The diagnostic dilemma of tumor induced osteomalacia: a retrospective analysis of 144 cases.

Diagnostic delay of tumor induced osteomalacia (TIO) is common in clinic practice. To investigate the diagnostic condition of TIO in China and raise clinicians' awareness of TIO, we retrospectively analyzed clinical manifestations, biochemical features, and specially evaluated missed diagnoses and misdiagnoses among 144 TIO patients from Peking Union Medical College Hospital during December 1982 to December 2014. Clinical presentations of TIO mainly included bone pain, difficulty in walking, pathological fractures, muscle weakness, and height loss. TIO patients demonstrated hypophosphatemia (0.48±0.13 mmol/L), elevated serum alkaline phosphatase (277.9±152.6 U/L), reduced tubular maximum for phosphorus/glomerular filtration rate (0.39±0.14) and markedly elevated serum fibroblast growth factor 23 (FGF23) (median level 302.9 pg/mL). The average time from onset to a correct diagnosis was 2.9±2.3 years while the mean duration from onset to tumor resection was 5.4±4.2 years. The initial misdiagnosis rate was 95.1% (137/144) and 240 case-times of misdiagnoses occurred among the 144 cases. The most frequent misdiagnoses were intervertebral disc herniation, spondyloarthritis (including ankylosing spondylitis) and osteoporosis. A total of 43.1% (62/144) cases with hypophosphatemia presented on their laboratory sheets were neglected and missed diagnosed. Our study showed that TIO was frequently misdiagnosed and missed diagnosed due to its rarity, insidious onset, nonspecific clinical manifestations and clinicians' poor recognition. It is necessary to test serum phosphorus in patients with musculoskeletal symptoms and difficulty in walking. The measurement of serum FGF23 is rather valuable. Once hypophosphatemia is discovered, TIO should be suspected and it is highly recommended to search for tumors and perform curative surgery.

[CDC73 gene mutation and parafibromin expression status of parathyroid carcinoma in Chinese].

OBJECTIVE: To explore the clinico-genetic characteristics and protein status of parathyroid carcinoma (PC) diagnosed at Peking Union Medical College Hospital from January 1980 to December 2012. METHODS: Genomic DNA was extracted from peripheral blood lymphocytes and paraffin-embedded tissue for analysis. The mutations of CDC73 gene were detected by direct sequencing. And the expression of parafibromin in tumor tissues was evaluated by immunohistochemical analysis. RESULTS: Twenty-four PC patients were recruited. The mean ages at the diagnosis of PHPT and PC were 42.2 and 42.6 years respectively. The serum calcium at the diagnosis of PHPT was 3.78 mmol/L, serum phosphorus 0.65 mmol/L and the median increment of serum parathyroid hormone (PTH) level 20.0. The recurrent rate was 76.2% during a 5-year follow-up.Genetic analysis identified 11 mutations of CDC73 gene (45.8%), among which c.34_35 insCT, c.626_629 delAACA, c.260_261 delGA, c.570 delG, c.40 C>T and IVS3+1 G>A were novel mutation first identified in our cohort. Nine of them had germline mutations. All tissue samples from normal parathyroid displayed strong positive immunostaining of parafibromin. Complete (55%, 11/20) or partial (45%, 9/20) loss of parafibromin expression was observed in PC tissues. The age at the diagnosis of PHPT, serum calcium, serum phosphorus, PTH, alkaline phosphatase (ALP), bone involvement rate, kidney stone/calcification rate, recurrent rate, metastatic rate and immunostaining level showed no significant difference between the patients with and without CDC73 mutation. CONCLUSION: In Chinese population, CDC73 mutation and complete/partial loss of immunohistochemical staining for parafibromin occur frequently in PC. Therefore it may be useful in the subset of tumors with equivocal histological examination.

[A case of adefovir dipivoxil induced hypophosphataemic osteomalacia and literature review].

OBJECTIVE: To investigate the clinical features and treatment protocol and prognosis for the hypophosphataemic osteomalacia related to adefovir dipivoxil. METHODS: Analysis was made upon a case of patient with chronic hepatitis B developed hypophosphataemic osteomalacia after administration of adefovir dipivoxil. Literature review was carried out to survey the global prevalence of hypophosphataemic osteomalacia after administration of adefovir dipivoxil among patients with chronic hepatitis B. RESULTS: The clinical symptoms started paralleling to the time taking adefovir dipivoxil, and alleviated after the patient withdrawn adefovir dipivoxil 10 weeks and was given phosphorus. Meanwhile, serum inorganic phosphorus recovered to normal (0.98 mmol/L), which lowest level was 0.77 mmol/L. Systematic review of the literature showed that hyperphosphaturia related to adefovir dipivoxil was dose-dependent, time-dependent and reversible. All reported cases of hypophosphataemic osteomalacia secondary to adefovir dipivoxil (10 mg/d) were from Asian population. CONCLUSIONS: Adefovir dipivoxil induced hypophosphataemic osteomalacia is rarely seen in clinical practice. Those patients with chronic hepatitis B who take adefovir dipivoxil, no matter dosages, should take periodical examinations including blood calcium and serum inorganic phosphorus to monitor whether hypophosphataemic osteomalacia occurs. Other anti-virus drugs could be used when it happens.

