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Am isoliert perfundierten Pankreas der Katze wurde die Wirkung der akuten Erhohung der extrazellularen Calciumkonzentration und des Vitamin D3, des 25-Hydroxycholecalciferols, des Dihydrotachysterins, des Parathormons und des Thyreocalcitonins auf die exokrine Pankreasfunktion untersucht. Bei Erhohung des Perfusatcalciumgehaltes trat initial eine kurzfristige und geringe Proteinausschuttung in den Pankreassaft ein, eine Calciummehrausscheidung wurde nicht regelmasig beobachtet, die hydrokinetische Funktionskomponente anderte sich nicht. Parathormon und insbesondere Thyreocalcitonin hemmten die stimulierte Protein- und Enzymsekretion des Pankreas, Vitamin D3 und 25-Hydroxycholecalciferol steigerten sie leicht. Bei akutem Calciumexzess fuhrte auch Vitamin D3 zu einer Hemmung der stimulierten Proteinsekretion, eine Anderung der Volumen- und Elektrolytausscheidung trat bei keiner Substanz ein. Die Relevanz dieser Befunde fur die Pathogenese der calcifizierenden Pankreatitis bei chronischer Hypercalcamie wurde diskutiert.

An experiment was conducted on 12 cows and 12 buffaloes for six weeks. These animals were further divided into four groups each having three animals. The four treatments were concentrate mixture with green grass (T1), concentrate mixture without green grass (T2), cotton seed with green grass (T3), and cotton seed without green grass (T4). The DCP requirements were met as per Sen and Ray (1971) feeding standards. At the end of each period, metabolism trials were conducted by conventional method. Nitrogen, phosphorous and calcium balance were positive in all the treatments for all the groups of buffaloes and cows. Treatment T1 and T2 have increased the milk yield but resulted in decrease in fat, while reverse was true for treatment T3 and T4.

SUMMARY. Adult Gammarus pulex lose about 42% body calcium into solution over a 2–3-day period preceding the moult. A further 54% body calcium is lost with the exuviae, leaving c. 4% in the newly moulted animal. Nearly all of the body calcium in a stage A (post moult) animal is contained in the hepatopancreas and a transient increase in the calcium content of this tissue is seen in some individuals. The haemolymph calcium compartment is heavily depleted at this stage. In stage B animals the hepatopancreas calcium level has returned to, or even fallen below, the intermoult level while the haemolymph calcium concentration remains lower than in intermoult animals. Animals switch from a strongly negative calcium balance to a state of rapid calcium uptake immediately following moult. Uptake at 10°C proceeds at a rate of between 3 and 10 μmol g−1 h−1 depending on the calcium concentration of the external medium. The lower rate is found in starved animals in 0.1 mM calcium and this concentration is probably close to a minimum for the satisfactory restoration of body calcium. Recalcification is completed in 10–14 days in 0.1 mM calcium and is apparently enhanced by the presence of food in the form of a portion of oak leaf together with the cast exuviae. In 1.0 mM calcium the recalcification period is shortened to 3–4 days. This is considerably longer than the time recorded for French populations of this species (Vincent, 1969), although reasons for this are offered.

Six aspects of newborn physiology–the birth weight gestational relationship, glucose metabolism, temperature regulation, calcium balance, infection, and fluid and electrolyte balance–are presented as examples of important consideration that must be understood to successfully manage the newborn surgical patient.

