Search PubMed⌕ Search

Biomedical subjects

M McGrath

Publications and source records attributed to M McGrath.

At least 55 records · Page 3Linked to original sources

Appropriateness of the Draw-A-Person test with Alaskan Native populations.

The appropriateness of the Draw-A-Person test with Alaskan Native populations was assessed by matching 33 White subjects to 33 Alaskan Native subjects, asking them to perform the DAP, and rating their performance according to eight criteria chosen for their clinical relevancy. Results indicated that neither level of commitment to Native culture nor ethnicity per se affected drawing ratings. It is hypothesized that the DAP is a useful clinical tool appropriate for use with Alaskan Native populations.

Acculturation↗

Molecular and immunophenotypic characterization of AIDS-associated, Epstein-Barr virus-negative, polyclonal lymphoma.

PURPOSE: A molecular analysis of non-Hodgkin's lymphomas (NHLs) from patients with AIDS was undertaken to determine the prevalence and immunophenotype of polyclonal B-cell lymphoma. MATERIALS AND METHODS: DNA was extracted from 40 diagnostic biopsy specimens obtained from patients seen at University of California, San Francisco (UCSF) between 1986 and 1990. Clonality, infection with Epstein-Barr virus (EBV), and presence of a rearranged c-myc gene were determined by Southern blot analysis. Lymphoma immunophenotypes were determined by frozen-section immunohistochemical analysis. RESULTS: The most prevalent genotype of lymphoma in this study was that of polyclonal, EBV-negative tumors with no evidence of c-myc rearrangement (14 of 40; 35%). Monoclonal, EBV-positive tumors with no evidence of c-myc rearrangement comprised the second most prevalent class (10 of 40; 25%), and polyclonal, EBV-positive tumors similar to those seen in transplant patients were observed in only a small subset (three of 40; 8%) of specimens analyzed. The immunophenotype of B cells in the polyclonal EBV-negative subset was equally divided into B-cell-predominant and mixed-phenotype lymphomas, with the latter category containing numerous infiltrating T cells. The B cells in each category were immunoglobulin M-positive (IgM+), CD20+, CD21-. All but one of the polyclonal NHLs had large-cell histology. CONCLUSIONS: EBV-negative, AIDS-associated, polyclonal B-cell lymphoma appears to be a new class of human immunodeficiency virus (HIV)-associated disease more prevalent in the current study than any other molecular subclass. The absence of CD21, the EBV receptor, may explain in part the absence of EBV within this polyclonal B-cell population.

Blotting, Southern↗

Localised application of an activating signal to a cell: experimental use of fibronectin bound to beads and the implications for mechanisms of adhesion.

Small beads derivatised with fibronectin or with bovine serum albumin are allowed to attach to BHK cells in suspension at low ratios of beads to cells. In this way populations of cells bearing predominantly one bead per cell can be prepared. We show that the attachment of one bead per cell affects the adhesion and spreading of that cell on substrata, raising adhesion and increasing spreading if the signal molecule is fibronectin, decreasing these quantities if the bead bears BSA. The experiments are conducted in the absence of other sources of exogenous fibronectin and in some cases in the additional absence of endogenous sources. The effects are especially marked if the substratum is adsorbed haemoglobin on which control cells show little attachment or spreading. We further show by interference reflection microscopy and by scanning electron microscopy that the beads are found on the non-adhering side (uppermost or outer) of the cell when fibronectin-bearing beads are used, presumably because fibronectin will not attach to haemoglobin. The increased adhesion and spreading found in such cases must be attributed to an activation produced by the bead, which spreads to other parts of the cell and which activates a fibronectin-independent mode of adhesion.

Animals↗

A turnover prevention program for child care workers: a failed effort?

This study describes efforts to reduce turnover of child care workers, one of the many activities undertaken within the Milieu Enhancement Project. This 3-year endeavor, funded by the Division of Nursing of the Department of Health and Human Services, allowed nurses to provide care for orphaned and disadvantaged children, test the value of a nursing practice model, analyze the cost-benefit and the cost-effectiveness of the project, computerize existing and model-derived health care records, and allow faculty and graduate students to practice autonomously in a nontraditional setting. The research question was: What is causing job dissatisfaction in child care workers? Nurses and social workers used the Milieu Enhancement Model to conceptualize, address, and evaluate factors contributing to turnover. While statistical significance was not obtained in the turnover rates before and after implementation of the Turnover Prevention Program, the milieu was enhanced in many ways. Data are presented to support many aspects of the program's success.

Adult↗

Human T cell lymphotropic virus types I and II in intravenous drug users in San Francisco: risk factors associated with seropositivity.