Infusion of ibandronate once every 3 months effectively decreases bone resorption markers and increases bone mineral density in Chinese postmenopausal osteoporotic women: a 1-year study.

The efficacy and safety of intravenous ibandronate were evaluated in postmenopausal osteoporosis women in China. In this multicenter, positive drug-controlled study, 158 postmenopausal osteoporotic women were randomized to receive 2 mg ibandronate given intravenously once every 3 months or 70 mg alendronate given orally once per week. All women also received supplemental calcium (500 mg) and vitamin D (200 IU) daily. One hundred fifty-one patients completed the 1-year study. Ibandronate produced mean increases in bone mineral density (BMD) by 4.27% at the lumbar spine, 3.48% at the femoral neck, and 2.03% at the trochanter. Mean increases in BMD by 4.24% at the lumbar spine, 2.72% at the femoral neck, and 2.99% at the trochanter were observed in the alendronate group. No significant difference was found between the two groups in BMD in all sites measured. Significant decreases in serum c-telopeptide of type I collagen (CTX) and alkaline phosphatase (ALP) were found in the two groups after 1 and 3 months of treatment, respectively; these serum CTX and ALP levels were then maintained at the decreased levels throughout the study period (12 months). No changes of stature were found in the patients of the two groups. Adverse events were similar in the two groups, except more mild muscle pain was observed in the first month after infusion of ibandronate than with oral alendronate (P < 0.001). The results observed in Chinese patients may support the observation that intravenous ibandronate significantly reduced bone resorption and increased BMD with good tolerance in Chinese postmenopausal osteoporotic women. Use of intravenous ibandronate possibly could potentially improve compliance as compared with other oral bisphosphonates because it may avoid the peptic side effects of oral bisphosphonate.

[Clinical and molecular genetic analyses for a sporadic parathyroid carcinoma].

OBJECTIVE: To analyze the clinical and molecular genetic characteristics of one patient with sporadic parathyroid carcinoma (s-PC). METHODS: The clinical profile, laboratory data and paraffin-embedded tissue sample of a s-PC patient were collected at our hospital. Genomic DNA was extracted from the leukocytes of peripheral blood and paraffin-embedded tissue of this patient. All 17 exons of HRPT2 gene including the flanking regions of introns were amplified by PCR. The mutations of HRPT2 gene were analyzed by directly sequencing the amplified DNA fragments. Parafibromin encoded by HRPT2 gene was analyzed by immunohistochemistry. RESULTS: The patient was diagnosed as s-PC by the clinical presentations, laboratory examinations and typical pathologic characteristics. HRPT2 germline mutation was identified as a base mutation at codon 222 (CGA > TGA) and caused a nonsense mutation at the codon (R222X) resulting in a truncated protein. Parafibromin was completely lost while comparing the normal parathyroid tissues by immunohistochemistry. CONCLUSION: The altered expression of parafibromin caused by HRPT2 gene mutation is one of the molecular mechanisms for explaining the clinical manifestations of this patient.

The efficacy and safety of calcitriol and/or Caltrate D in elderly Chinese women with low bone mass.

AIM: To observe the efficacy and safety of Rocaltrol (calcitriol) and/or Caltrate D (calicum carbonate plus vitamin D) in elderly Chinese women with osteopenia or osteoporosis. METHODS: One hundred fifty Chinese women aged over 65 years with osteopenia or osteoporosis from three centers were randomly divided into two groups. Seventy-six participants received Caltrate D as one pill daily; the other 74 participants received 0.25 mug Caltrate D plus Rocaltrol daily. The changes in bone mineral density (BMD) served as primary end-points. Height changes, the presence of new vertebral fractures, muscle strength and balance were evaluated. RESULTS: The following are the mean percentage changes (and SD) in BMD over 12 months: at L2-L4, 0.83+/-3.88 in the Caltrate D group and 2.84+/-4.04 in the Rocaltrol+Caltrate D group (P=0.003, by ANCOVA); at the femoral neck, 0.04+/-3.94 in the Caltrate D group and 2.01+/-5.45 in the Rocaltrol+Caltrate D group (P=0.085, by ANCOVA); and in the trochanter, 1.59+/-4.57 in the Caltrate D group and 3.76+/-6.25 in the Rocaltrol+Caltrate D group (P=0.053, by ANCOVA). The stand and maximal forward reach test (SMFRT) was significantly enhanced in both groups during the 12 months of treatment, but no significant differences were found between these two groups. No severe adverse event related to these medications occurred throughout the study. CONCLUSION: Treatment with Rocaltrol plus Caltrate D or Caltrate D for 12 months in elderly Chinese postmenopausal women effectively increased BMD at the lumbar spine. Rocaltrol plus Caltrate D was more effective at the lumbar spine than Caltrate D alone.

