Calcium Output Research Articles

P-19 A case of Birt Hogg Dube syndrome presented with parathyroid carcinoma

Abstract Introduction The Birt Hogg Dube syndrome is an autosomal dominant genodermatosis caused by a mutation in the folliculin gene. It is characterized by benign lung cysts with spontaneous pneumothorax, kidney tumors, and hair follicle tumors. Other solid tumors may accompany. Our case is a man with Birt Hogg Dube Syndrome who has parathyroid cancer. Clinical Case A 50-year-old male was referred to our clinic for treatment of hypercalcemia and elevated parathormone; he complained of weakness, muscle, and joint discomfort. His previous medical history included Renal Cell Carcinoma, Coronary artery by-pass graft, pulmonary thromboembolism, hypertension, nephrolithiasis, and stage 4 chronic kidney disease. There was a familial history of colon cancer, with both his aunt and uncle having been diagnosed. The systemic evaluation revealed the presence of constipation, polyuria, pollakiuria. A palpable 3 cm nodular lesion was discovered in the inferior lobe of the patient's left thyroid, and the patient's vital signs were stable. There were lesions on the inner surface of the right thigh and the skull. The biopsies obtained from the lesions on the skin revealed a lipoma on the cranium and a fibrofolliculoma on the thigh upon pathological examination. Regarding laboratory exams, both the hemogram and transaminase levels were within normal limits. Serum albumin was measured at 4.9 g/L creatinine at 2.5 mg/dl, calcium at 12 mg/dl, ionized calcium at 5.9 mg/dl, phosphorus at 2.4 mg/dl, parathormone at 373 ng/dL, and 25-OH Vitamin D at 32 ng/ml. Alkaline phosphatase was determined to be 66 U/L, and 24-hour calcium output was 60 mg/day. The thyroid function test results were euthyroid, while the anterior pituitary panel was normal. The patient underwent a left inferior parathyroidectomy after thyroid ultrasonography and parathyroid scintigraphy revealed a parathyroid adenoma. The parathyroid carcinoma is identified in the pathology report. The ultrasound-observed nodule on the isthmus of the thyroid has been identified as thyroid papillary carcinoma. Bone mineral density was normal. A previously performed CT scan of the thorax for dyspnea revealed the presence of multiple cystic structures in the lungs. Taking into account the patient's history of multiple malignancies, an 18-FDG-PET CT scan was performed, revealing a significant FDG uptake (SUV Max: 22) in the patient's sigmoid colon. Pathology analysis of the removed lesion confirmed that it was a tubulovillous adenoma with high-grade dysplasia. The patient, who showed heterozygosity for the Folliculin gene, was identified as having Birt-Hogg-Dube syndrome after further genetic panel testing. Conclusion According to the most recent literature evaluation, our patient is the first Birt Hogg Dube individual to present with parathyroid carcinoma. There is some evidence in the published literature linking somatic mutation of the Folliculin gene to the development of parathyroid cancer.

Heterogeneous presynaptic receptive fields contribute to directional tuning in starburst amacrine cells.

The processing of visual information by retinal starburst amacrine cells (SACs) involves transforming excitatory input from bipolar cells (BCs) into directional calcium output. While previous studies have suggested that an asymmetry in the kinetic properties of BCs along the soma-dendritic axes of the postsynaptic cell could enhance directional tuning at the level of individual branches, it remains unclear whether biologically relevant presynaptic kinetics contribute to direction selectivity (DS) when visual stimulation engages the entire dendritic tree. To address this question, we built multicompartmental models of the bipolar-SAC circuit and trained them to boost directional tuning. We report that despite significant dendritic crosstalk and dissimilar directional preferences along the dendrites that occur during whole-cell stimulation, the rules that guide BC kinetics leading to optimal DS are similar to the single-dendrite condition. To correlate model predictions to empirical findings, we utilized two-photon glutamate imaging to study the dynamics of bipolar release onto ON- and OFF-starburst dendrites in the murine retina. We reveal diverse presynaptic dynamics in response to motion in both BC populations; algorithms trained on the experimental data suggested that the differences in the temporal release kinetics are likely to correspond to heterogeneous receptive field properties among the different BC types, including the spatial extent of the center and surround components. In addition, we demonstrate that circuit architecture composed of presynaptic units with experimentally recorded dynamics could enhance directional drive but not to levels that replicate empirical findings, suggesting other DS mechanisms are required to explain SAC function. Our study provides new insights into the complex mechanisms underlying DS in retinal processing and highlights the potential contribution of presynaptic kinetics to the computation of visual information by SACs.

