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Biomedical subjects

K Patrick

Publications and source records attributed to K Patrick.

At least 37 records · Page 2Linked to original sources
PubMed1989

Human T cell responses to the Epstein-Barr nuclear antigen-1 (EBNA-1) as evaluated by synthetic peptides.

A panel of synthetic peptides derived from Epstein-Barr virus (EBV) nuclear antigen 1 (EB-NA-1) was used to examine human T cell responses to this antigen. In six of seven normal persons with past EBV infection, T cell precursors specific for five peptides (P27, amino acid residues 83-101;P62, 148-166;E31, 353-367;E41, 368-381; and E11, 461-474) were detectable. The precursor frequencies were in the range of 1:20,000 to less than 1:100,000 peripheral blood mononuclear cells as determined by limiting dilution analyses. Only two of these peptides were predicted as alpha-helices; all peptides were glycine-rich. Four other peptides were not reactive in the seven individuals tested. T cell responses were not detectable in donors without prior EBV infection. Infectious mononucleosis patients investigated 4-6 weeks after diagnosis had likewise no detectable peptide-specific T cell precursors. Thus, it appears that T cells recognizing peptides from EBNA-1 arise and persist in people with past EBV infection.

Amino Acid Sequence↗
PubMed1988

Student health. Medical care within institutions of higher education.

The field of student health care lacks a positive identity in medicine and is often not well understood by the higher education community. This article explores the history, organization, staffing, utilization, financing, and governance of student health centers (SHCs). Student health centers are available to approximately 10 million of the 12.5 million US university students. As many as 27,000 individuals, including probably more than 3000 physicians, work in SHCs. Sources and amount of funds expended for this care vary widely from campus to campus, as does the intensity of services offered. A survey of this nation's largest institutions suggests that an average of $102 per student per year is spent on SHCs. The total amount spent on student health care in this country may exceed $1 billion each year. Student health care faces opportunities and obstacles in the future as our ability to promote health and prevent disease improves, as institutions of higher education allocate their limited educational resources, and as society determines where to invest its limited medical resources.

Health Promotion↗
PubMed1987

Expression of a germline human kappa chain-associated cross-reactive idiotype after in vitro and in vivo infection with Epstein-Barr virus.

The mouse monoclonal antibody 17.109 recognizes a cross-reactive idiotype (CRI) associated with kappa IIIb light chains of human IgM-rheumatoid factor (RF) paraproteins. The 17.109 idiotypic determinant is encoded by one or a group of closely related V kappa genes. The association of the idiotype with IgM- and IgA-rheumatoid factors in certain autoimmune diseases necessitates an understanding of how human B lymphocytes can be induced to express the idiotype. To investigate the cellular expression of the 17.109 CRI, peripheral blood lymphocytes from normal donors were stimulated in vitro with Epstein-Barr virus (EBV) and pokeweed mitogen (PWM). EBV induced greater expression of IgM-associated 17.109 CRI than did PWM. The 17.109 CRI was preferentially associated with IgM rather than with IgG. In vivo EBV infection was studied in college students with infectious mononucleosis and displayed similar elevation of IgM-associated 17.109 CRI in sera obtained at presentation of clinical illness. Later, IgM levels declined while IgG-associated 17.109 CRI rose. The 17.109 idiotype was unrelated to antibodies against the Epstein-Barr virus nuclear antigen and the viral capsid antigen and was probably due to generalized activation of early B cells. These observations support the hypothesis that the 17.109 CRI is expressed by in vitro and in vivo EBV-infected cells. The 17.109 idiotype identifies a highly conserved V kappa gene product, which is expressed preferentially after EBV infection, but not exclusively with RF autoantibodies.

Animals↗
PubMed1986

Estrogen regulation of H59 antigen in vivo and in vitro.

H59 antibody, a murine monoclonal antibody, recognizes a cell surface peptide of approximately 30,000 MW which is estrogen regulated. The data supporting this conclusion have been generated from in vitro systems and indirectly from human tissue specimens. The antigen is detected only in estrogen regulated breast cancer cells in culture and is not detected in two estrogen independent cell lines, R3 and R27, which were derived from estrogen sensitive MCF-7 that contain the antigen. The antigen is increased in estrogen stimulated cells and decreased in tamoxifen inhibited cells. H59 antigen appears estrogen regulated in human breast colostrum and milk and in endometrium. The antigen is found in 40% of breast cancer and most, if not all, normal breast tissue. In the more than 300 breast cancer specimens studied, H59 antigen was detected in predominately estrogen and/or progesterone receptor containing tumors. This antigen was found only in about 50% of ER positive tumors. When the presence of H59 was compared to other prognostic factors in breast cancer, it appeared to be an independent variable and correlated only with the presence of estrogen and progesterone receptor. The antigen can be detected in normal serum, and studies are underway to determine if it will serve as a circulating marker protein in hormone dependent breast cancer.

