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MA Caudill AC Cruz JF Gregory AD Hutson LB Bailey 《Canadian Metallurgical Quarterly》1997,127(12):2363-2370
A metabolic study (84-d) was conducted to investigate the folate status response of pregnant subjects (n = 12) during their second trimester and nonpregnant controls (n = 12) to folate intakes approximating the current (400 microg/d) and former (800 microg/d) recommended dietary allowance (RDA). The overall goal of the study was to provide metabolic data to assist in the interpretation of the current RDA for folate. Subjects were fed a controlled diet containing 120 +/- 15 microg/d (mean +/- SD) folate and either 330 or 730 microg/d synthetic folic acid. Outcome variables between and within supplementation groups were compared at steady state. Serum folate was higher (P = 0.05) in pregnant women consuming 850 compared with 450 microg/d (44.6 +/- 13.4, 26.3 +/- 11.3 nmol/L, respectively, mean +/- SD). No differences (P > 0.05) were detected in serum folate between pregnant and nonpregnant women within the same supplementation group. Urinary 5-methyl-tetrahydrofolate excretion was greater (P = 0.05) in pregnant women consuming 850 compared with 450 microg/d (198.0 +/- 100.4, 9.5 +/- 3.2 nmol/d, respectively). No differences (P > 0.05) in 5-methyl-tetrahydrofolate excretion were detected between pregnant and nonpregnant women within supplementation groups. Differences (P = 0.05) were not detected in red cell folate between pregnant women consuming either 450 or 850 microg/d (1452.5 +/- 251.8, 1733.5 +/- 208.5 nmol/L, respectively) or between pregnant and nonpregnant women consuming 450 microg/d. Our data suggest that 450 microg/d (dietary folate + synthetic folic acid) is sufficient to maintain folate status in pregnant women. This level of intake equates to approximately 600 microg/d dietary equivalents, assuming 50 and 75% availability of dietary folate and synthetic folic acid consumed with meals, respectively. 相似文献
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CY Valenzuela 《Canadian Metallurgical Quarterly》1997,125(5):595-604
BACKGROUND: Chilean girls of middle and low socioeconomic levels are shorter than their European or North American counterparts. AIM: To challenge the hypothesis that undernutrition is the cause of the shorter stature of Chilean girls. MATERIAL AND METHODS: Height, weight, sexual maturation, biacromial and bi-iliac diameters of low and middle socioeconomic level Chilean children aged 0 to 20 years old, were compared with data from French, English and North American children in the same age range. RESULTS: Chilean girls had an earlier sexual maturation, had bigger biacromial and bi-iliac diameters and had a higher weight for height than European girls. Weight for height of these girls was over the values proposed by the Chilean Ministry of Health, that are based in NCHS/WHO tables. Chilean girls with recent European ancestry were taller than girls without this ancestry. Chilean boys were smaller and had lower weights than their foreign counterparts. Bi-iliac diameters were similar to those of French boys and sexual maturation was similar to English boys. CONCLUSIONS: These results indicate that genetics and not undernutrition is involved in the shorter height of Chilean girls, when compared with their European or North American counterparts. 相似文献
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Higgins Stephen T.; Heil Sarah H.; Badger Gary J.; Mongeon Joan A.; Solomon Laura J.; McHale Luke; Bernstein Ira M. 《Canadian Metallurgical Quarterly》2007,15(1):58
The present study was conducted to examine several different methods and cutpoints for determining smoking status in pregnant and recently postpartum women. Self-reported smoking status, urine cotinine levels determined by gas chromatography (GC) and by enzyme immunoassay testing (EMIT), and breath carbon monoxide (CO) levels were assessed at 28 weeks antepartum and 12 and 24 weeks postpartum in 131 women enrolled in studies on smoking cessation and relapse prevention. Classifications based on urine-cotinine GC testing served as the standard in most analyses. Overall agreement between self-reported smoking status and classification based on urine-cotinine GC testing was excellent (≥95%) at several cutpoints (50, 25, and 12.5 ng/ml) but highest at 25 ng/ml. Classifications based on EMIT urine cotinine levels were in nearly perfect (≥98%) agreement with those made by GC when the cutpoint for the former was set at approximately 80 ng/ml (79-87 ng/ml). Classifications based on breath CO were in relatively poor agreement (≤87%) with GC classifications at all cutpoints examined but best at 4 ppm. Overall, these results provide detailed information on several commonly used methods for classifying smoking in pregnant and recently postpartum women that should be practically useful to researchers and clinicians involved in efforts to eliminate smoking in this population. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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PW Geissler CE Shulman RJ Prince W Mutemi C Mnazi H Friis B Lowe 《Canadian Metallurgical Quarterly》1998,92(5):549-553
