Biomedical subjects
J Robinson
Publications and source records attributed to J Robinson.
Epidural top-ups solutions for emergency caesarean section.
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Modeling Medicare costs of PACE (Program of All-Inclusive Care for the Elderly) populations.
Historically, Medicare has paid PACE providers a monthly capitated rate equal to 95 percent of the site's county AAPCC multiplied by a PACE-specific frailty adjuster of 2.39. The Balanced Budget Act of 1997 makes PACE a permanent provider category and mandates that future Medicare payments be based upon the rate structure of the Medicare+Choice payment system, adjusted for the comparative frailty of PACE enrollees and other factors deemed to be appropriate by the Secretary of Health and Human Services. This study revisits the calculation of the PACE frailty adjuster and explores the effect of risk adjustment on that frailty adjuster.
Taking the leap to gerontological certification.
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Protecting the public interest: issues in contracting managed behavioral health care.
In recent years, state governments have begun contracting out behavioral health care to large managed for-profit organizations. This approach to mental health service delivery has resulted in realignment in roles for both state agencies and the managed care organizations. Overnight, state agencies have been transformed into contract managers of multi-million dollar capitated health plans. Managed care companies, in turn, moving into the public-sector market must adjust their service delivery to include key concepts of public interest involvement such as consumer input, public comment, and outreach. This article analyzes three public-sector transitions. Common issues in these transformations are used as a springboard for identifying key concerns which states need to monitor when developing managed care contracts.
The IMGT/HLA sequence database.
The IMGT/HLA database (wwwebi.ac.uk/imgt/hla/) specialises in sequences of the polymorphic genes of the HLA system, the humanmajor histocompatibility complex (MHC). This complex is located within the 6p213 region on the short arm of human chromosome 6 and contains more than 220 genes of diverse function. Many of the genes encode proteins of the immune system and these include the 21 highly polymorphic HLA genes, which influence the outcome of clinical transplantation and confer susceptibility to a wide range of non-infectious diseases. The database contains sequences for all HLA alleles officially recognised by the WHO Nomenclature Committee for Factors of the HLA System and provides users with online tools and facilities for their retrieval and analysis. These include allele reports, alignment tools, and detailed descriptions of the source cells. The online submission tool allows both new and confirmatory sequences to be submitted directly to the WHO Nomenclature Committee. The latest version (release 1.10.0 April 2001) contains 1329 HLA alleles, 61 HLA related sequences, derived from around 3350 component sequences from the EMBL/ GenBank/DDBJ databases. The IMGT/HLA database provides a model that will be extended to provide specialist databases for polymorphic MHC genes of other species.
Fermentability of the hemicellulose-derived sugars from steam-exploded softwood (douglas fir)
Steam explosion ofDouglas fir wood chips under low-severity conditions (log Ro = 3.08 corresponding to 175 degrees C, 7.5 min, and 4.5% SO2) resulted in the recovery of around 87% of the original hemicellulose component in the water-soluble stream. More than 80% of the recovered hemicellulose was in a monomeric form. As the pretreatment severity increased from 3.08 to 3.76, hemicellulose recovery dropped to 43% of the original hemicellulose found in Douglas fir chips while the concentration of glucose originating from cellulose hydrolysis increased along with the concentration of sugar degradation products such as furfural and hydroxymethylfurfural. Despite containing a higher concentration of hexose monomers (mainly glucose originating from cellulose degradation), the water-soluble fraction prepared under high-severity conditions (log Ro = 3.73 corresponding to 215 degrees C, 2.38 min, and 2.38% SO2) was not readily fermented. Only the two hydrolyzates obtained at low and medium (195 degrees C, 4.5 min, and 4.5% SO2) severities were fermented to ethanol using a spent sulfur liquor adapted strain of Saccharomyces cerevisiae. High ethanol yields were obtained for these two hydrolyzates with 0.44 g of ethanol produced per gram of hexose utilized (86% of theoretical). However, the best results of hemicellulose recovery and fermentability were obtained for the low-severity water-soluble fraction which was fermented significantly faster than the fraction obtained after medium-severity treatment probably because it contained higher amounts of fermentation inhibitors. Copyright 1999 John Wiley & Sons, Inc.
Stable exposure of the coreceptor-binding site in a CD4-independent HIV-1 envelope protein.
