An economic assessment of foot and mouth disease in Japan.

A large-scale foot and mouth disease (FMD) epidemic in Japan in 2010 caused severe economic losses for livestock and related industries. In this paper, the authors develop a clear and usable framework to estimate the economic impact of this FMD outbreak. An economic analysis is then conducted by combining this framework with an epidemiological model. The framework estimates the direct and indirect costs to livestock and related industries by applying an input-output model, as well as by addressing expenditure on disease control. The direct cost to the livestock industry was estimated at 51.2 billion Japanese yen (JPY), engendering an indirect cost to related industries of JPY 25.5 billion. The expenditure for disease control activities was estimated at JPY 8.2 billion. The total impact of the 2010 FMD epidemic was estimated at almost JPY 85 billion. Within the economic analysis, the authors evaluate several control measure scenarios: a baseline scenario, which assumes that the rapid disease spread observed in the early phase of the 2010 FMD epidemic would continue; prompt culling within 24 hours; early detection of the first case; and emergency vaccination within a radius of 10 km around the affected farms in either seven or 28 days. Prompt culling and early detection were superior from an economic point of view, reducing the total economic impact to 30% and 2% of that in the baseline scenario, respectively. Compared with these scenarios, vaccination was less cost effective. However, vaccination suppressed the speed of disease spread and shortened the duration of the epidemic, suggesting its potential effectiveness in curbing rapid disease spread in a densely populated area.

Une épizootie de fièvre aphteuse de grande envergure survenue au Japon en 2010 a entraîné de graves pertes économiques pour la filière de l'élevage et les secteurs connexes. Les auteurs proposent un cadre d'évaluation clair pour estimer l'impact économique de ce foyer de fièvre aphteuse. Ils effectuent ensuite une analyse économique dans laquelle ce cadre d'évaluation est relié à un modèle épidémiologique. Les coûts directs et indirects subis par la filière de l'élevage et par les secteurs connexes sont évalués dans ce cadre en appliquant un modèle entrées­sorties (input­output) et en prenant en compte les dépenses liées à la lutte contre la maladie. Le coût direct de la maladie pour la filière de l'élevage a été estimé à 51,2 milliards de yens japonais, auxquels s'ajoute le coût indirect pour les secteurs connexes estimé à 25,5 milliards de yens japonais. Les dépenses induites par la lutte contre la maladie s'élèvent à 8,2 milliards de yens japonais. L'impact total de l'épizootie de fièvre aphteuse de 2010 est estimé à près de 85 milliards de yens japonais. Dans leur analyse économique, les auteurs ont évalué plusieurs scénarios relatifs aux mesures de lutte appliquées : un scénario de base, qui suppose une propagation de la maladie au même rythme que durant la phase initiale de l'épidémie de 2010 ; l'abattage rapide des animaux en 24 heures ; la détection précoce du premier cas ; l'application de la vaccination d'urgence dans un périmètre de 10 km autour des exploitations affectées et dans un délai de sept ou de 28 jours. Par rapport au scénario de base, l'abattage rapide et la détection précoce sont les meilleurs scénarios du point de vue économique, réduisant l'impact économique total respectivement à 30 % et 2 % de celui du scénario de base. Comparativement à ces scénarios, la vaccination est la solution la moins efficiente économiquement. Néanmoins, la vaccination a freiné la propagation de la maladie et limité la durée de l'épidémie, ce qui laisse penser qu'elle permettrait d'infléchir la courbe de propagation de la maladie dans les zones à forte densité de bétail.

