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Dive into the research topics where Jose Miguel Yamal is active.

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Featured researches published by Jose Miguel Yamal.


JAMA | 2014

Effect of Erythropoietin and Transfusion Threshold on Neurological Recovery After Traumatic Brain Injury: A Randomized Clinical Trial

Claudia S. Robertson; H. Julia Hannay; Jose Miguel Yamal; Shankar P. Gopinath; J. Clay Goodman; Barbara C. Tilley; Athena Baldwin; Lucia Rivera Lara; Hector Saucedo-Crespo; Osama Ahmed; Santhosh Sadasivan; Luciano Ponce; Jovanny Cruz-Navarro; Hazem Shahin; Imoigele P. Aisiku; Pratik Doshi; Alex B. Valadka; Leslie Neipert; Jace M. Waguspack; M. Laura Rubin; Julia S. Benoit; Paul R. Swank

IMPORTANCE There is limited information about the effect of erythropoietin or a high hemoglobin transfusion threshold after a traumatic brain injury. OBJECTIVE To compare the effects of erythropoietin and 2 hemoglobin transfusion thresholds (7 and 10 g/dL) on neurological recovery after traumatic brain injury. DESIGN, SETTING, AND PARTICIPANTS Randomized clinical trial of 200 patients (erythropoietin, n = 102; placebo, n = 98) with closed head injury who were unable to follow commands and were enrolled within 6 hours of injury at neurosurgical intensive care units in 2 US level I trauma centers between May 2006 and August 2012. The study used a factorial design to test whether erythropoietin would fail to improve favorable outcomes by 20% and whether a hemoglobin transfusion threshold of greater than 10 g/dL would increase favorable outcomes without increasing complications. Erythropoietin or placebo was initially dosed daily for 3 days and then weekly for 2 more weeks (n = 74) and then the 24- and 48-hour doses were stopped for the remainder of the patients (n = 126). There were 99 patients assigned to a hemoglobin transfusion threshold of 7 g/dL and 101 patients assigned to 10 g/dL. INTERVENTIONS Intravenous erythropoietin (500 IU/kg per dose) or saline. Transfusion threshold maintained with packed red blood cells. MAIN OUTCOMES AND MEASURES Glasgow Outcome Scale score dichotomized as favorable (good recovery and moderate disability) or unfavorable (severe disability, vegetative, or dead) at 6 months postinjury. RESULTS There was no interaction between erythropoietin and hemoglobin transfusion threshold. Compared with placebo (favorable outcome rate: 34/89 [38.2%; 95% CI, 28.1% to 49.1%]), both erythropoietin groups were futile (first dosing regimen: 17/35 [48.6%; 95% CI, 31.4% to 66.0%], P = .13; second dosing regimen: 17/57 [29.8%; 95% CI, 18.4% to 43.4%], P < .001). Favorable outcome rates were 37/87 (42.5%) for the hemoglobin transfusion threshold of 7 g/dL and 31/94 (33.0%) for 10 g/dL (95% CI for the difference, -0.06 to 0.25, P = .28). There was a higher incidence of thromboembolic events for the transfusion threshold of 10 g/dL (22/101 [21.8%] vs 8/99 [8.1%] for the threshold of 7 g/dL, odds ratio, 0.32 [95% CI, 0.12 to 0.79], P = .009). CONCLUSIONS AND RELEVANCE In patients with closed head injury, neither the administration of erythropoietin nor maintaining hemoglobin concentration of greater than 10 g/dL resulted in improved neurological outcome at 6 months. The transfusion threshold of 10 g/dL was associated with a higher incidence of adverse events. These findings do not support either approach in this setting. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00313716.


Cancer Nursing | 2005

Predictors of Breast and Cervical Screening in Vietnamese Women in Harris County, Houston, Texas

Vi Ho; Jose Miguel Yamal; E. Neely Atkinson; Karen Basen-Engquist; Guillermo Tortolero-Luna; Michele Follen

