Total Plasma Calcium Concentration Research Articles

Cordymin alleviates osteoporosis induced by hindlimb unloading via regulating the gut - microelements -bone axis --for non-clinical studies

IntroductionThe purpose of this study was to evaluate the protective effects of cordymin on osteoporosis induced by hindlimb unloading(HLU) in rats and whether cordymin can prevent bone loss from HLU.Materials and methodsWe employed the hindlimb suspension rats model to mimic physiological changes concomitant with space travel.The mechanical strength in the femoral neck,cancellous bone volume, gut microbiota structure,serum calcium and phosphorus contents, bone mineral content and bone mineral content can be changed after hindlimb unloading. Oral cordymin was administered for 4 weeks,cordymin treatment significantly increased the mechanical strength through elevated bone volume/tissue volume (BV/TV), trabecular number (Tb. N), trabecular thickness (Tb. Th) and decreased trabecular separation (Tb. Sp).ResultsImportantly, 16 S rRNA sequencing showed cordymin treatment regulated the various genera that were imbalanced in hindlimb unloading rats. At the same time,The plasma total calcium and inorganic phosphate concentrations in hindlimb unloading rats decreased and bone mineral content in the lumbar vertebrae and femur increased after treatment with cordymin.ConclusionThese data indicate that the cordymin might exert bone protective effects indirectly via modulating the complex relationship between gut microbiota, microelements and bone loss.

Ionized hypercalcemia in cats with azotemic chronic kidney disease (2012-2018).

BackgroundHypercalcemia is associated with chronic kidney disease (CKD) in cats, but studies assessing the physiologically relevant ionized calcium fraction are lacking.ObjectivesTo describe the prevalence and incidence rate of ionized hypercalcemia, and to explore predictor variables to identify cats at risk of ionized hypercalcemia in a cohort of cats diagnosed with azotemic CKD.AnimalsOne hundred sixty‐four client‐owned cats with azotemic CKD.MethodsVariables independently associated with ionized hypercalcemia at diagnosis of azotemic CKD were explored by binary logistic regression. Cats that were normocalcemic at diagnosis of azotemic CKD were followed over a 12‐month period or until ionized hypercalcemia occurred and baseline predictor variables for ionized hypercalcemia explored using Cox proportional hazards and receiver operating characteristic curve analysis.ResultsIonized hypercalcemia (median, 1.41 mmol/L; range, 1.38‐1.68) was observed in 33/164 (20%) cats at diagnosis of azotemic CKD and was associated with male sex, higher plasma total calcium and potassium concentrations, and lower plasma parathyroid hormone concentrations. Twenty‐five of 96 initially normocalcemic (26%) cats followed for minimum 90 days developed ionized hypercalcemia (median, 1.46 mmol/L; range, 1.38‐1.80) at a median of 140 days after diagnosis of azotemic CKD (incidence rate, 0.48 per feline patient‐year). Only body condition score was independently associated with incident ionized hypercalcemia.Conclusions and Clinical ImportanceThe occurrence of ionized hypercalcemia is high in cats with CKD. Continued monitoring of blood ionized calcium concentrations is advised.

Risk factors and implications associated with renal mineralization in chronic kidney disease in cats.

