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Biomedical subjects

Y Tano

Publications and source records attributed to Y Tano.

At least 181 records · Page 10Linked to original sources
PubMed1995

Serum-induced collagen gel contraction.

PURPOSE: To understand the molecular events underlying disease-related vitreous gel contraction, the effect of serum components on collagen was investigated. METHODS: Bovine vitreous or dermal collagen was incubated with a mixture of transglutaminase (TG; factor XIIIa) and fibronectin (FN), and the biochemical changes of collagen were monitored by gel electrophoresis. In addition, serum-induced changes in the volume of the collagen gel were monitored. RESULTS: Gel electrophoresis revealed a new high-molecular-weight band (M(r) 240,000) presumably due to intermolecular cross-links of collagen peptides and FN. The serum components also were shown to cause a significant decrease in the volume of the collagen gel. CONCLUSION. Collagen gel contraction could be attributed to the collagen-FN-collagen cross-links catalyzed by TG.

Animals↗
PubMed1995

Possible role of herpes simplex virus in the origin of Posner-Schlossman syndrome.

PURPOSE/METHODS: We conducted this study to determine if the herpesviruses are possible etiologic agents in Posner-Schlossman syndrome. We aspirated aqueous humor samples from patients during acute attacks of the syndrome. Ten normal aqueous humor specimens from patients undergoing cataract surgery were used as controls. DNA was extracted and subjected to polymerase chain reaction amplification and Southern blot hybridization. RESULTS/CONCLUSION: All three specimens were positive for amplified genomic fragments of herpes simplex virus and negative for varicella-zoster virus and cytomegalovirus. Ten normal aqueous specimens were negative for all three. Herpes simplex virus may play a role in the origin of Posner-Schlossman syndrome.

Acute Disease↗
PubMed1995

[Eight cases of infection caused by the Streptococcus milleri group--significance of serum antibody titer and a comparative investigation of the backgrounds and factors of infections caused by Streptococcus milleri and Streptococcus pneumoniae].

Eight cases of infection caused by Streptococcus milleri were studied clinically, and a comparative study was made of the backgrounds and factors influencing the development of infectious diseases caused by Streptococcus milleri and Streptococcus pneumoniae. The patients (six males and two females) with infectious diseases caused by Streptococcus milleri ranged in age from 21 to 81 years old with an average age of 62.0 years. The infectious diseases encountered among the patients were pyothorax in three patients, and in one patient each pyothorax and lung abscess, pleurisy, a secondary infection of pulmonary emphysema, skin infection related to a tracheostomy, a subdural abscess and a brain abscess, respectively. Six out of the eight cases had infections which formed pus. An underlying disease existed in seven cases, and, in five of these seven cases, it influenced the general condition of these patients. Six serum antibody titers for the S. milleri groups were examined in the First Department of Internal Medicine, University of the Ryukyus. Three cases for S. anginosus, two cases for S. intermedius, and one case for S. constellatus showed high titers of X1024 or X2048. Therefore, the examination of the serum antibody titer seems useful for the diagnosis of infections caused by the S. milleri group. We also carried out a comparative investigation of the backgrounds and factors of infectious diseases caused by S. milleri and S. pneumoniae. There are more underlying diseases in infections caused by S. milleri than in those caused by S. pneumoniae. There were more smokers among the patients with infections caused by S. milleri than among those with S. pneumonia infections.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

A rapid method for isolation of retinal pigment epithelial cells from rat eyeballs.

A new, simple method for isolating retinal pigment epithelial (RPE) cells from rat eyeballs was developed: incubation of the eyeballs in 0.1% proteinase K solution. This method yielded an average of 4 x 10(4) viable RPE cells from each Sprague-Dawley rat eyeball in 1 h. These RPE cells were hexagonal and had cytokeratin in their cytoplasm and numerous microvilli on their surface, similar to RPE cells evaluated in vivo. The results of this study thus show that our method for incubating eyeballs in proteinase K can provide good-quality RPE cells in sufficient quantities for study in a short time.

Animals↗
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

[A case of sarcoidosis discovered by onset of pneumothorax].

A 24-year-old man was admitted to our hospital with left back and chest pain. A chest X-ray film showed left pneumothorax, bilateral hilar lymphadenopathy, mediastinal widening, and multiple nodular shadows in both lung fields. Chest CT showed a large nodule just under the pleura. High serum ACE and lyzozyme levels, and a noncaseating epithelioid granuloma (revealed by TBLB) led to the diagnosis of sarcoidosis. Steroid therapy was started to prevent a cardiac lesion. Pneumothorax secondary to sarcoidosis in its early stage is rare, and in this case the pneumothorax may have been caused by rupture into pleural space of the largest nodule in the left S9, as a result of necrosis.

Adult↗
PubMed1994

Detection of herpes simplex virus DNA in human tear film by the polymerase chain reaction.

