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Biomedical subjects

A Yoshida

Publications and source records attributed to A Yoshida.

At least 487 records · Page 27Linked to original sources
PubMed1995

Magnetic resonance imaging in the early diagnosis of cavernous sinus thrombosis.

A 55-year-old man reported a severe headache of 3 days' duration, left ptosis and left lid swelling before examination. The ocular examination revealed left eye proptosis, severe edema of the left bulbar conjunctiva and lid, increasing intraocular pressure of the left eye and ptosis on the left side with decreased extraocular movement. The right eye was normal. Hematologic studies indicated mild inflammation. An enhanced computed tomography scan revealed proptosis of the left globe and enlargement of the superior ophthalmic vein and cavernous sinus of the left side. Angiography revealed an area of interrupted blood flow in the left cavernous sinus. Enhanced magnetic resonance imaging (MRI) with Gd-DTPA revealed a low-intensity area that was suspected to be a blood clot in the enlarged left cavernous sinus. This case indicates the efficacy of enhanced MRI examination in the early diagnosis of cavernous sinus thrombosis.

Cavernous Sinus↗
PubMed1995

Effects of class IA antiarrhythmic drugs on the reentrant circuit in common human atrial flutter.

In 9 patients with the common type of atrial flutter (AF), a zone of slow conduction was observed proximal to the coronary sinus orifice. Class IA antiarrhythmic drugs were administrated intravenously in all 9 patients. AF was converted to sinus rhythm in only 1 patient. In the remaining 8 patients, although IA drugs suppressed conduction velocity, this effect was not preferential with regard to the zone of slow conduction. Conversion of AF to sinus rhythm by rapid pacing was achieved in these 8 patients. At a critical pacing cycle length, AF was interrupted just after conduction block developed in the zone of slow conduction. A progressive decrease in conduction velocity was observed in the zone of slow conduction for several beats just before the onset of conduction block. In conclusion, class IA drugs facilitate the interruption of AF by rapid atrial pacing by inducing conduction block in the zone of slow conduction.

Adult↗
PubMed1995

A low protein diet increases 4-nitrophenol-UDPglucuronosyltransferase but decreases chloramphenicol-UDPglucuronosyltransferase activity and mRNA level in livers of rats treated with polychorinated biphenyls.

We have examined the effects of dietary level of protein (5% or 30% in casein) on enzyme activities and mRNA levels of two xenobiotic-inducible UDPglucuronosyltransferase (UDPGT) enzymes, such as chloramphenicol-UDPGT (CP-UDPGT) and 4-nitrophenol-UDPGT (4NP-UDPGT), in the livers of rats treated or not treated with polychlorinated biphenyls (PCB). In animals fed 5% casein and not treated with PCB, CP-UDPGT activity tended to be lower than in rats fed 30% casein. In contrast, 4NP-UDPGT activity was higher in rats fed 5% casein. In rats treated with PCB, the activities of both enzymes were increased. CP-UDPGT mRNA level was higher (1.4-fold) in rats fed 30% dietary casein than in those fed 5% casein. In contrast, 4NP-UDPGT mRNA level was higher (2.8-fold) in rats fed 5% casein than in those fed 30% casein. These changes in mRNA levels paralleled those in the activities of the two enzymes. The data indicate that the dietary protein is an important factor controlling the expression of hepatic xenobiotic-inducible UDPGT genes and modulates the capacity of the liver to metabolize foreign compounds.

Animals↗
PubMed1995

Role of ornithine in urea synthesis in rats treated with thyroid hormone.

The purpose of this study was to find whether the regulation of urea synthesis was mediated through the activation of N-acetyglutamate synthesis by ornithine when the thyroid status was 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 neither PTU nor T3 (control). Urinary excretion of urea and the liver concentrations of ornithine and N-acetylglutamate in rats given PTU + T3 were significantly lower than in rats given PTU alone. The liver concentration of N-acetylglutamate was correlated with the liver concentration of ornithine (r = 0.920, p < 0.001). Ornithine administration (0.5 mmol/100 g body wt) elevated the liver concentration of N-acetylglutamate in all three groups. The results suggest that the greater concentration of ornithine in the hypothyroid (PTU alone) rats is likely to increase the N-acetylglutamate concentration in liver and stimulate urea synthesis.

Animals↗
PubMed1995

Development of hypercalcemic crisis in a Graves' hyperthyroid patient associated with central diabetes insipidus.

