Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Event History Analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed1997

Gene amplification and proliferative kinetics in relation to prognosis of patients with gastric carcinoma.

BACKGROUND: The differences in survival of gastric carcinoma patients who have identical clinical or pathologic stages prompted the authors to investigate the prognostic significance of biologic features that are known to affect the clinical aggressiveness of other tumor types. METHODS: One hundred twenty-four tumor samples from patients who had received radical or palliative surgery were analyzed for c-myc, c-K-ras, hst, and c-erb B-2 gene amplification by means of the Southern blot technique. Of these tumors, 70 were also examined for cell kinetics by means of the thymidine labeling index (TLI). RESULTS: The analysis of associations between gene amplification and the anatomicopathologic variables (TNM classification, site of tumor, and histology) showed that amplification represents a late event in the natural history of gastric carcinoma. Gene amplification showed a slight, statistically insignificant, negative impact on overall survival (OS) (P = 0.09). Amplification of c-erb B-2 correlated in a statistically significant way with reduced OS (P = 0.03). Cox multiple regression analysis revealed that neither c-erb B-2 amplification nor TLI had prognostic significance in relation to OS. CONCLUSIONS: These data indicate that amplification of the examined oncogenes did not reveal a new independent prognostic factor for patients with gastric carcinoma. However, the authors' results did show a strong correlation between gene amplification and tumor progression, which warrants further study involving larger series of patients. At the same time, the TLI results underlined the need to identify the most suitable biologic material for use in the estimation of proliferative indexes in gastric carcinoma.

Adult↗
PubMed2005

Longitudinal analysis of the group A Streptococcus transcriptome in experimental pharyngitis in cynomolgus macaques.

Identification of the genetic events that contribute to host-pathogen interactions is important for understanding the natural history of infectious diseases and developing therapeutics. Transcriptome studies conducted on pathogens have been central to this goal in recent years. However, most of these investigations have focused on specific end points or disease phases, rather than analysis of the entire time course of infection. To gain a more complete understanding of how bacterial gene expression changes over time in a primate host, the transcriptome of group A Streptococcus (GAS) was analyzed during an 86-day infection protocol in 20 cynomolgus macaques with experimental pharyngitis. The study used 260 custom Affymetrix (Santa Clara, CA) chips, and data were confirmed by TaqMan analysis. Colonization, acute, and asymptomatic phases of disease were identified. Successful colonization and severe inflammation were significantly correlated with an early onset of superantigen gene expression. The differential expression of two-component regulators covR and spy0680 (M1_spy0874) was significantly associated with GAS colony-forming units, inflammation, and phases of disease. Prophage virulence gene expression and prophage induction occurred predominantly during high pathogen cell densities and acute inflammation. We discovered that temporal changes in the GAS transcriptome were integrally linked to the phase of clinical disease and host-defense response. Knowledge of the gene expression patterns characterizing each phase of pathogen-host interaction provides avenues for targeted investigation of proven and putative virulence factors and genes of unknown function and will assist vaccine research.

Animals↗
PubMed2006

Stratifying the risk in unstable angina with dobutamine stress echocardiography.

OBJECTIVE: To evaluate the role of dobutamine stress echocardiography (DSE) in the risk stratification of low to moderate risk unstable angina (UA) patients, to predict the combined clinical outcome of cardiovascular death, myocardial infarction (MI), recurrent UA and the need of revascularization procedures in a 6 month period. METHODS: Multicenter prospective study. Patients should be admitted to the hospital and asymptomatic in the last 24 hours. The exam was performed up to 72 hours from the hospital admission and no medication was stopped prior to the test. RESULTS: Ninety-five consecutive patients were evaluated by DSE. Forty patients (42,1%) had a positive ischemic test and fifty five (57,9%) had a negative one. Clinical events occurred in twenty eight patients, twenty six of whom had a positive test. The rest of the patients (67) did not have clinical events and fifty three of them, had a negative test. The sensibility, specificity, accuracy, positive predictive value and negative predictive value of the test related to the clinical events were: 92,9%, 79,1%, 83,2%, 65% and 96,4%, respectively. Event-free survival after 6 months for pacients with a negative DSE was 96% compared to 35% for those with a positive DSE (p<0,001). The UA classification, left ventricular ejection fraction, rest and peak wall motion score index, DSE result and history of previous MI were associated with the combined end point by univariate analysis. The test result was the only independent predictor of cardiac events by multivariate analysis (p<0.001). CONCLUSION: O DSE has shown an excellent negative predictive value allowing for early hospital discharge without further exams. The positive test result was the only independent predictor for adverse cardiac events.

