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Biomedical subjects

S Kinoshita

Publications and source records attributed to S Kinoshita.

At least 73 records · Page 4Linked to original sources

[Effect of latanoprost on the barrier function of corneal epithelium].

PURPOSE: We evaluated the effect on corneal epithelium barrier function of instillation of prostaglandin F2 alpha ophthalmic solution (latanoprost) for one month. MATERIALS AND METHODS: Ten healthy volunteers and nine glaucoma patients were enrolled in this study. The barrier function was determined as uptake of topically applied sodium fluorescein by the central cornea measured with an anterior fluorophotometer(FL-500, Kowa Co. Ltd). Healthy volunteers and glaucoma patients received 0.005% latanoprost instillation once daily for one month. We measured the uptake of fluorescein by the cornea of each subject before and one month after instillation. RESULTS: Fluorescein uptake before the instillation was 22.2 +/- 16.0 ng/ml (mean +/- standard deviation) and 26.4 +/- 15.1 ng/ml one month after the treatment in the normal group, and it was 55.0 +/- 25.0 ng/ml before treatment and 57.8 +/- 37.0 ng/ml after treatment in the glaucoma group. There was no significant difference in the uptake of fluorescein before and after treatment in either of two groups. CONCLUSION: These results suggested that the barrier function of corneal epithelium was not compromised after the instillation of latanoprost for at least one month.

Adult↗

[A case of postoperative gastric cancer responding to adjuvant chemotherapy with TS-1--a novel oral formation of 5-fluorouracil].

TS-1 is a novel oral formation of 5-fluorouracil, developed using tegafur and two biochemical modulations. We report the case of a patient with multiple lymph node metastases from gastric cancer that markedly responded to TS-1. A 70-year-old man suffering from hematemesis was admitted to our hospital. Computed tomography showed advanced gastric cancer with huge lymph node metastases. After non-curative operation, he received adjuvant chemotherapy with TS-1 for 12 weeks. CT revealed that almost complete reduction of the metastatic nodes was obtained. No serious adverse reactions were observed.

Aged↗

Establishment of the anti-Klotho monoclonal antibodies and detection of Klotho protein in kidneys.

A novel gene, klotho (kl), which is involved in the development of a syndrome resembling human aging in mice, was recently identified. The kl gene encodes a single-pass membrane protein whose extracellular domain carries homology to beta-glucosidases. There also exists a splice variant of kl mRNA which encodes a putative secreted protein in both human and mouse. In this study, to characterize the physiological roles of Klotho protein, we established three monoclonal antibodies (mAbs) against the recombinant human Klotho protein. The mAbs are named KM2076 (rat IgG(2)a), KM2119 (rat IgG(2)b), and KM2365 (mouse IgG(1)). In Western blots, KM2076 and KM2119 specifically recognized a 130 kDa Klotho protein in the mouse and human kidney membrane fractions. To detect the human Klotho protein, the sandwich-type ELISA system with KM2076 and KM2365 was established. Using the ELISA system, we detected the human Klotho protein as low as 20 ng/ml in the supernatant of Chinese hamster ovary cells (CHO cells), introduced the human klotho gene. KM2076 and KM2119 specifically gave a positive staining by immunohistochemical staining in paraffin or frozen sections of the kidneys from wild-type mice but not in those from kl mice. Strong staining was observed especially in cortical renal tubules of the mouse kidney, where expression of klotho transcripts overlaps. KM2076 also showed a similar reaction pattern in the paraffin sections of rat and human kidneys. The mAbs established in this paper will serve as useful analytical, pathological, and diagnostic tools to disclose the role of Klotho protein in the suppression of a syndrome resembling human aging.

Aging↗

Tachycardia-dependent right bundle-branch block with supernormal conduction.