A 26-year-old man with Graves' hyperthyroidism associated with central diabetes insipidus (DI), initially showed hypercalcemic crisis. Initially, very low serum levels of intact parathyroid hormone (PTH) and 1,25-dihydroxy vitamin D3 and a moderate rise of serum C-terminal PTH related protein (C-PTHrP) were observed which strongly suggested a humoral hypercalcemia of malignancy due to PTHrP. However, the serum C-PTHrP level later became normal. Mild hyperprolactinemia, no responses of growth hormone (GH) to insulin-induced hypoglycemia despite a normal growth hormone releasing hormone (GRH) test and mild thickening of the pituitary stalk on magnetic resonance imaging were observed. Thus, an autoimmune nature of his central DI is considered; it is noteworthy that the serum C-PTHrP level may be elevated by renal failure in patients with hypercalcemia due to causes other than PTHrP.

Acute Disease↗
PubMed1995

Differentiation of Langerhans cells from interdigitating cells using CD1a and S-100 protein antibodies.

The present study shows that Langerhans cells can be differentiated from interdigitating cells at the light microscopic level. Superficial lymph nodes and skin taken from necropsies and the lymph nodes of dermatopathic lymphadenopathy (DPL) were used for this experiment. Sections of lymph node and skin were embedded using the acetone, methyl benzoate and xylene (AMeX) method and dendritic cells were immunostained with anti S-100 protein antibody (S-100, and OKT-6 (CD1a) using the restaining method. Langerhans cells in the skin were positive for both CD1a and S-100. Dendritic cells positive for both CD1a and S-100, and dendritic cells positive for S-100, but not for CD1a were observed in superficial lymph nodes. In normal superficial lymph nodes, there were more interdigitating cells than Langerhans cells. The majority of the dendritic cells in the DPL were Langerhans cells. We conclude that the S-100 and CD1a positive cells are Langerhans cells, and the S-100 positive-CD1a negative cells are interdigitating cells.

Antigens, CD1↗
PubMed1995

[Basic studies on aging of mandible--age-related changes of osteoblastic cells from mouse mandible].

To investigate the age-related changes of mandibular bones, three osteoblastic cell lines (11-4tc, 32-3c and 84-3c cells) with a high level of alkaline phosphatase (ALPase) activity were isolated from the mandibular bones of mice at the three different ages (11, 32 and 84 weeks old). Growth rate, ALPase activity, mineralization ability and the expressions of mRNAs of collagen alpha (I) (CO) and osteopontine (OP) were investigated in these cell lines. The effects of beta-glycerophosphate, retinoic acid, 1 alpha,25(OH)2D3 and estrogen on cellular activity were also examined. The results were as follows: 1. The doubling times of 11-4tc, 32-3c and 84-3c cells were 20, 16 and 39 hours respectively. 2. The maximum ALPase activity of 11-4tc, 32-3c and 84-3c cells in a confluent monolayer were 0.403, 0.020 and 0.035 mu moles phenol/min/mg protein respectively. 3. The mineralization ability and the growth response to estrogen were decreased with advancing age of the donor. 4. The mRNAs of CO and OP were expressed in these cells. 1 alpha,25(OH)2D3 and retinoic acid increased the expression of mRNAs of OP when 11-4tc cells were cultured for 7 days and when 32-3c and 84-3c cells were cultured for 18 days. These results suggest that the aging of the donor relates with the depression of proliferation, mineralization and biological responses to estrogen, 1 alpha,25(OH)2D3 and retinoic acid in osteoblastic cells in mandibular bones.

Adenosine Triphosphatases↗
PubMed1995

[Detection of food additives by enzyme immunoassay].

The analysis of synthesized food additives is generally performed by chromatography or spectrophotometry. However, the analytical procedures for natural food additives have been little reported so far because they are difficult to analyse chemically. We have attempted to apply enzyme immunoassay (EIA) to the analysis of natural food additives. Hen egg white lysozyme, as a food preservative, was determined by the competitive EIA, using mouse anti-HEL ascites. Carminic acid (CA), which is the main component of cochineal color, was determined by the competitive EIA, using monoclonal anti-CA antibody. Phycocyanin, which is the main component of spirulina color, was determined by the avidin-biotin sandwich EIA, using double monoclonal anti-phycocyanin antibodies.

Food Additives↗
PubMed1995

[Traumatic macular hole and posterior vitreous].

