Hypoxic condition promotes differentiation and mineralization of dental pulp cells in vivo.

AIM: To investigate the behaviour of dental pulp cells under hypoxic conditions in vivo using an experimental animal model. METHODOLOGY: A mini-screw was inserted into the inferior dental nerve canal of rats to arrest the blood supply, which resulted in a reduced oxygen level in the dental pulps of molar teeth used for the experimental group. The decrease in blood supply was evaluated by injected India ink in transparent specimens. The hypoxia marker hypoxyprobe-1 was investigated by immunohistochemical staining. The mRNA expressions of ATP-binding cassette transporter (ABC) G2 (ABCG2) which is a marker for the capacity to excrete metabolites and for stem-like cells as well as dentine sialophosphoprotein (DSPP) and osteocalcin (OCN) which are markers for mineralization were evaluated by RT-PCR. Protein was evaluated by immunohistochemical staining using ABCG2, dentine sialoprotein (DSP) and OCN. RESULTS: The evaluation of India ink indicated a decreased blood supply in the transparent specimens, and hypoxyprobe-1 immunohistochemical staining showed positive expression. ABCG2, DSPP and OCN mRNA expressions increased at 7 and 14 days. Immunohistochemically, ABCG2, DSP and OCN-positive cells were localized in the odontoblastic layer. CONCLUSIONS: Hypoxic conditions promoted mineralization and differentiation of dental pulp cells of the odontoblastic layer.

Chelation of trace elements in preservation medium influences the quality of boar spermatozoa during liquid preservation at 5°C for 4 weeks.

BACKGROUND: The addition of a metal chelator, ethylenediaminetetraacetic acid (EDTA), to semen extender has the purpose of capturing trace element ions. OBJECTIVE: This study was conducted to evaluate the effects of EDTA on the quality and in vitro fertilisability of liquid-preserved boar spermatozoa. METHODS: In Experiment 1, semen samples were preserved in the semen extender supplemented with 0, 3, 6, or 12 mM of Na-EDTA at 5 degree C for 4 weeks. In Experiment 2, semen samples were preserved in the extender supplemented with 3 mM of Na-EDTA, Ca-EDTA, or Zn-EDTA and without chelator EDTA. RESULTS: When Na-EDTA was used as a chelating substance in the extender, 3 mM was a most suitable concentration for sperm motility and viability after cold preservation. The supplementation of 3 mM Ca-EDTA had advantages regarding sperm motility, viability and plasma membrane integrity. CONCLUSION: Our findings indicate that 3 mM Ca-EDTA is the most suitable metal-chelating substance for the liquid preservation of boar semen.

Anastomosis between the hepatic artery and the extrahepatic collateral or between extrahepatic collaterals: observation on angiography.

Transcatheter arterial chemoembolisation for hepatocellular carcinoma is widely carried out not only through the hepatic artery but also through the extrahepatic collateral pathways. Anatomically, there are many anastomoses between the hepatic artery and the extrahepatic collateral as well as among the extrahepatic collaterals. However, these anastomoses may not be shown on angiography because the anastomosing branches are too small. These anastomoses may not only interfere with effective control of hepatocellular carcinoma by transcatheter arterial chemoembolisation but also cause unexpected procedure-related complications. Therefore, radiologists should have sufficient knowledge of these underlying anastomoses. In this report, we present our angiographic images.

Surface dose measurement in patients and physicians and effective dose estimation in patients during uterine artery embolisation.

Surface dose monitoring in patients and physicians during 29 uterine artery embolisation (UAE) procedures was performed using photoluminescence dosemeters and thermo-luminescence dosemeters. Organ or tissue doses were measured with an anthropomorphic phantom using UAE exposure conditions averaged from the 29 cases, and effective doses were estimated for the patient. Entrance surface dose of the patients at the maximum dose position ranged from 121.5 to 1650 mGy. Estimated doses ranged from 3.16 to 43 mGy for the ovary and from 3.8 to 51.8 mGy for the uterus. The effective dose was 1.09-14.8 mSv. Monitored doses on the body surface of physicians were relatively high in the upper arm (5.41+/-1.52 to 163+/-17.25 microGy) and the hand and fingers (0.85+/-1.18 to 222+/-16.4 microGy).

