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PubMed1998

Predicting the pathology results of radical prostatectomy from preoperative information: a validation study.

BACKGROUND: There are now over 13 published models for predicting the outcomes of radical prostatectomy using preoperative information. Because their ability to predict the pathology of the prostatectomy is key in deciding who benefits the most from this surgery, it is important to know how well these models work for new data. METHODS: The patients in this study were 100 men diagnosed with prostate carcinoma in the prostate specific antigen (PSA)-based screening program at Washington University Medical Center. To test the models, the authors used preoperative information and the published algorithms to predict postoperative pathology outcomes. Statistical methods included plots of predicted probability against observed probability, boxplots of predicted probability against observed outcomes, logistic regression, and linear regression. RESULTS: Although none of the published models predicted the outcomes of radical prostatectomy perfectly, those that predicted tumor volume performed best, and in general those that were multivariate also performed best. Nevertheless, the ability of any of these models to discriminate binary outcomes was not very great. CONCLUSIONS: The results of this study suggest that preoperative variables based on serum PSA and the results of needle biopsies can be used in multivariate models to predict tumor volume, but these models need to be improved. Predicting locally advanced tumor stage is likely to be more difficult and may require information beyond what needle biopsies can provide.

Aged↗
PubMed1999

A limited sampling approach in bioequivalence studies: application to long half-life drugs and replicate design studies.

OBJECTIVES: The objectives of this study was to develop a limited sampling model (LSM) to predict the area under the curve (AUC) and the maximum plasma concentration (Cmax) for the assessment of bioequivalence studies. METHODS: Two drugs (A and B) were selected for this purpose. Drug A was chosen to test bioequivalence of two formulations with a long half-life (> 35 hours), whereas drug B was chosen to test the bioequivalence of two formulations (half-life = 12 hrs) with a replicate design study. The LSM for both drugs was developed using 5 blood samples each from 15 healthy subjects. The relationship between plasma concentration (independent variable) at selected time points with the AUC or Cmax (dependent variable) was evaluated by multiple linear regression analysis. The multiple linear regression which gave the best correlation coefficient (r) for 5 sampling time vs AUC or Cmax was chosen as the LSM. The predicted AUC and Cmax from the LSM were then used to assess bioequivalence of two different formulations of each drug following a single oral dose. RESULTS: The model provided good estimates of both AUC and Cmax for both drugs. The 90% confidence intervals on log-transformed observed and predicted AUC and Cmax were comparable for both drugs. CONCLUSIONS: The method described here may be used to estimate AUC and Cmax for bioequivalence studies for drugs with long half-lives or for highly variable drugs which may require replicate design studies without detailed blood sampling.

Area Under Curve↗
PubMed2005

Menopause symptoms and quality of life in women aged 45 to 65 years with and without breast cancer.

OBJECTIVE: To compare the prevalence of menopause symptoms, sexual activity, and quality of life in women with and without breast cancer. DESIGN: A cross-sectional study using one group for comparison was conducted on women aged 45 to 65 years who had not received hormone therapy or tamoxifen during the last 6 months. Participants were recruited from the Menopause and Breast Cancer Outpatient Facilities. One hundred eighty-two women were included, 97 with breast cancer and 85 without breast cancer. Sociodemographic and clinical features and prevalence of menopause symptoms were assessed. The quality of life was assessed by the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) questionnaire. To compare sociodemographic and clinical features between groups, the Student's t test or Fisher exact test was used. Multiple logistic regression and linear regression models were used to control for potential confounding variables. RESULTS: The mean age of participants with breast cancer was 53.2 +/- 6.2 years, and the mean age of those without cancer was 57.8 +/- 4.9 years (P < 0.01). Age at menopause was 47.2 +/- 5.1 years and 47.4 +/- 4.9 years for women with and without breast cancer (P = 0.76), respectively. Approximately one-fourth of women with breast cancer and 4.7% of women without cancer were premenopausal (P < 0.01). The prevalence of menopause symptoms was similar between the groups. Women with breast cancer reported less sexual activity (51.5%) than women without cancer (62.4%) (P < 0.01). Quality of life scores were good in both groups. There was a significant difference regarding physical functioning, with a median score of 90 for the cancer group and 75 for the group without cancer (P < 0.01). CONCLUSION: The prevalence of menopause symptoms was similar in women with and without breast cancer. Sexual activity was less frequent in women with breast cancer. Quality of life was good in women from both groups, although women with breast cancer had the highest level of physical functioning.

