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Biomedical subjects

K Kuhn

Publications and source records attributed to K Kuhn.

At least 19 recordsLinked to original sources
PubMed1992

[The chemical composition of gallstones and their suitability for litholysis and lithotripsy].

The chemical composition of gallstones removed at surgery from 107 patients (81 women, 26 men; mean age 59 [18-85] years) was examined. In 64 women (79%) and 21 men (81%) microchemical analysis demonstrated concrements with a more than 50% cholesterol content (500 mg/g). Using as definition of cholesterol stones a 75% cholesterol content, only 35 women (43%) and 10 men (39%) would be classified as cholesterol stone carriers. Grossly visible layer formation was present in 18 stones; in eight stones calcium content was higher in the outer layer than in the core. There was no demonstrable relationship between gallstone composition and age.

Adolescent↗
PubMed1992

The relationship between serum lipids, nucleation time, and biliary lipids in patients with gallstones.

The relationship between biliary lipids, cholesterol saturation index, nucleation time, and serum lipids was studied in a group of 45 gallstone patients (10 male, 35 female; age 50.1 +/- 14.5 years). Bile was obtained by direct fine-needle puncture of the gallbladder under local anesthesia and sonographic monitoring. No significant correlation between the serum lipids and either the cholesterol saturation index or total biliary cholesterol levels was observed. We found a positive correlation between the nucleation time and serum triglycerides content (r = 0.45, p = 0.0018) and a negative correlation between nucleation time and biliary cholesterol level (r = -0.38, p = 0.009). The fatty acids derived from the triglycerides are primarily resynthesized to phospholipids in the liver. When the supply of free fatty acids exhausts the metabolic capacity of the liver as, for example, in fat-rich diets, triglycerides accumulate in the liver cells and may possibly by excreted in the bile. Free fatty acids stimulate mucin hypersecretion in the gallbladder. This mucosal hypersecretion has been assigned a significant role in the formation of gallbladder stones. We also found a positive correlation between the total biliary bile acids and serum high density lipoprotein (HDL)-cholesterol in patients with a rapid nucleation time (r = 0.50, p = 0.0128). This supports the findings of other researchers, which suggests that HDL-cholesterol is devoted primarily to bile acid synthesis. In patients with a short nucleation time, the cholesterol saturation index, total lipid concentration, biliary cholesterol, mean age, and biliary bile acids were statistically different in comparison with patients with a prolonged nucleation time.

Aged↗
PubMed1992

Hairless, a Drosophila gene involved in neural development, encodes a novel, serine rich protein.

Hairless is a dominant loss of function mutation in Drosophila affecting the formation of adult sensory organs. In the mutants, neuronal precursor cells do not differentiate, suggesting that Hairless might be involved in specifying or realizing neuronal fate in the fly, similar to the 'pro-neural' genes of the achaete-scute complex. As highlighted by the manifold phenotypic interactions of Hairless with most of the neurogenic loci, the gene might play an important role in nervous system development. Therefore, we initiated a molecular analysis of the Hairless locus in order to elucidate the function of its gene product and gain insight into the biochemical nature of the observed genetic interactions in which it participates. Here, we report the molecular cloning of the Hairless locus, confirmed by breakpoint and transformation analysis. Unexpectedly, Hairless activity peaks during embryogenesis, where transcripts accumulate primarily in endo- and mesodermal cell layers, and is lowest during larval stages, the lethal phase of Hairless mutants. The putative Hairless protein deduced from DNA sequencing is extremely basic and highly enriched in serine residues. Hairless appears to encode a novel protein without compelling homology to other known proteins which function in specifying peripheral nervous system development in Drosophila.

Amino Acid Sequence↗
PubMed1992

Lovastatin alters blood rheology in primary hyperlipoproteinemia: dependence on lipoprotein(a)?

