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Biomedical subjects

W Kratzer

Publications and source records attributed to W Kratzer.

68 records · Page 4Linked to original sources
PubMed1990

[Comparison of ultrasound-controlled fine needle and coarse needle puncture of defined lesions in the abdomen].

Within a 2-year period 677 diagnostic fine needle (DFP) and coarse needle punctures (DGP) were performed in 536 patients. In 34 patients (14 women; 20 men; 54 +/- 17.6 years) the abdominal tumour mass was punctured with the fine needle (22 g) as well as with the coarse (18 g) needle. Sensitivity of DGP accounted for 72%, sensitivity of DFP was 82.6%. Specificity was 100%, respectively. Complications could not be observed, neither with the coarse needle nor with the fine needle. Due to the high sensitivity of DFP this method should be employed first in the diagnostic work up of abdominal tumours.

Abdominal Neoplasms↗
PubMed1990

[Non-enzymatic glycation of human serum albumin: influence on thebinding kinetics of the benzodiazepine binding sites].

Human serum albumin was non-enzymatically glycated in vitro and the glycation rate determined using an affinity chromatography method. The influence of glycation on the binding of the model ligand, dansylsarcosine, at the benzodiazepine binding site was determined with a stopped-flow method. Fluorescence time curves were recorded during the binding process. As the glycation rate increased, the association velocity constant, k2, decreased from 533.3 s-1 (glycated albumin 0.048 of total serum albumin) to 218.1 s-1 (glycated albumin 0.158 of total serum albumin). The affinity constant, KA, showed a corresponding decrease from 7.61 x 10(5) l/mol (fraction of glycated albumin 0.048) to 2.60 x 10(5) l/mol (fraction of glycated albumin 0.158). The dissociation velocity constant, however, increased from 17.3 s-1 (fraction of glycated albumin 0.048) to 19.8 s-1 (fraction of glycated albumin 0.158). The inhibition of binding probably occurs via an allosteric mechanism.

Benzodiazepines↗
PubMed1990

[Preventing the recurrence of common bile duct calculi following endoscopic papillotomy with ursodeoxycholic acid].

The effect of ursodeoxycholic acid on recurrence prevention of choledochal calculi after endoscopic sphincterotomy (EPT) was evaluated in 46 patients, whose bile duct stones had been removed endoscopically. 22 patients received 500 mg of ursodeoxycholic acid once a day, 24 patients received placebo. 1 recurrent stone could be detected in the ursodeoxycholic acid treated group 19 months after EPT, whereas 4 recurrent stones occurred in the placebo group about 16 months after EPT. Cholesterol saturation index decreased significantly by the ursodeoxycholic acid treatment 12 and 24 months after EPT (0.93 +/- 0.17 vs. 0.69 +/- 0.12 vs. 0.72 +/- 0.07). The nucleation time increased statistically significant from 9.0 days to 20.4 (12 months) and 17.7 (24 months) days, respectively. Obviously, pharmacological effects of ursodeoxycholic acid exist which modify important processes in the gallstone's pathogenesis.

Aged↗
PubMed1978

[Aseptic meningitis following fourth ventricle surgery (author's transl)].

Postoperative aseptic meningitis may occur as a complication of brain neurosurgery, especially after opening of the fourth ventricle. The picture of bacterial meningitis may be simulated. Main symptoms are persistent spiking fever, meningism and pleocytosis of CSF. The usually long lasting course can be dramatically shortened by early steroid therapy.

Astrocytoma↗
PubMed1975

Fanconi's anemia. I. Case histories, clinical and laboratory findings in six affected siblings.

This is a study of the largest family with Fanconi's anemia known in the world literature, namely of 6 affected siblings. All patients showed the typical features of the disease, including pancytopenia, skeletal and kidney deformities, hyperpigmentation of the skin, and physical as well as mental retardation. Four of the patients have died of their disease, the 2 patients who are still living at present have a deteriorating clinical course. Case histories, clinical and laboratory findings are reported here. In the second and third part of this study [48, 52] endocrinologic and genetic findings will be reported.

Abnormalities, Multiple↗
PubMedDate not supplied

Kinetics of drug binding to human serum albumin: allosteric and competitive inhibition at the benzodiazepine binding site by free fatty acids of various chain lengths.

The inhibition of dansylsarcosine (DS) binding at the benzodiazepine binding site of human serum albumin has been studied in the presence of saturated and unsaturated free fatty acids (FFA) of various chain lengths (C6-C20, C18:1, C18:2). In order to determine the mechanism of displacement, velocity constants for association (k2) and dissociation (k-2) and binding constants (KA and KA') have been measured using the stopped-flow method. The inhibitory effect of FFA on DS binding kinetics at site II is dependent of their structure. With increasing amounts of FFA the association velocity constant of DS binding decreases from 520 s-1 (fatty acid free albumin) by a factor of 3-10 and affinity decreases according to FFA chain length. Inhibition is strongest in the presence of caprylic, capric and lauric acid (C8-C12) i.e. with more than one mole FFA per mole albumin, DS association could no longer be measured. Short chain caproic and the long chain FFA C14-C20 showed only a less inhibitory effect since in the presence of a twofold excess k2 ranged between 100 and 200 s-1. Dissociation velocity of DS from the benzodiazepine binding site could be measured in relationship to FFA chain length using ibuprofene, another drug binding at site II. Dissociation velocity constants k-2 remained constant up to 2 moles FFA per mole albumin (k-2 = 16-18 s-1). A rise in k-2 to 70 s(-1) was seen, however, when 2-4 moles capric, lauric, myristic and palmitic (C10-C16) acid were bound, whereas no change was observed when increasing concentrations of caproic, caprylic, stearic and arachic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding, Competitive↗
PubMedDate not supplied

Comparison of contrast-enhanced power Doppler ultrasound (Levovist) and computed tomography in alveolar echinococcosis.