Aged↗
PubMed2002

Quantitative structure-activity relationship study of recently synthesized 1,4-dihydropyridine calcium channel antagonists. Application of the Hansch analysis method.

The Hansch analysis method was applied to a series of recently synthesized nifedipine analogues containing nitroimidazolyl, phenylimidazolyl, and methylsulphonylimidazolyl groups at the C-4 position and different ester substituents at C-3 and C-5 positions of the dihydropyridine ring. Hydrophobic, electronic, inductive, and resonance substituent constants were used. The effect of these parameters on the biological activity of 1,4-dihydropyridines (calcium channel antagonist activity in Guinea-pig ileal cells, log (1/IC50)) was determined by multiple linear regression analysis. Linear and quadratic relationships were obtained between the activity and these parameters. It was found that both electronic and hydrophobic interactions occur between the nifedipine analogues and the receptor.

Animals↗
PubMed2006

Impact of renal impairment on eligibility for adjuvant cisplatin-based chemotherapy in patients with urothelial carcinoma of the bladder.

BACKGROUND: Perioperative cisplatin-based chemotherapy has shown benefit in patients with high-risk localized urothelial bladder cancer, but it is not widely used. Renal impairment may be a major factor limiting its use. The current study was designed to determine the proportion of patients ineligible to receive adjuvant cisplatin-based chemotherapy based on inadequate renal function alone. METHODS: Patients who underwent radical cystectomy for urothelial cancer of the bladder with evidence of extravesical disease (> or =pT3 or any N+) were identified. Patients who received neoadjuvant chemotherapy were excluded. Serum creatinine immediately before and nadir serum creatinine after cystectomy were used to calculate creatinine clearance (CrCl) or glomerular filtration rate (GFR) using the Cockroft-Gault (CG), Jelliffe, and Modification of Diet in Renal Disease (MDRD) study formulas. A cutoff of CrCl <60 mL/min or GFR <60 mL/min/1.73 m2 was used to determine ineligibility for cisplatin-based chemotherapy. The proportion of patients ineligible by each formula was compared by univariate logistic regression. Univariate linear regression was performed to determine the effect of age on CrCl or GFR. RESULTS: : Most patients were pT3 or greater; 39% were lymph node-positive. The overall proportion of patients ineligible for cisplatin-based chemotherapy was 28% by the CG formula, 52% by Jelliffe, and 24% by MDRD. Concordance between formulas was low. With all formulas the probability of ineligibility increased with age: by the CG equation, >40% of patients age >70 years were ineligible. CONCLUSIONS: : The widespread use of cisplatin-based perioperative chemotherapy in patients with high-risk localized bladder cancer may be significantly limited by the high prevalence of baseline renal insufficiency in this population. This finding is most striking in the elderly. Better selection of patients who may safely receive cisplatin and more effective regimens devoid of cisplatin are required to optimize outcomes in this group of patients.

Age Factors↗
PubMed2001

Population pharmacokinetics of fluconazole given for secondary prevention of oropharyngeal candidiasis in HIV-positive patients.

