Biomedical subjects

S Amano

Publications and source records attributed to S Amano.

At least 91 records · Page 5Linked to original sources

PubMed1999

Quadruple cancer including bilateral breasts, Vater's papilla, and urinary bladder: report of a case.

We herein report a rare case of quadruple carcinoma with heterochronous bilateral breast cancer, cancer of Vater's papilla, and cancer of the urinary bladder, which were all curatively resected. A 62-year-old woman previously underwent right and left modified radical mastectomies heterochronously. Recently, a dilatation of the lower bile duct, diagnosed as cancer of Vater's papilla, was resected by a pancreatoduodenectomy. Hematuria during surgery led to the discovery of a solid bladder tumor. The tumor was resected by a transurethral resection. The histopathologic findings differed for all four lesions. The patient had an uneventful postoperative course and to date has shown no recurrence.

Adenocarcinoma↗

PubMed1999

Functional and molecular evidence for Na(+)-HCO3- cotransporter in human corneal endothelial cells.

Although bicarbonate transport in corneal endothelium has been suggested to be coupled to Na+, the underlying molecular mechanism has not been clarified. In the present study we investigated whether a recently cloned Na(+)-HCO3- cotransporter (NBC-1) is responsible for this process, and, if so, whether the endothelium expresses a separate isoform or one of the other two isoforms that have recently been identified (kNBC-1 from kidney and pNBC-1 from pancreas). Using primers designed for specific and common regions we demonstrated by reverse transcriptase polymerase chain reaction (RT-PCR) that both kNBC-1 and pNBC-1 are expressed in cultured human corneal endothelial cells. In addition functional studies with a pH-sensitive fluorescence probe were performed. In the presence of HCO3-/CO2 a pH regulatory process was demonstrated which depends on the presence of Na+ and membrane potential, but is independent of Cl- and is inhibited by the disulfonic stilbene DIDS. These results support the presence of NBC-1 as the major bicarbonate transport system in corneal endothelium.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

PubMed1999

Laparoscopic treatment for common bile duct stones by transcystic papilla balloon dilatation technique.

The laparoscopic transcystic common bile duct (CBD) approach is becoming increasingly more refined as an ideal technique to deal with gallbladder stones (GBS) and common bile duct stones (CBDS) during a single operation. Our method, transcystic CBD exploration and papilla balloon dilatation (PBD), is an easier, safer, and less invasive technique than the transcystic approaches that have previously been reported. With our method, a sheath is introduced through the cystic duct into the CBD in order to allow catheter exchange, and the CBDS is flushed out through the papilla into the duodenum after PBD. We applied our new technique, without complication, to a patient with GBS and CBDS. Our technique is one of the safest, easiest, and least invasive methods for the treatment of patients with GBS and CBDS.

Ampulla of Vater↗

PubMed1999

Herpes simplex virus in the trabeculum of an eye with corneal endotheliitis.

PURPOSE: To report an eye with corneal endotheliitis and increased intraocular pressure in which the trabeculum demonstrated immunoreactivity for herpes simplex virus. METHOD: Case report. A 62-year-old man presented with increased intraocular pressure, keratic precipitates, and corneal stromal edema in his left eye. The tissue excised during trabeculectomy was immunohistochemically examined for herpetic viruses. RESULT: Immunoreactivity for herpes simplex virus was identified in the trabeculum. CONCLUSION: Herpes simplex virus may cause trabeculitis and increased intraocular pressure in patients with corneal endotheliitis.

Acyclovir↗

PubMed1999

Relationship between apparent accomodation and corneal multifocality in pseudophakic eyes.

OBJECTIVE: To investigate whether any association exists between apparent accommodation in pseudophakic eyes and multifocal corneal effects. DESIGN: A prospective observational case series. PARTICIPANTS: A total of 121 eyes of 98 patients who had undergone phacoemulsification and posterior chamber intraocular lens implantation were studied. METHODS: The amount of apparent accommodation was measured using an accommodometer. The degree of corneal multifocality was determined on the corneal topography by measuring the maximum and minimum corneal refractive powers within the pupillary area. Refractive astigmatism, keratometric astigmatism, pupillary diameter, and age were also analyzed. MAIN OUTCOME MEASURES: Apparent accommodation, corneal multifocality, refractive and keratometric astigmatism, pupillary diameter, and age. RESULTS: Multiple regression analysis revealed that corneal multifocality and pupillary diameter had significant positive correlations with apparent accommodation, whereas other explanatory variables showed no relationship with apparent accommodation. CONCLUSION: Multifocal corneal effects contribute to apparent accommodation in pseudophakic eyes.

