Search PubMed⌕ Search

Biomedical subjects

Y Ohashi

Publications and source records attributed to Y Ohashi.

At least 379 records · Page 21Linked to original sources
PubMed1995

Effects of human middle ear effusions on the mucociliary system of the tubotympanum in the guinea pig.

Effusion fluid resulting from otitis media contains a variety of inflammatory substances. This middle ear effusion (MEE) may be itself affect the mucosa of the tubotympanum and contribute to chronicity of the condition. The present study was designed to elucidate in vitro and in vivo effects of MEEs on the mucosa of the guinea pig tubotympanum. The results obtained demonstrated that the ciliary activity of the eustachian tube was reduced in the presence of human MEEs. This activity decreased to approximately 80% in the presence of serous MEE at 48 h and was 60% after exposure to mucoid MEE. Intratympanic inoculation of human MEEs resulted in accumulation of a serous effusion in the tympanic cavity. Histologic study of the tubotympanum in inoculated animals demonstrated mucociliary dysfunction as well as a general inflammatory process and increased vascular permeability. This damage was more prominent following inoculation with the mucoid MEEs. The ciliary depression and inflammation found in the tubotympanum suggest that the pathologic nature of MEEs may be, at least partially, responsible for the chronicity of otitis media.

Animals↗
PubMed1995

Age-related changes in the susceptibility to clofibric acid, a hypolipidemic agent, of male rat liver.

Age-related changes in the susceptibility to clofibric acid were investigated in male F344 rats of 8, 52, and 117 weeks old. Hepatomegaly, decrease of serum total cholesterol and triglyceride, increase of the total cytochrome P-450 contents, induction of the activities of microsomal omega-hydroxylation and peroxisomal beta-oxidation, proliferation of smooth endoplasmic reticulum and peroxisomes were detected in 8- and 52-week-old rats. In 117-week-old rats clofibric acid treatment resulted in decrease of serum total cholesterol, elevation of the activities of microsomal and peroxisomal enzymes, and slight proliferation of peroxisomes. These results suggest that the susceptibility of the male F344 rat liver to clofibric acid decreases in 117-week-old rats, though the effect is still recognizable.

Administration, Oral↗
PubMed1995

Reversal of abnormal corneal epithelial cell morphologic characteristics and reduced corneal sensitivity in diabetic patients by aldose reductase inhibitor, CT-112.

PURPOSE: A randomized clinical study was undertaken to determine whether a topically applied aldose reductase inhibitor, CT-112, was capable of reversing the abnormal morphologic characteristics of corneal epithelial cells, as well as the reduced corneal sensitivity, in diabetic patients. METHODS: Thirty-nine diabetic patients were randomly divided into two groups: one group was treated with topical aldose reductase inhibitor (CT-112) in an ophthalmic preparation, and a control group was treated with the same preparation without the inhibitor. Specular microscopy was performed to analyze the morphologic characteristics of corneal epithelial cells before and after the treatment. Corneal sensitivity was measured by means of the Cochet-Bonnet esthesiometer. RESULTS: The anterior surface area of superficial cells in the group treated with CT-112 was significantly decreased from a mean value of 881 to 728 microns2 (P < .0001), whereas the control group showed no significant changes. Corneal sensitivity remained decreased in the control group, whereas that in the group treated with CT-112 significantly improved, from 5.36 to 1.37 g/mm2 (P < .0001). CONCLUSIONS: These results indicate that treatment with topical CT-112 is capable of reversing abnormal morphologic characteristics of corneal epithelial cells and reduced corneal sensitivity in diabetic patients.

Aged↗
PubMed1995

Ocular surface abnormalities in aniridia.

