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Biomedical subjects

J Palmer

Publications and source records attributed to J Palmer.

At least 199 records · Page 11Linked to original sources
PubMed1990

A new radioimmunoassay for human alpha atrial natriuretic peptide and its physiological validation.

A new sensitive, specific radioimmunoassay for human alpha atrial natriuretic peptide (hANP) and a novel extraction method for hANP have been developed. Antiserum to hANP (Keq = 1.923 x 10(11) l/mol) showed no cross-reactivity with related analogues. Displacement of 50% bound 125I-hANP occurred at 4.7 +/- 0.1 fmol/tube (n = 15). The limit of detection of plasma hANP after extraction of 2 ml plasma with Florisil was 1.2 pmol hANP/litre plasma. The recovery of synthetic hANP from plasma over the range 6.5-162.5 pmol/l was 71.2 +/- 1.9%. Inter- and intra-assay coefficients of variation were 13.1% and 10.1% respectively. Extracted plasma was stored at -80 degrees C without loss in immunoreactivity. The radioimmunoassay was physiologically validated in man by measuring plasma hANP following central volume expansion - (a) plasma hANP rose from 2.5 +/- 0.5 to 4.1 +/- 0.6 pmol/l in 9 normal volunteers after postural change from seated to lying (b) infusion of normal saline (2 litre/2 hour) increased hANP from 1.6 to 4.3 pmol/l (n = 2). Infusion of hANP (2 pmol/kg/min) increased plasma hANP to 19.9 +/- 3.4 pmol/l (n = 6).

Animals↗
PubMed1990

Pinhole emission computed tomography: method and experimental evaluation.

A method for pinhole emission computed tomography (ECT) using the image-processing capabilities of a gamma camera system is described and evaluated. The tomographic imaging capability of the method was assessed by studies of phantoms and its practical use by the distribution of inhaled 99Tc(m)-labelled aerosol particles in rabbits. The phantom studies demonstrate the tomographic properties in central and non-central planes. A reconstructed resolution of 4.4 mm (FWHM) and an overall homogeneity of +/-10% was obtained for a radius of rotation of the pinhole of about 8 cm. Pinhole ECT showed the distribution of inhales particles to be considerably different in two rabbits, subjected to different modes of mechanical ventilation. In planar images, on the other hand, it was difficult to appreciate the difference.

Animals↗
PubMed1990

The social competence of children born prematurely: effects of medical complications and parent behaviors.

36-month-old, full-term children (n = 21) and low-birthweight (LBW) children of high (n = 25) and low (n = 23) medical risk status were observed in interactions with mothers in teaching and social context. Child compliance, self-directed behaviors, and problem behaviors were evaluated as well as associations among aspects of children's social competence, mothers' behaviors, and context factors. Degree of medical risk was associated with impairments in children's self-directed behavior and quality of response to maternal directives. Mothers of LBW children showed a smaller proportion of behaviors that provided choices compared to mothers of full-term children. Medical complications, children's cognitive status, and mothers' interactive behaviors were significantly associated with LBW children's social competence. Results of regression analyses suggested that mothers and LBW children influence each others' behavior in ways similar to mothers and full-term children in both teaching and social contexts.

Attention↗
PubMed1990

A center-based program for exercise change among black-American families.

A center-based program was designed and implemented to promote aerobic physical activity among healthy Black-American families with children in the fifth through seventh grades. Ninety-four Black-American families were actively recruited and randomly assigned to an experimental or control group. Families in the experimental group were encouraged to participate in a program with the following features: one education and two fitness sessions per week for 14 weeks; educational sessions that included individual counseling, small group education, aerobic activity, and snack components; located in a convenient building cherished by the community; aerobic activity sessions in a fitness center outfitted and staffed according to modern characteristics; a variety of incentives including free transportation and babysitting and reminders to promote attendance. Percent participation was low, with about 20% participating in the desired fitness center sessions by the end of the program. As a result of low participation, no differences were detected between experimental and control groups on indicators of cardiovascular fitness. In postprogram interviews, conflicts with work and school events were the most commonly reported reasons for nonattendance. We concluded that because of difficulties in attendance, center-based programs appear to have limited value as the sole modality for intervention in public health programs for promoting physical activity among healthy, low income Black-American families with young children. More comprehensive community-based programs are likely to be needed.

Adult↗
PubMed1990

Lack of systematically found insulin autoantibodies in spontaneously diabetic BB rats.

Insulin autoantibodies (IAAs) occur in newly diagnosed human insulin-dependent diabetes mellitus (IDDM) patients, but their presence in BB rats is controversial, possibly due to assay differences or variability in the animals studied. To resolve this controversy, IAAs were measured in well-characterized inbred BB rats both in radioligand assays with 125I-labeled rat insulin I or II, respectively, and in an enzyme-linked immunosorbent assay (ELISA) with rat insulin as antigen. In prospective studies, a total of 57 serums from 16 diabetes-prone (DP) BB rats were obtained during an interval ranging from 15 wk to the last week before onset and at onset of diabetes. At comparable ages, 21 serums were obtained from 8 DP BB rats not developing diabetes, and 70 matched serums were obtained from 19 diabetes-resistant (DR) BB rats. Levels of antibody binding increased slightly with increasing age in DP and matched DR rats. Two rats were positive at onset of IDDM in all assays but not in earlier samples. Otherwise, only few isolated serums from both types of rats regardless of diabetes had increased binding in one of the assays. In a cross-sectional study, the insulin-binding levels in 150-day-old DP rats (n = 20) that had not yet developed diabetes did not correlate with insulitis present in 3 of 20 rats and did not differ from 150-day-old DR BB rats (n = 20).(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1989

HLA class II typing using oligonucleotide probes.

