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Biomedical subjects

A Kohno

Publications and source records attributed to A Kohno.

At least 37 records · Page 2Linked to original sources
PubMed1998

Semliki Forest virus-based DNA expression vector: transient protein production followed by cell death.

We have constructed a novel DNA expression vector based on Semliki Forest virus (SFV). SFV produces non-structural proteins (nsPs) which replicate genomic RNA and amplify the mRNA encoding the structural proteins of SFV. A recombinant cDNA genome of SFV, in which the SFV structural genes were replaced by a polylinker cassette to allow for insertion of heterologous DNA, was placed under the control of a cytomegalovirus immediate-early enhancer/promoter with a polyadenylation signal. Transfection of mammalian cells with this SFV-based plasmid vector, pSFV3-CMV-lacZ-pA, resulted in transient high-level expression of a beta-galactosidase reporter gene. The expression level of beta-galactosidase from pSFV3-CMVlacZ-pA was more than 20-fold higher than that obtained from the plasmid with deleted nsPs genes, pSFV3A5976-lacZ, demonstrating that the nsPs genes were essential for the high level of expression. Substantial beta-galactosidase activity was detected in the medium of pSFV3-CMV-lacZ-pA-transfected cells, suggesting that the overproduction of beta-galactosidase caused cell death and release of the protein into the medium. We have demonstrated a high-level expression of the exogenous beta-galactosidase gene from pSFV3-CMV-lacZ-pA constructed using an SFV replication system.

Animals↗
PubMed1998

Biocompatibility of Clearfil Liner Bond 2 and Clearfil AP-X system on nonexposed and exposed primate teeth.

OBJECTIVE: Recent studies have demonstrated that acid etching of vital dentin and pulpal tissue does not retard pulpal healing, odontoblastoid cell differentiation, or dentinal bridge formation when the pulp is capped with adhesive resins. The purpose of this study was to evaluate the pulpal response in nonexposed and exposed monkey pulps to treatment with the Clearfil Liner Bond 2 and Clearfil AP-X system. METHOD AND MATERIALS: Class V and Class I cavities in nonexposed and exposed pulps were observed at 7 or 8, 27, and 97 days. RESULTS: There were no differences in pulpal inflammation between the Clearfil Liner Bond 2/Clearfil AP-X specimens and calcium hydroxide controls in either Class V or Class I cavities at the various time periods. CONCLUSION: Clearfil Liner Bond 2 and Clearfil AP-X system is not toxic to either nonexposed or exposed pulpal tissues when placed according to manufacturer's directions.

Animals↗
PubMed1998

[Influence on patients with Sjögren's syndrome after the Great Hanshin-Awaji Earthquake].

We investigated the influence of clinical findings on patients with Sjögren's syndrome after the Great Hanshin-Awaji Earthquake. Fifty eight (90%) of 64 patients were struck severely by the earthquake and 26 patients (42%) were forced to take refuge in emergency shelters. There was no aggravation of clinical findings or complications in eight patients inhabiting the area where the damage was mild. Dry eyes were deteriorated in 14 patients (22%). Dry mouth was aggravated in 6 patients (9%). However, the mean values of Schirmer's test and gum test were not different between pre-earthquake and postearthquake in these patients. Malaise was worsen in 8 patients (13%). The cause was cease of taking prednisolone for autoimmune hepatitis in 2 patients or was impossibility of taking T4 drug for hypothyroidism in 2 patients. Other 4 patients had not taken any medication. Arthralgia was deteriorated in 4 patients (5%). These findings indicated that deterioration of sicca symptoms, arthralgia and malaise was caused predominantly by the worsen living condition including shortage of water and polluted atmosphere in the affected regions.

Disasters↗
PubMed1997

In vitro toothbrush-dentifrice abrasion of resin-modified glass ionomers.

