Comparison of standardized prophylactic high-dose and intrathecal methotrexate for DLBCL with a high risk of CNS relapse

The efficacy of high-dose methotrexate (HD-MTX) for central nervous system (CNS) relapse prophylaxis in patients with high-risk diffuse large B-cell lymphoma (DLBCL) is controversial. We compared the prophylactic effects of HD-MTX and intrathecal methotrexate (IT-MTX) on CNS relapse in high-risk DLBCL, in a multicenter retrospective study. A total of 132 patients with DLBCL at high risk of CNS relapse who received frontline chemotherapy and IT-MTX from 2003 to 2013 (n = 34) or HD-MTX from 2014 to 2020 (n = 98) were included. After a median follow-up of 52 months (range: 9-174), 11 patients had isolated CNS relapse: six (6.1%) in the HD-MTX group and five (14.7%) in the IT-MTX group. The median time until CNS relapse was 38 months (range: 11-122), and the cumulative incidence of CNS relapse at 3 years was 3.9% in the HD-MTX group and 6.1% in the IT-MTX group (P = 0.93). Similar results were obtained after adjusting for background factors using propensity score-matched analysis (4.5% HD-MTX vs. 7.6% IT-MTX, P = 0.84). The CNS relapse rate in HD-MTX-treated patients was equivalent to that in IT-MTX patients, demonstrating that HD-MTX was not superior to IT-MTX in preventing CNS relapse.

Clinical benefits of precision medicine in treating solid cancers: European Society of Medical Oncology-Magnitude of Clinical Benefit Scale score-based analysis

Background

Precision and matched cancer medicine has the potential to complement the existing biomarker approaches in cancer treatment. However, despite their promising potential, certain negative results have highlighted their limitations in molecular biology-driven treatment strategies. This study aimed to evaluate the clinical benefits of precision therapies.

Materials and methods

Three reviewers independently identified and assessed precision and matched cancer treatment studies published between January 2015 and December 2020. Clinical benefits of the treatments included in our cohort were assessed using two established frameworks; the European Society of Medical Oncology-Magnitude of Clinical Benefit Scale version 1.1 (ESMO-MCBS) and the American Society of Clinical Oncology Value Framework.

Results

Of the 290 eligible studies, 130 were for lung cancer, 51 for solid tumors, 24 for melanoma, and 24 for breast cancer. The common targets were: epidermal growth factor receptor (N = 66), serine/threonine-protein kinase B-Raf (N = 40), anaplastic lymphoma kinase (ALK) (N = 34), breast cancer protein (N = 26), phosphatidylinositol-3 kinase/protein kinase B/phosphatase and tensin homolog (PI3K/AKT/PTEN) pathway (N = 19), receptor tyrosine-protein kinase erbB-2 (HER2) (N = 19), mitogen-activated protein kinase (RAS/RAF/MAPK) pathway (N = 18), programmed death-ligand 1 (N = 12), fibroblast growth factor receptor (N = 8), and others (N = 43). The ESMO-MCBS scales ranged from 0 to 4. Based on the clinical benefit values, tumor mutational burden/mismatch repair-deficient/microsatellite instability-high for immunotherapy, anaplastic lymphoma kinase, and neurotrophic receptor tyrosine kinase therapeutic targets were considered high, whereas RAS/RAF/MAPK and PI3K/AKT/PTEN were considered low. Additionally, we found a significant difference between each average score (P < 0.001).

Conclusions

This study showed that precision and matched cancer therapies require further improvement. This is consistent with the views of the tumor board and of clinicians that precision strategies need to be revised to improve their therapeutic effects.

•

Of the 290 eligible studies, 130 were for lung cancer, 51 for solid tumors, 24 for melanoma, and 24 for breast cancer.

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Precision strategies need to be revised to improve their therapeutic effects.

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Therapeutic targets need to be narrowed down to improve the efficacy of precision medicine in the clinical setting.

Successful treatment with lenalidomide for relapsed adult T-cell leukemia/lymphoma after cord blood cell transplantation

The prognosis for relapsed adult T-cell leukemia/lymphoma (ATL) after allogeneic hematopoietic stem cell transplantation is poor. Here, we report the case of a 67-year-old man who survived for 26 months after treatment with lenalidomide for post-transplant relapsed ATL. He underwent induction therapy with two cycles of modified VCAP-AMP-VECP and achieved complete remission. He received cord blood cell transplantation following a reduced-intensity conditioning regimen. Seven months after transplantation, swelling of the systemic lymph nodes appeared, and relapsed ATL was diagnosed based on a biopsy of the cervical lymph node. Treatment with 10 mg of lenalidomide induced partial remission. At 18 months after transplantation, skin tumors were successfully treated by increasing the dose of lenalidomide to 15 mg with the emergence of skin graft-versus-host disease. Although he died from ATL at 34 months after transplantation, systemic relapsed lesions were controlled by treatment with lenalidomide for 26 months. Our case suggests that lenalidomide is well tolerated and is an effective option for the treatment of post-transplant relapsed ATL.

Simple and low-cost tabletop NMR system for chemical-shift-resolution spectra measurements

We have been working on developing a low-cost tabletop NMR system. We reported that a field homogeneity as high as 50 ppm was achieved with a simple NMR magnet by employing two facing ferrite magnets with iron disks in between (Chonlathep et al., 2017). In this paper, we report two improvements added to our previous system: (1) an FPGA based signal processing unit to improve the S/N ratio and (2) a simple shimming mechanism to improve the field homogeneity. We obtained as high as 1 ppm field homogeneity in the best case. The signals from hydrogen nuclear spins in a methyl and carboxy group in acetic acid were resolved in NMR spectra.

Increased systemic inflammatory interleukin-1ß and interleukin-6 during agitation as predictors of Alzheimer's disease

OBJECTS

Identification of biomarkers for Alzheimer's disease (AD) is important for its early diagnosis and prevention and a key in advancing our understanding of its pathophysiology. The aim of this study was to determine whether systemic inflammatory interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) as well as hypertension (HT), diabetes mellitus (DM), and body mass index (BMI) are predictors of AD.

METHODS

We performed a 10-year follow-up study on 133 elderly who were institutionalized in a nursing home. The associations of IL-1ß and IL-6 at both rest and agitation, as well as HT, DM, and BMI at baseline, were analyzed with the incidences of vascular dementia (VD) and AD during a 10-year follow-up period.