En 2010 se produjo en el Japón una epidemia de fiebre aftosa de grandes proporciones, que causó graves pérdidas económicas a la industria ganadera y demás sectores conexos. Los autores describen un método claro para estimar el impacto económico de dicho brote. Acto seguido, llevan a cabo un análisis económico combinando este método con un modelo epidemiológico. El método permite estimar los costos directos e indirectos que soportan la industria ganadera y demás sectores conexos aplicando un modelo de «insumoproducto ¼ (input­output) y teniendo también en cuenta los gastos ligados al control de la enfermedad. Según los cálculos, el costo directo para la industria ganadera fue de 51 200 millones de yenes japoneses y el costo indirecto para los sectores conexos fue de 25 500 millones de yenes. Se estimó que las actividades de lucha contra la enfermedad supusieron gastos por valor de 8 200 millones. En total, pues, según estas estimaciones, el impacto económico de la epidemia de fiebre aftosa de 2010 se cifra en casi 85 000 millones de yenes. Como parte del análisis económico, los autores evalúan varias hipótesis relativas a las medidas de control: una hipótesis básica, en la cual prosigue sin trabas la veloz propagación de la enfermedad observada en la primera fase de la epidemia de 2010; la rápida implantación, en un plazo de 24 horas, de medidas de sacrificio sanitario; la pronta detección del primer caso; y la vacunación de emergencia dentro de un radio de 10 km alrededor de las explotaciones afectadas, en un plazo de siete días o en un plazo de 28 días. Desde un punto de vista económico, el rápido sacrificio sanitario y la pronta detección ofrecían mejores resultados, pues reducían el impacto económico total hasta un 30% y un 2%, respectivamente, del registrado en la hipótesis básica. En comparación con esas dos hipótesis, la vacunación ofrecía menos eficacia en relación con el costo, aunque frenaba la rápida propagación de la enfermedad y abreviaba la epidemia, de donde se infiere que puede resultar eficaz para contener la rápida dispersión de la enfermedad en áreas densamente pobladas.

Bone morphogenetic protein 7 induces cementogenic differentiation of human periodontal ligament-derived mesenchymal stem cells.

Bone morphogenetic protein 7 (BMP-7) is a multifunctional differentiation factor that belongs to the transforming growth factor superfamily. BMP-7 induces gene expression of protein tyrosine phosphatase-like, member A/cementum attachment protein (PTPLA/CAP) and cementum protein 1 (CEMP1), both of which are markers of cementoblasts and cementocytes. In the previous study, we reported that BMP-7 treatment enhanced PTPLA/CAP and CEMP1 expression in both normal and immortal human periodontal ligament (PDL) cells. To elucidate the molecular mechanisms of the gene expression of these molecules, in this study, we identified a functional transcription activator binding region in the promoter region of PTPLA/CAP and CEMP1 that is responsive to BMP signals. Here, we report that some short motifs termed GC-rich Smad-binding elements (GC-SBEs) that are located in the human PTPLA/CAP promoter and CEMP1 promoter are BMP-7 responsive as analyzed with luciferase promoter assays. On the other hand, we found that transcription of Sp7/Osterix and PTPLA/CAP was up-regulated after 1 week of BMP-7 treatment on purified normal human PDL cells as a result of gene expression microarray analysis. Furthermore, transcription of Sp7/Osterix, runt-related transcription factor 2 (RUNX2), and alkaline phosphatase (ALP) was up-regulated after 2 weeks of BMP-7 treatment, whereas gene expression of osteo/odontogenic markers such as integrin-binding sialoprotein (IBSP), collagen, type I, alpha 1 (COL1A1), dentin matrix acidic phosphoprotein 1 (DMP1), and dentin sialophosphoprotein (DSPP) was not up-regulated in purified normal or immortal human PDL cells as a result of qRT-PCR. The results suggest that BMP-7 mediates cementogenesis via GC-SBEs in human PDL cells and that its molecular mechanism is different from that for osteo/odontogenesis.

Injuries to staff engaged in foot-and-mouth disease eradication in Japan.

