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Biomedical subjects

J Ohno

Publications and source records attributed to J Ohno.

At least 19 recordsLinked to original sources
PubMed2001

Peripheral ameloblastoma with potentially malignant features: report of a case with special regard to its keratin profile.

A peripheral ameloblastoma with atypical features occurring on the left maxillary alveolar ridge of 40-year-old man is described, along with an immunohistochemical profile of its cytokeratin (CK). The lesion apparently originated from the surface gingival epithelium. The tumor nests or strands were highly cellular with a variable degree of squamous differentiation and microcyst formation. Occasional mitotic figures and dystrophic calcification, both of which are not seen in conventional ameloblastomas, were also observed. The tumor infiltrated deep into the alveolar mucosa, including the periodontal ligament, and showed histological and topographical evidence of atypism, resulting in resorption of the underlying alveolar bone. On the CK immunohistochemistry, CK19 was demonstrated in all the types of neoplastic epithelia, including microcyst-forming cells, densely packed round or spindle cells within the tumor nests, cells with squamous metaplasia, and peripheral tall columnar cells. The CK immunohistochemical findings suggest the lesion's cell of odontogenic origin; they may reflect an immature phenotypic expression of cell differentiation in the odontogenic epithelia during the tumor growth in the gingival mucosa.

Adult↗
PubMed2001

Telomerase activation and p53 mutations in urethane-induced A/J mouse lung tumor development.

The mouse telomerase holoenzyme, which synthesizes telomeric DNA de novo, is a ribonucleoprotein complex that includes the mouse telomerase RNA component (mTERC), mouse telomerase-associated protein (mTEP1) and mouse telomerase reverse transcriptase (mTERT). To determine the role of telomerase in urethane-induced lung tumorigenesis in A/J mice we examined telomerase activity and the expression of each telomerase subunit in 20 tumor samples, harvested at 16, 28, 40 and 50 weeks after urethane treatment. The telomeric repeat amplification protocol assay showed that statistically significant telomerase activation occurred both early and late in tumorigenesis. Semi-quantitative reverse transcription-polymerase chain reaction analysis revealed that mRNA expression levels of mTEP1 and mTERT were up-regulated during tumor progression, while mTERC expression was not significantly different between tumors and normal lung. We further examined mTEP1 protein expression in normal lung tissue and lung tumors; western blot analysis showed preferential expression of mTEP1 protein in lung tumors compared with normal lung and immunohistochemistry revealed that a majority of the adenoma cells were positively stained in the nucleus, whereas only a few of the adjacent normal alveolar cells were immunoreactive. In addition, we investigated DNAs of the 20 tumor samples by single strand conformation polymorphism and sequencing analyses to examine whether alterations of the p53 gene in exons 5-8 were associated with telomerase activity. Although we found one nonsense, two missense, two silent and one simultaneous double mutation at different codons in six late stage tumors, there was no apparent correlation between telomerase activity and p53 mutations. Collectively, these results suggest that mTEP1 as well as mTERT may be involved in the regulation of telomerase activity and that telomerase activation may contribute to lung tumorigenesis in A/J mice independently of p53 gene alterations.

Animals↗
PubMed2001

[Pathology of periodontal disease].

Periodontal diseases are usually divided into two categories, periapical and marginal periodontal diseases, according to the sites. The marginal periodontitis is common and causes loss of teeth in the adult. This begins as a marginal gingivitis, which usually progresses to destructive chronic periodontitis. The authors describe here the classification, pathology and various related factors of human adult periodontitis.

English Abstract↗
PubMed2000

Comparative image analysis of EGF immunoreaction in rat submandibular gland using 3,3'-diaminobenzidine with metal enhancer substrate.

We have shown the efficacy of image analysis using 3,3'-diaminobenzidine (DAB) with a metal enhancer substrate for demonstrating quantitative differences in the amount of epidermal growth factor (EGF) in the submandibular gland from normal, castrated, and testosterone propionate (TP) treated castrated rats. Immunohistochemical determination of EGF visualized by DAB-nickel reagent was performed with image analysis using a computed image analyzer system (ACAS 570). Immunohistochemistry for EGF disclosed positive staining in granular convoluted tubule cells in the tissue sections from each experimental group. Using the tools of a competent data program installed in the ACAS 570 software, we measured quantitative differences among the experimental glands examined. Castration was shown to elicit a significant reduction in the EGF-positive area and staining intensity, and administration of TP to the castrated animals restored these parameters to levels greater than those of normal rats. Our study demonstrates that a simple, inexpensive, commercially available metal enhancer substrate can be applied accurately to the computer assisted quantification of histochemical hormone-induction studies.

3,3'-Diaminobenzidine↗
PubMed1997

Glucose-loading thallium-201 myocardial SPECT.