This paper reports the case of a 76-year-old man in whom atrial flutter with varying atrioventricular block and intermittent right bundle-branch block was found. This is the first report on tachycardia-dependent right bundle-branch block associated with supernormal conduction in a case of atrial flutter. When an impulse is conducted to the ventricles beyond 0.72 s after a QRS complex of right bundle-branch block configuration, the impulse falls after the abnormally long effective refractor period of the right bundle branch and passes through the right bundle branch. When the conducted impulse occurs within 0.72 s after a QRS complex of right bundle-branch block configuration, the impulse usually falls in the refractory period and is blocked in the right bundle branch; however, only when the impulse occurs 0.48 or 0.49 s after that does it fall in the supernormal period and passes through the right bundle branch. The findings in the present report strengthen our previous suggestion that the presence of supernormal conduction plays an important role in the initiation of reentrant ventricular tachycardia.

Aged↗

Role of fracture hematoma and periosteum during fracture healing in rats: interaction of fracture hematoma and the periosteum in the initial step of the healing process.

To study the mechanisms of fracture healing, we investigated the interaction between fracture hematoma and periosteum during the early phase of fracture healing in rats. Experimentally induced fractures of the tibia in untreated rats were compared histologically with such fractures in rats in which either the bone marrow or the periosteum had been removed. The extent of periosteal cell proliferation and chondrogenesis in the fracture hematoma was evaluated on experimental days 3, 6, 10, and 14. On day 3, periosteal cell proliferation at the tibial fracture site was decreased in the bone marrow-removed rats compared with the proliferation in untreated rats. Little chondrogenesis in the fracture hematoma was seen through day 6 in the periosteum-removed rats. These results suggest that the periosteum is important for mediating the primary steps of chondrogenesis and enchondral ossification in the fracture hematoma and that the fracture hematoma may be essential for periosteal cell proliferation during fracture healing.

Animals↗

Gelatino-lattice corneal dystrophy: clinical features and mutational analysis.

PURPOSE: To report five unrelated Japanese individuals with "gelatino-lattice corneal dystrophy that clinically resembled, to some extent, gelatinous drop-like corneal dystrophy and lattice corneal dystrophy type 1. METHODS: Genomic DNA isolated from the five individuals with "gelatino-lattice corneal dystrophy was used as a template for polymerase chain reaction to amplify all exons of the candidate gene betaig-h3 and M1S1. The polymerase chain reaction product was then sequenced. RESULTS: In all cases, betaig-h3 was mutated in "gelatino-lattice corneal dystrophy (Arg124Cys), which is the same nucleotide change examined previously in lattice corneal dystrophy type 1. On the other hand, no mutation was detected in the entire coding region of M1S1. CONCLUSION: Based on the results of this study, it is suggested that "gelatino-lattice corneal dystrophy may be a subtype of lattice corneal dystrophy type 1.

Adult↗

Association of autosomal dominantly inherited corneal dystrophies with BIGH3 gene mutations in Japan.

PURPOSE: To evaluate the incidence of BIGH3 gene mutations in 164 unrelated Japanese patients with corneal stromal dystrophies with an autosomal dominant trait. METHODS: Data were collected at two major institutions in the eastern and western parts of Japan, where molecular genetic analysis was performed for diagnostic purpose. RESULTS: The incidence of mutations was ranked as follows: 118 patients (72%), the R124H mutation associated with Avellino corneal dystrophy; 23 patients (14%), the R124C mutation associated with lattice corneal dystrophy type 1; and 10 patients (6%), the P501T mutation associated with lattice corneal dystrophy type 3A. CONCLUSION: Avellino corneal dystrophy associated with the R124H mutation is the most common form of corneal stromal dystrophy in Japan. This dystrophy, which is diagnosed histopathologically, has also been called granular corneal dystrophy in Japan. The classification of these diseases according to genetic pathogenesis may be more appropriate than is the use of clinical or histological findings.

Corneal Dystrophies, Hereditary↗

Sinus escape-capture bigeminy and sinus extrasystolic bigeminy.

