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PubMedDate not supplied

Preoperative [131I]metaiodobenzylguanidine therapy of neuroblastoma at diagnosis ("MIBG de novo").

The observed response of [131I]metaiodobenzylguanidine (131I-MIBG) therapy in advanced neuroblastoma after conventional therapy had failed, the noninvasiveness of the procedure, and the high metabolic activity of untreated tumors led to a new protocol to use 131I-MIBG therapy in newly diagnosed patients instead of combination chemotherapy prior to surgery. The objectives of this study are to improve the overall outcome of patients with neuroblastoma by introducing 131I-MIBG therapy as the first therapy in the treatment schedule, in order to reduce the tumor volume, enabling adequate surgical resection and avoiding toxicity and the induction of early drug resistance. The advantages of this approach are that the child's general condition is unaffected before surgical resection is performed and that chemotherapy is reserved to treat minimal residual disease. So far, 13 patients with inoperable neuroblastoma (stage III and IV) were treated with 131I-MIBG initially and then submitted to surgery. More than 50% decrease of the volume of the primary tumor was noted in 7 of 10 evaluable patients; 8 patients have so far been operated with complete resection in 2, greater than 95% resection in 5 and 80% resection in one patient. Three patients are still undergoing 131I-MIBG treatment. The toxicity of 131I-MIBG de novo is in contrast with the previous experience of 131I-MIBG therapy after conventional therapy: only 4 patients had thrombocytopenia and only 1 of 7 patients with bone marrow involvement developed bone marrow depression.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Iodobenzylguanidine↗
PubMed1998

[Biochemical markers of bone remodeling in the prevention of postmenopausal osteoporosis].

Normal bone mass is one of the principal factors in the prevention of osteoporosis for women in advanced age. Therefore, it is necessary to have efficacious serum and urinary markers available to screen the bone development and the bone resorption. Even if we are also far from identifying an ideal marker, the measurement of some substances such as pyridinoline (Pyr) and deoxypyridinoline (D-Pyr) seems to be a first progress for efficacious and rather simple techniques.

Aged↗
PubMed1997

Development of bone marrow toxicosis after albendazole administration in a dog and cat.

Bone marrow toxicosis was detected in a dog and cat following albendazole administration. Both animals were admitted with pancytopenia. In the dog, pancytopenia was attributed to severe panmarrow hypoplasia, whereas the cat had hypoplasia of erythroid and megakaryocytic series, but with a left-shifted granulocytic hyperplasia. Results of cytologic examination of bone marrow from both animals were compatible with acute injury. Both animals had been treated with albendazole for giardiasis prior to the onset of clinical signs. Bone marrow toxicosis was attributed to albendazole administration for the following reasons: this was the only or most recent drug administered, other causes of bone marrow toxicosis were not found, and both animals recovered rapidly with supportive care that consisted of fluid and antibiotic administration. Albendazole induced toxicosis appeared to be dose related in the dog and idiosyncratic in the cat. On the basis of the findings in this report, there is a potential for the development of albendazole induced bone marrow toxicosis in dogs and cats; therefore, veterinarians should exercise caution when using this drug.

Albendazole↗
PubMed2006

Correlation between first trimester fetal bone length and maternal serum pregnancy-associated plasma protein-A (PAPP-A).

BACKGROUND: Pregnancy-associated plasma protein-A (PAPP-A) is produced by the embryo and placenta during pregnancy, and its maternal serum concentrations are related to subsequent fetal growth. Evidence from animal models and in vitro experiments suggests that PAPP-A is particularly involved in the regulation of bone development. The aim of this study was to assess the correlation between late first trimester fetal bone length and maternal serum levels of PAPP-A. METHODS: In a cross-sectional observational study, ultrasound measurements of fetal long bones and fluorimetric immunoassays for maternal serum PAPP-A were performed in 514 singleton pregnancies at 10-14 weeks of gestation. RESULTS: There were 501 uncomplicated pregnancies. There were significant correlations between PAPP-A values and length of humerus, femur and tibia [r values 0.12 (P = 0.01), 0.11 (P = 0.01) and 0.10 (P = 0.03), respectively]. The association with the length of ulna and foot did not reach statistical significance (r values 0.08 and -0.03, respectively). CONCLUSIONS: Maternal serum PAPP-A levels at 10-14 weeks of gestation are significantly associated with the length of fetal long bones such as humerus, femur and tibia. This provides further evidence that PAPP-A may be involved in the regulation of bone development.

