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Biomedical subjects

A Yoshida

Publications and source records attributed to A Yoshida.

At least 361 records · Page 20Linked to original sources
PubMed1997

Tonic block of the Na+ current in single atrial and ventricular guinea-pig myocytes, by a new antiarrhythmic drug, Ro 22-9194.

Ro 22-9194 reduced the Na+ current in the atrial myocytes as well as ventricular myocytes in a tonic block fashion. Ro 22-9194 had a higher affinity to the inactivated state Na+ channels (KdI = 3.3 microM in atrial myocytes, KdI = 10.3 microM in ventricular myocytes) than to those in the rested state (KdR = 91 microM in atrial myocytes, KdR = 180 microM in ventricular myocytes), which indicated that Ro 22-9194 had a higher affinity to the Na+ channels in atrial myocytes than in ventricular myocytes. Ro 22-9194 shifted the inactivation curve in the hyperpolarized direction in both atrial and ventricular myocytes. These findings suggest that Ro 22-9194 more strongly inhibited the Na+ channel of the atrial myocytes of the diseased hearts with the depolarized membranes potentials than the Na+ channels in ventricular myocytes.

Animals↗
PubMed1997

Myxoglobulosis in an extravasation mucocele of the lower lip.

A case of extravasation mucocele showing an unusual intraluminal globular organization of the mucous content is described. The cystic lesion was obtained from the lower lip of a 10-year-old Japanese girl and presented as a painless swelling of 1 year duration. Histologically, the cyst cavity was filled with round globules and encapsulated by a granulation tissue wall devoid of a lining epithelium. To our knowledge this peculiar histological pattern has not been previously described in an oral mucocele. Clinicopathological features of 'myxoglobulosis of the appendix', a morphological variant of appendiceal mucocele, appear to be related to the present case.

Child↗
PubMed1997

Arabinofuranosyl-terminated and mannosylated lipoarabinomannans from Mycobacterium tuberculosis induce different levels of interleukin-12 expression in murine macrophages.

Lipoarabinomannan (LAM) is a major surface lipoglycan of Mycobacterium tuberculosis. In the present study, we demonstrated that arabinofuranosyl-terminated LAM (AraLAM) derived from a rapidly growing Mycobacterium sp., but not extensively mannosylated LAM derived from the Erdman strain, is capable of inducing interleukin-12 (IL-12) expression in murine macrophages. Since IL-12 is known to drive the differentiation of naive T cells toward T-helper type 1 (Th1) cell development, AraLAM may be an effective adjuvant in vaccines and immunotherapies that need Th1 responses.

Animals↗
PubMed1997

Increased number of IgE positive Langerhans cells in the conjunctiva of patients with atopic dermatitis.

AIM: To determine the role of Langerhans cells (LCs) found to bear IgE in patients with atopic dermatitis (AD) by evaluating the surface distribution of these cells in the conjunctival epithelium and epidermis of skin lesions in patients with AD. METHODS: The double labelling method was used to evaluate IgE positive cells that were positive for anti-CD1a or anti-CD23 antibody in an epithelial sheet of the conjunctival limbus. Specimens of conjunctiva were obtained from 12 men, six of whom had AD and ocular complications. Five patients without atopic disease served as controls, plus one additional patient with asthma but no AD. A similar study was conducted using epidermal sheets obtained from two patients with AD and from one without AD. RESULTS: The number of CD1a+ cells present in the conjunctival epithelium of the patients with AD significantly exceeded that of the patients without AD. Most CD1a+ cells in the conjunctival epithelium and epidermis from the patients with AD bore IgE on their surfaces. Few such cells from patients without AD bore IgE. No CD23+ cells were found in the patients with or without AD. CONCLUSIONS: The presence of an increased number of LCs bearing IgE on their surfaces in the conjunctival epithelium of patients with AD suggests that these cells may be involved in eliciting the hypersensitivity reaction and participate in ocular inflammation.

Adolescent↗
PubMed1997

Copper-ion-catalyzed vitreous liquefaction in vivo.