[The efficacy and safety of intravenous bisphosphonates in the treatment of primary hyperparathyroidism complicated by hypercalcemia crisis].

OBJECTIVE: To study the efficacy and adverse events of intravenous bisphosphonates in the treatment of patients of primary hyperparathyroidism (PHPT) complicated by hypercalcemia crisis. METHODS: From October 2003 to December 2007, 14 patients admitted into our hospital were diagnosed as PHPT complicated by hypercalcemia crisis, which was defined as a serum calcium concentration greater than 3.50 mmol/L. Of them, 6 cases had parathyroid adenoma, 1 had hyperplasia and 7 had parathyroid carcinoma. One of the intravenous bisphosphonates including pamidronate, ibandronate and zoledronic acid was given for 29 times in all the 14 cases. Serum calcium, parathyroid hormone, hematology, and other biochemical markers were monitored. Adverse events were recorded. RESULTS: After intravenous bisphosphonates, the serum total calcium (Ca) levels decreased from (3.85 +/- 0.50) mmol/L to (2.86 +/- 0.39) mmol/L in (1.4 +/- 0.6) days, and were kept below 3.50 mmol/L for (10.14 +/- 8.54) days. There was no significant difference of the magnitude of decrease in serum Ca levels among the patients using pamidronate, ibandronate or zoledronic acid. The change of serum Ca level was associated with the serum Ca level before treatment. The response to intravenous bisphosphonates evaluated by the decrease of serum total calcium levels was more significant in patients with parathyroid adenoma or hyperplasia than those with parathyroid carcinoma. The most common adverse event was pyrexia, which occurred 15 times (51.7%) and 75% of the pyrexia events occurred after the first infusion. Other manifestations included fatigue, flu-like symptom, myalgia, arthralgia and diarrhea with an incidence of 3.4% each (one event in the 29 times of treatment). There were 2 events (6.7%) with mild increase of serum creatinine concentration. CONCLUSION: Bisphosphonates can decrease serum total calcium levels in hypercalcemia crisis caused by PHPT effectively with mild adverse events.

Age-related bone mineral density, bone loss rate, prevalence of osteoporosis, and reference database of women at multiple centers in China.

Our study surveyed age-related bone mineral density (BMD), bone loss rate, and prevalence of osteoporosis in women at multiple research centers in China. Survey results were used to establish a BMD reference database for the diagnosis of osteoporosis in Chinese women nationwide. We used dual-energy X-ray absorptiometry bone densitometers to measure BMD at posteroanterior (PA) lumbar spine (L1-L4; n=8142) and proximal femur (n=7290) in female subjects of age 20-89 yr from Beijing, Shanghai, Guangzhou, Chengdu, Nanjing, and Jiaxing. A cubic regression-fitting model was used to describe the change of BMD with age at various skeletal sites. Peak BMD occurred between 30 and 34 yr of age for femur neck and total femur, and between 40 and 44 yr for spine and trochanter measurement sites. Young adult (YA) BMD values (mean and standard deviation [SD], calculated as the average BMD in the age range of 20-39, were 1.116+/-0.12, 0.927+/-0.12, 0.756+/-0.11, and 0.963+/-0.13 g/cm2 at PA spine, femoral neck, trochanter, and total femur, respectively. The BMD of 85-yr-old women reflected a loss of 32% at the spine and 30-35% at femur measurement sites. The prevalence of osteoporosis, defined as a BMD of

Effect of fibroblast growth factor 9 on Runx2 gene promoter activity in MC3T3-E1 and C2C12 cells.

