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Biomedical subjects

B J Schmidt

Publications and source records attributed to B J Schmidt.

At least 55 records · Page 3Linked to original sources
PubMed1984

Lymphomatoid granulomatosis with isolated involvement of the brain.

A patient with biopsy-proven lymphomatoid granulomatosis of the brain as the sole manifestation of the disease is described. During 14 months of follow-up since surgical excision of the cerebral mass, no evidence of recurrent brain involvement or of extracranial lesions has been found. This case is unusual in the confinement of the disease to the central nervous system and in the favorable outcome following surgical treatment alone.

Brain Neoplasms↗
PubMed1984

Use of chromosomal integration in the establishment and expression of blaZ, a Staphylococcus aureus beta-lactamase gene, in Bacillus subtilis.

With several different vectors, attempts were made to establish blaZ, a Staphylococcus aureus beta-lactamase gene, in Bacillus subtilis. Stable establishment of blaZ in B. subtilis was achieved by use of a vector that allowed the integration of a single copy of the gene into the chromosome of that host. blaZ was expressed in the heterologous host since B. subtilis strains carrying integrated blaZ produced beta-lactamase and were more resistant to ampicillin than was wild-type B. subtilis. blaZ was stably inherited in such strains, as no loss of the ability to produce beta-lactamase was observed after growth in nonselective liquid medium or on solid medium. In contrast, a blaZ-containing restriction fragment could not be established in B. subtilis with either pUB110- or pC194-based vectors. Similarly, a pC194-based shuttle vector (pGX318) containing the 5' end of blaZ (including the promoter and the coding region for the signal sequence and the first few amino acids of the mature protein) was unable to transform B. subtilis. Two derivatives of pGX318 that could be stably established in B. subtilis were isolated. The structures of these derivatives suggested that inactivation of the blaZ promoter was associated with the acquisition of the ability to be established.

Ampicillin↗
PubMed1984

Mapping of the glucose dehydrogenase gene in Bacillus subtilis.

A 4.0-kilobase DNA fragment containing the developmentally regulated gene for glucose dehydrogenase (gdh) from Bacillus subtilis was incorporated into the plasmid pGX345, which contains a marker conferring chloramphenicol resistance (cat). The resistance marker of the resulting integration vector was used to map the gdh gene on the B. subtilis chromosome. Using PBS1 transduction, the gene order was determined to be aroI cat (gdh) mtlB dal. The cat (gdh) marker was also cotransformable with mtlB. The genetic location of the gdh gene established by this indirect method was confirmed by the fact that the original phage lambda EF2, containing a 10-kilobase B. subtilis DNA fragment from which the 4-kilobase gdh region had been subcloned, also contained the mtlB gene.

Bacillus subtilis↗
PubMed1984

Catecholamines and congenital pain insensitivity.

The congenital pain insensitivity syndrome is accompanied by: a) the presence of a yellow-brown pigment in the basal layer of the epidermis with the histochemical properties of melanin, b) decrease of urinary and blood concentration of dopamine and norepinephrine, c) excretion of melanin and of an abnormal as yet unidentified phenolic metabolite, d) increase in urinary p-hydroxyphenyllactic acid, p-hydroxyphenylacetic acid, indole acetic acid, and e) a high homovanillic acid/vanillylmandelic acid (HVA/VMA) ratio. In this report we show that analgesic patients differ from controls by: a) an increase in norepinephrine excretion after L-tyrosine administration, and b) an increase in norepinephrine, dopamine, DOPA + DOPAC excretion after L-DOPA administration. The administration of L-DOPA eliminates the difference in HVA/VMA ratio between patients and controls. Serum and platelet monoamine oxidase, dopamine beta-hydroxylase and catechol-O-methyltransferase are normal and urinary excretion of biopterins, morphine-like compounds and endorphins is also within the normal range. The comparison of catecholamine metabolism in patients with phenylketonuria, Lesh-Nyham syndrome, congenital sensory neuropathy with anhydrosis and familial dysautonomia on the basis of our data and those in the literature suggests that patients with congenital pain insensitivity display abnormal catecholamine metabolism.

Dopamine↗
PubMed1982

Tumor virus induction and host cell capacity inactivation: possible in vitro tests for photosensitizing chemicals.

