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Biomedical subjects

H Matsunaga

Publications and source records attributed to H Matsunaga.

At least 19 recordsLinked to original sources
PubMed1992

Polymyxin B octapeptide and polymyxin B heptapeptide are potent outer membrane permeability-increasing agents.

Polymyxin B octapeptide (PBOP) and polymyxin B heptapeptide (PBHP) were found to be effective permeabilizers of the outer membrane of Escherichia coli and Salmonella typhimurium. PBOP was as effective as polymyxin B nonapeptide (PMBN), the known very potent permeabilizer. As low a PBOP concentration as 1 microgram/ml sensitized E. coli to rifampicin by a factor of 100. Three micrograms of PBOP per ml was sufficient to sensitize this target to all the other tested hydrophobic antibiotics (erythromycin, fusidic acid, clindamycin, and novobiocin) by a factor of 30. Only a slightly higher (3-fold) concentration of PBHP was required for a similar sensitizing effect.

Amino Acid Sequence↗
PubMed1992

[Congenital bicuspid aortic valve: stenotic type and insufficient type].

Two-hundred and eighty-one patients underwent surgical treatment of the aortic valves during a 10-year period of 1981 to 1991, 32 of whom (11%) had bicuspid aortic valve. Bicuspid aortic valve is well known to cause calcified aortic stenosis, however, some of these cases develop pure aortic insufficiency of unknown etiology. In our studies of 32 patients with bicuspid aortic valve, 28 patients had aortic stenosis, 2 were aortic insufficiency and 2 were infective endocarditis. Pathogenesis of aortic insufficiency in patients with bicuspid aortic valves was discussed and compared with that of aortic stenosis.

Adult↗
PubMed1992

[A case of pulmonary rupture with primary pulmonary leiomyosarcoma--management by emergency surgical intervention].

We report a case of 18-year-old boy who was admitted to our hospital for hemoptysis and hemothorax caused by rupture in the pulmonary tissue. A tumoral mass was found protruding from the inferior aspect of the left lower lobe towards the diaphragma. A large hematoma was seen in the vicinity of the tumoral mass. An emergency left lower lobectomy was performed and the hematoma was removed. The tumor was yellow in color, soft and 7 cm in diameter. The histological diagnosis was that of primary pulmonary leiomyosarcoma. The resected lobe had a liver-like hard consistency due to extended infiltration of blood resulting from hemorrhages within the tissue located in and around the tumoral mass. Microscopically, the tumor was composed of the spindle-shaped cells with multinucleation along with some clear cell patterns. Recurrence of the tumor appeared six months after the operation, and a second resection of the recurrent leiomyosarcomatous tissue was performed. The patient is still alive for 1 year and 6 months after the first operation.

Adolescent↗
PubMed1992

[Gonadal function in young female affective illness associated with the menstrual cycle--in relation to the polycystic ovary syndrome].

The hypothalamo-pituitary-gonadal axis was studied in 10 young manic-depressive or psychotic women whose symptoms obviously fluctuated in association with the menstrual cycle. The common clinical features of these cases were (1) young female aged between 15 and 25, (2) the symptoms fluctuated obviously in association with the menstrual cycle, and (3) severe manic-depressive, or psychotic symptoms. While, in two cases, the depressive or psychotic phases had repeated many times for several years, the rest eight cases did not have a long psychiatric past history. The common hormonal features among these 10 cases were elevated basal LH (7 of 10 cases), decreased basal FSH (6 of 10), greater response of LH and normal response of FSH to LHRH (8 of 8), lack of or insufficient increase of progesterone in the luteal phase (7 of 8), and elevated serum testosterone (5 of 10), androstenedione (4 of 10) and DHEA-S (3 of 9). These abnormalities resemble those of polycystic ovary syndrome (PCOS). Five of the 10 cases showed mild hirsute signs such as mustache, acne, and/or well-developed musculo-skeletal system. An ultrasonographical study revealed polycystic changes in 7 of 10 cases. Ordinary psychotropic pharmacotherapy was not effective sufficiently and hormonal therapy was tried in these 10 cases. Clomiphene citrate was administered on Day 5-9 of the menstrual cycle at a daily dose of 50mg orally in 9 cases, and it was effective to prevent recurrence of manic episode in one case, and to improve manic-depressive or psychotic symptoms in 6 cases. In these 6 cases, the effects were commonly observed within 1 or 2 weeks subsequent to the administration being completed. Daily dexamethasone administration was effective in one case with high serum DHEA-S level in whom clomiphene citrate worsened the psychotic symptoms, and thyroid hormone was effective in one case. In comparison with the pathophysiology of PCOS, a possible relationship was suggested between psychiatric problems and the PCOS-like hormonal abnormalities in these cases.

