ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720301

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

Intracellular glycolytic regulating enzyme activities, pyruvate kinase (PK) and phosphofructokinase (PFK), adenylate kinase (AK), energy charge (Ech), free amino acids (ICAA), and protein synthesis (PS) were measured in polymorphonuclear leukocytes–used as a cell model–in 62 adults and 12 children with chronic renal failure, and 66 normal adults and 21 children as comparison controls. In normal subjects, children had significantly lower enzyme activities and cell amino acid levels but similar Ech and higher PS than adults. ICAA concentrations were significantly higher than plasma amino acid concentrations (PAA) in both groups, and the PAA were not correlated with, nor indicative of, the ICAA concentrations. The variance (R2) in PS could be largely accounted for by a combination (“set”) of six ICAA, as determined by multivariate analysis. The sets differed in children vs adults, suggesting that different proteins were being synthesized. In the uremic patients, reduced PF, PFK, Ech, most ICAAs and PS were indicative of cellular malnutrition. For the uremic adults, the abnormalities in cell metabolism were modified by therapy–nondialyzed uremics being worst, CAPD patients best and approximately normal, and hemodialyzed intermediate. The uremic CAPD children had reduced, PK, PFK, AK, most ICAA, and PS. Ech was increased. Cellular malnutrition in children with chronic renal failure may contribute to their poor growth.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720302

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

The deviations from normal health produced by abnormalities in trace mineral metabolism in patients with renal disease and renal disorders produced by deficiencies or excesses of these trace minerals serve as the focus for this symposium on trace minerals and the kidney. Zinc, the trace mineral of most interest of the nephrologist, and aluminum, the nonessential (toxic) trace element of most interest, are treated in separate reviews. Iron, copper, selenium, and silicon (essential trace elements) and cadmium, lead, mercury, and lithium (nonessential or toxic elements) are covered in this review.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720303

出版商:Routledge    

年代:1989

数据来源: Taylor

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720304

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

Abnormalities of Zn metabolism are well documented in patients with chronic renal disease, especially those with nephrotic disease and uremia. The causes of Zn deficiency in kidney disease are not clear. Decreased dietary Zn intake and intestinal absorption, increased endogenous Zn secretion, and increased urinary Zn excretion (as in the nephrotic syndrome and in renal transplant recipients) all may contribute to altered Zn metabolism. Zn depletion may account for decreased taste, sexual and gonadal dysfunction, hyperprolactinemia, glucose intolerance, hyperlipidemia, growth retardation in children, neuropathy, anemia, abnormalities of neutrophil and lymphocyte function, and delayed wound healing. The benefit of pharmacologic doses of Zn, in the treatment of such manifestations, requires further evaluation under controlled conditions. Before use of Zn routinely for therapeutic purposes in uremic subjects, the cause(s) of abnormal Zn metabolism should be identified.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720305

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

Loss of protein stores, reflected by negative nitrogen balance and accelerated accumulation if nitrogenous breakdown products, is an important factor in the morbidity of chronic renal failure and the high mortality rate of acute renal failure. Low protein intake intensifies the suppressed protein synthesis that results from impaired insulin-stimulated protein anabolism. The metabolic acidosis of uremia contributes to tissue loss, both by increasing muscle protein degradation, and by raising the requirements for essential amino acids. Correcting metabolic acidosis improves the nitrogen balance and reduces tissue wasting. It is important to ensure adequate nutrient intakes, rather than the low protein diet often prescribed to slow loss of renal function.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720306

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

The uremic syndrome is multifactorial, and affects most tissues and organs. Disturbances in protein and amino acid metabolism may play important roles, especially in chronic uremia, either directly or by production of toxic metabolites, with resultant negative nitrogen (N) balance, muscle wasting, reduced protein synthesis, and characteristically abnormal intracellular free amino acid concentrations. There are also grossly abnormal amino acid levels in the plasma of uremic patients, e.g., increases in conjugated amino acids, high levels of several nonessential and low levels of essential amino acids. The ratios of tyrosine/phenylalanine and of valine/glycine are decreased. The low tryptophan levels may contribute to encephalopathy as a result of an imbalance in neurotransmitter synthesis. Citrulline is found in excess; the explanation is unresolved. There are elevated concentrations of the sulfur-containing amino acids: cystine, taurine, cystathionine, and homocysteine. Excess of the latter is implicated in the atherogenesis of renal failure. Disturbed metabolism and interorgan exchange of amino acids in the uremic state explains some of the abnormalities in tissue and plasma concentrations of individual amino acids. Enzymatic defects are involved in the disturbed metabolism of branched chain amino acids (BCAA), with possible antagonism among them, which impairs growth and amino acid utilization. Carbohydrate intolerance, associated with insensitivity of peripheral tissues to insulin and hyperinsulinemia, elicits decreased plasma BCAA. Protein synthesis rates in normal and pathological conditions are more closely related to the intracellular amino acid pool than to plasma amino acid levels. Concentrations of individual amino acids in the plasma pool are poor indicators of their intracellular concentrations. Muscle contains the largest pool of protein and free amino acids in the body. In chronic renal failure patients, the intracellular concentrations of valine, threonine, lysine, and carnosine are low. With low protein diets and in hemodialysis, serine, tyrosine, and taurine often are also low. The low taurine may be related to fatigue and to uremic cardiomyopathies. The commonly used amino acid supplements generally fail to correct the intracellular amino acid deficits. A“New Formula”has been developed to correct these intracellular amino acid abnormalities, and to supplement a low protein diet. It provides more valine than leucine, increased tyrosine and threonine, and less histidine, leucine, isoleucine, lysine, methionine, and phenylalanine than in formulas customarily used for patients with chronic renal failure. It is uncertain whether other ap