Blocking conduction between the sinus node and the atria (SA block) can be responsible for symptomatic rhythm problems. However, in atrial escape-capture bigeminy with SA block, when atrial escape P waves originate in a site within or close to the sinus node, the diagnosis of SA block is not easy. Electrocardiograms were selected from 7 people with atrial bigeminy because (1) all atrial deflections (P waves) were almost the same in shape and in length of PR intervals, (2) comparatively long PP intervals alternated with comparatively short PP intervals, and (3) occasionally the atrial bigeminy changed to normal regular sinus rhythm in which 2 or more sinus P waves were found in succession. An attempt is made to clarify the mechanism for these cases. When regular sinus rhythm changed to bigeminal rhythm, the long PP interval introduced the bigeminy in 3 cases, indicating the presence of "sinus" escape-capture bigeminy; whereas the short PP interval introduced the bigeminy in the other 4 cases, indicating the presence of "sinus" extrasystolic bigeminy. In cases of sinus escape-capture bigeminy associated with SA block, the cases may occasionally be diagnosed wrongly as ordinary sinus arrhythmia not associated with SA block. Therefore, it seems that sinus escape-capture bigeminy is not so rare as is generally believed. Patients with SA block often require implantation of the artificial pacemaker. Thus, the authors believe that differentiation of sinus escape-capture bigeminy from other forms of "sinus" bigeminy is clinically important.

Adult↗

Concealed conduction in the reentrant pathway as a mechanism of stable ventricular quadrigeminy.

This is the first report on the stable occurrence of ventricular quadrigeminy as a manifestation of concealed bigeminy in a case of fixed and late coupled ventricular extrasystoles. A 46-year-old man is reported in whom the period of ventricular bigeminy alternated with the period of ventricular quadrigeminy. Coupling intervals of the extrasystoles were fixed and much longer than sinus QT intervals. When the heart rate is decreased, the period of bigeminy changed to the period of quadrigeminy without gradual decrease in coupling of the preceding extrasystoles. Once such a change occurred, stable quadrigeminy is maintained for a period. These findings suggest the possibility that concealed electrotonic conduction of blocked impulses and interference of conducted impulses may occur in the reentrant extrasystolic pathway as a mechanism of stable ventricular quadrigeminy.

Electrocardiography↗

Molecular cloning and expression analyses of mouse betaklotho, which encodes a novel Klotho family protein.

We report here the identification of mouse betaklotho (betakl), which encodes a type I membrane protein with high resemblance to Klotho (KL). Both betaKL and KL consist of two internal repeats with homology to family 1 glycosidases, while these essential glutamates for the enzymatic activities were not conserved. The identical pattern of substitution and variation in the substituted amino acids between these two proteins indicate that they likely to form a unique family within the glycosidase family 1 superfamily. During mouse embryonic development, strong betakl expression was detected in the yolk sac, gut, brown and white adipose tissues, liver and pancreas, and in the adult, predominantly in the liver and pancreas. Despite the high structural similarity between betaKL and KL, their expression profiles were considerably different and betakl expression was not induced in kl-deficient mouse mutants.

Amino Acid Sequence↗

Growth factors: importance in wound healing and maintenance of transparency of the cornea.

The mechanism of corneal wound healing has not been clarified yet. However, evidence has accumulated that various kinds of growth factor such as epidermal growth factor (EGF), fibroblast growth factor (FGF), transforming growth factor (TGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF) play a key role in corneal wound healing. For example, these growth factors are expressed in the corneal epithelial cells, keratocytes and endothelial cells, and their receptors are expressed in the corneal cells. Furthermore, these growth factors promote the proliferation of corneal cells and induce the migration of corneal cells. In addition to the growth factors, inflammatory cytokines such as interleukin (IL)-1, IL-6 and TNF-alpha are involved in corneal wound healing. These cytokines are expressed in the normal and inflammatory cornea after infections, alkaliburn, etc. where they control the growth of corneal cells and induce the migration of corneal cells. Thus, a number of growth factors and cytokines function in the regulation of corneal cell proliferation and in the maintenance of corneal transparency.

Animals↗

Prognosis of replanted primary incisors after injuries.

