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Biomedical subjects

R Martin

Publications and source records attributed to R Martin.

At least 487 records · Page 27Linked to original sources
PubMed1990

[Hormone receptor status in adenomatous hyperplasia of the endometrium and endometrial carcinoma].

1. In glandular hyperplasia and endometrial carcinoma a correlation exists between the increased proliferation rate and the rise of the ER/PR-quotient. 2. The decline of both receptor concentrations and the increase of ER/PR-Quotient in the tumor and neighbouring, non-diseased tissue was demonstrated with increasing dedifferentiation, comparing endometrial carcinoma of different stages (G1 and G2, respectively). 3. In adenomatous hyperplasia the two receptors are significantly increased compared to normal cycling and glandular-hyperplastic endometrium, respectively; there the ER/PR-quotient is smaller than 1. After gestagen therapy decrease of both receptor concentrations demonstrates the success of therapy on one hand. On the other hand the higher decrease of PR shows, that duration and success of therapy could be limited temporally. 4. In endometrial carcinoma, especially in case of progression, recurrence and/or metastases, the determination of receptor status could be useful for therapy conception in the individual patient.

Adult↗
PubMed1989

Autocrine tumor cell growth-inhibiting activities from human malignant melanoma.

Autocrine-secreted tumor cell growth-inhibiting activities were isolated from supernatants of a malignant melanoma cell line, HTZ 19-dM, established from a central nervous system melanoma metastasis. HTZ 19-dM was characterized by cyto- and immunocytochemistry and karyotyping; cells were propagated in defined serum-free tissue culture medium for up to 8 months. Supernatants were ultrafiltrated, dialyzed, lyophilized, and purified by Bio-Gel P-10 gel permeation chromatography, leading to three active fraction pools, MIAI [melanoma-inhibiting activity (MIA), 2 kDa), MIAII (Mr 11,500-17,000) and MIAIII (proteins at the cutoff of Bio-Gel P-10) inhibiting growth of 19-dM cells with 50% inhibitory concentrations of 0.79 microgram/ml (MIAI), 0.13 microgram/ml (MIAII), and 16.7 micrograms/ml (MIAII). MIAII could be further purified by reverse phase high pressure liquid chromatography; the main activity displayed a 50% inhibitory concentration of 0.33 microgram/ml. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis one major band (molecular weight about 14,000) and two minor bands (up to Mr 17,000) were identified. Macromolecular synthesis was inhibited in 19-dM cells up to greater than 99.5%; tumor stem cell colony formation was reduced by 99.89%; the inhibitory effect of MIAII was irreversible, nonsaturable, and partially antagonized by a serum factor (depending on purification stage). MIAII was heat stable (3 min at 100 degrees C) and trypsin labile. The effect of MIAII on allogeneic neuroectodermal tumors was also investigated; proliferation of two of three malignant melanomas and two of four glioblastomas was inhibited up to 85.2%; proliferation of a neuroblastoma cell line could be inhibited to 33.8%, whereas normal fibroblasts and low grade gliomas were not influenced in their proliferation.

Biological Factors↗
PubMed1989

Polymer support synthesis. XV. Behaviour of non-porous surface-coated silica gel microbeads in oligonucleotide synthesis.

Non-porous silica gel microbeads of diameter 1.5 microns have been investigated as supports for oligonucleotide synthesis. In the preparation of oligothymidylates of chain length up to 150 bases, with 5'-di-p-anisylphenylmethyl-3'-phosphoramidite as an intermediate, the average yields per chain elongation were up to 99%. Lower overall yields were observed in the case of a support which developed a strong tendency towards aggregation after the build up of an oligonucleotide coating.

Autoradiography↗
PubMed1989

Fetus amorphus or placental teratoma?

A differential diagnosis between fetus amorphus and placental teratoma based on the presence of an umbilical cord and/or skeletal organization in the fetus amorphus has been proposed (Fox and Butler-Manual: Journal of Pathology 88:137-140, 1964). We report a description of one new case of fetus amorphus, along with the results of a critical reexamination of 96 cases from the literature. Our findings fail to support the proposed criteria for distinguishing fetus amorphus from placental teratomas. We find that the presence or absence of an umbilical cord does not relate at all to the developmental state of the specimen. The extent of skeletal development may be a more valid criterion; however, the internal organization in the fetus amorphus forms an anatomical continuum with that of the placental teratoma, making a differential diagnosis meaningless. Additional research is necessary to solve this dilemma.

Abnormalities, Severe Teratoid↗
PubMed1989

Immunoreactive galanin-like material in magnocellular hypothalamo-neurohypophysial neurones of the rat.