Accommodation, Ocular↗

PubMed1999

Severe iridodialysis from phacoemulsification tip suction.

During cataract surgery, the iris of an 83-year-old woman was strongly sucked into the phacoemulsification tip twice, resulting in severe iridodialysis. The dehisced iris was sutured to the sclera using double-armed 10-0 polypropylene on a long curved needle. Intensive suction of the iris by the phacoemulsification tip can lead to severe iridodialysis. Machine setting parameters, particularly flow rate, should be lowered after the first iris suction to avoid further iris damage.

Aged↗

PubMed1999

Anesthetic dose and analgesic effects of sub-Tenon's anesthesia in cataract surgery.

PURPOSE: To compare the analgesic effects of different doses of sub-Tenon's anesthesia in cataract surgery by assessing patient response to visceral stimulus. SETTING: Inouye Eye Hospital, Tokyo, Japan. METHODS: A prospective study was done of 1019 eyes of 1019 patients having phacoemulsification and posterior chamber intraocular lens implantation. They received a 1.0 mL (391 eyes), 2.0 mL (366 eyes), or 3.0 mL (262 eyes) anesthetic infiltration into the sub-Tenon's space. Pain scores were recorded when the anterior chamber was irrigated with an acetylcholine chloride solution to attain miosis after lens implantation. RESULTS: The distribution of pain scores was significantly different among the 3 groups (P < .0001, Kruskal-Wallis test). Multiple comparison revealed that the 3.0 mL anesthetic infiltration offered significantly higher analgesic effects than the 2 lower doses. The 3.0 mL sub-Tenon's anesthesia effectively blocked the visceral stimulus. CONCLUSION: For cataract surgery, 3 mL is the optimal dose of anesthetic solution in sub-Tenon's anesthesia.

Aged↗

PubMed1999

Rapid method for detection and detoxification of heavy metal ions in water environments using phytochelation.

Phytochelatins (PCs, (gammaGlu-Cys)n-Gly (n = 2-11)) are produced by higher plants, algae, and some fungi in response to heavy metal ion exposure. A rapid and convenient method for quantifying heavy metal ion concentrations in water environments was developed using a chemically synthesized PC as a mediator. The chelating ability of the PC and quantification of the thiol group were utilized to measure heavy metal ions at low concentrations. The method requires only ten minutes for measurement and only 1 ml of a liquid sample. A range of homogeneous PCs (n = 4-7) were chemically synthesized using a peptide synthesizer. These, especially PC7, exhibited higher sensitivity and consistency of measurement than the native PC from Silene cucubalus, which produced a mixture of PC2, PC3, and PC4. Detoxification of heavy metal ions in vitro by PC was also investigated. Using the paper disc method, the cell growth inhibition zone caused by cadmium ion against Salmonella typhimurium TA1538 was significantly decreased by addition of PC. Furthermore, at the minimum inhibitory concentration of cadmium ion (200 microM) in a nutrient broth culture of S. typhimurium, cell growth was almost completely recovered by addition of PC to the medium.

Journal Article↗

PubMed1999

Comparison of sub-Tenon's anaesthesia by different delivery techniques in cataract surgery.

PURPOSE: To compare the analgesic effects of three different delivery techniques of sub-Tenon's anaesthesia in cataract surgery by assessing patients' response to the visceral stimulus. METHODS: A prospective, randomised study was conducted on 345 eyes of 345 patients undergoing phacoemulsification and posterior chamber intraocular lens implantation. They received anaesthetic infiltration into the sub-Tenon's space through a conjunctival incision (115 eyes), infiltration into the posterior sub-Tenon's space (retrobulbar space) through a conjunctival incision (114 eyes), or injection into the intra-Tenon's space (subconjunctival space) without making a conjunctival incision (116 eyes). Pain scores were recorded when the anterior chamber was irrigated with an acetylcholine chloride solution to achieve miosis after lens implantation. RESULTS: There were no significant differences in pain scores among the three groups (chi-squared test of homogeneity, p = 0.814). Approximately 10-20% of patients reported slight to severe pain at the time of acetylcholine administration. CONCLUSIONS: The three anaesthetic delivery methods of sub-Tenon's anaesthesia possess similar and reasonable analgesic effects in cataract surgery, but may not block visceral stimuli completely.

