X-ray microanalysis of mammalian salivary glands.

X-ray microanalysis was used to study the elemental composition of major salivary glands in rat and man. The elemental composition of the acinar cells is influenced by a variety of factors. Stimulation of fluid secretion by cholinergic, alpha-adrenergic or peptidergic agonists leads to a sustained increase of the Na/K ratio. The elemental composition and ultrastructure of the acinar cells of rat submandibular gland, as well as flow rate and composition of pilocarpinestimulated submandibular saliva are significantly affected by thyroxine, but less by the synthetic glucocorticoid dexamethasone. Hypercalcemia (induced by chronic vitamin D treatment) as well as hypocalcemia (induced by calcitonin) cause accumulation of intracellular mucus in the submandibular acinar cells, with concurrent increase in the cellular calcium concentration, and a significantly decreased flow rate after pilocarpine stimulation. Several animal models have been proposed for the generalized exocrinopathy cystic fibrosis (CF), which may be caused by a defective regulation of chloride transport in epithelial cells. A potential new model is proposed: the chronically furosemide-treated rat, which shows several abnormalities in salivary gland structure and function that parallel the abnormalities found in the human disease. Another experimental model of potential interest in the study of CF is short-term treatment of experimental animals with the adenylate-cyclase inhibitor alloxan.

Anoxic hepatocyte injury: role of reversible changes in elemental content and distribution.

Examination of anoxic isolated hepatocytes by light and electron microscopy indicated that initial morphologic changes were largely localized to the periphery of the cells. This early phase consisted of surface bleb formation but was not accompanied by alterations in parameters of plasma membrane integrity (leakage of cellular enzymes, exclusion of trypan blue). The time course of changes in structure was temporally related to alterations in the elemental distribution and content of various subcellular compartments. These studies, which employed electron probe X-ray microanalysis, demonstrated that rapid increases in the sodium and chlorine content and decreases in the potassium content of the cytoplasm, mitochondria and nucleus occurred, whereas no change in the calcium content of any subcellular compartment was detected. Concurrently, two cellular functions known to be dependent upon ion homeostasis, sodium-dependent taurocholate uptake and mitochondrial respiratory control, became markedly impaired. Reoxygenation within 30 min resulted in the restoration of both elemental distribution and the latter two functions to baseline. These data are consistent with the hypothesis that some early functional changes may be mediated by altered ion homeostasis. In contrast, additional studies indicated that sodium and water fluxes could be dissociated from the appearance of plasma membrane blebs. Thus, this study provides direct evidence that the structural and functional changes of early anoxic hepatocyte injury cannot be explained by a single mechanistic cascade, but apparently involve multiple mechanisms which may not be directly linked.

Nutrient balance studies in the preterm infant: crossover and parallel studies as methods of experimental design.

Crossover and parallel studies were compared as methods of experimental design during nutritional balance studies in the preterm infant. Twelve formula-fed infants (birth weight, 1,362 +/- 125 g, mean SD; gestational age, 32.3 +/- 1.7 weeks) were studied over 2 continuous weeks, "period" being the only obvious difference between the weeks. During each week, growth was determined, and 84-h nutrient balance was performed. Growth was adequate during both weeks. Increased absorption and retention (mg/kg/day and percent) of calcium and copper were noted during the 2nd week. Increased retention (mg/kg/day and percent) of phosphorus and magnesium was noted also, indicating increased nutrient assimilation due to a period effect. However, the variance due to the period effect (crossover) was less than that associated with "patient characteristics" (parallel study). In addition, sample size requirements were less, indicating that crossover studies are more efficient than parallel studies as a method of experimental design.

Electron probe X-ray microanalysis of the composition of hyaline articular and non-articular cartilage in young and aged rats.

