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PubMed1977

Prognotic significance of pretreatment proliferative activity in adult acute leukemia.

A statistical analysis of the prognostic significance of eight pretreatment variables was undertaken for 71 previously untreated adult patients with acute leukemia seen at M.D. Anderson Hospital over a 5 1/2-year period. None of the patients had received any prior therapy. Nearly all of the patients (68 of the 71) were treated with 4- or 5-day courses of arabinosyl-cytosine alone or in combination with cyclophosphamide, vincristine (oncovin) and prednisone (COAP). The pretreatment variables studied were age at diagnosis, the percent labeling index of the bone marrow leukemic cells, diagnosis, the highest temperature prior to start of treatment, the marrow clot section cellularity and smear differential percent of blasts, percent absolute marrow leukemic cell infiltrate and absolute number of blasts X 10(3)/mm3 in the peripheral blood. Fifty-one patients had acute myeloblastic leukemia (AML) and 20 patients had acute lymphoblastic leukemia (ALL). Using a statistical regression model approach, the only variables found to be of significant prognostic importance with respect to the probability of complete remission for AML patients were the pretreatment percent labeling index, the age of the patient and the highest temperature prior to start of treatment. Unlike AML, the initial percent labeling index did not appear to be of prognostic significance for ALL patients. AML patients with high labeling indices (larger than or equal to 9%) and young patients in general (especially those less than 40 years old) had the best remission rates. With respect to the length of complete remission and survival for all patients, the only important variables were the pretreatment percent labeling index and the age of the patient, respectively. Once in complete remission, an initially high labeling index was an unfavorable sign with respect to length of remission, regardless of the patient's diagnosis. The results of this study are supportive of studies in experimental systems demonstrating the importance of cytokinetic factors in the administration of chemotherapy and suggest that such factors may be of clinical importance in selecting approaches to therapy.

Adult↗
PubMed1998

Analytical and clinical performance characteristics of Tandem-MP Ostase, a new immunoassay for serum bone alkaline phosphatase.

The performance characteristics of the Tandem-MP Ostase assay, a new microplate immunoassay for bone-specific alkaline phosphatase (bone ALP; EC 3.1.3.1) in human sera, are described. Bone ALP is bound to streptavidin-coated microwells by a single biotinylated anti-bone ALP monoclonal antibody. Antigen is detected by the addition of p-nitrophenyl phosphate. The assay is performed at room temperature in <90 min. Imprecision was 2.3-6.1% with a detection limit of 0.6 microg/L. Method comparison of bone ALP measurements with the Tandem-MP Ostase assay and the mass-based Tandem-R Ostase assay (n = 285) indicated regression statistics of Tandem-MP Ostase = 1.03 Tandem-R Ostase + 0.22 microg/L, S(y/x) = 4.0 microg/L, r = 0.97. Serum bone ALP values in apparently healthy men and in pre- and postmenopausal women were also similar between the two Ostase assay formats. Liver ALP reactivity determined using the slope and heat inactivation methods was similar in both Ostase assays. Liver ALP reactivity ranged from 3 microg/L (heat inactivation) to 6 microg/L (slope method) per 100 U/L of liver ALP activity, whereas bone ALP reactivity was 37 microg/L per 100 U/L of bone ALP activity, indicating a liver ALP relative reactivity of 8.1-16.2%. Similar results were obtained with the Alkphase-B bone ALP immunoassay. The Tandem-MP Ostase bone ALP assay demonstrated increased concentrations of serum bone ALP in conditions where bone metabolism is increased and showed a rapid, temporal decrease in serum bone ALP in Paget disease patients on bisphosphonate therapy. In conclusion, the Tandem-MP Ostase assay for serum bone ALP is a rapid, simple, robust nonisotopic alternative to the Tandem-R Ostase immunoradiometric assay that provides an accurate and sensitive assessment of bone turnover.

Adolescent↗
PubMed1984

Multivariate analysis of factors associated with outcome of treatment for adults with acute myelogenous leukemia.

