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Biomedical subjects

S Misumi

Publications and source records attributed to S Misumi.

At least 19 recordsLinked to original sources
PubMed1995

Determination of N-myristoyl peptide sequence both by MALDI TOF MASS and with an N-myristoyl cleaving enzyme (polymyxin acylase).

Polymyxin acylase isolated from Pseudomonas sp. M-6-3 was used as an N-myristoyl cleaving enzyme in order to determine a part of the N-terminal amino acid sequence of N-myristoyl proteins. The enzyme hydrolyzed a number of N-myristoyl oligopeptides at various hydrolysis rates but not N-myristoyl proteins. The oncogenic protein (N-myristoyl-pp60c-src) was isolated from human colon adenocarcinoma cell line COLO 320DM by two-dimensional polyacrylamide gel electrophoresis. The protein was digested with trypsin and the resultant tryptic N-myristoyl tetrapeptide (N-myristoyl-Gly-Ser-Asn-Lys) was purified by HPLC and the structure was determined both by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI TOF MASS) and by a gas-phase protein sequencer before or after treatment with the polymyxin acylase. The results suggest that the N-myristoyl peptide sequence derived from N-myristoyl proteins was clearly determined by the combined use of MALDI TOF MASS and the N-myristoyl cleaving enzyme.

Amidohydrolases↗
PubMed1994

Thiamine disulfide as a potent inhibitor of human immunodeficiency virus (type-1) production.

Thiol and disulfide compounds were tested as an anti-HIV drug against transactivator (Tat)-mediated transactivation of HIV-1. Of all the compounds tested, thiamine disulfide, alpha-lipoic acid, and N-acetycysteine significantly depressed HIV-1 Tat activity. Thiamine disulfide alone in these compounds possessing anti-HIV-Tat activity markedly inhibited production of progeny HIV-1 in acute and chronic HIV-1-infected CEM at nontoxic concentrations of 500-1000 microM. Thiamine disulfide (500 microM) blocked 99.7% of HIV-1 production after 96 hr culture in acute HIV-1 (LAV-1) infection (m.o.i. = 0.002), whereas it inhibited 90-98% of HIV-1 production in chronic-infected cells (CEM/LAV-1, H9/MN, and Molt-4/IIIB). The results suggest that thiamine disulfide may be important for AIDS chemotherapy.

Acetylcysteine↗
PubMed1992

Suprasellar germinomas; relationship between tumour size and diabetes insipidus.

The clinical and neuro-endocrinological aspects of 17 suprasellar germinoma patients treated between 1972-1991 are reported. Surgical extirpation was not initially attempted, but all patients received irradiation with or without a biopsy. Sixteen of those have led useful lives with appropriate hormonal replacement therapy during a mean follow up of 8 years. Seven tumours at diagnosis were less than 2 cm in diameter (type 1), nine tumours more than 2 cm (type 2), and one double midline tumour was of unknown size. All 7 type 1 patients required 1-deamino-8-D-arginine-vasopressin (DDAVP) to control diabetes insipidus (DI), but only 2 of the 9 type 2 patients have needed DDAVP since completion of the treatment. Patients with smaller tumours required more DDAVP following tumour disappearance, than those with larger tumours. The prognostic indicators for the post-treatment course of DI and retarded growth appeared to be the tumour size and the age at diagnosis. We also emphasize the absence of metastasis in unoperated cases and the use of tumour markers as a diagnostic criterion which obviates surgical acquisition of tissue to make the diagnosis. Possible reasons are discussed and the literature reviewed.

Adolescent↗
PubMed1992

[Anaplastic astrocytoma 14 years after radiotherapy for pituitary adenoma].