OBJECTIVES: This study was conducted to compare the rate of abrasive wear and change in surface roughness of resin-modified and conventional acid-base glass ionomers when subjected to toothbrush-dentifrice abrasion. METHODS: Two resin-modified and two conventional glass ionomers were used. Samples of a high-copper amalgam and a hybrid resin composite were used as reference materials. Specimens of each material were prepared and subjected to toothbrush-dentifrice abrasion using 20,000 strokes of brushing. The amount of vertical loss of material was determined by profilometry (Surfcom-4A, Tokyo-Seimitsu, Tokyo, Japan). The surface characteristics after abrasion were evaluated on secondary electron images by SEM, and the surface hardness (KHN) was also measured for all materials. Data were analyzed by one-way ANOVA (p < 0.05), followed by a multiple comparisons test using LSD (Least-significant difference) at a level of p < 0.05. RESULTS: The abrasion resistance of resin-modified glass-ionomers was statistically lower for the amalgam and the resin composite reference materials. Statistically lower abrasion resistance and surface hardness were observed for the resin-modified glass ionomers than for their conventional acid-base counterparts when two forms of products from the same manufacturer were compared. SEM observations made after abrasion testing showed a significantly rougher surface for all glass ionomer materials than for the amalgam and the resin composite. SIGNIFICANCE: When comparisons were made between products from the same manufacturers, it was found that in vitro resistance to toothbrush-dentifrice abrasion of the resin-modified glass ionomers is inferior to that of the conventional acid-base glass ionomers. The lower abrasion resistance found in the resin-modified products appears to be related to their lower surface hardness.

Aluminum Hydroxide↗
PubMed1996

Induction of humoral and cellular anti-idiotypic immunity by intradermal injection of naked DNA encoding a human variable region gene sequence of an immunoglobulin heavy chain in a B cell malignancy.

The idiotypic determinants of a B cell neoplasia could provide a tumor-specific target for vaccinating patients against their B cell tumors. Several approaches for inducing idiotype-specific immunization have been reported, but their major theoretical focus was related to the induction of humoral immunity. We have investigated an immunization procedure with naked DNA encoding human variable region gene sequences of an immunoglobulin heavy chain (VH), which may generate both humoral and cellular immune responses against the idiotype of a B cell acute lymphoblastic leukemia (ALL). Using polymerase chain reaction (PCR) amplification, we investigated heavy chain variable region genes obtained from an ALL patient and whether they could induce humoral and cellular immune responses in DBA/2 mice. The VH sequence was cloned into a mammalian expression vector for intradermal DNA vaccination and into a bacterial expression vector to obtain VH protein for Western blotting. The mammalian expression vector encoding the VH gene was injected into mice three times at 7-day intervals and was transduced into P1HTR which is a syngeneic tumor of DBA/2, to serve as target cells to detect cellular immunity. Spleen cells from the inoculated mice exhibited a significant cytotoxic T lymphocyte response to the target cells. By Western blotting, we could also detect trace levels of anti-VH antibodies in all mice serum. This approach for the induction of cellular immunity by intradermal injection is easy and variable region-specific, and may be used as vaccines after chemotherapy treatment of B cell malignancies.

Amino Acid Sequence↗
PubMed1996

[Contrast enhanced CT].

Although CT is one of major diagnostic imaging methods, the role of CT in the detection and diagnosis of early carcinomas depends on the organ and character of the tumors. Because difference in attenuation between lung parenchyma and carcinomas is large, contrast enhanced CT is not effective to diagnose early lung carcinoma. However, difference in attenuation between parenchyma and tumor is small and change of the contour of the organ is not seen in many cases of small carcinomas in the liver, pancreas and kidneys, therefore helical (spiral) CT with contrast enhancement has markedly improved the diagnostic capability of small carcinomas in these organs. In the biliary tract, bladder, uterus and prostate small carcinomas can not be detected even on enhanced helical CT.

Bile Duct Neoplasms↗
PubMed1995

Construction and evaluation of a virG thyA double mutant of Shigella flexneri 2a as a candidate live-attenuated oral vaccine.

