Human skin penetration and local effects of topical nano zinc oxide after occlusion and barrier impairment.

Public health concerns continue to exist over the safety of zinc oxide nanoparticles that are commonly used in sunscreen formulations. In this work, we assessed the effects of two conditions which may be encountered in everyday sunscreen use, occlusion and a compromised skin barrier, on the penetration and local toxicity of two topically applied zinc oxide nanoparticle products. Caprylic/capric triglyceride (CCT) suspensions of commercially used zinc oxide nanoparticles, either uncoated or with a silane coating, were applied to intact and barrier impaired skin of volunteers, without and with occlusion for a period of six hours. The exposure time was chosen to simulate normal in-use conditions. Multiphoton tomography with fluorescence lifetime imaging was used to noninvasively assess zinc oxide penetration and cellular metabolic changes that could be indicative of toxicity. We found that zinc oxide nanoparticles did not penetrate into the viable epidermis of intact or barrier impaired skin of volunteers, without or with occlusion. We also observed no apparent toxicity in the viable epidermis below the application sites. These findings were validated by ex vivo human skin studies in which zinc penetration was assessed by multiphoton tomography with fluorescence lifetime imaging as well as Zinpyr-1 staining and toxicity was assessed by MTS assays in zinc oxide treated skin cryosections. In conclusion, applications of zinc oxide nanoparticles under occlusive in-use conditions to volunteers are not associated with any measurable zinc oxide penetration into, or local toxicity in the viable epidermis below the application site.

Implementation of a pharmacogenomics consult service to support the INGENIOUS trial.

Hospital systems increasingly utilize pharmacogenomic testing to inform clinical prescribing. Successful implementation efforts have been modeled at many academic centers. In contrast, this report provides insights into the formation of a pharmacogenomics consultation service at a safety-net hospital, which predominantly serves low-income, uninsured, and vulnerable populations. The report describes the INdiana GENomics Implementation: an Opportunity for the UnderServed (INGENIOUS) trial and addresses concerns of adjudication, credentialing, and funding.

Calcium-dependent calmodulin-binding proteins associated with mammalian DNA polymerase alpha.

Complex, multiprotein forms of bovine (calf thymus), hamster (Chinese hamster ovary cell), and human (HeLa) cell DNA polymerase alpha (Pol alpha) were analyzed for their content of calmodulin-binding proteins. The approach used an established autoradiographic technique employing 125I-labeled calmodulin to probe proteins in denaturing SDS-polyacrylamide gel electropherograms. All three Pol alpha enzymes were associated with discrete, Ca2+-dependent calmodulin-binding proteins. Conventionally purified calf thymus Pol alpha holoenzyme contained three prominent, trifluoperazine-sensitive species with apparent molecular masses of approx. 120, 80 and 48 kDa. The 120 and 48 kDa species remained associated with the polymerase.primase core of the calf enzyme during immunopurification with monoclonal antibodies directed specifically against the polymerase subunit. The patterns of the calmodulin-binding proteins displayed by conventionally purified preparations of hamster and human Pol alpha enzymes were similar to each other and distinctly different from the pattern of comparable preparations of calf thymus Pol alpha. Immunopurified preparations of the human and hamster Pol alphas retained significant calmodulin-binding activity of apparent molecular masses of approx. 55, 80 and 150-200 kDa.

Fibroblast matrix gene expression and connective tissue remodeling: role of endothelin-1.

This study examines endothelin-induced modulation of extracellular matrix synthesis and remodeling by fibroblasts, and its potential role in the pathogenesis of systemic sclerosis (scleroderma). Endothelin-1 promoted fibroblast synthesis of collagen types I and III, but not fibronectin, by a mechanism dependent upon both ETA and ETB receptors. Conversely, endothelin-1 inhibited both protein expression of matrix metalloproteinase 1 and zymographic activity exclusively via ETA receptors. A dual regulatory role for endothelin-1 in transcriptional regulation was suggested by the ability of endothelin-1 to enhance steady-state levels of collagen mRNA and activate the proalpha2(I) collagen (Col1a2) promoter, but in contrast to reduce matrix metalloproteinase 1 transcript expression and suppress transcription of a human matrix metalloproteinase 1 promoter reporter construct in transient transfection assays. Although endothelin-1 significantly enhanced remodeling of three-dimensional collagen lattices populated by normal fibroblasts, this was not observed for lattices populated by systemic sclerosis fibroblasts. Promotion of matrix remodeling was dependent upon ETA receptor expression and was blocked by specific inhibitors of tyrosine kinases or protein kinase C. Reverse transcriptase polymerase chain reaction, S1 nuclease, and functional cell surface binding studies showed that normal and systemic sclerosis fibroblasts express both ETA and ETB receptors (predominantly ETA), but that ETA receptor mRNA levels and ETA binding sites on fibroblasts cultured from systemic sclerosis skin biopsies are reduced by almost 50%. Endothelin-1 is thus able to induce a fibrogenic phenotype in normal fibroblasts that is similar to that of lesional systemic sclerosis fibroblasts. Moreover, reduced responsiveness to exogenous endothelin-1 in systemic sclerosis suggests that downstream pathways may have already been activated in vivo. These data further implicate dysregulated endothelin-receptor pathways in fibroblasts in the pathogenesis of connective tissue fibrosis.

