PubMed Health⌕ Search

Biomedical subjects

R Goodman

Publications and source records attributed to R Goodman.

At least 109 records · Page 6Linked to original sources
PubMed1990

Changes in levels of c-myc and histone H2B following exposure of cells to low-frequency sinusoidal electromagnetic fields: evidence for a window effect.

Human HL-60 cells were exposed for 20 min to an electromagnetic field at frequencies ranging from 15 to 150 Hz and at densities from 0.2 to 2.3 mT (2 to 23 gauss). Following each exposure, quantitative levels of c-myc and histone H2B transcripts were determined by dot-blot hybridization analyses and compared with unexposed control samples. The most pronounced increase in each transcript occurred after exposure at 45 Hz, with levels more than four times that found in unexposed controls.

Cell Line↗
PubMed1990

Amplitude windows and transiently augmented transcription from exposure to electromagnetic fields.

The exposure of cells to relatively low-intensity, pulsed, low-frequency electromagnetic fields can result in a transient augmentation of mRNA synthesis. Under certain conditions of irradiation, the augmentation is a function of the strength of the electromagnetic field. A linear, multi-step, chemical-reaction model accounts for many of the principal features that are observed in both the time- and intensity-dependent variations of transcriptional effects. The crucial assumption in the model is that the direct effect of electromagnetic fields on exposed cells is an increase in the rate constant that characterizes one of the intermediate sequential reactions in the synthesis of mRNA.

Electromagnetic Fields↗
PubMed1990

Combined alpha/beta-blockade versus beta 1-selective blockade in essential hypertension in black and white patients.

The purpose of this multicenter investigation was to determine the efficacy and safety of the alpha/beta-blocker labetalol versus the beta 1-selective beta-blocker atenolol in white and black patients with essential hypertension. Equal numbers of black and white patients were enlisted to form four treatment groups (white patients taking either labetalol or atenolol and black patients taking either labetalol or atenolol). Two hundred ninety-two patients (152 white and 140 black patients) with essential hypertension characterized by a standing diastolic blood pressure of 105 to 119 mm Hg (inclusive) were recruited for this trial. Patients were randomized to either labetalol (dosage titrated from 200 to 1600 mg/day) or atenolol (dosage titrated from 50 to 100 mg/day). The therapeutic goal was achievement of a standing diastolic blood pressure of 90 mm Hg or less or a fall of 15 mm Hg in diastolic pressure from baseline value at the end of the placebo run in period. At the end of the study there were no significant differences in blood pressure or heart rate changes in the supine position between the labetalol and atenolol groups. In contrast, labetalol produced greater reduction in both the standing systolic and diastolic blood pressure (-12/-13 mm Hg, respectively) compared with atenolol (-7/-9 mm Hg; p less than 0.05; p less than 0.005, respectively). The greatest decrease in blood pressure was observed in white patients receiving labetalol. In black patients the decrease in blood pressure was greater in those treated with labetalol compared with atenolol, particularly with respect to the systolic blood pressure. We conclude that the alpha 1-blocking property of labetalol provides an additional lowering of the blood pressure over that seen with beta 1-blockade alone, especially in the standing position, and this enhanced efficacy is not confined to one radical group.

Atenolol↗
PubMed1990

Computer simulation in the design of local exhaust hoods for shielded metal arc welding.

Computer simulations were used to examine competing exhaust hood configurations for shielded metal arc welding. The welder's breathing zone concentration appears to be an inverse linear function of the computer-predicted hood capture efficiency. Hood aspect ratio, hood flow, and the welder's position relative to the hood all have a significant effect on the breathing zone concentration. The height of the hood above the welding surface showed no significant effect in reducing breathing zone concentration. Further examination of breathing zone concentration as a function of capture efficiency is needed before reliable design methods can be developed using this parameter.

Air Movements↗
PubMed1990

Delayed visual maturation and autism.

Three boys are described with a mixed developmental disorder, which so far appears to have a relatively good prognosis. Each boy presented in early infancy with visual unresponsiveness, which spontaneously resolved. This delayed visual maturation was accompanied or followed by severe autistic impairment, general developmental delay, hypotonia and clumsiness. Subsequent progress has been unexpectedly favourable, with striking improvements in language, play, social interest and social competence. Widespread, patchy delay in brain maturation could possibly account for this combination of delayed visual maturation and autism, with a good prognosis.

Autistic Disorder↗
PubMed1990

A direct role for c-fos in AP-1-dependent gene transcription.

Transcription factor activator protein 1 (AP-1) is a protein fraction that contains c-fos, c-jun, and several other related proteins. Although this protein fraction can stimulate transcription in vitro, the relative contributions of c-fos and c-jun to the transcriptional effect of AP-1 are not clear. In order to approach this question, we have overexpressed both proteins using a baculovirus-mediated expression system and defined their DNA-binding and transcriptional enhancement activities in vitro. Gel mobility-shift and DNase 1 footprinting assays showed that c-jun protein specifically binds to DNA through an AP-1 binding site. Under the same conditions, no detectable binding of c-fos protein was observed. However, when the DNA binding assays were performed in the presence of both c-jun and c-fos, a marked increase in the affinity of c-jun for the AP-1 site was observed. An AP-1-dependent transcription assay was used to test the capability of both proteins to stimulate correctly initiated RNA synthesis in vitro. Under our conditions, c-jun protein was capable of stimulating specific RNA transcription in an AP-1 site-dependent manner. In contrast, c-fos protein showed no detectable transcriptional activation by itself. However, a transcription assay carried out in the presence of both c-fos and c-jun proteins showed that the c-fos/c-jun complex was more active as a transcriptional regulator than c-jun protein alone. These experimental results indicate that c-fos and c-jun proteins are required to reconstitute full AP-1-dependent transcriptional activation and directly demonstrate that c-fos is a regulator of gene expression.

