No description available.

No description available.

We have shown that nuclear matrix protein 4 (Nmp4) attenuates the response to intermittent parathyroid hormone (PTH) in healthy and ovariectomized (OVX) female mice using a global knockout of the Nmp4 gene. Additionally, these mice have increased bone marrow osteoprogenitors and CD8+ T-cells which support osteoblast differentiation. The animals were not protected from bone loss following OVX, but retained the hypersensitivity seen in the intact mice. Mesenchymal stem/progenitor cells (osteoprogenitors) demonstrated increased growth rate in culture and showed more robust differentiation into mineralizing bone cells. Chromosome precipitation followed by next generation sequencing and bioinformatics analysis characterized Nmp4 as a negative regulator of synthetic processes and suggested the IGF1/Akt and BMP2/Smad biochemical pathways which are likely targets for Nmp4 regulation. We have experimentally verified these pathways in immortalized bone marrow mesenchymal cells from wild type and Nmp4-KO mice. Disabling Nmp4 in estrogen replete or depleted mice confers an enhanced bone formation from intermittent parathyroid hormone.

Thesis (M.Sc.)--Memorial University of Newfoundland, Faculty of Medicine, 1999. / Bibliography: leaves 118-138.

INTRODUÇÃO: A paratireoidectomia total com auto-enxerto imediato heterotópico (PTH+AE) é uma das técnicas cirúrgicas hoje usadas no tratamento do hiperparatireoidismo secundário à doença renal crônica e do hiperparatireoidismo persistente após o transplante renal. Os níveis adequados de paratormônio sistêmico (PTHs) no pós-operatório ainda são controversos e o perfil funcional do auto-enxerto de tecido paratireóideo, pouco esclarecido. No presente estudo, nós analisamos a função do tecido paratireóideo implantado pacientes com hiperparatireoidismo secundário e terciário. MÉTODO E CASUÍSTICA: Em um estudo prospectivo observacional, 19 pacientes portadores de doença renal crônica (PDRC) e quatro pacientes transplantados renais (PTR) foram submetidos à PTX+AE com e seguidos por um ano. Todos os pacientes apresentaram PTHs indetectável no pós-operatório imediato (POi). Os níveis séricos de PTH em ambos os membros superiores, cálcio, fósforo, fosfatase alcalina e reposição de cálcio elementar e calcitriol foram verificados com um mês, dois, três, quatro, seis, nove e 12 meses após a cirurgia. A 25-Hidroxivitamina D (25OHD) foi medida no POi, seis e 12 meses após a cirurgia. A função do auto-enxerto foi classificada em estados funcionais (EF) de acordo com os níveis de PTHs. RESULTADOS: A maioria dos PDRC e PTR mostraram níveis detectáveis de PTHs já no primeiro mês. No segundo mês pósoperatório, todos os pacientes apresentaram níveis detectáveis de PTHs quando também houve estabilização dos níveis séricos em ambos os grupos. Os gradientes de concentração de PTH não mostraram correlação com o PTHs. No pós-operatório, a hipercalcemia foi observada em 73,7% dos PDRC em pelo menos um episódio, reduzindo ou inibindo a secreção de paratormônio em oito pacientes. Não houve melhora dos níveis de 25OHD em ambos os grupos, permanecendo com níveis insuficientes. Oito PDRC regrediram de EF ao final do estudo. CONCLUSÃO: O perfil funcional do AE é semelhante entre os PDRC e PTR. A função do AE, inicia-se no primeiro mês pós-operatório, atingindo um maior EF até o quarto mês pós-operatório na maioria dos pacientes, porém pode haver declínio da função ao longo do tempo / BACKGROUND: Total parathyroidectomy with immediate forearm transplantation (PTX+AT) is employed in renal hyperparathyroidism. Appropriate postoperative systemic parathyroid hormone (sPTH) levels are still controversial and autograft functional behavior is unclear. In the present study, we analyzed the function of autotransplanted parathyroid tissue in secondary and tertiary hyperparathyroidism. METHODS: In a prospective observational study, 19 dialysis patients (DPs) and 4 kidney transplant patients (KTPs) who underwent PTX+AT were followed. All patients had undetectable PTH in the early postoperative period (ePO). Autograft function and the following biochemical variables were assessed at one, two, three, four, six, nine and 12 months following the operation: serum calcium, phosphorus, alkaline phosphatase, and intact PTH before and after the operation. 25-Hidroxyvitamin D levels (25OHD) were measured in the ePO, six and twelve months. Oral doses of calcium and calcitriol were recorded. Autograft function was stratified into four functional status (FS) according to sPTH. RESULTS: All functioning grafts presented sPTH until the second month. On the second postoperative month, all patients had sPTH detectable levels also when serum levels were steady in both groups. PTH gradients showed no significant correlation with sPTH levels. In at least one occasion in the postoperative period, hypercalcemia was observed in 73.7% of DPs, and it reduced or inhibited PTH secretion in 8 patients. There was no improvement in levels of 25OHD in both groups, resulting in insufficient levels. Eight DPs changed to a lower FS at the end of the study. CONCLUSION: The function of the autotransplanted parathyroid tissue usually initiates during the first month following operation and is similar in patients. The most of the patients reachs FS2 during the fourth month but autograft function can decrease over time

