Production of three-dimensional tissue-engineered cartilage through mutual fusion of chondrocyte pellets.

In this study, the mutual fusion of chondrocyte pellets was promoted in order to produce large-sized tissue-engineered cartilage with a three-dimensional (3D) shape. Five pellets of human auricular chondrocytes were first prepared, which were then incubated in an agarose mold. After 3 weeks of culture in matrix production-promoting medium under 5.78g/cm(2) compression, the tissue-engineered cartilage showed a sufficient mechanical strength. To confirm the usefulness of these methods, a transplantation experiment was performed using beagles. Tissue-engineered cartilage prepared with 50 pellets of beagle chondrocytes was transplanted subcutaneously into the cell-donor dog for 2 months. The tissue-engineered cartilage of the beagles maintained a rod-like shape, even after harvest. Histology showed fair cartilage regeneration. Furthermore, 20 pellets were made and placed on a beta-tricalcium phosphate prism, and this was then incubated within the agarose mold for 3 weeks. The construct was transplanted into a bone/cartilage defect in the cell-donor beagle. After 2 months, bone and cartilage regeneration was identified on micro-computed tomography and magnetic resonance imaging. This approach involving the fusion of small pellets into a large structure enabled the production of 3D tissue-engineered cartilage that was close to physiological cartilage tissue in property, without conventional polyper scaffolds.

Tumor promotion by 12-O-tetradecanoylphorbol-13-acetate in an ultra-short-term skin carcinogenesis bioassay using rasH2 mice.

Assessment of the skin tumor-promoting potential of 12-O-tetradecanoylphorbol-13-acetate (TPA) after initiation with 7,12-dimethylbenz[a]anthracene (DMBA) was conducted using rasH2 transgenic (Tg) mice and their nontransgenic (non-Tg) littermates. Mice were treated with DMBA (50 µg/100 µL acetone) on clipped back skin at the commencement of the study, and 1 week thereafter, TPA was applied at 8 µg/200 µL or 4 µg/200 µL acetone, once or twice weekly, for 7 weeks. Skin nodules were observed in the rasH2 Tg mice from week 4, and the incidence reached 100% at weeks 5 and 6. The number of skin nodules (multiplicity) in the 8-µg twice-weekly, 8-µg once-weekly, 4-µg twice-weekly, and 4-µg once-weekly groups was 62.4, 46.2, 62.6, and 36.9, respectively. The non-Tg mice also developed skin nodules, but the sensitivity to induction in the rasH2 Tg mice was higher. No nodules were observed in the acetone groups, but single nodules were apparent in the no-treatment rasH2 Tg and non-Tg groups. In conclusion, skin promotion effects could be detected within only 8 weeks in the rasH2 mice, and the concentration of 4 µg TPA once weekly was sufficient as a positive control. This short-term skin carcinogenesis bioassay using rasH2 mice could represent a useful tool for the assessment of drug and chemical safety with cutaneous treatment.

Correlation between apparent diffusion coefficient and viscoelasticity of articular cartilage in a porcine model.

OBJECTIVE: Quantitative MR imaging techniques of degenerative cartilage have been reported as useful indicators of degenerative changes in cartilage extracellular matrix, which consists of proteoglycans, collagen, non-collagenous proteins, and water. Apparent diffusion coefficient (ADC) mapping of cartilage has been shown to correlate mainly with the water content of the cartilage. As the water content of the cartilage in turn correlates with its viscoelasticity, which directly affects the mechanical strength of articular cartilage, ADC can serve as a potentially useful indicator of the mechanical strength of cartilage. The aim of this study was to investigate the correlation between ADC and viscoelasticity as measured by indentation testing. MATERIALS AND METHODS: Fresh porcine knee joints (n = 20, age 6 months) were obtained from a local abattoir. ADC of porcine knee cartilage was measured using a 3-Tesla MRI. Indentation testing was performed on an electromechanical precision-controlled system, and viscosity coefficient and relaxation time were measured as additional indicators of the viscoelasticity of cartilage. The relationship between ADC and viscosity coefficient as well as that between ADC and relaxation time were assessed. RESULTS: ADC was correlated with relaxation time and viscosity coefficient (R(2) = 0.75 and 0.69, respectively, p < 0.01). The mean relaxation time values in the weight-bearing and non-weight-bearing regions were 0.61 ± 0.17 ms and 0.14 ± 0.08 ms, respectively. CONCLUSIONS: This study found a moderate correlation between ADC and viscoelasticity in the superficial articular cartilage. Both molecular diffusion and viscoelasticity were higher in weight bearing than non-weight-bearing articular cartilage areas.

SS-MIX: a ministry project to promote standardized healthcare information exchange.

