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Biomedical subjects

K Nishimura

Publications and source records attributed to K Nishimura.

At least 1,387 records · Page 77Linked to original sources
PubMedDate not supplied

Angiotensin II-generating system in dog and monkey ocular tissues.

1. Angiotensin II (AngII) is generated locally in several tissues, including ocular tissues. Recently, it has been suggested that in addition to angiotensin-converting enzyme (ACE), an alternative AngII-generating enzyme, chymase, is present in the present in the cardiovascular tissues of humans, monkeys and dogs and may be involved in the local production of AngII. The purpose of the present study was to determine whether chymase contributes to AngII generation in dog and monkey ocular tissues and to clarify the intraocular AngII-generating system. 2. Chymase-like and ACE activities were measured in dog and monkey ocular tissues, carotid artery, heart and lung. Their mRNA levels were quantified using the competitive reverse transcriptase-polymerase chain reaction (RT-PCR) method. 3. Chymase-like activity was detected in the anterior uveal tract, choroid and sclera in dog eyes, but not in the cornea, lens or fluid phase (vitreous body and aqueous humor). In monkey eyes, chymase-like activity was detected in the anterior uveal tract and it was higher here than in the heart. Angiotensin-converting enzyme activity was detected in the anterior uveal tract, choroid, retina, sclera and fluid phase in both dog and monkey eyes. Chymase and ACE mRNA were detected in tissues showing enzymatic activity. 4. These findings show for the first time that chymase, in addition to ACE, is expressed locally in dog and monkey ocular tissues and may be involved in local AngII generation in the eye.

Angiotensin II↗
PubMedDate not supplied

Surgical repair for supravalvular aortic stenosis: intermediate to long-term follow-up.

BACKGROUND AND AIM OF THE STUDY: Supravalvular aortic stenosis (SAS) has been surgically treated by either single-sinus or bisinus patch repair. This article reviews intermediate to long-term results of repair in patients with SAS at our institute. METHODS: Between 1974 and 1995, eight patients underwent surgical repair for SAS. The age range was 1.3 to 14 years (mean 7.3 years). The morphology was the discrete type in seven patients and the diffuse type in one patient. The pressure gradient across the obstruction was 20 to 105 mmHg (mean 68 mmHg). Two patients in the early period of the series underwent single-sinus patch repair, and six underwent bisinus patch repair (pantaloon-shaped patch, extended aortoplasty). RESULTS: There were no operative deaths, and the mean pressure gradient was reduced to 23 mmHg (p < 0.001) in the early postoperative period. The median follow-up period was 8.0 years (1.8-17.3 years). One patient with diffuse type SAS required reoperation 12.8 years later due to progression of the stenosis, and died after the operation. The remaining seven patients were alive and well at the last follow-up, when the pressure gradient ranged from 6 to 31 mmHg (reoperation excluded). CONCLUSION: Surgical repair for discrete type SAS provides satisfactory results in the intermediate to long-term follow-up.

Adolescent↗
PubMedDate not supplied

A rat model of dilated cardiomyopathy to investigate partial left ventriculectomy.

BACKGROUND: This study is the first to assess a small animal model of dilated cardiomyopathy (DCM) for evaluation of partial left ventriculectomy. METHOD: Eighteen Dahl salt-sensitive (DS) rats were divided into three groups. Six rats were fed an 8% high-salt diet from the age of 7 weeks (Group 1), and similarly six rats from 8 weeks (Group 2) and six from 9 weeks (Group 3). Blood pressure (BP) was measured by the tail-cuff method and left ventricular (LV) dimensions by echocardiography. RESULTS: In Groups 1 and 2, systolic BP rose and reached 200 mmHg by the 10th to 11th week, when all rats died within a week without signs of heart failure. However, in Group 3, systolic BP gradually rose to 196+/-15 mmHg (mean +/- SD) at the age of 14 weeks, when LV end-diastolic diameter (EDD) was 6.2+/-0.4 mm (control 5.1+/-0.7 mm) and LV fractional shortening (FS) was 77+/-3% (control 68+/-3%). At the age of 25 to 30 weeks, all rats in Group 3 showed signs of congestive heart failure, systolic BP remained high, EDD markedly increased (8.7+/-0.6 mm), and LVFS decreased (38.9+/-8.1%). From this stage, rats survived for 13.7+/-5.9 days. We employed the Group 3 model for our pilot PLV study. Eight rats had PLV with a beating heart by plicating the LV area between the papillary muscle bases. Two rats died perioperatively but the rest survived (60% survival 3 weeks after PLV). Postoperatively, the rats' LVEDD decreased and FS improved significantly. CONCLUSIONS: Using DS rats, we developed a DCM model for investigating PLV. The model may contribute to scientific investigation of PLV.

