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At least 127 records · Page 7Linked to original sources
PubMed2026

Personalized functional topography-based multisite brain age prediction modeling reveals divergent neurodevelopment in major depression.

Major depressive disorder (MDD) is associated with widespread alterations in functional brain networks across the lifespan. However, heterogeneity in atypical brain development among patients with MDD remains largely uncharacterized. Using a multisite resting-state functional MRI dataset consisting of 1,105 MDD patients and 1,065 healthy controls, we constructed a harmonized multicenter brain age prediction model based on individualized functional topography and identified two patient subgroups with positive or negative brain age gaps (BAGs). In patients with a positive BAG (BAG+), expansion of the salience network (SAL) into the dorsolateral prefrontal and ventrolateral prefrontal cortices, in addition to contraction of the sensorimotor and dorsal attention networks (DAN), contributes to accelerated brain aging. Conversely, in the negative BAG (BAG-) group, SAL expansion into the orbitofrontal cortex (OFC) and contraction of the visual and sensorimotor networks (SMN) were linked to delayed brain development. These subgroups also exhibited distinct neurodevelopmental trajectories. Clinically, BAG+ patients showed stronger associations between higher-order network topography and mood symptoms, whereas BAG- patients exhibited links between visual/default mode network topography and insomnia. At the molecular level, both groups showed enrichment of genes related to synaptic signaling but displayed distinct expression patterns and divergent expression trajectories in key neurodevelopmental gene sets. Notably, antidepressant treatment modulated the brain in ways that were specific to each subgroup. These findings reveal heterogeneous neurodevelopmental profiles in MDD with distinct biological and clinical signatures, offering insights into personalized precision medicine for this disorder.

Humans↗
PubMed1994

The role of renal function in outcome-prediction models.

General clinical scoring systems are relatively recently developed statistical tools available to clinicians for purposes including comparison of outcome data, evaluation of new therapies, quality assurance, and evaluation of resource utilization. As statistical devices, they are valid when applied to patient groups, not individual prognostication. The most well known general systems are the APACHE (Acute Physiology and Chronic Health Evaluation), SAPS (Simplified Acute Physiology System), and MPM (Mortality Prediction Model). Each of these systems has considered renal dysfunction as a contributor to mortality and, as the systems have matured, have given increasing importance to the presence of renal failure as a predictor of mortality. Cardiac surgery patients make up a large part of many critical-care physicians' practice, but are not presently considered in any of the general scoring systems. In addition, the outcome for these patients is well known to be significantly affected by the presence of renal failure. Specific scoring systems have been developed that evaluate cardiac surgery patients in much the same fashion as do the general scoring systems.

APACHE↗
PubMed1994

A prediction model for identifying alcohol withdrawal seizures.

A retrospective review of alcohol withdrawal seizures was performed at a private chemical-dependence treatment facility to help identify patients who were at high risk for having a seizure. Patients were identified by two means: controlled substance records were reviewed to determine patients having received intramuscular phenobarbital, and patient charts were reviewed for all patients with a discharge diagnosis of a seizure disorder. Two thousand and one patient records were reviewed; alcohol withdrawal seizure patients were identified. Twenty-eight randomly selected nonseizure patient records served as controls. The statistical test consisted of a discriminant function analysis. The data yielded a statistically significant predictive model for alcohol withdrawal seizures based on six interdependent patient variables which will be helpful in treating future patients undergoing alcohol withdrawal.

Adult↗
PubMed1986

Multivariate prediction model of kidney transplant success rates.

An excellent correlation of predicted and observed cadaver kidney graft survival rates was obtained using a nine-factor computer model. A total of 924 recipients for whom a greater than 80% 1-year survival rate was predicted had an observed rate of 84.6%, whereas 179 recipients with a predicted 1-year success rate of less than 40% had an observed rate of 38.2%. Our model gives improved results as compared with previously published methods. We anticipate that the model's predictive power can be further refined, and that patient selection and organ sharing will benefit from the application of sophisticated computer models for the prediction of transplant success.