We recently derived a CD4-independent virus from HIV-1/IIIB, termed IIIBx, which interacts directly with the chemokine receptor CXCR4 to infect cells. To address the underlying mechanism, a cloned Env from the IIIBx swarm (8x) was used to produce soluble gp120. 8x gp120 bound directly to cells expressing only CXCR4, whereas binding of IIIB gp120 required soluble CD4. Using an optical biosensor, we found that CD4-induced (CD4i) epitopes recognized by mAbs 17b and 48d were more exposed on 8x than on IIIB gp120. The ability of 8x gp120 to bind directly to CXCR4 and to react with mAbs 17b and 48d in the absence of CD4 indicated that this gp120 exists in a partially triggered but stable state in which the conserved coreceptor-binding site in gp120, which overlaps with the 17b epitope, is exposed. Substitution of the 8x V3 loop with that from the R5 virus strain BaL resulted in an Env (8x-V3BaL) that mediated CD4-independent CCR5-dependent virus infection and a gp120 that bound to CCR5 in the absence of CD4. Thus, in a partially triggered Env protein, the V3 loop can change the specificity of coreceptor use but does not alter CD4 independence, indicating that these properties are dissociable. Finally, IIIBx was more sensitive to neutralization by HIV-positive human sera, a variety of anti-IIIB gp120 rabbit sera, and CD4i mAbs than was IIIB. The sensitivity of this virus to neutralization and the stable exposure of a highly conserved region of gp120 suggest new strategies for the development of antibodies and small molecule inhibitors to this functionally important domain.
Probability analysis of variational crystallization and its application to gp120, the exterior envelope glycoprotein of type 1 human immunodeficiency virus (HIV-1).
The extensive glycosylation and conformational mobility of gp120, the envelope glycoprotein of type 1 human immunodeficiency virus (HIV-1), pose formidable barriers for crystallization. To surmount these difficulties, we used probability analysis to determine the most effective crystallization approach and derive equations which show that a strategy, which we term variational crystallization, substantially enhances the overall probability of crystallization for gp120. Variational crystallization focuses on protein modification as opposed to crystallization screening. Multiple variants of gp120 were analyzed with an iterative cycle involving a limited set of crystallization conditions and biochemical feedback on protease sensitivity, glycosylation status, and monoclonal antibody binding. Sources of likely conformational heterogeneity such as N-linked carbohydrates, flexible or mobile N and C termini, and variable internal loops were reduced or eliminated, and ligands such as CD4 and antigen-binding fragments (Fabs) of monoclonal antibodies were used to restrict conformational mobility as well as to alter the crystallization surface. Through successive cycles of manipulation involving 18 different variants, we succeeded in growing six different types of gp120 crystals. One of these, a ternary complex composed of gp120, its receptor CD4, and the Fab of the human neutralizing monoclonal antibody 17b, diffracts to a minimum Bragg spacing of at least 2.2 A and is suitable for structural analysis.
Evidence for fear of restriction and fear of suffocation as components of claustrophobia.
Recent investigations of the aetiology and treatment of specific phobias have focused on clarifying the concerns underlying phobic anxiety. It has been proposed that claustrophobic fear is comprised of separable confinement and suffocation components. This paper presents data from 78 general medical outpatients undergoing magnetic resonance imaging (MRI) scans in two major teaching hospitals. The findings support the two factor structure of claustrophobia, in that exposure to confinement reduced confinement subscale scores, but did not influence suffocation scores.
Transcervical embryo transfer as a risk factor for ectopic pregnancy.
OBJECTIVE: To evaluate the ease and timing of transcervical ET as risk factors for ectopic pregnancy (EP) after IVF. DESIGN: Retrospective study. SETTING: University-based IVF program in the United Kingdom. PATIENT(S): Eighteen consecutively seen patients with an EP after IVF and 314 patients with an intrauterine pregnancy after transcervical ET performed during the same period. INTERVENTION(S): Additional manipulation with a transfer catheter or the use of other instruments to assist transfer. Embryo transfer on day 2 or 3 after oocyte retrieval. MAIN OUTCOME MEASURE(S): Risk factors for EP (day 2 ET, difficult transfer overall and on days 2 and 3, history of tubal subfertility, and previous EP) presented as odds ratios with 95% confidence intervals. RESULT(S): The risk of EP was 2.26 (0.64-8.01) after day 2 ET, 3.91 (1.49-10.23) after difficult ET, 3.88 (1.34-11.24) after difficult ET on day 2, 2.7 (0.20-13.99) after difficult ET on day 3, 5.73 (1.99-16.62) when there was a history of tubal subfertility, and 5.41 (1.96-14.91) when there was a previous EP. CONCLUSION(S): A difficult ET significantly increases the risk of an EP. The risk is particularly high when the patient has a history of tubal damage or previous EP. The timing of ET is important only if the ET is difficult.