INTRODUÇÃO: A paratireoidectomia total com auto-enxerto imediato heterotópico (PTH+AE) é uma das técnicas cirúrgicas hoje usadas no tratamento do hiperparatireoidismo secundário à doença renal crônica e do hiperparatireoidismo persistente após o transplante renal. Os níveis adequados de paratormônio sistêmico (PTHs) no pós-operatório ainda são controversos e o perfil funcional do auto-enxerto de tecido paratireóideo, pouco esclarecido. No presente estudo, nós analisamos a função do tecido paratireóideo implantado pacientes com hiperparatireoidismo secundário e terciário. MÉTODO E CASUÍSTICA: Em um estudo prospectivo observacional, 19 pacientes portadores de doença renal crônica (PDRC) e quatro pacientes transplantados renais (PTR) foram submetidos à PTX+AE com e seguidos por um ano. Todos os pacientes apresentaram PTHs indetectável no pós-operatório imediato (POi). Os níveis séricos de PTH em ambos os membros superiores, cálcio, fósforo, fosfatase alcalina e reposição de cálcio elementar e calcitriol foram verificados com um mês, dois, três, quatro, seis, nove e 12 meses após a cirurgia. A 25-Hidroxivitamina D (25OHD) foi medida no POi, seis e 12 meses após a cirurgia. A função do auto-enxerto foi classificada em estados funcionais (EF) de acordo com os níveis de PTHs. RESULTADOS: A maioria dos PDRC e PTR mostraram níveis detectáveis de PTHs já no primeiro mês. No segundo mês pósoperatório, todos os pacientes apresentaram níveis detectáveis de PTHs quando também houve estabilização dos níveis séricos em ambos os grupos. Os gradientes de concentração de PTH não mostraram correlação com o PTHs. No pós-operatório, a hipercalcemia foi observada em 73,7% dos PDRC em pelo menos um episódio, reduzindo ou inibindo a secreção de paratormônio em oito pacientes. Não houve melhora dos níveis de 25OHD em ambos os grupos, permanecendo com níveis insuficientes. Oito PDRC regrediram de EF ao final do estudo. CONCLUSÃO: O perfil funcional do AE é semelhante entre os PDRC e PTR. A função do AE, inicia-se no primeiro mês pós-operatório, atingindo um maior EF até o quarto mês pós-operatório na maioria dos pacientes, porém pode haver declínio da função ao longo do tempo / BACKGROUND: Total parathyroidectomy with immediate forearm transplantation (PTX+AT) is employed in renal hyperparathyroidism. Appropriate postoperative systemic parathyroid hormone (sPTH) levels are still controversial and autograft functional behavior is unclear. In the present study, we analyzed the function of autotransplanted parathyroid tissue in secondary and tertiary hyperparathyroidism. METHODS: In a prospective observational study, 19 dialysis patients (DPs) and 4 kidney transplant patients (KTPs) who underwent PTX+AT were followed. All patients had undetectable PTH in the early postoperative period (ePO). Autograft function and the following biochemical variables were assessed at one, two, three, four, six, nine and 12 months following the operation: serum calcium, phosphorus, alkaline phosphatase, and intact PTH before and after the operation. 25-Hidroxyvitamin D levels (25OHD) were measured in the ePO, six and twelve months. Oral doses of calcium and calcitriol were recorded. Autograft function was stratified into four functional status (FS) according to sPTH. RESULTS: All functioning grafts presented sPTH until the second month. On the second postoperative month, all patients had sPTH detectable levels also when serum levels were steady in both groups. PTH gradients showed no significant correlation with sPTH levels. In at least one occasion in the postoperative period, hypercalcemia was observed in 73.7% of DPs, and it reduced or inhibited PTH secretion in 8 patients. There was no improvement in levels of 25OHD in both groups, resulting in insufficient levels. Eight DPs changed to a lower FS at the end of the study. CONCLUSION: The function of the autotransplanted parathyroid tissue usually initiates during the first month following operation and is similar in patients. The most of the patients reachs FS2 during the fourth month but autograft function can decrease over time

