Evaluation of Various Polishing Systems for Lithium Disilicate Glass-Ceramics.

OBJECTIVE: The aim of this study was to investigate the surface roughness of lithium disilicates (LS2s) polished using various polishing systems. MATERIALS AND METHODS: Two types of LS2 (A, Amber Mill and E, IPS e.max CAD) were polished using LS2-specific polishing systems (L-Edenta, L-Jota), a zirconia-specific polishing system (Z-Jota), and a conventional ceramic polishing system (P-Shofu) (n = 8 per group). The compositions of different polishing systems were analyzed using EDS. Surface roughness was measured using confocal laser scanning microscopy and analyzed using EDS and SEM. ANOVA and Tukey's tests were used for the statistical analyses (p = 0.05). RESULTS: The polishing systems were mainly composed of C, O, and Si. The L-Jota group exhibited rougher surfaces than the other groups. Amber Mill exhibited higher surface roughness than IPS e.max CAD (p⟨0.001). Among the polishing systems, the L-Jota group presented the highest roughness value (pp⟨0.001). The surface roughness of the AL-Jota group was higher than that of the other groups. CONCLUSIONS: A sufficiently smooth surface can be achieved without a LS2-specific polishing system. Further, the same polishing system can have different effects depending on the type of LS2.

Factors affecting quality of life in patients with vitiligo: a nationwide study.

BACKGROUND: Little is known about factors affecting the quality of life (QoL) of patients with vitiligo, and previous studies have shown conflicting results. OBJECTIVES: To explore the QoL of patients with vitiligo and to identify factors affecting QoL. METHODS: A nationwide questionnaire-based study was conducted with 1123 patients with vitiligo recruited from 21 hospitals in Korea from July 2015 to June 2016. Data were collected using a structured questionnaire for demographic information and the Skindex-29 instrument. Mild or severely impaired QoL in patients with vitiligo was assessed according to each domain (symptoms, functioning and emotions) of Skindex-29. Multivariate logistic regression analyses were performed to determine the factors associated with QoL. RESULTS: Of the enrolled participants, 609 were male and 514 female, with a mean age of 49·8 years (range 20-84). The median duration of disease was 3·0 years (range 0-60). Using multivariate logistic regression modelling, the involvement of visible body parts and a larger affected body surface area were consistently associated with QoL impairment in all three domains of Skindex-29. Additionally, the QoL of patients aged 20-59 years, who potentially had a more active social life than older patients, was associated with functional impairment. Furthermore, a higher educational background was associated with emotional impairment. CONCLUSIONS: A multitude of factors significantly influence the QoL of patients with vitiligo. A better appreciation of these factors would help the management of these patients.

The relationship between clinical characteristics including presence of exposed lesions and health-related quality of life (HRQoL) in patients with psoriasis: analysis from the nationwide epidemiologic study for psoriasis in Korea (EPI-PSODE study).

BACKGROUND: Psychological aspect and quality of life should be considered in treating patients with psoriasis. OBJECTIVE: We sought to ascertain which clinical characteristics including presence of exposed lesions are associated with impairment of health-related quality of life (HRQoL) in patients with psoriasis. METHODS: The EPI-PSODE study was a nationwide, multicenter, cross-sectional study conducted in Korea that included 1260 adult patients with psoriasis. In addition to clinical characteristics including presence of exposed lesions, data were collected using the Psoriatic Arthritis (PsA) Screening and Evaluation (PASE), Dermatology Life Quality Index (DLQI), MOS 36-Item Short-Form Health Survey (SF-36), Work Productivity and Activity Impairment Questionnaire Psoriasis (WPAI: PSO) and Medication Satisfaction Questionnaire (MSQ). RESULTS: Patients with a DLQI score > 5 (n = 990) were younger, had an earlier onset of psoriasis, scored higher on the Psoriasis Area and Severity Index (PASI), had higher body surface area (BSA) and had higher PASE scores than patients with DLQI ≤ 5 (n = 266). The group of patients with exposed lesions (n = 871) were younger and male predominance, earlier onset of psoriasis, longer disease duration, higher PASI/BSA score and a higher proportion with drinking and smoking history each than the group of patients without exposed lesions (n = 389). Presence of exposed lesions negatively influenced DLQI, 36-Item Short-Form Health Survey (SF-36) (mental component), presenteeism, total work productivity impairment and total activity impairment in the WPAI: PSO. In multiple regression model, PASI score was the only variable which was significantly associated with all HRQoL measures. Presence of exposed lesions was a significant factor affecting DLQI and SF-36 (mental). CONCLUSION: The presence of exposed lesions has a negative impact on quality of life, mental health and work productivity. Therefore, effective treatments are particularly needed for psoriasis patients with exposed lesions.