Ectopic pregnancy after transmyometrial embryo transfer: case report.
OBJECTIVE: To report a case of ectopic pregnancy after transvaginal transmyometrial ET. DESIGN: Case report. SETTING: University-based IVF program. PATIENT(S): A woman with tubal subfertility and a history of difficult ETs. INTERVENTION(S): Transvaginal transmyometrial ET performed to avoid a difficult transcervical ET. MAIN OUTCOME MEASURE(S): Expected improvement in the pregnancy rate in a selected group of patients. RESULT(S): Tubal pregnancy. CONCLUSION(S): Transmyometrial ET is an attractive alternative to difficult transcervical ET but is not free of complications.
The social ecology of syphilis.
Factors affecting the transmission of syphilis can be categorized into those acting at the level of individuals (e.g., number of sex partners) and others at the level of the sociophysical environment (e.g., availability of treatment services for curable infections). In a prior study, we identified several sociophysical factors correlated with the ten-year mean syphilis rate in a regression analysis of United States counties. In the present study we used qualitative methods to investigate additional aspects of some factors in the regression, as well as to identify entirely new factors. Twelve counties with populations less than 100,000 and ten-year mean syphilis rates that were greater or less than expected by the regression model were selected for a three to five day visit. The case study protocol included observations, unstructured interviews with care providers and county residents, and a standardized questionnaire completed by state and local sexually transmitted disease control personnel pertaining to characteristics and practices of the local health department. Comparisons of the field notes and questionnaires revealed patterns of factors of the sociophysical environment that potentially affect county syphilis rates. These included access to the health department STD clinic, race relations, employment opportunities for minorities, interagency coordination, STD outreach activities, the social acceptability of discussing STDs, and intercommunity dynamics. In addition we noted the disproportionate influence of particular individuals on these factors. Some of the factors identified are readily quantifiable and could enhance the predictive power of multivariable models of county syphilis rates. The hypotheses generated by this study may also lead to a better measurement and understanding of potentially important environmental determinants of community syphilis rates, and the development of new or enhanced prevention strategies.
Outcome and safety of transrectal US-guided percutaneous cryotherapy for localized prostate cancer.
OBJECTIVES: To assess the effectiveness and safety of ultrasound (US)-guided cryotherapy as a primary treatment for localized prostate cancer. MATERIALS AND METHODS: A prospective study of percutaneous transrectal US (TRUS)-guided cryotherapy was performed on 71 patients with T1-T3, N0, M0 prostatic cancer: 10 patients underwent two or more procedures. All cases were newly diagnosed and patients had no previous treatment for cancer. For all patients, TRUS biopsies were performed at 5-6 months. Patients were monitored at 6 weeks; 3, 6, 9, and 12 months; and twice yearly thereafter for prostate specific antigen (PSA) levels, complications, and clinical evidence of residual disease. RESULTS: Follow-up from 10 to 36 months was available for 70 of 71 patients; one patient died of unrelated disease. Initially, 10 of 69 patients had positive postcryotherapy biopsy results. After repeated treatment, nine of these 10 patients had negative biopsy results and one patient had no follow-up. Overall, 68 of 69 patients had negative biopsy results. At 1 year, 43 of 64 (67%) had an undetectable PSA level. Two patients had proven metastases. Complications include three cases with urethral sloughing requiring transurethral resection of the prostate (TURP). One patient had orchitis. Two patients had persistent incontinence, one as the result of a TURP. There was no death, acute serious morbidity, or fistula formation. Impotence was universal at 6 months, but many patients demonstrated late recovery. CONCLUSION: Cryoablation is an imaging-guided percutaneous intervention for prostate cancer that can safely yield disease-free status in a high percentage of patients with localized disease.
A patient with persistent wheezing, sinusitis, elevated IgE, and eosinophilia.
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Effect of maltreatment on preschoolers' narrative representations of responses to relieve distress and of role reversal.
A total of 80 low-socioeconomic status maltreated preschoolers were contrasted with 27 nonmaltreated preschoolers on their narrative representations. The children completed story stems, taken from the MacArthur Story-Stem Battery (MSSB; I. Bretherton, D. Oppenheim, H. Buchsbaum, R. N. Emde, & the MacArthur Narrative Group, 1990), that introduced stressful family situations. Using the MacArthur narrative coding manual (J. Robinson, L. Mantz-Simmons, J. Macfie, & the MacArthur Narrative Group, 1992), coders rated portrayals of parental and child character responses, as well as participant responses, to relieve children's distress. They also rated role reversal (children caretaking their parents) from the narrative emotion coding manual (S. L. Warren, L. Mantz-Simmons, & R. N. Emde, 1993). Maltreated preschoolers portrayed parents and children as responding less often--yet themselves as stepping into the story more often to relieve children's distress--than did nonmaltreated preschoolers. Abused children (sexually, physically, or both) portrayed the most participant responses, and neglected children (with no abuse) portrayed the fewest child responses. Role reversal was associated with physical abuse.
