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Biomedical subjects

T Ozaki

Publications and source records attributed to T Ozaki.

At least 19 recordsLinked to original sources
PubMed1992

Lamin A gene expression is specifically suppressed in v-src-transformed cells.

By a differential screening procedure, we have obtained several cDNAs the expression of which was down-regulated in v-src-transformed 3Y1 cells compared to parental 3Y1 cells. One of these cDNAs, termed N26, was extensively analyzed. Sequence analysis revealed that N26 cDNA was 3,095 nucleotides in length and contained an open reading frame of 665 amino acid residues. Based on an homology search at the nucleotide level, it was postulated that N26 gene encodes lamin A. The expression of the N26 gene was not suppressed in other types of transformed cells, such as v-mos-, v-ras- and SV40-transformed 3Y1 cells.

Amino Acid Sequence↗
PubMed1992

The effect of pituitary adenylate cyclase activating polypeptide (PACAP) on exocrine pancreatic secretion in dogs.

The effect of new hypothalamic peptides, PACAP38 and PACAP27, on exocrine pancreatic secretion was studied in five conscious dogs each with a chronic gastric fistula and a Thomas duodenal fistula. The intravenous injections of PACAP38 and PACAP27 (2.5-100 pmol/kg) induced dose-related increases in pancreatic fluid, bicarbonate, and protein secretion. The potency of PACAP27 was equal to that of VIP but was only 1/100 that of secretin; PACAP38 was less active (less than 1/10) than PACAP27. PACAP38 and PACAP27, in contrast to secretin and VIP, stimulated protein secretion; the potency of the former was about 1/10 that of the latter. The peak response to PACAP27 was about 44% of the maximal response to CCK8. Pancreatic protein secretion, but not fluid and bicarbonate secretion, in response to PACAP38 and PACAP27 was significantly (p less than 0.05) reduced by atropine. It is concluded that PACAP has a VIP-like action on pancreatic fluid and bicarbonate secretion in conscious dogs, but differs from VIP in stimulating protein secretion via a cholinergic mechanism.

Amino Acid Sequence↗
PubMed1992

Interdigestive gastric blood flow: the relation to motor and secretory activities in conscious dogs.

Blood flow in the left gastric artery was measured with an electromagnetic flowmeter in nine conscious beagle dogs. In the fasting state gastric motility and secretion exhibited periodical changes with an average cycle interval of 115.4 +/- 9.7 min. During a quiescent period, when gastric motility and secretion were minimal, the mean blood flow was stable at 33.9 +/- 3.8 ml/min. During the contracting phase each peristaltic contraction was coupled with a rapid fall and rise in blood flow (from 10.5 +/- 1.9 ml/min below to 21.2 +/- 3.8 ml/min above the precontraction levels) in 20-30 s. In addition there was a sustained elevation in blood flow (58.6 +/- 6.4 ml/min at the peak) lasting for 29.1 +/- 2.8 min. The onset of sustained blood flow elevation was preceded by that of motility in 63% of the cycles. In 23% of the cycles blood flow started to rise before the contracting phase began. Pepsin peaks coincided with blood flow peaks in two dogs and preceded the latter in the others. Feeding abolished periodic increases in motility and blood flow. It is concluded that left gastric arterial blood flow is not steady but exhibits dynamic changes in phase with periodic motor and secretory activities of the stomach in fasting conscious dogs.

Animals↗
PubMed1992

Varicella zoster virus DNA in throat swabs of vaccinees.

Ninety throat swabs from 30 healthy children who received varicella vaccine were tested for varicella zoster virus DNA by the polymerase chain reaction. Seroconversion was observed in 27 of 30 (90%) vaccinees. The positive rates were 7.4% (2/27) at one week and 0% (0/27) at four weeks after vaccination. These rates were considerably lower than those in normal children with varicella.

Blotting, Southern↗
PubMed1992

Correlation between reduction of polymorphonuclear leucocytes in glomeruli injected with a newly developed monoclonal antineutrophil antibody and proteinuria in Masugi nephritis.

