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PubMed2004

Tracking the anthropogenic drivers of ecological impacts.

Despite the pivotal role human factors (anthropogenic drivers) are presumed to play in global environmental change, substantial uncertainties and contradictory conclusions about them continue. We attempt to further discipline the human factors issue by estimating the effects of two anthropogenic drivers, population and affluence, on a wide variety of global environmental impacts, including greenhouse gas emissions, emissions of ozone depleting substances, and the ecological footprint. Population proportionately increases all types of impacts examined. Affluence typically increases impacts, but the specific effect depends on the type of impact. These findings refocus attention on population and material affluence as principal threats to sustainability and challenge predictions of an ameliorating effect of rising affluence on impacts.

Anthropology↗
PubMed2006

Significance of bile-duct changes in schistosomiasis.

Lesions involving the intra-hepatic biliary ducts in schistosomiasis have been reported in the literature, both in mice and man, but there are no data concerning their quantitative, evolutionary or post curative chemotherapeutic aspects on record. In order to obtain such data an investigation on this subject was attempted. Mice infected with 50 Schistosoma mansoni cercariae were submitted to a liver biopsy at the 9th week post-infection, and treated with 400 mg/bw praziquantel immediately afterwards. Infected and non-infected controls were submitted to the same procedures. By 19 weeks from cercarial exposure all surviving animals were sacrificed. The biliary ducts were counted on histological sections and the results were expressed as biliary ducts/portal spaces. This quantitative evaluation was compared with that from normal controls and revealed hyperplasia as the main biliary duct change (p<0.007) in schistosomiasis. Hyperplastic changes underwent only mild partial and not statistically significant regression after specific chemotherapy (p>0.05). Infected and untreated animals presented ductal changes that did not differ from those of the treated group. Measurements of serum bilirubin (total and direct), and gamma-glutamyl-transpeptidase (gamma-GT) did not reveal significant differences when animals from the several groups were compared. Thus, bile ducts exhibit a proliferative response in relation to neighboring S. mansoni injury to portal areas, but although these lesions are histopathologically impressive, they lack a functional or prognostic significance.

Animals↗
PubMed2006

Effect of war and postwar genotoxins on micronuclei frequency in Sarajevo study group.

During the 1992-1995 siege, as well as after the war activities, citizens of Sarajevo were most probably exposed to various potential genotoxic agents. The effects of those potential genotoxins were evaluated by micronucleus-cytokinesis blocked assay. The study included 30 individuals who resided in the area of Sarajevo during the war and the postwar period. Point bi-serial coefficient analysis did not reveal any relationship between the frequencies of binuclear cells with micronuclei as well as total number of micronuclei and smoking habits or gender. Simple linear regression revealed statistically significant positive correlation between the age and micronuclei formation. Due to the war related environmental contamination more extensive study is recommended.

Bosnia and Herzegovina↗
PubMedDate not supplied

Selected characteristics of senior citizens prescription drug payment and procurement in 1998 and 2001.

BACKGROUND: People without prescription drug coverage face greater financial burdens and may sometimes be unable to follow the courses of treatment prescribed by their physicians. The U.S. legislature is considering Medicare coverage for prescription drugs and the use of managed care approaches for containing costs associated with senior citizens. prescription drug therapy. OBJECTIVE: The purpose of this study was to describe selected characteristics of senior citizens. prescription drug payment and procurement. METHODS: Data were obtained via mailed survey from national random samples of senior citizens in 1998 and in 2001. Descriptive statistics and regression analyses were used to describe relationships among study variables. RESULTS: Of 2,434 deliverable surveys, 946 (39%) were returned. Of these, 700 (29%) respondents provided usable data for analysis. Results showed that in 2001, compared with 1998, the proportion of senior citizens without any prescription insurance coverage did not change significantly, 29% and 32%, respectively. However, the proportion of respondents with prescription drug coverage who had to share costs of prescriptions through copayments and coinsurance rose significantly, from 69% in 1998 to 89% in 2001. Between 1998 and 2001, the proportion of senior citizens using mail-order pharmacies rose significantly, from 17% to 27%, and the proportion who reported financial hardship also rose, from 19% in 1998 to 31% in 2001. Controlling for year, prescription drug use, and income, logistic regression analysis showed that respondents without any prescription insurance coverage were about 5 times more likely to report financial hardship compared with those having coverage. CONCLUSIONS: The proportion of senior citizens without any prescription drug insurance coverage did not change significantly between 1998 and 2001, but cost sharing in terms of the proportion that had cost-sharing requirements and the amount of the cost sharing through copayments and coinsurance rose significantly. Self-reported financial hardship and the use of mail-order pharmacies among seniors increased between 1998 and 2001.