BACKGROUND: In April 2010, a large-scale outbreak of foot-and-mouth disease, a highly infectious disease affecting cloven-hoofed animals, was reported in Miyazaki prefecture in Japan. Many staff were dispatched to the epidemic area to undertake containment measures. Various injuries were reported among the dispatched staff. AIMS: To study the characteristics of injuries that occurred during containment measures and to identify the characteristics of those injured. METHODS: We analysed records of injuries that occurred among staff dispatched from national organizations and prefectures other than Miyazaki prefecture. Based on these records, a qualitative analysis was conducted for veterinarians and non-veterinarian support staff as each group played a different role during the outbreak. RESULTS: Forty-seven veterinarians and 183 support staff were injured. The injury risk was significantly higher for support staff (13%) than for veterinarians (5%; P < 0.001). The most frequently reported injury resulted from exposure to disinfectant and the next was abrasions caused by friction from protective clothing and rubber boots. Among veterinarians, needlestick accidents were also frequently reported. CONCLUSIONS: Applying a less hazardous disinfectant and improving protective equipment to prevent skin abrasion may be effective in reducing the risk of these injuries among staff conducting containment measures. Reducing injuries among staff in such circumstances will assist effective control measures.

Development of craniofacial structures in transgenic mice with constitutively active PTH/PTHrP receptor.

Parathyroid hormone (PTH) and parathyroid hormone-related peptide (PTHrP) regulate calcium homeostasis, and PTHrP further regulates growth and development. A transgenic mouse carrying the constitutively active PTH/PTHrP receptor (HKrk-H223R) under the control of the mouse bone and odontoblast-specific alpha1(I) collagen promoter (Col1-caPPR) has been developed to demonstrate the complex actions of this mutant receptor in hard tissue formation. We have further characterized Col1-caPPR mice abnormalities in the craniofacial region as a function of development. Col1-caPPR mice exhibited a delay in embryonic bone formation, followed by expansion of a number of craniofacial bones including the maxilla and mandible, delay in tooth eruption and teratosis, and a disrupted temporomandibular joint (TMJ). These findings suggest that the Col1-caPPR mouse is a useful model for characterization of the downstream effects of the constitutively active receptor during development and growth, and as a model for development of treatments of human diseases with similar characteristics.

Sodium fluoride-induced morphological and neoplastic transformation, chromosome aberrations, sister chromatid exchanges, and unscheduled DNA synthesis in cultured syrian hamster embryo cells.

The effects of exposure of early-passage Syrian hamster embryo cells in culture to sodium fluoride have been studied with respect to induction of morphological and neoplastic transformation, chromosome aberrations, sister chromatid exchanges, and unscheduled DNA synthesis. Exposure of Syrian hamster embryo cells to NaF concentrations between 75 and 125 micrograms/ml for 24 hr caused approximately 90 to 40% cell survival and resulted in a dose-dependent increase in the frequency of morphological transformation of the cells. Mass cultures of cells treated with NaF (75 or 100 micrograms/ml) for 24 hr, followed by continuous cultivation for 35 to 50 passages, developed the ability to grow in soft agar and to produce anaplastic fibrosarcomas when injected into newborn hamsters. In contrast, no morphological and neoplastic transformation was observed in untreated cells. Furthermore, a significant increase in chromosome aberrations at the chromatid level, sister chromatid exchanges, and unscheduled DNA synthesis was induced by NaF in a dose- and time-dependent manner. These results indicate that NaF is genotoxic and capable of inducing neoplastic transformation of Syrian hamster embryo cells in culture. A potential for carcinogenicity of this chemical, which is widely used by humans, is suggested. However, the carcinogenic risk of this chemical to humans may be reduced by factors regulating in vivo dose levels.

Comparison of the computed tomography values of the bone fragment gap after sagittal split ramus osteotomy in mandibular prognathism with and without asymmetry.

The purpose of this study was to compare computed tomography (CT) Hounsfield unit values of bone fragment gaps after sagittal split ramus osteotomy (SSRO) in patients with and without asymmetry, and to evaluate differences between the deviated and non-deviated sides in asymmetric patients. Thirty-two patients who underwent a bilateral SSRO were included in this retrospective study. Patients were divided into symmetric and asymmetric groups by cephalometric analysis. CT values of the bone fragment gap were measured at 1 week and at 1 year after surgery. There were significant differences between CT values obtained at 1 week and at 1 year after surgery for all measurement points. However, there were no significant differences in CT values between symmetric and asymmetric patients at either 1 week or 1 year after surgery. Among asymmetric patients, there were no significant differences between the deviated and non-deviated sides at 1 week or 1 year after surgery. This study showed ossification of the bone fragments and adaptation to change the mandible form in patients with and without asymmetry following SSRO.