BackgroundNephrocalcinosis is a pathological feature of chronic kidney disease (CKD). Its pathophysiological implications for cats with CKD are unexplored.ObjectivesIdentify nephrocalcinosis risk factors and evaluate its influence on CKD progression and all‐cause mortality.AnimalsFifty‐one euthyroid client‐owned cats with International Renal Interest Society (IRIS) stages 2‐3 azotemic CKD.MethodsRetrospective cohort study. Histopathological kidney sections were assessed for nephrocalcinosis (von Kossa stain). Nephrocalcinosis severity was determined by image analysis (ImageJ). Ordinal logistic regressions were performed to identify nephrocalcinosis risk factors. The influence of nephrocalcinosis on CKD progression and mortality risk were assessed using linear mixed model and Cox regression, respectively. Cats were categorized by their owner‐reported time‐averaged phosphate‐restricted diet (PRD) intake, where PRD comprised ≥50%, 10‐50%, or none of food intake.ResultsNephrocalcinosis was rated as mild‐to‐severe in 78.4% and absent‐to‐minimal in 21.6% of cases. Higher baseline plasma total calcium concentration (tCa; odds ratio [OR] = 3.07 per 1 mg/dL; P = .02) and eating a PRD (10%‐50%: OR = 8.35; P = .01; ≥50%: OR = 5.47; P = .01) were independent nephrocalcinosis risk factors. Cats with absent‐to‐minimal nephrocalcinosis had increasing plasma creatinine (0.250 ± 0.074 mg/dL/month; P = .002), urea (5.06 ± 1.82 mg/dL/month; P = .01), and phosphate (0.233 ± 0.115 mg/dL/month; P = .05) concentrations over a 1‐year period, and had shorter median survival times than cats with mild‐to‐severe nephrocalcinosis.Conclusion and Clinical ImportanceHigher plasma tCa at CKD diagnosis and PRD intake are independently associated with nephrocalcinosis. However, nephrocalcinosis is not associated with rapid CKD progression in cats.

Poor performance of albumin or protein-adjusted plasma calcium to diagnose dyscalcemia in hospitalized patients: A confirmatory study in a general internal medicine department

IntroductionHypo- and hypercalcemia are common and some causes require urgent diagnosis and treatment. Measurement of ionized calcium is the reference test to diagnose calcium disorders but total calcium adjusted for protein or albumin concentration is more often used. MethodsPatients hospitalised in a general internal medicine department from September 2013 to December 2015 who had a total plasma calcium concentration and a serum albumin or protein concentration measured within 24h of a ionized calcium blood measurement were included. Total calcium was adjusted for protein or albumin concentration using widely used formulas and compared to ionized calcium as the gold standard. ResultsAmong 210 included patients, 46 (22%) had hypocalcemia, 124 (59%) normocalcemia and 40 (19%) hypercalcemia according to ionized calcium concentration. Total calcium had 50% sensitivity and 95% specificity to diagnose hypocalcemia and a 93% sensitivity and 89% specificity to diagnose hypercalcemia. Adjusting total calcium for protein or albumin concentrations did not increase and sometimes decreased diagnostic accuracy. ConclusionTotal calcium, with or without albumin/protein adjustment, is poorly sensitive to screen for hypocalcemia. Unadjusted total calcium is as sensitive as protein- or albumin-adjusted total calcium to screen for hypercalcemia. These data argue against the use of albumin- or protein-adjusted calcium. Ionized calcium measurement should be performed to confirm dyscalcemia in patients with abnormal total calcium concentration and to rule out hypocalcemia in patients with total calcium concentration in the lower range of normal values.

The association of prepartum urine pH, plasma total calcium concentration at calving and postpartum diseases in Holstein dairy cattle

The use of anionic salts to prevent milk fever in dairy cattle has been an effective nutritional strategy; however, the degree of acidification that determines the most acceptable productive responses and well-being of the cow is still a controversial topic. The objective of this study was to assess urine pH in prepartum Holstein cows fed anionic diets and determine its association with plasma total Ca, Mg, P, β-hydroxyl-butyrate (BHB) concentrations at parturition and the occurrence of peripartum disorders. This investigation consisted of 2 studies. Study 1 was conducted on a grazing dairy. Between February and May 2019, 60 prepartum multiparous cows were tested for urine pH and plasma metabolite concentration at parturition. Total Ca, P, Mg and BHB at day 1 in milk (DIM) were assessed and statistically analyzed by ANOVA (models for polynomial regression). Study 2 was conducted on a drylot dairy farm. Between July 2018 and January 2019, 203 cows were evaluated for urine pH and followed-up for 30 DIM to obtain the incidence of dystocia, stillbirths, milk fever, retained fetal membranes, metritis, clinical mastitis and ketosis. Cows were categorized based on their last urine pH as group 1: pH > 7.0 (n = 135); group 2: pH between 6.0 and 7.0 (n = 46) and group 3: pH < 6.0 (n = 22). A logistic regression model for each health event was conducted considering urine pH group as the main effect. Urine sample was collected at 2.71 ± 2.84 days before parturition. In study 1, there was a quadratic effect of urine pH on total Ca. Total Ca concentration was higher between urine pH 6.0 and 7.0, while decreasing below pH 6.0 and above pH 7.0. There was a trend (P = 0.11) for a quadratic effect of urine pH on the concentration of plasma BHB at parturition. β-Hydroxyl-butyrate was lower approximately between urine pH 6.5 and 7.5. In study 2, the odds for a stillborn in cows with urine pH < 6.0 was 2.39 (95% CI = 1.06–5.40) times the odds for a stillborn in cows with urine pH ≥ 7.0. There was no association between urine pH and the other diseases. In conclusion, cows with prepartum urine pH < 6.0 and >7.0 had lower concentration of plasma total Ca and tended to have a higher concentration of BHB. Cows with urine pH < 6.0 had a higher incidence of stillbirths than cows with urine pH > 7.0.