Aged↗
PubMedDate not supplied

Relationship between retinoic acid receptor alpha gene expression and growth-inhibitory effect of all-trans retinoic acid on canine tumor cells.

Retinoids show antitumor effects on human acute promyelocytic leukemia and other tumors via retinoid receptors. In dogs, the role of retinoid receptors in inhibiting tumor development remains unclear. To evaluate the correlation between the degree of expression of retinoic acid receptor alpha (RARalpha) mRNA and the antiproliferative effects of all-trans retinoic acid (ATRA) treatments, expression analysis of RARalpha mRNA and cell growth inhibition assay were performed on 17 established canine tumor cell lines, including 6 mammary gland tumor (MGT) cell lines, 3 osteosarcoma cell lines, 5 melanoma cell lines, and 3 mast cell tumor (MCT) cell lines. Among the cell lines investigated, all 3 MCT cell lines showed high expression of RARalpha, and the most effective cell growth inhibition was observed in ATRA-treated MCT cell lines. However, remarkable antiproliferative effects of ATRA treatments were not observed on other tumor cell lines with moderate or low RARalpha mRNA expression. As a result of the relationship between RARalpha mRNA expression and ATRA treatment with regression analysis, statistically significant correlation was suggested. Furthermore, real-time quantitative polymerase chain reaction analysis of RARalpha was performed on MCT tissue samples of dogs with spontaneous disease, and 5 of 9 tissues showed high expression. These results suggest that ATRA may be an effective antitumor agent for MCT in dogs, and that prior measurement of expression of RARalpha mRNA may be a good indicator of the effectiveness of ATRA treatment.

Animals↗
PubMed2000

Periodontal disease progression.

BACKGROUND: The objective of this investigation is to use noninvasive, state-of-the-art, diagnostic techniques to measure periodontal disease progression and model periodontal disease activity over time. In this investigation, digital subtraction radiography and an electronic controlled force periodontal probe capable of attachment level measurement were used to measure bone loss and attachment loss, respectively. The use of these nearly continuous measures of attachment and bone loss allowed detection of small amounts of disease activity and provided data to be used in modeling of the disease process over time. METHODS: Forty-four patients were studied for 18 months. Examinations used clinical attachment level measures at 1-month intervals and quantitative radiology at 6-month intervals. The sites were analyzed by regression for statistically significant changes. These data were used to determine sites of periodontal disease activity for testing various models of periodontal disease progression. RESULTS: Overall 22.8% of sites lost attachment, 5.4% gained, and 71.7% demonstrated no statistically significant change. The mean time to lose 1 mm of attachment was 8.4 +/- 0.6 months. In the first model tested a step-wise discriminant analysis was used to determine whether or not baseline measurements of plaque (PI), gingival inflammation (GI), attachment loss, and probing depth (PD) could be used to derive a satisfactory model for disease progression. Although the overall model was statistically significant with PI, PD, and GI contributing to the model (Wilks' lambda = 0.859, F = 5.71, P <0.0012), its predictive power was relatively weak. A considerably stronger significant model resulted when the rate of attachment loss over the first 6 months, baseline PI, and baseline GI were included (Wilks' lambda = 0.712, F = 14.17, P<0.00001). A significant model also resulted when bone loss during the first 6 months and baseline probing depth were included (Wilks' lambda = 0.438, F = 61.48, P<0.00001). When the last model was applied to each site, the sensitivity in predicting disease progression was 80.0% and the specificity in ruling out progressive disease was 93.9%. CONCLUSIONS: This study indicates that clinically significant progression of attachment loss in posterior tooth sites occurs as a frequent event in adult periodontitis. The modeling data also suggest that short-term (6 month) measures of periodontal disease progression greatly improve the ability to model attachment loss over a longer period in untreated periodontitis patients.