Preparation of oligozoospermic and/or asthenozoospermic semen for intrauterine insemination using the SpermPrep semen filtration column.

OBJECTIVE: To improve the quality of oligozoospermic and/or asthenozoospermic semen by the SpermPrep (Fertility Technologies Inc., Natick, MA) semen filtration column. DESIGN: The SpermPrep column was applied for semen manipulation in oligozoospermia and/or asthenozoospermia (sperm count less than 20 x 10(6)/mL, sperm motility less than 40%). After concentration of motile sperm using a 40% Percoll density gradient centrifugation, the sperm suspension was filtered through the SpermPrep column. The percentage yield of motile sperm by the SpermPrep method was compared with those by a two-layer Percoll density gradient (Pharmacia, Uppsala, Sweden) centrifugation and a swim-up method. Infertile couples with poor quality semen were treated with intrauterine insemination (IUI) with motile sperm by the three preparations through three cycles. SETTING: Department of Obstetrics and Gynecology, Osaka University Hospital. PATIENTS: Twenty-one couples with long-standing infertility because of poor quality semen. MAIN OUTCOME MEASURE: Recovery of motile sperm, sperm motility, and outcome of IUI were evaluated among three semen preparations. RESULTS: Motility was improved by the SpermPrep method in 32 of 33 cases of oligozoospermia and/or asthenozoospermia. Percentage yield of motile sperm by the SpermPrep method was significantly greater than those by the two-layer Percoll density gradient and swim-up methods (42.7 +/- 4.6 versus 22.1 +/- 3.1 and 13.8 +/- 3.5), but there is no significant difference in the sperm motility among three semen preparations. After one treatment cycle for each preparation, 2 of 21 women conceived after IUI with motile sperm separated in the SpermPrep method. CONCLUSIONS: The SpermPrep method is an improved semen manipulation method for oligozoospermia and/or asthenozoospermia.

Comparison of stem-cell-mediated osteogenesis and dentinogenesis.

The difference between stem-cell-mediated bone and dentin regeneration is not yet well-understood. Here we use an in vivo stem cell transplantation system to investigate differential regulation mechanisms of bone marrow stromal stem cells (BMSSCs) and dental pulp stem cells (DPSCs). Elevated expression of basic fibroblast growth factor (bFGF) and matrix metalloproteinase 9 (MMP-9, gelatinase B) was found to be associated with the formation of hematopoietic marrow in BMSSC transplants, but not in the connective tissue of DPSC transplants. The expression of dentin sialoprotein (DSP) specifically marked dentin synthesis in DPSC transplants. Moreover, DPSCs were found to be able to generate reparative dentin-like tissue on the surface of human dentin in vivo. This study provided direct evidence to suggest that osteogenesis and dentinogenesis mediated by BMSSCs and DPSCs, respectively, may be regulated by distinct mechanisms, leading to the different organization of the mineralized and non-mineralized tissues.

The Dentin matrix protein 1 (Dmp1) is specifically expressed in mineralized, but not soft, tissues during development.

Dentin Matrix Protein 1 (Dmp1) was originally identified from dentin. However, its expression and function in vivo are not clear. To clarify these two issues, we have generated mice carrying a truncated Dmp1 gene by using gene targeting to replace exon 6 with a lacZ gene. Northern blot analysis shows the expected 5.8-kb Dmp1-lacZ fusion transcript and loss of the wild-type 2.8-kb Dmp1 transcript, confirmed by a lack of immunostaining for the protein. Using heterozygous animals, we demonstrate that Dmp1 is specific for mineralized tissues. Not previously shown, Dmp1 is also expressed in pulp cells. Dmp1-deficient embryos and newborns display no apparent gross abnormal phenotype, although there are a modest expansion of the hypertrophic chondrocyte zone and a modest increase in the long bone diameter. This suggests that DMP1 is not essential for early mouse skeletal or dental development.