Heterogeneous presynaptic receptive fields contribute to directional tuning in starburst amacrine cells

The processing of visual information by retinal starburst amacrine cells (SACs) involves transforming excitatory input from bipolar cells (BCs) into directional calcium output. While previous studies have suggested that an asymmetry in the kinetic properties of BCs along the soma-dendritic axes of the postsynaptic cell could enhance directional tuning at the level of individual branches, it remains unclear whether biologically relevant presynaptic kinetics contribute to direction selectivity (DS) when visual stimulation engages the entire dendritic tree. To address this question, we built multicompartmental models of the bipolar–SAC circuit and trained them to boost directional tuning. We report that despite significant dendritic crosstalk and dissimilar directional preferences along the dendrites that occur during whole-cell stimulation, the rules that guide BC kinetics leading to optimal DS are similar to the single-dendrite condition. To correlate model predictions to empirical findings, we utilized two-photon glutamate imaging to study the dynamics of bipolar release onto ON- and OFF-starburst dendrites in the murine retina. We reveal diverse presynaptic dynamics in response to motion in both BC populations; algorithms trained on the experimental data suggested that the differences in the temporal release kinetics are likely to correspond to heterogeneous receptive field properties among the different BC types, including the spatial extent of the center and surround components. In addition, we demonstrate that circuit architecture composed of presynaptic units with experimentally recorded dynamics could enhance directional drive but not to levels that replicate empirical findings, suggesting other DS mechanisms are required to explain SAC function. Our study provides new insights into the complex mechanisms underlying DS in retinal processing and highlights the potential contribution of presynaptic kinetics to the computation of visual information by SACs.

Patients with oral lichen planus display lower levels of salivary acidic glycoproteins than individuals without oral mucosal disease

ObjectivesSalivary proteins, acidic glycoproteins, and free calcium might take part in oral mucosal defence against inflammation in oral lichen planus (OLP). The study aimed to investigate whether the levels of sulfated and sialylated glycoproteins, total protein, and free calcium in saliva from patients with OLP differ from those of individuals without oral mucosal diseases.Material and MethodsPatients diagnosed with OLP (n = 25) and two control groups without any oral mucosal disease; age- and gender-matched controls (n = 25, 65.6 ± 2.9 years), and younger controls (n = 25, 41.8 ± 2.5 years) were included. Subjective dry mouth (xerostomia) was assessed by asking a single-item question. Chew-stimulated whole saliva was collected to measure sulfated and sialylated glycoproteins by the Alcian Blue method. The total protein was determined spectrophotometrically, and the free calcium measured using an electrode.ResultsThe output of salivary sulfated and sialylated glycoproteins in the OLP group (21.8 ± 2.4 µg/min) was lower than in the age- and gender-matched controls (43.0 ± 2.9 µg/min, p = 0.0002), whereas the total protein and calcium output did not differ between the three groups (p > 0.05). The prevalence of xerostomia was significantly higher in the OLP group compared to both control groups (p = 0.038).ConclusionsPatients with OLP showed a high prevalence of xerostomia and lower levels of salivary acidic type glycoproteins compared to the individuals without oral mucosa disease.Clinical relevanceIt is relevant to investigate the role of acidic glycoproteins in the pathogenesis of OLP.

Cross-Disciplinary Approach of Adrenal Tumors: Insights into Primary Aldosteronism-Related Mineral Metabolism Status and Osteoporotic Fracture Risk.