Serologic assays for human T cell lymphotropic virus types I and II (HTLV I/II) infection were done in 676 intravenous drug users (IVDUs) in San Francisco between 1985 and 1987: 150 in 1985, 44 in 1986, and 482 in 1987. All sera were tested by Western blot, ELISA, and p24 RIA. A total of 111 participants were seropositive in a minimum of two assays. Duration of intravenous heroin use was strongly associated with the risk of HTLV I/II seropositivity: greater than or equal to 21 years odds ratio, 6.1 (95% confidence interval [CI], 2.2-17.5), compared with less than 10 years of heroin use. Additional independent risk factors included black or Hispanic race, female sex, and the use of drugs in a shooting gallery. Coinfection of HTLV I/II and human immunodeficiency virus was less frequent than expected by chance (P less than .02). Longitudinal specimens were available in 154 participants. The age- and race-adjusted seroconversion rate was 3.4% (95% CI, 1.3-8.9) per person per year. Of the 349 homosexual men tested, none were HTLV I/II-seropositive.

Adult↗

Peptides derived from the CDR3-homologous domain of the CD4 molecule are specific inhibitors of HIV-1 and SIV infection, virus-induced cell fusion, and postinfection viral transmission in vitro. Implications for the design of small peptide anti-HIV therapeutic agents.

Peptides 12-25 amino acids in length from the V1J1 region of the CD4 molecule (residues 1-120) were synthesized as randomly derivatized, deliberately derivatized, or pure peptide products, and tested for their ability to inhibit HIV-1-induced cell fusion, HIV-1 and SIV infection of CD4-positive human cells, HIV-1 envelope glycoprotein binding to the CD4 molecule, CD4-neutralizing antibody binding to the CD4 holoreceptor, and CD4-dependent cellular immune function in the mixed lymphocyte and cytotoxic T-cell bioassays. Only peptides derived from the complementarity-determining region 3 (CDR3)-homologous domain of CD4, in particular CD4(81-92) and CD4(81-101), were effective antiviral agents. Within the CD4(81-92) series, R-group derivatization of selective amino acid residues was an absolute requirement for biological activity. The prototype compound T1C4E5-tribenzyl-K10-acetyl-TYICEVEDQKEE inhibited HIV-1-induced cell fusion at 32 microM, HIV-1 infection of CEM-SS cells at 10 microM, SIV infection of CEM-174 cells at less than 125 microM, gp120/CD4 binding at 60 microM, and postinfection cell-mediated viral transmission at 10-15 microM. Compounds of identical structure and derivatization, but of altered primary sequence, were substantially less active, or without activity, in these assays. These data indicate that the effect of amino acid derivatization of the CD4(81-92) peptide was most likely restriction of the flexible underivatized peptide backbone to a conformation closely approximating that of the CDR3-homologous gp120 binding site of the native CD4 molecule. Peptide antiviral activity was specific, as judged by lack of cytotoxicity, lack of inhibition of HTLV-1-induced cell fusion, and lack of inhibition of CD4-dependent cellular immune function in vitro. Further derivatization of the prototype compound involving the production of cyclic congeners yielded peptides with submicromolar potency to block HIV-1 infection, strengthening the hypothesis that previous peptide derivations accomplished partial restriction of the conformation of CD4(81-92) to one favorable for interaction with gp120. Concentrations of the original prototype compound T1C4E5-tribenzyl-CD4(81-92) that inhibited infection in vitro more than 50% could be achieved for several hours by intravenous infusion in primates and were well-tolerated at these levels. The peptide was not efficacious to inhibit establishment of viral infection at these doses; however, peptide treatment did lower average viral antigenemia and delay the cumulative time to morbidity relative to the control group.

Acquired Immunodeficiency Syndrome↗

Food safety and pharmacokinetic studies which support a zero (0) meat and milk withdrawal time for use of sometribove in dairy cows.

Sometribove (SB) is a synthetic form of bovine somatotropin (BST) whose amino acid sequence is the same for 190 of the 191 amino acids in BST. Administration of 500 mg of SB to dairy cows every 14 d increases the efficiency of milk production. Regulatory agencies have authorized a zero (0) milk and meat withdrawal time for investigational use of SB. The scientific basis for this authorization is as follows: 1) BST and other non-primate somatotropins are not active in humans, due to differences in the amino acid sequence from human somatotropin, which limits the ability of BST to bind to receptors on human tissues. 2) SB is not orally active, as it is degraded like other proteins when eaten. Administration of 50,000 microgram/kg/d SB to rats for 90 d produced no growth response. 3) Residual levels of SB in meat/milk are very low (ppb) and comparable to endogenous BST levels. 4) Residual levels (ppb) of insulin-like growth factor I (IGF-I) in meat and milk are only marginally increased by SB treatment (somatotropin stimulates local production of IGF-I in tissues to mediate some of its biological effects. 5) IGF-I was not orally active when fed to rats at doses ranging from 200 to 2,000 microgram/kg for 14 d.

