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Biomedical subjects

S Brandt

Publications and source records attributed to S Brandt.

At least 19 recordsLinked to original sources

Fibrosarcoma cells transduced with the IL-6 gene exhibited reduced tumorigenicity, increased immunogenicity, and decreased metastatic potential.

Murine fibrosarcoma cell lines transduced with retroviral vectors containing the murine interleukin 6 (IL-6) gene constitutively secreted IL-6. When injected s.c. into normal mice these IL-6-secreting tumors exhibited reduced tumorigenicity. This reduced tumorigenicity was not seen in nude or irradiated mice, implicating a T-cell-dependent, radiosensitive host response activated by the cytokine. Subcutaneous IL-6-secreting tumor did not retard the growth of distant deposits of wild-type tumor in the same host. However, animals rejecting IL-6-secreting tumors exhibited resistance to later challenge with wild-type tumor. When injected i.v. in an experimental metastasis model the IL-6-secreting tumors failed to or were extremely inefficient in giving rise to pulmonary nodules; this was observed in both normal and immunoincompetent mice, implicating a second, nonimmune mechanism affecting the growth of the tumor modified to secrete IL-6.

Animals

Isoliquiritigenin, a strong nod gene- and glyceollin resistance-inducing flavonoid from soybean root exudate.

Isoflavonoid signal molecules from soybean (Glycine max (L.) Merr.) seed and root exudate induce the transcription of nodulation (nod) genes in Bradyrhizobium japonicum. In this study, a new compound with symbiotic activity was isolated from soybean root exudate. The isolated 2',4',4-trihydroxychalcone (isoliquiritigenin) is characterized by its strong inducing activity for the nod genes of B. japonicum. These genes are already induced at concentrations 1 order of magnitude below those required of the previously described isoflavonoid inducers genistein and daidzein. Isoliquiritigenin is also a potent inducer of glyceollin resistance in B. japonicum, which renders this bacterium insensitive to potentially bactericidal concentrations of glyceollin, the phytoalexin of G. max. No chemotactic effect of isoliquiritigenin was observed. The highly efficient induction of nod genes and glyceollin resistance by isoliquiritigenin suggests the ecological significance of this compound, although it is not a major flavonoid constituent of the soybean root exudate in quantitative terms.

Benzopyrans

The Yankton Model Program.

Changes in medical education towards a student-centered, problem-based learning, with continuity care experience in ambulatory settings have been recommended. The University of South Dakota School of Medicine has developed such an educational model for third year medical students named the Yankton Model Program and is herein described.

Curriculum

Alpha 2-adrenergic binding sites in the medulla oblongata of tree shrews demonstrated by in vitro autoradiography: species related differences in comparison to the rat.

Alpha 2-adrenergic binding sites in the medulla oblongata of tree shrews and rats were detected and quantified by in vitro-autoradiography with the alpha 2-antagonist 3H-rauwolscine (3H-RAUW). The autoradiographic pattern of the radioligand binding in the tree shrew medulla oblongata resembles that which has been described by others for the human myelencephalon. This pattern coincides well with the occurrence of catecholaminergic structures detected by immunocytochemistry with antibodies against phenylethanolamine-N-methyltransferase and tyrosine hydroxylase. In contrast to the rat, where only the nucleus tractus solitarii and the nucleus dorsalis nervi vagi were labeled, five discrete nuclei specifically bound 3H-RAUW in tree shrews. The highest number of binding sites was detected in the nucleus dorsalis nervi vagi (nX; Bmax: 333 fmoles/mg) and the nucleus tractus solitarii (NTS; 311 fmoles/mg), followed by the nucleus nervi hypoglossi (nXII; 297 fmoles/mg), the nucleus reticularis parvocellularis (FRS; 230 fmoles/mg), and the area of the catecholamine cell groups A1 and C1 (area C1; 202 fmoles/mg). Maximal binding in the two labeled nuclei of the rat was 158 fmoles/mg. The discrete nuclei of the two species also showed different affinities for 3H-RAUW with Kd ranging from 0.17 to 0.83 nM in tree shrews and 1.80 to 1.95 nM in rats. Competition experiments revealed that the radioligand bound specifically to alpha 2-binding sites. In the tree shrew, nX, nXII and the area C1, also have a relatively high affinity for the alpha 1-antagonist prazosin which is a quality of the adrenoceptor subtype alpha 2B. Furthermore, in the area C1, 3H-RAUW binding was inhibited by the dopamine antagonist haloperidol. There are thus species related as well as regional differences with respect to the number, the affinity, and the pharmacological properties of alpha 2-binding sites in the medulla oblongata. In tree shrews, alpha 2-adrenoceptors can be autoradiographically quantified in regions which are not labeled in the rat, although former data predicted the existence of such receptors, e.g., in the area of the adrenaline cell group C1.