Cell cycle dependence of cytotoxicity and clastogenicity induced by treatment of synchronized human diploid fibroblasts with sodium fluoride.

To study the cell cycle dependence of cytotoxicity and clastogenicity of sodium fluoride (NaF), synchronized human diploid fibroblasts were treated with NaF during different phases of the cell cycle and analyzed. Exponentially growing cells were synchronized by the following two procedures. (1) The cells were synchronized at G0/G1 phase by a period of growth in medium containing 1% serum (low serum medium). (2) The cells were synchronized at the G1/S boundary by growth in low serum medium, followed by hydroxyurea treatment (Tsutsui et al., 1984a). Synchronized cells were treated with NaF for 3 h during the G1 phase or G2 phase, and for each of three 3-h periods during the S phase which lasted 9 h. Cytotoxicity, as determined by a decrease in colony-forming ability, was dependent upon the phase of the cell cycle during which NaF treatment was administered. The highest lethality was induced in cultures treated with NaF during the first 3 h of S phase (early S phase). Moderate lethality was observed when the cultures were treated with NaF during the second or third 3 h of S phase (middle or late S phase, respectively), or G2 phase. Little lethality was observed in cultures in G1 phase. Inducibility of chromosome aberrations of the cells following treatment with NaF was also dependent upon the phase of the cell cycle. A significant increase in the incidence of chromosome aberrations was observed only in cultures treated with NaF during early and/or middle S phases of cell cycle. These results suggest that cytotoxicity and clastogenicity of NaF to cultured human diploid fibroblasts are cell cycle dependent, and that the cells in early and middle S phases are more sensitive to the effects.

Clastogenic activity of sodium fluoride to rat vertebral body-derived cells in culture.

The US National Toxicology Program has shown equivocal evidence of carcinogenic activity of sodium fluoride (NaF) in male F344/N rats based on the occurrence of five osteosarcomas in treated animals. In the study the osteosarcomas developed mainly in the rat vertebrae. To provide a possible mechanistic basis for the observed tumors, the genotoxic effects of NaF on the possible target organ of NaF carcinogenesis were examined. Rat vertebral body-derived (RVBd) cells were established from trabecular bone of vertebral bodies of a male F344/N rat 6 weeks of age and treated with NaF. RVBd cells in secondary culture exhibited a high level of alkaline phosphatase (ALP) activity when the cells at confluence were assayed by ALP staining. When the histochemical examination was performed on RVBd cell colonies, most of the colonies were stained positively for ALP. Confluent RVBd cells were responsive to 10(-8) M 1 alpha.25-dihydroxyvitamin D3 with a 7.7-fold increase in osteocalcin production over base line values. The von Kossa staining demonstrated that in the presence of 2 mM beta-glycerophosphate, RVBd cells that were allowed to grow past confluence for approximately 2 months formed mineralized nodules. When RVBd cells in tertiary culture were treated with NaF at 0.5-2.0 mM for 24-72 h, the growth and/or survival of the treated cells was reduced in a dose-dependent manner. Significant increases in the frequencies of chromosome aberrations were induced in a dose- and treatment time-dependent fashion when NaF was administered to RVBd cells at 0.5 and 1.0 mM for 24 and 48 h. The results indicate that NaF is genotoxic to rat vertebrae, providing a possible mechanism for the vertebrae, as a target organ of NaF carcinogenesis.

Induction of unscheduled DNA synthesis in cultured human oral keratinocytes by sodium fluoride.

