14 resultados para Botticelli, Sandro, 1444 or 5-1510

em DigitalCommons@The Texas Medical Center


Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study addresses the questions of whether the frequency of generation and in vivo cross-reactivity of highly immunogenic tumor clones induced in a single parental murine fibrosarcoma cell line MCA-F is more closely related to the agent used to induce the Imm$\sp{+}$ clone or whether these characteristics are independent of the agents used. These questions were addressed by treating the parental tumor cell line MCA-F with UV-B radiation (UV-B), 1-methyl-3-nitro-1-nitrosoguanidine (MNNG), or 5-aza-2$\sp\prime$-deoxycytidine (5-azaCdR). The frequency of Imm$\sp{+}$ variant generation was similarly high for the three different agents, suggesting that the frequency of Imm$\sp{+}$ generation was related more closely to the cell line than to the inducing agent used. Cross-reactivity was tested with two Imm$\sp{+}$ clones from each treatment group in a modified immunoprotection assay that selectively engendered antivariant, but not antiparental immunity. Under these conditions each clone, except one, immunized against itself. The MNNG-induced clones engendered stronger antivariant immunity but a weaker variant cross-reactive immunity could also be detected.^ This study also characterized the lymphocyte populations responsible for antivariant and antiparental immunity in vivo. Using the local adoptive transfer assay (LATA) and antibody plus complement depletion of T-cell subsets, we showed that immunity induced by the Imm$\sp{+}$ variants against the parent MCA-F was transferred by the Thy1.2$\sp{+}$, L3T4a$\sp{+}$, Lyt2.1$\sp{-}$ (CD4$\sp{+}$) population, without an apparent contribution by Thy1.2$\sp{+}$, L3T4a$\sp{-}$, Lyt2.1$\sp{+}$ (CD8$\sp{+}$) cells. A role for Lyt2.1$\sp{+}$T lymphocytes in antivariant, but not antiparent immunity was supported by the results of LATA and CTL assays. Immunization with low numbers of viable Imm$\sp{+}$ cells, or with high numbers of non viable Imm$\sp{+}$ cells engendered only antivariant immunity without parental cross-protection. The associative recognition of parental antigens and variant neoantigens resulting in strong antiparent immunity was investigated using somatic cells hybrids of Imm$\sp{+}$ variants of MCA-F and an antigenically distinct tumor MCA-D. An unexpected result of these latter experiments was the expression of a unique tumor-specific antigen by the hybrid cells. These studies demonstrate that the parental tumor-specific antigen and the variant neoantigen must be coexpressed on the cell surface to engender parental cross-protective immunity. (Abstract shortened with permission of author.) ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Obesity and diabetes are frequently associated with cardiovascular disease. When a normal heart is subjected to brief/sublethal repetitive ischemia and reperfusion (I/R), adaptive responses are activated to preserve cardiac structure and function. These responses include but are not limited to alterations in cardiac metabolism, reduced calcium responsiveness, and induction of antioxidant enzymes. In a model of ischemic cardiomyopathy inducible by brief repetitive I/R, we hypothesized that dysregulation of these adaptive responses in diet-induced obese (DIO) mice would contribute to enhanced myocardial injury. DIO C57BL/6J mice were subjected to 15 min of daily repetitive I/R while under short-acting anesthesia, a protocol that results in the development of fibrotic cardiomyopathy. Cardiac lipids and candidate gene expression were analyzed at 3 days, and histology at 5 days of repetitive I/R. Total free fatty acids (FFAs) in the cardiac extracts of DIO mice were significantly elevated, reflecting primarily the dietary fatty acid (FA) composition. Compared with lean controls, cardiac FA oxidation (FAO) capacity of DIO mice was significantly higher, concurrent with increased expression of FA metabolism gene transcripts. Following 15 min of daily repetitive I/R for 3 or 5 days, DIO mice exhibited increased susceptibility to I/R and, in contrast to lean mice, developed microinfarction, which was associated with an exaggerated inflammatory response. Repetitive I/R in DIO mice was associated with more profound significant downregulation of FA metabolism gene transcripts and elevated FFAs and triglycerides. Maladaptive metabolic changes of FA metabolism contribute to enhanced myocardial injury in diet-induced obesity.