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Biomedical subjects

R Maurer

Publications and source records attributed to R Maurer.

At least 145 records · Page 8Linked to original sources
PubMed1984

Comparative in vitro/in vivo autoradiography using the opiate ligand 3H-(-)-bremazocine.

Autoradiograms of rat brain sections were compared obtained from animals receiving a tritiated drug through intravenous injection or from precut sections incubated in vitro. The benzomorphan analogue 3H-(-)-bremazocine was used as ligand and its distribution to all different opioid binding sites was followed. Although the general distribution of opioid binding sites visualized on 3H-LKB ultrofilms was independent of the methodological approach used, the maximal number of such sites (Bmax) was greater in brain sections incubated in vitro than after in vivo drug application. Since the number of binding sites is highly dependent on the particular incubation condition used, this finding has no further relevance.

Animals↗
PubMed1984

Autoradiographic localization of drug and neurotransmitter receptors: focus on the opiate receptor.

Receptors for drugs and neurotransmitter can be visualized at the light microscopic level by autoradiography after "in vitro" labelling of slide-mounted tissue sections. This methodology is illustrated by the localization of mu, delta and kappa opiate receptors in the rat, guinea-pig and human brains using the opiate ligand 3H-(--)-bremazocine. The differential anatomical localizations of these sites and their relationship with opiate effects is discussed.

Animals↗
PubMed1984

[Clinical aspects of sudden deafness].

Sudden deafness is a disease of multifactorial genesis. The cause remains as ever unknown. In addition to the vascular theory, the possibility of a perilymphatic fistula due to rupture of the oval or the round window membranes has gained more significance. Therefore the treatment of sudden deafness should begin as soon as possible. We treat such patients with infusions of Dextran 40. BVK and Complamin in increasing amounts, in addition to stella-ganglion block. It is not justifiable, for legal reasons to withhold treatment, and therapy should begin immediately.

Adult↗
PubMed1983

[Calcitonin-producing duodenal carcinoid in Recklinghausen's neurofibromatosis. Clinical case report and review of the literature].

In a 32-year-old woman presenting with fever, vomiting and right upper abdominal pain a tumor of the papilla of Vater was detected endoscopically and removed surgically. Histologically it was a carcinoid shown immunohistochemically to produce calcitonin. The tumor had metastasized to a lymph node in the hepatoduodenal ligament. Clinically the patient showed typical signs of von Recklinghausen neurofibromatosis. A survey of the literature suggests that carcinoid of the papilla of Vater may be more frequent in patients with neurofibromatosis. Possible relationships between neurofibromatosis and carcinoid are discussed in the light of the pertinent literature.

Adult↗
PubMed1983

[Non-Hodgkin lymphoma of the testis].

Non-Hodgkin's lymphomas of the testis comprise 25-50% of testicular tumors in men over 50 years of age. Using the Rappaport histologic terminology, most testicular lymphomas are of the diffuse histiocytic type. Concomitant involvement of Waldeyer's ring or of paranasal sinuses frequently occurs. Eight patients with primary non-Hodgkin's lymphoma of the testis and 2 patients with a lymphoma which arose in the paranasal sinuses and later involved the testis are reported. The median age of the 10 patients was 57 years. 5 of 8 patients with primary testicular lymphoma were in clinical stage IE. 8 of the 10 patients had diffuse histiocytic lymphoma. Using the Kiel histologic terminology, 4 of these 8 patients had diffuse centroblastic lymphoma and 4 had immunoblastic sarcoma. 5 of the 8 patients with primary testicular lymphoma had complete remission after orchiectomy followed by radio- and/or chemotherapy. The median survival of the 8 patients with primary testicular lymphoma was 30 months. The median survival of patients with complete remission was 44 months and in patients without remission 12 months. Careful staging of patients with testicular lymphoma is of decisive therapeutic and prognostic significance.

Humans↗
PubMed1983

Multiple opiate receptor in human brain: an autoradiographic investigation.