Acetylcholine↗

PubMed1999

Pretreatment of human keratinocyte sheets with laminin 5 improves their grafting efficiency.

Laminin 5 is essential in epithelial attachment to stromal tissues, suggesting that it might improve keratinocyte attachment in a variety of clinical situations. In this study, we examined the effect of exogenous laminin 5 upon the efficiency of transplantation of keratinocyte sheets in animal models. Keratinocyte sheets were prepared according to the method of Rheinwald & Green (1975). Purified laminin 5 was added to the sheets of group 1 (1.0 microg per cm2), Dulbecco's modified Eagle's medium alone was added to group 2. The sheets were grafted to the panniculus carnosus of nude mice (BALB/C nu/nu) (n = 12) and nude rats (Fisher 344) (n = 15). The take rate was assessed by measurement of the area of surviving epithelium at 7 d postgrafting. Laminin 5 bound the keratinocyte sheets of group 1. At 7 d postgrafting, the area of epithelialization of group 1 was significantly larger than that of group 2. Immunohistochemistry staining showed that collagen IV, laminin 5, and collagen VII stained more strongly at the dermal-epidermal junction in group 1 than in group 2. Integrin chains alpha6 and beta4 were similar in both groups. Electron microscopy at day 3 after grafting, showed the lamina densa of group 1 to be more continuous than in group 2. Pretreatment of cultured human keratinocyte sheets with laminin 5 improved the extent of epithelial coverage and increased the rate of neobasement membrane formation. The results suggest that laminin 5 promotes epithelial attachment by increasing the rate of basement membrane assembly.

Animals↗

PubMed1999

Quantitative analysis of regular and irregular astigmatism induced by pterygium.

PURPOSE: To quantitatively evaluate the influence of pterygium and its removal surgery on both regular and irregular corneal astigmatism. METHODS: In 19 eyes of 19 patients undergoing pterygium surgery, videokeratographic measurements were taken before and 1 month after surgery. Using Fourier harmonic analysis, dioptric data on mire rings were decomposed into spherical, regular astigmatism, and irregular astigmatism (decentration and higher order irregularity) components. The distance between the line of sight and the advancing edge of pterygium was measured, and the eyes were classified into two groups: large pterygium group (the distance <2.0 mm, n = 7) and small pterygium group (> or =2.0 mm, n = 12). Fifteen eyes of 15 subjects served as age-matched normal control eyes. RESULTS: Before surgery, the magnitudes of regular astigmatism and higher order irregular astigmatism showed significant correlation with the size of pterygium. Regular astigmatism, asymmetry, and higher order irregularity in the large pterygium group were significantly greater than those of normal control eyes. The pterygium removal surgery significantly improved these changes, but regular astigmatism and higher order irregularity in the large pterygium group still remained significantly greater than those in the normal control eyes. CONCLUSION: Pterygium induces a significant amount of regular and irregular astigmatism in proportion to its size. The removal surgery can improve these changes, but corneal distortion does not normalize completely in eyes with advanced pterygium.

Aged↗

PubMed1999

Accuracy of standardized uptake value measured by simultaneous emission and transmission scanning in PET oncology.

We assessed the accuracy of the standardized uptake value (SUV) measured by simultaneous emission and transmission scanning in cancer patients using FDG positron emission tomography (PET). Conventional, independent emission (E)/transmission (T) scans and simultaneous E/T scans were conducted consecutively in 30 patients who underwent FDG PET examinations. The SUVs of 35 mass lesions and 34 selected normal tissues were derived from the independent E/T scan and simultaneous E/T scan. Experimental studies using a cylindrical phantom were also conducted to evaluate the accuracy and reproducibility of the SUV derived from a simultaneous E/T scan. The SUVs of 18F solution in the phantom were estimated to be approximately 1, with high reproducibility in the range of total counts observed in the clinical examinations. There were no significant differences in the SUVs in 35 tumours derived from simultaneous E/T scans and those derived from independent scans, and there was a strong positive correlation between the two (r = 0.99, P < 0.01). There were also no significant differences in the SUVs in 34 normal tissue regions derived from simultaneous E/T scans and those derived from independent scans. In conclusion, simultaneous E/T scanning with FDG in patients with malignant tumours is a valid method, since the SUV derived from the simultaneous scan is accurate and reproducible.

Algorithms↗

PubMed1999

[Overview of models on spoken word recognition].