Calibration↗
PubMed2003

Statistical procedures for calculating the residual virulence of Brucella abortus strain 19 (S19) and Brucella melitensis strain Rev 1 vaccines in mice: theoretical basis and practical applications.

Regular control of the biological quality of live Brucella abortus strain 19 (S19) and B. melitensis strain Rev 1 vaccines is essential for the successful management of ruminant brucellosis in affected countries. The reference procedures recommended by the OIE (World organisation for animal health) and the European Pharmacopoeia include the determination of residual virulence, expressed as the recovery time 50 (RT50), of the tested (problem) vaccine in a reference mouse model compared with the RT50 of the corresponding reference strains in the same assay. The underlying statistical procedure applied is based on a parallel line assay and a classical probit model. In practice, the currently recommended procedure for calculating the RT50 is based on a graphical method which has never been described in detail. This paper provides a full description of this graphical method with the aim of making the technique comprehensible and accessible to all interested biologists. The procedure is somewhat cumbersome and very few laboratories apply the OIE and European Pharmacopoeia recommendations on a regular basis. Moreover, since this reference graphical method shows some statistical inconsistencies, a dedicated internet interface has been developed to perform RT50 calculations and is now available free of charge on the web (www.afssa.fr/interne/rev2.html).

Animals↗
PubMed2001

Selective risk taking among needle exchange participants: implications for supplemental interventions.

OBJECTIVES: This study characterized social network context of HIV risk behavior among injection drug users who participated in a needle exchange program. METHODS: Interviews were conducted with 1184 injection drug users at the Baltimore Needle Exchange Program enrolled in an evaluation cohort. Analysis consisted of multiple logistic regression with statistical adjustment for the interdependence of observations. RESULTS: Of the 203 (17.1%) injection drug users who reported using a syringe after someone else, 78.3% reported sharing with close friends, and the adjusted odds ratio of any sharing and sharing with close friends was 30.9. Injection drug users were more likely to report sharing with a strong-tie close friend (adjusted odds ratio = 1.52) and less likely to report sharing with other close friends if those friends were weak ties and new to their network. Friendship ties were not stable, with fewer than 30% of the friends being repeat nominations. CONCLUSIONS: These data show that many injection drug users engage in selective risk taking that may minimize their disease risk exposure in the short term. The turnover in networks, however, suggests that programs need to emphasize the importance of exclusive use.

Adult↗
PubMed2003

Nondaily smokers: who are they?

OBJECTIVE: We sought to understand who constitutes the sizable population of nondaily, or some-day (SD), smokers. METHODS: We analyzed descriptive statistics and regression results using the 1998-1999 Current Population Survey Tobacco Use Supplement to determine the prevalence of SD smokers, their sociodemographic characteristics, and the smoking patterns and histories of groups differentiated by the length and stability of their SD smoking. RESULTS: SD smokers make up 19.2% of all current smokers. Among SD smokers, 44.6% have smoked less than daily for at least 1 year, no more than 14.4% are just starting to smoke, and the rest are likely in transition. Overall, SD smokers smoked a mean of 102 cigarettes per month (compared to 566.4 for daily smokers), on an average of 14.5 days out of the past 30. CONCLUSIONS: SD smokers make up a substantial segment of the smoking population. They are not just beginning to smoke nor trying to quit. Many have developed a long-standing pattern of nondaily smoking, smoking relatively few cigarettes on the days when they do smoke. They are not substantially younger than daily smokers, as one might expect.

