Megakaryocyte interaction with subendothelial extracellular matrix is associated with adhesion, platelet-like shape change, and thromboxane A2 production

We have examined the morphological and secretory behavior of rat and guinea pig megakaryocytes exposed for up to 24 hours to extracellular matrix produced by cultured bovine endothelial cells. By phase-contrast microscopy of living cells and in more detail by scanning electron microscopy, the megakaryocytes showed a nonreversible adherence, an extensive formation of filopodia around the periphery like the rays of the sun, and a tendency toward flattening. These filopodia were generally linear with attenuated tips and were larger than, but resembled the filopodia of, rat or guinea pig platelets exposed to this extracellular matrix. In contrast, isolated megakaryocytes on glass or on uncoated plastic surfaces did not show these responses; adherence, in the face of gentle agitation before fixation, was minimal, with rare filopodia and no flattening. Megakaryocytes that interacted with the extracellular matrix produced significant amounts of thromboxane A2, but this did not occur on uncoated surfaces and could not be attributed to other contaminating cells in the megakaryocyte suspensions. The appearance in megakaryocytes of these typical platelet responses indicates that megakaryocytes acquire the functional capabilities of platelets by the synthesis and assembly of platelet substances and organelles. Thromboxane production by megakaryocytes stimulated by the extracellular matrix is a readily quantifiable measure of this capacity.     

Economics methods in the Clinical Outcomes Utilizing percutaneous coronary Revascularization and Aggressive Guideline-driven drug Evaluation (COURAGE) trial

Percutaneous coronary intervention (PCI) remains a major therapeutic option for the treatment of chronic coronary artery disease. In the COURAGE trial, 2287 patients with chronic coronary disease were randomized between PCI with medical management and medical management alone. Embedded within the COURAGE trial is a detailed economic analysis being conducted in three health care systems: the US Veterans Administration (VA), Canada, and the US non-VA. Resource use and costs are being collected for each system and overall. Survival is assessed internally in the trial with mean follow-up of 4.5 years. Long-term mean survival will be estimated by projecting survival beyond the trial period by extrapolating the in-trial hazard rates. Utility is being assessed at baseline and at 1, 3, and 6 months and annually thereafter, using a computer-administered standard gamble. Quality-adjusted life years are calculated by multiplying survival by utility. The incremental cost-effectiveness ratio of PCI will be defined as the additional cost of PCI divided by the gain in life years and quality-adjusted life years. The 95% confidence regions of efficacy and costs will be determined by bootstrap over a range of acceptability thresholds, which will then be displayed in the cost-effectiveness plane and as a cost-effectiveness acceptability curve. A multilevel regression model will assess cost-effectiveness from a net benefit perspective. These approaches should provide the most detailed assessment available of the cost-effectiveness of PCI for coronary artery disease.     

Research and applications: Effects of health information exchange adoption on ambulatory testing rates

Objective

To determine the effects of the adoption of ambulatory electronic health information exchange (HIE) on rates of laboratory and radiology testing and allowable charges.

Design

Claims data from the dominant health plan in Mesa County, Colorado, from 1 April 2005 to 31 December 2010 were matched to HIE adoption data on the provider level. Using mixed effects regression models with the quarter as the unit of analysis, the effect of HIE adoption on testing rates and associated charges was assessed.

Results

Claims submitted by 306 providers in 69 practices for 34 818 patients were analyzed. The rate of testing per provider was expressed as tests per 1000 patients per quarter. For primary care providers, the rate of laboratory testing increased over the time span (baseline 1041 tests/1000 patients/quarter, increasing by 13.9 each quarter) and shifted downward with HIE adoption (downward shift of 83, p<0.01). A similar effect was found for specialist providers (baseline 718 tests/1000 patients/quarter, increasing by 19.1 each quarter, with HIE adoption associated with a downward shift of 119, p<0.01). Even so, imputed charges for laboratory tests did not shift downward significantly in either provider group, possibly due to the skewed nature of these data. For radiology testing, HIE adoption was not associated with significant changes in rates or imputed charges in either provider group.

Conclusions

Ambulatory HIE adoption is unlikely to produce significant direct savings through reductions in rates of testing. The economic benefits of HIE may reside instead in other downstream outcomes of better informed, higher quality care.     

Toward a more comprehensive assessment of depression remission: the Remission Evaluation and Mood Inventory Tool (REMIT)

Objective

Depression remission continues to be defined in terms of resolution of the Diagnostic and Statistical Manual of Mental Disorders criteria symptoms. However, it may be useful to assess additional symptoms as part of a more complete evaluation of remission. We sought to develop an adjunct self-report measure that can be used with commonly used depression measures when assessing remission.

Methods

Secondary data analysis and expert input were used to develop candidate items that were evaluated cross-sectionally in 1003 primary care clinician-identified depressed patients from two practice-based research networks. Multivariable regression analysis, with self-assessed recovery as the dependent variable, identified five symptoms that contributed significantly beyond the Patient Health Questionnaire (PHQ)-8. Further analysis was performed in selected subsamples.

Results

Emotional control, contentedness, future seeming dark, ability to bounce back and happiness yielded an 11% increase in R² beyond 60% yielded by the PHQ-8. The summed Remission Evaluation and Mood Inventory Tool (REMIT) 5 items have a mean=9.6 (S.D.=4.5), range 0-20 and reliability of 0.86. Subsample analysis showed incremental R² ranging from 9% in men to 15% in African-Americans.

