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Eight multiparous and 4 primiparous Jersey cows averaging 92 d of lactation were utilized in a replicated 4 x 4 Latin square design with 28-d periods to determine responses to bovine somatotropin (bST) and ruminally protected Met and Lys when diets were fed that contained supplemental fat. Treatments were 1) control [no bST or ruminally protected amino acids (AA)], 2) control plus bST, 3) control plus ruminally protected AA, and 4) control plus bST plus ruminally protected AA. Dry matter intake was increased by bST but was unaffected by ruminally protected AA. Milk yield was increased by bST but was not altered by ruminally protected AA compared with the control diet. The bST tended to increase percentages of fat and total solids in milk and increased yields of fat, protein, 3.5% fat-corrected milk, and total solids. Ruminally protected AA increased percentages of fat, protein, and total solids in milk; however, yields of milk components were unaffected by ruminally protected AA. Body weight and body condition scores were unaffected by treatment. Concentrations of essential AA in plasma were unaffected by bST administration. Ruminally protected Met and Lys increased the concentration of Met and tended to increase the concentration of Lys in plasma. The lack of an increase in yields of milk and milk protein when ruminally protected AA were fed suggests that adequate amounts of Met and Lys were supplied by the control diet and protein reserves of the cows to meet the AA requirements for synthesis of milk and milk components. 相似文献
123.
RC Klesges KD Ward JW Ray G Cutter DR Jacobs LE Wagenknecht 《Canadian Metallurgical Quarterly》1998,66(6):987-993
This study examined the relationship between smoking status and weight change from baseline to Year 7 in a large biracial cohort, the Coronary Artery Risk Development in Young Adults study. Unadjusted for covariates, only male smokers weighed less than nonsmokers, with no effect among women. Adjusted for covariates, male and female smokers weighed less than nonsmokers at baseline, adjusted for age, total energy intake, alcohol intake, and physical fitness. Over the 7-year follow-up, all smoking status groups gained weight, including continuous smokers and initiators. Weight gain was greatest among those who quit smoking. Weight gain attributable to smoking cessation was 4.2 kg for Whites and 6.6 kg for Blacks. Smoking had a small weight-attenuating effect on Blacks. No such effects, however, were observed among Whites. These results suggest, at least in younger smokers, that smoking has minimal impact on body weight. 相似文献
124.
Feil IK; Platas AA; van den Akker F; Reddy R; Merritt EA; Storm DR; Hol WG 《Protein engineering, design & selection : PEDS》1998,11(11):1103-1109
Members of the cholera toxin family, including Escherichia coli heat-labile enterotoxins LT-I and LT-II, catalyze the covalent modification ofintracellular proteins by transfer of ADP-ribose from NAD to a specificarginine of the target protein. The ADP-ribosylating activity of thesetoxins is located in the A-subunit, for which LT-I and LT-II share a 63%sequence identity. The flexible loop in LT-I, ranging from residue 47 to56, closes over the active site cleft. Previous studies have shown thatpoint mutations in this loop have dramatic effects on the activity of LT-I.Yet, in LT-II the sequence of the equivalent loop differs at four positionsfrom LT-I. Therefore five mutants of the active site loop were created by astepwise replacement of the loop sequence in LT-I with virtually all thecorresponding residues in LT- II. Since we discovered that LT-II had noactivity versus the artificial substratediethylamino-benzylidine-aminoguanidine (DEABAG) while LT-I does, ouractive site mutants most likely probe the NAD binding, not the argininebinding region of the active site. The five hybrid toxins obtained (Q49A,F52N, V53T, Q49V/F52N and Q49V/F52N/V53T) show (i) great differences inholotoxin assembly efficiency; (ii) decreased cytotoxicity in Chinesehamster ovary cells; and (iii) increased in vitro enzymatic activitycompared with wild type LT-I. Specifically, the three mutants containingthe F52N substitution display a greater Vmax for NAD than wild type LT-I.The enzymatic activity of the V53T mutant is significantly higher than thatof wild type LT-I. Apparently this subtle variation at position 53 isbeneficial, in contrast to several other substitutions at position 53 whichpreviously had been shown to be deleterious for activity. The most strikingresult of this study is that the active site loop of LT- I, despite greatsensitivity for point mutations, can essentially be replaced by the activesite loop of LT-II, yielding an active 'hybrid enzyme' as well as 'hybridtoxin'. 相似文献
125.
This study tried to show the contributory role of ions (cations and anions) to great contrast in the goitre prevalence between Bassa and Jos Local Government Areas, both of Plateau State, Nigeria. In pursuance of this, the concentration of cations (Ca++, Fe++, K+, Mg++, Na+, & Zn++) and anions (C1-, F, I-, & NO-3) in soil and drinking water in the two LGAs were determined and their results compared and correlated with the goitre prevalence of these areas. It was observed that both Bassa and Jos LGAs have very low but similar amounts of iodide ions in their soils. Besides, Bassa LGA contained more ions in both soil and drinking water than Jos LGA. In conclusion, the results appear to suggest that the higher ion contents of both soil and drinking water in Bassa LGA exacerbated the coexisting low iodide condition of the LGA, thus resulting in the higher goitre prevalence found in the LGA. 相似文献
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S Bastian JL Paquet C Robert B Cremers B Loillier JF Larrivée DR Bachvarov F Marceau D Pruneau 《Canadian Metallurgical Quarterly》1998,253(3):750-755
Near-haploidy is a rare cytogenetic finding in childhood acute lymphoblastic leukaemia (ALL) and is associated with a poor prognosis. A second hyperdiploid line, occurring presumably by endoreduplication of the near-haploid stemline, is often observed. We present a case of common ALL in relapse characterized morphologically by a dual population of small and large lymphoblasts. Cytogenetic analysis supplemented with fluorescence in-situ hybridization (FISH) studies localized near-haploidy and hyperdiploidy to the small and large blast population respectively. DNA ploidy determination confirmed two abnormal clones with near-haploidy as the predominant one. A novel t(9;12)(q11;q13) was present in the near-haploid clone and was duplicated in the hyperdiploid clone. This finding identified cells bearing near-haploidy to be the clonogenic population following malignant transformation and confirmed endoreduplication as the mechanism for the presence of associated hyperdiploidy. 相似文献
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