Angina, Unstable↗
PubMed2000

A Bayesian framework for the analysis of cospeciation.

Information on the history of cospeciation and host switching for a group of host and parasite species is contained in the DNA sequences sampled from each. Here, we develop a Bayesian framework for the analysis of cospeciation. We suggest a simple model of host switching by a parasite on a host phylogeny in which host switching events are assumed to occur at a constant rate over the entire evolutionary history of associated hosts and parasites. The posterior probability density of the parameters of the model of host switching are evaluated numerically using Markov chain Monte Carlo. In particular, the method generates the probability density of the number of host switches and of the host switching rate. Moreover, the method provides information on the probability that an event of host switching is associated with a particular pair of branches. A Bayesian approach has several advantages over other methods for the analysis of cospeciation. In particular, it does not assume that the host or parasite phylogenies are known without error; many alternative phylogenies are sampled in proportion to their probability of being correct.

Animals↗
PubMed2004

High dose human serum albumin for the treatment of acute ischemic stroke: a safety study.

INTRODUCTION: In animal models of focal cerebral ischemia, albumin infusions at doses ranging from 0.6 to 2.5 g/kg are neuroprotective. It is not known whether patients with stroke, often elderly and with underlying cardiovascular disease, can safely tolerate such degrees of volume expansion. Therefore, we retrospectively reviewed the safety of high-dose albumin treatment in patients with acute ischemic stroke. MATERIALS AND METHODS: Within 24 hours of ischemic stroke onset, patients who received at least 0.7 g/kg albumin were identified by a review of medical records. Each albumin recipient was assigned two control patients, who received standard fluid management. Controls were matched by age, number of stroke risk factors, stroke severity, and stroke subtype. Medical records were reviewed for treatment-related adverse events, defined as cardiopulmonary complications and mortality. RESULTS: Thirty cases (mean age 62.9+/-11.4 years) and 60 controls (mean age 62.5+/-11.8 years) were identified between July 1999 and November 2001. The two groups were evenly matched. The mean dose of albumin infusion was 171 g (2.4 g/kg). Cardiopulmonary complications or death developed in 37% of cases and 18% of controls (p=0.056). Mortality was 7% in both groups. Multivariate regression analysis showed that a history of congestive heart failure and higher total albumin dose were independently associated with the occurrence of adverse events. CONCLUSION: Albumin treatment was associated with a nonsignificant trend toward increased cardiopulmonary adverse events. However, these adverse events did not result in excess mortality.

Aged↗
PubMed1995

Prognostic significance of ST-segment depression during adenosine perfusion imaging.

To determine the significance of ST-segment depression during adenosine perfusion imaging for predicting future cardiac events, 188 patients with interpretable electrocardiograms were assessed 1 to 3 years (mean 21.5 +/- 6.6 months) after adenosine testing. At least 1 mm of ST-segment depression was observed in 32 (17%) patients, with > or = 2 mm of ST-segment depression in 10 (5.3%). Thirty-seven cardiac events occurred during the study period: 2 cardiac deaths, 5 nonfatal myocardial infarctions, 6 admissions for unstable angina, and 24 revascularizations. Univariate predictors of events were a history of congestive heart failure, previous non-Q-wave myocardial infarction, previous coronary angioplasty, use of antianginal medication, ST-segment depression during adenosine infusion (particularly > or = 2 mm), any reversible perfusion defect, transient left ventricular cavity dilation, and the severity of perfusion defects. Multivariate analysis identified > or = 2 mm ST-segment depression as the most significant predictor of cardiac events (relative risk [RR] = 6.5; p = 0.0001). Other independent predictors of events were left ventricular dilation (RR = 3.8; p = 0.002), previous coronary angioplasty (RR = 3.3; p = 0.001), a history of non-Q-wave myocardial infarction (RR = 2.3; p = 0.01), and the presence of any reversible defect (RR = 2.0; p = 0.05). We conclude that ST-segment depression occurs uncommonly during adenosine infusion, but the presence of > or = 2 mm of ST-segment depression is an independent predictor of future cardiac events and provides information in addition to that obtained from clinical variables and the results of adenosine perfusion imaging.

