OBJECTIVETo evaluate the precision of rat bone mineral density (BMD) measurements by Norland Excellplus dual-energy X-ray absorptiometry (DXA) and to investigate the BMD changes in ovariectomized (Ovx) rats in vitro.

METHODS(1) The coefficients of variation (CV) for BMD measurements at various skeletal regions were repeatedly determined by DXA in 10 Wistar rats in vitro. (2) BMD in lumbar vertebra (L5) and both sides of femurs was measured in total 90 rats. And (3) changes in BMD between Ovx and sham rats were compared.

RESULTS(1) The short-term CVs of BMD measurements in different regions by DXA were as follows, 1.58% for lumbar vertebra (L5), 0.90% for left femur, and 0.86% for right femur, respectively. The long-term CVs were 2.22% for lumbar vertebra (L5), 1.09% for left femur, and 1.20% for right femur. (2) The BMD values in 90 Wistar rats were (127.5 +/- 12.3) in lumbar vertebra (L5), (82.6 +/- 11.3) in corpus vertebra (L5'), (150.7 +/- 10.6) in left femur and (149.9 +/- 10.6) mg/cm2 in right femur, respectively. The correlation coefficient of BMD measurements between left and right femurs was 0.792 (P < 0.001). (3) In Ovx group, the BMD values of corpus vertebra (L5') and distal femurs were significantly decreased, that was 10.0%-17.5% lower in comparison with sham group (P < 0.001).

CONCLUSIONSMeasurement of rat BMD in vitro by Norland Excellplus DXA is a useful method, and it can reflect the changes in rat bone masses with good precision.

Absorptiometry, Photon ; Animals ; Bone Density ; Female ; In Vitro Techniques ; Ovariectomy ; Rats ; Rats, Wistar

OBJECTIVETo investigate the role of lung resistance-related protein (LRP) in intrinsic multidrug resistance (MDR) of bladder cancer and detect the relationship of LRP expression with the clinical pathologic parameters.

METHODS66 patients were studied with newly diagnosed primary bladder cancer (T(a) = 12, T(1) = 26, T(2) = 11, T(3) = 10, T(4) = 7; G(1) = 35, G(2) = 19, G(3) = 12). No patient was treated preoperatively with either radiation or chemotherapy. Reverse transcription-polymerase chain reaction (RT-PCR) was performed for measure of mRNA expression for LRP, multidrug-resistance gene 1 (MDR1), and multidrug resist nce-associated protein 1 (MRP1). Expressions of LRP, P53 and P63 proteins were examined by immunohistochemistry staining.

RESULTSLRP mRNA had the highest expression rate (64%, 42/66) among three MDR markers in primary bladder cancers without chemotherapy and its level was significantly higher in normal bladder tissue than in TCC of bladder (t = 2.82, P < 0.01), in low grade than in high grade cancers (t = 4.14, P < 0.01), and in superficial than in invasive cancers (t = 3.58, P < 0.05). LRP mRNA expression showed no correlation with either MDR1 or MRP1, but close correlation with LRP protein level (r = 0.89, P < 0.01). LRP was associated with low-grade (r = 0.81, P < 0.01) and low-stage (r = 0.78, P < 0.05) cancers, but not with tumor suppressor P53 or P63 (P > 0.05).

CONCLUSIONSThe grade and stage-related expression pattern of LRP indicates that it may be a predictive index for intrinsic MDR in bladder cancer. Anti-cancer drugs out of the MDR spectrum of LRP may be more effective for patients with early bladder cancer.

ATP-Binding Cassette, Sub-Family B, Member 1 ; biosynthesis ; genetics ; Adult ; Aged ; Carcinoma, Transitional Cell ; genetics ; metabolism ; pathology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Female ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Multidrug Resistance-Associated Proteins ; biosynthesis ; genetics ; Neoplasm Proteins ; biosynthesis ; genetics ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Urinary Bladder Neoplasms ; genetics ; metabolism ; pathology ; Vault Ribonucleoprotein Particles ; biosynthesis ; genetics

OBJECTIVETo investigate the relationship of protein kinase C-alpha (PKCalpha) expression/activation with tumor differentiation and resistance to chemotherapy drugs in superficial bladder carcinoma.

METHODSExpression of PKCalpha was measured by Western-blot analysis in 76 samples including tumor and normal tissues, respectively. A human RT4 bladder cancer cell line stably expressing green fluorescent protein (GFP)-PKCalpha (RT4/PKCalpha) was established. The sensitivity of the RT4/PKCalpha and parental cells to adriamycin (ADM) was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The change of sensitivity of the RT4/PKCalpha to ADM were observed under the conditions of PKC activation and inhibition, respectively.

RESULTSTotal level of PKCalpha expression and the ratio of the amount of PKCalpha expression or PKC activity in membrane to that in cytosol (M/C) were all more higher in cancerous tissues than in normal tissues (P < 0.01); With the increase of tumor grade, the relative level of PKCalpha expression significantly increased in membrane (P < 0.01) and decreased in cytosol (P < 0.01), M/C of PKCalpha was significantly elevated (P < 0.01), and total relative level of PKCalpha expression significantly increased (P < 0.01). Thirty-eight cases recurred during the follow-up period in total seventy cases. Multivariate analysis showed that high M/C of PKCalpha was independent prognostic factor for tumor recurrence after standard ADM treatment in the 2-year follow-up (RR = 3.98, 95% CI 1.22-5.68, P = 0.03). Transfection of PKCalpha increased resistance of RT4 cells to ADM [resistance index (RI): 6.97, t = 3.24, P < 0.01]. PKCalpha activation further greatly promoted the resistance (RI: 148.11, t = 5.18, P < 0.001) while inhibition of PKCalpha did conversely (RI: 1.6, t = 1.29, P > 0.05).

CONCLUSIONThe abnormal activation and expression level of PKCalpha closely correlate with both tumor grade and intrinsic resistance to ADM in patients with superficial bladder carcinoma.

Aged ; Antibiotics, Antineoplastic ; pharmacology ; Carcinoma, Transitional Cell ; enzymology ; pathology ; Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; physiology ; Enzyme Activation ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Neoplasm Staging ; Protein Kinase C-alpha ; metabolism ; Transfection ; Tumor Cells, Cultured ; Urinary Bladder Neoplasms ; enzymology ; pathology