RESULTS

The Kaplan-Meier method with log-rank test and Cox regression analyses for the total of 133 subjects showed significantly higher incidences of both VD and AD in subjects with DM or HT at baseline. Resting IL-1ß or IL-6 value, or agitation score, was not significantly associated with the subsequent development of VD or AD. The analyses of 40 subjects who had shown agitation at least once in the previous 3 months demonstrated that IL-1ß and IL-6 values at the agitation stage were significantly associated with AD, but not with VD.

CONCLUSION

Our results indicate that systemic inflammatory IL-1ß and IL-6 at the agitation stage are risk factors for the development of AD, but not VD. Inflammatory mechanisms for AD seem to be causal and specific to the development of AD.

Association between altered systemic inflammatory interleukin-1beta and natural killer cell activity and subsequently agitation in patients with Alzheimer disease

OBJECTIVE

Alzheimer's disease (AD) is a neurodegenerative disorder that is the most common cause of dementia in the elderly and is frequently accompanied by emotional disorder, including agitation. Although evidence of neuroendocrine immune and inflammatory functions during emotional changes has been accumulated, the pathogenic mechanisms in the development of agitation accompanied by AD remain to be elucidated.

METHODS

To clarify the involvement of neuroendocrine and immune and inflammatory systems in agitation in AD, we examined agitation levels, circadian rhythms of behavior, cortisol, interleukin-1beta (IL-1beta), and natural killer cell activity (NKCA) in controls without dementia and 16 AD patients who were recognized to be easily agitated in their nursing homes. These behavioral and blood indicators were assessed according to the progress of the stage of agitation in 16 AD patients (stable, pre-agitation, and agitation stages).

RESULTS

Elevations in night behavior and blood cortisol, IL-1beta and an reduced blood NKCA level in the evening were observed not only in the agitation stage, but also when stable in AD patients as compared to the control. Increased IL-1beta and decreased NKCA occurred in both the morning and evening in pre-agitation and agitation stages in AD.

CONCLUSIONS

The increased IL-1beta and decreased NKCA with the progress of agitation in AD suggest that inflammation produces agitation and aggravates AD.

Concurrent chemoradiotherapy with S-1 and cisplatin for locally advanced esophageal cancer

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Background: Both oral fluoropyrimidine anti-cancer agent (UFT, S-1) and cisplatin can enhance the effectiveness of radiotherapy. We previously reported a phase II trial of UFT and cisplatin combined with radiotherapy (Int J Clin Oncol 8 (2003): 305–311) and a phase I trial of S-1 and cisplatin combined with radiotherapy (Jpn J Cancer Chemother 33 (2006): 224–229) for advanced esophageal cancer. The present study analyzes the efficacy of concurrent chemoradiotherapy by using S-1 and cisplatin for locally advanced esophageal cancer. Methods: Chemoradiotherapy consisted of two courses. The first course included 30 Gy of radiotherapy given over 3 weeks, together with daily oral administration of S-1 (80 mg/m2/day) for 2 weeks and a 24-h infusion of cisplatin (70 mg/m2) on day 8. The second course of chemoradiotherapy was administered after 2 weeks. For patients who exhibited an objective response to chemoradiotherapy, at least 2 four-week courses consisting of chemotherapy of S-1 and cisplatinon were administered. If a patient was unable to take S-1 as a capsule, S-1 was administered in the powdered form with water. Results: Fifty-nine patients were enrolled. They had the following characteristics: median age 65 years; M/F 52/7; PS 0/1/2: 33/19/7. There were 9 patients with stage II tumors and 50 with stage III. Fifty-four patients (92%) completed 2 courses of chemoradiotherapy. The major toxicity was myelosuppression. Fifteen patients (25%) developed grade 3 leukocytopenia, while 7 patients (12%) developed grade 4 leukocytopenia. Nonhematologic toxicity was moderate: grade 2 nausea/vomiting, pain, oral mucositis, and renal dysfunction occurred in 20%, 12%, 5% and 5% of patients, respectively. In stage II cases, complete response (CR), partial response (PR), and response rates were 78%, 22%, and 100%, respectively. In stage III cases, CR, PR, and response rates were 58%, 32%, and 90%, respectively. All stage II patients survived. In stage III cases, the 1-year survival rate was 70% and the 3-year survival rate was 44%. Conclusions: Chemoradiotherapy with S-1 and cisplatin is convenient, tolerable, and effective, and may be a promising nonsurgical management option for patients with locally advanced esophageal cancer.

No significant financial relationships to disclose.

A phase I study of S-1 administration and a 24-h infusion of cisplatin plus paclitaxel in patients with advanced gastric cancer

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Background: S-1 may have a major role in the treatment of gastric cancer as single agent or as a component of combination chemotherapy in Japan. We previously reported a multicentric phase II study of S-1 combined with a 24-h infusion of cisplatin in patients with advanced gastric cancer. This combination was active, safe and had the possibility of being combined with other anticancer drug. Combination chemotherapy with S-1 and cisplatin plus paclitaxel for advanced gastric cancer might yield a stronger antitumor effect. The objective of this study was to determine the dose-limiting toxicity (DLT), the maximum tolerated dose (MTD), the recommended dose (RD), and the preliminary antitumor activity of S-1 and cisplatin plus paclitaxel for advanced gastric cancer. Methods: Paclitaxel was administered on day 1. A fixed dose of S-1 (70 mg/m2/day) was orally administered for 14 consecutive days from day 1, and a 24-h infusion of a fixed dose of cisplatin (60 mg/m2) was administered on day 14 of every 28-day cycle. Four dose escalation levels of paclitaxcel were studied (120, 140, 160, and 180 mg/m2). The DLT was defined as any of the following: grade 3 neutropenia lasting more than 5 days, grade 4 hematological toxicity, grade 3 non-hematological toxicity, or treatment delay of greater than 2 weeks as a result of toxicity. Results: Twenty patients were enrolled. Hematological and non- hematological toxicity of over grade 2 was not observed at dose level 1 and 2. Three patients started at dose level 3. One developed grade 3 neutropenia for 5 days following by grade 2 neutropenia lasted more than 10 days. Five more patients were added at this level. The treatment was delayed over 2 weeks in 1 out of 8 patients. Three patients started at dose level 4. One developed grade 3 neutropenia and needed longer than 14 days to recover. Three patients added this level. In total, at dose level 4 the treatment was delayed over 2 weeks in 3 out of 6 patients as a result of neutropenia. We considered level 4 is the MTD and the RD of paclitaxcel was 160 mg/m2 (dose level 3). The overall response rate was 75%. Conclusions: Triple combination chemotherapy consisting of S-1, cisplatin, and paclitaxel showed a tolerable dose of adverse reactions and favorable antitumor activity for gastric cancer.

No significant financial relationships to disclose.

