Interactive Modeling and Evaluation of Tumor Growth

This paper addresses the need to quantify tumor growth and detect changes as this information is relevant to manage the patient treatment and to aid biotechnological efforts to cure cancer (Silva et al. 2008). An interactive tumor segmentation technique is used to recover the shape and size of tumors without imposing shape constraints. This segmentation algorithm provides good convergence, is robust to the initialization conditions, and requires simple and intuitive user interactions. A parametric approach to model tumor growth analytically is proposed in this paper. The preliminary experimental results are encouraging. The segmentation method is shown to be robust and simple to use, even in situations where the tumor boundary definition is challenging. Also, the experiments indicate that the proposed model potentially can be used to extrapolate the available data and help predict the tumor size (assuming unconstrained growth). Additionally, the proposed method potentially can provide a quantitative reference to compare the tumor shrinkage rate in cancer treatments.     

Effect of emotional context on bucco-facial apraxia

Patients with left- and right-hemisphere cerebrovascular pathology and normal adult controls were videotaped while executing tasks of bucco-facial praxis in emotional and nonemotional conditions. Each practic movement was assessed for accuracy and motor execution. Left-brain-damaged patients were significantly impaired on these tasks relative to right-damaged patients and controls. When emotional context was provided, apractic performance improved significantly.     

The nursing shortage and provider attitudes: a political perspective

The nursing shortage has been labeled a significant crisis in the health sector. This shortfall could severely threaten both the nursing profession and the entire American health care system. Numerous studies have focused on nurses' satisfaction with their work and the factors leading to positive and negative evaluations. A major deficiency of these endeavors, however, is that none have examined the attitudes of the nurses toward the shortage nor the activities which might be undertaken to rectify it. Moreover, political competence and the nurses' perceptions of the political arena have not been addressed and related to the shortage. The purpose of this paper is to help fill these gaps in the literature.     

Prisoner Blood Donors and Posttransfusion (Icteric) Viral Hepatitis

A retrospective study of the incidence of posttransfusion viral hepatitis in two state-operated hospitals with different kinds of blood procurement programs was undertaken for a nine-year period. Although one hospital relied mainly on prison donors and the other secured blood primarily from volunteer donors, no significant difference in the incidence of posttransfusion hepatitis could be demonstrated. These results suggest that carefully selected prison populations may be an important potential source of high quality donors, without undue risk of transmitting hepatitis. However, because this is a retrospective study and because it is not known whether the single penal institution studied in this report is unique, prospective studies of prisoner donors are necessary before such sources can be accepted generally.     

Using the PRACTICE mnemonic to apply cultural competency to genetics in medical education and patient care.

Medical education curricula increasingly are incorporating courses on cultural competency and skills development in working with ethnically diverse patient populations as well as courses on genetics and genomics. The authors support these efforts and believe the next step is integration of genetics into cultural competency programs and similarly, cultural competency into genetics curricula. In this paper, the authors describe the work of the Genetics in Primary Care Faculty Development Working Group on Cultural Competency, a federally-funded initiative to prepare generalist faculty to teach genetics as part of ambulatory education. Over a 12-month period, this team wrote a module on cultural competency and nine new clinical cases, and developed the PRACTICE mnemonic (prevalence, risk, attitude, communication, testing, investigation, consent, empowerment) to help health care professionals integrate cultural competency skills in genetics into primary care. More specifically, the PRACTICE mnemonic integrates information emerging from experts in health disparities and doctor-patient communication to build a comprehensive model for addressing the relevance of culture and ethnicity in the delivery of genetic services. Lastly, this paper illustrates a systematic method of covering key areas of cultural competency through discussion of a patient with a genetic disorder as well as presents an argument as to why cultural competency is highly relevant to the delivery of genetic services especially as part of generalists' clinical practice.     

Progress and challenges toward an AIDS vaccine: Brother,can you spare a paradigm?

The development of a safe and effective vaccine for prevention of AIDS has thus far proven to be exceedingly difficult due to the complexities associated with HIV pathogenesis including but not limited to antigenic hypervariability, multiple routes and modes of transmission, a lack of defined correlates of protective immunity, and a tropism for infection of immunoregulatory cells which are essential for orchestrating an effective host immune response. Recent observations, including the identification of significant differences between primary isolates of HIV circulating in the population and laboratoryadapted isolates, animal model protection studies demonstrating prevention of AIDS-like disease progression in nonhuman primates in the absence of sterilizing immunity, and epidemiologic studies which question the current dogma surrounding HIV variation and control, have led to the development of novel approaches for antigen presentation and adjuvant development targeted at AIDS vaccine development. The goal of developing a safe and effective AIDS vaccine will likely occur when continued advances in understanding the immunopathogenesis of HIV is balanced with a healthy dose of empirical testing of innovative candidate AIDS vaccines.     

Prevention of hepatitis C virus infection

Despite the promising progress made in the development of experimental HCV hyperimmune globulin preparations and recombinant vaccines, prevention of HCV infection will continue to be an important research front for many years. Until effective and safe immunoprophylaxis is available, preventive efforts will require further understanding of risk factors associated with infection and implementation of strategies to reduce such exposures.     

Pretreatment Evaluation of Chronic Hepatitis C: Risks, Benefits, and Costs

Context.— Chronic hepatitis C (CHC) infection affects nearly 4 million people in the United States. Treatment with interferon alfa-2b has been limited by its cost and low likelihood of long-term response. Objective.— To examine the cost-effectiveness of alternative pretreatment management strategies for patients with CHC. Design.— Decision and cost-effectiveness analysis using a Markov model to examine prevalence of genotypes, viral load, and histological characteristics in relation to the sustained response rate with treatment. Data were based on a previously published decision model and a MEDLINE literature search for hepatitis C, biopsy, and liver from 1966 to 1996. Patients.— A hypothetical population of patients with CHC infection and elevated serum alanine aminotransferase level. Interventions.— Combinations of liver biopsy, genotyping, and quantitative viral load determination prior to a single 6-month course of interferon alfa-2b; empirical interferon treatment; and conservative management. Main Outcome Measures.— Proportion of sustained responders, lifetime costs, life expectancy, and quality-adjusted life expectancy. Results.— Strategies involving hepatitis C virus (HCV) RNA testing had marginal cost-effectiveness ratios up to $4400 per discounted quality-adjusted life-year gained but would miss up to 36% of sustained responders. Empirical interferon treatment had a marginal cost-effectiveness ratio of $12,400 per discounted quality-adjusted life-year gained and reached all potential sustained responders. Strategies involving liver biopsy were more expensive and would miss 6% of sustained responders and yield slightly lower life expectancies. Conclusions.— Routine liver biopsy before treatment with interferon increases the cost of managing patients with CHC without improving health outcomes. Using quantitative HCV RNA testing to guide therapy misses some potential sustained responders. Empirical interferon treatment has a marginal cost-effectiveness ratio within the bounds of other commonly accepted therapies and misses none of the sustained responders.