Effect of measuring bone mineral density on calcium intake

The diet in Japan has improved, but calcium intake has not increased for the past ten years, and it remains insufficient. To prevent osteoporosis, instruction in nutrition is directed at increasing calcium intake. We studied the effect of measuring bone mineral density on calcium intake in people receiving nutrition education. Intake of other nutrients was also measured. The subjects were 87 healthy women living in an agricultural region (Yamanashi Prefecture). They were members of a group formed to improve the diet of people in their area. For three days in October 1992 and in August 1994 food-weight records were obtained. A total of 76 of the 87 women chose to have their bone mineral density measured. The measurements before the first nutrition assessment in 1992. The intake of almost all nutrients tended to be greater in 1994 than in 1992. Calcium intake exceeded the minimum daily requirement (600mg). Calcium intake increased between 1992 and 1994 only in the subjects whose bone mineral density had been measured. Calcium intake decreased in the other subjects. Therefore, nutrition education programs aimed at preventing osteoporosis may be more effective if bone mineral density is measured. In addition, an appropriate balance of other nutrients can be maintained as the intake of calcium is increased.     

Effect of various dietary constituents on gastrointestinal absorption of aluminum from drinking water and diet

The influence of some frequent dietary constituents on gastrointestinal absorption of aluminum from drinking water and diet was investigated in mice. Eight groups of male mice received lactic (57.6 mg/kg/day), tartaric (96 mg/kg/day), gluconic (125.4 mg/kg/day), malic (85.8 mg/kg/day), succinic (75.6 mg/kg/day), ascorbic (112.6 mg/kg/day), citric (124 mg/kg/day), and oxalic (80.6 mg/kg/day) acids in the drinking water for one month. At the end of this period, animals were killed and aluminum concentrations in liver, spleen, kidney, brain, and bone were determined. All the dietary constituents significantly increased the aluminum levels in bone, whereas brain aluminum concentrations were also raised by the intake of lactic, gluconic, malic, citric, and oxalic acids. The levels of aluminum found in spleen were significantly increased by gluconic and ascorbic acids, whereas gluconic and oxalic acids also raised the concentrations of aluminum found in kidneys. Because of the wide presence and consumption of the above dietary constituents, in order to prevent aluminum accumulation and toxicity we suggest a drastic limitation of human exposure to aluminum.     

Diabetic ketoacidosis and rhabdomyolysis following excessive intake of a weight reducing diet

We describe two unusual cases in sheep of subclinical mastitis caused by Streptococcus parasanguinis. This bacterium has been associated with the development of experimental endocarditis; its presence at relatively high concentrations in apparently healthy sheep milk may pose a health risk in persons with predisposing heart lesions.     

Effect of interstitial cystitis on drug absorption from urinary bladder

Borna disease (BD) is a virus-induced immunopathologic disease of the central nervous system in a variety of species from birds to primates and probably in humans. Severe inflammatory reactions lead to tissue destruction and finally to cortical brain atrophy. After experimental infection of the rat, intraparenchymal CD8+ T cells, MHC class I Ags on Borna disease virus (BDV)-infected neurons, and numerous nerve cell lesions were present. Treatment of BDV-infected rats with the mAb OX-8 directed against CD8+ cells inhibited the immunopathologic reactions and reduced MHC class I Ag expression. Neuronal lesions were minimal and no loss of brain substance could be observed. Because BDV has no acute cytopathic effects, we provide evidence that the presence of CD8+ T cells within the brain parenchyma and the expression of MHC class I Ags on neurons play a major role for immunopathologic brain tissue destruction and virus-infected neurons in vivo can be destroyed by T cell-mediated cytotoxicity.     

Comments on a meta-analysis of the relation between dietary calcium intake and blood pressure