Kinetics and Mechanism of (CF3)2CHOCH3 Reaction with OH Radicals in an Environmental Reaction Chamber

The atmospheric chemistry of (CF3)2CHOCH3, a possible HCFC/HFC alternative, was studied using a smog chamber/FT-IR technique. OH radicals were prepared by the photolysis of ozone in a 200-Torr H2O/O3/O2 gas mixture held in an 11.5-dm3 temperature-controlled chamber. The rate constant, k1, for the reaction of (CF3)2CHOCH3 with OH radicals was determined to be (1.40 +/- 0.28) x 10(-12) exp[(-550 +/- 60)/T] cm3 molecule(-1) s(-1) by means of a relative rate method at 253-328 K. The value of k1 at 298 K was (2.25 +/- 0.04) x 10(-13) cm3 molecule(-1) s(-1). The random errors are reported with +/-2 standard deviations, and potential systematic errors of 15% could increase k(1). In considering OH-radical reactions, we estimated the tropospheric lifetime of (CF3)2CHOCH3 to be 2.0 months using the rate constant at 288 K. The degradation mechanism of (CF3)2CHOCH3 initiated by OH radicals was also investigated using FT-IR spectroscopy at 298 K. Products (CF3)2CHOC(O)H, CF3C(OH)2CF3, CF3C(O)OCH3, and COF(2) were identified and quantified. The branching ratio, k1a/k1b, was estimated to be 2.1:1 for reactions (CF3)2CHOCH3 + OH --> (CF3)2CHOCH2*+ H2O (k1a) and (CF3)2CHOCH3 + OH --> (CF3)2C*OCH3 + H2O (k1b).

Free electron laser induces specific immobilization of heparin on polysulfone films

Covalent immobilization of heparin has been developed to reduce the amount of heparin administered systematically during long-term dialysis. Recently, it was doubted partially because of the complexion during immobilization process. In this study, we investigated a novel method for specific immobilization of heparin on polysulfone (PSF) via free electron laser (FEL) irradiation. Laser wavelengths of 6.18 or 6.31 microm, the typical absorption bands of carboxyl groups of heparin and aromatic rings in PSF, respectively, were chosen to irradiate the thin heparin membrane formed on PSF surfaces. The amount of heparin immobilized on PSF was measured by the toluidine blue method. The binding of heparin on PSF was analyzed by X-ray photoelectron spectroscopy (XPS). The immobilization of heparin resulted in a hydrophilic surface on which decreased platelet adhesion was observed. The efficiency differences, depending on laser wavelengths, were discussed from the point of view of structural and environmental differences of light-absorbing groups.

Anisotropy effects of Hele-Shaw cells on viscous fingering instability in dilute polymer solutions

We study the effect of anisotropy of the Hele-Shaw cell on the viscous fingering instability in dilute polymer solutions with shear thinning. In isotropic cells, the tip-splitting instability is observed at the same pressure gradient for a fixed polymer concentration, whereas in anisotropic cells the side oscillation instability occurs at higher pressure gradient than the tip-splitting instability. Narrowing of the finger width in the isotropic cell is well correlated with the tip-splitting instability, whereas the finger width in the anisotropic cell is almost independent of the sample. The modified Darcy's law, where the constant viscosity is replaced by the shear thinning viscosity, gives good agreement with the experiments, irrespective of the cell and the fluid.

Simultaneous induction of galectin-3 phosphorylated on tyrosine residue, p21(WAF1/Cip1/Sdi1), and the proliferating cell nuclear antigen at a distinctive period of repair of hepatocytes injured by CCl4

The period of repair of hepatocytes injured by CCl4 and signaling proteins intrinsic to this period were examined. A 30 kDa polypeptide detected by immunoblot analysis using anti-phosphotyrosine antibody in livers from rats 48 to 72 h after administration of a single dose of CCl4 was identified as galectin-3 induced in cytoplasm of periportal hepatocytes and phosphorylated on tyrosine residue(s). Simultaneously, these hepatocytes induced p21(WAF1/Cip1/Sdi1) in the nucleus and the proliferating cell nuclear antigen in both the nucleus and the cytoplasm, suggesting that hepatocytes during this distinctive period are quiescent and repair cellular damage. Trabecular architecture of hepatocytes with the proliferating cell nuclear antigen only in the nucleus was found at 96 h. These findings indicate that galectin-3 is a novel member of signaling proteins downstream of tyrosine kinase, and suggest that it plays roles in supporting repair or survival of the injured hepatocytes rather than their proliferation that is likely to be initiated later than 72 h.

Oxygen ion implantation at 20 to 2000 keV into polysulfone for improvement of endothelial cell adhesion

The irradiation effects of oxygen on polysulfone have been investigated at energies of 20 keV, 150 keV and 2 MeV. The strong improvement of endothelial cell adhesion and proliferation is found on ion irradiated polysulfone at 20 keV. Such improvement is declined with increasing ion energy. The changes of surface color and free energy are strongly dependent on ion energy and dose. The formation of amorphous carbon phase is demonstrated by Raman spectroscopy and its degree is correspondent to the color changes observed. The formations of hydroxyl and carboxyl groups are confirmed by the attenuated total reflectance (ATR) FTIR spectroscopy. The depletions of heteroatoms are conjectured by detail analysis of X-ray photoelectron spectroscopy (XPS). Since no single one of these changes can be related directly to the improved adhesion and proliferation of endothelial cells on irradiated surface, we argue that the distribution of functional groups is crucial in promoting the adhesion of endothelial cells. Although the distribution cannot directly be detected at present, the irradiation effects were related to the results of TRIM simulation. The surface changes can be controlled by adjusting the size energy and dose of irradiating ion for the optimum morphology to cell adhesion.

Transcription modulation by a rat nuclear scaffold protein, P130, and a rat highly repetitive DNA component or various types of animal and plant matrix or scaffold attachment regions

The XmnI fragment, a highly repetitive DNA component, and animal and plant matrix or scaffold attachment region (MAR/SAR) were examined for similarity in interaction with nuclear scaffold. As the XmnI fragment bound a 130 kDa scaffold protein (P130) in vitro, various types of MAR/SAR fragments could bind 130 and 123 kDa scaffold proteins. The native XmnI and MAR/SAR fragments clearly augmented SV40 promoter-mediated luciferase gene transcription following transient transfection of recombinant plasmids into various types of recipient cells. In contrast, the XmnI fragment methylated at the cytosine base of the unique HindIII site, and a synthetic variant DNA deficient in base unpairing characteristic of MAR/SAR, could neither bind P130 nor augment this transcription. These two types of genomic regions appeared to have similar properties of interaction with nuclear scaffold, by which the activity of appropriately positioned promoter can be modulated.