Immunoreactive galanin-like material was recently shown to co-exist with vasopressin in parvocellular and magnocellular perikarya of the paraventricular nucleus in the anterior hypothalamus of the rat (Melander et al. 1986). Since this distribution pattern differed from our observation of oxytocin-associated galanin-like immunoreactivity (LI) in the neurohypophysis, we compared in series of 0.5-microns thick sections the localisation of galanin-LI with the localisation of oxytocin and vasopressin/dynorphin in the hypothalamus, the median eminence and the neurohypophysis. In the oxytocin system, galanin-LI was intense in oxytocin varicosities of the neurohypophysis. Oxytocin perikarya of the hypothalamic supraoptic and paraventricular nuclei exhibited galanin-LI only after intraventricular injection of colchicine and when sections were treated with trypsin prior to application of the antibody. In the vasopressin/dynorphin system galanin-LI was intense in hypothalamic perikarya after colchicine injection and in neurohypophysial varicosities after treatment of the sections with trypsin. In these neurones, galanin-LI was absent or weak in all elements when treatments with colchicine or trypsin were omitted. Galanin-LI in the neurohypophysis was not co-localised with the numerous fine endings showing GABA-LI. These observations indicate that galanin-like material coexists with vasopressin and oxytocin in the respective magnocellular neurones, although not always in an immunoreactive form.

Animals↗
PubMed1989

Meningoradiculitis and encephalomyelitis due to Borrelia burgdorferi: a follow-up study of 72 patients over 27 years.

In 1987, follow-up studies were conducted on 72 patients who had had meningoradiculitis and encephalomyelitis (8 patients) due to Borrelia burgdorferi 5-27 years previously. These patients had not been treated with antibiotics, either during the acute disease or during the interval prior to follow-up studies. The patients had exhibited the typical symptoms of Bannwarth's syndrome during the acute phase. At the follow-up studies, 33 patients showed no, and 23 only mild, clinical residual symptoms including normal CSF findings and low-positive serum IgG borrelia antibody titres (IFT; ELISA). Three patients without sequelae exhibited persistent intrathecal secretion of oligoclonal B. burgdorferi-specific CSF IgG antibodies (Immunoblot; positive borrelia CSF IgG antibody titres). Thirteen patients exhibited mild-to-medium sequelae with persistent intrathecal formation of oligoclonal B. burgdorferi-specific CSF IgG antibodies, up to 21 years after the acute illness. This persistence can be interpreted as an "immunological scar syndrome". Our follow-up studies appear to indicate that neurological manifestations of B. burgdorferi infections are generally (with few exceptions) of a benign nature. Most patients can be classified as having been cured without antibiotic therapy. No late manifestations of chronic progressive CNS borreliosis comparable to that of neurosyphilis have been seen following acute untreated neuroborreliosis.

Adolescent↗
PubMed1989

Intrathecal synthesis of virus-specific oligoclonal antibodies in patients with enterovirus infection of the central nervous system.

Cerebrospinal fluid (CSF) and serum samples from six patients with enterovirus infections were investigated by isoelectric focusing (IEF) and affinity-mediated immunoblot AMI) for the clonal distribution of entervirus-specific antibodies. In two patients with either acute meningitis or encephalitis and in one patient with a relapse of multiple sclerosis, oligoclonal IgG bands specific for enteroviruses were found predominantly in the CSF, revealing intrathecal synthesis of these antibodies. In three other patients with neurological symptoms probably unrelated to a current enterovirus infection, IEF and AMI disclosed nearly identical patterns of coxsackievirus-B-specific oligoclonal bands in the CSF and serum, indicating diffusion of these antibodies from the serum into the CSF. Although the number of patients in this study is small, the results suggest that intrathecally synthesized enterovirus-specific antibodies may be used as a means of identifying an enterovirus infection of the CNS.

Adult↗
PubMed1989

Visualization of polyribosomes in the postsynaptic area of the squid giant synapse by electron spectroscopic imaging.

Giant axons from squids (Loligo vulgaris and Loligo pealii) were studied by conventional electron microscopy and by electron spectroscopic imaging: electrons with a characteristic energy loss due to interaction with phosphorus atoms were used to image phosphorus-rich elements such as ribosomes. Patches of granular material were seen in the proximal region of giant axons, especially in the postsynaptic area of the giant synapse, but not on the presynaptic side. They were rare or absent in the more distal part of the axon. With electron spectroscopic imaging the patches emitted strong phosphorus signals, indistinguishable from signals of ribosomes in neuronal perikarya, confirming their identification as RNA-rich elements. In the part of the axon near the perikarya in the giant fibre lobe, the patches consisted of sacs of rough endoplasmic reticulum. It is suggested that patches of rough endoplasmic reticulum are transported to the synaptic region where ribosomes detach from the cisterns and aggregate into polyribosomes.

