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Background: Although iron deficiency occurs commonly in vulnerable groups of women of reproductive age, infants, and children, less is known about the iron nutriture of the elderly., Objective: Our objective was to evaluate the iron status of a noninstitutionalized, elderly US population, with a particular focus on 2 concerns unique to the elderly: 1) potential confounding effects of chronic disease on iron measures and 2) increased occurrence of elevated iron stores., Design: Multiple iron measures, including serum ferritin (SF), transferrin saturation, mean cell volume, and hemoglobin, were used to evaluate the prevalence of iron deficiency (ID), iron deficiency anemia (IDA), and other measures of iron nutriture in 1016 elderly white Americans aged 67-96 y from the Framingham Heart Study. "Diseased" subjects were defined as those with possible pathologically altered iron measures due to inflammation, infection, elevated liver enzymes, hereditary hemochromatosis, or cancer. The effect of altered iron status on various prevalence estimates was assessed., Results: The elderly subjects had a low prevalence of ID (2.7%), IDA (1.2%), and depleted iron stores (3%; SF < 12 microg/L). In contrast, 12.9% had elevated iron stores (SF > 300 microg/L in men and SF > 200 microg/L in women), of which only 1% was attributable to chronic disease. The prevalence of ID, IDA, and depleted iron stores was unaffected by the presence of chronic disease., Conclusions: The Framingham Heart Study cohort is an iron-replete elderly population with a high prevalence of elevated iron stores in contrast with a low prevalence of iron deficiency, with insignificant effects of chronic disease on these iron status estimates. The likely liability in iron nutriture in free-living, elderly white Americans eating a Western diet is high iron stores, not iron deficiency.

Background: The active hormonal form of vitamin D (1,25-dihydroxyvitamin D) is the primary regulator of intestinal calcium absorption efficiency. In vitamin D deficiency, intestinal calcium absorption is low leading to an increased risk of developing negative calcium balance and bone loss. 1,25-dihydroxyvitamin D has been shown to stimulate calcium absorption in experimental animals and in human subjects. However, the molecular details of calcium transport across the enterocyte are not fully defined. Recently, two novel epithelial calcium channels (CaT1/ECaC2 and ECaC1/CaT2) have been cloned and suggested to be important in regulating intestinal calcium absorption. However, to date neither gene has been shown to be regulated by vitamin D status. We have previously shown that 1,25-dihydroxyvitamin stimulates transcellular calcium transport in Caco-2 cells, a human intestinal cell line., Results: In the current study, we have demonstrated that Caco-2 cells express low but detectable levels of CaT1 mRNA in the absence of 1,25-dihydroxyvitamin D treatment. CaT1 mRNA expression is rapidly up regulated (4-fold increase at 4 h and 10-fold at 24 h) by treatment with 1,25-dihydroxyvitamin D (10(-7) moles/L). Moreover, the increase in CaT1 mRNA expression preceded by several hours the vitamin D induction of calbindin D9K, a putative cytosolic calcium transport protein., Conclusion: These observations are the first to demonstrate regulation of CaT1 expression by vitamin D and are consistent with a new model of intestinal calcium absorption wherein vitamin D-mediated changes in brush border membrane CaT1 levels could be the primary gatekeeper regulating homeostatic modulation of intestinal calcium absorption efficiency.

In early 19th-century Moravia, breeders of animals and plants joined with other interested citizens in the Moravian and Silesian Agricultural Society to debate economic priorities. Several of the senior members had a profound influence upon breeding theory: J.K. Nestler, Professor of Natural History and Agriculture at the University of Olomouc, left a collection of influential writings. In the context of sheep breeding he defined 'inheritance capacity' (Vererbungsfähigkeit), 'hereditary history' (Vererbungsgeschichte) and 'developmental history' (Entwicklungsgeschichte). His linking of the last two terms, as two sides of the same coin, puts Mendel's use of the second one in context. Professor F. Diebl taught the same topics as Nestler at the Philosophical Institute in Brno, with a bias towards plants. Diebl's lectures were attended by Mendel who gained top marks in three examinations. Diebl stressed the importance of artificial pollination to produce new varieties and recognised peas and beans as suitable subjects for the procedure. Prelate Cyrill Napp, abbot before Mendel, had a deep interest in heredity and how it was transmitted through both sexes. He generously supported Mendel's research. A happy blend of economic and academic influences, together with original talent and inner drive, led to Mendel's great discovery.

Leading Moravian sheep breeders, who joined with university professors and other educated citizens to form a Sheep Breeders' Society in 1814, looked to science to provide a reliable basis for breeding. Their activities reached a climax in the 1830s, when they defined and focused on heredity as the central research goal. Among the members taking part was Abbot Cyrill F Napp, who in 1843 would accept Mendel into the monastery. The contributions of Abbot Napp to the sheep breeders' view of heredity are here described. After 1900, when Moravian animal breeding sought to embrace Mendelism, in competition with other theories, a major influence was exerted by Jaroslav Krízenecký (1896-1964). In 1963, Krízenecký accepted responsibility for establishing the Mendel Museum (Mendelianum) in Brno as a vehicle for historical research into the origin and essence of Mendel's discovery.

The assessment of marginal zinc status is problematic. Currently, there is no universally accepted single measure to assess zinc status in humans. The development of a reliable measure of marginal or moderate zinc status would be useful for a variety of purposes. For example, a simple, yet sensitive and accurate measure of zinc nutritional status is critically needed to further our limited understanding of the possible associations between zinc status and the risk of developing various chronic diseases and in predicting favorable health outcomes in patient populations. A convenient and reliable zinc assessment tool is needed to identify subpopulations who are at a risk of zinc deficiency and as an objective guidepost to determine the need for initiation of zinc supplementation or zinc fortification of the food supply, as well in the refinement of recommendations of dietary zinc allowances. In frank zinc deficiency, clinical signs and static measures of zinc concentrations in a variety of readily available tissues, such as plasma, various blood cell types and hair, may uniformly confirm the presence of depleted body zinc stores. However, in general, the relative insensitivity or imprecision of these measurements has resulted in general disappointment in their use to assess marginal zinc status. Therefore, the search continues to find a useful and reliable marker of marginal zinc deficiency. In an attempt to speculate on possible future developments in the zinc status assessment field, a number of new and potentially promising approaches to this problem are highlighted.