Analysis of Variance↗
PubMed1982

A prognostic factor analysis for use in development of predictive models for response in adult acute leukemia.

The pretreatment characteristics of 325 adults with acute leukemia who were treated at the M. D. Anderson Hospital between 1973 and 1977 have been evaluated to assess their value as prognostic indicators. The patient population includes all patients treated with an anthracycline (Adriamycin or rubidazone), cytosine arabinoside, vincristine, and prednisone during the time period. Most patients had one of the variants of acute myelogenous leukemia (75%), and the remaining patients had acute lymphoblastic leukemia (16%) or undifferentiated leukemia (8%). Twenty-one factors were found to be significantly associated with probability of obtaining a complete response. In addition to characteristics previously known to provide prognostic information such as age, temperature status at the start of treatment, morphology, the presence of Auer rods, sex, and hemoglobin level, we identified the presence of a documented antecedent hematologic disorder and the finding of insufficient metaphases on cytogenetic analysis using the squash technique as being major prognostic variables. In addition, the pretreatment biochemical characteristics of hypoalbuminemia and elevated blood urea nitrogen and creatinine were found to adversely influence prognosis. The prognostic significance of factors such as the leukocyte count and platelet count, identified in earlier studies, was not confirmed in this group of patients. From this natural-history analysis predictive models for response have been developed using multivariate logistic regression techniques. One of these models has been used to evaluate the effect of morphology, treatment, and cytogenetic pattern on response to the combination of drugs used.

Acute Disease↗
PubMedDate not supplied

Failure to validate a predictive model for refusal of care to emergency-department patients.

OBJECTIVE: To determine whether previously developed triage criteria for refusal of care to patients presenting to an emergency department (ED) with nonurgent problems could be validated for an independent patient population. METHODS: A convenience sample of 534 adults presenting to a municipal hospital ED between July 1, 1992, and October 15, 1992, who met preestablished criteria for refusal of care were entered into a prospective, observational, cohort study. The single target outcome variable was hospitalization. In order to optimize the criteria's performance, both the triage nurse and the physician caring for the patient had to agree that all criteria for "refusal of care" were specifically met. No patient was refused care, nor was a patient's management or disposition interfered with in any way by the investigators. All patients were followed until hospital admission or release from the ED. RESULTS: Six (1.1%) of 534 patients (95% CI 0.4-2.4) who met the criteria for refusal of care were hospitalized. This represents a greater than 50-fold difference in incidence of hospitalization when compared with that found by other investigators, who reported that only 0.02% (95% CI 0.0004-0.04) of those patients who were refused care subsequently required hospitalization (p < 10 (-7)). CONCLUSION: The authors were unable to validate a previously developed predictive model for refusal of care to patients presenting to an ED. Refusal of care to selected ED patients based on current guidelines is not a viable solution to overcrowding. Alternative strategies must be sought.

Adult↗
PubMed1995

Testing models predicting severity of respiratory syncytial virus infection on the PICNIC RSV database. Pediatric Investigators Collaborative Network on Infections in Canada.

OBJECTIVES: To determine the sensitivity and specificity of published prognostic models to predict morbidity resulting from lower respiratory tract disease caused by respiratory syncytial virus in an independent pediatric population and to assess the accuracy of single risk factors in predicting adverse outcome. DESIGN: All articles obtained from a MEDLINE search that used the terms prognosis or sequelae and respiratory syncytial virus, and from the references of these articles, were reviewed. Studies were included if risk factors and outcomes were defined and if information was available in a database of prospectively enrolled patients with respiratory syncytial virus infections. A probability of adverse outcome was assigned to each patient in the cohort using prognostic models described in the articles. A test was considered positive if the probability of the adverse outcome was 5% or more. PATIENTS: Six hundred eighty-nine patients hospitalized with respiratory syncytial virus in seven tertiary care centers across Canada were prospectively enrolled in the Pediatric Investigators Collaborative Network on Infections in Canada database. MAIN OUTCOME MEASURES: The sensitivity and specificity of single predictors and of models in predicting severe disease were determined. RESULTS: The sensitivity of single predictors varied from 17% to 46%. A model that used age and oxygen saturation at admission in previously well infants had a sensitivity of 98% and a specificity of 47% when predicting intensive care unit admission. Another model that included age at hospitalization, gestational age, presence of an underlying condition, and respiratory syncytial virus subtype used to predict the outcome of a high severity index had a sensitivity of 77% and a specificity of 76%. When the above model was modified by exclusion of viral subgroup, sensitivity increased to 94%, but specificity decreased to 46%. CONCLUSION: Previously described prognostic models were generalizable to an independent study population.