Our objective was to overview the novel aspects in the field of adrenal gland neoplasms, namely, the management of bone status with respect to primary aldosteronism (PA). In the current narrative review, a PubMed study was conducted from inception until June 2023. The inclusion criteria were: human (clinically relevant) studies of any study design (at least 10 patients per study); English papers; and the following combination of key words within the title and/or abstract: "aldosterone" AND "bone", "skeleton", "osteoporosis", "fracture", "calcium", "parathyroid", "DXA", "osteocalcin", "P1NP", "alkaline phosphatase", "bone marker", "trabecular bone score", or "FRAX". The exclusion criteria were in vitro or animal studies, reviews, and case reports/series. We screened 1027 articles and finally included 23 studies (13 of case-control type, 3 cross-sectional, 5 prospective, 1 observational cohort, and 1 retrospective study). The assessments provided in these studies were as follows: nine studies addressed Dual-Energy X-ray Absorptiometry (DXA), another study pointed out a bone microarchitecture evaluation underlying trabecular bone score (TBS), and seven studies investigated the bone turnover markers (BTMs) profile. Moreover, 14 studies followed the subjects after adrenalectomy versus medical treatment, and 21 studies addressed secondary hyperparathyroidism in PA patients. According to our study on published data during a period of almost 40 years (n = 23, N = 3965 subjects aged between 38 and 64, with a mean age 56.75, and a female-to-male ratio of 1.05), a higher PTH in PA versus controls (healthy persons or subjects with essential hypertension) is expected, secondary hyperparathyroidism being associated in almost half of the adults diagnosed with PA. Additionally, mineral metabolism anomalies in PA may include lower serum calcium and higher urinary calcium output, all these three parameters being reversible under specific therapy for PA, regardless medical or surgical. The PA subgroup with high PTH seems at higher cardiovascular risk, while unilateral rather than bilateral disease was prone to this PTH anomaly. Moreover, bone mineral density (BMD) according to central DXA might show a higher fracture risk only in certain adults, TBS being a promising alternative (with a still unknown perspective of diabetes' influence on DXA-TBS results in PA). However, an overall increased fracture prevalence in PA is described in most studies, especially with respect to the vertebral site, the fracture risk that seems correctable upon aldosterone excess remission. These data recommend PA as a cause of secondary osteoporosis, a treatable one via PA intervention. There is still an area of debate the way to address BMTs profile in PA, the case's selection toward specific bone evaluation in every day practice, and further on, the understanding of the potential genetic influence at the level of bone and mineral complications in PA patients.

Abstract P2136: TpTe Interval Behavior And Mortality In Wistar Rats Submitted To Cardiac Ischemia And Reperfusion Treated With The Heparin Fragment Trisulfated Disaccharide

Introduction: The Tp-Te ekg interval reflects ventricular transmural dispersion, being used for prediction of ventricular arrhythmia and sudden death. The heparin fragment called Trisulfated Disaccharide (TD), which has no effect on blood coagulation and acts on the sodium-calcium exchanger accelerating the output of calcium from the cell, decreases cytoplasmic calcium concentrations in situations of calcium overload due to ischemia and reperfusion (I-R). Objective: To evaluate the behavior of the Tp-Te interval and mortality due to cardiac arest in Wistar rats submitted to surgicaly induced I-R under treatment with TD at reperfusion. Materials and Method: Wistar rats (n=8) with average weight of 300g were anesthetized and under assisted breathing were electrocardiographically monitored and submitted to surgical cardiac ischemia by ligation of the anterior descending artery for 10 min, with reperfusion thereafter. The Tp-Te interval was analyzed before ischemia, at 10 min after ischemia induction and at 10 min after reperfusion, The incidence of arrhythmias was determined throughout the recording period. In the study group intravenous (0.2 mg/kg) TD was injected concomitantly with the reperfusion. In the control group (n=8), the same procedure was performed, without the TD infusion. Results: During ischemia there was a similar alteration of the Tp-Te interval in both groups when compared to the pre-ischemic phase, with an increase of about 90% in magnitude, as well as the presence of ventricular arrhythmias, without animal mortality. During reperfusion Tp-Te interval returned to normal in the treated group and there was no mortality. In the control group, the magnitude of the Tp-Te increase was maintained. The presence of ventricular arrhythmias was similar, but total atrioventricular block and/or sustained arrhythmia occurred in 50% of the animals, followed by animals death. Conclusion: Treatment with TD at the time of reperfusion normalized the Tp-Te interval 10 min after TD infusion as well as reduced mortality in wistar rats submitted to I-R, and may be useful in the protection of organs submitted to the same I-R conditions (transplants, surgical and hemodynamic procedures), where calcium overload is determinant in morbidity and mortality.

