scholarly journals No Observed Adverse Effects on Health Were Detected in Adult Beagle Dogs When Fed a High-Calcium Diet for 40 Weeks

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1799
Author(s):  
Jujhar Atwal ◽  
Jonathan Stockman ◽  
Matthew Gilham ◽  
David Allaway ◽  
Helen Renfrew ◽  
...  
Keyword(s):  
Filtration Rate ◽  
Fold Increase ◽  
Diet Group ◽  
Test Diet ◽  
Beagle Dogs ◽  
Adverse Health Effects ◽  
Mineral Balance ◽  
High Calcium ◽  
High Calcium Diet

The implications of long-term high calcium (Ca) intake are well documented in growing dogs and in adult dogs of large breed size, however, the consequences on other breeds and breed sizes are yet to be determined. Eighteen neutered adult beagles, nine males and nine females aged 1.4–4.4 years, were randomized to control or test diets providing in g∙4184 kJ−1 (1000 kcal−1): 1.44 and 7.19 total Ca balanced with 1.05 and 4.25 total phosphorus, respectively, for 40 weeks. Health parameters, ultrasound scans, radiographs, glomerular filtration rate, and mineral balance were measured at eight-week intervals. All dogs remained healthy with no measured evidence of orthopedic, urinary, or renal disease. The test diet resulted in a 5.2 fold increase in fecal Ca excretion. Apparent Ca digestibility (%) and Ca balance (g/d) did not significantly (p > 0.05) change from baseline in the test diet group, although dogs displayed a positive Ca balance (maximum at week 8, 1.11 g/d with 95% CI (0.41, 1.80)) before a neutral Ca balance was restored at week 32. Despite an initial positive Ca balance, we can conclude that no measurable adverse health effects were observed as a result of the test diet fed in this study in beagles over a period of 40 weeks.

scholarly journals Effect of Silicon Supplementation in Diets with Different Calcium Levels on Bone Mineral Metabolism and Bone Status in Growing Female Rats

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1817-1817
Author(s):  
Mi-Hyun Kim ◽  
Mi-Kyeong Choi
Keyword(s):  
Bone Mineral ◽  
Calcium Intake ◽  
Mineral Metabolism ◽  
Diet Group ◽  
Female Rats ◽  
Bone Mineral Metabolism ◽  
Calcium Diet ◽  
Low Calcium Diet ◽  
High Calcium ◽  
High Calcium Diet

Abstract Objectives Silicon is important for the growth and development of bone and connective tissues. However, few studies have investigated effects of silicon supplementation on bone metabolism on growing females. We evaluated the effect of silicon supplementation on bone mineral metabolism and bone status in growing female rats fed diet with different calcium levels. Methods Sixty 6-wk-old Sprague-Dawley female rats were divided into 6 groups and fed diet with different levels of calcium (0.1%, 0.5%, 1.5%) and silicon (5 ppm, 500 ppm) for 10 weeks. We used a two-way ANOVA test to examine the difference and a significant level was set at P < 0.05. Results Silicon retention significantly increased by silicon supplementation and significantly decreased by high calcium diet (1.5%). Mg retention significantly decreased by high calcium diet. Serum calcium and silicon contents were not significantly different among the 6 groups. Low calcium diet (0.1% calcium) significantly increased serum osteocalcin and C-telopeptide cross-links of type I collagen (CTX) levels, and silicon supplementation significantly decreased CTX levels in the low calcium diet group. Bone mineral density was significantly increased along with greater calcium level in the diet, but was decreased by silicon supplementation in the high calcium diet. Rats in the 0.5% calcium diet group had significant increase in strength of the tibia by silicon supplementation. Conclusions According to our findings, the effect of silicon supplementation on bone metabolism may differ according to the calcium intake levels in growing females. Although further research is needed, when supplementing silicon to improve bone health in growing females, the calcium intake level should be considered. Funding Sources Korea Research Foundation.

High-calcium diet modulates effects of long-term prolactin exposure on the cortical bone calcium content in ovariectomized rats

2007 ◽  
Vol 292 (2) ◽  
pp. E443-E452 ◽  
Author(s):  
Narattaphol Charoenphandhu ◽  
Kukiat Tudpor ◽  
Kanogwun Thongchote ◽  
Wasana Saengamnart ◽  
Supaporn Puntheeranurak ◽  
...  
Keyword(s):  
Calcium Content ◽  
Ovariectomized Rats ◽  
Calcium Deposition ◽  
Total Calcium ◽  
Adult Rats ◽  
Calcium Diet ◽  
High Calcium ◽  
Bone Calcium ◽  
High Calcium Diet

