Additive effect of erythropoietin and heme on murine hematopoietic recovery after azidothymidine treatment [see comments]

The ability of combination treatment with erythropoietin (Epo) and heme to rescue hematopoietic activity in mice from the suppressive effect of azidothymidine (AZT) was determined. Exposure of mice to AZT for 5 weeks produced marked anemia, thrombocytopenia, neutropenia, and weight loss, whereas mice that received Epo and heme for 3 subsequent weeks showed significant alleviation of AZT cytotoxicity. Treatment with Epo (10 U for 5 times/week) stimulated hematopoietic recovery in the AZT- treated animals and reduced the severe anemia and thrombocytopenia by 3 weeks. Administration of a lower Epo dose (1 U Epo) resulted in only a modest retardation of AZT-induced anemia, although, when combined with heme, there was a great improvement in recovery of erythropoiesis. The combination of heme with Epo (10 U) produced the optimum response, resulting in almost normal recovery of bone marrow cellularity as well as recovery of burst-forming units-erythroid (BFU-E) and splenic hematopoietic progenitor content (colony-forming unit-spleen [CFU-S]) by the end of 3 weeks of post-AZT treatment. Treatment with heme alone markedly enhanced the recovery of BFU-E and CFU-S, as well as body weight post-AZT; however, this recovery was not to the extent seen in combination with Epo (10 U). Long-term bone marrow cultures (LTBMCs) established from mice exposed to AZT for 8 weeks showed a marked reduction in cellularity and this was completely alleviated when mice received heme and Epo (10 U) for 3 weeks after 5 weeks of AZT administration. The additive effect of heme and Epo was seen in BFU-E production, as well as in CFU-S production, in LTBMCs. Thus, heme exerts a significant protective effect on hematopoietic progenitors in vivo and may be of potential clinical use in combination with Epo to promote effective erythropoiesis in the setting of AZT therapy.     

CD18-dependent and L-selectin-dependent neutrophil emigration is diminished in neonatal rabbits

Human neonatal neutrophils manifest decreases in mobility, adherence, and emigration compared with adult neutrophils that may contribute to the increased susceptibility of neonates to infection. In a developmental rabbit model, we show a reduced ability of neutrophils from 1-day-old rabbit pups to emigrate to inflamed peritoneium (3.7 +/- 0.35 x 10(6) neutrophils/mL peritoneal exudate) compared with 14-day- old (8.5 +/- 0.7 x 10(6)/mL) and adult rabbits (9.4 +/- 1.4 x 10(6) mL, P < .05) despite significantly increased blood neutrophil counts. Because the reductions in functional Mac-1 (CD11b/CD18) as well as the amount of surface L-selectin are hypothesized to be primarily responsible for the differences in human neonatal neutrophil mobility, we examined CD11b/CD18 and L-selectin in our model. Using flow cytometric analysis we found that similar to human neonates, neutrophils from 1-day-old rabbit pups had 57% of adult rabbit levels of L-selectin and, in contrast with adults, failed to show significant decreases in L-selectin after chemotactic stimulation. In addition, neutrophils from 1-day-old pups compared with adults showed a significantly diminished capacity to upregulate CD11b/CD18 after chemotactic stimulation in vitro, or after emigration to the inflamed peritoneum. Systemic administration of anti-L-selectin monoclonal antibody (MoAb) resulted in significant reduction in peritoneal neutrophils in adult (47%, P < .05) and 14-day-old rabbits (47%, P < .05), but was without effect in 1-day-old rabbits. Administration of anti-CD18 MoAb resulted in significant reduction in peritoneal neutrophil accumulation in all age groups though less in 1 day and 14 day (58% and 65%, respectively) than in adults (91%, P < .05). Only in the 14-day-old rabbits was there an additive effect of anti-L-selectin and anti-CD18 MoAbs compared with anti-CD18 alone (84% v 65%, P < .05). The findings in this in vivo rabbit model support the hypothesis that the previously described in vitro defects in human neonatal L-selectin and CD11b/CD18 may be major contributors to human neonatal inflammatory deficits.     

Characterization and quantitation of the circulating forms of serum transferrin receptor using domain-specific antibodies

To characterize the nature of the immunoreactive transferrin receptor in human serum, antisera were developed to peptide sequences of the extracellular domain of human transferrin receptor between amino acids 107 and 120 and the intracellular domain between amino acids 40 and 54. Antisera against the extracellular domain exhibited reactivity against both purified intact receptor and immunopurified circulating receptor, whereas antisera against the intracellular domain reacted only with intact receptor. Using competitive binding enzyme-linked immunosorbent assays, transferrin receptor in ultracentrifuged sera from normal subjects and patients with sickle cell anemia could be detected with antisera against the extracellular but not the intracellular domain. When the pellet obtained by ultracentrifugation of these sera was assayed after solubilization in 1% teric (polyoxyethylene-9-lauryl ether), only 0.6% of total serum receptor was detected in normal subjects and 3.8% in subjects with sickle cell disease. Roughly equal amounts of this pelleted immunoactivity were detected with antibodies against the extracellular and intracellular domains. These results indicate that less than 1% of transferrin receptor in normal human sera is intact receptor consistent with an exosomal origin and that virtually all circulating transferrin receptor is in the form of a truncated extracellular domain.     

