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Biomedical subjects

H Tashiro

Publications and source records attributed to H Tashiro.

At least 217 records · Page 12Linked to original sources
PubMed1991

MELAS of infantile onset: mitochondrial angiopathy or cytopathy?

An 83-day-old male infant had convulsions, hypertrophic cardiomyopathy, and lactic acidosis. Cranial computed tomography revealed low-density areas in both parieto-occipital lobes and in the left temporal lobe. Muscle biopsy did not reveal ragged-red fibers, but abnormal mitochondria were found in the capillary endothelial cells as well as in the muscle fibers. At 5 months of age, the patient developed purpura on the soles and palms. Skin biopsy showed degeneration of the endothelial cells with abnormal mitochondria in the arterioles and capillaries. Myelinated nerves in the skin had vacuolated axons with swollen mitochondria, and their myelin sheaths showed vacuolation. At 9 months of age, he died of heart failure, and autopsy revealed abnormal mitochondria in the myocardium but not in the coronary vessels. Our findings indicate that the symptoms of the mitochondrial encephalopathy, myopathy, lactic acidosis, and strokelike episodes (MELAS) syndrome cannot be fully explained by the mitochondrial angiopathy alone.

Acidosis, Lactic↗
PubMed1991

Guide groove for pinning subcondylar fractures.

For pinning subcondylar fractures, a guide groove cut on the lateral surface of the mandibular ramus is a useful method of directing a Kirschner wire into the correct position. An extended groove correctly guides the pin in difficult cases.

Bone Nails↗
PubMed1991

Evaluation of masticatory function following orthognathic surgical correction of mandibular prognathism.

Masticatory function was examined in 17 patients with mandibular prognathism before and after bilateral sagittal splitting osteotomy of the mandibular rami. Masticatory efficiency was measured by means of a spectrophotometer, using adenosine triphosphate (ATP) granules, the biting force and occlusal contact area. Masticatory functions showed a tendency to gradual improvement postoperatively. Concerning masticatory efficiency, mean values of absorbance of ATP granules in patients with mandibular prognathism were inferior to those of subjects who possess a normal occlusion, even 12 months after operation.

Bite Force↗
PubMed1991

Unusual ameloblastoma with extensive stromal desmoplasia.

A clinicopathological study of 5 cases of unusual ameloblastoma was performed. Three cases were characterized by marked stromal desmoplasia. The lesions occurred in the tooth-bearing areas of the anterior or premolar regions of the jaw. They were relatively small and showed a honeycomb appearance radiographically. Histologically, the islands of tumour cells were small and discrete in the widely extended desmoplastic stroma. They lacked obvious ameloblastic polarity in many parts. The other 2 cases were hybrid lesions of desmoplastic and conventional types. The former appeared in the alveolar part and the latter in the lower part of the mandible. It was concluded that the desmoplastic variant of ameloblastoma could be categorized as a new distinct type histologically, clinically and radiographically.

Adult↗
PubMed1991

Ischemic bowel necrosis induced by endothelin-1: an experimental model in rats.

Local intra-arterial administration of endothelin-1 induced small intestinal mucosal damage in rats in a dose-dependent manner. A remarkable decrease in mucosal blood flow (15% of control values) was observed by a laser Doppler flowmetry 10 min after injection of endothelin-1 (1 nmol/kg). Endothelin-1 at this dose induced significant hemorrhagic and necrotic lesions in the small intestinal mucosa 30 min after the injection. Decreased mucosal blood flow was attenuated to some extent by the pretreatment with platelet-activating factor (PAF) inhibitor, CV-6209, superoxide dismutase plus catalase or the calcium antagonist, nicorandil. All these inhibitors significantly prevented the endothelin-1-induced ischemic necrotic damage in the small intestine. These results suggest a potential role of endothelin-1 in the pathogenesis of ischemic bowel diseases in clinical situations and also the possibility that PAF and oxygen-derived free radicals may be involved as secondary mediators in endothelin-induced intestinal tissue damage.