The effects of the reduction of neutrophils in glomeruli on the improvement of proteinuria and glomerular injuries were determined in the first (heterologous) phase of Masugi (nephrotoxic) nephritis. Male (6-week-old) WKA/Hkm rats were initially injected with 2.0 ml of a newly developed monoclonal antineutrophil antibody and then injected with 1.0 ml of nephrotoxins. This monoclonal anti-neutrophil antibody was found to have selectively reduced the number of neutrophils in the glomerular capillary lumen in cases of Masugi nephritis by light microscopy. Malondialdehyde (MDA) levels or superoxide dismutase (SOD) activities in renal tissues of such rats were also examined. However, there were no significant differences in the levels of proteinuria and the number of glomerular cells containing resident cells and infiltrated mononuclear cells in the first phase of Masugi nephritis with or without pretreatment with antineutrophil antibody. No significant differences were observed in the levels of MDA or SOD activities in renal tissues of Masugi nephritis with or without pretreatment with such an antibody either. It appeared that infiltration of neutrophils in the glomeruli might not be related to proteinuria and glomerular injuries in the first phase of Masugi nephritis. It was postulated that the massive proteinuria in the first phase of Masugi nephritis might be correlated with the activities of reactive oxygen species induced by the glomerular cells, i.e. glomerular resident cells and infiltrated mononuclear cells.

Animals↗
PubMed1992

Neutrophil chemotactic factors in the respiratory tract of patients with chronic airway diseases or idiopathic pulmonary fibrosis.

This study was designed to clarify the contributions of specific neutrophil chemotactic factors (NCF) in neutrophil accumulation in the human respiratory tract associated with various diseases. The activity and characteristics of the NCF in the bronchoalveolar lavage (BAL) fluid and culture media of alveolar macrophages obtained from normal volunteers, control patients, patients with chronic airway diseases (CAD) and patients with idiopathic pulmonary fibrosis (IPF) were examined. The BAL fluid from normal volunteers contained NCF comparable with the chemotactic factors interleukin-8 (IL-8) and leukotriene B4 (LTB4). Analysis of the biochemical characteristics of NCF released from alveolar macrophages suggests that they are derived from alveolar macrophages. The NCF activities in BAL fluids from patients with CAD and IPF were higher than those in BAL fluids from normal volunteers and control patients. Biochemical analysis demonstrated that several kinds of NCF, including those derived from the complement component C5 and alveolar macrophages, were present in the BAL fluid from patients with CAD and respiratory infections. The especially marked increase of C5-derived NCF indicate their importance in neutrophil accumulation in the respiratory tract of patients with CAD. Alveolar macrophages released different types of NCF after different lengths of culture periods (4 h and 24 h). Alveolar macrophages from patients with IPF released larger amounts of NCF than alveolar macrophages from normal volunteers, indicating the importance of alveolar-macrophage-derived NCF as well as C5-derived NCF in neutrophil accumulation in the respiratory tract of patients with IPF. These results suggest that various types of NCF increase in response to different disease states of the respiratory tract and serve to regulate the accumulation of neutrophils.

Adult↗
PubMed1992

Clinical study of malignant tumors originating in the pelvic region.

We evaluated the surgical problems encountered during treatment of 14 patients with malignant tumors originating in the pelvic region at our department. The tumor involved the iliac bone in 6 patients, the ischial bone in 2, the pubic bone in 2, and the gluteal region in 4. Invasion to the sacrum was observed in 7 patients. Twelve patients underwent surgical procedures consisting of intralesional resection in 6, marginal resection in 3, and wide margin resection in 3. Six of the 7 patients with sacral invasion developed local recurrence. Two patients with chondrosarcoma and one with parosteal osteosarcoma survived for 4 or more years, but the mean survival period in those with high grade malignant tumors was 11 months. These findings indicate the difficulties encountered in the treatment of malignant pelvic tumors.

Adolescent↗
PubMed1992

Gadolinium-DTPA enhanced magnetic resonance imaging of bone and soft tissue sarcomas in comparison with pathological findings.

We compared gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) enhanced T1-weighted images (T1-Gd) with the histopathological findings in 13 patients with bone or soft tissue sarcomas. Signal intensity of the viable tumor tissue was increased in T1-Gd in 92% of the patients. The necrotic or cystic areas in the tumor were not enhanced, rendering them distinctly. The degree of enhancement of the edematous area around the tumor was similar to or more marked than that of the tumor in 54% of the patients. Area showing inflammatory cells infiltration and edematous areas in the tumor tissue were also enhanced. Thus, the effect of preoperative chemotherapy in tumor tissues other than necrotic and cystic areas tended to be underestimated in T1-Gd. Its effect should be comprehensively evaluated based on not only T1-Gd but also T2-weighted images and findings of other imaging techniques.

Antineoplastic Agents↗
PubMed1992

Peristaltic movement evoked in intestinal tube devoid of mucosa and submucosa.