OBJECTIVES: To determine fluconazole population pharmacokinetics and explore the relationships between fluconazole average concentration and treatment effectiveness or microbiological resistance induction during a study aimed at evaluating the efficacy, tolerability and resistance induction after secondary prevention with fluconazole (150 mg weekly) versus placebo in human immunodeficiency virus-positive (HIV+) patients with oropharyngeal candidiasis. METHODS: Population pharmacokinetic parameters of fluconazole determined from 458 serum drug concentration measurements obtained over 37 months in 132 HIV + patients not receiving highly active antiretroviral therapy. Mean estimates and variabilities were generated using non-linear regression analysis. Logistic and linear regression analyses were used to explore the relationships between the estimated average concentration of fluconazole and candidiasis relapse or fungal resistance towards fluconazole. RESULTS: Fluconazole kinetics were best described by a one-compartment model with first-order oral absorp tion from the gastrointestinal tract. The pharmacokinetics were influenced only by body weight. No effect was observed for gender, age, height or lymphocyte CD4 counts. The mean apparent population clearance was 0.79 l/h, the volume of distribution 571 and the absorption constant (ka) 0.93 h(-1). Inter-occasion variability in clearance (45%) was large relative to intersubject variability (21%). Taking into account the average fluconazole concentration or the time above the minimal inhibitory concentrations did not clinically improve the prediction of the occurrence of oropharyngeal relapse or microbiological resistance. CONCLUSION: The relationship between fluconazole concentrations and preventive effectiveness was poor. Together with the rather large inter-occasion variability in fluconazole clearance, this suggests no role of therapeutic drug monitoring in optimising fluconazole treatment for secondary prevention.

AIDS-Related Opportunistic Infections↗
PubMed1989

Quantitative structure-activity relationships for the toxicity of selected shale oil components to mixed marine bacteria.

The toxicity of 32 shale oil components to a mixed marine bacterial culture was assessed utilizing an acute static bioassay protocol. Structure-activity relationships were examined between toxicity and 39 physicochemical properties and molecular descriptors, many of which have not been previously utilized in quantitative structure-activity relationship (QSAR) research. The toxicity could be predicted with reasonable accuracy using simple linear regression equations. However, multiparametric linear regression (MLR) equations yielded improved correlation coefficients and predictive capabilities. Such equations allow the inclusion of two or more characteristics in one relationship. The best MLR equations combined carbon number and interatomic distance between the most positive and negative charges, solubility, the approximate sigma electron density, and a variety of other parameters. These multiparametric QSARs with high predictive capabilities require computer-generated data which may not be readily available. Other MLR equations combine parameters such as the octanol water partition coefficient and the specific molecular connectivity index. These latter equations have lower correlation coefficients and yet are probably of more practical use as the data required are readily available or can be calculated. The presented multiparametric QSARs are applicable within the log Kow range of 0.6 to 5.5.

Bacteria↗
PubMed2026

Metabolomic Signatures of Inflammation in Chronic Kidney Disease.

RATIONALE & OBJECTIVE: Inflammation is associated with adverse kidney, cardiovascular, and mortality outcomes. Investigation of the metabolic milieu as it relates to inflammation may provide important insights into these disease processes. STUDY DESIGN: Prospective cohort. SETTING & PARTICIPANTS: African American Study of Kidney Disease and Hypertension (AASK), Atherosclerosis Risk in Communities (ARIC) study, and Boston Kidney Biopsy Cohort (BKBC) participants with available metabolomics and inflammatory protein data. PREDICTORS: Baseline blood levels of 718 metabolites. OUTCOMES: Baseline and longitudinal changes in blood levels of tumor necrosis factor receptors 1 and 2 (TNFR1, TNFR2), tumor necrosis factor-alpha (TNF-&#x3b1;), interferon-gamma (IFN-&#x3b3;), interleukins 6, 8, and 10 (IL-6, IL-8, IL-10), uromodulin (UMOD), and epidermal growth factor (EGF). ANALYTICAL APPROACH: Multivariable linear regression and linear mixed-effects models. RESULTS: Among 491 AASK participants (mean age 54 years; 37% women; mean glomerular filtration rate, 45 mL/min/1.73 m2), 367 cross-sectional associations between metabolites and inflammatory proteins were significant after correction for multiple comparisons. The direction of association was mostly positive for TNFR1 (97%), TNFR2 (97%), IL-8 (77%), and IL-10 (100%); negative for UMOD (80%) and EGF (97%); and variable for TNF-&#x237a;, IFN-&#x3b3;, and IL-6. Pathways were distinct for several inflammatory proteins (eg, tryptophan metabolism for TNFR2). Forty-five associations between metabolites and longitudinal change in inflammatory proteins were identified. Notable metabolites included tigylcarnitine and N 2,N 5-diacetylornithine, which were associated with 2-year increases in TNFR1 and/or TNFR2, and 1,5-anhydroglucitol, where lower levels were associated with decreases in UMOD. In ARIC (n = 3,773) and BKBC (n = 413), replication of cross-sectional associations was excellent for TNFR1 (ARIC 83%; BKBC 85%) and TNFR2 (ARIC 64%; BKBC 79%) but poor for IL-8 (ARIC 3%; BKBC 3%). LIMITATIONS: Metabolite data limited to baseline visit; potential for residual confounding. CONCLUSIONS: Using an untargeted approach, multiple metabolites were cross-sectionally and longitudinally associated with inflammatory proteins in persons with chronic kidney disease.

