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Biomedical subjects

T Shitara

Publications and source records attributed to T Shitara.

At least 19 recordsLinked to original sources
PubMed1992

Synthesis of 5-deoxy-5-fluoro and 5-deoxy-5,5-difluoro derivatives of kanamycin B and its analogs. Study on structure-toxicity relationships.

5-Deoxy-5-fluoro- (1), 5.3'-dideoxy-5-fluoro- (2), and 5,3',4'-trideoxy-5-fluoro-kanamycin B (3) have been prepared by treatment of 5-epihydroxyl precursors (prepared by the Mitsunobu reaction) with DAST as the key step. 5,3'-Dideoxy-5,5-difluoro- (26) and 5,3',4'-trideoxy-5,5-difluoro-kanamycin B (27) were also prepared by treatment of the corresponding 5-oxo derivatives with DAST. These 5-deoxy-5-fluoro and 5-deoxy-5,5-difluoro derivatives showed markedly decreased toxicity as compared with the parent compounds.

Carbohydrate Sequence↗
PubMed1992

A case of congenital leukemia with monosomy 7.

A case of congenital leukemia with monosomy 7 is reported. Immunological study of the blast cells using monoclonal antibodies was suggestive of both myelomegakaryocytic and T-lymphoblastic leukemia. Chromosomal analysis of the bone marrow cells showed monosomy 7. Chemotherapy was initiated with a combination of adriamycin, cytosine arabinoside, 6-mercaptopurine, and prednisolone. The patient obtained complete remission, which has been maintained for 4 years and 1 month. He receives no chemotherapy now. Our case shows that monosomy 7 in congenital leukemia is rare, but the presence of monosomy 7 in congenital leukemia does not necessarily indicate a poor prognosis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Reversal of the malignant phenotype by an anti-ras ribozyme.

In this study a ribozyme (catalytic RNA) was designed to site specifically cleave the mRNA of the activated H-ras gene expressed in human bladder carcinoma EJ cells. The optimal conditions for catalytic cleavage by the ribozyme were demonstrated in vitro. A synthetic DNA encoding the ribozyme was cloned into a mammalian expression vector (pH beta APr-1) and transfected into EJ cells. The expressed ribozyme significantly altered the morphology and suppressed the growth of EJ cells in vitro. These cell lines were examined for their malignant potential in athymic (nude) mice by an orthotopic (transurethral) implantation model, which recapitulates the invasive potential of various bladder carcinomas. EJ tumors expressing the H-ras ribozyme were characterized by a marked reduction in tumor take and invasion compared to those formed by control EJ cells. These differences resulted in almost a twofold increase in survival of mice implanted with ribozyme-containing EJ cells. These results further elucidate the role of ras genes in tumorigenicity and invasion, as well as introduce ribozymes as a new class of anticancer agents.

Animals↗
PubMed1992

[The effect of aging on observation in hearing in the same individuals over a 5 year period].

The purpose of this study was to investigate the process of changes in hearing of pure tones with aging. Among individuals who had undergone thorough medical examination for the purpose of annual health-checks, 293 males (586 ears) whose hearing level had been examined for five years or more were enrolled in this study. Cases having conductive deafness or known sensori-neural deafness were excluded. Since the most typical change with aging is observed at 8 kHz, the investigation was carried out only on hearing at 8 kHz. Hearing level increasingly declined with advancing age. Hearing distribution for young subjects showed a peak in the normal hearing level range. This peak decreased with aging, and another peak appeared at 50 dB. Investigation of differences in hearing in the individuals over the five years showed that most subjects had a hearing level difference of 0 dB up to 54 years of age. From 55 years old onward, however, the difference was 5 dB. This indicates that gradual deterioration of hearing level with aging occurs most frequently. On the other hand, in some subjects, deafness progressed faster. Thirty-four and a half percent of the subjects had deteriorations of 20 dB or more in a single year during the entire observation period. A deterioration of 20 dB or more was noted in 4% of the young and 8% of the elderly. Such rapid progression of deafness was believed to be involved in formation of the 50 dB peak in the hearing distribution.

Adult↗
PubMed1991

Erythroleukemia in a child associated with monosomy 7.

A case of erythroleukemia (EL) associated with monosomy 7 is reported. The EL was diagnosed 20 months after the initial diagnosis of monosomy 7 was made. An immunologic study of the blast cells using a monoclonal antibody was positive for glycophorin A, which suggested that they were of erythroid origin; this was confirmed by electron microscopy. Chemotherapy was started with low dose cytarabine. However, the patient had severe bone marrow suppression and died of pneumonia. Our case shows that monosomy 7 is an abnormality of the pluripotential stem cells, including erythroid cells, that resulted in a true erythroid neoplasm.

Child, Preschool↗
PubMed1991

[Primary carcinoid tumor of the testis with metastasis to the upper vertebrae. Report of a case].