Renal stone disease is a painful condition that affects 1-20% of the general population. Therapy aimed at decreasing the incidence of recurrent stones includes dietary advice. Dietary considerations include intake of both calcium and protein. Calcium restriction in stone formers is not recommended because it can have adverse effects on bone and the incidence of stones. Although a high-protein diet can elevate urinary calcium, uric acid, and sulfate and decrease urinary citrate, which may alter the propensity to form stones, restriction of protein to less than the current RDA for the management of stone disease can not be recommended at this time.

A major modification to the sterile insect technique is described, in which transgenic insects homozygous for a dominant, repressible, female-specific lethal gene system are used. We demonstrate two methods that give the required genetic characteristics in an otherwise wild-type genetic background. The first system uses a sex-specific promoter or enhancer to drive the expression of a repressible transcription factor, which in turn controls the expression of a toxic gene product. The second system uses non-sex-specific expression of the repressible transcription factor to regulate a selectively lethal gene product. Both methods work efficiently in Drosophila melanogaster, and we expect these principles to be widely applicable to more economically important organisms.

This paper describes the design and testing of a flow-through ultrasonic separation device that allows the concentration of particles within a fluid. The device operates without the use of an acoustically transparent element. Three models are used to examine the behaviour of the cell, dealing with acoustic-particle interaction, electro-acoustic characteristics, and fluid flow. The device is able to concentrate up to 84% of the 60 microns sand particles in the 'dirty' stream, 13% in the intermediate stream and 3% in the 'clean' stream. Flow rates of up to 20 lh-1 (equating to an inlet velocity of 10(-2) ms-1) have been used with an electrical power input of up to 50 W (10 kWm-1).

Cleft lip and palate malformations are the most common congenital craniofacial abnormalities. Patients with these deformities require coordinated care involving multiple disciplines from birth throughout adolescence. The primary care provider plays a vital role in facilitating the provision of care for these patients, who often have numerous health care needs, including feeding difficulties, speech disorders, chronic ear infections, and dental and orthodontic problems. The emotional issues of patients with these deformities and their families are significant and include disrupted parent and child bonding, body image disturbances, and impaired socialization. The role of the primary care provider is to be a stable source of support for these patients and to assist in coordinating care for the many physical and emotional problems they may have.

Calcium transport in the apical-to-basolateral (A-to-B) or B-to-A direction was examined in cells treated with 10 nM 1, 25-dihydroxyvitamin D3 [1,25(OH)2D3, calcitriol] for up to 72 h. Net A-to-B calcium transport was positive at all time points and increased from 0.14 +/- 0.06 to 0.50 +/- 0.01 nmol. well-1. min-1 after 72 h of calcitriol treatment. Neither phenol red transport nor transepithelial electrical resistance was altered by calcitriol treatment, suggesting that the increase in net A-to-B calcium transport was not due to paracellular movement. Neither 25-hydroxyvitamin D3 nor 24,25-dihydroxyvitamin D3 (100 nM, 48 h) alters basal or calcitriol-stimulated A-to-B calcium transport. Treatment with the calmodulin antagonist trifluoperazine (50 microM) reduced calcitriol-stimulated A-to-B Ca transport by 56%. The transcription inhibitor actinomycin D inhibited calcitriol-regulated A-to-B calcium transport as well as calbindin D9k and 24-hydroxylase mRNA accumulation. These data demonstrate that calcitriol-mediated A-to-B calcium transport in Caco-2 cells is a specific, transcellular process that requires transcriptional events normally mediated through the vitamin D receptor.

Shear has been known to exist for many years in the topographic structure of the primary visual cortex, but has received little attention in the modeling literature. Although the topographic map of V1 is largely conformal (i.e. zero shear), several groups have observed topographic shear in the region of the V1/V2 border. Furthermore, shear has also been revealed by anisotropy of cortical magnification factor within a single ocular dominance column. In the present paper, we make a functional hypothesis: the major axis of the topographic shear tensor provides cortical neurons with a preferred direction of orientation tuning. We demonstrate that isotropic neuronal summation of a sheared topographic map, in the presence of additional random shear, can provide the major features of cortical functional architecture with the ocular dominance column system acting as the principal source of the shear tensor. The major principal axis of the shear tensor determines the direction and its eigenvalues the relative strength of cortical orientation preference. This hypothesis is then shown to be qualitatively consistent with a variety of experimental results on cat and monkey orientation column properties obtained from optical recording and from other anatomical and physiological techniques. In addition, we show that a recent result of Das and Gilbert (Das, A., & Gilbert, C. D., 1997. Distortions of visuotopic map match orientation singularities in primary visual cortex. Nature, 387, 594-598) is consistent with an infinite set of parameterized solutions for the cortical map. We exploit this freedom to choose a particular instance of the Das-Gilbert solution set which is consistent with the full range of local spatial structure in V1. These results suggest that further relationships between ocular dominance columns, orientation columns, and local topography may be revealed by experimental testing.

The newly identified hemochromatosis gene, HFE, and a candidate iron transporter gene, Nramp2, have been proposed as key factors responsible for the regulation of intestinal iron absorption. Although the exact functions of these proteins in intestinal iron absorption are unknown, HFE may be required for the down-regulation of iron absorption that occurs with increasing iron status, and Nramp2 may up-regulate iron absorption when iron status is low. Thus, we examined whether the expression of the HFE and Nramp2 genes are regulated by iron status in the human intestinal cell line Caco-2. HFE mRNA and HFE protein were increased and Nramp2 mRNA was decreased by increasing cellular iron status in Caco-2 cells. This iron-mediated modulation of mRNA levels was specific to iron. Moreover, super-induction of HFE mRNA in the presence of cycloheximide suggests that HFE gene expression may be controlled by a short-lived repressor protein. HFE and Nramp2 mRNA levels also changed in opposite directions during cellular differentiation. This reciprocal modification of the HFE and Nramp2 gene expression during both iron treatment and cell differentiation in Caco-2 cells is consistent with an opposing role for these proteins in homeostatic regulation of human intestinal iron absorption.

Gene mapping techniques to identify gene mutations in humans and animals with phenotypic abnormalities in iron metabolism are providing important insights into the probable molecular mediators of intestinal iron absorption. Positional gene cloning in humans with hereditary hemochromatosis has identified a mutation in a novel major histocompatibility complex (MHC) gene called HFE that is likely to be involved in regulating intestinal iron absorption. In addition, recent observations based on positional cloning strategies in the mk/mk mouse and the Belgrade (b/b) rat rodent models of hypochromic, microcytic anemia have shown that the phenotypic abnormality in iron metabolism is associated with a mutation in the Nramp2 gene. Functional cloning studies in Xenopus oocytes have characterized DCT1 (Nramp2) as an iron-regulated proton-coupled divalent cation transporter. Nramp2 is likely to be the membrane transporter that functions in controlling iron entry across the apical membrane and in the export of iron out of endosomal vesicles. The observation that the expression of both HFE and Nramp2 mRNAs are reciprocally regulated by cellular iron status in Caco-2 cells, a human intestinal cell line, lends additional credence to the notion that these proteins may work in concert to regulate intestinal iron absorption.

