Search PubMed⌕ Search

Biomedical subjects

S Newman

Publications and source records attributed to S Newman.

At least 19 recordsLinked to original sources
PubMed1992

Pulmonary deposition of inhaled terbutaline: comparison of scanning gamma camera and urinary excretion methods.

Deposition from a multidose powder inhaler (Turbuhaler, Astra) delivering 500 micrograms of terbutaline sulfate per metered dose was compared by two techniques in a group of six healthy volunteers. The deposition of the radionuclide 99mTc, which was used to label terbutaline sulfate powder, was quantified by gamma camera (G-method). Simultaneously, the gastrointestinal absorption of swallowed drug was blocked with activated charcoal, and the amount of terbutaline in a urine sample, collected over a period of 48 h and corrected by a pharmacokinetic internal standard of intravenous deuterated terbutaline, was used as a measure of lung deposition (U-method). The mean (standard deviation) depositions in lung were 26.9 (3.8%) of the dose for the G-method and 21.1 (3.2)% of the dose for the U-method. Possible reasons for the differences between the two means are discussed. Both methods are suitable for assessing deposition from medical aerosol inhalers; the U-method requires access to gas chromatography-mass spectrometric equipment, and the G-method requires access to gamma camera facilities.

Administration, Inhalation↗
PubMed1992

Developmental expression of G protein alpha subunits in mouse spermatogenic cells: evidence that G alpha i is associated with the developing acrosome.

Guanine nucleotide-binding proteins (G proteins) are important signal transducing molecules found in all cells. G proteins are associated with the plasma membrane/outer acrosomal membrane region of acrosome-intact sperm and at least one G protein is involved in the zona pellucida-induced acrosome reaction. With the goal of elucidating the functions of these proteins during spermatogenesis, we investigated the types of G proteins present in spermatogenic cells and when they first become associated with the developing acrosome. Using bacterial toxin-catalyzed [32P]ADP-ribosylation in conjunction with immunoprecipitation and immunofluorescence utilizing antibodies directed against specific regions of various G protein isotypes, the alpha subunits of Gi1, Gi2, Gi3, and G(o) were detected in mouse spermatocytes and spermatids. An antiserum recognizing a conserved sequence of G alpha i subtypes localized to the proacrosomal granules of spermatocytes and the developing acrosome of spermatids. Levels of G alpha o diminished as spermatocytes developed into spermatids such that G alpha o was not detected in cauda epididymal sperm. Immunoreactivity using G alpha o-specific antisera did not display a distinct regionalization within any of the spermatogenic cell types. G alpha s was not detected in the developing spermatogenic cells or sperm. The association of G alpha i with the developing acrosome suggests a role for G proteins may have a role in acrosome biogenesis as well as being part of a complex required later for signal transduction leading to acrosomal exocytosis.

Acrosome↗
PubMed1992

Interactions among emergent relations during equivalence class formation.

The interactions among symmetry, transitivity, and equivalence tests during the formation of 3-member equivalence classes were studied with 14 college students. After training AB and BC, a test with BA, CB, AC, and CA was conducted concurrently. Failure led to serial testing with probes for CA equivalence, BA symmetry, CA equivalence, CB symmetry, CA equivalence, AC transitivity, and CA equivalence. For five subjects, equivalence tests were passed immediately once BA and CB symmetry as well as AC transitivity had been induced. Thus, symmetry and transitivity were precursors for successful performance on equivalence tests. The conjoint function of symmetry and transitivity was assessed with the equivalence probes. As the equivalence probes were passed immediately, the presence of symmetry alone and transitivity alone were sufficient for their conjoint function without additional intervention. For different subjects, transitivity alone and symmetry were induced either directly with BA, CB, or AC probes or indirectly with equivalence probes. Equivalence probes can also induce various combinations of symmetry and transitivity. Thus, different subjects formed classes in various patterns at different rates.

Adolescent↗
PubMed1992

Tuberculosis among institutionalized elderly in Alberta, Canada.

