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Biomedical subjects

A Weber

Publications and source records attributed to A Weber.

At least 361 records · Page 20Linked to original sources
PubMed1991

[Sonographic versus radiological assessment of chronic outer ligament instability of the upper ankle joint].

Chronic instability of the lateral upper ankle joint ligament is usually diagnosed by clinical and radiological examination. For the evaluation of an ultrasound method of testing lateral instability of the ankle joint we carried out a prospective study. We examined 23 adults who were actively engaged in some form of sport (21 male, 2 female, mean age 32 years) and had a preexisting lateral instability of the ankle. The instability was measured in the standard planes using Scheuba's stress apparatus with simultaneous ultrasound monitoring. The ultrasound examination was performed by positioning the 5-MHz applicator on the lateral side of the Achilles tendon, thus defining a plane from which the instability could be measured in both examination planes by observing the deviation between dorsal inferior edge of the tibia and the dorsal border of the talar roll. For the two examination planes, Spearman's rank-correlation coefficient between the radiological and ultrasound methods was 0.83 and 0.92. The sensitivity of the ultrasound method was 0.90, and the specificity was 0.85. Our study showed a good correlation between the two methods. A pathological talar tilt according to radiological criteria was also revealed by ultrasonography. Thus, all the advantages of ultrasound are now available for the evaluation of chronic lateral instability of the ankle joint.

Adult↗
PubMed1991

Probenecid pharmacokinetics in cystic fibrosis.

Probenecid pharmacokinetics were studied in 5 cystic fibrosis (CF) subjects and 5 control subjects at oral dosages of 5, 15, and 30 mg/kg. Serum and urine samples were collected for 8 h after administration and assayed by reverse phase high performance liquid chromatography. Pharmacokinetic parameters were estimated by model-independent methods. All parameters were compared by 2-tailed analysis of variance with two major groupings: patient and dose. Both CF subjects and controls demonstrated dose-dependent kinetics, i.e., decreased elimination constant and decreased total body clearance with increasing dosage. The volume of distribution and time to peak were the only parameters that were not significantly dose dependent. At all dosages studied, we found no significant difference in total body clearance by CF subjects. Urinary recovery in an 8-hour period was not significantly different between CF subjects and controls nor was the percentage of dose recovered in the urine at each dosage level. Time to peak concentration varied widely between 0.5 and 4 h in both CF subjects and controls. We conclude, that CF patients have normal probenecid clearance, and that the standard dose for a CF patient is sufficient to attain a serum area under the curve equivalent to that of controls.

Administration, Oral↗
PubMed1991

Serum prolactin concentration and hypothalamic-pituitary hormone release in CF-children.

Some experimental data from animals suggest that prolactin (PROL) is involved in sweat production and modulates the chloride concentration of sweat. We determined the serum PROL level by RIA in 38 CF-patients (age: 3-24 years) and 48 patients with bronchial asthma (age: 2-18 years) and found no concentration differences between the two groups each taken as a whole; the TSH level was increased in CF (p less than 0.05). Separate analysis showed a significantly higher PROL level in CF-females and in CF-children (male and female) under 12 years old (p less than 0.05). To assess the hypothalamic-pituitary system we performed the metoclopramide test (by Cerucal) on 30 children suffering from CF (n = 10), bronchial asthma (n = 10) or pyelonephritis (n = 10) for PROL, LH, FSH, TSH and HGH. The hormone release was normal for all kinds checked in all groups of patients. Hence it follows that the neurohormonal system of prolactin is normal in CF-patients and the increased serum PROL and TSH concentrations in CF should be seen as a regulatory phenomenon but not as a mechanism associated with the basic defect of the CF-disease.

Adolescent↗
PubMed1991

Reversal of intrapulmonary shunting in cirrhosis after liver transplantation demonstrated by perfusion lung scan.

A young girl with biliary atresia leading to cirrhosis developed respiratory complications with hypoxemia. Intrapulmonary shunting was diagnosed with a 99mTc-MAA perfusion lung scan, which showed marked systemic activity. The shunting resolved after liver transplantation. The perfusion lung scan offers an efficient method to screen patients with cirrhosis in whom intrapulmonary shunts are suspected and to follow their progress.

Child↗
PubMed1990

Microring electrode/optical waveguide: electrochemical characterization and application to electrogenerated chemiluminescence.