BACKGROUND: Fibroblast growth factor 9 (FGF9), expressed in brain, kidney and developing skeletal tissues, can physiologically inhibit endochondral ossification; but little is known about how FGF9 affects osteoblasts and its detailed regulatory mechanism. Here we examined the effect of FGF9 on the activity of the murine Runt-related transcription factor 2 (Runx2) gene promoter in preosteoblast MC3T3-E1 and premyoblast C2C12 cells. METHODS: Plasmids containing the Runx2 promoter region were transfected into MC3T3-E1 and C2C12 cells and stably transfected cell lines were established. The method of luciferase reporter gene activation was used to examine the effects of FGF9 on the promoter activity. RESULTS: FGF9 (10 ng/ml) increased Runx2 promoter activity in MC3T3-E1 cells. When MC3T3-E1 cells were treated with FGF9 plus the various inhibitors or activator of the intracellular signaling transducation pathways, including 10 micromol/L U0126 (the inhibitor of mitogen-activated protein kinase kinase), 10 micromol/L SB203580 (the inhibitor of p38/mitogen activated protein kinase), or 1 micromol/L C6 ceramide (an activator of mitogen activated protein kinase), the luciferase expression did not change significantly compared with that of the cells treated with FGF9 only. However, when C2C12 cells were treated with 10 ng/ml FGF9, Runx2 gene promoter activity first decreased and then increased over a period of 1 to 5 days. Among the above inhibitors, only U0126 (10 micromol/L) completely blocked the effects of FGF9 on Runx2 gene promoter activity. CONCLUSIONS: Our data showed that FGF9 can affect Runx2 gene promoter activity in MC3T3-E1 and C2C12 cells. The action of FGF9 appears to depend partly on the mitogen-activated protein kinase kinase/mitogen-activated protein kinase pathways in C2C12 cells.

[Association of calcium-sensing receptor gene polymorphism with serum calcium level in healthy young Han women in Beijing].

OBJECTIVE: To investigate the distribution of calcium-sensing receptor (CASR) gene polymorphisms in healthy young women of Han nationality in Beijing area and to explore the association of CASR genotypes and serum calcium, parathormone (PTH) level in healthy women. METHODS: 202 healthy young women aged (27 +/- 5) years of Han nationality in Beijing area were recruited in this study. Whole blood genome DNA was extracted with QIAGEN DNA extraction kit. A986S and G990R genotypes were determined with mutagenically separated polymerase chain reaction (MS-PCR) and PCR-restriction fragment length polymorphisms (RFLP), respectively. Serum calcium, albumin, phosphorus, PTH were determined. RESULTS: (1) There were A986S and G990R polymorphisms in healthy young women of Han nationality in Beijing. The frequencies of genotypes were as follows: SS absent, AA 95.0% and AS 5.0% for A986S, RR21.3%, GR51.0% and GG27.7% for G990R. Hardy-Weinberg equilibrium was evident. (2) In subjects carrying AA and AS genotype, serum Ca was (2.46 +/- 0.09) mmol/L vs (2.45 +/- 0.08) mmol/L, calcium adjusted by albumin was (2.31 +/- 0.10) mmol/L vs (2.30 +/- 0.09) mmol/L, serum P was (1.23 +/- 0.14) mmol/L vs (1.24 +/- 0.11) mmol/L, serum PTH was (41.6 +/- 18.6) ng/L vs (50.0 +/- 25.1) ng/L. There were no significant differences among them. (3) In subjects carrying GG, GR and RR genotype, serum Ca was (2.44 +/- 0.10), (2.46 +/- 0.08) and (2.48 +/- 0.08) mmol/L; calcium adjusted by albumin was (2.30 +/- 0.10), (2.32 +/- 0.09) and (2.32 +/- 0.10) mmol/L; serum P was (1.22 +/- 0.13), (1.24 +/- 0.15) and (1.20 +/- 0.15) mmol/L, serum PTH was (37.6 +/- 16.0), (42.1 +/- 20.2) and (45.9 +/- 18.1) ng/L. There were significant difference in serum Ca, calcium adjusted by albumin and PTH (P = 0.042, 0.020 and 0.014, respectively). CONCLUSIONS: (1) There are A986S and G990R polymorphisms in CASR gene in Han nationality in Beijing area. The frequencies of genotypes are as follows: SS absent, AA 95.0% and AS 5.0% for A986S, RR21.3%, GR51.0% and GG27.7% for G990R. Hardy-Weinberg equilibrium is evident. A and G alleles are more common. It is indicated that the distribution of CASR gene polymorphisms in Chinese is different from that in Caucasians. (2) G990R polymorphism is associated with serum calcium and PTH levels in healthy women. Subjects with R allele have higher levels of serum calcium and PTH. There is no correlation between A986S polymorphism and serum calcium or PTH.

[Bone loss is more severe in younger Cushing's syndrome women than in older ones: comparison of bone mineral density between Cushing's syndrome and healthy women].

