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Biomedical subjects

J S Roberts

Publications and source records attributed to J S Roberts.

At least 37 records · Page 2Linked to original sources
PubMed1995

Pregnancy, lactation, and menopause: how physiology and gender affect the toxicity of chemicals.

We explore ways in which biological events and nonbiological gender factors in women's lives can mediate the toxicity of chemicals to women. We examine the physiologic changes that accompany pregnancy, lactation, and menopause in order to discuss how these changes might influence the target organ dose and distribution of toxic chemicals within women's bodies. We suggest that the interactions between divalent metals and calcium metabolism and those between lipophilic chemicals and fat metabolism could modulate the toxicity of metallic and lipophilic toxins in women over the course of a lifetime. These hypotheses need careful research consideration.

Drug-Related Side Effects and Adverse Reactions↗
PubMed1994

Efficacy of Haemophilus influenzae type b conjugate vaccine PRP-T.

Efficacy of the Haemophilus influenzae type b (Hib) conjugate vaccine PRP-T (Pasteur-Merieux) was evaluated in a controlled community intervention study in the Oxford region, UK. PRP-T was offered to infants from May 1, 1991 in three of the region's eight districts and from July 1, 1991, in a fourth district. It was given by separate injection in addition to the standard diphtheria, tetanus, and pertussis vaccine according to an accelerated 2, 3, and 4 month schedule without a booster dose in the second year of life. By October 1, 1992, more than 90% of infants in vaccine districts had received at least one dose of PRP-T. None of the infants given three doses had developed Hib infection, whereas 11 infections occurred in the control population (vaccine efficacy 100%, 95% CI 80-100%). Intention-to-treat analysis also showed a high estimate of efficacy for the vaccine (90%, 50-99%). Follow-up of study children until November 1, 1993, has shown only 1 vaccine failure in an infant, and no invasive infections in those older than 1 year (average age 22 months). PRP-T vaccine had high protective efficacy with an accelerated immunisation schedule. Furthermore, the vaccine appears to remain protective through the second year of life without a booster dose. These findings provide encouragement for use of PRP-T in the Expanded Programme of Immunisation.

Child, Preschool↗
PubMed1994

Measuring, managing, and improving quality in the end-stage renal disease treatment setting: committee statement.

The Institute of Medicine (IOM) committee that organized the conference reported in this issue of the journal on assessing quality of care and quality of life, wishes to emphasize that it regards the task of measuring quality as one that can be approached systematically, albeit with caution. Outcomes of end-stage renal disease (ESRD) care by dialysis and transplantation (and variations of outcomes among treatment units) and related processes of care need to be measured in ways useful to clinicians. In addition to clinical measures of outcome, the committee also favored giving greater attention to functional outcomes and health-related quality of life. The interest in maintaining and improving quality in the treatment setting reflects an underlying need to encourage its systematic assessment on a sustained basis, with appropriate weight devoted to practical issues.

Humans↗
PubMed1994

Linking outcomes measurement to continual improvement: the serial "V" way of thinking about improving clinical care.

BACKGROUND: Outcomes measurement, process improvement, and continual improvement all have been used to improve quality in health care. However, the mutually complementary approaches have been used primarily in isolation from each other. The "Serial V" ("Vee") concept attempts to integrate these approaches to provide a fuller assessment and practical approach to quality improvement. METHODS: Outcomes measurement is used primarily to identify variations in care and possibly to determine corrective actions that may minimize those variations. Process improvement focuses on breaking down the components of a specific process of health care delivery, identifying or reworking problem areas in the process, then rebuilding the process. Continual improvement involves pinpointing a particular area for improvement, proposing specific changes, testing the instituted changes, and evaluating the success of such changes. The Serial V concept is an integrative strategy that incorporates aspects of all three approaches to create a comprehensive way to evaluate, institute, and reflect on change aimed at improvement. While this way of thinking appears complex at first glance, a practical worksheet that details each step in the process can be used to begin the clinical improvement work. Use of the Serial V approach, which unites measurement of outcomes, analysis of the clinical process, and repeated pilot tests to improve outcomes in real-world clinical settings, will accelerate improvement in health care outcomes and eliminate unnecessary costs.

Clinical Protocols↗
PubMed1993

Cell migration in cultured cerebral cortical slices.

In order to investigate the cellular mechanisms of migration and lamination in the mammalian cerebral cortex, we have cultured living slices of the developing telencephalon and tracked the migration of newly generated cortical neurons. Slice cultures made from neonatal ferret cortex were maintained in roller tubes and survived well for several weeks in vitro. Cells generated on Postnatal Day (P) 0 or 1 were labeled with the thymidine analog 5-bromo-2-deoxy-uridine (BrdU), and their movements were tracked during the subsequent culture period. At the beginning of the culture period, labeled cells were found almost exclusively in the proliferative zones of the cerebral wall, the ventricular and subventricular zones. Over the first week in culture, there was a dramatic movement of labeled cells out of the proliferative zones and into the cortical plate, the final destination of neocortical neurons. Comparison of the patterns of cell movement in cultured slices with that in intact littermate controls revealed that the initial migration of labeled cells into the cortical plate is similar in cultured slices and normal animals. The primary difference between migration in slice cultures and in vivo is that after longer times in culture, cells that migrate into the cortical plate fail to form the tightly clustered laminae characteristic of cells in the intact brain. Labeled cells are instead distributed more widely throughout the cortical plate and other regions of the cerebral wall. Thus, at least during the initial period of migration, cultured slices provide an experimentally manipulable system in which cell migration can be directly observed in a histotypically normal environment.