Subcutaneously inoculated cells and implanted pancreatic cancer tissue show different patterns of metastases in Syrian golden hamsters

CONTEXT

We studied behavior of the subcutaneously implanted pancreatic tumors and the process of metastasis using syngeneic Syrian golden hamsters.

DESIGN

HaP-T1, a cell line derived from nitrosamine-induced pancreatic cancer in Syrian golden hamsters was used for this experiment. Thirty-five animals were divided into two groups: subcutaneous cell inoculation and subcutaneous tissue implantation. The tumor tissue was obtained from subcutaneously implanted cancer cells. One month after implantation, the tumors were resected and studied histopathologically. The animals were followed-up weekly by palpation of the peripheral lymph nodes in order to identify local recurrence. After death, necropsy was performed. Liver, lungs and pancreas specimens were taken for histopathogical study and detection of K-ras point mutation using the PCR/RFLP method.

RESULTS

The mean survival time in the subcutaneous cell inoculation group was 151+/-17.5 days, and in the subcutaneous tissue implantation group was 137 +/-12.9 days. During the follow-up, 13 subcutaneously cell inoculated hamsters (86.7%) had right axillary lymph node metastasis while subcutaneously tissue implanted hamsters did not show any palpable lymph nodes. After necropsy, 10 of the 20 subcutaneously tissue implanted animals (50%) showed metastases in the lungs at the histopathological level. However, 16 of the 20 subcutaneously tissue implanted animals (80%) showed K-ras point mutation in the lung specimens. The lungs of the animals of the subcutaneous cell inoculation group did not show any metastases. No metastases were found in the liver or the pancreas in either group.

CONCLUSION

This study suggests that homologous subcutaneous cell inoculation and subcutaneous tissue implantation models showed completely different patterns of metastasis. These models may aid further research to clarify the mechanisms of metastasis in pancreatic cancer.

Interaction of albumin mRNA with proteins from rat liver with CCl(4)-induced injury

Acute phase responses to intragastric administration of a single dose of CCl(4) were examined with albumin mRNA turnover as a marker. Based on the combination of the changes in stability of albumin mRNA and activity of transcription of its gene, the entire course of liver injury was classified into three stages, the first stage for aggravation of injury until 9 h, the second from 9 to 24 h, and the third for repair of injury or regeneration of liver after 48 h. Liver S100 fractions from normal and CCl(4)-treated rats contained, in total, 11 polypeptides cross-linked with part of albumin mRNA, although they did not appear to be specific to this mRNA. Their profiles were altered together with the changes in stability of albumin mRNA in different stages. These findings suggest that the polypeptides with distinct properties play roles in physiologically significant processes involved in utilization and turnover of albumin mRNA, apparently altering its stability.

Usefulness of dental implants in maxillofacial reconstruction

Fabricating maxillofacial prosthesis can be challenging. Placement of implants can have a dramatic effect on the stability and retention of the prosthesis in patients. This article provides clinical retrospective analysis of osseointegrated implants used for maxillofacial reconstruction. Patient charts and radiographs were reviewed to determine implant status, stability of prosthesis, and masticatory and speech function. Of the 104 implants placed, there were 4 implant failures. The overall survival rate for implants in this patient population was 96.1%. The stability of maxillofacial prostheses demonstrated significant improvement after anchorage to implants. Implant-borne maxillofacial prostheses are better stabilized and retained than non-implant-borne prostheses, providing an improved quality of life to patients requiring prosthesis rehabilitation of maxillofacial defects.

[Functional arrangement of genomic DNA and structure of nuclear matrix]

The nuclear matrix (nuclear scaffold), the RNA-protein skeleton of the nucleus, has a role in the organization and function of nuclear DNA. Nuclear processes associated with the nuclear matrix include transcription, replication, repair and splicing. We have purified a nuclear matrix protein, P130, which binds to several matrix attachment regions (MARs). Since the nucleotide sequence of P130 cDNA cloned by us was closely similar to that of matrin 3 cDNA cloned, except for two incorrect nucleotides within the matrin 3 coding region, and since the functions of matrin 3 were unknown, P130, referred to as P130/Mat3, was functionally characterized. The primary structure deduced for P130/Mat3 contained two DNA binding domains with C2H2-type zinc finger motif and two RNA binding domains. In addition, there were a nuclear localization signal and several phosphorylation sites for tyrosine or serine/threonine protein kinases, suggesting its multiple functions. MAR inserted upstream from the SV40 promoter in pMAR/luc assisted luciferase gene transcription in a transient expression system in Ac2F cells. Cotransfection of a plasmid carrying P130/Mat3 cDNA downstream from the CMV promoter into Ac2F cells produced this protein a level 4 times higher than that in wild-type Ac2F, causing 20 times higher luciferase activity from pMAR/luc than that induced by pMAR/luc alone. These findings indicated that MAR functions as a cis-element to which P130/Mat3 binds as one of the possible transactivators. Nuclear matrix proteins, which are tissue- and cell-type-specific, are altered with transformation and state of differentiation. We have shown that an MAR binding protein, P230, is detectable in rat hepatoma cells but not in normal liver, and suggested that this protein is a diagnostic and prognostic marker for liver cancer. It is clear that nuclear matrix proteins hold a considerable promise as diagnostic tools for pathologists. Present evidence, including our data, suggests that nuclear matrix proteins may be useful biomarkers of neoplastic disease in the serum, body fluids, and tissues. Nuclear matrix proteins are also potential candidates for the use as tumor prognostic factors and targets of anticancer drugs through apoptosis. We will discuss screening of drugs that interact with nuclear matrix proteins and influence nuclear events.

[Analysis of micronuclei induced under hyperthermic conditions in human lymphocyte culture by fluorescence in situ hybridization (FISH) and spectral karyotyping (SKY) methods]

The spectral karyotyping (SKY) method is a novel molecular cytogenetic technique which simultaneously discerns entire chromosomes. In order to elucidate the origins of micronuclei induced under hyperthermic conditions in human lymphocyte culture, peripheral blood cells were cultured at 40 degrees C or 42 degrees C for 3-24 h, using the cytokinesis-block method with cytochalasin B. The induced micronuclei were identified by the fluorescence in situ hybridization (FISH) and SKY methods. At 42 degrees C for more than 6 h, the frequency of occurrence of micronuclei in binucleated cells rose with increasing incubation time. By the FISH method, 83.3% of micronuclei induced in 24 h culture at 42 degrees C were shown to be positive for the human centromeric probes. By the SKY method, each micronucleus induced under the hyperthermic conditions was identified unequivocally and shown to contain a specific chromosome. These results suggest that the micronuclei induced under the hyperthermic conditions in human lymphocyte culture contain chromosomes which do not migrate to the poles at the anaphase of the cell cycle because of the breakdown of the spindle apparatus.