As part of a randomized, single-blind, comparative study evaluating the efficacy of lovastatin and bezafibrate retard in the treatment of primary hypercholesterolemia, hemorheologic parameters (whole blood viscosity, hematocrit, plasma viscosity, red blood cell aggregation and deformability, and fibrinogen) were studied in 35 patients. Whole blood viscosity and plasma viscosity improved significantly after 3 months of treatment with lovastatin, whereas other hemorheologic variables remained unchanged. Stratifying 24 patients by their lipoprotein Lp(a) levels showed that in those with low Lp(a) (less than or equal to 25 mg/dL) high-density lipoprotein cholesterol increased and red blood cell aggregation as well as deformability decreased considerably, whereas in the group with high Lp(a) levels (greater than 25 mg/dL), the opposite behavior was observed. Treatment of primary hypercholesterolemia with lovastatin may not only reduce the risk for atherosclerotic complications by its pronounced decrease of low-density lipoprotein cholesterol, but also may favorably alter blood rheology, and may decrease insudation of plasmatic components into the arterial wall and improve tissue perfusion, in particular on the microcirculatory level. The possible relevance of Lp(a) levels for the hemorheologic effects of lovastatin remains to be elucidated.

Bezafibrate↗
PubMed1992

Increased gallbladder residual volume in nonresponders to extracorporeal shock wave lithotripsy of gallbladder stones.

In a prospective study of 63 patients, we purposed to determine whether gallbladder contractility or gallbladder volume before biliary lithotripsy are predictors of fragment disappearance. Percentage gallbladder contraction was calculated from the fractional difference in the sonographically measured gallbladder volume after a standard fatty meal. Statistical analysis showed no significant differences in gallbladder contractility between the fragment-free group and the residual-fragment group before (77.2 +/- 12.7% vs. 71.9 +/- 19.3%; p = 0.1044) biliary lithotripsy and after the termination of adjuvant cholelitholysis therapy (76.4 +/- 12.9% vs. 72.2 +/- 17.1%; p = 0.1341). Before treatment, there was no significant difference in fasting gallbladder volume in either group (29.9 +/- 15.4 ml vs. 36.6 +/- 18.8; p = 0.0682), but postprandial gallbladder volume was greater in nonresponders (10.4 +/- 9.4 ml vs. 6.5 +/- 3.8; p = 0.0164). After termination of the therapy, both the fasting gallbladder volume (41.2 +/- 24.2 ml vs. 29.8 +/- 10.3 ml; p = 0.0093) and the postprandial gallbladder volume (11.9 +/- 11.7 ml vs. 7.3 +/- 5.3 ml; p = 0.0267) were greater in the residual-fragment group. The increase of the fasting gallbladder volume in the residual-fragment group was statistically not significant. Our results indicate that the increased residual volume is a significant cause of therapeutic failure in nonresponders.

Chenodeoxycholic Acid↗
PubMed1992

[The value of ultrasound and computerized tomography in detection of cystic changes in chronic pancreatitis].

Intra- or extrapancreatic pseudocysts (PP) are the most common local complication in chronic pancreatitis. Aim of this study was to investigate frequency, localisation and size of pseudocysts in patients with chronic pancreatitis by means of ultrasound (US) and computed tomography (CT). 155 patients (females 35, males 120) with chronic pancreatitis, that underwent simultaneous (within two weeks) CT and US examinations, from January 1982 to June 1989, were included in this study. Cystic lesions were detected in 62% by CT, in 52% by US. Sensitivity in detection of cysts based on intraoperative findings (gold standard) was 98% for CT and 94% for US. 80% of the pseudocysts were smaller than 6 cm. 46% were in the range from 2 to 66 cm and 34% were smaller than 2 cm. The most common localisation was the pancreatic head region (50%), 20 of 102 patients with chronic pancreatitis were found to have a direct communication of a pseudocyst with the ductal system by ERP. No specific clinical or laboratory pattern were associated with the presence of pseudocysts. Increased pancreatic serum amylase concentration was detected in 29% of patients with and in 27% of patients without pseudocysts.

Adolescent↗
PubMed1992

Structured reporting of medical findings: evaluation of a system in gastroenterology.