UNLABELLED: This study was designed to evaluate the feasibility of assessing myocardial viability using glucose loading followed by 201Tl SPECT. METHODS: First, the effect of insulin on the kinetics of 201Tl uptake was evaluated in isolated perfused rat hearts. Second, glucose-loading 201Tl myocardial SPECT was performed in 13 nondiabetic patients with histories of anterior myocardial infarction. Thirty minutes before acquiring rest 201Tl SPECT, 20 g of glucose were intravenously injected into the fasting subjects. Thallium perfusion defects were compared to those of conventional rest-redistribution SPECT images obtained within a 2-wk interval. SPECT images were divided into 21 segments, and a defect score in 17 segments was calculated as a sum of the semiquantitative defect scores (0 = normal; 1 = mildly decreased uptake; 2 = severely decreased uptake; 3 = absence of uptake). RESULTS: Thallium-201 uptake in isolated hearts showed a significant increase of 26% after insulin loading. Eleven (24%) of 45 segments showing perfusion defects on the conventional rest SPECT images demonstrated 201Tl uptake on glucose-loading SPECT imaging. Defect scores decreased significantly on the glucose-loading SPECT images (9.9 +/- 2.2 in early images; mean +/- s.e.) compared with the conventional rest-redistribution SPECT images (12.6 +/- 6.9 in delayed images, p < 0.05). CONCLUSION: Glucose-loading SPECT represents a superior method for assessing myocardial viability using 201Tl.

Adult↗
PubMed1995

Cerebral infarction due to a spontaneous tumor embolus from lung cancer.

A cerebral infarction of the left occipital lobe developed in a 65-year-old man with squamous cell carcinoma of the right lung. Neurological examinations and brain CT showed findings typical of ordinary infarction. Postmortem examination revealed a tumor embolus within the posterior cerebral artery. Such spontaneous tumor emboli large enough to obstruct a larger-sized artery are rare.

Aged↗
PubMed1995

[Central ocular hypotensive effect of noradrenaline].

We investigated the effects of topical and central administration of noradrenaline (NA) on the intraocular pressure (IOP) in pigmented rabbits. Unilateral instillation of NA (200 micrograms) produced no significant change in IOP. On the other hand, intracerebroventricular (ICV) administration of NA (0.01-1 micrograms) decreased IOP in both eyes in a dose-related fashion. The ocular hypotensive effect of NA was diminished by sympathectomy of the superior cervical sympathetic nerve or by ICV pretreatment with yohimbine hydrochloride 1-10 micrograms). These results suggest that the hypotensive effects of contrally administered NA might be mediated by alpha 2-adrenoceptor stimulation in the central nervous system.

Administration, Topical↗
PubMed1994

Humoral hypercalcemia of malignancy associated with parathyroid hormone-related protein producing transitional cell carcinoma of the ureter.

A 78-year old male with ureteral carcinoma manifesting hypercalcemia is reported. He was diagnosed as having ureteral carcinoma of the left side 2 years previously and was treated by nephrectomy with ureterovesicostomy. In October 1991, he was admitted for anorexia. A clinical examination revealed recurrence of the ureteral carcinoma with metastasis to the rectum and liver. His serum calcium level was elevated (13.9 mg/dl). In addition to rehydration and furosemide, treatment with eel-calcitonin and prednisolone failed to decrease his serum calcium level. Finally, he was administered mithramycin but he died 13 days later. He had no evidence of bone metastasis or hyperparathyroidism. Nephrogenic cAMP and urinary parathyroid hormone-related protein (PTHrP) were markedly elevated. Immunohistochemical study demonstrated expression of PTHrP in the tumor cells. Thus, the hypercalcemia was thought to be mediated by PTHrP secreted from the neoplastic tumor. Although there have been several reports of ureteral carcinoma associated with humoral hypercalcemia of malignancy, this is considered to be the first case associated with elevation of PTHrP.

Aged↗
PubMed1994

Control of in vivo fate of albumin derivatives utilizing combined chemical modification.

Three types of bovine serum albumin (BSA) derivatives such as lactosylated BSA (LBSA), mannosylated BSA (Man-BSA), and cationized BSA (cBSA) were synthesized and their hepatic disposition characteristics in mice were evaluated by pharmacokinetic analysis. At lower doses (< or = 1 mg/kg), LBSA and Man-BSA were very rapidly eliminated from the blood circulation due to uptake by parenchymal and nonparenchymal cells of the liver, respectively, via receptor-mediated endocytosis (Nishikawa et al., 1992; Nishida et al., 1991a, b). These uptake processes were nonlinear and the apparent hepatic uptake clearances (CLliver) were decreased at administered doses higher than 1 mg/kg, e.g. 10, 20, and 100 mg/kg. The liver accumulation of cBSA was also nonlinear, but its binding and/or uptake capacity in the liver was larger than those of LBSA and Man-BSA; i.e., CLliver decreased at doses higher than 20 mg/kg. In the next step, we modified these BSA derivatives by attaching polyethylene glycol (PEG), a modifier known to reduce the hepatic uptake and increase plasma retention, to achieve precise control of the in vivo disposition characteristics of BSA derivatives. By conjugation with PEG having a molecular weight of 10 kDa, the CLliver values of LBSA, Man-BSA, and cBSA were decreasing to one-seventh, one-fortyfifth, and one-onehundredthirtieth, respectively. However, liver accumulation of PEG modified LBSA and Man-BSA at 24 h after i.v. injection was not significantly different from unmodified BSA derivatives. These results suggest that it is possible to control the hepatic uptake of protein drugs by a combination of introduction of charge or sugar moieties and PEG conjugation.