A comparison of the production of reactive oxygen species by suspended particulate matter and diesel exhaust particles with macrophages.

Oxidative stress has emerged as a pivotal mechanism that underlies the toxic pulmonary effects of suspended particulate matter (SPM). Experimental evidence shows that redox-active transition metals, redox-cycling quinoids, and polycyclic aromatic hydrocarbons (PAHs) contained in SPM act synergistically, producing reactive oxygen species (ROS). The direct production of superoxide anion and the damaging hydroxyl radical has been studied in aqueous and dimethyl sulfoxide (DMSO) suspensions of SPM both with and without H2O2; however, no study has reported on the release of ROS from ingesting macrophages with SPM. We investigated the time course of the ability to induce lucigenin-dependent chemiluminescence (CL) from human monocyte-derived macrophages exposed to SPM, carbon black particles, and diesel exhaust particles (DEP). We also examined hydroxyl radical generation from the same experimental system using the 2-deoxy-d-robse method. We found an increase of CL for SPM, but not for carbon black particles or for DEP. Hydroxyl radical generation was observed in both SPM and DEP, but the release from DEP was more frequent than that from SPM. These results suggest that certain components of SPM are important in the response of ROS from ingesting macrophages with SPM, and that those components are discharged from SPM into the atmosphere.

[Survey of surgical treatment of malignant pleural mesothelioma in Japan].

Surgical results of patients with malignant pleural mesothelioma (MPM) in Japan was surveyed from the results of a questionnaire sent to members of the Japan Lung Cancer Society. and a total of 132 surgical cases of MPM from 1997 to 2002 were analyzed. They consisted of 112 males and 20 females. By histological type, 87 cases had epithelial type, 10 had sarcomatous type, 26 had mixed type and 2 had uncommon type of MPM (the histology of 7 cases was not indicated). As to the surgical mode, extrapleural pneumonectomy (EPP) was performed in 73 cases, and limited surgery such as decortication and tumorectomy was performed in 59 cases. The tumor was potentially completely resected in 83 cases. Postoperative adjuvant therapy was performed in 56 cases. The 1-, 2- and 3-year survival rates of the present cases were 54, 33 and 21%, respectively, and the perioperative mortality rate was 5%. These survival and mortality rates in the present series were almost similar to those of the MPM cases in the previously reported series from 1987 to 1996 by Takagi et al. According to Cox regression analysis, prognostic factors for survival included postoperative adjuvant therapy (p=0.003) and complete resection (p=0.037) significantly, and International Mesothelioma Interest Group (IMIG) stage (p=0.051) and performance status (p=0.086) with a marginal significance, indicating that complete surgical resection of the tumor and perioperative adjuvant therapy could be effective treatment for MPM in Japan. Thus, the development of multimodality therapy including surgical treatment for this disease may be required to improve surgical results of MPM patients.

Effect of size of man-made and natural mineral fibers on chemiluminescent response in human monocyte-derived macrophages.

Fiber size is an important factor in the tumorigenicity of various mineral fibers and asbestos fibers in animal experiments. We examined the time course of the ability to induce lucigenin-dependent chemiluminescence (CL) from human monocyte-derived macrophages exposed to Japan Fibrous Material standard reference samples (glass wool, rock wool, micro glass fiber, two types of refractory ceramic fiber, refractory mullite fiber, potassium titanium whisker, silicon carbide whisker, titanium oxide whisker, and wollastonite). We determined how fiber length or width might modify the response of cells. We found that the patterns of time-dependent increase of CL (sigmoid type) were similar for each sample except wollastonite. We observed a strong correlation between geometric-mean length and ability to induce CL in seven samples > 6 microm in length over the time course (largest r(2) = 0.9760). Although we also observed a close positive correlation between geometric-mean width and the ability to induce CL in eight samples < 1.8 microm in width at 15 min (r(2) = 0.8760), a sample of 2.4 microm in width had a low ability to induce CL. Moreover, the relationship between width and the rate of increase in ability to induce CL had a negative correlation at 30-60 min (largest r(2) = 0.7473). Our findings suggest that the release of superoxide from macrophages occurs nonspecifically for various types of mineral fibers depending on fiber length.