OBJECTIVE: To investigate the influence of age on bone mass in Cushing's syndrome patients. METHODS: Measurement of bone mineral density (BMD) was conducted among 57 women with Cushing's syndrome (CS) and 49 healthy women. There were 14 CS women and 14 healthy women in the group aged 20 - 29; 27 CS women and 15 healthy women in the group aged 30 - 39; and 16 CS women and 20 healthy women in the group aged 40 - 49. RESULTS: Among the healthy women the peak bone mass of lumbar spine was in the group aged 30 - 39, while the peak bone mass of hip was in the group aged 20 - 29. The BMD values of the CS women were lower than those of the healthy women, especially those in lumbar spine and in Ward's triangle. The younger the CS women, the lower the BMD Z-score (for the BMD Z-score of lumbar spine P = 0.021, for the BMD Z-score of femoral neck P = 0.020, and for the BMD Z-score of Ward's triangle P = 0.026). Seventeen of the 57 (29.8%) CS women had osteoporosis, 29 (50.9%) of the 57 had osteopenia, and 15 (26.3%) had fractures. The CS women with bone fractures had lower BMD Z-score than those without fractures (for lumbar fracture P = 0.003). CONCLUSION: The BMD of CS women is lower than that of the healthy women. Bone loss is more severe in younger CS women than in older ones. CS women with low BMD are prone to have bone fracture.

[Skeletal biomechanical properties improvement in ovariectomized osteoporotic rats of teriparatide was retarded by alendronate].

OBJECTIVE: To implore the effects of teriparatide (PTH) and alendronate (Alen) on skeletal biomechanical properties of ovariectomized (OVX) osteoporotic rats. METHODS: 70 female Wistar rats of 6 months were randomly divided into 7 groups: (1) Baseline: sacrificed at baseline; (2) OVXb: sacrificed in 6 weeks after OVX; (3) Sham operation; (4) OVXe: sacrificed 14 weeks after OVX; (5) PTH: 40 microg.kg(-1).d(-1); (6) Alen: 100 microg.kg(-1).d(-1); (7) A + P: PTH 40 microg.kg(-1).d(-1) and Alen 100 microg.kg(-1).d(-1). In group (5)-(7), different medicines were injected 5 times per week from 6th to 14th week after OVX. The cancellous biomechanical properties were measured with indentation test and the cortical properties were investigated with three-point bending test. RESULTS: (1) The can load and can stiff of distal femur of OVXb were significantly lower than those of baseline (P < 0.01). It is indicated that osteoporotic rat models with impaired bone strength were established. (2) The can load and can stiff of distal femur of PTH [(36.3 +/- 9.2) N, (160.7 +/- 48.0) N/mm(2)], Alen [(42.7 +/- 13.0) N, (122.9 +/- 35.6) N/mm(2)] and A + P [(44.3 +/- 18.2) N, (105.2 +/- 58.4) N/mm(2)] groups were all higher than those of OVXe [(19.5 +/- 8.5) N, (83.2 +/- 37.7) N/mm(2), P < 0.001 or P < 0.01]. In femoral shaft, maximal load and elastic load in PTH, Alen and A + P groups were higher than those of OVXe (P < 0.001, P < 0.01 or P < 0.05). (3) Can stiff in distal femur was higher in PTH than that in Alen and A + P groups (P < 0.05). Elastic load, maximal load and energy absorption in femoral shaft were higher in PTH and A + P groups than those in Alen group (P < 0.05), and maximal stress was higher in PTH than that in A + P and Alen group (P < 0.05). CONCLUSION: PTH and Alen were effective in improving the skeletal mechanical properties of OVX rats, but improvement in Alen and A + P was not so good as that in PTH group. It is indicated that anabolic effects of PTH was retarded by Alen's significant inhibition of bone turnover, therefore, PTH and Alen should not be utilized simultaneously.

[RET gene cys 634 trp mutation in a multiple endocrine neoplasia type 2A kindred].

OBJECTIVE: To identify the genotype of RET gene in one multiple endocrine neoplasia type 2A (MEN2A) kindred. METHODS: Genome DNA was extracted from peripheral blood leucocytes. The DNA sequence of gel-purified polymerase chain reaction (PCR) products was determined with the previously reported 6 pairs of primers of PCR amplification of 10, 11, 13, 14, 15, and 16 exons of RETgene. RESULTS: No abnormalities were found in exon 10, 13, 14, 15, and 16. C to G replacement in nucleotide 14 996 of exon 11 was identified in DNA samples obtained from both peripheral blood of 2 affected brothers. This missense point mutation arisen in heterozygosity and caused a substitution of Cys to Trp residue at codon 634 ( Cys 634 Trp) in RET protein. CONCLUSION: The genotype of the family is identified as Cys 634 Trp substitution of RET gene.

Zoledronic acid-induced hepatotoxicity relieved after subsequent infusions in a Chinese woman with glucocorticoid-induced osteoporosis.