Animals

Glutaric aciduria in progressive choreo-athetosis.

The clinical symptoms in a 10-year-old girl with progressive dystonic cerebral palsy are described. The biochemical findings were dominated by large amounts of glutaric acid in the urine. The disorder is caused by impairment of the degradation of glutaryl-CoA. A survey is given of the clinical and biochemical symptoms, based on the five cases reported so far. It is concluded that patients with progressive dystonic palsy should be examined for disorders in the metabolism of organic acids.

Acyl Coenzyme A

[Continuous education for people who work with the aged, especially for people who run homes for the aged (author's transl)].

In accordance with Paolo Freire learning is not only an intake of knowledge, but it is reflection of one's own life situation and finding of new solutions. The consequence for continuous education of people who run homes for the aged is that the process of learning has to be connected with the practical experience of the participants. The long termed course of continuous education for directors of homes for the aged therefore always starts with a definition of their tasks. That leads to a definition of learning goals, which will be approached by working out and following a planned schedule for the whole course.

Adult

6-Plate element for recording of cutaneous blood flow.

A 6-plate element for isocaloric recording of cutaneous blood flow is described. Co-heating, penetrating depth and influence of a larger vessel simulated in a model were examined. The 6-plate element is less influenced by inhomogenous and anisotropic blood flow than the conventional 2-plate element and thus particularly suitable for routine measurements and repeated applications.

Humans

Glutaric aciduria: clinical and laboratory findings in two brothers.

In two siblings with dystonic cerebral palsy the urinary metabolic profiles of organic acids were dominated by glutaric acid, a metabolite not normally present in urine. The exretion of glutaric acid amounted to several grams per day. The urinary excretion of beta-OH-glutaric acid and glutaconic acid was also enhanced. Imparied metabolism of glutaryl-CoA by leukocytes indicates that the patients suffer from an inborn error of lysine, tryptophan, and hydroxylysine metabolism. A defective oxidation of glutaryl-CoA to crotonyl-CoA, probably due to a deficiency of glutaryl-CoA dehydrogenase, is consistent with these findings.

Amino Acid Metabolism, Inborn Errors

Aphasia and epilepsy in childhood.

The syndrome of progressive aphasia and epilepsy in childhood is delineated. Four cases are presented, three of which show the typical gradual onset, fluctuating course and EEG changes with bilateral foci of spike and spike-wave activity, and, finally, normalization after some years of the EEG. Also the aphasia tends to subside, but often with considerable delay in relation to the other features. Neuropsychological assessment showed varying residual defects mainly on language functions. The aetiology is unknown. No pathoanatomical data on this disorder has hitherto been published. In one of the present cases a cortical biopsy was performed on suspicion of a left temporal tumour. The biopsy showed changes indicative of a slow virus infection. It is therefore suggested that the newly established language function in children particularly is vulnerable to a subchronic viral encephalitis affecting both hemispheres.

Adolescent

Juvenile neurolipidosis of Bernheimer-Seitelberger's type. Histopathological and biochemical findings.

Two children are reported, who became diseased at the age of 4 and 2 years, respectively, with progressive upper motor neuron symptoms leading to severe disability within a few years. The boy died at age 10 and autopsy disclosed a severe gangliolipidosis throughout the central nervous system, maximal in the brain stem and cerebrellum, corresponding with his early and dominantly bublar symptoms. The girl is still living, although severly disabled. The etiology was confirmed through biochemical studies which showed lower activity of galactosaminidase and galactosidase in frontal lobe tissue from the boy, in liver tissue from the girl. The activity of galactosaminidase A isoenzyme was more than 50 per cent lower in serum from the girl and in serum from healthy relatives of the boy, the father, mother and one of two brothers. Furthermore, the galactosidease activity was within or below the lower normal range limit in leucocytes from relatives of the boy with exception of the father. This abnormality was also encountered in serum from our girl patient.

Adolescent