Detection of anti-HTLV-I Tax antibodies in HTLV-I enzyme-linked immunosorbent assay-negative individuals

The HTLV-I tax gene protein (Tax) is not packaged within the mature viral particle from which the proteins for the commercially available enzyme-linked immunosorbent assay (ELISA) are derived. Screening of 162 individuals within a cohort of white intravenous (IV) drug abusers, previously identified as having an increased incidence of HTLV-I infection, demonstrated that seven of them had antibodies to the HTLV-I Tax protein but tested negative in HTLV-I ELISAs and Western blots prepared from purified virion proteins. Three out of 35 individuals in other behaviorally defined high-risk groups also displayed this limited pattern of reactivity to HTLV-I proteins. The presence of the anti-HTLV- I p40/Tax antibodies was determined by radioimmunoprecipitation assay (RIPA), which also revealed low levels of anti-env reactivity. The specificity of the anti-p40 reactivity was confirmed on specific Tax ELISAs and Western blots prepared from recombinantly produced Tax. In vitro gene amplification by the polymerase chain reaction (PCR) was used to establish the presence of sequences homologous to HTLV-I proviral DNA in four/four of these HTLV-I ELISA negative, Tax ELISA/Tax western blot/RIPA positive individuals. These data suggest that the true incidence of HTLV-I infection within high-risk cohorts is greater than previously reported.     

Availability of ulipristal acetate: A secret shopper survey of pharmacies in a metropolitan area on emergency contraception

ObjectivesTo assess levonorgestrel (LNG) and ulipristal acetate (UPA) availability in pharmacies in a metropolitan area.MethodsA cross-sectional survey was conducted of all identified pharmacies within 25 miles of an urban medical center in Kansas City, KS. We categorized the pharmacies as dedicated commercial (national chains), store-associated (affiliated with a general merchandise or grocery store), or independent. We assessed LNG and UPA availability or time to availability if not currently stocked.ResultsWe contacted 165 pharmacies. Of the 165 pharmacies, few stocked UPA (12/165, 7%) whereas the majority stocked oral LNG (128/165, 78%). Dedicated commercial pharmacies were more likely to carry UPA than store-associated and independent pharmacies (11/84 [13%] vs. 1/61 [1%] vs. 0/20, respectively; P = 0.016). Most pharmacies that did not stock UPA reported that they could obtain it within 24 hours (94/153, 62%). Dedicated commercial pharmacies were most likely report the ability to obtain UPA in 24 hours (P = 0.016).ConclusionFew pharmacies stock UPA, the most effective form of oral emergency contraception. Enhanced communication between medical providers and pharmacists within current laws and regulations could enhance patient access to UPA.     

Modified heparin-bonded catheter for cannulation of the coronary sinus from the femoral vein

Serial sampling from the coronary sinus is an attractive technique for drawing blood samples to be used in the characterization of procoagulant activity during coronary interventions. We have developed a modified Simmons catheter for rapid cannulation of the coronary sinus from the femoral approach. The catheter design incorporates heparin bonding and distal side-holes to minimize blood sampling artifacts. Coronary sinus cannulation was performed via the femoral approach in 186 patients by use of a multipurpose catheter (n = 8), an unmodified Simmons I or II catheter (n = 64), or the modified Simmons catheter (n = 114). The coronary sinus was cannulated successfully with the modified Simmons catheter in 97% of patients; the success rate with the unmodified Simmons II catheter was 87% (P = 0.02). The modified Simmons catheter represents an improved technique for cannulation of the coronary sinus from the femoral vein. © Wiley-Liss, Inc.     

A diurnal rhythm in cerebrospinal fluid corticotrophin-releasing hormone different from the rhythm of pituitary-adrenal activity

Corticotrophin-releasing hormone (CRH) appears to be involved in the pathophysiology of various neuropsychiatric illnesses. Because of the potential importance of determining CRH concentrations in cerebrospinal fluid (CSF) in humans and the constraints on human experimentation, we used a rhesus monkey model to study factorsaffecting CSF-CRH concentrations and the association between CRH concentrations and changes in plasma ACTH and cortisol levels. CSF-CRH concentrations followed a diurnal rhythm not closely linked to that of the anterior pituitary-adrenal system. Manipulations that increased release of pituitary ACTH did not affect CSF-CRH concentrations. Our data show that sampling time should be controlled in human CSF-CRH studies and suggest that altered CSF-CRH levels reflect dysregulation of extrahypothalamic CRH neurons.     

Phenotypic characterization of human colorectal cancer stem cells

Recent observations indicate that, in several types of human cancer, only a phenotypic subset of cancer cells within each tumor is capable of initiating tumor growth. This functional subset of cancer cells is operationally defined as the "cancer stem cell" (CSC) subset. Here we developed a CSC model for the study of human colorectal cancer (CRC). Solid CRC tissues, either primary tissues collected from surgical specimens or xenografts established in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice, were disaggregated into single-cell suspensions and analyzed by flow cytometry. Surface markers that displayed intratumor heterogeneous expression among epithelial cancer cells were selected for cell sorting and tumorigenicity experiments. Individual phenotypic cancer cell subsets were purified, and their tumor-initiating properties were investigated by injection in NOD/SCID mice. Our observations indicate that, in six of six human CRC tested, the ability to engraft in vivo in immunodeficient mice was restricted to a minority subpopulation of epithelial cell adhesion molecule (EpCAM)(high)/CD44+ epithelial cells. Tumors originated from EpCAM(high)/CD44+ cells maintained a differentiated phenotype and reproduced the full morphologic and phenotypic heterogeneity of their parental lesions. Analysis of the surface molecule repertoire of EpCAM(high)/CD44+ cells led to the identification of CD166 as an additional differentially expressed marker, useful for CSC isolation in three of three CRC tested. These results validate the stem cell working model in human CRC and provide a highly robust surface marker profile for CRC stem cell isolation.