University of Texas Health Science Center at Houston

About: University of Texas Health Science Center at Houston is a education organization based out in Houston, Texas, United States. It is known for research contribution in the topics: Population & Cancer. The organization has 27309 authors who have published 42520 publications receiving 2151596 citations. The organization is also known as: UTHealth & The UT Health Science Center at Houston.

A Missense Mutation in KIT Kinase Domain 1 Correlates with Imatinib Resistance in Gastrointestinal Stromal Tumors

Abstract: KIT gain of function mutations play an important role in the pathogenesis of gastrointestinal stromal tumors (GISTs). Imatinib is a selective tyrosine kinase inhibitor of ABL, platelet-derived growth factor receptor (PDGFR), and KIT and represents a new paradigm of targeted therapy against GISTs. Here we report for the first time that, after imatinib treatment, an additional specific and novel KIT mutation occurs in GISTs as they develop resistance to the drug. We studied 12 GIST patients with initial near-complete response to imatinib. Seven harbored mutations in KIT exon 11, and 5 harbored mutations in exon 9. Within 31 months, six imatinib-resistant rapidly progressive peritoneal implants (metastatic foci) developed in five patients. Quiescent residual GISTs persisted in seven patients. All six rapidly progressive imatinib-resistant implants from five patients show an identical novel KIT missense mutation, 1982T→C, that resulted in Val654Ala in KIT tyrosine kinase domain 1. This novel mutation has never been reported before, is not present in pre-imatinib or post-imatinib residual quiescent GISTs, and is strongly correlated with imatinib resistance. Allelic-specific sequencing data show that this new mutation occurs in the allele that harbors original activation mutation of KIT .

Why healthcare workers don't wash their hands: a behavioral explanation.

Abstract: Objective. To elucidate behavioral determinants of handwashing among nurses. Design. Statistical modeling using the Theory of Planned Behavior and relevant components to handwashing behavior by nurses that were derived from focus‐group discussions and literature review. Setting. The community and 3 tertiary care hospitals. Participants. Children aged 9‐10 years, mothers, and nurses. Results. Responses from 754 nurses were analyzed using backward linear regression for handwashing intention. We reasoned that handwashing results in 2 distinct behavioral practices—inherent handwashing and elective handwashing—with our model explaining 64% and 76%, respectively, of the variance in behavioral intention. Translation of community handwashing behavior to healthcare settings is the predominant driver of all handwashing, both inherent (weighted \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepack...

Aggressive Variants of Castration-Resistant Prostate Cancer

Abstract: A subset of patients with advanced castration-resistant prostate cancer may eventually evolve into an androgen receptor (AR)-independent phenotype, with a clinical picture associated with the development of rapidly progressive disease involving visceral sites and hormone refractoriness, often in the setting of a low or modestly rising serum prostate-specific antigen level. Biopsies performed in such patients may vary, ranging from poorly differentiated carcinomas to mixed adenocarcinoma-small cell carcinomas to pure small cell carcinomas. These aggressive tumors often demonstrate low or absent AR protein expression and, in some cases, express markers of neuroendocrine differentiation. Because tumor morphology is not always predicted by clinical behavior, the terms "anaplastic prostate cancer" or "neuroendocrine prostate cancer" have been used descriptively to describe these rapidly growing clinical features. Patients meeting clinical criteria of anaplastic prostate cancer have been shown to predict for poor prognosis, and these patients may be considered for platinum-based chemotherapy treatment regimens. Therefore, understanding variants within the spectrum of advanced prostate cancer has important diagnostic and treatment implications.

Roles of transition nuclear proteins in spermiogenesis

Abstract: The transition nuclear proteins (TPs) constitute 90% of the chromatin basic proteins during the steps of spermiogenesis between histone removal and the deposition of the protamines. We first summarize the properties of the two major transition nuclear proteins, TP1 and TP2, and present concepts, based on their time of appearance in vivo and in vitro properties, regarding their roles. Distinct roles for the two TPs in histone displacement, sperm nuclear shaping, chromatin condensation, and maintenance of DNA integrity have been proposed. More definitive information on their roles in spermiogenesis has recently been obtained using mice with null mutations in the Tnp1 or Tnp2 genes for TP1 and TP2, respectively. In these mice, histone displacement and sperm nuclear shaping appear to progress quite normally. Spermatid nuclear condensation occurs, albeit in an abnormal fashion, and the mature sperm of the Tnp -null mutants are not as condensed as wild-type sperm. There is also evidence that sperm from these mutant mice contain an elevated level of DNA strand breaks. The mutant sperm showed several unexpected phenotypes, including a high incidence of configurational defects, such as heads bent back on midpieces, midpieces in hairpin configurations, coils, and clumps, other midpiece defects, reduced levels of proteolytic processing of protamine 2 during maturation, and reduced motility. The two TPs appear partly to compensate for each other as both Tnp1 - and Tnp2 -null mice were able to produce offspring, and appear to have largely overlapping functions as the two mutants had similar phenotypes.

Effectiveness of Comprehensive Professional Development for Teachers of At-Risk Preschoolers

Abstract: This study compared effectiveness of "business as usual" to that of 4 professional development (PD) programs that targeted teachers of at-risk preschool children. A 2 X 2 design was used to cross mentoring and progress monitoring conditions among the 4 PD programs. Specifically, some teachers received both in-classroom mentoring and detailed, instructionally linked feedback concerning children's progress in language and literacy. Some teachers received no mentoring but did receive the detailed, instructionally linked feedback concerning children's progress. Some teachers received in-classroom mentoring but only limited feedback on children's progress, which was not linked to curricular activities. Finally, some teachers received no mentoring and only limited feedback concerning children's progress. All 4 PD conditions included the same year-long, facilitated online course that emphasized language and literacy instruction, practice of learned material in one's classroom, and participation in online message boards with fellow teachers. Across 4 states, 158 schools (N = 262 classrooms) were randomly assigned to I of the 4 PD conditions or business as usual. The condition that included online coursework combined with mentoring and detailed, instructionally linked feedback yielded the greatest improvements in teaching behavior and children's school readiness