Computerized analysis of video-recorded peristalsis was made in a preparation of guinea-pig ileum tube from which both mucosa and submucosa were mechanically scraped off. Threshold value for provoking peristalsis was higher, conduction velocity of peristalsis was slower, and peristaltic force was weaker in comparison with the ileum tube from which only mucosa was scraped off and with the normal ileum tube. A histological control of the preparation proved that there was no nerve cell body of submucous plexus on the surface of separated circular muscle. It was concluded that peristalsis, though impaired, could be provoked by way of activation of the reflex arch consisted by neural circuit of myenteric neurons which should be produced by excitation of stretch receptors in the muscularis externa.

Animals↗
PubMed1992

[Increased granulocyte/macrophage colony stimulating factor production by mononuclear cells from patients with bronchial asthma].

The in vitro production of granulocyte/macrophage colony stimulating factor (GM-CSF) by mononuclear cells from the peripheral blood of patients with bronchial asthma (BA) was examined by enzyme-linked immunosorbent assay (ELISA). In 3 of 12 cases studied, mononuclear cells from BA patients produced GM-CSF without stimulation. And in 5 of 12 cases studied, mononuclear cells from BA patients produced GM-CSF in response to IL-2. Mononuclear cells from patients with other diseases (n = 13) and healthy volunteers (n = 6) did not release any detectable (> or = 7.5 pg/ml) GM-CSF. The culture media of mononuclear cells from BA patients showed activities for stimulating the proliferation and survival of eosinophils, and these activities were partially inhibited by anti-GM-CSF antibodies. GM-CSF production by mononuclear cells from BA patients treated with prednisolone was lower than that of mononuclear cells from untreated BA patients. And prednisolone showed a reduction in the GM-CSF production from mononuclear cells in response to IL-2. These results suggest that GM-CSF production by mononuclear cells may play a role in the pathogenesis of BA.

Adult↗
PubMed1992

[Detection of estrogen receptor (ER) mRNA by use of reverse transcriptase-polymerase chain reaction (RT-PCR) assay; comparison with dextran coated charcoal (DCC) assay and immunocytochemical assay].

A new method for estrogen receptor (ER) mRNA was performed on 33 human breast tumors, using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay by the method of Fuqua et al. In a preliminary experiment using the MCF-7 breast tumor cell line, ER/beta-actin ratio was almost same. ER protein was estimated by a dextran coated charcoal (DCC) assay and by an ER-immunocytochemical (ER-ICA) assay using a specific monoclonal antibody. We found RT-PCR assay correlates with ER-ICA assay (r = 0.664, p less than 0.01), whereas no significant correlation was seen between RT-PCR assay and DCC assay. These results suggests that RT-PCR assay is suitable for detection of ER from small amounts of tissue.

Blotting, Southern↗
PubMed1992

[Selection of graft materials in case of emergency coronary bypass surgery following failed angioplasty].

The clinical characteristics of selection of graft materials were analysed for patients undergoing emergency coronary artery bypass surgery (CABG) following failed coronary angioplasty (PTCA). Ten emergency CABGs were performed from January 1983 to December 1991. Perioperative variables and follow-up were compared to 18 patients undergoing elective CABG after PTCA. The emergency group had shorter operative time (p less than 0.01) and shorter bypass time (p less than 0.05). Moreover the emergency group had decreased use of the internal thoracic artery (ITA) (40% vs 94.4%, p less than 0.01). There was no use of bilateral ITAs in the emergency group. There was not significant difference in hospital mortality and medium term follow-up between two groups. In conclusion, emergency CABG carries a significantly less use of ITA graft than elective CABG although ITAs are superior to SVGs about long term patency rate. So it is desirable that arterial graft should be used under an appropriate selection at emergency operation.

Aged↗
PubMed1992

[Induction by local injections of IL-2 of antitumor effector cells and secondary production of cytokines in malignant pleural effusion].

The present study was undertaken to examine the effects of intrapleural administration of IL-2 on induction of cytotoxic killer cells and on secondary production of cytokines in malignant pleural effusions. During daily local administration of IL-2, significant in vivo induction of cytotoxic activity was observed after 3-7 days, followed by a decrease in this activity in pleural mononuclear cells (MNC) to almost zero by day 15. IL-4 suppressed induction of IL-2-inducible killer cells from MNC in blood and pleural effusion, but significantly augmented the killer induction from pleural effusion MNC obtained after local 7-day administration of IL-2. Before therapy, malignant pleural effusions contained various levels of IL-6 and M-CSF, but no IL-4 or IFN-gamma. Daily intrapleural instillation of IL-2 resulted in significant augmentation of the levels of IL-4, IL-6, IFN-gamma and M-CSF. Chromatographical fractionation of the pleural effusion showed only one major peak with a MW of 24 kD, which had IL-6 activity. The level of the latent form of TGF-beta also increased during local IL-2 therapy. In contrast, significant levels of TNF (alpha, beta), IL-1 beta or IFN-alpha were not detectable in pleural effusions before or during therapy. These data suggest that IL-2 is an important inducer of secondary production of various cytokines in vivo, responsible for up- or down-regulation of induction of IL-2-inducible killer activity.

