Influence of a low calcium and phosphorus diet on the anabolic effect of human parathyroid hormone (1-38) in female rats.

Parathyroid hormone (PTH) or synthetic N-terminal PTH fragments administered intermittently have been established as anabolic agents in animal and human bones. In the present study, the influence of a low calcium diet on the anabolic effect of human PTH(1-38) [hPTH(1-38)] was investigated. Forty-eight 10-week-old female Sprague-Dawley rats were randomly assigned to a diet with a low calcium content (LCa) or a diet with the recommended amount of calcium (RCa). After an adaptation period of 15 days, the rats were randomly assigned to hPTH(1-38) treatment (+LCa/+RCa) or vehicle only (-LCa/-RCa) for an additional 14 days. Total bone mineral density (BMD) values of several bones were determined using quantitative computed tomography and from ratios of ash weight to volume. Biomechanical competence of the fourth lumbar vertebrae and of the right femora was assessed. An anabolic effect could be detected in both PTH-treated groups. However, the bones of the +LCa group showed significantly lower BMD and also a diminished increase in maximal breaking force compared with those of the +RCa group. The study demonstrates that the anabolic effect of hPTH(1-38) is blunted by the LCa diet. This suggests that, during PTH treatment, dietary calcium intake is critical.

Direct determination of selenium and other trace elements in serum samples by ICP-MS.

Selenium belongs to a group of trace elements of special interest in biological samples for clinical diagnosis. Selenium has antioxidizing functions and is essential for providing the organism with triiodothyronine produced from thyroxine. Among several analytical techniques used to determine the Se concentration in serum, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) has been used in the past because of its high sensitivity. Interference problems originating from different ions on the major Se isotopes have been described to be a limiting factor for the direct determination of Se in these matrices. Standard addition calibration or isotope dilution is often required to overcome carbon-enhanced ionisation effects in biological sample matrices. In most cases, the typical serum sample volume which is available for the analysis is limited to 0.5 ml or less, making multiple sample preparation for standard addition calibration impractical. Isotope dilution requires enriched isotopes and substantial sample preparation. Furthermore, the approximate Se concentration in every sample has to be known to adjust the appropriate amount of spike to each sample. Matrix matching with methanol has been described to overcome ionisation effects but we found limiting factors of this application when other trace elements are also determined within one sample run. This paper describes an effective sample preparation method which allows the direct determination of Se in serum without limiting the analytical capabilities for the additional determination of Al, Cu, Ni, Co, Cd, Mn and Zn in a single sample run by ICP-MS. Optimization procedures are presented and results of the analysis of reference samples are discussed, with a comparison of more than 150 serum data with those obtained by the GF-AAS method.

Simultaneous measurement of the trace elements Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum and their reference ranges by ICP-MS.

The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n = 110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.

Concentration of 17 trace elements in serum and whole blood of plains viscachas (Lagostomus maximus) by ICP-MS, their reference ranges, and their relation to cataract.

The reference ranges of the trace elements Al, As, Be, B, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Li, Rb, Se, Sr, and Zn were determined by inductively coupled plasma-mass spectrometry (ICP-MS) in sera of a group of free-ranging plains viscachas of the pampa grasslands of Argentina. The values were compared with those of a small group of captive plains viscachas of the Zurich Zoo with diabetes and bilateral cataracts. In addition, a method for digestion of whole-blood samples is described for the trace element determination. Significant differences in the concentration of trace elements in the two groups of animals are discussed. No correlation was found between the levels of selenium and of other trace elements compared to the formation of cataracts.

Activities of NADPH-dependent reductases and sorbitol dehydrogenase in canine and feline lenses.

OBJECTIVE: To measure activities of NADPH-dependent reductases and sorbitol dehydrogenase in lenses from healthy dogs and cats. SAMPLE POPULATION: Lenses from 37 dogs and 23 cats. All animals were healthy and had serum glucose concentrations within reference limits. PROCEDURE: Lenses were homogenized, and activities of NADPH-dependent reductases and sorbitol dehydrogenase were measured spectrophotometrically. RESULTS: Activities of NADPH-dependent reductases and sorbitol dehydrogenase were significantly lower in lenses from cats than in lenses from dogs. However, the ratio of NADPH-dependent reductases activity-to-sorbitol dehydrogenase activity was significantly higher in lenses from cats than in lenses from dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that during periods of hyperglycemia, sorbitol would accumulate at a faster rate in the lenses of cats than in the lenses of dogs. Thus, the higher incidence of diabetic cataracts in dogs, compared with cats, is likely not attributable to a difference in the ratio of NADPH-dependent reductases activity-to-sorbitol dehydrogenase activity.

