Biomedical subjects

M Masuda

Publications and source records attributed to M Masuda.

At least 127 records · Page 7Linked to original sources

PubMed2000

[5'-DFUR chemoprophylaxis in superficial bladder cancer. Kanagawa Urology 5'-DFUR Study Group].

5'-Deoxy-5-fluorouridine (5'-DFUR), an oral fluorinated pyrimidine carbamate, is widely used in patients with gastrointestinal and breast cancers because of its effectiveness. However, in bladder cancer, response rates have only been reported in Phase II clinical trials. Therefore, we conducted a prospective randomized trial to investigate chemoprophylactic effect of 5'-DFUR against recurrence of superficial bladder cancer after transurethral bladder tumor resection (TUR-Bt). The subjects were grouped as follows: 1) 5'-DFUR group (n = 31), received 600 mg/day of 5'-DFUR starting 2-3 weeks after TUR-Bt for 2 years; and 2) control group (n = 31) received no 5'-DFUR. Although there was no significant difference between groups, the cumulative recurrence rates was more favorable in the 5'-DFUR group (p = 0.256) than in the controls. Results according to cancer factors showed that, in patients with G2 based on grading, those in the 5'-DFUR group tended to have a lower recurrence rate than the control group (p = 0.070). There was a 40% incidence of adverse drug reactions (12/30 patients), primarily slight gastrointestinal symptoms which disappeared or improved with drug discontinuation. The results of the present study suggest that 5'-DFUR might be the choice of treatment to prevent recurrence of superficial bladder cancer.

Adult↗

PubMed2000

[A case of tracheobronchomegaly].

We report a rare case of tracheobronchomegaly with crescent-type tracheobronchomalacia. A 77-year-old man with a chronic cough was referred to our hospital because of fever and dyspnea. Radiographic examination showed enlargement of the trachea and main bronchi. On chest radiography, the transverse diameter of the trachea was 31 mm, and consolidation shadows were seen in both upper lung fields. Tracheobronchomegaly with pneumonia was diagnosed. The pneumonia was improved by administration of PAPM/BP. On bronchoscopic examination, the trachea and main bronchi were extremely dilated on inspiration, and were collapsed on expiration. The biopsy specimen from the bronchial mucosa showed non-specific chronic inflammation.

Aged↗

PubMed2000

[A case of primary pulmonary artery myxosarcoma associated with severe pulmonary hypertension].

A 50-year-old man presented with progressive dyspnea on exertion, but with no history of chest pain or syncope. Chronic pulmonary thromboembolism was suspected and he was referred to our hospital. On ausculation, a grade 3 systolic murmur was heard, that was loudest in the fifth intercostal space lateral to the right sternal border. Chest radiography showed mild cardiomegaly and ventilation-perfusion scan revealed absence of perfusion in the left lung and the upper field of the right lung. Contrast-enhanced helical CT showed large mural defects in both main pulmonary arteries, clearly delineated by contrast medium. The left pulmonary artery was nearly completely occluded, and eccentric defects were observed projecting into the lumen of the pulmonary trunk. A tumor originating in the pulmonary artery was suspected, but a definitive diagnosis of the mass could not be made with pulmonary angiography and magnetic resonance imaging. The mean pulmonary arterial pressure was 50 mmHg. Further radiologic examinations failed to reveal the source of the embolus or tumor. It was decided to attempt surgical excision under total cardiopulmonary bypass. At operation, a gelatinous, lustrous, yellowish mass was found partially occluding the right main pulmonary artery and completely occluding the left. The tumor adhered tightly to the intima of the vessel and was inoperable. The patient could not be weaned from percutaneous cardiopulmonary support and died 3 days after surgery. Histologic examination of the excised specimen revealed myxosarcoma.

Chronic Disease↗

PubMed2000

[Compensatory growth of residual lung after pneumonectomy in childhood].

Though pneumonectomy proved to be a potent stimulus to compensatory growth in the animal model, the literature on this subject in human patients is sparse. We report a rare case of compensatory growth after pneumonectomy in childhood. A 17-year-old man was admitted to our hospital because of chest pain. He had been capable of normal exercise despite a history of pneumonectomy at the age of 4. Chest radiography showed pneumothorax and a displaced heart. In a chest CT scan, both pleural spaces were filled with the enlarged left lung. Since thoracoscopic examination showed a bulla at the surface of S3, bullectomy was performed. The specimen resected from the lung showed slight dilatation of the alveoli. It is considered that the enlargement of the residual lung had occurred as a result of alveolar multiplication rather than by dilatation of the existing alveoli. This case demonstrates lung regeneration in childhood.

Adolescent↗

PubMed2000

[Anesthetic management for a patient with mental retardation and unexamined complex congenital heart disease].