We studied retrospectively the clinical features of 18 eyes of 18 patients with traumatic macular hole. The macular hole was elliptical with irregular edges in 17 eyes (94%) and its size ranged from 1/5 to 1/2 of the disc diameter. Posterior vitreous detachment was found in 3 eyes (17%); the vitreous was detached from the macula in only one of these 3 eyes. Commotio retinae, vitreous hemorrhage, hyphema, or choroidal rupture was also found in several eyes. These findings suggest that traumatic macular hole develops usually in the absence of posterior vitreous detachment and its pathogenesis is independent of the occurrence of posterior vitreous detachment. We speculate that blunt trauma-induced deformity of the eyeball or impact on the posterior pole provides a mechanical cause for the macular rupture.

Adolescent↗
PubMed1995

Immunohistochemical localization of Na(+)-dependent glucose transporter in the rat digestive tract.

Glucose is actively absorbed in the intestine by the action of the Na(+)-dependent glucose transporter. Using an antibody against the rabbit intestinal Na(+)-dependent glucose transporter (SGLT1), we examined the localization of SGLT1 immunohistochemically along the rat digestive tract (oesophagus, stomach, duodenum, jejunum, ileum, colon and rectum). SGLT1 was detected in the small intestine (duodenum, jejunum and ileum), but not in the oesophagus, stomach, colon or rectum. SGLT1 was localized at the brush border of the absorptive epithelium cells in the small intestine. Electron microscopical examination showed that SGLT1 was localized at the apical plasma membrane of the absorptive epithelial cells. SGLT1 was not detected at the basolateral plasma membrane. Along the crypt-villus axis, all the absorptive epithelial cells in the villus were positive for SGLT1, whose amount increased from the bottom of the villus to its tip. On the other hand, cells in the crypts exhibited little or no staining for SGLT1. Goblet cells scattered throughout the intestinal epithelium were negative for SGLT1. These observations show that SGLT1 is specific to the apical plasma membrane of differentiated absorptive epithelial cells in the small intestine, and suggest that active uptake of glucose occur mainly in the absorptive epithelial cells in the small intestine.

Animals↗
PubMed1995

[Vitreous videography with a scanning laser ophthalmoscope].

We used a scanning laser ophthalmoscope (SLO) to attempt better visualization of the posterior vitreous than conventional biomicroscopy. We observed the posterior vitreous using the SLO in patients with age- or disease-related vitreous changes. We compared the results using lasers of several wavelengths. The detailed structure of the posterior hyaloid membrane, its collagen mesh structure with premacular defect, and the prepapillary glial ring were clearly visualized by direct laser illumination. Persistent attachment of the vitreous gel to the macula through the oval defect in the posterior hyaloid membrane was seen even with repeated eye rotations. Short wavelength laser was preferable to a long wavelength one for observing the posterior hyaloid membrane. Vitreous opacities were clearly visualized with all lasers as dark spots with fundus monitoring by retro illumination. Thus in vivo visualization of the posterior hyaloid membrane and vitreous gel was achieved using this new technique, which is more advantageous than the conventional biomicroscopy because of its monochromatic laser delivery system with confocal light detection.

Adolescent↗
PubMed1995

[Differential diagnosis of macular breaks by microperimetry with a scanning laser ophthalmoscope].

To improve differential diagnosis of macular breaks, microperimetry with a scanning laser ophthalmoscope (SLO) was performed. Fifty consecutive macular breaks were detected by biomicroscopy and indirect ophthalmoscopy, and SLO microperimetry was performed on each. Of the 50 eyes, 22 eyes were diagnosed with idiopathic macular breaks by biopmicroscopy and indirect ophthalmoscopy because of a cuff. SLO microperimetry also showed dense scotoma within the macular break and relative scotoma on the cuff in the 22 eyes. However, diagnosis was not done only by biomicroscopy and indirect ophthalmoscopy in the other 28 eyes because of the absence of a cuff. SLO microperimetry differentiated the full thickness macular breaks from pseudo-or lamellar breaks in these eyes. SLO microperimetry is useful for differentiating their prognosis, and determining the need for surgical treatment.

Aged↗
PubMed1995

[Analysis of T cell receptor V beta gene expression in bronchoalveolar lavage fluid lymphocytes from patients with idiopathic interstitial pneumonia].