Use of reconstituted influenza virus virosomes as an immunopotentiating delivery system for a peptide-based vaccine.
Immunopotentiating reconstituted influenza virosomes (IRIV) were used as a delivery system for the synthetic peptide-based malaria vaccine SPf66. The reduced SPf66 peptide molecules containing terminal cysteine residues were covalently attached to phosphatidylethanolamine with the heterobifunctional crosslinker gamma-maleimidobutyric acid N-hydroxysuccinimide ester. The SPf66-phosphatidylethanolamine was incorporated into IRIV and BALB/c mice were immunized twice by intramuscular injection with peptide-loaded virosomes. Titres of elicited anti-SPf66 IgG were determined by ELISA. These titres were significantly higher and the required doses of antigen were lower, when mice had been preimmunized with a commercial whole virus influenza vaccine. After preimmunization with the influenza vaccine, SPf66-IRIV elicited far more consistently anti-SPf66 antibody responses than SPf(66)n adsorbed to alum. MoAb produced by four B cell hybridoma clones derived from a SPf66-IRIV-immunized mouse cross-reacted with Plasmodium falciparum blood stage parasites in immunofluorescence assays. All four MoAbs were specific for the merozoite surface protein-1 (MSP-1)-derived 83.1 portion of SPf66. Sequencing of their functionally rearranged kappa light chain variable region genes demonstrated that the four hybridomas were generated from clonally related splenic B cells. Biomolecular interaction analyses (BIA) together with these sequencing data provided evidence for the selection of somatically mutated affinity-matured B cells upon repeated immunization with SPf66-IRIV. The results indicate that IRIV are a suitable delivery system for synthetic peptide vaccines and thus have a great potential for the design of molecularly defined combined vaccines targeted against multiple antigens and development stages of one parasite, as well as against multiple pathogens.
The global distribution of physicians and nurses.
AIM: To explore the global distribution of physicians and nurses and the influence of gross national product per capita on this distribution, using available United Nations' (UN) sources. OBJECTIVES: to compare the international distribution of physicians and nurses by country; to examine the influence of gross national product per capita (GNP) on the global distribution of physicians and nurses; to explore the assumptions underlying the recommendations of The World Development Report 1993 Investing in Health for health workforce substitution; and to consider the implications for future studies of global health labour distribution. DESIGN: A database was compiled from various UN sources on 147 countries. Using some of the variables from this database, a general linear regression model for log GNP per capita on each of the two dependent variables (log nurses and log physicians per 1000 population) was produced. Standardized residuals obtained from these bivariate regressions were calculated and plotted against each other to determine the relationship between the global distribution of physicians to population and that of nurses. From this analysis outlying countries could also be identified. RESULTS: Ratios of physicians to population by country varied from 0. 02 to 4.4 per 1000 population (or from 1 to 227 and 1-50,000 population), and nurses from 0.03 to 16.4 (or from 1 to 61 and 1-33, 000 population). There was a positive correlation (r = 0.84, P < 0. 001) between the number of physicians per 1000 population and the number of nurses per 1000 population. GNP explained 49% of the variation in physicians and 40% in nurses. Ranking of countries according to their standardized deviation from mean regression lines for GNP against health personnel in countries with both the lowest incomes and lowest numbers of health personnel, resulted in little change from the original rankings of ratios of physicians and nurses relative to population. For some of the wealthiest countries, there was a marked fall in global ranking and for some middle income countries a marked improvement in ranking. CONCLUSION: 70% of the distribution of nurses globally can be explained by the distribution of physicians, and the influence of GNP per capita on the global distribution of physicians and nurses appears to be substantial. In only a minority of the world's very poorest countries is there evidence to suggest that higher numbers of nurses substitute for low numbers of physicians. Standardization of the distributions by GNP demonstrates that many countries (but not the poorest) regress to within one standard deviation of the mean expected distribution. This suggests that countries could set optimum levels of physicians and nurses within the limits of their GNP. More realistically, the findings suggest that recommendations for modification of the structure of countries' health labour forces as a component of health care reform may be more difficult to achieve than at first appears. The potential unreliability of the data sources used, and the implications for the accuracy of the findings, are discussed.