Search PubMed⌕ Search

Biomedical subjects

J Gardner

Publications and source records attributed to J Gardner.

At least 613 records · Page 34Linked to original sources
PubMed1991

Modelling adolescent blood pressure patterns and their prediction of adult pressures.

Tracking of blood pressure in adolescent boys is investigated using a mathematical model that corresponds to progression along a constant percentile. A more general analysis, based on the method of principal components, is also proposed that determines various alternative tracks or patterns that are most prevalent in the longitudinal blood pressure data. The degree of tracking along a constant percentile curve for systolic pressure was moderately high, as evidenced by a tracking index of .78 explaining 81% of the variance, but less strong for diastolic (tracking index of .60) where tracking along a percentile explained 66% of the variance. The value of the more general analysis of blood pressure patterns may lie in the assessment of adolescent risk factors for elevated adult blood pressure. Using adolescent patterns determined by either statistical model, adult systolic at age 38 was predicted (R2 = .22) by the concept of a systolic fixed percentile curve in adolescence, and similarly for diastolic (R2 = .21). However, the more general analysis based on longitudinal principal components further suggests that boys who have a larger than usual systolic peak at age 14 years, which is near the time of the adolescent physical growth spurt in these boys, may be more likely to have higher systolic pressures at age 38. Because the adult data were incomplete and highly unbalanced, these findings were obtained using random-effects models for longitudinal data.

Adolescent↗
PubMed1990

Utility of Tc-99m DTPA aerosol inhalation scans following perfusion lung scans in the diagnosis of pulmonary embolism.

The authors report their experience with the use of Tc-99m DTPA aerosol following a perfusion lung scan. The study includes 422 consecutive patients with suspected pulmonary embolism. The final diagnosis was determined by (a) clinical follow-up for 2 months or more, (b) pulmonary angiography, or (c) autopsy. There were 79 patients (19%) who had a normal or near-normal perfusion study and in whom no aerosol study was required. Interpretation groups were classified and divided as follows: Normal or low probability 281 (66.5%) High probability 75 (18.0%) Intermediate 60 (14.0%) Technically inadequate 6 (1.5%) There was autopsy or angiographic confirmation of 72 patient studies with confirmation of the scan diagnosis in 29 of 31 classified as normal or low probability and 24 of 25 classified as high probability. The background perfusion albumin activity was not computer-subtracted from the combined aerosol-perfusion image. Technical improvements included the use of eight standard views for both the perfusion and the subsequent aerosol scan, and the use of 75 mCi (2,775 MBq) of Tc-99m DTPA in the radioaerosol nebulizer. This allowed for easy accumulation of more than three times the count rate in a posterior aerosol image when compared with the previous posterior perfusion image. The authors' experience shows that the perfusion lung scan followed by this radioaerosol technique is a reliable means to evaluate suspected pulmonary embolism.

Administration, Inhalation↗
PubMed1990

Cell surface phenotype, cytokines, and antibody gene expression in immortalized human B cell lines.

In an attempt to gain some insight into the many factors influencing antibody gene expression in human B cell lines, we have examined in detail the relationship between cell surface phenotype, cytokines, and the growth and antibody-producing capacity of a panel of immortalized human B cell lines. The cell panel comprised lines secreting either high or low titers of antibodies against Rhesus D, hepatitis B surface, and tetanus toxoid antigens. All the transformed cell lines exhibited a cell surface phenotype characteristic of well-differentiated peripheral blood cells strongly expressing CD23 and CD38 while weakly expressing CD10 and CD21. There was no obvious relationship between the antibody-body-secreting and proliferative capacity of the cell lines and their cell surface phenotype. Antibody secretion by the cells was rarely improved by the addition of a wide range of doses of recombinant IL-2, IL-4, or IL-6. In addition, such treatment frequently inhibited proliferation. Supernatants from some of the cell lines promoted the growth of unrelated cell lines but failed to influence antibody production. Such supernatants contained the highest concentration of IL-1, TNF beta, TGF beta, and soluble CD23. In contrast, the heterohybrid supernatant which inhibited cell growth secreted low levels of these cytokines. None of the cell lines secreted detectable amounts of IL-2, IL-4, INF gamma, or GCSF. There was no obvious relationship between cytokine production and antibody secretion. Finally, LPS had a slight but variable effect on antibody secretion but failed to influence cell growth.