Adolescent↗
PubMed2000

Irbesartan: an updated review of its use in cardiovascular disorders.

Irbesartan interrupts the renin-angiotensin system via selective blockade of the angiotensin II subtype 1 receptor; the latter being responsible for the pressor related effects of angiotensin II. As treatment for mild to moderate hypertension, irbesartan 150 mg/day controlled diastolic BP in 56% of patients according to pooled data from several phase III studies and 77% of patients in a large phase IV study. in comparative trials, irbesartan was significantly more effective than losartan and valsartan as treatment for mild to moderate essential hypertension and as effective as enalapril or atenolol. Results from many studies show an additive antihypertensive effect when hydrochlorothiazide is added to irbesartan monotherapy. The drug also induces statistically significant regression of left ventricular mass in patients with hypertension and left ventricular hypertrophy, and preliminary evidence suggests it has beneficial haemodynamic effects in patients with heart failure. Irbesartan is very well tolerated, exhibiting an adverse event profile similar to that seen with placebo in comparative trials. In conclusion, although the role of irbesartan as a treatment for heart failure is little clearer than it was 2 years ago, the place of the drug in the management of hypertension is now better established. There is evidence to suggest the drug may have a role as initial therapy for hypertension, although formal recommendation in management guidelines will almost certainly not occur until long term morbidity and mortality benefits are established.

Angiotensin II↗
PubMed1996

A 15.5-year cohort study on risk factors for possible myocardial infarction and sudden death within 24 hours in a rural Japanese community.

A 15.5-year follow-up study of ischemic heart disease among residents 40 years and older in a rural community, A-I district, Shibata City, Niigata Prefecture, Japan, was completed in 1992. The response rate for the initial examination was 84.5% of 1,182 men and 92.6% of 1,469 women. Nine hundred and eighty-five men and 1,344 women who were initially free of ischemic heart disease were followed from July 1977 through December 1992. The person-year incidence of possible myocardial infarction (PMI) was 1.01 per 1,000 for men and 0.59 for women, and that of sudden death within 24 hours (24SD) was 1.08 for men and 0.64 for women. In the sex-, and age-stratified univariate analyses by the Cox proportional hazard regression model, statistically significant relative risk of PMI was observed for systolic (SBP), diastolic (DBP) and mean blood pressure (MBP), body mass index and smoking. For 24SD, DBP and albuminuria were selected as significant risk factors. In the multivariate analyses, MBP and smoking were selected as independent risk factors for PMI. No significant association of any factor with 24SD was detected. The influence of serum cholesterol on occurrence of PMI appeared to be subtle.

Adult↗
PubMed1992

Risk factors for breast cancer in women undergoing mammography.

To determine risk factors for carcinoma of the breast, we compared women with cancer on screening and diagnostic mammography with those in whom cancer was not detected. For 39 months, medical histories were collected by mammography technologists on 3492 women having routine screenings or diagnostic mammograms at our institution. Potential risk factors of women with biopsy-proved breast cancer were compared with those in women who had normal findings on mammograms or negative biopsy results (control subjects). Of the 3492 women, 49 had biopsy-proved breast cancer. There were 3361 patients in the control group, including those women with normal findings on mammograms (3294) and those with negative biopsy results (67). Eighty-two women had incomplete questionnaires or were lost to follow up. Nearly all of the patients with breast cancer were postmenopausal compared with 68% of the control subjects. The mean length of lactation for breast cancer patients was significantly less than for control subjects: 5.6 vs 7.5 weeks (p = .015). This was true also for the postmenopausal patients: 8.1 vs 6.1 weeks (p = .041). Postmenopausal breast cancer patients had menstruated significantly more years (p = .016) than the postmenopausal control subjects: 34 vs 31 years, although the mean age at menarche was not different. When corrected for age, there was no significant difference in the total duration of menstruation in the postmenopausal cancer patients compared with the postmenopausal control subjects. Postmenopausal breast cancer patients had a significantly greater (p = .021) average body weight than postmenopausal control subjects: 71.7 vs 66.7 kg, although body weight was the same when all patients were considered. Similar results were found when Quetelet's index for obesity (weight in kg/height in cm2) (p = .004) was calculated for postmenopausal patients: 28 for cancer patients and 26 for control subjects. There was no significant difference in height between the cancer patients and control subjects when all patients or just the postmenopausal patients were considered. History of oral contraceptive use was significantly less common among postmenopausal breast cancer patients than among postmenopausal control subjects: 9% vs 20%. Patients with breast cancer had lower parity than the control subjects. In our series of patients, women in whom breast cancer was detected on mammography lactated less, showed no significant difference in years of menstruation when corrected for age, had a greater average body weight, used oral contraceptives less often, and had fewer children than women in whom no cancer was detected on mammography.