PURPOSE: The purpose of this study was to examine ocular surface abnormalities in aniridia. METHODS: We prospectively studied the ocular surface in nine consecutive patients (18 eyes) with virtually total aniridia. Of the 18 eyes, two eyes (two patients) were excluded from the study because severe surgical damage was likely to be the main cause of their corneal abnormalities. Six volunteers whose eye examinations yielded normal results served as control subjects. Detailed slit-lamp biomicroscopic examinations were performed to assess corneal findings and confirm the presence or absence of the palisades of Vogt. Goblet cell density on the peripheral corneal epithelium and inferior conjunctival epithelium was calculated via impression cytology and was statistically compared between aniridic eyes and control eyes. RESULTS: All 16 aniridic eyes had superficial corneal opacification and vascularization of either the peripheral or entire cornea. Palisades of Vogt were completely absent all around the limbal area. Goblet cell density on the peripheral cornea and inferior conjunctiva showed a statistically significant increase in the aniridic eyes (226 +/- 169 cells/mm2 and 406 +/- 203 cells/mm2), as compared with the control eyes (O cells/mm2 and 181 +/- 89 cells/mm2) (P = .0005 and P = .0102). CONCLUSIONS: These findings suggest that, in the aniridic eye, conjunctival epithelium invades the cornea because of corneal epithelial stem cell deficiency.

Adolescent↗
PubMed1995

Two of three promoter elements identified in a rice gene for proliferating cell nuclear antigen are essential for meristematic tissue-specific expression.

Proliferating cell nuclear antigen (PCNA) is an auxiliary protein of DNA polymerase delta, and it is highly conserved among eukaryotes. The rice PCNA promoter, truncated to position -263, was previously shown to confer meristematic tissue-specific expression in transgenic plants. By DNasel footprinting and gel retardation analysis, three cis-acting elements were defined in this truncated promoter, which designated site I (-201 to -194, CCAGGTGG), site IIa (-197 to -188, TGGGCCCGT) and site IIb (-178 to -169, TGGTCCCAC). Site I resembles the G-box, and sites IIa and IIb resemble the conserved motif (T/GGTCCCAT) that is found in promoter regions of auxin-regulated genes. Functional analysis of expression of a PCNA-GUS gene fusion in transgenic tobacco plants revealed that a mutation in site I in the full-length 2.0 kb promoter had no significant effect on the activity. However, the mutation in site I in the truncated -263 promoter, which had 14% of the activity of the full-length promoter, caused a considerable decrease in the activity, suggesting that site I contributes in part to transcriptional activation. Simultaneous disruption of sites IIa and IIb in the full-length promoter caused about 80-85% loss of promoter activity, while separate disruption of site IIa or site IIb resulted in no marked change on the activity. These observations suggest that site IIa and site IIb play an important role in the meristematic tissue-specific expression of the rice PCNA gene, presumably by mediating putative enhancer activities dependent on the far-upstream region.

Base Sequence↗
PubMed1995

Duration of apnoea in anaesthetized children required for desaturation of haemoglobin to 95%: comparison of three different breathing gases.

In this study, we compared three gas compositions to determine if the duration of apnoea for SpO2 to decrease is proportionate to the oxygen fraction of the gas prior to apnoea. Twenty-five patients ASA physical status 1-2 aged two months to 12 years were included in the study. Anaesthesia was induced via a mask with 5% sevoflurane and 66% N2O in oxygen. After paralysis with vecuronium (0.12 mg.kg-1, i.v.) the trachea was intubated and anaesthesia was maintained with sevoflurane and N2O in oxygen. When cardiovascular stability was obtained, the patient was randomly set to breathe one of three gas compositions: 1. oxygen (FiO2 1.0), 2. N2O/O2 (FiO2 0.4), and 3. air/O2 (FiO2 0.4). All three gas compositions included 2-4% of sevoflurane to maintain anaesthesia. After more than eight min of each gas breathing, apnoea was begun by disconnecting the breathing circuit from the tracheal tube. The time from the start of apnoea (SpO2 100%) to SpO2 of 95% (T95) was measured. T95 measured after breathing N2O/O2 and air/O2 were 34.6 +/- 5.7 and 28.8 +/- 4.7% of that measured after oxygen breathing (P < 0.001 vs oxygen breathing, P < 0.001 vs oxygen and N2O/O2 breathing), respectively. Preoxygenation before intubation was validated to delay the haemoglobin desaturation brought about by apnoea. An induction technique using a low FiO2 will allow rapid haemoglobin desaturation.

