Reliability of endoscopic esophageal mucosectomy using TxHood, a multipurpose treatment hood

Endoscopic mucosectomy, comprising both endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), is a minimally invasive treatment for patients with early esophageal carcinoma. The use of ESD is appropriate for mucosal lesions of any size. However, ESD techniques are relatively difficult and can lead to serious complications such as perforation and massive bleeding, which have been reported more frequently after ESD than after EMR. This study describes a novel technique for ESD using a newly designed multipurpose treatment hood (TxHood) as well as basic experiments to ensure its safety. The TxHood includes various therapeutic tools such as an electric needleknife, a snare wire, and an injection needle, and the lines can be selected freely before insertion of an enodoscope covered by a TxHood. The main techniques for ESD are endoscopic submucosal saline injections on demand through a working channel of the endoscope or TxHood and a cut or swing cut with a needleknife attached to the TxHood. Moreover, the target area can be grasped with a grasping forceps through a working channel of the endoscope to obtain effective countertraction. In these experiments, an electric needleknife set parallel to the shaft of the endoscope offered safety and ease of handling for the dissecting procedures. Altogether, 16 resections of mucosa with an average size of 3.5 x 2.5 cm (range, 2 x 2 to 7 x 4 cm) were performed. The average time required for each targeted endoscopic resection area was about 15 min. No perforations or instances of uncontrollable bleeding occurred. In conclusion, this basic study demonstrates that the new ESD technique with the TxHood provides a useful treatment for early esophageal carcinoma and may be applicable for all mucosal or submucosal tumors in the gastrointestinal tract.

Ecdysone response element in a baculovirus immediate-early gene, ie1, promoter

A computer-assisted analysis identified tentative target sequences for regulatory proteins including ecdysone-inducible factors such as BmFTZ-F1 and Broad-Complex Z4 (BR-C Z4) in the ie1 promoter of BmNPV. A transient expression experiment using BmN cells and a series of truncated ie1 promoter constructs demonstrated that the activity of the ie1 promoter responded to alpha-ecdysone and 20-hydroxyecdysone, which required a tridecameric nucleotide stretch (ie1EcRE, 5'-GTGTTATCGACCT-3') homologous to the ecdysone response element reported for Drosophila (DmEcRE). RT-PCR demonstrated the expression of BmEcR and BmUSP, which are required as ecdysone-specific activators for EcRE-mediated activation, in BmN cells. Furthermore, the ie1 EcRE-mediated response was confirmed by using a recombinant BmNPV possessing a luciferase gene under the control of the ie1 promoter with or without ie1 EcRE. This is the first report of an ecdysone response element in a baculoviral gene promoter. These results also suggested that the regulation of the ie1 by ecdysone may militate viral replication at least under certain conditions during natural infections in vivo.

Optical gain spectra for near UV to aquamarine (Al,In)GaN laser diodes

Optical gain spectra presented for (Al,In)GaN laser diodes with lasing wavelength ranging from UV (375 nm) to aquamarine (470 nm) show a strong increase in inhomogeneous broadening, caused by Indium composition and quantum well width fluctuations which increase with Indium mole fraction. These gain spectra provides a standard data set for the calibration of microscopic many-body simulations. We demonstrate by comparison with basic simulations that the different assumptions of a global constant carrier density or of global constant quasi-Fermi levels for electrons and holes lead to a strikingly different dependency of optical gain on carrier density. For constant quasi-Fermi levels the threshold carrier density becomes insensitive to inhomogeneous broadening for realistic parameters. This is in agreement with the observation that the threshold current is nearly independent over the wavelength range from near UV to aquamarine.

Possibility of selection of chondrogenic progenitor cells by telomere length in FGF-2-expanded mesenchymal stromal cells

Telomere length plays an important role in regulating the proliferative capacity of cells, and serves as a marker for cell cycle history and also for their remaining replicative potential. Mesenchymal stromal cells (MSC) are known to be a significant cell source for therapeutic intervention and tissue engineering. To investigate any possible limitations in the replicative potential and chondrogenic differentiation potential of fibroblast growth factor-2-expanded MSCs (FGF(+)MSC), these cells were differentiated at various population doublings (PDs), and telomere length and telomerase activity were measured before and after differentiation. FGF(+)MSC cultured at a relatively low density maintained proliferation capability past more than 80 PD and maintained chondrogenic differentiation potential up to at least 46 PD and long telomeres up to 105 PD, despite expressing low levels of telomerase activity. Interestingly, upon chondrogenic differentiation of these cells, telomeres showed a remarkable reduction in length. This shortening was more extensive when FGF(+)MSC of higher PD levels were differentiated. These findings suggest that telomere length may be a useful genetic marker for chondrogenic progenitor cells.