Risk factors associated with disturbances of calcium homeostasis after initiation of a phosphate-restricted diet in cats with chronic kidney disease.

BackgroundDietary phosphate restriction improves survival in cats with chronic kidney disease (CKD). However, feeding a phosphate‐restricted diet may disrupt calcium homeostasis leading to hypercalcemia in some cats.ObjectivesTo identify risk factors associated with increasing plasma total calcium (tCa) concentration after transition to a phosphate‐restricted diet and to explore its role in CKD‐mineral and bone disorder (CKD‐MBD) in cats.AnimalsSeventy‐one geriatric (≥9 years) euthyroid client‐owned cats with International Renal Interest Society (IRIS) stage 2 to 3 azotemic CKD.MethodsRetrospective cross‐sectional cohort study. Changes in plasma tCa concentration in the first 200 days of diet transition were assessed using linear regression. Binary logistic regressions were performed to identify risk factors for increasing calcium concentration. Changes in clinicopathological variables associated with CKD‐MBD over time were explored using linear mixed model and generalized linear mixed model analyses.ResultsLower baseline plasma potassium (odds ratio [OR] = 1.19 per 0.1 mmol/L decrease; P = .003) and phosphate (OR = 1.15 per 0.1 mmol/L decrease; P = .01) concentrations remained independent risk factors for increasing plasma tCa concentration. Plasma creatinine (β = .069 ± .029 mg/dL; P = .02), symmetric dimethylarginine (β = .64 ± .29 μg/dL; P = .03), phosphate (β = .129 ± .062 mg/dL; P = .04), and ln[FGF23] (β = .103 ± .035 pg/mL; P = .004) concentrations had significantly increased rates of change in cats with increasing plasma tCa concentration over time.Conclusion and Clinical ImportanceLower plasma potassium or phosphate concentrations or both at the time of transition of cats with CKD to a phosphate‐restricted diet are independently associated with increased risk of an increase in plasma tCa concentration. Increasing plasma tCa concentration is associated with progression of CKD.

Comparison of Selected Blood Parameters of Captive Eastern Indigo Snakes (Drymarchon couperi) Housed Indoors vs. Outdoors in Central Florida, USA

Eastern indigo snakes (Drymarchon couperi) have unique physiological features that are still not well understood. The objective of this study was to evaluate the effects of indoor vs. outdoor housing on plasma biochemistry analytes of eastern indigo snakes. Thirty-two captive eastern indigo snakes were divided into two groups: one group was housed indoors and the other group was housed outdoors in central Florida, USA. Packed cell volume and several plasma biochemistry analytes were evaluated: sodium, potassium, chloride, total magnesium, ionized magnesium, total calcium, ionized calcium, phosphorus, pH, glucose, uric acid, glutamate dehydrogenase, aspartate aminotransferase, creatinine kinase, total protein, protein gel electrophoresis, albumin (bromocresol method), cholesterol, calcidiol, and calcitriol. Significant differences were seen in plasma total calcium and calcidiol concentrations between indoor and outdoor female groups. Significant differences were also seen in packed cell volume and plasma total calcium and calcidiol concentrations between male and female eastern indigo snakes. All of the eastern indigo snakes in this study had markedly elevated plasma total calcium concentrations, similar to previous reports by others.