The role of dietary calcium in the etiology of hypertension is controversial. In 1995, Cappuccio et al. (American Journal of Epidemiology,1995;142:935-45) examined this issue in a meta-analysis of observational studies published between 1983 and 1993. The author of the present paper reviewed the original studies underlying this meta-analysis and discovered that data from one study had been inappropriately extracted and converted, leading to an understatement of the calcium-blood pressure relation by a factor of about 30. This review also raised questions about the extraction and conversion of data from several other studies and about the statistical methods used. The author repeated the meta-analyses and discovered an unadjusted regression slope between dietary calcium and systolic blood pressure of -0.34 mmHg/100 mg per day (95% confidence interval (CI) -0.46 to -0.22) for men, -0.15 mmHg/100 mg per day (95% CI -0.19 to -0.11) for women, and -0.39 mmHg/100 mg per day (95% CI -0.47 to -0.31) for men and women. For diastolic blood pressure, the pooled regression slope for men was -0.22 mmHg/100 mg per day (95% CI -0.32 to -0.13), while for women it was -0.051 mmHg/100 mg per day (95% CI -0.090 to -0.012); for men and women it was -0.35 mmHg/100 mg per day (95% CI -0.67 to -0.02). These slopes are still modest but are larger than those reported in the original analysis. However, since all of these analyses were based on zero-order correlations or regressions, extreme caution must be exercised in interpreting the results.     

Influence of food intake on the absorption of diftalone in man

An average 2.2-fold increase in the peak plasma concentrations of the non-steroidal anti-inflammatory agent diftalone in the presence of food was observed in three studies carried out with healthy volunteers who received an oral dose of 0.75 g (6 subjects, study 1), 0.25 g (10 subjects, study II) and 0.5 g (6 subjects, study V) of the compound at 9:00 a.m. both in fasting conditions and after a meal. The effect does not depend on the unusual time (8:00 a.m., selected for experimental needs) at which the subjects were given the meal. In fact, a 2.5-fold increase in plasma concentrations was observed when an oral dose of 0.75 g of diftalone was administered to 2 subjects (study II) both at 8:00 a.m. in fasting conditions and at 1:00 p.m. after a meal. A similar enhancement in the absorption of diftalone was observed when 5 healthy volunteers (study VI) received an oral dose of 0.5 g of the compound both as plain capsules and as capsules containing dry ox bile. However, the absorption of diftalone was not modified when the compound was administered orally as an aqueous suspension or in tensioactive vehicles, or after 20 mg of metoclopramide (study II). Also, the results of a study (IV) on 2 subjects partly deprived of bile after surgery, showed that diftalone does not undergo enterohepatic circulation. The hypothesis that the increase in diftalone absorption is mainly due to bile flow following food intake is supported by all the above experimental results.     

Accelerating effect of chitosan intake on urinary calcium excretion by rats

The effect of chitosan on calcium (47Ca) metabolism was investigated in rats. The whole-body retention of 47Ca by rats fed on a 5% chitosan diet was significantly decreased when compared with that of rats fed on a cellulose diet, but showed no significant difference from that of rats fed on a fiber-free diet. Although there was no significant difference in the fecal excretion of 47Ca between the chitosan group and the cellulose or fiber-free group, the urinary excretion of 47Ca was significantly increased in the chitosan group when compared with the cellulose group. These results suggest that dietary chitosan would affect the calcium metabolism in animals.     

Effect of an elemental vs a complex diet on L-citrulline production from L-arginine in rat isolated enterocytes

Robot systems are being tested in stereotactic neurosurgical interventions, orthopedic surgery of the hip or knee and advancal endoscopic systems for minimally invasive surgery. In contrast to most industrially manufactured products, objects for medical treatment are characterized by plasticity as well as by complex and individual forms. Thus, features of robots in this field have to be further developed in terms of advanced sensory and specific micromotoric systems. Safety and cooperation between surgeon and robot on the patient in the operating room have to be guaranteed. Extensive three-dimensional diagnosis, computer-aided planning and simulation of the intervention as well as sensory systems that monitor the actual performance of the operation are mandatory parts of this concept. In our interdisciplinary study, we aim to examine whether a robot-given a complete preoperative planning and simulation procedure-is able to perform certain surgical operations more precisely than the surgeon. Examples are drilling with depth control, shaping of bone surface by milling, sawing with defined depth in cranial osteotomies, defined preparation of implant sites and the positioning and insertion of dental and other surgical implants, whereby autonomous employment of the robot is not that which is aspired to in these interventions but rather the interactive support of the surgeon.     

Effect of a high-beef diet on the fecal bacterial flora of humans

Ten human volunteers completed a 4-month diet series consisting of 1 month each of a control diet, a meatless diet, a high-beef diet, and the same control diet. Fat and fiber contents were essentially the same in all four diets, but protein content was doubled during the high-beef diet. During the 4th week on each diet, three stool specimens collected from each volunteer were analyzed for chemical composition and content of facultative, aerobic, and anaerobic bacteria. The bacteriological data are presented in this paper. High beef protein consumption had little effect on the composition of the intestinal flora. There were no significant differences in total counts of facultative and aerobic or anaerobic organisms in the feces when volunteers were on meatless or high-beef diets. At the species level, when counts during the two control diets were comparable, in only three instances did the change from the meatless to a high-beef diet significantly influence the bacterial numbers. The ratio of mean counts of anaerobic to facultative and aerobic organisms was approximately 15:1 during the meatless diet and 34:1 during the high-meat diet. The data indicate that animal protein consumption has little effect on the fecal bacterial profile in humans.     

