proven adenocarcinoma, in particular in eight of nine lymph node and four of five liver metastases. Scans of two patients with chronic pancreatitis confirmed by surgery revealed a normal FDG distribution. Contrast between tumour and normal tissue depended the metabolic situation prior to FDG injection. High ratios were found in fasting patients whereas no elevated FDG uptake was measured in an insulin-dependent diabetic suffering from carcinoma of the pancreatic head. We conclude that FDG PET might have the potential for detection and even differentiation of pancreatic carcinoma from chronic pancreatitis. Further studies are necessary to substantiate these preliminary findings and to optimize results in diabetic patients.

Adenocarcinoma↗
PubMed1993

Mn-DPDP in MR imaging of pancreatic adenocarcinoma: initial clinical experience.

Manganese (II) N,N'-dipyridoxylethylenediamine-N,N'-diacetate 5,5'-bis(phosphate) (DPDP) was tested as a contrast agent for magnetic resonance imaging of pancreatic adenocarcinoma in 15 patients. At enhanced T1-weighted spin-echo (SE) and enhanced T1-weighted gradient-echo (GRE) imaging, statistically significant increases in signal-to-noise ratio (S/N) for the pancreas (21% and 92%, respectively) and contrast-to-noise ratio (C/N) (91% and 209%, respectively) were found. The C/N at enhanced T1-weighted SE imaging was superior to that at unenhanced imaging, including T2-weighted SE imaging (P = .001). Subjective image analysis showed that delineation of the pancreas and pancreatic tumors was clearly improved (P = .05) on enhanced T1-weighted SE and GRE images compared with on unenhanced T1- and T2-weighted images. The liver enhanced 19% at T1-weighted SE imaging and 90% at T1-weighted GRE imaging. There was a significantly higher S/N increase in hepatic parenchyma than in pancreatic tissue at enhanced T1-weighted GRE imaging (P = .0026) but not at enhanced T1-weighted SE imaging.

Adenocarcinoma↗