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Biomedical subjects

K McCormick

Publications and source records attributed to K McCormick.

At least 37 records · Page 2Linked to original sources
PubMed2001

Primary hepatocytes from mice treated with IL-2/IL-12 produce T cell chemoattractant activity that is dependent on monokine induced by IFN-gamma (Mig) and chemokine responsive to gamma-2 (Crg-2).

The IFN-gamma-inducible proteins monokine induced by IFN-gamma (Mig) and chemokine responsive to gamma-2 (Crg-2) can contribute to IL-12-induced antiangiogenic and leukocyte-recruiting activities, but the extent to which leukocytes vs parenchymal cells in different organs contribute to the production of these molecules remains unclear. The results presented herein show that IFN-gamma-dependent induction of Mig and Crg-2 gene expression can occur in many nonlymphoid organs, and these genes are rapidly induced in purified hepatocytes isolated from mice treated with IL-2 plus IL-12, or from Hepa 1-6 hepatoma cells treated in vitro with IFN-gamma. In addition to depending on IFN-gamma, the ability of IL-12 or IL-2/IL-12 to induce Mig and Crg-2 gene expression in purified hepatocytes also is accompanied by the coordinate up-regulation of the IFN-gamma R alpha and beta-chains, in the absence of IL-12R components. Supernatants of primary hepatocytes obtained from mice treated in vivo with IL-2/IL-12 or from hepatocytes treated in vitro with IFN-gamma contain increased chemotactic activity for enriched human and mouse CD3(+) T cells, as well as mouse DX5(+) NK cells. The hepatocyte-derived chemotactic activity for mouse T cells but not NK cells was ablated by Abs specific for Mig and Crg-2. These results suggest that parenchymal cells in some organs may contribute substantially to initiation and/or amplification of inflammatory or antitumor responses.

Animals↗
PubMed2001

Postjunctional alpha(2C)-adrenoceptor contractility in human saphenous vein.

The postjunctional alpha(2)-adrenoceptor-mediated contractility was characterized in human saphenous vein derived from coronary artery bypass graft surgery. Human saphenous vein contracted to alpha(2)-adrenoceptor selective agonists BHT-920 (5,6,7,8-Tetrahydro-6-(2-propenyl)-4H-thiazolo[4,5-d]azepin-2-amine dihydrochloride; pD(2)=6.7+/-0.1) and UK 14,304 (5-Bromo-6-(2-imidazolin-2-ylamino)quinoxaline; pD(2)=7.2+/-0.1). BHT-920-induced contractions were inhibited by the alpha(2)-adrenoceptor antagonist yohimbine (17-Hydroxy-yohimban-16-carboxylic acid methyl ester hydrochloride; pA(2)=8.7+/-0.5), but not by the alpha(1)-adrenoceptor antagonist prazosin (1-[4-Amino-6,7-dimethoxy-2-quinazolinyl]-4-[2-furanylcarbonyl]-piperazine hydrochloride; 300 nM). In contrast, prazosin (pK(b)=7.9+/-0.2) potently antagonized contractions elicited by the alpha(1)-adrenoceptor agonist phenylephrine ((R)-3-Hydroxy-alpha-[(methylamino)methyl] benzenemethanol hydrochloride; pD(2)=4.9+/-0.1), indicating that both alpha(2)- and alpha(1)-adrenoceptor evoke human saphenous vein contractions. Functional antagonist activity estimates (pA(2) or pK(b)) obtained for the alpha-adrenoceptor antagonists ARC 239 (2-[2-(4-(2-Methoxyphenyl)piperazin-1-yl)ethyl]-4,4-dimethyl-1,3-(2H,4H)-isoquinolindione dihydrochloride), WB 4101 (2-(2,6-Dimethoxyphenoxyethyl)aminomethyl-1,4-benzodioxane hydrochloride) and HV 723 (alpha-ethyl-3,4,5-trimethoxy-alpha-(3-((2-(2-methoxyphenoxy) ethyl)amino)propyl)benzeneacetonitrile) against BHT-920-induced human saphenous vein contractions were 7.0+/-0.6, 8.3+/-0.6 and 7.7+/-0.3, respectively. The alpha(2)-adrenoceptor subtype affinities (pK(i)) obtained in recombinant human alpha(2A)-, alpha(2B)- and alpha(2C)-adrenoceptor competition binding assays were 8.6, 8.3 and 8.6 for yohimbine; 6.3, 8.4 and 7.0 for ARC 239; 8.4, 7.5 and 8.4 for WB 4101 and 7.5, 7.4 and 7.9 for HV 723, respectively. Taken together, the binding and functional antagonist activity estimates obtained in these investigations indicate that alpha(2C)-adrenoceptor is the predominant postjunctional alpha(2)-adrenoceptor subtype in human saphenous vein.