Chronic kidney disease↗
PubMed1999

Heparin-coated cardiopulmonary bypass equipment. I. Biocompatibility markers and development of complications in a high-risk population.

OBJECTIVES: 1. To study possible clinical benefits of heparin-coated cardiopulmonary bypass in patients with a broad range of preoperative risk factors. 2. To evaluate the correlation between the terminal complement complex and clinical outcome. 3. To identify clinical predictors of complement activation and correlates of granulocyte activation during cardiac surgery. METHODS: Blood samples from adults undergoing elective cardiac surgery with Duraflo II heparin-coated (n = 81) or uncoated (n = 75) cardiopulmonary bypass sets (Duraflo coating surface; Baxter International, Inc, Deerfield, Ill) were analyzed for activation of complement (C3 activation products, terminal complement complex), granulocytes (myeloperoxidase, lactoferrin), and platelets (beta-thromboglobulin) by enzyme immunoassays. Preoperative risk was assessed by means of the "Higgins' score." Complications (cardiac, renal, pulmonary, gastrointestinal, and central nervous system dysfunction, infections, death) were registered prospectively. Data were analyzed by analysis of variance, logistic regression, and linear regression. RESULTS AND CONCLUSIONS: Sixty-seven percent of the patients had predefined risk factors. Complications developed in 53 patients (34%), equivalently with and without heparin-coated bypass sets (P =. 44-.82), despite a significant reduction in complement and granulocyte activation by heparin coating. No clear-cut relationship between the terminal complement complex and outcome was found, even if it was significant in the models for renal and central nervous system dysfunction and infections (P =.006). The Higgins' score was significantly related to complement activation (P <.05). Approximately 50% of the variation in granulocyte activation was explained by complement (P </=.01) and platelet activation (P <.05), heparin/protamine dose ratio (P =.02), duration of cardiopulmonary bypass (P <.01), and gender (P <.05). Therefore measures reducing complement activation alone will not necessarily reduce granulocyte activation sufficiently for clinical significance.

Aged↗
PubMed2001

Multiple intracranial lesions in head injury: clinical considerations, prognostic factors, management, and results in 95 patients.