Indiana University-Purdue University Indianapolis (IUPUI) / PTH increases osteoclasts by upregulating RANKL in cells of the osteoblastic lineage, but the precise differentiation stage of the PTH target cell remains undefined. Recent findings demonstrate that PTH regulates gene expression in osteocytes and that these cells are an important source of RANKL. We therefore investigated whether direct regulation of the RANKL gene by PTH in osteocytes is required to stimulate osteoclastic bone resorption. To address this question, we examined bone resorption and RANKL expression in transgenic mice in which PTH receptor signaling is activated only in osteocytes (DMP1-caPTHR1) crossed with mice lacking the distal control region regulated by PTH in the RANKL gene (DCR -/-). Longitudinal analysis of circulating C-terminal telopeptide (CTX) in male mice showed elevated resorption in growing mice that progressively decreased to plateau at 3-5 month of age. Resorption was significantly higher (~100%) in DMP1-caPTHR1 mice and non-significantly lower (15-30%) in DCR -/-mice, versus wild type littermates (WT) across all ages. CTX in compound DMP1-caPTHR1; DCR -/-mice was similar to DMP1-caPTHR1 mice at 1 and 2 months of age, but by 3 months of age, was significantly lower compared to DMP1-caPTHR1 mice (50% higher than WT), and by 5 months, it was undistinguishable from WT mice. Micro-CT analysis revealed lower tissue material density in the distal femur of DMP1-caPTHR1 mice, indicative of high remodeling, and this effect was partially corrected in compound vi mice. The increased resorption exhibited by DMP1-caPTHR1 mice was accompanied by elevated RANKL mRNA in bone at 1 and 5 months of age. RANKL expression levels displayed similar patterns to CTX levels in DMP1-caPTHR1; DCR -/-compound mice at 1 and 5 month of age. The same pattern of expression was observed for M-CSF. We conclude that resorption induced by PTH receptor signaling requires direct regulation of the RANKL gene in osteocytes, but this dependence is age specific. Whereas DCR-independent mechanisms involving gp130 cytokines or vitamin D 3 might operate in the growing skeleton, DCR-dependent, cAMP/PKA/CREB-activated mechanisms mediate resorption induced by PTH receptor signaling in the adult skeleton.

Development of chimeric, recombinant peptides, proteins and enzymes expands the availability of protein/enzyme–based tools for cellular analysis and new assay platforms. Ideal protein reagents for cellular analysis must translocate into a variety of cells with minimum cell damage, retain stability and biological activity within the cell during analysis, and provide a reliable, measurable signal. This work focused on development, characterization and utilization of chimeric recombinant peptide, protein and enzyme reagents for cellular analysis and immunoassays. A cell-penetrating, fluorescent protein substrate (PKAS) was developed to monitor intracellular protein kinase A activity in cells without the need for cellular transfection. PKAS translocated into HeLa cells, βTC-3 cells and pancreatic islets with minimal toxicity. Upon cellular loading, glucose dependent phosphorylation of PKAS was observed in both βTC-3 and pancreatic islets via capillary zone electrophoresis. In pancreatic islets, maximal PKAS phosphorylation (83 ± 6 %) was observed at 12 mM glucose, whereas maximal PKAS phosphorylation (86 ± 4 %) in βTC-3 cells was with 3 mM glucose indicating a left-shifted glucose sensitivity. A cell-penetrating luciferase chimera (Luc-TAT) and a cell-penetrating phospholipid nanoshell entrapped luciferase (Luc-PPN) was constructed to monitor dynamic changes in intracellular ATP levels in mammalian cells. Upon cellular loading, the activity of Luc-TAT and Luc-PPN was monitored with time. Luc-TAT lost approximately 50% activity within one hour, and decreased rapidly over time. In contrast Luc-PPNs retain approximately 95% activity in 1 hour and 77% after 12 hours showing longer biological lifetime. Luc-PPNs were able to detect dynamic ATP changes in intact HeLa cells in the presence of KCN and NaN3. The bioluminescence returned to background levels within 8-10 minutes after treatment with KCN, whereas NaN₃ showed ~ 40% reduction. Two novel recombinant human parathyroid hormone (hPTH) analogs hPTHEGFP and hPTH-Cys were prepared to develop immunoassays for PTH detection in clinical samples. Initial experiments show promise for these analogs for use in CZELIF based immunoassays. The analogs present a number of distinctive advantages for clinical assays and can be used to develop several immunoassay platforms.

No description available.

