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.

Apoptosis and necrosis. Basic types and mechanisms of cell death.

Abstract: Apoptosis and necrosis are two fundamental types of cell death. Current knowledge indicates that the key mechanism of apoptosis is endonuclease activation leading to internucleosomal double-stranded chromatin (DNA) breaks, whereas the key mechanism of necrosis is cell membrane damage. The initial alterations of cellular metabolism and electrolyte homeostasis induced by an injurious agent may activate at least four major pathways leading to loss of membrane integrity: membrane phospholipid degradation, production of amphipathic lipids, damage to the cytoskeleton, and generation of toxic oxygen species and free radicals. These insights point the way for further research to establish definitive causes of specific types of cell injury and cell death, and they provide important clues for the design of improved diagnostic approaches and therapeutic interventions.

Role of endothelium in thrombosis and hemostasis

Abstract: Vascular endothelium is strategically located at the interface between tissue and blood. It is pivotal for protecting against vascular injury and maintaining blood fluidity. Normal endothelium releases prostacyclin and nitric oxide, potent inhibitors of platelet and monocyte activation and vasodilators. Their syntheses are governed by isoforms of enzymes. Normal endothelial surface expresses ecto-adenosine diphosphatase, which degrades adenosine diphosphate and inhibits platelet aggregation; thrombomodulin, which serves as a binding site for thrombin to activate protein C; and heparin-like molecules, which serve as a cofactor for antithrombin III. Normal endothelium secretes tissue plasminogen activator, which activates the fibrinolysis system. Endothelium produces and secretes von Willebrand factor, which mediates platelet adhesion and shear-stress-induced aggregation. Injury to endothelium is accompanied by loss of protective molecules and expression of adhesive molecules, procoagulant activities, and mitogenic factors, leading to development of thrombosis, smooth muscle cell migration, and proliferation and atherosclerosis.

Transthoracic vertebrectomy for metastatic spinal tumors

Abstract: Object. Anterior approaches to the spine for the treatment of spinal tumors have gained acceptance; however, in most published reports, patients with primary, metastatic, or chest wall tumors involving cervical, thoracic, or lumbar regions of the spine are combined. The purpose of this study was to provide a clear perspective of results that can be expected in patients who undergo anterior vertebral body resection, reconstruction, and stabilization for spinal metastases that are limited to the thoracic region. Methods. Outcome is presented for 72 patients with metastatic spinal tumors who were treated by transthoracic vertebrectomy at The University of Texas M. D. Anderson Cancer Center. The predominant primary tumors included renal cancer in 19 patients, breast cancer in 10, melanoma or sarcoma in 10, and lung cancer in nine patients. The most common presenting symptoms were back pain, which occurred in 90% of patients, and lower-extremity weakness, which occurred in 64% of patients. All patients underwe...

Defining Responses to Therapy and Study Outcomes in Clinical Trials of Invasive Fungal Diseases: Mycoses Study Group and European Organization for Research and Treatment of Cancer Consensus Criteria

Abstract: Invasive fungal diseases (IFDs) have become major causes of morbidity and mortality among highly immunocompromised patients. Authoritative consensus criteria to diagnose IFD have been useful in establishing eligibility criteria for antifungal trials. There is an important need for generation of consensus definitions of outcomes of IFD that will form a standard for evaluating treatment success and failure in clinical trials. Therefore, an expert international panel consisting of the Mycoses Study Group and the European Organization for Research and Treatment of Cancer was convened to propose guidelines for assessing treatment responses in clinical trials of IFDs and for defining study outcomes. Major fungal diseases that are discussed include invasive disease due to Candida species, Aspergillus species and other molds, Cryptococcus neoformans, Histoplasma capsulatum, and Coccidioides immitis. We also discuss potential pitfalls in assessing outcome, such as conflicting clinical, radiological, and/or mycological data and gaps in knowledge.

Lack of Clinical Significance of Early Ischemic Changes on Computed Tomography in Acute Stroke

Abstract: ContextThe prevalence and clinical significance of early ischemic changes (EICs) on baseline computed tomography (CT) scan of the head obtained within 3 hours of ischemic stroke are not established.ObjectiveTo determine the frequency and significance of EIC on baseline head CT scans in the National Institute of Neurological Disorders and Stroke (NINDS) rt-PA (recombinant tissue plasminogen activator) Stroke Trial.Design and SettingThe original study, a randomized controlled trial, took place from January 1991 through October 1994 at 43 sites, during which CT images were obtained within 3 hours of symptom onset and prior to the initiation of rt-PA or placebo. For the current analysis, detailed reevaluation was undertaken after October 1994 of all baseline head CT scans with clinical data available pretreatment (blinded to treatment arm).PatientsOf 624 patients enrolled in the trial, baseline CT scans were retrieved and reviewed for 616 (99%).Main Outcome MeasuresFrequency of EICs on baseline CT scans; association of EIC with other baseline variables; effect of EICs on deterioration at 24 hours (≥4 points increase from the baseline National Institutes of Health Stroke Scale [NIHSS] score); clinical outcome (measured by 4 clinical scales) at 3 months, CT lesion volume at 3 months, death at 90 days; and symptomatic intracranial hemorrhage (ICH) within 36 hours of treatment.ResultsThe prevalence of EIC on baseline CT in the combined rt-PA and placebo groups was 31% (n = 194). The EIC was significantly associated with baseline NIHSS score (ρ = 0.23; P<.001) and time from stroke onset to baseline CT scan (ρ = 0.11; P = .007). After adjusting for baseline variables, there was no EIC × treatment interaction detected for any clinical outcome, including deterioration at 24 hours, 4 clinical scales, lesion volume, and death at 90 days (P≥.25), implying that EIC is unlikely to affect response to rt-PA treatment. After adjusting for NIHSS score (an independent predictor of ICH), no EIC association with symptomatic ICH at 36 hours was detected in the group treated with rt-PA (P≥.22).ConclusionsOur analysis suggests that EICs are prevalent within 3 hours of stroke onset and correlate with stroke severity. However, EICs are not independently associated with increased risk of adverse outcome after rt-PA treatment. Patients treated with rt-PA did better whether or not they had EICs, suggesting that EICs on CT scan are not critical to the decision to treat otherwise eligible patients with rt-PA within 3 hours of stroke onset.