Biochemical effects of calcium supplementation in postmenopausal women: influence of dietary calcium intake

We studied the biochemical effects of calcium supplementation during a 2-mo course in postmenopausal women (x +/- SD: 64 +/- 5 y of age and 14.5 +/- 6.7 y since menopause). The effects on calcium homeostasis and bone remodeling were assessed after 1 and 2 mo of daily administration of either calcium carbonate (1200 mg elemental Ca/d, n = 60) or a placebo (n = 56). The daily dietary calcium intake assessed before the beginning of calcium supplementation was 786 mg/d. We found a significant inverse relation between baseline intact parathyroid hormone (iPTH) and dietary calcium intake before supplementation (r = -0.48, P = 0.0002). A significant increase in urinary excretion of pyridinoline was observed when the dietary calcium intake was lower than the median value. Calcium supplementation resulted in a significant increase in 24-h urinary calcium (39%, P < 0.02) and a significant reduction of bone alkaline phosphatase at 2 mo and of all bone-resorption markers (hydroxyproline, pyridinoline, and deoxypyridinoline) at I and 2 mo without significant changes in 44-68 PTH fragments or iPTH concentrations. When the dietary calcium intake was low (mean +/- SD: 576 +/- 142 mg/d), calcium supplementation was responsible for a greater increase in urinary calcium excretion and a greater decrease in markers of bone turnover. The greatest variations were observed for deoxypyridinoline at 1 and 2 mo (-18.5%, P < 0.05) and for pyridinoline at 1 mo (-16.3%, P < 0.01). Two months of calcium supplementation in postmenopausal women was efficient in reducing markers of bone turnover, with a greater effect in women with a low dietary calcium intake.     

Evaluation of cholesterol absorption in rats using markers labeled with stable isotopes. Effect of complete bile diversion

BACKGROUND/AIMS: An easily performed method to measure cholesterol absorption with isotope labeled cholesterol and beta-sitostanol in humans is described. The first aim of the study was to show whether this method can also be used in rats. Secondly, to see whether complete bile diversion results in a complete loss of cholesterol absorption. METHODOLOGY: Cholesterol absorption was evaluated in rats by the constant isotope feeding method using [2H6]cholesterol and [2H4]sitostanol as markers. Fecal samples were analyzed by gas-chromatography/mass spectrometry. RESULTS: In 8 rats with intact enterohepatic circulation of bile acids, cholesterol absorption averaged 61 (3% (SD) (range: 54-69%)). Complete bile diversion was followed by an almost total loss of cholesterol absorption (5.5+/-0.6%, range: 2.4-6.9%, n=7). CONCLUSIONS: The results indicate that deuterated cholesterol and deuterated sitostanol are reliable markers for measurement of cholesterol absorption in rats and that bile acids are essential for cholesterol absorption.     

The hyperphagic effect of a high-fat diet and alcohol intake persists after control for energy density

This study was performed to investigate the effect of a high-fat diet and alcohol (high-fat, alcohol) intake on subsequent spontaneous energy intake when controlling for food energy density. Twelve adults males participated in two 1-d randomly assigned sessions that only differed by the macronutrient composition of the appetizer served at lunchtime. Dietary energy was mainly provided by lipid and alcohol in one appetizer whereas carbohydrate was the main source of energy in the other appetizer. The energy density, content, and weight of the foods were comparable in the two appetizers. Ad libitum energy intake measured at lunchtime after ingestion of the high-fat, alcohol appetizer exceeded that observed after the high-carbohydrate appetizer by >812kJ (P<0.01). This overfeeding had no detectable effect on postprandial hunger and was not compensated by changes in energy intake at dinnertime. In conclusion, this study demonstrates that a high-fat diet and alcohol favor subsequent overfeeding, which is not due to their higher energy density.     