Models of spoken word recognition, such as logogen model, cohort model, new cohort model, trace model, shortlist model, and neighborhood activation model, were examined from the viewpoints of lexical processing. Although none of these models were good enough to explain all the results of studies on activation, competition, and composition of word candidates, the trace and shortlist models were less problematic than the other models.

Auditory Perception↗

PubMed1999

[Immunohistochemical study of p16MTS1/INK4a and Ki-67 expression in esophageal squamous cell carcinomas].

We evaluated the clinical significance of p16 and Ki-67 expressions in esophageal squamous cell carcinomas. Operative specimens obtained from 64 patients with esophageal squamous cell carcinomas were investigated by staining with antibodies against p16 and Ki-67. The possible correlations among p16 and Ki-67 expression, clinicopathologic factors and prognosis were studied. The expression of p16 was observed in 68.9%, and it related to histologic classification, lymphatic invasion and clinicopathological stage. Survival rate was significantly better in the patients with p16 positive tumors than in those with p16 negative tumors. Ki-67 positive index (Ki-67-PI) related to only histologic classification. It is suggested that immunohistochemical assessment on the p16 expressions would be useful to select more suitable treatment of squamous cell carcinoma of the esophagus.

Aged↗

PubMed1999

Hyaluronan synthase expression in bovine eyes.

PURPOSE: Hyaluronan (HA), a high-molecular-weight linear glycosaminoglycan, is a component of the extracellular matrix (ECM). It is expressed in eyes and plays important roles in many biologic processes, including cell migration, proliferation, and differentiation. Hyaluronan is produced by HA synthase (HAS), which has three isoforms: HAS1, HAS2, and HAS3. In this study, the HAS expression in the anterior segment of bovine eyes was investigated to determine the significance of HA in eyes. METHODS: To obtain bovine HAS probes, degenerate oligonucleotide primers, based on well-conserved amino acid sequences including the catalytic region of each HAS isoform, were used for reverse transcription-polymerase chain reaction to amplify mRNA from bovine corneal endothelial cells (BCECs). Hyaluronan synthase-1 expression in the anterior segment of bovine eyes at the protein level was investigated by immunohistochemistry. RESULTS: All three HAS isoforms were expressed in BCECs at the mRNA level. Amplified cDNA fragments of HAS1, HAS2, and HAS3 from BCECs can be aligned to human counterparts, showing similarities of 100%, 97.3%, and 100%, respectively, at the amino acid level. Hyaluronan synthase 1 was expressed at the protein level in corneal epithelium, keratocyte, corneal endothelium, conjunctival epithelium, ciliary epithelium, capillary endothelium, and trabecular meshwork. CONCLUSIONS: Hyaluronan synthase isoforms were expressed in the ocular anterior segment and are speculated to be involved in HA production in situ.

Amino Acid Sequence↗

PubMed1999

18F alpha-methyl tyrosine PET studies in patients with brain tumors.

UNLABELLED: We have developed 18F-labeled alpha-methyl tyrosine (FMT) for PET imaging. The aim of this study was to evaluate the clinical application potential of FMT for patients with brain tumors. METHODS: Eleven healthy volunteers and 20 patients with brain tumors were injected with 185 MBq (5 mCi) FMT. In 3 healthy volunteers, whole-body imaging and urinary and plasma analysis were conducted for the assessment of the biodistribution of FMT. The normal range of cortical standardized uptake value (SUV) as a reference for comparing tumor SUV of FMT was estimated by using PET data obtained at 30 min postinjection in 8 healthy volunteers. Dynamic PET scans were conducted for 100 min in 4 healthy volunteers and for 30 min in 15 patients with brain tumors. The 10-min static images in another 4 volunteers and all patients were obtained at 30 min postinjection. In 13 patients, FMT uptake in the brain tumor was compared with 18F-fluorodeoxyglucose (FDG). Tumor-to-normal cortex count (T/N) ratio and tumor-to-white matter count (T/W) ratio and SUVs of brain tumors were determined on FMT and FDG PET images. RESULTS: Approximately 1480 MBq (40 mCi) FMT were produced in one radiosynthesis. Percentage injected dose (%ID) of FMT in the brain ranged from 2.8% to 4.9%, and approximately 50%ID of FMT was excreted in urine during 60 min postinjection, of which 86.6% was unmetabolized FMT. A faint physiological brain uptake with SUV of 1.61 +/- 0.32 (mean +/- SD, n = 8) was observed in healthy volunteers. Tumor SUV of FMT ranged from 1.2 to 8.2, with mean value of 2.83 +/- 1.57 (n = 23), which was significantly higher than that of the cortical area in healthy volunteers (P < 0.01). T/N and T/W ratios of FMT were significantly higher than those of FDG (2.53 +/- 1.31 versus 1.32 +/- 1.46, P < 0.001; 3.99 +/- 2.10 versus 1.39 +/- 0.65, P < 0.0001, respectively). CONCLUSION: FMT, like other radiolabeled amino acids, can provide high-contrast PET images of brain tumors.