The effect of treatment of cultured human oral keratinocytes with sodium fluoride (NaF) has been investigated with respect to induction of unscheduled DNA synthesis (UDS). Oral keratinocytes were isolated from excised buccal mucosa of normal individuals by trypsinization at 4 degrees C overnight, followed by separation of the epithelium of mucosa from lamina propria mucosae with forceps. Isolated cells were cultured in vitro and all experiments were performed with secondary cultures. For detection of UDS, the keratinocytes were cultivated with medium containing 1% fetal calf serum (FCS) for 2 days and then treated with 100-300 micrograms/ml NaF for 4 h in medium containing 1% FCS and 10 mM hydroxyurea (1% FCS-HU medium). Following treatment with NaF, UDS was measured by direct scintillation counting of [3H]thymidine incorporated into DNA of the cells in 1% FCS-HU medium. Significant levels of UDS were induced in a dose-related fashion by NaF treatment. The results suggest that NaF causes DNA damage in cultured human oral keratinocytes.

Cytotoxicity, chromosome aberrations and unscheduled DNA synthesis in cultured human diploid fibroblasts induced by sodium fluoride.

The effects of exposure of cultured human diploid fibroblasts (JHU-1 cells) to sodium fluoride have been studied with respect to cytotoxicity and induction of chromosome aberrations and unscheduled DNA synthesis (UDS) Cytotoxicity of NaF on JHU-1 cells, as determined by a decrease in colony-forming ability, linearly increased with increasing dose of NaF (50-150 micrograms/ml) or exposure time (1-24 h). Treatment of the cells with 50 micrograms/ml NaF for 24 h resulted in a lethality (approximately 70%) similar to that obtained with 100 micrograms/ml for 12 h. A linear increase in cytotoxicity was observed as a fraction of the product of NaF treatment time and dose. JHU-1 cells treated with 20-50 micrograms/ml NaF for 12 or 24 h were analyzed for chromosome aberrations. A significant increase in the frequency of chromosome aberrations at the chromatid level was observed in treated cells in a dose-dependent manner. For detection of UDS, confluent JHU-1 cells were cultured with medium containing low serum and then exposed to NaF in the presence of 10 mM hydroxyurea. Treatment with 100-400 micrograms NaF/ml for 4-24 h reproducibly elicited UDS in a dose-related fashion as determined by direct scintillation counting of [3H]thymidine incorporated into DNA during repair synthesis. These results suggest that NaF causes DNA damage in human diploid fibroblasts in culture.

No increases in chromosome aberrations in human diploid fibroblasts following exposure to low concentrations of sodium fluoride for long times.

To study whether exposure to fluoride at low concentrations for long times induces chromosome aberrations in human cells, human diploid fibroblasts in the quiescent phase were treated with sodium fluoride (NaF) at 1-10 micrograms/ml (equivalent to fluoride ion at 0.45-4.5 ppm) for 1-3 weeks. Quiescent cells were obtained by a 10-day culture in medium containing 1% serum following overnight incubation of cells in the logarithmic phase. Significant levels of cytotoxicity, as determined by a decrease in the number of cells, were not induced by treatment of the cells with NaF at 5 or 10 micrograms/ml for 1-3 weeks. No increase in the frequency of chromosome aberrations was elicited in cultures treated for 1-3 weeks with NaF over the range of doses examined. In contrast, a dose-dependent increase in the frequency of chromosome aberrations was observed in cultures treated with N-methyl-N'-nitro-N-nitrosoguanidine, used as a positive control. The results indicate that fluoride might be not clastogenic to human fibroblasts when exposed at low levels, equivalent to those in the communal water supplies.

Quantitative comparison of cytotoxicity of dental antiseptics to normal human oral keratinocytes in vitro.