Between 1979 and 1997, 58 avulsed primary teeth were treated at the Pedodontic Clinic of Niigata University Dental Hospital. Among these, we replanted six avulsed incisors of four patients and treated two teeth of two patients replanted at other dental clinics. Referring to the clinical records, oral photographs and radiographs, we examined the injury age, cause of injury, condition of tooth storage, length of time until replantation, and also the prognosis after replantation. Three teeth of two cases remained until eruption of their permanent successors, and one tooth of one case remained under observation without extraction. Although the other four teeth of three cases resulted in extraction, no secondary infection was detected due to replantation. The following reasons were suspected for the poor prognosis of the four teeth. One avulsed tooth was not fixed immediately after replantation. One replanted tooth might not have been compatible with the alveolar socket. In the other two teeth, the periodontal vital tissues might have been removed before replantation. It is generally suggested that replantation of primary teeth is not a good option. However, from the present results, it was considered that replantation can be an effectual method when the condition of the avulsed primary tooth is suitable.

Age Factors↗

Macular corneal dystrophy type I and type II are caused by distinct mutations in a new sulphotransferase gene.

Macular corneal dystrophy (MCD; MIM 217800) is an autosomal recessive hereditary disease in which progressive punctate opacities in the cornea result in bilateral loss of vision, eventually necessitating corneal transplantation. MCD is classified into two subtypes, type I and type II, defined by the respective absence and presence of sulphated keratan sulphate in the patient serum, although both types have clinically indistinguishable phenotypes. The gene responsible for MCD type I has been mapped to chromosome 16q22, and that responsible for MCD type II may involve the same locus. Here we identify a new carbohydrate sulphotransferase gene (CHST6), encoding an enzyme designated corneal N-acetylglucosamine-6-sulphotransferase (C-GlcNAc6ST), within the critical region of MCD type I. In MCD type I, we identified several mutations that may lead to inactivation of C-GlcNAc6ST within the coding region of CHST6. In MCD type II, we found large deletions and/or replacements caused by homologous recombination in the upstream region of CHST6. In situ hybridization analysis did not detect CHST6 transcripts in corneal epithelium in an MCD type II patient, suggesting that the mutations found in type II lead to loss of cornea-specific expression of CHST6.

Amino Acid Sequence↗

Apparent bradycardia-dependent sinoatrial block associated with respiration.

In our previous patients, apparent bradycardia-dependent block has been shown in the atrioventricular (AV) junction and in the accessory pathway. It was suggested that these previous cases were not of true bradycardia-dependent block; namely, that, as a result of periodic increases in vagal tone associated with respiration, conductivity in the AV junction or in the accessory pathway was depressed to a greater degree than automaticity in the sinus node. In the present article, 3 patients with frequent sinoatrial (SA) block were reported. In 1 patient, sinus escape-capture bigeminy caused by SA block was found. In these present patients, when the sinus cycle lengthened, SA block occurred. The purpose of the present article is to show that the patients have apparent bradycardia-dependent SA block, namely, not true bradycardia-dependent SA block. In all patients, the respiration curve was recorded simultaneously with the electrocardiogram. In all patients, during inspiration, the sinus cycle gradually shortened; on the other hand, during expiration, the sinus cycle gradually lengthened, and then a sinus impulse was blocked in the SA junction. These findings suggested that increased vagal tone during expiration depressed conductivity in the SA junction to a greater degree than automaticity in the sinus node.

Bradycardia↗

Isolation and characterization of a Ca(2+)-activated chloride channel from human corneal epithelium.

