Federation proceedings最新文献_第5页

Age and aerobic power: the rate of change in men and women. 年龄和有氧能力:男性和女性的变化率。

Federation proceedings Pub Date : 1987-04-01

E R Buskirk, J L Hodgson

引用次数: 0

Photoprotection by carotenoids. 类胡萝卜素的光保护作用。

Federation proceedings Pub Date : 1987-04-01

M M Mathews-Roth

引用次数: 0

New approaches for the analysis of mast cell maturation, heterogeneity, and function. 肥大细胞成熟、异质性和功能分析的新方法。

Federation proceedings Pub Date : 1987-04-01

S J Galli

引用次数: 0

Photodegradation of riboflavin in neonates. 新生儿核黄素的光降解。

Federation proceedings Pub Date : 1987-04-01

T R Sisson

{"title":"Photodegradation of riboflavin in neonates.","authors":"T R Sisson","doi":"","DOIUrl":"","url":null,"abstract":"The biologically most important flavins are riboflavin and its related nucleotides, all highly sensitive to light. It is because of its photoreactivity and its presence in almost all body fluids and tissues that riboflavin assumes importance in phototherapy of neonatal jaundice. The absorption maxima of both bilirubin and riboflavin in the body are nearly identical: 445-450 (447) nm. In consequence, blue visible light will cause photoisomerization of bilirubin accompanied by photodegradation of riboflavin. This results in diminished erythrocyte glutathione reductase, which indicates generalized tissue riboflavin deficiency and red cell lysis. Single- and double-strand breaks in intracellular DNA have occurred with phototherapy. This light exposure of neonates may result also in alterations of bilirubin-albumin binding in the presence of both riboflavin and theophylline (the latter frequently given to prevent neonatal apnea). Many newborns, especially if premature, have low stores of riboflavin at birth. The absorptive capacity of premature infants for enteral riboflavin is likewise reduced. Consequently, inherently low stores and low intake of riboflavin plus phototherapy for neonatal jaundice will cause a deficiency of riboflavin at a critical period for the newborn. Supplementation to those infants most likely to develop riboflavin deficiency is useful, but dosage, time, and mode of administration to infants undergoing phototherapy must be carefully adjusted to avoid unwanted side effects.","PeriodicalId":12183,"journal":{"name":"Federation proceedings","volume":"46 5","pages":"1883-5"},"PeriodicalIF":0.0,"publicationDate":"1987-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14679268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Diet and alcohol effects on the manifestation of hepatic porphyrias. 饮食和酒精对肝性卟啉症表现的影响。

Federation proceedings Pub Date : 1987-04-01

D J Cripps

{"title":"Diet and alcohol effects on the manifestation of hepatic porphyrias.","authors":"D J Cripps","doi":"","DOIUrl":"","url":null,"abstract":"Porphyria cutanea tarda (PCT) is the most frequently reported type of porphyria. The average patient is male more than 40 years old with a history of alcohol consumption. In women the incidence of PCT has increased with use of estrogens for birth control. The cutaneous features are those of chronic porphyrin photosensitivity on the light-exposed area of the skin: pigmentation, hirsuitism and fragility, and vesiculobullae, which has prompted the expression bullosa actinica et mechanica. One-third of the patients have glucose intolerance. PCT has been reported frequently among the Bantu people in South Africa as resulting from combinations of alcohol and cooking in ironware. The average patient has a higher than normal hematocrit, which is used as a guide to treatment by phlebotomy ranging from 8 to 14 units removed every 2-4 wk. Chemically induced PCT has been reported with chlorinated hydrocarbons, the best-known of which is hexachlorobenzene (HCB). Porphyria was noted in more than 3,000 patients in southeast Turkey between 1955 and 1961, because of consumption of seed wheat treated with HCB. In addition, more than 1,000 children under the age of 1 year died because HCB was transferred from the mother, either via the placenta or through breast milk.","PeriodicalId":12183,"journal":{"name":"Federation proceedings","volume":"46 5","pages":"1894-900"},"PeriodicalIF":0.0,"publicationDate":"1987-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14679271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Estrogen carcinogenesis in Syrian hamster tissues: role of metabolism. 雌激素在叙利亚仓鼠组织中的致癌作用:代谢的作用。