BACKGROUND: The goal of this study was to identify clinical and radiological predictors of prognosis in patients with multiple post-traumatic intracranial lesions. METHODS: We reviewed 95 patients (75 male and 20 female) between the ages of 18 and 70 (average 38) admitted between 1993 and 2000 with multiple post-traumatic intracranial lesions. Intracranial pressure (ICP) monitoring was carried out in 67 patients (70%); 77 received intensive care unit (ICU) treatment. Since in all cases it was possible to identify a clearly predominant lesion, 3 groups of patients emerged from the data: the first with extradural hematoma (EDH), the second with a combination of homolateral subdural (SDH) and intracerebral hematoma (ICH), and the third with pure focal intracerebral hematoma (ICH). RESULTS: Twenty-seven patients were treated conservatively, 2 of whom died (7.4%); both had bilateral ICH and compression of the basal cisterns. Sixty-eight patients underwent one or more surgeries; 8 died (11.7%). In the group with EDH-predominant lesions (27 cases) all patients were operated (16 for multiple lesions); no one died. In the group with SDH+ICH-predominant lesions, 26 of 32 patients were operated (10 had multiple procedures); 6 died (18.7%), 3 were vegetative. In the group with ICH-predominant lesion, 15 of 36 patients were operated (7 bilaterally); 4 died (11%). Decompressive craniectomy proved to be a useful means to control ICP. Bilateral lobectomy is not recommended because of poor results. Immediate postoperative computed tomography (CT) scan proved to be mandatory to detect additional surgically treatable lesions (16 cases). Statistical analysis was performed by means of chi(2) analysis and multiple linear regression model. The multiple linear regression model was used to ascertain risk factors independently associated with the outcome. The type of lesion (presence of SDH+ICH predominant lesion), the worst recorded Glasgow Coma Scale (GCS) score, the presence of prolonged increased ICP, and the absence of pupillary reflexes were all statistically significant predictors of a bad outcome (dead or vegetative state). CONCLUSIONS: Multiple lesions have the same prognosis as the corresponding single lesions; therefore, their management should be guided by the predominant pathology.

Adult↗
PubMed2003

Insensitivity of the microdialysis zero-net-flux method to nonlinear uptake and release processes.

In the microdialysis zero-net-flux (ZNF) method the extraction efficiency is conventionally obtained by linear regression. The linear analysis may become invalid for certain analytes that have nonlinear uptake/release processes in the tissue. To examine this hypothesis, a nonlinear model was used to numerically investigate the nonlinearity of the ZNF plot caused by nonlinear uptake and release processes. Three findings from this analysis are: (i) the ZNF method is markedly insensitive to the nonlinear active processes; (ii) a slow infusion rate or a long probe membrane can suppress the nonlinearity; (iii) the release under autoreceptor control does not affect the slope and linearity of the concentration difference plot. It is concluded that in the nM infusion range, the ZNF method is unable to distinguish whether or not the tissue clearance process is nonlinear. During electrical stimulation, neurotransmitter overflow may cause the microdialysis ZNF method to exhibit nonlinearity.

Diffusion↗
PubMed1991

Reversible changes in osmoregulation of vasopressin release due to impaired water excretion.

Studies of renal water handling and the effects of altered hydration and posture on the osmoregulation of vasopressin release were performed on a chronically hyponatremic patient with complete cervical spinal cord transection at the C-5 level. Acute oral water loading studies showed marked reduction in free water clearance and urine diluting ability, despite appropriate suppression of plasma vasopressin concentrations. Orthostatic reductions in arterial blood pressure during head-up tilting and following the assumption of sitting posture were also demonstrable, and may have contributed to, but could not fully account for, the defect in renal water excretion, which persisted in supine posture. Hypertonic sodium chloride infusion studies performed before fluid restriction showed that low preinfusion plasma osmolality was associated with a reduced osmotic threshold for vasopressin release, which was subsequently corrected by a period of fluid restriction that restored the patient's plasma osmolality to a normal level. This shift in osmotic threshold can be inferred from both linear regression and log-linear regression analysis of the data. These studies show that marked impairment of renal water excretion coupled with unrestricted water intake can result in altered osmoregulation of vasopressin release in association with persistent plasma hypo-osmolality, which can be corrected by fluid restriction.

Arginine Vasopressin↗
PubMed1997

Relation between ambulatory electrocardiographic monitoring and myocardial perfusion imaging to detect coronary artery disease and myocardial ischemia: an ACIP ancillary study. The Asymptomatic Cardiac Ischemia Pilot (ACIP) Investigators.

