Biomedical subjects

S Masuda

Publications and source records attributed to S Masuda.

At least 127 records · Page 7Linked to original sources

PubMed1998

Epidemiologic typing of methicillin-resistant Staphylococcus aureus in neonate intensive care units using pulsed-field gel electrophoresis.

To elucidate the mode of dissemination of methicillin-resistant Staphylococcus aureus (MRSA) in neonate intensive care units (NICUs), a total of 223 isolates from 3 separate hospitals were investigated between 1994 and 1996 by a DNA fingerprinting technique with pulsed-field gel electrophoresis (PFGE). Exoprotein profiles of some strains were also examined using SDS-polyacrylamide gel-electrophoresis (SDS-PAGE) and the assessment of enzyme/toxin production such as coagulase, enterotoxin and TSST-1. Judging from the strain typing data from PFGE results and the epidemiological data, 2 different types of PFGE patterns (A and B) and their subtypes (A', A'' and B') were identified. The A type including A' and A'' (comprising approximately 95% of the isolates) was markedly dominant. Only 5% of the isolates belonged to type B and subtype B'. On the other hand, MRSA isolated from adult patients admitted to the same hospital showed many different PFGE patterns. The results strongly suggested that some strain(s) with specific PFGE pattern(s) is prevalent in NICUs. Furthermore, isolates which expressed the same PFGE pattern did not always express the same SDS-PAGE pattern. There were some isolates with different abilities to produce coagulase, enterotoxin C and toxic-shock syndrome toxin (TSST)-1, and the abilities had no relation with a particular type of PFGE pattern. Therefore, a combination of PFGE analysis and biochemical analyses of coagulase, enterotoxin C and TSST-1 may provide us with more detailed information for the epidemiological study of MRSA in NICUs.

Adult↗

PubMed1998

Different effects of fibronectin on the phagocytosis of Staphylococcus aureus and coagulase-negative staphylococci by murine peritoneal macrophages.

Fibronectin is known to be an important factor in colonization by Staphylococcus aureus of host tissues as well as other extracellular matrix proteins such as collagen and laminin. We investigated the effect of fibronectin on the phagocytosis of the S. aureus Cowan I strain by macrophages and of coagulase-negative staphylococci (CNS) strains for comparison. Fibronectin-reduced serum in place of normal serum lowered the phagocytic activity of the macrophages on the Cowan I strain. Purified fibronectin enhanced the phagocytic activity of the strain in a dose-dependent manner. On the other hand, fibronectin did not show any opsonic effect on the ingestion of CNS strains, though the binding of fibronectin occurred equally well in CNS strains and the Cowan I strain. Fibronectin-binding protein (FnBP), the specific fibronectin receptor on the surface on S. aureus, was detected in both the Cowan I strain and CNS strains. Polymerase chain reaction confirmed that not only the Cowan I strain, but also CNS strains possessed the FnBP gene. These results indicate that fibronectin shows an opsonic effect on the S. aureus, Cowan I strain but not on CNS strains, and suggest that the binding of fibronectin to FnBP is not sufficient for efficient phagocytosis of the staphylococci strains by macrophages.

Adhesins, Bacterial↗

PubMed1998

Ectopic prostatic tissue outside the urinary tract: a case report.

A 64-year-old man with a 4-month history of dysuria and urinary frequency had a mass behind the bladder. The preoperative diagnosis was a tumor of the left seminal vesicle, but a histologic examination revealed benign prostatic tissue. This is the seventh reported case of ectopic prostatic tissue situated outside the urinary tract.

Acid Phosphatase↗

PubMed1998

Distribution and synthesis of apolipoprotein J in the atherosclerotic aorta.

