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Biomedical subjects

A Miller

Publications and source records attributed to A Miller.

At least 613 records · Page 34Linked to original sources

Low somatomedin activity in cord serum from infants with intrauterine growth retardation.

Somatomedin activity was determined by the simultaneous incorporation of 35S-sulfate and 3H-methyl thymidine into costal cartilage from hypophysectomized rats in cord sera from term and preterm infants and infants with intrauterine growth retardation. Mean Sm activity by sulfate incorporation was 0.49 +/- 0.04, 0.35 +/- 0.05, and 0.09 +/- 0.03 units/ml (+/- SE) in the term, preterm, and IGR cord sera, respectively. The levels for each group were significantly different from each of the other groups. There was no significant difference between the mean Sm activity by thymidine incorporation in cord sera from term (0.92 +/- 0.09 units/ml) and preterm (0.87 +/- 0.08 units/ml) infants. These levels were significantly higher, however, than the Sm activity by sulfate incorporation for the respective groups, P less than 0.001 for both groups. The mean Sm activity by thymidine incorporation in cord sera for IGR infants was 0.36 +/- 0.13 units/ml, and significantly lower than the levels in cord sera of term and preterm infants (P less than 0.01). Inhibition of Sm activity by mixing cord serum and pooled adult serum was found in one of the two cord specimens tested from IGR infants. The low levels of Sm activity in cord sera from IGR infants may reflect altered intrauterine nutrition. The discrepancy in the thymidine and sulfate incorporation by the costal cartilage bioassay for term and preterm cord sera might result from Sm-like factors in human fetal serum with greater mitogenic or thymidine transport activity compared to the activity for proteoglycan synthesis in cartilage.

Anencephaly↗

Synthesis of 8-aryltetrahydroisoquinolines as dopamine antagonists and evaluation for potential neuroleptic activity.

The synthesis of 8-(methoxyphenyl)-1,2,3,4-tetrahydroisoquinolines using aryloxazolines as key intermediates is described. Nucleophilic displacement on an o-methoxyphenyloxazoline by an aryl Grignard reagent, followed by electrophilic substitution at the other ortho position, provided a specific route to the properly substituted benzene intermediates necessary for conversion to the tetrahydroisoquinolines. These compounds and 8-phenyl- and 2-methyl-8-phenyl-1,2,3,4-tetrahydroisoquinolines, which are ring-opened analogues of apomorphine, were found to be dopamine antagonists by in vitro dopamine receptor studies. In vivo evaluation, however, did not substantiate potential usefulness as antipsychotic agents when they were compared with standard neuroleptic agents.

Animals↗

Polycythemia vera with myelofibrosis and myeloid metaplasia. Acute hepatic failure following splenectomy.

Myelofibrosis with myeloid metaplasia developed during the course of polycythemia vera in a middle-aged man. Severe megakaryocytopenia and thrombocytopenia were early features of this illness and were unresponsive to splenectomy. After splenectomy, hepatic enlargement and acute hepatic failure developed. Extensive extramedullary hematopoiesis dilating hepatic sinusoids and compressing liver cells was the major pathologic finding in the liver. The mechanism of hepatic failure in this disorder is uncertain.

Adult↗

Antegrade testicular vein phlebography and funicular lymphography in testicular tumors.

Antegrade phlebography of a testicular vein in connection with orchidectomy was performed in 29 patients and funicular lymphography was successful in 26 of these. Eleven patients had retroperitoneal metastases and 18 were normal. The phlebographic and lymphographic findings in both groups are described and discussed as well as the collateral pathways in cases with stenosis of the testicular vein. Antegrade phlebography is recommended but funicular lymphography does not merit a place in the routine examinations of patients with testicular tumor.

Adult↗

Hb S, Hb G-Philadelphia and alpha-thalassemia-2 in a Black family.

