Effect of oxygen pressure during incubation with a (10)B-carrier on (10)B uptake capacity of cultured p53 wild-type and mutated tumor cells: dependency on p53 status of tumor cells and types of (10)B-carriers.

Purpose To evaluate the effect of oxygen pressure during incubation with a (10)B-carrier on (10)B uptake capacity of cultured p53 wild-type and mutated tumor cells. Materials and methods Cultured human head and neck squamous cell carcinoma cell line transfected with mutant TP53 (SAS/mp53), or with a neo vector as a control (SAS/neo) was incubated with L-para-boronophenylalanine-(10)B (BPA) or sodium mercaptoundecahydrododecaborate-(10)B (BSH) as a (10)B-carrier at the (10)B concentration of 60 ppm for 24 h under aerobic (20.7% of oxygen) or hypoxic (0.28% of oxygen) conditions. Immediately after incubation, cultured tumor cells received reactor thermal neutron beams, and a cell survival assay was performed. (10)B concentration of cultured SAS/neo or SAS/mp53 cells incubated under aerobic or hypoxic conditions was determined with a thermal neutron guide tube. Results Hypoxic incubation significantly decreased (10)B concentration of cultured cells with a clearer tendency observed following BPA than BSH treatment in both SAS/neo and SAS/mp53 cells. Following neutron beam irradiation, SAS/mp53 cells showed significantly higher relative biological effectiveness values than SAS/neo cells because of the significantly lower radiosensitivity of SAS/mp53 to γ-rays than SAS/neo cells. Conclusion Oxygen pressure during incubation with a (10)B-carrier had a critical impact on (10)B uptake of cultured tumor cells.

Significance of Fractionated Administration of Thalidomide Combined With γ-Ray Irradiation in Terms of Local Tumor Response and Lung Metastasis.

BACKGROUND: The aim of this study was to evaluate the significance of fractionated administration of thalidomide combined with γ-ray irradiation in terms of local tumor response and lung metastatic potential, referring to the response of intratumor quiescent (Q) cells. METHODS: B16-BL6 melanoma tumor-bearing C57BL/6 mice were continuously given 5-bromo-2'-deoxyuridine (BrdU) to label all proliferating (P) cells. The tumor-bearing mice then received γ-ray irradiation after thalidomide treatment through a single or two consecutive daily intraperitoneal administrations up to a total dose of 400 mg/kg in combination with an acute hypoxia-releasing agent (nicotinamide) or mild temperature hyperthermia (MTH). Immediately after the irradiation, cells from some tumors were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (= P + Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumor-bearing mice, 17 days after irradiation, macroscopic lung metastases were enumerated. RESULTS: Thalidomide raised the sensitivity of the total cell population more remarkably than Q cells in both single and daily administrations. Daily administration of thalidomide elevated the sensitivity of both the total and Q cell populations, but especially the total cell population, compared with single administration. Daily administration, especially combined with MTH, decreased the number of lung metastases. CONCLUSION: Daily fractionated administration of thalidomide in combination with γ-ray irradiation was thought to be more promising than single administration because of its potential to enhance local tumor response and repress lung metastatic potential.

Perioperative d-dimer levels in patients with musculoskeletal tumors.

BACKGROUND: D-dimer (DD) levels have been reported as a sensitive but non-specific indicator for deep vein thrombosis (DVT) and pulmonary embolism (PE). Few reports have examined perioperative DD levels in musculoskeletal tumor. MATERIALS/METHODS: Subjects comprised 77 patients who had undergone oncological resection of musculoskeletal tumor. DD levels were assessed preoperatively and on postoperative days 1 and 7. Multidetector-row computed tomography (MD-CT) was performed to detect DVT/PE for cases with DD level >10.0 microg/ml. RESULTS: Mean preoperative DD level was 0.84 microg/ml. Significant elevation of postoperative DD levels was confirmed. DD levels were significantly changed by various clinical conditions, such as malignancy, age and prosthetic reconstruction. In 4 of 5 cases with postoperative DD levels >10.0 microg/ml, DVT/PE was detected. CONCLUSION: Activation of the coagulation system by surgery and heterogeneity of DD levels under various clinical conditions in musculoskeletal tumor patients were suggested.

[Genotyping of methicillin-resistant Staphylococcus aureus isolated from inpatients and medical workers in orthopaedics ward].

Methicillin-resistant Staphylococcus aureus (MRSA) strains were isolated from the inpatients in orthopaedics ward hospitalized from March 1998 to November 2000, hospital environments, medical workers and the inpatients transferred from TCC (Trauma and Critical Care Center). Genotype by pulsed field gel electrophoresis (PFGE) and biotype according to the production of coagulase, enterotoxin and toxic-shock syndrome toxin-1 (TSST-1) were determined for the MRSA strains to analyze the infection source and transmission route of the infection. Out of 673 S. aureus strains isolated from the inpatients, 390 strains (57.5%) were MRSA. In 89 medical workers in orthopaedics ward, MRSA were isolated in 23 (25.8%) and 7 (7.9%) workers from nasal cavity and hand, finger, respectively. In contrast, no MRSA was isolated from hospital environments. Eighty MRSA strains (80%) from the inpatients and 8 MRSA strains (75%) from the medical workers were shown to have same biotype; coagulase II-enterotoxin C-TSST-1 (+) (II-C- (+)). MRSA strains isolated from the inpatients were grouped into 24 types according to PFGE patterns, and types 17 (17 strains), 12 (13 strains), 1 (8 strains), 4 (8 strains) and 13 (6 strains) were dominant among the MRSA strains isolated. It was shown that MRSA strains with the same PFGE genotype were detected at the same time in the different wards. In addition, MRSA strains isolated from medical workers were all PFGE genotypes 1 and 4. MRSA strain isolated from a new inpatient had a different PFGE type from the 24 kinds of genotype. These results suggest that the involvement of the medical workers might be important as infection source and for transmission of MRSA in hospital.