Hypocalcemia in the Critically Ill Pediatric Patients: A Review

Hypocalcemia is common in the critically ill pediatric patients. However, the diagnosis of hypocalcemia in this population is complicated by interpretation of the total plasma calcium concentration. These limitations are principally the result of the effects of hypoalbuminemia and disorders of acid-base balance on the total calcium concentration. Thus, measurement of ionized calcium can be critical in determining an individual’s true serum calcium status. In this review, we first described the regulation of normal calcium metabolism and then focus on the various etiologies of hypocalcemia, which are encountered in the pediatric critical care settings. The approach to the treatment of hypocalcemia and the current consensus on treatment of hypocalcemia in the critically ill pediatric patient is also presented.&#x0D; DS (Child) H J 2019; 35(2) : 156-161

Plasma total calcium concentration is associated with blood pressure and systemic vascular resistance in normotensive and never-treated hypertensive subjects

Purpose: The underlying causes of primary hypertension are not fully understood. Evidence on the relation of plasma calcium concentration with blood pressure (BP) is inconsistent and relies largely on studies utilizing office BP measurements in populations using cardiovascular drugs. In many studies adjustment for confounders was not optimal. In this cross-sectional study we examined the association of plasma total calcium concentration with the haemodynamic determinants of blood pressure.Subjects and methods: Supine haemodynamics were recorded using pulse wave analysis, whole-body impedance cardiography, and heart rate variability analysis in 618 normotensive or never-treated hypertensive subjects (aged 19–72 years) without diabetes, cardiovascular or renal disease, or cardiovascular medications. Linear regression analysis was used to investigate factors associated with haemodynamic variables.Results: Mean age was 45.0 years, body mass index 26.8 kg/m2, seated office BP 141/89 mmHg, and 307 subjects (49.7%) were male. Mean values of routine blood and plasma chemistry analyses were within the reference limits of the tests except for low-density lipoprotein cholesterol (3.05 mmol/l). In the laboratory, mean supine radial BP was 131/75 mmHg, and both systolic and diastolic BP correlated directly with plasma total calcium concentration (r = 0.25 and r = 0.22, respectively, p < 0.001 for both). In regression analysis plasma total calcium concentration was an independent explanatory variable for radial and aortic systolic and diastolic BP, and systemic vascular resistance, but not for cardiac output, pulse wave velocity, or any of the heart rate variability parameters.Conclusion: Plasma total calcium concentration was directly associated with systolic and diastolic BP and systemic vascular resistance in normotensive or never-treated hypertensive subjects without comorbidities and cardiovascular medications. Higher plasma calcium concentration potentially plays a role in primary hypertension via an effect on vascular resistance.

Blood Biochemical, Hormonal and Mineral Status of Cyclic, Acyclic, Endometriotic and Pregnant Crossbred Cows

A study was carried out on infertile (acyclic and endometriotic) crossbred cows under field and normal cyclic (all 4 phases of cycle) as well as pregnant (3, 6, 9 month) crossbred cows of University farm to evaluate the plasma progesterone (P4) and estradiol (E2) hormones by RIA, and plasma total protein, cholesterol, calcium and phosphorus concentrations by using assay kits on chemistry analyzer. The mean progesterone levels in cows during the diestrus phase and in pregnancy were significantly (p less than 0.05) higher than those during proestrus, estrus, metestrus, anestrus, and endometritis status. At six month of gestation, the mean P4 level was significantly (p less than 0.05) higher than at early or late gestation. The mean E2 values at estrus and 9th month of gestation were highest (p less than 0.01) as compared to another status. The mean plasma total protein and cholesterol levels were significantly (p less than 0.05) lower during six and nine months of pregnancy than during cyclic and acyclic stages. The cholesterol profile of all three stages of pregnancy and endometriotic cows were statistically similar, though distinctly low at 9 month of pregnancy. Plasma levels of P4 and E2 thus correlated with the physiological and clinical status of cows, while cholesterol levels reflected steroidogenic status. The mean plasma calcium and inorganic phosphorus concentrations of cyclic, acyclic, pregnant and endometriotic cows, however, did not differ significantly.