The Vietnamese are a quickly growing, important part of the Texas population. Breast cancer is known to have different biologic characteristics in Vietnamese women. In order to develop appropriate intervention and screening strategies, we conducted a study of barriers to cervical and breast screening in Vietnamese women in Harris County, Tex. Our objective was to characterize the demographic factors, beliefs, and barriers to cervical and breast cancer screening in our study population and test the effect of these on Papanicolaou test, breast self-examination (BSE), medical breast examination (MBE), and mammography use. The Health Belief Model Scales for Measuring Beliefs Related to Breast Cancer (Champion VL, Nursing Research 1993;42:139–143) was the framework used to assess attitudes regarding risk of breast cancer and to design a component assessing risk of cervical cancer. The questionnaire addressed susceptibility, seriousness, benefits, barriers, and health about screening for breast and cervical cancer. It was translated into Vietnamese and back-translated into English prior to use. The questionnaire was mailed to Harris County residents. Those returned were entered into a database. The data were analyzed for validity using Chronbachs alpha. Simple descriptive analyses and nominal logistic regression identified predictors of Papanicolaou test, BSE, MBE, and mammography use. Twelve hundred surveys were mailed out to Vietnamese women using the telephone directory and the church directories in Harris County; 209 were returned and entered into the database. Of the respondents, 67% had ever received a Papanicolaou test; of these, 89% had received a Papanicolaou test within the past year; 55% of respondents had performed a BSE, 45% of patients received an MBE, and 45% of respondents had ever received a mammogram (15% of respondents had a mammogram during the previous year). The most significant predictors of Papanicolaou test, BSE, MBE, and mammography use were marital status (being married), high educational level, lack of barriers, a family history of the cancer, older age, and increased perception of seriousness. Compared to other studies of Vietnamese women, the women in Texas are among the highest users of the Papanicolaou test, BSE, MBE, and mammography. Barriers and incentives to breast and cervical screening were similar to those in other studies.


International Journal of Radiation Oncology Biology Physics | 2003

Dosimetric consequences of using a surrogate urethra to estimate urethral dose after brachytherapy for prostate cancer.

Hoon K. Lee; W D'Souza; Jose Miguel Yamal; Alan Pollack; Andrew K. Lee; Matthew B. Palmer; Deborah A. Kuban

PURPOSE To assess the accuracy and dosimetric consequences of defining a surrogate urethra at the geometric center of the prostate in postimplant CT scans. METHODS AND MATERIALS Eighty postimplant CT scans were obtained with a Foley catheter in place at Day 0 and at 1 month for 40 patients who had undergone (125)I prostate brachytherapy. The percentage of urethral volume receiving at least 275% of the prescribed dose (uV(275)), uV(250), uV(200), uV(150), maximal dose received by 90% of urethral volume (uD(90)), uD(70), uD(30), and uD(1) were measured for the Foley catheter and surrogate urethra. The distance between the Foley catheter and surrogate urethra was measured at the base, middle, and apex of the prostate. RESULTS A statistically significant difference was found in all the above-listed dosimetric parameters between the Foley catheter and surrogate urethra at Day 0 (p <or= 0.001). At 1 month, the uD(90), uD(70), and uD(1) remained significantly different between the Foley catheter and surrogate urethra (p <or= 0.05). The difference in the uV(275) (p = 0.055) and uV(150) (p = 0.059) between the Foley catheter and surrogate urethra showed a trend toward statistical significance at 1 month. The uV(250), uV(200), and uD(30) were greater for the surrogate urethra than for the Foley catheter at 1 month, but were not significantly different statistically. The mean distance between the Foley catheter and the surrogate urethra was greatest at the base (1.2 cm) in the vertical axis at Day 0 and decreased substantially to 0.87 cm at 1 month (p = 0.0004). CONCLUSION Using a surrogate urethra at the geometric center of the prostate may significantly overestimate the urethral dose at Day 0 and certain dosimetric parameters at 1 month. An alternative position for a surrogate urethra accounting for the difference in the location of the Foley catheter near the base of the prostate at Day 0 and 1 month could be considered in future studies.


Stroke | 2015

Benefits of Stroke Treatment Using a Mobile Stroke Unit Compared With Standard Management The BEST-MSU Study Run-In Phase

Ritvij Bowry; Stephanie Parker; Suja S. Rajan; Jose Miguel Yamal; Tzu Ching Wu; Laura Richardson; Elizabeth A. Noser; David Persse; Kamilah Jackson; James C. Grotta

