HIV-related enteropathy in Zambia: a clinical, microbiological, and histological study

To investigate the etiology of chronic diarrhea associated with human immunodeficiency virus (HIV) infection in Lusaka, we studied 63 HIV-positive patients and 36 seronegative controls clinically and endoscopically. Stools were studied for morphology and for opportunist infections. Fifty-five percent of patients seropositive for HIV who presented with a history of chronic diarrhea had parasites; the most common were Cryptosporidium (32%), Isospora belli (16%), and Strongyloides stercoralis (6%). As indicated by villous blunting and inflammation on duodenal histology, those with diarrhea and parasites showed the most severe damage. We could not implicate mycobacteria or bacterial overgrowth as causes for the enteropathy associated with HIV.     

Fibronectin binding to thrombin-stimulated platelets: evidence for fibrin(ogen) independent and dependent pathways

Plasma fibronectin binds in a specific and saturable manner to thrombin- stimulated platelets. gamma-Thrombin stimulated 80% as much fibronectin binding to platelets as alpha-thrombin with conversion of less than or equal to 1% of platelet fibrinogen to fibrin. Afibrinogenemic and normal platelets bound similar quantities of fibronectin in the presence of calcium or magnesium-ethylene glycol tetra-acetic acid (EGTA). These observations indicate that fibronectin can interact with platelets without involvement of fibrin or fibrinogen. Nevertheless, two different effects of fibrin(ogen) on fibronectin binding were observed. First, exogenous fibrinogen inhibited fibronectin binding to thrombin-stimulated platelets. This inhibition was unidirectional, as fibronectin did not inhibit fibrinogen binding to ADP or thrombin- stimulated cells. Second, formaldehyde-fixed cells with surface- associated fibrin bound significant quantities of fibronectin. This interaction required calcium and did not occur on fixed cells with or without surface-bound fibrinogen. A portion of the ligand bound to fixed cells with surface-associated fibrin was modified to form a derivative with a molecular weight identical to that of the fibronectin subunit cross-linked to the alpha-chain of fibrin. This high mol wt derivative was also observed to a variable extent with living cells in the presence of magnesium or calcium but not in the presence of magnesium-EGTA. Thus, fibronectin binds to platelets by at least two mechanisms: (1) a fibrin(ogen)-independent pathway that requires divalent ions and is inhibited by exogenous fibrinogen; and (2) a fibrin-dependent pathway with an absolute calcium requirement. With nonaggregated, thrombin-stimulated platelets, the former pathway appears to predominate.     

Molecular Epidemiology of Influenza A(H1N1)pdm09 Virus among Humans and Swine,Sri Lanka

After multiple discrete introductions of influenza A(H1N1)pdm09 virus into Sri Lanka, the virus was transmitted among humans, then swine. The spread of virus between geographically distant swine farms is consistent with virus dispersal associated with a vehicle used for swine transportation, although this remains unproven.     

Measurement of Cancer Health Literacy and Identification of Patients with Limited Cancer Health Literacy

Health literacy is related to a broad range of health outcomes. This study was designed to develop a psychometrically sound instrument designed to measure cancer health literacy along a continuum (CHLT-30), to develop another instrument designed to determine whether a patient has limited cancer health literacy (CHLT-6), and to estimate the prevalence of limited cancer health literacy. The Cancer Health Literacy Study involving 1,306 Black and White cancer patients was conducted between April 2011 and April 2013 in the Virginia Commonwealth University Massey Cancer Center and surrounding oncology clinics. A continuous latent variable modeling framework was adopted to dimensionally represent cancer health literacy, whereas discrete latent variable modeling was used to estimate the prevalence rates of limited cancer health literacy. Self confidence about engaging in health decisions was used as the primary outcome in external validation of new instruments. Results from a comprehensive analysis strongly supported the construct validity and reliability of the CHLT-30 and CHLT-6. For both instruments, measurement invariance tests ruled out item/test bias to explain gender and race/ethnicity differences in test scores. The limited cancer health literacy rate was 18%, a subpopulation consisting of overrepresented Black, undereducated, and low-income cancer patients. Overall, the results supported the conclusion that the CHLT-30 accurately measures cancer health literacy along a continuum and that the CHLT-6 efficiently identifies patients with limited cancer health literacy with high accuracy.