Nutritional Infertility and Ameliorative Measures in Dairy Animals of Middle Gujarat

Fertility improvement camps were organized in different villages of middle Gujarat covering 1481 breedable cattle and buffaloes with the history of impaired fertility. The reproductive status of animals was ascertained through gynaeco-clinical examination per rectum. Blood sampling (n=305) was done from representative groups of animals to know the nutritional status. All non-infectious infertile animals were dewormed using either Inj. Ivermectin 100 mg s/c or bolus Fenbendazole + Ivermectin 3.0 g orally. Anestrus animals (n=265) were then nutritionally supplemented either with chelated area specific mineral mixture (ASMM, 50-60 g/d/h) or multi-minerals boli - one on alternate day, with and without bypass fat (75-80 g/d/h) for one month along with an advice to improve feeding level, estrus detection and timely breeding. Revisits were made after 2.5-3.0 months to check the reproductive status. The mean blood glucose concentrations were significantly lower (p less than 0.05), while total cholesterol and zinc levels were higher (p less than 0.05) in anestrus than in subestrus and/or repeat breeding cows and buffaloes. Moreover, the plasma total cholesterol levels in buffaloes were just one half to those of cows. Further, the plasma total protein, calcium, phosphorus, magnesium, iron, copper and cobalt concentrations were found to be nonsignificantly higher in repeat breeders than in anestrus or subestrus cows and buffaloes. Calcium was deficient in some 20% animals and calcium: phosphorus ratio varied from 1:1 to 1.8:1 in animals under different areas of study indicating its role in causing infertility in dairy animals. Supplementation of ASMM, multi-mineral boli alone or in combination with bypass fat in pubertal /postpartum anestrus animals resulted in 34-56% estrus induction response and 33-50% conception rate, both being better with mineral plus bypass fat supplementation than minerals alone.

Plasma calcium concentrations are decreased at least 9 hours before parturition in multiparous Holstein-Friesian cattle in a herd fed an acidogenic diet during late gestation

Calcium homeostatic mechanisms are challenged in periparturient multiparous dairy cattle due to the rapid transport of large amounts of calcium into the mammary gland associated with colostrogenesis, resulting in decreased plasma total calcium concentration ([Ca]). An unresolved issue is the timing of the decrease in plasma [Ca] relative to the time of parturition, with the consensus view being that plasma [Ca] does not decrease until after parturition. The objective of this study, therefore, was to characterize the change in plasma [Ca] over time in periparturient dairy cattle. Plasma and mid-stream urine samples were collected daily starting 3 d before calving from 104 periparturient Holstein-Friesian dairy cows in a herd fed an acidogenic total mixed ration during the late dry period. Mixed-models ANOVA and linear and multivariable regression analyses were conducted. Plasma [Ca] decreased in periparturient multiparous cattle (n = 70) but not in primiparous cattle (n = 34). Compared with mean values approximately 72 h before parturition ([Ca] = 2.32 mmol/L), mean plasma [Ca] in multiparous cattle first decreased at 9 h before parturition (2.13 mmol/L) and remained decreased for up to 48 h after parturition, with the lowest mean value (1.87 mmol/L) occurring at 28 h after parturition. Mean 24-h urine Ca excretion was calculated to decrease by 3.5 to 3.8 g in periparturient multiparous cattle. Regression analysis indicated that plasma [Ca] in the 12-h period before and 24-h period after parturition was strongly and negatively associated with age but was also negatively associated with milk production indices. We conclude that plasma [Ca] was decreased at least 9 h before parturition in multiparous dairy cattle fed an acidogenic diet in late gestation, and that calcium homeostasis was disrupted for 2 to 3 d around parturition.