A novel optoelectrochemical microprobe has been developed that allows the combination of optical and electrochemical methods in a very small system. The key element is a gold-coated optical fiber polished to a flat surface, such that the gold forms a microring electrode surrounding the optical fiber. The electrochemistry of the microring has been characterized; cyclic voltammetric and chronoamperometric limiting currents agree well with published theoretical treatments. The probe has also been used for electrogenerated chemiluminescence with tris(2,2'-bypyridine)ruthenium(II) with persulfate in 50:50 MeCN:H2O. Detection limits of 4.3 X 10(-8) M Ru(bpy)3(2+) have been obtained.

Electrochemistry↗
PubMed1990

[Pilot study of the practicability of a commercially-available Salmonella rapid test for the detection of the Salmonella content of cattle fecal samples].

100 faeces samples of cattle were investigated in comparison to a recent commercially available Salmonella Rapid Test (OXOID) and a cultural standard method (non-selective enrichment in buffered peptone water, selective enrichment in RAPPAPORT-VASSILIADIS-medium) for presence of Salmonella. The Salmonella Rapid Test showed in positive results an accuracy ("sensitivity") of 94.7% and in negative results an assurance ("specificity") of 97.5% and is therefore suitable for rapid detection (within 2 days) of faeces sample of cattle with Salmonella.

Animals↗
PubMed1990

Kinetics of the interaction of a 41-kilodalton macrophage capping protein with actin: promotion of nucleation during prolongation of the lag period.

A 41-kilodalton macrophage capping protein (MCP) has been isolated which is capable of forming complexes with actin monomers in addition to capping the barbed ends of actin filaments (Southwick & DiNubile, 1986). The protein is calcium activated in a fully reversible manner. Using kinetic assays, we determined a capping constant, defined here as a modified Kd, of 1 nM and a Kd of 3-4 microM for MCP-actin monomer complex formation. MCP weakly nucleates actin polymerization: more than 0.5 microM MCP is necessary to shorten the lag period, and 1 microM MCP at an actin/MCP ratio of 10 reduces the average length of actin filaments to about 200 molecules per filament. We determined that the actin nucleus that survives MCP inactivation contains a minimum number of five actin molecules. These experiments also make a point with respect to the interpretation of the prolongation of the lag period. We directly demonstrate that in the presence of an actin binding protein a prolongation of the lag period can be associated with increased nucleation, contrary to the usual interpretation in the literature that it indicates no or decreased nucleation by the actin binding protein.

Acrosome↗
PubMed1990

Construction and use of a template block for radial immunodiffusion.

Details for design and construction of template blocks for the increased sensitivity of radial immunodiffusion (RID) assays are described. The sensitivity of the template RID was 10-fold higher for quantifying albumin and 5-fold higher for IgG than the conventional RID with wells cut into the agarose. The system described in this communication resulted from the unit which provided the most consistent results from a variety of trials with different block thicknesses, chamber sizes and depths, and chamber arrangements.

Antigens↗
PubMed1990

Fluoronaphthyridines and quinolones as antibacterial agents. 2. Synthesis and structure-activity relationships of new 1-tert-butyl 7-substituted derivatives.

A number of 7-substituted-1-tert-butyl-6-fluoroquinolone-3-carboxylic acids and 7-substituted-1-tert-butyl-6-fluoro-1,8-naphthyridine-3-carboxylic acids have been prepared and tested for antibacterial activities. Among those the 7-aminopyrrolidinyl 20b and the 7-diazabicyclo naphthyridine 18b are the most potent compounds in vitro and in vivo. Physicochemical data and acute toxicity are also discussed. Compound 18b, BMY 40062, exhibits the most favorable overall properties, considering in vitro and in vivo microbiological activity, its low toxicity, and pharmacokinetic profile, and was selected for clinical evaluation.

4-Quinolones↗
PubMed1990

Pharmacokinetics of ticarcillin in patients with cystic fibrosis: a controlled prospective study.