Animals↗
PubMed1991

Basic studies on ursodeoxycholyl-para-aminobenzoic acid for evaluation of intestinal microflora.

A newly synthesized conjugate of ursodeoxycholic acid with para-aminobenzoic acid (PABA) was investigated to determine its suitability for evaluation of enteric bacteria. This compound, PABA-UDCA, was deconjugated by cholylglycine hydrolase to release free PABA, whereas it was completely resistant to deconjugation by pancreatic and intestinal mucosal enzymes. In bacteriologic experiments almost all the microorganisms that split glycocholic acid deconjugated PABA-UDCA. In rat experiments urinary excretions of PABA were measured during 6 h after oral administration of 10 mg PABA-UDCA (PABA-UDCA administration test). Ten control rats excreted 338.5 +/- 13.8 micrograms (mean +/- SE) of PABA; 10 rats with intestinal stagnant loop excreted more (673.6 +/- 70.2 micrograms; P less than 0.01); whereas 10 rats in each of 7 groups pretreated with oral administration of various antibiotics excreted less (P less than 0.001; polymixin B + tinidazole, 14.0 +/- 2.5 micrograms; polymixin B, 224.9 +/- 23.5 micrograms; tinidazole, 42.7 +/- 8.6 micrograms; kanamycin, 50.3 +/- 5.8 micrograms; clindamycin, 57.4 +/- 7.4 micrograms; vancomycin, 70.4 +/- 8.5 micrograms; and paromomycin, 160.4 +/- 16.4 micrograms). This result was reflected by the bacterial mean count of feces. In the PABA-UDCA administration test, after 2 months of feeding with different diets, rats with high-fiber diet (n = 10) excreted less PABA in urine (70.9 +/- 15.9 micrograms; P less than 0.001) than rats on a control diet (n = 10) and a high-protein-high-fat diet (n = 10) (288.9 +/- 34.5 micrograms and 386.7 +/- 61.2 micrograms, respectively). Fecal bacteriologic status was consistently altered. In human volunteers 250 mg PABA-UDCA was tested. Amounts of PABA excreted in urine during 6 h after dosing were 21.11 +/- 2.02 mg in controls (n = 5) and 12.20 +/- 1.01 mg in the group treated with polymixin B plus tinidazole (n = 5; P less than 0.01). No adverse effect was observed. These basic studies indicate that this compound is likely to offer a simple and rapid method for evaluation of the intestinal microorganisms without use of radioisotopes or expensive, special equipment.

4-Aminobenzoic Acid↗
PubMed1991

Trigeminal neuralgia caused by compression from arteries transfixing the nerve. Report of three cases.

The authors present three patients with trigeminal neuralgia due to compression by an artery that transfixed the sensory root of the fifth cranial nerve. These cases represented 0.8% of 384 patients with trigeminal neuralgia treated by microvascular decompression at the authors' clinic during the past 12 years. In the remaining 381 cases, the compressing vessels were successfully removed from the trigeminal nerve without much difficulty, for an initial cure rate of 94.3%. In the three cases reported, however, the compressing artery penetrating the nerve could not easily be maneuvered away from the nerve. In the first two cases, partial rhizotomy perpendicular to the axis of the nerve at the site of arterial transfixion made it possible to separate the artery from the nerve. However, these two patients developed postoperative facial sensory impairment. In the third case, rhizotomy was performed longitudinal to the axis of the nerve at the site of arterial transfixion, making it possible to reposition the artery peripherally beyond the root entry zone of the nerve without causing any postoperative sensory deficits of the face. No recurrent pain has developed in more than 2 1/2 years since surgery in any of these three cases. When performing microvascular decompression surgery on patients in whom the compressing artery penetrates the nerve, the technique used in our third patient is the procedure of choice.

Aged↗
PubMed1991

[Effects of EGF and retinoic acid on differentiation of squamous cell carcinoma cells].