The Importance of Interpreting Urine Calcium:Creatinine Ratio in PHPT Within Ethnic Context

A 56-year-old Afro-Caribbean lady was found to have incidental hypercalcaemia on routine GP investigations. Tiredness was the only elicitable hypercalcaemic symptom and aside from early menopause at age 40, she had no significant past medical or family history. Examination was unremarkable. Blood results showed a raised adjusted calcium 2.68mmol/L (2.2–2.6), normal phosphate 1.06mmol/L (0.80–1.50), raised parathyroid hormone (PTH) 14.1pmol/L (1.6–7.2) and low 25-hydroxyvitamin D 28.1nmol/L (70–150).She had osteopaenia of the femora and left radius on DEXA scan but no nephrocalcinosis on renal ultrasound. On initial investigation, her urinary calcium output was low at 1.55mmol/day resulting in a 24h calcium:creatinine ratio (UCCR) of 0.0065. Although suggestive of Familial Hypocalciuric Hypercalcaemia (FHH), her notable Vitamin D deficiency was considered to contribute to the observed hypocalciuria. After Vitamin D repletion, a repeat UCCR improved to 0.012, however, remained in the indeterminate range. No known pathogenic variant was identified on genetic analysis for FHH.Her PTH and Calcium levels remained persistently high within 9.7–17.1pmol/L and 2.65-2.82mmol/L respectively, suggestive of Primary Hyperparathyroidism (PHPT) given the end organ damage and negative genetic studies. Based on her symptom of fatigue, osteopaenia at a young age and hypercalcaemia, localisation studies were arranged which showed no definitive evidence of a parathyroid adenoma and explorative surgery was planned.The negative genetic testing, PTH level 17.1pmol/L, osteopaenia, low-normal magnesium and phosphate level collectively support a diagnosis of PHPT in this case, despite a low UCCR which however is observed in some PHPT patients. Indeed, a lower UCCR ratio has been reported in the healthy Afro-Carribean population across all age groups, as well as in Afro-Carribean patients with PHPT [1]. The underlying mechanism for this is yet to be determined but may be due to increased renal sensitivity to PTH or altered activity of the tubular calcium reabsorptive pathways. One can further speculate regarding an evolutionary reason behind a protective homeostatic system favouring renal calcium reabsorption over excretion in this frequently vitamin D deficient population.Clinical practice relies heavily on the use of UCCR in aiding the biochemical differentiation of PHPT and FHH. However, as this case highlights, its use can be misleading in Afro-Carribean patients and therefore should be interpreted within an ethnic context.

Bone turnover is altered during 72 h of sleep restriction: a controlled laboratory study.

The objective of the study was to evaluate how controlled, short-term sleep restriction (SR; 72 h) alters markers of bone formation and resorption and urinary calcium (Ca) output. Ten healthy, sleep-adequate, male soldiers were housed in the research facility one day prior to and for the duration of SR. Diet was controlled to provide adequate energy balance and macronutrient distribution, meeting the recommended dietary allowance (RDA) for Ca. Subjects engaged in light activities to maintain wakefulness and were allowed 2 h of sleep per night (0430-0630 hours). Blood samples were collected each morning at 0 h (baseline) and 24, 48, and 72 h of SR. Serum was assayed for parathyroid hormone (PTH), bone alkaline phosphatase (BAP), tartrate-resistant acid phosphatase (TRAP), and C-terminal telopeptide of type I collagen (CTX). Urine was collected in 24 h increments during SR for measurement of Ca and creatinine (Cr). BAP was reduced at 24 h (P= 0.015) and resorption markers TRAP and CTX were increased after 48 and 72 h of SR compared to baseline (P < 0.05). The ratio of BAP:TRAP was significantly lower (P= 0.017) at 48 and 72 h of SR. In contrast, total 24 h urinary Ca and Ca/Cr excretion were unchanged. Markers of bone formation and resorption are uncoupled in response to as little as 48 h of SR even when Ca intake is at the RDA. Sleep deprivation may be a risk factor for reduced bone health due to perturbations in bone turnover.

The Skeleton Is a Storehouse of Mineral That Is Plundered During Lactation and (Fully?) Replenished Afterwards.