T lymphocytes in bronchoalveolar lavage (BAL) from idiopathic interstitial pneumonia (IIP) patients are considered to recognize unknown antigens, such as dust, fume, virus or degenerated autoantigens. To analyse the nature of these T lymphocytes, we investigated T cell receptor (TCR) V beta gene usage (22 kinds) in BAL Lymphocytes and Peripheral blood lymphocytes from 10 11P patients and 9 normal controls, using reverse transcriptase-polymerase chain reaction method. In BAL lymphocytes, predominant usage of V beta genes (> 15% of the sum of all V beta transcripts) was recognized in 7 of 10 IIP patients, which appeared to vary in individuals (Case 1: V beta 14, case 2: V beta 3, V beta 5.1, case 5: V beta 2, case 6: V beta 6, case 7: V beta 8, case 8: V beta 7, V beta 20, case 9: V beta 6), whereas no predominant V beta usage was demonstrated in normal controls. It remains to be elucidated whether the BAL lymphocytes expressing predominant V beta genes are involved in the activation of alveolar macrophages, fibroblasts, thereby inducing the production of autoantibodies.

Base Sequence↗
PubMed1995

[Natural outcome of idiopathic macular hole].

To ascertain the natural outcome of idiopathic macular holes, we studied 186 eyes with the disorder: stages 1 (48 eyes), 2 (30 eyes), 3 (71 eyes), and 4 (37 eyes), which were followed for over twelve months. In 11 (23%) eyes with stage 1 lesions full-thickness macular hole developed during the follow-up period, and in 12 (25%) eyes visual acuity decreased two or more Snellen lines. Twenty-five (83%) and 21 (70%) eyes with stage 2 lesions, 39 (55%) and 22 (31%) eyes with stage 3 lesions, and 7 (19%) and 5 (14%) eyes with stage 4 lesions had enlarged macular holes and decreased visual acuity during the follow-up, respectively. The present results suggest that different stages of macular holes have different natural outcomes and the treatment should be based on their stages.

Aged↗
PubMed1995

Changes of corneal redox state in diabetic animal models.

Metabolic and biochemical changes of the corneal epithelium and endothelium were studied in experimental diabetic animal models. Ocular redox fluorometry was used to noninvasively determine tissue reduction-oxidation (redox) changes in organ cultured rabbit corneas incubated in high glucose concentration media, alloxan-induced diabetic rabbits, and nonobese diabetic mice. The ratio of autofluorescence from reduced pyridine nucleotide to oxidized flavoproteins (PN/Fp) was used as the indicator of the redox state. Chemical assays for NADH and NAD+ were performed on in vitro materials. Analysis of corneal endothelial morphology using specular microscopy was performed to study possible correlations with metabolic changes. Both the PN/Fp and NADH/NAD+ ratios increased in the corneal endothelium under all experimental conditions. Changes in redox state were not observed in the corneal epithelium in any of the models. Morphologic analysis of the corneal endothelium revealed no significant changes. These results indicate that redox changes occur in the diabetic corneal endothelium, but not the corneal epithelium. Ocular redox fluorometry is capable of detecting changes in the corneal endothelial redox state noninvasively.

Animals↗
PubMed1995

Antiarrhythmic drugs inhibit the G-protein and K+ channels in the cultured thyroid cell line.

We examined the effects of antiarrhythmic drugs on the induction of cAMP by TSH (thyroid-stimulating hormone), using continuously cultured FRTL-5 rat thyroid cells. Group Ia antiarrhythmic drugs had no effect, but Group Ib antiarrhythmic drugs suppressed cAMP induction by TSH. These drugs suppressed cAMP induction in response to cholera toxin but did not inhibit TSH receptor binding or cAMP induction by forskolin. These results indicate that Group Ib antiarrhythmic drugs inhibit thyroid G-protein, resulting in a decrease in cAMP induction by TSH. We also examined the effect of antiarrhythmic drugs on K+ channels. Group Ia antiarrhythmic drugs had no effect on K+ channel activation by TSH and cAMP. On the other hand, Group Ib antiarrhythmic drugs suppressed K+ channel activation by TSH and cAMP. This indicates that the mechanism of suppression is not inhibition of TSH receptors or G-proteins but the direct suppression of K+ channels. Group Ib antiarrhythmic drugs inhibited thyroid Gs-protein and thyroid K+ channels. Considering the close relationship between G-protein and ion channels in the cardiac cell membrane, these different effects of Group Ia and Group Ib antiarrhythmic drugs on G-proteins and K+ channels are of interest. Further investigation is necessary to clarify the relationship between thyroid G-proteins and thyroid K+ channels.

Animals↗