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Biomedical subjects

H Miyata

Publications and source records attributed to H Miyata.

At least 109 records · Page 6Linked to original sources
PubMed2001

[The stress-reducing effect of cigarette smoking and the influence of trait-anxiety on its manifestation].

The purpose of the present study was to clarify the stress-reducing effect of cigarette smoking and the involvement of other factors such as trait-anxiety on the above effect of smoking. The subjects were 32 smokers who met DSM-IV criteria for substance dependence and 16 nonsmokers. The smokers were randomly assigned to a smoking group or a sham-smoking group. Immediately after the subjects performed a laboratory task, the State-Trait-Anxiety Inventory was administered for evaluating the levels of state-anxiety and trait-anxiety. The subjects were required to smoke a cigarette in a smoking group, sham-smoke in a sham-smoking group, or take a rest in a nonsmokers's group. After that, the same inventory was again administered. The decrease of state-anxiety in a smoking group was significantly more marked in degree than in a sham-smoking group and was comparable to that in a nonsmokers' group. A stepwise regression analysis revealed that the trait-anxiety levels significantly contributed to a decrease of state-anxiety levels in a smoking group. The present study indicated that cigarette smoking exhibited a stress-reducing effect and that the trait-anxiety levels were related to the effect of smoking.

Adult↗
PubMed2000

Lens Epithelial Cell Damage and Apoptosis in Atopic Cataract. Histopathological and Immunohistochemical Studies.

Purpose: To elucidate the relationship between damage of lens epithelial cells and apoptotic cell death in patients with atopic cataract.Methods: Histopathological and immunohistochemical studies were carried out using anterior lens capsules obtained at surgery from 13 patients with atopic cataract and from 25 patients with senile cataract.Results: No specific histopathological findings were found in the lens epithelial cells in atopic cases. However, the frequency and severity of histopathological findings such as flattening, nuclear pyknosis, and loss of cells were more frequent and more severe in atopic cases than in senile cases. The terminal deoxynucleotidyl transferase (Tdt)-mediated dUTP-biotin nick end labelling (TUNEL) method revealed that the mean ratio of cells containing fragmented DNA to whole epithelial cells was almost the same in both atopic and senile cases. However, the mean ratio of Bax-positive cells was significantly higher in atopic cases (mean +/- standard deviation, 29.1 +/- 35.0%) than in senile cases (2.7+/-7.0%) (P<.05). The mean ratio of Bcl-2-positive cells was significantly lower in atopic cases (1.4+/-3.4%) than in senile cases (44.3+/-35.7%) (P<.05).Conclusion: These results suggest that apoptotic cell death may play an important role in the development of lens epithelial cell damage in atopic cataract.

Journal Article↗
PubMed2000

Overexpression of bcl-2 in transient abnormal myelopoiesis associated with Down syndrome.

Transient abnormal myelopoiesis (TAM) is a haematological complication found in Down syndrome. To determine the mechanisms of sustained proliferation of TAM cells, we studied the expression of apoptosis-related proteins, such as bcl-2, Fas (APO-1/CD95) and p-53, in peripheral blood cells from a new-born infant with Down syndrome and TAM. Using flow cytometry, peripheral blood mononuclear cells (PBMCs), consisting mostly of blast cells, showed marked expression of bcl-2 protein but not of Fas or p-53 products. DNA gel electrophoresis of PBMCs, cultured in the absence of serum factors, revealed no marked fragmentation. Our findings suggest that bcl-2 overexpression may be associated with prolonged cell survival of TAM cells.

Down Syndrome↗
PubMed2000

High frequency of postnatal transmission of TT virus in infancy.