Adrenergic alpha-Agonists↗
PubMed2001

An assessment of cancer clinical trials vocabulary and IT infrastructure in the U.S.

Twenty-three cancer research centers in the U.S. were assessed to determine data standards, vocabularies, and information infrastructure used in support of clinical trials. Eighteen of the 23 responded. Major findings were related to: 1) clinical trials infrastructure information, 2) current systems environment, 3) technical details, and 4) vocabulary and data standards. The size of the facility correlated with the quality, features and functionality of the clinical trials system (CTS). One facility had as many as 22 separate CTS. There were only 2 sites that had integrated clinical information systems (CIS) with CTS. The responses included the major vocabularies and data standards used in CTS. The majority used some automation but many also reported manual data entry. CTS had more manual entry than CIS because of regulatory reporting requirements. The assessment identified opportunities for guidance in defining vocabularies and standards for cancer clinical trial systems in the US.

Clinical Trials as Topic↗
PubMed2000

Characteristics of Latino mental health clinicians: a preliminary examination.

The purpose of this study was to explore a variety of characteristics of experienced Latino psychotherapists in an attempt to clarify elements of cultural competence. The sixty five subjects were from a sample of convenience recruited from mental health agencies serving predominantly Latino clients in the San Francisco Bay area. The first part of the study consisted of two focus groups with Latino clinicians to discuss culturally competent services and to generate ideas to inform a preliminary questionnaire. The second part consisted of administering the questionnaire to the sample. Results were mixed, revealing a combination of responses indicating clinical interventions based upon universally accepted principles, and those uniquely used with Latino clients which were more clearly associated with the cultural traits of Latinos.

Adult↗
PubMed2000

Effects of cocoa extracts on endothelium-dependent relaxation.

The aim of this study was to examine the effects of procyanidins derived from cocoa on vascular smooth muscle. Two hypotheses were tested: 1) extracts of cocoa, which are rich in procyanidins, cause endothelium-dependent relaxation (EDR), and 2) extracts of cocoa activate endothelial nitric oxide synthase (NOS). The experiments were carried out on aortic rings obtained from New Zealand White rabbits. The polymeric procyanidins (tetramer through decamer of catechin) caused an EDR. In addition, the Ca(2+)-dependent NOS activity, measured by the L-arginine to L-citrulline conversion assay, was significantly increased in aortic endothelial cells exposed to polymeric procyanidins, whereas monomeric compounds had no such effect. These findings demonstrate that polymeric procyanidins cause an EDR that is mediated by activation of NOS.

Animals↗
PubMed1999

Role of cytomegalovirus in the T cell changes seen in elderly individuals.

The effect of prior cytomegalovirus (CMV) infection on the immune system was evaluated in young and elderly volunteers. Prevalence of IgG antibodies to CMV was higher in the elderly volunteers. In both age groups, there was a strong association with CMV seropositivity and increased number of CD28- CD4 or CD8 T cells, as well as with increased numbers of T cells expressing CD56 or DR. Although these changes have previously been reported to be age-related, they were independent of age when CMV serological status was taken into account. In contrast, both age group and CMV status were important determinants of the total number of T cells, the number of CD8 T cells, and the number of CD8 T cells expressing CD45RA or CD28. These findings indicate that prior infection with CMV, as reflected by CMV serological status, has important effects on T cell subsets and surface markers and must be considered whenever evaluating age-related changes in immunological parameters.

Adult↗
PubMed1999

Mitomycin C-augumented trabeculectomy with postoperative wound modulation in pediatric glaucoma.