A system using structured reporting of findings was developed for the preparation of medical reports and for clinical documentation purposes in upper abdominal sonography, and evaluated in the course of routine use. The evaluation focussed on the following parameters: completeness and correctness of the entered data, the proportion of free text, the validity and objectivity of the documentation, user acceptance, and time required. The completeness in the case of two clinically relevant parameters could be compared with an already existing database containing freely dictated reports. The results confirmed the hypothesis that, for the description of results of a technical examination, structured data reporting is a viable alternative to free-text dictation. For the application evaluated, there is even evidence of the superiority of a structured approach. The system can be put to use in related areas of application.

Attitude to Computers↗
PubMed1992

Increased incidence of gallstones and prior cholecystectomy in patients with large bowel cancer.

In a retrospective study, the frequency of occurrence of gallstones and cholecystectomy in 479 patients with colorectal cancer was compared with that of 483 matched control patients with other malignancies. The mean interval between cholecystectomy and colon cancer diagnosis was 15.1 +/- 9.9 yr (range 2-53 yr), and there was no statistically significant difference, compared with the control group at 13.9 +/- 8.2 yr (range 2-31 yr). In patients with colon cancer, the general increased relative risk of concomitant diagnosed gallstones (relative risk 1.73, p = 0.0123) and the relative risk of cholecystectomy (relative risk 2.08, p = 0.0074) was statistically significant. However, when the data with regard to sex were analyzed, significant differences were observed only in women. Women affected by right colon cancer also had a statistically significant higher incidence of previous cholecystectomy (relative risk 2.86, p = 0.0096), but no significantly higher incidence of concomitant gallstones. The general increased relative risk in patients with right colon cancer and decreased risk in patients with left colon cancer of concomitant gallstones and prior cholecystectomy was statistically significant. Our data provide evidence for the hypothesis that both gallstones and cholecystectomy increase the general risk of large bowel cancer. Therefore, they are also compatible with the possibility that common risk factors causes the association between gallstones and large bowel cancer.

Aged↗
PubMed1992

[Electronic documentation of findings, performance statistics and image analysis in endoscopy].

Endoscopic data processing in endoscopy departments can hardly be performed without electronic data management nowadays. Written report and endoscopic image storage have to be performed in parallel applying modern sophisticated electronic systems. Sufficient storage capacity has to be taken care for. In the near future image processing of electronically storage endoscopic images will become available.

Computer Systems↗
PubMed1991

[Gallstone treatment by electrohydraulic extracorporeal shockwave lithotripsy].

Extracorporeal shockwave lithotripsy (ESWL) with an electrohydraulic system was performed in 124 patients (33 men, 91 women; mean age 50.1 +/- 12.7 years). Sufficient stone fragmentation was achieved in 122 patients (98.3%). ESWL was repeated in 29 patients (23.3%), twice in 7 patients (5.6%). Average shockwave application per patient was 1,441 +/- 414 impulses, at a mean energy of 20.0 +/- 1.6 kV. Mean stone diameter before ESWL was 16.2 +/- 4.2 (7-30) mm, 7.1 +/- 4.1 (0-19) mm after ESWL. Computed tomography, performed immediately after ESWL in 88 patients demonstrated hypodense thickening (3-10 mm) of the gallbladder wall in 28.4% of patients. This was interpreted as wall oedema, reversible in all. One patient had a covered gallbladder rupture and two had biliary pancreatitis. None of the patients required emergency surgery. 93 patients (74.9%) had no stones 12 months later. A high success rate can be achieved if certain criteria are adhered to and suitable patients are selected.

Adult↗
PubMed1991

Vitamin B12 and folic acid deficiency in chronic pancreatitis: a relevant disorder?

