Felicia Stern

Energy restriction controls aging through neuroendocrine signal transduction.

Since the work of McCay in 1935, demonstrating the effect of energy restricted diet on the lifespan of rats, many studies have confirmed these findings in different species. Several mechanisms have been suggested, including among others, growth retardation, diminished apoptosis, decreased oxidative damage, altered glucose utilization, changes in gene expression, enhanced stress responsiveness and hormesis. There is some evidence that energy restriction (ER) exerts important metabolic effects on the aging process and longevity through intra- and intercellular signal transduction transmitters, with several signaling pathways mediating its beneficial action.

Hyperhomocysteinemia and vitamin score: correlations with silent brain ischemic lesions and brain atrophy.

Elevated fasting plasma total homocysteine concentration (tHcy) and lower vitamin status are associated with atherosclerotic states. Silent brain ischemic lesions and brain atrophy, prevailing in the elderly, are affected by tHcy and vitamin status. The study was performed on 56 outpatients who had undergone brain computed tomography (CT) before the onset of the study. According to brain CT evaluation, three groups were set: minor brain ischemia, brain atrophy and control. Brain CT, tHcy, plasma pyridoxal phosphate (PLP), vitamin B12, folic acid and cognitive and functional capacities were measured or evaluated in all of the subjects. Plasma vitamin score for three vitamins was calculated. In subjects with minor brain ischemic lesions (n = 21), tHcy was higher by 5.6 µM, whereas vitamin score and cognitive function were lower than in controls (n = 24). In subjects with brain atrophy (n = 11), plasma PLP and cognitive function were lower. Particular attention should be paid to tHcy monitoring, vitamin status assessment and brain impairment evaluation.

Macronutrient consumption and nutritional status in a selected well-established group of elderly people in a home for the aged in Israel.

OBJECTIVE To evaluate the distribution pattern of the main macronutrients (protein, fat, carbohydrates) and fiber in a selected well-established group of elderly people, average age above 80 years. METHOD Dietary consumption was evaluated in a well-established group of 21 elderly people in a home for the aged by in-person interview using a food frequency questionnaire. RESULTS Daily energy intake was 1.87 Mcal (7.8 MJ) or 29.3 kcal/kg body weight, a value which lies within the range of 1.6 to 2.0 Mcal or 25 to 30 kcal/kg, found in 12 other studies conducted on elderly people. The average percentage of energy derived from macronutrients (with an individual range) was: protein 17.5 (13-22); fat 32.9 (25-44); and carbohydrates 49.6 (35-61). Fiber intake was 8.6 g/Mcal, lower than that found in three other studies. Positive coefficients of correlation were found between protein intake and the following parameters: serum urea (r = 0.28), cholesterol (r = 0.48) and DBP (r = 0.43). CONCLUSIONS In our small group of elderly, energy derived from protein was higher than that in most of other studies reviewed, and that from fat was higher than in half of those studies. These values were remarkably higher than the suggested values. Energy derived from carbohydrates was close to that found in other studies. Monitoring of dietary macronutrients might improve the nutritional and the physiological status of the elderly.

Pellagra complicating Crohn's disease

A 20-year-old woman had a 6-month history of an apparent photosensitivity eruption that was refractory to topical steroid treatment. The patient had had Crohns disease since 11 years of age with intermittent exacerbations. Examination revealed mildly erythematous plaques with thin atrophic wrinkling and fine scale on the bridge of the nose, both sides of the mouth, sides of the neck, extensor aspects of the forearms and shins, and on the dorsal aspects of the hands and feet. They were sharply demarcated by a dark-brown, hyperpigmented zone. Abdominal examination disclosed hyperactive peristalsis. The neurologic examination revealed mild disturbances in immediate and midterm memory. Barium meal and follow-through x-ray revealed extensive involvement of the small intestine with many stenotic segments. A biopsy specimen taken from the rim of a plaque on the left arm showed psoriasiform epidermal hyperplasia, spongiosis, parakeratosis, and a few neutrophils in the stratum corneum. Laboratory tests showed low serum levels of iron (41 #g/d0, zinc (65 #g/d1), carotene (32 gg/dl), folate (2.6 ng/ml), a low serum iron binding capacity (141 #g/dl), and a high fecal fat excretion (9.3 gin/day). Levels of vitamin Btz, magnesium, copper, as well as coagulation function tests and repeated urine samples for porphyrins and amino acids were all normal or negative. The patient was treated with nicotinic acid, B complex, and an adequate nutritional dietary regimen; prompt cutaneous and neurologic improvement was noted.

Turnover of short-lived proteins in chick leukocytes following dietary treatments

The effect of protein intake (10 vs. 20%) on synthesis and degradation of short-lived leukocyte proteins in vitro was shown in 21-day-old chicks. Protein synthesis was measured for 1 or 2 h and protein degradation for 1.5 or 4 h following an 8-day dietary treatment. Leukocyte proteins were fractionated on a slab gel into 11 or 100 fractions, and the imaging radioactivity was calculated for protein synthesis and degradation. The degradation rates in most of the protein fractions were higher in the leukocytes of chicks fed 20% dietary protein than in those fed 10% protein. Protein fractions of M(r) approximately 25-37 kD exhibited the most marked differences between the two dietary treatments. This technique of measuring turnover rates of short-lived proteins in leukocytes could potentially be used to examine the effect of nutritional treatments in animals and man as well as to check the effect of catabolic conditions in humans on protein turnover.