Using monoclonal antibody, G6K12, a novel differentiation marker of keratinocyte, we examined the effect of EGF and retinoic acid on the differentiation of SCC-25, a cell line established from human squamous cell carcinoma. EGF inhibited the expression of cell-surface differentiation marker in low cell-density, but not in high cell-density. Retinoic acid (more than 10(-8) M) inhibited the expression of the antigens. The terminal differentiation of SCC-25 cells occurred at the condition of high cell density. These results obtained demonstrate that EGF and retinoic acid inhibit the terminal differentiation of SCC-25 cells, and that the cell density is the important factor for the commitment of the terminal differentiation.

Carcinoma, Squamous Cell↗
PubMed1991

Clinical usefulness of serum squamous cell carcinoma antigen for early detection of squamous cell carcinoma arising in mature cystic teratoma of the ovary.

Squamous cell carcinoma arising in mature cystic teratoma of the ovary is rarely diagnosed preoperatively. We measured the pre-treatment serum levels of squamous cell carcinoma antigen in three stage I patients in order to evaluate its usefulness as a tumor marker for early detection of the disease. The serum levels were elevated in each case, to 26.9, 5.1, and 3.2 ng/mL, respectively, and rapidly dropped to within the normal range after treatment. All patients are recovered and show no evidence of recurrence, and the levels of serum squamous cell carcinoma antigen have remained within normal limits. These results suggest that measurement of the serum squamous cell carcinoma antigen level may be useful in diagnosing an early-stage primary squamous cell carcinoma arising in a mature cystic teratoma of the ovary. An elevated preoperative serum level of squamous cell carcinoma antigen may indicate the need for a rapid pathologic examination of the tumor to look for malignant elements and may influence the surgical regimen.

Adult↗
PubMed1991

[Response to rechallenged tamoxifen of metastatic breast cancer relapsed after surgical adjuvant tamoxifen treatment].

Tamoxifen (TAM), an antiestrogen was administered 20 mg b.i.d. to 20 patients with recurrent breast cancer at the time of first relapse who had been treated with the adjuvant therapy including TAM 10 mg b.i.d.. Patients who had been treated with TAM at least 1 year and in which the relapse had occurred after 3 months or more after the cessation of adjuvant treatment were enrolled in the study. Sixteen patients were evaluated, and a complete response was observed in 3 (19%), partial response in 1 (6%), no change in 5 (31%), and progressive disease in 7 (44%). The response rate was shown to be 25% with 95% confidence interval: 3.8-46.2%. The duration of response ranged from 23+ to 32 weeks. Patients who have received postoperative adjuvant therapy including TAM and have relapsed after the cessation of therapy may retain hormone dependency in responding to a further TAM treatment at the time of relapse of malignancy.

Administration, Oral↗
PubMed1990

Rapid method for construction of yeast artificial chromosome human DNA libraries involving the trapping of cells in agarose films.

A simple method for the molecular cloning of fragments of more than one hundred kilobase pairs of exogenous DNA, by the encapsulation of cells in agarose beads, was reported previously for the construction of a human genomic DNA library in a yeast artificial chromosome (YAC) vector (in situ YAC construction) [1]. The efficiency of this procedure is impaired by the step in which agarose beads that contain human DNA fragments are melted before transformation. The incomplete solubility of the ligated human DNA fragment-YAC vector often results in lower than desirable frequencies of transformation. To overcome this problem we have developed a new improved method that involves use of an agarose film. The technical manipulations involved in the construction of clones of very large segments of human DNA are discussed.

Chromosomes↗
PubMed1990

Differential effects of estrogen and antiestrogen on in vitro clonogenic growth of human breast cancers in soft agar.