We investigated the role of circulating 1,25-dihydroxycholecalciferol (1,25(OH)2D) and intestinal resistance to 1,25(OH)2D in the diminished intestinal calcium absorption capacity of the senescent rat. We measured plasma 1,25(OH)2D, total and unoccupied duodenal vitamin D receptor, duodenal calbindin D9k protein (calbindin D), and net dietary calcium absorption in rats at several ages. As expected, circulating 1,25(OH)2D, calbindin D, and net calcium absorption decreased with age. However, no age-related changes were evident in intestinal vitamin D receptor levels. We then measured duodenal calcium absorption from in situ intestinal loops after continuous s.c. infusion of 1,25(OH)2D for up to 6 days and found that despite a marked elevation of plasma 1,25(OH)2D duodenal calcium absorption was significantly lower in old compared with young rats. To assess calcium absorption over a wide physiological range of plasma 1,25(OH)2D, in a dose-response study we altered plasma 1,25(OH)2D by continuous infusion of 1,25(OH)2D (at 0, 4, or 14 ng/100 g BW/day) for 9 days. We found that the slope of the linear regression between plasma 1,25(OH)2D and duodenal Ca transport in old rats was only 46% of that observed in young rats, suggesting an age-related resistance of the duodenal calcium transport process to the hormonal action of 1,25(OH)2D. Collectively, our observations suggest a dual defect in vitamin D metabolism in old animals: one defect related to the low circulating levels of 1,25(OH)2D and a second defect related to a relative intestinal resistance to the action of 1,25(OH)2D, which is apparently not due to a reduction in intestinal vitamin D receptor levels.

A collagen membrane technique, based on the membrane blood-feeding system of Cosgrove et al. (1994), was used to compare repellents against Aedes aegypti mosquitoes. Repellency was defined in terms of inhibition of probing (ED50 and ED90) after 5 min exposure. A direct comparison was made with repellency from probing after 5 min on five male volunteers. Four repellent products were compared with technical DEET as the standard. The liquid formulations tested were: Autan (20% deet; Bayer); Repel Plus (20% deet plus 0.05% permethrin; Boots); permethrin (Zeneca) and citronellal (Sigma). Membrane and arm tests gave similar results. Deet formulations required less active compound than citronellal for the same degree of repellency. Pure deet and Autan gave similar results, dose for dose. Permethrin was highly repellent at very low doses, but Repel Plus did not enhance the immediate repellency of deet. A technique using the same membrane system was developed to evaluate persistence of Autan, which declined to 75% after 1 h against Ae. aegypti, and to about 50% after 2-4 h.

Background: Increasing the inorganic phosphorus content of total parenteral nutrition (TPN) formulas has been shown to decrease TPN-induced hypercalciuria in experimental animals and humans. The mechanism of this effect, however, has been uncertain., Methods: By using a randomized cross-over design, seven patients on cyclic TPN were given otherwise identical formulas providing either 15 or 45 mmol/d of inorganic phosphorus. Urinary calcium excretion, serum ultrafilterable calcium, filtered calcium load, fractional calcium excretion, urinary cyclic adenosine 5'-monophosphate (cAMP), and serum levels of ionized calcium, parathyroid hormone (PTH), and vitamin D metabolites were determined at the end of each study period., Results: Urinary calcium excretion was significantly lower when the patients received the higher inorganic phosphorus formula. Increasing the inorganic phosphorus in the TPN formula did not change ultrafilterable calcium or filtered calcium load, but significantly reduced fractional calcium excretion. No differences in serum levels of ionized calcium, PTH, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, or urinary cAMP were observed between treatments., Conclusions: These results demonstrate that increasing the inorganic phosphorus content of the TPN formula decreases urinary calcium excretion by increasing renal tubular calcium resorption. This effect is not due to alterations in the PTH-1,25-dihydroxyvitamin D axis, but likely reflects a direct action of inorganic phosphorus on the renal tubules.

Epidemiologic studies have found a relation between body iron stores and risk of chronic disease. Iron-absorption studies from single meals have shown that many dietary factors can influence nonheme-iron bioavailability. However, little is known about the association of these dietary factors with iron stores in free-living elderly populations. To address this question, we investigated the consumption of various dietary components and iron stores in an elderly sample of The Framingham Heart Study participants. Serum ferritin was used as a measure of body iron stores in 634 free-living elderly (67-93 y of age), and dietary intake during the previous year was assessed by a food-frequency questionnaire. The relation between serum ferritin and various dietary factors was assessed by multiple regression analysis. Subjects whose ferritin concentrations might be pathologically elevated because of infection, inflammation, liver disease, or genetic hemochromatosis were excluded from the analysis. After we controlled for sex, age, body mass index, total energy intake, smoking, and use of aspirin and other medications known to affect blood loss, we found five significant dietary factors associated with iron stores. Heme iron, supplemental iron, dietary vitamin C, and alcohol were positively associated with serum ferritin, whereas coffee intake had a negative association. As expected, sex was a strong predictor of serum ferritin-women having significantly lower mean concentrations than men. However, age was not related to serum ferritin in our elderly population. Our results suggest that in typical Western-style diets, a small number of dietary factors probably modulate the bioavailability of dietary iron and influence the accumulation of iron stores.

Purpose: The purpose of this study was to determine the relationship between taste preference and total fluid intake during a 90-min run at 60% VO2max as well as during a 90-min period of seated recovery under hyperthermic conditions (30 degrees C, 50% RH), comparing the ad libitum intake of water and two carbohydrate-electrolyte drinks (one containing 6% CHO and the other 8% CHO) randomized over three trails., Methods: Fifteen men runners and triathletes, 18 to 40 yr of age, completed an initial test to determine VO2max, a practice 90-min run at 60% VO2max, and three experimental 90-min run/90-min recovery trials on separate days approximately 1 wk apart., Results: There were no differences across the three treatments in fluid intake, rectal temperature, or RPE during exercise, but subjects consumed 54% and 59% more fluid during recovery with the two carbohydrate-electrolyte drinks compared with water. When comparing the subjects' trials with the most liked versus the least liked of the three fluids, they consumed more of the most liked fluid during exercise (1.10 vs 0.97 L.90 min-1) but not during recovery (1.02 vs 0.90 L.90 min-1.ns)., Conclusions: Thus, perceived taste of a beverage is important for fluid replacement during exercise.