A case of primary carcinoid tumor of the right testis with metastases to the cervical and thoracic vertebrae and epidural is reported. A 53-year-old man was first recognized as being with dysthesia of the left arm and shoulder in April 1986. In June, 1987, he was admitted to the Neurology service, complaining of sudden occurrence of abasia. Myelography and computerized tomography demonstrated an epidural mass and several high density areas in the vertebral bodies of Th1 and Th2. The patient underwent laminectomy from C7 to Th2. At operation, the neurosurgeons noticed a tumor mass in the right scrotum and requested our consultation. Thus right high orchiectomy was performed. Pathological examination including Grimerius' and Fontana-Masson's stain revealed carcinoid tumor of the right testis associated with metastases to the spinal column. Postoperatively, tumor maker studies revealed elevation of blood 5-hydroxytryptophan and marked increase of urinary 5-hydroxy-indoleacetic acid excretion. They showed remarkable decreases after a course of PVB chemotherapy. The patient has been under our observation as an out-patient for the past 27 months with metastases. This is the first case of primary carcinoid tumor of the testis with metastases so far reported in the domestic literature.

Carcinoid Tumor↗
PubMed1991

[Incidental renal cell carcinoma].

We reviewed the cases of incidental renal cell carcinoma that had been treated at the Kitasato University Hospital between July, 1971 and December, 1989. Forty one of the 170 (24.1%) cases were found without any direct signs of renal cell carcinoma. The patients were between 30 and 78 years old (mean 55.0 years) and consisted of 29 males and 12 females. Fifteen cases were detected at the general health check-up and the remaining 26 during the postoperative follow-up for other malignant tumors or other diseases. Twenty three cases were identified by ultrasonography followed by computed tomography (CT) and excretory pyelography in 4 cases each. Especially, the number of patients incidentally found by ultrasonography had increased in the recent 8 years. Urinalysis did not show any microhematuria in 31 of the 37 cases (83.7%), and no tumor mass could be detected by excretory pyelography in 3 cases. We believe that ultrasonography may be valuable as a screening modality for early detection of renal cell carcinoma and should be used as a screening method at the routine health check-up.

Adult↗
PubMed1990

[Clinical feature of odontogenic maxillary sinusitis--symptomatology and the grade in development of the maxillary sinus in cases of dental maxillary sinusitis].

Odontogenic maxillary sinusitis may occur by draining of an apical dental root abscess into the maxillary sinus. It has been reported that the disease is usually frequent in cases aged of the second and third decades. In most of them, either the first or second molar tooth is assumed to be the origin of the disease. As clinical characteristic symptoms, it is mentioned that an acute unilateral sinusitis appears since the onset and the patient complains a fetid purulent nasal discharge from an early stage. The symptom and its clinical time course in 43 cases with dental maxillary sinusitis, who had been treated by surgical procedures in ENT Clinic in Kitasato University Hospital during past 14 years from 1972 to 1985, were studied retrospectively. The size of the affected maxillary sinus in each case of the disease was measured from the X-ray films. An influence of development of the maxillary sinus to the occurrence of dental sinusitis was discussed by comparing the sizes of the maxillary sinuses in both the group of the disease and the group of simple unilateral maxillary sinusitis.

Adolescent↗
PubMed1986

Cystic duplication of the cecum lined by dermal type squamous epithelium.

This is a case report of a cystic duplication of the cecum in a 6-month-old female infant, which was lined by both columnar and squamous epithelium. This squamous epithelium did not resemble esophageal epithelium but dermal epithelium. The so-called split notochord theory can explain the possibility of the coexistence of ectoderm and entoderm components. However, the present case had no vertebral abnormalities.

Cecal Diseases↗
PubMed1981

Hodgkin's disease complicated by nephrotic syndrome. New clinical observations on the response of both diseases to radiotherapy to the neck.

The clinical course of a 14-year-old boy who developed biopsy-proven minimal change nephrotic syndrome (MCNS) prior to institution of therapy for Hodgkin's disease (HD), mixed cellularity histologic subtype, is presented. In the first week of radiotherapy to the major site of disease in the neck, BUN and creatinine levels rose to 98 mg% and 8.4 mg%, respectively. During the second week of treatment, levels gradually decreased becoming normal in the third week. Body weight gradually decreased in the second week of radiotherapy, falling rapidly in the third and fourth week when diuresis was greatest. Although urine protein concentration fell initially, the concentration remained 1 + or more for 10 weeks following radiotherapy. Following radiotherapy to the neck, staging laparotomy demonstrated a single focus of Hodgkin's disease in the spleen. Radiotherapy was given to the splenic pedicle: six courses of multiagent chemotherapy (MOPP) followed. The boy remains free of any evidence of either HD or MCNS 33 + months from the time of the diagnosis. Circulating lymphocytes showed normal responses to stimulation by phytohemaglutinin, Concanavalin A, and pokeweed mitogens. The patient's monocyte-macrophage-mediated antibody-dependent cellular cytotoxicity (ADCC) was low both prior to and following radiotherapy. Lymphocyte-mediated ADCC was normal at both of these times.

Adolescent↗