Isolation and partial characterization of DNA polymerases from Crithidia fasciculata.

Two types of DNA polymerase activity were partially purified from Crithidia fasciculata. The alpha-type, DNA polymerase A, was of high molecular weight and sensitive to N-ethylmaleimide, whereas the beta-type, DNA polymerase B, was of low molecular weight and resistant to N-ethylmaleimide. Phosphocellulose chromatography revealed multiple peaks of DNA polymerase A activity the properties of which, such as pH optimum, salt sensitivity, utilization of synthetic template-initiator complexes and response to DNA polymerase inhibitors were similar. The response of the C. fasciculata DNA polymerase A enzymes to some of these inhibitors and utilization of poly(rA) X oligo(dT)11 showed these enzymes to be markedly different from mammalian DNA polymerase alpha.

Provider choice and use of mental health care: implications for gatekeeper models.

OBJECTIVE: To examine the ways in which the costs of nonresidential mental health care depend on (1) the type of provider who initiates the treatment episode and (2) the level of cost sharing imposed on the patient. STUDY SETTING: The 1987 National Medical Expenditure Survey, a national probability sample of the U.S. civilian, noninstitutionalized population. DATA COLLECTION: Data were collected during four personal interviews conducted during 1987 and 1988. Key variables include the type of provider contacted at the beginning of treatment (psychiatrist, other physician, nonmedical mental health care specialist) and the cost (total actual payments from all sources) for the treatment episode. METHODS OF ANALYSIS: An episodic model of demand for mental health care is estimated using a two-step procedure. Multinomial probit analysis is first used to determine the factors that influence the choice of initial provider type. Right-censored Tobit analysis is used to determine the factors that affect the costs of care, including the type of provider who initiates the care episode. PRINCIPAL FINDINGS: Results indicate that out-of-pocket price does significantly (p < .05) affect the patient's initial choice of provider type but that, after controlling for the endogeneity of provider choice, price is no longer significant in explaining overall treatment costs. After controlling for selection effects, care episodes initiated by nonspecialist physicians are found to be as expensive as those initiated by psychiatrists and significantly more expensive than episodes initiated by nonphysicians. CONCLUSIONS: The results suggest that nonmedical mental health care specialists may be more effective than physicians in controlling costs when used as case managers in the care of persons with mental illnesses.

Significance of plasma N-terminal pro-brain natriuretic peptide in patients with systemic sclerosis-related pulmonary arterial hypertension.

OBJECTIVES: A single centre pilot study to investigate the role of the plasma N-terminal pro-brain natriuretic peptide (N-T proBNP) assay to risk stratify patients with suspected pulmonary arterial hypertension (PAH) from a background SSc population. METHODS: Out of 49 SSc patients, 23 had and 26 did not have PAH. Right ventricular haemodynamic variables, six-minute walk test and plasma N-T proBNP levels were recorded from patients catheterised for suspected PAH (23 with PAH and 11/26 without PAH). RESULTS: Mean value of N-T proBNP for SSc patients with PAH was 3365 (standard error 1095) pg/ml compared to 347 (174) pg/ml for patients without PAH. There was a statistically significant correlation (P < 0.05) between N-T proBNP values and (i) mean pulmonary artery pressure (r = 0.53), (ii) right ventricular end diastolic pressure (r = 0.59) and (iii) pulmonary vascular resistance (r = 0.49). Receiver operator characteristic curve analysis showed that a cut-off value of 395.34 pg/ml had a sensitivity of 0.69 and specificity of 1.0. CONCLUSIONS: N-T proBNP estimation in systemic sclerosis-related pulmonary hypertension is a potentially useful diagnostic tool with a high specificity and negative predictive value. This test has the potential to have an important role in risk stratification and monitoring of therapy in the future.

Measurement of short term health effects in economic evaluations.

Short term health effects can significantly impact health-related quality of life (HR-QOL). Appropriate healthcare priorities can be set only if they are based on health status measurements which are consistent with how people value both short and long term health effects. This article discusses methods by which such health effects may be measured using health state utilities. The standard discounted quality-adjusted life-year model, in which the values of the various health states are weighted by the time spent in each state, generally fails to capture the true impact of temporary ill health on HR-QOL. Instead, a scenario approach is recommended in which valuations are based on holistic descriptions of health states which include all short and long term health effects experienced.

A QALY-based societal health statistic for Canada, 1985.

This paper assesses the appropriateness of QALYs (quality adjusted life years) as a foundation for an index of societal health, and the feasibility of using such an index to guide health care policy. Results of this paper suggest that the standard aggregate QALY index imposes an ethical position on policy makers which may promote inequality in well-being associated with health. It is possible to rectify this problem in theory, but current data are insufficient to estimate such corrected indices. A QALY-based index, constructed using the best available data, indicates morbidity has a significant effect on Canadian health status (e.g. life expectancy figures alone overstate community health by about 10%), that the impact of morbidity is unequal across regions and gender, and that role (the ability to fulfil social functions) and mobility dysfunction are important determinants of ill-health in this population.