Animals↗
PubMed1985

Normal human blood density gradient lymphocyte subset analysis: I. An interlaboratory flow cytometric comparison of 85 normal adults.

An interlaboratory flow cytometric comparison of several commercially available human lymphocyte subset reagents was undertaken in three different laboratories. Fresh Hypaque-Ficoll purified blood mononuclear cells were stained at 4 degrees C or 22 degrees C. Direct or indirect surface immunofluorescence was carried out at all sites using an EPICS V flow cytometer. Fullbright, 10-micron fluorescent polystyrene microspheres were used for optical alignment and standardization. A log integral fluorescent histogram gated on forward and right angle scatter was collected on 1-2 X 10(4) cells for each reagent and the proportion, of positive cell determined for each reagent. With the exception of one reagent, anti-B1, which showed an approximately twofold variation, all three laboratories showed remarkable agreement. Thus there was no significant difference noted for the following reagents: OKT4, CCT4, Leu 3a, Leu 2a, OKT8, or CCT8. We attribute these findings to the availability of quality reagents, precision instrumentation, and a standard lymphocyte preparation.

Adult↗
PubMed1985

Decreased serotonin content of embryonic raphe neurons following maternal administration of p-chlorophenylalanine: a quantitative immunocytochemical study.

Previous studies from this laboratory have suggested that serotonergic (5-HT) neurons may influence the differentiation of their embryonic target cells in the developing rat brain. The present study was designed to determine whether or not maternal p-chlorophenylalanine (pCPA) administration could deplete serotonin (5-HT) in developing 5-HT neurons during embryonic days 13-15, when the effects of pCPA on neuronal genesis have been observed previously. For this study, pCPA was administered to timed-pregnant rats and embryos were sacrificed at two different gestational ages, embryonic days 13-14 (E13-14) and 14-15 (E14-15). Immunotitration experiments were carried out on tissue sections, using an antiserum to 5-HT-hemocyanin conjugates to obtain a relative estimate of the amount of 5-HT contained within individual 5-HT neurons of embryos from pCPA-treated and control mothers. Diminished immunoreactivity as a consequence of addition of increasing amounts of antigen was then quantitated on a relative scale by comparison with the amount of immunoreactivity present when no antigen was added to the primary antiserum. Two major findings resulted from this study: maternal pCPA treatment depleted 5-HT by approximately 50% in developing 5-HT neurons at embryonic ages E13-14 and E14-15, but depletion appeared to be greatest in the youngest embryos; developing 5-HT neurons increased their content of neurotransmitter by approximately 10-fold during this one day of embryonic development, an effect which could be observed in both pCPA-treated and control animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Imitation in toddlers as a function of motor and verbal aspects of modeling.

This study investigated the effects of the motor and verbal aspects of modeling on imitation. The subjects were 2- and 3-year-old children (N = 96). The child's imitation responses were recorded during the play period that followed each modeled act. Each child observed the model in one of four modeling conditions. In Condition 1, the model "flew" a telephone while saying that he or she was flying an airplane. Imitation was recorded as motor if the child flew the telephone but was recorded as verbal and realistic if the child flew an airplane. In Condition 2, the model flew an airplane while saying that he or she was flying a telephone. Imitation was recorded as verbal if the child flew the telephone. In Condition 3, the model flew an airplane and said that he or she was flying an airplane. If the child flew an airplane, imitation was scored as motor, verbal, and realistic. In Condition 4, the model flew a telephone and said that he or she was flying a telephone. Imitation was scored as motor and verbal if the child flew the telephone but was scored as realistic if the child flew the airplane. In Condition 1, 2-year-olds displayed more motor imitation than 3-year-olds, and 3-year-olds displayed more verbal-reality imitation than 2-year-olds. Boys displayed more motor imitation than girls. There were no age or sex differences in Condition 2. In Condition 3, 2-year-olds imitated more than 3-year-olds, with 3-year-old girls imitating the least. In Condition 4, reality imitation was largely due to 2-year-old boys' imitation of masculine-type acts.