DNA of TT virus (TTV), a novel human circovirus, was tested for in 116 mother-infant pairs who had participated in the adult T-cell leukemia prevention program (APP) in Nagasaki, Japan, and refrained from breast-feeding. By polymerase chain reaction with Okamoto's seminested primers, 36 of the 115 (31%) mothers were positive. At the age of 6-8 months, 7 of 29 (24%) and 6 of 72 (8%) infants born to infected and uninfected mothers were positive, respectively (P = 0.047; RR, 2.90). Maternal TTV DNA load did not correlate with infantile infections. Since 99 of 100 (99%) cord blood samples were negative and all the mothers refrained from breast-feeding, the infantile TTV transmission would not be intrauterine or milk-borne. Between 6-8 and 12-21 months of age, 4 of 12 (33%) and 5 of 22 (23%) children born to infected and uninfected mothers turned positive, respectively (NS). At 12-21 months of age, 8 of 21 (38%) and 12 of 32 (38%) children born to infected and uninfected mothers were positive, respectively (NS). These results indicate that the TTV infection prevails in children at a frequency comparative to that in their mothers within the first 2 years of life, regardless of the maternal TTV status.

Adult↗
PubMed2000

A case of Meniere's disease with vertical nystagmus after administration of glycerol.

A 62-year-old woman who complained of repetitive vertigo with a left fluctuating hearing loss was admitted to our hospital three times. A glycerol test was done on the third admission. Two hours after the administration of glycerol, the patient complained of rotatory vertigo with a downbeat vertical nystagmus. This nystagmus then changed its direction upward. Her left hearing loss was improved during the glycerol test. On the day after the glycerol test, a caloric test was done. The caloric response of the right ear was remarkably improved. Although she had not felt a hearing loss in the right ear, an overwritten audiogram showed a fluctuation of hearing in the right ear. The bilateral caloric responses fluctuated. From these findings, it appears that the function of the inner ear on both sides fluctuating. We speculate that the administration of glycerol elicited an asymmetry in the function of the inner ear on both sides and ocuured vertigo with vertical nystagmus because of the irritation of both ears.

Audiometry↗
PubMed2000

Treatment of malignant melanoma of the lower eyelid using anterolateral thigh flap.

Malignant melanoma is a poor prognostic disease with the potential for high mortality despite early diagnosis and currently available treatment. Surgical judgment pertaining to the extent of primary resection and regional node dissections must be tempered by cosmetic considerations and by the anatomically diffuse pathways for lymphatic spread in certain lesions. We reported a case of malignant melanoma of the left lower eyelid, and presented the surgical excision and reconstruction using anterolateral thigh flap for skin defect. It is evident that comprehensive treatment using radical surgery and adjuvant chemotherapy is necessary for cutaneous malignant melanoma of head and neck areas.

Adult↗
PubMed2000

Evaluation of the histologic effect of chemoradiation therapy for squamous cell carcinomas of the esophagus by assessing morphologic features of surgical specimens.

The histologic effects of chemoradiation therapy (CRT) for esophageal cancer, which determine the benefit obtained from a salvage operation, are difficult to evaluate preoperatively. We therefore investigated whether or not the morphologic features of esophageal cancer tissue after CRT can be correlated with the histologic features of the tissue. Seventy-six patients with advanced esophageal squamous cell carcinoma underwent CRT followed by esophagectomy. The effects of CRT were evaluated by histologic examination of the residual tumors in the surgical specimen and correlated with clinicopathologic factors, including postoperative prognosis. The histologic effects of CRT were used to classify tumors as grade 1 (CRT poorly effective; 23 cases, 30.3%); grade 2 (CRT moderately effective; 31 cases, 40.8%); or grade 3 (CRT completely effective with no residual tumors; 22 cases, 28.9%). Among the gross findings of the removed esophagus, significant correlation with the CRT effects was observed in the case of wall thickness and ulceration but not in the case of longitudinal tumor length. Tumors with no wall thickening or ulceration were never classified as grade 1, whereas tumors with both wall thickening and ulceration were frequently rated as grade 1 (18/30, 60%). Microscopic examination of grade 2 tumors (23/31, 74.1%) revealed residual tumor cells growing below the mucosal layer, whereas tumor cells were exposed to the esophageal surface in 22 out of 23 patients with grade 1 tumors. The morphologic features after CRT can be used to evaluate its histologic effect, especially in the case of grade 1 tumors. However, the detection and prediction of grade 2 tumors remains difficult because of the presence of small amounts of residual tumor underneath the mucosa.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Inhibitory effects of tranilast on the proliferation and functions of human pterygium-derived fibroblasts.