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND: Given the fragmentation of outpatient care, timely follow-up of abnormal diagnostic imaging results remains a challenge. We hypothesized that an electronic medical record (EMR) that facilitates the transmission and availability of critical imaging results through either automated notification (alerting) or direct access to the primary report would eliminate this problem. METHODS: We studied critical imaging alert notifications in the outpatient setting of a tertiary care Department of Veterans Affairs facility from November 2007 to June 2008. Tracking software determined whether the alert was acknowledged (ie, health care practitioner/provider [HCP] opened the message for viewing) within 2 weeks of transmission; acknowledged alerts were considered read. We reviewed medical records and contacted HCPs to determine timely follow-up actions (eg, ordering a follow-up test or consultation) within 4 weeks of transmission. Multivariable logistic regression models accounting for clustering effect by HCPs analyzed predictors for 2 outcomes: lack of acknowledgment and lack of timely follow-up. RESULTS: Of 123 638 studies (including radiographs, computed tomographic scans, ultrasonograms, magnetic resonance images, and mammograms), 1196 images (0.97%) generated alerts; 217 (18.1%) of these were unacknowledged. Alerts had a higher risk of being unacknowledged when the ordering HCPs were trainees (odds ratio [OR], 5.58; 95% confidence interval [CI], 2.86-10.89) and when dual-alert (>1 HCP alerted) as opposed to single-alert communication was used (OR, 2.02; 95% CI, 1.22-3.36). Timely follow-up was lacking in 92 (7.7% of all alerts) and was similar for acknowledged and unacknowledged alerts (7.3% vs 9.7%; P = .22). Risk for lack of timely follow-up was higher with dual-alert communication (OR, 1.99; 95% CI, 1.06-3.48) but lower when additional verbal communication was used by the radiologist (OR, 0.12; 95% CI, 0.04-0.38). Nearly all abnormal results lacking timely follow-up at 4 weeks were eventually found to have measurable clinical impact in terms of further diagnostic testing or treatment. CONCLUSIONS: Critical imaging results may not receive timely follow-up actions even when HCPs receive and read results in an advanced, integrated electronic medical record system. A multidisciplinary approach is needed to improve patient safety in this area.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Recent reports have suggested the possible association of status epilepticus and multiple organ system failure. The purpose of this case control study was to investigate this association and to identify factors that predispose individuals with status epilepticus (SE) or aborted status epilepticus (ASE) to develop multiple organ system failure (MOSF) or multiple organ system dysfunction (MODS).^ For the purpose of the study, definitions of SE, ASE, MOSF, and MODS were operationalized as follows: SE was defined as any seizure lasting for a duration of $\ge$30 minutes or intermittent seizures lasting for $\ge$30 minutes from which the patient does not regain consciousness. ASE was defined as any seizure lasting for a duration of $\ge$10 minutes but $<$30 minutes and which was aborted as a result of a medical intervention. MOSF was defined as the failure of $\ge$2 organ systems in the same patient; organ system failure was said to be present whenever standard MOSF criteria were met. MODS was defined as the dysfunction of $\ge$2 organ systems in the same patient; organ system dysfunction was said to be present, whenever the monitor(s) of that organ's function exceeded the normal range for the physiological or laboratory parameters.^ Medical records of 686 individuals between the age of 5 and 44 years, with history of seizures needing hospitalization at the Texas Children's Hospital or Methodist Hospital, Houston, Texas, between 1991-95 were reviewed and 100 individuals with SE/ASE were identified. Of these 100 individuals with SE/ASE, 45 developed MOSF/MODS during their hospitalization and 9 of these individuals died. Using multivariate analyses, it was found that adult individuals who had an "acute" etiology of their seizure disorder (OR = 5.23; 95%CI: 0.41, 66.24) and children who had a "remote" etiology of their seizure disorder (OR = 3.92; 95%CI: 0.53, 29.22), were more likely to develop MOSF/MODS compared with those who had other etiologies of the seizure disorder. Individuals with SE lasting more than one hour were more likely to develop MOSF/MODS compared with individuals with SE lasting less than 1 hour (OR = 6.51; 95%CI: 1.63, 25.92). Individuals who presented with the SE/ASE episode as their first seizure episode were more likely to develop MOSF/MODS compared to those with a previous history of seizure episodes (OR = 1.78; 95%CI: 0.36, 8.82).