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Biomedical subjects

R Bauer

Publications and source records attributed to R Bauer.

At least 469 records · Page 26Linked to original sources
PubMed1982

A high probability of an orientation shift between layers 4 and 5 in central parts of the cat striate cortex.

On the postlateral gyrus of the cat striate cortex the cells' preferred orientation was measured as a function of cortical depth in penetrations as parallel as possible to the radial fibre bundles. According to the penetration angle and in agreement with the current model of orientation columns, there was a low orientation drift in layers 2-4. At the transition between layers 4 and 5 an orientation shift of 45-90 deg was found in most penetrations. The orientation differences between adjacent recording sites in lower layers was normally low too, but clearly higher than in upper layers. The results are discussed in terms of more independent orientation mechanisms in upper and lower layers.

Animals↗
PubMed1982

Tc-generators - yield of 99mTc and ratio to 'inactive' 99Tc.

A large amount of inactive 99Tc in some delicate labeling techniques may adversely affect the results obtained. Therefore, it is important to know the ratio Q(t) of inactive 99Tc to active 99mTc, which is dependent on the time (t) elapsed since the last elution. On the other hand, in optimizing the use of Tc-generators it is desirable to know the actual yield Y(t) at any time (t) after a preceding elution. It this paper, formulas both for Q(t) and for Y(t) are derived and numerical values are tabulated. In combination with a table of the amount of 99Mo left, M(t), all the properties of a Tc-generator and of its eluates may be derived and theoretical and practical results compared. This information will help in both optimizing the use of Tc-generators and improving quality control in radiopharmaceutical laboratories.

Molybdenum↗
PubMed1982

[Obliteration of the bulla of the guinea pig with a Kieler bone chip].

The obliteration of the sinus frontalis after removal of the chronically inflamed and irreversibly transformed mucous is a common surgical treatment. There is no definite answer to the question of the most suitable material for obliteration. The suitability of the Kieler Knochenspan was, therefore, tested in animal experiments. After trepanation and removal of the mucous of the bulla of 30 guinea pigs, the cave was filled up with Kieler Knochenspan. The animals were killed 2 weeks, 1, 2, 3, and 4 months after implantation. The implanted nonvital spongy substance of the Kieler Knochenspan was first enclosed in granulation tissue. Then, depending on the duration of implantation, this granulation tissue turns into bony substance first peripherically and then centrally. Immunologically conditioned reactions were never observed. Thus, the transformation of the Kieler Knochenspan in the pneumatic system of the guinea pig is the same as in human tubular bones. So the conclusion is drawn that Kieler Knochenspan might be used in the obliteration of the human frontal sinus.

Animals↗
PubMed1982

[Head and neck cancers. What's new in clinical oncology for the practicing ENT physician?].

An interdisciplinary evaluation is made of the most common forms of head and neck cancer, with emphasis on certain aspects.--In the field of x-ray diagnostics, computed tomography dominates varying importance being given to the individual organs. Nuclear medicine pays particular attention to skeletal scintigraphy and gallium scintigraphy. In radiation therapy, progress has been made especially through the use of optimal radiation planning as well as the use of the after-loading technique and neutron radiation. Antineoplastic chemotherapy is currently being used as palliative treatment, adjuvant chemotherapy and as the first step towards a curative therapy.

Antineoplastic Agents↗
PubMed1981

Magnification factor and receptive field size in foveal striate cortex of the monkey.

Receptive field size and magnification have been studied in striate cortex of awake, behaving rhesus monkeys at visual eccentricities in the range of 5-160 min. The major findings that emerge are (1) magnification in the foveola achieves values in the range of 30 mm/deg, (2) mean field size is not proportional to inverse magnification in contrast with previous reports, and (3) the product, magnification X aggregate field size, is greater in central vision than in peripheral vision. Thus, a point of light projected onto foveal retina is "seen" by larger numbers of striate cortical cells than a point of light projected onto peripheral retina. Implications of these findings for visual localization and two-point discrimination are discussed.

Animals↗
PubMed1981

Differential effects of l-amphetamine on ontogeny of active avoidance, intertrial responses, and locomotor activity.

Two experiments examined the effects of various doses of l-amphetamine on locomotor activity, two-way avoidance, and intertrial responses in rats that were 15, 17, 21, 36, and 90 days of age. In the first experiment, testing began 20 min after drug administration and 100 avoidance trials were given. In the second experiment, testing began immediately after drug treatment and 200 trials were given. In the two youngest groups, shuttle crossings during adaptation were increased by the highest doses. The typical inverted U-shaped function between amphetamine dose and locomotor activity found in adults began to emerge at 36 days of age. Generally, at the two youngest ages, there was a dose-related increase in avoidance and intertrial responses on the first few blocks of trials and then a decrease across trials. In 21-day rats, the drug increased avoidance on the first few trial blocks but acquisition was altered only slightly. Acquisition of 36- and 90-day rats was increased, but this increase was greater in adults. It appears likely that development of CNS catecholaminergic neurons is responsible for the age-dependent behavioral effects of l-amphetamine.

Adaptation, Physiological↗
PubMed1981

Clinical tolerability of ibopamine hydrochloride (SB 7505).