BACKGROUND: To date, no study has compared unenhanced and contrast-enhanced (Levovist) power Doppler ultrasound with three-phase helical computed tomography (CT) for the analysis of the vascularization of hepatic lesions in patients who have alveolar echinococcosis. METHODS: Fifteen patients (11 female and four male; average age, 45.8 years) with confirmed Echinococcus multilocularis infection underwent unenhanced and contrast-enhanced (Levovist) power Doppler ultrasound (2- to 5-MHz transducer head) and three-phase helical CT. The largest identified lesion in each patient was studied. RESULTS: CT visualized vascularization peripheral or central to the largest echinococcal lesions in 11 of 15 patients. Vascularization in the area of the echinococcal lesions was not visualized by unenhanced or contrast-enhanced power Doppler ultrasound in any of the 15 patients studied. CONCLUSION: Three-phase helical CT visualizes the vascularization associated with Echinococcus multilocularis lesions in the liver. Neither unenhanced nor contrast-enhanced ultrasound in power mode is suitable for this application.

Adult↗
PubMedDate not supplied

Alveolar liver echinococcosis: a comparative study of three imaging techniques.

BACKGROUND: We compared the imaging findings in patients with alveolar liver echinococcosis using ultrasound (US), computerized tomography (CT) and magnetic resonance imaging (MRI) in a prospective study. PATIENTS AND METHODS: 30 patients with alveolar echinococcosis (AE) were examined with the above imaging techniques. RESULTS: 30 lesions were detected with all three methods and most lesions (n = 55) were detected with CT. Calcifications were seen in 15 lesions with US, in 21 with CT and in 16 with MRI. MRI best detected necrotic areas and multivesicuLar structures. CONCLUSION: US is the screening method of choice and should primarily be complemented by CT due to its ability to detect the greatest number of lesions and clear demarcation of the characteristic calcifications. MRI may facilitate the diagnosis in uncertain cases with noncalcified or partially calcified lesions by showing the characteristic multivesicular structure, necrotic areas and proximity to vascular structures.

Adult↗
PubMedDate not supplied

Solitary versus multiple gallstones: the importance of total biliary protein concentration and other factors.

BACKGROUND: Nucleating and antinucleating factors play an important role in the pathogenesis of cholesterol crystal nucleation. PATIENTS AND METHODS: In 88 gallstone patients (59 female, 29 male) bile was examined for total biliary protein and glycoprotein concentration, nucleation time and cholesterol saturation index. Gallstone density was measured by in vivo computed tomography. RESULTS: Total biliary protein concentration was positively correlated with the number of gallstones (r = 0.84, p < 0.01) and higher in radiologically detectable isodense gallstones as compared to non-isodense stones (p < 0.01). A negative correlation between total biliary protein concentration, glycoprotein concentration and nucleation time was observed (r = -0.45, p < 0.01 and r = -0.49, p < 0.05). Nucleation time was significantly shorter in the case of multiple versus solitary stones (2.6 +/- 1.3 versus 8.5 +/- 3.0 days, p < 0.01). Cholesterol saturation index and biliary cholesterol concentration were similar in both cases, however a negative correlation between cholesterol saturation index and stone density (r = -0.79, p < 0.01) was found. No correlation was found between cholesterol saturation index and nucleation time (r = -0.04, p > 0.1), independent of gallstone number. None of the examined parameters was related to sex, age, weight or gallbladder function. CONCLUSIONS: Multiple gallbladder stones seem to be associated with shorter nucleation time and higher biliary concentrations of total protein and glycoprotein than solitary stones.

Bile↗
PubMedDate not supplied

Difficult bile duct stone recurrence after endoscopy and extracorporeal shockwave lithotripsy.

BACKGROUND/AIMS: In a prospective study, we investigated stone recurrence in high risk patients with difficult common bile duct stones treated with extracorporeal shockwave lithotripsy (ESWL) after futile endoscopic attempts at stone extraction with sphincterotomy. METHODOLOGY: Endoscopic stone extraction proved unsuccessful in 35 of 659 patients presenting with common bile duct stones (5.5%, 11 males and 24 females: mean age 71.0+/-10.0 yrs; BMI 25.8+/-3.9; ASA-Classification 2.63+/-0.65), due to large stone size (10 patients), incarcerated stones (15 patients), stones inaccessible to the Dormia basket (7 patients) or an impacted Dormia basket (3 patients). The stones were localized radiologically. ESWL was performed using the HM3 lithotripter (Dornier, Munich/FRG). RESULTS: Immediately following ESWL, 17.1% of the patients treated showed complete stone clearance. In an additional 57.1%, further endoscopic stone extraction was required to achieve complete stone clearance, while 20.0% were discharged with small residual stone fragments. The remaining 2 patients (5.7%) required surgical intervention. Thirty four of 35 patients (97.1%) were followed-up for an average of 27+/-11 months. Five patients (14.3%) experienced stone recurrence at an average of 13.8+/-5.7 months post ESWL. CONCLUSIONS: ESWL is a useful and safe adjunct to endoscopic management of difficult common bile duct stones in older, high-risk patients. The stone recurrence rate was about 14% after one year. All recurrent stones were treatable by endoscopy.

Aged↗