A DQ beta locus-specific oligonucleotide probe is used to identify DQ beta alleles present in six insulin-dependent diabetes mellitus (IDDM) multiplex families. Results of genotyping using this technique agree with those from cDNA probes and are often clearer. Allele-specific oligonucleotide probes for the DR beta locus are used to identify subtypes (Dw4 and Dw14) of the DR4 specificity in five IDDM multiplex families. This distinction cannot be made with available cDNA probes.

Blotting, Southern↗
PubMed1989

HLA DQ beta 3.2 identifies subtypes of DR4+ haplotypes permissive for IDDM.

The HLA class II-related susceptibility to type I insulin-dependent diabetes mellitus (IDDM) is examined in 94 multiplex families sorted by the presence or absence of a DR4+ haplotype in at least one diabetic family member. The families with DR4+ haplotypes are then sorted by the presence or absence of a DR4-linked DQ beta 3.2 allele. Further analysis assumes each multiplex family to represent a single diabetic genetic event and identifies the HLA class II haplotype(s) present in all affected members. The DQ beta 3.2 allele is present in over 95% of the multiplex families where DR4+ haplotypes segregate with IDDM, implying a major permissive role in determining susceptibility to IDDM.

Diabetes Mellitus, Type 1↗
PubMed1989

Computed tomographic findings in bowel ischemia.

Computed tomography (CT) has been used in the evaluation of 11 patients with ischemic bowel lesions before confirmation of the disease with surgery or autopsy. The CT abnormalities were thickened bowel wall (10 patients) with post-contrast enhancement (9 patients), dilated fluid-filled bowel (9 patients), intramural low attenuation zones (5 patients), intramural gas (8 patients), and focal or diffuse free intraperitoneal fluid (5 patients). The diagnosis of bowel ischemia should be considered when performing CT in patients with abdominal pain of unknown etiology.

Adult↗
PubMed1989

Student alcohol use and perceived problems with peers and adults.

The authors examined the relationship between students' use of alcohol and the problems they experience with friends their own age and with four groups of adults, including the students' teachers or principal, police, parents or family, and adults in the neighborhood. Patterns among students' problems with friends and adults, and problems experienced by students who use alcohol, frequently get drunk, and frequently come to school drunk are explored. Using a stratified random cluster sample, 10,259 seventh through 12th grade North Carolina students were surveyed in spring 1987. For this study, the sample was limited to 6,526 students who reported drinking. No clear patterns emerged among the different groups of individuals with whom students could have problems, revealing a lack of coordinated intervention efforts among these groups. It was evident that teachers failed to detect and confront students who frequently come to school drunk. The need for increased intervention efforts is discussed.

Adolescent↗
PubMed1988

Quantitative evaluation of tomographic 201-thallium myocardial scintigraphy.

Myocardial 201Tl emission computed tomography was performed on 25 normal subjects and 27 patients with angiographically significant coronary artery disease. A semi-automatic computer program was designed to define the left ventricular myocardial volume in all short axis sections. Within this volume the relative mean myocardial pixel count was calculated. This parameter was found to separate the 2 patient groups with a sensitivity of at least 81% at a specificity of 100%.

Adult↗
PubMed1988

Alpha-interferon in superficial bladder cancer: a Northern California Oncology Group Study.

Thirty-five patients with superficial transitional carcinoma of the bladder were treated intravesically with escalating doses of recombinant alpha-2-interferon administered weekly for 8 weeks. Of the 19 patients with high-grade intraepithelial neoplasia (17 carcinoma in situ [CIS], two severe dysplasia, all cytology positive), six (32%) had complete resolution of all histologic and cytologic evidence of disease (complete response). An additional three patients (16%) had complete resolution of CIS, but the interval appearance of a low-grade transitional cell neoplasm. Five (26%) had a partial response (complete resolution of all evidence of CIS on multiple bladder biopsies but persistently positive cytologic preparations). Sixteen patients with recurrent papillary tumors and extensive prior therapy were also treated. Four (25%) had a complete response. Twenty-three of the 35 patients had prior intravesical therapy. Seven of the 23 (30%) patients with prior intravesical chemotherapy or immunotherapy had a complete or partial response to interferon, while eight of the 12 patients (67%) without prior intravesical treatment responded. These responses were achieved with minimal local and systemic toxicity. Of the ten complete responders, five remain in continuous unmaintained remission for 18+ to 37+ months. Intracavitary alpha-2-interferon is an effective new treatment for some patients with bladder cancer.

Adult↗