Osteoporosis is a metabolic bone disease characterized by low bone mass and deterioration of bone tissue that leads to bone fragility and an increase in fracture risk. It is a disease with a complex etiology that includes genetic and environmental contributors. Environmental factors that influence bone density include dietary factors-such as intakes of calcium, alcohol, and caffeine-and lifestyle factors-such as exercise and smoking. Ethnic differences in the propensity to nontraumatic bone fracture suggest that genetic factors are important. Recently, common allelic variations in he vitamin D receptor gene have been found to be associated with bone mineral density in racially diverse population groups, as well as in prepubertal girls, young adult and postmenopausal women, and men. However, many studies have not been able to find this association. Additional approaches, such as sib-pair analysis, will probably be necessary in the future to identify the important determinants of osteoporosis.

A breeding scheme to isolate X chromosomes sensitive to drive by the T8 (Trinidad) Y chromosome of Aedes aegypti (the MD haplotype) is reported. Crosses with an Australian strain Th.I (Thursday Island) revealed not only sensitive and resistant X chromosomes but also some with the capacity to drive against the T8 Y chromosome. Four strains were created in which sex ratio was male-distorted (28-36 per cent Female) for 10 generations, with no regression towards sexual parity. The proportion of females varied significantly between generations in each of the four strains. Further selection produced strains with normal sex ratios, capable of generating fewer than 15 per cent Female on outcrossing to T8 males.

Optimal calcium intakes of 37.5 mmol(1500 mg)/d have been proposed for elderly people. We investigated the effects of calcium supplementation on zinc absorption and balance in 18 relatively healthy, postmenopausal women aged 59-86 y. All subjects received a standardized basal diet of typical foods supplying 269 mumol (17.6 mg) Zn/d and 22.2 mmol (890 mg) Ca/d during the 36-d study. In two of three experimental periods, an additional 11.7 mmol (468 mg) Ca/d as either milk or an inorganic calcium phosphate supplement was provided. Net zinc absorption and zinc balance were significantly reduced by approximately 2 mg/d during both high-calcium treatments. In a second study, conducted in a separate group of men and women aged 21-69 y, a whole-gut lavage, zinc-absorption test was used to investigate the acute effect of a 15-mmol CaCO3 (600 mg Ca) supplement, with and without extra zinc, on zinc absorption from a single test meal supplying 111.7 mumol (7.3 mg) Zn. Zinc absorption was reduced significantly by 50% when the calcium supplement was given with the meal. Inclusion of an extra 119.3 mumol (7.8 mg) Zn as part of a calcium supplement offset the detrimental effect of calcium on zinc absorption. Our findings suggest that high-calcium diets can reduce net zinc absorption and balance and may increase the zinc requirement in adult humans.

This study compared the measurement of oxygen saturation of haemoglobin (SaO2) by two pulse oximeters (Ohmeda Biox 3700e and Criticare 504 USP) with the measurement of SaO2 in arterial blood samples by CO-oximetry. Unlike many previous validation studies, arterial blood was sampled in ground glass rather than plastic syringes. Twenty men, 11 well-trained cyclists (mean +/- SE, age = 23.3 +/- 1.5 years, mass = 71.4 +/- 1.1 kg VO2max = 77 +/- 1 ml.kg1.min-1) and 9 relatively untrained subjects (age = 27.1 +/- 2.8 years, mass = 78.1 +/- 2.2 kg VO2max = 51 +/- 3 ml.kg 1.min-1) performed two maximal cycle ergometer tests each in an hypobaric chamber. The tests were at 745 mm Hg or 695 mm Hg with simultaneous measurement of SaO2 by the pulse oximeters and the CO-oximeter at rest, minute 7 of exercise and at VO2max. The best correlations, to the Co-oximeter measurement (SCO-OXO2) were found when all data from rest and exercise were combined (Criticare: r = 0.94; Ohmeda: r = 0.91). The bias measurements showed the Ohmeda underestimated SCO-OXO2 at all levels (mean = -2.5 +/- 1.9%) and the Criticare overestimated SCO-OXO2 at all levels, although to a lesser degree (mean = 0.9 +/- 1.5%). In conclusion, these results highlight the need for validation of individual pulse oximeters and that the effect of dyshaemoglobins must also be considered.

Endoscopically assisted surgery has gained wide popularity in plastic surgery. Its major uses have been in aesthetic procedures. In this article we demonstrate the safety and utility of these techniques to a pediatric population. All patients younger than 20 years who underwent an endoscopically assisted plastic surgical procedure by one of the authors were pooled and their medical records reviewed. Complications were determined. For those children having an excision of a forehead mass, the duration of the procedure, length of incision, specimen size, and length of hospital stay were determined. Additionally, parents of these children were contacted by telephone after the excisions to determine satisfaction with the procedures. Sixteen patients' records were reviewed. Patients' ages ranged from 6 months to 15 years (mean, 5.8 years). The procedures performed included removal of forehead mass (n = 9), placement of tissue expanders (n = 5), excision of gynecomastia (n = 1), and malar soft tissue elevation (n = 1). All procedures were completed with endoscopic assistance. One procedure had to be converted to an open technique. No hematomas were observed. For forehead mass excisions, the average duration of the procedure was 46.9 min. Incision length was 1.1 cm, and specimen volume was 0.5 cm3. Parent satisfaction with the endoscopic procedures was high, with 100% responding favorably. No significant complications were observed. Many of the procedures were performed as outpatients. Parental acceptance of and satisfaction with the endoscopic techniques was high. Our experience supports the use of endoscopic techniques in the pediatric plastic surgical patient.

The purpose of this study was to evaluate the application of bioabsorbable fixation devices in reconstructive craniofacial procedures in the pediatric population. We reviewed 22 cases in which bioabsorbable plates and screws were used in craniofacial surgery for reconstruction. The procedures were performed in a 7-month period. The patients ranged in age from 5 to 228 months at the time of surgery (mean, 76.7 months). The postoperative clinical follow-up ranged from 2 to 16 weeks. The fixation devices were evaluated with regards to satisfactory fixation at the time of procedure. The postoperative follow-up evaluated clinical wound healing, signs of infection or local inflammation, and visibility or palpability of plates through the skin. All patients except one showed satisfactory wound healing with no sign of infection or local inflammation. The plates provided satisfactory fixation and were not visible through the skin. Two patients had plates that were palpable at the 4-month follow-up period. One patient with repair of a blow-out fracture of the orbit with resorbable mesh had redness and swelling over the wound site 2 weeks postoperatively with resolution 4 weeks postoperatively. Our early experience suggests reabsorbable fixation is an attractive option in pediatric plastic and craniofacial surgery. With further experience, this technology may represent the standard of care in reconstruction of the infant calvarium.