Bone and Bones↗
PubMed2005

Tyrosine phosphatase MEG2 modulates murine development and platelet and lymphocyte activation through secretory vesicle function.

MEG2, a protein tyrosine phosphatase with a unique NH2-terminal lipid-binding domain, binds to and is modulated by the polyphosphoinositides PI(4,5)P2 and PI(3,4,5)P3. Recent data implicate MEG2 in vesicle fusion events in leukocytes. Through the genesis of Meg2-deficient mice, we demonstrate that Meg2-/- embryos manifest hemorrhages, neural tube defects including exencephaly and meningomyeloceles, cerebral infarctions, abnormal bone development, and >90% late embryonic lethality. T lymphocytes and platelets isolated from recombination activating gene 2-/- mice transplanted with Meg2-/- embryonic liver-derived hematopoietic progenitor cells showed profound defects in activation that, in T lymphocytes, was attributable to impaired interleukin 2 secretion. Ultrastructural analysis of these lymphocytes revealed near complete absence of mature secretory vesicles. Taken together, these observations suggest that MEG2-mediated modulation of secretory vesicle genesis and function plays an essential role in neural tube, vascular, and bone development as well as activation of mature platelets and lymphocytes.

Animals↗
PubMed1992

The effects of exercise mode, swimming vs. running, upon bone growth in the rapidly growing female rat.

The purpose of this study was to compare the effects of two programs of endurance training, of equal duration and intensity, on bone development in female rats. Thirty-eight female Wistar rats were randomly assigned to one of three groups: run-trained (RUN), swim-trained (SWIM) or control (CON). The RUN group ran at a speed of 27 m/min up an 8 degrees incline. Swim trained animals swam with 2% of body weight attached to their tails. Training sessions were 2 h/day, 5 days/week and were conducted over a 10-week period. Hindlimb and forelimb muscles were removed upon sacrifice and analyzed for citrate synthase (CS) activity, liver (LG) and muscle (MG) glycogen. The parametrial fat pads were removed, digested with collagenase, and 2-deoxy-D-[3H]glucose uptake measured in isolated cells. Bone weight, length, diameter, ponderal index and bone mineral content (BMC) were measured in the femur and humerus of each animal. The LG, MG, fat cell volume, glucose uptake of the adipocyte and adrenal weight data indicate that the training response was identical. The CS activity of the muscles indicated that mechanical and recruitment patterns of the upper and lower body differ and could be responsible for bone development patterns found in this study. Exercise had a minimal effect on bone growth in the run-trained animals but did stimulate development in the swim-trained animals. The humerus of the SWIM was significantly (P < 0.05) heavier, wider and had a greater BMC when compared with those of the RUN and CON rats. The results of this study indicate that the muscular forces applied by the swim training protocol produced greater bone adaptations than the forces applied by a running protocol of equal duration and intensity.

Animals↗
PubMed2006

Assisted exercise and bone strength in preterm infants.

Studies have previously demonstrated that brief (4 weeks) passive range-of-motion exercise is beneficial for bone development in very low birth weight (VLBW) preterm infants. However, the optimal duration of exercise for bone development in preterm infants is yet unknown. The aim of the present study was to examine the effect of 8 weeks of assisted exercise on bone strength and metabolism in VLBW premature infants. Sixteen infants (mean +/- standard error of the mean birth weight 1,009 +/- 55 g and gestational age 27.3 +/- 0.3 weeks) were randomly assigned into exercise (n = 8) and control (n = 8) groups. The intervention started at the first week of life and involved 8 weeks of daily passive extension and flexion range-of-motion exercise of the upper and lower extremities. Biochemical markers of bone turnover were measured at enrollment and after 8 weeks. Bone strength was measured weekly by quantitative ultrasound measurement of tibial bone speed of sound (SOS). Bone SOS decreased significantly in the control group (-108.1 +/- 33.7 m/second, P < 0.0001) during the study period, while remaining stable in the exercise group (11.3 +/- 22.8 m/second). The main beneficial effect of exercise occurred in the first 4 weeks of the intervention. There were no significant differences in the bone turnover marker changes between the groups. There is a significant postnatal decrease in bone SOS in VLBW preterm infants. Eight weeks of assisted range-of-motion exercise attenuates the decrease in bone strength and may decrease the risk of osteopenia in premature infants.