Molecular characterisation and expression of parathyroid hormone-related protein in the caudal neurosecretory system of the euryhaline flounder, Platichthys flesus

Parathyroid hormone-related protein (PTHrP) is a hypercalcemic factor in fish, but the source of circulating PTHrP remains unclear. In this study investigation of the caudal neurosecretory system (CNSS), considered one of major sources of PTHrP in fish, provided valuable insights into this regulatory system. We report pthrpa and pthrpb gene cloning, characterization, expression, and responses to low salinity and hypocalcemia challenge in flounder. The pthrpa and pthrpb precursors, isolated from a European flounder CNSS library, consist of 166 and 192 amino acid residues, respectively, with an overall homology of approximately 59.2%. Both precursors contain a signal peptide and a mature peptide with cleavage and amidation sites. The flounder PTHrPA and PTHrPB peptides share only 41% sequence identity with human PTHrPA. Quantitative PCR analysis demonstrated that the bone and bladder, are respectively major sites of pthrpa and pthrpb expression in flounder. Urophysectomy confirmed the CNSS as a likely contributor to circulating PTHrP peptides. There were no significant differences in CNSS pthrpa and pthrpb mRNA expression or plasma PTHrP levels between seawater (SW) and freshwater (FW)-adapted fish, though plasma total calcium concentrations were higher in FW animals. The intraperitonial administration of EGTA rapidly induced hypocalcemia and concomitant elevation in plasma PTHrP accompanied by increases in both pthrpa and pthrpb expression in the CNSS. Together, these findings support an evolutionary conserved role for PTHrP in the endocrine regulation of calcium.

New candidate markers of phosphorus status in beef breeder cows

Determining the phosphorus (P) status of cattle grazing P-deficient rangelands in northern Australia is important for improving animal production in these areas. Plasma inorganic P concentration is currently the best diagnostic marker of dietary P deficiency in growing cattle but is not suitable for assessing the P status of breeder cows, which often mobilise substantial bone and soft tissue reserves in late pregnancy and lactation. Markers of bone turnover offer potential as markers of P status in cattle, as they reflect bone mobilisation or bone formation. Recent experiments investigating the physiology of beef breeder cows during diet P deficiency have indicated that the ratio of plasma total calcium concentration to plasma inorganic P concentration might be suitable as a simple index of P deficiency. However, a more specific measure of increased bone mobilisation in P-deficient breeders is plasma concentration of C-terminal telopeptide of Type 1 collagen. Also, plasma concentration of bone alkaline phosphatase is a marker of defective bone mineralisation in dietary P deficiency. These candidate markers warrant further investigation to determine their predictive value for P deficiency in cattle.

Calcium mobilisation following shell damage in the Pacific oyster, Crassostrea gigas

Shell growth of oysters requires calcium uptake from the environment and transport to the area of shell formation. A shell regeneration assay in combination with radiolabelled calcium was used to investigate uptake and distribution of calcium to different tissues and hemolymph fractions in Pacific oysters, Crassostrea gigas (Bivalvia, Ostreoida). Oysters were notched at the shell margin and subsequently sampled for hemolymph and grading of shell regeneration during a two week experimental period. Half of the oysters were additionally exposed to 45Ca and sampled for hemolymph and tissues. Total plasma calcium concentrations increased in notched oysters compared to controls on 1, 2 and 7days after notching. A decrease in plasma calcium levels was apparent on day 4, for both total and ionic calcium. The shell regeneration assay in the notched oysters resulted in a visible deposition of CaCO3 onto the regenerate from day 7 onwards. This was coinciding with an increased uptake of total calcium on days 11 and 14 as well as free, i.e. ionic and ligand-bound calcium, on day 14. At day 1, notching also increased calcium uptake into the mantle tissues, in areas above the notch and near the hinge. During the experiment, both the total hemocyte count and the number of granulocytes increased in notched compared to control oysters. The present study suggests that induced shell damage results in a dynamic regulation of the calcium uptake from the environment and the distribution of calcium within the body, starting directly after notching. Increases in both total calcium concentrations and uptake rates coincided with the visible depositions of CaCO3 on the regenerate shell. C. gigas was found to transport calcium mainly in the ionic form in the hemolymph, with only minor parts being bound to proteins or smaller ligands. Hemolymph measurement also revealed that C. gigas is able to regulate the extracellular concentrations of calcium and potassium. The changes in plasma calcium concentrations and speciation, concomitant with increases in granulocytes indicate that multiple calcium transport processes are activated after induced shell damage.

Effect of exercise on serum markers of muscle inflammation in Spanish Greyhounds.