Background: Histoacryl Blue (HAB), a tissue adhesive, has been shown to decrease laceration repair time, cause less pain to the child, eliminate the need for suture removal, and result in a similar short-term cosmetic outcome compared with conventional suturing. Reports suggest that poor correlation can exist between the short-term and long-term cosmetic outcomes for lacerations repaired by conventional suturing. Therefore, this study compares the long-term cosmetic outcome of HAB to conventional suturing for laceration repair in children., Design: Prospective, randomized clinical trial., Participants: Children presenting an urban pediatric emergency department for laceration repair between October 1994 and February 1995 were eligible. Patients less than 1 or more than 18 years old, those with lacerations more than 5 cm in length, or in areas of high tension or mobility were excluded., Interventions: After routine wound management, including subcutaneous closure when deemed necessary, patients were randomized to receive skin sutures or HAB for cutaneous closure. Photographs taken at the 2-month and 1-year follow-up visits were evaluated for cosmetic appearance by two plastic surgeons blinded to the method of repair., Results: Sixty-one children were enrolled: HAB (N = 30), suture (N = 31). Thirty HAB and 25 sutured patients were assessed at 2 months, while 17 HAB and 15 sutured patients were reevaluated at 1 year. Patients that followed-up at 2 months and 1 year were comparable to those with no follow-up in: treatment group (HAB vs suture), demographics, wound characteristics, and initial parental satisfaction. The two plastic surgeons graded the cosmetic appearance of the wounds repaired by HAB to be comparable to those repaired by conventional suturing at both the 2-month and 1-year follow-up., Conclusions: The use of HAB is an ideal alternative to conventional suturing for the cutaneous closure of low tension lacerations in children with a long-term cosmetic outcome comparable to conventional suturing.

While the National Institutes of Health Consensus Conference on Calcium has recommended that all elderly persons need calcium intakes of 1500 mg/day, it also recognizes that adverse effects of high-calcium diets may occur at intakes greater than 2000 mg/day. The purpose of this paper is to highlight adverse effects of high-calcium diets that could have a negative impact on health.

The objective of this study was to report the effect of gingivoperiosteoplasty on growth of the midfacial skeleton 6 years following primary surgical repair. Patients with complete unilateral cleft lip and palate who underwent primary cleft lip and nose repair with and without gingivoperiosteoplasty (GPP) were retrospectively compared by means of a lateral cephalogram. Mean age at the time of evaluation was 5.7 years. All patients were treated at the Institute of Reconstructive Plastic Surgery, New York University Medical Center. All surgery and presurgical orthopedics was performed by the same surgeon and the same orthodontist. Twenty-five consecutively treated patients who presented with complete unilateral clefts of the primary and secondary palate were included in the study. Of these, 20 patients were available for 6-year follow-up cephalometric documentation and review. All patients received preoperative orthopedics with passive molding appliances, followed by repair of the lip, alveolus, and nose in a single stage at the age of 3 months. The repair was performed using the rotation/advancement technique. The difference between the two groups was whether or not gingivoperiosteoplasty was performed. The reason for not performing gingivoperiosteoplasty was incomplete approximation of the alveolar segments usually due to a late start in beginning therapy. Lateral cephalograms (68.5 months post primary surgery) were obtained and traced. Cranial base (S-N), maxilla (ANS-PNS), and mandible (Go-Pg) were digitized for shape coordinate analysis. No significant difference in the mean position of ANS-PNS was found between groups (with or without gingivoperiosteoplasty). There was, however, a significant difference in the variance of position for the points ANS-PNS between the groups (p < .002). We were unable to observe any difference (anteroposterior or supero-inferior) in the average position of the hard palate (ANS-PNS) between groups. We conclude that gingivoperiosteoplasty results in a more uniform position of the hard palate (ANS-PNS) relative to patients that did not receive gingivoperiosteoplasty. We were unable to demonstrate any clear impairment of maxillary growth in the patients treated with gingivoperiosteoplasty when compared to patients treated without gingivoperiosteoplasty.

This case describes a repair of a unilateral cleft lip complicated by a lip hemangioma. The relevant issues regarding timing of the repair include safety of the procedure by minimizing blood loss during excision of the hemangioma and minimizing anesthesia risk. In obtaining a lasting cosmetic result, excision of the hemangioma would need to be done when the potential for residual tumor growth would be least likely (during tumor involution). Finally, the difficult issue of psychosocial concerns would balance the need for traditional early cleft repair with a definitive repair prior to increased social interaction in school. All these concerns were met with a delayed single-stage repair after partial involution of the hemangioma. We feel that a single-stage excision and lip repair is an acceptable option. It is reasonable to delay the cleft lip repair until significant involution of the hemangioma has occurred. An acceptable aesthetic result is obtainable.

Objective: To determine the effectiveness of a tissue adhesive, Histoacryl Blue (HAB), for laceration repair in children., Design: Prospective, randomized clinical trial., Setting: A tertiary care pediatric emergency center at Egleston Children's Hospital., Participants: Children who presented for laceration repair between October 1994 and February 1995 were prospectively evaluated. Patients less than 1 or greater than 18 years of age, those with lacerations greater than 5 cm, and those with lacerations located on the eyelids, ears, nose, lips, hands, feet, joints, or perineum were excluded., Interventions: Following consent and routine wound management, including subcutaneous closure when deemed necessary, patients were randomized to receive skin sutures or HAB for cutaneous closure., Methods: Length of time required for laceration repair was recorded. Parental perception of the pain experienced by their child was assessed using a visual analogue scale. Photographic documentation of scar appearance at the 2-month follow-up visit was evaluated by plastic surgeons using a visual analogue scale., Results: Sixty-one children were enrolled: HAB group (N = 30), suture group (N = 31). No differences occurred between groups in laceration length, depth, location, or patient demographics. Length of time required for repair was decreased (median, HAB 7 minutes vs suture 17.0 minutes) and parental assessment of their child's pain was significantly less in the HAB group. Parents were more likely to recommend HAB over suturing to other parents or guardians. Cosmetic outcome in the HAB group was assessed to be as good as, or better than, the cosmetic outcome in the suture group as evaluated by two plastic surgeons., Conclusion: The use of HAB for laceration repair is an acceptable alternative to conventional suturing with a comparable cosmetic outcome. Advantages include less pain to the child, no need for suture removal, and more efficient use of physician time. Parents were also more likely to recommend HAB over suturing for laceration repair.