^ The major limitations of this study includes the relatively small sample size and the study being performed in only two institutions. However, this is the first study of this kind and should therefore be viewed as largely exploratory in nature. Future studies should investigate the relationship of the risk factors identified in this study using a larger number of institutions and patients. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Birth defects are a leading cause of infant mortality in the developed countries. They are also of increasing concern in many developing countries, such as China. However, prevalence and causes of birth defects in China are inadequately understood.^ The purpose of the present study was to estimated prevalence of birth defects in surviving children under seven years of age in Tianjin, China and investigate determinants of birth defects in the study area.^ The present study took place in Tianjin, China in 1986, involving 22,081 surviving children under seven years of age. Children with birth defects were ascertained through physical examinations by physicians during household visits and ascertainment of birth defects was verified through multiple sources. Of 22,081 surviving children, 524 had birth defects (23.7 per 1,000). The study noted a striking discrepancy in the prevalence of birth defects between urban and rural area. The prevalence of birth defects was 16.3 per 1,000 in the urban and 33.2 per 1,000 in the rural area.^ Using cases of birth defects ascertained from surviving children, a case-control study was carried out. The study observed that first-trimester maternal flu was associated with increased risk of both major and minor birth defects in children after controlling for other maternal factors (adjusted odds ratio (OR) = 8.7, 95% confidence interval (CI) = 4.3-17.3; OR = 3.6, 95% CI = 1.7-7.5). This association could be biased by different reporting of exposure between mothers of children with birth defects and mothers of children without defects. This study indicated that maternal flu was also associated with congenital heart defects and polydactyly after controlling for other maternal factors (adjusted OR = 32.3, 95% CI = 13.3-78.3; adjusted OR = 5.5, 95% CI = 1.1-27.7). The associations remained when affected controls (children with similar birth defects other than congenital heart defects or polydactyly) were used (adjusted OR = 4.3, 95% CI = 1.2-15.3; OR = 1.4, 95% CI = 1.4-7.9). A weak association between first-trimester vaginal bleeding and selected groups of birth defects was found in this study, but the association may be confounded by other factors. Maternal smoking during pregnancy was modestly associated with cleft lip with or without cleft palate (OR = 1.4, 95% = 0.4-4.9), but the association may be due to chance. Some major limitations in this study warrant caution in interpretation of the findings, especially the causal relation. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A new technique for the detection of microbiological fecal pollution in drinking and in raw surface water has been modified and tested against the standard multiple-tube fermentation technique (most-probable-number, MPN). The performance of the new test in detecting fecal pollution in drinking water has been tested at different incubation temperatures. The basis for the new test was the detection of hydrogen sulfide produced by the hydrogen sulfide producing bacteria which are usually associated with the coliform group. The positive results are indicated by the appearance of a brown to black color in the contents of the fermentation tube within 18 to 24 hours of incubation at 35 (+OR-) .5(DEGREES)C. For this study 158 water samples of different sources have been used. The results were analyzed statistically with the paired t-test and the one-way analysis of variance. No statistically significant difference was noticed between the two methods, when tested 35 (+OR-) .5(DEGREES)C, in detecting fecal pollution in drinking water. The new test showed more positive results with raw surface water, which could be due to the presence of hydrogen sulfide producing bacteria of non-fecal origin like Desulfovibrio and Desulfomaculum. The survival of the hydrogen sulfide producing bacteria and the coliforms was also tested over a 7-day period, and the results showed no significant difference. The two methods showed no significant difference when used to detect fecal pollution at a very low coliform density. The results showed that the new test is mostly effective, in detecting fecal pollution in drinking water, when used at 35 (+OR-) .5(DEGREES)C. The new test is effective, simple, and less expensive when used to detect fecal pollution in drinking water and raw surface water at 35 (+OR-) .5(DEGREES)C. The method can be used for qualitative and/or quantitative analysis of water in the field and in the laboratory. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction. A vast majority of studies conducted in both developed and developing nations have focused on the epidemiology of HBV (Hepatitis B virus) and HCV (Hepatitis C virus) in high-risk populations; low-risk populations have been neglected. Recently Hwang et al conducted a unique large cross-sectional study in American university students that focused on cosmetic procedures and drug use for acquiring these infections among a low-risk young adult population In Houston. ^ Methods. This study is a secondary data analysis of the cross-sectional study conducted by Hwang et al. Data for this anonymous study were collected from 7,960 college students, among whom were the 2,561 non US/Canadian born students included in this study. All students completed a self-administered questionnaire and provided a blood sample. The epidemiology of HBV/HCV and risk factors for acquiring HBV/HCV infection was studied by comparing those with HBV/HCV infection versus those without. Both univariate and multivariate logistic regression was used to analyze the data. ^ Results. Overall prevalence of HBV and HCV infections were 22% and 0.8% respectively. By multivariable analysis, the factors that were independently associated with increased prevalence of HBV infection were increasing age per year (OR=1.06, 95% C.I=1.04-1.08), Black or Asian race (OR=6.21, 95% C.I=3.14-12.27), history of household contact with hepatitis (OR=1.87, 95% C.I=1.15-3.05), and having sexual partner with hepatitis (OR=5.20, 95% C.I=1.5-18.00). For HCV these factors included increasing age per year (OR= 1.08, 95% C.I=1.03-1.14), history of blood transfusion prior to 1991 (OR=25.45, 95% C.I=7.58-85.40), and Injection drug use. (OR=78.15, 95% C.I=12.19-500.85). Cosmetic procedures like tattooing were not significant risk factors for either HBV or HCV infection. ^ Conclusions. In a low-risk adult foreign born population, cosmetic procedures are not significant risk factors for HBV or HCV infection. The prevention strategies of these infections in this population should focus on safe sexual practices/abstinence and HBV vaccination should be provided to adolescents and sexually active adults. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction. Cervical cancer is the most common and lethal cancer among Mexican women. A nationwide cervical cancer screening program established in 1974 has had little impact on cervical cancer incidence or mortality rates. This case-control study was designed to determine the association between knowledge factors and structural, organizational, and sociocultural perceptions related to adherence to cervical cancer screening guidelines among women living and working in Monterrey, Mexico.^ Methods. Cases were defined as sexually active female store clerks ages 18-64 who do not adhere to cervical cancer screening guidelines in accordance with the Official Mexican Standard (Norma Oficial Mexicana, NOM 014-SSA2-1994). Controls were defined as sexually active female store clerks ages 18-64 who do adhere to cervical cancer screening guidelines in accordance with the NOM. Participants (N = 229) answered survey questions regarding cervical cancer screening practices as well as their knowledge and perceptions about screening for cervical cancer. Two multivariate logistic regression models were built to analyze (1) knowledge factors and (2) perceptions significantly associated with adherence in univariate analysis.^ Results. Having no or inaccurate knowledge of national cervical cancer screening guidelines (OR = 11.05, 95%CI: 4.28, 28.54) and no knowledge of the utility of the Papanicolaou (Pap) exam (OR = 6.77, 95%CI: 0.99, 46.43) were risk factors for non-adherence to cervical cancer screening guidelines. Perceptions of fear or embarrassment of the Pap exam (OR = 16.17, 95%CI: 5.08, 51.49) and lower levels of spousal or partner acceptance of the Pap exam (OR = 5.82, 95%CI: 1.34, 25.31) were risk factors for non-adherence to cervical cancer screening guidelines.^ Conclusion. Knowledge factors and sociocultural perceptions related to cervical cancer screening were strong predictors of adherence to screening guidelines. Future studies may be able to further explore these findings with larger sample sizes and in other populations in Mexico. By identifying these factors, future population-specific recommendations and interventions to increase screening rates can be formulated with the long-term goal of reducing morbidity and mortality from cervical cancer among Mexican women.