Canada↗
PubMed1995

Validation and comparison of models predicting survival following intracerebral hemorrhage.

OBJECTIVE: To compare the performance of two previously reported logistic regression models using data independent from those data used to derive the models. DESIGN: Prospective. SETTING: Acute stroke unit of a tertiary care hospital. PATIENTS: One hundred twenty-nine patients with supratentorial intracerebral hemorrhage. MEASUREMENTS AND MAIN RESULTS: Model 1 contains the initial Glasgow Coma Scale score, hemorrhage size, and pulse pressure. The more complex model 2 includes, in addition to those three variables, the presence or absence of intraventricular hemorrhage and a term representing the interaction of intraventricular hemorrhage and Glasgow Coma Scale score. The areas under the receiver operating characteristic curves generated for each model were statistically indistinguishable. CONCLUSIONS: Model 1 predicts 30-day patient status as well as the more complex model 2. Model 1 provides a valid, easy-to-use means of categorizing supratentorial intracerebral hemorrhage patients in terms of their probability of survival.

Cerebral Hemorrhage↗
PubMed1991

Pharmacokinetics of acetaminophen, antipyrine, and salicylic acid in the lactating and nursing rabbit, with model predictions of milk to serum concentration ratios and neonatal dose.

The rabbit was utilized for examining the pharmacokinetics of three compounds (acetaminophen, AC; antipyrine, AN; and salicylic acid, SA) in nursing adults and their suckling offspring and for assessing the ability of a diffusional model to predict milk to serum drug concentration ratios (M/S) from in vitro experiments. AC, AN, and SA serum concentration time profiles declined monoexponentially for both adults and their pups. The mean systemic clearance (Cls) for AC in the adults and pups was 16.1 and 13.7 ml/min/kg, respectively. The mean half-lives of AC (t1/2) were 25.5 and 33.3 min in the adult and pup groups, respectively. AN declined in parallel for adult rabbits and an older group of suckling pups (23-25 days old). In a younger group of pups (18-21 days old) it declined with a longer t1/2 (97.5, 95.1, and 347.6 min in the adults, older pups, and younger pups, respectively). The mean AN Cls in the adults, the older pups, and the younger pups was 5.34, 6.30, and 1.91 ml/min/kg, respectively. The time course of SA was prolonged in the suckling pups (t1/2 of 633 min in the pups vs 78.7 min in the adult). The mean Cls values in the adults and the pups were 1.05 and 0.27 ml/min/kg, respectively. The mean systemic clearance of unbound drug (Clu) for SA was 11.2 ml/min/kg in the adults and 0.92 ml/min/kg in the pups. The serum protein binding of AC and AN was limited, whereas the mean free fraction for SA was 9.7% in adult serum and 32.5% in pup serum. AC and AN in milk paralleled serum drug profiles; a time lag was noted for milk SA. M/S ratios were determined in vivo (M/Sobs; AN = 0.885, AC = 0.580, and SA = 0.125) using area under the milk and serum concentration time profiles. Predicted M/S values (M/Spred; AN = 0.779, AC = 0.578, and SA = 0.085) were calculated from in vitro measurements of the unbound fractions of drug in skim milk and serum, the skim to whole milk drug concentration ratio, milk and serum pH, and the pKa of the model compound. Mean values for M/Sobs were highly correlated with M/Spred values (r2 = 0.976) when the present data were combined with previous data for propranolol, phenobarbital, phenytoin, and diazepam (Fleishaker, J.C., and McNamara, P.J., J. Pharmacol. Exp. Ther. 244, 919, 1988). These results support the usefulness of the diffusional model for predicting M/S in vivo, provided that the distributional process is governed by passive diffusion.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetaminophen↗
PubMed1990

Evaluation of a spectrum target prediction model in speech perception.