Animals↗
PubMedDate not supplied

Existence of prokallikrein in the kidney. Its biochemical properties compared to three active glandular kallikreins from the kidney, serum, and urine of the rat.

Prokallikrein in the kidney was partially purified with immunoaffinity and DEAE Sephadex A-50 column chromatographies, and its biochemical properties were studied in comparison to three active glandular kallikreins purified from kidney, serum, and urine of the rat. The properties of the enzyme obtained by trypsin activation of prokallikrein were identical with those of active glandular kallikreins from the kidney, serum, and urine of the rat. Apparent molecular weights of prokallikrein, trypsin-activated kallikrein, active renal kallikrein, and glandular kallikrein in rat serum were 38,000 and of active urinary kallikrein, 37,000. Prokallikrein fraction was activated only by trypsin, but not by acidification, pepsin, and rat urinary esterase A treatments. Renal kallikrein, purified in the presence of soybean trypsin inhibitor (SBTI), contained 85% prokallikrein, but the enzymic fraction, purified in the absence of SBTI, contained 23% prokallikrein. Prokallikrein contents of urinary kallikrein and glandular kallikrein in rat serum were 16% and 20% respectively. These results suggest that prokallikrein is produced in the kidney and activated easily by a trypsin-like enzyme. Since rat serum contains active glandular kallikrein, kallikrein in the kidney may be secreted not only into the urine, but also into the blood.

Animals↗
PubMedDate not supplied

A possible route to large-scale production of SWNTs through a combination of the substrate and floating catalyst methods.

We describe a possible route for large-scale synthesis of single wall carbon nanotubes (SWNTs) by a combination of the substrate and floating methods. The template prohibits metal particle aggregation, resulting in high-purity SWNT growth, and the three-dimensional floating seeded state of the template induces improved yields of SWNTs in a semi-continuous system. The SWNTs obtained by this method exhibit large variations of texture (isolated tubes and bundles) and a wide range of diameters (0.4-4 nm).

Catalysis↗
PubMedDate not supplied

Cytokeratin expression in subungual squamous cell carcinoma.

Cytokeratin expression in subungual squamous cell carcinoma was investigated in order to evaluate the origin and state of differentiation of the tumour. The tumour nests contained cytokeratin 14, 16 and 17, which were also expressed in the nail bed. Therefore, cytokeratin expression in subungual squamous cell carcinoma may reflect its indolent clinical prognosis.

Aged, 80 and over↗
PubMedDate not supplied

Chlamydospore formation by Paracoccidioides brasiliensis mycelial form.

To investigate the role of some adverse environmental conditions in chlamydospore formation by the mycelial form of P. brasiliensis, we cultured four P. brasiliensis isolates (18, Bt4, 1183, Pb9) at 25 degrees C within solid agar medium either rich or poor in nutrients. Isolates 18 and 1183 were also cultured under anaerobiosis in a nitrogen atmosphere. Isolate 18 produced great number of terminal and intercalary chlamydospore after 7-10 days of culture in a medium poor in nutrients (2% agar with 0.1% dextrose and polypepton). The three other isolates also produced chlamydospores under the same conditions, but in lower numbers. Chlamydospore production by isolate 18 was abolished when the fungus was cultured in two agar media rich in nutrients (brain heart infusion and potato dextrose agar). Anaerobic incubation of isolate 18 under an atmosphere of N2 showed small mycelial outgrowth with numerous chlamydospores. At the electron microscopical level, the chlamydospores showed one or various nuclei and numerous mitochondria, indicating great potential for further development. Accordingly, chlamydospores produced multiple budding after only 24 h incubation at 35 degrees C. The results demonstrate that under adverse environmental conditions P. brasiliensis mycelial form produces chlamydospores within a short period of time.

Culture Media↗
PubMedDate not supplied

Experimental paracoccidioidomycosis in hamster: transmission electron microscopy of inoculation site lesion.

Interaction between Paracoccidioides brasiliensis (Pb) and inflammatory cells in hamster testis was studied sequentially by transmission electron microscopy. In early lesions (six hours after inoculation), polymorphonuclear neutrophils (PMNs) were the major and mononuclear cells and eosinophils were the minor constituents of the inflammatory cells. PMNs were later replaced by mononuclear cells. Viable Pb cells were phagocytosed or surrounded by inflammatory cells. Preserved Pb cells usually had broad host-parasite interphases, whereas dying ones had narrow interphases. The outer layer of the fungus wall was sometimes broken by PMN in some focal points, broken pieces being peeled off and phagocytosed. Small Pb cells were uninuclear, and were often related to broad interphase. Large Pb cells were multinucleated with irregularly shaped wall, and sometimes had lomasome and/or myelin like structures. Different interaction patterns of Pb with inflammatory cells may be due to functionally different host cell flow to the inoculation site or due to the age of Pb cells or both.