We investigated the use of the polymerase chain reaction for detecting genomes of herpes simplex virus, varicella-zoster virus, and cytomegalovirus from tear film of patients with clinically diagnosed herpes simplex virus keratitis. Using the polymerase chain reaction with a herpes simplex virus detection sensitivity adjusted to 1.0 plaque-forming units/ml, we detected herpes simplex virus genomic sequences in 12 of 12 epithelial keratitis specimens, two of six stromal keratitis specimens, but in none of 20 normal specimens. Neither varicella-zoster virus nor cytomegalovirus genomic sequences were detected in any sample. These results suggest that polymerase chain reaction quickly performed with reduced sensitivity is useful as a diagnostic tool for confirming clinical observations.

Base Sequence↗
PubMed1994

Marked increase in glutamate-aspartate transporter (GLAST/GluT-1) mRNA following transient retinal ischemia.

We have demonstrated the cellular localization of glutamate-aspartate transporter (GLAST/GluT-1) mRNA in the rat retina and its induction after ischemia by in situ hybridization. GLAST mRNA was expressed in the inner two-thirds of the inner nuclear layer (INL) and in sparse small cells in the inner portion of the ganglion cell layer (GCL) of the adult rat retina. GLAST mRNA was also found in about 90% of cells in the optic nerve head where more than 90% of cells express glial fibrillary acidic protein (GFAP) mRNA. Moreover, experimental occlusion of the central retinal artery followed by reperfusion for 48 h resulted in degeneration of neurons and a marked increase in GLAST mRNA expression in the INL. These findings suggest that GLAST may be expressed in Müller cells and astrocytes in the retina, and may play an important role in regulation of extracellular glutamate concentration especially under ischemic conditions.

Amino Acid Transport System X-AG↗
PubMed1994

Localization of 63-kDa calmodulin-stimulated phosphodiesterase mRNA in the rat brain by in situ hybridization histochemistry.

We studied the localization of 63-kDa Ca2+/calmodulin stimulated phosphodiesterase mRNA in the rat brain by in situ hybridization histochemistry using an oligonucleotides probe specific to this enzyme. The signals were especially concentrated in several brain regions such as the olfactory tubercle, accumbens nucleus, caudate putamen, fundus striati, dentate gyrus of the hippocampus, pontine nuclei and dorsal tegmental nucleus. These results suggest that in the neuronal groups containing the strong signals this enzyme is involved in calcium-dependent signal transduction system coupled to cyclic nucleotides messenger systems.

Animals↗
PubMed1994

[Comparison of the prevalence of symptoms, elevated serum antibody, antibody types and complications between two outbreaks of influenza in a ward].

We experienced two outbreaks of influenza in the respiratory ward of our hospital in Feb. 1990 and Feb. 1993. Influenza-like symptoms were recognized in 42 of 67 cases (63%) in 1990, and in 22 of 56 cases (39%) in 1993. In the former outbreak, the prevalence of the serum CF titer for anti-influenza antibody was elevated in 25 of 42 cases (60%) (only the A2 antibody titer in 2 cases, B antibody titer in 4 cases in the latter one). Among asymptomatic inpatients, the serum titer was elevated in 3 of 25 cases (12%) in the former outbreak, but in 1 of 8 cases which the serum CF titer for anti-influenza antibody was measured in the latter one. A respiratory complications secondary to influenza were observed in 6 (2 cases pneumonia, 3 cases lower respiratory tract infection, 1 case asthma attack) of 67 cases during the former period, but only 1 of 56 cases during the latter period. In the two outbreaks of influenza in the respiratory ward we found the same results concerning the occurrence of influenza-like symptoms, an elevation of the serum antibody titer, but a significant difference was noted with regard to the phenotype of the prevalent influenza and the occurrence of complications.

Aged↗
PubMed1994

Reactive oxygen species involved in phenazine-methosulfate-induced rat lens opacification. An experimental model of cataract.

The excised rat crystalline lens opacified when incubated aerobically with phenazine methosulfate, but no opacification was observed under anaerobic conditions. Morphological studies revealed development of opacification in the cortex. The opacification resembled that often seen in the early period of senile cataract as well as in naphthalene-induced and UV cataract. Both an increase in hydration and in electrolyte imbalance accompanied this opacification. Na,K-ATPase activity of the opacified lens was found to decrease. In order to investigate if activated oxygen is involved in these processes, we conducted an electron spin resonance study by means of a spin trapping technique. When the lens homogate was incubated with phenazine methosulfate, OH radicals were generated under aerobic but not under anaerobic conditions. Reduced pyridine nucleotides must be involved in the process, because the mixture of nicotinamide adenine dinucleotide phosphate [NAD(P)] and phenazine methosulfate did not generate OH radicals, but the mixture of NAD(P)H and phenazine methosulfate generates OH radicals, indicating that reduced phenazine methosulfate was involved in the OH radical generation. Probably, the generated OH radicals inactivated Na,K-ATPase residing in the epithelium of the lens, which eventually caused opacification of the lens. The present experiment system may be used for the elucidation of lens opacification (cataract) involved with reactive oxygen species.

Animals↗
PubMed1994

Epithelial wound healing in the denervated cornea.