Reflux of bile acids from the duodenum into the rumen of cows with a reduced intestinal passage.

The purpose of this study was to find out whether the concentration of bile acids in the rumen of healthy cows differs from that of cows with a reduced gastrointestinal passage. The investigations were performed on 277 heifers and cows of the Swiss Braunvieh, Simmental and Swiss Holstein breeds. Forty of these had traumatic reticuloperitonitis, 30 had right or left abomasal displacement, 14 had an ileus of the duodenum, 36 had an ileus of the jejunum and 54 had a caecal dilatation. The other 103 animals had disorders which did not affect the digestive system and were used as controls. The mean (+/- se) bile acid concentration in the rumen fluid of the control animals was 1.0 +/- 0.30 mumol/litre. The bile acid concentrations in the rumen fluid of the cows with a duodenal or jejunal ileus were significantly higher than those of the other groups, demonstrating that bile acids may reflux from the duodenum into the rumen of cows with an ileus in the small intestine.

Selenium and vitamin E in blood sera of cows from farms with increased incidence of disease.

Selenium and vitamin E concentrations were measured in the blood sera of 287 cows in 91 herds. Herds with chronic mastitis and muscle diseases had significantly lower selenium concentrations (10.4 +/- 5.26 and 11.7 +/- 8.63 micrograms/litre serum, respectively) than healthy control herds (17.7 +/- 15.00 micrograms/litre). The selenium concentrations in herds with low fertility did not differ from control herds. The vitamin E concentrations were similar in all the herds. Supplementation of the mineral mixture with 20 mg sodium selenite and 2 g vitamin E/kg on 15 farms with a deficient selenium supply increased the selenium concentrations in the blood within two months in 12 of the herds. The vitamin E concentrations were hardly influenced by the supplementation.

Antithrombin-III activity in plasma of healthy and sick cattle.

Antithrombin-III (AT-III) activity was determined in the plasma of 32 healthy cows. The range of activities was between 105 and 160 per cent of a human reference plasma; the median activity was 132.5 per cent, and the 5 per cent and the 95 per cent quartiles were 111.1 per cent and 153.9 per cent of the standard. The activity of AT-III was also determined in 82 cows with a variety of internal diseases. In cows with hepatopathy, acute enteritis, generalised peritonitis, blood loss, idiopathic cardiomyopathy, glomerulonephritis and disseminated coagulopathy, the activity of AT-III was lower than in healthy animals. The lower values were due to decreased synthesis, increased consumption, or the loss of AT-III. An acquired deficiency of AT-III appears to favour the development of thrombophlebitis.

Long-term excessive magnesium supplementation is deleterious whereas suboptimal supply is beneficial for bones in rats.

The long-term effects of a suboptimal magnesium supply inducing a marginal or moderate deficiency or of an excessive magnesium supplementation corresponding to a basal diet with a high pharmacological intake were investigated in 36 growing Sprague-Dawley female rats. The rats were randomly divided in three groups and received a purified diet with 7 g calcium, 5 g phosphorus and either 0.2, 0.5 or 2 g magnesium per kg diet for 7 months. At the end of the trial, plasma and erythrocyte total magnesium concentrations were significantly lower in the magnesium-deficient group than in the respective control group. Serum concentrations of 1,25-dihydroxyvitamin D, PTH and IGF-I and the length of the right humeri were not affected by the dietary treatment. The volumes corrected for body weight, the medio-lateral diameters and the ratios dry weight/length of the right humeri, and the dry weight corrected for body weight of the left tibiae and of the right humeri were significantly smaller in the magnesium-supplemented group than in the two other groups. The magnesium contents of the left tibiae and of the first lumbar vertebrae were significantly lower in the magnesium-deficient group than in the two other groups. In the right femora, dual energy X-ray absorptiometry revealed significantly smaller areas in the proximal part and significantly smaller mineral contents in the second proximal quarter in the magnesium-supplemented group compared with the two other groups. Peripheral quantitative computer tomography of the right humeri revealed in the cortex significantly larger values for the relative area, mineral content, mineral density and thickness in the magnesium-deficient group compared with the control group. The maximum point of the load-deformation curve was significantly reduced in the fifth lumbar vertebrae and in the proximal femoral metaphyses of the magnesium-supplemented group. These results indicate that the long-term suboptimal magnesium supply improved some of the parameters indicators of bone health whereas the long-term supplementation was deleterious.