Summary: Twenty-six low birthweight infants with no differences in the neonatal status were allocated into three groups. Group A (10 infants), Group B (8 infants), and C (8 infants) received formulae with 2.4, 1.6, and 4.1 Calcium/Phosphate (Ca/Pi) ratio respectively. Formula C was supplemented with calcium lactate 800 mg/ kg/day, which yielded 12.7 ± 0.4 mg of Ca and 0.04 ± 0.002 mg of Mg per each 100 mg of salt (mean ± S.D.). The osmolality of the C formula before its administration was 361 ± 52 mOsm/kg. Balances (mean ± S.D.) from the first feeding up to a period of 3 days were obtained. The intestinal product before any feeding contained: Ca, 1.3 ± 0.6 mg/kg; Mg, 2.9 ± 1.5 mg/kg, and Pi, 1.5 ± 2.3 mg/kg. Calcium intake (mg/kg/day) was 89.7 ± 13.8 for formula A, 71.1 ± 12.5 for formula B, and 156.8 ± 19.8 for formula C. Their net retention (mg/kg/day) was 50.8 ± 15.9, 39.3 ± 12.8 (P < 0.05), and 105.2 ± 21.9 (p < 0.001) respectively. Net retention of Pi was comparable in the three groups (A, B and C) ranging 24.7–25.7 mg/kg/day. Small variations in intake are finely compensated by parallel urinary excretion (range 6.3–12.8 mg/kg/day). Magnesium absorption did not show differences among the three formulae. The evolution of plasmatic values for magnesium was fairly normal in the three groups. Phosphatemia was significantly (P < 0.01) lower in group A (lowest Pi containing formula) on the 3rd day. Patients on formula B (smaller Ca content) showed a mean blood calcium of 7.9 mg/dl, which was significantly lower than in the other groups. In two instances, blood calcium was lower than 6.9 mg/dl (Z = 6.32; P < 0.05). Net retention of calcium correlates positively with Ca/Pi ratio (r = 0.82) and with absolute Ca intake (r = 0.84). Calcium lactate supplementation did not modify acid base equilibrium, lactatemia nor digestive tolerance. Speculation: To prevent demineralization in the early postnatal period of preterm babies, the net retention of calcium could be improved more effectively by adding a calcium supplement to the formula rather than by decreasing its Pi content, even though both procedures lead to a comparable Ca/Pi quotient.

Calcium intake has been implicated in the etiology of age-related osteoporosis. There is evidence to suggest that many postmenopausal women consume inadequate calcium to maintain calcium balance. One of the most accurate methods of calculating dietary intake is the weighed food record; however, that method is time consuming and unsuitable for large numbers of individuals. To determine the adequacy of calcium intake in the large numbers of postmenopausal women at risk of osteoporosis, simpler methods of assessing calcium intake are required. We therefore developed a food frequency questionnaire and tested it against a 4-day weighed food record in 54 Caucasian women, between 29 and 72 years of age. Twenty-six of the women (Group 1) completed a 4-day record and questionnaire within 1 week. Another 28 women (Group 2) completed the questionnaire 1 to 12 months after completing the 4-day food diary. A good correlation (r = .79, p less than .001) was found between the two methods of calculating calcium intake for the 54 women. Independent analysis of Group 1 and Group 2 showed correlation coefficients of 0.81 and 0.78, respectively. The correlation for postmenopausal women (r = .84) was similar to that of premenopausal women (r = .79). The data show that a short, simple questionnaire can be used to rank individuals according to adequacy of calcium intake as a prerequisite to nutrition intervention.

SUMMARY During treatment of renal osteodystrophy with lα-hydroxyvitamin D3 in eleven patients, regional changes in the skeleton have been compared with long-term calcium balance as assessed by whole-body calcium. Radial bone changes did not correlate well with calcium balance, but spinal calcium changes were of a similar magnitude when changes were large. Bone alkaline phosphate changes correlated well with changes in spinal calcium, but less well with changes in radial bone density.

The anabolic effect of Formebolone on the retention of nitrogen, phosphorus and calcium in adult male volunteers was evaluated over a period of 21 days. The study was divided into a pre-dosc period to establish baseline data, a period where the drug was given daily followed by a third period after treatment had ceased to investigate whether the effects were in any way prolonged. Formebolone was well tolerated and showed a positive effect on nitrogen balance and bodyweight change in all subjects. The effects on calcium and phosphorus balance were less clear-cut but indicated increased retention of both elements.

1. Chromium sesquioxide (Cr2O3; 1·5 g/day) and [51Cr]chromic chloride [31CrCl3 (0·3 μCi/day)] were compared as continuously administered non-absorbed markers for the correction of faecal recoveries in 14 calcium balance studies each lasting at least 18 days. 2. The mean recoveries of each, 98·4% for Cr2O3 and 101·9% for 51CrCl3, were not significantly different from 100. 3. The two markers reduced the uncertainty in a typical 3 × 6 day calcium balance study to a similar extent (sd = 1·4 mmol/day for Cr2O3 and sd = 1·5 mmol/day for 51CrCl3). 4. 5lCrCl3 is a convenient and satisfactory alternative to Cr2O3 when the laboratory hazards associated with estimating the latter cannot easily be eliminated.

