Fasting plasma glucose reference values among young Japanese women requiring 75g oral glucose tolerance tests

OBJECTIVE

Currently there are various discussions on the upper limit of FPG (Fasting Plasma Glucose) levels. In Japan, when abnormal levels of FPG are detected at general health checkups or complete physical examinations, 75g Oral Glucose Tolerance Tests (75g OGTT) are often conducted in follow-up examinations. Therefore we investigated the appropriate upper limit of FPG levels to decide whether 75g OGTT are actually necessary.

RESEARCH DESIGN AND METHODS

Based on the FPG levels of 256,309 women with an age range of 20 to 79, we established the upper limits of FPG levels by 5-year intervals, using a method equivalent to the National Committee for Clinical Laboratory Standards (NCCLS) used in the U. S. [4]. We also obtained the ROC curve from the 75g OGTT results from 160 women aged 20 to 39. We then divided those 160 women into four categories based on their 75g OGTT results, and compared the abnormal rates of their 2-hour post-75g OGTT glucose levels, HOMA-R and Insulin Index using the Kruskal-Wallis test.

RESULTS

The upper limits of FPG levels were 99 mg/dl in the 20-29 age range, 101 mg/dl in the 30-34 age range, and 104 mg/dl in the 35-39 age range. The upper limits of the FPG reference intervals increased almost proportionally up to the age 50, and showed little difference thereafter. The point on the ROC curve where the total value of sensitivity plus specificity reached the highest had an FPG level of 99.5 mg/dl. For 2-hour post-75g OGTT glucose levels and HOMA-R, there was a significant difference in abnormal rates between the categories of FPG ≤ 99 mg/dl and 100 ≤ FPG ≤ 109 mg/dl, but not in Insulin Index.

CONCLUSIONS

We believe that 75g OGTT are necessary for Japanese women aged 20 to 39 with FPG levels of 100 mg/dl or above.

Effect of V(2)O(5) on the sintering behavior, microstructure, and electrical properties of (Na(0.5)K(0.5))NbO(3) ceramics

Well-sintered (Na(0.5)K(0.5))NbO(3)-x mol% V(2)O(5) ceramics (abbreviated as NKN-V) with fine electrical properties were successfully prepared by conventional solid-state reaction through the careful control of processing conditions. The sintering behavior, phase structure, and electrical properties of the V(2)O(5)-doped NKN ceramics were investigated. Results show that when the V(2)O(5) content is 0.6 mol%, the NKN ceramics attained the maximum density of 4.46 g/cm(3) (about 98.9% of the theoretical density) at 1060 degrees C, and therefore possessed enhanced electrical properties. But when the V(2)O(5) content continued increasing, the density decreased. The secondary phase (Na(2)V (6)O(16)) could be detected by XRD analysis in all samples except x = 0 mol%. The Curie temperature of the NKN-based materials was found to decrease with the increase of V(2)O(5). The dielectric properties of NKN ceramics doped with 0.6 and 0.9 mol% V(2)O(5) were better than that of pure NKN ceramics. In addition, annealing treatment was proved to be an effective technique for improving dielectric properties and reducing the leakage current density.

Effects of the sol-concentration on the structural and dielectric properties of Pb(0.3)Sr(0.7)TiO(3) thin films derived by the sol-gel method

Pb(0.3)Sr(0.7)TiO(3)(PST) thin films were deposited on Pt coated Si(100) substrates by sol-gel techniques using different sol-concentrations. The structural and dielectric characteristics of lead strontium titanate (PST) thin films as a function of the sol concentration were investigated. PST thin films reveal a columnar texture through the thickness when the sol-concentration is lower than 0.30 M. PST thin films derived from 0.35 M sol show better dielectric characteristics with the dielectric constant, dielectric loss, tunability, and field of motion (FOM) (tunability/ dissipation) of 200, 0.01, 47% and 47, respectively. The temperature dependence of the dielectric constant, dielectric loss and tunability of PST thin films were investigated in the temperature range of -140 to 120 degrees C exhibiting a dielectric peak of about -45 degrees C.

Renal differentiation of amniotic fluid stem cells

OBJECTIVES

The role of stem cells in regenerative medicine is evolving rapidly. Here, we describe the application, for kidney regeneration, of a novel non-genetically modified stem cell, derived from human amniotic fluid. We show that these pluripotent cells can develop and differentiate into de novo kidney structures during organogenesis in vitro.