OBJECTIVES: This study sought to explore the relation between markers of ischemia detected by ambulatory electrocardiographic (AECG) monitoring and stress myocardial perfusion single-photon emission computed tomography (SPECT). BACKGROUND: Stress myocardial SPECT and AECG monitoring are both utilized in evaluating patients with coronary artery disease. However, information is limited regarding the relation between the presence and extent of ischemia as detected by these two modalities. METHODS: This was an ancillary study of the Asymptomatic Cardiac Ischemia Pilot (ACIP) trial. One hundred six patients with previous coronary angiography underwent AECG monitoring and stress SPECT within a close temporal time period. The frequency and duration of ischemia as assessed by AECG monitoring and the total and ischemic stress-induced myocardial perfusion defect sizes as assessed by SPECT were quantified in separate core laboratories. Multivariate logistic regression and linear regression analysis were used to determine associations between AECG and SPECT abnormalities with regard to angiographic, demographic and treadmill exercise variables. RESULTS: Seventy-four percent of patients with significant (> or = 50%) coronary artery stenosis had SPECT abnormalities, whereas 61% had ischemia by AECG monitoring. The most important predictors of SPECT abnormalities were severity (p < 0.001) of coronary artery stenosis, followed by total exercise duration (p = 0.016) and patient age (p = 0.04). The only predictor of AECG abnormalities was the presence of ST segment depression on the initial exercise treadmill test (p = 0.021). Only a 50% concordance for normalcy or abnormalcy was observed between the SPECT and AECG results, and no relation was observed between the frequency or duration of AECG ischemia and the quantified total or ischemic myocardial perfusion defect size as assessed by SPECT. CONCLUSIONS: Ischemia as detected by AECG monitoring does not correlate with the presence and extent of ischemia as quantified by stress SPECT. Because these techniques appear to detect different pathophysiologic manifestations of ischemia, they may be complementary in more fully defining the functional significance of coronary artery disease and, in particular, which patients are at highest risk for adverse cardiac events.

Adult↗
PubMed2004

Analysis of multiple endocrine disruptors in environmental waters via wide-spectrum solid-phase extraction and dual-polarity ionization LC-ion trap-MS/MS.

An analytical method for the determination of 35 endocrine disrupting chemicals (EDCs) present in the aquatic environment was developed and validated. The procedure includes an off-line solid-phase extraction of 500-mL water samples using wide-spectrum polymer packing material combined with two LC-ESI-MS/MS runs, in negative and positive ionization modes. Limits of quantitation were established between 0.1 and 20.0 ng/L. Satisfactory recoveries were obtained ranging from 80.1 to 110.2%. Calibration, using deuterated internal standardization, was performed by linear regression analysis. Linearity (R(2) > 0.99) was demonstrated over individually specified ranges using seven calibration points for each analyte. Intrabatch and interbatch precision, as well as accuracy (n = 5), were investigated at low, medium, and high concentrations. Precision for all compounds, expressed as the RSD, proved to be less than 17.8 and 20.0%, respectively, for intra- and interbatch. Accuracy, expressed as the mean recovery, was between 83.1 and 108.4% at all concentrations. Stability experiments showed no significant loss or deterioration for any of the analytes. Finally, the method was applied on real samples.

Animals↗
PubMed1980

Relationship between concentration and anticoagulant effect of heparin in plasma of normal subjects: magnitude and predictability of interindividual differences.