Background and Purpose— Faster treatment with intravenous tissue-type plasminogen activator (tPA) is likely to improve outcomes. Optimizing prehospital triage by mobile stroke units (MSUs) may speed treatment times. The Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit (BEST-MSU) study was launched in May 2014 using the first MSU in the United States to compare stroke management using an MSU versus standard management (SM). Herein, we describe the results of the prespecified, nonrandomized run-in phase designed to obtain preliminary data on study logistics. Methods— The run-in phase consisted of 8 MSU weeks when all-patient care occurred on the MSU and 2 SM weeks when the MSU nurse met personnel on scene or at the emergency department to ensure comparability with MSU patients. Telemedicine was independently performed in 9 MSU cases. Results— Of 130 alerts, 24 MSU and 2 SM patients were enrolled. Twelve of 24 MSU patients received tPA on board; 4 were treated within 60 minutes of last seen normal, and 4 went on to endovascular treatment. There were no hemorrhagic complications. Four had primary intracerebral hemorrhage. Agreement on tPA eligibility between the onsite and telemedicine physician was 90%. Conclusions— The run-in phase provided a tPA treatment rate of 1.5 patients per week, assured us that treatment within 60 minutes of onset is possible, and enabled enrollment of patients on SM weeks. We also recognized the opportunity to assess the effect of the MSU on endovascular treatment and intracerebral hemorrhage. Challenges include the need to control biased patient selection on MSU versus SM weeks and establish inter-rater agreement for tPA treatment using telemedicine.


Obstetrics & Gynecology | 2011

Prior Preterm or Small-for-Gestational-Age Birth Related to Maternal Metabolic Syndrome

Janet M. Catov; Rhiannon Dodge; Jose Miguel Yamal; James M. Roberts; Linda B. Piller; Roberta B. Ness

OBJECTIVE: To estimate whether women who deliver small babies due to preterm birth or growth restriction have excess risk for cardiovascular disease and diabetes later in life. METHODS: Eight years after pregnancy, we estimated the prevalence of metabolic syndrome and its components in a cohort study of women with prior preterm (preterm birth before 37 weeks, n=181) or small for gestational age ([SGA], less than the tenth percentile, n=192) births, compared with women with term births (37 or more weeks, n=306). Women delivered at Magee-Womens Hospital in Pittsburgh, Pennsylvania, and those with preeclampsia or prepregnancy diabetes or hypertension were excluded. Women underwent a structured interview and fasting blood sampling. RESULTS: Women were, on average, 8 years postpartum and 39 years old at evaluation. Women with a prior preterm birth had higher blood pressure, triglycerides, and LDL-cholesterol compared with those in a term control group. Women with prior SGA births were leaner and more likely to smoke compared with those with term births. Women with prior preterm birth had elevated risk of metabolic syndrome, adjusted for demographic, smoking and body size factors (23% preterm compared with 17% control group; odds ratio [OR] 1.76 [1.06, 2.80]). In women with a prior preterm birth, low HDL (11% preterm compared with 5% control group; OR 2.6 [1.2, 5.2]), hypertriglyceridemia (22% compared with 14%; OR 1.9 [1.2, 2.9]), and elevated glucose (24% compared with 19%; OR 1.5 [1.0, 2.3]) accounted for this excess metabolic syndrome. In women with SGA, the only element of metabolic syndrome that was aberrant was glucose metabolism. CONCLUSION: Eight years after pregnancy, women with prior preterm or SGA births had evidence of metabolic syndrome compared with women with term births. Screening and intervention in these women after pregnancy may delay or prevent disease. LEVEL OF EVIDENCE: II


International Journal of Cancer | 2011

Accuracy of optical spectroscopy for the detection of cervical intraepithelial neoplasia: Testing a device as an adjunct to colposcopy

Scott B. Cantor; Jose Miguel Yamal; Martial Guillaud; Dennis D. Cox; E. Neely Atkinson; John L. Benedet; Dianne Miller; Thomas Ehlen; Jasenka Matisic; Dirk van Niekerk; Monique Bertrand; Andrea Milbourne; Helen E. Rhodes; Anais Malpica; Gregg Staerkel; Shahla Nader-Eftekhari; Karen Adler-Storthz; Michael E. Scheurer; Karen Basen-Engquist; Eileen H. Shinn; Loyd A. West; Anne Therese Vlastos; Xia Tao; J. Robert Beck; Calum MacAulay; Michele Follen

