Cone-Beam Computed Tomography to evaluate changes in trabecular lower jawbone microstructure caused by bone loss and antiresorptive treatment.

Unlabelled: For decades, conventional histomorphometry has been the gold standard for analyzing trabecular bone microarchitecture. In recent years, micro-computed tomography (μCT) devices have been validated and are now considered the gold standard for quantifying bone microstructure.

Aim: The aim of this preliminary report is to evaluate the usefulness of CBCT to assess trabecular mandible microstructural properties in normal ewes and to compare the quantitative changes associated with ovariectomy and antiresorptive treatment.

Does Vitamin D Insufficiency Influence Prebiotic Effect on Calcium Absorption and Bone Retention?

Higher calcium (Ca) absorption would partially compensate for Ca intake below requirements for bone health. Previously, we found that GOS/FOS prebiotic mixture (PM) increases Ca absorption in the colon and retention in bone. Ca absorption and retention are regulated by vitamin D (VD).

Aminobisphosphonate-treated ewes as a model of osteonecrosis of the jaw and of dental implant failure.

Background: Bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) and dental implant failure are two negative side effects of chronic aminoBP treatment.

Methods: Eleven ovariectomized (OVX) ewes and four ewes subjected to sham surgery (SHAM) were treated as follows: OVX (n = 5): OVX plus saline solution; zoledronic acid-treated group (ZOL) (n = 6): OVX plus ZOL; SHAM (n = 4): SHAM plus saline solution. Extraction of the first upper molar was performed at 1 year, dental implant placement at 2 years, and sacrifice at 28 months.

Effect of Adding a Galacto-Oligosaccharides/Fructo-Oligosaccharides (GOS/FOS®) Mixture to a Normal and Low Calcium Diet, on Calcium Absorption and Bone Health in Ovariectomy-Induced Osteopenic Rats.

Menopause is associated with bone loss. Prebiotics increase Ca, inorganic phosphorus (Pi), and Mg absorption, improving bone health. These increases would supply an extra amount of minerals, decreasing bone resorption and possibly reversing ovariectomy-induced bone loss.

Effect of a mixture of GOS/FOS on calcium absorption and retention during recovery from protein malnutrition: experimental model in growing rats.

Introduction: During growth, protein deprivation impairs epiphyseal growth plate (EGP) height, bone volume (BV) and endochondral ossification. During catch-up growth, Ca availability becomes essential to ensure the extra amount needed to achieve optimal peak bone mass and strength. GOS and FOS improve mineral absorption in the colon.

Effect of a combination GOS/FOS® prebiotic mixture and interaction with calcium intake on mineral absorption and bone parameters in growing rats.

Aim: Increasing calcium intake is the most effective strategy for avoiding Ca deficit. However, if intake remains inadequate, improving Ca absorption becomes an important tool to optimize Ca homeostasis and bone health.

Purpose: The effect of a mixture of GOS/FOS(®) 9:1 added to a normal- or low-Ca diets on Ca absorption and bone mineralization, density and structure was investigated, in a model of growing rats.

Low dietary calcium and obesity: a comparative study in genetically obese and normal rats during early growth.

Purpose: A low calcium intake (LCaI) may predispose to obesity, and excessive fat mass may be detrimental to bone. The impact of Ca inadequacy would be greater in subjects predisposed to obesity. LCaI effect on obesity development during the rapid growth period was compared in two strains of rats: spontaneously obese IIMb/β (O) and Wistar (W).

Low protein intake magnifies detrimental effects of ovariectomy and vitamin D on bone.

Protein-induced changes in bone and calcium homeostasis could potentially be greater in the elderly and in women at risk for osteoporosis. We hypothesize that a low protein intake would magnify the negative changes in bone metabolism seen in vitamin D (vitD) insufficiency and/or estrogen deficiency. The present study was undertaken to better understand how a low protein diet along with vitD insufficiency could affect bone metabolism using a rodent ovariectomized (OVX) model.

Effect of dietary calcium (Ca) on body composition and Ca metabolism during growth in genetically obese (β) male rats.

Introduction: Obese β rats may be a suitable model to evaluate the association between calcium intake (CaI) and obesity during growth.

Objective: The present study comparatively evaluated Ca absorption and retention, and changes in body composition in spontaneously genetically obese (β) male rats fed three different dietary Ca levels: high 0.9% (HCa); normal: 0.

Salivary bone turnover markers in healthy pre- and postmenopausal women: daily and seasonal rhythm.

No studies had investigated circadian and circannual rhythms of bone biomarkers in whole saliva. We evaluated the salivary daily and seasonal rhythm of carboxy-terminal telopeptide of type I collagen (CTX) and bone alkaline phosphatase (b-ALP). Forty clinical and oral healthy ambulatory pre- and postmenopausal women from two southern Argentine cities: Comodoro Rivadavia (latitude 45º S) and Ushuaia (latitude 54º S) were included in the study.

Comparative 25-OH-vitamin D level in institutionalized women older than 65 years from two cities in Spain and Argentina having a similar solar radiation index.

Objective: The present study evaluated and compared vitamin D nutritional status and calcium-phosphorus metabolism in institutionalized women >65 y from two cities that have a similar sun irradiation index (heliophany).