The purposes of this investigation were to determine the magnitude of inter- and intraindividual variations in the relationship between heparin concentration and anticoagulant effect in normal adults, and to determine whether these variations are asociated with, and therefore predictable from, certain physiologic characteristics of individual subjects. Citrated plasma was obtained from 12 men and 5 women, 21 to 35 yr old. Heparin was added to the plasma to yield concentrations of 0.05 to 1.0 U/ml and the activated partial thromboplastin time (APTT) was determined. These studies were repeated once or twice over 65 days. Baseline APTT values (i.e., ATPP without added heparin) ranged from 25.6 to 36.2 sec and the hematocrit ranged from 39% to 50%. Both measures showed little intrasubject variation on the same day or on different days. There was an excellent linear relationship between In APTT and heparin concentration in the 0.05- to 0.8-U/ml range (r2 > 0.987 in all cases). The slope value for this relationship ranged from 1.51 to 3.88 ml/U and these interindividual differences were well reproducible on repeated testing. Women had lower hematocrits (p < 0.05) and higher slope values (p < 0.01) than men. Multiple linear regression analysis revealed a linear relationship between observed slope values and slope values calculated as a function of both hematocrit and baseline APTT. Age, weight, and the concentrations of various plasma proteins did not contribute significantly to the predictability of the slope. A multiple linear regression equation with hematocrit and baseline APtt as independent variables yielded a multiple correlation coefficient of 0.875 (p < 0.01). Thus, it may be possible to predict the APTT value produced by a given concentration of heparin in an individual subject from the subject's baseline APTT and hematocrit.

Adult↗
PubMed1999

Magnetic resonance imaging and neurological recovery in acute spinal cord injury: observations from the National Acute Spinal Cord Injury Study 3.

STUDY DESIGN: Data are from a multicenter, randomized, double blind clinical trial of acute spinal cord injury. OBJECTIVES: To evaluate the prognostic value of magnetic resonance imaging (MRI) for randomized patients in the National Acute Spinal Cord Injury Study 3 (NASCIS). SETTING: Sixteen spinal cord injury centers throughout the United States and Canada. METHODS: Of 499 patients randomized in NASCIS 3 between December 1991 and September 1995, MRI was electively done on 191 patients within 72 h of injury. Indications of hemorrhage, edema, and contusion were recorded by standard protocol. Neurological impairment as determined by motor function, response to pin prick and light touch was assessed at admission to the participating center and 6 weeks after injury. Change in neurological function was obtained by subtracting the score of each neurological parameter at admission from that measured at 6 weeks. Spinal cord surgery performed within the 3 days after injury was noted. Data were analyzed by: chi square, analysis of variance, multiple logistic regression and linear regression models. RESULTS: Patients with hemorrhage were much more likely to have a complete injury (OR=2.88, 95 Cl 1.32, 6.23); however this association was much reduced when the initial neurological examination was taken into account (AOR=1.43, 95% Cl 0.55, 3.73) and was no longer a significant predictor of injury. MRI evidence of cord edema was the strongest predictor of reduced improvement in motor function (-3.34 points, P=0.06) and light touch sensation (-3.41 points, P=0.05) at 6 weeks. CONCLUSIONS: Cord hemorrhage, contusion, and edema on MRI were not associated with diagnosis of a complete cord injury after neurological assessment from the initial clinical examination was taken into account. Prediction of a worse 6 week neurological status was weakly associated with the presence of edema diagnosed by MRI. As MRI technology improves, these diagnostic and predictive capabilities need to be re-assessed. SPONSORSHIP: NASCIS 3 was funded by the National Institute of Neurological Disorders and Stroke at the National Institutes of Health, Washington, DC, USA. Pharmacia and Upjohn provided study drugs and placebos; they also monitored data quality, and funded additional tests, in accordance with Food and Drug Administration regulatory requirements. Dr Bracken has served as an occasional paid consultant to Pharmacia and Upjohn.

Adolescent↗
PubMed2000

Some factors influencing the sensitivity of body temperature to activity in neonates.