The distribution of apolipoprotein (apo) J during the development of atherosclerosis in the human aorta was evaluated by immununohistochemical observation, together with the other apolipoprotein A-I, A-II, B, C-III, and E. Although apoJ was never observed in the normal aorta (ie, without any intimal lesions or intimal thickening), it was distributed not only in the intima but also in the media of aortas with diffuse, intimal thickening or atherosclerotic lesions. Double immunostaining with antibodies for apoJ and alpha-smooth muscle actin revealed apoJ deposition in smooth muscle cells (SMCs) or the aortic stroma in the vicinity of SMCs. The extent of apoJ distribution in the aortic wall increased with the degree of atherosclerosis development. In addition, the distribution pattern of apoJ was very similar to that of apoA-I and E. In situ hybridization with human apoJ cDNA demonstrated intense signals in cells scattered within the subendothelial space and medial SMCs of the aorta with advanced atherosclerosis but not in those of the normal aorta without intimal thickening. Furthermore, reverse transcriptase-polymerase chain reaction of the cultured human aortic SMCs revealed apoJ mRNA expression in these cells. The results indicate that apoJ in the aortic wall originates from not only apoJ circulated in the plasma but also apoJ produced by SMCs in the aortic wall. Considering the similarities of the distribution between apoJ and apo-A-I or E, we hypothesize that apoJ possibly has a protective role against human atherosclerosis by its involvement with cholesterol transport from the aortic wall to the liver.

Adolescent↗

PubMed1998

Binding position of tolbutamide to human serum albumin.

The interaction between drugs (tolbutamide (1), 1-butyl-3-(methylsulfonyl)urea (2)) and human serum albumin (3) was investigated by equilibrium dialysis and NMR spectroscopy. The binding of 1 and 2 to 3 was concluded to be hydrophobic and hydrophilic, respectively, on the basis of the dependence of the binding constants on temperature, ionic strength, and chain length of fatty acid added. In 1H-NMR spectra of 1, there were no significant shifts with change in concentration or addition of 3. The spin-lattice relaxation time (T1) and spin-spin relaxation rate (1/T2) of the respective protons of 1 were independent of concentration, but depended on the concentration of 3 added. The binding position was determined from the ratio of 1/T2 of 1 bound to 3 and free 1. 1 and 2 were found to bind to 3 through the tolyl group and sulfonylurea group, respectively. The binding property of 1 was considered to be governed by the competition between the hydrophobic effect of the tolyl group and the hydrophilic effect of the sulfonylurea group in the molecule.

Binding Sites↗

PubMed1998

Changes of ischemic heart disease in Utsunomiya, Japan, over 10 years: a survey of primary care physicians.

A total of 502 patients presenting in Utsunomiya city and its suburbs during a 10-year period were studied to determine the clinical features of ischemic heart disease and to identify coronary risk factors. The male/female ratio was 1.21, but the ratio decreased with increasing age. The duration of chest pain showed a continuous spectrum between angina and infarction, with a short duration of chest pain not being useful for excluding the diagnosis of myocardial infarction. Hypertension was more common than hypercholesterolemia in this study, although the prevalence of the latter increased slightly with time, along with the shift towards a modernized occupational pattern. Smoking was a more important risk factor for ischemic heart disease in younger individuals than in the elderly, and diabetes mellitus was highly associated with the development of myocardial infarction. The incidence of radiologically diagnosed cardiac hypertrophy and aortic calcification decreased over time. These changes may have resulted in part from improved blood pressure control and the development of new anti-hypertensive and cholesterol-lowering agents.

Age Factors↗

PubMed1998

Early experience of minimally invasive valve surgery.

In this paper we report on our early results of minimally invasive cardiac valve surgery. A series of 6 consecutive patients with valvular disease underwent valve repair and valve replacement via a right parasternal incision; aortic valve replacement 3, mitral valve replacement 1, mitral valve repair 2. There were no intraoperative complications requiring median sternotomy. Five patients had no blood transfusion. There was only one postoperative event; this patient had a sudden massive bleeding from the chest tube after extubation of the endotracheal tube, an immediate re-suture of the aortotomy was performed. The reoperative course was uneventful. Minimally invasive cardiac surgery for aortic and mital valves is an excellent option for most patients affected by isolated valvular disease.