Animals↗

Behavioral and psychophysiologic assessment of the preterm infant.

Cardiorespiratory activity was recorded during attentional responsivity on the Brazelton scale in term and preterm infants. Preterm infants showed less heart rate deceleration, less heart rate variance and less power in the ECG spectrum at frequencies associated with respiratory sinus arrhythmia and oscillations in blood pressure: A lower threshold for attentional stimulation in the preterm infant may trigger a CNS mechanism that protects the infant from stimulus overload. Study of the coordination between behavioral and physiological reactivity provides an understanding of the role of the CNS in mediating information processing.

Child Behavior↗

Need for respite-care services for caregivers of persons with mental retardation.

The initial findings of a survey of 190 families caring for people with mental retardation in the districts of Arfon and Anglesey, North Wales, were reported. Attention was focused on the way informal caregivers define the problems of care. Analysis was concentrated on the relations between the management of challenging behavior, which seems most critical to caregivers, rather than the management of physical dependency, and the largely unmet needs for a range of support services. Types of relief and respite-care services for caregivers emerged as clear priorities. Further analysis identified some of the characteristics of families who appear to have marked preference for this type of support. Policy and practice implications were discussed.

Activities of Daily Living↗

AIDS-associated non-Hodgkin's lymphoma in San Francisco.

The characteristics of acquired immunodeficiency syndrome-associated non-Hodgkin's lymphoma in 84 patients diagnosed and treated at San Francisco General Hospital are presented herein. While the majority were high-grade B-cell lymphomas, one cutaneous T-cell and one peripheral T-cell lymphoma were observed. In addition, three other tumors were suspicious for T-cell lymphoma. Sixty-seven percent of patients had stage IV disease, often at unusual sites. Epstein-Barr virus DNA sequences were identified in only five of 15 tumors by dot-blot analysis. Patients were treated with a variety of standard chemotherapeutic regimens, with radiation therapy alone, or with a novel chemotherapy protocol (COMET-A). No significant differences in complete response rates were observed. The most important predictor of survival was the total number of CD4-positive lymphocytes. Other predictors of survival included history of a diagnosis of acquired immunodeficiency syndrome, Karnofsky performance score, and the presence of extranodal disease. Survival was shorter among patients who received higher doses of cyclophosphamide (greater than 1 g/m2), including those treated with the COMET-A regimen. Implications for therapeutic decision making are discussed.

Acquired Immunodeficiency Syndrome↗

Consumer participation in service planning--the AWS (All Wales Strategy) experience.

This paper provides a case study of the involvement of carers in planning services for mentally handicapped people under the All Wales Strategy (AWS). After describing the structure for consumer participation in the AWS in Gwynedd, reasons for the low level of participation found are examined before considering what can be learnt from these early experiences. Major changes in the planning structure implemented after a review of the system are outlined. The paper ends with a discussion of the major operational principles which might underlie an effective system of consumer participation.

Child↗

Psychosocial characteristics and coping skills in children maintained on chronic dialysis.

Psychosocial character traits and coping skills were examined in 12 children with end-stage renal failure. Six of the children were maintained on in-center hemodialysis and 6 were treated with home peritoneal dialysis. All of the patients felt a lack of ability to control their lives. The incidence of anxiety, depression, and hostility did not appear to vary from a population of healthy adolescents. Personal and social adjustment scores were, on average, on the 20th percentile. Coping skills appeared to be most influenced by the mode of dialysis treatment. Home peritoneal dialysis patients utilized self-reliance as a coping process more often than their counterparts on hemodialysis. We conclude that children maintained on chronic dialysis therapy demonstrate reasonable psychological adjustment with some differences in social and emotional functioning when compared with healthy children, and that the type of treatment chosen may influence the development of certain coping skills.

Adaptation, Psychological↗

MHC control of cell position in vitro.

Two-dimensional sorting-out behaviour (segregation) in mixtures of pulmonary endothelial cell lines derived from congenic strains of mice was examined using dense confluent cultures in which mitosis is rare. Cell MHC type was detected by autoradiographic labelling or by immunofluorescence techniques. For autoradiography cultures of one type were previously labelled with [3H]thymidine and one component of the mixed cell types was prepared from these cultures. Autoradiographs were prepared from the fixed cultures. Counts of contiguous neighbours (labelled or unlabelled around a randomly chosen central labelled cell) were made: these were analysed statistically using a new model for such a system. The results show that segregation of a clustering type took place if the alleles of the D locus in the H-2 complex were mismatched in the mixed strains, but that matching at the IC locus (or some locus to the right of IJ) overrides the effect of D mismatch. After 2 days culture sorting-out was easily detectable when the cells were stained for their histocompatibility antigens and groups of up to 12 cells of the same type were associated together.

Animals↗