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Biomedical subjects

Y Ohashi

Publications and source records attributed to Y Ohashi.

At least 451 records · Page 25Linked to original sources
PubMed1993

Immortalization of rabbit corneal epithelial cells by a recombinant SV40-adenovirus vector.

PURPOSE: Cultured corneal epithelial cell is detrimental because of its short life span and its heterogeneity. We have tried to establish an immortalized epithelial cell line. METHODS: Primary cultured rabbit corneal epithelial cells were infected with a recombinant SV40-adenovirus vector and were cloned three times. RESULTS: The immortalized cell continued to grow by more than 400 generations through 100 passages. SV40-associated large T antigen was demonstrable on the nuclear membrane of these immortalized cells by immunofluorescence technique. This cell line exhibited a similar cobblestone-like appearance as normal corneal epithelial cells. Transmission electron microscopy showed a line of evidence for stratification, including desmosome formation and microvilli development at the superficial cell layer. As the culture grew, these cells began to express cornea-specific 64 kD cytokeratins. In contrast to cultured normal corneal epithelial cells, this cell line had a good proliferative ability after a long-term storage in liquid nitrogen. CONCLUSIONS: Because this particular cell line shares properties consistent with normal corneal epithelial cells and is easy to handle in vitro, it may serve as a useful tool in corneal epithelial research.

Animals↗
PubMed1993

[Role of eosinophils and lymphocytes in the pathogenesis of bronchial asthma].

Lymphocytes and eosinophils are the two major inflammatory cells in the airways of patients with asthma. We studied the phenotypic composition and activation status of eosinophils and lymphocytes in bronchial biopsies obtained from asymptomatic and symptomatic asthmatics and nonasthmatic controls. The number of EG2-positive cells (activated eosinophils), CD3- and CD4-positive cells, and CD25-positive cells (activated lymphocytes) were significantly increased in the symptomatic asthmatics. In addition, significant correlations were noted between the density of CD4- and CD25-positive cells and the degree of eosinophil infiltration and activation. These data suggest that activated eosinophils and lymphocytes are involved in the pathogenesis of asthma and that activated helper T-lymphocytes play a central role in eosinophil infiltration and activation in the airways of asthmatics. Recently, eosinophil infiltration has been though to induce airway hyperresponsiveness by damaging airway epithelium through eosinophil granule proteins. To test this hypothesis, we investigated whether the number of clusters of desquamated respiratory epithelial cells in sputum is related to the eosinophil granule proteins in sputum and whether the ultrastructural changes in the bronchial epithelium are related to the presence of eosinophils in the bronchial mucosa. The results of both studies supported the hypothesis.

Asthma↗
PubMed1993

Effect of S-carboxymethylcysteine on ciliary activity in chronic sinusitis.

This study was designed to investigate the possible pharmacological effect of S-carboxy-methylcysteine (S-CMC) on the ciliary activity, using an in vitro experimental system after removing mucus. Ciliary activity from healthy rabbit maxillary sinus and from healthy human nasal mucosa demonstrated no significant change in RPMI 1640 containing S-CMC. On the other hand, the effect of S-CMC on the reduced ciliary activity from patients with chronic sinusitis was quite varied among the cases examined. S-CMC demonstrated no stimulatory effect on the beating activity of cilia that have a baseline activity of less than 400 beats/min. However, S-CMC was able to enhance the beating activity of cilia that demonstrated a baseline activity of more than 400 beats/min. S-CMC at 0.5% induced a larger ciliostimulatory effect than 0.05% S-CMC. In conclusion, our study has clearly demonstrated that S-CMC could directly enhance ciliary activity of chronic sinusitis in the absence of significant organic change of ciliated cells.

Animals↗
PubMed1993

Herpes simplex virus latency in human cornea.

The authors attempted to demonstrate the latency of herpes simplex virus type 1 (HSV-1) in corneas obtained during penetrating keratoplasty from patients with herpetic stromal keratitis in the nonactive (subsided) stage. The subjects comprised 20 patients (9 men, 11 women; average age 43.5 years). Infectious virus was not detected in the supernatants following corneal homogenization and centrifugation. Latent virus was detected in the cultured supernatants of the corneal sections from 8 patients. Although the ganglion trigger theory by Hill et al is conventionally supported as the mechanism of recurrence of herpetic keratitis, the present results suggest a ganglion and skin trigger theory, in which proliferation from latent HSV-1 in the cornea (peripheral tissue) might stimulate the ganglion.

Adult↗
PubMed1993

[Anesthetic management for cesarean section in two parturients with quintuplet gestation].

