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Biomedical subjects

W Grimm

Publications and source records attributed to W Grimm.

At least 127 records · Page 7Linked to original sources

Agonist- and mitogen-induced desensitization of isoproterenol-stimulated cyclic AMP formation in mouse epidermis in vivo.

Injection of the beta-adrenergic agonist isoproterenol causes a rapid desensitization of cyclic AMP formation to subsequent beta-adrenergic challenge in mouse epidermis. Long-lasting catecholamine refractoriness is also observed after prolonged treatment of mouse skin with certain mitogens such as the phorbol ester TPA (tumor promoter), 12-retinoylphorbol-acetate, the TPA-analogue C14:4phorbol acetate or the divalent cation ionophore A 23187 but not after mitogenic stimulation by phorbol-12,13-dibenzoate and 4-O-methyl-TPA or by means of chemical depilation, removal of the horny layer or skin massage. Thus no clear-cut correlation exists between the desensitizing efficacy of a given treatment and its ability to provoke epidermal hyperplasia and to promote skin tumor formation. Both, agonist- and mitogen-induced desensitization are dependent on protein synthesis in epidermis, the mitogen-induced effect is in addition dependent on RNA synthesis. The putative desensitizing protein is not cyclic AMP phosphodiesterase but could be a feedback inhibitor of receptor-cyclase interaction ("refractoriness protein") which has recently been proposed to be responsible for catecholamine tachyphylaxis in certain in vitro systems. In contrast to epidermal hyperproliferation mitogen-induced tachyphylaxis is not mediated by prostaglandin synthesis and is apparently also independent of initial cyclic AMP formation. It can be prevented, however, by the antimitotic synthetic corticoid fluocinolone acetonide but not by colchicine, vincristine cytochalasin B or adrenergic blockers.

Adenylyl Cyclases↗

[Treatment of pains from bone metastases with 90Y (author's transl)].

For palliation of pain caused by bone metastases beta radiation isotope therapy was successful. As shown in experimental work on animals bone uptake of 90Y with its shorter half-life is high when it is administered as a citrate complex. 90Y can be eluted with high purity from a 90Sr "cow". The retention in man was found by whole-body counting to be higher than 80%. In preliminary trials on 16 patients the analgetic effect was the same as that of 89Sr. The properties of 90Y therapy are discussed.

Bone Neoplasms↗

[Distribution in rats after intravenous injection of 88Y compounds (author's transl)].

88Y was given to rats in form of citrate, diphosphonate or chloride to determine its accumulation in various organs. The activity in the bones was high but not as high as that of calcium. The application of methylene-diphosphonate showed high enrichment in the liver because of intravital colloid formation. Elimination by the kidneys depends on the type of the 88Y compound applied.

Animals↗

[Thyroid function after mantle field radiation therapy (author's transl)].

48 patients with malignant lymphoma received a 60Co-radiation dose of 30 to 50 Gy using the mantle field technique. Thyroid function tests were performed 34 to 92 months after radiation therapy. One patient developed myxedema, ten (20.8%) had subclinical hypothyroidism and six (12.5%) latent hypothyroidism. The incidence of hypothyroidism after treatment of malignant lymphomas is summarized in a review of the literature. Discrepancies on the incidence of hypothyroidism were found, and their possible cause is discussed. Periodic examinations of all patients with thyroid radiation exposure are recommended. The examination can be limited to measurement of TSH concentration and palpation of the thyroid for nodules.

Adolescent↗

[Studies on the excretion of contrast media passing through the biliary system (author's transl)].

Opacification of the bile ducts was found to be optimal 30-60 minutes after drip infusion for 20-60 minutes. The radiographs were taken at times between 15 and 120 minutes after the infusion. Opacification was assessed subjectively by the radiologists and objectively by transmission densitometry. The concentration of the contrast material in the blood shows a multi-compartment system with a rapid component of 30 minutes and a slow component of 2-4 hours. The normal; normalization can be expected after about 3 months.

Bile Ducts↗

Best retinal focus for various fication distances in phakic and aphakic eyes.

When an eye focuses on a distant target, it is often found that the long wavelength rays are focused on the receptors, but when the same eye looks at a target close to the eye, the green or blue rays are in focus in the retinal receptors. The authors investigated this phenomenon by means of a laser optometer to find out whether the shift in focus represented an attempt to reduce accommodative effort, or was used to aid distance judgement, or was simply a by-product of the control mechanisms. Six phakic individuals showed a shift of 50 nm over an accommodation range of 2.75 D. The single aphakic observer preferred a retinal focus within a very narrow wavelength range. The authors favor the view that the wavelength shift is an inability of the accommodative control mechanism to make a precise response to a given stimulus.