Estimation of the emission factors of PAHs by traffic with the model of atmospheric dispersion and deposition from heavy traffic road

In order to consider the total atmospheric loadings of the PAHs (polycyclic aromatic hydrocarbons) from traffic activities, the emission factors of PAHs were estimated and from the obtained emission factors and vehicle transportation statistics, total atmospheric loadings were integrated and the loadings into the water body were estimated on a regional scale. The atmospheric concentration of PAHs was measured at the roadside of a road with heavy traffic in the Hiroshima area in Japan. The samplings were conducted in summer and winter. Atmospheric particulate matters (fine particle, 0.6-7 microm; coarse particle, over 7 microm) and their PAH concentration were measured. Also, four major emission sources (gasoline and diesel vehicle emissions, tire and asphalt debris) were assumed for vehicle transportation activities, the chemical mass balance method was applied and the source partitioning at the roadside was estimated. Furthermore, the dispersion of atmospheric particles from the vehicles was modelled and the emission factors of the sources were determined by the comparison to the chemical mass balance results. Based on emission factors derived from the modelling, an atmospheric dispersion model of nationwide scale (National Institute of Advanced Industrial Science and Technology - Atmospheric Dispersion Model for Exposure and Risk assessment) was applied, and the atmospheric concentration and loading to the ground were calculated for the Hiroshima Bay watershed area.

Tissue engineered cartilage: utilization of autologous serum and serum-free media for chondrocyte culture

BACKGROUND

Standard culture medium contains bovine serum. If standard culture methodology is used for future human tissue-engineering, unknown risks of infection from bovine disease or immune reaction to foreign proteins theoretically might occur. In this study we wished to evaluate the potential of chondrocyte expansion using autologous and serum free media.

METHODS

Autologous auricular cartilage was harvested in a swine model. An initial concentration of 100x10(3) cells per group were expanded in three groups. Group A, F-12 with 10% fetal calf serum; Group B, F-12 supplemented with 10% autologous serum; Group C, F-12 supplemented with growth factors. Cell numbers were counted at days 3, 6, 9 and 12.

RESULTS

The cells in all the three groups exhibited normal chondrocyte morphology. At early time points there was a statistically significant difference in the number of cells between Group A and the two other groups (p<0.05). By day 12, both Groups A and C demonstrated greater cell number as compared to Group B (p<0.05).

CONCLUSION

The results suggest that both autologous serum as well as serum free media might be substituted for the expansion of the number of chondrocytes, thus avoiding the potential need for a bovine serum supplement.

Phase I/II study of S-1 combined with irinotecan for metastatic advanced gastric cancer

A dose-escalation study of irinotecan (CPT-11) combined with S-1, an oral dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine, was performed to determine the maximum-tolerated dose (MTD), recommended dose (RD), dose-limiting toxicities (DLTs), and objective response rate (RR) in advanced gastric cancer (AGC). S-1 was administered orally at 80 mg m⁻² day⁻¹ from day 1 to 14 of a 28-day cycle and CPT-11 was given intravenously on day 1 and 8 at an initial dose of 70 mg m⁻² day⁻¹, stepping up to 100 mg m⁻². The treatment was repeated every 4 weeks, unless disease progression was observed. In the phase I portion, the MTD of CPT-11 was presumed to be 100 mg m⁻², because 66.6% of patients (two of three) developed DLTs. All three patients at the initial RD of CPT-11 (90 mg m⁻²) experienced grade 4 haematological or grade 3 nonhaematological toxicities at second course, followed by the dose reduction of CPT-11 from the third course. Considering safety and the ability to continue treatment, the final RD was determined to be 80 mg m⁻². In the phase II portion, 42 patients including seven patients in the final RD phase I portion were evaluated. The median treatment course was five (range: 1–13). The incidences of severe (grade 3–4) haematological and nonhaematological toxicities were 19 and 10%, respectively, but all were manageable. The RR was 62% (26 of 42, 95% confidence interval: 47.2–76.6%), and the median survival time was 444 days. Our phase I/II trial showed S-1 combined with CPT-11 is effective for AGC and is well tolerated, with acceptable toxicity.