Adenosine↗
PubMed1998

Results of percutaneous coronary angioplasty in patients <40 years of age.

This study examined factors influencing the outcome of percutaneous transluminal coronary angioplasty (PTCA) in patients <40 years of age. We followed 86 patients (mean age 37 years) treated from 1982 to 1994. The primary procedural success was 90%. At follow-up of 83 patients (97%) at a mean of 48 +/- 33 months (range 5 to 147), there had been 3 late deaths. Actuarial survival at 5 and 10 years was 95% and 91%, respectively. At review only 5% of patients had class III angina and no patient had class IV angina. Repeat revascularization (PTCA alone in 21 [25%], surgery in 8 [10%], or both in 10 [12%] patients) was performed for restenosis in 29 patients (35%) and for disease progression at other sites in 10 patients (12%). On multivariate analysis, a history of diabetes mellitus (p <0.02) was the only factor associated with death or a subsequent cardiovascular event (myocardial infarction, stroke, or hospital admission with unstable angina). At follow-up, 20 patients (24%) still smoked, 64 (77%) had a total cholesterol level > or = 200 mg/dl, 20 (24%) had a body mass index > or = 30, and 15 (18%) were not taking aspirin. In conclusion, PTCA in adults <40 years of age has excellent early results with a low morbidity and mortality. The medium-term prognosis and control of symptoms was good, although by 5 years, further revascularization was required in almost half of the patients.

Adult↗
PubMed2005

Rapid emergence of effect of atorvastatin on cardiovascular outcomes in the Collaborative Atorvastatin Diabetes Study (CARDS).

AIMS/HYPOTHESIS: The aim of this study was to determine the pattern of the effect of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor atorvastatin on cardiovascular events in patients with type 2 diabetes and no prior history of cardiovascular disease (CVD). MATERIALS AND METHODS: A post hoc analysis of data from the Collaborative Atorvastatin Diabetes Study (CARDS), a randomised, placebo-controlled trial of 2,838 patients with type 2 diabetes, was performed. Patients received atorvastatin (10 mg daily) or placebo and were evaluated for cardiovascular and other outcomes over a median follow-up period of 3.9 years. Cox proportional hazards modelling was carried out, and the hazard ratios calculated for various times after randomisation to treatment were investigated. RESULTS: A reduction in the primary endpoint of major CVD events was apparent and statistically significant as soon as 18 months after treatment initiation. The effect of atorvastatin on CHD events was apparent by 6 months, and at 1 year was similar to the 37% relative risk reduction observed at trial closure. CONCLUSIONS/INTERPRETATION: Atorvastatin alters the pathogenesis of CVD rapidly, such that the effect on cardiovascular events is apparent within months of initiation of therapy.

Anticholesteremic Agents↗
PubMed2004

Abdominal aortic aneurysms after heart transplantation.

BACKGROUND: In recent years abdominal aortic aneurysms were diagnosed in several heart transplant recipients at our center. Only case reports or small series have been reported previously and little is known about abdominal aortic aneurysms after heart transplantation. Therefore, the goals of this study were to estimate the incidence of this condition after heart transplantation, to identify risk factors for its development, and to assess its clinical consequences. METHODS: Our investigation was a retrospective, single-center cohort study of 368 consecutive patients transplanted between 1984 and 1999. RESULTS: During a mean follow-up of 75 +/- 49 months, 37 of the 368 (10%) transplant recipients and 36 of 202 (18%) of the sub-group with a history of ischemic heart disease were found to have an abdominal aortic aneurysm. All patients were male, and all except 1 had a history of ischemic heart disease. A history of ischemic heart disease prior to heart transplantation was the sole independent risk factor for developing an aneurysm by multivariate analysis. Aneurysm-related events occurred earlier and more frequently in the 7 transplant recipients who already had a dilated abdominal aorta prior to transplantation. The abdominal aortic aneurysm was the direct or indirect cause of death in at least 9 patients. CONCLUSIONS: Abdominal aortic aneurysms are relatively frequent after heart transplantation, occur at a younger age than in the general population, and have serious clinical consequences. Close ultrasonographic follow-up of patients with a history of ischemic heart disease or with an abnormal abdominal aorta prior to heart transplantation seems indicated.