Enhancement of excision repair of cisplatin-DNA adducts by cell-free extract from a cisplatin-resistant rat cell line

To characterize the enhanced repair synthesis of defined DNA lesions, oligodeoxyribonucleotides were synthesized and inserted into plasmid DNA. The inserted plasmid DNA was treated with cis-diamminedichloroplatinum(II) (cisplatin) and subjected to in vitro DNA repair assay with soluble extract from the rat liver cell line Ac2F. All cisplatin adducts tested stimulated DNA repair synthesis. Moreover, two cisplatin-resistant cell lines, Ac2F-CR4 and Ac2F-CR10, were established by stepwise exposure of Ac2F cells to this drug. The DNA repair synthesis was enhanced 3- to 4-fold in the extract from cisplatin-resistant Ac2F cells relative to that from Ac2F cells. Such repair synthesis was suppressed by the specific DNA polymerase inhibitor aphidicolin. The results of the present study suggested that the enhanced repair activity induced by a cisplatin adduct can be detected by in vitro DNA repair assay with soluble cell extract.

Application of bis-eugenol to a zinc oxide eugenol cement

OBJECTIVES

To assess the usefulness of dimerized eugenol (bis-eugenol) in dentistry, the physical properties of zinc oxide eugenol cement (ZOE) with bis-eugenol and the cytotoxicity of bis-eugenol were studied.

METHODS

Setting time, compressive strength, solubility and disintegration of ZOE cement with bis-eugenol according to the specifications of JDMAS315 were evaluated. The cytotoxicity of bis-eugenol and eugenol toward two different cell types, HGF (a primary culture of human gingival fibroblast) and HSG (a human epidermoid carcinoma cell line derived from a salivary gland) was evaluated by the MTT test and in terms of cell survival.

RESULTS

Addition of bis-eugenol to ZOE did not decrease the physical properties when employed at the ratio of 9:1 or 6:1 (liquid ND:bis-eugenol, w/w). Bis-eugenol was less toxic than eugenol in the cell culture tests.

CONCLUSIONS

The results of this assay demonstrated that bis-eugenol is useful in ZOE.

Continuous treatment with morphine increases diazepam binding inhibitor mRNA in mouse brain

Effects of acute and chronic morphine treatment on the expression of diazepam binding inhibitor (DBI) mRNA in the mouse brain were examined. Cerebral DBI mRNA expression significantly increased in morphine-dependent mice, and this increase is more remarkable in morphine-withdrawn mice, whereas a single administration of morphine (50 mg/kg) produced no changes in the expression. Simultaneous administration of naloxone (3 mg/kg) with morphine completely abolished the increase in cerebral DBI mRNA expression observed in morphine-dependent and -withdrawn mice. These results indicate that a chronic functional interaction between morphine and opioid receptors has a critical role in increases in DBI mRNA expression.

Involvement of DNA methylation in binding of a highly repetitive DNA component to nuclear scaffold proteins from rat liver

Experimental reduction of the amount of CpG methylation in a highly repetitive DNA component was achieved by growth of Ac2F cells in the presence of 5-aza-2'-deoxycytidine or procainamide, as judged by the results of methyl-sensitive restriction endonuclease digestion and colony hybridization. Modification of genomic DNA with these DNA methylation inhibitors increased the release of 370-bp highly repetitive DNA from rat chromosomal DNA by HindIII digestion. This result indicated that highly repetitive DNA components in the nuclear scaffold fraction are hypermethylated. On the other hand, methylated DNA was used for southwestern analysis to investigate the protein(s) which bind specifically to the DNA in the nuclear scaffold fraction. The introduction of additional methylated cytosines within a highly repetitive DNA component affected the binding of DNA to the nuclear scaffold proteins. Thus, cytosine methylation may be involved in the regulation of gene expression and construction of the higher-order structure of chromatin.

Removal of hydroxyl radical facilitates Ca2+-dependent [3H]GABA release by peroxynitrite

We investigated mechanisms for enhancement of peroxynitrite (OONO-; 5 microM)-evoked [3H] gamma-aminobutyric acid (GABA) release. Hydroxyl radical scavengers such as N,N'-dimethylthiourea (DMTU), mannitol, and uric acid, significantly increased OONO--evoked [3H]GABA release, whereas urea showed no effects on the release. Removal of Ca2+ from incubation buffer abolished the enhancement of the release by DMTU, although DMTU showed no effects on the basal release with and without Ca2+ in extracellular space. These results indicate that hydroxyl radical scavengers facilitate OONO--evoked [3H]GABA release dependent on Ca2+.

Mechanisms for facilitation of nitric oxide-evoked [3H]GABA release by removal of hydroxyl radical

We have investigated the mechanisms for enhancement of nitric oxide (NO)-evoked gamma-[3H]aminobutyric acid ([3H]GABA) release from mouse cerebrocortical neurons by hydroxyl radical (.OH) scavengers. .OH scavengers, such as N,N'-dimethylthiourea (DMTU), uric acid, and mannitol, dose-dependently facilitated NO-evoked [3H]GABA release evoked by NO liberated from S-nitroso-N-acetylpenicillamine. Ionomycin-evoked [3H]GABA release, which was significantly inhibited by hemoglobin and an NO synthase, N(G)-methyl-L-arginine, was also enhanced by DMTU. These results indicate that GABA release evoked by both endogenous and exogenous NO is facilitated by .OH scavengers. These enhancing actions of .OH scavengers were completely abolished by Ca2+ removal from incubation buffer and by an L-type voltage-dependent Ca2+ channel (VDCC) inhibitor, nifedipine, whereas each .OH scavenger showed no effects on [3H]GABA release in the absence of NO. Inhibitors for P/Q- and N-type VDCCs had no effects on the enhancement. NO-induced 45Ca2+ influx was also dose-dependently enhanced by .OH scavengers, although 45Ca2+ influx was not altered by .OH scavengers in the absence of NO. Nifedipine abolished this enhancement of the NO-induced 45Ca2+ influx by .OH scavengers. These results indicate that the removal of .OH by its scavengers facilitates the NO-evoked [3H]GABA release dependent on Ca2+ and that this enhancement is due to the increase in Ca2+ influx via L-type VDCCs.