Cytokines↗
PubMed1992

The adverse effects of l-methamphetamine on the development of explanted rat embryos.

The adverse effects of l-methamphetamine on the development of rat embryos were studied by means of a whole culture system. The embryos explanted at 12.5th days of gestational age were cultured for a total of 24 hours. After pre-culturing for 6 hours, 4 groups of embryos received additional culturing for 18 hours with saline or various concentrations of l-methamphetamine; 0.5, 2.0 and 5.0 mumol/dl. There was no significant difference in the survival rate among 4 groups. The groups over 2.0 mumol/dl of l-methamphetamine showed significant reduction of crown-rump length, somite number, protein content, DNA content, and protein/DNA ratio. It is suggested that over 2.0 mumol/dl of l-methamphetamine reduces the development but not the survival of rat embryos under whole culture system.

Animals↗
PubMed1992

[Surgical repair of discrete subaortic stenosis complicated with prosthetic valve endocarditis--a case report].

A 46-year-old man was referred to our hospital because of prosthetic valve regurgitation. Eight years previously he had undergone aortic valve replacement because of aortic regurgitation due to infective endocarditis. At reoperation, we found prosthetic valve endocarditis and discrete subaortic stenosis. The obstructing fibrous tissue was resected and the aortic valve was replaced. Because discrete subaortic stenosis is usually located just below the aortic valve, the aortic valve cusps are liable to become thickened by the jet through the discrete stenosis and thus are vulnerable to infective endocarditis. It is pointed out that care must be taken not to overlook discrete subaortic stenosis in the presence of other associated cardiac disorders.

Aortic Valve↗
PubMed1992

Two-color analysis of lymphocyte subpopulations in patients with nephrotic syndrome due to membranous nephropathy.

Two-color flow cytometry was carried out to determine the correlation between cell-mediated immunity and the levels of proteinuria in 30 patients with membranous nephropathy. Lymphocyte subpopulations were measured by two-color flow cytometry using various monoclonal antibodies of the Leu series. Clinically, the patients were divided into four stages as follows: 1. untreated nephrotic stage, 2. prednisolone (PSL) treated nephrotic stage, 3. persistent proteinuric stage (incomplete remission, ICR) and 4. complete remission (CR). Two-color flow cytometry showed a significant decrease in Leu 2a+15+ (suppressor T) cells and relative increase in Leu 3a+8+ (suppressor inducer T) cells in the untreated nephrotic stage. The mean Leu 3a+8-/Leu 2a+15+ (helper/suppressor) cell ratio was normalized in the persistent proteinuric stage or complete remission after treatment with PSL. Patients with membranous nephropathy showed a significant elevation of Leu 2a+DR+ cells after treatment with PSL. The abnormalities of suppressor T cells and suppressor inducer T cells in the peripheral blood appear to reflect the levels of proteinuria in patients with membranous nephropathy. It was concluded that PSL might stimulate Leu 2a positive cells and then increase the number of Leu 2a+15+ cells in the peripheral blood of patients with membranous nephropathy.

Adult↗
PubMed1979

Effects of stimulation of Auerbach's plexus on both longitudinal and circular muscles.

The effects of repetitive electrical stimulation of a node of Auerbach's plexus on both longitudinal and circular muscles were investigated by simultaneous recording of both muscle contractions. L-formed muscle strips, longitudinal and circular muscle strips, were made from a segment of rabbit small intestine. One strip was cut along, another strip was cut at 90 degrees to the oral-anal axis. The longitudinal muscle strip was peeled and Auerbach's plexus was exposed. Under a stereodissecting microscope the stimulating electrode, with tip diameter of 5--10 micron, was placed on a node of Auerbach's plexus situated at the junction of both muscle strips. Repetitive electrical stimulation of a node produced a mainly excitatory effect on spontaneous contractions of an orally-directed longitudinal muscle strip, excitatory and inhibitory effects on an anally-directed longitudinal muscle strip and a mostly excitatory effect on a circular muscle strip which always appeared with a delay after that on the longitudinal muscle. In a few instances the inhibitory effect of nodal stimulation was observed on the circular muscle. The evoked excitatory effect of longitudinal muscle was mainly due to a cholinergic mechanism, while that of circular muscle was partially due to cholinergic and partially noncholinergic activity. The evoked inhibition was nonadrenergic.

Acetylcholine↗