The responses of two in vitro mammalian virus-host cell systems to the photosensitizing chemicals proflavine sulfate and 8-methoxypsoralen (8-MOP) in the presence of light are described. Infectious simian virus 40 (SV40) could be induced from SV40-transformed hamster cells by treatment with proflavine plus visible light or 8-MOP plus near UV radiation. The same photosensitizing treatments inactivated the capacity of monkey cells to support the growth of herpes simplex virus. SV40 induction and inactivation of host cell capacity for herpesvirus growth might be useful as screening systems for testing the photosensitizing potential of chemicals. Advantages and disadvantages associated with each system are discussed.

Animals↗
PubMed1980

Effect of noradrenaline and 5-hydroxytryptamine depletion on locomotion in the cat.

It has recently been hypothesized that stimulation of the mesencephalic locomotor region (MLR) can give rise to locomotion in mesencephalic cats due to activation of descending monoaminergic pathways to the spinal cord. This notion is based on the findings that monoamine agonists and precursors can induce hindlimb stepping in acute low spinal animals, and on the similarities between the effects of the noradrenaline (NA) precursor, L-DOPA, and stimulation of the MLR. The hypothesis that the descending monoamine systems comprise the only pathways which control the initiation of locomotion has been tested in the present study. NA was depleted from the CNS using intraspinal and intraventricular injections of 6-hydroxydopamine and i.v. injections of the NA synthesis inhibitor, alpha-methyltyrosine. Depletion of 5-hydroxytryptamine (5-HT) was achieved using intraventricular injections of 5,6-dihydroxytryptamine and i.p. p-chlorophenylalanine. These treatments did not abolish evoked locomotion in spite of substantial depletion of NA and 5-HT in the spinal cord and brain stem (maximal depletions of NA up to 14% of control in lumbar cord and 16% of control in pons; maximal depletions of 5-HT up to 19% of control in sacral cord and 25% of control in medulla). Combined depletion of NA and 5-HT did not abolish evoked locomotion in mesencephalic cats, although the treated animals displayed pronounced ataxia prior to decerebration. Depletion of NA or 5-HT alone did not alter locomotion in otherwise intact animals. A previous report that phenoxybenzamine antagonizes the effects of MLR stimulation was not confirmed. The results therefore do not support the hypothesis that descending pathways containing monoamines are essential for locomotion evoked by brain stem stimulation.

5,7-Dihydroxytryptamine↗
PubMed1978

Studies of antithyroid antibodies in Down's syndrome.

The presence of antithyroid antibodies (antithyroglobulin and antimicrosomal) in serum of patients with Down's syndrome and their respective mothers were studied based on data from the literature, showing a possible correlation between the presence of these antibodies in the serum of mothers and the birth of mongoloid children. Antithyroid antibodies were studied in 40 patients with Down's syndrome, with ages ranging from 5 months to 21 years old, 24 males and 16 females and in the respective mothers whose ages varied from 22 to 66 years. In none of the analyzed sera of the mongoloids as well of their mothers, the authors were able to detect the antithyroid antibodies studied.

Adolescent↗
PubMed1977

Studies on thyroid and hypophysary thyrotrophic hormone (TSH) in Down syndrome.

Serum TSH was studied in 22 patients with Down syndrome, from 4 to 15 years old. In 6 of these patients radioidine uptake by thyroid gland after 2 and 24 hours of administration and clearance rates before and after TSH stimulus (10 mul-IM) were measured. Results show that serum TSH was normal in 17 patients and above normal limits in 5 patients. Thyroid uptake after 2 hours as well clearance rates, both below normal, had a response to TSH stimulus with normal or below values. These data along with previous reports, suggest, that in children with Down syndrome, there is a thyroid dysfunction in which a slow response no TSH stimulus seems to be the basic defect.

Adolescent↗
PubMed1975

Studies of the thyroid function in children with Down's syndrome.

The thyroid function (T-3 triiodothyronine; T-4 tetraiodothyronine and the captation of the I131 through the thyroid, in 2 and 24 hours after the intake of isotope radium), was studied in patients with Down's syndrome and the results being compared to those obtained from the respective siblings, all clinically normal. The comparative results showed no significant differences, except in the 2 hours captation of the I131 through the thyroid (P smaller than 0.01). The findings suggest that the hypothalamus-hypophysary or the response of the thyroid gland would be slow, but compensated when analyzed after 24 hours.

Adolescent↗