An 18-year old female with mental retardation and unexamined complex congenital heart disease received dental care under general anesthesia. Anesthesia was induced and maintained successfully without any significant hemodynamic changes with inhalation of nitrous oxide, oxygen (FIO2 0.25-0.3) and sevoflurane after a heavy premedication (morphine 10 mg, scopolamine 0.3 mg and midazolam 5 mg i.m.). After induction of anesthesia, cardiac anomaly was diagnosed by transesophageal echocardiography as TGA, VSD, PS, and operation was completed without any problem. Two points are considered important in this case; first, to appropriately estimate preoperative cardiac function and second, to adequately manage anesthesia to avoid any hemodynamic fluctuation.

Abnormalities, Multiple↗

PubMed2000

[A patient with hemorrhage originating from an unknown coagulation pathway inhibitor].

The hemorrhagic disorders associated with circulating anticoagulant are rare but well known as the disease derived from inhibitors(alloantibody or autoantibody), which arise against specific coagulation factors. We encountered a patient with hemorrhage at the lower limbs originating from an unknown coagulation pathway inhibitor. Activated partial thromboplastin time(APTT) prolonged and cross mixing test indicated a coagulation pathway inhibitor. Levels of coagulation factors VIII, IX, XI, and XII were extremely low. Predonine therapy was effective to stop the hemorrhage. To clarify the inhibitor, we treated the patient's plasma with protein A Sepharose, and the factor VIII activity was recovered to a normal level after passing through the column. Gel filtration of the patient's plasma and protein A Sepharose adsorbed fraction of the patient's plasma with Superdex 200 revealed that the inhibitor activity against blood coagulation eluted at the position of IgG, which was detected by the prolongation of APTT of normal pooled plasma. These data indicated that the inhibitor was IgG and its inhibitory spectrum was non-specific and broad. The results of laboratory tests and the clinical features in our patient were similar to those in a previous study by Dahlback(Blood 62, 218-225, 1983). The hemorrhagic abnormality of that patient was derived from the autoantibody to phospholipid, which inhibits the activation of prothrombin. An investigation into the effect of anti-phospholipid antibody in our patient is currently being performed in our laboratory.

Adult↗

PubMed1999

Magnesium insertion by magnesium chelatase in the biosynthesis of zinc bacteriochlorophyll a in an aerobic acidophilic bacterium Acidiphilium rubrum.

To elucidate the mechanism for formation of zinc-containing bacteriochlorophyll a in the photosynthetic bacterium Acidiphilium rubrum, we isolated homologs of magnesium chelatase subunits (bchI, -D, and -H). A. rubrum bchI and -H were encoded by single genes located on the clusters bchP-orf168-bchI-bchD-orf320-crtI and bchF-N-B-H-L as in Rhodobacter capsulatus, respectively. The deduced sequences of A. rubrum bchI, -D, and -H had overall identities of 59. 8, 40.5, and 50.7% to those from Rba. capsulatus, respectively. When these genes were introduced into bchI, bchD, and bchH mutants of Rba. capsulatus for functional complementation, all mutants were complemented with concomitant synthesis of bacteriochlorophyll a. Analyses of bacteriochlorophyll intermediates showed that A. rubrum cells accumulate magnesium protoporphyrin IX monomethyl ester without detectable accumulation of zinc protoporphyrin IX or its monomethyl ester. These results indicate that a single set of magnesium chelatase homologs in A. rubrum catalyzes the insertion of only Mg(2+) into protoporphyrin IX to yield magnesium protoporphyrin IX monomethyl ester. Consequently, it is most likely that zinc-containing bacteriochlorophyll a is formed by a substitution of Zn(2+) for Mg(2+) at a step in the bacteriochlorophyll biosynthesis after formation of magnesium protoporphyrin IX monomethyl ester.

Acetobacteraceae↗

PubMed1999

Study of a rat skin in vivo micronucleus test: data generated by mitomycin C and methyl methanesulfonate.

We have developed an in vivo micronucleus (MN) test that uses rat skin as the target organ. Sample preparation involves cold-treating the epidermis with trypsin, peeling it off with a fine forceps, treating it in hypotonic solution, and staining it with acridine orange (A.O.). We evaluated the assay using mitomycin C (MMC) and methyl methanesulfonate (MMS) as model clastogens, applying them as single and repeat treatments. Both chemicals induced a significant, dose-dependent increase in MN frequency in basal cells. One treatment per day for 3 days was optimal for MN induction.

Acridine Orange↗

PubMed1999

Clonality of acquired primary pure red cell aplasia.