To investigate copper-ion (Cu2+)-catalyzed vitreous liquefaction in vivo, Cu2+ solution (10 mumol) was injected into the vitreous cavity of rabbits. At 24 h after the injection, the gel and liquid vitreous were weighed, and the percent of vitreous liquefaction was calculated. Cu2+ injection resulted in liquefaction of 58% of the vitreous, although control eyes had 12% liquefaction (p < 0.1). The vitreous liquefaction was more pronounced in the presence of exogenous ascorbic acid. However, the addition of mannitol, a hydroxyl-radical-specific scavenger, significantly suppressed the Cu(2+)-catalyzed vitreous liquefaction. The free radicals generated by the Cu(2+)-catalyzed oxidation system may cause vitreous liquefaction in vivo.

Animals↗
PubMed1997

Effect of timolol and UF-021 (a prostaglandin-related compound) on pulsatile ocular blood flow in normal volunteers.

The effects of topically applied timolol (a nonselective beta-blocker) and UF-021 (a prostaglandin-related compound) on pulsatile ocular blood flow (POBF) were investigated in 9 healthy volunteers. One drop of either UF-021 or timolol was instilled in one randomly selected eye and the fellow eye received physiologic saline. Before and 90 min after drop instillation, we measured intraocular pressure (IOP), POBF, heart rate (HR) and blood pressure (BP). After a washout interval of at least 1 week, the other drug was instilled in the previously treated eye. IOP, POBF, HR, and PB were measured following the same protocol. After timolol administration, IOP and POBF decreased significantly in the treated eye (26%, p = 0.01, and 13%, p = 0.02, respectively) and in the fellow eye (11%, p = 0.01, and 11%, p = 0.03, respectively). HR also decreased (10%, p = 0.03), but BP did not change significantly. After UF-021 administration, no significant changes were found in IOP, POBF, HR, or BP. Our results suggest that in normal subjects timolol decreases POBF in both the treated and the untreated eyes, whereas UF-021 has no action on either IOP or POBF.

Administration, Topical↗
PubMed1997

Cytogenetic survey of 1,007 infertile males.

The aim of this study was to investigate the influence of a chromosome abnormality on male infertility. The subjects consisted of 1,007 males with the chief complaint of infertility. Karyotyping was conducted mainly by G banding. Major chromosome abnormalities were observed in 62 patients (6.2%) in total and consisted of sex chromosome abnormalities were observed in 62 patients (6.2%) in total and consisted of sex chromosome abnormalities in 38 patients (3.8%) and autosomal chromosome abnormalities in 24 (2.4%). Among the patients with sex chromosome abnormalities, 28 cases were 47, XXY, 3 were 47,XYY, and 7 cases had a Y chromosome abnormality. Autosomal chromosome abnormalities comprised 10 cases of reciprocal translocation, 8 cases of Robertsonian translocation, 5 cases of inversion, and 1 case of ring chromosome. In patients with a sperm density < 5 x 10(6)/ml, a total motile sperm count < 1 x 10(6), a follicle-stimulating hormone value > or = 30.1 mIU/ml, a luteinizing hormone value > or = 8.9 mIU/ml, a testosterone value < or = 2.69 ng/ml, or an average testis volume < or = 8 ml, the incidence of major chromosome abnormalities was significantly higher. These findings suggest that patients who need microinsemination should undergo chromosome analysis. We should counsel patients about obtaining adequate information on each chromosome abnormality.

Adult↗
PubMed1997

Cystoid macular edema as an initial symptom of inflammatory orbital pseudotumor.

We report a patient with pseudotumor with cystoid macular edema (CME). The initial finding in our case was only CME with a bilateral visual acuity decrease to 20/25. Approximately 3 months later, the visual acuity dropped to light perception in the right eye and 20/200 in the left eye. Computed tomography scan revealed a mass in the right orbital apex and band-shaped enhancement in the cavernous sinus and along the upper margin of the petrous bone. However, no mass was found intraoperatively, and a biopsy specimen of the bulging levator muscle showed polymorphonuclear leukocyte infiltration. The CME resolved postoperatively. The tumor also seemed to resolve; however, after 1 year, the tumor recurred and invaded the brain tissue. A temporal lobectomy revealed widespread inflammatory cell infiltration. To ensure early diagnosis, pseudotumor should be considered in patients with CME of which the cause is uncertain.