Antibody Formation↗
PubMed1989

Differences of Ca2+ regulation in skin fibroblasts from blacks and whites.

Black people have a higher propensity than caucasians toward essential hypertension. To explore the possibility that this racial difference relates to cellular Ca2+ metabolism, we measured 45Ca2+ washout and uptake and cytosolic free concentration of Ca2+ [Ca2+]i in serially passed skin fibroblasts from normotensive black and white males. Depending on the experimental conditions, 45Ca2+ washout in these cells was described by either two or three exponential functions, whereas 45Ca2+ uptake was described only by a two-exponent function. There were no racial differences in 45Ca2+ uptake and washout of unstimulated fibroblasts. However, stimulation by human serum resulted in an increase in the 45Ca2+ washout that was higher in fibroblasts from blacks than from whites. The racial differences were expressed primarily by higher values of the apparent washout rate constant (k1) of 45Ca2+ from the largest and most rapidly exchangeable cellular pool. The effect of human serum was not related to its origin (blacks vs. whites). In 2 mM Ca2+ medium and 10% serum from blacks, the respective k1 (mean +/- SEM; x 10(-2)/min) values for fibroblasts from blacks and whites were 89.68 +/- 5.23 and 73.29 +/- 4.0; in the presence of 10% serum from whites, the k1 values for cells from blacks and whites were 84.14 +/- 2.80 and 76.36 +/- 3.23 (overall significance of P less than .01). In Ca2+-deficient medium in the presence of 10% human serum, the k1 for fibroblasts from blacks and whites were 115.57 +/- 3.76 and 102.15 +/- 3.30 (P less than .05). Serum substantially increased the 45Ca2+ uptake in fibroblasts from both blacks and whites; however, racial differences were not observed. Basal levels of [Ca2+]i were not different in fibroblasts of blacks vs. whites (46.8 +/- 6.8 and 43.2 +/- 7.1 nM for blacks and whites, respectively). However, the peak response of Cai2+ transients for cell stimulated by 5% human serum was significantly higher in blacks than whites (blacks = 963 +/- 213, whites = 481 +/- 162 nM; P = .0286). We conclude that Ca2+ regulation is different in serum-stimulated fibroblasts from blacks and whites and that, at least in part, this difference may relate to a greater agonist-induced mobilization of Ca2+ in fibroblasts from blacks.

Adult↗
PubMed1989

Sexual activity, contraception, genital infections, and cervical cancer: support for a sexually transmitted disease hypothesis.

A case-control study was conducted in Utah between 1984 and 1987 to examine risk factors for cervical cancer. Interviews were completed with 266 histologically confirmed carcinoma in situ and invasive squamous cell cervical cancer cases who were categorically matched by age to 408 controls. Among the factors identified as altering risk for cervical cancer, after adjustment for age, education, church attendance, and cigarette smoking, were: having numerous sex partners (odds ratio (OR) = 8.99 for 10 or more partners); the current mate having several sex partners (adjusted OR for 10 or more partners = 8.62); using foam or jelly as a contraceptive method (OR, adjusted for number of sex partners, = 0.44); reported Trichomonas infection (OR, adjusted for number of sex partners, = 2.10); and herpes simplex virus type 2 infection as determined by 2:1 neutralization index values above 100 (OR = 2.70). A protective effect was noted from the use of diaphragms (OR = 0.67) or condoms (OR = 0.53) in women who reported more than one sex partner. These data support the hypothesis that cervical cancer is a sexually transmitted disease.