Asbestos-related lung cancer and mesothelioma in Japan.

In Japan, crocidolite had been used for asbestos cement pipe and spraying, and amosite had been used for building board and spraying. These two types of asbestos had stopped to use in Japan in the late 1970s. An extreme increase in imported asbestos (all 3 commercial types) was observed between 1960 and 1974. In 1960, 77,000 tons of asbestos were imported, and reached the peak as 352,316 tons in 1974. This extreme rise of asbestos imports corresponds with the recent rapid increase in mortality of malignant pleural mesothelioma. Between 1995 and 1999, an estimated mean annual death from pleural mesothelioma was about 500. The annual number of compensated occupational respiratory cancers due to asbestos exposure has also been increasing. Up to the end of March 2000, 162 cases with malignant mesothelioma and 197 cases with lung cancer were compensated. As for lung cancer, epidemiological studies are scanty in Japan. Limited environmental data of the working places in asbestos textile factories suggests that heavy asbestos exposure in the past made deaths from respiratory diseases. Less asbestos exposure will enable exposed workers to survive enough to reach cancer age. Even now smoking rate among males in Japan are over 50%. So lung cancer deaths caused by the interaction between smoking and asbestos exposure will be continuing.

Epidemiology of occupational asbestos-related diseases in China.

In 1950s and 60s, asbestosis had been a major health hazard for asbestos exposed workers. In the late 1970s, lung cancers with or without asbestosis were found among asbestos workers. All cohort studies on asbestos workers and on chrysotile miners in China showed excess deaths from lung cancer. In a large scale of cohort study on asbestos workers, a synergistic effect was found between cigarette smoking and asbestos exposure in the production of lung cancer. There have been not so many cases of malignant mesotheliomas reported, so far. In the cohort of chrysotile miners, 4 cases of pleural mesothelioma were observed. In the large scale of cohort study on asbestos workers in 9 factories using only chrysotile only one case of pleural mesothelioma was detected for 10 years' observation. In another 2 cohort studies, 2 cases of peritoneal mesotheliomas were found, one in Shanghai asbestos factory where a small amount of crocidolite had been used in 1960s, and one in Anqing asbestos factory that was located near tremolite mine. Further study is needed especially for the relationship between exposure to Chinese chrysotile and malignant mesotheliomas.

The chemiluminescent response from human monocyte-derived macrophages exposed to various mineral fibers of different sizes.

The aims of the present work were to quantify ability to induce lucigenin-dependent chemiluminescence (CL) from 6-9 day-old human monocyte-derived macrophages exposed to various mineral fibers, and to examine the relationship between ability to induce CL and fiber size. All fiber samples induced the CL response from the cells. The relationship between the number of fibers administered and the CL response was examined on all fiber samples by linear regression. The slope of the regression line supplies an approximation of the ability to induce CL. A strong increased correlation between geometric-mean length of fibers and ability to induce CL was observed for the seven fiber samples more than 6 microns in length (r = 0.9895). Geometric-mean width and the ability to induce CL showed no correlation. However, among the two fiber samples having a similar length distribution (RF2, RF3), the wider width sample (RF3, 2.4 microns) demonstrated lower ability to induce the CL than the narrower width sample (RF2, 1.1 microns). The present method enabled comparison of ability to induce lucigenin-dependent CL from human monocyte-derived macrophages for various mineral fibers with different sizes. Our findings suggested the possibility that ability to induce O2- production increased with fiber length, when fibers are longer than approximately 6 microns.