Testing emerging technologies involves the evaluation of biologic plausibility, technical efficacy, clinical effectiveness, patient satisfaction, and cost‐effectiveness. The objective of this study was to select an effective classification algorithm for optical spectroscopy as an adjunct to colposcopy and obtain preliminary estimates of its accuracy for the detection of CIN 2 or worse. We recruited 1,000 patients from screening and prevention clinics and 850 patients from colposcopy clinics at two comprehensive cancer centers and a community hospital. Optical spectroscopy was performed, and 4,864 biopsies were obtained from the sites measured, including abnormal and normal colposcopic areas. The gold standard was the histologic report of biopsies, read 2 to 3 times by histopathologists blinded to the cytologic, histopathologic, and spectroscopic results. We calculated sensitivities, specificities, receiver operating characteristic (ROC) curves, and areas under the ROC curves. We identified a cutpoint for an algorithm based on optical spectroscopy that yielded an estimated sensitivity of 1.00 [95% confidence interval (CI) = 0.92–1.00] and an estimated specificity of 0.71 [95% CI = 0.62–0.79] in a combined screening and diagnostic population. The positive and negative predictive values were 0.58 and 1.00, respectively. The area under the ROC curve was 0.85 (95% CI = 0.81–0.89). The per‐patient and per‐site performance were similar in the diagnostic and poorer in the screening settings. Like colposcopy, the device performs best in a diagnostic population. Alternative statistical approaches demonstrate that the analysis is robust and that spectroscopy works as well as or slightly better than colposcopy for the detection of CIN 2 to cancer.


Ultrasound in Medicine and Biology | 2011

Axial-shear strain elastography for breast lesion classification: further results from in vivo data.

Arun K. Thittai; Jose Miguel Yamal; Louise M. Mobbs; Christina M. Kraemer-Chant; Srinivasa Chekuri; Brian S. Garra; Jonathan Ophir

The purpose of this work was to investigate the potential of the normalized axial-shear strain area (NASSA) feature, derived from axial-shear strain elastograms (ASSE), for breast lesion classification of fibroadenoma and cancer. This study consisted of previously acquired in vivo digital radiofrequency data of breast lesions. A total of 33 biopsy-proven malignant tumors and 30 fibroadenoma cases were included in the study, which involved three observers blinded to the original BIRADS-ultrasound scores. The observers outlined the lesions on the sonograms. The ASSEs were segmented and color-overlaid on the sonograms, and the NASSA feature from the ASSE was computed semi-automatically. Receiver operating characteristic (ROC) curves were then generated and the area under the curve (AUC) was calculated for each observer performance. A logistic regression classifier was built to compare the improvement in the AUC when using BIRADS scores plus NASSA values as opposed to BIRADS scores alone. BIRADS score ROC had an AUC of 0.89 (95% CI = 0.81 to 0.97). In comparison, the average of the AUC for all the three observers using ASSE feature alone was 0.84. However, the AUC increased to 0.94 (average of 3 observers) when BIRADS score and ASSE feature were combined. The results demonstrate that the NASSA feature derived from ASSE has the potential to improve BIRADS breast lesion classification of fibroadenoma and malignant tumors.


Journal of Womens Health | 2013

Prior preterm birth and maternal subclinical cardiovascular disease 4 to 12 years after pregnancy

Janet M. Catov; Rhiannon Dodge; Emma Barinas-Mitchell; Kim Sutton-Tyrrell; Jose Miguel Yamal; Linda B. Piller; Roberta B. Ness

BACKGROUND We considered that women with prior preterm birth (PTB) would have evidence of subclinical atherosclerosis, endothelial dysfunction, and arterial stiffness. METHODS Four to 12 years after pregnancy, blood pressure and fasting lipids were analyzed, and women underwent evaluation, following standardized protocols, of carotid intima-media thickness (IMT), brachial flow-mediated dilation (FMD), and pulse wave velocity (PWV). Women with prior preterm (<37 weeks, n=181) or term births (>= 37 weeks, n=306) were compared. Those with preeclampsia or term small-for-gestational-age (SGA) births were excluded. RESULTS Women with a prior preterm vs. term birth had higher blood pressure, on average, and a more atherogenic lipid profile. They also had marginally higher IMT (0.579 standard error [SE] 0.005-vs. 0.567 [0.004] mm, p=0.06), adjusted for body size, demographics, and smoking. IMT differences were greater among those with non-preeclamptic-indicated PTB (0.034 mm, p=0.05) and PTB<34 weeks (0.024 mm, p=0.04) compared to those with term births. These differences appeared to be explained in part by the atherogenic lipid elevations in women with preterm birth. Women with prior PTB<34 weeks tended to have lower FMD, but results were not statistically significant. PWV did not differ according to PTB. CONCLUSIONS In the decade following pregnancy, women with non-preeclamptic-indicated PTB or PTB delivered before 34 weeks had higher blood pressure, atherogenic lipids, and IMT compared to women with term births. There may be subgroups of women with a prior PTB with excess cardiovascular risk that is detectable before overt clinical disease.