Two parturients with quintuplet pregnancy underwent urgent or elective cesarean section under general anesthesia at 30 and 29 week gestational ages respectively. Since multiple gestation pregnancy requires enough medical staffs and instruments for preterm newborn resuscitation, emergency cesarean delivery was avoided. For cesarean delivery, the operation was started immediately after crash induction and intubation, and less than 1% isoflurane balanced with 60% nitrous oxide was used before birth in attempt to maintain uterine relaxation and sufficient utero-placental perfusion. After the delivery, aggressive maneuvers with PGE1 infusion, intravenous ergometrine and oxytocin, and interruption of volatile anesthetic inhalation (replaced by buprenorphine) were employed for decreasing the blood loss. The anesthesia and postoperative course of two patients and their babies were uneventful. Thus, anesthetic considerations may include; 1) high risk pregnancy related with huge pregnant uterus, 2) preterm labor, 3) preparation of sufficient man-power and instruments, 4) to avoid uterine contraction before delivery for fetal oxygenation, and 5) the puerperal promotion of uterine contraction to decrease blood loss.

Adult↗
PubMed1993

[Reliability of evaluating grade of diabetic retinopathy].

The inter-rater and intra-rater reliability of stage-evaluation for diabetic retinopathy using Fukuda's classification was assessed by the kappa coefficient. The raters consisted of 16 ophthalmologists in 3 institutions. The kappa coefficient was calculated to evaluate the inter-rater reliability. Evaluation was performed twice. The value of the kappa coefficient for the first evaluation was 0.18 and that for the second time evaluation was 0.081. The kappa coefficient for evaluation of the change of retinopathy grade was 0.24. The agreement of evaluation using color fundus photographs was higher than that using both color fundus photographs and fluorescein angiograms. The agreement of the evaluation of retinopathy grades did not correlate with periods of experience as ophthalmologists. The intra-rater agreement of the evaluation of retinopathy grades was 60-70%. These results suggested that the reliability of the evaluation of retinopathy grades was not high among ophthalmologists and that standardization in clinical investigation of diabetic retinopathy was necessary using fundus photographs and fluorescein angiograms.

Diabetic Retinopathy↗
PubMed1993

[The anesthetic management of cesarean section for multiple pregnant patients].

Anesthetic management of cesarean section for twenty multiple pregnant patients, who were pregnant with triplet or quadruplet, was compared with that for 325 single pregnant patients and 21 twin pregnant patients. For anesthetic methods, spinal anesthesia was chosen most frequently in the multiple pregnant patients, as in single and twin (more than 75 percent). In multiple pregnant patients, the incidence of emergency operation was less. In multiple pregnant patients who received spinal anesthesia, gestational age was lower; birth weight was lighter; length of fundus uteri was longer; and blood loss including amniotic fluid was larger. In triplets, the third infants' UID-time was prolonged and their Apgar score was lower.

Anesthesia, Epidural↗
PubMed1993

[Transforming growth factor-beta (TGF-beta) inhibits epithelial wound healing of organ-cultured rabbit cornea].

Transforming growth factor-beta (TGF-beta) is a unique polypeptide growth factor which has been found to stimulate mesenchymal cell proliferation and inhibit epithelial cell growth. Whether or not TGF-beta inhibits corneal epithelial wound closure remains controversial. This study evaluated the effects of TGF-beta on corneal epithelial wound healing in vitro. Rabbit corneas with an artificial 8 mm epithelial defect were organ-cultured for 48 hr in TC-199 supplemented with TGF-beta (100 pg/ml, 1 ng/ml, or 10 ng/ml). The contralateral eye served as control. TGF-beta at 1 ng/ml and 10 ng/ml concentrations showed significant decrease in wound-healing rate compared with the control. 5-bromo-2'-deoxyuridine-immunohistochemistry showed a significant decrease in S-phase cell count in the 1 ng/ml group compared with the control. These results strongly suggest that TGF-beta inhibits corneal epithelial wound healing.

Animals↗
PubMed1993

[Corneal epithelial wound healing in the denervated eye].

We investigated the rate of corneal epithelial wound healing in rabbits which had undergone surgical trigeminal denervation. Seven New Zealand albino rabbits underwent unilateral neurotomy of postganglionic trigeminal nerves via intracranial route. At 14 days after operation, 10 mm diameter central corneal epithelial defects were created in both eyes by n-heptanol. The area of epithelial defect was then photographed at 12-hour intervals and the epithelial healing rate was calculated (1st experiment). At 14 days after epithelial wound closure, the corneal epithelium was again denuded in a similar fashion (2nd experiment). The epithelial healing rate of the denervated and control eyes respectively were 1.28 +/- 0.25 and 1.39 +/- 0.31 (mm2/hr) in the first experiment, and 1.05 +/- 0.20 and 1.44 +/- 0.22 (mm2/hr) in the second. There was a statistically significant difference in the epithelial healing rate between the two groups in experiment 2 (p < 0.05), These results indicate that corneal epithelial wound healing is impaired in the denervated eye.