During lactation, mammals resorb mineral from the maternal skeleton to provide calcium to milk. Rodents lose 25% to 35% of skeletal ash weight, ash calcium content, and bone mineral content as measured by dual-energy X-ray absorptiometry (DXA), and have compromised material properties of bone as assessed by crushing vertebrae and 3-point bend tests of femora or tibias. The strength, stiffness, and toughness of vertebrae, femora, and tibias are reduced by as much as 60%. The effects of lactation are not uniform throughout the skeleton, but instead resorption is much more marked in the trabecular-rich spine than in the appendicular skeleton or whole body. Women who breastfeed exclusively lose an average of 210 mg calcium in milk each day, whereas nursing of twins or triplets can double and triple the output of calcium. Clinical data are also consistent with skeletal calcium being released during lactation to provide much of the calcium needed for milk production. Lumbar spine bone mineral density (BMD), as assessed by DXA, declines by a mean of 5% to 10% among numerous studies during 3 to 6 months of exclusive lactation, whereas largely cortical sites (hip, forearm, whole body) show half that loss or no significant changes. Micro-CT of rodents and high-resolution peripheral quantitative computed tomography (HR-pQCT) imaging of women confirm that lactation causes microarchitectural deterioration of bone. These skeletal losses occur through two pathways: upregulated osteoclast-mediated bone resorption and osteocytic osteolysis, in which osteocytes remove mineral from their lacunae and pericanalicular spaces. After weaning, the skeleton is fully restored to its prior mineral content and strength in both animal models and humans, despite persistent microarchitectural changes observed in high-resolution imaging. Osteoblasts upregulate to lay down new osteoid, while osteocytes remineralize their surroundings. The factors that stimulate this post-weaning skeletal recovery remain unclear. In most studies, a history of lactation does not increase the risk, but may protect against, low BMD and fragility fractures. © 2017 American Society for Bone and Mineral Research.

Calcium requirements for Chinese adults by cross-sectional statistical analyses of calcium balance studies: an individual participant data and aggregate data meta-regression

Background Chinese dietary reference intakes for calcium are largely based on foreign studies. We undertook meta-regression to estimate calcium requirements for Chinese adults derived from calcium balance data in Chinese adults. Methods We searched PubMed, Cochrane CENTRAL, and SinoMed from inception to March 5, 2014, by using a structured search strategy. The bibliographies of any relevant papers and journals were also screened for potentially eligible studies. We extracted a standardized data set from studies in Chinese adults that reported calcium balance data. The relationship between calcium intake and output was examined by an individual participant data (IPD) and aggregate data (AD) meta-regression. Results We identified 11 metabolic studies in Chinese adults within 18–60 years of age. One hundred and forty-one IPD (n=35) expressed as mg/d, 127 IPD (n=32) expressed as mg·kg body wt-1·d-1, and 44 AD (n=132) expressed as mg/d were collected. The models predicted a neutral calcium balance (defined as calcium output (Y) equal to calcium intake (C)) at intakes of 460 mg/d (Y=0.60C+183.98) and 8.27 mg·kg body wt-1·d-1 (Y=0.60C+3.33) for IPD, or 409 mg/d (Y=0.66C+139.00) for AD. Calcium requirements at upper intakes were higher than that at lower intakes in all these models. Conclusion Calcium requirement for Chinese adults 18–60 years of age approximately ranges between 400 mg/d and 500 mg/d when consuming traditional plant-based Chinese diets.

Soil acidification and basic cation use efficiency in an integrated no-till crop–livestock system under different grazing intensities

Under integrated crop–livestock production system (ICLS), the animal acts as a catalyzer, modifying and accelerating fluxes by ingesting forage nutrients (grazing) and returning them to the soil as urine and dung in a continuous process whose magnitude and direction depend on grazing intensity. Thus, ICLS may change soil acidification processes and rates. The objective of this research was to verify the influence of grazing intensities on soil acidification through measurements of the soil chemical attributes in the soil profile and the efficiency of basic cation use in a soybean–beef cattle integration system nine years after surface liming under long-term no-till conditions in southern Brazil. An experiment established in 2001 in a Rhodic Hapludox with soybean (summer) and a mix of black oat+Italian ryegrass (winter) succession was used. Treatments consisted of different grazing intensities during the winter season: intensive grazing (IG), moderate grazing (MG), and no-grazing (NG). The experiment was set up in a randomized complete blocks design with three replicates. To evaluate soil chemical attributes, soil was sampled up to 40cm, in May 2010, nine years after lime application. To quantify basic cations budgets and efficiencies, the inputs and outputs of calcium, magnesium, and potassium, as well as their initial and final exchangeable soil stocks were evaluated. Areas under grazed treatments, regardless of the intensity (IG or MG), presented lower soil acidification. Calcium and magnesium budgets were negative under NG and positive under MG. Potassium budgets were always negative, regardless of the management system, due to soybean grain harvest exportation and non-productive outputs. The soybean–beef cattle integrated system, with either IG or MG, was more efficient in calcium and magnesium utilization to produce protein; however, grazing does not affect potassium use efficiency.

