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Biomedical subjects

G Lang

Publications and source records attributed to G Lang.

At least 91 records · Page 5Linked to original sources
PubMed1990

Monoamine oxidase inhibition by moclobemide and 2-amino-ethyl carboxamide derivatives: mode of action and kinetic characteristics.

The selective, reversible inhibitors of monoamine oxidase (MAO) moclobemide and Ro 41-1049 (selective for MAO-A), as well as of Ro 16-6491 and Ro 19-6327 (selective for MAO-B) inhibited the enzyme with an initial competitive phase, followed by a time-dependent inhibition of MAO. Ro 41-1049, Ro 16-6491 and Ro 19-6327, being activated by MAO into reversible adducts, fit into the classification as mechanism-based inhibitors. Conversely, since no product formation was observed after incubation of tissue homogenates with moclobemide, this drug probably belongs to the class of the "slow-binding" MAO inhibitors.

Animals↗
PubMed1990

The histogenetic origin of cervical mesonephric hyperplasia and mesonephric adenocarcinoma of the uterine cervix studied with immunohistochemical methods.

Forty-four cases of mesonephric hyperplasia (MH) and two adenocarcinomas arising from mesonephric remnants (MA) in the cervix were compared immunohistochemically with 10 embryonic and fetal mesonephric tissues. The mesonephric cells retained their pattern for intermediate filaments during ontogenesis, as well as in the mature, hyperplastic, and neoplastic states: they expressed cytokeratin 8, cytokeratin 13, and vimentin, the two latter in variable amounts. In embryonic mesonephric tissues, cytokeratin was absent, whereas the staining for vimentin was intense. Fetal mesonephric cells stained for cytokeratin 13 and vimentin, but that staining diminished as maturation progressed. All MH and MA expressed cytokeratin 8, whereas only 20-30% of the cells in MH and 10-20% of carcinomatous mesonephric cells showed positive reactions with anti-cytokeratin 13 and anti-vimentin. CEA was always negative in cells of mesonephric origin. We regard these results to be important, since the reactions with anti-CEA and anti-vimentin enable one to distinguish cervical adenocarcinomas of mesonephric origin from those of endocervical origin, the latter being CEA-positive and vimentin-negative. Clinical studies revealed that approximately 75% of the patients with MH had used oral contraceptives for several years, 46% had precancerous lesions of the cervix, and in 62% the cervical mucosa showed adenomatous microglandular hyperplasia. We believe that hyperplasia of mesonephric remnants in the cervix may occur more often in patients with disturbed hormonal balance. However, the lack of a control population does not enable us to advance this hypothesis with assurance.

Adult↗
PubMed1990

trans activation of the thymidylate synthase promoter of herpesvirus saimiri.

Herpesvirus saimiri has been shown to possess a thymidylate synthase (TS) gene that is unusual in its transcriptional regulation. Although TS is believed to be required for viral DNA synthesis, the TS-specific 2.5-kb mRNA was found most abundantly during the late phases of asynchronous virus replication in permissive cultures. To study the kinetics of gene activation, the TS promoter and regulatory sequences were cloned upstream of the chloramphenicol acetyltransferase (CAT) gene. No CAT expression or transcripts were found after transfection of fusion genes into permissive owl monkey kidney (OMK) cells. However, the promoter was strongly activated when CAT plasmids were cotransfected with intact herpesvirus saimiri virion DNA or were transferred to OMK cells that were lytically infected with herpesvirus saimiri or a related herpesvirus, herpesvirus ateles. CAT was expressed at reduced levels in cultures when viral DNA replication was inhibited by phosphonoacetic acid; this indicates that the gene is activated during the delayed-early phase. However, the highest amounts of mRNA were present in the late period of replication. Deletion analyses localized essential response elements for trans activation in the promoter upstream region between nucleotides -311 and -56; they consisted of related tandem repeats and perfect palindromes. A sequence with two overlapping palindromes of 16 and 18 bp was found to be a major target for activation of the herpesvirus saimiri TS promoter. These palindromes did not have any significant homologies with known sequences of herpesviruses or cellular DNA; the 18-bp palindrome had, however, a certain structural similarity with a conserved sequence of the E2-responsive cis sequence that is required for transcription regulation of early papillomavirus genes.

Animals↗
PubMed1990

The hypolipidemic effect of lifibrol during a long term treatment of pigs.