Full-genome sequence analysis of an uncommon norovirus genotype, GII.21, from South Korea.

Noroviruses (NoVs) are major causal agents of acute gastroenteritis in humans. NoV GII.4 is the predominant genotype globally. However, uncommon and minor types of NoVs are consistently detected and some have been shown to dominate over GII.4. Therefore, the prevalence of dominant and uncommon NoVs makes the identification of these viruses important for the prediction and prevention of pandemics. In this study, the full-genome sequence of a NoV (strain JW) detected in Korea was extensively characterized. The full-length genome was 7510 nucleotides long, and phylogenetic analysis based on the whole-genome sequences, including open reading frame (ORF)1, ORF2, and ORF3, indicated that it belonged to the GII.21 genotype. Strain JW showed maximum identity with strain YO284; however, comparison of the amino acid sequence of ORF2, which functions as an antigen, showed substitutions in several amino acids. GII.21 is not a prevalent epidemiological agent of acute gastroenteritis in humans, but it is consistently found in gastroenteritis patients from several countries. The present study provides the first full-genome sequence analysis of NoV GII.21 isolated from a patient in Korea. Our findings provide not only valuable genome information but also data for epidemiology studies, epidemic prevention, and vaccine development strategies.

Optimal maintenance treatment with calcipotriol/betamethasone dipropionate gel in Korean patients with psoriasis vulgaris: a multicentre randomized, controlled clinical trial.

BACKGROUND: There is a lack of response data for topical treatments for psoriasis vulgaris in Asian patients. OBJECTIVES: To determine the optimal maintenance regimen for topical treatment with calcipotriol monohydrate/betamethasone dipropionate gel in Korean patients with psoriasis vulgaris, by comparing the efficacy of three 8-week maintenance regimens. METHODS: This was a multicentre, prospective, randomized, controlled, parallel-group, open-label, phase 4 clinical trial, conducted in South Korea. Patients with psoriasis vulgaris on the limbs/trunk received once-daily treatment with calcipotriol monohydrate (50 µg/g)/betamethasone dipropionate (500 µg/g) gel for 8 weeks (induction phase). Responders (defined as an Investigator's Global Assessment of Disease Severity (IGA) grade of 'clear' or 'almost clear') were then randomized to receive 8 weeks' maintenance treatment with Xamiol® gel once daily as needed [pro re nata (PRN Group)], once daily every day (Continuous group), or twice weekly - on Saturday and Sunday (Weekend group). The primary endpoint was the percentage of IGA responders at week 16. RESULTS: At the end of the induction phase, 62.18% of patients were IGA responders. At the end of the maintenance phase (week 16), the responder rate was 63.89% for the PRN group, 67.5% for the Continuous group and 31.43% for the Weekend group. The PRN and Continuous groups were statistically superior to the Weekend group (P = 0.0109 and P = 0.0015), but the PRN and Continuous groups did not differ statistically. The incidence of adverse events did not differ significantly between the groups. CONCLUSION: Among Korean patients with psoriasis vulgaris, maintenance treatment with calcipotriol monohydrate/betamethasone dipropionate using a continuous daily regimen or an 'as needed' daily regimen provided similar efficacy, whereas a twice-weekly regimen was significantly less efficacious than either of these regimens.

Involvement of T cells in early evolving segmental vitiligo.