A virG thyA double mutant of Shigella flexneri 2a was constructed as a candidate live-attenuated oral vaccine. In the keratoconjunctivitis model it did not provoke any adverse reaction by itself on guinea pigs' eyes and completely protected them from provoking keratoconjunctivitis. When (2.7-4.8) x 10(10) of the vaccine was inoculated intragastrically after 1 day fasting in cynomolgus monkeys three times at weekly intervals, a watery stool was observed at 40% as a side-effect. Upon intragastric challenge after 1 day fasting with 7.5 x 10(9) of the virulent strain four weeks after the last vaccination, a statistically significant difference was obtained in the mortality rate but not in the morbidity rate between the vaccine and the control group, although the clinical findings were less severe in the vaccine group than in the control group. These results together with the histopathological and immunological findings indicate that the vaccine deserve further detailed studies.

Animals↗
PubMed1995

Flexural properties of resin-modified "hybrid" glass-ionomers in comparison with conventional acid-base glass-ionomers.

The mechanical properties of resin-modified "hybrid" glass-ionomers, for both restorative and liner/base applications, were assessed by a flexural test and compared with those of conventional acid-base glass-ionomers. Flexural strength, flexural modulus, and the modulus of resilience were determined 30 minutes after mixing, and at 24 hours and 3 months after aging in distilled water at 37 degrees C. With a microscope and SEM observations, a comparison of marginal breakdown was made between a resin-modified and a conventional glass-ionomer restoration in bovine cavities, after cyclic loading with steel balls. It was found that resin-modified glass-ionomers were stronger, more flexible, and more resilient than conventional acid-base glass-ionomers. This was in accord with the finding that less marginal breakdown and surface deterioration occurred in a resin-modified glass-ionomer than in a conventional analogue. For some materials the flexural properties progressively improved between 24 hours and 3 months, while others showed no improvement or even deteriorated.

Analysis of Variance↗
PubMed1995

Low-dose granulocyte colony-stimulating factor enables the efficient collection of peripheral blood stem cells after disease-oriented, conventional-dose chemotherapy for breast cancer, malignant lymphoma and germ cell tumor.

Peripheral blood stem cells (PBSCs) were collected from 29 adult patients (median age 42 years, range 14-59 years) with breast cancer, germ cell tumor and malignant lymphoma after disease-oriented, conventional-dose chemotherapy combined with daily subcutaneous injections of low-dose (50 micrograms/m2 or 2 micrograms/kg) granulocyte colony-stimulating factor (G-CSF). The median number of colony-forming units-granulocyte macrophage (CFU-GM) collected in an apheresis was 2.37 (range 0-60.6) x 10(4)/kg body weight. Taking into consideration the minimum number of CFU-GM for hematopoietic reconstitution (at least 1 x 10(5) CFU-GM/kg), it was suggested that sufficient PBSCs could be collected by a few leukaphereses, although the cell yields of PBSCs tended to differ among the chemotherapeutic regimens. Twelve patients subsequently received high-dose chemotherapy followed by peripheral blood stem cell transplantation (PBSCT), including four receiving PBSCT alone and eight both PBSCT and autologous bone marrow transplantation (BMT). When compared with the 20 patients who received high-dose chemotherapy followed by autologous BMT alone, the median day of recovery of a neutrophil count > 0.5 x 10(9)/l and a platelet count > 20 x 10(9)/l was significantly shortened in those who received PBSCT (9 vs 12 days; P < 0.01 and 14 vs 30.5 days; P < 0.001), resulting in a lower platelet transfusion requirement (4.5 vs 9; P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Ultrasonographic features of recurrent parotitis in childhood.

Six children with recurrent parotitis were studied by ultrasound. Of the 12 parotid glands thus observed, 5 were swollen and 7 were not enlarged. Multiple round hypoechoic areas measuring 2-4 mm in diameter were seen in all 5 enlarged parotid glands and in 5 non-enlarged glands. These small hypoechoic areas were larger than the punctate pools of contrast medium shown by sialography. We consider that these hypoechoic areas represented both peripheral sialectasis and surrounding lymphocytic infiltration. We propose that ultrasonography may be useful for the diagnosis and follow-up of recurrent parotitis in childhood.

