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Biomedical subjects

D A Lipschitz

Publications and source records attributed to D A Lipschitz.

At least 91 records · Page 5Linked to original sources
PubMed1980

The clinical significance of ferritinuria.

Urinary ferritin levels were measured by a "2-site" immunoradiometric assay in normal volunteers and in patients with various hematologic disorders. The mean urinary ferritin concentration in normal subjects averaged 2.2 microgram/liter, only 3% of the serum ferritin level. Elevated urinary ferritin levels averaging 45 microgram/liter were observed in patients with hematologic malignancies, but there was a proportional increase in serum ferritin so that the urinary level still averaged only 7% of the serum value. The highest urinary ferritin values (mean 170 microgram/liter) were associated with chronic hemolytic anemia, and in these patients, urinary ferritin rose disproportionately in relation to the serum, averaging 82% of it. This higher urinary level apparently reflects increased ferritin in renal tubular cells due to glomerular filtration of unbound hemoglobin, a mechanism that is supported by a highly significant correlation between urinary ferritin and serum haptoglobin levels. In normal subjects and in patients with malignancy, the source of urinary ferritin appears different, since a highly significant correlation was observed between urinary ferritin and reticuloendothelial iron stores as measured by serum ferritin or total iron-binding capacity. In this setting, the most likely source of urinary ferritin is the iron contained in renal tubular cells, which is apparently in equilibrium with body iron stores.

Adult↗
PubMed1979

Absorption of monoferric phytate by dogs.

Recent studies have shown that the iron in wheat is predominantly in the form of monoferric phytate (MFP). Unlike phytate complexed with two or more iron atoms, MFP is soluble at pH 7.0 and above and may therefore be a relatively available form of dietary iron. To examine this point, we tested iron absorption in adult dogs using a double radioisotope method and total body counting. When given without food, MFP was about one-half as available as ferrous sulphate at an iron-equivalent dose of 1.5 mg and only about one-seventh as available at a dose of 15 mg iron. When administered with food, MFP underwent complete isotopic exchange with the nonheme pool of dietary iron. When added to meals of either high or low iron availability in amounts that might be used for iron fortification, the absorption was the same for MFP iron as for the major pool of dietary inorganic iron.

Animals↗
PubMed1975

Ferritin in formed blood elements (38539).

The ferritin concentration of the formed elements of the blood has been measured. Nearly equal amounts were found in plasma, red cells, granulocytes, and in the mononuclear (monocyte and lymphocyte) cell fraction. Platelets contained a negligible amount. Concentrations of ferritin were greatest in blood leukocytes, amounting to approximately 24 mug/ml. Changes occurring with iron depletion and iron overload were consistent with those expected in body tissues in general. With infection, increased levels of ferritin were observed in the mononuclear cell fraction, consistent with that which occurs in RE cells.

Adolescent↗
PubMed1975

Relationship of maternal and infant iron stores as assessed by determination of plasma ferritin.

Using plasma ferritin derminations, iron stores have been evaluated at the end of pregnancy in 26 women and followed sequentially in their healthy, full-term infants. It has been shown that the iron storage status of the mother does not affect the iron status of the infant. Determinations of plasma ferritin in the infants have demonstrated that by 6 months of age the iron status of the infant reflects the adequacy of the dietary intake of iron. In the absence of effective iron supplementation during the first six months, plasma ferritin levels fall to low levels, indicating the depletion of iron stores in the infant.

Adult↗
PubMedDate not supplied

Effect of age on the fatty acid composition of phospholipids in human lymphocytes.

We have examined the fatty acid composition of phospholipids of unstimulated and PHA-stimulated T cells from young and old donors. Our results demonstrate that aging is accompanied by decreases in the saturated fatty acids, myristic acid, and palmitic acid, and a concomitant increase in the unsaturated arachidonic acid. Following activation with PHA for 24 h, age-associated differences in fatty acids could no longer be detected. In contrast to the lymphocyte, aging did not affect the fatty acid composition of either serum or neutrophil phospholipids. Exposure of lymphocytes from old donors to myristic acid complexed medium increased the levels of myristate in the phospholipids to levels similar to that seen in lymphocytes from young donors. We conclude from these studies that aging is accompanied by an alteration in the fatty acid profiles of phospholipids, and that incubation in myristic acid complexed medium modulates these profiles. These alterations are unique to lymphocytes and may contribute to the age-related declines in lymphocyte function.

Adult↗
PubMedDate not supplied

Arm length measurement as an alternative to height in nutritional assessment of the elderly.

The use of long bone measurements as an alternative to height in nutritional assessment of the elderly was investigated in 100 young and 63 aged individuals. Highly significant correlations between height and total arm length, humerus length, forearm length, and proximal phalanx length were found. Compared to young subjects, values for the elderly were shifted significantly, demonstrating a reduction in height not paralleled by decreases in arm length measurements. In subsequent studies, lean body mass was evaluated by creatinine excretion in groups of young and elderly male and female volunteers. In both males and females, when creatinine excretion was related to height, ideal body weight, or total arm length, significantly lower values were found in the elderly as compared to the young. In all groups highly significant correlations between the use of arm length and the other two methods of expressing creatinine excretion were found. This validates the use of arm length measurement as an alternative to height for nutritional assessment. Since arm length is less affected than height by the aging process and more easily obtained in the bedfast patient, it should provide a more accurate reflection of stature when performing nutritional assessments of the elderly. These preliminary data emphasize the need for appropriate standards for subjects of different ages when evaluating lean body mass.

Adult↗
PubMedDate not supplied

Nutritional evaluation and supplementation of elderly subjects participating in a "meals on wheels" program.

A nutritional assessment of 33 elderly subjects participating in a "meals on wheels" program revealed a high prevalence of nutritional deficiencies. Twelve of these subjects, who were considered to be at high risk for protein calorie malnutrition, received 240 ml of a polymeric dietary supplement three times daily for 16 wk. This resulted in a significant (50%) increase in total caloric and protein intake which was maintained for the entire 16 wk of study. In seven of the 12 subjects a weight gain of greater than 2 kg was found. Modest but significant elevations in serum albumin and highly significant elevations of the total iron binding capacity, serum and red cell folate, leukocyte ascorbate, and serum vitamin B12 provided strong evidence for improved nutritional status. In contrast no improvement in the hemoglobin, total lymphocyte count, T cell number, T suppressor cells, T helper, or B cells was noted. In no anergic subjects was skin test conversion found. In addition no increase in serum trace metals or vitamin B6 levels were noted. Thus this study demonstrates that nutritional supplementation results in significant improvement in selected nutritional parameters. The fact that the hematopoietic and immunological status of these patients was unchanged suggest that the abnormalities may be age rather than nutritionally related or that a critical nutritional deficiency was not corrected.

Aged↗