Acquired primary pure red cell aplasia (PRCA) has frequently been shown to be associated with T cells that inhibit marrow erythropoiesis. A 41-year-old female presented with anemia in December 1985. Bone marrow examination revealed 1.8% erythroid cells. A diagnosis of PRCA was made. She received prednisolone, and her hemoglobin level recovered to 12 g/dl. In February 1995, her hemoglobin level decreased to 5.8 g/dl, and acquired primary PRCA recurred. Surface markers of peripheral blood mononuclear cells demonstrated CD4/8 ratio inversion. The T-cell receptor (TCR)-beta chain gene showed germ line configuration by Southern blot analysis of the mononuclear cells in peripheral blood. However, stepdown polymerase chain reaction analysis revealed that the TCR-beta gene of peripheral blood mononuclear cells was rearranged. With highly sensitive polymerase chain reaction analysis, clonality of T cells was confirmed. We propose that some acquired primary PRCA patients have a T-cell clonal disorder, similar to some PRCA patients with large granular lymphocytes leukemia or thymoma.

Adult↗

PubMed1999

Cyclin D2, but not cyclin D1, overexpression closely correlates with gastric cancer progression and prognosis.

Expression of cyclins D1 and D2, as well as cyclin-dependent kinase 4 (cdk4), was investigated by means of immunohistochemistry in 455 gastric cancer cases. Additional western blotting was performed for four breast cancer and four gastric cancer cell lines and 35 fresh frozen gastric cancer samples, to confirm the cyclin D1, D2, and cdk4 data. Cyclin D1 was restricted to the nucleus of cancer cells with a few exceptions, whereas cyclin D2 was present in both cell compartments, but predominantly in the cytoplasm. Cdk4 was intermediately expressed. Cyclin D1 was overexpressed in 93 cases (20.4 per cent) and cyclin D2 in 105 (23.0 per cent). In the cyclin D2 cases, this correlated with greater age (p=0.0004), better differentiation (p=0.0023), greater depth of cancer invasion (p=0. 003), the presence of lymph node metastasis (p=0.0014), vascular invasion by cancer cells (p< 0.0001), and poor prognosis (p< 0.0001), while cyclin D1 did not correlate with any of these except age (p=0.00193). Multivariate analysis revealed cyclin D2 overexpression to be an independent prognostic factor, in addition to depth of cancer invasion and lymph node status. Cdk4 overexpression was linked to cyclin D1, but not cyclin D2 overexpression. The results indicate that cyclin D2 up-regulation plays an important role in the progression and prognosis of gastric cancer independently of cdk4, whereas cyclin D1 overexpression does not.

Adult↗

PubMed1999

Pyruvate dehydrogenase kinase 4 mRNA is increased in the hypertrophied ventricles of carnitine-deficient juvenile visceral steatosis (JVS) mice.

We isolated a mouse homologue cDNA of pyruvate dehydrogenase (PDH) kinase 4 (PDK4) with differential mRNA display as an up-regulated gene in the hypertrophied ventricles of juvenile visceral steatosis (JVS) mice with systemic carnitine deficiency. The PDK4 mRNA level was 5 times higher in JVS mice than in control mice under fed conditions. After 24 h starvation, this level increased to 20 times in JVS and 7 times in control, compared with the control fed level. On the other hand, carnitine administration reduced the high level of PDK4 mRNA in JVS mice to the control fed level. In control mice, the change in PDK4 mRNA was inversely correlated with the change in PDH activity. In JVS mice, however, the PDK4 mRNA level was not always correlated with the active-form PDH level.

Amino Acid Sequence↗

PubMed1999

A successful case of pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension with a thrombus in the right ventricle.

Chronic thromboembolism is a frequent cause of progressive hypertension and carries a poor prognosis. Medical treatment is not effective and surgery provides the only potential for a cure at present. We herein report a successful case of thromboendarterectomy treated via a median sternotomy with intermittent circulatory arrest. A 43-year-old man was admitted to our hospital complaining of progressive dyspnea, edema of the lower extremities, and a fever with an unknown origin. A subsequent definitive evaluation showed him to be suffering from surgically accessible chronic thromboembolic pulmonary hypertension with a thrombus in the right ventricle. He underwent a pulmonary thromboendarterectomy and thrombectomy via a median sternotomy with intermittent circulatory arrest on November 24, 1994. Postoperatively he showed a marked improvement in his hemodynamic status and blood gas analysis. He has also returned to work with no trouble. Deep vein thrombosis appeared to be the pathogenesis of this case, but we could not find the origin of his unknown fever. He is currently being controlled by treatment with methylprednisolone as before.

Adult↗

PubMed1999

A possible balance of magnesium accumulations among bone, cartilage, artery, and vein in single human individuals.