Previous studies in the US have suggested that the risk of tuberculosis is increased among elderly residents of nursing homes. This registry-based study determined and compared the tuberculosis incidence rate for the elderly in nursing homes and community dwellings in Alberta, Canada, over the 5-year period 1979-1983. Rate ratios (RR) using the community elderly rate as baseline, were estimated for all notified cases and for culture positive cases only. Adjustment was made for the variables age, sex, and ethnicity. The nursing home elderly in Alberta did not have an increased risk of tuberculosis: adjusted RR = 1.09, 95% CI : 0.38-1.80.

Aged↗
PubMed1992

Selection for postweaning growth in inbred Hereford cattle: the Fort Keogh, Montana line 1 example.

Demographic characteristics and genetic trends in birth weight and pre- and postweaning ADG were examined in a population of Hereford cattle (Line 1). Line 1 was founded largely from two paternal half-sib sires and has been selected for postweaning growth. There were pedigree records on 951 members of the base population that predated 1935, when data collection began. Numbers of records analyzed using mixed-model methodology were 4,716 birth weight, 4,427 preweaning ADG, and 3,579 postweaning ADG. Birth weight and preweaning ADG were considered to have direct and maternal genetic components. Inbreeding accumulated rapidly from 1935 to 1960 and more slowly (.22%/yr) thereafter. Any reduction in additive genetic variance due to inbreeding and selection may have been offset by a concurrent reduction in generation interval that was observed as time progressed. Expected selection differential for 365-d weight, averaged over sexes, was 31.2 kg per generation. For birth weight, annual genetic trends in direct and maternal effects were 42 +/- 3 g and 15 +/- 3 g, respectively. Annual direct and maternal genetic trends for preweaning ADG were .70 +/- .06 g/d and .63 +/- .06 g/d, respectively. Direct response in postweaning ADG was linear and equal to 5.3 +/- .6 g.d-1.yr-1. As a result, estimated breeding values of birth weight, 200-d weight, and 365-d weight increased by 3.2 kg, 14.5 kg, and 62.4 kg, respectively, from 1935 to 1989. Selection within Line 1 was effective in increasing genetic potential for growth over 13 generations. No selection plateau was observed in any of the traits examined.

Age Factors↗
PubMed1991

Social support, disability and depression: a longitudinal study of rheumatoid arthritis.

The objectives of this study were (i) to assess aspects of the reliability and validity of an instrument measuring social support and social relationships, in the field of physical disability; (ii) to assess the impact of disability on social relationships and (iii) to examine effects of social support upon psychological well-being over time. One hundred and forty nine individuals with rheumatoid arthritis (RA) were assessed on two occasions separated by 15 months. Social support was assessed by means of the Interview Schedule for Social Interaction. The instrument was found to have satisfactory reliability and validity. It revealed that more diffuse social relationships were more affected by RA. Scores for social relationships were as strongly related to depressed mood over time as were disease and disability variables.

Arthritis, Rheumatoid↗
PubMed1991

Identification of a group of children with dyslexia by means of IQ-achievement discrepancies.

The reading and spelling abilities of 462 school children of mean age 8 years 7 months were examined in relation to their intellectual abilities (as assessed by the WISC-R) by means of cluster analysis. The analysis identified five groups. In one group reading and spelling were considerably poorer than their intellectual abilities. The performance of the five groups was examined on a number of cognitive tests commonly associated with dyslexia. The group identified as having significant discrepancies showed the poorest performance on many of these tests. In addition this group showed other features associated with dyslexia. Further analysis indicated the existence of two subgroups which differed significantly in performance on the cognitive tests.

Achievement↗
PubMed1991

Organisation of veterinary public health in Australasia and the Pacific Islands.

The authors present the structure and functions of the Veterinary Public Health Services in Australasia and the Pacific Islands. Services in the region range from the extensive and highly developed organisations of Australia and New Zealand to those meeting the needs of the subsistence agriculture economies of some of the smaller island groups. Geographic isolation and strict quarantine measures have kept the region free from serious infectious animal diseases, and veterinary public health efforts are concentrated on preventing and combating epizootic diseases.

Animals↗
PubMed1990

Alcoholism--North America and Asia. A comparison of population surveys with the Diagnostic Interview Schedule.