The cytotoxicities of antiseptics used in dentistry were examined with normal human keratinocytes from the oral cavity by the uptake of neutral red (NR assay). The NR assay is a quantitative in vitro assay that distinguishes between viable, damaged or dead cells. Cultures from different individuals were established, and secondary cultures in serum-free medium were used. The amount of NR extracted from cells after a 3-hr uptake of the dye was linearly proportional to the number of cells exposed to the dye. The cytotoxicity of antiseptics used on mucous membranes in the oral cavity was determined from the dose-response curves of inhibition of NR uptake in cells treated with antiseptics for 2 days. As a quantitative measure of cytotoxicity, NR(50) (i.e. the concentration of antiseptics that resulted in a 50% decrease in NR uptake relative to untreated controls) was extrapolated from dose-response curves. The rank-order of cytotoxicities (NR(50)) was Hyamine (10% benzethonium chloride solution) > Hibitane (5% chlorhexidine gluconate solution) > acrinol (0.2% acrinol solution) > Iodine Carbol (liquefied phenol with 3% iodine) > iodine glycerin (glycerin with 10% iodine) > dilute iodine tincture (3% iodine solution) approximately iodine tincture (6% iodine solution) approximately Isodine (10% povidone-iodine solution) > Oxydol (3% hydrogen peroxide solution). These results provide useful estimates of relative toxicities of antiseptics to human cells, which can be compared with antimicro-organism activity to maximize therapeutic benefit with minimal toxicity.

In vitro cytotoxicity of diverse preparations used in dental practice to human gingival keratinocytes.

The cytotoxicities of diverse preparations used for dental practice were examined with normal human keratinocytes from gingival tissues by the uptake of neutral red (NR assay). Cultures from different individuals were established, and secondary cultures in serum-free medium were used. The cytotoxicities to cells treated for 2 days with gargles, mouthwashes, gingival massages, fluoride preparations, dentifrices and local anaesthetics were determined from the dose-response curves of inhibition of NR uptake. As a quantitative measure of cytotoxicity, NR(50) (the concentration of the preparations that resulted in a 50% decrease in NR uptake relative to untreated controls) was interpolated from dose-response curves. Dentifrices examined showed cytotoxicity similar to gingival massages but were more cytotoxic than any fluoride preparations, local anaesthetics, and most gargles and mouthwashes. The cytotoxicities of dentifrices were at least 6.5-fold those of fluoride preparations and 7.9-fold those of local anaesthetics. The results provide useful estimates of relative toxicities of dental preparations to human oral mucosa and are useful as a standard for cytotoxic assessment of newly developed preparations for dental use.

A stochastic-modeling evaluation of the foot-and-mouth-disease survey conducted after the outbreak in Miyazaki, Japan in 2000.

When foot-and-mouth-disease (FMD) was identified in Miyazaki prefecture in March 2000, Japan conducted an intensive serological and clinical survey in the areas surrounding the index herd. As a result of the survey during the 21 days of the movement-restriction period, two infected herds were detected and destroyed; there were no other cases in the months that followed. To evaluate the survey used for screening the disease-control area and surveillance area, we estimated the herd-level sensitivity of the survey (HSe) through a spreadsheet model using Monte-Carlo methods. The Reed-Frost model was incorporated to simulate the spread of FMD within an infected herd. In the simulations, 4, 8 and 12 effective-contact scenarios during the 5-day period were examined. The estimated HSes of serological tests (HSeE) were 71.0, 75.3 and 76.3% under the 4, 8 and 12 contact scenarios, respectively. The sensitivity analysis showed that increasing the number of contacts beyond 12 did not improve HSeE, but increasing the number of sampled animals and delaying the dates of sampling did raise HSeEs. Small herd size in the outbreak area (>80% of herds have <20 animals) seems to have helped in maintaining HSeE relatively high, although the serological inspection was carried out before sero-positive animals had a chance to increase in infected herds. The estimated herd-level specificity of serological tests (HSpE) was 98.6%. This HSpE predicted 224 false-positive herds (5th percentile estimate was 200 and 95th percentile was 249), which proved close to the 232 false-positive herds actually observed. The combined-test herd-level sensitivity (serological and clinical inspections combined; CTHSe), averaged 85.5, 87.6 and 88.1% for the 4, 8 and 12 contact scenarios, respectively. Using these CTHSes, the calculated probability that no infected herd was overlooked by the survey was > or =62.5% under the most-conservative, four-contact scenario. The probability that no more than one infected herd was overlooked was > or =89.7%.

