Search PubMed⌕ Search

Biomedical subjects

C Zimmermann

Publications and source records attributed to C Zimmermann.

107 records · Page 6Linked to original sources
PubMed1985

[Visual evoked potentials: methodologic problems--variations of stimulus parameters].

The evaluation of visual potentials (VEP) evoked by pattern reversal includes the latency and amplitude of P100. An increase in the mean brightness or contrast of the checkerboard stimulus results in an increase in amplitude and a decrease in latency of P100. A square edge subtense of 20' in checkerboard pattern or a spatial frequency of 3-4 cyc/degrees in stripe pattern produce maximum responses. Transient VEPs are recorded at low repetition rates (less than 2 Hz), steady state VEPs at temporal frequencies above 8 Hz. In the latter condition the VEP takes the character of a sinusoidal train of waves which, compared to transient stimulation allows for a better measurement of VEP amplitude. The latency of P100 increases with the age of the subject. The influence of the different stimulus parameters and recording techniques must be known and have to be kept constant in order to record reliable and reproducible VEPs.

Adolescent↗
PubMed1982

[The part of Na+K+-ATPase in total energy consumption in slices of brain and kidney cortex as well as in reticulocytes: a damaging effect of ouabain on brain cells].

A progressive inhibition of the respiration of brain cortex slices by ouabain (0.2 mM) is not only caused by a specific inhibition of the Na+K+-ATPase, but is also due to damage of the cell membrane. It involves efflux and degradation of NADH or NAD. In contrast, the respiration of kidney cortex slices and reticulocytes exhibits only a rapid and constant inhibition by ouabain in concentrations of 0.2, 0.5 and 1.0 mM, respectively. Ouabain causes a decrease in O2-consumption of 12%, 45% and 23% in reticulocytes, slices of kidney cortex and brain cortex, respectively.

Animals↗
PubMed1981

[Coronary-left ventricular fistulae].

The authors report a case of fistulae between the right and left coronary arteries and the left ventricle. A 58 year old man was investigated for inaugural unstable angina without infarction. Coronary angiography showed multiple communications between the terminal branches of the septal arteries of the left anterior descending, the terminal segments of the left diagonal and the terminal portion of the right coronary artery and the apical region of the left ventricle. Angiography in the ascending aorta confirmed the diagnosis of coronary-left ventricular fistulae. The dilatation and rapid emptying of the entire coronary circulation were indirect signs of increased flow due to the shunt. There was no coronary alternation or stenosis. The rarity of coronaro-cardiac fistulae, especially involving both main coronary arteries and the left ventricle, is emphasised. The symptoms of angina are explained by the coronary "steal" syndrome : the diagnosis is angiographic; rare cases with high flow and a favourable anatomical set up may be managed surgically.

Coronary Vessel Anomalies↗
PubMed1975

N-desmethyldiazepam and amylobarbitone sodium as hypnotics in anxious patients. Plasma levels, clinical efficacy and residual effects.

Drug plasma levels of N-desmethyldiazepam (10 and 20 mg/day given at night) and amylobarbitone sodium (200 mg/day given at night) were determined in 45 patients after 1 and 7 days of treatment together with estimates of hypnotic and residual effects. No relationships were found between clinical rati ngs of hypnotic effect and drug plasma levels, while significant correlations were observed between some performance taska and drug plasma concentrations of amylobarbitone sodium, and of the higher dose of N-desmethyldiazepam.

Adult↗
PubMedDate not supplied

Overestimation of serum concentrations of gamma-aminobutyric acid in patients with hepatic encephalopathy by the gamma-aminobutyric acid-radioreceptor assay.

Sera of patients with hepatic encephalopathy strongly inhibit the specific binding of gamma-aminobutyric acid to synaptic membranes. In a previous study, this inhibition of specific gamma-aminobutyric acid binding was attributed to gamma-aminobutyric acid itself, and it was assumed that serum gamma-aminobutyric acid is increased 5- to 30-fold in patients with hepatic encephalopathy. The findings of that study, however, were not confirmed by other analytical methods. Therefore, the validity of the gamma-aminobutyric acid-radioreceptor assay was tested. In view of the increased serum concentrations of several amino acids in hepatic encephalopathy, the effects of L-alpha-amino acids on the assay were studied. Five amino acids inhibited specific gamma-aminobutyric acid binding at a concentration of 0.5 mM or lower: glutamine; glutamate; taurine; proline, and OH-proline. Equimolar amounts of aminooxyacetate prevented the inhibition of specific gamma-aminobutyric acid binding by glutamine and glutamate but had no effect on that of gamma-aminobutyric acid, taurine, proline and OH-proline. Aminooxyacetate had no effect on specific gamma-aminobutyric acid binding itself. The inhibitory activity of a serum sample from a patient with hepatic encephalopathy was inhibited by 0.5 mM aminooxyacetate. The gamma-aminobutyric acid binding inhibitory activity of a serum sample of a patient with hepatic encephalopathy was purified by gel chromatography and contained several amino acids at concentrations of about 0.1 mM, 3.5 mM glutamine but no detectable gamma-aminobutyric acid. Accordingly, the gamma-aminobutyric acid binding inhibitory activity is not mediated by gamma-aminobutyric acid alone and is most likely due to glutamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMedDate not supplied

Parental representations in drug-dependent patients and their parents.