Optimization of a four-crystal stretcher geometry whole-body (WB) counter was performed. The measured geometric characteristic did not differ significantly from the theoretically calculated characteristic (p greater than 0.05). The linearity of the WB counter was high in the range 3.7 kBq to 3.7 MBq. Longtime variability of local background was CV = 3.7 per cent. In vivo sensitivity was calculated to 18 cpm/kBq and the detection limit to about 5 kBq. The reproducibility was estimated to 0.7 per cent. The WB counter was used in 47Ca turnover and calcium balance studies of 15 normal individuals. The data were analysed according to a modification of the expanding calcium pool model using an improved Bauer-Carlsson-Lindquist formulation. Variability and method errors of main parameters for calcium metabolism were evaluated.

Methods for the measurement of calcium in the diet, urine and faeces for the performance of a calcium balance study are described, along with experiments on analytical procedures including recovery values. A means of calculating the inherent “technical error” in such a balance is given, and a method for determining the significance of any change in a patient's balance is described. These are illustrated by worked examples of data from a patient suffering from Paget's disease and one with osteoporosis before and after treatment with calcitonin.

The study was designed to determine the calciuretic effect of furosemide and its impact upon calcium balance during chronic (25 days) furosemide administration to growing rats. Experiments were performed on 18 six-wk-old rats. Nine animals received furosemide, and 9 served as controls. The administration of furosemide in a dose of 40 mg resulted in a significant increase in calcium excretion in the treated group; urinary calcium excretion almost doubled that of the controls during the first 24-hr collection (3.74 +/- 0.44 mg in the treated animals compared with 1.90 +/- 0.15 mg in the controls; P less than 0.05). The average daily urinary calcium excretion during each of four subsequent 6-day periods remained approximately three-fold higher in animals which received furosemide compared with controls (P less than 0.001 for each 6-day period). The furosemide-induced increase in urinary calcium excretion did not diminish with time. Sodium excretion did not significantly increase either acutely or chronically in response to furosemide. Daily urinary volume increased approximately 40 to 60% in the furosemide-treated group compared with that of the controls (P less than 0.001). The cumulative calcium balance in the control group exceeded by 7% that of the furosemide-treated animals [2696.3 +/- 20.8 mg versus 2518.6 +/- 20.1 mg (P less than .001]. The findings indicate that distal nephron compensatory mechanisms effecting sodium conservation following furosemide do not result in similar conservation of calcium. Calcium balance may be deleteriously affected.

The effect of protein intake (47, 95, and 142 g) on calcium retention, calcium absorption, and urinary calcium of 33 young adult males was determined at calcium intakes of 500, 800, and 1400 mg daily. Magnesium intake was 400 (27 subjects) or 490 mg (six subjects). The calcium-to-phosphorus ratio was 1.0 (1400 mg calcium intake), 0.8 (800 mg calcium intake), and 0.6 (500 mg calcium intake). When consuming the 47-g protein intake, the subjects were consistently in calcium balance and the amount of calcium retained was unaffected by the calcium intake. At the 95-g protein intake, none of the subjects were in calcium balance when 500 mg calcium was given, but they did achieve balance when 800 mg was given. When 142-g protein was ingested, no subject was in balance at either the 500- or 800-mg calcium intake and only three of 15 subjects were in balance at the 1400-mg intake. Calcium absorption was not affected by dietary protein at an intake of 500 mg calcium, but significantly more calcium was absorbed at medium or high protein intakes than at low when 800 or 1400 mg calcium was given, the maximal protein effect having been reached at the 95-g protein level. Urinary calcium was significantly affected by protein intake. All subjects, regardless of level of calcium intake, excreted less calcium when given the low protein diet than when given the medium, and all except two subjects excreted less when given the medium than when given the high protein diet.