Enhancement of peroxynitrite-evoked acetylcholine release by hydroxyl radical scavengers from mouse cerebral cortical neurons

We investigated the effects of hydroxyl radical scavengers on peroxynitrite (OONO-)-evoked acetylcholine (ACh) release from mouse cerebral cortical neurons. N,N'-dimethylthiourea, a hydroxyl radical scavenger, dose-dependently increased OONO(-)-evoked ACh release. Other hydroxyl radical scavengers such as uric acid and mannitol, also enhanced OONO(-)-evoked ACh release, although these enhancing effects were not found in the absence of OONO-. In addition, OONO(-)-induced [45Ca2+]influx was significantly facilitated by the scavengers, whereas no effects of the scavengers on [45Ca2+]influx was observed in the absence of OONO-. These results indicate that hydroxyl radical scavengers enhance OONO(-)-evoked ACh release via the facilitation of OONO(-)-induced [45Ca2+]influx.

New superselective intra-arterial infusion via superficial temporal artery for cancer of the tongue and tumour tissue platinum concentration after carboplatin (CBDCA) infusion

We developed a new technique of superselective intra-arterial chemotherapy for tongue cancer using a modified (1.35 mm) angiographic catheter. The catheter was confirmed to be inserted into the lingual artery by the new technique. We measured the platinum concentrations in resected tumour tissues after infusion of carboplatin (CBDCA) at 20 mg/m2 over 30 min from 30 min before tumour resection in 12 patients with cancer of the tongue (6 patients: superselective intra-arterial infusion; 6 patients: conventional intra-arterial infusion). The mean platinum concentration in tumour tissue was 10.5 +/- 1.2 micrograms/g wet, which was more than twice higher than, and significantly different from, 4.3 +/- 3.8 micrograms/g wet by the conventional intra-arterial infusion method. This new superselective intra-arterial infusion method allows direct infusion of the anticancer agent into the artery supplying the tumour and is expected to become a new therapeutic modality for cancer of the tongue.

Continuous treatment with nicotine increases diazepam binding inhibitor (DBI) and its mRNA in the mouse brain

Effect of chronic treatment with nicotine on DBI and its mRNA in mouse cerebral cortex were examined. Continuous treatment of mice with nicotine significantly increased DBI content and its mRNA expression, which was completely abolished by simultaneous administration of mecamylamine (1 mg/kg, i.p.). These results indicate that chronic functional interaction between nicotine and nicotinic acetylcholine receptors has a critical role in increases in DBI content and its mRNA expression.

Involvement of phosphorylation in binding of nuclear scaffold proteins from rat liver to a highly repetitive DNA component

The results of our previous work [Hibino et al., Biochim. Biophys. Acta 1174 (1993) 162-170] suggested that a highly repetitive DNA component facilitates bending of the helix axis to be recognized by the nuclear scaffold proteins from rat liver, P123 and P130. In the present experiment, it was shown that binding of these proteins to such a repetitive DNA component from rat liver nuclei (370-bp XmnI fragment) is based on a cooperative mode of interaction, although the binding activity of P130 is much higher than that of P123. The immunoblot analysis with anti-phosphoamino acid antibodies suggested that phosphorylation of serine and threonine residues occurs on P123 and P130, but also of tyrosine residue(s) on P130. The phosphatase assay showed that phosphoryl groups on these proteins may be involved in altering the DNA binding activities of the proteins. Thus, the results in the present study imply that phosphorylation of a nuclear scaffold protein in addition to the degree of bending of the DNA helix axis plays an important role in anchoring chromatin to the nuclear scaffold and in construction of a higher-order chromatin structure.

Functional involvement of benzodiazepine receptors in ethanol-induced increases of diazepam binding inhibitor (DBI) and its mRNA in the mouse brain

We have attempted to clarify the mechanisms for alcohol (EtOH)-induced elevation of diazepam binding inhibitor (DBI) mRNA and to investigate whether the increase in DBI mRNA is paralleled with that in DBI using EtOH-treated mice and primary cultured neurons. Both the DBI content and the expression of DBI mRNA were elevated in the cerebral cortex of EtOH-inhaled and -withdrawn mice. Simultaneous administration of flunitrazepam (FLN) and Ro15-1788 with EtOH vapor completely abolished the EtOH-induced elevation of DBI mRNA. In addition, the exposure of the neurons for 3 days significantly elevated the expression of DBI mRNA, which was completely inhibited by concomitant exposure of FLN, Ro15-4513 and Ro-15-1788 with EtOH, while muscimol and bicuculline showed no effects on the EtOH-induced increase of DBI mRNA expression. These results indicate that functional interaction between EtOH and benzodiazepine (BDZ) receptors is a critical role in the increased expression of DBI mRNA.

Multiple actions of nitric oxide on voltage-dependent Ca2+ channels in mouse cerebral cortical neurons

We investigated the effects of nitric oxide (NO) on voltage-dependent Ca2+ channels (VDCCs) by examining [45Ca2+]influx into mouse cerebral cortical neurons. S-nitroso-N-acetylpenicillamine (SNAP) induced a dose-dependent increase in [45Ca2+]influx, which was completely abolished by hemoglobin, tetrodotoxin and dibucaine. The NO-induced [45Ca2+influx was significantly inhibited by verapamil and omega-agatoxin VIA (omega-AGX), whereas omega-conotoxin GVIA (omega-CTX) had no effects on the NO-induced [45Ca2+]influx. KCl (30 mM) stimulated [45Ca2+]influx, and verapamil, omega-CTX and omega-AGX reduced the KCl-induced [45Ca2+]influx by about 40, 26 and 34%, respectively, indicating that the neurons used here possess L-, N- and P-typed VDCCs. SNAP itself reduced KCl-induced [45Ca2+]influx by about 28.5%. In the presence of both KCl and SNAP, omega-CTX showed no effects on the influx, while verapamil and omega-AGX significantly inhibited the influx and the concomitant presence of verapamil and omega-AGX completely abolished the influx. These results indicate that NO induces [45Ca2+] influx via the opening of L- and P-typed VDCCs subsequent to neuronal membrane depolarization and that NO itself inhibited the function of N-typed VDCC in the cerebral cortical neurons.