Adult↗

PubMed1998

Reduction of Escherichia coli O157:H7 populations in soy sauce, a fermented seasoning.

We studied five Escherichia coli O157:H7 strains in soy sauce which was incubated at 4, 18, or 30 degrees C after inoculation. The cell numbers of E. coli O157:H7 decreased to an undetectable level (<20 CFU/ml) within 9 days in all the soy sauce samples at 30 degrees C, but did not decrease in the 0.1 M phosphate-buffered saline (pH 7.0) control solution under the same conditions. Soy sauce reduced the cell numbers of bacteria at 18 degrees C to a lesser extent than at 30 degrees C, but to a greater extent than at 4 degrees C. Components of soy sauce such as 10% or 16% NaCl, 5% ethanol, lactic acid, or acetic acid at pH 4.5, sodium benzoate (0.6 g/kg), or p-hydroxybenzoic acid n-butyl ester (0.05 g/liter) caused a reduction of the E. coli O157:H7 population at 30 degrees C, and the anti-E. coli O157:H7 effect of each component was less than that of soy sauce. The fate of E. coli O157:H7 cells in a buffered solution containing various components of soy sauce resembled that in soy sauce at 30 degrees C, which demonstrated the importance of the combination of the soy sauce components for its anti-E coli O157:H7 action.

Acetic Acid↗

PubMed1998

[Resection of asymptomatic infected bulla associated with pulmonary tuberculosis].

The patient was a 49-year-old man. A physical examination in 1995 had disclosed the presence of a bulla in his left lung. Chest x-ray films taken in February 1997 disclosed niveau formation as an abnormal shadow in contact with the bulla. The patient was given a diagnosis of an infected bulla, and underwent an operation for partial resection of the S 6 portion of the left lung. The intracystic fluid was serous and no general bacteria or mycobacteria were detected. However, histopathological examination found granulation tissue associated with caseous necrosis and containing mycobacteria. The patient is currently receiving tuberculostatic agents on an outpatient basis.

Blister↗

PubMed1998

Ultrastructural study in canine prostatic hyperplasia--effect of antiandrogen.

Ultrastructural changes in canine prostates after treatment with chlormadinone acetate (CMA) were investigated. Old male beagle dogs (5-8 years old ) were divided into two experimental groups; group 1 consisted of benign prostatic hyperplasia (BPH) controls, and group 2 received 0.3 mg/kg/day CMA orally for 6 months. In group 1 animals, the most striking ultrastructural changes were detected in the rough endoplasmic reticulum (rER) and Golgi complexes. The secretory granules were lined up along the apical plasma membrane, and exocytosis was frequently seen. In group 2 animals, the cytoplasm was electron-lucent and contained relatively few, poorly developed organelles. The rER was sparse and consisted of a few scattered, short profiles studded with ribosomes. The Golgi complexes were inconspicuous. The secretory granules were markedly decreased in both number and size. Furthermore, mitochondrial degeneration such as swollen or disappeared mitochondrial cristae or decreased electron density of the matrix were frequently seen in the smooth muscle cells. Based on our data, atrophy after treatment with CMA may be due to shrinkage of both glandular and stromal compartments in the prostate tissue.

Animals↗

PubMed1998

[Ganglioneuroma arising in the adrenal medulla: a case report].

We report a case of adrenal ganglioneuroma. A 33-year-old woman visited our clinic with a complaint of epigastralgia. Abdominal computed tomography (CT) and magnetic resonance imaging (MRI) revealed a round mass, 4 cm in diameter, in the left suprarenal fossa. Laboratory data including endocrinological study were normal except for a mild increase of urinary excretion of dopamine. Under the diagnosis of left non-functioning adrenal tumor, surgery was performed on August 9, 1996 through flank incision. The excised tumor was well-demarcated and weighed 36.6 g. The cut surface revealed an ash-colored round tumor surrounded by thin stretched adrenal tissue. Histological diagnosis of the tumor was a ganglioneuroma originating from the adrenal medulla.