PURPOSE: We studied the possibility that tranilast, an antiallergic and antiproliferative drug, may be beneficial for the treatment of pterygium. METHODS: Pterygium-derived cells were identified by immunohistochemical methods. Growth rate of pterygium-derived cells was determined by using a hemocytometer. Chemotaxis was determined in a microchemotaxis chamber. Pterygium-derived cells were cultured on floating collagen gel, and the contracted diameter was measured. Collagen synthesis by pterygium-derived cells was determined by the collagenase digestive method. Tranilast was added to the culture medium at final concentrations of 0, 12.5, 25, 50, and 100 microg/ml. RESULTS: Pterygium-derived cells were stained with anti-prolylhydroxylase and anti-alpha-smooth muscle actin, and identified as fibroblasts. Tranilast inhibited the proliferation and chemotaxis of pterygium-derived fibroblasts, and the collagen-gel contraction induced by these cells, but it exerted no inhibitory action on collagen synthesis by pterygium-derived fibroblasts. CONCLUSION: Tranilast may be useful for suppressing the recurrence and, possibly, the development of pterygium.

Actins↗
PubMed2000

Three spliced mRNAs of TT virus transcribed from a plasmid containing the entire genome in COS1 cells.

A permuted whole-genome construct of a TT virus (TTV), named VT416, had 3,852 nucleotides (nt) 98.2% similar to the prototype TA278 genome. To allow the transcription of TTV from the internal promoter, pBK*VT416(1.3G), carrying 1.3 units of VT416, was constructed. The poly(A)(+) RNAs expressed in COS1 cells 48 h posttransfection contained three TTV mRNA species 3.0, 1.2, and 1.0 kb in length, which were recovered in the 13 DNA clones from a lambda phage cDNA library. These mRNAs in the antigenomic orientation possessed in common the 3' terminus downstream of a poly(A) signal (A(3073)ATAAA) and the 5' terminus downstream of a cap site (C(98)ACTTC). A common splicing to join nt 185 with nt 277 was detected in all mRNAs. The coding region of the largest open reading frame (ORF) was maintained in 3.0-kb mRNA, because this splicing was located upstream of its initiation codon (A(589)TG). The second splicing was detected in 1.2-kb mRNA to join nt 711 with nt 2374 and in 1.0-kb mRNA to bind nt 711 to nt 2567. They linked a proposed ORF2 to another ORF for creating new ORFs over nt 2374 to 2872 in frame 2 and nt 2567 to 3074 in frame 3. The donor and acceptor sites of all three splicings matched the consensus sequence and were conserved in most of the 16 TTVs of distinct genotypes retrieved from the database. The observed transcription profile is unique to TTV among known members in the family Circoviridae.

Animals↗
PubMed2000

Evolution in the hypervariable region of hepatitis C virus in infants after vertical transmission.

To elucidate the clonal evolution of hepatitis C virus (HCV) during mother-to-infant transmission, we prospectively analyzed HCV clones of the hypervariable region in four HCV RNA-positive infants and compared them with those of the mother. Cord blood samples from three of the four infants were positive for the HCV RNA (< or =10(3) copies/mL), and all of the four infants had the HCV RNA titer of >10(6) copies/mL within 2 mo after birth. The hypervariable region clones detected in the infants were closely related to those in the respective mothers. The results suggest the perinatal transmission of HCV. The hypervariable region clones transmitted to infants were not a single selected clone or minor clones in the mother. None of the clones specific to the low-density fraction in the mother was transmitted to the infants. Moreover, the proportion of HCV in the low-density fraction was minimal in the first few months of life, but increased several months after birth in association with the elevation of alanine aminotransferase. These results suggest that the increase of HCV in the low-density fraction reflect the evolution of immune response in infants. We also demonstrated that the emergence of quasispecies in infants precedes the infantile antibody response.