A case of anaplastic astrocytoma following radiotherapy for growth hormone secreting pituitary adenoma is presented with a review of the literature. A 43 year old female was admitted with the signs of acromegaly and hypertension. An eosinophilic pituitary adenoma was subtotally removed by transsphenoidal approach, and followed by 60 Gy irradiation using a 2 x 2 cm lateral opposed field. Fourteen years later at the age of 57, she suffered from headache, recent-memory disturbance and uncinate fits. CT scan and MRI disclosed ring-like enhanced mass lesion in the left temporal lobe, corresponding to the previous irradiated field. 18F-FDG PET showed hypermetabolism at the lesion. Left frontotemporal craniotomy was performed, and a reddish gray gelatinous tumor containing necrotic center and cyst was partially removed. Histologically, the tumor consisted of hypercellular astrocytic cells with perivascular pseudorosette. Coagulation necrosis at the center of the tumor, and hyalinosis and fibrosis of the blood vessels in and around the tumor, which might have been caused by the antecedent radiotherapy, were recognized. Postoperative radio- and chemotherapy were given, however, she expired 13 months after the operation. Seven cases, including ours, of malignant glioma following radiotherapy for pituitary adenoma were reported in the literature. A total dose of irradiation varies from 45 to 95 Gy with a mean of 50 Gy. The period of latency before tumor occurrence ranges from 5 to 22 years with a mean of 10 years. The differentiation of radiation-induced gliomas from radionecrosis of the brain is also discussed.

Adenoma↗
PubMed1991

[Multiple liver metastases of a suprasellar germ cell tumor treated with combined chemotherapy of cisplatin and etoposide].

A 23-year-old man was admitted with progressively disturbed vision and easy fatigability. CT scans demonstrated an enhanced mass in the sellar region. Physical and endocrinological examinations revealed atrophy of both optic nerves, temporal field cuts in both eyes, and panhypopituitarism. Concentrations of human chorionic gonadotropin (HCG) in the serum and cerebrospinal fluid were 12 and 33IU/L, respectively. On November 11, 1987, the tumor was partially removed using the transsphenoidal approach. The histological diagnosis was germinoma with syncytiotrophoblastic giant cells. Following postoperative craniospinal irradiation (whole brain, 30Gy; local, 18Gy; spinal canal 28Gy), CT scans showed no residual tumor and the HCG levels decreased until they were undetectable. Eighteen months later, the patient complained of abdominal pain. His serum HCG level had increased to 2,554 IU/L. CT scans of the abdomen revealed multiple low density areas in the liver. Chest X-ray was negative. A Ga scintigram disclosed only liver metastasis. Administration of a chemotherapy was started on June 26, 1989. Cisplatin and etoposide in doses of 20mg and 40mg respectively were given for 5 consecutive days in one course. Following four courses of the combined chemotherapy, the tumor entirely disappeared on CT scans and the HCG level returned to normal. The patient is now able to work well without evidence of recurrence. Multiple liver metastases of an intracranial germ cell tumor had been fatal in previous reports. This may be the first case with liver metastases in which the victim is still alive. The present case indicates that combined chemotherapy with cisplatin and etoposide is effective for extraneural metastases of an intracranial germ cell tumor.

Adult↗
PubMed1989

[Dihydroergotoxine mesylate in the treatment of functioning pituitary adenoma].

Although it is well known that bromocriptine (BC) is effective in the treatment of functioning pituitary adenoma, this agent sometimes causes severe gastrointestinal side effects. In this study, dihydroergotoxine mesylate (EX), which is composed of ergot alkaloids and is similar to BC, was administered to 11 patients with functioning pituitary adenomas who could not tolerate the adverse effects of BC. Three patients (27%) showed clinical improvement with EX treatment alone (1 to 6 mg/day). In another patient, computed tomography demonstrated tumor shrinkage. The remaining seven patients experienced adverse effects while taking EX. These results indicate that EX is a useful alternative to BC in the treatment of functioning pituitary adenoma, particularly in patients who cannot tolerate the side effects of BC. Moreover, pretreatment with EX appears to reduce the incidence of side effects of BC.

Adenoma↗
PubMed1988

[Treatment of delayed brain injury after pituitary irradiation].