Adrenal Gland Neoplasms↗

PubMed1998

[Long-term clinical outcome of extracorporeal shock wave lithotripsy monotherapy for staghorn calculi].

We treated 97 patients with staghorn calculi by ESWL monotherapy using a Lithostar Lithotriptor (Siemens) between January 1989 and December 1996. Seventeen patients (18 renal units) out of 45 patients (47 renal units) who could be followed up for more than 12 months after ESWL had no stones on radiographs at 3 months after the treatment. The actuarial non-recurrence (or stone-free) rate was 88.9% at 1 year, 79.0% at 3 years, and 63.2% at 5 years after ESWL (Kaplan-Meier method). The actuarial non-regrowth rate (regrowth < 1 mm) was 96.6% at 1 year, 72.8% at 3 years, and 63.7% at 5 years (Kaplan-Meier method). History of urinary stones was a significant risk factor for stone recurrence, while patient sex, affected side, stone number, pyuria (> or = 10/HPF), hydronephrosis on DIP, and staghorn type were not significantly associated with stone recurrence or regrowth (Cox proportional hazard model). Late complications associated with ESWL included renal dysfunction (serum Cr > or = 1.1 mg/dl) in 2 patients, hypertension (> or = 160 mmHg) in 3, and renal atrophy (two-dimensional size < or = 80%) in 5. ESWL exerted adverse effects in a session-dependent manner on the kidney resulting in renal atrophy. Therefore, we highly recommend that ESWL should be limited to less than 10 sessions.

Adult↗

PubMed1998

Functional characteristics and membrane localization of rat multispecific organic cation transporters, OCT1 and OCT2, mediating tubular secretion of cationic drugs.

We have isolated a kidney-specific organic cation transporter, rat OCT2, which is distinct from rat OCT1 (Okuda M, Saito H, Urakami Y, Takano M and Inui K (1996) Biochem Biophys Res Commun 224:500-507). In our study, the functional characteristics and membrane localization of OCT1 and OCT2 were investigated by uptake studies using MDCK cells transfected with rat OCT1 or OCT2 cDNA (MDCK-OCT1 or MDCK-OCT2) and immunological studies. Tetraethylammonium (TEA) uptake by both MDCK-OCT1 and MDCK-OCT2 cells was markedly elevated when TEA was added to the basolateral medium, but not to the apical medium. Efflux of TEA from MDCK-OCT1 and MDCK-OCT2 cells was not changed by extracellular pH from 5.4 to 8.4, whereas TEA uptake by both transfectants was decreased by acidification of extracellular medium. Apparent Km values for TEA uptake by MDCK-OCT1 and MDCK-OCT2 cells were 38 and 45 microM, respectively. Although various hydrophilic organic cations such as 1-methyl-4-phenylpyridinium, cimetidine, quinidine, nicotine, N1-methylnicotinamide and guanidine markedly inhibited TEA uptake by both MDCK-OCT1 and MDCK-OCT2 cells, there were no significant differences in the apparent inhibition constants (Ki) against these organic cations between both transfectants. Furthermore, immunological studies using a polyclonal antibody against OCT1 revealed that OCT1 was expressed in the basolateral membranes but not in the brush-border membranes of the rat kidney. These results suggested that both OCT1 and OCT2 are basolateral-type organic cation transporters with broad substrate specificities, mediating tubular secretion of cationic drugs.

Animals↗

PubMed1998

[A case of mediastinal cavernous hemangioma resected through thoracoscope].

A case of mediastinal cavernous hemangioma was reported. An abnormal shadow on the chest X-ray film was pointed out in a 55-year-old male. CT scan and MRI revealed a right posterior mediastinal tumor but did not aid in the final diagnosis. We underwent extirpation of the tumor through thoracoscope and confirmed to be a cavernous hemangioma histologically. No major vascular connections between the tumor and major vessels were found. It was useful of thoracoscopic surgery in this case.