BACKGROUND: Zoledronic acid (ZOL) is widely used for treatment of glucocorticoid-induced osteoporosis. The most common adverse effects of ZOL treatment are post-dose symptoms. ZOL-induced hepatotoxicity has very rarely been reported. CASE REPORT: Here, we described a 50-year-old Chinese woman who had vertebral fractures and severe back pain after glucocorticoid therapy for Behcet disease for 13 years. Three days after ZOL 5 mg infusion in April 2012, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT) levels increased by 7.7, 4.9 and 3.0 times, respectively, compared with pre-treatment values. Liver protective agents were administered per os. Her hepatic enzyme levels returned to nearly normal range 9 days post-infusion. In the subsequent ZOL infusion with 1 year interval, serum ALT, AST and GGT levels increased slightly after the second infusion and were sustained to be normal after the third infusion. Her post-dose symptoms alleviated in the meantime. CONCLUSIONS: Hepatotoxicity due to ZOL therapy is a rare, but possible adverse effect which may be relieved after subsequent infusions.

[Association of polymorphisms of vitamin D receptor gene start codon and 3'-end region with bone mineral density in postmenopausal women].

OBJECTIVE: To determine whether vitamin D receptor(VDR) gene start codon polymorphisms and 3'-end region polymorphisms exerted a combined influence on bone mineral density(BMD) in Han postmenopausal women in Beijing area. METHODS: The VDR Fok I and 3'-end region genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism in 110 unrelated postmenopausal women. BMD was measured at the lumbar spine (L(2-4)), femoral neck(Neck), Ward's triangle(Ward's) and trochanter (Troch) using duel-energy X-ray absorptiometry. RESULTS: The frequencies distribution of Fok I, Apa I, Bsm I and Taq I alleles in this cohort all followed the Hardy-Weinberg equilibrium. No significant association of Fok I, Apa I or Taq I genotype with BMD in postmenopausal women was found when these polymorphisms were considered independently, except for Bsm I genotype. When a combined analysis of VDR gene Fok I and 3'-end region polymorphisms was carried out, cross-genotyping Fok I and Apa I polymorphisms was significantly associated with BMD at the L(2-4) (P<0.001), and cross-genotype of Fok I and Taq I was also significantly associated with BMD at the Neck and Troch sites (P<0.05). However, cross-genotyping Fok I and Bsm I polymorphisms was not significantly associated with BMD. Cross-genotyping Apa I and Bsm I or Taq I polymorphisms was not associated with BMD in postmenopausal women, either. CONCLUSION: Although Fok I polymorphisms of VDR gene were not significantly associated with BMD in postmenopausal women, VDR gene Fok I and 3'-region polymorphisms (Apa I and Taq I) had a combined effect on the BMD in postmenopausal women.

[The effects of continuous stimulation with different doses of parathyroid hormone 1-34 fragment on human SaoS-2 cells].

OBJECTIVE: To observe the effects of different doses of human parathyroid hormone fragment (hPTH)1-34 on SaoS cells and to explore the signal pathway and mechanism. METHODS: 5 x 10(4) cells/ml SaoS cells were seeded. Doses of 5, 50, 500 and 5 000 micro g/L hPTH1-34 were supplemented respectively. Total RNA was extracted by Trizol kit. Alkaline phosphatase (ALP), osteocalcin (BGP) and cAMP concentrations were measured by chemical, radioimmunoassay and competitive protein binding methods. c-fos gene expression level was semi-quantified by reverse transcriptase (RT)-PCR. RESULTS: ALP activity was higher in 500 micro g/L dose (P < 0.05 vs. control). BGP level was inhibited in 5 000 micro g/L dose (P < 0.05 vs. control and pretreatment). 50 and 500 micro g/L hPTH1-34 enhanced cAMP level significantly (P < 0.05 vs. control). No obvious increase of cAMP level was found in 5 000 micro g/L and 5 micro g/L dose groups (P > 0.05 vs. control and pretreatment). c-fos expression was higher in 50 and 500 micro g/L group. CONCLUSION: Different doses of hPTH1-34 exert distinct effects on osteoblasts. hPTH1-34 affects ALP and c-fos depending on protein kinase A signal pathway. hPTH1-34 exerts its action via regulation of osteoblasts by c-fos.

[Bone mineral density and leptin receptor polymorphism Gln223Arg in Han women in Beijing].

OBJECTIVE: To investigate the association between bone mineral density (BMD) and leptin receptor (LEPR) polymorphism (Gln223 Arg) in young women and postmenopausl osteoporotic women. METHODS: BMD values were determined by dual energy X-ray absorptiometry. The Gln223 Arg genotypes of LEPR were analyzed by using polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: Hardy-Weinberg equilibrium was evident for LEPR polymorphism. The subjects carrying the GG genotype of LEPR had significantly higher BMD at lumbar spine as compared with the subjects with GA and AA genotype in young women [(1.213 +/- 0.127) g/cm(2) vs (1.154 +/- 0.124) g/cm(2), P < 0.05]. There were no significant differences in BMD at the proximal femur among GG, GA and AA genotype in young women. No significant differences in BMD at all sites were observed among GG, GA and AA genotype in postmenopausl osteoporotic women. Correlation was found between BMD and leptin receptor polymorphism (Gln223 Arg) at lumbar spine (r = -0.151, P < 0.05). CONCLUSION: Leptin receptor polymorphism (Gln223 Arg) has association with peak bone mass in young women, which may be used as genetic marker in predicting the risk of developing osteoporosis in Chinese women of Han nationality.