Treatment for delayed brain injury after pituitary irradiation is discussed. Six cases with delayed brain injury were treated with a combination of dexamethasone or betamethasone, with heparin, glycerol, dextran 40 and some vasodilators. Two cases with temporal lobe syndrome were treated in the early stages of brain injury for a period of over 12 months were almost completely cured, another two cases with chiasma syndrome were treated in the relatively late stages, showed a partial improvement. One case which was irradiated 120 GY during 13 years did not improve. The final case treated with steroids for a short period also resulted in failure and the patient underwent an operation for the removal of the necrotic mass three years after the radiotherapy. Steroid therapy started in the early stages of brain injury after irradiation for over the 12 months is thought to be effective. Heparin therapy was also effective in one out of three cases, but in one of the cases subarachnoid hemorrhage from a traumatic aneurysm occurred during the therapy. In an acute phase, showing edematous change of the injured brain, the administration of glycerol is also thought to be useful. But the effectiveness of the other medicines containing some vasodilators was obscure or doubtful. We propose the following: (1) A meticulous observation is essential for the patients who received high doses of irradiation to diagnose brain injury in the early reversible stage. (2) Steroids should be given immediately in this reversible stage of brain injury before the irreversible "necrosis" occurs. (3) Steroids should be maintained for a long period over 12 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1987

Pituitary enlargement with target organ deficiency: hypothyroidism and hypogonadism.

Three women with pituitary enlargements associated with preexisting target organ failures are reported. Two pituitary enlargements owing to primary hypothyroidism and one to primary hypogonadism were shown to be regressed on computed tomography after the replacement therapy. Clinically and pathologically, the differentiation of a pituitary hyperplasia from a pituitary adenoma is often very difficult. Moreover, the treatments for these conditions are quite different. Adequate medication can diminish a pituitary enlargement because of the feedback mechanism. Existence of the target organ deficiency should always be checked before the management of pituitary tumor.

Adult↗
PubMed1986

Germ cell tumor in the basal ganglia: immunohistochemical demonstration of alpha-fetoprotein, human chorionic gonadotropin, and carcinoembryonic antigen.

A case of germ cell tumor in the basal ganglia and its vicinity was successfully treated surgically and by radiation. alpha-Fetoprotein, human chorionic gonadotropin, and carcinoembryonic antigen were found in the tumor tissue, using the immunoperoxidase method. The presence of three immunohistochemically demonstrated tumor markers in a single germ cell tumor is extremely unusual. These results strongly suggest a cell differentiation or transformation in germ cell tumors.

Adolescent↗
PubMed1986

Simple management of cerebrospinal fluid rhinorrhea after pituitary surgery.

A simple procedure for managing postoperative cerebrospinal fluid rhinorrhea after pituitary surgery is described. Under local anesthesia, a needle is introduced manually through a nostril toward the sella turcica and EDH adhesive or fibrin glue is injected into the sellar cavity or sphenoid sinus, or both. This procedure is simple and safe to perform, acceptable to the patient, and can be done in a short hospital stay.

Aprotinin↗
PubMed1986

Spontaneous resolution of chronic subdural hematomas.

Four patients with chronic subdural hematomas, all of which resolved spontaneously, were followed from the time of injury to resolution of the chronic subdural hematoma. Periodic computed tomographic (CT) scans showed spontaneous resolution 78, 174, 231, and 326 days after the development of the chronic subdural hematoma, respectively. Features of the CT scans and a possible mechanism of spontaneous resolution are discussed.

Adult↗
PubMed1986

[Growth hormone-producing pituitary adenoma in an 8-year-old girl: case report].

A rare case of pituitary adenoma in childhood presenting as giantism is reported. A 6-year-old girl came to our attention in 1982 because of excessive growth noted since the age of 3 yr. Her appearance revealed giantism. She also had a 4 year history of genital bleeding, but no development of external genitalia nor mammary gland. Endocrinological studies revealed markedly elevated serum basal levels of both growth hormone (GH) and prolactin (PRL). She had a bromocriptine therapy for 1 year and 8 months, but it was difficult to suppress her excessive growth rate. So she was admitted at the age of 8 years to undergo the operation. Visual fields were intact. X-ray examination of the skull demonstrated a slightly enlarged sella turcica. Computerized tomography revealed an isodense mass at the pituitary fossa without extrasellar extention. Repeated endocrinological studies were carried out. Basal levels of GH and PRL were 43.8 ng/ml and 67 ng/ml. All other pituitary function were normal, except for puberal responses of luteinizing hormone (LH) and follicle stimulating hormone in LH-RH loading test. 50 g oral glucose tolerance test was normal. Transsphenoidal microsurgery was performed in August 1984. The tumor filled up the pituitary fossa with fibrous element. Histological examination disclosed a mixed adenoma, predominantly chromophobe, with a few granulated eosinophils. Immunoperoxidase staining was also performed on the adenoma. Most of the tumor cells stained for GH, and a few of them stained for PRL. Postoperatively hypopituitalism was not complicated. Surgery produced a decrease in serum PRL level under 20 ng/ml, but serum GH level was not enough reduced under 10 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1985