OBJECTIVE: To report a case of methemoglobinemia in a patient receiving dapsone for prophylaxis of Pneumocystis carinii pneumonia (PCP). CASE SUMMARY: A 69-year-old white woman was hospitalized to rule out sepsis. Two years prior to this admission, the patient received an orthotopic liver transplant after which she required hemodialysis three times weekly. Because of intolerance to trimethoprim/ sulfamethoxazole and aerosolized pentamidine, she was prescribed dapsone therapy on hospital day 13, that was continued for 11 days. On hospital day 45 the patient received a cadaveric kidney transplant, and dialysis treatments were scheduled only as needed. One week after the transplant, dapsone therapy was resumed. Nine days into this course of dapsone, the patient developed dyspnea and oxygen desaturation of unknown etiology. The patient was evaluated for and diagnosed with methemoglobinemia. She received two doses of intravenous methylene blue and one dose of oral activated charcoal due to fluctuating methemoglobin concentrations. DISCUSSION: The elimination of dapsone is not completely understood. Several case reports of dapsone-induced methemoglobinemia are present in the literature. Most have occurred in patients who have accidentally or deliberately overdosed. Cases of methemoglobinemia in patients receiving therapeutic doses of dapsone are discussed. CONCLUSIONS: The growing numbers of immunosuppressed patients due to transplantation of HIV may result in increased dapsone use for the prevention of PCP. Clinicians should be aware of the adverse effects associated with dapsone therapy, and patients with dyspnea and hypoxemia of unclear etiology should be evaluated for methemoglobinemia. 相似文献
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Using cloned kDNA sequences from the reference strain of Leishmania tropica IC-067, we have screened leishmanial isolates from Laikipia District of Kenya and identified these isolates as L. tropica. One isolate, IC-331, from a rat (Rattus rattus) was typed as L. tropica. This is the first time that L. tropica has been isolated from a wild rodent in Kenya and thus the first indication that the disease caused by L. tropica might be a zoonosis. The leishmanial isolates, especially those of sandflies, display extensive heterogeneity, prompting a need for selecting local and/or regional reference strains to generate species-specific DNA probes for use in identifying field isolates. 相似文献
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A sample of 215 adolescents (16.9 +/- 0.7 y; 13-18 y) from a low socioeconomic level of Valencia, Venezuela, at their first trimester of pregnancy were studied in order to identify nutritional risk. Socioeconomic, anthropometrical, hematological and dietary characteristic were assessed. Pregestational weight, actual weight, height, arm circumference (AC), triceps skin fold (TS), fat and muscle area (FA/MA) and pregestational body mass index (PBMI) were determined. Hemoglobin (Hb) and ferritin were measured by colorimetric and ELISA methods. Two 24 hour recalls were obtained. According to age, two groups were created. Pregnant adolescents were grouped by age: Group 1, 13 to 15 years old and Group 2, 16 to 18 years old. Nutritional risk was defined as: Gynecological age lower than 4 years since menarche. PBMI < 19.8 kg/m2, height below 10th Percentile of reference, Hb below 11 g/dL and ferritin < 12 micrograms/L. Almost all the adolescents (96.3%) were in poverty. 83.3% were single, 83.3% were at elementary school before pregnancy but 84.1% were attending house chores at the time of exam. There were significant differences (p < 0.001) for gynecological age and menarche age, but not for anthropometrical, hematological and dietary variables when Group 1 was compared to group 2. 35.3% of the adolescents had a gynecological age lower than 4 years, 23.3% were below 10th percentile for height, 36.3% had a PBMI lower than 19.8 kg/m2, 26.5% were below 10th percentile for arm circumference, anemia was present in 13.7% and low levels of ferritin in 18.4% of the adolescents. Calorie intake was below recommendation in 87.3% and adequacy for vitamin A and C, calcium and zinc were below 2/3 of recommendation in 36.3%. 25.9%, 88.7% and 73.5% of the adolescents respectively. Studied adolescents had a high prevalence of risk factors for nutritional deficiencies (short age, poverty, low weight, anemia and deficient intake). Early assessment of this conditions allows to identify the risk, to establish interventions and to monitor pregnancy evolution. 相似文献
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CH Jones CG Newstead EJ Will SW Smye AM Davison 《Canadian Metallurgical Quarterly》1997,12(7):1406-1413