Recent studies have suggested an overlapping autoimmune mechanism between segmental vitiligo (SV) and nonsegmental vitiligo (NSV). Although T-cell infiltration is observed in the margins of active lesions in NSV, the histopathological characteristics of the active margin of SV are not well known. To determine if T-cell inflammatory responses are present in the active margin of SV lesions, biopsies were taken from the active margin of a lesion in 12 patients with early or actively spreading SV and compared with a normal control sample (on the symmetrical, opposite site of the same dermatome). The samples were stained for CD4, CD8, CD25 and interferon-γ. Lymphocytic infiltration was seen in 70% of patients. CD4+ T cells infiltrated the dermis, while CD8+ T cells were present in the epidermis or attached to the basal layer. The increase in the number of CD8+ T cells was significant (P < 0.04), while CD4+ or CD25+ T cells also appeared to be increased in number, but this was not significant. These results suggest that SV also has an autoimmune mechanism in the early evolving stage.

Characteristics of primary cutaneous lymphoma according to WHO-EORTC classification in Korea.

BACKGROUND: Primary cutaneous lymphoma (PCL) is an extranodal non-Hodgkin lymphoma with primary involvement of the skin. Epidemiological data on PCLs according to the World Health Organization/European Organization for Research and Treatment of Cancer classification (WHO-EORTC) has not been investigated in Korea to date. AIM: To evaluate the demographic characteristics, clinical and histological features, and survival data of patients with PCL according to the WHO-EORTC classification. METHODS: In total, 93 patients with PCL were retrospectively identified from an extensive review of medical records over a 16-year period. RESULTS: The tumours found included primary cutaneous CD30+ lymphoproliferative disorders, extranodal natural killer/T-cell lymphoma and primary cutaneous diffuse large B-cell lymphoma. We found that 81.6% of the patients had primary cutaneous T-cell and natural killer-cell lymphoma, and 16.2% had primary cutaneous B-cell lymphoma, with 2.2% having precursor haematological neoplasms. The median age was 52 years (range 3-95) and the male : female ratio was 1: 1.16. The 5-year survival rate was 92.5%. CONCLUSIONS: The incidence rates of many PCL subtypes in Koreans differ from those of other countries.

Investigations on silver/polyaniline electrodes for electrochemical supercapacitors.

Polyaniline (PANI) and silver doped polyaniline (Ag/PANI) thin films were deposited on stainless steel substrates by a dip coating technique. To study the effect of doping concentration of Ag on the specific capacitance of PANI the concentration of Ag was varied from 0.3 to 1.2 weight percent. Fourier transform-infrared and Fourier transform-Raman spectroscopy, and energy dispersion X-ray techniques were used for the phase identification and determination of the doping content in the PANI films, respectively. The surface morphology of the films was examined by Field Emission Scanning Electron Microscopy, which revealed a nanofiber like structure for PANI and nanofibers with bright spots of Ag particles for the Ag/PANI films. There was decrease in the room temperature electrical resistivity of the Ag/PANI films of the order of 10(2) with increasing Ag concentration. The supercapacitive behavior of the electrodes was tested in a three electrode system using 1.0 M H(2)SO(4) electrolyte. The specific capacitance increased from 285 F g(-1) (for PANI) to 512 F g(-1) for Ag/PANI at 0.9 weight percent doping of Ag, owing to the synergic effect of PANI and silver nanoparticles. This work demonstrates a simple strategy of improving the specific capacitance of polymer electrodes and may also be easily adopted for other dopants.

Butyl paraben-induced changes in DNA methylation in rat epididymal spermatozoa.

Parabens have been shown to affect male rodent reproductive parameters, including testosterone levels and sperm production. In this study, we examined the effect of long-term exposure to butyl paraben (BP) on rat epididymal sperm DNA methylation. Adult male rats were exposed to BP (0, 10, 100 and 1000 mg kg(-1) per day) according to OECD TG407 for a repeated 28-day oral toxicity study. Sperm DNA methylation was examined by differential display random amplification of polymorphic DNA (RAPD) following methylation-specific restriction digestion of DNA. Among the 57 RAPD amplicons, six were methylation specific. Of these, five amplicons increased by 1.4- to 3.8-fold in epididymal sperm DNA at testing dose of BP. This indicates that BP can cause DNA hypermethylation in germ cells from the mitotic through post-meiotic stage in adult rat testes. To our knowledge, this is the first report on the epigenetic modification of sperm DNA by parabens.