Animals↗
PubMedDate not supplied

Isolation of fungi from nature in the region of Botucatu, state of São Paulo, Brazil, an endemic area of paracoccidioidomycosis.

In an attempt to isolate Paracoccidioides brasiliensis from nature 887 samples of soil from Botucatu, SP, Brazil, were collected cultured in brain heart infusion agar supplemented with dextrose, in potato dextrose agar and in yeast extract starch dextrose agar, all with antibiotics, at 25 degrees and 37 degrees C. Five thermo-dependent dimorphic fungi morphologically resembling P. brasiliensis were isolated; two from armadillo holes; further studies of the biology, antigenicity and genetic features of the five dimorphic fungi are necessary to clarify their taxonomy and their possible relation to P. brasiliensis. In addition, 98 dematiaceous fungi and 581 different species of Aspergillus spp. were also isolated. Our findings emphasize that armadillos and their environment are associated with thermo-dimorphic fungi and confirm the ubiquity of pathogenic dematiaceous fungi and Aspergillus spp.

Animals↗
PubMedDate not supplied

[Predictive factor for TESE (testicular sperm extraction)--ICSI (intracytoplasmic sperm injection) for non-obstructive azoospermia].

BACKGROUND: TESE-ICSI has been used very successfully in the treatment of the patients with non-obstructive azoospermia but its indication is still controversial. We performed retrospective study concerning parameters to predict successful recovery of testicular sperm from the patients and outcomes of ICSI. PATIENTS AND METHODS: 44 patients with non-obstructive azoospermia who underwent TESE-ICSI from July, 1997 to September 1999 were studied retrospectively. RESULTS: 1) Testicular sperm were retrieved from 32 patients (72.7%). ICSI was performed in 29 patients and the partner of 15 patients (46.9%) got pregnant. From 10 patients with histology of Sertoli-cell-only, we could retrieve sperm in 3 patients (30%). 2) Testicular volume, Johnsen's score count (JSC), and FSH were significant parameter to predict the recovery of testicular sperm from the patients, but if we see only the patients with JSC less than 7, there were no significant parameter. Chromosomal abnormality was not a significant parameter. 3) The partner's age, motility of recovered sperm and testicular volume correlated with fertilization rate. Chromosomal abnormality was not significant parameter to predict fertilization. CONCLUSIONS: There was no absolute parameter to predict the recovery of testicular sperm from the patients with non-obstructive azoospermia. All patients with non-obstructive azoospermia can be the indication of TESE-ICSI.

Adult↗
PubMedDate not supplied

Intussusception: the role of general anesthesia during hydrostatic barium reduction.

MATERIALS AND METHODS: A total of 74 patients with intussusception were divided into two groups: 43 cases in 39 patients between April 1974 and June 1988 were treated under general anesthesia, and 39 cases in 35 patients between July 1988 and January 1994 were treated without it. We compared the success rates of barium reduction of intussusception in the two groups and used Fisher's exact probability test to assess whether they differed significantly. RESULTS: The overall success rates with general anesthesia and without general anesthesia were 91% (39/43) and 95% (37/39), respectively. The use of general anesthesia did not significantly affect the success rate of barium reduction (p > 0.3). CONCLUSION: The use of general anesthesia for hydrostatic barium reduction of intussusception did not improve the success rate of this procedure. Therefore we recommend that, in view of its associated disadvantages, general anesthesia should not be used during this procedure.

Anesthesia, General↗
PubMedDate not supplied

Simultaneous bilateral thalamic hemorrhage: case report.

A 60-year-old man presented with an extremely rare case of simultaneous hypertensive bilateral thalamic hemorrhage manifesting as left hemiparesis with headache followed by deterioration in consciousness and tetraparesis. CT scan confirmed the bilateral thalamic hemorrhages 17 hours after onset. Magnetic resonance imaging showed the bilateral thalamic lesions had similar signal intensities, consistent with the simultaneous onset, and had no evidence of hemorrhagic reason. Conservative treatment achieved some neurological improvement, but he died of pneumonia six months after onset. The prognosis of a patient with bilateral hemorrhages is worse than would be indicated by the size of the hemorrhages.

Brain↗
PubMedDate not supplied

Usefulness of three-dimensional CT cholangiography for patients prior to laparoscopic cholecystectomy.