Age Factors↗
PubMed1995

Topical aldose reductase inhibitor for correcting corneal endothelial changes in diabetic patients.

BACKGROUND: Marked variations in cell size (polymegethism) and shape (pleomorphism) are characteristic of the corneal endothelium in diabetic patients and animals. METHOD: Wide field specular microscopy was used to evaluate the clinical efficacy of treating the diabetic corneal endothelium with topical instillation of 0.5% aldose reductase inhibitor, CT-112. RESULTS: Morphological variations (polymegethism and pleomorphism) of the endothelium in eight eyes from eight patients receiving CT-112 resolved within 3 months after initiation of treatment. In contrast, no change in endothelial morphology was noted in five eyes from five patients who received placebo. CONCLUSION: These observations suggest that aldose reductase may be involved in the aetiology of corneal endothelial variations in diabetic patients.

Administration, Topical↗
PubMed1995

Craniosynostosis with joint contractures, ear deformity, cleft palate, scoliosis, and other features.

A case of craniosynostosis with joint contractures, ear deformity, cleft palate, scoliosis, and many other features is presented. The patient's skull was round with craniosynostosis of the coronal suture. The fingers were slender and long; the finger joints were contracted. Trismus was also present. Contracture of the temporomandibular joint was suspected. The helices were flat, antihelices were minimal, and the ears protruded. Furthermore, the facial and cranial features of this patient included mild hypertelorism, ocular proptosis, short pons nasi, flat radix nasi, mild retrognathia, and small oral fissure. In the oral cavity, a relatively wide cleft extended from the soft palate to the uvula. A frontal chest radiograph revealed a mild scoliosis. Differential diagnoses are discussed in reported syndromes with craniosynostosis.

Abnormalities, Multiple↗
PubMed1995

Urinary albumin fragments as a new clinical parameter for the early detection of diabetic nephropathy.

Urinary albumin fragments (uAF) from patients with NIDDM were analyzed as a possible factor in the early discovery of diabetic nephropathy before emergence of microalbuminuria. SDS-PAGE and immunoblot assay were employed for detection of uAF. Samples from 252 patients with NIDDM, 158 patients with non-diabetic diseases, and 48 healthy volunteers were examined; uAF were detected in 139 (55.2%), 94 (59.5%), only one (2.1%), respectively. In diabetic patients with normoalbuminuria, uAF were detected in 48 out of 159 cases (30.2%). Two years after the initial study, 3 of the 17 diabetic patients (17.6%) with normoalbuminuria and uAF showed micro- or macroalbuminuria. It was concluded that detection of uAF might be useful for the early detection of diabetic nephropathy in NIDDM.

Adolescent↗
PubMed1995

Prospective study of lipoprotein(a) as a risk factor for atherosclerotic cardiovascular disease in patients with diabetes.

OBJECTIVE: To assess whether lipoprotein(a) [Lp(a)] is a risk factor for atherosclerotic cardiovascular disease in diabetes. RESEARCH DESIGN AND METHODS: We studied 221 patients with non-insulin-dependent diabetes mellitus (NIDDM) without diabetic complications who were followed for 2.2-3.1 years. Their serum Lp(a) levels were semiquantified by a rapid electrophoretic method that accurately discriminates high from low serum Lp(a) at the 20 mg/dl level. RESULTS: Seven of 105 diabetic patients with a high serum Lp(a) experienced a clinical event related to atherosclerotic cardiovascular disease. This incidence was significantly higher than that of the 110 diabetic patients with a low serum Lp(a). The logistic regression analysis revealed that Lp(a) was an independent risk factor for the event. CONCLUSIONS: Lp(a) is a significant risk factor for atherosclerotic cardiovascular disease in NIDDM.