MATERIALS AND METHODS

Human amniotic fluid-derived stem cells (hAFSCs) were isolated from human male amniotic fluid obtained between 12 and 18 weeks gestation. Green fluorescent protein and Lac-Z-transfected hAFSCs were microinjected into murine embryonic kidneys (12.5-18 days gestation) and were maintained in a special co-culture system in vitro for 10 days. Techniques of live microscopy, histology, chromogenic in situ hybridization and reverse transcriptase polymerase chain reaction were used to characterize the hAFSCs during their integration and differentiation in concert with the growing organ.

RESULTS

Green fluorescent protein and Lac-Z-transfected hAFSCs demonstrated long-term viability in organ culture. Histological analysis of injected kidneys revealed that hAFSCs were capable of contributing to the development of primordial kidney structures including renal vesicle, C- and S-shaped bodies. Reverse transcriptase polymerase chain reaction confirmed expression of early kidney markers for: zona occludens-1, glial-derived neurotrophic factor and claudin.

CONCLUSIONS

Human amniotic fluid-derived stem cells may represent a potentially limitless source of ethically neutral, unmodified pluripotential cells for kidney regeneration.

Hemangiogenic response after pre-operative COX2 inhibition predicts recurrence in esophageal cancer

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Background: Growth of esophageal cancer involves a proliferative hemangiogenic component. Biomarkers that predict this propensity in esophageal cancer and the impact of anti-angiogenic strategy on their levels as well as clinical response remain unknown. Methods: A multimodular approach was devised to assess hemangiogenic parameters in a cohort of chemotherapy naïve patients with locally advanced (T2-T3N0, T1-T3N1M0M1a) esophageal cancer pre- and 4 days post-celecoxib neoadjuvant treatment. Patients went on to receive neoadjuvant therapy with celecoxib, paclitaxel and carboplatin for 3 cycles, followed by surgical resection. This bioassay panel consists of 5 components: i) HUVEC-based angiogenic scale for functional plasma angiogenic activity, ii) flow cytometry to quantify CD133+VEGFR2+ circulating endothelial progenitors (CEPs), iii) hematopoietic colony-forming assay to quantify circulating hematopoietic progenitors (CHPs), iv) plasma SDF-1 level, and v) platelet VEGF-A level. Results: The cohort consists of 8 consecutive patients (6 men, 2 women) with median age of 58. After 18 months of followup, 6 patients remained alive and without evidence of recurrence, while 2 had tumor recurrence and metastasis. Analysis of the positive responders (pre-celecoxib baseline versus 4 days post treatment) revealed a global suppression of hemangiogenic parameters with reduction of the functional HUVEC-based angiogenic scale (mean score of 3.3 versus 1.8; p<0.05), 2.2-fold decrease in CEPs (p<0.05), and 3-fold decrease in CHPs (p<0.05). This trend also correlated with decreased plasma SDF-1 and platelet VEGF-A levels . However, in the 2 cases of tumor recurrence, the initial hemangiogenic response was blunted with no significant difference in all parameters tested during the celecoxib monotherapy period. Conclusion: Esophageal cancer development involved a hemangiogenic switch toward increased CEPs, CHPs, and functional plasma pro-angiogenic activity. COX2 inhibition with celecoxib normalized the hemangiogenic profile. Collective assessment of hemangiogenic biomarkers during neoadjuvant setting may be a promising tool in predicting clinical outcomes, recurrence, and for validating impact of anti-angiogenic therapy on esophageal cancer.

No significant financial relationships to disclose.

A Method of Recognizing Finger Motion Using Wavelet Transform of Surface EMG Signal

In this paper, an identification method of finger motions using the wavelet transform of multi-channel electromyography (EMG) signal is presented. The first step of this method is to analyze surface EMG signal detected from the subject's upper arm using the multi-resolution of wavelet transform, and extract features using the variance, maximum and mean absolute value of the wavelet coefficients. In this way, a new feature space is established by wavelet coefficients. The second step is to import the feature values into an Artificial Neural Network (ANN) to identify the finger motion. Based on the results of experiments, it is concluded that this method is effective in identification of finger motion. Thus, it provides an alternative approach to use the surface EMG in controlling the finger motion of a multi-fingered prosthetic hand.

