Texas Medical Center

About: Texas Medical Center is a healthcare organization based out in Houston, Texas, United States. It is known for research contribution in the topics: Population & Cancer. The organization has 2845 authors who have published 2394 publications receiving 79426 citations.

Dithiothreitol, a disulfide‐reducing agent, inhibits capacitation, acrosome reaction, and interaction with eggs by guinea pig spermatozoa

Abstract: Capacitation of guinea pig spermatozoa in vitro was inhibited by the disulfide-reducing agent dithiothreitol (DTT). Even a brief treatment with DTT inhibited capacitation unless an oxidizing agent (glutathione disulfide) was present in the posttreatment medium. Precapacitated spermatozoa were unable to undergo the acrosome reaction in the presence of DTT, indicating that this reagent also blocks the acrosome reaction. Acrosome-reacted spermatozoa were incapable of attaching to and penetrating the zona pellucida in the presence of DTT. Even when acrosome-reacted spermatozoa were directly brought to the surface of zona-free eggs, they were unable to bind to and fuse with the egg plasma membrane so long as DTT was present in the medium. These observations suggest that the tertiary and quaternary structures of sperm surface proteins regulated by their thioldisulfide status are of critical importance in the physiology and function of spermatozoa preliminary to and in the process of fertilization.

Career Choice Processes

Abstract: It is postulated that there exist patterns of career choice which are 'based on a series of situational decisions which, individually, have no rational connection with the choice of a- particular occupation but, nonetheless, comprise the process of embarkation upon a career. The data are from a study of student nurses.

Prospective, open-label safety study of intravenous recombinant tissue plasminogen activator in wake-up stroke

Abstract: Objective It is estimated that one of four ischemic strokes are noticed upon awakening and are not candidates for intravenous recombinant tissue plasminogen activator (rtPA) because their symptoms are >3 hours from last seen normal (LSN). We tested the safety of rtPA in a multicenter, single-arm, prospective, open-label study (NCT01183533) in patients with wake-up stroke (WUS). Methods We aimed to enroll 40 WUS patients with disabling deficits. Patients were 18 to 80 years of age, National Institutes of Health Stroke Scale (NIHSS) ≤25, and selected only on the appearance of noncontrast computed tomography (ie, over one-third middle cerebral artery territory hypodensity). Standard-dose (0.9mg/kg) intravenous rtPA had to be started ≤3 hours of patient awakening. The primary safety outcome was symptomatic intracerebral hemorrhage (sICH) with preplanned stopping rules and data safety board oversight. Other endpoints included: asymptomatic intracerebral hemorrhage; clinical improvement in NIHSS; and 90-day modified Rankin Scale (mRS) score. Results Between October 2010 and October 2013, all 40 preplanned patients were enrolled (50% men) at five stroke centers. Four patients (10%) were subsequently determined to be mimics. Patients had a mean age of 60.8, median NIHSS of 6.5 (range, 2–24), and received thrombolysis at a mean time of 10.3 ± 2.6 LSN and 2.6 ± 0.6 hours from awakening with deficits. No sICH or parenchymal hematomas occurred. At 3 months, 20 of 38 (52.6%) patients achieved excellent recovery with mRS scores of 0 or 1 (2 patients were lost to follow-up). Interpretation Intravenous thrombolysis was safe in this prospective WUS study of patients selected by noncontrast CT. A randomized effectiveness trial appears feasible using a similar, pragmatic design. Ann Neurol 2016;80:211–218

Atelosteogenesis type III : a distinct skeletal dysplasia with features overlapping atelosteogenesis and oto-palato-digital syndrome type II

Abstract: We present 5 cases of a short-limb dwarfism syndrome whose manifestations overlap those of atelosteogenesis and oto-palato-digital syndrome Type II. Clinical, radiographic, genetic, and histologic data are presented which demonstrate differences between our patients and previously reported cases of these other conditions. We conclude that the disorder seen in these children represents a distinct chondrodysplasia for which we propose the name atelosteogenesis Type III.

A NOTCH1 gene copy number gain is a prognostic indicator of worse survival and a predictive biomarker to a Notch1 targeting antibody in colorectal cancer

Abstract: Dysregulation of the Notch1 receptor has been shown to facilitate the development and progression of colorectal cancer (CRC) and has been identified as an independent predictor of disease progression and worse survival. Although mutations in the NOTCH1 receptor have not been described in CRC, we have previously discovered a NOTCH1 gene copy number gain in a portion of CRC tumor samples. Here, we demonstrated that a NOTCH1 gene copy number gain is significantly associated with worse survival and a high percentage of gene duplication in a cohort of patients with advanced CRC. In our CRC patient-derived tumor xenograft (PDTX) model, tumors harboring a NOTCH1 gain exhibited significant elevation of the Notch1 receptor, JAG1 ligand and cleaved Notch1 activity. In addition, a significant association was identified between a gain in NOTCH1 gene copy number and sensitivity to a Notch1-targeting antibody. These findings suggest that patients with metastatic CRC that harbor a gain in NOTCH1 gene copy number have worse survival and that targeting this patient population with a Notch1 antibody may yield improved outcomes.