Measurement of hydraulic pressure on the sinus membrane for safer control during transcrestal sinus lifting.

The aim of this study was to determine the hydraulic pressures necessary to separate and lift the sinus membrane from the sinus floor in order to ensure a more controlled and safer hydraulic transcrestal sinus lifting surgery and prevent sinus membrane perforation. A flow-regulating hydrodynamic device with a pressure sensor was used in nine patients. The hydraulic pressure was found to increase steadily up to a mean peak of 25.0±13.0kPa, which is comparable to the medium suction power of ordinary vacuum cleaners. Subsequently, there was a short plateau followed by a sharp decrease in the hydraulic pressure.

Preoperative MRI Evaluation of Thyroid Cartilage Invasion in Patients with Laryngohypopharyngeal Cancer: Comparison of Contrast-Enhanced 2D Spin-Echo and 3D T1-Weighted Radial Gradient Recalled-Echo Techniques.

BACKGROUND AND PURPOSE: Accurate assessment of thyroid cartilage invasion on preoperative imaging influences management in patients with laryngeal and hypopharyngeal cancers. We evaluated the clinical usefulness of contrast-enhanced 3D T1-weighted radial gradient recalled-echo for preoperative assessment of thyroid cartilage invasion in patients with laryngohypopharyngeal squamous cell carcinoma, compared with 2D spin-echo T1WI. MATERIALS AND METHODS: Preoperative MR images of 52 consecutive patients who were diagnosed with laryngeal or hypopharyngeal cancer and underwent partial or total laryngectomy were analyzed. Pathologic specimens served as reference standards. Two independent head and neck radiologists evaluated the presence of thyroid cartilage invasion in both contrast-enhanced 2D spin-echo T1WI and 3D gradient recalled-echo sequences. The sensitivity, specificity, and accuracy of the 2 modalities were compared. The area under the curve was a measure of diagnostic performance. RESULTS: Pathologic neoplastic thyroid cartilage invasion was identified in 24 (46.2%) of the 52 patients. The sensitivity (75.0%), specificity (96.4%), and accuracy (86.5%) of contrast-enhanced 3D gradient recalled-echo were significantly higher than those of 2D spin-echo T1WI (58.3%, 89.3%, and 75.0%; P = .017, .003, and .002, respectively). 3D gradient recalled-echo had significantly better diagnostic performance (area under the curve = 0.963) than 2D spin-echo T1WI (area under the curve = 0.862; P = .010). CONCLUSIONS: Contrast-enhanced 3D gradient recalled-echo was diagnostically superior in identifying neoplastic thyroid cartilage invasion compared with 2D spin-echo T1WI in patients with laryngohypopharyngeal cancer, and therefore, may provide more accurate preoperative staging.

MRI Features May Predict Molecular Features of Glioblastoma in Isocitrate Dehydrogenase Wild-Type Lower-Grade Gliomas.

BACKGROUND AND PURPOSE: Isocitrate dehydrogenase (IDH) wild-type lower-grade gliomas (histologic grades II and III) with epidermal growth factor receptor (EGFR) amplification or telomerase reverse transcriptase (TERT) promoter mutation are reported to behave similar to glioblastoma. We aimed to evaluate whether MR imaging features could identify a subset of IDH wild-type lower-grade gliomas that carry molecular features of glioblastoma. MATERIALS AND METHODS: In this multi-institutional retrospective study, pathologically confirmed IDH wild-type lower-grade gliomas from 2 tertiary institutions and The Cancer Genome Atlas constituted the training set (institution 1 and The Cancer Genome Atlas, 64 patients) and the independent test set (institution 2, 57 patients). Preoperative MRIs were analyzed using the Visually AcceSAble Rembrandt Images and radiomics. The molecular glioblastoma status was determined on the basis of the presence of EGFR amplification and TERT promoter mutation. Molecular glioblastoma was present in 73.4% and 56.1% in the training and test sets, respectively. Models using clinical, Visually AcceSAble Rembrandt Images, and radiomic features were built to predict the molecular glioblastoma status in the training set; then they were validated in the test set. RESULTS: In the test set, a model using both Visually AcceSAble Rembrandt Images and radiomic features showed superior predictive performance (area under the curve = 0.854) than that with only clinical features or Visually AcceSAble Rembrandt Images (areas under the curve = 0.514 and 0.648, respectively; P < . 001, both). When both Visually AcceSAble Rembrandt Images and radiomics were added to clinical features, the predictive performance significantly increased (areas under the curve = 0.514 versus 0.863, P < .001). CONCLUSIONS: MR imaging features integrated with machine learning classifiers may predict a subset of IDH wild-type lower-grade gliomas that carry molecular features of glioblastoma.