Circulating endothelial progenitor cells correlate to stage in patients with invasive breast cancer

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Background: Tumor growth and metastasis is dependent on neo-angiogenesis. Both pre-existing and circulating vascular cells have been shown to contribute to the assembly of tumor neo-vessels in specific tumors. Mobilization of endothelial progenitor cells (EPCs) from the bone marrow constitutes a crucial step in the formation of de novo blood vessels, and levels of peripheral blood EPCs have been shown to be increased in certain malignant states. However, the role of circulating EPCs in breast cancer is largely unknown. Methods: We recruited twenty-five patients with biopsy-proven invasive breast cancer (BC) at Weill Cornell Breast Center to participate in a pilot study investigating the correlation of circulating EPCs to extent of disease and initiation of chemotherapy. For each patient, a baseline sample was drawn before systemic treatment, and for seventeen of those patients, a second sample was taken after the first round of chemotherapy. Levels of peripheral blood EPCs, as defined by co-expression of CD133 and VEGFR2, were quantified by flow cytometry. Results: BC patients with stage III & IV disease had statistically higher levels of circulating EPCs than did patients with stage I & II disease (median=165,000 EPCs/5×106MNCs vs. median=6,920 EPCs/5x106MNCs, respectively, p < 0.0001 by Wilcoxon rank-sum test). In addition, in late-stage patients, levels of EPCs demonstrated a statistically significant drop after initiation of chemotherapy (median=162,500 EPCs/5x106MNCs [pre] vs. median=117,500 EPCs/5x106MNCs [post], p = 0.01 by Wilcoxon signed-rank test). Conclusion: These results suggest that circulating EPCs may serve as a potential tumor biomarker in breast cancer and that EPCs may represent a plausible target for future therapeutic intervention. Supported in part by the Mentored Medical Student in Clinical Research Program (General Clinical Research Center/National Institutes of Health Grant M01RR00047), Madeline & Stephen Anbinder Clinical Scholar Award, and Anne Moore Breast Cancer Research Fund

No significant financial relationships to disclose.

[The relationship between angiotensin converting enzyme gene polymorphism and risk factors for cerebral infarct]

OBJECTIVE

To explore the relationship between angiotensin converting enzyme (ACE) gene polymorphism and risk factors of cerebral infarct (CI) in Chinese Han nationality.

METHODS

One hundred and sixty-five cases with cerebral infarct, 101 cases of essential hypertension patients with 106 normal persons in Chinese Han serving as controls were detected using polymorase chain reaction (PCR) and genetic methods. ACE contents in serum were measured by colorimetric method. Risk factors of cerebral infarct were assessed by standard questionnaire, physical examination and blood tests.

RESULTS

ACE DD genotype appeared more common in patients of cerebral infarct when comparing with essential hypertension groups (0.43 versus 0.31, chi 2 = 4.03, P < 0.05) and normal controls (0.43 versus 0.17, chi 2 = 19.86, P < 0.01). D:I allele frequency appeared to be 0.66:0.34 in cerebral infarct patients and 0.41:0.59 in controls (chi 2 = 32.85, P < 0.01). In basal ganglia infarct and thalamus infarct groups, ACE DD genotype and allele ratio distribution were remarkably different to that in normal subjects (chi 2 = 18.30, 12.41, P < 0.01). The mean levels of serum in cerebral and hypertension were higher than in normal controls (F = 2,240.06, P < 0.01), and serum ACE activity in ACE DD genotype was significantly higher than that in ACE DI and II genotype in cerebral group (F = 8.83, P < 0.01).

CONCLUSIONS

The ACE gene deletion polymorphism might serve as an independent risk factor for cerebral infarct in Chinese Han nationality while circulation ACE activity might be related to gene deletion polymorphism.

Significance of chymase-dependent angiotensin II-forming pathway in the development of vascular proliferation

BACKGROUND

Vascular tissues of humans and dogs contain chymase as an angiotensin II-forming enzyme. In this study, we investigated whether chymase-dependent angiotensin II formation plays a crucial role in the development of vascular proliferation in dog grafted veins.

METHODS AND RESULTS

The right external jugular vein of dogs was grafted to the ipsilateral carotid artery. As a control group, the right external jugular veins in dogs that had not received grafts were used. In the chymase inhibitor-treated group, the vein was infiltrated with 10 micromol/L Suc-Val-Pro-Phe(P)(OPh)(2) and was grafted to the carotid artery. In the placebo-treated group, ACE activity in the grafted veins was significantly lower than that in the control veins up to 7 days after the operation, whereas chymase activity was increased significantly. After 7 days, the mRNA levels of collagen I, collagen III, and fibronectin, all of which are induced by an increase of angiotensin II action, were significantly increased in the grafted veins, and the intima-media ratio of the grafted veins was also increased. In the chymase inhibitor-treated group, the chymase activity in the grafted veins 7 days after the operation was suppressed to 12.1%. The elevated mRNA levels of fibronectin, collagen I, and collagen III in the grafted veins were significantly suppressed by treatment with the chymase inhibitor, and the intima-media ratio was also decreased significantly.