A formulated protein meal developed by Kogan (1990) for adult female Aedes aegypti mosquitoes was evaluated and modified to increase egg and pupal yield. A vigorous laboratory colony was maintained with the females fed exclusively on this dietary formula for about twenty-five generations over more than 2 years. Extra modifications were made to produce a diet suitable for Anopheles arabiensis and Anopheles stephensi females to produce eggs. Both formulations contain bovine albumin, haemoglobin and globulin in a ringer based solution, plus ATP as a phagostimulant for Ae.aegypti. Compared to Kogan's original, our Aedes formula doubled the production of pupae per female after a single meal, although the yield was still significantly lower than from mosquitoes fed on animal hosts or defibrinated pig blood. In varying the proportions of different constituents during attempts to optimize the formula, no relationship was found between total protein content (within the range 80-220 mg/ml) and fecundity, percentage hatch or pupal yield of Ae.aegypti. Equivocal results were found when an isoleucine supplement was added to the formula.

This study utilized a hypobaric chamber to compare the effects of mild hypobaria (MH; 50 mmHg, approximately 580 m altitude) on blood O2 status and maximal O2 consumption (VO2max) in 9 untrained and 11 trained (T) cyclists with VO2max values of 51 +/- 3 and 77 +/- 1 ml.kg-1.min-1, respectively. In both groups, arterial O2 saturation (SaO2) decreased significantly during maximal exercise, and this effect was enhanced with MH. Both these responses were significantly greater in the T cyclists in whom the final SaO2 during MH was 86.5 +/- 0.9%. When the group data were combined, approximately 65% of the variance in SaO2 could be attributed to a widened alveolar-arterial Po2 difference. The arterial PO2 during maximal exercise at sea level in the T group was on the steeper portion of the hemoglobin-O2-loading curve (T, 68.3 +/- 1.3 Torr; untrained, 89.0 +/- 2.9 Torr) such that a similar decrease in arterial PO2 in the two groups in response to MH resulted in a significantly greater fall in both SaO2 and calculated O2 content in the T group. As a consequence, the VO2max fell significantly only in the T group (mean change, -6.8 +/- 1.5%; range, + 1.2 to - 12.3%), with approximately 70% of this decrease being due to a fall in O2 content. This is the lowest altitude reported to decrease VO2max, suggesting that T athletes are more susceptible to a fall in inspired PO2.

Several 1 alpha,25-(OH)2-vitamin D3 (1 alpha,25-(OH)2-D3) analogs have significant antiproliferative effects in vitro but do not elevate serum calcium in vivo. We tested whether the lack of a calcemic response of a vitamin D analog in vivo is due to its inability to stimulate intestinal calcium absorption by examining the effect of several such compounds on transepithelial calcium transport in the human colonic carcinoma cell line Caco-2. The relative stimulations of calcium transport by the four A-ring diastereomers of 1 alpha, 25-(OH)2-D3 (1 alpha,3 beta) and a 3 beta-bromoacetate analog (1 alpha,3 beta-BrAc) of the vitamin following 48-h treatment of cells at 10 nM were 1 alpha,3 beta (=100%), 1 alpha,3 alpha (+45.2%), 1 beta,3 beta (-15.6%), 1 beta,3 alpha (+6.5%), and 1 alpha,3 beta-BrAc (+50.6%). This was similar to the reported affinity of these compounds for the vitamin D receptor (VDR) and suggests that VDR binding predicts calcium transport. In contrast, three noncalcemic, sidechain- or D-ring-modified analogs of vitamin D, 1 alpha,25-(OH)2-16-ene-D3, 1 alpha,25-(OH)2-16-ene-23-yne-D3, and 1 alpha,25,28-(OH)3-D2 (at 10 nM for 48 h), showed a different relationship between VDR affinity (150, 60, and 63% of 1 alpha, 25-(OH)2-D3, respectively) and calcium transport (74.1, 126, and 10%, respectively). Elevated calcium transport was accompanied by higher 24-hydroxylase and calbindin D9k mRNA levels. The data demonstrate that although some vitamin D compounds cannot stimulate calcium transport due to an inability to interact with the VDR (e.g., 1 beta isomers), other factors, e.g., differential cellular metabolism, may account for variations in biological response in vivo to various vitamin D analogs.

Anecdotal evidence suggests that the 610 m altitude of the Australian Institute of Sport in Canberra may affect athletic performances, despite the lack of theoretical evidence to support this. Also, the lower air resistance at altitude could alter the mechanics of air-braked exercise ergometers. Therefore, this study compared performance on a Concept II Rowing Ergometer at sea level (SL) and at Canberra (CB). Fourteen male junior rowers (age 16.1 +/- 0.6 years, weight 73.4 + or - 4.1 kg height 182.7 + or - 43 cm) completed two six-minute all-out rowing ergometer tests, in random order at either SL or CB. There was a significantly different (p < 0.001) peak VO2, 4.12 + or - 0.24 (SL) and 3.97 + or - 0.25 l-min-1 (CB). However there was only a small but non-significant difference in the distance completed; 1672 + 39 m (SL) to 1666 + or - 44 m (CB). The similar work completed at CB despite a lowered peak VO2 could not be explained by an increased energy contribution by glycolysis or by changes in rowing efficiency. Peak VI ATP was similar at both locations, although when corrected to STPD was significantly different (p < 0.001). Mean FEO2 was 17.29 + or - 0.25 (SL) and 17.09 + or - 0.28 (CB) indicating a greater O2 extraction at CB, which partially compensated for the lower PIO2. This effect on VO2 at such a low altitude has not been shown before, and means that altitude should always be considered in the interpretation of the results of aerobic fitness tests.

