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Biomedical subjects

K Kuhn

Publications and source records attributed to K Kuhn.

At least 19 recordsLinked to original sources
PubMed1996

Homeobox genes in the cnidarian Eleutheria dichotoma: evolutionary implications for the origin of Antennapedia-class (HOM/Hox) genes.

In order to test current hypotheses on the early evolution of Antp-class (HOM/Hox) genes in metazoan animals, we surveyed the diploblastic hydrozoan Eleutheria dichotoma for the presence of these genes. By means of PCR with different sets of degenerate primers, three new homeobox sequences were identified, in addition to two previously found fragments. Following RACE amplification of the 3' and 5' flanking regions, we classified all five genes, Cnox-1 to Cnox-5, as belonging to the Antp-class. Homeodomain identity to the most similar HOM/Hox genes from Drosophila and human ranges from 58 to 72%. Each of the Cnox genes contains diagnostic residues of more than one Antp-class family known from triploblastic animals. These data are at odds with a previously proposed ancestral HOM/Hox cluster composition, with respect to both the number and types of Antp-class homeobox genes found.

Amino Acid Sequence↗
PubMed1996

Gallstone recurrence after successful dissolution therapy.

After successful dissolution therapy of cholesterol gallbladder stones bile again becomes supersaturated and recurrent gallstones may develop. Three different postdissolution treatments [500 mg ursodeoxycholic acid (UDCA) per day (N = 14, group I), 100 mg aspirin per day (N = 14, group II) and diet (N = 15, group III) versus a control group (no treatment, N = 15, group IV) aimed at preventing recurrence of gallstones were investigated in a prospective, randomized study in 58 gallstone patients (33 female, 25 male) after complete stone clearance. Bile samples (prior to dissolution therapy and at stone recurrence) were investigated for biliary cholesterol (C), phospholipids (PL), total bile acid concentration (BA), cholesterol saturation index (CSI), total lipid concentration (TLC), total biliary protein concentration (TP), and nucleation time (NT). In group IV multiple gallstones tended to recur more often than solitary stones (66.7% vs 16.7%) whereas in groups I-III only solitary stones recurred. Recurrent gallbladder stones were detectable in 10 patients (eight patients in group IV and one each in groups I and II, respectively) within one year after dissolution and in two patients (one each in groups III and IV, respectively) after 15 months. Furthermore, the probability of stone recurrence was significantly higher in untreated patients as compared to treated patients. In nine (group IV) of 12 patients with recurrent stones NT, C, CSI, PL, BA, TLC, TP, and bile acid spectrum remained nearly unchanged as compared to their pretreatment values, whereas in three (groups I-III) of 12 cases a decrease in C, CSI, and TP was observed during therapy. However, in each of these three patients, initial and after-treatment TP was significantly higher and NT shorter as compared to groups I-IV. Furthermore, in these cases (N = 3) NT was prolonged, whereas no significant changes were found in PL, BA, TLC, and bile acid spectrum. Recurrence of gallstones, which seems to occur more likely in patients with multiple stones as compared to solitary stones, will happen in the early stage after stone clearance, again causing biliary pain. UDCA, aspirin or diet will reduce the probability for recurrent stones after complete gallstone dissolution.

Adult↗
PubMed1996

Phytohemagglutinin-dependent T-cell proliferation is not impaired by morphine.

Opioids have been reported in the literature to have immunosuppressive properties. Thus, we investigated the influence of morphine, morphine-3-glucuronide and morphine-6-glucuronide in vitro on phytohemagglutinin-stimulated proliferation of peripheral mononuclear cells from healthy humans. Furthermore, the effects of a 1-week treatment with morphine in a range of 30-240 mg/day on proliferation of lymphocytes from patients with chronic pain syndromes were evaluated. In addition, human peripheral mononuclear cell membranes were tested for specific opioid radioligand binding. The results show that i) morphine and its main metabolites do not influence mitogen-induced T-cell proliferation, ii) treatment of patients with sustained release morphine for 1 week did not impair the lymphocyte proliferative response, and iii) no specific binding of mu-, delta- and kappa-radioligands could be demonstrated to membranes of peripheral lymphocytes obtained from healthy humans. These results do not indicate an impairment of phytohemagglutinin-induced T-cell proliferation during pain treatment with sustained release morphine.

Analgesics, Opioid↗
PubMed1995

Electrogastrography in healthy subjects. Evaluation of normal values, influence of age and gender.

Electrogastrography (EGG) permits measurements of the gastric electrical activity. However, normal values of electrical activity are poorly defined. In addition, limited data are available on the effect of age and gender. Therefore, in 40 healthy subjects (age range: 19-90 years) normal values for several EGG parameters were assessed after an overnight fast for 1 hr in the fasting and fed state after ingestion of a standardized solid-liquid meal. The electrical signals were captured by a pair of surface electrodes sonographically placed on the skin overlying the gastric antrum. The dominant electrical frequency was predominantly in the defined normal frequency range between 2 and 4 cycles per minute (cpm) (P < 0.001) and was higher in the postprandial than in the preprandial period (3.1 cpm vs 2.8 cpm, P = 0.02). The instability of the electrical rhythm calculated by a dominant frequency instability coefficient (DFIC) was postprandially lower than in the fasting state (P = 0.04). The electrical power (amplitude) increased postprandially (postprandial to fasting power ratio = 2.4). To evaluate the influence of age and gender on normal values the subjects were divided into four groups (median age: male, 28 and 69 years; female, 25 and 67 years). The most parameters did not differ significantly between the groups. However, DFIC was different between the groups (P < 0.05), with elderly women revealing lowest DFIC. In conclusion, normal values for several EGG parameters evaluated in this study should be included in the analysis of gastric electrical activity. The magnitude of electrical frequency and power are not influenced by age and gender, whereas the instability of the electrical frequency is influenced by these factors.