Accommodation, Ocular↗

[Gastric mucosal blood flow after selective proximal vagotomy (author's transl)].

Gastric mucosal blood flow in dogs was estimated by radioactive labelled microspheres after SPV. The measurements were taken before and after gastric acid stimulation. The results show that under physiologic conditions a stimulation of gastric acid secretion is associated with an increased mucosal blood flow. After SPV, mucosal blood flow is increased, although it is known that gastric acid secretion is decreased. After histamine our results indicate a reversal of the effects of SPV into physiologic ranges. This observation is contrary to the generally accepted view that stimulation of acid secretion always is associated with an increase in gastric mucosal blood flow.

Animals↗

[Improvement of growth-hormone stimulation with l-dopa/l-carbidopa by simultaneous administration of propranolol (author's transl)].

The effect of simultaneous administration of 250 mg L-dopa + 25 mg L-carbidopa (Nacom) and 1 mg propranolol/kg body weight (maximal dose 40 mg propranolol) on growth-hormone secretion was tested in 96 children with growth retardation. The results were compared with those in a group of children that had been receiving only L-dopa and L-carbidopa. The additional administration of propranolol reduced the number of children unresponsive to adequate growth-hormone stimulation from 16% to 9.5%. There was no significant difference in mean maximal growth-hormone level between both groups, but the addition of propranolol caused a more long-lasting rise in serum growth hormone levels. Some of the children who previously had failed to have a satisfactory rise in growth-hormone level after L-dopa and L-carbidopa showed satisfactory stimulation when propranolol was added. Since only three blood samples need be taken (0, 45 and 90 minutes) and no significant side effects were noted, the combined treatment is suitable for out-patient use.

Carbidopa↗

[The influence of primidone on thyroid function (author's transl)].

The influence of primidone on thyroxine level, T3 index, FT4 index, triiodothyronine level, T3 (RIA)/T4 (RIA) quotient as well as on the TSH basal and stimulated values was investigated in 30 children on long-term treatment. The values obtained were compared statistically with those of a normal group. During primidone treatment a drop in T4 level and in FT4 index as well as an increase in T3 (RIA)/T4 (RIA) quotient was observed. On the other hand the triiodothyronine level and the T3 index were not influenced. The TSH basal and stimulated values were not statistically different from the control group. Thus the primidone-treated children are euthyroid according to the TRH test. Primidone probably stimulates hepatocellular thyroxine breakdown.

Child↗

Transient hypothyroidism associated with prematurity, sepsis, and respiratory distress.

Serial TSH and T4 determinations were performed in sixty neonates admitted to our hospital for neonatal intensive care within a period of three months. Seven patients (12%) showed transient hypothyroidism on the basis of low T4 and high TSH values. Only one of these patients, who had meconium aspiration and pneumonia, did not have the respiratory distress syndrome. In addition, 4 of these patients had sepsis. All of the patients were born before 37 gestational weeks and had birth weights under 2200 g. In addition, two patients of this gestational age and birth weight group had a progressive fall of T4 to extremely hypothyroid values without simultaneous elevation of TSH. Two of the 5 patients who died had histological studies of their thyroids. These revealed colloid-depleted vesicles, desquamated epithelium, and prominent vascularisation of the thyroid. The results of this study show that early recognition and therapy of transient hypothyroidism may be live saving.

Birth Weight↗

The effect of (6-D-(O-TERT-B)-Ser)-gonadoliberin-(1--9) nonapeptide-ethylamide on gonadotropin release in prepubertal boys.

(6-D-(o-tert-B)-Ser)-gonadoliberin-(1--9) nonapeptide-ethylamine, (HOE 766), a highly active LH-RH analogue, was studied with regard to its effects on the release of follicle stimulating hormone (FSH) and luteinizing hormone (LH) in 29 prepubertal boys given different doses (1 microgram, 2,5 microgram, 5 microgram or 7,5 microgram respectively). The effect of HOE 766 is dose dependent for FSH, but not for LH. There are important differences in the reaction of these young subjects from those of adults. Whereas LH levels barely rose, FSH secretion was superior to that seen in adults.

Child↗

Depressed prostaglandin release from peritoneal cells induced by a T cell adjuvant, lentinan.

PGE and PGF release from peritoneal exudate cells was studied in mice after injection with two beta (1-3) glucans, the antitumor active lentinan and the inactive pachyman, 4 days after injection of both polysaccharides, the spontaneous and phagocytosis-induced PGE and PGF release was markedly suppressed. However, only the immunopotentiator lentinan induced peritoneal exudate cells which exhibited a longer lasting diminished PG release. The data suggest that the T cell adjuvant lentinan may potentiate cellular immune responses by reducing synthesis of immune suppressive prostaglandins from peritoneal exudate cells.

Adjuvants, Immunologic↗