[Prospective study of pamidronate disodium in treatment of Paget's disease of bone].

OBJECTIVE: To determine the efficacy of pamidronate disodium (pamidronate) in treatment of Paget's disease of bone. METHODS: Intravenous drip of pamidronate was given at the dose of 30 - 60 mg per day for 2 - 3 weeks with a total dosage of 90 - 270 (168 +/- 84) mg to 5 patients with Paget's disease of bone, 2 males and 3 females, aged 27 - 74 (61 on average) with the course of disease of 4 - 48 years (24 years on average), all of them having multiple bone lesions, 2 being in grade 4 of pain assessment and bedridden and 3 being in grade 3 with impaired mobility. Pain assessment, biochemical markers of bone turnover, including serum alkaline phosphatase (ALP), carboxy-terminal propeptide of type I collagen (PICP), carboxy-terminal cross-linked telopeptide of type I collagen (ICTP) and urinary hydroxyproline (HOP), and side effects of pamidronate were observed before treatment, by the end of treatment, and 4, 12, 24, and 48 weeks after treatment. RESULTS: The Pagetic bone pain was significantly reduced by the end of treatment in all patients. The degree of pain assessment declined from grade 4 to grade 2 in 2 patients, and from grade 3 to grade 1 in 3 patients. The mobility was markedly improved without bone pain 12 weeks after treatment and relief of pain lasted for 1 year in all patients. Serum ALP, PICP, ICTP and urinary HOP concentrations were significant decrease by the end of treatment. Moreover, the mean percentage decreases for above biochemical markers at 12 and 24 weeks after treatment were 50% or over. The values of serum ALP, PICP, ICTP and urinary HOP decreased from 398 u/L (median), 818 ng/L (median), (29 +/- 14) ng/L and (71 +/- 16) mg/24 h urine respectively to 159 u/L, 129 ng/L, (12 +/- 4) ng/L and (34 +/- 7) mg/24 h urine respectively 48 weeks after treatment (all P < 0.05). Side effects, including a transient increase in body temperature, skin eruption and pruritus, and a transient increase of serum aspartate aminotransferase concentration, were negligible. CONCLUSION: Intravenous infusion of pamidronate is effective on Paget's disease of bone. Pamidronate of the dose of 90 - 270 mg administered within 2 - 3 weeks produces a year-long remission. Side effects of pamidronate are slight and transient.

[Evaluation of bone architecture and biomechanic properties by peripheral quantitative computed tomography in rats].

OBJECTIVES: To evaluate the value of peripheral quantitative computed tomography (pQCT) in measuring bone architecture and biomechanic properties. METHODS: 50 virgin female Wistar rats six months old were randomly divided into 4 groups: (1) 8 rats were killed as baseline group; (2) 8 rats underwent sham operation and then were killed 14 weeks after (sham operation group); (3) 16 rats underwent bilateral ovariectomy (OVX) without further intervention. Six and 14 weeks after the operation each 8 rats were killed (OVX group); and (4) 18 rats underwent OVX too. After the OVX 9 of the 18 rats were treated with 17beta-estradiol 20 micro g/kg/d IH and 9 rats were treated with estradiol valerate 800 micro g/kg/d po for 8 weeks respectively. Then the 18 rats were killed (OVX plus estrogen group, O + E group). The right tibiae of the rats were taken for histomorphometric analysis, and the right femora were prepared for pQCT scanning and bone biomechanical measurement with indentation test and three-point bending test. RESULTS: Histomorphometric analysis showed that the trabecular volume of proximal tibia (Cn-BV/TV) in the OVX group was 8.1 +/- 1.4%, significantly lower than that in the sham operation group (19.5 +/- 1.5%, P < 0.01). pQCT scanning showed that the femoral trabecular bone mineral content (Trab BMC) in the OVX group was 1.7 +/- 0.3 mg/mm, significantly lower than that in the sham operation group (3.2 +/- 0.5 mg/mm, P < 0.01) and the femoral trabecular bone mineral density (Trab BMD) in the OVX group was 158 +/- 32 mg/mm(3), significantly lower than that in the sham operation group (320 +/- 39 mg/mm(3), P < 0.01). The cancellous maximal load (Can load) of the distal shaft of femur in the OVX group was 12.5 +/- 2.5 N, significantly lower than that in the sham operation group (45.9 +/- 3.2 N, P < 0.01). The cancellous stiffness (Can Stiff) of the distal shaft of femur in the OVX group was 226 +/- 48 N/mm, significantly lower than that in the sham operation group (396 +/- 72 N/mm, P < 0.01). The Can load of O + E group was 21.8 +/- 3.7 N, significantly higher than that in the OVX group (P < 0.05). The Can Stiff of the O + E group was 382 +/- 54 N/mm, significantly higher than that in the OVX group (P < 0.05). There were no significant differences in cortical bone determined by pQCT as well as biomechanic properties in measured by three point test after OVX and estrogen treatment. A significant positive correlation was shown between Trab BMD and Cn-TV/BV and between Trab BMD and Tb N (r = 0.88 and 0.73, both P < 0.01). Similarly, both Trab BMC and Trab BMD of the femur were significantly correlated with the Can load and Can Stiff determined by indentation test (r = 0.47 - 0.68, all P < 0.01). There was also a significant correlation of parameters measured by pQCT in cortical bone with the maximal load and stiffness for the femur midshaft, and the best correlation was found between the maximal load of femur midshaft and Crt BMC and Crt A (both r = 0.76 and P < 0.01). CONCLUSION: The geometric, densitometric and mechanical properties in cortical and trabecular bones of rat can be well described by pQCT.