The Diagnostic Interview Schedule (DIS) is a highly structured instrument that enables lay examiners to gather the clinical information necessary to generate psychiatric disorders according to the DSM-III, Feighner, and Research Diagnostic Criteria. It was developed originally as the diagnostic interview for the Epidemiologic Catchment Area (ECA) survey. Because it adheres to DSM-III and can be used by lay interviewers, thus making it practical for studies involving large samples, it has been used for other population surveys in North and South America, Europe, and Asia. This investigation compares the epidemiology of DSM-III-defined alcohol abuse and addiction in DIS-based population surveys cross-nationally (in St Louis, Mo; Edmonton, Canada; Puerto Rico; Taipei City, Taiwan; and South Korea). We found considerable variation in the lifetime prevalence of alcoholism but a similarity in the age of onset, the symptomatic expression, and the associated risk factors. We also found an inverse correlation between the prevalence of alcoholism and the strength of the association of the risk factors we examined. The work described herein demonstrates the utility of consistent definition and method in cross-cultural psychiatric research. The substantive findings have implications for the definition of alcoholism and for a better understanding of genetic and environmental interactions in its etiology.

Adolescent↗
PubMed1990

The effects of nodality on the formation of equivalence classes.

A four-member equivalence class (A----B----C----D) can be formed by training AB, BC, and CD. The nodal stimuli, B and C, mediate all of the derivative (transitive and equivalence) relations in the class. The derivative relations AC, CA, BD, and DB are separated by one node, whereas AD and DA are separated by two nodes. How do the number of nodes that separate the stimuli in a derivative relation influence the induction of stimulus control exerted by that relation? Seven college students learned two four-member classes made up of nonsense syllables. After training, all derivative relations were presented repeatedly without informative feedback. Stimulus control exerted by each derivative relation was assessed concurrently. For the 7 subjects, control exerted by the derivative relations increased gradually with repeated presentations. With 6 of the 7 subjects, the one-node relations exerted more control than the two-node relations during the process. However, the disparity between the one- and two-node relations decreased with repeated presentations. Eventually, all derivative relations exerted complete control. The control exerted by derivative relations during induction was inversely related to the number of nodes separating the terms in the derivative relations. These results demonstrate that nodal distance is a determinant of the relatedness of stimuli in equivalence classes. The findings are discussed in terms of remote association, semantic memory networks, and the study of transitive inference.

Adult↗
PubMed1989

Subjective reports of cognition in relation to assessed cognitive performance following coronary artery bypass surgery.

Evidence has accumulated to indicate that a proportion of patients who undergo coronary artery bypass surgery (CABS) do develop significant cognitive deficits. This study examines whether those patients who report cognitive deterioration after CABS do show cognitive changes as assessed by neuropsychological testing. The patients who considered that aspects of their cognitive function had deteriorated, were not found to have reduced functions as assessed on appropriate neuropsychological tests. When mood state was examined, it was found that those who report a deterioration in a particular cognitive function, tended to have significantly higher levels of depression as assessed by the Beck Depression Inventory and, to a lesser extent, have higher levels of state anxiety. These findings emphasise that subjective reports of cognitive function following CABS do not reflect actual changes in cognition but rather appear to be sensitive to mood state.

Adult↗
PubMed1989

Impairment of cerebral function following cardiac and other major surgery.

Patients undergoing routine coronary artery surgery (N = 76) were compared with those undergoing other major operations (N = 29) in a prospective multidisciplinary study designed to define the incidence of neurological and psychological sequelae. The preoperative state of the carotid and vertebral arteries was defined by digital subtraction angiography. Changes in clinical neurological examination, detailed neuropsychological testing, psychiatric assessment and cerebral blood flow were measured. All preoperative studies were repeated 8 days and 8 weeks after surgery. Clinical neurological examination was repeated in addition on the 1st postoperative day. New focal neurological signs were found in 8% of the cardiac patients and none of the comparison group 24 h after operation (P = 0.9). Global transient neurological dysfunction occurred in 59% of the coronary group in the 1st postoperative day compared with 21% in other forms of surgery (P = 0.0007) but this correlated with postoperative narcotic and sedative drugs. A deterioration in neuropsychological performance was detectable in 73% of coronary cases at 8 days which was more likely to occur with increasing age, longer bypass time and lower perfusion pressure, but similar neuropsychological changes also occurred in 50% of the comparison group. By 8 weeks, there was a significant improvement in the cardiac patients (37%, P less than 0.001) but not in the other group. Cerebral blood flow was reduced at 8 days in the coronary bypass patients but not in the comparison group suggesting that the mechanism of cerebral change may be different in the two groups.