Body Height↗
PubMed1998

Vector autoregressive modeling analysis of frequently sampled oral glucose tolerance test results. 1. A new method for quantifying insulin resistance and secretion.

To elucidate abnormalities in the feedback relationships between plasma glucose and plasma insulin levels in diabetic patients, we have introduced the vector autoregressive modeling method as a new for tool feedback analysis. This technique was applied to plasma glucose and insulin level data from a series of 977 frequently-sampled oral glucose tolerance tests (FS-OGTT). Neither special instruments nor medications were used in FS-OGTT. We were able to predict the degree of the plasma glucose response occurring after an impulse-like increase in plasma insulin at 1 mU/mL, as well as the plasma insulin response triggered by an impulse-like increase in plasma glucose at 1 mg/dL, in the form of "impulse response curves". The predicted impulse response curve of glucose to insulin gradually changed from negative to positive with incremental changes in the fasting plasma glucose level, reflecting increased insulin resistance. Furthermore, the response of insulin to glucose decreased in a stepwise fashion with the incremental changes in the fasting plasma glucose level. Our findings confirm the usefulness of impulse response curves as clinical indicators. In addition, analytical data point to a possible contribution of excessive hepatic glucose production to the pathogenesis of the insulin resistance in non-insulin-dependent diabetes mellitus.

Administration, Oral↗
PubMed2002

Inheritance of hypoadrenocorticism in bearded collies.

OBJECTIVE: To assess heritability and mode of inheritance for hypoadrenocorticism in Bearded Collies. ANIMALS: 635 Bearded Collies. PROCEDURES: Dogs were classified as affected by hypoadrenocorticism or unaffected. Phenotypic and pedigree data were analyzed. Heritability was estimated by use of Bayesian statistical methods. Regressive logistic models for complex segregation analyses were used to characterize mode of inheritance. RESULTS: Hypoadrenocorticism was diagnosed in 60 (9.4%) dogs. Heritability of hypoadrenocorticism was estimated to be 0.76 with both sexes affected with equal probability. Evaluation of the pedigrees did not support a Mendelian autosomal dominant mode of inheritance. Evidence from the complex segregation analysis for a single locus of large effect on hypoadrenocorticism was not convincing. CONCLUSIONS AND CLINICAL RELEVANCE: Hypoadrenocorticism in Bearded Collies is highly heritable. Although a precise genetic mechanism responsible for inheritance of the disorder remains undetermined, breeding decisions must include consideration of the genetic likelihood of passing on this deleterious disorder to offspring of affected dams and sires.

Adrenal Insufficiency↗
PubMed1987

Effects of depression upon reading: a case for distinguishing effortful from automatic processes.

This study was designed to test the view that depression would have selective effects upon effortful but not automatic aspects of reading. Relationships were determined between 59 fifth graders' depression scores (on the Children's Depression Inventory and a teacher's rating of depression) and their performance on measures of automatic aspects of reading (word recognition and word attack skills) and effortful aspects of reading (comprehension). A stepwise multiple regression, using statistical controls for sex and mental ability, showed expected relationships of depression to over-all comprehension for the 7 teachers' ratings, but not for the inventory. As expected, relationships of depression to word recognition and word attack scores were statistically non-significant.

Child↗