Animals↗
PubMed1993

[Risk factors for occurrence and progression of diabetic retinopathy].

The risk factors for the occurrence and progression of diabetic retinopathy were estimated in 1084 diabetic subjects (4358 person-years) by logistic regression analysis. The diabetic duration, the average of HbA1C for every year of observation, the range of HbA1C, the difference of HbA1C between the first visit to our clinic and the average of one year of HbA1C were statistically significant covariates for the risk of the occurrence of retinopathy. The relative risks of the occurrence of retinopathy as compared with the diet were estimated as 2.02 in oral administration of medicine and 1.86 in insulin therapy. The interaction between the difference of HbA1C and the average of HbA1C was statistically significant for the progression of retinopathy. When the response surface was estimated, the risk of progression of retinopathy differed greatly according to the blood glucose control level.

Adolescent↗
PubMed1993

[Phase II study of a novel combination regimen composed of cisplatin, carboplatin and etoposide against unresectable non-small cell lung cancer].

Phase II study of a novel combination regimen composed of cisplatin, carboplatin and etoposide (CPVP) was conducted against unresectable non-small cell lung cancer. The treatment schedule consisted of cisplatin 50 mg/m2 on day 1, carboplatin 200 mg/m2 on day 1, and etoposide 100 mg/m2 on days 1, 3, 5 every 3 or 4 weeks. The response rate and toxicities were evaluated in 28 patients, who were diagnosed and treated in the Cancer Institute Hospital (GANN-KEN) from March 1991 to September 1992. Partial response (PR) was found in sixteen out of 28 patients (57.1%). In myelotoxicities, 5 out of 28 patients (17.9%) showed grade 4 thrombocytopenia, but, white blood cell count and hemoglobin level stayed at grade 3 or milder in most patients, revealing safety of this regimen. In gastrointestinal toxicities, the median number of days in the patients suffered from nausea and loss of appetite was about 3 and 7 days, respectively. Median weight loss of the patients through the entire treatment was 2.3 kg. These results suggest that CPVP regimen is no less effective, but more tolerable, in other words, more favorable in QOL than standard regimens, and that it warrants further study in phase III trials.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

[Expression of major histocompatibility complex antigens, and kinetics of infiltrated lymphocytes in murine herpetic keratitis].

Immunohistochemical techniques were used to study expression of HSV-1 antigen, induction of class I and II major histocompatibility complex (MHC) antigens, and infiltration of L3T4+ and Lyt2+ cells were analyzed during the acute phase of herpetic keratitis. The results were as follows: 1) HSV-1 antigens were detectable in the corneal epithelium at 2 days post infection (p.i.), then localized in the stroma after 5 days p.i.. 2) Class I MHC antigens (H-2d) were evenly expressed in all layers of infected as well as uninfected corneas. On the other hand, class II MHC antigens (Iad) were induced in the superficial corneal stroma 2 days p.i., then gradually spread in the entire corneal stroma with increased intensity. 3) L3T4+ (helper/inducer) cells penetrated the stroma at 2 days p.i.. These cells infiltrated the central stroma at 5 days p.i.. Lyt2+ (suppressor/killer) cells were first seen in the corneal stroma as late as at 5 days p.i.. These results imply that L3T4+ cells play a role in the early immunological events concerning class II MHC antigens and viral antigens, both concomitantly expressed in the corneal stroma.

Animals↗
PubMed1993

[Phase I clinical study of TT-62. Research group of TT-62].

TT-62 is a new derivative of FdUMP, which is the active metabolite of 5-FU. A phase I clinical study of TT-62 was conducted by a cooperative study. The same patients received single and 2-week oral administration of TT-62. Starting from 60 mg/m2 (1n), the dose was escalated to 420 mg/m2 (7n). In the single administration, the maximum tolerated dose (MTD) could not be determined. In the 2-week administration, MTD was 420 mg/m2, and the dose limiting factor was gastro-intestinal disturbances such as anorexia, nausea, vomiting and diarrhea. Increases in GOT.GPT and a decrease in hemoglobin content were observed. After administration was stopped all side effects disappeared. TT-62 was detected mainly in the plasma, while trace amounts of 5-FU and FUdR were also detected. TT-62 was excreted mostly in the urine, as alpha-fluoro-beta-alanine (FBAL). The cumulative urinary excretion of FBAL was about 80% of the total dose, and the oral absorption of TT-62 was thus thought to be good.