The prevalence of pleural plaques and/or pulmonary changes among construction workers in Okayama, Japan.

BACKGROUND: Since asbestos has been widely used in Japanese building materials since 1960s, a large number of Japanese construction workers may be exposed to asbestos occupationally. METHODS: Among 2951 construction workers in Okayama, Japan, the prevalence of asbestos-induced pleural or pulmonary changes was examined by screening chest x-rays; these findings were confirmed by computed tomography (CT) scanning of the chest. RESULTS: Among 2951 construction workers, 168 (5.7%) were found to have significant findings for pleural plaque or pulmonary changes on chest x-ray. Seventy-four had both pleural plaque and asbestosis, 85 pleural plaques alone, and 9 asbestosis alone. In 11 subjects, pleural plaques were suggested by chest x-ray, but neither pleural plaque nor asbestosis was demonstrated by chest CT. Honeycombing as one of the characteristic findings of asbestosis was found in 29 subjects. Others showed subpleural spots or curvilinear shadow, which suggested the early stage of asbestosis. The occupations of these workers were carpenters (64), plasterers (27), and concrete board cutters (14). About 30% of the workers with these findings were aware that they were handling asbestos in activities such as installation of asbestos boards, and/or asbestos spraying. CONCLUSIONS: As the incidence of malignant mesothelioma and primary lung cancer associated with asbestos exposure are high, screening by chest CT is necessary for detecting asbestos-induced pulmonary and/or pleural lesions. Education for protection such as telling about the presence of asbestos in building materials is also necessary.

Clinical, pathological and mineralogical features in two autopsy cases of workers exposed to agalmatolite dust.

An agalmatolite miner and processor showed large shadows at the bilateral hila accompanied by surrounding emphysematous changes and irregular shadows on chest X-ray films. Chest CT scans were characterized by a mixture of tiny irregular structures and small round opacities. Histopathological examination revealed massive fibrosis, which corresponded to large shadows, but only a small number of typical silicotic nodules, indicating mixed dust pneumoconiosis. Mineralogical examination of the autopsy lungs showed quartz, pyrophyllite, mica, and kaolinite. Quartz accounted for 70% of the amount of all mineral dust in both patients, but pyrophyllite accounted for 10.8% and 14.4%. The pulmonary mineral dust composition in the two patients was well consistent with the mineral composition of the raw clays in the agalmatolite mine. In the two patients, chest X-ray findings and histopathological findings of the lungs also suggested agalmatolite pneumoconiosis, which was confirmed by mineral analysis of the lungs.

Hepatic tumor rupture following effectual treatment with irinotecan in a patient with highly refractory malignant lymphoma.

We describe a patient with highly refractory malignant lymphoma who died of hepatic tumor rupture following treatment with irinotecan (CPT-11). This 60-year-old man with non-Hodgkin's lymphoma (diffuse large B-cell lymphoma) demonstrated disease recurrence in the liver and the vertebrae following high-dose chemotherapy and autologous hematopoietic stem cell transfusion. He was treated with CPT-11 at a dose of one third of the conventional dose used for non-Hodgkin's lymphoma in Japan. The tumor in the liver markedly decreased in size but then ruptured. Although pathologic hepatic tumor rupture is a rare complication in patients with malignant lymphoma of the liver, this case demonstrates that hepatic tumor rupture may occur in refractory malignant lymphomas that reveal extensive degradation by this new, effective salvage therapy.

A retrospective cohort study of male workers exposed to PVA fibers.