[Selenium in the serum of healthy and diseased calves]. / Selen im Blutserum von gesunden und kranken Kälbern.

Between 1988 and 1990, selenium concentrations were measured in the serum of 188 calves admitted for various conditions to the University of Zurich veterinary hospital, and in 64 healthy calves that served as controls. The lowest mean concentration was measured in the controls and it was 14.5 micrograms/L. The mean concentrations in patients not previously supplemented with selenium for the three years were 29.1, 27.5 and 23.0 micrograms/L, respectively, and the concentrations in the patients after supplementation were 61.7, 88.7 and 72.6 micrograms/L, respectively. The differences between the two groups of patients, and between controls and calves of 1989 without selenium supplementation were statistically significant (P < 0.05). There were no significant differences between mean selenium concentrations of calves of different age groups or between calves of different disease groups. Selenium concentrations were not correlated with blood pH, plasma protein and fibrinogen concentrations. The low values measured in untreated calves paralleled results of previous studies in calves and cows in Switzerland.

[Determination of hematologic and blood chemical reference values in fattening pigs of different ages]. / Bestimmung hämatologischer und blutchemischer Referenzwerte bei Mastschweinen verschiedenen Alters.

In swine medicine, the determination of hematology and blood chemistry parameters is of primary interest in connection with the detection of herd problems. For the evaluation of laboratory results the availability of reference values is a prerequisite. So far, no reference values of fattening pigs have been available in Switzerland. For this reason, in the present study reference values for hematology and blood chemistry were determined for two bodyweight categories, 40-60 kg (group 1) and 85-110 kg (group 2). Hematocrit, hemoglobin and RBC counts were lower in animals in group 1. The number of segmented neutrophils was markedly higher in group 1. Lymphocyte counts exceeded neutrophil values in both groups. Concentrations of total bilirubin, AST, CK and LDH partly reached very high levels due to hemolysis or contamination of the blood samples with muscle tissue.

Haematology, blood chemistry and urine parameters of free-ranging plains viscachas (Lagostomus maximus) in Argentina determined by use of a portable blood analyser (i-STAT) and conventional laboratory methods.

Haematology, blood chemistry and urine values were determined for 44 adult free-ranging plains viscachas (Lagostomus maximus; Rodentia, Chinchillidae) in their pampas habitat in central Argentina. The study animals were captured in the wild and anaesthetized with a ketamine-xylazine combination for physical examination and sampling. Blood was obtained by venipuncture of the saphenous vein. Results for many of the blood parameters fall within the reference ranges for pet chinchillas. Differentiation of white blood cells revealed a predominantly neutrophil count for plains viscachas, while chinchillas have predominantly lymphocytes. Mean values for blood urea nitrogen, creatinine, aspartate aminotransferase and sodium were higher than the upper limit of the reference range for pet chinchillas. The results of seven analytes (haematocrit, haemoglobin, glucose, blood urea nitrogen, sodium, potassium, chloride) were compared by using both a portable blood analyser (i-STAT) in the field and conventional laboratory methods. In general, correlation and agreement between the two methods were low for most parameters.

Comparative determination of selenium in the serum of various animal species and humans by means of electrothermal atomic absorption spectrometry.