Administration, Oral↗
PubMed1993

[A case report of adenosquamous cell carcinoma of the stomach responding well to combination chemotherapy].

A 51-year-old man with unresectable adenosquamous cell carcinoma classified Borrmann type 3 of the stomach was treated with combination chemotherapy. The treatment consisted of two parts: intraabdominal administration of CBDCA (400 mg/body) during the operation, and transcatheteral intraabdominal infusion of CDDP(100 mg/m2) on day 1 and oral administration of UFT (400 mg/m2) on day 1 to 28 from a month after the operation. The latter therapy was performed every four weeks, and was administered two times. Primary gastric region was improved like a type II-C endoscopically, and metastatic lymphnode measuring 5 cm diameter disappeared on a computed tomography after the treatment. Thus, total gastrectomy was performed. No cancer cells were shown in both the resected stomach and dissected lymphnodes upon histological examination. Generally, patients with unresectable gastric cancer have a poor prognosis. But we concluded that the survival time and the quality of life in this patient were remarkably improved by the effective combination chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

A novel saccharide structure, Xyl 1----3 Gal 1----(SO3-)3,4 Fuc----, is present in acrosome reaction-inducing substance of the starfish, Asterias amurensis.

The jelly coat of echinoderm eggs contains a glycoconjugate, acrosome reaction-inducing substance (ARIS), that is essential for triggering the acrosome reaction in homologous spermatozoa. In the starfish, Asterias amurensis, ARIS is a sulfated glycoprotein of an apparent molecular size of greater than 10(7). Since its biological activity is dependent mostly on its sugar moiety, oligosaccharides liberated by hydrolysis with 10 mM H2SO4 for 60 min at 100 degrees C from pronase digests of ARIS (P-ARIS) were chemically analyzed. The main oligosaccharide purified by high-performance anion-exchange chromatography was determined to be Xyl1----3Gal1----(SO3-)3,4Fuc by compositional analysis and FAB mass spectrometry. This structure indicates that ARIS possesses a novel saccharide chain having sulfated fucose as an internal residue.

Acrosome↗
PubMed1992

Analysis of the 5' flanking region of the rat proliferating cell nuclear antigen (PCNA) gene.

The proliferating cell nuclear antigen (PCNA), highly conserved among eukaryotes, is an auxiliary factor for DNA polymerase delta. In this report we sequenced 1560 nucleotides (nt) of the 5' flanking region of the rat PCNA gene and located the transcription initiation site. The sequence contains 1435 nt upstream of the cap site and promotes transcription of a linked heterologous reporter gene in rat, mouse and human cells. Transient expression assays using a series of 5' deletion mutants revealed that 240 nt of the upstream sequence are sufficient for full promoter activity. Three GC boxes and several other binding sites of transcription factors were observed, but neither a TATA nor a CCAAT sequence was found in this region. The results also suggested the existence of a negative regulatory element(s) between -968 and -691. Cotransfection with early region 1 (E1) genes of human adenoviruses activated the expression of the reporter gene, suggesting that an E1-responsive element is located at the proximal promoter region within 81 nt upstream of the transcription initiation site.

3T3 Cells↗
PubMed1992

Multiple intracellular signaling pathways of the neuropeptide substance P receptor.

The rat substance P (SP) receptor cDNA has been transfected into cultured rat KNRK cells, and a stable cell line expressing functional SP receptors established. Upon stimulation with SP, these cells responded by simultaneously activating two signaling pathways: the mobilization of intracellular Ca2+ and the raising of cyclic adenosine triphosphate (cAMP) levels. Both Ca2+ and cAMP responses were elicited in a similar dose-dependent manner with half maximal concentrations of approximately 5 x 10(-10) M. Following ionomycin treatment SP-dependent Ca2+ responses were abolished, whereas cAMP responses were preserved. Forskolin eliminated the SP-dependent cAMP elevation, however, the SP-induced Ca2+ mobilization remained unchanged. Furthermore, treatment with phorbol esters had no significant effect on either of the two SP-induced responses. Thus it appears that the SP receptor is capable of independently activating Ca2+ mobilization and cAMP pathways. These results may provide new insights for further understanding the diverse activities of SP in various systems in vitro and in vivo.

Animals↗