We studied the epithelial healing of denervated corneas in New Zealand albino rabbits with their left trigeminal ganglia surgically amputated. On the 14th day after amputation, the corneas were keratectomized (in 8.5 mm diameter) and documentation of the healing process began. We calculated the epithelial healing rate using simple regression analysis. We observed a mean healing rate of 0.463 +/- 0.059 mm2/hr (mean +/- SE) in the denervated corneas, compared to 0.609 +/- 0.031 mm2/hr in the control corneas; a statistically significant difference of P < 0.001. We performed scanning electron microscopic observation (SEM) at three points; before keratectomy, 48 hrs after keratectomy, and 14 days after keratectomy. SEM observation revealed that, in contrast to the control corneas, the surface of the epithelial cells in denervated corneas appeared rough with numerous exfoliating cells observed. This indicates that the epithelial cells might attach only weakly to the floor in denervated corneas. Transmission electron microscopic observation (TEM) performed at 48 hrs and 14 days after keratectomy also supports this finding. For example, the intercellular space is widened and fewer desmosomes are observed in denervated corneas. Using immunohistochemistry, the surface of the wound bed was covered with fibronectin in a similar fashion to the control. In the late stage, the denervated corneas demonstrated spontaneous epithelial breakdown with 83% of them having persistent epithelial defects. Epithelial healing in the control corneas displayed no abnormal signs. On the 14th day after keratectomy, these eyes were enucleated for immunohistochemistry using bromodeoxyuridine (Brd U) to observe dividing cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Immortalization of rat corneal epithelial cells by SV40-adenovirus recombinant vector].

Using a SV40-adenovirus recombinant vector, we have successfully established a rat corneal epithelial cell line (RatCE) and studied its biological characteristics. RatCE continued to grow for more than 400 generations. It proliferated centrifugally in the early phase of the culture (1-3 days in culture) and had a cobblestone-like appearance in confluency. Desmosomes and microvilli were clearly seen under a transmission electron microscope. RatCE could be stored in liquid nitrogen and its biological characteristics were: doubling time, 18.3 hrs, colony forming ability, 36%, and growth ability in soft agar, 2%. When the insoluble extract from RatCE was electrophoresed, insoluble proteins were seen at 36 kD, 40 kD, 44 kD, 48 kD, 56 kD, and 64 kD. Anti-64 kD cytokeratin antibody strongly reacted with numerous filaments in the cytoplasm of RatCE. Hence, RatCE possessed 64 kD corneal specific keratin. A large amount of fibronectin was also assessed at focal contact by immunohistochemistry. Thus, RatCE retains several kinds of epithelial characteristics, is derived from one clone, and is immortalized. RatCE will be a useful tool in studies of the corneal epithelium.

Animals↗
PubMed1994

Suppression of graft rejection in rat keratoepithelioplasty by anterior chamber inoculation of donor lymphocytes.

A newly developed model of keratoepithelioplasty (KEP) in the rat was used to analyze the effect of anterior chamber-associated immune deviation on the suppression of corneal allograft rejection. The right eyes of Fisher rats received an anterior chamber (AC) injection of lymphocyte suspension from Dark Agouti (DA) rats (DAL group) or phosphate-buffered saline (positive control group). Seven days later, DA corneal lenticules were grafted onto both eyes of the recipients. Delayed type hypersensitivity (DTH) was also assessed in another group of Fisher rats receiving an AC injection of DA lymphocytes in the right eye. Within 15 days, 88% of the eyes in the positive control group demonstrated vigorous epithelial edema, a large area of epithelial defect, and vascularization. By contrast, in the DAL group, only 37% of the eyes showed slight epithelial edema, a small area of epithelial defect, and rare vascularization; suppression of graft rejection was observed in both eyes. DTH assay demonstrated significant suppression in the recipients of the AC injection of donor-type lymphocytes. This study indicates that the AC injection of donor-type lymphocytes prior to corneal grafting suppresses allograft rejection in the rat KEP model, correlative with the suppression of DTH reaction.

Animals↗
PubMed1994

[Bacterial flora of the respiratory tract in patients with long term tracheostomy--colonization of the lower respiratory tract by Pseudomonas aeruginosa].

Throat secretions (TS) and bronchial secretions aspirated from tracheostomy sites (TSTA) from six subjects with long term tracheostomy were simultaneously collected and then cultured every two weeks from January, 1990, to December, 1992. Isolated bacteria were mainly alpha-streptococci (96.2%) and Neisseria (69.6%) in TS, and Pseudomonas aeruginosa (75.7%) in TSTA. In all cases, P. aeruginosa was isolated from and colonization of the lower respiratory tract by this organism was apparent 24.4 months, on average, after tracheostomy. There were ten episodes of respiratory infection in five cases, eight of which occurred after colonization. P. aeruginosa was the causative organism in seven of these episodes. Findings in patients with long term tracheostomy indicated separate colonization of the upper and lower respiratory tracts and that P. aeruginosa colonized the lower respiratory tract. The colonization of the lower respiratory tract by P. aeruginosa would thus appear to be an important factor inducing respiratory infection.

Adult↗