A method to elicit utilities for interpersonal comparisons.

This paper examines how values should be assigned to health states when policy decisions must be made about who should receive treatment. The paper demonstrates that, if priority were to be assigned to those people who would benefit most from treatment, standard health-state utilities might fail to identify resource allocations that would maximize total health-related well-being in society. A new measurement instrument is proposed that is based on the direct comparison of the well-being achieved by different people in various health states and thus captures such community priorities. A sample of 72 health administration students used the instrument to evaluate speech and mobility dysfunctions as they afflicted hypothetical people who differed by gender, family status, and occupational type. This preliminary analysis indicates that the instrument is feasible to use, and that the valuations of respondents did, for some health conditions, significantly depend on the type of person afflicted.

What should be reported in a methods section on utility assessment?

BACKGROUND: The measurement of utilities, or preferences, for health states may be affected by the technique used. Unfortunately, in papers reporting utilities, it is often difficult to infer how the utility measurement was carried out. PURPOSE: To present a list of components that, when described, provide sufficient detail of the utility assessment. METHODS: An initial list was prepared by one of the authors. A panel of 8 experts was formed to add additional components. The components were drawn from 6 clusters that focus on the design of the study, the administration procedure, the health state descriptions, the description of the utility assessment method, the description of the indifference procedure, and the use of visual aids or software programs. The list was updated and redistributed among a total of 14 experts, and the components were judged for their importance of being mentioned in a Methods section. RESULTS: More than 40 components were generated. Ten components were identified as necessary to include even in an article not focusing on utility measurement: how utility questions were administered, how health states were described, which utility assessment method(s) was used, the response and completion rates, specification of the duration of the health states, which software program (if any) was used, the description of the worst health state (lower anchor of the scale), whether a matching or choice indifference search procedure was used, when the assessment was conducted relative to treatment, and which (if any) visual aids were used. The interjudge reliability was satisfactory (Cronbach's alpha = 0.85). DISCUSSION: The list of components important for utility papers may be used in various ways, for instance, as a checklist while writing, reviewing, or reading a Methods section or while designing experiments. Guidelines are provided for a few components.

The formal mental health care burden among recently deinstitutionalized patients.

This article examines the extent to which the costs of formal health care are shifted from third-party payers to the patient and his or her family, especially during the transition to the community after discharge from a state hospital. Findings indicate that patients residing in the community are as likely to receive some care as their counterparts in institutions, but are at higher risk for uncovered care. Uncovered care is more likely to manifest as an unmet need for patients who have been recently discharged, especially for racial minorities, and as an out-of-pocket expense for patients who are established in the community.

Opportunities for the replacement of animals in the study of nausea and vomiting.

Nausea and vomiting are among the most common symptoms encountered in medicine as either symptoms of disease or side effects of treatments. Developing novel anti-emetics and identifying emetic liability in novel chemical entities rely on models that can recreate the complexity of these multi-system reflexes. Animal models (especially the ferret and dog) are the current gold standard; however, the selection of appropriate models is still a matter of debate, especially when studying the subjective human sensation of nausea. Furthermore, these studies are associated with animal suffering. Here, following a recent workshop held to review the utility of animal models in nausea and vomiting research, we discuss the limitations of some of the current models in the context of basic research, anti-emetic development and emetic liability detection. We provide suggestions for how these limitations may be overcome using non-animal alternatives, including greater use of human volunteers, in silico and in vitro techniques and lower organisms.

Studies on the inhibition of highly purified calf thymus 8S and 7.3S DNA polymerase alpha by aphidicolin.

On activated DNA aphidicolin competitively inhibits the incorporation of dCMP by both calf thymus DNA polymerase alpha A2 and C enzymes and inhibits the incorporation of the other three deoxynucleoside monophosphates apparently non-competitively. However, aphidicolin does not inhibit the incorporation of dAMP into poly(dT) . oligo(A)10 nor does it inhibit the incorporation of dGMP into poly(dC) . oligo(dG)10, but, it does competitively inhibit the incorporation of dTMP into poly(dA) . oligo(dT)10.

In vitro phosphorylation of human immunodeficiency virus type 1 Tat protein by protein kinase C: evidence for the phosphorylation of amino acid residue serine-46.

Human immunodeficiency virus type-1 Tat protein is phosphorylated by protein kinase C in a calcium-, diacylglycerol-, and phosphatidylserine-dependent manner. Maximum phosphorylation is reached at a stoichiometry of between 0.45 and 0.5 mol of phosphate per mol of Tat. Several Tat peptides, containing serine at position 46, are the only ones which are phosphorylated at significant rates. Several other Tat peptides containing potential protein kinase C phosphorylation sites are not phosphorylated.