A model of a spectrum target prediction mechanism is proposed and evaluated by comparing predicted values with results of psychoacoustic experiments. When the trajectory of the cepstrally smoothed LPC spectrum is approximated by a second-order critically damped system, the proposed model can estimate target values using short-period spectrum sequences (50 ms) without being given the onset positions of the spectral transition. Additionally, this model decreases the length of transitional sounds and recovers vowel characteristics neutralized by coarticulation. Moreover, this model compensates for the transitions of syllables and extracts stable characteristics from syllable transitions. This model is applicable to coarticulation recovery in speech signal processing.

Humans↗
PubMed2026

Dissecting genetic variance structure and evaluating genomic prediction models for single-cross hybrids derived from Stiff Stalk and Non-Stiff Stalk maize heterotic groups.

The early 20th-century discovery of heterosis and the establishment of heterotic groups transformed maize (Zea mays L.) into a keystone of global agriculture. However, maize breeding faces two significant challenges: the gradual decline of general combining ability (GCA) variance within heterotic groups and the impracticality of testing all possible single crosses in the early stages of a breeding program. Here, we developed genomic best linear unbiased prediction (GBLUP)-based multikernel models, using additive and two alternative nonadditive genomic relationship matrices, to estimate the variance components associated with the general combining ability of Stiff Stalk (SS) and Non-Stiff Stalk (NSS) heterotic groups and the specific combining ability arising from their crosses. We further applied these models to predict the performance of untested single-cross combinations under varying levels of parental information. We showed that the SS and NSS groups retained significant GCA variance across traits in both early- and late-maturity groups. The SS group, in contrast, exhibited no detectable GCA variance in grain yield for the intermediate-flowering subset of hybrids, highlighting a limitation for future genetic improvement. Furthermore, our results showed that GBLUP-based multikernel models effectively identified superior hybrids when parental information was available. In the absence of this information, however, these models underperformed compared to covariance-based approaches. Both nonadditive matrices yielded similar results, indicating that they capture comparable genetic relationship patterns despite their distinct formulations. Overall, this study sheds light on the future use of US maize commercial germplasm and demonstrates how GBLUP-based multikernel models can improve the efficiency of hybrid breeding programs.

Zea mays↗
PubMed1994

Evaluation of a predictive model for the shelf life of cod (Gadus morhua) fillets stored in two different atmospheres at varying temperatures.

The shelf life of fish and food in general is difficult to predict especially if stored at varying temperatures. Shelf life models were constructed (Einarsson, 1992) for cod fillets stored at constant temperatures. The aim of this study was to evaluate if these models could be used to predict spoilage and bacterial growth in cod fillets stored in air and modified atmosphere at constant and varying temperatures. Fresh fillets were packed and stored at constant or varying temperatures between -2 degrees C and 5 degrees C. Samples were taken at regular intervals for bacteriological and sensory evaluation. The results showed that fish stored at +0.6 degrees C in air had a shelf life (assessed by sensory analysis) of 11 days which is close to what could be expected and predicted. The increase in bacterial number observed was generally less than predicted. For fish fillets, stored in air at +5 degrees C for 3 days, then at +0.6 degrees C for 3 days and finally at -2 degrees C, the shelf life was found to be 7 days which was in good agreement with the predicted shelf life. The shelf life of fillets stored at same the temperatures in modified atmosphere was found to be 9 days but by prediction 11 to 12 days. The models for predicting changes in sensory score were more accurate than those predicting changes in bacterial numbers.