Action of the Salivary Microorganisms having Sorbitol as Substratum

ABSTRACT Microorganisms living in the saliva are able to ferment some sweetener types and to promote the fall of pH that has its critical point around 5.5; in this situation, they equal the input and the calcium output in the processes of remineralization and demineralization. For iteration of the three essential factors to the installation of the dental caries (microorganism, host and diet) suggested the accomplishment of a work that involved one of these factors. This work aims to study this issue, through the indication of substitute sweetener of the saccharose, whenever possible, it solved to evaluate pH of the saliva, exposed to sorbitol. How to cite this article Amaral FR, Tonetto MR, Pinzan- Vercelino CRM, da Silva MB, Assunção ELF, Bhandi SH, de Andrade MF, Youssef MN, Saad JRC. Action of the Salivary Microorganisms having Sorbitol as Substratum. World J Dent 2014;5(4):218-222.

Comparison of serum and urinary calcium profile of immobilized and ambulant trauma patients

BackgroundHypercalcemia occurs more frequently than is recognized in patients who are immobilized, but most of these patients are asymptomatic. This study is to determine serum and urinary calcium levels, incidence of hypercalcemia and hypercalciuria in immobilized and ambulant trauma patients. MethodsA prospective comparative study was carried out over a period of seven months. Total serum calcium level and 24-hour urinary calcium output were measured weekly over 4weeks in 55 immobilized trauma patients as study group and 51 ambulant trauma patients as control group. ResultsMean total serum calcium of immobilized patients increased progressively (on admission: 2.315±0.056mmol/l and week 4: 2.552±0.231mmol/l, p<.001) while that of ambulant patients did not change significantly (on admission: 2.306±0.041mmol/l, and week 4: 2.300±0.028mmol/l, p=.348). There is a significant difference in overall mean total serum calcium between immobilized and ambulant patients (p<.001). In immobilized and ambulant patients, mean 24-hour urinary calcium increased progressively from baseline (3.044±0.480mmol/day and 3.056±0.540mmol/day respectively), till the end of the study (8.543±2.142mmol/day and 6.783±1.372mmol/day respectively). Overall mean 24-hour urinary calcium is significantly different between immobilized and ambulant patients {multivariate Pillai F (5,100)=883.124, p<.001}. Incidence of hypercalcemia increased progressively in immobilized patients (end of week 1=7.27% and end of week 4=29.09%) while none of the ambulant patients had hypercalcemia. Incidence of hypercalciuria also increased progressively in immobilized patients (end of week 1=7.27% and end of week 4=63.64%) while ambulant patients only had hypercalciuria at the end of week 3 (9.8%) and week 4 (21.57%). ConclusionMean total serum calcium increased with increased duration of immobilization in trauma patients. Both immobilized and ambulant trauma patients developed hypercalciuria but it is worse and earlier in the immobilized trauma patients.

Antiurolithiatic Activity of Extract and Oleanolic Acid Isolated from the Roots of Lantana camara on Zinc Disc Implantation Induced Urolithiasis

The present study was done to evaluate the antiurolithiatic activity of ethanolic extract of roots (ELC 200 mg/kg) and oleanolic acid (OA 60 mg/kg, O.A. 80 mg/kg, O.A. 100 mg/kg) isolated from roots of Lantana camara in albino wistar male rats using zinc disc implantation induced urolithiatic model. The group in which only zinc disc was implanted without any treatment showed increase in calcium output (23 ± 2.7 mg/dL). Cystone receiving animals showed significant protection from such change (P < 0.01). Treatment with OA and ELC significantly reduced the calcium output at a dose of OA 60 mg/kg (P < 0.01), OA 80 mg/kg (P < 0.01), ELC 200 mg/kg (P < 0.01), and OA 100 mg/kg (P < 0.001), as compared with zinc disc implanted group. The average weight of zinc discs along with the deposited crystals in the only disc implanted group was found to be 111 ± 8.6 mg. Group that received Cystone 500 mg/kg showed significant reduction in the depositions (P < 0.001). Similarly, the rats which received OA and ELC showed reduced formation of depositions around the zinc disc (P < 0.001). The X-ray images of rats also showed significant effect of OA and ELC on urolitiasis. Thus, OA and ELC showed promising antiurolithiatic activity in dose dependant manner.