PURPOSE: The aim of this study was to demonstrate three-dimensional biliary anatomy by using spiral CT scanning for patients prior to laparoscopic cholecystectomy. MATERIALS AND METHODS: We studied 22 patients (11 men, 11 women; mean age, 60 years) with preoperative imaging. All patients had normal serum bilirubin levels. Either 50 ml (in 10 cases) or 100 ml (in 12 cases) of meglumine iotroxate was infused intravenously over 30 minutes. Spiral CT scanning was started immediately after the infusion was finished. Volumetric data through the entire biliary tracts were obtained during one breath-hold. The data were reconstructed by using a maximum intensity projection algorithm and three-dimensional shaded surface rendering. RESULTS: In all patients, the anatomical relationship between the cystic duct and the common bile duct was clearly depicted, including one with junctional anomaly. The intrahepatic biliary ducts and the confluence of the hepatic ducts were displayed from all angles. The third or higher intrahepatic branches were delineated in 11 of the 12 (92%) patients with the use of 100 ml of the cholangiographic agent and in seven of the 10 (70%) with 50 ml. CONCLUSION: Three-dimensional CT cholangiography was able to provide adequate information about precise biliary anatomy.

Aged↗
PubMedDate not supplied

Adenosine A3 receptor-mediated airway microvascular leakage: role of mast cells and tachykinins.

To determine whether adenosine A3 receptor stimulation produces airway inflammation and, if so, what the mechanism of action is, we studied microvascular permeability in the rat trachea. After intravenous injection of Evans blue dye, adenosine and various adenosine analogues were given by inhalation, and the tracheal microvascular permeability was determined by a photometric measurement of extravasated dye. N6-2-(4-aminophenyl)-ethyladenosine (APNEA), an adenosine A3 receptor agonist, dose dependently increased plasma protein extravasation, whereas adenosine, the A1-receptor agonist N6-(R-phenylisopropyl)-adenosine, or the A2-receptor agonist 5'-N-ethyl-carboxamidoadenosine had no effect. The effect of APNEA was not altered by the adenosine A1/A2 receptor antagonist 8-(p-sulphophenyl)-theophylline, but was reduced by depletion of mast cell-derived mediators with compound 48/80 or pretreatment with the tachykinin NK1 receptor antagonist CP99,994. These results suggest that activation of A3 receptor specifically increase airway microvascular permeability probably via mast cell-derived mediators and tachykinins.

Adenosine↗
PubMedDate not supplied

Functional analysis of Kaposi's sarcoma-associated herpesvirus RTA in an RTA-depressed cell line.

OBJECTIVE: The viral transcriptional activator encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame 50 (RTA) is expressed in the immediate-early phase of reactivation. We isolated an RTA-depressed cell line, BLS50-4, by subcloning from the KSHV-infected cell line, BCBL-1. RESULTS: In addition to RTA, induction of some lytic gene expressions was also remarkably reduced in BLS50-4 cells, but that of the K8.1 and ORF65 gene expressions was not. Both the replication of the KSHV genome and the release of KSHV DNA into the medium were greatly reduced. Transfection of RTA into BLS50-4 cells restored the expression of K9 (vIRF) and ORF59, but not K8.1. CONCLUSIONS: Thus, we showed that expression of late genes was not directly controlled by RTA, unlike the other groups concluded. We also showed that, by isolating the RTA-depressed cell line, the RTA protein had a critical role in viral DNA replication and the expression of several lytic genes.

Cell Line↗
PubMedDate not supplied

Glutathione S-transferase gene polymorphisms in Japanese patients with rheumatoid arthritis.

OBJECTIVE: To investigate the role of polymorphisms of the glutathione S-transferase M1 (GSTM1), GSTT1, and GSTP1 genes in determining susceptibility to rheumatoid arthritis (RA) and association with the clinical features. METHODS: Polymorphisms of the GSTM1, GSTT1, and GSTP1 genes in 108 Japanese patients with RA and in 143 healthy controls were analyzed by polymerase chain reaction (PCR) or PCR-restriction fragment length polymorphism. RESULTS: The frequency of the GSTM1 null genotype was significantly higher among RA patients than among control subjects (60.2% and 44.1%, respectively. P = 0.011). Moreover, the female patients with GSTM1 homozygous null genotype showed significantly higher serum MMP-3 level than the female patients with non-null genotype (P = 0.030). Frequencies of the GSTT1 and GSTP1 gene polymorphism were not different between RA patients and controls. CONCLUSION: The GSTM1 homozygous null genotype could be a genetic factor that determines susceptibility to RA and may have influence on the disease process.

Adult↗