Endoscopy↗

PubMed1998

[Japanese cedar pollinosis in children in our allergy clinic].

Recently, it is pointed out that the incidence of Japanese cedar pollinosis has increased in children. We studied on the rate of sensitization and the onset of the disease in children under sixteen who visited allergy clinic in the Department of Otorhinolaryngology in Mie University Hospital. The percentage of positive rate of skin test and IgE antibodies of house dust mite was about 80 to 90% in 1981, 1991, and 1996. However, the percentage of positive rate of skin test and IgE antibodies of Japanese cedar pollen was 43% and 26%, respectively in 1981, but both increased to 58% in 1996. Most of Japanese cedar pollinosis patients also had house dust mite allergy. Among 115 pediatric patients who visited our allergy clinics in the past seven years, 32.2% were allergic to house dust mite alone, 8.6% were allergic to Japanese cedar pollen alone, 40.9% were allergic to both, and 6.1% were allergic to house dust mite, Japanese cedar pollen, and orchard grass pollen. 68% of the total 115 patients were boys, but significantly more girls had the pollinosis. 17.4% of those who are sensitized to the pollen were asymptomatic during the pollen season. Thus, it was confirmed that the rate of children sensitized to the pollen has apparently increased for the past twenty years. We should take care of those children who are sensitized to the pollen but asymptomatic during the pollen season.

Adolescent↗

PubMed1997

The complete genome sequence of the gram-positive bacterium Bacillus subtilis.

Bacillus subtilis is the best-characterized member of the Gram-positive bacteria. Its genome of 4,214,810 base pairs comprises 4,100 protein-coding genes. Of these protein-coding genes, 53% are represented once, while a quarter of the genome corresponds to several gene families that have been greatly expanded by gene duplication, the largest family containing 77 putative ATP-binding transport proteins. In addition, a large proportion of the genetic capacity is devoted to the utilization of a variety of carbon sources, including many plant-derived molecules. The identification of five signal peptidase genes, as well as several genes for components of the secretion apparatus, is important given the capacity of Bacillus strains to secrete large amounts of industrially important enzymes. Many of the genes are involved in the synthesis of secondary metabolites, including antibiotics, that are more typically associated with Streptomyces species. The genome contains at least ten prophages or remnants of prophages, indicating that bacteriophage infection has played an important evolutionary role in horizontal gene transfer, in particular in the propagation of bacterial pathogenesis.

Bacillus subtilis↗

PubMed1997

Purification of a vascular apoptosis-inducing factor from hemorrhagic snake venom.

Hemorrhagic snake venom induces apoptosis in vascular endothelial cells specifically. We report here the purification of an apoptosis-inducing factor from the venom of the rattlesnake Crotalus atrox. The purified factor was a homodimeric protein with a molecular mass of 110 kD and an isoelectric point of 8.5. When exposed to the factor, vascular endothelial cells in culture died, with the characteristic features of apoptosis, such as fragmentation of cells and cleavage of DNA into fragments that yielded a characteristic ladder pattern upon electrophoresis. The activity seemed to be specific to endothelial cells. This factor may prove to be a useful tool for studies of the molecular mechanisms of vascular apoptosis.

Animals↗

PubMed1997

mRNA distribution and membrane localization of the OAT-K1 organic anion transporter in rat renal tubules.

OAT-K1, a renal organic anion transporter, which mediates methotrexate uptake, was analyzed for mRNA distribution along microdissected nephron segments and the immunolocalization in isolated plasma membranes from rat kidney. By using a reverse transcription-coupled PCR, OAT-K1 mRNA was detected predominantly in the superficial and juxtamedullary proximal straight tubules. Western blotting with antiserum for OAT-K1 revealed that the transporter protein with the apparent molecular mass of 40 kDa was expressed exclusively in the brush-border membranes from rat kidney. These findings suggest that the OAT-K1 is localized in the brush-border membranes of the renal proximal straight tubules.

Amino Acid Sequence↗