Of 534 human primary breast cancers provided for clonogenic assay in vitro, 276 (51.7%) developed distinctive colony formation by the soft-agar method. Estrogen receptors (ERs) were assayed by dextran-coated charcoal methods. A total of 65 (23.7%) of 274 breast cancers responded to added 10 nM 17 beta-estradiol (E2) by an increase in the number of colonies per dish of 150% or more of that in the controls treated with dextran-coated charcoal. The ER-positive and ER-negative tumors differed significantly in their response to E2: 55 (29.9%) of 184 ER-positive tumors responded versus 10 (11.1%) of 90 ER-negative tumors. The cancers in which the number of colonies increased to 150% or more of that of the controls were considered to be estrogen dependent; those in which the number of colonies increased to less than 150% of the control values were considered to be estrogen independent. When 1 microM tamoxifen (TMX) was added to the medium, 48 (21.3%) of 225 cancers showed a decreased in the number of colonies to 50% or less of that of the controls. Thus, we could separate breast cancers that were TMX sensitive (No. of colonies less than or equal to 50% of that of controls) from those that were TMX resistant (No. of colonies greater than 50% of that of controls). The response to TMX of the ER-positive cancers was significantly higher than that of the ER-negative tumors: 39 (25.5%) of 153 ER-positive tumors responded versus nine (12.5%) of 72 ER-negative tumors. In 153 ER-positive and 71 ER-negative tumors, we evaluated the correlation between the response to E2 and the response to TMX. ER-positive and ER-negative tumors differed significantly in their sensitivities to the two drugs. The TMX sensitivity did not completely correlate with the E2 dependence.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Neoplasms↗
PubMed1990

[An overview of breast cancer mass screening in Japan].

To establish the effective mass screening projects for the breast cancer, our study group cosponsered by the Welfare Ministry was organized by 11 regional groups. From 1968 to 1986, 643, 513 women at the initial screening and 719, 189 women at the subsequent screening were examined by physical examination. Out of them, abnormalities were present in 24, 864 women (3.9%) and 23,880 (3.3%), respectively. A detection of cancer was made in 833 women (detection rate 1.3%) and 428 women (0.6%), respectively. As the examinees increased from year to year, the subsequent examinees were over the initial ones. It was suggested that most of examinees had been fixed year by year and the detection rate of initial screening had been higher than that of the subsequent one. Then more initial examinees are expected to be increased. Women 30 to 59 years of age were mostly screened, but women aged 60 or more should be increased. Of women with abnormal physical findings, women over 90% took the second examination. But more effective, economical and safer screening instruments are expected to be developed and be used at the first examination.

Adult↗
PubMed1990

Multiple endocrine neoplasia type 3: three cases with mucosal neuromata.

Three female patients (ages 10, 18 & 25 years) with multiple endocrine neoplasia type 3 are reported. They had all characteristic facial appearances, with mucosal neuromata, rubbery swollen lips, tubercles on the tongue and eversion of the eye lids. Clinical signs and symptoms appeared to be progressive with increase in age, suggesting the importance of the correct diagnosis and early evaluation of endocrine function leading to a better prognosis for the patient.

Adolescent↗
PubMed1990

Calcified metastatic brain tumor.

The case of a 57-year-old woman with a calcified metastatic brain tumor, histologically confirmed to be a squamous cell carcinoma, is reported. This patient is unusual because this metastatic squamous cell carcinoma contained an extraordinary huge conglomerated calcification, that was well-defined radiographically. This case is documented with a discussion of the pathogenesis of the calcification.

Brain Neoplasms↗
PubMed1990

Tumor growth rate and prognosis of breast cancer mainly detected by mass screening.

To investigate the relationship between the tumor growth rate of the primary breast cancer and its prognosis, records for 122 breast cancer patients in 9 hospitals in Japan were retrospectively reviewed. These records contained at least two measurements of the same tumor mass in the breast. So the growth rate was estimated from these measurements taken at different points in time. The doubling time of the breast tumors showed an approximately log-normal distribution. The geometric mean of doubling times for all cases was 174 days. The solid-tubular histologic type of carcinoma had the shortest geometric mean of doubling time (126 days), the scirrhous carcinoma had the second shortest one (205 days), and the papillotubular carcinoma had the longest one (252 days). The patients with shorter doubling time of tumor tended to have a poorer prognosis. The Cox multiple regression analysis showed that the tumor growth rate was related significantly with survival, after adjusting for other covariates such as clinical stage, lymph node metastasis, age of patient, histological type, and year of treatment.

Adult↗