Aortic Aneurysm, Abdominal↗
PubMed2005

Association between a functional variant of the KLOTHO gene and high-density lipoprotein cholesterol, blood pressure, stroke, and longevity.

We previously identified a functional variant of KLOTHO, termed KL-VS, that is associated with human aging and early-onset occult coronary artery disease. Here, we determine whether the KL-VS allele influences cardiovascular disease risk factors, cardiovascular events, and ultimately, mortality. A total of 525 Ashkenazi Jews composed of 216 probands (age > or =95 years) and 309 unrelated individuals (ages 51 to 94) were genotyped for the KL-VS allele. In concordance with our previous data in Czech individuals (age > or =79; P<0.01), a heterozygous advantage for longevity was observed for individuals > or =79 years of age (P<0.004). Combined analysis indicates a 1.57-fold (95% CI, 1.23 to 1.98) increased odds ratio (OR) for 5-year survival in two independent populations (P<0.0002). Cardiovascular disease risk factors were assessed through multivariate regression analysis, demonstrating that high-density lipoprotein cholesterol (HDL-C; P<0.05) and systolic blood pressure (SBP; P<0.008) are associated with KL-VS genotype. History of vascular events was analyzed using logistic regression, indicating that after adjustment for traditional risk factors, heterozygous individuals were at significantly lower risk for stroke than wild-type individuals (OR, 5.88; 95% CI, 1.18 to 29.41), whereas homozygous KL-VS individuals had the highest risk (OR, 30.65; 95% CI, 2.55 to 368.00). Similarly, prospective analysis of mortality in probands using Cox regression indicates that wild-type individuals have a 2.15-fold (95% CI, 1.18 to 3.91) and homozygous KL-VS individuals a 4.49-fold (95% CI, 1.35 to 14.97) increase in relative risk for mortality after adjusting for potential confounders. Thus, cross-sectional and prospective studies confirm a genetic model in which the KL-VS allele confers a heterozygous advantage in conjunction with a marked homozygous disadvantage for HDL-C levels, SBP, stroke, and longevity.

Aged↗
PubMed1997

Effect of antihypertensive treatment in patients having already suffered from stroke. Gathering the evidence. The INDANA (INdividual Data ANalysis of Antihypertensive intervention trials) Project Collaborators.

BACKGROUND AND PURPOSE: Drug treatment of high blood pressure has been shown to reduce the associated cardiovascular risk. Stroke represents the type of event more strongly linked with high blood pressure, responsible for a high rate of death or invalidity, and with the highest proportion of events that can be avoided by treatment. Hypertensive patients with a history of cerebrovascular accident are at particularly high risk of recurrence. Specific trials of blood pressure lowering drugs in stroke survivors showed inconclusive results in the past. METHODS: We performed a meta-analysis using all available randomized controlled clinical trials assessing the effect of blood pressure lowering drugs on clinical outcomes (recurrence of stroke, coronary events, cause-specific, and overall mortality) in patients with prior stroke or transient ischemic attack. RESULTS: We identified 9 trials, including a total of 6752 patients: 2 trials included 551 hypertensive stroke survivors; 6 trials of hypertensive patients included a small proportion of stroke survivors (536 patients); 1 trial included stroke survivors, whether hypertensive or not (5665 patients). The recurrence of stroke, fatal and nonfatal, was significantly reduced in active groups compared with control groups consistently across the different sources of data (relative risk of 0.72, 95% confidence interval: 0.61 to 0.85). There was no evidence that this intervention induced serious adverse effect. CONCLUSIONS: Blood pressure lowering drug interventions reduced the risk of stroke recurrence in stroke survivors. Available data did not allow to verify whether such benefit depends on initial blood pressure level. More data are needed before considering antihypertensive therapy in normotensive patients at high cerebrovascular risk.