Air↗
PubMed1978

A predictive model for visual recovery following retinal detachment surgery.

By multiple regression analysis we have identified 26 out of 200 observations which significantly affect the visual acuity following retinal detachment surgery. In addition, we have developed a highly significant mathematical model, which is able to predict in rather broad ranges of visual acuity to approximately 67% accuracy. There is still a large percentage of patients for whom we cannot account for the variability in final vision, a problem requiring future investigation. Potentially important factors which were not analyzed in this study include duration of macular detachment, afferent pupil defect, drainage of subretinal fluid, extent of the scleral-buckling procedure, and postoperative follow-up longer than six months. While most of the variables are fixed and cannot be alterd, such as age, senile cataract, and refractive error, improved knowledge of influential factors may allow us to manipulate some of them and provide mechanisms for improving results in recovery or maintenance of macular function after retinal detachment surgery.

Adult↗
PubMed1987

Performance of dust respirators with facial seal leaks: II. Predictive model.

A performance model for half-mask and single-use respirators is presented. It represents a possible alternative to field measurements of respirator performance. Experimental data on filter and leak performance given in Part I were used to develop a model that allows one to predict 1) the overall respirator penetration as a function of particle size for any work rate and 2) overall total mass penetration for any work rate and exposure aerosol-size distribution for a known respirator filter and facial seal leak condition. A simplified method based on general regression equations is presented that allows one to estimate these quantities based on QNFT (quantitative fit testing) measurements and a knowledge of the exposure aerosol-size distribution. Example calculations are given for a situation in which QNFT gives a fit factor of 50 for a half-mask with dust, fume and mist filter cartridges, but predicted protection factors for various use conditions range from 20 to 81 depending on exposure particle-size distribution and work rate of the wearer.

Aerosols↗
PubMed1993

Model predictions for anthelmintic resistance amongst Haemonchus contortus populations in southern Brazil.

A computer model developed to study Ostertagia circumcincta resistance to anthelmintics in UK sheep flocks has been adapted for use with Haemonchus contortus under southern Brazilian conditions. The model simulates the effect of different anthelmintic control regimens on the year-to-year pattern of resistance in breeding ewes. The nematode control regimen most used by Brazilian sheep farmers was found to increase the frequency of genes which confer resistance from approximately 3% to 14% in an H. contortus population over a 20 year period. The effect of early versus late season anthelmintic treatment was investigated. This indicated that early season treatment would select for resistance rapidly, whereas late season treatments would not, owing to large numbers of untreated parasites accumulating at the beginning of the season. A model which can predict the development of anthelmintic resistance in parasites of ewes is a valuable tool in the understanding of the effect of different strategies on nematode control programmes and merits further consideration.

Animals↗
PubMed1986

Prediction modeling of physiological responses and human performance in the heat.

Over the last two decades, our laboratory has been establishing the data base and developing a series of predictive equations for deep body temperature, heart rate and sweat loss responses of clothed soldiers performing physical work at various environmental extremes. Individual predictive equations for rectal temperature, heart rate and sweat loss as a function of the physical work intensity, environmental conditions and particular clothing ensemble have been published in the open literature. In addition, important modifying factors such as energy expenditure, state of heat acclimation and solar heat load have been evaluated and appropriate predictive equations developed. Currently, we have developed a comprehensive model which is programmed on a Hewlett-Packard 41 CV hand held calculator. The primary physiological inputs are deep body (rectal) temperature and sweat loss while the predicted outputs are the expected physical work--rest cycle, the maximum single physical work time if appropriate, and the associated water requirements. This paper presents the mathematical basis employed in the development of the various individual predictive equations of our heat stress model. In addition, our current heat stress prediction model as programmed on the HP 41 CV is discussed from the standpoint of propriety in meeting the Army's needs and therefore assisting in military mission accomplishment.

Acclimatization↗