The pharmacologically defined kappa agonist 3H-(-)-bremazocine and the mu-agonists 3H-dihydromorphine and 3H-D-Ala2,MePhe4, Gly-ol5-enkephalin bind to unique sites in microtome sections of human brain tissue. Kappa binding sites were visualized by autoradiography under conditions where mu- and delta-sites were blocked by D-Ala2,MePhe4,Gly-ol5 and D-Ala2,D-Leu5-enkephalin. A heterogenous distribution of opiate binding sites was found with the neocortical and cerebellar cortices being very rich, brainstem generally poor and white matter very poor in opiate receptor sites. A clear difference in anatomical distribution of opiate binding types was observed. In the midbrain the ventral tegmental area was enriched in mu- and the substantia nigra in kappa-sites. The deep laminae of the neocortex were enriched in kappa-, whereas the molecular layer of the cerebellum contained predominantly mu-sites. Within the hippocampal formation the stratum lacunosum moleculare was enriched in kappa- and the dentate gyrus in delta-sites.

Aged↗
PubMed1983

Kappa opiate binding sites in the substantia nigra and bulbus olfactorius of the guinea pig as shown by in vitro autoradiography.

The purpose of the present study was to further map the distribution of the kappa subtype of opiate binding sites in the guinea pig brain. Cryostat sections of brain were incubated in 2 nM [3H] (-)-bremazocine with or without the addition of D-Ala2,MePhe4,Gly-ol5-enkephalin and/or D-Ala2,D-Leu5-enkephalin at 1 - 3000 nM. A sheet of [3H] Ultrofilm R (LKB) was exposed to the dry sections for up to 207 days. A computer coupled to a microdensitometer and a television camera was used to convert grey areas of the film to femtomoles of binding sites per mg protein. The substantia nigra and lamina plexiformis externa of the bulbus olfactorius remained densely labeled even in the presence of 3000 nM of both enkephalins. The guinea pig is the only species studied thus far which exhibits this distribution, but the physiological significance is not yet understood.

Animals↗
PubMed1983

[Angio-follicular lymph node hyperplasia (Castleman's lymphoma)].

Two patients with angio-follicular lymph node hyperplasia are described, and the literature is reviewed. In one symptom-free man, the chest x-ray showed a tumour of the upper mediastinum the size of a fist (which is known to have been present for 20 years), in another man there was a 4 cm. node in the right hilum, which was shown by computer tomography not to be due to vessels. In each case the tumour was removed. Histologically they proved to be a hyaline-vascular type of angio-follicular lymph node hyperplasia. This is probably an inflammatory-reactive process.

Adolescent↗
PubMed1983

Simultaneous differentiation of three opiate receptor subpopulations by computer modelling.

[3H]-(-)-bremazocine was displaced from guinea-pig brain membrane homogenates by three compounds having different specificity to opiate receptor subpopulations. A three site receptor model showed the best fit of the calculated to the measured value for the opiate mu (DAla2,MePhe4,Gly(ol)5-enkephalin) and the delta specific compound (DAla2,DLeu5-enkephalin). Computer modelling of data from displacement curves with the opiate kappa specific compound U-50.488H favored a two site receptor model.

Animals↗
PubMed1983

Selective distribution of beta- and alpha 1-adrenoceptors in rat lung visualized by autoradiography.

The distribution of beta- and alpha 1-adrenoceptors was studied in rat lung by autoradiography using two ligands: 125-Iodocyanopindolol for beta-adrenoceptors, and 125-Iodo-BE 2254 for alpha 1-adrenoceptors. Beta-adrenoceptors were widely distributed in the lung parenchyma and on the walls of the airways (bronchioles). The epithelium of the bronchioles showed a higher density of beta-adrenoceptors than the smooth muscle. The blood vessels (veins) seemed to have very few beta-adrenoceptors. Alpha 1-adrenoceptors were found in approximately ten fold smaller amounts than beta-adrenoceptors in the lung parenchyma and on the small veins. On the bronchioles, an extremely small number of alpha 1-adrenoceptors was visible.