Utilizing multivariate logistic regression statistical analysis, the authors evaluated prognostic features associated with achievement of complete remission (CR) and remission and survival duration in acute myelogenous leukemia (AML). These clinical variables were analyzed in 77 consecutive adult patients who underwent 108 courses of remission induction therapy with daunomycin, cytosine arabinoside, and 6-thioguanine (DAT) chemotherapy for newly diagnosed and first relapse of AML. Eight patients had developed leukemia in the setting of other malignant or immunologic diseases (therapy-linked AML) and 69 patients had not (primary AML). Sixty-three percent of patients with primary AML achieved CR with median remission and survival durations of 11 and 24 months, respectively. Significant unfavorable predictive features for achievement of CR were splenomegaly, and elevated leukocyte count or serum alkaline phosphatase levels. Patients who had leukocyte counts of less than or equal to 10,000/mm3 at diagnosis or less than or equal to 40,000/mm3 at the start of therapy, and those who received greater than 120 mg/m2 of daunomycin had significantly longer remissions and survival than those who did not. Fifty-seven percent of patients in first relapse also achieved CR; however, relative to first remissions, second remission durations were significantly shorter (median, 4.6 months). Sixty-two percent of patients with therapy-linked AML achieved CR, but remission durations (median, 2.8 months) were significantly shorter than first remissions of primary AML patients. These data identify clinical features associated with increased risk of failure to achieve CR and potential for short remission duration and survival. Alternative forms of therapy should be considered for such high-risk patients.

Adolescent↗
PubMed1999

Risk factors associated with Cryptosporidium parvum infection in dairy cattle in southeastern New York State.

An observational analytical epidemiologic study was carried out to identify factors associated with the risk of infection with Cryptosporidium parvum in dairy herds in southeastern New York state. A random sample of 2943 cattle on 109 farms was selected from the target population. Fecal samples were collected from animals in three different age groups and examined for the presence of C. parvum using a quantitative centrifugation concentration flotation method. Data on intrinsic, preweaning, postweaning, maternity, and general management factors were collected and evaluated for their association with the risk of infection with C. parvum. Indices for each of these categories of management were developed from factors significantly associated with the risk of infection with C. parvum. Significant factors were identified using the logistic regression statistical technique. A final analysis, including the indices, age, and season, was performed to identify factors significantly associated with the risk of infection with C. parvum while simultaneously controlling for the effect of other factors. The farm effect was evaluated using a mixed effect model. Preweaning factors found to be significantly associated with a decreased risk of infection were: use of ventilation in calf rearing areas, daily addition of bedding, feeding of milk replacer, daily disposal and cleaning of bedding, and use of antibiotics. Postweaning factors such as moving of the animals after weaning, cleaning of soiled bedding, and use of antibiotics and ionophores as preventive measures were significantly associated with the decreased risk of an infection with C. parvum. Consideration of maternity management factors showed that winter housing of cows individually within 2 months of calving, use of fresh colostrum to feed calves, and having a concrete floor in the calving area were significantly associated with decreased risk of C. parvum infection. The total number of dairy cattle, total number of other species of agricultural animals on the farm, and the distance of the barn water source from the septic system were found to be significantly associated with increased risk of C. parvum infection. In the final analysis, the risk of infection with C. parvum was significantly decreased with an increased value of the maternity management index score. The general management significantly affected the risk of infection with C. parvum where the risk increased with the increase of the value of the index. The risk of infection significantly decreased with increase in the age of the animal.

Age Factors↗
PubMed2005

Allometric scaling of mammalian metabolism.