INTRODUCTION: In CAPD patients serum albumin is frequently used as an index of nutritional status, although it is recognized that hypoalbuminaemia may be caused by many factors. We have further examined the relationship between serum albumin and nutrition. METHODS: Nutritional status was assessed by biochemistry, anthropometry, mid-arm muscle circumference, muscle strength (hand grip and back), and lean body mass (from anthropometry, creatinine kinetics and bioimpedance) in a group of 76 stable CAPD patients. Correlations between biochemical and nutritional parameters were sought and data were compared between patient groups defined by serum albumin (> or = 37 vs < 37 g/l on two occasions 2 months apart) and separately according to subjective global assessment score (normal nutrition, A vs mild to moderate, B, and severe, C, malnutrition). RESULTS: In patients with a low SGA score, actual body weight, body mass index, mid-arm muscle circumference, lean body mass, subscapular skinfold thickness, hand grip strength (males and females) and iliac and triceps skinfold thicknesses and back strength (females only) were all significantly less than in patients with a normal SGA score. In contrast, none of these variables differed in either gender when patients were compared according to serum albumin. Serum albumin was correlated with serum creatinine (r = 0.45, P = 0.01), daily urine protein excretion (r = -0.42, P = 0.02) and uncorrected weekly creatinine clearance (r = -0.39) in females, but not with any index of body composition in either gender. CONCLUSION: Whilst SGA identified a patient group with significantly abnormal body mass, muscle mass and muscle strength, serum albumin did not. Serum albumin is not a useful marker of malnutrition in stable patients on CAPD. 相似文献
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R Dieter 《Canadian Metallurgical Quarterly》1998,114(2):661-662
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PA Fried 《Canadian Metallurgical Quarterly》1980,6(6):415-424
In a prospective study of 291 mothers-to-be, 20 per cent reported some use of marihuana before and/or during pregnancy. A significant increase in symptoms associated with nervous system abnormalities was observed among babies born to heavy regular marihuana users and visuals responses were affected in two- to three-day-old infants in a dose-related fashion. No relationship between marihuana use and maternal weight again, length of gestation, duration of labor or birthweight was found. 相似文献
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DA Himmelgreen R Pérez-Escamilla S Segura-Millán N Romero-Daza M Tanasescu M Singer 《Canadian Metallurgical Quarterly》1998,107(3):351-361
BACKGROUND: The structural basis of adaptation of enzymes to low temperature is poorly understood. Dimeric citrate synthase has been used as a model enzyme to study the structural basis of thermostability, the structure of the enzyme from organisms living in habitats at 55 degrees C and 100 degrees C having previously been determined. Here the study is extended to include a citrate synthase from an Antarctic bacterium, allowing us to explore the structural basis of cold activity and thermostability across the whole temperature range over which life is known to exit. RESULTS: We report here the first crystal structure of a cold-active enzyme, citrate synthase, isolated from an Antarctic bacterium, at a resolution of 2.09 A. In comparison with the same enzyme from a hyperthermophilic host, the cold-active enzyme has a much more accessible active site, an unusual electrostatic potential distribution and an increased relative flexibility of the small domain compared to the large domain. Several other features of the cold-active enzyme were also identified: reduced subunit interface interactions with no intersubunit ion-pair networks; loops of increased length carrying more charge and fewer proline residues; an increase in solvent-exposed hydrophobic residues; and an increase in intramolecular ion pairs. CONCLUSIONS: Enzymes from organisms living at the temperature extremes of life need to avoid hot or cold denaturation yet maintain sufficient structural integrity to allow catalytic efficiency. For hyperthermophiles, thermal denaturation of the citrate synthase dimer appears to be resisted by complex networks of ion pairs at the dimer interface, a feature common to other hyperthermophilic proteins. For the cold-active citrate synthase, cold denaturation appears to be resisted by an increase in intramolecular ion pairs compared to the hyperthermophilic enzyme. Catalytic efficiency of the cold-active enzyme appears to be achieved by a more accessible active site and by an increase in the relative flexibility of the small domain compared to the large domain. 相似文献
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Fairbrother Nichole; Hutton Eileen K.; Stoll Kathrin; Hall Wendy; Kluka Sandy 《Canadian Metallurgical Quarterly》2008,20(2):150
Although fatigue is a common experience for pregnant women and new mothers, few measures of fatigue have been validated for use with this population. To address this gap, the authors assessed psychometric properties of the Multidimensional Assessment of Fatigue (MAF) scale, which was used in 2 independent samples of pregnant women. Results indicated that the psychometric properties of the scale were very similar across samples and time points. The scale possesses a high level of internal consistency, has good convergent validity with measures of sleep quality and depression, and discriminates well from a measure of social support. Contrary to previous evaluations of the MAF, data strongly suggest that the scale represents a unidimensional construct best represented by a single factor. Results indicate that the MAF is a useful measure of fatigue among pregnant and postpartum women. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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JA Clausen 《Canadian Metallurgical Quarterly》1999,161(4):450-451