Adolescent↗
PubMed1992

[Strategy for therapy of malignant ascites using MTT assay].

Since the prognosis of patients with malignant ascites is generally poor, the establishment of a therapeutic plan should be done as soon as possible. In order to select the most suitable antitumor agent, a drug-sensitivity test was done by MTT assay using fresh autologous tumor cells as targets. Autologous tumor cells were collected from their ascitic fluids. Results obtained here indicate a possible strategy for the treatment of patients with malignant ascites by MTT assay.

Antineoplastic Agents↗
PubMed1991

Nonradioactive detection of nucleic acid by the universal probe system.

A convenient and nonradioactive method for DNA hybridization tests termed the "Universal probe system" has been developed. This method is based on the principle of sandwich hybridization. This system consists of two single-stranded DNA probes (a primary probe and a biotin-labeled secondary probe). The primary probe is prepared from a chimeric phage-plasmid vector containing the complementary sequence to a target gene. The secondary probe has a sequence complementary to the vector portion of the primary probe and is labeled with biotin via the transamination reaction. An advantage of this method is that the single-stranded primary probe can be prepared with ease by using the chimeric phage-plasmid vector system, thereby avoiding tedious labeling of individually different probes. As the primary probe is not modified with biotin and other labels, it conserves the sequence to be hybridized with a target. Accordingly, the primary probe containing a relatively short hybridizing region (ca. 50 bp) can efficiently hybridize with the target. In fact, the universal probe is sensitive enough to detect a single-copy human gene on Southern blots.

Biotin↗
PubMed1991

Preparation of enzyme-conjugated DNA probe and application to the universal probe system.

A general procedure for the cross-linking of enzyme to DNA has been developed for use as a nonradioactive probe. In this method, DNA is transaminated with diaminopropane to introduce primary amino groups into the cytosine residues. Then the amino groups are converted to thiol groups using a heterobifunctional cross-linker. The thiolated DNA is conjugated with the maleimide-introduced enzyme. With this method, alkaline phosphatase was cross-linked to a single-stranded DNA (sspUCRf1). The conjugate was able to detect 5 pg of target DNA (pUCf1 plasmid, 3.2 kbp) fixed onto the nitrocellulose membrane, using a colorimetric assay. The enzyme-conjugated DNA was applied to "the universal probe system," which consisted of two single-stranded DNA probes (a primary probe and a labeled secondary probe). Using alkaline phosphatase-conjugated sspUCRf1 DNA as the secondary probe, the c-myc gene and HBV DNA were detected effectively on Southern and dot-blot hybridization.

Alkaline Phosphatase↗
PubMed1991

Ion channel activities of cultured rat mesangial cells.

We used the patch-clamp technique to clarify the nature of ion channels in renal mesangial cells in culture. In the cell-attached mode most patches were silent in the absence of agonists. In some patches a 25-pS nonselective channel was observed. This 25-pS cation channel was consistently observed in inside-out patches, and it was activated by intracellular Ca2+. Excised patch experiments also revealed the existence of a 40-pS K+ channel, which was activated by intracellular Ca2+. This 40-pS K+ channel was observed infrequently in the cell-attached mode. The activities of both channels were increased by arginine vasopressin or angiotensin II, resulting from an increase in intracellular Ca2+ concentration.

Angiotensin II↗
PubMed1991

The outer membrane permeability-increasing action of deacylpolymyxins.

The outer membrane permeability-increasing action of deacylpolymyxins was compared to the well-known potent action of polymyxin B nonapeptide (PMBN). Deacylpolymyxin B (DAPB), prepared by treating polymyxin B with polymyxin acylase, was found to be a slightly more effective permeabilizer than PMBN. As low a DAPB concentration as 1 microgram/ml sensitized Escherichia coli to the probe antibiotics (rifampin, fusidic acid, erythromycin, clindamycin, novobiocin) by factors 30-100 and Salmonella typhimurium by factors 10-100. A higher concentration (3 micrograms/ml) of DAPB elicited further sensitization. Also deacylcolistin (DAC) was found to be an effective permeabilizer.