Federation proceedings Pub Date : 1987-04-01

J J Li, S A Li

{"title":"Estrogen carcinogenesis in Syrian hamster tissues: role of metabolism.","authors":"J J Li, S A Li","doi":"","DOIUrl":"","url":null,"abstract":"Evidence for a role of estrogen metabolism in hormonal carcinogenesis was obtained with the Syrian hamster as an in vivo model system. Both natural and synthetic estrogens are capable of inducing a high incidence of renal carcinomas in this species. A high incidence of hepatocellular carcinomas can also be induced in the hamster with synthetic estrogens such as ethinyl estradiol or diethylstilbestrol, provided alpha-naphthoflavone (ANF) is present in the diet. Although steroid receptor-mediated hormonal events appear to be intimately involved in the process of in vivo cell transformation of both tissues, certain observations strongly suggest that nonhormonal events are also important. Despite their potent estrogenic activity at the doses used, ethinyl estradiol and alpha-zearalanol induce relatively low renal tumor incidences after 9.0 and 10.0 months of continuous treatment, respectively. A role for the metabolism of estrogens to reactive intermediates is also suggested by studies showing estrogen-induced renal tumorigenesis can be partially inhibited by concomitant administration of ANF or ascorbic acid. Consistent with this is the general correlation between the amount of catechol estrogen formed by a compound, as mediated by estrogen 2-/4-hydroxylase, and renal carcinogenicity data. Recently, additional supporting evidence has been obtained from studies involving the irreversible binding of reactive metabolites of steroidal or stilbene estrogens to hamster liver microsomal proteins.","PeriodicalId":12183,"journal":{"name":"Federation proceedings","volume":"46 5","pages":"1858-63"},"PeriodicalIF":0.0,"publicationDate":"1987-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14163828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cardiovascular adaptations to exercise training in the elderly. 老年人心血管对运动训练的适应。

Federation proceedings Pub Date : 1987-04-01

A A Ehsani

{"title":"Cardiovascular adaptations to exercise training in the elderly.","authors":"A A Ehsani","doi":"","DOIUrl":"","url":null,"abstract":"Maximal O2 uptake (VO2max) and left ventricular function decrease with age. Endurance exercise training of sufficient intensity, frequency, and duration increases VO2max in the elderly. The mechanisms underlying the increased VO2max in the elderly are enhanced O2 extraction of trained muscle during maximal exercise leading to a wider arteriovenous O2 difference, and higher cardiac output in the trained state. However, increased cardiac output during true maximal exercise has not been documented in elderly subjects. Endurance exercise training results in a lower heart rate and rate pressure product during submaximal exercise at a given intensity. However, no improvement in left ventricular function has been reported in the elderly after exercise training. Highly trained master athletes exhibit proportional increases in the left ventricular end-diastolic dimension and wall thickness suggestive of volume-overload hypertrophy compared with age-matched sedentary controls. The magnitude of left ventricular enlargement is similar to that in young athletes. The failure of exercise training to alter the age-related deterioration of left ventricular function in the elderly may reflect an insufficient training stimulus rather than the inability of the heart to adapt to training in elderly subjects.","PeriodicalId":12183,"journal":{"name":"Federation proceedings","volume":"46 5","pages":"1840-3"},"PeriodicalIF":0.0,"publicationDate":"1987-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14678634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of exercise on longevity of rats. 运动对大鼠寿命的影响。