High physiological prolactin induced positive calcium balance by stimulating intestinal calcium absorption, reducing renal calcium excretion, and increasing bone calcium deposition in female rats. Although prolactin-induced increase in trabecular bone calcium deposition was absent after ovariectomy, its effects on cortical bones were still controversial. The present investigation, therefore, aimed to study the effect of in vivo long-term high physiological prolactin induced by either anterior pituitary (AP) transplantation or 2.5 mg/kg prolactin injection on cortical bones in ovariectomized rats. Since the presence of prolactin receptors (PRLR) in different bones of normal adult rats has not been reported, we first determined mRNA expression of both short- and long-form PRLRs at the cortical sites (tibia and femur) and trabecular sites (calvaria and vertebrae) by using the RT-PCR. Our results showed the mRNA expression of both PRLR isoforms with predominant long form at all sites. However, high prolactin levels induced by AP transplantation in normal rats did not have any effect on the femoral bone mineral density or bone mineral content. By using 45Ca kinetic study, 2.5 mg/kg prolactin did not alter bone formation, bone resorption, calcium deposition, and total calcium content in tibia and femur of adult ovariectomized rats. AP transplantation also had no effect on the cortical total calcium content in adult ovariectomized rats. Because previous work showed that the effects of prolactin were age dependent and could be modulated by high-calcium diet, interactions between prolactin and these two parameters were investigated. The results demonstrated that 2.0% wt/wt high-calcium diet significantly increased the tibial total calcium content in 9-wk-old young AP-grafted ovariectomized rats but decreased the tibial total calcium content in 22-wk-old adult rats. As for the vertebrae, the total calcium contents in both young and adult rats were not changed by high-calcium diet. The present results thus indicated that the adult cortical bones were potentially direct targets of prolactin. Moreover, the effects of high physiological prolactin on cortical bones were age dependent and were observed only under the modulation of high-calcium diet condition.

scholarly journals Adult dogs are capable of regulating calcium balance, with no adverse effects on health, when fed a high-calcium diet

2017 ◽  
Vol 117 (9) ◽  
pp. 1235-1243 ◽  
Author(s):  
Jonathan Stockman ◽  
Phillip Watson ◽  
Matthew Gilham ◽  
David Allaway ◽  
Jujhar Atwal ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Fold Increase ◽  
Metabolic Effects ◽  
Calcium Balance ◽  
High Calcium ◽  
The Impact ◽  
Labrador Retrievers ◽  
Made In ◽  
Health Parameters

AbstractAlthough the implications of long-term high Ca intakes have been well documented in growing dogs, the health consequences of Ca excess in adult dogs remain to be established. To evaluate the impact of feeding a diet containing 7·1 g/4184 kJ (1000 kcal) Ca for 40 weeks on Ca balance and health parameters in adult dogs, eighteen neutered adult Labrador Retrievers, (nine males and nine females) aged 2·5–7·4 years were randomised to one of two customised diets for 40 weeks. The diets were manufactured according to similar nutritional specifications, with the exception of Ca and P levels. The diets provided 1·7 and 7·1 g/4184 kJ (1000 kcal) (200(SD26) and 881(SD145) mg/kg body weight0·75 per d, respectively) Ca, respectively, with a Ca:P ratio of 1·6. Clinical examinations, ultrasound scans, radiographs, health parameters, metabolic effects and mineral balance were recorded at baseline and at 8-week intervals throughout the study. Dogs in both groups were healthy throughout the trial without evidence of urinary, renal or orthopaedic disease. In addition, there were no clinically relevant changes in any of the measures made in either group (all P>0·05). The high-Ca diet resulted in a 3·3-fold increase in faecal Ca excretion (P<0·001), whereas apparent Ca digestibility (%) and net Ca balance (g/d) did not significantly change from baseline or differ between the groups at any time point (both P>0·05). Ca intakes of up to 7·1 g/4184 kJ (1000 kcal) are well tolerated over a period of 40 weeks, with no adverse effects that could be attributed to the diet or to a high mineral intake.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

Repeated Occupational Exposure to Low-level Blast in the Canadian Armed Forces: Effects on Hearing, Balance, and Ataxia

2021 ◽  
Author(s):  
Ann Nakashima ◽  
Oshin Vartanian ◽  
Shawn G Rhind ◽  
Kristen King ◽  
Catherine Tenn ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Occupational Exposure ◽  
Armed Forces ◽  
Cross Sectional ◽  
Low Level ◽  
Additional Information ◽  
Adverse Health Effects ◽  
Blast Overpressure ◽  
Blast Exposure