Adult↗
PubMed1995

[Classification of middle ear anomalies by a correspondence analysis method].

We studied on 70 cases of middle ear anomalies by a standard correspondence analysis method. The external meatus of these cases was open. We classified these 70 cases into the following four groups: type D: disruption between the long process of the incus and the movable oval window (54.3%), type F: immovable oval window with no disruption between the long process of the incus and the oval window (14.3%), type DF: anomalies with both immovable oval window and disruption between the long process of the incus and the oval window (18.6%), type O: anomalies of neither type D nor type F (12.9%). Half of these 70 cases had other miscellaneous anomalies, however, they did not affect the present results.

Ear, Middle↗
PubMed1995

Ocular resurfacing and alloepithelial rejection in a murine keratoepithelioplasty model.

PURPOSE: To determine definitively the epithelial origin of corneal resurfacing and to elucidate the immunologic mechanisms of epithelial rejection in a murine keratoepithelioplasty (KEP) model. METHODS: After corneal epithelial removal and peritomy, donor corneal lenticules were grafted around the limbus (KEP procedure). The process of corneal reepithelialization was observed with 0.25% methylene blue staining. The origin of the renewed epithelium was determined by immunofluorescence. Syngeneic corneal lenticules were grafted to BALB/c mice. C3H/He, C57BL/6, BALB.K, DBA/2, and B10.D2 allogeneic corneal lenticules were grafted to BALB/c mice, and A.SW and A.TL allogeneic corneal lenticules were grafted to A.TH mice. Alloepithelial rejection was evaluated on the basis of clinical findings and histologic changes in grafted corneas. RESULTS: All KEP grafts were reepithelialized entirely at 3 days after surgery. The renewed epithelium proved to be derived from the lenticules in BALB/c eyes receiving C3H/He lenticules. In syngeneic grafts 5 days after KEP, the cornea recovered clarity and smoothness, which persisted to the end of the study. After complete reepithelialization, all allogeneic grafts also experienced a short duration of clear cornea. Then followed four characteristic phases of inflammatory epithelial response: initial phase, acute phase, chronic phase, and rejected phase. Histologic examination confirmed the progress and severity of inflammatory response. The mean onset times of initial phase in assorted grafts with mismatched histocompatibility antigens were: 7.9 +/- 1.8 days for both major and minor disparity grafts, 9.5 +/- 3.8 days for major disparity grafts, 18.2 +/- 5.5 days for major histocompatibility class I disparity grafts, 25.6 +/- 7.2 days for major histocompatibility class II disparity grafts, and 9.2 +/- 2.2 days for multiple minor disparity grafts. CONCLUSIONS: In donor corneal lenticule grafting to host eyes with corneal epithelium removed and conjunctival peritomy, the ocular surface was reepithelialized by lenticule-derived epithelium. Alloepithelial rejection in this model displayed characteristic manifestations and well-defined processes, enabling easy and precise evaluation of onset and intensity of graft rejection. Both major and minor histocompatibility antigens are related to corneal epithelial rejection.

Animals↗
PubMed1995

An SV40-immortalized human corneal epithelial cell line and its characterization.