Animals↗
PubMed1993

Nematolysosomes (elongate lysosomes) in rat hepatocytes: their distribution, microtubule dependence, and role in endocytic transport pathway.

The distribution of lysosomes in rat hepatocytes was examined by three-dimensional electron microscopy combined with acid phosphatase (ACPase) cytochemistry. In the 2-microns-thick sections observed under 200- or 1000-kV TEM, it was apparent that ACPase activity localized on elongate lysosomes (we refer to them as nematolysosomes) with a diameter of 70-100 nm and lengths of several micrometers, as well as spherical lysosomes and trans-Golgi cisternae. Though most spherical lysosomes were located within the pericanalicular region, nematolysosomes were widely distributed throughout the hepatocytes. Typically, it appeared that the nematolysosomes elongated from the subsinusoidal region to the pericanalicular-Golgi complex area and they frequently formed a network at the cell periphery along the sinusoidal front. Furthermore, the formation of nematolysosomes was independent of new protein synthesis, but highly dependent on the integrity of microtubules. After a 6-8 h colchicine treatment, nematolysosomes were shrunk and/or fragmented, becoming roughly spherical lysosomes scattered throughout the cells. Nematolysosomes recovered their normal profiles after 24 h due to the reversible effect of the drug on microtubules. When the hepatocytes were exposed to horseradish peroxidase (HRP) in vitro or in vivo, HRP was quickly sequestered in nematolysosome-like structures via pinocytosis from the sinusoidal surface and transported to an area near the Golgi complex. These findings raise the possibility that the nematolysosomes engage in microtubule-dependent transport of macromolecules from the sinusoidal circulation to the Golgi complex area.

Acid Phosphatase↗
PubMed1993

Immunohistochemical detection of sialyl Le(x) antigen on mucosal Langerhans cells of human oral mucosa following neuraminidase pretreatment.

Histochemical assessment of selected carbohydrate sequences on Langerhans cells of human oral mucosa was made by combined use of enzyme digestion and immunostaining with monoclonal antibodies against specific carbohydrate structures. In both frozen sections and epithelial sheets without the enzyme pretreatment, mucosal Langerhans cells, identified by positive staining with anti-CD1a and HLA-DR antibodies, did not express any carbohydrate antigens on their surface. In contrast, following neuraminidase pretreatment of both types of material, the fucosylated type 2 chain (Le(x)) became detectable on Langerhans cells, indicating that sialic acid is the terminal residue of this sequence. Other enzymes were ineffective in this apparent unmasking, and the staining patterns of the other related carbohydrate sequences (Le(y)+, Le(a), Le(b)) remained unaffected by pretreatment with any of the enzymes used. These findings suggest that the mucosal Langerhans cells possess a unique carbohydrate chain, the sialyl fucosylated type 2 sequence (sialyl Le(x) antigen).

Adolescent↗
PubMed1992

The relationship between polysaccharide antigen and interleukin-1 beta producing activity in Porphyromonas gingivalis.

Strains of Porphyromonas gingivalis were serologically classified into three groups (a, b, and c) by immunodiffusion test using the autoclave extracted antigens. All tested strains had proteolytic activity, but the activity differed from strain to strain, regardless of serogroup. It was found that serogroup a strains had more collagenolytic activity than did serogroup b (p < 0.05), but that the three groups have no remarkable differences in trypsin activity. All autoclave extracted serogroup-specific antigens induced the release of interleukin-1 beta (IL-1 beta) from human peripheral monocytes. Serogroup-specific antigen of an invasive strain designated 16-1 (serogroup b) induced the highest release of IL-1 beta among all samples. The results of immunoblotting tests and IL-1 beta production indicated that there are serogroup-specific polysaccharide other than lipopolysaccharide in P. gingivalis.

Antigens, Bacterial↗
PubMed1991

Light and electron microscopic demonstration of wheat germ agglutinin binding in the pericellular matrix of rat mandibular condylar cartilage.

