Expression of MMP-13 in osteoblast cells and rat tibia after exposure to gamma rays or accelerated carbon ions.

In past research, we found that carbon ion irradiation increased bone volume in rats, and a significant amount of cartilage remained inside the carbon ion-irradiated trabeculae. The amounts of matrix metalloproteinase 13 (MMP-13) mRNA in osteoblast-like MC3T3-E1 cells tended to decrease after carbon ion irradiation. The level of MMP-13 mRNA in non-irradiated cells was stable during the experimental period, but in gamma ray-irradiated cells it tended to increase. When localization of MMP-13 in locally irradiated experimental rats was investigated, it was found in the marginal trabeculae in both non-irradiated and gamma ray-irradiated animals. MMP-13 was detected in osteoid and neogenetic bone in the trabeculae surface. The trabeculae in carbon ion-irradiated bone remained cartilaginous. Carbon ion-irradiated rats exhibited weak expression of MMP-13 around the cartilage inside the trabeculae. We conclude that carbon ion irradiation reduced expression of MMP-13, thus suppressing both chondrocyte maturation and cartilage resorption. Increases in hyperplasia of the bone trabeculae and of bone volume were caused by ongoing bone addition and calcification in the absence of sufficient cartilage resorption.

Pattern of local relapse of maxillary sinus carcinoma.

Maxillary sinus carcinoma (MSC) is a rare disease with a variety of treatment options. The present study was undertaken to review the outcome of patients with treated MSC in order to clarify the factors related to local recurrence by analyzing CT findings. The study group comprised of 47 cases, 40 males and 7 females with a median age of 61 years (range, 40- 84 years) treated between 1988 to 1996 at the department of radiotherapy. CT was taken with a slice thickness of 5 mm and contrast material was routinely used. The mean follow-up period for the group was 45.0 months (range, 3-125 months). The treatment policy was either preoperative radiotherapy of 40Gy/16fr followed by maxillectomy or radical radiotherapy of 65Gy/26fr with partial maxillectomy during the course of radiotherapy. By using CT-simulation, wedge pair techniques were used in most patients with Cobalt or 6MV X-ray machines as treatment sources. Tumor extension was categorized into the following anatomical sites: orbital contents, other paranasal sinuses, posterior wall of the maxillary sinus, pterygoid plate/muscle, nasopharynx, infra-temporal fossa, base of the skull, anterior wall of the maxillary sinus, subcutaneous tissue, cheek mucosa, hard palate and alveolar bone. Local control was computed by using the Kaplan-Meier method and p value was measured by using Chi-squared test. The 5-year overall local control rates for all patients were 56%. The local recurrence was found in 19 of 47 patients (40.4%). Tumors extending to pterygoid plates (n=13) and pterygoid muscles (n=10) showed higher rate of local recurrences as compared to those without extensions (9/13 [69%] vs 10/34 [29%], p<0.02 and 7/10 [70%] vs 12/37 [32%], p<0.05, respectively). Extensions to nasopharynx (6/9, 66%) and base of skull (4/6, 66%) also showed higher rates of recurrence; however, those were not statistically significant. More than 80% of the relapse became manifest within 12 months of diagnosis and isolated local failure was the most common pattern. This analysis indicates that tumor extension to pterygoid plate/muscles, results in higher rates of recurrences. This may due to the difficult surgical accessibility of the tumor. During radiotherapy planning, special emphasis should be given to this sites of tumor extension to avoid possible local recurrence.

[Clinical effects of combination therapy with cefozopran and amikacin for infections in patients with hematological disorders].

Cefozopran (CZOP) and amikacin (AMK) were used concomitantly to treat infections complicated by hematological diseases. A total of 103 subjects were evaluated, and the all over efficacy rate was 69.9%. Acute leukemia was found in the largest number of patient, 57, followed by 29 cases of malignant lymphoma and 7 cases of myelodysplastic syndrome. By type of infection, patients having unknown origin were the largest in number, being 66, and the efficacy rate was 71.2%. The efficacy rates for sepsis, pneumonia and upper respiratory infection were 42.9% (7 cases), 71.4% (14 cases) and 90% (10 cases) respectively. The efficacy rates by neutrophil counts before administration of CZOP and AMK and at 1 week after administration were both 53.3% in the group of less than 100/microliter, both 60% in the group of less than 500/microliter. The efficacy rate by neutrophil counts at 1 week after administration was 58.6% in the group of less than 100/microliter. The efficacy rate was 75.4% in the group of granulocyte colony stimulating factor (G-CSF) concomitant usage, and 61.9% in the group of non-concomitant usage group. The efficacy rates by serum albumin levels before administration of CZOP and AMK and at 1 week after administration were both 92.9% in the group of over than 4 g/dl, both 50% in the group of less than 3 g/dl. Concomitant treatment with CZOP and AMK exhibited a high level of safety and efficacy rates in infections complicated by hematological diseases.

Radiation effects of carbon ions and gamma ray on UDMA based dental resin.