Effects of pre‐partum milking of dairy cows on calcium metabolism at start of milking and at calving

This experiment studied the effect of pre-partal milk removal on calcium metabolism at start of milking and at calving. Nine cows of the Swedish Red breed were milked for 1-7days pre-partum. The average milk yield at the first milking was 4.8l, and the average yield the last day prior to calving was 13.4l. Five cows were used as control cows and were only milked post-partum. Samples of plasma and urine were taken to determine the effect of pre-partum milking and calving on levels of calcium, magnesium, parathyroid hormone and plasma C-terminal crosslinked telopeptide of type 1-collagen (CTx), used as a marker of bone resorption. Pre-partum milking resulted in a decrease in plasma calcium that was evident 2days after the first milking. Parathyroid hormone increased at the same time, and CTx started to increase from 24h after the first milking. There were no effects on plasma magnesium or urinary output of calcium or magnesium. The first week after calving, there were no differences between pre-partum milked cows and control cows in plasma or urine variables, or in milk yield. In conclusion, pre-partum milking activated the calcium-restoring mechanisms but did not improve calcium status at calving.

Nuclear Calcium Sensors Reveal that Repetition of Trains of Synaptic Stimuli Boosts Nuclear Calcium Signaling in CA1 Pyramidal Neurons

Nuclear calcium is a key signal in the dialogue between synapse and nucleus that controls the genomic responses required for persistent adaptations, including memory and acquired neuroprotection. The amplitude and duration of nuclear calcium transients specify activity-induced transcriptional changes. However, the precise relationship between synaptic input and nuclear calcium output is unknown. Here, we used stereotaxic delivery to the rat brain of recombinant adeno-associated viruses encoding nuclear-targeted calcium sensors to assess nuclear calcium transients in CA1 pyramidal neurons after stimulation of the Schaffer collaterals. We show that in acute hippocampal slices, a burst of synaptic activity elicits a nuclear calcium signal with a regenerative component at above-threshold stimulation intensities. Using classical stimulation paradigms (i.e., high-frequency stimulation (HFS) and θ burst stimulation (TBS)) to induce early LTP (E-LTP) and transcription-dependent late LTP (L-LTP), we found that the magnitude of nuclear calcium signals and the number of action potentials activated by synaptic stimulation trains are greatly amplified by their repetition. Nuclear calcium signals and action potential generation were reduced by blockade of either NMDA receptors or L-type voltage-gated calcium channels, but not by procedures that lead to internal calcium store depletion or by blockade of metabotropic glutamate receptors. These findings identify a repetition-induced switch in nuclear calcium signaling that correlates with the transition from E-LTP to L-LTP, and may explain why the transcription-dependent phase of L-LTP is not induced by a single HFS or TBS but requires repeated trains of activity. Recombinant, nuclear-targeted indicators may prove useful for further analysis of nuclear calcium signaling in vivo.

Glucocorticoids and body fat associated with renal uric acid and oxalate, but not calcium excretion, in healthy children

In patients with hypercortisolism, who are frequently obese, the prevalence of elevated urinary excretion rates of the potential lithogenic factors (calcium, oxalate, and uric acid) is increased. We examined whether the 24-hour urinary excretion rates of calcium, oxalate, and uric acid are already associated with body fat and endogenous glucocorticoids in healthy free-living children, taking relevant nutritional and acid-base factors into account. Urinary analyte excretions were determined in 24-hour urine samples of 300 healthy children aged 4 to 14 years. Potentially bioactive free glucocorticoids were assessed as urinary free cortisol + urinary free cortisone. Associations of glucocorticoids and percentage body fat with the outcome variables were examined in regression models adjusted for sex, height, growth velocity, urinary volume, net acid excretion, and relevant nutritional factors. Percentage body fat and urinary free cortisol + urinary free cortisone explained most of the growth-independent variation of urinary uric acid and also a relevant part of oxalate, but none of calcium. Net acid excretion, an indicator of endogenous acid production, and dietary protein, salt, and fiber intakes were also variably associated with the outcomes urinary calcium, oxalate, and uric acid. In conclusion, body fatness and potentially bioactive free glucocorticoids (even in the physiologic range) appear to affect urinary excretion rates of oxalate and uric acid, whereas urinary calcium output is more strongly related to dietary factors in healthy children. Our data provide the first in vivo–based evidence that the obesity- or hypercortisolism-associated urolithiasis may be a pathophysiologic continuation of the corresponding endocrine metabolic variations in healthy children.