PURPOSE: The authors attempted to immortalize human corneal epithelial cells; it is difficult to propagate primary human corneal epithelial cells because of scarcity of available tissue. However, cell immortalization by virus is always accompanied by shedding of free virus. The current study was performed to establish a cell line that produces no free viral particle. METHODS: Primary cultured human corneal epithelial cells were infected with a recombinant sv40-adenovirus vector and were cloned three times to obtain a continuously growing cell line. Morphologic, cytologic, and biochemical characteristics of this cell line were analyzed. RESULTS: This cell line continued to grow for more than 400 generations, exhibiting a cobblestone-like appearance similar to normal corneal epithelial cells in culture. Transmission electron microscopy showed the evidence for the characteristic features of epithelial cells, including desmosome formation and development of microvilli. It expressed cornea-specific, 64-kD cytokeratin in addition to five major insoluble proteins. By enzymatic analysis using NADP as a coenzyme and a gas chromatograph mass spectrometer, this cell line was found to possess 8.71 IU/mg protein of aldehydedehydrogenase activity. When this cell line was grown at air-liquid interface on collagen type I gel, it differentiated in a multilayered fashion. CONCLUSIONS: The authors have established an SV40-immortalized human corneal epithelial cell line with properties similar to normal corneal epithelial cells.

Aldehyde Dehydrogenase↗
PubMed1995

Sulphate reduction and methanogenesis in the ovine rumen and porcine caecum: a comparison of two microbial ecosystems.

A series of experiments was conducted to study the relationship between methanogenesis and sulphate reduction in ovine rumen and porcine caecum. Effect of 2-bromoethane sulphonate on hydrogen production by digesta suggested that the most important H2-disposal system in the rumen is methanogenesis and that methanogenesis is not predominant H2-disposal system in the porcine caecum. This inference was supported by the difference in predominant H2-utilizers in these two microbial ecosystems; Methanogenic bacteria (MB) were predominant in the rumen and sulphate reducing bacteria (SRB) were predominant in porcine caecum. Free sulphate levels in digesta appear to affect the relationship between MB and SRB. Sulphate levels in the rumen were likely to be insufficient for SRB to outcompete MB.

Animals↗
PubMed1995

Establishment and characterization of a novel human immature megakaryoblastic leukemia cell line, M-MOK, dependent on fibroblasts for its viability.

A novel fibroblast-dependent human immature megakaryoblastic leukemia cell line (M-MOK) was established from the bone marrow of a girl with acute megakaryoblastic leukemia, and its growth was determined to be completely dependent on the presence of human embryonic lung-derived fibroblasts, HEL-O. Adhesive interaction between M-MOK and HEL-O was crucial for viability; once HEL-O was removed from the culture, mortality was total within a few days. On HEL-O cells, M-MOK could be passaged for more than 2 years. With regard to surface marker profile, the established cells were positive for CD11a, CD13, CD18, CD33, CD34, CD41b, CD42b, CD54, and c-kit antigens, but negative for HLA class II antigen and glycophorin. Histochemically, the cells were negative for myeloperoxidase, nonspecific esterase, and naphthol ASD chloroacetate esterase staining. Electron-microscope examination revealed the cells to be negative for platelet peroxidase (PPO). After induction of differentiation by a phorbol ester, however, the cells were demonstrated to be positive for PPO with a morphological change to megakaryocytes. From these results, M-MOK was considered to represent an immature cell line of megakaryocyte lineage. Studies of the mechanisms sustaining the HEL-O-dependent continuous in vitro growth of M-MOK cells revealed the following results: (1) M-MOK could grow even when separated from HEL-O by a nucleopore membrane; (2) conditioned medium (CM) from HEL-O supported the growth of M-MOK for more than 1 month without feeder cells; (3) the growth of M-MOK on HEL-O or CM supplement was nearly entirely inhibited by anti-GM-CSF (1 microgram/mL); (4) GM-CSF mRNA was detected in HEL-O cells; and (5) HEL-O was found to secrete GM-CSF into the culture medium. Taken together, the growth of M-MOK might therefore be driven by a soluble factor, that is, GM-CSF secreted from HEL-O cells. The presence of HEL-O, however, inhibited anti-GM-CSF-induced M-MOK death. Co-culture of M-MOK and HEL-O cells thus offers a useful experimental model for analysis of interactions between hematopoietic stem cells and stromal cells.

Base Sequence↗