In humans, the progressive loss in skeletal bone mass with aging increases the risk of osteoporosis and bone fractures in the elderly. As parathyroid hormone (PTH) and growth hormone (GH) may both be anabolic in bone, we tested if the combination of these hormones would increase bone mass more than either agent alone in aging multiparous and virgin female rats. In four separate studies, female rats (15-18 months old) were treated for 12 or 15 days with synthetic human parathyroid hormone (hPTH 1-34) at 80 micrograms/kg per day given once daily, alone or combined with ovine GH at 1 mg/kg per day given twice daily. Bone of distal femurs, proximal tibias and lumbar vertebrae, dietary mineral (Ca, P, Mg) excretion and balance and serum chemistry were assessed. PTH alone stimulated bone formation and increased bone mass in three of four experiments and consistently increased serum 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) and mineral retention. GH alone did not change either bone formation or bone mass, but combined with PTH increased mineral retention and serum 1,25-(OH)2D3), more than either hormone alone. Despite this stimulatory effect on Ca retention, GH did not further enhance the anabolic effect of hPTH 1-34 on bone mass of aging multiparous and virgin female rats.

It has been demonstrated that distraction osteogenesis is an effective clinical tool with applications for the entire human skeleton. Therapeutic exploitation in the correction of the asymmetrical and hypoplastic mandible has been reported previously. However, the main criticism of this technique has been the residual cutaneous scars resulting from the surgical incision and the path of the expansion device. In order to obviate the need for skin incisions, we have developed and demonstrated the feasibility of a miniaturized mandibular bone lengthener that is suitable for intraoral placement. Ten growing mongrel dogs were studied. Under general anesthesia, a buccal mucosal incision was made along the oblique line, and the body and ramus of the mandible were exposed in a supraperiosteal plane. Two 2.0-mm half-pins were placed percutaneously in the area of the angle of the mandible, and two other pins were placed 3.5 cm anteriorly. The clamps of the lengthening device were then attached to the half-pins in an intraoral position. An osteotomy was made by connecting percutaneously made drill holes between the clamps in a line positioned posterior to the third molar. The mucosa was closed loosely over the device. Distraction was commenced on the eighth postoperative day. The results were assessed with pre- and post-lengthening photographs, cephalograms, and CT scans with three-dimensional reconstruction. All animals demonstrated a contralateral cross-bite. The newly developed bone also was examined histologically. The intraoral method of mandibular lengthening offers the same advantages of extraoral lengthening but without the need for a cutaneous incision and resulting scar.

Poor mineral nutrition reported in elderly people is attributed in large part to low dietary intake. Evaluation of the adequacy of mineral nutriture is limited for several minerals because of inadequate methods for assessing mineral status. In addition, there is a general lack of information about mineral nutriture and metabolism in very old people (> 85 y). Given these reservations, the 1989 recommended dietary allowance (RDA) for iron, zinc, and selenium appears adequate for elderly people, as does the estimated safe and adequate daily dietary intake (ESADDI) recommendation for copper. In contrast, the current RDAs for calcium and magnesium and the ESADDI for chromium need careful reevaluation. Current recommendations for calcium may be too low, whereas those for magnesium and chromium may be higher than necessary. For phosphorus, iodine, manganese, fluoride, and molybdenum the available data are insufficient to make a critical judgment about the appropriateness of the dietary recommendations for elderly people.

Membrane feeding of 3 mosquito species, Aedes aegypti, Anopheles stephensi, and Anopheles arabiensis, with formulated protein meals was carried out at a range of temperatures. The response was evaluated in terms of probing after 5 min, engorgement after 90 min, and 50% feeding time. Aedes aegypti showed a satisfactory feeding response across the complete temperature range investigated, 28-40 degrees C, although engorgement was significantly faster between 36 and 40 degrees C. Anopheles stephensi fed best between 32 and 40 degrees C. Anopheles arabiensis showed a poor probing and feeding response at all temperatures, although the best responses were recorded at 38-40 degrees C.

Objective: Low gastric pH is generally believed to be an important factor in intestinal mineral absorption. Thus, hypochlorhydria could be an important risk factor for mineral malabsorption and the development of marginal mineral status. We studied whether the hypochlorhydria associated with treatment with the anti-ulcer medication omeprazole, a potent gastric proton pump inhibition, would affect intestinal calcium, phosphorus, magnesium, or zinc absorption from food., Methods: Thirteen normal, healthy adults were assigned to either a control group (n = 5) receiving no drug treatment or an omeprazole treatment group (n = 8) to produce increased gastric pH. Omeprazole treatment of normal volunteers resulted in a significant change in postprandial gastric pH (pH 6.4 +/- 0.3 vs. 3.6 +/- 0.5 in control subjects, p < 0.01) and baseline fasting pH (pH 5.8 +/- 0.5 vs. pH 1.8 +/- 0.3 in controls, p < 0.01) after an overnight fast. Net mineral absorption from a standard test meal was measured using a whole gut lavage technique. Mineral absorption was measured twice in each subject, once with 120 mL of 0.1 mol/liter hydrochloric acid and a second time with 120 mL of distilled water alone., Results: We found that despite marked changes in gastric pH due to drug treatment or administration of exogenous HCl, no change in the intestinal absorption of calcium, phosphorus, magnesium or zinc from a standard test meal was evident., Conclusions: These findings suggest that changing the gastric pH alone does not modify the net intestinal absorption of several minerals from food. Therefore, it is unlikely that moderate hypochlorhydria resulting from short-term omeprazole treatment substantially increases the risk for developing calcium, phosphorus, magnesium, or zinc deficiencies due to mineral malabsorption.

A recent study by Ahluwalia and colleagues used a discriminant statistical analysis approach to determine that a combination of serum ferritin, plasma transferrin receptor concentration, and erythrocyte sedimentation rate was the optimal set of variables for differentiating iron deficiency and the anemia associated with chronic disease in a group of elderly women. Iron deficiency was defined as a significant response in hemoglobin concentration after iron supplementation. The findings of this study suggest that iron deficiency can be relatively common among elderly anemic women with rheumatoid arthritis. Use of these three biochemical measures should be clinically useful to differentiate iron deficiency in the anemia of chronic disease.