The importance of size as a determinant of metabolic rate (MR) was first suggested by Sarrus and Rameaux over 160 years ago. Max Rubner's finding of a proportionality between MR and body surface area in dogs (in 1883) was consistent with Sarrus and Rameaux's formulation and suggested a proportionality between MR and body mass (Mb) raised to the power of 2/3. However, interspecific analyses compiled during the first half of the 20th century concluded that mammalian basal MR (BMR, ml O2 h(-1)) was proportional to Mb3/4, a viewpoint that persisted for seven decades, even leading to its common application to non-mammalian groups. Beginning in 1997, the field was re-invigorated by three new theoretical explanations for 3/4-power BMR scaling. However, the debate over which theory accurately explains 3/4-power scaling may be premature, because some authors maintain that there is insufficient evidence to adopt an exponent of 3/4 over 2/3. If progress toward understanding the non-isometric scaling of BMR is ever to be made, it is first essential to know what the relationship actually is. We re-examine previous investigations of BMR scaling by standardising units and recalculating regression statistics. The proportion of large herbivores in a data set is positively correlated both with the scaling exponent (b, where BMR=aMb b) and the coefficient of variation (CV: the standard deviation of ln-ln residuals) of the relationship. Inclusion of large herbivores therefore both inflates b and increases variation around the calculated trendline. This is related to the long fast duration required to achieve the postabsorptive conditions required for determination of BMR, and because peak post-feeding resting MR (RMRpp) scales with an exponent of 0.75+/-0.03 (95% CI). Large herbivores are therefore less likely to be postabsorptive when MR is measured, and are likely to have a relatively high MR if not postabsorptive. The 3/4 power scaling of RMRpp is part of a wider trend where, with the notable exception of cold-induced maximum MR (b=0.65+/-0.05), b is positively correlated with the elevation of the relationship (higher MR values scale more steeply). Thus exercise-induced maximum MR (b=0.87+/-0.05) scales more steeply than RMRpp, field MR (b=0.73+/-0.04), thermoneutral resting MR (RMRt, b=0.712+/-0.013) and BMR. The implication of this observation is that contamination of BMR data with non-basal measurements is likely to increase the BMR scaling exponent even if the contamination is randomly distributed with respect to Mb. Artificially elevated scaling exponents can therefore be accounted for by the inclusion of measurements that fail to satisfy the requirements for basal metabolism, which are strictly defined (adult, non-reproductive, postabsorptive animals resting in a thermoneutral environment during the inactive circadian phase). Similarly, a positive correlation between Mb and body temperature (Tb) and between Tb and mass-independent BMR contributes to elevation of b. While not strictly a defined condition for the measurement of BMR, the normalisation of BMR measurements to a common Tb (36.2 degrees C) to achieve standard metabolic rate (SMR) further reduces the CV of the relationship. Clearly the value of the exponent depends on the conditions under which the data are selected. The exponent for true BMR is 0.686 (+/-0.014), Tb normalised SMR is 0.675 (+/-0.013) and RMRt is 0.712 (+/-0.013).

Animals↗
PubMed2000

Studies on some 3(2H)-pyridazinone derivatives with antinociceptive activity.

Nineteen new [6-(4-methoxyphenyl)-3(2H)-pyridazinone-2-yl]-acetamide (1-10) and 3-[6-(4-methoxyphenyl)-3(2H)-pyridazin-one-2-yl]propanamide (11-19) derivatives have been synthesized in this study. The structures of the compounds have been elucidated by their IR and NMR spectral data and elemental analysis. Antinociceptive activity of the compounds has been investigated by modified Koster's Test in mice, using aspirin as a reference. All the compounds (at 100 mg/kg dose) except 1 and 9 have been found more potent than aspirin. Compound 6 in the group of acetamide derivatives and compound 15 in the group of propanamides exhibited the highest antinociceptive activity. In addition, the propanamides have generally been found more potent than acetamides. In addition to these studies, the quantitative relationships between some structural parameters (such as log P, parachor, molar refractivity, and molecular connectivity indices) and antinociceptive activity of the compounds have been investigated. Statistical regression analysis has shown a close relationship to exist between the first-order molecular connectivity index (1 chi) and the antinociceptive activity.

Acetamides↗
PubMed2000

Gabapentin for essential tremor: a multiple-dose, double-blind, placebo-controlled trial.

Essential tremor (ET) is a common movement disorder that often becomes refractory to conventional pharmacologic management. Open-label studies suggest that gabapentin is efficacious for ET, but the results of controlled trials have been mixed. To determine the efficacy and tolerability of gabapentin in ET, we conducted a double-blind, placebo-controlled, cross-over trial evaluating two doses (1800 mg per day and 3600 mg per day; N = 25). Patients on other ET medications were maintained on their concurrent medications for 3 months prior to study initiation and throughout the study. Twenty patients (mean age, 69.9 +/- 6.1 yrs) completed the study. Overall, patient global assessments (p <0.05), observed tremor scores (p <0.005), water pouring scores (p <0.05), and activities of daily living scores (p <0.005) significantly improved. Accelerometry scores, spirographs, and investigator global impression scores did not improve. The results were similar for high and low doses. Statistical regression models did not demonstrate any significant predictors for response. Gabapentin may be effective in some cases of ET.