In order to ascertain whether PVA fibers can produce cancer in humans or not, we have conducted a retrospective cohort study of workers exposed to PVA fibers. A total of 447 exposed and 2416 non-exposed male workers who were engaged before 1980 were followed up until the end of 1996. The SMR for all causes was 0.57 (observed 38, 95% CI: 0.41-0.78) for the exposed, and 0.66 (observed 210, 95% CI: 0.58-0.75). As for lung cancer, its SMR was 0.77 (observed 3, 95% CI: 0.15-2.24) for the exposed workers and 0.67 (12 observed, 95% CI: 0.34-1.16) for the non-exposed workers. Lung cancer SMR was 0.86 (observed 2, 95% CI: 0.10-3.11) for the workers with 20 or more years' employment. This study showed no difference in lung cancer risk between the workers exposed to PVA fibers and the non-exposed workers.

Anthophyllite exposure and endemic pleural plaques in Kumamoto, Japan.

OBJECTIVES: This study explored the high prevalence of pleural plaques in the town of Matsubase in Kumamoto, Japan. METHODS: Small-size chest X-ray film was used for screening, and all persons with pleural plaques were confirmed by computed tomography (CT). The prevalence rate of pleural plaques in the 4 districts of Matsubase and its surrounding towns and cities were also examined. The age-adjusted mortality rate for lung cancer in this town was compared with that of its surrounding towns and cities. RESULTS: Pleural plaques were found in 1357 persons (724 men and 633 women) among the inhabitants who were more than 20 years of age in Matsubase between 1988 and 1993. CT scans ascertained 938 cases with pleural plaques among the 11 14 persons who participated. Thus at least 9.5% of the inhabitants over 20 years of age in this town had pleural plaques. The neighboring towns had a higher rate than the more distant towns. A large-scale open-cast asbestos mine and mill had been in operation in Matsubase between 1883 and 1970. Mineral analysis revealed anthophyllite fibers. Most of the plaques were found in persons who had never worked in the mine or mill. CONCLUSIONS: The high prevalence of pleural plaques in Matsubase was due to anthophyllite exposure, mainly environmental. No mesotheliomas were found, however. These findings agree with those from an earlier study from Finland.

Spectroscopic properties of Nd 3 + and Pr 3 + in gallate glasses with low phonon energies.

Absorption and fluorescence spectra of Nd3 +were measured in potassium tantalum gallate, lead bismuth gallate (PBG), fluorozirconate (ZBLAN), and Ge-Ga-S glasses. A Judd -Ofelt analysis was performed to determine the spontaneous emission probability and stimulated emission cross section of the4 F3/2 ?4 I11/2 transition of Nd3 +. Raman spectra were studied to clarify the maximum phonon energies of the glasses. The fluorescence of the1 G4?3 H5 transition of Pr3 + in a dehydrated PBG glass was observed for the first time to our knowledge. The PBG glass has a higher quantum efficiency than that of ZBLAN glass based on the Judd -Ofelt analysis.

[A case report of small cell carcinoma of the esophagus with remarkable response to neoadjuvant chemotherapy].

A 61-year-old male consulted our hospital with complaints of pain in swallowing. The X-ray Barium studies and upper gastrointestinal (UGI) scope revealed an irregular ulcerated lesion in the middle portion of the esophagus. He was diagnosed as having small cell carcinoma of the esophagus by means of biopsy specimens. Three courses of combined chemotherapy with CDDP, etoposide and 5-FU were used before operation. Following the chemotherapy, according to the UGI scope findings, the tumor of the esophagus disappeared. An esophagectomy through a thoracolaparotomy was performed. The chemotherapy resulted in a Grade 2 response, as ascertained by means of pathological findings for the resected specimen. After an additional course of chemotherapy, the patient was discharged from the hospital. Although we performed the curative resection for this patient, extensive recurrences and distant metastasis to the mediastinal lymph nodes and lung were found in less than a year. It is said that this tumor has a poor prognosis, and the one-year survival rate is about 10% following the treatment. It is necessary to combine surgery with effective chemotherapy and irradiation to obtain a good prognosis after resection of small cell carcinoma of the esophagus.