^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction. Breast cancer has the highest incidence and mortality rates of all cancers in Sao Paulo and Mexico City women with rates expected to rise due to increasing elderly populations. While mammograms could reduce the breast cancer burden, little information exists about screening behavior factors in these areas. The primary objective of this study is testing the association of socio-demographic, geographic, and health access/health status variables on mammogram screenings in elderly females in both cities. Studying the regions' healthcare systems and their screening impact is the ancillary objective. ^ Methods. Accounting for the complex sample design (weights, stratification, and clusters) of the 1999-2000 SABE study, analysis of mammogram utilization in the past two years was performed. The sample consisted of 1239 women from Sao Paulo and 1349 women from Mexico City. ^ Results. Having private insurance in Sao Paulo (OR = 5.86) and Mexico City (OR = 4.09) increased the chance of having a mammogram in the targeted women. In both cities, women with higher levels of education had higher likelihoods of screening (Sao Paulo OR = 4.56 and Mexico City OR = 3.04). Age, regular medical care, and health status were significant in Sao Paulo; however, the factors showed no significance in Mexico City. ^ Discussion. Mammogram utilization can reduce mortality from breast cancer, and understanding screening factors is crucial to screening adherence. Addressing key variables may lead to increased screening and decreased breast cancer mortality in elderly women in Sao Paulo, Mexico City, and similar regions. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background. Insufficient and poor quality sleep among adolescents affects not only the cognitive functioning, but overall health of the individual. Existing research suggests that adolescents from varying ethnic groups exhibit differing sleep patterns. However, little research focuses on sleep patterns and associated factors (i.e. tobacco use, mental health indicators) among Hispanic youth. ^ Methods. The study population (n=2,536) included students in grades 9-12 who attended one of the three public high schools along the Texas-Mexico border in 2003. This was a cross sectional study using secondary data collected via a web-based, confidential, self-administered survey. Separate logistic regression models were estimated to identify factors associated with reduced (<9 hours/night) and poor quality sleep on average during weeknights. ^ Results. Of participants, 49.5% reported reduced sleep while 12.8% reported poor quality sleep. Factors significantly (p<0.05) associated with poor quality sleep were: often feeling stressed or anxious (OR=5.49), being born in Mexico (OR=0.65), using a computer/playing video games 15+ hours per week (OR=2.29), working (OR=1.37), being a current smoker (OR=2.16), and being a current alcohol user (OR=1.64). Factors significantly associated with reduced quantity of sleep were: often feeling stressed or anxious (OR=2.74), often having headaches/stomachaches (OR=1.77), being a current marijuana user (OR=1.70), being a current methamphetamine user (OR=4.92), and being a current alcohol user (OR=1.27). ^ Discussion. Previous research suggests that there are several factors that can influence sleep quality and quantity in adolescents. This paper discusses these factors (i.e. work, smoking, alcohol, etc.) found to be associated with poor sleep quality and reduced sleep quantity in the Hispanic adolescent population. A reduced quantity of sleep (81.20% of the participants) and a poor quality of sleep (12.80% of the participants) were also found in high school students from South Texas. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