ABSTRACT Introduction Recently, there has been increasing concern about the adverse health effects of long-term occupational exposure to low-level blast in military personnel. Occupational blast exposure occurs routinely in garrison through use of armaments and controlled blast detonations. In the current study, we focused on a population of breaching instructors and range staff. Breaching is a tactical technique that is used to gain entry into closed spaces, often through the use of explosives. Materials and Methods Initial measurements of blast overpressure collected during breaching courses found that up to 10% of the blasts for range staff and up to 32% of the blasts for instructors exceeded the recommended 3 psi exposure limit. Using a cross-sectional design, we used tests of balance, ataxia, and hearing to compare a sample of breachers (n = 19) to age-and sex-matched military controls (n = 19). Results There were no significant differences between the two groups on the balance and ataxia tests, although the average scores of both groups were lower than would be expected in a normative population. The prevalence of hearing loss was low in the breacher group (4 of 19), and hearing thresholds were not significantly different from the controls. However, the prevalence of self-reported tinnitus was significantly higher in the breacher group (12 of 19) compared with the controls (4 of 19), and all breachers who were identified as having hearing loss also reported tinnitus. Conclusions Our results suggest that basic tests of balance, ataxia, and hearing on their own were not sensitive to the effects of long-term occupational exposure to low-level blast. Some of the blast exposure levels exceeded limits, and there was a significant association of exposure with tinnitus. Future studies should supplement with additional information including exposure history and functional hearing assessments. These findings should be considered in the design of future acute and longitudinal studies of low-level blast exposure.

scholarly journals Long-term Diet Quality and Gut Microbiome Functionality: A Prospective, Shotgun Metagenomic Study among Urban Chinese Adults

2021 ◽  
Vol 5 (4) ◽  
Author(s):  
Danxia Yu ◽  
Yaohua Yang ◽  
Jirong Long ◽  
Wanghong Xu ◽  
Qiuyin Cai ◽  
...  
Keyword(s):  
Diet Quality ◽  
Gut Microbiome ◽  
Metabolic Pathways ◽  
Gene Families ◽  
Diet Group ◽  
Healthy Diet ◽  
Chinese Adults ◽  
Α Diversity ◽  
Unhealthy Diet

ABSTRACT Background Diet is known to affect human gut microbiome composition; yet, how diet affects gut microbiome functionality remains unclear. Objective We compared the diversity and abundance/presence of fecal microbiome metabolic pathways among individuals according to their long-term diet quality. Methods In 2 longitudinal cohorts, we assessed participants’ usual diets via repeated surveys during 1996–2011 and collected a stool sample in 2015–2018. Participants who maintained a healthy or unhealthy diet (i.e., stayed in the highest or lowest quintile of a healthy diet score throughout follow-up) were selected. Participants were excluded if they reported a history of cancer, cardiovascular disease, diabetes, or hypertension; had diarrhea or constipation in the last 7 d; or used antibiotics in the last 6 mo before stool collection. Functional profiling of shotgun metagenomics was performed using HUMAnN2. Associations of dietary variables and 420 microbial metabolic pathways were evaluated via multivariable-adjusted linear or logistic regression models. Results We included 144 adults (mean age = 64 y; 55% female); 66 had an unhealthy diet and 78 maintained a healthy diet. The healthy diet group had higher Shannon α-diversity indexes of microbial gene families and metabolic pathways (both P &lt; 0.02), whereas β-diversity, as evaluated by Bray-Curtis distance, did not differ between groups (both P &gt; 0.50). At P &lt; 0.01 [false discovery rate (FDR) &lt;0.15], the healthy diet group showed enriched pathways for vitamin and carrier biosynthesis (e.g., tetrahydrofolate, acetyl-CoA, and l-methionine) and tricarboxylic acid (TCA) cycle, and increased degradation (or reduced biosynthesis) of certain sugars [e.g., cytidine monophosphate (CMP)-legionaminate, deoxythymidine diphosphate (dTDP)-l-rhamnose, and sucrose], nucleotides, 4-aminobutanoate, methylglyoxal, sulfate, and aromatic compounds (e.g., catechol and toluene). Meanwhile, several food groups were associated with the CMP-legionaminate biosynthesis pathway at FDR &lt;0.05. Conclusions In a small longitudinal study of generally healthy, older Chinese adults, we found long-term healthy eating was associated with increased α-diversity of microbial gene families and metabolic pathways and altered symbiotic functions relevant to human nutrition and health.

