Biomedical subjects

M Kojima

Publications and source records attributed to M Kojima.

At least 523 records · Page 29Linked to original sources

PubMed1992

Immunological detection and quantitation of DNA adducts formed by 4-aminoazobenzene species in vivo.

Antibodies to 3-methoxy-4-aminoazobenzene (3-MeO-AAB) and 2-methoxy-4-aminoazobenzene (2-MeO-AAB) DNA adducts were raised in rabbits against in vitro-adducted DNA samples. The enzyme-linked immunosorbent assay (ELISA) was used to determine the sensitivity and specificity of these antibodies. They proved highly specific for the modified DNA used as the immunogen, but cross-reacted with each other. Moreover, they showed cross reactivity with DNA modified by 4-(o-tolylazo)-o-toluidine, but not by other carcinogens, such as 4-aminobiphenyl or 4-nitroquinoline 1-oxide. The 50% inhibition level of antibody binding in the competitive ELISA was at 10-20 fmol of modified base per assay (equivalent to 1-2 adducts per 10(6) bases). Immunohistochemical staining indicated that these antibodies bind specifically to nuclear components of the liver in rats given either 3-MeO-AAB or 2-MeO-AAB at the dose of 50 mg/kg body weight.

Animals↗

PubMed1992

Malignant lymphomas of the nasal cavity and paranasal sinuses. A clinicopathologic and immunohistochemical study.

The clinicopathologic and immunohistological features of 20 Japanese patients with non-Hodgkin's lymphomas (NHLs) limited to the sinonasal area were studied using a broad panel of T- and B-cell markers on paraffin-embedded and fresh frozen tissue. All cases showed a diffuse growth pattern. Nine cases were B-cell lymphomas (immunoblastic n = 4, centroblastic n = 3, immunocytoma n = 1, centrocytic n = 1), and nine were T-cell lymphomas (pleomorphic medium and large cell n = 8, angioimmunoblastic n = 1). In two cases, the cell lineage could not be determined. No morphologic features of angiocentric/angiodestructive lymphoproliferative lesions or lymphoepithelial lesions in ductal or glandular epithelium were seen in our series. Eight (89%) of the nine T-cell tumors and four (44%) of the nine B-cell neoplasms involved both the nasal cavity and paranasal sinuses. Six of the nine T-cell neoplasms showed a clinical presentation of rhinitis, whereas all of the B-cell neoplasms showed tumor masses in the nasal cavity and/or paranasal sinuses. The two-year survival rate for T-cell lymphomas was poorer than that for B-cell lymphomas. The five-year survival of patients with NHLs involving both the nasal cavity and paranasal sinuses was also poorer than that of patients in whom NHLs were limited to the nasal cavity.

Adult↗

PubMed1992

Blood-ocular barrier permeability in monkeys.

The permeability of the blood-ocular barrier was investigated in five monkeys using vitreous fluorophotometry (VFP). Inward permeability (Pin) of the blood-retinal barrier was calculated by a computer simulation method. Kinetic VFP was performed after intravitreal injection of fluorescein (F) or fluorescein monoglucuronide (FG). The estimated mean value of Pin (x10(-6) cm/min) was 4.8 (SD 1.2). The mean rates of loss (per hour) of F from the anterior chamber (Ka) and the vitreous (Kv) were 0.11 (SD 0.01) and 0.13 (SD 0.03), respectively, which were approximately three and four times greater than those of FG (0.04 (SD 0.01) and 0.03 (SD 0.01), respectively). Probenecid administered intraperitoneally decreased both the Ka and the Kv of F significantly but had no effect on the Ka or the Kv of FG, suggesting that F was excreted from the eye with the aid of the active transport mechanism. The results of comparative studies of the rates of loss of F from the anterior chamber (Ka) and from the vitreous (Kv) suggested that active transport was more predominant in the blood-retinal barrier than in the blood-aqueous barrier.

Animals↗

PubMed1992

Role of endogenous ANP in sodium excretion in rats with experimental pulmonary hypertension.