Acetates↗
PubMed1984

The body build and composition of Samoan children: relationships to infant feeding patterns and infant weight-for-length status.

The relationships between infant feeding patterns, infant weight status, and subsequent growth are not yet firmly established. This study attempts to address these topics among Samoan children. The study population consists of 1,186 children born between October 1974 and September 1976 who were subsequently seen in the Well Baby Clinic in American Samoa. On the basis of the clinic records the children were categorized into feeding groups (breast vs. bottle) and weight-for-length groups (less than 25th percentile or greater than 75th percentile of National Center for Health Statistics ( NCHS ) standards). A survey of 74 of these children was conducted in 1982. The average age of the children was 6.6 years. Twenty anthropometric measurements were taken and divided into three groups: skeletal, adipose, and mixed. Multiple analysis of variance was used on each of the groups of measurements to assess effects of infant feeding and weight-for-length. This analysis demonstrated significant relationships between infant weight-for-length and childhood skeletal size (heavy infants are larger children); between infant feeding patterns and childhood adiposity (bottle-fed children are fatter); and between both infant patterns and the mixed measurements (heavy and bottle-fed infants are heavier children with larger circumferences). The relationship between infant weight-for-length and skeletal size may be a continuation of infant patterns of high musculoskeletal weight in heavy infants. The relationship between infant feeding and childhood fatness was not affected by family income.

Birth Weight↗
PubMed1986

Ultrasonic measurements of subcutaneous adipose tissue thickness in man.

Subcutaneous adipose tissue thickness (SCATT) has for many years been measured using skinfold calipers, but calipers have several disadvantages, not least that they compress the skinfold. Measuring SCATT using ultrasound was validated by comparing thicknesses at 12 sites with soft-tissue radiographs in 24 adults and with depth gauge measurements on a cadaver. Correlation coefficients ranged from 0.87 to 0.99, and the regression statistics showed no significant difference between ultrasound and the other procedures. The standard errors of estimate of body density from SCATT measured by calipers and ultrasound in 63 young men was +/- 7.8 and 7.3 kg X m-3, respectively. Although problems in the identification of the adipose tissue-muscle interface can arise, ultrasound is a viable alternative to skinfold calipers and is to be preferred when measuring uncompressed SCATT.

Adipose Tissue↗
PubMed2005

Predictors and outcomes of surgeons' referral of older breast cancer patients to medical oncologists.

BACKGROUND: Older women are less likely than younger women to receive definitive care for a new diagnosis of breast cancer, but the reasons are not well understood. Although coordination of referral among specialists is an important component of quality of care, it has not been studied as a factor that contributes to observed age-related variations in breast cancer care. METHODS: Treatment recommendations by 191 surgeons of 559 patients aged > or = 65 years with Stage I to IIIa breast cancer provided patient-specific assessments of comorbidity and medical oncologist referral. Demographic, tumor, and treatment characteristics from medical records and telephone interviews were evaluated by statistical regression methods to identify factors associated with referral to a medical oncologist and to evaluate whether a referral resulted in discussion and prescription of tamoxifen. RESULTS: Estrogen receptor protein negativity and higher tumor stage increased the likelihood of referral (odds ratio [OR] = 5.6, 95% confidence interval [CI] = 1.9-16.7, and OR = 4.2, 95% CI = 1.7-10.3, respectively), whereas a moderate to severely ill health status decreased the likelihood of referral (OR = 0.4, 95% CI = 0.2-0.9). Those referred were twice as likely to report having a discussion about tamoxifen (OR = 2.0, 95% CI = 1.06-3.7) and to have been prescribed tamoxifen (OR = 2.1, 95% CI = 0.99-4.3). CONCLUSIONS: Referral to medical oncologists is associated with receipt of adjuvant tamoxifen therapy. The current study findings suggest that more consistent referral of older women to medical oncologists may enhance quality of discussion and participation in decisions concerning treatment options.

Age Factors↗
PubMed1993

Reproductive variables, tobacco, ethanol, coffee and somatometry as risk factors for ovarian cancer.