Extended defect states of Ge/Si quantum dots using optical isothermal capacitance transient spectroscopy.

We investigated the hole emission processes of optically induced charges on the defect states and confined states of self-assembled Ge quantum dots (QDs) embedded in a p-i-n Si diode. Optical deep level transient spectroscopy (ODLTS) and optical isothermal capacitance transient spectroscopy (OICTS) were used to study the defect states in ten stacked Ge quantum dots. Using ODLTS and OICTS for QD-embedded samples, the peaks related to the defect states of Ge QDs could be classified distinctly; it was about 20-50 times higher in intensity than that for the bulk defect states. The charges emitted from the QD defect state were observed near 93 K, and the activation energy was calculated to be E(V)+177 meV. The defect state followed the logarithmic capture kinetics and the Arrhenius-determined apparent activation energy decreased in the band gap as the optical injection width increased. We suggest that Ge QD defect states in Si could exist as extended states.

Only tetracaine and not other local anaesthetics induce apoptosis in rat cortical astrocytes.

BACKGROUND: The potential risks of neurotoxicity due to local anaesthetics after regional anaesthesia have been suggested recently. To evaluate the neurotoxicity of commonly used local anaesthetics, primary cultured rat cortical astrocytes were treated with lidocaine, ropivacaine, bupivacaine, levobupivacaine, and tetracaine. METHODS: Cell death after local anaesthetic treatment was evaluated with a lactate dehydrogenase (LDH) assay. To examine the mechanisms of cell death, reactive oxygen species (ROS) measurement and western blots of poly-ADP ribose polymerase (PARP), procaspase-3, and mitogen-activated protein kinases family members were performed. RESULTS: Of the local anaesthetics, which were applied at <1 mM for 18 h, only tetracaine significantly increased LDH leakage (P<0.05) and cell death in a dose- and time-dependent manner. Hoechst 33258-propidium iodide staining and western blots with PARP and procaspase-3 antibodies suggested that tetracaine induced apoptosis. ROS levels increased 2-fold at 30 min after tetracaine treatment compared with the control and then decreased. The antioxidants, N-acetylcysteine and trolox, markedly inhibited tetracaine-induced apoptosis. CONCLUSIONS: Tetracaine induced apoptosis through ROS generation. Further studies focusing on the neurotoxicity of tetracaine are needed.

Expression of occludin in testis and epididymis of wild rabbits, Lepus sinensis coreanus.

Tight junctions (TJs) in inter-Sertoli junctional areas and epididymal epithelia build up the blood-testis barrier (BTB) and the blood-epididymal barrier (BEB), respectively. In this study, the expression of occludin, an integral member of the TJs, was examined in testis and different regions of epididymis of Lepus sinensis coreanus, an Korean wild rabbit species. In testis, intense occludin immunoreactivity was found in the basally located inter-Sertoli junctional area together with diffused immunoreactivity of occludin in the cytoplasm of Sertoli cells. It can be suggested that occludin is one of the robust elements of BTB in seminiferous tubules of rabbit testis. In proximal and distal caput epididymis, occludin immunoreactivity was found in the lateral as well as apical contacts of epithelial cells. In corpus epididymis, intense occludin immunoreactivity was found in the basolateral as well as apical contacts of epithelial cells together with cytoplasmic signal. In cauda epididymis, occludin immunoreactivity in luminal epithelia was relatively strong but largely found in the cytoplasm. This suggests that intriguing regulatory mechanisms differentially recruit occludin to the TJ in the different regions of epididymal epithelia. The differences in the subcellular localization as well as expression levels of occludin among the epididymal segments may reflect differential paracellular permeability of epithelia along the epididymal tubules and be correlated with sperm maturation in rabbit. In Western blot, a major form of occludin was MW 62 kDa together with small fragments of MW 34-39 kDa in testis and epididymis, suggesting the peptide cleavage of occludin. This is the first report on the molecular nature of TJs in a wild rabbit testis and epididymis.