PURPOSE: The purpose of this study was to evaluate mitomycin C-augmented trabeculectomy combined with postoperative subconjunctival 5-fluorouracil and laser suture lysis in the treatment of refractory pediatric glaucoma. METHODS: Twenty-one consecutive cases (17 patients) with refractory pediatric glaucoma treated with mitomycin C trabeculectomy (0.4 mg/mL for 3 to 5 minutes) and postoperative 5-fluorouracil, laser suture lysis, or both were retrospectively reviewed. Success was defined as intraocular pressure between 4 and 16 mm Hg without further glaucoma surgery or devastating complication. RESULTS: The median age of the study population was 2.6 years (range, 0.05 to 16 years). The overall success rate was 52.4%, with a median follow-up of 23 months for successful cases. Success rates for patients older than 1 year of age versus those younger than 1 year of age at surgery were 73% and 30%, respectively. Success rates for phakic versus aphakic eyes were 64% and 29%, respectively. Age and lens status, taken together, were significant predictors of outcome (P = .013). Reasons for failure in this study were uncontrolled intraocular pressure (8 cases), persistent wound leak (1 case), and endophthalmitis (1 case); the latter 2 cases required bleb excision. Other complications encountered included chorioretinal detachment, shallow anterior chamber, 5-fluorouracil toxicity, and cataract formation. No irreversible visual deficits could be attributed to the trabeculectomy procedure or subsequent complications in any of these cases. CONCLUSIONS: Mitomycin C-augmented trabeculectomy combined with postoperative suture lysis and 5-fluorouracil is a viable option for older phakic children with refractory glaucoma. This procedure has a lower success rate in infants and in aphakic eyes. Both early and late postoperative complications are common, and diligent lifelong long-term follow-up is needed to detect bleb leaks and infection. The addition of postoperative suture lysis and 5-fluorouracil to mitomycin C-augmented trabeculectomy did not provide any convincing improvement in the success of this procedure in pediatric patients with refractory glaucoma and may have increased the complication rate.

Adolescent↗
PubMed1999

Body composition of preterm infants during infancy.

AIMS: To examine body composition in preterm infants. METHODS: Body composition was measured by dual energy x-ray absorptiometry (DEXA) at hospital discharge, term, 12 weeks, and at 6 and 12 months corrected age in 125 infants (birthweight < or = 1750 g, gestational age < or = 34 weeks). RESULTS: Body weight derived by DEXA accurately predicted that determined by conventional scales. In both sexes lean mass (LM), fat mass (FM), %FM, bone area (BA), bone mineral mass (BMM), and bone mineral density (BMD) increased rapidly during the study; significant changes were detectable between discharge and term. At 12 months, LM, BA, and BMM, but not FM, %FM, or BMD were greater in boys than in girls. Corrected for age, LM was less than those of the reference term infant; FM and %FM were similar; BMM was greater. Corrected for weight, LM was similar to those of the reference infant, while the FM and %FM of study infants were slightly greater. CONCLUSIONS: DEXA accurately measures body mass. Body composition in preterm boys and girls differs. Interpretation of DEXA values may depend on whether age or body weight are regarded as the appropriate reference.

Absorptiometry, Photon↗
PubMed1999

Feeding preterm infants after hospital discharge: effect of diet on body composition.

Our purpose in this study was to examine whole body composition, using dual energy x-ray absorptiometry (DEXA) during dietary intervention in preterm infants (< or = 1750 g birthweight, < or = 34 wk gestation). At discharge, infants were randomized to be fed either a preterm infant formula (discharge-6 mo; group A) or a term formula (discharge-6 mo; group B), or the preterm formula (discharge-term) and the term formula (term-6 mo; group C). Nutrient intake was measured between each clinic visit. To measure body composition, DEXA was used at discharge, term, 12 wk, 6 mo, and 12 mo corrected age. The data were analyzed by ANOVA. At discharge, no differences were noted in patient characteristics between groups A, B, and C. Although energy intakes were similar, protein and mineral intakes differed between groups (A > C > B; p < 0.0001). During the study, weight gain and LM gain were greater in group A than B. At 12 mo, weight, LM, FM, and BMM but not % FM or BMD were greater in group A than B. However, the effects of diet were confined to boys, with no lasting effects seen in girls. In summary, therefore, DEXA was precise enough to detect differences in whole body composition during dietary intervention. Increased weight gain primarily reflected an increase in LM and is consistent with the idea that the preterm formula more closely met protein and/or protein-energy needs in rapidly growing preterm male infants.

Absorptiometry, Photon↗
PubMed1998

Leptin does not affect adipocyte glucose metabolism: studies in fresh and cultured adipocytes.