Blocks of articular cartilage were taken from tibiae of young adult (8 week) and aged adult (50-60 week) rats; xiphisternal cartilage was obtained from young adult rats. Specimens were quench-frozen in nitrogen slush, freeze-fractured and examined by low-temperature scanning electron microscopy. The results of X-ray microanalysis of frozen-hydrated bulk cartilage are semi-quantitative. The composition of chondrocyte nuclei and cytoplasm are only marginally different. Xiphisternal chondrocytes contain lipid inclusions which show an absence of element peaks and are designated as being neutral lipid. Intra- and extracellular Na, P, S, Cl, K and Ca count rates are significantly different. Cartilage from older rats contains more S and Ca, and less K and Cl in the intercellular matrix than that from young rats. Intracellular K levels are lower in aged than in young rats. The intercellular matrix of xiphisternal cartilage contains larger amounts of S, Na and K, and a smaller amount of Cl compared to that of tibial articular cartilage.

Body composition in malignant disease.

It has been suggested that adaptation to starvation may be impaired in patients with malignant disease and that this may contribute to the development of cancer cachexia. We have investigated this by comparing the body composition, as well as the tissue composition of weight loss, of a group of 49 patients with gastrointestinal carcinomas and 91 patients with benign gastrointestinal disease all of whom had sustained a weight loss greater than 10% of their recalled pre-illness weight. Total body protein was calculated from total body nitrogen measured by in vivo neutron activation analysis which also provided absolute values of sodium, chlorine, phosphorus, and calcium. The masses of muscle and nonmuscle protein were estimated using a validated compartmental analysis. Total body fat was derived using anthropometry. Total body water was estimated from the difference between body weight and the sum of body protein, fat, and minerals. The loss of body weight incurred by patients with both benign and malignant disease was primarily muscle mass and body fat. Both groups of patients retained nonmuscle protein. All patients manifested, with increasing weight loss, a progressive loss of muscle protein, fat, and water, which must represent the tissue composition of weight loss. No significant differences between patients with benign or malignant disease were demonstrated for any of the body composition parameters measured. The results of this study do not support the hypothesis that adaptation to starvation in patients with cancer is in anyway different from that which occurs in patients with benign disease.

X-ray microanalysis of resting and stimulated rat pancreas.

The elemental distribution in acinar cells of rat pancreas was investigated by X-ray microanalysis of thin, freeze-dried cryosections. In the resting cell, the highest calcium concentrations were found in the basal part of the cell (including the endoplasmic reticulum) and in the zymogen granules. Mitochondrial calcium concentrations were low. Zymogen granules were rich in sulphur, but low in phosphorus, sodium and potassium. Stimulation of the pancreas by perfusion in vivo with the cholinergic agonist carbachol caused a significant decrease of the calcium concentration in the basal part of the cell and an increase in the calcium concentration in the apical part of the cell. The mitochondrial calcium concentration was not significantly altered. In addition, increased sodium and decreased potassium concentrations, giving rise to a significant increase in Na/K ratio were observed in all cell compartments measured, except in the zymogen granules.

Cadmium, copper and zinc-binding protein (metallothionein) in the liver of the water lizard Triturus pyrrhogaster.

A low-Mr copper (Cu) and zinc (Zn)-binding protein was present in the liver of a control water lizard Triturus pyrrhogaster. Cadmium (Cd) accumulated in the liver of the animals after intramuscular injections of Cd salt and was bound to Cu- and Zn-binding protein of a single isoform that had properties characteristic of metallothionein (MT). Effects of Cd loading on several essential elements in the liver and kidney were also determined.

[Dietary intake and urinary excretion of various mineral substances in patients with hypertension and ischemic heart disease]. / O prieme s pishchei i vydelenii s mochoi nekotorykh mineral'nykh veshchestv u bol'nykh gipertonicheskoi bolezn'iu i ishemicheskoi bolezn'iu serdtsa.