scholarly journals Continuous Long-Term Exposure to Low Concentrations of MWCNTs Induces an Epithelial-Mesenchymal Transition in BEAS-2B Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1742
Author(s):  
Hélène Barthel ◽  
Christian Darne ◽  
Laurent Gaté ◽  
Athanase Visvikis ◽  
Carole Seidel
Keyword(s):  
Epithelial Mesenchymal Transition ◽  
Mesenchymal Transition ◽  
Pulmonary Exposure ◽  
Adverse Health Effects ◽  
Low Concentrations ◽  
Mitotic Abnormalities ◽  
Epithelial Marker ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

In the field of nanotechnology, the use of multi-walled carbon nanotubes (MWCNTs) is growing. Pulmonary exposure during their production, use, and handling is raising concerns about their potential adverse health effects. The purpose of this study is to assess how the physical characteristics of MWCNTs, such as diameter and/or length, can play a role in cellular toxicity. Our experimental design is based on the treatment of human bronchial epithelial cells (BEAS-2B) for six weeks with low concentrations (0.125–1 µg/cm2) of MWCNTs having opposite characteristics: NM-403 and Mitsui-7. Following treatment with both MWCNTs, we observed an increase in mitotic abnormalities and micronucleus-positive cells. The cytotoxic effect was delayed in cells treated with NM-403 compared to Mitsui-7. After 4–6 weeks of treatment, a clear cellular morphological change from epithelial to fibroblast-like phenotype was noted, together with a change in the cell population composition. BEAS-2B cells underwent a conversion from the epithelial to mesenchymal state as we observed a decrease in the epithelial marker E-cadherin and an increased expression of mesenchymal markers N-cadherin, Vimentin, and Fibronectin. After four weeks of recovery, we showed that the induced epithelial-mesenchymal transition is reversible, and that the degree of reversibility depends on the MWCNT.

scholarly journals Transitional Cell Carcinomas of the Urinary Tract in a Colony of Beagle Dogs

1989 ◽  
Vol 26 (6) ◽  
pp. 455-461 ◽  
Author(s):  
K. J. Nikula ◽  
S. A. Benjamin ◽  
G. M. Angleton ◽  
A. C. Lee
Keyword(s):  
Urinary Tract ◽  
Transitional Cell ◽  
Clinical Signs ◽  
Conclusive Evidence ◽  
Whole Body ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Significant Difference ◽  
Microscopic Features

Gross and light microscopic features of transitional cell carcinomas (TCC) of the urinary tract were examined in Beagle dogs used for the study of the long-term effects of low-dose, whole-body, 60Co gamma radiation. Thirty-eight cases of TCC occurred among 990 dogs that were from 0 to 14 years of age. There was no conclusive evidence of a radiation effect. The 38 TCC were equally divided between male and female dogs, but there was a significant difference in the sex distribution of urethra-origin TCC. Eleven males had a primary urethral TCC compared to only two females. There was no significant difference between the urethra-origin and bladder-origin TCCs in the number of tumors that caused clinical signs, metastasized, or that contributed to the death of the dog. All cases of urethral TCC in male dogs occurred in the prostatic urethra. The majority of these cases were not recognized to be neoplasms at gross necropsy, but microscopic examination revealed the TCC. Our findings differ from previous reports stating that TCC occurs more frequently in female than male dogs, and they especially differ from reports claiming that urethra-origin TCC is predominately a disease of female dogs.

Parathyroid Hormone- and Deoxycorticosterone Acetate-Induced Hypertension in the Rat

1980 ◽  
Vol 58 (5) ◽  
pp. 365-371 ◽  
Author(s):  
A. Berthelot ◽  
A. Gairard
Keyword(s):  
Parathyroid Hormone ◽  
Hormone Secretion ◽  
Sprague Dawley ◽  
Physiological Concentration ◽  
Deoxycorticosterone Acetate ◽  
Calcium Diet ◽  
Arterial Blood ◽  
Sprague Dawley Rats ◽  
High Calcium ◽  
High Calcium Diet

1. Hypertension induced by treatment with deoxycorticosterone acetate and sodium chloride was studied in male Sprague-Dawley rats and related to parathyroid hormone secretion. 2. Lack of parathyroid hormone (due to parathyroidectomy) or decreased parathormone secretion (due to a high-calcium diet) partially inhibited the development of arterial hypertension. 3. In contrast, in thyroparathyroidectomized rats supplemented with thyroxine, the administration of parathyroid hormone rapidly elevated arterial blood pressure. 4. Maintaining a physiological concentration of serum calcium in the absence of parathyroid hormone (by feeding a high-calcium diet to parathyroidectomized rats) was not sufficient to establish mineralocorticoid hypertension. 5. These results show that parathyroid hormone is necessary for the complete development of mineralocorticoid hypertension.

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