[Tuberculosis sequelae: pathophysiological aspect (ventilation)].

The percentage of the patients with PaCO2 more than 60 Torr and PaO2 more than 50 Torr were 13% in the patients with tuberculosis sequela (N = 502) and 4% in the patients with chronic obstructive lung disease (COLD, N = 727), who were treated with home oxygen therapy in the western region of Japan. Patients with chronic respiratory failure caused by tuberculosis sequela have higher PaCO2 than patients with COLD. Although the prognosis of patients with hypercapnia and moderate hypoxemia is not necessarily poor, some patients may need treatment for severe hypoventilation to prevent respiratory muscle fatigue and abnormal breathing during sleep. In this study, nine patients with hypercapnic chronic respiratory failure caused by tuberculosis sequela were ventilated by Chest Negative Pressure Ventilation (CNPV). The patients were monitored as in polysomnography by transcutaneous PCO2 (PtcCO2) electrode and Respiratory Inductance Plethysmography (RIP). Tidal volume induced by CNPV was larger during mouth breathing (504 +/- 128 ml, mean +/- s.d.) than during nose breathing (438 +/- 109 ml) calculated from RIP in awake state (N = 7). Oxygen saturation measured by ear oximeter and PtcCO2 were 94.4 +/- 2.9% and 57.8 +/- 12.2 Torr in awake state. Following CNPV SaO2 and PtcCO2 were 95.7 +/- 3.0%, 42.7 +/- 12.1 Torr in awake state (N = 9) and 93.0 +/- 4.4%, 57.0 +/- 15.7 Torr in Non-REM sleep (N = 5), respectively. CNPV is effective in these patients in awake state. During Non-REM sleep, CNPV maintains the PtcCO2 level only in awake state.

[Experimental reconstruction of the urinary bladder using atelocollagen sponge].

An experimental reconstruction of the urinary bladder using specially designed bovine cross linked atelocollagen sponge was performed after partial cystectomy in 12 male rabbits. Bladder reconstruction with hybrid type biomaterials using both atelocollage sponge and cultured autologous cells were performed in 5 rabbits (the 1st group). The autologous cells were collected from the mucosa and muscular layer of the urinary bladder and were seeded on the atelocollagen sponge before reconstruction. Reconstruction using atelocollagen sponge without autologous cells were performed in the other 7 rabbits (the 2nd group). In 9 of these 12 rabbits, atelocollagen sponge was successfully implanted in the native urinary bladder. Histopathological findings revealed that seeded autologous cells and growth of surrounding host cells could be seen similarly in the atelocollagen sponge but these could not be differentiated by these could not be differentiated by routine histopathological techniques. In conclusion, these results showed a possibility of construction of artificial urinary tract using both atelocollagen sponge and autologous cells.

[The effect of intra-urethral catheter for prostatic hypertrophy patients who are unfit for operation and suffer from urinary retention].

The effect of double Malecot type polyurethane intraurethral catheter (IUC) was examined in 17 benign prostatic hypertrophy patients who were unfit for operation and suffered from urinary retention. Patients were aged 68 to 90 (mean 80.5) years old and the causes of IUC insertion were cardiac, cerebrovascular, respiratory and gastrointestinal diseases, diabetes mellitus and aging. IUC was selected among three types (55, 60, 65 mm) according to the length of prostatic urethra. Insertion of IUC was carried out easily under fluoroscopic guidance without endoscopy. All patients could void by themselves just after insertion of IUC and the longest indwelling period was 10 months. The length of IUC need not be longer than that of prostatic urethra and patients with normal or hypertonic bladder could void better than those with atonic bladder. Urinary tract infection did not get worse in any patients with indwelling IUC. Double Malecot type polyurethane IUC is a safe and an effective alternative method in place of urethral balloon catheter for inoperable prostatic hypertrophy patients in urinary retention.