Vitamin B12 malabsorption was reported earlier to occur in patients with exocrine pancreatic insufficiency, and pancreatic extracts were shown to improve the absorption of vitamin B12. We investigated serum levels of vitamin B12 and serum folate in patients with chronic pancreatitis and different degrees of pancreatic insufficiency. 137 patients (84 males, 53 females, age 34-72 years) with chronic pancreatitis (C.P.) were included in the study. 123 of 137 (89.8%) patients had a pathologic pancreatic function test result, classified into mild (n = 24), moderate (n = 61) or severe (n = 38) insufficiency. The normal range of serum vitamin B12 and folic acid was established in 58 healthy controls and was found to be 190-1020 pg/ml for serum vitamin B12 and 2.4-16.1 ng/ml for folic acid. 7 patients (5.7%) with C.P. had vitamin B12 serum levels below 190 pg/ml; 4 of these had severe and 3 had mild or moderate exocrine pancreatic insufficiency. However there was no overall correlation between the degree of pancreatic insufficiency and vitamin B12 values. Serum levels of Vitamin B12 were 512 +/- 48 pg/ml in mild, 493 +/- 52 pg/ml in moderate and 428 +/- 45 pg/ml in severe exocrine insufficiency. Serum folic acid below 2.4 ng/ml were present in 5 patients (3.6%). Folic acid serum levels were 8.34 +/- 0.76 ng/ml in mild, 6.34 +/- 0.52 ng/ml in moderate and 7.45 +/- 0.53 ng/ml in severe exocrine insufficiency. We conclude that vitamin B12 deficiency is a rare finding in chronic pancreatitis and does not strictly depend on the degree of exocrine pancreatic insufficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

The quality of gastroenterological reports based on free text dictation: an evaluation in endoscopy and ultrasonography.

The majority of physicians consider the use of free dictation for medical reports to be essential in many domains. One of the main criticisms of structured data entry is the possible lack of flexibility and completeness. Electronic documentation systems exist for endoscopy and ultrasonography examinations which are based on structured input as well as on free dictation. Endoscopy and ultrasonography reports based on free dictation were evaluated for omissive errors. The data evaluated was drawn from a database of 18,239 gastroscopy and 3,340 colonoscopy reports dictated by 28 physicians over 74 months, and 18,834 ultrasonography reports dictated by 37 physicians over 42 months. The error rates varied from 0% to 41.8% depending upon the particular feature and the particular examination, but were usually below 15%. The results were independent of the experience of the examiner. This study provides baseline measurements of omissive error rates for selected findings in gastrointestinal endoscopy and abdominal ultrasonography which can be used as standards for the development and evaluation of systems for collection of clinical data.

Database Management Systems↗
PubMed1991

Nucleation time, cholesterol saturation index, and biliary bile acid pattern. A comparison in responders and nonresponders to systemic litholysis with bile acids.

In a 24-month trial of a combination therapy with ursodeoxycholic acid and chenodeoxycholic acid complete dissolution of radiolucent gallstones was achieved in 15 of 55 patients (27.3%). A decrease of stone volume of greater than 35% was achieved in a further 28 patients (50.9%). In 12 patients (21.8%) inadequate compliance (3.6%), a nonfunctioning gallbladder (3.6%), absence of size decrease (10.9%), or acute cholecystitis (3.6%) required interruption of therapy. Determination of the cholesterol saturation index (CSI) did not facilitate patient selection, nor was there a statistically significant difference between responders and nonresponders to dissolution therapy. In the course of treatment the average CSI showed a statistically significant decrease from 1.54 +/- 0.12 to 0.82 +/- 0.06 (p less than 0.001). Patients in whom complete dissolution was achieved and those in whom no improvement was observed differed significantly in nucleation time (4.7 +/- 0.8 versus 15.0 +/- 2.2 days; p less than 0.001) and initial gallstone volume (274 +/- 78 versus 1045 +/- 180 mm3). The nucleation time increased statistically significantly during the therapy in the successfully treated group. The percentages of glycocholic acid (8.1 +/- 1.13 versus 4.1 +/- 0.55%; p less than 0.01), taurocholic acid (2.2 +/- 0.45 versus 0.8 +/- 0.23%; p less than 0.05), and glycodeoxycholic acid (4.9 +/- 0.70 versus 1.4 +/- 0.37%; p less than 0.001) were statistically significantly different after the treatment. There were no statistically significant differences between patients with complete and incomplete stone dissolution with regard to age, mean body weight, or laboratory variables.