In adult humans, core temperature is influenced by activity; the sensitivity of core temperature to such effects shows a phase dependence and is also influenced by the environment and whether the individual is asleep or awake. We have investigated if similar effects are evident in neonates, in whom thermoregulation and the circadian rhythm of core temperature are not fully developed. Eleven full-term, healthy babies were studied singly (light 07:00-19:00) at 2 days of age and again 4 weeks after birth; between these times, they were tended routinely on a communal ward. On study days, 10-minute recordings were made of rectal and skin (abdominal) temperature, heart rate (HR), and behavioral state. Sensitivities of the temperatures to activity ("arousal") were assessed throughout the 24h by measuring the gradient of (temperature/HR). Sensitivities measured at 01:00, 05:00, 09:00, 13:00, 17:00, and 21:00 were used as dependent variables in stepwise regression and linear regression analyses, with "subjects," "light versus dark," "behavioral state," and "difference between time of measurement and the acrophase of the endogenous component of the temperature rhythm" (ignoring sign) as possible predictors. (Acrophases of the temperature rhythms had been estimated from 24h data purified using the behavioral state record.) Light versus dark acted as a significant predictor of the sensitivity of rectal temperature to arousal on day 2 and week 4, the sensitivity increasing in the light, and there was limited evidence for behavioral state acting as a predictor on day 2. Neither factor was a significant predictor when the sensitivity of the babies' skin temperatures to arousal was investigated. There was also some evidence that the difference between the time of measurement and the temperature acrophase acted as a predictor of sensitivity to arousal in both rectal (day 2) and skin (week 4) temperature, with larger differences decreasing the sensitivity. These results indicate that there are masking effects on body temperature due to arousal in neonates, the size of which depends on both internal and external factors. However, this sensitivity of temperature to arousal shows differences from the sensitivity of temperature to physical activity in both adult humans and adult mice. One possible explanation of this result is that temperature regulation and the circadian system are not fully developed in humans at this age.

Adult↗
PubMed1999

Hospital characteristics associated with colonization of water systems by Legionella and risk of nosocomial legionnaires' disease: a cohort study of 15 hospitals.

OBJECTIVE: To investigate an increase in reports of legionnaires' disease by multiple hospitals in San Antonio, Texas, and to study risk factors for nosocomial transmission of legionnaires' disease and determinants for Legionella colonization of hospital hot-water systems. SETTING: The 16 largest hospitals in the cities of San Antonio, Temple, and Austin, Texas. DESIGN: Review of laboratory databases to identify patients with legionnaires' disease in the 3 years prior to the investigation and to determine the number of diagnostic tests for Legionella performed; measurement of hot-water temperature and chlorine concentration and culture of potable water for Legionella. Exact univariate calculations, Poisson regression, and linear regression were used to determine factors associated with water-system colonization and transmission of Legionella. RESULTS: Twelve cases of nosocomial legionnaires' disease were identified; eight of these occurred in 1996. The rise in cases occurred shortly after physicians started requesting Legionella urinary antigen tests. Hospitals that frequently used Legionella urinary antigen tests tended to detect more cases of legionnaires' disease. Legionella was isolated from the water systems of 11 of 12 hospitals in San Antonio; the 12th had just experienced an outbreak of legionnaires' disease and had implemented control measures. Nosocomial legionellosis cases probably occurred in 5 hospitals. The number of nosocomial legionnaires' disease cases in each hospital correlated better with the proportion of water-system sites that tested positive for Legionella (P=.07) than with the concentration of Legionella bacteria in water samples (P=.23). Hospitals in municipalities where the water treatment plant used monochloramine as a residual disinfectant (n=4) and the hospital that had implemented control measures were Legionella-free. The hot-water systems of all other hospitals (n=11) were colonized with Legionella. These were all supplied with municipal drinking water that contained free chlorine as a residual disinfectant. In these contaminated hospitals, the proportion of sites testing positive was inversely correlated with free residual chlorine concentration (P=.01). In all hospitals, hot-water temperatures were too low to inhibit Legionella growth. CONCLUSIONS: The increase in reporting of nosocomial legionnaires' disease was attributable to increased use of urinary antigen tests; prior cases may have gone unrecognized. Risk of legionnaires' disease in hospital patients was better predicted by the proportion of water-system sites testing positive for Legionella than by the measured concentration of Legionella bacteria. Use of monochloramine by municipalities for residual drinking water disinfection may help prevent legionnaires' disease.

Cohort Studies↗