Point mutation of C-terminal region of CD20 molecule predicts rituximab-induced complement-dependent cytotoxicity and clinical response to rituximab in non-Hodgkin’s lymphoma

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Background: Although rituximab is commonly used as induction and maintenance therapy for malignant lymphoma, some patients become refractory to treatment and the mechanism of resistance is unclear. The aim of this study was to investigate the relationship between CD20 mutations and rituximab resistance. Methods: To investigate whether CD20 mutations affect response to rituximab, fresh CD19+ lymphoma cells were isolated from the lymph nodes, or bone marrow of 68 patients with NHL. The cells were subsequently sorted by flow cytometry. RNA was prepared from the isolated cells and RT-PCR was performed. The PCR products were sequenced, subcloned into an expression vector pTARGET, transfected into K562 cells. CD20 expression was examined by flow cytometry and laser scanning confocal microscopy. Results: In all 68 patients, overall response rate (CR+CRu+PR) to rituximab was 91.2% (62/68), but t four cases became PD after PR. DNA sequence analysis revealed that point mutations were mostly observed in three CD20 domains - extracellular/cytoplasmic domains, the third transmembrane domain and the C-terminal cytoplasmic domain. Two cases had point mutations in extracellular/cytoplasmic domains, one patient had point mutations in the transmembrane domain, four cases showed point mutations in the C-terminal cytoplasmic domain and six cases had non-specific CD20 mutations, which did not affect CD20 expression. 56 patients showed no mutations of CD20 gene. CD20 expression was very weak in patients with point mutations in the C-terminal cytoplasmic domain, whereas expression was increased in patients with point mutations in the transmembrane domain. Conclusions: Point mutations in CD20 may cause rituximab resistance and identification of CD20 mutations upon diagnosis may help to predict a patient’s response to rituximab.

No significant financial relationships to disclose.

Expression of foreign type I ribulose-1,5-bisphosphate carboxylase/ oxygenase (EC 4.1.1.39) stimulates photosynthesis in cyanobacterium Synechococcus PCC7942 cells

A reporter gene assay revealed that promoters derived from Synechococcus PCC7942 (S.7942) psbAI and Synechocystis PCC6803 (S.6803) psbAII were suitable for the expression of foreign ribulose-bisphosphate carboxylase (RuBisCO; EC 4.1.1.39) in S.7942 cells. Transformational vectors with a promoter and a foreign RuBisCO gene, cvrbc originated from Allochromatium vinosum, were constructed on a binary vector, pUC303, and introduced to S.7942 cells. When the cvrbc was expressed with the S.7942 psbAI promoter, the total RuBisCO activity increased 2.5- to 4-fold than that of the wild type cell. The S.6803 psbAII promoter increased the activity of the transformant 1.5-2 times of that of wild type cell. There was a significant increase in the rate of photosynthesis depending on the increase of RuBisCO activity. The maximum rate of photosynthesis of the transformant cell was 1.63 times higher than that of the wild type under the illumination of 400 micromol m(-2) s(-1), at 20 mM bicarbonate and at 30 degrees C. Although the photosynthesis of the higher plant is limited by the ability of photosystems under high irradiance and the high CO(2 )concentration, that of the S.7942 cell is limited by the RuBisCO activity, even at high CO(2) concentrations and under high irradiance.

Observation of all the components of elastic constants using tetragonal hen egg-white lysozyme crystals dehydrated at 42% relative humidity

Success in measuring transverse sound velocity allowed us to determine, for the first time, all six elastic constants of a protein crystal. An ultrasonic pulse-echo method was used to perform sound velocity measurements on tetragonal hen egg-white (HEW) lysozyme crystals that were partially dehydrated at 42% relative humidity. The measurements were performed using the (110), (101), and (001) crystallographic faces. Thus, all six elastic constants of the dehydrated tetragonal HEW lysozyme crystals were determined: C11=C22=12.44 GPa, C12=7.03 GPa, C13=C23=8.36 GPa, C33=12.79 GPa, C44=C55=2.97 GPa, and C66=2.63 GPa. In addition, for the hydrated crystals, the longitudinal sound velocities along the [110] direction and the direction normal to the (101) face were measured. From these results, all the components of elastic constants in the hydrated crystals were extrapolated.