Effects of molinate on survival and development of Bombina orientalis (Boulenger) embryos.

Molinate, a thiocarbamate chemical is a slightly to moderately toxic herbicide in EPA (Environmental Protection Agency) toxicity class III, and is a registered as a General Use Pesticide (GUP). Bombina orientalis is one of the most common amphibians in the world and comprise a large proportion of their total number in Korea. B. orientalis spawns in the rice fields at spring when the massive application of agricultural chemicals occurs. In the present study, we examined the effects of molinate on embryonic survival and developmental abnormality in B. orientalis embryos. The difference in survival rate between vehicle control and molinate treated embryos was not observed until the blastula stage. The first statistically significant decrease in embryonic survival was observed at mouth open stage following exposure to 100 microM molinate (46.8% vs. 81.1% in control). When the embryos develop to tadpole stage survival was significantly decreased at 50 microM molinate (35.9% vs. 68.9% in control), suggesting that the lowest observed effective dose (LOED) for systemic toxicity in B. orientalis embryos is 50 microM. In survived embryos molinate exposure produced several types of severe developmental abnormalities in order of frequency with bent trunk, neurula with yolk plug, bent tail, tail dysplasia, ventral blister, eye dysplasia, thick-set body and cephalic dysplasia. This suggests that molinate targets multiple events in embryonic and larval development in this frog species. Together this suggested that molinate was detrimental for survival and development following zygotic transcription after midblastula transition in B. orientalis embryos.

The rivaroxaban-adjusted normalized ratio: use of the prothrombin time to monitor the therapeutic effect of rivaroxaban.

Background: The prothrombin time may be used to monitor the plasma concentration of rivaroxaban. However, there is variability in the responsiveness of rivaroxaban to different thromboplastins. We aimed to develop a rivaroxaban-monitoring method using the prothrombin time to reduce the differences in the sensitivity among reagents. Methods: Rivaroxaban-spiked pooled normal plasma at a 0-1000 ng/ml concentration was used to generate a rivaroxaban-adjusted sensitivity index (SI) values, and was tested with three thromboplastins. The warfarin-adjusted international sensitivity index (ISI-warfarin), rivaroxaban-adjusted sensitivity index (SI-rivaroxaban), international normalized ratio (INR) calculated with ISI-warfarin, normalized ratio (NR) calculated with SI-rivaroxaban, and their coefficient of variances (CVs) were compared. The NR-rivaroxaban value was compared with the results of an anti-Xa assay. Results: The ISI-warfarin and SI-rivaroxaban using different thromboplastins were 1.02 and 1.88, respectively, with Thromborel S, 0.90 and 1.00 using Recombiplastin 2G, and 1.30 and 1.15 using Neoplastin CI-plus. Between-thromboplastin variability expressed as CV were 6.3%-25.1% when expressed as INR-warfarin and 1.7%-4.7% when expressed as NR-rivaroxaban. CVs for the NR-rivaroxaban with another laboratory were significantly lower than those for INR-warfarin. Anti-Xa assay v NR-rivaroxaban correlation coefficients were 0.97-0.99. Conclusion: Using a rivaroxaban-specific NR effectively minimises inter-thromboplastin variability. By utilizing a NR-rivaroxaban, standardized prothrombin time results could be rapidly obtained, especially useful in standardizing the therapeutic effect of rivaroxaban.

Validation of reflex testing rules and establishment of a new workflow for body fluid cell analysis using a Sysmex XN-550 automatic hematology analyzer.