Purification and characterization of a DNA binding protein in a nuclear scaffold fraction from rat ascites hepatoma cells

Our most recent work [Hibino et al. (1995) Cancer Lett., 88, 49-55] has shown that the selective binding affinities of highly repetitive DNA components for a nuclear scaffold protein from rat ascites hepatoma cells (P230) depend on the degree of sequence-directed bending of the helix axis. In the present experiment, this protein has been highly purified and isolated by a series of column chromatographic procedures to migrate as a single band to a molecular weight position of 230 kd on a SDS-polyacrylamide gel. A filter binding assay showed that the binding of a repetitive AT-rich component (369 bp XmnI fragment) from the hepatoma nucleus, which has a strongly bent overall structure, to isolated P230 is based on a cooperative mode of interaction. Distamycin A, which binds specifically to AT-rich DNA, removed the bend in the XmnI fragment and inhibited binding to this protein. These results suggest that AT-rich regions in highly repetitive DNA cause bending of the helix axis to be recognized by nuclear scaffold protein(s). Moreover, it has been shown that the nuclear scaffold fraction from rat liver or an actively growing hepatocyte cell line (Ac2F cells) does not contain P230, but does have a repetitive bent DNA binding protein (P130), which has an apparent molecular weight of 130 kd. In addition, the immunoblot analysis showed that mouse anti-P130 antiserum reacts with P230. Thus, the results in the present study imply that there is some difference in the higher order structure of the nuclear DNA attachment region between rat liver or actively growing hepatocytes and the hepatoma, although P230 appears to be immunochemically similar to P130.

Clinical results of cultured epithelial cell grafting in the oral and maxillofacial region

Cultured epithelium has proven to be a good grafting material for skin defects. In our experience two kinds of epithelial cells, skin keratinocytes and mucosal cells, have been used to fabricate cultured epithelial sheets and autografted to the patients. Traumatic scars of the face were treated by cultured epidermal epithelium (CEE). The skin graft in the oral cavity was replaced by mucosa using cultured mucosal epithelium (CME). Also, the CME was applied to the skin defects at the donor sites of split-thickness skin grafts. Postsurgical follow-up showed good results. As a result, CME was useful in improving the biological environment around the abutments of dental implants, and it also promoted the re-epithelialization of skin defects. From our investigations, CEE/CME are promising treatment modalities which can reduce pain and speed up the healing process in burn patients. Therefore, cultured epithelium banks are worth establishing for auto- and allografting of skin/mucosal defects.

[Morphology and origin of micronuclei induced by mitotic inhibitors]

In order to elucidate the morphological variation and the origin of erythrocytic micronuclei induced by mitotic inhibitors, each of clastogens (mitomycin C and cyclophosphamide) and spindle poisons (vincristine and colchicine) was administered intraperitoneally into a rat. After 24 h, the bone marrow smear was prepared and subjected to the microscopic analysis. In consequence, the sizes of micronuclei (MNSs) induced by spindle poisons were generally larger than those (MNCs) induced by clastogens. On the other hand, the bone marrow cells containing micronucleated erythrocytes were fractionated by cellulose column chromatography and then Percoll-gradient centrifugation. The micronuclear DNA was extracted from the resulting erythrocyte fraction and subjected to the dot blot hybridization with a centromeric or telomeric DNA probe. This experiment showed that centromeric and/or telomeric DNAs are enriched more in MNSs than in MNCs. Thus, such hybridization techniques and the morphological analysis would be available for classifying micronucleus-inducing drugs.

Structural changes and cell viability of cultured epithelium after freezing storage

Numerous clinical reports have shown the utility of cultured epithelial grafting in the field of plastic and reconstruction surgery. Recently, freezing storage of the cultured epithelium has been tried and has successfully grafted after thawing. It is clinically convenient if it is possible for cultured epithelium to keep its normal structure and viability. However, few papers have described the structural changes in cultured epithelium after freezing storage. In the present study, the morphological changes and cell viability of cultured mucosal epithelial sheets after freezing were studied in comparison with cultured epidermal sheets. Furthermore, we discuss the effect of storage temperature and cryoprotectants. As a result, there were some structural changes such as vacuolar degeneration in the cultured mucosal sheets using dimethyl sulphoxide (DMSO) as a cryoprotectant. Such changes were more clearly observed at -80 degrees C than at -196 degrees C with DMSO. However, little morphological change was observed in both epithelial sheets cultured with glycerin. The cell viability analysed by flow cytometry showed that more than 62% of the cells kept their viability after freezing storage. These results suggest that the optimum conditions of freezing for cultured epithelium were -196 degrees C storage by slow cooling methods with glycerin as a cryoprotectant.

Enhancement of DNA repair activity in rat-liver cells exposed to cisplatin

Rat-liver cells (Ac2F cells) were transfected with cisplatin-damaged eucaryotic expression vectors carrying luciferase cDNA (cis-DDP-pVJ3luc) and incubated. The lysate of the incubated cells was subjected to a luciferase activity assay. Graded decrease in the activity was observed with increasing levels of platination of the plasmid DNA. In another experiment, Ac2F cells were pre-incubated in the presence of cisplatin ranging in concentration from 0.5 to 3 mu M. The viable cells were transfected with cis-DDP-pVJ3luc and incubated in the absence of this drug. The lysate of the incubated cells was subjected to the same assay. The level of the luciferase activity was raised with increasing cisplatin concentration. These results suggest that the repair activity for cis-DDP-pVJ3luc DNA is enhanced in Ac2F cells exposed to cisplatin.

Cisplatin-modified DNA-binding proteins in a nuclear extract of rat-liver cells

A mobility shift DNA-binding assay showed that cisplatin-modified DNA-binding proteins are present in the nuclear extract of rat-liver cells (Ac2F cells). The major binding proteins of 22.5, 23, 96.5 and 112 kDa were identified in vitro. The binding activity of the 23 kDa protein was markedly enhanced in the cells that were cultured in the presence of cisplatin, and was inhibited by addition of cycloheximide to the culture. Our previous work [Hibino et al. (1994) Biochem. Biophys. Res. Commun. 202, 749-756] has shown that an Mg(2+)-dependent endo-exonuclease activity endogenous to Ac2F-cell nuclei is enhanced in the presence of cisplatin. Thus, the results of the present study imply that specific binding of the nuclear proteins to cisplatin-DNA lesions in rat-liver cells is involved in the mechanism of enhancement of this nuclease activity.

Binding affinities of highly repetitive DNA components for a nuclear scaffold protein from rat-ascites hepatoma cells

Separate samples of a self-ligated tandem dimer of a highly repetitive DNA component (369-bp HindIII fragment) from rat-ascites hepatoma nuclei were digested with different restriction enzymes that cleave only once in the monomer. The resulting 369-bp sequence-permuted monomers showed anomalously slow gel electrophoretic mobility. Of them, the XmnI fragment had the slowest mobility. This suggests that bending of the helix axis is the strongest in this fragment. Our previous work has shown that such a repetitive bent DNA has selective affinities for two nuclear scaffold proteins from rat liver that have molecular weights of 123,000 and 130,000 Hibino et al. (1992) Biochem. Biophys. Res. Commun., 184, 853-858; Hibino et al. (1993) Biochim. Biophys. Acta, 1174, 162-170). In the present experiment, it has been found that the nuclear scaffold fraction from rat-ascites hepatoma cells does not contain these proteins, but does have a repetitive bent DNA-binding protein that has a molecular weight of about 230,000. These results imply that there is some difference in the structure of nuclear DNA attachment region between rat liver and the hepatoma.