A total of 150 inpatients were examined for the content of mineral substances (sodium, potassium, calcium, magnesium) in the blood, daily diet and daily urine. In normal subjects, intake of liquid and the elements was found to slightly exceed their excretion with urine. In patients with stage IIA essential hypertension and circulatory failure, stage I-II, the excretion of the elements exceeded their intake, which was likely to be associated with intake of diuretics. In patients with coronary heart disease, potassium was eliminated in a greater amount and calcium in a less amount as compared with the amounts supplied with the diet. The most demonstrable retention of sodium was recorded in patients with stage III essential hypertension. These patients showed a certain elevation of sodium concentration and potassium lessening in red cells. In making up the diets for patients, it is desirable to consider the pattern of changes in the ratio of the amount of mineral substances supplied with food and excreted with urine, plasma and red cell concentrations of sodium and potassium (which are mainly excreted by the kidneys), as well as those of calcium and magnesium, but with a certain reservation, since the latter ones are excreted from the body via the gastrointestinal tract.

Nutrient bioavailability from nasojejunally administered enteral formulas: comparison to solid food.

The net absorption and retention of energy, fat, nitrogen, and six elements (potassium, phosphorus, calcium, magnesium, sodium, and chloride) from two intrajejunally infused enteral formulas were compared to solid food. Undernourished patients (group 1) underwent two consecutive 7-day balance studies on a predigested protein-low fat (elemental) formula and an intact protein-standard fat (polymeric) formula, the initial diet selected randomly. Periods were isocaloric and isonitrogenous, but differed in the amounts of remaining elements. The undernourished patients in group 2 ate a solid food standard hospital diet for the 7-day balance study in an amount equal in energy and protein to group 1. There were no major differences in the nutrient absorption between the three diets. Nitrogen balance was similar for the two formulas (mean +/- SD) (elemental 6.1 +/- 3.5 g/day; polymeric 4.8 +/- 3.2 g/day) and solid food (5.2 +/- 3.5 g/day), and the balance for the six remaining elements was approximately proportional to the amount supplied. Subjective tolerance of both formulas was good, with a tendency for superior tolerance of the polymeric formula. We conclude that for the nutrients investigated, 1) intrajejunally administered enteral formulas are capable of renourishing hospitalized patients with an efficacy similar to that of solid food, and 2) predigestion of the formula does not improve absorption.

Availability of macro and microelements from edible domestic waste fed to sheep.

Young Awassi rams fitted with rumen cannula and T-shaped cannulas in duodenum and terminal ileum were used to study net absorption of calcium, phosphorus, magnesium, zinc, manganese, and copper from edible domestic waste in comparison with a conventional concentrate diet. Mean net absorptions (% of intake) of calcium, phosphorus, and magnesium from edible domestic waste and control diets were 15.3, -.9; 54.4, 37.0; and 46.4, 58.8. The small intestine was the major site for calcium and phosphorus absorption and the rumen for absorption of magnesium. Net absorption of zinc, manganese, and copper was low in both diets, probably as a result of excessive supply and low physiological demands. There was a net gain of manganese and copper and a net loss of zinc in the stomachs. In addition to potential for energy and protein, edible domestic waste supplies macro and microelements for ruminants, and thus, it can be regarded as a complete concentrate diet.

Effect of age and sex on the composition of muscle and skin from a commercial broiler strain.

The effects of age and sex have been studied on the proximate composition and inorganic constituents in breast, thigh, drumstick and skin from a commercial British broiler strain (Ross 1). Protein content generally increased with age in all muscles and decreased in skin. Protein content in skin of males was always higher than that in females. Moisture content in all muscles decreased with age. In the skin, moisture decreased with age considerably more in females than in males. Fat content increased with age in all tissues, while ash content of breast, thigh and skin decreased with age. Phosphorus, chloride, magnesium and potassium all decreased with age in all the tissues. Thigh and skin calcium content were affected by age, as was the sodium content of drumstick and skin. The sex effect on the inorganic constituents was variable.

Intracellular calcium store and transport of elements in acinar cells of the salivary gland determined by electron probe X-ray microanalysis.