To explore the roles of endogenous atrial natriuretic peptide (ANP) in the volume regulation, we examined effects of antiserum for ANP or a neutral endopeptidase inhibitor, thiorphan, in rats with monocrotaline (MCT)-induced pulmonary hypertension. ANP concentrations in the plasma and right ventricle and ANP mRNA in the right ventricle of MCT-treated rats were higher than in vehicle-treated rats. The administration of the ANP antiserum into the MCT-treated rats did not affect the right atrial pressure or blood pressure but significantly decreased urinary excretion of Na by 60%. No decrease occurred in the control rats. Thiorphan dose dependently increased the urinary excretion of Na by 140% without influencing the right atrial pressure or blood pressure. This natriuresis was associated with 50 and 450% increases in ANP concentrations in the plasma and urine, respectively. The degrees of increases in urinary Na excretion, ANP, and guanosine 3',5'-cyclic monophosphate were significantly greater in the MCT-treated rats than in the control rats. Thus an increased secretion of ANP in pulmonary hypertension actually contributes to Na excretion. The augmentation of endogenous ANP activity may further potentiate the compensatory role of this peptide in the regulation of body fluid volume.

Animals↗

PubMed1992

Enzymatic distribution patterns of rat lenses and the changes that occur during naphthalene cataract development.

The topographic distribution of enzyme activities in normal rat lenses and their changes occurring during naphthalene cataract development were investigated. Cataract formation was documented by slit images according to the Scheimpflug principle. Before the onset of visible changes and after the development of early visible opacities, the animals were sacrificed, their lenses removed and biochemically analyzed. The lenses were divided reproducibly into 6 parts--the equatorial ring and 5 layers of central cylinders from the anterior to the posterior cortex. The enzyme activity spectra (AR, SDH, GR, GPX, PFK, ALD, GAP-DH, and LDH) showed region-related patterns, which could not be detected with analysis of the total lens. Image analysis of the first signs of opacity showed that changes in the activities of several enzymes correlate with density changes in the corresponding lens layers.

Animals↗

PubMed1992

Biochemical and morphological changes in rat lenses after long-term UV B irradiation.

The aim of the present study was to investigate biochemical and morphological changes in rat lenses following long-term UV B irradiation. After an irradiation period of 156 days with follow-up documentation by means of Scheimpflug photography, section-related biochemical analyses of the lenses as well as histological investigations were performed. The video-based Scheimpflug photography (Zeiss SLC) again proved to be an excellent method for the documentation of the UV cataract induced in rats. The biochemical analyses provided indications to potential damaging mechanisms; the section-related technique used allows more precise analyses than the processing of whole lenses in a cataract type restricted to a certain layer, as is the case with UV B damage. The most prominent biochemical findings were a significant decrease in glyceraldehyde-3-phosphate dehydrogenase in the equatorial region in the group with the highest irradiation dosage and a decrease in lactate dehydrogenase in the nuclear region. The histological results reflect the local extent of the UV damage as well as its progression after a prolonged irradiation period.

Animals↗

PubMed1992

Application of a new Scheimpflug camera (EAS-1000) to animal cataract models.

A newly developed anterior eye segment system, EAS-1000, was applied to animal experiments. Since the device was developed to be used with human eyes, several minor changes were made to facilitate the use with animals. These changes included an animal-holding place instead of a chin rest, an additional monitor screen for help in alignment, a foot pedal for flushing and image cancellation and variable illumination for adjusting the volume of the retroillumination image. The examined animals were mice, rats, rabbits, dogs and monkeys. The image quality of this camera was almost always satisfactory. One advantage of this device is that the quality of the images can be checked instantly, making it possible to store only images of superior quality. The mean of the repeatability test had a coefficient of variation of 6%.

Animals↗

PubMed1992

Cellular mechanisms for synthesis and secretion of atrial natriuretic peptide and brain natriuretic peptide in cultured rat atrial cells.