To investigate effects of exercise on hematologic and biochemical values (especially markers of inflammation and muscle damage) in Spanish Greyhounds used for hunting without previous training. 32 Spanish Greyhounds and 31 dogs of other breeds. Hematologic variables and concentrations of C-reactive protein (CRP) and other biochemical markers were compared in samples obtained from Spanish Greyhounds 24 hours after exercise (eg, a hunting race) and 2 months after exercise (ie, at rest) and from non-Spanish Greyhounds at rest. All dogs were healthy. Hematologic and biochemical analyses were performed within 24 hours after samples were obtained, and results were compared by means of a Student t test. CRP concentration and muscle enzyme (creatine kinase, lactate dehydrogenase, and aspartate aminotransferase) activities were significantly higher and serum iron concentration was significantly lower for Spanish Greyhounds after exercise than at rest. The WBC and neutrophil counts were significantly higher after exercise then at rest. Plasma alanine transaminase activity and total protein, calcium, and phosphorus concentrations were significantly higher after exercise than at rest. Spanish Greyhounds at rest had higher RBC counts, PCVs, and hemoglobin concentrations and lower WBC, neutrophil, and lymphocyte counts, compared with values for non-Spanish Greyhounds at rest. Exercise of Spanish Greyhounds without prior training activated an acute-phase response represented by an increase in serum CRP concentration and decrease in serum albumin and iron concentrations. These changes, along with leukocytosis and neutrophilia, were indicative of a subclinical inflammatory state in Spanish Greyhounds.

EFFECT OF CALCIUM AND CHOLECALCIFEROL SUPPLEMENTATION ON SEVERAL PARAMETERS OF CALCIUM STATUS IN PLASMA AND URINE OF CAPTIVE ASIAN (ELEPHAS MAXIMUS) AND AFRICAN ELEPHANTS (LOXODONTA AFRICANA)

The aim of the current study was to assess the effect of oral calcium and cholecalciferol supplementation on several parameters of calcium status in plasma and urine of captive Asian (Elephas maximus; n=10) and African elephants (Loxodonta africana; n=6) and to detect potential species differences. Calcium and cholecalciferol supplementation were investigated in a feeding trial using a crossover design consisting of five periods of 28 days each in summer. From days 28-56 (period 2), elephants were fed the Ca-supplemented diet and from days 84-112, elephants were fed the cholecalciferol-supplemented diet (period 4). The control diet was fed during the other periods and was based on their regular ration, and the study was repeated similarly during winter. Periods 1, 3, and 5 were regarded as washout periods. This study revealed species-specific differences with reference to calcium and cholecalciferol supplementation. Asian elephants showed a significant increase in mean plasma total calcium concentration following calcium supplementation during summer, suggesting summer-associated subclinical hypocalcemia in Western Europe. During winter, no effect was seen after oral calcium supplementation, but a significant increase was seen both in mean plasma, total, and ionized calcium concentrations after cholecalciferol supplementation in Asian elephants. In contrast, evidence of subclinical hypocalcemia could be demonstrated neither in summer nor in winter in African elephants, although 28 days of cholecalciferol supplementation during winter reversed the decrease in plasma 1,25(OH)2-cholecalciferol and was followed by a significant increase in mean plasma total calcium concentration. Preliminary findings indicate that the advisable permanent daily intake for calcium in Asian elephants and cholecalciferol in both elephant species at least during winter might be higher than current guidelines. It is strongly recommended to monitor blood calcium concentrations and, if available, blood parathyroid hormone levels to adjust the nutritional supplementation for each individual elephant.