Adult↗
PubMed1989

Memory of food intake in the distant past.

Long term recalls of dietary intake are frequently used in case-control studies, but their validity and reliability have not been established. In this study, 91 middle-aged adults (median age, 50 years) who were participants in the Longitudinal Study of Child Health and Development at the Harvard School of Public Health in Boston, Massachusetts, starting in the early 1930s, were asked in 1984-1985 to report present food intake and to recall food intakes at ages 5-7 years. 18 years, and 30 years using food frequency questionnaires. Their recalled intakes were validated by comparison with historical records of intake collected during the earlier time periods. Recall of food intake in the distant past was a better predictor of historical intake than was current diet. However, correlations between recalled and historical consumption for individual foods and food groups were generally low, rarely exceeding 0.3. Current intakes exerted a powerful influence on accuracy of recall. The consideration of participant characteristics did not prove to be consistently useful in explaining variations in food item and food group-related recall. The authors conclude that recall of food intake in the distant past may be a sufficiently valid estimate of past intake to justify its collection.

Boston↗
PubMed1989

Accuracy of recalled smoking data.

Validity of recalled cigarette data was assessed among 87 middle-aged adults by comparing recall to longitudinal records. Agreement on smoking status and amount smoked 20 years ago occurred for 87 per cent and 71 per cent of subjects, respectively. Corresponding proportions for 32-year recall were 84 per cent and 55 per cent. Gender did not influence recall accuracy. Ex-smokers tended to make the most errors. Accuracy of recalled smoking information 20 years ago was comparable to that of alcohol status and consumption frequency category.

Female↗
PubMed1989

The greeting behavior of fragile X males.

Mentally retarded males with a fragile site on the X chromosome (Xq27) were observed to exhibit a highly idiosyncratic but well-coordinated, stereotypic form of gaze avoidance during greeting ceremonies that involved the whole upper body. A comparison group of persons with other etiologically defined syndromes of mental retardation did not. Results suggest that the aberrant greeting behavior may be uniquely associated with one syndrome of mental retardation with a defined genetic etiology. The behavior pattern does not appear until middle childhood, however, and its developmental induction remains to be explained.

Adolescent↗
PubMed1989

A comparison of food frequency and diet recall methods in studies of nutrient intake of low-income pregnant women.

The aim of this study was to develop a self-administered food frequency questionnaire for use with low-income pregnant women and to evaluate its performance in classifying women according to nutrient intake. Index nutrients used were energy, protein, calcium, iron, zinc, and vitamins A, B-6, and C. Two hundred ninety-five Massachusetts women, aged 14 to 43 years, participated in the field test of the questionnaire. A subset of 95 women provided three 24-hour diet recalls for use in comparative studies. Correlation coefficients between questionnaire and diet recall scores were adjusted for measurement error resulting from the limited number of 24-hour recalls per subject, and their confidence intervals were computed. When subjects with implausibly high energy scores (greater than 4,500/day) were removed from the sample, reducing sample size by about 15%, correlation coefficients increased substantially (25% to 64%) for all nutrients except vitamin A. Adjusted correlation coefficients exceeded 0.5, excluding vitamin A (r approximately 0.15), and quintile comparisons indicated that the questionnaire would correctly identify a high proportion of the women having low intake of selected nutrients. We conclude that a self-administered questionnaire can provide useful data about individual recent intake of selected nutrients in a majority of English-speaking, low-income pregnant women, but that overestimation of food use may occur among up to 20% of this population.

Adolescent↗
PubMed1989

Evaluation of the use of standardized recommendation forms in admissions in radiologic technology, medical technology, and dietetics.