A Black family is described in which Hb S, Hb G-Philadelphia and alpha-thalassemia-2 determinants occurred in different combinations. The propositus was a healthy fullterm neonate who had 46% Hb G-Philadelphia and about 5% Hb Bart's in cord blood together with a relative microcytosis (MCV = 85 fl) and hypochromia (MCH = 28 pg). This is consistent with a diagnosis of Hb G-Philadelphia trait in association with a homozygous alpha-thalassemia-2 (alpha 0 alpha/alpha 0 alpha G; beta A/beta A). The mother and another son also had Hb G-Philadelphia in association with Hb S trait but with 37% Hb G-Philadelphia and with 39% Hb S. Hemotological and biosynthetic studies confirm the assignment of the alpha alpha/alpha 0 alpha G; beta A/beta S genotype in both and that of the alpha alpha/alpha 0 alpha; beta A/beta A genotype in the father. Despite this evidence for a moderate alpha chain deficiency in the propositus, the biosynthetic alpha/non-alpha value in the neonatal period was a high 1.2. Similar values were observed in 8 control cord blood samples if the incubation was not delayed longer than 3 hours after collection (alpha/non-alpha = 1.28 +/- 0.14). When the propositus was studied again, but at six months of age, the proportion of Hb G-Philadelphia in peripheral blood was unchanged, a marked microcytosis and hypochromia were observed, and a distinct deficiency of alpha chain synthesis (alpha/non-alpha = 0.56) was present.

Adult↗

Hemoglobinopathies observed in the population of the Southeastern United States (SE-USA).

A survey of nearly 250,000 citizens of Georgia and South Carolina conducted during the past twenty years has led to the detection of over 40 abnormal hemoglobins and several additional hemoglobinopathies. The presence of some of these hemoglobin abnormalities cause (severe) clinical symptoms but others remain undetected unless a specific search is initiated. The incidence of Hb S varies slightly among the populations of different areas, and appears to be the highest in the coastal counties of Georgia and South Carolina. A survey of over 17,000 persons of mainly high school and college age has shown that a significant number of cases with clinically significant hemoglobinopathies will remain undetected unless such surveys are actively promoted.

Adolescent↗

Primary hemochromatosis with hereditary spherocytosis.

A patient with both hereditary spherocytosis and hemochromatosis is described. At the time of the initial diagnosis of hereditary spherocytosis and shortly after splenectomy, 8 g of iron was removed by phlebotomy. During the next 15 years, the patient continued to accumulate excess iron despite splenectomy-induced remission of the hemolytic disorder. Thus the hemochromatosis in this patient was not secondary to the hereditary spherocytosis but rather represented a primary, ie, genetic abnormality of iron absorption.

Adult↗

A predominant idiotype on anti-hen egg white lysozyme antibodies from diverse mouses strains.

A predominant idiotype was detected on almost all antibody molecules directed against the multideterminant antigen, hen egg white lysozyme (HEL). This idiotypic set was defined by rabbit and quinea pig antiidiotypic antisera raised against a rare cross-reactive antibody population isolated and from a heterogeneous BALB/c anti-human lysozyme (HUL) humoral response. This isiotype was fond on the majority of all HEL-reactive antibody from all strain tested; its presence was independent of Ig-1 allotype of H-2 haplotype. The idiotype was also present on the majority of anti-HEL antibody from nonresponder mice immunized with keyhole limpet hemocyanin coupled to HEL. The idiotype was not found on normal mouse immunoglobulin or on antibodies specific to two other proteins, HUL and ribonuclease, which are similar to HEl in size and charge. Individual idiotype-positive anti-HEL antibody populations exhibited specificity differences when analyzed for reactivity toward other avian lysozymes, suggesting that distinct clonal products shared the idiotype specificities. Fractionation of heterogeneous anti-HEL antibodies by preparative isoelectric focusing yielded distinct antibody fractions that were demonstrated to share the relevant idiotype determinants. The data are discussed in terms of the HEL peptide specificites of idiotype-positive and -negative antibodies.