We investigated the hypolipidemic property of lifibrol in male and female minipigs in a long term trial over a treatment period of 6 months. Oral dosages between 12.5 mg/kg BW and 100 mg/kg BW lifibrol resulted in a strong reduction of serum cholesterol after only two weeks of treatment. The hypocholesterolemic effect was not counterbalanced and reached -76% at the end of the trial in the male pigs and -70% in the female pigs (100 mg/kg BW lifibrol). The reduction of serum cholesterol was mainly brought about by the reduction of LDL-cholesterol. Serum triglycerides seemed to be less influenced by lifibrol than serum cholesterol. The application of lifibrol had no significant influence on the weight gain of the pigs and did not alter the serum levels of AST and ALT. Lifibrol was well tolerated and the animals showed no symptoms of incompatibility.

Alanine Transaminase↗
PubMed1990

[Typical CT findings with the intrathecal infusion test in post-traumatic disorders of cerebrospinal fluid dynamics].

Simultaneous computer tomographic and cerebrospinal fluid dynamics examinations in patients with high-pressure hydrocephalus, normal pressure hydrocephalus and cerebral atrophic processes are presented and discussed. Exclusive CT and MR examinations do not allow a differentiation of patients with normal pressure hydrocephalus and patients with cerebral atrophy. In the simultaneous examinations the morphological substrate during the intrathecal infusion test is represented.

Adult↗
PubMed1990

[Surgery for backache].

All types of lumbar pain are of course not an indication for surgery. However, an operation may bring relief from lymbodynia in given conditions, owing to the better knowledge of spinal physiopathology and to the evolution of the surgical technique. This is the case for intervertebral disk pathology, lesions of the posterior articular structures, lumbar canal stenosis, vertebral tumors or malunions, as well as for some cases of painful frontal or sagittal deviation of the spine. State-of-the art techniques utilize arthrodesis, often with a plate or CD-material osteosynthesis, but future surgery should be aimed at preserving motion.

Back Pain↗
PubMed1989

Human CD2 3'-flanking sequences confer high-level, T cell-specific, position-independent gene expression in transgenic mice.

We have localized a set of T cell-specific DNAase I hypersensitive sites in the 3'-flanking region of the human CD2 gene. A 5.5 kb BamHI-XbaI fragment containing these DNAase I hypersensitive sites conferred efficient, copy number-dependent, T cell-specific expression of a linked human CD2 minigene, independent of the position of integration in the transgenic mouse genome. When linked to the mouse Thy-1.1 gene or the human beta-globin gene, this fragment conferred the same T cell-specific expression, independent of its orientation. These results suggest that this flanking region is both necessary and sufficient for full tissue-specific activation of homologous and heterologous genes in transgenic mice.

Animals↗
PubMed1989

Electrodiagnosis of human dorsal sacral nerve roots by recording afferent and efferent extracellular action potentials.

Single extracellular nerve action potentials from afferent fibres with various functions were recorded from human sacral nerve roots. It was shown that the potentials from these fibres can have different wave forms (amplitude, duration) and conduction velocities. The smaller potentials with longer durations have lower cut-off frequencies for certain identification than the larger potentials of shorter duration. The conduction velocity diagnosis covers a range of velocities with a factor of about 10. The slowest measured conduction velocities were between 4 and 10 m/sec. The identification of the functions of afferents in nerve roots is possible by calculating conduction velocities and stimulated activity increase measurements. Besides touch and pain fibres from the skin, afferents from mechano-receptors of the urinary bladder and the anal canal could be detected in dorsal sacral roots. There is evidence of motoneurons in the dorsal sacral roots supplying fatigue resistant muscle fibres. Sacral nerve root electrodiagnosis can be used in operations to identify physiologically-stimulated afferents and reflex activated motoneurons and, therefore, possibly will be useful in nerve anastomoses and nerve root stimulations in paraplegia.

Action Potentials↗
PubMed1989

[Immunohistochemical receptor findings in the endometrium and therapeutic consequences in endogenous and exogenous functional disorders and cancer].