Child↗
PubMed1993

Dietary soybean protein compared with casein retards senescence in the senescence accelerated mouse.

The effects of replacing dietary casein with soybean protein on mean life span, mean life span of the last one-tenth of a group, grading scores of senescence and deposition of senile amyloid were investigated in senescence accelerated mice (SAM-P/1) compared with a control strain (SAM-R/1). SAM-R/1 mice fed the soybean protein-containing diet had mean life spans of 618 +/- 42 d (males) and 578 +/- 62 d (females), 58% (males) and 44% (females) longer than those of corresponding casein fed mice (P < 0.01). Similarly, in SAM-P/1 mean life-spans were 265 +/- 16 d (males) and 307 +/- 23 d (females) in the soybean diet group, 27% (males) and 30% (females) longer than in the casein diet groups (P < 0.01). The mean life span of the last one-tenth of each group fed soybean protein was significantly longer than the corresponding group fed casein. In SAM-R/1 mice, pathological studies revealed that severe secondary amyloid deposition (amyloid A protein) in the kidneys, spleen, stomach and liver was significantly suppressed, in males only, by replacing casein with soybean protein (P < 0.01). The occurrence of contracted kidneys caused by the infiltration of amyloid A protein was suppressed in SAM-R/1 mice fed the soybean protein-containing diet (P < 0.05). The deposition of senile amyloid in SAM-P/1 mice with aging was retarded by replacing casein with soybean protein (P < 0.01). These results indicate that dietary protein source is important in modulating the advance of senescence in SAM mice.

Aging↗
PubMed1993

Differences in clinicopathological characteristics and major prognostic factors between B-lymphoma and peripheral T-lymphoma excluding adult T-cell leukemia/lymphoma.

A total of 541 consecutive patients treated between 1975 and 1985, 449 with B-lymphoma and 92 with peripheral T-lymphoma, excluding adult T-cell leukemia/lymphoma (ATL), termed peripheral non-ATL T-lymphoma, were analysed. Clinicopathological features that were predominantly associated with B-lymphoma were low and intermediate grades (defined by the Working Formulation), diffuse large cell type, stage II disease, bulky disease, favourable extranodal sites that are defined as a group of primary tumors such as the eye, Waldeyer's ring, thyroid, and stomach, while other features predominantly associated with peripheral non-ATL T-lymphoma were high grade pathology, diffuse mixed-cell and immunoblastic type, systemic "B" symptoms, poor performance status (PS), generalized lymphadenopathy, involvement of organs such as liver, skin, and nose, leucocytosis, and a high levels of serum alkaline phosphatase. The survival curve for B-lymphoma was better (P < 0.01) than that for peripheral non-ATL T-lymphoma. Multivariate analysis revealed that the major prognostic factors were pathology, stage, and primary site for B-lymphoma, while stage, PS, and total protein levels were important for peripheral non-ATL T-lymphoma. These results indicate that B- and peripheral non-ATL T-lymphomas appear to have different biological characteristics.

Adult↗
PubMed1993

Hemorrhagic cystitis associated with allogeneic and autologous bone marrow transplantation for malignant neoplasms in adults.