HIV-1 infected children display a highly variable rate of progression to AIDS. Data about reasons underlying the variable progression to AIDS among vertically-infected children is sparse, and the few studies that have examined this important question have almost exclusively been done in the developed world. This is despite the fact that Sub-Saharan Africa is home to over 90% of all HIV infected children around the world.^ The main objective of this study was to examine predictors of HIV-1 slow progression among vertically infected children in Botswana, using a case control design. Cases (slow progressors) and controls (rapid progressors) were drawn from medical records of HIV-1 infected children being followed up for routine care and treatment at the BBCCCOE between February 2003 and February 2011. Univariate and Multivariate Logistic Regression Analyses were performed to identify independent predictors of slow disease progression and control for confounding respectively. ^ The study population comprised of 152 cases and 201 controls with ages ranging from 6 months to 16 years at baseline. Low baseline HIV-1 RNA viral load was the strongest independent predictor of slow progression (adjusted OR = 5.52, 95% CI = 2.75-11.07; P <0.001). Other independent predictors of slow disease progression identified were: lack of history of PMTCT with single dose Nevirapine plus Zidovudine (adjusted OR = 4.45, 95% CI = 1.45-13.69; P = 0.009) and maternal vital status (alive) (adjusted OR = 2.46, 95% CI = 1.51-4.01; P < 0.00 ).^ The results of this study may help clinicians and policy-makers in resource-limited settings to identify, at baseline, which children are at highest risk of rapid progression to AIDS and thus prioritize them for immediate intervention with HAART and other measures that would mitigate disease progression. At the same time HAART may be delayed among children who are at lower risk of disease progression. This would enable the highly affected, yet impoverished, Sub-Saharan African countries to use their scarce resources more efficiently which may in turn ensure that their National Antiretroviral Therapy Programs become more sustainable. Delaying HAART among the low-risk children would also lower the occurrence of adverse drug reactions associated with antiretroviral drugs exposure.^ Keywords. Slow Progressors, Rapid Progressors, HIV-1, Predictors, Children, Vertical Transmission, Sub-Saharan Africa^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The neu gene encodes the transmembrane tyrosine kinase growth factor receptor, p185. To study neu induced cellular transformation, we developed revertant cells from the neu transformed NIH 3T3 cell line, B104-1-1, by treating the cells with the chemical mutagen ethylmethane sulfonate. The morphologically normal revertant cells were first selected by their ability to either attach to culture plates or survive in the presence of the cytotoxic reagents colchicine or 5-fluoro-2deoxyuridine. Two of the 21 candidate revertant cell lines isolated were further characterized and were found to lose their anchorage independence and ability to grow in 1% calf serum, indicating that they were nontransformed even though they still expressed p185 oncoprotein. The tyrosine residues of p185 in these two revertants were underphosphorylated, which may have contributed to their nontransformed status. Also, the p185 oncoprotein lacked significant tyrosine kinase activity. In addition, these revertants also resisted transformation by neu and several additional oncogenes (H-ras, N-ras, v-mos, v-abl, and v-fos) as determined by focus forming assays. These results indicated that we had successfully developed, from neu transformed cells, revertants which exhibited defective tyrosine phosphorylation and kinase activity of the neu oncoprotein. The results also suggested that neu and several other oncogenes may share common elements in their pathways for the induction of cellular transformation. ^

Relevância:

40.00% 40.00%

Publicador:

Resumo:

OBJECTIVE: The primary objective of this trial was to evaluate the response rate for trimetrexate in conjunction with 5-FU and leucovorin (LV) (= TFL) in the treatment of advanced gastric cancer in a phase II, cooperative group setting. METHODS: Patients with locally advanced, unresectable, or metastatic adenocarcinoma of the stomach received trimetrexate 110 mg/m IV over 60 minutes day 1, followed by 5-FU 500 mg/m IV bolus and LV 200 mg/m IV over 60 minutes day 2, followed by oral LV 15 mg every 6 hours x 7 doses, all weekly for 6 weeks followed by 2 weeks of rest, continued until progression. RESULTS: Characteristics for 37 eligible patients: median age 63 (range: 23-83); male/female: 69% of 31%; performance status 0/1/2 15/20/1. The confirmed response rate was 19%, and median overall survival was 6 months. Two patients died as a result of therapy, 1 because of infection without significant neutropenia, and 1 due to perforation of a responding gastric lesion. Seventy-two percent experienced grades 3 and 4 toxicity, most commonly diarrhea, fatigue, and lymphopenia. CONCLUSIONS: This regimen achieves response rates comparable to other 5-FU-based regimens, when used in treatment of incurable gastric cancer. Toxicity appears manageable.