HD is beneficial for enzymatic conversion of some amino-acids in the elderly

Many different causes of abnormal amino acid profile in uremic patients including: inadequate nutritional intake, uremic disturbances in amino acid metabolism, loss or fibrosis of renal tissues, metabolic acidosis and hormonal derangement. Some of these factors; such as metabolic acidosis are particularly corrected with dialytic therapy; but others such as decreased intake or hormonal disturbances may persist or worsen after initiation of dialysis. This study was done to investigate the plasma amino acids profile in uremic elderly patients. The present study was carried out on three matched groups: [G1] on HD, [G2] CRF and a control. A significant uniform decrease of Threonine, Valine and Leucine in both HD and CRF. However, a peculiar situation of significant increase in phenylalanine in HD in comparison to CRF and to control. This is similar to the significant increase of Arginine in HD group in comparison to the others. In contrast, phenylalanine was significantly decreased in CRF in comparison to both HD group and the control. The latter was similar to the decrease of Leucine in CRF in comparison to the other two groups. Hence, Phenylalanine was the only AA that was found to be significantly increased in HD and significantly decreased in CRF in comparison to control. Moreover, only Phenylalanine and Arginine were significantly increased in HD group in contrast to the rest of the essential amino-acids, which showed either decrease or no change. Tyrosine and lysine were significantly lower in pre -dialysis CRF group in comparison to patients on HD and the control. This may imply that HD can correct the deficiency of tyrosine and lysine in uremic patients probably due to less inhibition of phenylalanine hydrorxylase. Inter-conversion of phenylalanine to tyrosine was reported to be impaired in CRF; whereas tyrosine metabolism per se does not seem to be grossly affected by uremia. However; Serine was significantly lower in both groups of uremic patients in the current study compared with the control group, with no significant difference in-between pre -dialysis patients and patients on HD. In conclusion, our study showed that HD may be beneficial in restoring the enzymatic turnover of certain amino-acids including: Phenylalanine hydroxylase to normalize tyrosine plasma level, Arginine synthetase to convert citrulline to Arginine. On the other hand, HD may be injurious to the production of other amino-acids like serine due to complete lost of the renal tissue that is responsible of its production from glycine

Study of renal functional reserve in the elderly

Fifteen elderly subjects with normal renal function and 10 healthy young subjects were tested for renal reserve after infusion of 500 ml of a mixture of amino acids solution [vamin] over 2 hours. The renal reserve was calculated from the difference between maximal creatinine clearance and basal creatinine clearance. As regards the base line GFR, creatinine clearance of the elderly was significantly lower than the young subjects. After amino acids infusion, creatinine clearance increased significantly in both groups. However, there was no significant difference between the 2 groups as regards renal reserve

Subcellular and enzymatic alterations in senescent human jejunal mucosa

This work included 9 elderly males between 60 and 70 years [group A], and 11 males above age of 70 [group B], in addition to 10 young healthy males. The senescent subjects were clinically free from any ailment which could affect the gastrointestinal tract. Jejunal biopsies were taken and subjected to histopathological, and electron microscopic examination, also histochemical study for ATP- ase enzyme. The results showed that all cases of group A and 55% of group B subjects had normal mucosa. The remaining had atrophic villus changes and many significant changes were demonstrated by electron microscopy, including under-development of the glycocalyx, separation of the junctional complex with edema fluids, increased thickness of the basement membrane and infiltration with polymorphs, lymphocytes and plasma cells. The epithelial cells showed also dilatation of the endoplasmic reticulum, dilated mitochondria with disrupted cristae, numerous dense bodies and vaculations as well as shortened and irregular microvilli were demonstrated in two cases. The work demonstrated also decreased ATP-ase activity, particularly in the elderly subjects with villus atrophy and mitochondrial changes. It was suggested that all the above findings may contribute in impairing the jejunal absorption in the elderly

Assessment of bone mass in the elderly

The present study was planned to assess bone mass in elderly. Three groups were included in the study: Group A included 10 elderly males, group B included 10 elderly females, while group C was represented by 5 young males [C1] and 5 young females [C2]. The study depended on two main parameters, radiodensitometric measurement of optical bone density and measurement of fasting urinary hydroxyproline/creatinine ratio as an index of collagen turnover and activity of bone loss. In the present study, serum calcium was significantly reduced in group B, while marked osteopenia among elderly males and females was a constant feature of senescence. Both trabecular and cortical bones showed proportionate bone loss with nearly similar rates. The trabecular bone is not greatly influenced by menopause. Elderly females had an active bone loss proved by significantly high hyp/Cr ratio

Study of heart size in diabetic patients

The study demonstrated an increase in heart size in diabetic patients. No reasonable etiology was accused; however, a myocardial element might be responsible and could not be ruled out. The study represented also a sample and practical noninvasive method for measuring the heart size