To investigate the cellular mechanism for the synthesis and secretion of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), we examined the effects of vasoactive agents on the secretion rates and gene expression of ANP and BNP in cultured rat atrial cells. Endothelin (10(-7) M, +61%), 12-O-tetradecanoylphorbol 13-acetate (TPA, 10(-6) M, +62%), the calcium ionophore A23187 (10(-6) M, +95%), and Bay K 8644 (10(-6) M, +34%) (p < 0.05 each) all increased the secretion of ANP into the culture media in a dose-dependent fashion. On the other hand, endothelin (10(-7) M, +57%) and TPA (10(-6) M, +55%) (p < 0.01 each) increased the secretion of BNP in a dose-dependent manner, whereas A23187 (10(-6) M, -45%, p < 0.001) suppressed the secretion of BNP in a dose-dependent manner, and Bay K 8644 caused no significant effects on BNP secretion. The molecular forms of intracellular ANP were exclusively gamma-ANP, whereas those of BNP were gamma-BNP and its carboxy terminal 45-amino-acid peptide, BNP-45. The ratio of media to cell contents was much higher in BNP than in ANP. Northern blot analysis revealed that both ANP mRNA and BNP mRNA levels were significantly increased by 10(-7) M endothelin (ANP mRNA, +52%; BNP mRNA, +36%; p < 0.05 each) and 5 x 10(-5) M 1-oleoyl-2-acetylglycerol (ANP mRNA, +296%; BNP mRNA, +133%; p < 0.01 each) but not by 10(-6) M A23187. Thus, the secretion of ANP is stimulated by both the elevation of [Ca2+]i and the activation of protein kinase C, whereas its synthesis is increased mainly by the activation of protein kinase C. The synthesis and secretion of BNP are augmented by the activation of protein kinase C rather than the elevation of [Ca2+]i. Furthermore, the processing and secretion of ANP and BNP may be regulated in different manners.

Animals↗

PubMed1992

Positron-emitting N-[18F]fluoroalkyl and [18F]fluoropyrrolidinyl analogues of eticlopride as potential in vivo radioligands for dopamine D2 receptors.

N-Fluoroalkyl and 4-fluoropyrrolidinyl eticlopride analogues with high affinity toward central nervous system dopamine D2 receptors in vitro were labelled with positron emitting fluorine-18 (t1/2 = 110 min), and their in vivo biodistribution was investigated in rats. N-[18F]Fluoro-ethyl and -propyl eticlopride derivatives showed poor in vivo selectivity in the rat brain. On the other hand, 4-[18F]fluoropyrrolidinyl eticlopride exhibited almost constant and relatively high striatal concentration. The striatal/cerebellar radioactivity ratio, which corresponds to the ratio of a brain D2 receptor-rich to poor region, gradually increased to 5.2-6.4, 90 min after the injection. The striatal accumulation was selectively inhibited by pre-injection of haloperidol, a dopamine D2 antagonist, without affecting accumulation in other tissues. Thus, the selective striatal accumulation of 4-[18F]fluoropyrrolidinyl eticlopride in striatal tissue appears to be due to the specific binding to dopamine D2 receptors.

Animals↗

PubMed1992

Hypolipidemic effect of ethyl all-cis-5,8,11,14,17-eicosapentaenoate (EPA-E) in rats.

We examined the effect of ethyl all-cis-5,8,11,14,17-eicosapentaenoate (EPA-E) with high purity on circulating lipids in rats under several experimental conditions. In normolipidemic rats, EPA-E decreased the lipids in a dose-dependent manner. Clofibrate (100 mg/kg/day) was more potent in lowering the lipids than EPA-E (1000 mg/kg/day). In high cholesterol diet-fed rats, EPA-E (300 mg/kg/day) decreased the total cholesterol. However, clofibrate (300 mg/kg/day) had little effect on the total cholesterol. In hypertriglycemic rats induced by corn oil, EPA-E (300 mg/kg/day) or clofibrate (100 mg/kg/day) reduced the rise of triglycerides. EPA-E (300 mg/kg/day), clinofibrate (100 mg/kg/day) or clofibrate (300 mg/kg/day) caused a significant reduction in the lipids induced by the injection of Triton WR-1339. Furthermore, EPA-E (300 mg/kg/day) or clinofibrate (100 mg/kg/day) decreased the elevation of lipids produced by feeding the rats a casein-rich diet. These results show that EPA-E possesses potent inhibitory activity on experimental hyperlipidemia induced either exogenously or endogenously.