Federation proceedings Pub Date : 1987-04-01

J O Holloszy, E K Smith

引用次数: 0

Metabolic activation of pesticides with proestrogenic activity. 具有促雌激素活性农药的代谢激活。

Federation proceedings Pub Date : 1987-04-01

D Kupfer, W H Bulger

{"title":"Metabolic activation of pesticides with proestrogenic activity.","authors":"D Kupfer, W H Bulger","doi":"","DOIUrl":"","url":null,"abstract":"The role of metabolism in the estrogenic activity of chlorinated hydrocarbon pesticides was examined. Whether the estrogenic activity in technical grade preparations of the pesticide methoxychlor is due to methoxychlor or to contaminants was also investigated. Identified compounds in technical methoxychlor were examined by an in vitro method to determine whether they are estrogens or proestrogens. This method showed that purified methoxychlor and MDDE, an olefinic derivative of methoxychlor, are proestrogens and that monohydroxymethoxychlor and monohydroxy-MDDE are estrogens. Thus, the estrogenic activity in technical methoxychlor is due to both methoxychlor and contaminants. MDDE is an in vivo metabolite of methoxychlor, and the mono- and bishydroxy derivatives of methoxychlor and MDDE are metabolites of methoxychlor and MDDE, respectively. These metabolites exhibited in vitro estrogenic activity in the following order of potency: bis-OH-MDDE greater than bis-OH-methoxychlor greater than mono-OH-MDDE greater than mono-OH-methoxychlor. A similar order of potency was observed in vivo, demonstrating that metabolites of methoxychlor are potent estrogens. In addition to phenolic products, hepatic monooxygenases metabolize methoxychlor and MDDE to reactive intermediates that bind covalently to microsomal proteins. Further studies are needed to determine the factors controlling the two pathways of methoxychlor metabolism and determine whether covalent binding is associated with cellular and organ toxicity.","PeriodicalId":12183,"journal":{"name":"Federation proceedings","volume":"46 5","pages":"1864-9"},"PeriodicalIF":0.0,"publicationDate":"1987-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14678638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Genetically mast cell-deficient W/Wv mice as a tool for studies of differentiation and function of mast cells. 遗传肥大细胞缺陷小鼠作为肥大细胞分化和功能研究的工具。

Federation proceedings Pub Date : 1987-04-01

T Nakano, Y Kanakura, T Nakahata, H Matsuda, Y Kitamura

{"title":"Genetically mast cell-deficient W/Wv mice as a tool for studies of differentiation and function of mast cells.","authors":"T Nakano, Y Kanakura, T Nakahata, H Matsuda, Y Kitamura","doi":"","DOIUrl":"","url":null,"abstract":"Genetically mast cell-deficient W/Wv mice are useful for the analysis of mast cell biology, especially as recipients of bone marrow cells and skin pieces. Inasmuch as suspension and clonal cultures of mast cells have been developed, we combined these in vivo and in vitro systems. Suspension-cultured mast cells had morphological and biochemical characteristics similar to those of mucosal mast cells (MMC). However, i.p. injection of such cultured mast cells gave rise to development of cells with characteristics similar to those of connective tissue mast cells (CTMC). When peritoneal cells of normal +/+ mice were cultured in methylcellulose, pure mast cell colonies appeared. Cells from individual mast cell colonies were divided and injected into the skin and stomach wall of W/Wv mice; CTMC developed in the skin and MMC in the stomach mucosa. This indicates the presence of a common precursor for CTMC and MMC. Morphology of such bipotent mast cell precursors was studied by using micromanipulation. About 4% of morphologically identifiable peritoneal mast cells may function as the bipotent precursors. Although W/Wv mice showed a defect in resistance against ixodid ticks, injection of suspension-cultured mast cells normalized the defect. The four examples mentioned above indicate that combinations of in vivo and in vitro systems increase the usefulness of W/Wv mice.","PeriodicalId":12183,"journal":{"name":"Federation proceedings","volume":"46 5","pages":"1920-3"},"PeriodicalIF":0.0,"publicationDate":"1987-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14679273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0