[The mechanism of potentiation of the antitumor effect of 5-fluorouracil by methionine-free intravenous amino acid solution (AO-90) in rats]

AO-90, a methionine-free intravenous amino acid solution (7.43%) showed to potentiate the antitumor effect of 5-fluorouracil (5-FU) when concomitantly used as the nitrogen source in total parenteral nutrition (TPN) in Yoshida sarcoma (YS)-bearing rats. In the present experiment, this potentiation mechanism was studied by determining the serum methionine level and tumor methylenetetrahydrofolate (CH2FH4) content in YS-bearing Donryu rats given AO-90 (nitrogen 0.73g/kg on the 1st day and 1.46g/kg for the remaining 6 days) by TPN for 1 week. The rats were subcutaneously inoculated with 10(4) YS cells in the dorsum 3 days before the start of TPN. Inhibition of thymidylate synthase activity in tumor tissue after dosing of AO-90 (nitrogen 0.68g/kg on the 1st day and 1.36 g/kg for the remaining 6 days) by TPN along with daily intraperitoneal dosing of 5-FU (10 mg/kg) was also evaluated with the inoculation of 10(6) tumor cells. The results were compared with those in tumor-bearing rats given TPN with a commercially available amino acid solution containing methionine. On day 5 of TPN, the tumor-bearing rats given AO-90 showed a significantly lower serum methionine level than the control rats: 101 +/- 11 mumol/l versus 29 +/- 14 mumol/l (p < 0.01); and a higher CH2FH4 content in tumor: 7.0 +/- 2.8 pmol/g protein versus 23.7 +/- 16.6 pmol/g protein (p < 0.05). Thymidylate synthase inhibition was 81.2 +/- 5.1% in the AO-90 group and 30.9 +/- 26.3% in the control group (p < 0.01). The results of the present study suggest that AO-90 potentiate the antitumor effect of 5-FU by biochemical modulation. AO-90 concomitantly given with 5-FU for 7 days was effective not only in the allogeneic tumor model, but also in WKAH and SHR rats previously inoculated with 10(6) of syngeneic KDH-8 hepatoma cells and SST-2 adenocarcinoma cells, respectively. Weight of SST-2 adenocarcinoma in SHR rats after the TPN period was significantly smaller in the AO-90 group than in the control rats given methionine-containing TPN and 5-FU: 2.66 +/- 0.91 versus 5.12 +/- 2.11 (p < 0.05).

Enhancement of an Mg(2+)-dependent nuclease activity in rat liver cells exposed to cisplatin

An Mg(2+)-dependent deoxyribonuclease activity was highly purified from a 0.6 M NaCl extract of rat-liver nuclei. The template primer activity assay with a Klenow polymerase suggested that this nuclease plays a role in incision/excision of cisplatin-modified DNA strands to form single-strand gaps. In another experiment, rat-liver (Ac2F) cells were cultured in the presence of cisplatin. A 0.6 M NaCl extract was prepared from the cultured-cell nuclei and subjected to the activity blotting analysis [Seki et al. (1993) J. Chromatography 618, 147-166]. The nuclease activity of the extract was enhanced in response to cisplatin, but not in the presence of cycloheximide. These results imply that cisplatin-DNA lesions induce the Mg(2+)-dependent deoxyribonuclease activity in Ac2F cells to provide priming sites for the repair synthesis.

Productions of interferon-gamma and nitrite are induced in mouse splenic cells by a heteroglycan-protein fraction from culture medium of Lentinus edodes mycelia

A xylose-rich heteroglycan-protein fraction (LAP1) was prepared from a solid culture medium in which Lentinus edodes mycelia were growing actively. Mouse splenic cells (SPs) were incubated with [3H]TdR in the presence of LAP1. The incubated SPs were fractionated into plastic adherent splenic cells (ADs), nylon-column effluent splenic cells (NEs) and sIg-expressed splenic cells (SIs), which are rich in Mac-1+, Thy-1.2+ and Ly-5+ cells, respectively. The incorporation of [3H]TdR in response to LAP1 was enhanced in each of the fractionated cell populations. Northern or dot blot hybridization showed that productions of IFN-gamma and its receptor mRNAs are induced predominantly in NEs. In another experiment, SPs were fractionated into ADs, NEs and SIs. Then, NE-AD, SI-AD and NE-SI mixtures were prepared and incubated in the same manner. A significant incorporation of [3H]TdR was shown only in the NE-AD mixture. The enzyme-linked immunosorbent assay showed that IFN-gamma production in response to LAP1 is induced in SPs or in the NE-AD mixture, but not in NEs alone. The level of the production was about 5 times higher in the mixture than in SPs after a 72 h incubation. Moreover, LAP1 was capable of inducing NO2- production in SPs. Thus, the present studies imply that this heteroglycan-protein fraction stimulates productions of IFN-gamma and nitrite in mouse splenic cells, augmenting antitumor immune response(s).

Photosensitivity in Ge-doped silica optical waveguides and fibers with 193-nm light from an ArF excimer laser

Photosensitivity in optical fibers and waveguides has been associated with the bleaching of an absorption band located near 5.0 eV (or 242 nm). We present new results for Bragg grating formation and UV bleaching experiments carried out using 193-nm light from an ArF excimer laser instead of the usual laser sources operating near 242 or 248 nm.

Properties of a DNA-binding protein from rat nuclear scaffold fraction

Our previous work [Hibino et al. (1992) Biochem. Biophys. Res. Commun. 184, 853-858] has shown that a highly repetitive component in rat nuclear DNA forms a sequence-directed bend to have the binding affinity for the nuclear scaffold protein, P130. In the present experiment, the mobility shift DNA-binding assay suggested that the formation of the repetitive component-P130 complex is based on some cooperative mode of interaction. The DNase I footprint analysis revealed that the major binding region of this protein in the DNA is located near the center of the 370-bp XmnI repeat which has a strongly bent overall structure. These results imply that a nuclear scaffold protein such as P130 binds to sequence-directed bend(s) in a highly repetitive DNA to play an important role in construction of a higher-order chromatin structure.