PURPOSE: Transparency of the cornea is maintained through the activity of secretory mechanisms in the epithelium and endothelium, which offset the tendency of the stroma to imbibe fluid and swell. These secretory mechanisms establish osmotic gradients thereby providing the osmotic driving forces for coupled fluid transport from the stroma into both the tears and the anterior chamber. To further characterize the mechanism of epithelial Cl secretion, we cloned a cDNA encoding a Ca(2+)-dependent chloride channel, an abundant mRNA in human corneal epithelium. We investigated the abundance of all known human chloride channels in corneal epithelium to identify those responsible for regulating chloride conductance in this tissue. METHODS: For the isolation of a full-length cDNA clone, a probe was selected from a set of expressed sequenced tag (EST) clones classified as unique to corneal epithelium (http://bodymap. ims.u-tokyo.ac.jp). The expression patterns of the corresponding gene encoding novel chloride channel gene in human cornea and other tissues were examined by reverse transcription-polymerase chain reaction (RT-PCR). Quantitative PCR was performed to clarify the expression level of the novel chloride channel gene in cornea relative to that in other human tissues. RESULTS: We cloned a new Ca(2+)-activated chloride channel, CLCA2, from corneal epithelium. The full length cDNA clone encoded 943 amino acids with 62% identity to bovine Ca(2+)-activated chloride channel. The CLCA2 gene mapped to human chromosome 1p32. Quantitative expression analysis by RT-PCR showed that it is the most abundant chloride channel in corneal epithelium. CONCLUSION: High and tissue specific expression of the CLCA2 gene in human corneal epithelium implies an important role in corneal transparency maintenance.

Amino Acid Sequence↗

Amniotic membrane as a substrate for cultivating limbal corneal epithelial cells for autologous transplantation in rabbits.

PURPOSE: To examine the viability of using human amniotic membrane as substrate for culturing corneal epithelial cells and transplanting them onto severely injured rabbit eyes. METHODS: An ocular-surface injury was created in the right eye of eight rabbits by a lamellar keratectomy extending 5 mm outside the limbus. Next, from the limbal region of the uninjured left eyes of five of these animals, a small biopsy of corneal epithelial cells was taken and cultured on acellular human amniotic membrane. One month later, the invading conjunctiva that covered the corneal surface of all eight injured eyes was surgically removed. Five of the eyes then received grafts of amniotic membrane containing autologous cultured epithelial cells, whereas the other three received grafts of acellular amniotic membrane alone. RESULTS: A confluent primary culture of limbal corneal epithelial cells was established on acellular human amniotic membrane after 14 days. Cells were partially stratified and fairly well attached to the underlying amniotic membrane, although a fully formed basement membrane was not evident. The three rabbits that received amniotic membrane transplantation alone all had total epithelial defects on the graft in the early postoperative period. Eyes that were grafted with amniotic membrane that contained cultivated epithelial cells, however, were all successfully epithelialized up to 5 days after surgery. CONCLUSION: Autologous transplantation of cultivated corneal epithelium is feasible by using acellular amniotic membrane as a carrier.

Amnion↗

The spectrum of beta ig-h3 gene mutations in Japanese patients with corneal dystrophy.

PURPOSE: This study was undertaken to identify beta ig-h3 gene mutations in Japanese patients with granular corneal dystrophy (GCD), Avellino corneal dystrophy (ACD), lattice corneal dystrophy (LCD), and Reis-Bücklers' corneal dystrophy (RBCD). R124H, R124C, R555W, and R555Q mutations have been reported in Europe to cause ACD, LCD type I, GCD, and RBCD, respectively. METHODS: In total, 91 Japanese patients who had been clinically diagnosed with GCD, LCD, or RBCD were investigated to determine whether they had mutations in the beta ig-h3 gene. Genomic DNA was amplified using the polymerase chain reaction and analyzed using single-strand conformation polymorphism techniques. Mutations were identified using the direct sequencing method. RESULTS: In 68 unrelated patients who had been diagnosed with GCD, 62 patients (91%) were found to have the R124H mutation, which has been reported to cause ACD, whereas only six patients (9%) had the R555W mutation. In LCD patients, 10 patients with type I disease had the R124C mutation, and 10 patients with type IIIA disease had a P501T mutation. One patient with atypical LCD had an L527R mutation. In two patients with RBCD, one had an R555Q mutation and the other patient with geographic opacities was found to have an R124L mutation. CONCLUSIONS: Depending on the specific mutation in the beta ig-h3 gene, the phenotypes of corneal dystrophy may differ. Our results indicate that assay of mutations in the beta ig-h3 gene is required to establish a correct diagnosis.

Corneal Dystrophies, Hereditary↗