Biochemical markers of calcium and bone metabolism during 18 months of lactation in Gambian women accustomed to a low calcium intake and in those consuming a calcium supplement

The effect of 18 months of lactation on indexes of calcium and bone metabolism was studied in 60 Gambian women accustomed to a very low calcium intake. Half the women consumed a calcium supplement from 10 days postpartum for 52 weeks (supplement, 714 mg Ca/day; total Ca intake, 992 +/- 114 mg/day), and half consumed placebo (total Ca intake, 288 +/- 128 mg/day). Fasting blood and 24-h urine samples were collected at 1.5, 13, 52, and 78 weeks of lactation and analyzed for calciotropic hormones (intact PTH, 1,25-dihydroxyvitamin D, and calcitonin), bone turnover markers (osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline), and plasma minerals (calcium and phosphate). The first months of lactation were associated with increased bone turnover and plasma phosphate, and decreased PTH and 1,25-dihydroxyvitamin D. These effects diminished by 52 weeks, although breast milk volumes remained high. The Gambians had higher PTH, 1,25-dihydroxyvitamin D, and bone formation than British women with a greater customary calcium intake. None of the biochemical indexes was affected by calcium supplementation, with the possible exception of bone alkaline phosphatase (-29% at 52 weeks; P = 0.015). These data demonstrate that lactation-associated changes in calcium and bone metabolism are physiological and are independent of dietary calcium supply in women with very low calcium intakes.     

The effect of calcium restriction in the diet of calcium transport in rat small intestine

1. The everted-sac technique has been used to study the time-dependent effect of low-calcium diet on calcium active transport along rat small intestine. 2. In animals maintained on standard diet active translocation of calcium was limited to proximal 10 cm of the intestine. 3. In response to calcium restriction, calcium transport in duodenum was highly stimulated after 3 days, then gradually declined and after 28 days almost disappeared. In proximal jejunum it was the highest between 7 and 21 days. In distal ileum, the transport appeared after 3 days and increased progressively until 21 days, but markedly decreased at the 28-th day. The normal pattern of calcium transport was reestablished on refeeding the animals with standard diet.     

Predictors of calcium intake patterns: A longitudinal analysis.

Objective: The study was guided by the precaution adoption process model; the author examined factors associated with (a) stage of change with respect to calcium intake at 4 time points and (b) calcium intake patterns across time. Design: Data were collected by mailed questionnaire at baseline and at 3 follow-up assessments over 1 year. Main Outcome Measures: The primary outcome measures were calcium intake, stage of change with respect to calcium intake, and pattern of calcium intake across follow-up. Three patterns were identified: successful maintenance (adequate calcium intake at all 3 follow-ups), vacillation (adequate calcium consumption at 1 or 2 follow-ups), and inertia (inadequate calcium consumption at all 3 follow-ups). Results: Five hundred six women completed baseline questionnaires, and 346 completed 3 follow-up assessments. Even after baseline stage of change was controlled for, longitudinal analyses revealed 3 variables that predicted different patterns of behavior across time. Isolated instances of adequate calcium intake were predicted by higher levels of knowledge and perceived benefits, whereas long-term maintenance was predicted by lower levels of perceived difficulty. Conclusion: These findings provide support for a central premise of the model, that different factors are important at different points in the behavior change process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of genetically modified, low-phytic acid maize on absorption of iron from tortillas

BACKGROUND: Genetically modified, low-phytic acid strains of maize were developed to enhance mineral absorption, but have not been tested previously in humans. OBJECTIVES: We evaluated the mineral and phytic acid contents of a low-phytic acid "flint" maize (LPM, the lpa-1-1 mutant) and its parent, wild-type strain (WTM) and measured iron absorption from tortillas prepared with each type of maize and from a reference dose of ferrous ascorbate. DESIGN: Proximate composition and mineral and phytic acid contents were measured by standard techniques. Iron absorption from tortillas was evaluated by using the extrinsic tag method and was measured as the incorporation of radiolabeled iron into the red blood cells of 14 nonanemic men 2 wk after intake. RESULTS: The phytic acid content of LPM was 3.48 mg/g, approximately 35% of the phytic acid content of WTM; concentrations of macronutrients and most minerals were not significantly different between strains. Iron absorption results were adjusted to 40% absorption of ferrous ascorbate. Iron absorption was 49% greater from LPM (8.2% of intake) than from WTM (5.5% of intake) tortillas (P < 0.001, repeated-measures analysis of variance). CONCLUSION: Consumption of genetically modified, low-phytic acid strains of maize may improve iron absorption in human populations that consume maize-based diets.