INTRODUCTION: We developed and validated reflex testing rules for the microscopic examination (ME) of body fluids (BFs) on the Sysmex XN-550 (Sysmex Corporation) instrument. METHODS: We assessed the detection limits, precision, linearity, and carryover. To develop the reflex testing rules (derivation arm), we tested 515 samples and then validated the rules using another 507 samples (validation arm). RESULTS: All analytical performances were acceptable, and the carryover was negligible. There was agreement between the automated count and ME of red blood cells (r = .98) and total nucleated cells (TNCs) (r = .98), as well as the differential counts of neutrophils (r = .90) and lymphocytes (r = .84). We developed reflex testing rules: TNCs <10/µL, cell 2/cell 1 ratio ≤0.7, HF-BF cells >7.9/100 white blood cells, LY-X ≥85 or LY-Y ≥90, and eosinophils >2.5%. In the validation arm, implementation of the rules resulted in 126 rule-negative samples (24.9%) that were well correlated between the 2 methods. We propose a new workflow for BF cell analysis based on automated counting. CONCLUSION: The Sysmex XN-550 can be a suitable alternative to ME for BF cell analysis, especially for screening samples and subsequent automatic reporting under the rational use of laboratory-specific rules.

The mechanical properties and osteoconductivity of hydroxyapatite bone scaffolds with multi-scale porosity.

The relative osteoconductivity and the change in the mechanical properties of hydroxyapatite (HA) scaffolds with multi-scale porosity were compared to scaffolds with a single pore size. Non-microporous (NMP) scaffolds contained only macroporosity (250-350 microm) and microporous (MP) scaffolds contained both macroporosity and microporosity (2-8 microm). Recombinant human bone morphogenetic protein-2 (rhBMP-2) was incorporated into all scaffolds via gelatin microspheres prior to implantation into the latissimus dorsi muscle of Yorkshire pigs. After 8 weeks, only the MP scaffolds contained bone. The result demonstrates the efficacy of the MP scaffolds as drug carriers. Implanted and as-fabricated scaffolds were compared using histology, microcomputed tomography, scanning electron microscopy, and compression testing. Implanted scaffolds exhibited a stress-strain response similar to that of cancellous bone with strengths between those of cancellous and cortical bone. The strength and stiffness of implanted NMP scaffolds decreased by 15% and 46%, respectively. Implanted MP scaffolds lost 30% of their strength and 31% of their stiffness. Bone arrested crack propagation effectively in MP scaffolds. The change in mechanical behavior is discussed and the study demonstrates the importance of scaffold microporosity on bone ingrowth and on the mechanical behavior of HA implant materials.

Therapeutic use of granulocyte-colony stimulating factor could conceal residual malignant cells in patients with AML1/ETO+ acute myelogenous leukemia.

We have experienced a number of cases of AML1/ETO+ acute myelogenous leukemia that showed remission based on bone marrow (BM) morphological criteria, but that revealed clonal abnormalities in most cells by fluorescence in situ hybridization (FISH). Interestingly, most of these cases had AML with AML1/ETO rearrangement. The malignant cells were differentiated and considered mature cells after granulocyte-colony stimulating factor (G-CSF) treatment. To clarify the possible mechanisms underlying this phenomenon, we investigated the expression levels of G-CSFR in AML cells with AML1/ETO rearrangement by flow cytometry and real-time polymerase chain reaction (PCR). The number of AML1/ETO+ cells expressing G-CSFR at baseline was significantly higher than that of AML1/ETO- AML cells (2673 vs 522). In addition, the G-CSFR gene was more highly expressed in AML1/ETO+ cells than in AML1/ETO- cells by real-time PCR. This study reveals that cases showing remission after treatment with G-CSF mostly had leukemia with AML1/ETO rearrangement. This finding might be explained by the higher expression of G-CSF receptor in AML1/ETO+ cells than in AML1/ETO- cells. We recommend that remission should be confirmed by FISH, because malignant clones can be differentiated and masked in morphological examination or chromosome test, especially for AML with AML1/ETO rearrangement.