The radiation effects on the mechanical and physical properties of photo-polymerized UDMA resin without filler was investigated by various mechanical tests and spectroscopic measurements. The radiation sources were carbon ion (12C ion) and gamma ray (gamma-ray). With 640 Gy of 12C ion radiation, Vickers hardness increased by about 40%, the degree of abrasion decreased by 30%, and the flexural strength increased by 20%. With the same dose of gamma-ray radiation, only Vickers hardness increased by 19%. The spectra taken by the Fourier Transform Infrared Spectrometer (FT-IR), Raman spectroscopy, and Fluorescence spectrophotometer showed little change in the peak configuration and background intensities. The relative degree of conversion (DC) of carbon double bonds by radiation to the state of non-radiated samples were estimated by FT-IR. Spectroscopic results were indicative for the formation of cross-linking between carbon chains. Cross-linking of carbon molecules induced by radiation might be one of the reasons for the improved mechanical properties of UDMA resin.

Three-phase bone scintigraphy and viability of vascularized bone grafts for mandibular reconstruction.

Three-phase bone scintigraphy was undertaken to check the anastomotic patency and monitor the viability of vascularized bone grafts. Ten consecutive patients who underwent vascularized bone grafting of the mandible were reviewed. A successful clinical outcome was achieved in 8 patients. The graft failed in 2 patients. In this series, 3-phase bone scintigraphy of radiolabeled (99m)Tc-methylene-diphosphonate was performed at 7 days, and at 1, 3, 6, and 12 months after reconstruction. Assessments made using 3-phase bone images were compared with the clinical findings. The clinical outcome of the cases presented in our series correlated extremely well with 3-phase bone images. Three-phase bone scintigraphy is a useful method for the assessment of patency and viability of vascularized bone grafts. The use of this method can be very helpful in assessing the anastomotic patency and viability of a graft which for clinical reasons is suspected of being non-viable.

Somatic cell mutation induced by sunlight in Drosophila.

There is ample epidemiological evidence showing that sunlight can cause skin cancer in the human. In experimental studies, simulated sunlight or UV lamps are used for demonstrating carcinogenesis and other biological effects. Little studies, however, have been performed using natural sunlight itself. In this work, we have examined the mutagenicity of natural sunlight in Drosophila. The Drosophila wing spot test is useful to detect somatic cell mutations. Third instar larvae in petri dishes were exposed to sunlight (ultraviolet region with < 290 nm wavelength cut off by a plastic cover) in the yard of Okayama University campus (north latitude: 34 degrees 39', east longitude: 133 degrees 55'). The sunlight was mutagenic in Drosophila larvae and produced pyrimidine dimers in their DNA. In the observed mutagenicity, there was dependence on the exposure period and UV fluence. During the two-year monitoring, the highest induction of mutant spot observed was 1.98 total spots/wing on June 25, 1998, and the lowest was 0.64 on December 29, 1998, while non-exposure spontaneous spots were 0.29 and 0.32 on these days, respectively. Thus, solar radiation was mutagenic both in summer and in winter.

Scintigraphic evaluation of long-term salivary function after bilateral whole parotid gland irradiation in radiotherapy for head and neck tumour.

In 25 patients with head and neck tumour, in whom bilateral whole parotid glands were totally included in the irradiation volume, parotid gland function was estimated and compared with that of 58 non-irradiated parotid glands in 29 patients, by symptomatic grading and radioisotope (RI) sialography. Sequential follow-up by RI sialography has suggested that if the total dose to the parotid gland is less than 52 Gy or if the time-dose fractionation (TDF) value is less than 80, then partial recovery of salivary function can be expected 1 or 2 years after irradiation, even if patients show severe xerostomia during the first 6 months. Long-term recovery rarely occurs in parotid glands which have been irradiated at doses exceeding 55 Gy or with TDF values of 88 or higher. The 50% complication probability (ED50) was less than 33 Gy for subacute xerostomia during the first 6 months and 52.5 Gy for chronic xerostomia after 12 months, respectively. Although a prospective study will be required for confirmation, differences between the dose-response curves of xerostomia at subacute and chronic phases suggest a basis in different biological mechanisms.

Hepatocellular carcinoma metastatic to the mandible.

A case of hepatocellular carcinoma metastatic to the mandible is described. The patient reported swelling, pain, and trismus after a pathologic fracture. After a systematic examination with the use of 99mTc-methylene diphosphonate, 67Ga-citrate, and 99mTc-pyridoxyl-5-methyl triptophan scintigraphy the primary focus was discovered in the right lobe of the liver. The focus was confirmed by computed tomography and magnetic resonance imaging. The histopathologic diagnosis of hepatocellular carcinoma was made from a biopsy specimen of the mandibular lesion.

Radiation-induced hypoplasia of the teeth and mandible. A case report.

Hypoplasia of the mandible and teeth is reported in a 4-year-old boy who had cystic hygroma. At age 7 months he had been treated with 60Co-gamma-radiation (24 Gy to the head and neck, 45 Gy to the mediastinum) followed by surgery. Panoramic and periapical radiographs showed hypoplasia of the roots of the primary canines, molars, and permanent teeth and no evidence of tooth germs. The patient was followed up to age 13 years.