We conducted a study to determine whether a recently described restriction fragment length polymorphism in the vitamin D receptor gene (VDR-RFLP) predicts bone mineral density (BMD) in unrelated, premenopausal women as well as to determine the racial contribution to any genotypic influences on BMD. White (n = 83) and black (n = 72) women between 20 and 40 years of age were genotyped based on the presence (b) or absence (B) of a BsmI restriction enzyme site in the VDR gene, and BMD in the lumbar spine and femur neck was determined for each subject. There were 16 BB, 73 Bb, and 66 bb women. No significant difference was observed in genotypic distribution between the racial groups. The interaction of race by genotype on age- and body mass index (BMI)-adjusted BMD was not significant at either site. Age- and BMI-adjusted BMD was higher in black women at the spine (by 7.2%, p = 0.046) and femur neck (7.3% higher, p = 0.004). In the group as a whole, mean BMD in the femur neck was lower in the BB women that the bb (by 8.1%, p = 0.034) or Bb women (by 9.3%, p = 0.015) after controlling for age, BMI, race, and the race by genotype interaction. Adjusted lumbar spine BMD was lower in the BB women than the Bb women (6.4% lower, p = 0.036) in the group as a whole. No difference were detected between Bb and bb women at either site. A similar pattern of low BMD at the femur neck and the lumbar spine was seen in BB women of both races.(ABSTRACT TRUNCATED AT 250 WORDS)

Midface hypoplasia, often associated with exorbitism and malocclusion, has been traditionally corrected by using Le Fort advancement osteotomies through wide surgical exposure. These procedures suffer the disadvantages of hemorrhage, unpredictable bone graft resorption, the need for retained hardware, and bone graft donor-site morbidity. We present an investigation of midface distraction in the canine without osteotomies. Five canines were the subjects of this study and were divided into two groups. At the time of placement of the lengthening devices, Group 1 animals were 10 weeks of age and Group 2 animals were 5 years of age. Under general anesthesia, four modified Hoffman bone distractors were mounted on 2-mm half pins placed individually across the nasofrontal and the zygomaticotemporal sutures on each side of the craniofacial skeleton. Distraction of all devices was begun on postoperative day 1 at the rate of 0.5 mm/day for 4 days and then 1.0 mm/day for 28 days, after which interval the devices were removed. The dogs were serially monitored and examined for 3 months. One dog in the first group served as a sham control. The results were assessed by standardized cephalograms, and craniofacial computed tomographic scans with three-dimensional reconstruction performed before device placement as well as after removal of the device. In one Group 1 animal, computed tomographic scanning was performed every 2 to 4 weeks for 3 months. Gross examination of the Group 1 animals demonstrated the development of enophthalmos, dolichocephaly, and a class II malocclusion-overbite.(ABSTRACT TRUNCATED AT 250 WORDS)

A convenient, electronically controlled, in situ, membrane feeding system is described. Evaluation of the system for feeding single pair-mated Aedes aegypti with defibrinated, refrigerated pig blood indicated no significant difference from mouse-fed controls in rat of egg maturation, fecundity, or pupal yield. The feeding system is also suitable for use with substitute protein meals.

A recent study of postmenopausal women has shown that the administration of 60-120 mmol potassium bicarbonate can neutralize net acid excretion and significantly lower urinary calcium (Ca). The changes in urinary calcium loss were sufficient to improve calcium balance and skeletal metabolism in these subjects. However, the design of the study was such that the relevance of these findings to the prevention and treatment of osteoporosis is suspect.

Aged (16-month-old) female rats (n = 8/treatment) were injected for 12 days with GH (100 micrograms/100 g x day), PTH (8 micrograms/100 g x day), GH plus PTH, or vehicle (V) in an experiment designed to determine the effects of these hormones on intestinal mineral absorption in senescent rats. PTH and GH increased fractional net calcium absorption to a similar extent (PTH, 1.6-fold; GH, 1.4-fold) even though PTH increased serum 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] 3.7-fold, and GH had no significant effect. GH plus PTH caused no further increase in serum 1,25-(OH)2D3 above that caused by PTH alone, but resulted in an additive effect on net calcium absorption (2.3-fold increase). PTH and GH also had statistically independent effects on phosphate absorption; magnesium absorption was elevated only by PTH. Duodenal calbindin-D9k levels were increased by GH (from 3.79 +/- 0.72 to 6.98 +/- 0.73 micrograms/mg protein) and PTH (from 3.23 +/- 0.46 to 7.55 +/- 0.75 micrograms/mg protein); PTH plus GH treatment resulted in an additive effect on calbindin-D9k levels. Additional in vitro transport studies in the human intestinal cell line Caco-2 showed that 72 h of pretreatment with the local mediator of GH action, insulin-like growth factor-I (at 10 and 100 ng/ml), stimulated transcellular calcium transport (22% and 44%, respectively) regardless of concomitant 1 nM 1,25-(OH)2D3 pretreatment (80% increase). Our findings suggest a 1,25-(OH)2D3-mediated mechanism for PTH-induced changes in calcium and phosphorus absorption. In contrast, the effects of GH in the senescent rat are independent of changes in circulating 1,25-(OH)2D3 and our data suggest that these effects may be mediated by insulin-like growth factor-I.

We have identified and quantified specific mRNAs in the human colonic carcinoma cell line Caco-2 by reverse transcriptase-polymerase chain reaction. Initial examination revealed that like rat duodenal mucosa, Caco-2 cells possessed mRNA for the vitamin D receptor. Using primers for human calbindin we found a 237-bp PCR product in Caco-2 cell RNA, but not from rat duodenal RNA. Primers for rat calbindin did not amplify calbindin mRNA in Caco-2 RNA, confirming a high degree of mismatch between rat and human sequences. 1,25(OH)2 vitamin D3 treatment (10 nM) significantly elevated calbindin mRNA levels 50% by 12 h, with maximal levels occurring by 48 h (fivefold elevation). Increasing concentrations of 1,25(OH)2 vitamin D3 (from 15 pM to 100 nM) caused progressive increases in calbindin mRNA levels following 48 h of treatment. Elevated calbindin mRNA levels were associated with enhancement of transcellular calcium transport. Our results are the first demonstration of vitamin D-regulated calbindin mRNA in a human intestinal cell line.

We measured zinc absorption in humans from two different foods, using a whole-gut lavage technique. Healthy adults (n = 8) were given test foods containing approximately 4 mg (61.2 mumol) Zn as either beef or a high-fiber, ready-to-eat breakfast cereal. Basal zinc loss in the gut was measured after giving only 200 mL water alone after an overnight fast. Mean polyethylene glycol (PEG) recovery, a nonabsorbable fecal marker, was 95 +/- 2% (mean +/- SE). There was no significant difference of PEG recoveries with the various treatments. True absorption of zinc was 11.0 +/- 5.4 mumol (716.3 +/- 355.9 micrograms) for breakfast cereal and 34.8 +/- 3.5 mumol (2274.1 +/- 230.2 micrograms) for beef. Fractional zinc absorption was significantly lower for breakfast cereal compared with beef, 14.7 +/- 6.7% vs 55.1 +/- 4.6%, respectively. Our findings demonstrate that zinc absorption can be measured in humans from single foods containing a physiological dose of zinc by using the whole-gut lavage absorption technique and that zinc bioavailability from beef is about fourfold greater than from a high-fiber breakfast cereal.