Net absorption of calcium, calcium balance and bone mineral content were studied in 83 patients with small-bowel resections of various lengths, mainly owing to CIBD, while they were receiving a standardized diet supplying 70 g fat and 800 mg calcium. Median duration of disease was 9 years (range, 5 months to 53 years) and median length of time from resection 3 years (range, 2 months to 18 years). In the whole case material net absorption of calcium ranged from +573 to −268 mg/day; median, +65 mg/day (+56% to −26% of dietary calcium; median, +6%). A weak inverse correlation was found between net absorption of calcium and length of resected small bowel, both in patients with ileostomy (no. = 32, r = −0.43, p < 0.01) and in patients with part of or the whole colon in function (no. = 51, r=−0.34, p < 0.01). Net absorption of calcium and urinary calcium correlated only weakly (no. = 78, r = 0.39, p < 0.001). In all patients studied the median calcium balance was −49 mg/day (range. +447 to −339 mg/day). No diff...

The Hypertension Detection and Follow-up Program was a randomised trial to compare all-cause mortality of patients receiving antihypertensive therapy in special clinics with those referred to the usual sources of care. All-cause mortality was significantly reduced overall, and in the mildest hypertensives, by stepped care. This specificity of the antihypertensive effect was shown by the proportionate lowering of stroke deaths, and the persistence of the mortality effect, when analysed by time-dependent co-variants, which took into account the amount of antihypertensive therapy the patients were receiving. Cardiovascular and coronary heart disease mortality were reduced in stepped care, as judged by death certificates. The benefits of stepped care were still present when analyses were confined to those with baseline ECG abnormalities. The 5-year incidence of angina pectoris and myocardial infarction, as judged by the Rose Questionnaire, was decreased in stepped care. Serum alkaline phosphatase fell in thiazide treated patients, suggesting a favourable influence on calcium balance. Eight-year analyses suggest that the favourable influence on mortality persisted after the end of the program for all except the eldest participants.

The unique interrelationship between excess dietary protein, calcium metabolism, and osteoporosis with its associated ridge resorption has been reviewed. Recommendations for the prevention and management of osteoporosis have been discussed with concern for the calciuretic effect of a high protein diet customarily consumed in American society. Positive calcium balance promoted by the suggested treatment regimen may help to preserve ridge integrity and at the same time prevent the serious debilitating effects of generalized osteoporosis. Further research to evaluate for retardation and possible reversal of osteoporotic ridge resorption as affected by dietary protein intake is warranted.

A large percentage of subjects receiving a normal calcium intake of 800 mg per day was in negative calcium balance and increasing the calcium intake to various levels up to 2200 mg per day showed a plateau of the calcium balance at the 1200 mg per day intake, indicating a threshold of calcium absorption at this intake level. Dietary factors, such as a phosphorus intake up to 2000 mg per day and complex proteins, such as red meat, do not cause calcium loss. Several commonly used drugs induce significant calcium loss, particularly aluminum-containing antacids, and, if used for prolonged periods of time, can contribute to the development of osteoporosis.

We studied the effects of one session of hemofiltration on the mineral metabolism in a group of uremic children. We observed an increase of calcemia, accompained by positive calcium balance, and a decrease of plasma phosphate and PTH-MM. No substantial loss of plasma 25-OH D was found. It is concluded that hemofiltration has a positive effect on calcemia and is very effective in removing phosphate, but it acts only temporarily on PTH removal. An adequate calcium concentration must be provided in the substitution fluid.

In the last 20 years, the biomedical problems facing man in space have been brought into sharper focus. Space motion sickness is presently the most serious problem. Its etiology remains obscure, but the 'sensory conflict' theory appears most plausible. No valid predictive tests of susceptibility exist and presently medication for prevention or mitigation of symptoms must be relied on. Adaptation/biofeedback techniques may prove useful. Cardiovascular 'deconditioning' may be effectively attenuated by use of anti-g suits or plasma expanding techniques. Recent bedrest simulation studies would seem to indicate that concerns about chronically elevated central venous pressure during space flight are unfounded. The loss of red cell mass in space flight appears to be self-limited, independent of mission duration, and not of clinical concern, based on recent Soviet experiences. And finally, clodronate, a new diphosphonate effective in preventing hypercalciuria and negative calcium balance in normal human bedrested subjects, may prove effective in preventing or lessening skeletal mineral loss in space.

The effect of low protein intake from plant sources on calcium excretions and calcium balance of seven young adults was investigated. The diets (four combinations of egg, groundnut and soyabean nitrogen) furnished 43 g protein (0.58 g protein/kg) and 550 mg calcium daily.