CONCLUSIONS

We demonstrate for the first time that chymase-dependent angiotensin II formation plays an important role in the development of vascular proliferation in the grafted veins.

[Anterior thoracolumbar K-plate fixation system: design and clinical application]

OBJECTIVES

To develop an anterior thoracolumbar K-plate fixation system and to report its preliminary clinical application.

METHODS

The K-plate system was developed with titanium alloy(TC4, Ti6A14V) and self-locking screw design was used. In 23 cases treated with this system, 13 had thoracolumbar fracture, 9 tuberculosis, and back syndrome after lumbar TFC operation.

RESULTS

All the 23 cases were followed up for one to ten months, averaging 4.5 months. In the 13 cases of fracture, body height of injured vertebra were regained completely, and neurologic deficits improved 2.1 grades in Frankel scale. In the 9 cases of tuberculosis, neurologic functions recovered and no local recurrence was noted. In one case of back syndrome, symptoms and signs did not occur after anterior TFC removal, interbody fusion, and K-plate fixation. This patient received second operation to remove K-plate 3 months after solid osseous fusion, and no electric erosion or obvious tissue reaction was found. 18 of the 23 cases were followed up for four months or more, and solid fusion was found in these patients in three to four months after surgery. No early complications related to implant were noted during the follow-up.

CONCLUSION

This K-plate system is suitable for reconstruction of thoracolumbar stability after anterior decompression in indicated patients.

Oral administration of a specific chymase inhibitor, NK3201, inhibits vascular proliferation in grafted vein

Chymase may play an important role in vascular proliferation, as shown by in-vitro experiments, but the role of chymase in vivo has been unclear. In this study, we investigated the effect of a novel chymase inhibitor, NK3201, on this proliferation in dog grafted veins. NK3201 inhibited human and dog chymases, but not rabbit ACE. NK3201 suppressed the Ang I-induced vascular contraction in isolated dog arteries in the presence of an ACE inhibitor, and the IC50 value of chymostatin and NK3201 in dog artery was 320 nM. In dog, the concentration of NK3201 in blood was about 10 microM at 24 h after oral administration of the drug (5 mg/kg). In the group treated with NK3201, each dog was administered orally 5 mg/kg per day from 5 days before to the day before the removal of the grafted veins. Each dog underwent right common carotid artery bypass grafting with the ipsilaterial external jugular vein. By 28 days after grafting, a significant vascular proliferation was observed in the grafted veins and the chymase activity was also increased significantly. Treatment with chymase inhibitor significantly suppressed the proliferation of the grafted veins and the increased chymase activity. In this study, we demonstrate for the first time that oral administration of a specific chymase inhibitor, NK3201, appears useful for preventing vascular proliferation.

A simple flow-injection on-line clean-up system for microwave plasma-torch atomic emission spectrometry

A simple flow injection (FI) on-line clean-up system has been developed for microwave plasma-torch atomic emission spectrometry (MPT-AES). A non-selective strongly acidic cation-exchange resin was used to achieve the goal of "on-line clean-up". Ag and Zr, which form halogen-complex anions in halide acid media, and Cr, Mo, and P, which exist as acid group anions or acids (neutral) in acidic solution, were determined and the interfering matrix cations were removed on-line. Satisfactory analytical results were obtained from some practical samples by use of this procedure.

[Development and clinical application of posterior STBtrade mark thoracolumbar transpedicular screw-plate fixation system]

OBJECTIVE

To develop a posterior STBTM thoracolumbar transpedicular screw-plate system and to apply it clinically.

METHODS

A posterior STBTM thoracolumbar transpedicular screw-plate system was developed with titanium alloy (TC4, Ti64A14V) and was used, from December 1999 to July 2000, to treat 63 cases with thoracolumbar or lumbar injuries or diseases, including thoracolumbar fracture/dislocation (33 cases), lumbar spondylosis and spondylolisthesis (16 cases), lumbar spondylosis and disk protrusion (6 cases), degenerative lumbar instability (4 cases), kyphosis due to ankylosing spondylitis (2 cases), and tuberculosis of spine (2 cases).