Binding of wheat germ agglutinin to rat mandibular condylar cartilage was investigated with the avidin-biotin peroxidase complex. Binding sites were observed in the pericellular matrix of the hypertrophic cell zone. Two distinct patterns were identified: one showed binding to the pericellular matrix without apparent contour; in the other binding was confined to the matrix but with conspicuous condensation forming a pericellular rim. The first binding pattern was seen particularly in the upper part of the hypertrophic cell zone adjoining the mature cell zone; the second was localized in the lower part of this zone adjacent to the site of endochondral calcification. The binding sites in the pericellular matrix are assumed to be NANA and/or GlcNAc in view of the sugar specificity of this lectin. The presence of these binding sites in this region may be due to a structural alteration or modification of proteoglycans in the course of preparation for endochondral calcification.

Animals↗
PubMed1990

Glycoconjugate expression of cells of human anagen hair follicles during keratinization.

Changes in the expression of glycoconjugates in cells of the inner root sheath (IRS) and outer root sheath (ORS) of human anagen hair follicles were investigated by lectin histochemistry. Concanavalin A (Con A) and Ricinus communis (RCA-I) stained hair follicle cells regardless of their differentiation stages. In IRS, Ulex europeaus-I (UEA-I) bound to the surface of the cells as soon as they were morphologically defined, and Glycine max (SBA) stained as their differentiation progressed. Innermost (IM) cells of ORS layers were reactive with UEA-I at the stage where Henle's cells were keratinized, while the reactivity of UEA-I was lost at the site of the completion of IRS keratinization where SBA reaction was detected. Staining of both UEA-I and SBA was prominent in other ORS cells at the levels where SBA binding in IM cells became strong. The staining intensity increased up to the position of the follicular isthmus. In addition, a sugar residue recognized by Dolichos biflorus (DBA) was detected in differentiated cells of ORS. In contrast, the DBA reaction was not found at all in cells of IRS, infundibulum, and epidermis. These findings identified a complexity of carbohydrate metabolism in the cells of different layers at various stages of keratinization. IM cells differentiate independently from other ORS cells but seem responsive to the degree of IRS keratinization. All ORS cells possess a unique sugar moiety not found in other keratinocytes either in the hair or epidermis.

Concanavalin A↗
PubMed1990

[Report on clinico-pathological examinations in Meikai University (formerly Josai Dental University) Hospital (4)].

This clinico-pathological study was conducted to examine biopsies and surgical specimens for histopathological diagnosis from April 1983 to March 1988 in Meikai University (formerly Josai Dental University) Hospital. The following statistical results were obtained: 1) The total number of the specimens examined was 2705, 2026 from the dental clinic and 679 from the medical clinic. 2) Concerning age distribution, most specimens from the dental clinic were from patients in the 40's age bracket, whereas most from the medical clinic were from those under 10 years of age. With regard to sex distribution, the difference between males and females was not so much in the dental clinic specimens, but the number from the medical clinic was greater for males than for females. 3) Concerning classification of the tumors from the dental clinic, 181 cases were benign; and of them 41 were odontogenic and 140 were non-odontogenic tumors. Among the odontogenic tumors, ameloblastoma, cementoma, and odontoma were the most numerous. Among non-odontogenic tumors, fibroma was the most common, followed by pleomorphic adenoma. Malignant tumors comprised 77 cases. Of them squamous cell carcinoma was the most commonly found, with the grade-2 type being most numerous. Of the medical clinic tumors, nevus was the most common benign tumor observed; and adenocarcinoma, the most common malignant one. 4) Concerning the distribution of main lesions in the dental clinic specimens, most specimens were cysts or cystic lesions, followed by inflammatory lesions and tumors. Among medical clinic specimens, inflammatory lesions were the most common. 5) Regarding the dental clinic specimens, the most frequently observed case was the radicular cyst (301 samples) among the odontogenic cysts (514 samples); and among non-odontogenic cysts (290 samples), the most common was the mucous cyst (159 samples). 5) In terms of the distribution by location, tissue or organ, most tumors from the dental clinic were from the jaws, followed in descending frequency by those from gingiva and alveolar mucosa, maxillary sinus, lip, buccal mucosa, and tongue. Among the medical clinic tumors, the paranasal cavity and tonsils were the most frequent locations.

Adult↗
PubMed1990

[Epidermoid cyst of the oral floor with massive deposition of melanin in the cystic epithelium].

Dermoid cyst or epidermoid cyst of the oral cavity usually occurs in the floor of the mouth. We encountered a 21-year-old woman who had developed epidermoid cyst in the oral floor. Since infancy she had been aware of a swelling in the oral floor. Recently, the swelling began to grow larger gradually. The lesion was excised under general anesthesia by intraoral approach. The swelling was spherical in shape, measured 50 x 45 x 40 mm in size, and weighed 40 g. Histopathological examination revealed keratinized, stratified squamous epithelium on the cyst wall and marked deposition of melanin at the base of the epithelium.

Adult↗