Conclusion

Depression remission is a multidimensional concept that includes important nondepressive symptom dimensions. These important dimensions can be measured using a self-report instrument feasible for routine primary care. Pending longitudinal validation, REMIT5 is a promising tool for depression management.     

Beyond race or ethnicity and socioeconomic status: predictors of prenatal testing for Down syndrome

OBJECTIVE: To identify predictors of prenatal genetic testing decisions and explore whether racial or ethnic and socioeconomic differences are explained by knowledge, attitudes, and preferences. METHODS: This was a prospective cohort study of 827 English-, Spanish-, or Chinese-speaking pregnant women presenting for care by 20 weeks of gestation at 1 of 23 San Francisco Bay-area obstetrics clinics and practices. Our primary outcome measure for women aged less than 35 years was any prenatal genetic testing use compared with none, and for women aged 35 years or older, prenatal testing strategy (no testing, screening test first, straight to invasive diagnostic testing). Baseline questionnaires were completed before any prenatal test use; test use was assessed after 30 gestational weeks. RESULTS: Among women aged less than 35 years, no racial or ethnic differences in test use emerged. Multivariable analyses yielded three testing predictors: prenatal care site (P = .024), inclination to terminate pregnancy of a Down-syndrome-affected fetus (odds ratio 2.94, P = .002) and belief that modern medicine interferes too much in pregnancy (odds ratio .85, P = .036). Among women aged 35 years or older, observed racial or ethnic and socioeconomic differences in testing strategy were mediated by faith and fatalism, value of testing information, and perceived miscarriage risk. Multivariable predictors of testing strategy included these 3 mediators (P = .035, P < .001, P = .037, respectively) and health care system distrust (P = .045). A total of 29.5% of screen-positive women declined amniocentesis; 6.6% of women screening negative underwent amniocentesis. CONCLUSION: Racial or ethnic and socioeconomic differences in prenatal testing strategy are mediated by risk perception and attitudes. Screening is not the best choice for many women. Optimal prenatal testing counseling requires clarification of risks and consideration of key attitudes and preferences regarding the possible sequence of events after testing decisions.     

Effects of P-MAPA Immunomodulator on Toll-Like Receptors and p53: Potential Therapeutic Strategies for Infectious Diseases and Cancer

Background

Compounds that can act as agonists for toll-like receptors (TLRs) may be promising candidates for the development of drugs against infectious diseases and cancer. The present study aimed to characterize the immunomodulatory effects of P-MAPA on TLRs in vitro and in vivo, as well as to investigate its potential as adjuvant therapy in infectious diseases and cancer.

Methods

For these purposes, the activity of P-MAPA on TLRs was assayed in vitro through NF-??B activation in HEK293 cells expressing a given TLR, and using an in vivo animal model for bladder cancer (BC). The antimicrobial activity of P-MAPA was tested against Mycobacterium tuberculosis (TB) in vitro in an MIC assay, and in vivo using an aerosol infection model of murine tuberculosis. Antitumor effects of P-MAPA were tested in an animal model with experimentally induced BC. Moxifloxacin (MXF) and Bacillus Calmette-Guerin (BCG) were used as positive controls in the animal models.

Results

The results showed that P-MAPA, administered alone or in combination with MXF, induced significant responses in vivo against TB. In contrast, the compound did not show antimicrobial activity in vitro. P-MAPA showed a significant stimulatory effect on human TLR2 and TLR4 in vitro. In BC, TLR2, TLR4 and p53 protein levels were significantly higher in the P-MAPA group than in the BCG group. The most common histopathological changes in each group were papillary carcinoma in BC group, low-grade intraepithelial neoplasia in BCG group and simple hyperplasia in P-MAPA group. Concerning the toxicological analysis performed during BC treatment, P-MAPA did not show evidence for hepatotoxicity and nephrotoxicity.

Conclusions

In conclusion, P-MAPA acted as TLR ligand in vitro and improved the immunological status in BC, increasing TLR2 and TLR4 protein levels. P-MAPA immunotherapy was more effective in restoring p53 and TLRs reactivities and showed significantly greater antitumor activity than BCG. The activation of TLRs and p53 may provide a hypothetical mechanism for the therapeutic effects in both cancer and infectious diseases. Taken together data obtained will encourage the further investigation of P-MAPA as a potential candidate for the treatment of cancer and infectious diseases.     

The Prevalence of Cryptosporidium spp. in Children,Taiz District,Yemen

Background

This is the first work done on cryptosporidiosis among the children in Taiz, Yemen.

Methods

A number of 712 samples were collected from children of different ages (ranging from 1 month to 12 years) from Dec 2006 to Aug 2007. The collected samples were examined by Sheather''s sugar floatation and Modified Ziehl- Neelsen stain as well as ELISA methods. The test results were statistically analyzed by SPSS software.

Results

The overall positive percentage was 43.7%. The higher incidence (36.2%) was occurred in males while the lowest incidence (32.7%) was observed in females (r=0.876; P=0.001). The correlation between infected cases and the type of drinking water was r =0.121. Among the cases examined by ELISA (92 cases), 26.1% were infected. The correlation between seropositivity and gender was r=0.652 (P=0.031).

Conclusion

Cryptosporidium spp. is a significant pathogen among children at Taiz. Fresh water supplies, education, eating habits and domestic animals are considered the main sources for transmission of cryptosporidiosis.