Adult↗
PubMed1995

Diagnostic value of fine-needle puncture of the gallbladder: side effects, safety, and prognostic value.

Bile sampling without the risk of contamination by pancreatic and duodenal secretions and avoiding unpredictable influences of general anesthesia during biliary surgery on biliary analytics are feasible with percutaneous puncture of the gallbladder. In 207 patients with gallstones, gallbladder puncture was performed under local anesthesia with a 22-gauge spinal needle under continuous real-time ultrasound guidance. Bile samples were investigated for biliary lipids and nucleation time. Complete aspiration of gallbladder bile could be achieved in all patients without complications such as bleeding, bile leak, or inflammation. Of these patients, 11.6% reported mild abdominal problems, 3.4% required analgetics, and in 1.0% biliary colics were observed. Elective cholecystectomy was performed in 1 patient. Of the bile samples, 10.1% were contaminated with bactobilia. Biliary lipids, cholesterol saturation index (CSI), total lipid concentration (TLC), and bacteriological contamination were independent of gallstone number, whereas patients with solitary gallbladder stones exhibited a significantly longer nucleation time (NT) in comparison with those with multiple stones. In patients with gallstones, fine-needle puncture of the gallbladder represents an important diagnostic procedure and can be performed within minutes without major side effects if performed by an experienced sonographer.

Adult↗
PubMed1994

Natural hybridization in freshwater animals. Ecological implications and molecular approaches.

The number of cases where the phenomena of hybridization and gene introgression have been found in species interactions is steadily increasing, in both plant and animal taxa. During the last few years, many examples have been detected even in otherwise well-known freshwater animal taxa. We discuss the topic with respect to ecology and evolutionary processes and compare the main potentials and limitations of allozymes, mitochondrial DNA, and RAPD markers to address some important genetic issues of interspecific hybridization in natural populations of selected freshwater model systems.

Amphibians↗
PubMed1994

Specificity and generality of motivational components in depression: a personal projects analysis.

Features of depression, as measured by the Beck Depression Inventory (BDI), were distinguished from anxiety, as assessed by the Beck Anxiety Inventory (BAI), and were explored from a goals perspective using the Personal Projects Analysis methodology (B.R. Little, 1983). Depression and anxiety were found to reflect a "negative" appraisal pattern characterized by goals rated high in stress and difficulty, and low in structure, control, perceived skill, and positive outcome expectancy. Depression also revealed distinctive features not found in anxiety (e.g., goals that are perceived as being less visible to important others). A goal-based approach to research and diagnosis is presented, and implications for future research are discussed.

Adult↗
PubMed1994

An integrated knowledge-based system to guide the physician during structured reporting.

A routinely used system for report generation, based on direct physician data entry, has been combined with a knowledge-based module. The knowledge-based system is operating in the background, and guides the user by dynamically suggesting diagnoses and generating hints regarding the actual and possible further diagnostic procedures. Hybrid technology with neural networks and rules is used. A laboratory evaluation has shown good agreement between diagnoses suggested by the system and confirmed diagnoses, with a kappa coefficient of 0.85 and an area under the ROC curve of 0.92. In a survey following a 14-day test period, physicians stated that the system was both sensible and helpful. The current application domain is ultrasound reporting.

Artificial Intelligence↗
PubMed1994

An infrastructure for cooperation and communication in an advanced clinical information system.

In a research project, organizational and technological requirements for an advanced clinical information system have been analysed, and a concept has been developed. From the application's perspective, medical personnel is more actively relieved from routine tasks by support of organizational tasks and by coordination of distributed activities. Program development is supported by a concept of simple and complex services with well-defined interfaces, and by the use of activity templates, i.e. pre-modeled activities describing possible sequences of services. The concept is based on an open systems approach, with a reliable and secure communication infrastructure. In addition, monitoring facilities are provided.

Computer Communication Networks↗
PubMed1993

Structured data collection and knowledge-based user guidance for abdominal ultrasound reporting.

This paper describes a system for structured data collection and report generation in abdominal ultrasonography. The system is based on a controlled vocabulary and hierarchies of concepts; it uses a graphical user interface. More than 17,000 reports have been generated by 43 physicians using this system, which is integrated into a departmental information system. Evaluations have shown that it is a well accepted tool for the fast generation of reports of comparatively high quality. The functionality is enhanced by two additional components: a hybrid knowledge-based module for "intelligent" user guidance and an interactive tutoring system to illustrate the terminology.

Abdomen↗
PubMed1993

[Structured documentation of findings and user acceptance--results of a study of abdominal ultrasound].

Structured reporting of medical findings is known to have positive effects on data quality, whereas user acceptance tends to be low because of time requirements. This paper presents the results of a survey among 19 physicians who worked for 14 months with a computer system using structured data input for abdominal ultrasonography. During this time, they prepared 8.827 reports. The two most important results are that it is feasible to realize well accepted documentation systems with high data quality by using modern computer technology, and that graphic user interfaces tend to increase user acceptance. For comparable systems, evaluation studies are suggested.

Attitude of Health Personnel↗
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↗