A hospital-based case-control study of ovarian cancer was conducted in Athens from 1989 to 1991. The cases were 189 women, residents of Greater Athens and less than 75 years old, with histologically confirmed common malignant epithelial tumors of the ovary, operated in the 2 major cancer hospitals of the Greater Athens area. Controls were women residents of Greater Athens, less than 75 years old, who had never had cancer or had an ovary removed and who had visited patients hospitalized in the same wards as the ovarian cancer cases at the same time. The data were analyzed by modeling through multiple logistic regression. Statistically significant associations were found with induced menopause without oophorectomy [relative risk (RR) 0.17; 95% confidence interval (CI) 0.04 to 0.72], age at menopause (for an increment of 5 years RR 1.42; CI 1.00 to 2.01), hormone-replacement therapy (RR 5.73; CI 1.07 to 30.80), parity (RR 0.48; CI 0.24-0.96) and, marginally, age at first birth (for an increment of 5 years RR 1.30; CI 0.99 to 1.70). Non-significant but previously suggested or biologically plausible associations were noted with use of oral contraceptives (inverse), weight before onset of the disease (positive), and consumption of more than 2 glasses of alcoholic drinks per day (positive). There were no consistent associations with coffee, tobacco, moderate alcohol intake, broad occupational group, induced abortions, or age at menarche.

Adult↗
PubMed1994

Incidence and risk factors for childhood brain tumors in the Ile de France.

A case-control study investigating risk factors for childhood brain tumors was conducted in the Ile de France (Paris region). During a 2-year period (1985-1987) 109 newly diagnosed cases were identified and, of these, 75 could be interviewed. In the same region, 113 population controls, frequency-matched for year of birth, were interviewed. Odds ratios adjusted for child's age and sex and for maternal age were estimated for each risk factor present in utero or during childhood by conditional logistic regression. Statistically significant associations were found for the following risk factors: farm residence, cat scratches, home treated with pesticides, passive smoking, family history of cancer, antihistamine intake. Intake of vitamin supplements during childhood was associated with a decrease in risk. This study is part of a multicentric case-control study coordinated by the International Agency for Research on Cancer and its results will be compared for consistency, and pooled with those of other centers using the same protocol.

Adolescent↗
PubMed1978

Electronic structure--activity relationships of antibacterial acridines.

The antibacterial activity of a series of amino- and fluorinated acridines was studied in the framework of their electronic structures. To calculate the electronic structure, a simple Hückel molecular orbital theory was used. A statistical regression analysis revealed linear correlations between the activity and the electronic indexes, particularly the electron density at the ring nitrogen.

Acridines↗
PubMed2005

Reference ranges for serial measurements of blood velocity and pulsatility index at the intra-abdominal portion, and fetal and placental ends of the umbilical artery.

OBJECTIVE: To construct reference ranges for serial measurements of umbilical artery (UA) blood flow velocity and pulsatility index (PI) at standardized insonation sites during the second half of pregnancy. METHODS: This was a prospective longitudinal study of the umbilical circulation. UA blood flow velocities were measured at the intra-abdominal portion, fetal end and placental end at 4-weekly intervals at 19-42 weeks of gestation in 130 low-risk singleton pregnancies. A total of 513 observations were used to construct the reference ranges using regression statistics and multilevel modeling. RESULTS: UA blood velocities and PI were higher at the intra-abdominal portion and fetal end than at the placental end. The gestational age-related increase of end-diastolic velocity was greater than the corresponding increase of the peak systolic velocity at all locations. The mean differences (delta values) of UA blood velocities between the fetal and placental ends increased and that of PI decreased with advancing gestational age. CONCLUSION: UA Doppler parameters vary significantly at different locations. We have established new reference ranges for the UA velocities and PI at standardized locations based on longitudinal observations, which should be useful for the surveillance of fetuses with repeated observations.

Blood Flow Velocity↗
PubMed2000

Salivary cortisol and social status among Dominican men.