Animals↗

PubMed1992

A novel and efficient method for enzymatic synthesis of high purity maltose using moranoline (1-deoxynojirimycin).

A transglycosylation reaction with moranoline (1-deoxynojirimycin) was done with soluble starch as the glucosyl donor and Bacillus macerans amylase as a cyclodextrin glycosyltransferase [EC 2.4.1.19]. The resultant transglycosylation products with moranoline, obtained by treating the reaction mixture with a strong cation exchange resin, were hydrolyzed by beta-amylase [EC 3.2.1.2] from sweet potatoes. The hydrolysate was treated with a strong cation exchange resin, and high purity maltose was obtained.

1-Deoxynojirimycin↗

PubMed1992

Isolation and genetic analysis of an Agrobacterium tumefaciens avirulent mutant with a chromosomal mutation produced by transposon mutagenesis.

A transposon 5 (Tn5) insertion was introduced into the genome of A. tumefaciens (A-208 strain harboring a nopaline type Ti-plasmid) using a conjugative pJB4JI plasmid containing Tn5. Five thousand transconjugants were assayed for virulence on carrot (Daucus carota L.) disks; 54 isolates were avirulent or very attenuated. The cellular localization (plasmid or chromosome) of the Tn5 insertion in those isolates were identified by Southern hybridization analysis. An avirulent mutant (B-90 strain) with the Tn5 insertion in the chromosome was selected and characterized. The mutant had the same growth rate as that of the parent strain in L-broth. The mutant and the parent strain had similar attachment ability to carrot root cells. Tn5 was inserted into one site of the chromosome. The wild-type target chromosomal region (1281 base pairs) was cloned and sequenced. An open reading frame (ORF) consisting of 395 base pairs was identified. The wild-type DNA fragment (1.6 kb) containing the ORF introduced into B-90 strain complemented the avirulent phenotype of the strain. A soluble protein was predicted from the ORF. The Tn5 was inserted near the 3'-terminal of the ORF. Homology search of this ORF found no significant homology to known genes and proteins. Thus, the ORF identified in this paper seems to be a new chromosomal virulence gene of A. tumefaciens.

Agrobacterium tumefaciens↗

PubMed1992

Effects of intravesically administered verapamil HC1 (calcium entry blocker) on the bladder function in unanesthetized rats.

The effects of intravesically administered verapamil HCl (calcium entry blocker) on the bladder function were investigated using an experimental model for unanesthetized rats. Intravesical verapamil HCl caused a marked suppression of maximum intravesical pressure accompanied by an increase of residual urine in a dose-dependent manner. The effect almost disappeared 90 min after the elimination of verapamil HCl. It is tentatively suggested that the intravesical instillation of verapamil HCl could be a potent therapy for disorders of bladder function, such as uninhibited contraction.

Administration, Intravesical↗

PubMed1992

[Clinical significance of tonsillar provocation test in diagnosis of tonsillar focal infection--by indirect irradiation of ultra-micro waves].

The tonsillar provocation test by indirect irradiation of ultra-microwaves was clinically evaluated for its ability to diagnose tonsillar focal infection. Body temperature, erythrocyte sedimentation rate (ESR), urinary findings, white blood cell count (WBC), changes in skin lesions and arthralgia were used as parameters as in the former tests. The clinical usefulness of the provocation test was assessed based on a long-term progress observation on post-tonsillectomy. WBC was most changeable among the parameters, however, ESR was the most reliable parameter judging from the ratio of correct diagnosis. According to the clinical evaluation of tonsillar provocation test by indirect irradiation of ultra-microwaves, the positive diagnostic standardization will be proposed as follows: Chronic low grade fever group: increase in the body temperature by 0.3 degree C or over or increase of ESR by 12 mm or over. Skin disease group: increase of ESR by 9 mm or over. Kidney disease group: increase of ESR by 11 mm or over.

Adolescent↗

PubMed1992

Re-evaluation of skin lesion distribution in atopic dermatitis. Analysis of cases 0 to 9 years of age.