Aging↗
PubMed2000

Spinal projections of cat primary afferent fibers innervating caudal facet joints.

The spinal projections of afferent fibers innervating the facet joints between caudal vertebrae were examined by the use of anterograde transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP). Experiments were performed on 5 adult cats in which spinal dorsal roots below the 2nd sacral segment (S2) on the right side were cut. Injections of WGA-HRP into the caudal facet joints gave rise to extensive cranio-caudal distribution of WGA-HRP positive products along the spinal cord, indicating that many afferent fibers innervating unilateral facet joints terminate bilaterally in laminae I-II, V-VI and X of the thoracic, lumbar, sacral and caudal spinal cord. These afferent fibers may convey a series of sensory information from the caudal facet joints to the spinal cord.

Afferent Pathways↗
PubMed2000

Does edema formation occur in the rabbit brain exposed to head-down tilt?

Earlier studies showed that exposure to microgravity caused cephalad fluid shift, increased capillary pressure in the head, and produced facial edema and nasal congestion. In the present study, edema formation in the brain was investigated in rabbits exposed to simulated microgravity, head-down tilt (HDT), by measuring water content and histological examinations. Water content in the brain tissues of rabbits exposed to 2 and 8 days of HDT did not increase significantly compared with that of control animals. Neither vital staining using Evans blue nor immunohistochemical examination demonstrated extravasation of plasma constituents in the brain tissues of the HDT rabbits. Although marked congestion was noted in the brain, hematoxylin and eosin staining did not show edematous changes, such as distension of the perivascular and pericellular spaces and vacuolar appearance, in the tissues obtained from HDT rabbits. Transmission electron microscopy revealed that tight junctions of the capillary endothelium were intact in the HDT rabbits. These results suggest that either HDT up to 8 days does not cause brain edema in rabbits or it induces only a slight brain edema which is hard to be demonstrated by measurement of water content or histological examinations.

Animals↗
PubMed2000

Highly efficient kinetic resolution of beta-halohydrins catalyzed by a chiral 1,2-diamine.

Kinetic resolution of racemic beta-halohydrins has been achieved by reaction with benzoyl chloride in the presence of a catalytic amount (0.3 mol%) of a chiral diamine combined with diisopropylethylamine to afford the corresponding benzoates and unreacted beta-halohydrins in good to excellent enantioselectivities. The benzoate can be converted to the corresponding allylic benzoate without loss of optical purity by treatment with (1,5-diazabicyclo[4.3.0]non-5-ene).

Acylation↗
PubMed2000

[Lens epithelial cell damage and apoptosis in atopic cataract--histopathological and immunohistochemical studies].

PURPOSE: To elucidate the relationship between damage of lens epithelial cells and apoptotic cell death in patients with atopic cataract. METHODS: Histopathological and immunohistochemical studies were carried out using anterior lens capsules obtained at surgery from 13 patients with atopic cataract and from 25 patients with senile cataract. RESULTS: No specific histopathological findings were found in the lens epithelial cells in atopic cases. However, the frequency and severity of histopathological findings such as flattening, nuclear pyknosis, and loss of cells were more frequent and more severe in atopic cases than in senile cases. The terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labelling (TUNEL) method revealed that the mean ratio of cells containing fragmented DNA to whole epithelial cells was almost the same in both atopic and senile cases. However, the mean ratio of Bax-positive cells was significantly higher in atopic cases (mean +/- standard deviation, 29.1 +/- 35.0%) than in senile cases (2.7 +/- 7.0%) (p < 0.05). The mean ratio of Bcl-2-positive cells was significantly lower in atopic cases (1.4 +/- 3.4%) than in senile cases (44.3 +/- 35.7%) (p < 0.05). CONCLUSION: These results suggest that apoptotic cell death may play an important role in the development of lens epithelial cell damage in atopic cataract.

Adult↗