Electron probe X-ray microanalysis using freshly frozen hydrated and dried thin sections of dog submandibular gland was performed to determine the distribution of elements and water in the acinar cells of resting and stimulating states. The results obtained are as follows: (a) The secretory granules contained high concentrations of Ca and S while high concentrations of K and P were present in the cytoplasm and/or nucleus of acinar mucous cells of the gland in the resting state. (b) With pilocarpine stimulation, the concentration of Ca increased in the cytoplasm and decreased in the secretory granules, while there was an increase in the concentration of Na and Cl in both the cytoplasm and secretory granules of the cells. (c) The local dry-mass fractions of acinar cells, estimated by comparing the continuum radiation of X-ray spectrum from the frozen hydrated sections with that from the frozen dehydrated sections, were approximately 20 and 33% in the cytoplasm and secretory granules of resting acinar cells, respectively, and each value was not significantly altered under conditions of stimulation having a tendency to decrease slightly. Therefore, the passive Na and Cl influx and the cytoplasmic Ca flowed in from extracellular spaces and released from secretory granules, an intracellular calcium store, by secretory stimulation probably triggers the passive or active Na and Cl extrusion and consequently the osmotic water flux from the basal part of acinar cells to the secretory granules and the lumen, as well as the serial exocytosis of the granules in the luminal side of the acinar cells.

Metabolic balance studies and dietary protein requirements in patients undergoing continuous ambulatory peritoneal dialysis.

Balance studies for nitrogen, potassium, magnesium, phosphorus, and calcium were carried out in eight men undergoing continuous ambulatory peritoneal dialysis (CAPD) to determine dietary protein requirements and mineral balances. Patients were fed high energy diets for 14 to 33 days which provided either 0.98 (seven studies) or 1.44 g (six studies) of primarily high biological value protein/kg body wt/day. Mean nitrogen balance was neutral with the lower protein diet (+0.35 +/- 0.83 SEM g/day) and strongly positive with the higher protein diet (+2.94 +/- 0.54 g/day). With the higher protein diet the balances for potassium, magnesium, and phosphorus were strikingly positive, there was an increase in body weight in all patients, and a rise in mid-arm muscle circumference in five of the six patients. The relation between protein intake and nitrogen balance suggests that the daily protein requirement for clinically stable CAPD patients should be at least 1.1 g/kg/day; to account for variability among subjects 1.2 to 1.3 g protein/kg/day is probably preferable. Potassium balance correlated directly with nitrogen balance (r = 0.81). High fecal potassium losses (19 +/- 1.2 mEq/day) in all patients probably helped maintain normal serum potassium concentrations. Mean serum magnesium was increased (3.1 +/- 0.1 mg/dl), and magnesium balances were positive suggesting that the dialysate magnesium of 1.85 mg/dl is excessive. The net gain of calcium from dialysate was 84 +/- 18 mg/day; this correlated inversely with serum calcium levels (r = -0.90).

Whole body calcium deficit in cadmium-exposed workers with hypercalciuria.

Whole body elemental composition of 15 men occupationally exposed to cadmium was determined by total body in vivo neutron activation analysis and whole body counting. A significant deficit (P less than 0.01) in calcium was observed, compared with two groups of control subjects. The deficit increased with length of time exposed to cadmium.

Element and polychlorinated biphenyl deposition and effects in sheep fed cabbage grown on municipal sewage sludge.

Sheep were fed a diet containing 30 per cent (dry weight) cabbage which had been grown on municipal sewage sludge from Syracuse, NY for 77 days. Slight increases were found in the concnetration of nickel in kidney, copper in liver and cadmium in certain animal organs as compared to those in sheep fed a control ration containing cabbage grown on soil. Polychlorinated biphenyls were also found at higher levels in the sludge-grown cabbage and in the livers of the respectively fed sheep as compared to controls. An increase in liver weight, proliferation of hepatic smooth endoplasmic reticulum and various degenerative changes were noted in the livers of the sheep fed the sludge-grown cabbage ration as compared to the controls.