Aged↗
PubMed1991

Psychiatric history and related exposures as risk factors for Alzheimer's disease: a collaborative re-analysis of case-control studies. EURODEM Risk Factors Research Group.

Data from case-control studies of Alzheimer's disease (AD) were pooled to examine the possible roles of history of depression, anti-depressant treatment and adverse life events as risk factors. History of depression was found to be associated with AD, although the effect was confined to late onset cases. The association held for episodes of depression more than 10 years before AD onset, as well as for episodes occurring within a decade of onset. No association was found with anti-depressant treatment. However, data were only available from two studies, limiting the power of the analysis. Also, no association was found with the three major life events considered in the pooled analysis: death of spouse, death of a child and divorce.

Alzheimer Disease↗
PubMed1983

A predictor analysis of clinical assessment of outcome among patients operated on for duodenal ulcer. A 1-year prospective study.

During a period of 1 year, data concerning life events, non-specific psychological symptoms, individual social history, and ulcer history were obtained for consecutive cases of patients about to have elective surgical treatment for duodenal ulcer. At the 1-year follow-up examination a blind, clinical evaluation was performed (dumping, dyspepsia, recurrence, and Visick grading), and information concerning the 94 patients' assessment of outcome was obtained. A multivariate predictor analysis was performed. Most patients (85%) benefited from treatment. The excess rate of non-specific psychological symptoms indicating impairment remained unchanged. The patients assessments of outcome were correlated with the clinical assessment. A positive correlation was found for women to have dumping and poor Visick grade and for unmarried persons to have postoperative dyspepsia and a poor Visick grade. A negative correlation between a long ulcer history and postoperative dyspepsia and a positive correlation between pyloroplasty and dumping were found. Non-specific psychological symptoms predicted poor clinical assessments. It is suggested that it is relevant to apply the patients' assessments for the purpose of evaluation, supplementing the clinical assessment of the more biomedical aspects of outcome.

Adult↗
PubMed1991

[Patient-specific determinants of delay in goal-oriented patient behavior in acute myocardial infarct. Results of the post-infarct late potential study].

369 (63%) of 586 consecutive patients with confirmed myocardial infarction were admitted to hospital within 6 h of symptom onset. Patients' arrival to hospital followed a characteristic circadian distribution with a marked morning increase between 0600 and 1200 hours, and a corresponding decrease in the late night hours. There were no differences in the occurrence of late potentials and in ECG data between early and late arrival group. The early group (less than 5.9 h) was, however, characterized by significantly higher cardiac enzyme levels than the late group (greater than 6.0 h); they also experienced more arrhythmic events in the acute phase (16.0% vs. 9.7%; p less than 0.032). Catecholamines were significantly more often necessary (26.4% vs. 10.3%; p less than 0.0001). Six-month prognosis after AMI was markedly worse. The time between symptom onset and hospital arrival was not affected by age and risk factors. In univariate analysis, pain history and recurrent infarction also had no influence on delay of admission to hospital. The time interval was, however, significantly shorter when the acute event occurred during the night (18.4% vs. 8.3%; p less than 0.0001). Absence of prodromi in the prehospital phase (18.5% vs. 12.0%; p less than 0.04) and a higher socio-economic level (68.3% vs. 61.0%; p less than 0.077) also shortened the admission time, whereas a hyperactive behavioral pattern prolonged the delay time (21.1% vs. 28.9%; p less than 0.05).

Adult↗
PubMed2004

Testing the hypothesis of a recombinant origin of the SARS-associated coronavirus.