SummaryEarlier papers in this series reported discrepancies between observed rates of Ca uptake by apple fruits and the rates calculated on the basis of a simple mass-flow hypothesis. Results from three further types of experiment designed to investigate these differences are presented. Rates of Ca deposition on filter papers suspended in the orchards were not adequate to explain the greater than expected rate of fruit Ca accumulation early in the season. Analyses of Ca distribution between different tissues of fruiting spurs provided no evidence for remobilization of Ca from the woody tissues of the spur as fruits developed. Different concentrations of CaCl2 were either perfused through stem segments or allowed to equilibrate with samples of fruit cortex at different dates during the season. In each case an apparent equilibrium concentration for the perfusing solution could be determined, at which the concentration of Ca did not change with perfusion. The equilibrium concentration was of the same order a...

In a calving area on western Hardangervidda, Norway, shed antlers of female reindeer, Rangifer tarandus tarandus L., have been collected for several years. Many of these antlers have been chewed on by reindeer. In the literature antler chewing has been reported to take place on both shed and unshed antlers. Our observations support these findings. Based on the present observations it is suggested that the antlers may subserve the mineral householding of the animals under special conditions. The female reindeer has to pass through a nutritionally marginal season which often coincides with calving. Bringing the bony antlers to the calving areas seems advantageous in the maintenance of calcium balance. The growth of antlers may therefore be looked upon as part of a mineral saving strategy. The mineral stored in the antler thus represents a reserve to be used during pregnancy and lactation. This is in contrast to the common view that shedding of antlers is just waste of mineral when there is a great need for calcium.

Calcium balance performance was evaluated in 130 normal perimenopausal women ages 35 to 50, studied on their usual, self-selected dietary calcium intakes. Two distinct balance methods were used, one based on customary intake and output measurements, and the other based on absorption and clearance of two simultaneously administered calcium isotopes. Both methods yielded essentially identical results. Under study conditions as closely approximating normal living as possible, these women averaged -24 and -31 mg Ca/day by the two balance methods (exclusive of unmeasured dermal losses). More significantly, there was a positive correlation between intake and balance, with women on higher self-selected intakes exhibiting more positive balance than women selecting lower intakes. The calcium intake predicted from our data which would be required to produce an average balance of zero was 1.241 g/day. This is significantly in excess of the current recommended dietary allowance for calcium. The implications and significance of this discrepancy are explored in detail.

Four Indonesian goats fed Leucaena leucocephala with a calcium to phosphorus ratio in excess of 6:1 for 472 days developed mandibular osteodystrophy fibrosa to varying degrees ranging from severe to slight. The animals appeared to grow normally but the animal with the most severe clinical symptoms lost weight for 35 days prior to the termination of the experiment. The other three animals either maintained or gained weight during this period. A balance study performed part way through the experiment revealed that the animal which subsequently lost weight was probably not storing calcium or phosphorus whereas the other animals had a positive calcium balance and were probably storing small amounts of phosphorus. Histological examination of tissues taken after a post-mortem revealed that the kidney, parathyroid and thyroid glands and long bones were normal.

Distribution of true fractional absorption of calcium in estrogen-deprived, nonos- teoporotic, middle-aged women was examined in 273 person-studies, using a double-tracer method. Fractional absorption averaged 0.266 (±0.096). Calcium intake averaged 0.802 g/day (±0.419) and urine calcium, 0.144 g/day (±0.062). Fractional absorption was inversely correlated with intake. Using parameters ofthe regression equation for the two variables, each absorption value was adjusted to the mean intake ofthe group so that absorption could be evaluated apart from the effect of intake. The distribution of such diet-adjusted values revealed that 55% of these estrogen-deprived women had insufficient absorption to maintain calcium balance at an intake equal to the 1980 RDA. Nearly one-fourth would still be in negative balance at an intake of 1.5 g/day. Since urine calcium was positively correlated with absorbed calcium (r = 0.521), we conclude that defective absorption and not bone breakdown is the basis for low absorptive performance in these women. Am J C/in Nutr l986;43:299-305.