RESULTS

The 33 cases with thoracolumbar fracture/dislocation showed perfect reduction and fixation after the operation. The height of injured vertebral bodies returned to normal. One month later, all patients with neurological deficits, except the 6 cases with neurological deficits of Frankel grade A, showed improvement by 1 approximately 3 Frankel grades. The radicular symptoms in the 26 patients with lumbar spondylolisthesis, lumbar spondylosis and disk protrusion, and degenerative lumbar instability disappeared after operation. Among those cases, complete reduction was achieved in the 7 cases with grade I spondylolisthesis and 7 out of the 9 cases with grade II spondylolisthesis, and incomplete reduction (grade I) was seen in the remaining 2 cases with grade II spondylolisthesis. Forty cases were followed up for 5 months or over in out-patient department, no complication was found.

CONCLUSION

The posterior STBTM thoracolumbar transpedicular screw-plate system has the advantages of biological stability, excellent reduction capacity, easiness of operation, and positive clinical effectiveness.

Multiple pathways of angiotensin I conversion and their functional role in the canine penile corpus cavernosum

Multiple pathways of angiotensin (Ang) I conversion and their functional role in the canine penile corpus cavernosum were investigated. Biochemical analysis revealed high activities of angiotensin-converting enzyme (ACE) (6.9 +/- 1.7 mU/mg of protein, mean +/- S.E.M., n = 8) and chymase-like enzyme (4.0 +/- 1.4 mU/mg of protein). Functional recording of isometric tension showed that Ang I (3 x 10(-7) M) induced a tension of 0.17 +/- 0.05 g (n = 5), which was reduced to about 60% by pretreatment with an ACE inhibitor, lisinopril (10(-6) M), and almost completely blocked by lisinopril in combination with a chymase inhibitor, chymostatin (10(-4) M). Binding sites for ACE and Ang II receptors were studied by in vitro autoradiography using 125I-351A and 125I-[Sar1, Ile8]Ang II as ligands, respectively. Dense binding of ACE appeared in the endothelial layer of the corpus cavernosum penis, and Ang II receptors were localized in the trabecular smooth muscle layer. An AT1 receptor antagonist, CV-11974 (10(-6) M), markedly displaced 125I-[Sar1, Ile8]Ang II bindings, indicating that the corpus cavernosum penis contains AT1 receptors exclusively. Immunohistochemical studies demonstrated ACE in the endothelium of the corpus cavernosum penis. Mast cells that produce chymase were present mainly in the cavernosal area. These results demonstrate that chymase, in addition to ACE, is involved in the contraction of canine penile corpus cavernosum through local Ang II formation.

Possible roles of cardiac chymase after myocardial infarction in hamster hearts

The significance of cardiac chymase after myocardial infarction (MI) was evaluated using a hamster model of MI. At 1, 3, 7, 14, 28 and 56 days after MI, tissues were removed for measurements of angiotensin-converting enzyme (ACE) and chymase activities. The mean infarct size 3 days after left coronary artery ligation was 47.3 +/- 5.9% of the left ventricle circumference. The ratio of left ventricle weight to body weight was significantly increased from 3 days after MI. The level of plasma renin activity in the MI hamsters was significantly increased at the early phase of MI (1-3 days), while no significant changes in plasma ACE activity were observed. The ACE activity in the infarcted left ventricle was significantly increased starting from 3 days after MI and this increase was sustained up to 28 days. The chymase activity in the infarcted left ventricle was significantly increased starting from 1 day after MI and this increase was sustained up to 56 days. The number of chymase-positive mast cells in the infarcted left ventricle was significantly higher than in the sham group 3 and 7 days after operation. Treatment with an angiotensin (Ang) II type 1 receptor antagonist (candesartan cilexetil, 10 mg/kg per day) starting 3 days before the induction of MI significantly reduced the mortality rate during 14 days of observation following MI, whereas treatment with an ACE inhibitor (lisinopril, 20 mg/kg per day) did not. A significant improvement in hemodynamics (maximal negative and positive rates of pressure development, left ventricular systolic pressure and end-diastolic pressure, mean arterial blood pressure) was observed by the treatment with candesartan cilexetil, but not with lisinopril, 3 and 14 days after MI. These results suggested that Ang II produced by chymase may participate in the pathophysiologic state after MI in hamsters.