Introdução A baixa concentração sérica de vitamina D tem sido associadas com a hipertensão no mundo todo. A hipovitaminose D tem sido observada mesmo na nossa população. Objetivo Investigar as concentrações séricas de vitamina D e sua associação com a pressão arterial (PA) em indivíduos adultos residentes na cidade de São Paulo. Métodos Para esta dissertação foram desenvolvidos dois artigos. Na revisão (artigo 1), foram selecionados artigos indexados nas bases de dados Pubmed, Lilacs e Medline, incluindo estudos realizados no Brasil. O artigo original (artigo 2) descreve o estudo transversal realizado com 332 adultos, 65 por cento mulheres, onde foi avaliada a associação entre vitamina D, paratormônio intacto (PTHi) e PA. Foram feitas: aferição da PA e coleta de medidas antropométricas e amostras sanguíneas. A concentração sérica de 25(OH)D3 foi mensurada pela técnica de cromatografia líquida de alta eficiência (HPLC). O valor médio de 2 medidas de PA foi considerado para as análises. Os participantes foram divididos em 3 grupos: (1) PA normal; (2) PA elevada; (3) PA normal pelo uso de medicação. A insuficiência de vitamina D foi considerada quando 25(OH)D3 75 nmol/L e o PTHi elevado quando > 65 pg/mL. A relação entre vitamina D, PTHi e PA foi ajustada pelo índice de massa corpórea (IMC), circunferência da cintura (CC) e perfil lipídico. Resultados Na revisão foi enfatizada a relação da vitamina D com doenças cardiovasculares, considerando, inclusive, os diferentes mecanismos fisiológicos propostos. No artigo original, observou-se idade média e desvio padrão de 50 (15) anos, IMC 29 (6) kg/m² e CC 97 (13) cm. Entre os indivíduos avaliados, 75 por cento tinham sobrepeso ou obesidade. PA média foi 129/80 (18/11) mmHg. A concentração média de cálcio sérico foi 9,3 (0,5) mg/dL, PTHi 40,8 (18,7) pg/mL e vitamina D 55,8 (17,1) nmol/L. O PTHi elevado e a insuficiência de vitamina D estiveram presentes em 12 por cento e 86 por cento da amostra, respectivamente. Não foram observadas diferenças nas prevalências de insuficiência de vitamina D e PTHi elevado entre os grupos de PA. Não foram observadas associações entre vitamina D e PA. Entretanto, uma correlação positiva foi observada entre PTHi e PA sistólica (r=0,168; p=0,002) e diastólica (r=0,168; p=0,002), IMC (r=0,125; p=0,023), CC (r=0,172; p=0,002) e por cento de massa gorda (r=0,158; p=0,004). O PTHi manteve-se correlacionado com a PA mesmo após realização dos ajustes. Conclusão A associação entre PTH e pressão arterial, observada por este estudo, acrescenta novas informações com relação ao envolvimento do metabolismo da vitamina D na regulação da pressão arterial. Mais estudos são necessários para esclarecer as vias metabólicas existentes entre metabolismo do PTH, da vitamina D e da pressão arterial / Background Low vitamin D has been associated with hypertension worldwide. Hypovitaminosis D has also been observed in our population. Objective To evaluate whether vitamin D status are related to blood pressure (BP) in adults living at Sao Paulo city. Methods For this dissertation, two articles were developed. In review (article 1), articles indexed in database Pubmed, Lilacs and Medline were selected, including Brazilian studies. Original article (article 2) describe cross-sectional study performed with 332 adults, 65 per cent women, that evaluate the association between vitamin D, intact parathyroid hormone (iPTH) and BP. Anthropometric measurements, BP and a fasting blood sample were obtained. Serum concentration of 25(OH)D3 was measured by highperformance liquid chromatography (HPLC) technique. Mean value of two measures of BP was considered to analysis. Participants were divided in three categories of blood pressure: (1) normal blood pressure; (2) high blood pressure; (3) normal blood pressure by medication. Vitamin D insufficiency was defined by 25(OH)D3 75 nmol/L, high iPTH > 65 pg/mL. The relationship between vitamin D, iPTH and BP were adjusted for body mass index (BMI), waist circumference (WC), blood lipids. Results In review, the relationship of vitamin D with cardiovascular disease was emphasized considering the different physiological mechanisms proposed. In the original article, mean age and standard deviation was 50 (15) years, BMI 29 (6) kg/m², WC 97 (13) cm. Overweight and obesity was present in 75 per cent of individuals. Mean BP was 129/80 (18/11) mmHg. Mean serum calcium concentration was 9.3 (0.5) mg/dL, iPTH 40.8(18.7) pg/mL and vitamin D 55.8 (17.1) nmol/L. Elevated iPTH and vitamin D insufficiency was present in 12 per cent and 86 per cent of the sample, respectively. No differences were observed on prevalence of vitamin D insufficiency and high iPTH among blood pressure groups. No significant association was observed between BP and vitamin D. However, a positive correlation was observed between iPTH and systolic (r=0.168; p=0.002) and diastolic BP (r=0.168; p=0.002), BMI (r=0.125; p=0.023), WC (r=0.172; p=0.002) and per cent FM (r=0.158; p=0.004). The iPTH remained correlated with BP even with adjustments. Conclusion The association between PTH and blood pressure observed in this study adds a new piece of information in literature regarding the involvement of the vitamin D metabolism with blood pressure. More studies are necessary to clarifying the metabolic pathways existing between PTH, vitamin D and blood pressure