Acute Disease↗
PubMed1991

Comparison of different HMG-CoA reductase inhibitors.

The HMG-CoA reductase inhibitors have been shown to cause marked reduction of cholesterol and offer a new and effective approach to treatment of hyperlipoproteinemia. Three agents, pravastatin (P), lovastatin (L) and simvastatin (S), have been studied with reference to long-term lipid-lowering effect, tolerance and clinical safety. Following a dietary lead-in period of at least 6 weeks in every case, patients with primary hypercholesterolemia were enrolled from participants of short-term controlled studies which after completion were extended as open studies. Treatment was administered over 6 months with 20 mg S (84 patients), L (42 patients) or P (23 patients) twice daily. Total cholesterol was decreased with S by 30.2% of basal, with L by 25.5%, and with P by 28.2%. The decrease in apolipoprotein B was 28.4%, of basal, with S 16.4% and in P 19.2%. Triglycerides were lowered by 19.6% of basal with S by 17.4%, with L, and by 6.4% with HDL-cholesterol increased in the S group by 23% of basal, by 9.7% in the L group, and by 8.0% in the P group. No serious clinical or laboratory abnormalities were observed. In the S group headache (3.6% of patients), abdominal discomfort (2.4%), sleeping disturbances (3.6%), and muscle pain (2.4%) were reported. In the L group headache (7.1%), abdominal discomfort (4.8%), sleep disorders (4.8%), and muscle pain (4.8%) were observed. In the P group one patient complained of abdominal discomfort (8.7%) and one of sleep disorders (8.7%). Increases in CPK were observed in the S group (4.8% of patients) and in the L group (11.9%).(ABSTRACT TRUNCATED AT 250 WORDS)

Anticholesteremic Agents↗
PubMed1991

[The intracavity radiotherapy of cervical carcinoma with flexible applicators following the vesicovaginal interposition of the uterus].

Advantages of new flexible intracervical applicators treating cervical cancer with high dose rate afterloading brachytherapy are reported: The insertion of the flexible applicator is usually possible without anesthesia and dilation of the cervix. Therefore the treatment can be performed on an outpatient basis. The risks of perforation and infection are minimal. Dosimetry and documentation of the applicator geometry are possible, if the planning system allows the definition of individual curves of an individual applicator. We now prefer flexible applicators instead of rigid steel applicators treating cervix carcinoma.

Brachytherapy↗
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

Comparison of gall bladder bile and endoscopically obtained duodenal bile.

In 10 patients with gall stone disease (eight women, two men; mean (SD) age 47.4 (13) years), bile was obtained by endoscopic aspiration after stimulation of the gall bladder with ceruletid and also by fine needle puncture of the gall bladder under local anaesthetic. The total lipid concentration of the puncture bile samples was mean (SD) 11.9 (4.7) g/dl, significantly higher than the endoscopic bile samples (3.9 (3.3) g/dl, p less than 0.001). Total bile acids, phospholipids, and biliary cholesterol (expressed in mol%) and cholesterol saturation index showed no significant differences between the two types of samples. The glycocholic acid concentration in the endoscopically obtained bile (27.7 (6.6) mol% v 23.3 (5.4) mol%; p less than 0.01) was significantly higher than the puncture bile samples. Puncture bile exhibited a significantly shorter nucleation time (3.5 (3.3) days v 19.6 (11.9) days; p less than 0.001). For determination of the nucleation time, endoscopic bile aspiration after gall bladder stimulation with ceruletid led to adequately concentrated samples in 50% of the study subjects. Cholesterol monohydrate crystal formation in native bile was observed in six samples of puncture bile and in three samples of the endoscopically obtained bile. The presence of cholesterol crystals and the determination of nucleation time in the puncture bile were the best discriminants between cholesterol and pigment gall stones and correlated well with computed tomogram analysis.

Adult↗