Journal of Neurotrauma | 2015

Effect of Hemoglobin Transfusion Threshold on Cerebral Hemodynamics and Oxygenation

Jose Miguel Yamal; M. Laura Rubin; Julia S. Benoit; Barbara C. Tilley; Shankar P. Gopinath; H. Julia Hannay; Pratik Doshi; Imoigele P. Aisiku; Claudia S. Robertson

Cerebral dysfunction caused by traumatic brain injury may adversely affect cerebral hemodynamics and oxygenation leading to worse outcomes if oxygen capacity is decreased due to anemia. In a randomized clinical trial of 200 patients comparing transfusion thresholds <7 g/dl versus 10 g/dl, where transfusion of leukoreduced packed red blood cells was used to maintain the assigned hemoglobin threshold, no long-term neurological difference was detected. The current study examines secondary outcome measures of intracranial pressure (ICP), cerebral perfusion pressure (CPP), and brain tissue oxygenation (PbtO2) in patients enrolled in this randomized clinical trial. We observed a lower hazard for death (hazard ratio [HR]=0.12, 95% confidence interval [CI]=0.02-0.99) during the first 3 days post-injury, and a higher hazard for death after three days (HR=2.55, 95% CI=1.00-6.53) in the 10 g/dl threshold group as compared to the 7 g/dL threshold group. No significant differences were observed for ICP and CPP but MAP was slightly lower in the 7 g/dL group, although the decreased MAP did not result in increased hypotension. Overall brain tissue hypoxia events were not significantly different in the two transfusion threshold groups. When the PbtO2 catheter was placed in normal brain, however, tissue hypoxia occurred in 25% of patients in the 7 g/dL threshold group, compared to 10.2% of patients in the 10 g/dL threshold group (p=0.04). Although we observed a few differences in hemodynamic outcomes between the transfusion threshold groups, none were of major clinical significance and did not affect long-term neurological outcome and mortality.


Journal of Neurosurgery | 2016

Progressive hemorrhagic injury after severe traumatic brain injury: effect of hemoglobin transfusion thresholds

Aditya Vedantam; Jose Miguel Yamal; Maria Laura Rubin; Claudia S. Robertson; Shankar P. Gopinath

OBJECT There is limited literature available to guide transfusion practices for patients with severe traumatic brain injury (TBI). Recent studies have shown that maintaining a higher hemoglobin threshold after severe TBI offers no clinical benefit. The present study aimed to determine if a higher transfusion threshold was independently associated with an increased risk of progressive hemorrhagic injury (PHI), thereby contributing to higher rates of morbidity and mortality. METHODS The authors performed a secondary analysis of data obtained from a recently performed randomized clinical trial studying the effects of erythropoietin and blood transfusions on neurological recovery after severe TBI. Assigned hemoglobin thresholds (10 g/dl vs 7 g/dl) were maintained with packed red blood cell transfusions during the acute phase after injury. PHI was defined as the presence of new or enlarging intracranial hematomas on CT as long as 10 days after injury. A severe PHI was defined as an event that required an escalation of medical management or surgical intervention. Clinical and imaging parameters and transfusion thresholds were used in a multivariate Cox regression analysis to identify independent risk factors for PHI. RESULTS Among 200 patients enrolled in the trial, PHI was detected in 61 patients (30.5%). The majority of patients with PHI had a new, delayed contusion (n = 29) or an increase in contusion size (n = 15). The mean time interval between injury and identification of PHI was 17.2 ± 15.8 hours. The adjusted risk of severe PHI was 2.3 times higher for patients with a transfusion threshold of 10 g/dl (95% confidence interval 1.1-4.7; p = 0.02). Diffuse brain injury was associated with a lower risk of PHI events, whereas higher initial intracranial pressure increased the risk of PHI (p < 0.001). PHI was associated with a longer median length of stay in the intensive care unit (18.3 vs 14.4 days, respectively; p = 0.04) and poorer Glasgow Outcome Scale scores (42.9% vs 25.5%, respectively; p = 0.02) at 6 months. CONCLUSIONS A higher transfusion threshold of 10 g/dl after severe TBI increased the risk of severe PHI events. These results indicate the potential adverse effect of using a higher hemoglobin transfusion threshold after severe TBI.

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Barry R. Davis

University of Texas at Austin

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Michele Follen

Texas Tech University Health Sciences Center

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Barbara C. Tilley

University of Texas Health Science Center at Houston

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E. Neely Atkinson

University of Texas MD Anderson Cancer Center

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Calum MacAulay

University of British Columbia

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James C. Grotta

University of Texas Health Science Center at Houston

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