Animals↗
PubMed1982

Autoradiographic localization of opiate kappa-receptors in the guinea-pig brain.

Opiate binding sites of the kappa-subtype were visualized in guinea-pig brain sections using in vitro autoradiography. kappa-Binding sites, defined as [3H](-)-bremazocine binding in the presence of high concentrations of [D-Ala2,MePhe4,Gly-ol5]enkephalin and [D-Ala2,D-Leu5]enkephalin, were found in the cortical laminae V and VI, hippocampal dentate gyrus, and lateral habenulae. The distribution of kappa-sites in the guinea-pig differs considerably from the distribution of mu- and delta-sites which others have found in the rat.

Animals↗
PubMed1982

Multiplicity of opiate receptors in different species.

Three populations of opiate binding sites (mu, delta and kappa) could be distinguished by displacement studies with the mu-agonist (D)-Ala2-MePhe4-Glyol5-enkephalin and the kappa-agonist [3H](-)-bremazocine in brain membranes of different species. Whereas brain membranes from pig or guinea-pig and human cortical membranes had a proportion of approximately 35-50% kappa-, 29-40% mu-, and 21-30% delta-binding sites, rat membranes contained much less kappa-sites (12% kappa, 62% mu and 25% delta).

Aged↗
PubMed1982

[Idiopathic splenomegaly: the preliminary stage of a malignant lymphoma? Report on 2 cases].

Two patients with splenomegaly and a mild degree of hypersplenism are presented. Both underwent diagnostic splenectomy and in both the histologic examination of the spleen disclosed follicular lymphoid hyperplasia. The clinical picture and histologic findings were compatible with the diagnosis of idiopathic splenomegaly. 33 months after splenectomy a non-Hodgkin lymphoma was diagnosed in one patient. The literature on idiopathic splenomegaly is reviewed and the high incidence of non-Hodgkin lymphoma in the follow-up of such patients is pointed out.

Adult↗
PubMed1982

[The neuroendocrine Merkel cell carcinoma of the skin].

Seven primary skin tumors from 5 women and 2 men were analyzed by light and electron microscopy and immunocytochemistry. The tumors were localized on the face (3 tumors) and on the extremities. The maximum diameter was between 1 and 3.5 cm. Two tumors metastasized to the regional lymph nodes 4 months after excision of the primary, 1 tumor metastasize to the regional lymph nodes after 5 years and the patient died of multiple metastases 8 years after excision of the primary on the forearm. No local recurrences developed. The tumors occurred in the dermis with frequent infiltration of the subcutaneous tissue. The epidermis was intact. The tumor cells formed large solid clusters, while their cytoplasm was faintly basophilic and formed a small rim round the large pale nucleus. In electron microscopy many cells displayed cytoplasmic electron-dense secretory granules with a mean diameter of approx. 100 nm. Immunocytochemistry showed that a large number of cells in all tumors contained neuron specific enolase and many cells of 4 tumors yielded formaldehyde-induced fluorescence. The tumors are therefore of neuroendocrine origin and may derive from merkel cells. They frequently give rise to erroneous diagnosis of metastasis of carcinoma or malignant lymphoma to the skin.

Aged↗
PubMed1982

Opiate antagonistic properties of an octapeptide somatostatin analog.

The somatostatin analog D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-NH-CH(CH2OH)CHOHCH3 (SMS 201-995) displaces [3h[naloxone from its binding sites (IC50, 38 +/- 60 nM), being more than 200 times more potent than somatostatin. As measured by the difference between [3H]dihydromorphine, [3H][D-Ala2,D-Leu5]enkephalin, and (-)-[3H]bremazocine binding, SMS 201-995 appears to be highly specific for the opiate mu binding site. Electrophysiological data from hippocampal cultures and results from animal studies (tail flick, mydriasis) demonstrate the opiate antagonistic properties of SMS 201-995. SMS 201-995 is an opiate mu antagonist with a peptide structure. That this property is displayed by a somatostatin analog is somewhat unexpected.

Action Potentials↗