Studies of nonhuman primates indicate that social subordinance associates with chronic elevated cortisol, but this finding has not been replicated among humans. This topic was examined in a study of 31 healthy adult male Dominican villagers ages 17 to 49 years. Each subject's mean cortisol level was calculated using multiple time-standardized salivary cortisol samples (minimum = 6, mean = 14. 8 samples per subject) determined by radioimmunoassay. Semistructured ethnographic interviews were used to collect several measures of social status. Data were analyzed with a backward stepwise multivariate linear regression model. Partial regression statistics revealed four significant associations with cortisol: (i) men with reputations for illicit social behavior had higher cortisol; (ii) men who reported more frequent distressed mood had higher cortisol; (iii) men rated as less trustworthy, agreeable, influential, and helpful by their peers had higher cortisol; and (iv) men whose fathers were absent as a childhood caretaker had higher cortisol. No associations were found between cortisol and (a) a composite of educational attainment, income, and material wealth; (b) frequency of tobacco consumption; (c) frequency of perceived social stressors; or (d) a composite of number of children and dependents.

Adolescent↗
PubMed2002

Coexistence in MacArthur-style consumer-resource models.

The nature of and conditions for permanent coexistence of consumers and resources are characterized in a family of models that generalize MacArthur's consumer-resource model. The generalization is of the resource dynamics, which need not be of Lotka-Volterra form but are subject only to certain restrictions loose enough to admit many resource dynamics of biological interest. For any such model, (1) if there is an interior equilibrium, then it is globally attracting, else some boundary equilibrium is globally attracting-thus permanent coexistence is coexistence at a globally attracting equilibrium; (2) there is an interior equilibrium if and only if for any species, the equilibrium approached in the absence of that species and the presence of the others is invasible by that species--thus permanent coexistence is equivalent to mutual invasibility; (3) for resources without direct interactions, the conditions for permanent coexistence of the consumers admit an instructive formulation in terms of regression statistics. The significance and limitations of the models and results are discussed.

Animals↗
PubMed1998

A normative study on visual reaction times and two Stroop colour-word tests.

Two-hundred and nine normal subjects underwent a study aimed at providing norms for some attention tests currently used in neuropsychological examination. Norms were calculated taking into account the demographic variables. Our battery included single visuo-manual and go/no-go reaction times, and two versions of the Stroop Colour-Word Test. For the latter test, we employed a traditional version based on card presentation and a new version based on computer-assisted presentation. We evaluated the intercorrelation of the different tests, and studied the statistical regression models in order to adjust the original scores according to age, education and gender. Normative values were calculated following the Equivalent Scores method. The pattern of intercorrelation of our battery and the regression models of the scores are discussed with reference to the literature. The newly developed computer-assisted presentation of the Stroop test offers some advantages over the traditional version, especially with patients affected by spatial disorders.

Adolescent↗
PubMed1994

Resection surgery for partial epilepsy. Relation of surgical outcome with some aspects of the epileptogenic process and surgical approach.

In spite of the progressive improvement of the results of resective surgery for epilepsy, the number of not significantly benefited patients remains high. An attempt was made to find out a relation between outcome and some aspects of the pathophysiological organization of the epileptogenic process and of the surgical procedure. Chi-square and logistic regression statistic analyses were utilized. The study was retrospectively performed on 138 surgically treated patients having a minimum follow-up of three years. Three classes of surgical outcome were considered: completely seizure free (including aura; 86 cases, 62.3%), significant seizure reduction (31 cases, 22.5%), and no significant improvement (21 cases, 15.2%). What follows was brought into evidence by the study. 1) On the diagnostic side, the spatial arrangement (focal, unilateral, multifocal) of both the interictal and the ictal epileptic electrocerebral activities are significantly associated with the surgical outcome. Their relative impact on outcome is related to the presence of a structural lesion: when a lesion is documented, the interictal activity has the higher value: vice versa, when no lesion is apparent, the role of the ictal activity is prevalent. However, the presence, as well as the nature of the lesion, per se, are not significantly associated with outcome. 2) On the surgical side, the extent of resection of both the structural lesion and of the epileptogenic zone are highly associated with the surgical result; the extent of lesion resection prevails on that of the epileptogenic zone. The type of surgical approach (hemispherectomy: 17 cases; temporal lobectomy: 67 cases; extratemporal resection: 54 cases) has no significant relation to the outcome. The value and the limits of the results obtained are discussed.

Adolescent↗