[Interaction effects between 1,25-dihydroxyvitamin D3 and transforming growth factor-beta1 on the proliferation and differentiation of human embryonic osteoblasts].

OBJECTIVE: To characterize the interaction effects between 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] and human transforming growth factor-beta1 (hTGF-beta1) on the proliferation and differentiation of human embryonic osteoblasts. METHODS: Human embryonic osteoblasts were cultured. 1,25(OH)(2)D(3), of the concentration of 50 nmol/L, hTGF-beta1 of different concentrations (1 x 10(-8) g/L, 1 x 10(-7) g/L, 1 x 10(-6) g/L, and 1 x 10(-5) g/L), and both hTGF-beta1 of different concentrations and 1,25(OH)(2)D(3) of the concentration of 50 nmol/L were added into the cultures with a stimulation time of 96 hours. 3-(4, 5-dimethylthiazol-2-yl) - 2, 5 - diphenyl - tetrazolium bromide (MTT) was added into the cultures. ELISA technique was used to measure the optical density values so as to observe cell's number and proliferation. Alkaline phosphatase (ALP) activity was tested by King's method. Osteocalcin (OC) was tested by radioimmunoassay. The mRNA expression level of SMAD proteins, the key proteins of the TGF-beta signal transduction passageway, was detected by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: MTT staining showed an absorbance of 0.086 +/- 0.022 in the 1,25(OH)(2)D(3) group, significantly lower than that of the control group (0.124 +/- 0.031, P < 0.05). The ALP activity in the culture of 1,25(OH)(2)D(3) group, hTGF-beta1 groups, and combined 1,25 (OH)(2)D(3) and hTGF-beta1 groups were 1.3 - 2.0 times that of the control group (all P < 0.05). When the concentration of hTGF-beta1 is 1 x 10(-6) g/L, an interaction effect was found between 1,25(OH)(2)D(3) and hTGF-beta1 on the ALP activity of human embryonic osteoblasts. The OC value in cell medium was 5.3 micro g/L +/- 1.6 micro g/L and 5.4 micro g/L +/- 0.9 micro g/L respectively in the hTGF-beta1 1 x 10(-6) g/L and 1 x 10(-5) g/L combined with 1,25(OH)(2)D(3) (50 nmol/L) groups, significantly higher than that in the control group (P < 0.05), but no interaction effect was found between 1,25(OH)(2)D(3) and hTGF-beta1 on the OC production. hTGF-beta1 of different concentrations and hTGF-beta1 of different concentrations combined with 1,25(OH)(2)D(3) all increased the SMAD3 mRNA expression level in human embryonic osteoblasts (all P < 0.05). When the human embryonic osteoblasts were treated with 1,25(OH)(2)D(3) combined with 1 x 10(-6) g/L hTGF-beta1, its SMAD3 mRNA level reached the peak, about 6-fold that of the control group. 1,25(OH)(2)VD(3) and/or hTGF-beta1 did not influenced the SMAD4 mRNA expression. CONCLUSION: 1,25(OH)(2)D(3) inhibits the proliferation of human embryonic osteoblasts and increases the expression of osteoblastic markers, such as ALP and OC, thus promoting its differentiation. An interaction effect exists between 1,25(OH)(2)D(3) and hTGF-beta1 on the differentiation of human embryonic osteoblasts, which may be partly induced by SMA D(3) protein in the TGF-beta signal transduction passageway.