Inhibitory Mechanism of Daphnodorins for Human Chymase

We investigated the inhibitory mechanisms of daphnodorins for human chymase using three-dimensional molecular modeling. In daphnodorin A-human chymase complex, daphnodorin A was fixed to the active site via hydrogen bonds with Ala177, Phe29, and Gly199 in human chymase, and it formed hydrogen bonds with Ser182 and Gly180, and this complex was formed stably. In daphnodorin B-human chymase complex, daphnodorin B formed hydrogen bonds with Lys28 and Phe29 in human chymase, but it could not form hydrogen bonds with Gly199, Ala177, and Lys179. The phenyl group of daphnodorin B shifted from the P1 hole in human chymase in comparison with that of daphnodorin A. For the inhibition of human chymase by daphnodorins, we indicated that it was significant whether daphnodorins formed hydrogen bonds with Ala177 located in the P1 hole, Ser182 located in the active site, Gly180 located in the anion hole, and with Gly199, Phe29, and Lys28 in human chymase.

An orally active chymase inhibitor, BCEAB, suppresses heart chymase activity in the hamster

We investigated the effects of a novel chymase inhibitor, BCEAB (4-[1-[[bis-(4-methyl-phenyl)-methyl]-carbamoyl]-3-(2-ethoxy-benzyl)-4-oxo-azetidine-2-yloxy]-benzoic acid). The IC50 value of BCEAB for purified human chymase was 5.4 nM, whereas BCEAB did not inhibit the angiotensin-converting enzyme, elastase and tryptase. In isolated dog arteries, the IC50 value of BCEAB for the angiotensin I-induced contraction in the presence of 1 microM lisinopril was 2.8 microM. In the hamster, the heart chymase activities were significantly suppressed to 42.0% and 26.9% 3 h after oral administration of 100 and 300 mg of BCEAB/kg of body weight, respectively. In conclusion, BCEAB is a useful chymase inhibitor for studying the role of chymase in vivo.

12-Hydroxyeicosatetraenoic acid potentiates angiotensin II-induced pressor response in rats

We studied whether 12-hydroxyeicosatetraenoic acid (HETE) affected the angiotensin II-induced pressor response in rats. After intravenous administration of 1 and 3 microg/kg 12-HETE, the angiotensin II-induced pressor response was not potentiated. However, 10, 20 and 30 min after the administration of 10 microg/kg 12-HETE, the angiotensin II-induced pressor responses were increased by 7.5, 6.8 and 4.8 mm Hg, respectively. The significant pressor response was observed at 10 and 20 min after the administration. In this study, we clearly demonstrated that 12-HETE potentiated the angiotensin II-induced pressor response.

[The biological function of platelet-derived growth factor-BB in the osteoblast-osteoclast co-culture system]

OBJECTIVE

To investigate the biological effects of platelet-derived growth factor (PDGF)-BB on the osteoclasts in the osteoblast-osteoclast co-culture system.

METHODS

The human osteoblasts and osteoclasts were isolated from the iliac crest of patients and co-cultured in the same system. The PDGF-BB or PDGF-BB + NO synthase inhibitor, N(G)-monomethyl-L-arginine (L-NMMA) was administered to the co-culture system. The tartrate-resistant acid phosphatase (TRAP) activities in the medium were measured by enzyme kinetics. The resorption pits were stained by toludine blue. The area and number of the resorption pits were determined with the Leica Quantimet 500 system.

RESULTS

Under the stimuli of PDGF-BB in the co-culture system, TRAP activities changed from 1.40 U/L +/- 0.12 U/L to 1.46 U/L +/- 0.08 U/L (P > 0.05) in the medium, and the area and number of resorption pits was changed from (427 +/- 149) micrometer(2) and (13.3 +/- 0.9) per slice to (436 +/- 147) micrometer(2) and (14.1 +/- 1.2) per slice respectively (P > 0.05). After the L-NMMA was applied to the system, the TRAP activities rose significantly from 1.46 U/L +/- 0.10 U/L to 2.47 U/L +/- 0.38 U/L along with the increase of dose of PDGF-BB, and the number and area of the resorption pits increased significantly from 436 micrometer(2) +/- 147 micrometer(2) and (14.1 +/- 1.2) per slice to 592 micrometer(2) +/- 171 micrometer(2) and (22.5 +/- 1.7) per slice. Both the TRAP activities and resorption pits rose significantly after the L-NMMA was administered. Comparisons of different treatment groups were made using analysis of variance (ANOVA) with multiple comparisons and a Student-Newman-Keuls test.

CONCLUSIONS

The nitric oxide (NO) was produced by osteoblasts stimulated by PDGF-BB in the osteoblast-osteoclast co-culture system. Therefore, the direct promotion effects of PDGF-BB on the osteoclasts were inhibited.