It was the goal of this paper to establish total selenium reference values for Switzerland in different animal species and in humans. To this purpose, a flameless atomic absorption method with deuterium background compensation utilizing a graphite furnace atomization system with a pyrolytic platform inside and palladium solution as matrix modifier was developed for the measurement of selenium in serum. The method was characterized by rapid performability, small sample requirement, acceptable detection limit (0.04 mumol/L) and precision and a linear range of measurement up to 4 mumol/L. The method proved to be suited for routine application in species with low selenium concentrations, such as cattle. It may be useful wherever small amounts of serum have to be analysed, e.g. in neonatology. Reference values of serum selenium concentration were determined in healthy subjects of various species, including man. They were as follows (min = 5%, max = 95% percentile values in mumol/L): humans (20-60 years): 0.78-1.48, humans (60-100 years): 0.61-1.73, horse: 0.36-1.68, dog: 1.90-4.31, cat: 3.60-10.09, cattle greater than 9 months: 0.10-0.82, calves 3-9 months: 0.19-0.65, sheep: 0.09-0.54, goat: 0.14-1.42, chicken: 1.68-4.28 and pig: 1.97-3.32. From the data it was concluded (i) that the serum selenium concentration depended on the amount of selenium in the food, and on the type of digestive tract; (ii) that carnivors had the highest and ruminants the lowest selenium values; and (iii) that up to 20% of the geriatric donors had inadequate selenium levels.

Influence of the dosing frequency of parathyroid hormone-(1-38) on its anabolic effect in bone and on the balance of calcium, phosphorus and magnesium.

The effect of the frequency of administration of synthetic human parathyroid hormone fragment 1-38 [hPTH-(1-38)] on bone formation and on the balance of calcium, phosphorus, and magnesium was investigated in 32 9-week-old female Sprague-Dawley rats, using a randomly complete block design. Rats received subcutaneously during 14 days either the vehicle solution once a day or 50 micrograms hPTH-(1-38)/kg BW once a day at 8:00 a.m., twice a day at 8:00 a.m. and 5:00 p.m. or three times a day at 8:00 a.m., 0:30 p.m., and 5:00 p.m. The balance study was performed during the last 48 h of the hPTH-(1-38) treatment schedule after which femora, tibiae, and lumbar vertebrae were removed for the determination of the dry weight, volume, and contents of Ca, P, Mg, hydroxyproline, and DNA. PTH treatment was associated with a significant increase of the apparent intestinal absorption of Ca, P, and Mg. Mean urinary Ca excretion augmented with the increase of the frequency of dosing. Urinary Ca excretion correlated negatively with the Ca apparent intestinal absorption and with the Ca content of the tibiae in the 2 groups with the highest frequency of dosing. The mean Ca, P, and Mg balances, the mean contents of bone Ca, P, and Mg and the mean bone dry weights were significantly increased with PTH treatment. In contrast to the mean volume of tibiae which was not affected by the PTH administration, the mean volume of the fifth lumbar vertebrae increased with the treatment. With the 2 times and 3 times daily treatments, mean hydroxyproline concentrations in the femora were significantly higher than the control values. An increase of the mean hydroxyproline content of the third lumbar vertebrae was evidenced with the 1 time and 2 times daily treatment, but the mean of the highest frequency of dosing was not different from that of the control group. The DNA content of femoral and of the fourth lumbar vertebrae significantly decreased with the frequency of dosing.

Deactivation of macrophages with interleukin-4 is the key to the isolation of Tropheryma whippelii.

Whipple's disease is a systemic illness caused by a specific agent. Despite recognition of bacteria in lesions, efforts to isolate the causative agent remained futile. A novel strategy was devised to culture Whipple bacilli in deactivated mononuclear phagocytes. Infected tissue was inoculated into human phagocytes deactivated with interleukin (IL)-4, IL-10, and dexamethasone. Within 8-10 days, diastase-resistant periodic acid-Schiff-positive inclusions appeared, corresponding to intact and degenerating bacteria shown to be Tropheryma whippelii by electron microscopy and molecular analyses. T. whippelii was passaged several times in deactivated monocytes and a monoblastic cell line. Time-kinetics growth studies and comparative polymerase chain reaction analysis documented multiplication of T. whippelii in deactivated macrophages. Complementary studies showed that IL-4 rendered phagocytes permissive for T. whippelii, a strong indication that host factors contribute to the pathogenesis of Whipple's disease. The propagation of T. whippelii will permit microbiologic, immunologic, seroepidemiologic, and therapeutic studies of this pathogen.