Search results for "parathyroid hormone"

Midregion PTHrP and Human Breast Cancer Cells

2010

PTHrP is a polyhormone undergoing proteolytic processing into smaller bioactive forms, comprising an N-terminal peptide, which is the mediator of the “classical” PTH-like effect, as well as midregion and C-terminal peptides. The midregion PTHrP domain (38-94)-amide was found to restrain growth and invasionin vitroof some breast cancer cell lines, causing striking toxicity and accelerating death; the most responsive being MDA-MB231, whose tumorigenesis was also attenuatedin vivo. In addition, midregion PTHrP appears to be imported in the nucleoplasm of cultured MDA-MB231 cells andin vitro, it can bind chromatin of metaphase spread preparations and also an isolated 20-mer oligonucleotide, the…

PTHrP in differentiating human mesenchymal stem cells: Transcript isoform expression, promoter methylation, and protein accumulation

2013

Human PTHrP gene displays a complex organization with nine exons producing diverse mRNA variants due to alternative splicing at 5' and 3' ends and the existence of three different transcriptional promoters (P1, P2 and P3), two of which (P2 and P3) contain CpG islands. It is known that the expression of PTHrP isoforms may be differentially regulated in a developmental stage- and tissue-specific manner. To search for novel molecular markers of stemness/differentiation, here we have examined isoform expression in fat-derived mesenchymal stem cells both maintained in stem conditions and induced toward adipo- and osteogenesis. In addition, the expression of the splicing isoforms derived from P2 …

Parathyroid hormone and insulin-resistance in essential hypertension

2000

Relationship between PTH and PSA Values in Patients with Pathological Finding of Benign Prostatic Hyperplasia

2012

The functional relationship between parathyroid glands and prostatic gland is commonly very well known. The aim of our study was to investigate the relationship between serum levels of PTH and serum levels of PSA in patients with pathological finding of BPH. According to 261 transrectal ultrasound-guided prostatic biopsies performed from March 2009 to March 2010, 75 patients, responding to our inclusion criteria, were selected. 26 patients (34.6%) ended the study. All patients with high serum levels of PSA (>4 ng/mL), with histological diagnosis of benign prostatic hyperplasia, underwent the assay of serum levels of PTH. We observed high levels of PTH (> 66 pg/mL) in 9 patients (35.2…

Hematopoietic stem cell function in b-thalassemia is impaired and is rescued by targeting the bone marrow niche

2020

Abstract Hematopoietic stem cells (HSCs) are regulated by signals from the bone marrow (BM) niche that tune hematopoiesis at steady state and in hematologic disorders. To understand HSC-niche interactions in altered nonmalignant homeostasis, we selected β-thalassemia, a hemoglobin disorder, as a paradigm. In this severe congenital anemia, alterations secondary to the primary hemoglobin defect have a potential impact on HSC-niche cross talk. We report that HSCs in thalassemic mice (th3) have an impaired function, caused by the interaction with an altered BM niche. The HSC self-renewal defect is rescued after cell transplantation into a normal microenvironment, thus proving the active role of…

Vitamin D, parathyroid hormone, and bone mass in adolescents.

2005

This article provides a review of the evidence identifying the factors related to vitamin D status in adolescents. The prevalence of vitamin D deficiency based on 25-hydroxyvitamin D [25(OH)D] of <25 nmol/L ranges from 0 to 32% depending on the season measured and the latitude of the population assessed. The factors that have been reported to affect serum 25(OH)D in adolescents include ethnicity, gender, puberty stage, parathyroid hormone (PTH), dietary vitamin D intake, and sun exposure. Vitamin D supplementation studies are limited to small populations and with supplementation focused on winter months when sunlight may be inadequate. The effects of vitamin D status and supplementation on …

Preliminary Findings: 25(OH)D Levels and PTH Are Indicators of Rapid Bone Accrual in Pubertal Children

2007

The objective of this study was to evaluate the role of serum levels of 25(OH)D and PTH on the accumulation of whole body bone mass in a cohort of children.This was a longitudinal study (1.98 +/- 0.07 y) of sixty-nine children (89% Caucasian, 44% male) enrolled in a calcium supplementation trial. Bone area, bone mineral content (BMC) and density (BMD) of the whole body and radius were assessed using a QDR 2000 (Hologic, Inc) dual energy x-ray absorptiometer. Serum PTH and 25(OH)D were measured using radioimmunoassays.Vitamin D stores were inversely related gain in bone area (p0.002), BMC (p0.002) BMD (p0.027), as well as to PTH levels (p0.0001). Compared to those with adequate vitamin D sto…

Intermittent administration of parathyroid hormone improves the repairing process of rat calvaria defects: A histomorphometric and radiodensitometric…

2014

Background: The aim of this study was to evaluate the effects of intermittent treatment of parathyroid hormone (PTH (1-34)) on the bone regeneration of critically-sized rat calvarial bone defects. Material and Methods: Thirty-two male rats were trephined (4mm fullthickness diameter), in the central part of the parietal bones and divided into 2 groups of 16. The PTH group received subcutaneous injections of PTH (1-34) at 40μg/kg, 3 times a week and the control (CTL) group received the vehicle in the same regimen. The rats were sacrificed at 4 weeks post-treatment regimen, the parietal bones were extracted and samples were evaluated through histomorphometry and radiodensitometry. Results: The…

Vitamin D status is linked to biomarkers of oxidative stress, inflammation, and endothelial activation in obese children.

2012

To examine vitamin D, parathyroid hormone, and serum calcium-phosphorus levels relationships to biomarkers of oxidative/nitrosative stress, inflammation, and endothelial activation, potential contributors for vascular complications in obese children.Cross-sectional clinical study of 66 obese Caucasian children aged 7 to 14 years. Cardiovascular risk factors were assessed. Malondialdehyde and myeloperoxidase as measures of oxidative stress, and plasma nitrite+nitrate, urinary nitrate, and 3-nitrotyrosine as markers of nitrosative stress were measured. Adipocytokines, inflammatory molecules (high-sensitivity C-reactive protein, interleukin-6, and tumor necrosis factor-α), endothelial activati…

A new heterozygous mutation (D196N) in the Gs alpha gene as a cause for pseudohypoparathyroidism type IA in a boy who had gallstones

2011

Background Pseudohypoparathyroidism (PHP) is characterized by hypocalcemia and hyperphosphatemia in association with an increased secretion of parathyroid hormone (PTH) due to decreased target tissue responsiveness to PTH. Patients with PHP type Ia are not only resistant to PTH, but also to other hormones that bind to receptors coupled to stimulatory G protein (Gsalpha). PHP Ia and Albright hereditary osteodystrophy (AHO) are caused by a reduced activity of the Gsalpha protein. Heterozygous inactivating Gs alpha (GNAS) gene mutations have been identified in these patients. Methods We studied a boy with PHP Ia. During follow-up the patient developed elevated liver enzyme serum levels and abd…