Management of polyuria subsequent to pituitary surgery based on the diurnal pattern of urinary excretion.

Polyuria subsequent to pituitary surgery was studied in 64 cases. Most cases of postoperative polyuria were due to diabetes insipidus. These cases showed a triphasic pattern in daily urinary volume. Observation of hourly urinary volume in polyuria revealed four diurnal patterns of urinary excretion: rhythmic, continuous, transient, and unspecific. Clinical observation of diurnal patterns has an advantage, in terms of simplicity of procedure, in immediately determining the nature of the polyuria, prognosticating diabetes insipidus, and eliminating inappropriate procedures in treatment. Indomethacin suppository is considered to be a favorable agent in reducing polyuria without disturbing the diurnal pattern in diabetes insipidus.

Adenoma↗
PubMed1985

The incidence of delayed traumatic intracerebral hematoma with extradural hemorrhages.

After introduction of computerized tomography (CT), we experienced 22 patients with traumatic extradural and intracerebral combined hematomas, of whom 15 underwent sequential CT scans. In 14 of the 22 patients or 13 of the 15 patients whose initial CT scans were performed early, within 6 hours after injury, intracerebral hematomas developed more slowly than extradural hematomas. In ten of the 13 patients, development of intracerebral hematomas was demonstrated only after removal of extradural hematomas, and in four patients acute brain swelling was observed during surgery. Therefore it is emphasized that the incidence of post-surgical intracerebral hematoma with extradural hemorrhages is high and that acute brain swelling during surgery for extradural hematomas is largely caused by the delayed intracerebral hematomas.

Adult↗
PubMed1985

Synthesis and unusual reactivity of (1,5)pyrimidino(6,9)purinophane.

In order to elucidate the driving force of the unusual high reactivity of (1,3)pyrimidino(6,9)purinophanes 2 toward nucleophiles at 6-position, title compound 1 is synthesized. It is concluded on the basis of the similar unusual behavior of 1 to 2 that the stereoelectronic effect in the fairly rigid tetrahedral intermediate is responsible for the high reactivity of 1 and 2.

Indicators and Reagents↗
PubMed1984

Intracranial germ-cell tumors. Immunohistochemical study of three autopsy cases.

Histological and immunohistochemical findings in three cases with primary intracranial germ-cell tumors are reported. Based on histological examination, they were diagnosed, respectively, as an endodermal sinus tumor with immature teratoid differentiation, teratoma and embryonal carcinoma, and choriocarcinoma and germinoma. The first case was presumed to be a combination of endodermal sinus tumor and germinoma. An immunohistochemical examination showed positive reactions to alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) in the endodermal sinus tumor, and to human chorionic gonadotropin (HCG) in the choriocarcinoma, but showed no reaction in the embryonal carcinoma. Human chorionic gonadotropin was demonstrated in syncytiotrophoblastic cells and CEA in a gland-like structure. The value of measuring CEA in cases of germ-cell tumors, in addition to AFP and HCG assays, is stressed, and the characteristics of CEA-positive tissue are discussed.

Adolescent↗
PubMed1984

Synthesis, structure, and hypochromism of (2,9)(6,9)purinophane.

The title compound 1 was synthesized via 8 steps from phthalimide derivative 2. The molecular structure of 1 was determined by X-ray analysis and the relationship between the hypochromism and the stacking mode of two purine rings was discussed.

Indicators and Reagents↗