Mechanical assessment of effects of grape seed proanthocyanidins extract on tibial bone diaphysis in rats

We studied the effects of grape seed proanthocyanidins extract (GSPE) given as a ratio of 3 mg in 100 g in a standard diet, on the tibial bone diaphysis in low-calcium fed rats. Measurements of bone density, mineral content, geometry, and bone strength using peripheral quantitative computed tomography (pQCT). Further, the whole tibia bones were tested for mechanical resistance using a material-testing machine, and mineral elements were also determined. Forty male Wistar rats, 5 weeks old, were divided into control (Co), low-calcium diet (LC), low-calcium diet . standard diet (LCS), and low-calcium diet . standard diet with supplementary GSPE (LCSG) groups. We found no significant differences in body weight among the 4 groups, whereas all of the bone parameters in LC were significantly lower than those in Co (p<0.01, except in periosteal perimeter (Peri) p<0.05). The cortical bone mineral content (CtBMC), cortical bone density (CtvBMD) and Peri in LCSG were significantly higher than those in LCS (p<0.01; p<0.01; p<0.05, respectively). All bone parameters in LCSG were significantly higher than those in LC (p<0.01, except in Peri, and stress strain index to reference axis x (xSSI) p<0.05)). In addition, Ca, P, and Zn contents in LCSG were significantly higher than those in LCS (p<0.01; p<0.01; p<0.05, respectively). Our results suggest that GSPE included in a diet mixture with calcium has a beneficial effect on bone formation and bone strength for the treatment of bone debility caused by a low level of calcium.

Serum LECT2 level as a prognostic indicator in acute liver failure

In the present study, we investigated the relationship between serum leukocyte cell-derived chemotaxin2 (LECT2) levels and liver function in patients with acute liver failure, and its use as a prognostic indicator. We studied six acute liver failure patients (two women, four men; 49.8 +/- 20.7 years old) admitted to our hospital in 2002. These patients had diagnoses of fulminant hepatitis due to acute liver failure (1) from congestive heart failure; (2) from portal venous gas, and (3) from postoperative disseminated intravascular coagulation (DIC). We measured serum LECT2, GOT, and GPT levels, the last two being inversely proportionate to the serum LECT2 levels. When the serum GPT levels peaked, the serum LECT2 levels were the lowest. When the liver function recovered, serum LECT2 levels increased. Three of four patients died due to liver failure, one to congestive heart failure. Maximum serum LECT2 levels among the expired group were significantly lower than those among the alive group (0.96 +/- 0.8 ng/mL vs 12.9 +/- 4.3 ng/mL). Serum LECT2 levels may be a prognostic indicator of recovery from liver failure. The present study suggests that in clinical medicine LECT2 participates in regeneration after injury of hepatocytes.

Changes in serum LECT 2 levels during the early period of liver regeneration after adult living related donor liver transplantation

We investigated changes in serum leukocyte cell-derived chemotaxin2 (LECT2) levels between donors and recipients in the early period during liver regeneration following adult living related donor liver transplantation (LRDLT). Five recipients (three women, two men; 37.0 +/- 15.8 years old), all of whom had end-stage liver failure, underwent LRDLT from healthy five donors (two women, three men; 41.6 +/- 14.3 years old) between June 2000 and February 2001. FK506 and methylprednisolone were used as immunosuppressants for recipients. Serum LECT2 levels decreased immediately after both the hepatectomy in all donors and the implantation of liver graft in all recipients. Donors showed a nadir at 3 to 12 hours, increasing at 24 to 48 hours. The nadir in recipients occurred several hours after the donors. The serum LECT2 levels of donors were significantly higher than those of recipients on day 5 (9.5 +/- 5.9 ng/mL vs 3.1 +/- 2.2 ng/mL, P = .04) and on day 7 (9.3 +/- 3.8 ng/mL vs 3.5 +/- 1.1 ng/mL, P = .04). Serum GPT and GOT levels were inversely proportionate to the serum LECT2 levels. The present studies suggest that LECT2 participates in liver regeneration and injury following hepatectomy.

Use of RNAi technology to confer enhanced resistance to BmNPV on transgenic silkworms

dsRNA is a powerful tool for gene-specific silencing in plants and animals. In this study, we examined the use of gene silencing in generating transgenic silkworms resistant to the Bombyx mori nucleopolyhedrovirus (BmNPV). Using a transposon piggyBac system, we first generated BmN cells (rBmN-lef1), which carried artificial genes designed for expressing dsRNAs with sequences of the essential viral gene lef-1. NPV DNA microarray analysis revealed that the accumulation of lef-1 mRNA was successfully inhibited in rBmN-lef1 infected with BmNPV. The virus titer in the culture medium of rBmN-lef1 at 48 hr post-infection (h.p.i.) was 50% of that of the control cells. Moderate BmNPV-resistance caused by transgenesis of the artificial dsRNA-expressing gene was confirmed in the transgenic silkworms. Virus production was reduced in transgenic silkworms relative to controls up to 96 hrs after viral inoculation. Although complete protection was not achieved and the transgenic larvae ultimately died, this is the first report to show the use of RNAi in confering enhanced viral resistance on transgenic animals.