The Parental Bonding Instrument (PBI), a measure of perceived parental care and protection, was administered to drug-dependent patients and their parents with the aim to assess the reliability of the instrument in such samples and to compare the parental representations across generations. Ninety drug-dependent patients and 44 mothers and 35 fathers participated. Reliability indices were calculated, and parental representations of parents and their offspring were compared. Linear regression analyses were performed with the patient's PBI score as the dependent variable and the mother's and father's PBI scores as predictor variables. The reliability indices were highly satisfactory and varied between 0.61 and 0.91. The parental bonding of patients, fathers, and mothers was similar. All three groups reported high maternal and paternal control and low maternal care, a pattern characteristic of an "affectionless control" rearing style. Maternal care received by the fathers and paternal protection received by the mothers predicted the care and protection they themselves gave to their drug-dependent offspring.

Adult↗
PubMedDate not supplied

NMR studies of water diffusion and relaxation in hydrating slag-based construction materials.

The NMR relaxation properties of hydrating blast-furnace slag cements have recently been shown to be dominated by the effect of water self-diffusion in internal magnetic field gradients in the pastes. While this was suggested on the basis of NMR relaxometry and magnetic susceptibility data, we report here the results from first direct studies of the water self-diffusion in the hydrating paste using a specialized PFG sequence and very intensive magnetic field gradient pulses.

Construction Materials↗
PubMedDate not supplied

[An instrument for evaluating th medical interview in general practice: VR-MICS/D (Verona-Medical Interview Classification System/Doctor)].

OBJECTIVE: To assess the reliability of the VR-MICS/D (Verona-Medical Interview Classification System/Doctor) and to identify the verbal behaviour by general practitioners in interviews conducted with primary care attenders with medical complaints and emotional distress. SETTING: Two general practices in South-Verona. SAMPLE: 100 primary care patients attending for a new illness episode with a GHQ-12 score > or = 3. The five participating GPs contributed each with 20 audiotaped interviews of 10 patients judged by GP as emotionally distressed and of 10 judged without emotional distress. MAIN OUTCOME MEASURES: The VR-MICS/D classifies GPs' verbal behaviour during the medical interview into 16 categories in terms of form (question or statement) and content and allows to assess their interview skills. PROCEDURE: Two raters classified 30 interviews (15 with patients judged by their GP as emotionally distressed and 15 with patients judged without emotional distress). Having established satisfactory reliability, the overall verbal performance, based on 100 interviews, was assessed and GPs' verbal behaviours with patients judged as emotionally distressed was compared with that adopted with patients judged without emotional distress. RESULTS: The reliability was satisfactory (Kappa 0.93). Percentage agreements for categories varied between 78.2% and 96.4%. The most frequent verbal behaviours were closed ended questions and information giving (58% of a total of 5522 classified verbal units). Interviews with patients judged as emotional distressed contained a greater number of psychological and psychosocial contents, facilitating comments and clarifications. These differences, however, were small, despite their statistical significance. CONCLUSIONS: The VR-MICS/D is a reliable measure for describing GPs' verbal behaviour during the interview with emotional distressed patients. The interview style of the GPs in this study was similar to that reported in the literature for GPs without formal training in communication skills and was characterised by a prevalently doctor-centred approach. This approach, particularly with emotional distressed patients, has severe limitations and underlines the necessity of the introduction of communication skills training.

Communication↗
PubMedDate not supplied

[The Verona Medical Interview Classification System/Patient (VR-MICS/P): the tool and its reliability].

OBJECTIVE: To assess the reliability and to describe the categories and the procedure to apply the VR-MICS/P (Verona-Medical Interview Classification System/Patient). SETTING: The interviews used for the reliability study were audiotaped. Five general practitioners (GPs) working in two general practices in South-Verona recorded their consultations. SAMPLE: 50 interviews selected randomly from 120, 10 for each GP. The selection criterion for the participating patients was a GHQ-12 score of 3 and the consultation for a new illness episode. MAIN OUTCOME MEASURES: The VR-MICS/P classifies patients' verbal behaviours into 21 categories, 15 of them are defined by form (cue or statement) and content. PROCEDURE: Two trained raters classified 50 interviews. Before applying the classification system each interview is divided into units which are numbered to define doctor's and patient's sequence of speech. RESULTS: The reliability of VR-MICS/P was satisfactory (Kappa 0.85). Similarity Index (Dice, 1945) for categories varied between 0.71 and 0.94. Reliability for form and content classification was satisfactory too (Similarity Index between 0.81 and 0.89 and between 0.84 and 0.94, respectively). CONCLUSIONS: The VR-MICS/P is a reliable measure for describing patients' verbal behaviours during medical interviews. It can be used together with the VR-MICS/D (Verona-Medical Interview Classification System/Doctor; Saltini et al., 1998) to describe the medical interview, the quality of doctor-patient interview and can be used as a measure of patient centredness.

Humans↗
PubMedDate not supplied

Elevated muscle tissue oxygen tension in short-term insulin-dependent diabetes mellitus.

In order to assess hemodynamic changes in early phases of insulin-dependent diabetes mellitus, muscle tissue oxygen tensions were determined in 7 newly diagnosed insulin-dependent diabetic patients and in 6 healthy control subjects matched for sex, age and weight. Muscle tissue oxygen tension was measured by polarrographic needle probes while breathing ambient air and oxygen enriched air with an oxygen concentration of 40 per cent as well. Three times during the experiment, heart rates, blood pressures, blood glucose concentrations, and capillary oxygen tensions were obtained. Heart rate, blood pressure, peripheral and autonomic nerve functions did not differ between the 2 groups studied. While breathing ambient air, muscle tissue oxygen tensions were significantly (p = 0.025) higher in the diabetic patients than in the control subjects. In contrast to the control subjects, diabetic patients did not increase muscle tissue oxygen tensions after inhalation of oxygen enriched air despite of an equal increase in capillary oxygen tensions (2p less than 0.05). Local tissue hypoxia does not seem to be a leading cause of hemodynamic abnormalities in the early phases of diabetes.

Adult↗