OBJECTIVES: To promote healthcare information exchange between providers and to allow hospital information systems (HIS) export information in standardized format (HL7 and DICOM) in an environment of wide-spread legacy systems, which only can export data in proprietary format. METHODS: Through the Shizuoka prefecture EMR project in 2004-2005, followed by the ministry's SS-MIX project, many software products have been provided, which consist of 1) a standardized storage to receive HL7 v2.5 messages of patient demographics, prescription orders, laboratory results, and diagnostic disease in ICD-10, 2) a referral letter creation system, 3) a formatted document creation system, 4) a progress note/nursing record system, and 5) an archive/viewer to incorporate incoming healthcare data CD and allow users to view on HIS terminal. Meanwhile, other useful applications have been produced, such as adverse event reporting and clinical information retrieval. To achieve the above-mentioned objectives, these software products were created and propagated, because users can use these software products, provided that their HIS can export the above information to the standardized storage in HL7 v2.5 format. RESULTS: In 20 hospitals of Japan, the standardized storage has been installed and some applications have been used. As major HIS vendors are shipping HIS with HL7 export function since 2007, HIS of 594 hospitals in Japan became capable of exporting data in HL7 v2.5 format (as of March 2010). CONCLUSIONS: In high CPOE installation rate (85% in 400+ bed hospitals), though most of them only capable of exporting data in proprietary format, prefecture and ministry projects were effective to promote healthcare information exchange between providers. The standardized storage became an infrastructure for many useful applications, and many hospitals started using them. Ministry designation of proposed healthcare standards was effective so as to allow vendors to conform their products, and users to install them.

High speed clinical data retrieval system with event time sequence feature: with 10 years of clinical data of Hamamatsu University Hospital CPOE.

OBJECTIVES: This paper illustrates a high speed clinical data retrieving system, from 10 years of data of operating hospital information system for the purposes of research, evidence creation, patient safety, etc., even incorporating time sequence of causal relations. METHODS: Total of 73,709,298 records of 10 years at Hamamatsu University Hospital (as of June 2008) are sent from HIS to retrieval system in HL7 v2.5 format. Hierarchical variable length database is used to install them. RESULTS: A search for "listing patients who were prescribed Pravastatin (Mevalotin and generic drugs, any titer)" took 1.92 seconds. "Pravastatin (any) prescribed and recorded AST >150 within two weeks" took 112.22 seconds. Searching conditions can be set to be more complex, connected by Boolean operator and/or. This system called D*D is in operation at Hamamatsu University Hospital since August 2002. It is used for 48,518 times (monthly average of 703 searches). Neither searching, nor background export of data from HIS caused delay of routine operating CPOE. CONCLUSIONS: Search database outside of routine operating CPOE, with daily export of order data in HL7 v2.5 format, is proved to provide excellent search environment without causing trouble. Hierarchical representation gives high-speed search response, especially with time sequence of events.

Fat-saturated diffusion-weighted imaging of the rat pelvis using three-dimensional MP-RAGE MR sequence.

In this work we report on the development of a novel technique for fat-saturated three-dimensional (3D) diffusion-weighted (DW) MRI sequence based upon 3D magnetization-prepared rapid gradient-echo (3D-MP-RAGE). In order to saturate fat, two kinds of procedures were competed CHESS-DW-3D-MP-RAGE sequence (CHESS-3D-DWI) and DW-3D-MP-WE-RAGE sequence (WE-3D-DWI) "chemical shift selective: CHESS method vs. water-excitation: WE method". The CHESS-3D-DWI sequence and WE-3D-DWI sequence were compared in terms of their degree of fat suppression. In CHESS-3D-DWI sequence a preparation phase with a "CHESS-90 degrees RF-motion probing gradient: MPG-180 degrees RF-MPG-90 degrees RF" pulse-train was used to sensitize the magnetization to fat-saturated diffusion. In contrast, WE-3D-DWI sequence a RAGE-excitation pulse with a "binominal-pulse 1-1 or 1-2-1" was selected to water-excited (fat-saturated) diffusion imaging. These imaging were done during in vivo studies using an animal experiment. From experimental results obtained with a phantom, the effect of diffusion weighting and the effect of fat-saturation were confirmed. Fat-saturation was much better in the WE-3D-DWI sequence than CHESS-3D-DWI sequence. From rat experimental results, fat-saturated diffusion-weighted image data were obtained. This sequence was useful for in vivo imaging.

Large-scale biological monitoring in Japan.

Data from the large-scale biological monitoring program in Japan were assembled and analyzed and the following results were obtained. All workers handling lead and eight kinds of major organic solvents received physical examinations and biological monitoring at the same time. Therefore, the number of workers handling industrial chemicals and that received physical examinations and the number of workers been examined by biological monitorings were similar to each other. The total number of cases examined from 1989 to 1994 was about 661,000 for lead in the blood and about 4,173,000 for the urinary metabolites of eight organic solvents. The results were classified into three categories and category 3 consists of workers having exposure concentrations above the 1988-1989 biological exposure indices of the ACGIH with the exception of lead concentration in the blood where the limit in Japan was set at 40 micrograms/100 ml. The percentage of exposed workers in category 3 was 1.4% for blood lead and 0.2-2.4% for the urinary metabolites of the eight organic solvents. The percentage of exposed workers in category 3 for blood lead, delta-aminolevulinic acid, urinary mandelic acid, N-methylformamide and 2,5-hexanedione in the urine has decreased with time. In ambient monitoring, the percentage of workplaces in classification 3 for lead and styrene also has decreased with time.