Body Weight↗
PubMed2002

An investigation of calcium citrate-malate as a calcium source for young broiler chicks.

Two experiments were conducted to compare a sample of calcium citrate-malate (CC-M) with a sample of commercial-grade limestone in starting broiler chick diets. In the first experiment, with 0.7 or 0.9% calcium from limestone or CC-M, no differences in bone development (dry fat-free tibia, tibia weight, tibia ash, or tibia calcium) were observed due to calcium source. However, chicks fed the diets based on CC-M had better 0- to 18-d body weight gains and feed conversion ratios than those fed limestone. In the second experiment with 0.50, 0.55, 0.60, 0.65, or 0.70% calcium from limestone or CC-M, chicks again had better body weight gains when fed CC-M compared to those fed limestone. Chicks fed diets based on CC-M and NaP2PO4 had very similar bone development and tibial dyschondroplasia pathology to those fed limestone and Na2H2PO4. However, a control group of chicks fed 0.70% calcium from limestone and dicalcium phosphate did not grow as well as the others and had lower weights of tibia and tibial bone ash, calcium, and phosphorus compared to the others. It is concluded that CC-M is a good calcium source, comparable in bioavailability to limestone. Although CC-M may improve broiler growth, its action is not through increased bioavailability of calcium.

Animal Nutritional Physiological Phenomena↗
PubMed1986

Morphological and radiological findings in induced abnormal bone growth in lambs.

Unilateral hip excision arthroplasty in skeletally immature lambs resulted in altered load bearing and posture in the contralateral limb. Derangement of endochondral bone growth occurred in distal tibiae and metatarsi and both angular and torsional deformities developed. There was no absolute correlation between torsional and angular deformities. Although femoral torsion was variable, the unoperated pelvic limbs frequently developed exaggerated internal torsion of tibiae and metatarsi. Tibiae of operated limbs developed less torsion than was seen in control animals. These findings suggest that functional limb loading can modify developing bone torsion and that torsional deformities in lambs may be a consequence of increased functional torque.

Animals↗
PubMed2002

Natural killer activity in the experimental privational rickets.

To study the 'in vivo' importance of vitamin D on the natural killer (NK) activity, rats were submitted to privational rickets induced by a diet deficient in vitamin D and phosphorus (D-P-). Thirty days after the beginning of treatment the animals showed low body weight, changes in the bone development, and decreased levels of 25-hydroxyvitamin D(3) (25-OH D(3)). NK activity, evaluated using a cytotoxicity assay against 51Cr-labeled Yac.1 target cells, was not modified by the rickets-inducing treatment during the first 30 days. Following a long-term treatment (60 days) the rachitic rats (D-P-) exhibited higher NK activity than control animals (D+P+) (P<0.05). On the other hand, D-P+ animals showed higher cytotoxic activity than D-P- and D+P+ groups. Feed replacement to the rachitic rats by a complete diet (D-P-/D+P+) led to a partial recuperation of growth, bone development, and 25-OH D(3) serum levels. The NK activity was also influenced by vitamin D intake, decreasing after treatment.

Animals↗
PubMed1996

Parathyroid hormone-related protein, bone metastases and hypercalcaemia of malignancy.

Breast cancer patients frequently develop bone metastases. A newly discovered peptide, Parathyroid Hormone Related Protein (PTHrP), causes humoral hypercalcaemia of malignancy. We have studied whether production of this protein by breast cancers leads to the development of bone metastases or hypercalcaemia. PTHrP was produced by nearly 60% of early breast cancers and its production by the tumours was associated with malignant mammographic microcalcification, and the development of both bone metastases and hypercalcaemia. The hypercalcaemia associated with bone metastases has been shown to have a significant humoral component and measurement of plasma PTHrP in patients with hypercalcaemia is diagnostically useful. Potential mechanisms of preventing bone metastasis are discussed.

Biomarkers, Tumor↗