Distribution of skin lesions was studied in 1,012 patients under 10 years of age, with atopic dermatitis. Of these, 812 (80.2%) had an atopic history; 200 did not. Both categories were divided by age into five subgroups (3-5 months, 6-11 months, 1 year, 2-4 years and 5-9 years) and the incidence of lesions in each of 52 skin regions was compared between the positive and negative history groups and between different age groups. The results were as follows. 1. There was a change in predilection site, from the head (the scalp, face and peri-auricular area) to the neck and flexures (cubital and popliteal fossae) between 1 and 2 years of age. 2. The trunk (shoulders, chest, abdomen and back) was the most common predilection site in both infants and children. 3. Only the upper arm was affected more frequently on the external side than the internal side in all age groups. 4. The nose, mamillae, palms and feet were the least affected areas in all age groups. 5. Incidences in the positive history group were no higher than in the negative group.

Age Factors↗

PubMed1992

Effect of short-term egg exclusion diet on infantile atopic dermatitis and its relation to egg allergy: a single-blind test.

A unique, single-blind, controlled trial of egg exclusion was performed in infants under 3 years of age, with atopic dermatitis, and/or their breast-feeding mothers. All subjects were put on an exclusion diet, but assessment of the effect of egg exclusion was made without knowing the results of allergy the tests. Results showed that there was a statistically significant correlation between the effect of egg exclusion and egg allergy, but only in infants 3-6 months old. Combination with other allergies did not seem to affect the results at this age. These findings indicate that egg exclusion is effective in ameliorating skin symptoms of atopic dermatitis only in early infancy and in the presence of egg allergy, irrespective of combination with other food allergies. This may be correlated to high RAST scores to egg at this age.

Child, Preschool↗

PubMed1992

A new approach to drug penetration study.

To investigate the route of drug penetration into the eye and drug distribution patterns in the lens, the distribution of aldose reductase inhibitor (AL-04114) in the lens was measured in short term bovine lens organ cultures and topical administration to rabbit eyes. A micro lens sectioning technique was applied to determine drug localization within the lens. Freshly enucleated bovine lenses were incubated with different concentrations of an ARI (AL-04114)-containing medium for 3 hours. For the in vivo study, 40 microliters of 0.3% AL-04114 (ophthalmic solution) were administered into the cul de sacs of rabbits 3 times at 3 hour intervals. After the incubation and final instillation, the lenses were divided into an equatorial ring and several layered sections. Drug concentration was measured by a reversed-phase HPLC system. The drug concentration was highest within the layer of the posterior shallow cortex > equator > anterior shallow cortex. No drug penetration was observed in the anterior/posterior deeper cortex or nucleus in vitro. The in vivo experiment revealed drug penetration in the equator and anterior shallow cortex, but not in any other lens layers. Drug penetration was detected within the serum and aqueous humor, but not in the vitreous.

Absorption↗

PubMed1992

Malignant histiocytosis. A report of three cases.

Three cases of malignant histiocytosis were immunohistochemically studied. The cases included the following three patients: a 38-year-old man, a 44-year-old man, and a girl aged 5 years 9 months. All three patients died within 3 months of hospitalization. They had a high fever (temperature over 38.5 degrees C), lymph node swelling, hepatosplenomegaly, and pancytopenia. Blastoid and hemophagocytic cells proliferated in the bone marrow and lymph nodes, especially in the sinuses of the latter. We diagnosed malignant histiocytosis in the three cases based on clinical features, extremely poor prognoses, and the morphologic features and growth pattern of blastoid and hemophagocytic cells. Blastoid and hemophagocytic cells expressed phenotype Mac-387+/KP1+/lysozyme+/polyclonal CD3+. The Mac-387 and KP1 antigens and lysozyme are markers for monocytes/macrophages, and polyclonal CD3 is a marker for T lymphocytes. Therefore, we suggest that a certain number of cases of malignant histiocytosis have a biphenotypic nature, namely, the T cell and macrophage, although many cases of malignant histiocytosis have been reported as expressing only T-lymphocyte antigens.

Adult↗