Leptin, the 16-kd hormone produced by white fat cells, regulates energy homeostasis, satiety, and multiple sites in the neuroendocrine system. Leptin receptors have been identified in the central nervous system (CNS) and are widespread in peripheral tissues, including fat. Given the association between insulin resistance and obesity, it is important to establish whether leptin has additional effects on peripheral insulin action and glucose metabolism. This study examined whether leptin has a direct autocrine/paracrine action on glucose metabolism in both freshly isolated and 24-hour cultured rat fat cells. Freshly isolated rat adipocytes were incubated for 30 minutes with 200 ng/mL recombinant murine leptin. Thereafter, basal and insulin-stimulated (10(-8) mol/L) glucose transport, glycolysis-Krebs oxidation and lipogenesis ([6-14C]glucose conversion to [14C]O2 and to [14C]triglyceride), and lipolysis were measured. Upon leptin exposure, no statistical differences were detected in glucose transport or metabolism. Increasing the leptin concentration to 1 to 2 microg/mL or prolonging the duration of preincubation with the fat cells to 60 minutes before the metabolic assays did not alter the results. Finally, using two disparate fat cell culture methods with differing substrate additions (pyruvate and high or low glucose concentrations), there was no effect of 24-hour exposure to leptin (200 ng/mL) on basal and insulin-stimulated glucose transport or lipogenesis. We conclude that leptin does not modulate basal or insulin-stimulated glucose metabolism in isolated and cultured fat cells in vitro. However, in vivo, higher pericellular leptin concentrations, as well as other cellular or soluble serum factors, may exist that might lead to a physiologically relevant autocrine action of leptin.

Adipocytes↗
PubMed1998

Feeding preterm infants after hospital discharge: effect of dietary manipulation on nutrient intake and growth.

The objective of this study was to compare formula intake, the time of weaning, and growth in preterm infants (< or = 1750-g birth weight, < or = 34-wk gestation) fed a standard term or preterm infant formula after initial hospital discharge. Infants were randomized at hospital discharge to be fed a preterm infant formula from discharge to 6 mo corrected age (group A), a term formula from discharge to 6 mo (group B), or the preterm formula (discharge to term) and the term formula (term to 6 mo (group C). Infants were seen biweekly (discharge to term) and monthly (term to 6 mo), when intake was measured and anthropometry and blood sampling were performed. The results were analyzed using ANOVA. Although nutrient intake was similar, at 6 mo girls were lighter (6829 versus 7280 g) and shorter (64.4 versus 66.0 cm) than boys (p < 0.05). Patient characteristics were similar between the treatment groups. Although the volume of intake differed (B > C > A; p < 0.001), energy intake was similar in the groups. Because of differences in formula composition, protein, calcium, and phosphorus intakes differed (B < C < A; p < 0.001). Lower protein intakes were related to lower blood urea nitrogen levels (B < C < A; p < 0.001). At 6 mo, infant boys in B and C were lighter (6933, 6660 < 7949 g), shorter (65.3, 64.9 < 67.1 cm), and had a smaller head circumference (43.7, 43.7 < 44.8 cm; p < 0.05) than infants in group A. Preterm infants were found to increase their volume of intake to compensate for differences in energy density between formulas. After hospital discharge, infant boys fed a preterm formula grew faster than infant girls fed a preterm formula or infant boys fed a term formula.

Blood Urea Nitrogen↗
PubMed1996

Nursing on the electronic highway.

Notes prepared by Helen Hamilton, Lois Hazelton and Keith O'Brien, from a paper presented by Dr Kathleen McCormick at Royal College of Nursing, Australia's National Forum, Canberra in May 1996. The original paper identified the potential, current trends and applications of electronic technology, and also discussed some of the difficulties and barriers to realising the full potential of this technology in health care, education and research.

Computer Communication Networks↗
PubMed1995

Wavelet variations on the Shannon sampling theorem.

The Shannon sampling theorem asserts that a continuous square-integrable function on the real line which has a compactly supported Fourier transform is uniquely determined by its restriction to a uniform lattice of points whose density is determined by the support of the Fourier transform. This result can be extended to the wavelet representation of functions in two ways. First, under the same type of conditions as for the Shannon theorem, the scaling coefficients of a wavelet expansion will determine uniquely the given square-integrable function. Secondly, for a more general function, there is a unique extension from a given set of scaling coefficients to a full wavelet expansion which minimizes the local obstructions to translation invariance in a variational sense.

Fourier Analysis↗