Animals↗
PubMed1990

Reliability of measurements of active and damaged joints in psoriatic arthritis.

Our aim was to test the reliability of clinical measurements in psoriatic arthritis. The study involved clinical assessments of inflammatory activity as well as damage in 10 patients with psoriatic arthritis seen at the psoriatic arthritis clinic. Five rheumatologists examined these patients according to a latin square design. For the clinical measurements of actively inflamed joints and damaged joints there was no significant observer effect. This suggests that these are reliable measurements. There was, however, significant observer effect in the radiologic assessment, and further refinement of the measurement is required.

Arthritis, Psoriatic↗
PubMed1989

Exposure of human cells to low-frequency electromagnetic fields results in quantitative changes in transcripts.

The exposure of human cultured cells to electromagnetic signals with extremely low repetition rates resulted in an increased level of selected RNA transcripts. RNA with homology to beta-actin, histone H2B, and v-myc DNA was monitored by dot blot hybridization following 20 min exposures of HL60 cells to five different electromagnetic signals. The experiments used three asymmetric electromagnetic signals with different repetition rates, and two symmetric sinusoidal signals, delivered at 60 and 72 Hz. The degree of increase in homologous transcripts was dependent on the signal characteristics.

Actins↗
PubMed1989

Infantile autism: a syndrome of multiple primary deficits?

Attempts to explain infantile autism in terms of just one underlying neurological or psychological deficit may be misguided. As in the case of many neurological syndromes, autism may involve multiple functional deficits due to multiple coexistent neurological deficits. Comparison with Asperger's syndrome and the developmental dysphasias suggests that the autistic syndrome results from the coexistence of at least two distinct constellations of functional impairments: deficits in mechanical language skills, as in the developmental dysphasias; and deficits in social relatedness, play, and nonverbal communication, as in Asperger's syndrome. Possible neurological underpinnings are considered, including the relative contribution of the two cerebral hemispheres. Implications for etiology and research are discussed.

Aphasia↗
PubMed1989

A twin study of hyperactivity--I. An examination of hyperactivity scores and categories derived from Rutter teacher and parent questionnaires.

In a representative sample of 570 13-yr-old twins, higher hyperactivity scores from parent and teacher ratings were associated with male sex, lower intelligence, inattention, specific learning problems, and behavioural deviance (mainly antisocial). This pattern of correlates also characterized all three hyperactivity categories: to a marked degree in pervasive hyperactivity; less markedly in school hyperactivity; and least markedly in home hyperactivity. Children with pervasive hyperactivity had more attentional and educational problems than non-hyperactive children who were pervasively antisocial. By contrast, children with school or home hyperactivity resembled non-hyperactive children who were situationally antisocial. These findings cast doubt on the validity of combining situational and pervasive hyperactivity into a single diagnostic category such as Attentional Deficit Disorder with Hyperactivity (ADDH).

Adolescent↗
PubMed1989

A twin study of hyperactivity--II. The aetiological role of genes, family relationships and perinatal adversity.

In a large representative sample of 13-year-old twins, monozygotic pairs were more alike than same-sex dizygotic pairs on objective measures of attentiveness and on parent and teacher ratings of hyperactivity. Comparison of recognized and unrecognized monozygotic pairs indicated that parents and teachers rated twins more similarly when the twins were perceived as "identical" rather than "non-identical". After allowing for this stereotyping, genetic effects accounted for approximately half of the explainable variance of hyperactivity and inattentiveness. Data from mixed-sex pairs did not support a 2-threshold genetic explanation for the male excess of hyperactivity. The link between adverse family factors and hyperactivity was weak. Perinatal adversity was not related to later hyperactivity.

Adolescent↗
PubMed1989

Neuronal misconnections and psychiatric disorder. Is there a link?

Brain damage can induce anomalous neuronal connections in experimental animals, which can sometimes result in maladaptive behaviour, particularly when damage occurs early in development. Anomalous patterns of neuronal connection can also arise from genetic disorders. In humans, neuronal misconnections could be involved in a variety of psychiatric disorders. For example, they may account for the link between hyperkinesis and childhood hemiplegia, and for the link between schizophrenia and 'alien tissue' lesions of the temporal lobes. Predictions from misconnection hypotheses can potentially be tested in neuropathological, neurophysiological, and clinical studies.

Brain↗
PubMed1989

Successive unfolding of two different collagen vascular diseases in the same patient.

Genetic factors may be important in the development of autoimmune disease. We describe the development of fulminant systemic lupus erythematosus in a patient 5 years after recovery from polymyositis. The successive unfolding of different autoimmune diseases in the same individual is suggestive of sequential gene activation.

Antibodies, Antinuclear↗
PubMed1988

Kinetic analysis of an E.coli phenylalanine-tRNA synthetase mutant.

A mutation in the pheS gene, encoding phenylalanyl-tRNA synthetase, in E. coli NP37 confers temperature-sensitivity on the organism. A five-fold increase in tRNA(phe) levels complements the mutation. Analysis of the kinetic properties of the mutant enzyme indicates that the KM is 20-fold higher than the wild-type and the dissociation constant of the tRNA(phe)-synthetase complex for the mutant is at least 10-fold higher. These results indicate that the mutation in E. coli NP37 directly affects the tRNA(phe) binding site on the cognate synthetase.

Amino Acyl-tRNA Synthetases↗