Integumentary calcium loss was studied in 16 healthy young men. The daily loss by the 16 ambulatory but relatively sedentary young men in 52 determinations of 6-day periods each was 8.7 ± 1.9 mgJm2 per day (average 15.8 mg/man per day). The amount lost was not influenced by calcium intake (0. 1 to 2.3 g/day). In contrast to urinary calcium excretion, which is directly related to protein intake, there was no significant change in integumentary calcium loss with varying protein intakes ( I to 96 g nitrogen per day). No compensatory relationship between urinary and integumentary calcium excretion was noted. During strenuous exercise calcium loss increased to an average of 25 mg in 40 mm. There was no compensatory decrease in urinary excretion on the day of strenuous exercise. It was also noted that integumentary calcium loss was not affected by general calcium balance. Am. J. Clin. Nutr. 32: 1699-1702, 1979.

Twelve normal subjects have been studied using calcium balance techniques and47Ca to provide normal reference values for metabolic calcium studies in adult humans. A composite graph of plasma and urinary calcium specific activities is presented at intervals from 0.1 to 300 hours after isotope injection. It is suggested that an adequate representation of this data may be made by means of two power functions, and the practicality of this interpretation is discussed.

The medical treatment of senile cataract has interested ophthalmologists for at least a hundred years. A voluminous literature has accumulated and, in spite of much empiricism in treatment, a few noteworthy observations have been recorded. Aside from a small group of cases in which cataracts develop upon the basis of physical agents, such as intense light and heat, and trauma to the lens or adjacent structures, it is apparent that the common type of cataract is more intimately associated with general bodily disturbances. This disturbance is apparently related to metabolic changes as noted in the juvenile with tetany with probable alterations of the calcium balance, especially noted in endemic goitrogenous regions. Whether the parathyroid or thyroid glands are at fault is not clearly understood. Then we find a group of cases where the changes in the lens, and other structures of the eye, are associated with diabetes and frequently improve as the diabetes is brought under control. By far the largest group o...

Two groups of Single Comb White Leghorn pullets, 4 months of age, were fed 1·85 and 2·70% calcium in the diet, respectively, for twelve consecutive periods, each consisting of 4 weeks.Records of egg production and egg weight were kept throughout the entire experiment for each hen. Calcium balance and egg-shell quality studies were conducted with 16 pullets for 5 consecutive days out of each 28-day period.A highly significant difference between the lots favouring the high-calcium birds was found in egg production, shell weight, and calcium retention. There were no significant differences between the lots in percentage calcium retention, food consumption, and body weight. The high-calcium group was shown to retain more calcium from the feed and excrete more calcium through eggs. Calcium retention and percentage calcium retention increased upon commencement of egg production to reach a maximum at the second period of production. Both remained fairly constant thereafter.The hens went into negative balance early in production and returned to positive balance during the later part of the first laying year. The return to positive balance could be explained by an increase in calcium retention and a decrease in egg production. There was no reduction in shell weight, or shell weight per unit surface area during the period covered by this trial.

Human synthetic calcitonin has produced a striking clinical and biochemical remission in each of five patients with Paget's disease treated for four to twelve months. Bone pain was relieved and skin temperature over affected limbs reduced. Elevated total urinary hydroxyproline levels fell to within the normal range and serum-alkaline-phosphatase to normal or near normal values. In two patients in whom quantitative histological studies were carried out, the number of osteoclasts was markedly reduced. The new bone formed during therapy had a normal lamellar structure. As assessed by the 47-calcium kinetic studies, the enhanced rate of bone-calcium turnover fell progressively. Calcium balance became positive or more positive. In each of the three patients studied, plasma-parathyroid-hormone levels were within the normal range after treatment for at least nine months. Two patients in remission relapsed slowly when calcitonin was withheld; they responded fully with further treatment.

The previous contributors to this symposium have emphasized the physiological factors which help to maintain a constant internal environment. I want to emphasize the behavior factors, or the responses of the total organism, which also contribute to this end. The examples that I will give are drawn from the field of internal secretions. We know, for instance, that the maintenance of a normal water balance depends largely on the secretion of antidiuretic hormones from the posterior lobe of the pituitary gland; that a constant body temperature is maintained largely through the secretions from the anterior lobe of the pituitary; further, that the normal salt balance depends on the secretions from the cortex of the adrenals; and that the calcium balance depends on the secretions from the parathyroids. In the normal body the secretions from these various glands help to maintain the constancy of internal environment. After removal of any one of them we find that, if the animals remain in their same surroundings and have the same amount of food, water, salt, or calcium, their internal environment will be changed so much that they will develop deficiency symptoms or die in a short time. What do these animals, deprived of their physiological means of regulation, themselves do to maintain life and a constant internal environment? The first example concerns the regulation of water balance. In the normal animal the secretions from the posterior lobe of the pituitary gland play an important part in the maintenance of water balance. Removal of this gland takes away the organism’s most important internal means of regulating water metabolism. Without the anti-diuretic secretions the kidneys excrete urine unchecked