We studied immunohistochemically cryostat sections made from fresh endometrial tissue, immediately frozen after removal (86 hysterectomy specimens, 6 curettages) for their content of oestrogen receptors (ER) using the ER-ICA assay. Routine histological sections were prepared from parallel specimens of the endometria for determining endometrial functions. The evaluation of the immunohistiological preparations showed that the ER content in the endometrium was closely related to the endogenous hormone stimulation. A further refinement and differentiation of that relationship became possible and correlated well with the various forms of follicle and corpus-luteum insufficiencies. The results indicated that it is now possible to recommend therapy of functional disorders of the endometrium, esp. in sterility cases, without need or knowledge of serum hormone levels. As the endometrial glandular proliferation increases, the density of the ER becomes more intense. In contrast, under therapy with predominantly gestagenic preparations or after these are discontinued, the ER are decreased more than found in normal glands at that degree of proliferation. Whereas the atrophic endometria of old age contained greatly diminished but still detectable ER, no ER could be found in endometrial atrophy induced by oral contraceptives. Carcinomatous endometria revealed a heterogeneous distribution of ER. The better the tumour cells were differentiated, the greater was the density of the ER. By contrast, the carcinomas derived from metaplastic Müllerian epithelium contained few or no ER. This difference is of practical importance, since an adjuvant anti-oestrogen therapy seems of value only with ER-positive carcinomas. The immunohistochemical determination of ER is more exact than the biochemical determination, for each single cell can be evaluated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1989

[The injured cervical spine with and without lesions of the nerve structures. Clinical results of surgical therapy].

The operative treatment of the cervical spine injuries with and without neurological deficit was active developed in the last 25 years. The surgical management has been determined by the type of deformity, and also by the anatomical and functional specialties. The indication, the diagnostical and therapeutical strategy and the results of surgical treatment of 304 cases are discussed.

Bone Plates↗
PubMed1989

Growth of fresh-frozen pulmonary allograft conduit in growing lambs.

To investigate the fate of cryopreserved pulmonary conduit allografts, an experimental model was used in lambs. The lambs underwent resection of the pulmonary trunk and valve to the level of the bifurcation of the pulmonary arteries and then were replaced by cryopreserved (CryoLife, Incorporated, Laboratories) pulmonary conduit allografts obtained from lambs of similar size. Lambs were operated on at 4 weeks of age and followed up with cardiac catheterization and cineangiography every 3 months for a period of 18 months. Lambs were electively sacrificed in the following order: two at 1 month, two at 3 months, one at 6 months, two at 12 months, and five at 18 months. To assess the structure of the conduit tissue, sections for light microscopy were obtained from the proximal, midportion, and distal ends of the conduit. While the lambs grew from a weight of 11.7 kg at the time of implant to more than 70 kg at 18 months, the diameter of the pulmonary conduit distended from 16 mm at the time of implant to 17.7, 19.1, 24.9, 34.3, and 33.7 mm at 1, 3, 6, 12, and 18 months, respectively. The length of the conduit also extended from an original inner length of 25 mm and an original outer length of 32 mm to the following dimensions: inner lengths of 27.9, 32.7, 38.8, 43.6, and 45.3 mm, respectively, at 1, 3, 6, 12, and 18 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

The structure of the human CD2 gene and its expression in transgenic mice.

We report the genomic organization of the human CD2 gene and its expression in transgenic mice. A 28.5 kb segment of DNA consisting of 4.5 kb 5' flanking sequences, 15 kb containing the gene's five exons and 9 kb of 3' flanking sequences can direct the expression of the CD2 gene only on thymocytes, circulating T cells and megakaryocytes of the transgenic mice. The expression of each copy of the human CD2 transgene appears to be as high as the endogenous mouse CD2 gene and as high as the expression on the surface of human T lymphocytes, independent of the site of integration and dependent on the copy number of genes that have integrated.

Amino Acid Sequence↗
PubMed1988

The enhancer in an MHC class II gene, in vitro and in mouso.

The E alpha class II gene of the major histocompatibility complex is expressed in a variety of immunocompetent cells. Part of the control of tissue-specific expression is mediated by a block of sequences found far upstream of the transcriptional startsite; this stretch is necessary for expression in the B lymphocytes of transgenic mice, but largely dispensable elsewhere. We review the evidence for the role of this region in E alpha transcription in transgenic animals, as well as data from transfections into tissue-culture cells, which indicate that this region has non-specific enhancer activity. We discuss possible models to explain how a non-specific enhancer can participate in cell-specific control.

Animals↗