Adult↗
PubMed1989

Retinal microembolism and neuropsychological deficit following clinical cardiopulmonary bypass: comparison of a membrane and a bubble oxygenator. A preliminary communication.

To observe and quantify cerebrovascular microembolic events in the central nervous system during cardiopulmonary bypass, 40 patients having elective uncomplicated coronary surgery had retinal fluorescein angiograms 5 min before bypass was discontinued. Each patient also had 10 neuropsychological tests before and after surgery. A Harvey H1700 bubble oxygenator was used for 23 patients and a Cobe CML sheet membrane oxygenator was used for 17 patients. All 23 (100%) of patients in the bubble oxygenator group had retinal microvascular occlusions consistent with microembolism compared to 8/17 (47%) in the membrane oxygenator group (P less than 0.001). In those retinas with occlusions, the mean resultant area of non-perfusion was less in the membrane oxygenator group (0.11 mm2; n = 8) than in the bubble oxygenator group (0.29 mm2; P less than 0.01). Arterial PO2 levels during bypass were similar in both groups at moderate hypothermia, but the mean PaO2 during rewarming was higher in the bubble oxygenator group (27 kPa) than in the membrane group (13 kPa; P less than 0.001). Neuropsychological deficits were more common and more severe after bubble oxygenation than after membrane oxygenation, but in this small patient group, the difference was not statistically significant. We conclude that flat sheet membrane oxygenation during cardiopulmonary bypass may confer significant protection against cerebrovascular microembolism.

Cardiopulmonary Bypass↗
PubMed1989

Neuropsychological consequences of circulatory arrest with hypothermia--a case report.

This case study reports on the neuropsychological consequences of prolonged circulatory arrest with hypothermia and barbiturate "protection". Measurements performed during surgery showed a prolonged absence of EEG. The neuropsychological assessment revealed a remarkable preservation of function, with the exception of delayed verbal memory and performance on the Trial Making Test. The findings are discussed in relation to the safe duration of circulatory arrest and the protection afforded the brain by hypothermia and barbiturate.

Aged↗
PubMed1989

A comparison of measures of health status in rheumatoid arthritis.

One hundred and five patients with rheumatoid arthritis were assessed on two occasions separated by 15 months, by means of the ARA functional scale, the Mallya and Mace index, the Health Assessment Questionnaire (HAQ) and the Functional Limitations Profile (FLP). Thirty three per cent of patients were assessed as clinically changed in terms of the ARA scale. On both occasions cross-sectional correlations were strongest between the health status measures (HAQ and FLP) and grip strength and the Ritchie articular index. The sensitivity and specificity of the two health status measures in relation to clinical change were calculated and overall the HAQ and FLP achieved similarly modest levels of sensitivity and specificity. The greater amount of precision and information provided by the FLP has to be weighed against the simpler measurement assumptions and shorter time required to administer the HAQ.

Arthritis, Rheumatoid↗
PubMed1989

Cerebrovascular disease and functional outcome after coronary artery bypass surgery.

A series of patients undergoing coronary artery bypass surgery was studied prospectively to see if angiographic evidence of cerebrovascular disease proved predictive of the incidence of neuropsychological deficit 8 days or 8 weeks after surgery. In 47 patients, intravenous digital subtraction angiography was carried out preoperatively to assess the presence and severity of atheromatous changes in the carotid arteries; 51% had evidence of vessel wall disease and 17% had stenosis of at least one carotid artery in the neck, although only one patient had severe narrowing. Overall, 77% of these 47 patients showed a neuropsychological deficit as defined by a significantly reduced score in at least two of 10 tests administered 8 days after surgery. Eight weeks after surgery 36% still showed a deficit. The incidence of neuropsychological deficit was not significantly greater among those patients with angiographically visible carotid artery disease. The mechanism of surgery-related cognitive impairment is briefly discussed in the light of these findings.

Brain↗