Adult↗
PubMed1997

Effect of a thyroid hormone treatment on brain protein synthesis in rats.

The effect of the thyroid hormone on the rate of brain protein synthesis in rats was studied. Experiments were conducted on three groups of rats given 6-propyl-2-thiouracil (PTU, a thyroid inhibitor) without a triiodothyronine (T3) treatment, those treated with PTU + T3, and those treated with neither PTU nor T3 (control). The fractional rates of protein synthesis in the brain, liver, and kidney of rats given PTU + T3 were significantly greater than those in rats given PTU alone. In the brain and kidney, the RNA activity [g of protein synthesized/(g of RNA.d)] were significantly correlated with the fractional rates of protein synthesis. In the liver and kidney, the RNA concentration (mg of RNA/g of protein) was related to the fractional rate of protein synthesis. These results suggest that the thyroid hormone treatment would be likely to increase the rate of protein synthesis in the brain of rats, and that the RNA activity is, at least partly, related to the fractional rate of brain protein synthesis.

Animals↗
PubMed1997

Fractures of the coracoid process.

We reviewed 67 consecutive patients with fractures of the coracoid process, classifying them by the relationship between the fracture site and the coracoclavicular ligament. The 53 type-I fractures were behind the attachment of this ligament, and the 11 type-II fractures were anterior to it. The relationship of three fractures was uncertain. Type-I fractures were associated with a wide variety of shoulder injuries and consequent dissociation between the scapula and the clavicle. Treatment was usually by open reduction and fixation for type-I fractures and conservative methods for type-II. At follow-up of the 45 available patients, 87% had excellent results, with no significant differences between the operative and non-operative groups or between the type-I and type-II fractures. We consider that operative treatment should be reserved for patients with multiple shoulder injuries with severe disruption of the scapuloclavicular connection.

Adolescent↗
PubMed1997

A safety study on rat's eye after 13-week oral administration with fenitrothion.

The potential of ocular toxicity of fenitrothion (O,O-dimethyl O-4-nitrom-tolyl phosphorothioate) was assessed in Sprague-Dawley (Crj:CD) rats of both sexes receiving a diet containing the test compound at concentrations of 0, 2.5, 5, 10, or 30 ppm for 13 weeks. The animals were observed daily for clinical signs and their body weights and food consumption were measured weekly during the study. At termination of treatment, surviving animals were subjected to ophthalmoscopy, electroretinography, and biochemical analyses of plasma, erythrocyte, and brain cholinesterase (ChE). Histopathological examinations of ocular tissues were performed on all animals by light microscopy and on two animals/sex/dose by electron microscopy. There were no treatment-related changes in clinical signs, body weights, and food consumption. A significant inhibition of ChE activity was observed in males (plasma and erythrocyte ChE) and females (plasma, erythrocyte, and brain ChE) at 30 ppm and in females (plasma ChE) at 10 ppm. Ophthalmological and histopathological examinations revealed neither functional nor morphological alterations in the visual system at any dose level. Under the conditions of the present study, there was no evidence of ocular toxicity of fenitrothion for male and female rats at dose levels up to 30 ppm (1.70 mg/kg/day for males and 1.96 mg/kg/day for females) where distinct inhibition of ChE activity was observed.

Administration, Oral↗
PubMed1997

Isolation and characterization of the dnaKJ operon from Actinobacillus actinomycetemcomitans.

The dnaKJ operon of Actinobacillus actinomycetemcomitans Y4 was cloned by the DNA-probing method using synthetic oligonucleotides designed on the basis of two conserved regions in DnaK/hsp70 proteins and sequenced by inverse PCR. The sequenced region was shown to contain two open reading frames coding for proteins analogous to DnaK and DnaJ.

Aggregatibacter actinomycetemcomitans↗
PubMed1997

Role of ornithine transport into mitochondria in urea synthesis of rats treated in thyroid hormone.