Serum and stimulated whole saliva parathyroid hormone in menopausal women with oral dry feeling

The aim of this study was to evaluate the correlation of severity of oral dryness (OD) with serum and saliva parathyroid hormone (PTH) and calcium levels, and to compare serum and stimulated whole saliva PTH and calcium between menopausal women with/without OD. A case-control study was carried out in 76 (38 as case and 38 as control) selected menopausal women with/without OD conducted at the Clinic of Oral Medicine, Tehran University of Medical Sciences (TUMS). Xerostomia Inventory (XI) score was also used as an index of OD severity. Serum and saliva Ca(+2) concentrations were assessed colorimetrically by Arsenazo reaction. PTH concentration was analyzed by enzyme-linked immunosorbent assay (ELISA). Statistical analysis of Student t test and Spearman correlation was used. The mean saliva calcium and PTH concentrations and outputs, and serum PTH were significantly higher in the case group, compared with control. However, there were no significant differences in serum calcium concentration and stimulated saliva flow rate between groups. XI score correlated significantly with serum PTH (r = 0.387, P = .004), saliva concentration (r = 0.382, P = .002) and output (r = 0.346, P = .007) of PTH; and also with saliva concentration (r = 0.326, P = .013) and output (r = 0.315, P = .018) of calcium; but not with serum calcium and saliva flow rate. OD severity correlated positively with serum and stimulated whole saliva PTH, and with saliva calcium levels in this group of menopausal women. Thus, salivary calcium and PTH levels appear associated with OD and menopause.

A Mediterranean Dietary Style Improves Calcium Utilization in Healthy Male Adolescents

Objective: To examine the effects of consuming a diet based on the Mediterranean patterns on calcium availability and metabolism in male adolescents.Design: A longitudinal study divided into two periods: a 3-day basal period, during which the subjects (n = 20; 12.9 ± 1.14 years) consumed their usual diet (basal diet, BD), and a 28-day nutritional intervention period, in which an intervention Mediterranean-type diet - was consumed (ID).Methods: Dietary calcium utilization was assessed by means of calcium intake in food and calcium output in feces and urine as measured by flame absorption spectrophotometry. In addition, markers of calcium metabolism (serum Ca, parathyroid hormone and total alkaline phosphatase) and bone resorption (urine deoxypiridinoline) were measured.Results: No differences in total calcium intake were found between the two diets, but food sources of dietary calcium varied significantly. Compared with the BD, the consumption of the ID resulted in significant increases in calcium absorption (∼ 40%, p = 0.04) and retention (∼ 80%, p = 0.008), and a considerable decrease in urinary calcium excretion (∼ 40%, p = 0.01).The variations observed in bone markers reflected a higher bone turnover rate after the ID consumption.Conclusions: A varied diet based on Mediterranean diet patterns during adolescence greatly improves dietary calcium utilization, which may help to maximize the peak bone mass and prevent related diseases, such as osteoporosis.

Calcium requirements: new estimations for men and women by cross-sectional statistical analyses of calcium balance data from metabolic studies

Background: Low intakes of calcium are associated with an increased risk of both osteoporosis and cardiovascular disease.Objective: To provide new estimates of the average calcium requirement for men and women, we determined the dietary calcium intake required to maintain neutral calcium balance.Design: Calcium balance data [calcium intake –(fecal calcium + urinary calcium)] were collected from 155 subjects [women: n = 73; weight: 77.1 ± 18.5 kg; age: 47.0 ± 18.5 y (range: 20–75 y); men: n = 82; weight: 76.6 ± 12.5 kg; age: 28.2 ± 7.7 y (range: 19–64 y)] who participated in 19 feeding studies conducted in a metabolic unit. Balance data from the final 6–12 d of each dietary period (minimum length:18 d) of each study (1–9 observations per subject) were analyzed. Data were excluded if individual intakes of magnesium, copper, iron, phosphorus, or zinc fell below the estimated average requirements or exceeded the 99th percentile of usual intakes from the 1994 Continuing Survey of Food Intakes by Individuals (for iron, above the upper limit). Daily intakes of calcium ranged between 415 and 1740 mg. The relation between intake and output was examined by fitting random coefficient models. Coefficients were included to test for sex and age differences.Results: The models predicted a neutral calcium balance [defined as calcium output (Y) equal to calcium intake (C)] at intakes of 741 mg/d [95% prediction interval (PI): 507, 1035; Y = 148.29 + 0.80C], 9.4 mg·kg body wt−1·d−1 [95% PI: 6.4, 12.9; Y = 1.44 + 0.85C], or 0.28 mg·kcal−1·d−1 [95% PI: 0.19, 0.38; Y = 0.051 + 0.816C]. Neither age nor sex affected the estimates when calcium intakes were expressed as mg/d or as mg·kg body wt−1·d−1.Conclusion: The findings suggest that the calcium requirement for men and women is lower than previously estimated.