We compared the pharmacokinetics of ticarcillin at a dose of 120 mg/kg in 11 patients with cystic fibrosis to 11 control subjects matched for age and sex. The mean elimination half-life of ticarcillin in serum was 70.8 minutes in the control subjects and 53.1 minutes in the patients with cystic fibrosis. The total body clearance of ticarcillin was significantly higher in cystic fibrosis patients (65.6 +/- 22.0 versus 46.2 +/- 10.9 ml/min/m2 in control subjects; p = 0.017). The nonrenal clearance of ticarcillin was also significantly higher in patients with cystic fibrosis (24.8 +/- 11.1 versus 13.3 +/- 6.0 ml/min/m2 for the control group; p = 0.006). There was no significant difference in volume of distribution between the two groups. We concluded that the shorter elimination half-life and the higher total body clearance of ticarcillin in patients with cystic fibrosis are a result of an increase in both renal and nonrenal elimination.

Adolescent↗
PubMed1990

[Microsurgery of the nasal cavity and paranasal sinuses].

Out of a total of 295 cases in which endonasal microsurgery of the nasal cavity and the paranasal sinuses was performed, 221 were submitted to a detailed analysis. Compared with transfacial sinus surgery, the rate of complications was significantly lower. Further advantages of the transnasal microsurgical technique are better functional results, considerably fewer complaints during the postoperative period, and a reduced duration of hospitalization.

Follow-Up Studies↗
PubMed1990

Effects of low-dose nifedipine on a cold provocation test in patients with Raynaud's disease.

The effects of 5 mg sublingual nifedipine on a standardized cold provocation test were compared with that of placebo in a double-blind, cross-over trial in 10 patients with Raynaud's disease. The percentage decrease of finger systolic pressure in the cooled finger (as compared with the contralateral control finger) was significantly lower at 10 degrees C (p less than 0.02) and 15 degrees C (p less than 0.05) after nifedipine than after placebo. These improved digital pressure values on cooling were associated with a decreased systolic blood pressure (SBP) from 131.2 (SD 10.8) to 126.2 (SD 10.1) mm Hg (p less than 0.001) and an increased heart rate (HR) from 65.5 (SD 16.1) to 69.6 (SD 16.7) beats/min (p less than 0.002) but without significant changes in diastolic blood pressure (DBP), digital blood flow (BF), or peripheral vascular resistance (PVR) in cutaneous vascular bed. Three patients experienced headache under nifedipine, but this side effect was disagreeable in only one case. These data suggest using low-dose nifedipine (5 mg sublingually) 15-30 min before predictable cold exposure and Raynaud's phenomenon. Such a procedure might be more effective and safer than chronic intake of higher doses of nifedipine, as currently recommended in Raynaud's attacks.

Adolescent↗
PubMed1990

Tuberous sclerosis: report of a case with fibromatosis of the facial soft tissues.

Tuberous Sclerosis (TS) is a dominantly inherited disorder which is characterised by a triad of mental deficiency, epilepsy and angiofibromas of the face. Sub- and periungual fibromas, shagreen patches usually found in the lumbosacral region and hypopigmented skin lesions are less often seen. Paraventricular calcifications, skeletal disorders and rarely, ophthalmic tumours are also described. Oral manifestations include whitish confluent nodules on the mucosa, enamel hypoplasia, mandibular cysts, and oral fibromas. A case of fibromatosis of the subcutaneous tissue overlying the angle of the mandible is described together with TS. To the best knowledge of the authors, this is the first such case reported in the literature.

Child, Preschool↗
PubMed1990

[Significance of sonography of the breast for surgical treatment of breast cancer].

In a prospective study of 119 patients with breast carcinoma the value of ultrasonography for surgical therapy was compared with the value of clinical results and mammography. The tumor localization (in 96.8%) and the exact preoperative staging following the pTNM-system (tumor size in 85.8%, lymph node involvement in 77.2%) were better predicted by ultrasonography than by mammography and clinical examination. Especially the multicentric-multifocal carcinomas (20 of 29 cases) were better detected. Preoperative ultrasonography especially improves planning a conservative management of breast cancer.

Breast Neoplasms↗
PubMed1990

[Disseminated candidiasis in a calf. Case report].

The pathological-anatomical and histological examinations of different organs from a calf that died at the age of 9 weeks indicated a disseminated candidiasis. Candida albicans was isolated from brain, lung, liver, spleen, kidney, intestinal lymph nodes and small intestinal contents. The antibiotics administered to the calf by the owner probably initiated the disseminated candidiasis.

Animals↗