The purpose of this study was to find whether or not the ornithine transport into mitochondria regulated urea synthesis when the thyroid status is manipulated. Experiments were done on three groups of rats: given 6-propyl-2-thiouracil (PTU, a thyroid inhibitor) without triiodothyronine (T3) treatment, treated with PTU+T3 or receiving neither PTU nor T3 (control). The urinary excretion of urea, liver concentration of ornithine and ornithine transport into isolated hepatic mitochondria in rats given PTU+T3 were significantly lower than in rats given PTU alone. Ornithine transport was significantly inhibited by the addition of lysine specifically. This response was achieved well within the physiological concentration of lysine. Compared with rats given PTU without T3 treatment, the liver concentration of lysine was significantly higher in rats treated with PTU+T3 and control rats. Ornithine transport into hepatic mitochondria was closely correlated with the excretion of urea. The results suggest that the greater ornithine transport in the hypothyroid (PTU alone) rats is likely to stimulate urea synthesis. A thyroid hormone-induced increase in lysine concentration may be at least partly responsible for the changes in ornithine transport into mitochondria.

Animals↗
PubMed1997

[Early ocular changes in a tree shrew model of diabetes].

We developed a tree shrew model of diabetes using streptozotocin (STZ), and studied early ocular changes of diabetes (after one week of diabetes) by fluorophotometry. STZ was injected intraperitoneally at doses of sixty to 400 mg/kg body weight. Animals injected with more than 300 mg/kg of STZ developed diabetes. Corneal autofluorescence was significantly increased one week after STZ injection. These changes may be related to impairment of the ocular homeostatic mechanisms due to the onset of diabetes. Using this model, we might be able to obtain diabetic ocular impairment data closer to human data than in previous models of diabetes, because tree shrews are primates.

Animals↗
PubMed1997

Role of the vitreous and macular edema in branch retinal vein occlusion.

BACKGROUND AND OBJECTIVE: To determine the relationship between macular edema associated with branch retinal vein occlusion (BRVO) and the condition of the vitreous. PATIENTS AND METHODS: The authors retrospectively studied 58 patients (58 eyes) who underwent vitreous examination. The eyes were classified as having vitreomacular attachment (VMA) or vitreomacular separation (VMS), and were divided into two groups based on the mean age of the patients. RESULTS: Macular edema was found in 39 (67%) of the eyes. The prevalence of VMA was 81% (22 of 27 eyes) in group 1 (patients who were 64 years old or younger) and 45% (14 of 31 eyes) in group 2 (patients who were older than 64 years). Although no significant relationship was found, 77% (17 of 22) of the eyes with VMA in group 1 had macular edema. The incidence of macular edema was significantly higher in eyes with VMA (93%, 13 of 14) than in eyes with VMS (41%, 7 of 17, P = .009) in group 2. CONCLUSION: The authors' findings suggest that VMA may influence the presence of macular edema associated with BRVO.

Adult↗
PubMed1997

Quantitative immunohistochemical determination of 8-hydroxy-2'-deoxyguanosine by a monoclonal antibody N45.1: its application to ferric nitrilotriacetate-induced renal carcinogenesis model.

The DNA base-modified product 8-hydroxy-2'-deoxyguanosine (8-OHdG) is one of the most commonly used markers for the evaluation of oxidative DNA damage. A monoclonal antibody specific for 8-OHdG (N45.1) was characterized and applied in quantitative immunohistochemistry. N45.1 recognized both the modified base and deoxyribose structure of 8-OHdG and required a concentration two orders higher of 8-hydroxyguanosine as a competitor in the ELISA. In addition, N45.1 did not cross-react with the original four deoxyribonucleosides, other DNA base-modified products such as 8-hydroxy-2'-deoxyadenosine and O6-methyl-2'-deoxyguanosine, or urine components such as uric acid, creatine, and creatinine. A ferric nitrilotriacetate-induced rat renal carcinogenesis model was used for the evaluation of quantitative immunohistochemistry. The 8-OHdG index of quantitative immunohistochemistry, as analyzed by NIH image freeware, correlated reasonably well with the 8-OHdG amount determined by high-performance liquid chromatography with an electrochemical detector-except for a difference in peak time, which could be attributed to the selection of target location. The present method has advantages over the high-performance liquid chromatography/electrochemical detector, gas chromatography/mass spectrometry, and 32P-postlabeling methods in that it allows localization of 8-OHdG to be specified without the risk of artifactual production of 8-OHdG during the DNA extraction and hydrolytic processes.

8-Hydroxy-2'-Deoxyguanosine↗