We investigated the occurrence of hemorrhagic cystitis in 30 consecutive adult patients undergoing bone marrow transplantation (BMT) for hematological and non-hematological malignancies. Ten patients with hematological malignancies received allogeneic BMT, and twenty patients, seven with hematological and 13 with non-hematological malignancies, received autologous BMT. All 30 patients received high-dose cyclophosphamide-containing regimens (120 mg/kg in 16, 200 mg/kg in one, 6000 mg/m2 in 13) as preparative therapies. They all received 2-mercaptoethane sulphonate sodium (mesna) combined with hyperhydration 3 liter/day as prophylaxis for hemorrhagic cystitis. Bladder irrigation was not performed. Overall, five patients (16.7%) developed hemorrhagic cystitis; early-onset (within 48 hours of the end of the high dose chemoradiotherapy) hemorrhagic cystitis occurred in one (3.3%; 95% confidence interval, 0.6-16.7%) and late-onset occurred in four (13.3%; 95% confidence interval, 5.3-29.7%). In three of the four late-onset cases, adenovirus was isolated from the urine specimens at the onset of the hemorrhagic cystitis. Among the 13 patients with non-hematological malignancies receiving autologous BMT, one with recurrent breast cancer developed late-onset hemorrhagic cystitis associated with adenovirus type 11. We conclude the prophylactic measure with mesna and hyperhydration to be effective enough to prevent cyclophosphamide-induced hemorrhagic cystitis of early onset. Some BMT recipients, however, even those with non-hematological malignancies undergoing autologous BMT, develop late-onset hemorrhagic cystitis in which adenovirus is considered a principal causative agent.

Adult↗
PubMed1990

Features of the beta-amylase isoform system in dry and germinating seeds of alfalfa (Medicago sativa L.).

Five isoforms of beta-amylase were purified to homogeneity from alfalfa seeds (Medicago sativa L.) by chromatofocusing and cation-exchange chromatography. These isoforms were identified as beta-amylase based on their catalytic mode to the substrates. These isoforms of beta-amylase were also found in germinating seeds of alfalfa. All the isoforms existed in free form, because they could be extracted without reducing agent. The five isoforms had different isoelectric points (5.05, 4.97, 4.85, 4.82 and 4.77), but their Mr was the same (61 kDa) on SDS-polyacrylamide gels. The amino acid compositions were similar, but not identical, to each other. An antiserum raised against one of the five isoforms cross-reacted with all of other isoforms, but did not recognize the component 2 of soybean beta-amylase. The amounts of five isoforms increased during seed germination, which was responsible for significant increase of the beta-amylase activity in germinating seeds.

Amino Acids↗
PubMed1990

Purification and properties of thermostable xylanase and beta-xylosidase produced by a newly isolated Bacillus stearothermophilus strain.

We isolated a thermophilic bacterium that produces both xylanase and beta-xylosidase. Based on taxonomical research, this bacterium was identified as Bacillus stearothermophilus. Each extracellular enzyme was separated by hydrophobic chromatography by using a Toyopearl HW-65 column, followed by gel filtration with a Sephacryl S-200 column. Each enzyme in the culture was further purified to homogeneity (62-fold for xylanase and 72-fold for beta-xylosidase) by using a fast protein liquid chromatography system with a Mono Q HR 5/5 column. The optimum temperatures were 60 degrees C for xylanase and 70 degrees C for beta-xylosidase. The isoelectric points and molecular masses were 5.1 and 39.5 kDa for xylanase and 4.2 and 150 kDa for beta-xylosidase, respectively. Heat treatment at 60 degrees C for 1 h did not cause inhibition of the activities of these enzymes. The action of the two enzymes on xylan gave only xylose.

Geobacillus stearothermophilus↗
PubMed1990

Gradual increases in marginal leakage of resin composite restorations with thermal stress.

The effects of thermal stress on the marginal leakage of resin composite restorations in bovine teeth were investigated by a method that preserved the specimens. The changes in marginal leakage of specimens with increasing numbers of thermal cycles were measured by an electrical conductivity method. Four brands of posterior resin composites were used to fill cylindrical cavities (2.0 mm in diameter and 1.5 mm in depth) on the labial surfaces of bovine incisors, according to the manufacturer's instructions. Thermal cycling stress was applied to the specimens for up to about seven weeks (9000 cycles). During this time, the electrical conductance between the pulp and a drop of physiological saline solution covering the resin restoration was measured periodically by application of an electrical potential (60 Hz, 10 Vp-p). Thermal stress increased the marginal leakage gradually, rather than step-wise. Even before application of any thermal stress, wide variations of marginal leakage were found among different specimens restored with the same brand of resin. Specimens with less initial leakage showed less increase in leakage, and vice versa, throughout the experimental period.

Animals↗