It is known that a large quantity of magnesium contains bones, and the magnesium contents in spongy bones decrease gradually with advancing age. To elucidate the relationships between a decrease of mineral contents in human bones and an accumulation of minerals in the other human tissues, the content of magnesium was analyzed by inductively coupled plasma-atomic emission spectrometry among human bones, arteries, veins, and cartilages in 27 subjects (17 men and 10 women). These were resected from the subjects who died in the age range 40-98 yr. Calcanei were chosen for analysis of magnesium contents in contrast with femoral, popliteal, and common carotid arteries, internal jugular and femoral veins, superior and inferior venae cavae, and pubic symphyses. The magnesium contents in the calcanei decreased gradually with aging, whereas they increased progressively in the arteries, veins, and pubic symphyses with aging. It was found that as the magnesium contents decreased in the calcanei, they increased in the arteries, such as the femoral, popliteal, and common carotid arteries, whereas they decreased inversely in the veins, such as the internal jugular and femoral veins and superior and inferior venae cavae. Furthermore, as the magnesium contents decreased in the calcanei, they hardly changed in the pubic symphyses. These suggest that magnesium released from bones is accompanied by accumulation of magnesium in the arteries.

Adult↗

PubMed1999

High accumulation of calcium and phosphorus in human iliac arteries.

To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.

Aged↗

PubMed1999

Element content of human umbilical artery and vein in umbilical cord.

To elucidate the element content of newborn blood vessels, umbilical arteries and veins in human umbilical cords, which had the advantage of easy sampling, were examined by ICP-AES. Umbilical cords were removed after birth. Mothers' ages ranged from 26 to 35 yr. It was found that the content of sulfur was the highest in both umbilical arteries and veins, being higher than the content of calcium and phosphorus. With respect of the content of sulfur, calcium, and magnesium, there were significant differences between the arteries and veins.

Aged↗

PubMed1999

Overexpression of p53 nuclear protein in premalignant and malignant laryngeal lesions.

To investigate the role of p53 nuclear protein mutations in the initiation and progression of laryngeal carcinoma, 111 premalignant and malignant laryngeal lesions (19 specimens with hyperkeratosis and 92 with carcinoma) were studied immunohistochemically. Over-expression of p53 was observed in 8 cases (42%) of laryngeal hyperkeratosis and 44 cases (47%) of laryngeal carcinoma. However, the expression of p53 showed no relationship to patients' clinical courses. Our study confirms that p53 overexpression can be found in laryngeal carcinogenesis and is an early event but not a useful prognostic marker.

Carcinoma, Squamous Cell↗

PubMed1999

Induction of apoptosis in maxillary sinus cancer cells by 5-fluorouracil, vitamin A and radiation (FAR) therapy.

The triple combination of 5-fluorouracil (5-FU), vitamin A and radiation (FAR therapy) has been used since 1972 to treat malignant tumors of the head and neck at Kyushu University. Using nick end labeling of tumor specimens, cells of human maxillary sinus carcinomas were observed previously to undergo apoptosis in response to FAR therapy. The present study evaluated the in vitro effects of FAR therapy on a human maxillary sinus cancer (IMC-4) cell line. We further compared the effects of FAR therapy on this cell line with those effects seen on tissue samples taken from patients with maxillary sinus cancers. DNA electrophoresis and electron microscopic examination of the IMC-4 cells after treatment with FAR therapy revealed typical apoptotic features. The effects of 50-100 micrograms/ml 5-FU, 10(-4) M all-trans-retinoic acid and radiation to 6 Gy on IMC-4 cells were evaluated by trypan blue dye exclusion and a cell colony formation assay. 5-FU and radiation caused direct cell death, while vitamin A mainly inhibited cell growth. The combination of these treatment as FAR therapy synergistically enhanced cell death and inhibited cell growth. Flow cytometry demonstrated that FAR-treated cells were arrested in the G1 phase of the cell cycle before undergoing apoptosis. To further investigate possible biological parameters influencing a tumor's apoptotic sensitivity, we also examined the expression of p53 in human maxillary sinus cancer cells and analyzed the relationship between p53 expression and apoptosis. However, no relationship was found between these two markers at the time point studied.

Antineoplastic Agents↗

PubMed1999

Stomal recurrence invading the cervicothoracic esophagus and upper mediastinum: resectability and the creation of a safe anterior mediastinal tracheostoma.

Surgical salvage for stomal recurrence is a for midable problem for head and neck surgeons. The two factors of considerable significance are resectability and establishment of a safe anterior mediastinal tracheostoma. A case of stomal recurrence invading the cervicothoracic esophagus and upper mediastinum is presented. Total esophagectomy and upper mediastinal dissection was performed. The esophagus was reconstructed immediately with a pedicled gastric flap. The omentum on the gastric pedicle was wrapped around the trachea to reduce the likelihood of erosion into the great vessels and to supplement the lateral blood supply to the trachea. No serious postoperative complications were observed. We believe that the total esophagectomy improved the resectability, and that the bulk of the gastric pedicle and the use of the omentum prevented significant postoperative complications associated with an anterior mediastinal tracheostoma.

Anastomosis, Surgical↗