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Biomedical subjects

W Rao

Publications and source records attributed to W Rao.

10 recordsLinked to original sources
PubMed1999

Bone classification: clinical-histomorphometric comparison.

This study was aimed to correlate the hand clinical assessment of the bone quality to the histologic structure quantified by histomorphometric evaluation of bone density. Small bone biopsies were harvested in 56 patients during oral implant surgery, and were utilized for histomorphometric evaluation. The bone scoring was recorded during drilling of the implant bed, based on the hand-felt perception of the drilling resistance. The bone biopsies were then processed to obtain thin ground sections. The results of histomorphometric analysis were expressed as percentage of bony trabeculae over the total biopsy area, and the Spearman's rank correlation test, was applied to calculate the statistical differences of the clinically assessed classes of bone density and linear regression was calculated. Samples from the D1 showed a mean histomorphometric density of 76.54% +/- 16.19. Samples from D2 showed a mean value of 66.78% +/- 15.82. D3 specimens had a mean histomorphometric density scoring 59.61% +/- 19.55%. D4 samples had a mean value of 28.28% +/- 12.02. The interclass correlation analysis of the variance, showed that the clinically assessed classes D1 (P = 0.01) and D4 (P = 0.0006) were significantly different from the population. On the other hand, the classes D2 (P = 0.6) and D3 (P = 0.4) were not significantly different. This study demonstrated that hand feeling allows to distinguish, with statistically significant confidence, D1 and D4 bone, but failed to distinguish between the intermediate classes of bone quality.

Alveolar Process↗
PubMed1999

[The efficacy of p16, p53 and p21 genes on the proliferation of lung cancer cells in vitro].

OBJECTIVE: Whether the p16, p21 and p53 genes inhibit the proliferation of lung cancer cells after transfecting the genes alone or jointly was examined. METHODS: The p16, p21 and p53 genes mediated by Stearylamine/DOPE (SA liposome) were introduced alone and jointly into the non-small cell lung cancer (NSCLC) cell line A549 and small cell lung cancer (SCLC) SH77. The effect of the genes on the growth of the cells was detected by MTT method at day 1, 3, 5 after gene transfection. RESULTS: The p16, p53 and p21 genes alone mediated by SA liposome can inhibit obviously the growth of NSCLC cell line A549 cells, while the genes were slightly effective on SCLC cell line SH77 cells at day 1, 3, 5 after transfecting the genes. But co-transfecting p16 and p21 or p16 and p53 can enhance the inhibiting effect on both A549 and SH77 cells significantly. CONCLUSIONS: The tumor suppressor genes p16, p53 genes and CDK inhibitor p21 gene may be candidate for gene replacement therapy of NSCLC. Co-transfecting p16 gene and p53 gene may be a better choice.

Carcinoma, Non-Small-Cell Lung↗
PubMed1998

[Investigation on computative spectrophotometry employed in the assay of peaonol in cortex moutan].

OBJECTIVE: To investigate the easibility of employed computative spectrophotometry in the assay of traditional Chinese medicines. METHOD: Make contents of peaonol in 10 samples of Cortex Moutan were determined by three-wavelength spectrophotometry and dual wavelength K-ratio spectrophotometry, and then compared with the method in Chinese Pharmacopeia. RESULT: The differences of the UV spectrum of different lots of samples bring about relative error. sometimes up to 10%-30% for computative spectrophotometry. CONCLUSION: Computative spectrophotometry should be used carefully in assaying traditional Chinese medicines.

Acetophenones↗
PubMed1998

The bone growing chamber: a new model to investigate spontaneous and guided bone regeneration of artificial defects in the human jawbone.

Spontaneous bone repair and regeneration of jawbone defects have been insufficiently studied in the dental literature. The present study analyzes a new human model designed to evaluate the basis for spontaneous bone regeneration in human jawbones. Hollow titanium cylinders, termed "bone growing chambers," were prepared with commercially pure titanium. Ten volunteers undergoing routine implant surgery were enlisted. A properly calibrated drill was used to prepare the bone-growing-chamber bed. The bone growing chamber was inserted inside the bone defect, and care was taken to submerge the cylinder at the level of the bone crest. After an adequate healing period, the bone growing chambers were retrieved with a small quantity of peripheral bone using a calibrated trephine bur. The retrieved specimens were processed to obtain thin undecalcified ground sections. The stable bone growing chambers showed bone tissue inside the growing space. The maturity of the regenerated bone was related to the time of removal. The bone growing chamber provides a well-defined space that is easy to prepare and to retrieve; its dimensions are always identical and it allows quantitative measurements of bone regeneration inside the chamber space.

Alveolar Process↗
PubMedDate not supplied

Evaluation of linear polyethyleneimine/nitric oxide adduct on wound repair: therapy versus toxicity.

A full-thickness wound model was used to evaluate the effects of a topically applied polyethyleneimine-based nitric oxide donor on wound repair in aged rats. Polymer applications were applied over a 10-day period on days 0, 2, 4, 6, and 8 comparing treatment (linear polyethyleneimine-nitric oxide) and control groups (linear polyethyleneimine). Urinary nitrate excretion was quantified as a measure of nitric oxide released. The nitric oxide released from the linear polyethyleneimine-nitric oxide group was significant compared with controls (p </= 0.001), with a maximal nitrate level of 40 micromol on day 1 and an average sustained delivery of 34 micromol/day for the remainder of the study. Wound closure was examined using a computer-based video-imaging analysis system. The wounds of both the linear polyethyleneimine- nitric oxide treatment and linear polyethyleneimine control groups exhibited minimal wound closure; however, the wound closure of the treatment group was significant as compared with the control group (p </= 0.05). A phosphate- buffered saline solution-wounded control was performed that showed cleaner and faster healing wounds, similar to normal healing, than either of the polymer application groups. The histological data showed very little wound healing, on a cellular level, implicating the linear polyethyleneimine-nitric oxide as well as the carrier compound as contributing to the adverse tissue reactions that occurred in the wound bed. Thus, we report the toxic effects of a polyethyleneimine-based compound, as well as the toxic effects of sustained delivery of excess levels of nitric oxide on the wound- repair process. Our findings suggest that there exists indeterminate parameters between therapy and toxicity of nitric oxide delivery to wounds.

Administration, Cutaneous↗
PubMedDate not supplied

A histometric comparison of smooth and rough titanium implants in human low-density jawbone.

The aim of this investigation was to conduct a comparative histometric analysis of bone-implant interface between a rough titanium surface and smooth implants in low-density human jawbone after 3, 6, and 12 months of submerged, undisturbed healing. Six adult volunteer patients undergoing standard implant placement were enrolled in this project. Each patient received 1 smooth and 1 rough implant. After 3, 6, and 12 months, the implants were harvested for histometric analysis. The values of bone-implant contact were the following: 3 months smooth 6.2%, 3 months rough 58.9%, 6 months smooth 3.55%, 6 months rough 72.9%, 12 months smooth 6.7%, and 12 months rough 76.75%. The results showed that in low-density bone the rough surface dramatically enhanced the amount of bone-to-implant contact. Because of the small number of implants examined, definite conclusions cannot be drawn, even though the statistical analysis showed significant differences between the smooth and rough groups (P = .0129; F = 76.065). Nevertheless, a trend was evident in these observations: while a rough implant surface may enhance the rate of osseointegration, it is not able to significantly change the bone density, and an implant placed low-density bone is at a higher risk of failure when occlusal loading begins.

Adult↗