Crystal structures of the trimeric human immunodeficiency virus type 1 matrix protein: implications for membrane association and assembly.

The human immunodeficiency virus type 1 (HIV-1) matrix protein forms a structural shell associated with the inner viral membrane and performs other essential functions throughout the viral life cycle. The crystal structure of the HIV-1 matrix protein, determined at 2.3 angstrom resolution, reveals that individual matrix molecules are composed of five major helices capped by a three-stranded mixed beta-sheet. Unexpectedly, the protein assembles into a trimer in three different crystal lattices, burying 1880 angstrom2 of accessible surface area at the trimer interfaces. Trimerization appears to create a large, bipartite membrane binding surface in which exposed basic residues could cooperate with the N-terminal myristoyl groups to anchor the protein on the acidic inner membrane of the virus.     

Assessing the Legacy of a Legislative Workgroup for Bidirectional Integration of Services

Across the USA, health care systems are recognizing the value of integrating behavioral health services and primary care. The Texas Legislature took a unique approach to integration, passing legislation creating a Workgroup to explore key issues, identify best practices, and recommend policy and practice changes. This article situates the Workgroup in a rapidly evolving policy environment, describing the passage of integrated health care legislation in Texas, the Integration of Health and Behavioral Health Services Workgroup that was created by the legislation, and the policy recommendations that emerged from the Workgroup. The article analyzes how the Workgroup process intersected with a changing policy environment in Texas and nationally, opening the door for essential collaboration and partnership. The Workgroup ultimately laid the groundwork for integration's key role in a comprehensive Medicaid transformation waiver designed to expand access, improve population health and satisfaction with treatment, while better managing costs.     

Discrete Choice Experiment to Estimate Breast Cancer Patients’ Preferences and Willingness to Pay for Prophylactic Granulocyte Colony-Stimulating Factors

ObjectivesRising out-of-pocket costs for cancer patients have increased shared decision making. Clinical guidelines recommend prophylactic granulocyte colony-stimulating factor (G-CSF) for patients receiving chemotherapy with a 20% or greater risk of febrile neutropenia. A discrete choice experiment was conducted to explore breast cancer patients’ preferences and willingness to pay (WTP) for prophylactic G-CSF to decrease the risk of chemotherapy-induced febrile neutropenia.MethodsAn online discrete choice experiment questionnaire survey of a national US convenience sample of self-reported breast cancer patients with prior chemotherapy treatment was conducted. Sixteen paired G-CSF treatment scenarios, each with four attributes (risk of disruption to chemotherapy schedule due to low white blood cell counts, risk of developing an infection requiring hospitalization, frequency of administration, and total out-of-pocket cost) were presented with a follow-up “no treatment” option. Participant preferences and WTP out of pocket were estimated by logistic regression.ResultsParticipants (n = 296) preferred G-CSF regimens with lower out-of-pocket costs, lower risk of chemotherapy disruption, lower risk of infection, and greater convenience (one G-CSF injection per chemotherapy cycle). Participants’ WTP was $1076 out of pocket per cycle to reduce the risk (high to low) of disrupting their chemotherapy schedule, $884 per cycle to reduce the risk (24% [high] to 7% [low]) of infection, and $851 per cycle to decrease the number of G-CSF injections (11 to 1) per cycle.ConclusionsParticipants highly valued specific features of prophylactic G-CSF treatment including maintaining their chemotherapy schedule, lowering their risk of infection, and reducing the number of injections. Physicians should consider patient preferences to inform the best treatment choices for individual patients.     

Trust in government and support for governmental regulation: the case of electronic health records

Background

This paper presents results from a public engagement effort in Nebraska, USA, which measured public opinions about governmental involvement in encouraging the use of electronic health records (EHRs).

Objective

We examine the role of trust in government in contributing to public support for government involvement in the development of EHR technologies. We hypothesize that trust in government will lead to support for federal and state governmental encouragement of the use of EHRs among doctors and insurance companies. Further, because individual experiences with health‐care professionals will reduce perceptions of risk, we expect that support for governmental involvement will be tempered by greater personal experience with the health‐care industry.

Design and Results

Examining a small survey of individuals on the issue, we find general support for both of our hypotheses. The findings suggest that trust in government does have a positive relationship with support for government involvement in the policy domain, but that the frequency of personal experiences with health‐care providers reduces the extent to which the public supports governmental involvement in the development of EHR technology.

Discussion and Conclusion

This inquiry contributes to our understanding of public attitudes towards government involvement in EHRs in the United States specifically and contributes to social science examining links between trust in government and support for governmental activity in the emerging policy domain regarding electronic health records systems.