Animals↗

Lysozyme-induced T-suppressor cells and antibodies have a predominant idiotype.

The existence of shared idiotypic determinants on the surfaces of T and B cells is now firmly established, suggesting that on both these cell types immunoglobulin variable regions are expressed which presumably function as antigen receptors. In most systems this has been inferred through the use of anti-idiotypic antibody instead of antigen to induce either helper or suppressor T cells. Recent evidence demonstrates that antigen-specific suppressor or helper factors can also bear idiotypic determinants. It is possible that these factors represent released receptors or portions of receptors. We show here the direct elimination of an antigen-induced T-suppressor population by an anti-idiotypic serum and complement. These suppressor T cells as well as the idiotypic population used to generate the antiserum are each specific for the same limited portion of the multi-determinant antigen, lysozyme. Apparently, these suppressor cells are restricted in specificity as well as share idiotypy with antibodies of the same specificity.

Animals↗

An analysis of a continuing medical education questionnaire sent to psychiatrists in the Southern Transvaal.

The problem of continuing medical education (CME) for psychiatrists was studied by questionnaire. Of the 16 out of 40 people who responded, all felt CME was necessary and most favoured symposia, lectures and congresses. While nearly everyone read journals in psychiatric and non-psychiatric fields, group journal reviews as a form of CME were categorically rejected. Most respondents are prepared to contribute time and effort. The implications of CME are discussed, and the need for further research is emphasized.

Congresses as Topic↗

Fine specificity of regulatory T cells. II. Suppressor and helper T cells are induced by different regions of hen egg-white lysozyme in a genetically nonresponder mouse strain.

We have examined the ability of two purified peptide fragments derived from hen (chicken) egg-white lysozyme (HEL); N-terminal, Co-terminal peptide (a.a. 1--17:cys 6--cys 127:120--129) and mixed disulfide LII peptide (LII) (a.a. 13--105) to induce antigen-specific suppression or help in B10 (H-2b) nonresponder and B10.A (H-2a) responder mice. An anti-HEL primary in vitro antibody response can be obtained in either strain by stimulation with HEL coupled to erythrocytes (RBC). Preimmunization with HEL-complete Freund's adjuvant-(CFA) or N-C-CFA-induced suppression of the anti-HEL PFC response to HEL-RBC in spleen cell cultures from B10 mice, whereas helper activity was demonstrated in cultures from B10.A mice similarly immunized. LII-CFA priming elicited helper cells in both C57BL/10 Sn (B10) and B10.A/SgSn (B10.A) mice. The genetic nonresponsiveness of B10 mice to HEL can therefore be attributed to the activation of suppressor T cells by a limited portion of the molecule (e.g., N-C) which prevent the potential response directed against other epitopes on the same molecule (e.g., LII). One manifestation of major histocompatibility complex gene activity appears to be the intramolecular selection of different antigenic determinants leading to activation of functionally different T-cell subpopulations.

Amino Acid Sequence↗

Decrease in vital capacity in PCB-exposed workers in a capacitor manufacturing facility.

Pulmonary function was evaluated in 243 workers exposed to PCB in the manufacture of capacitors. Mean employment was greater than 15 years. Thirty-four of the workers (14%) were found to have a reduced Forced Vital Capacity (FVC less than 80% of Morris' predicted). Of the 34 with reduced FVC, 27 (80%) demonstrated a restrictive pattern of impairment (FEV1/FVC greater than 0.7). Only one of these 27 workers had an abnormal chest roentgenogram (greater than or equal to 1/0 by ILO UC Classification of Radiographs of Pneumoconioses). These findings are of interest in view of recent experimental data indicating the accumulation of PCBs and PCB metabolites in lung tissue (Brandt and Jansson). Restrictive spirometric impairment with no radiographic change is unusual in occupational exposure.

Adult↗