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720307

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

One hundred fifty-three men, age 48-96, 86% white, had resided in this Nursing Home for an average of 6.3 years (range 1.3-36) as of August 1984. At that time, we reviewed their medical charts to record the numbers and sites of fractures which had been diagnosed during the preceding 1 to 5 years of Nursing Home residence, the duration of this period depending on the duration of institutionalization. In addition, a clinical database was compiled comprising 70 attributes, including diagnoses, drugs, plasma (serum) chemistries, and measures of hematologic, nutritional, and functional status. Fractures during the studied period of Nursing Home residence had occurred in 24 of 153 men; six residents had experienced two or more fractures. Fracture rates in hip, spine, and wrist were 2564, 366, and 549 per 100,000 patient years, respectively. The total fracture rate, hip fracture rate, and limb fracture rate were five to 11 times higher than in the age-matched general population of white men in the United States; in Rochester, MN; in Dundee, England; in Oxford, England; or in Finland. Univariate statistical analysis showed that the rates for hip fracture or for fracture at any site were significantly associated with 13 attributes: directly with age, plasma somatomedin C, blood urea N, serum creatinine, serum uric acid, serum 25-hydroxyvitamin D (25-OH-D), degree of functional impairment, and chronic urinary tract infection, and inversely with serum 1,25-dihydroxyvitamin D [1,25-(OH)2-D], serum albumin, hematocrit, and hemoglobin. There was not a significant correlation with the number of falls/month which occurred during the 7 months after August 1984. After the effect of age was partialed out, somatomedin C, 25-OH-D, 1,25-(OH)2-D, and the diagnosis of urinary tract infection were still significantly related to the occurrence of fractures. The fact that Nursing Home fracture cases had significantly higher blood urea nitrogen and 25-OH-D, and significantly lower 1,25-(OH)2-D, than their non-fracture counterparts suggests that impaired renal production of the latter vitamin D metabolite contributed to the excessive rate of fractures.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720308

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

Blood pressure was studied in urban and rural samples of the Melanesian and Indian populations of Fiji during a National Cardiovascular Disease and Diabetes Survey in 1980. Mean blood pressures rose with age and tended to be higher in urban than in rural populations, particularly in the middle age range. There was no clear or significant difference between the ethnic groups. When the prevalence of hypertension was studied (using WHO criteria) similar age, geographic and ethnic differences were found. Comparisons with data from 1960 revealed no significant change in mean blood pressures during the 20-year interval. Rural populations were leaner and appeared to consume less salt than did urban groups. There were positive and significant correlations between blood pressure and triceps skinfold thickness in most subgroups.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720309

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

The dietary intake (assessed through dietary history) of 539 apparently healthy, independently living elderly aged 65-79 years, was evaluated in a nationwide random sample. Except for pyridoxine, the intake of vitamins, minerals, and water was adequate according to the Dutch recommended dietary allowances. Fat intake (40 energy%) as well as P/S ratio (0.41) was assessed as being unfavorable, whereas the intake of vitamin B6 was marginal. The prevalence of obesity was higher among the women, while food selection was healthier as reflected in the higher nutrient density than among the men. Food consumption of elderly men (26%) and women (33%) on a dietary regimen was more prudent and nutrient density higher than among the elderly not on a diet. Our results are in accordance with previous food consumption studies among elderly in The Netherlands, but differ substantially from dietary intake figures for American elderly. Although the intake of energy and nutrients was lower among elderly men than among younger men, we conclude that age per se is not an important determinant of dietary intake among Dutch apparently healthy elderly aged 65-79 years.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720310

出版商:Routledge    

年代:1989

数据来源: Taylor