Methods: The study was carried out in women living in similar social-status institutions from geographic cities having a similar solar radiation index (Lleida, Spain, n=49, and suburban Buenos Aires, Argentina [BA], n=48) at the end of summer.

Results: Fish consumption was higher in the Lleida group, as was red-meat consumption in the BA group.

[Body composition by simple anthropometry, bioimpedance and DXA in preschool children: interrelationships among methods].

Objective: To examine the interrelationships of body composition variables derived from simple anthropometry, bioelectrical impedance (BIA) and dualenergy X-ray absorptiometry (DXA).

Population, Material And Methods: A total of 230 healthy preschool children (118 males and 112 females) age 4-6 years, attending a day care center, were examined to determine body mass index (BMI) and waist circumference (WC). Percentage of body fat content (%BF) was predicted by BIA (Maltron BF- 900) and DXA (Lunar DPX-L, pediatric software).

Correlation between salivary and serum markers of bone turnover in osteopenic rats.

Background: Previously, we measured bone alkaline phosphatase (b-ALP) and terminal C-telopeptide of collagen type I (CTX) in saliva. The present longitudinal experimental study sought to determine whether salivary concentrations of b-ALP and CTX have the same response as in serum samples under different conditions: normal, increased, and reduced bone remodeling.

Methods: Thirty rats were ovariectomized (OVX) to induce osteopenia 60 days after surgery, and 10 rats were sham operated.

[Calcium and protein intake and bone markers in premenopausic and posmenopausic women with normal bone mineral density from Comodoro Rivadavia (Argentina)].

Unlabelled: Healthy premenopausal women (Pre n=28) and posmenopausal (Pos n=22), living in Comodoro Rivadavia (Argentina), with normal femoral neck and lumbar spine bone mineral density (BMD) were studied. Usual daily calcium intake (CaI) and protein intake (PrI) were calculated according to an special questionaire and the National Food Composition Tables. Fasting blood samples and 24 h urine were collected.

[Bone remodeling markers in saliva as compared to serum in rats].

Bone markers are useful tools to measure bone remodeling; currently they are assessed in serum and urinary samples; however there is little information concerning their measurement in saliva. The present experimental study evaluates the possibility to measure collagen type I carboxiterminal telopeptide (CTX) and bone alkaline phosphatase (b-AP) in saliva, its correlation with serum samples in normal conditions and in the increase of the bone remodeling due to estrogen deficiency. Twenty four normal adult Wistar rats (300 +/- 20 g) [12 SHAM and 12 rats after 1 week of bilateral ovariectomy (OVX)] were studied.

Vitamin D insufficiency reduces the protective effect of bisphosphonate on ovariectomy-induced bone loss in rats.

The present study was carried out to obtain an experimental model of vitamin D (vit D) insufficiency and established osteopenia (experiment 1) to then investigate whether vit D status, i.e. normal or insufficient, interferes with bone mass recovery resulting from bisphosphonate therapy (experiment 2).

[Serum beta-type I collagen carboxyterminal telopeptide (beta-CTXs) and bone involvement in chronic renal failure].

An increase in parathyroid hormone (PTH) levels in chronic renal failure (CRF) induces bone abnormalities known as renal osteodystrophy (ROD). The aim of the present study was to evaluate alternative biochemical methods to bone biopsy, to evaluate changes in bone remodeling in renal patients. Intact PTH (iPTH) and bone markers were measured in 43 predialysis (PD), 49 hemodialysis patients (HD) and 185 controls.

Interrelationship between bone turnover markers and dietary calcium intake in pregnant women: a longitudinal study.

This longitudinal study evaluated bone turnover and the interrelationship between changes in bone biomarkers and habitual dietary calcium intake during pregnancy in a group of women ranging widely with regard to dietary calcium intake. Thirty-nine healthy pregnant and 30 nonpregnant women were studied. Calcium, phosphorus, 1alpha,25-dihydroxyvitamin D (1,25diHOD), bone alkaline phosphatase (bALP), carboxyterminal propeptides of type I procollagen (PICP) and carboxyterminal telopeptides of type I collagen (betaCTX and ICTP) were measured in serum and calcium, and creatinine and aminoterminal telopeptide (NTX) were determined in urine.

[Imbalance diets in preschool children: study in a day-care center in the Province of Buenos Aires, Argentina].

The purpose of this study was to investigate the impact of low fat diets in children aged 2 to 5. Eighty two children (40 females and 42 males) attending a school cafeteria (Province of Buenos Aires, Argentina), in a cross sectional study, were evaluated. Body weight (W), height (H) and body composition (BC) by bioimpedance were recorded.

Olpadronate prevents the bone loss induced by cyclosporine in the rat.

The aim of the present in vivo experimental study was to investigate changes in bone turnover and bone mineral density (BMD) induced by cyclosporine (CsA) administration. The effectiveness of olpadronate (OPD) in preventing bone loss associated with CsA treatment was also evaluated. Forty male Sprague-Dawley rats (approximately 5 months old) were treated as follows: Group I: CsA+OPD vehicles (control); Group II: CsA 15 mg/kg + OPD vehicle; Group III: CsA 15 mg/kg + 4 ug OPD/100g rat; Group IV: CsA 15 mg/kg + 8 ug OPD/100g rat; Group V: CsA 15 mg/kg + 16 ug OPD/100g rat.