The continuing decline in the number of applicants to allied health educational programs combined with the need to ensure that graduates are competent has made essential the development of reliable predictors that more fully assess the potential of all individuals in the restricted applicant pool. The letter of recommendation is the most commonly requested information that relates to personal qualities in college applicants, but little research has been conducted on the value of this predictor. The purpose of this study was to retroactively review how attribute ratings in letters of recommendation submitted on standardized forms (N = 500) related to the source of the reference and the admission status of students applying to allied health educational programs. Results indicated that some attribute ratings distinguish between students and some do not, that standardized forms can be refined by elimination of items that failed to distinguish students, that ratings vary significantly by type of rater, and that the relationship between rating scores and admission status supports the efficacy of the standardized recommendation forms.

Allied Health Personnel↗
PubMed1988

Recall of childhood illnesses.

Recall of eight childhood communicable diseases and other illnesses was validated among 95 adults by comparison to longitudinal childhood health records. Self-reports at age 50 of several illnesses were highly accurate; however, German measles was correctly recalled by only 34% of subjects. Similar levels of accuracy were consistently found among a subset who also completed health history interviews 8 and 20 years earlier. Over-reporting of some health events was common. Past exposure to viral or bacterial agents is sometimes assessed in case-control studies by self-reports. Misclassification of prior exposure due to faulty recall may distort true associations between childhood illness and chronic disease in later life.

Accidents↗
PubMed1987

Heterogeneous cytogenetic abnormalities in small cell lung cancer cell lines.

Ten cell lines were established from different biopsies from nine patients with small cell lung cancer (SCLC). These were established from metastases in the marrow (7), breast (1), pleural fluid (1), and spinal cord (1) and had been in culture for periods varying from 1 to 11 months. All cell lines exhibited typical cytological features of SCLC, and produced neuron specific enolase. All lines examined (5) contained dense core granules and were tumorigenic when injected intracranially into nude mice. None of the six cell lines tested had an amplified oncogene (c-myc or n-myc) previously reported to be amplified in SCLC. Detailed chromosome analyses were undertaken and showed that a structural abnormality of chromosome 3(p11p23) was a frequent (6 of 10) but not invariable finding. Our study and one other indicate that there is not a unique chromosome abnormality present in all cases of SCLC, although loss of chromosome 13 and structural abnormalities of chromosome 3 were frequently found. A feature of these SCLC cell lines established from metastatic deposits was the complexity of the karyotypes due to numerical and structural chromosomal abnormalities.

Biopsy↗
PubMed1987

NE-19550: a novel, orally active anti-inflammatory analgesic.

NE-19550, N-(3-methoxy-4-hydroxybenzyl)oleamide, is a capsaicin analogue that has been shown to possess oral activity in the 55 degrees C rat hot-plate and mouse phenylquinone abdominal constriction analgesia tests. The compound also displayed anti-inflammatory activity orally in the carrageenan-inflamed rat-paw test and topically in the croton oil-inflamed mouse-ear test. NE-19550 activity in the thermal analgesia assay was not blocked by the opioid antagonist naloxone, and no inhibition of prostanoid synthesis in rat platelets or tissues was seen following a high analgesic and anti-inflammatory oral dose (300 mg/kg). A wide variety of known neuronal antagonists (adrenergic, serotonergic, dopaminergic, cholinergic, GABA-ergic, histaminergic) were found not to inhibit NE-19550 analgesia, further indicating a lack of involvement of known drug receptors mediating analgesic responses. Analgesic doses of NE-19550 were also found to lack the acute toxicity and thermoregulatory desensitization characteristics of the parent natural product capsaicin. It appears to represent a new class of potent-acting, non-narcotic, anti-inflammatory analgesic agents.

Administration, Oral↗
PubMed1986

School health practices for children with complex medical needs.

Concern is growing about the adequacy and safety of health services provided for medically complex children in public schools. A national survey of state health and education agencies was conducted to learn if guidelines existed governing the practice of eight selected nursing procedures in schools. Thirteen states (26%) had no written guidelines, 13 states (26%) had guidelines only for medication administration, and only six states (12%) had guidelines for the eight selected nursing procedures.

Adolescent↗