The origin of severe acute respiratory syndrome-associated corona-virus (SARS-CoV) is still a matter of speculation, although more than one year has passed since the onset of the SARS outbreak. In this study, we implemented a 3-step strategy to test the intriguing hypothesis that SARS-CoV might have been derived from a recombinant virus. First, we blasted the whole SARS-CoV genome against a virus database to search viruses of interest. Second, we employed 7 recombination detection techniques well documented in successfully detecting recombination events to explore the presence of recombination in SARS-CoV genome. Finally, we conducted phylogenetic analyses to further explore whether recombination has indeed occurred in the course of coronaviruses history predating the emergence of SARS-CoV. Surprisingly, we found that 7 putative recombination regions, located in Replicase 1ab and Spike protein, exist between SARS-CoV and other 6 coronaviruses: porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), bovine coronavirus (BCoV), human coronavirus 229E (HCoV), murine hepatitis virus (MHV), and avian infectious bronchitis virus (IBV). Thus, our analyses substantiate the presence of recombination events in history that led to the SARS-CoV genome. Like the other coronaviruses used in the analysis, SARS-CoV is also a mosaic structure.

Computational Biology↗
PubMed2006

Evolutionary history of the ABCB2 genomic region in teleosts.

Gene duplication, silencing and translocation have all been implicated in shaping the unique genomic architecture of the teleost MH regions. Previously, we demonstrated that trout possess five unlinked regions encoding MH genes. One of these regions harbors ABCB2 which in all other vertebrate classes is found in the MHC class II region. In this study, we sequenced a BAC contig for the trout ABCB2 region. Analysis of this region revealed the presence of genes homologous to those located in the human class II (ABCB2, BRD2, psiDAA), extended class II (RGL2, PHF1, SYGP1) and class III (PBX2, Notch-L) regions. The organization and syntenic relationships of this region were then compared to similar regions in humans, Tetraodon and zebrafish to learn more about the evolutionary history of this region. Our analysis indicates that this region was generated during the teleost-specific duplication event while also providing insight about potential MH paralogous regions in teleosts.

ATP-Binding Cassette Transporters↗
PubMed2001

Monozygotic twins discordant for major depression: a preliminary exploration of the role of environmental experiences in the aetiology and course of illness.

BACKGROUND: Genetic effects upon behaviour are pervasive. To what extent are the many correlates of major depression (MD) due to individual-specific environmental experiences versus genetic factors correlated with risk for MD? METHODS: From a population-based twin registry, we identified 72 female monozygotic pairs discordant for a lifetime history of MD and compared the affected and unaffected members on a wide range of putative correlates of MD. RESULTS: The affected twin differed from her unaffected co-twin on many variables, eight of which were maximally discriminating: (i) maternal protectiveness; (ii) conflictual parent-child relationship; (iii) low optimism; (iv) current stressful life events; (v) financial difficulties and a history of (vi) phobia, (vii) nicotine dependence; and (viii) divorce. A cluster analysis suggested three 'environmental pathways' to MD characterized by: (i) childhood vulnerability and anxiety; (ii) acting-out and demoralization; and (iii) interpersonal difficulties. CONCLUSION: Important precursors and sequelae of MD originate in environmental experiences unique to the individual and are not mediated through genetic factors or family-of-origin effects. Such environmental factors cause pervasive differences in monozygotic twins discordant for MD, especially in the areas of interpersonal difficulties, psychopathology, social problems and self-concept. These findings should be interpreted in the context of possible retrospective recall bias and the difficulty of distinguishing risk factors from sequelae in co-twin-control studies.

Adult↗
PubMed2004

Educational research at Johns Hopkins University School of Medicine: a grassroots development.

The Divisions of General Internal Medicine at Johns Hopkins University School of Medicine have been a rich source of educational research. To better understand the facilitators and barriers to educational research within the divisions, the authors reviewed published educational research from the divisions published between 1995-2004 and examined the history, leadership decisions, and sentinel events that have allowed educational scholarship within the divisions to grow. The authors' analysis suggests a grassroots model of programmatic growth that includes a growing cadre of clinician-educator scholars, effective mentorship, a faculty development program, access to learners, access to research expertise, protected time for scholarship, some funding, and an institutional culture that stimulates scholarship. A medical education fellowship was integral to the model; fellows were first authors for 47% of reviewed manuscripts. Extramural funding has helped build an infrastructure that supports educational scholarship; however, only 12% of the publications have had extramural funding. Protected time for faculty is the characteristic of this model most at risk. While there has been a move toward more institutional support of educational research, it is clear that further growth in the educational research program will require noninstitutional resources.

Baltimore↗