Parathyroid hormone concentration in geriatric cats with various degrees of renal function

To determine whether cats in the nonazotemic stages of chronic kidney disease have increased plasma parathyroid hormone (PTH) concentrations as a compensatory physiologic mechanism to maintain plasma phosphate concentration within the reference interval. Prospective longitudinal study. 118 client-owned geriatric cats with various degrees of renal function. For each cat, a blood sample was obtained for plasma biochemical analysis and determination of plasma PTH concentration, and a urine sample was obtained for determination of urine specific gravity at study entry (baseline) and after 12 months. For a subset of 30 cats, plasma calcitriol concentration was determined at baseline. Cats were categorized into 1 of 3 groups on the basis of kidney function at the end of 12 months. At baseline and after 12 months, plasma concentrations of variables associated with calcium homeostasis were compared between the 3 groups and also within groups over time. Multivariable linear regression was used to identify variables associated with plasma PTH concentration. Plasma PTH concentration was significantly increased in cats that developed azotemia, compared with PTH concentration in cats that remained nonazotemic, and PTH concentration increased before changes in plasma calcium and phosphate concentrations were detected. A moderate positive association between plasma calcitriol and PTH concentrations was identified. Plasma PTH concentration was associated with age and plasma urea, creatinine, and total calcium concentrations in the final multivariable model. Results suggested that renal secondary hyperparathyroidism can develop prior to azotemia in cats, even in the absence of hyperphosphatemia and hypocalcemia.

Lateral approach to nephrotomy in the management of unilateral renal calculi in a rabbit (Oryctolagus cuniculus)

A 5-year-old 2.23-kg (4.91-lb) spayed female Lop rabbit (Oryctolagus cuniculus) was evaluated because of a history of lethargy, polyuria, and polydipsia of 1 month's duration. The referring veterinarian made a presumptive diagnosis of hypercalcemia of unknown etiology on the basis of a plasma total calcium concentration of 14.0 mg/dL. Physical examination findings were unremarkable. Hematologic and plasma biochemical analysis revealed nonregenerative, normocytic, normochromic anemia (PCV, 28%) with heteropenia (23%; 1,334 heterophils/mL) and a total plasma calcium concentration of 16 mg/dL. Radiographic and ultrasonographic examination revealed radiodense and hyperechoic structures in both renal pelves and right unilateral nephrolithiasis. Nephrotomy was performed via laparotomy with a right lateral approach. A nephrolith composed of calcium carbonate and carbonate apatite was removed from the right renal pelvis. The rabbit's plasma tested positive for antibodies against Encephalitozoon cuniculi by means of an indirect immunofluorescence assay, and fenbendazole (20 mg/kg [9.1 mg/lb], p.o., q 24 h) was administered for 28 days. Although plasma calcium concentration was not substantially decreased after treatment (values were 14.1 and 15.1 mg/dL 1 week and 3 months after surgery, respectively), the patient did not have clinical signs of hypercalcemia and died of unrelated causes approximately 1 year after surgery. To the authors' knowledge, this is the first report of a nephrotomy performed in a rabbit via a lateral abdominal approach. This approach allowed easy location of the kidney and also reduced manipulation, thus decreasing the risk of damaging the abdominal viscera and potentially decreasing postoperative pain.

Intoxicación por sobredosificación de vitamina D en un lactante

The objective of this technical note describes and comments on a recent clinical case of poisoning by overdose of vitamin D, and the correct interpretation of clinical and laboratory parameters. Vitamin D is a fat-soluble vitamin involved in the absorption of calcium and phosphorus in the intestine. Administration of high doses for prolonged periods can cause hypercalcemia, leading to kidney failure and renal calcifications. Clinical caseMale, 6 months old in treatment with Biominol® (vitamin D supplement), was admitted to the emergency department because of a state of decline and irritability. The initial analytical results showed an ionized calcium concentration in blood of 2.11mmol/L (reference interval (RI): 1.15 - 1.29mmol/L), and plasma total calcium concentration of 5.5mmol/L (RI: 2.25–2.75mmol/L). In our laboratory, Vitamin D2 and D3 were determined by liquid chromatography high resolution (HPLC), and an electrochemiluminescence method. The results showed a vitamin D2 419ng/mL and total vitamin D 482ng/mL (RI: 30–100ng/mL). It was found that the vitamin D overdose was of exogenous origin, due to increased vitamin D2.The definitive diagnosis of this patient was severe hypercalcemia secondary to exogenous vitamin D poisoning, and nephrocalcinosis secondary to this with normal renal function with hypercalciuria.In conclusion, the correct dosing of patients and determination of different forms of vitamin D to trace its origin and making a correct interpretation is important.