Animals↗
PubMed1990

Influenza vaccine and anticoagulation control in patients receiving warfarin.

The effects of a trivalent split virion influenza vaccine on anticoagulation control were prospectively evaluated in a sample of well-controlled warfarin recipients. Vaccine-induced changes in prothrombin time ratios were not detected during one month of follow-up after immunisation. The results are supported by the findings of other studies conducted in this country and the USA, which have all refuted the conclusions of early reports that suggested a possible interaction between warfarin and influenza vaccine.

Aged↗
PubMed1989

An evaluation of measles, mumps and rubella vaccine in a population of Yorkshire infants.

In October 1988 combined measles, mumps and rubella (MMR) vaccination replaced monocomponent measles as part of the routine childhood vaccination programme in the United Kingdom. Prior to this policy change a study was undertaken in 335 children aged 15 months, to evaluate the clinical reactions and immunogenicity of the new combined MMR vaccine (Trimovax, Immravax, Merieux), in comparison with an established monocomponent measles vaccine (Rouvax, Merieux). Parents were asked to select whether their child should receive MMR vaccine or measles monocomponent; over 95% chose MMR. Children who were given the MMR vaccine had seroconversion rates of 96% for measles, 97% for mumps and 100% for rubella, whilst those who received monocomponent measles vaccine had a seroconversion rate of 100%. The number of side effects reported was similar with both vaccines; all were mild and self-limiting. The results from this study confirm the efficacy and low reactogenicity of MMR vaccine and support its use as part of the routine childhood immunisation programme in the United Kingdom.

Female↗
PubMed1989

Phenotypic heterogeneity of spontaneous lymphomas of CWD mice.

Animals of the inbred mouse strain, CWD, express endogenous murine leukemia viruses early in life and have a high incidence of spontaneous neoplasms. We found that approximately one half of these animals died of malignant lymphoma by the age of 16 months. Splenic enlargement was seen in all mice, but thymic involvement was unusual. One half of the CWD tumors were diffuse lymphoblastic or immunoblastic lymphomas while the remainder were large cell, small cell, or mixed cell lymphomas. Analysis of DNAs from 12 tumors for immunoglobulin and T-cell receptor gene rearrangements revealed that all six of the lymphoblastic and immunoblastic lymphomas were of T-cell origin, as was one tumor of small cleaved cells. Four of the others were clonal B-cell lymphomas and one was of uncertain lineage. Assays of a limited number of tumors for the expression of the Thy 1.2 and IgM molecules confirmed the diversity in the cellular phenotype. The results indicate that CWD mice develop primarily splenic lymphomas with an unusual degree of heterogeneity in the tumor cell phenotypes as compared with the thymic lymphomas found in other high leukemia strains. The CWD strain is a useful new model for studies of retroviral leukemogenesis and the relationship between the histopathology and immunophenotype of malignant lymphomas.

Animals↗
PubMed1989

Tuberculin testing: comparison of imotest with Heaf and Mantoux.

Immunisation against tuberculosis is still recommended for secondary school children in the UK. Only children who do not react to tuberculin tests are offered vaccination. We report the results of two studies, carried out to evaluate a new applicator of the disposable Imotest multiple puncture tuberculin test. The results demonstrate that Imotest is well tolerated and compares favourably with the Heaf and Mantoux tests. Imotest detected significantly more tuberculin responders than Heaf.

Child↗
PubMed1988

Mechanism of selection of class II recombinant murine leukemia viruses in the highly leukemic strain CWD.

The development of spontaneous lymphomas in CWD mice is associated with the expression of endogenous ecotropic murine leukemia viruses (MuLV) and the formation of recombinant viruses. However, the pattern of substitution of nonecotropic sequences within the envelope genes of the CWD class II recombinant viruses differs from that seen in class I recombinant MuLVs of AKR, C58, and HRS mice. To determine how CWD host genes might influence the envelope gene structure of the recombinant viruses, we characterized the responses of these mice to two different types of exogenous MuLVs. Neonatal mice injected the HRS class I recombinant PTV-1 became infected and developed T-cell lymphomas more rapidly than controls did. The inoculation of CWD mice with the leukemogenic AKR ecotropic virus SL3-3 led to the formation of recombinant MuLVs with a novel genetic structure and class II-like envelope genes, although SL3-3 generates class I recombinants in other strains. These results suggest that the absence of class I recombinant MuLVs in CWD mice is not related to the restriction of the replication or oncogenicity of class I viruses or to the absence of an appropriate ecotropic virus that can generate class I recombinants. More likely, the genes of CWD mice that direct the formation or selection of class II recombinant viruses affect the process of recombination between the ecotropic and nonecotropic envelope gene sequences.

Animals↗
PubMed1988

Privilege delineation in a demanding new environment.

The delineation of clinical privileges is one of the most important means for hospitals to ensure high-quality care. Competition, cost control, and public accountability have created the need for hospitals to assure effective privilege delineation processes. Hospitals should focus on issues of practice variation, continuity of care, volume of services provided and planned, and the integration of ethical considerations into clinical decisions. How information is obtained, verified, and acted upon is reviewed within the organizational framework of the hospital. Several leaders within the hospital, such as the clinical department chairs and members of the medical staff executive committee, have important functions in the clinical privilege delineation process. Granting clinical privileges is a critical hospital function that requires a commitment by the governing body, management, and medical staff leaders.

Clinical Competence↗