Adolescent↗

PubMed1999

Suppression of hypoxia-associated vascular endothelial growth factor gene expression by nitric oxide via cGMP.

PURPOSE: To investigate the suppressive effect of nitric oxide (NO) on vascular endothelial growth factor (VEGF) gene expression and to elucidate its mechanism of action. METHODS: Immortalized human retinal epithelial (RPE) cells, H-ras-transfected murine capillary endothelial cells, and nuclear factor-kappaB (NF-kappaB) RelA knockout 3T3 fibroblasts had VEGF gene expression stimulated by hypoxia, TPA (phorbol ester 12-O-tetradecanoylphorbol-13 acetate), and ras-transfection. The dose response and time course of inhibition of VEGF gene expression by NO were characterized by northern blot analysis, ribonuclease protection assay, and enzyme-linked immunosorbent assay. The effects of NF-kappaB and cGMP in the NO-induced suppression of VEGF gene expression were quantitated. cGMP production was inhibited by LY 83583 (6-anilino-5,8-quinolinedione), a specific inhibitor of guanylate cyclase production, and cGMP accumulation was quantitated by immunoassay. RelA knockout 3T3 fibroblasts were used to assess the contribution of NF-kappaB to the downregulation of VEGF by NO. RESULTS: The NO donor sodium nitroprusside (SNP) decreased hypoxia-induced VEGF gene expression in a dose- and time-dependent manner. One hundred fifty micromolar SNP completely suppressed hypoxia-induced VEGF mRNA levels for at least 24 hours. Constitutive VEGF expression was not altered by SNP. The SNP-mediated decreases in VEGF expression were associated with increases in intracellular cGMP and were blocked by LY 83583. Sodium nitroprusside was able to decrease hypoxia-induced VEGF mRNA increases in fibroblasts deficient in the RelA subunit of NF-kappaB. Nitric oxide was also effective at suppressing increased VEGF expression secondan, to mutant ras and TPA. CONCLUSIONS: These data indicate that NO decreases hypoxia-induced VEGF via a cGMP-dependent mechanism and suggest that NO may serve as an endogenous inhibitor of both hypoxia- and non- hypoxia-enhanced VEGF expression in vivo.

3T3 Cells↗

PubMed1999

[Usefulness of hypoallergenic rice (AFT-R 1) and analysis of the salt insoluble rice allergen molecule].

An involvement of rice allergy in development and exacerbation of recalcitrant atopic dermatitis (AD) has been suggested in some cases, and it has been also known that elimination diet of rice results in improvement of AD and reduction of the doses of steroid ointment and anti-allergic drugs used for the treatment. We prepared the hypoallergenic rice grain, AFT-R 1 (Allergen-free Technology Lab. Inc.-Rice 1), with alkali treatment from the rice material, Koshihikari, which is popular in Japan. Its usefulness was evaluated clinically and serologically. The serological study with IgE-ELISA showed that the major allergic protein were remarkably reduced to less than 1/6400 of them in the AFT-R 1. Then it was applied to the clinical trial, and evaluated as useful by the clinical effect in 14 (93%) out of 15 patients, who were diagnosed to have rice allergy by the elimination (in 15 case) and ingestion (in 12 cases) of the regular rice. The serum taken from the patient, whom the AFT-R 1 was evaluated as unuseful in the clinical trial, was shown to have IgE antibodies reactive to the remaining protein in AFT-R 1 by IgE-ELISA, and the 60 kd protein band was detected as an IgE-binding component of AFT-R 1 by IgE-immunoblotting with the same serum. This 60 kd rice protein was identified as ADP (UDP)-glucose-starch glycosyl transferase (EC: 2.4.1.21) by N-terminal amino acid analysis. These results indicated that AFT-R 1 is very useful as a substitute of rice in many AD patients with rice allergy, although IgE-binding component such as the 60 kd protein is remaining in one.

Adolescent↗