Child Development↗
PubMed1984

Clinical correlates of methylphenidate blood levels.

The clinical correlates of methylphenidate blood levels in hyper-active children and normal adults were examined in five studies. Although occasional correlations between blood levels and neuroendocrine response were noted within subjects along the pharmacokinetic time profile of the drug, no significant associations were found between blood levels and clinical response in behavioral measures or laboratory tests of attention or activity. It is unlikely that routine methylphenidate blood level determinations will become a part of the routine clinical management of hyperactive children.

Adult↗
PubMed1983

High frequency jet ventilation in experimental airway disruption.

Anecdotal observations suggest that high frequency jet ventilation (HFJV) is beneficial in major airway disruption. Quantitative evaluation is, however, unavailable. In 12 healthy mongrel dogs, a tracheal window of increasing size, from 0.5 x 1 cm to 1.5 x 2 cm, was opened. Dogs were supported on volume-cycled ventilation (VCV) and on HFJV, using injector cannulas of 1.06 and 1.62 mm internal diameter. The tracheal window was then closed and an upper lobectomy performed, followed by total pneumonectomy. Arterial blood gases were obtained after 10 min in each experimental condition. VCV could maintain life-supporting blood gases only with the tracheal window of 0.5 x 1 cm. HFJV, delivered with a 1.06-mm injector cannula, was adequate with a tracheal window of 1 x 1 cm, or after a lobectomy. In all experimental conditions, HFJV delivered with a 1.62-mm injector effectively maintained alveolar ventilation and arterial oxygenation. Gas transport on HFJV is based, in part, on the principles of jet mixing and entrainment; increasingly large tidal volumes can be delivered under conditions of low and constant pressure. Air leaks through pathological openings remain constant even when tidal volume is increased, so that alveolar ventilation can be adequately maintained.

Airway Obstruction↗
PubMed1983

Pharmacokinetics of methylphenidate in man, rat and monkey.

The pharmacokinetics and bioavailability of methylphenidate (MPH) and a metabolite, ritalinic acid (RA), were studied in normal adults, children with hyperactivity, monkeys and rats. Adult males received 0.15 or 0.3 mg/kg of MPH orally and MPH and RA were analyzed in plasma samples obtained at various times after treatment. Maximal MPH concentrations in plasma were found to occur 2.2 hr after administration of either dose (range: 1.0-4.0). The mean (+/-S.E.) maximal concentration in plasma for MPH was 3.5 +/- 0.4 ng/ml after 0.15 mg/kg and 7.8 +/- 0.8 ng/ml after 0.3 mg/kg. MPH clearances were high (10.1 liters/hr/kg) and variable (range: 3.6-23.2) for the 0.3 mg/kg dose. Pharmacokinetic parameters for children receiving 0.3 mg/kg were essentially the same as for adults. RA plasma levels were 50 to 100 times greater than MPH levels in normal adults. The clearance of RA is less than that of MPH. The absolute bioavailability of MPH was found to be 0.19 in the rat and 0.22 in the monkey, suggesting substantial presystemic elimination of MPH.

Adult↗
PubMed1982

Impact of a family practice residency on a community hospital: a case study of costs and benefits.

A modified framework of cost-benefit analysis, including explication of direct, indirect, and intangible costs and benefits, is used to assess the financial impact of a university-affiliated family practice residency program upon a community hospital. During resident year 1978-79 it was found that a community hospital affiliated with the University of Utah Family Practice Residency Program may have experienced a net financial benefit of as much as $243,543 or a net financial cost of as much as $12,537. At the same time, the hospital is likely to have experienced substantial intangible benefits and moderate intangible costs. This approach may have utility in similar settings where community hospitals support family practice resident education.

Cost-Benefit Analysis↗
PubMed1980

Medical care for vacationers: health services at Yellowstone National Park.

Medical services provided to vacationers and employees in Yellowstone National Park were reviewed for the years 1975 through 1977. Both ambulatory and inpatient data were obtained, including diagnoses, place of residence, medications prescribed, and methods of payment. The types of problems and modes of treatment did not differ from typical primary care practices. Health maintenance was the most common reason for outpatient visits. The distribution of diagnoses among park visitors and employees was the same within age categories, although the employees' rate of utilization was nearly twice that of the visitors. Distance from home was directly related to the frequency with which visitors used clinic services.

Camping↗