Two new cases of pseudohypoparathyroidism are described, in each of which there was a selective deficiency of thyrotropin. Hypothyroidism is very common in pseudohypoparathyroidism and, in all cases appropriately studied thus far, appears attributable to a probable deficiency of thyroid stimulating hormone (TSH). Thyroid function should be evaluated in all patients with pseudohypo-parathyroidism and appropriate replacement therapy should be given when indicated. There was no evidence of resistance to hormones other than parathyroid hormone. Calcium balance was strongly positive. Parathyroid hormone could not be detected in the serum by radioimmunoassay. A chromosomal abnormality, clearly unrelated to pseudohypoparathyroidism, was present in one patient.

FOURTEEN to sixteen days before the onset of egg production, (Hurwitz, 1964), the pullet undergoes profound changes in its mineral metabolism. This stage coincides with the development of the primary and secondary sex organs and is characterized by increased plasma calcium, increase in calcium retention and formation of medullary bone (Simkiss, 1961). Such an intense mineral metabolism is preceded by a period of about two months of low intensity mineral metabolism during which the calcium and phosphorus requirements are extremely low (Berg et al., 1964). During the pre-laying period the calcium and phosphate retention reach 800 and 400–500 mg./day, respectively (Taylor and Moore, 1958). It thus must follow that the mineral requirements during the pre-laying period are increased. It has been shown that during the early production period, the young hen is in a negative calcium balance (Morgan and Mitchell, 1938) which cannot be alleviated by high dietary calcium…

THE retention of radiocalcium or radiostrontium in bones of humans (Spencer et al., 1961), rats (Cohn et al., 1961) and non-laying pullets (Hurwitz, 1965a), following a single intravenous dose, is reduced by the feeding of high-calcium diets. However, in the laying hen, the severe calcium depletion from bone during calcium restriction (Taylor and Moore, 1954; Hurwitz and Griminger, 1961) would suggest the possibility of reducing the body burden of bone-seeking radiosotopes by calcium restriction. It was the purpose of the present study to investigate the effects of variation in dietary calcium level and sources, and the timing of this variation, on the retention of calcium-45 and strontium-85 in various bone segments, and the deposition of these nuclides in the egg shell. METHODS AND RESULTS General procedure: The method for preparation of samples for analysis was given in detail in the preceding paper (Hurwitz and Bar, 1966). For calcium-45 determinations, calcium …

A method of determining dermal calcium losses in connection with calcium balance studies is described. The method involves collection of arm sweat in a plastic bag, rinsing with deionized water, determination of the Ca K ratio in the diluted sweat, and determination of dermal potassium losses. The latter losses are determined on the basis of the potassium balance and simultaneous determinations of changes in total exchangeable potassium. Arm sweat seems to be representative for whole body sweat with respect to the Ca K ratio. The dermal calcium loss varied between 20 and 365 mg. in 13 patients (mean 120 mg./day). These losses are of considerable importance in connection with calcium balances which is illustrated in a number of cases.

For the purpose of obtaining the data for the standard of calcium requirement of Japanese people, the following experiments were atempted.First of all, a experiment for adult women was performed and four healthy college women were employed as subjects.Total experimental period was 20 days; from Aug 8. to 27 in 1954 and was divided into four stages of five days; the 1st was the stage for preparation, the 2nd was for the basal diet, the 3rd was for milk calcium supplement: daily with 100gm. of yoghurt and the 4 th was for supplementing with 30gms. of fat beside the basal diet.It would be estimated that the calcium maintenance may be obtained if during the period in which the calcium balance was zero or near to zero. If the rate of calcium retention was estimated as 30per cent, the average calcium balance of the subjects might be obtained with the intake of 413mg; 8.3mg per kg. of body weight.