Animals↗
PubMed1989

Platelet aggregation in transient global amnesia.

We found a correlation between increased platelet aggregation parameters and transient global amnesia and no differences between patients with transient global amnesia and transient ischemic attacks. Our findings support the theory of a vascular mechanism for transient global amnesia.

Amnesia↗
PubMed1989

The position of the trachea in infants and children with right aortic arch.

In infants, the site of the aortic arch is frequently inferred from the position of the intrathoracic trachea. We retrospectively reviewed the plain frontal chest radiographs of 72 patients with cyanotic congenital heart disease and right aortic arch documented by cardiac catheterization. In infants, the position of the trachea was variable: 47% had the trachea on the right, 33% had the trachea midline and in 7% the trachea was on the left. As the child grows, the aortic arch progressively indents the trachea, and the descending aorta is better visualized. Since the position of the trachea in infants with right aortic arch is variable, one must be cautious in inferring the site of the aortic arch by the position of the trachea.

Aorta, Thoracic↗
PubMed1989

Aminoglycoside suppression at UAG, UAA and UGA codons in Escherichia coli and human tissue culture cells.

We have compared the suppression of nonsense mutations by aminoglycoside antibiotics in Escherichia coli and in human 293 cells. Six nonsense alleles of the chloramphenicol acetyl transferase (cat) gene, in the vector pRSVcat, were suppressed by growth in G418 and paromomycin. Readthrough at UAG, UAA and UGA codons was monitored with enzyme assays for chloramphenicol acetyl transferase (CAT), in stably transformed bacteria and during transient expression from the same plasmid in human 293 tissue culture cells. We have found significant differences in the degree of suppression amongst three UAG codons and two UAA codons in different mRNA contexts. However, the pattern of these effects are not the same in the two organisms. Our data suggest that context effects of nonsense suppression may operate under different rules in E. coli and human cells.

Alleles↗
PubMed1989

Subcellular distribution of titanium in the liver after treatment with the antitumor agent titanocene dichloride. A study using electron spectroscopic imaging.

In the present study, the subcellular distribution of titanium in the liver of mice was determined 24 and 48 h after application of a therapeutic (ED100; ED = effective dose) and a toxic (LD25; LD = lethal dose) dose (60 and 80 mg/kg, respectively) of the antitumor agent titanocene dichloride by electron spectroscopic imaging at the ultrastructural level. At 24 h, titanium was mainly accumulated in the cytoplasm of endothelial and Kupffer cells, lining the hepatic sinusoids. Titanium was detected in the nucleoli and the euchromatin of liver cells, packaged as granules together with phosphorus and oxygen. One day later titanium was still present in cytoplasmic inclusions within endothelial and Kupffer cells, whereas in hepatocyte nucleoli only a few deposits of titanium were observed at 48 h. At this time titanium was mainly accumulated in the form of highly condensed granules in the euchromatin and the perinucleolar heterochromatin. It was found in the cytoplasm of liver cells, incorporated into cytoplasmic inclusion bodies which probably represent lysosomes. Sometimes these inclusions were situated near bile canaliculi and occasionally extruded their content into the lumen of bile capillaries. This observation suggests a mainly biliary elimination of titanium-containing metabolites. These results confirm electron spectroscopic imaging to be an appropriate method for determining the subcellular distribution of light and medium-weight elements within biological tissues. Insights into the cellular mode of action of titanocene complexes or titanocene metabolites can be deduced from the findings of the present study.

Animals↗
PubMed1989

Atracurium and vecuronium interaction with gentamicin and tobramycin.

Drug interactions between the aminoglycosides (tobramycin and gentamicin) and atracurium and vecuronium were studied prospectively in 44 patients. Twenty-two patients had therapeutic serum levels of tobramycin or gentamicin and 22 served as controls. Onset time, clinical duration, and time to spontaneous recovery of T4/T1 ratio of 0.70 after atracurium or vecuronium injection were measured. No statistically significant differences were found in onset time, but clinical duration and time to recovery were significantly longer in patients receiving tobramycin or gentamicin and paralyzed with vecuronium than for controls (P less than 0.01 for clinical duration and P less than 0.0005 for recovery). The neuromuscular block produced by atracurium was not significantly influenced by the presence of therapeutic serum levels of tobramycin or gentamicin. We conclude that for patients treated with these antibiotics, atracurium may present some advantages over vecuronium when a prolonged block is not desired.

Adult↗