Amino Acid Sequence↗
PubMed1991

[Current problems in valvular surgery].

Based upon our experiences of 661 valvular operations for these 10 years, we discussed about three major topics in valvular surgery. The first is the current status of valve repair versus replacement. The second is on the changing aspects of patients undergoing valvular surgery. Finally difficult problems in the treatment of infective endocarditis was discussed.

Aged↗
PubMed1991

[Mitral valve disease with pulmonary hypertension: two surgical cases].

Two surgical cases of mitral valve disease with severe pulmonary hypertension were reported, in which pulmonary hypertensive crisis (PHC) was a really serious problem to be treated. The first case (60-year-old woman) had atrial fibrillation and her pulmonary artery pressure was 68/32 mmHg (Pp/Ps = 0.63) and mean pulmonary wedge pressure was 26 mmHg with a high v wave (46 mmHg). PHC developed immediately after the cessation of artificial cardiopulmonary bypass, and intraaortic balloon pumping was performed. However, it was difficult to wean from the assist circulation, and then PGE1 and isoproterenol were given into the pulmonary artery and epinephrine and norepinephrine were given into the left atrium, and we succeeded in weaning from the assist circulation. The second case (58-year-old woman) had high pulmonary artery pressure (86/37 mmHg) and the Pp/Ps was 0.73. According to the experience of the first case, prevention of PHC started during cardiopulmonary bypass, giving PGE1, nitroglycerin and torazoline into the pulmonary artery. This led to the easy weaning from cardiopulmonary bypass. PHC may be seen even in cases of acquired valvular disease, and the prevention is mandatory for uneventful surgery.

Cardiopulmonary Bypass↗
PubMed1991

[Surgical approach and long-term results on replacement of the aortic valve and ascending aorta with a composite graft].

From March, 1980 to January, 1991, 18 patients, 14 male and 4 female patients ranging in age from 22 to 63 years, were operated on for aortic regurgitation associated with an aneurysm of the ascending aorta. Twelve patients had annuloaortic ectasia; six had DeBakey type I or II dissection; three had Marfan syndrome; and one had aortitis syndrome. The surgical treatment consisted of 16 Bentall operations and 2 modified Cabrol operations with a composite graft and aortic wrapping. The operative mortality was 5.6% (one death). The late mortality has been 4/15. The actuarial survival rate is 82.6% at 5 years and 72.3% at 7 years. Modified Cabrol technique consists of two short interposed grafts with equine pericardial miniskirts between coronary ostia and composite graft, in which Carbomedics mitral valve (No. 23 or 25) is placed 5-10 mm above the proximal extremity. This technique is a safe and reliable method with no bleeding nor mortality and excellent long-term results.

Adult↗
PubMed1991

[Results and problems of cardiac surgery in the elderly (70 years of age or older)].

Fifty-nine cardiac patients with 70 years of age or older were operated in our Department from 1979 to 1990. The mean age was 73.1 years old, and the male/female ratio was 27/32. The operative procedures performed were CABG in 35 cases, the closure of VSP in 4 cases, the valve surgery in 17 cases and the others in 3 cases. In CABG cases, the operative and late mortalities of the elderly patients were both 2.9% (1 case each), which were comparable to those of the younger patients. The restriction of the bypass grafting only to the key coronary arteries to reduce the operative time was considered to be important. In VSP cases, three of four patients were operated in the acute phase, one being lost because of in-hospital contamination. In the valve group, 24% (4 cases) were lost in the early postoperative period, which was much higher than that of the younger patients (7.2%). The earlier decision of the operation and the use of smaller prosthetic valve avoiding time-consuming aortic root enlargement were considered to be important to reduce the mortality. It is concluded that the results of cardiac surgery in the elderly patients could be satisfactory if one considers its peculiarity well.

Age Factors↗
PubMed1991

[A case of primary mediastinal seminoma].

Primary mediastinal seminoma is a rare clinical entity. Because of its high malignancy, we often find it only when it grows very large so we can't resect it completely. Our patient came with asthma attack and abnormal shadow on chest X-ray was pointed out. Germinal cell tumor was diagnosed by thoracoscopy and resection of the tumor was performed. Postoperative radiation therapy also was performed. Our case is alive in good health for 1 year postoperatively and good prognosis will be expected.

Adult↗