The clinical tolerance of ibopamine hydrochloride (Sb 7505) was investigated in 12 volunteers. The drug was administered on alternate days (2nd, 4th, 6th, 8th, 10th, 12th), starting at 100 mg and increasing by 50 mg each time to reach 350 mg on the 12th day. On the other days (1st, 3rd, 5th, 7th, 9th, 11th and 13th) a placebo was given. Diuresis increased progressively with the dose, reaching a maximum increase of 88% after the last dose, and showing a small residual effect on each subsequent placebo day. Body weight showed a marginal change and decreased by 2% in the last two days of treatment. Heart rate, systolic, diastolic and mean blood pressure showed only marginal fluctuations of about 7% around the mean values, which were of little statistical and of no clinical significance. Haematological and biochemical parameters were not affected. No side effect was noticed. The dose of 350 mg may probably be increased without leading to side effects.

Blood Pressure↗
PubMed1981

Renal effect of SB 7505: a double-blind study.

Two groups of 20 patients with no evidence of cardiovascular, hepatic, renal or gastrointestinal failure were treated orally for five days with placebo or SB 7505 100 mg/day. No change was observed in heart rate or blood pressure. Urine output, the excretion of Na, K and Cl, and creatinine clearance were significantly increased.

Aged↗
PubMed1981

Effectiveness of ibopamine in the management of ascitic liver cirrhosis--a controlled study v placebo and frusemide.

1 Thirty in-patients of both sexes suffering from ascitic liver cirrhosis were divided into three groups treated with (a) a placebo, (b) ibopamine (SB 7505, a new oral dopaminergic drug) and (c) frusemide, for 10 days. 2 Body weight decreased with both frusemide and ibopamine, diuresis and urinary excretion of Na+ and Cl- increased with both drugs; whereas urinary excretion of K+ increased only with frusemide. 3 An important difference between the frusemide and ibopamine treatment was encountered in creatinine clearance, which increased only with ibopamine, and in blood uric acid which increased only with frusemide. 4 The antidiuretic hormone (ADH) in the plasma of cirrhotic patients was lower than the sensitivity limit of the radioimmunoassay method, whereas in a group of healthy subjects it could be clearly measured. 5 The treatments did not affect systolic or diastolic blood pressure, heart rate, or a series of haematochemical parameters. 6 The increase in diuresis and creatinine clearance and the very good tolerability encountered with ibopamine highlight this new oral dopamine agonist as a useful drug in the management of liver cirrhosis.

Adult↗
PubMed1981

Trimethylmethoxyphenyl-retinoic acid (Ro 10-1670) inhibits mitogen-induced DNA-synthesis in peripheral blood lymphocytes in vitro.

Trimethylmethoxyphenyl-retinoic acid (TMMP-retinoic acid, Ro 10-1670) is the main metabolite of the aromatic retinoid Ro 10-9359 (Tigason, etretinate), which is now in clinical use. Therefore, we selected this metabolite for our in vitro studies on human lymphocytes. The following findings were obtained: TMMP-retinoic acid is practically insoluble in aqueous solution. It remains partly in solution only if bound to protein. Under these conditions it had no influence on DNA-synthesis of human peripheral blood lymphocytes added in vitro without lectins (5--12.5 ng/ml culture medium). However, if human peripheral blood lymphocytes were cultured in vitro with lectins (ConA, PHA-M, PHA-P and PWM) and in the presence of TMMP-retinoic acid (25 microgram/ml culture medium) no induction of DNA-synthesis was seen. The altered lymphocytic response in presence of TMMP-retinoid in vitro was clearly dose-dependent at these levels. Trypan blue exclusion tests showed no evidence of cytotoxicity. Our studies clearly indicate that TMMP-retinoic acid inhibits the biological response of human blood lymphocytes to lectins in vitro, at dosages close to therapeutic levels in vivo. They confirm that retinoids may exert distinct effects on dermal cells in addition to their influence on keratinocytes, and suggest that the therapeutic action of the drug may be also related to the altered lymphocytic response.

Acitretin↗
PubMed1981

An appraisal of methods of evaluating training in psychiatry.

A survey of American chief residents in psychiatric training centres was carried out to assess how these training programmes gathered feedback on teacher effectiveness and programme content. The chief resident in each programme was asked to report how his or her department elicited information from their residents about course and teacher quality. Responses from 184 training centres in the United States were obtained and accounted for 75% of the existing centres. Fifty questionnaires were returned with the survey results and were analysed. The seven factors of clinical teacher effectiveness previously described in the literature were used to evaluate these questionnaires. The majority lacked consistent coverage of the teaching factors with the percentages of questionnaires covering a specific behaviour as follows: teacher organization, 58%; instructor knowledge, 42%; group interactional skills, 42%; instructor enthusiasm, 30%; clinical supervision skills, 25%; display of professional characteristics, 19%; and clinical competence, 17%.

Behavior↗
PubMed1981

[Development of "mixed connective tissue disease" (MCTD) from discoid lupus erythematosus].

A patient with discoid lupus erythematosus is reported which turned into a mixed connective tissue disease (MCTD) within five months. THe patient developed a severe polysymptomatic clinical picture with frailty, myositis, generalized erythema and livedo racemosa features, but without renal involvement. Combined therapy with prednisolone and azathioprine led to rapid regression of all symptoms. After releasing from the hospital a mitigated relapse could be controlled by increasing the dose of cortico-steroids. No other relapse occurred during the following year. Since the onset of disease the indirect immunofluorescence showed antinuclear antibodies of the speckled pattern. Also we could mark antibodies against ENA. We regard this finding as an indication, that in patients with discoid lupus erythematosus and antinuclear antibodies of the speckled pattern the risk of progressing into MCTD had to be considered. Repeated controls for symptoms of other collagenoses, therefore, should follow for a period of two years.

Antibodies, Antinuclear↗