Search PubMed⌕ Search

Biomedical subjects

T Imai

Publications and source records attributed to T Imai.

At least 739 records · Page 41Linked to original sources
PubMed1991

[The effect of AH 21-132 on airway hyperresponsiveness induced by ozone exposure].

We examined the effect of AH 21-132, which has been reported to relax airway smooth muscle and inhibit platelet activating factor (PAF)-induced airway hyperreactivity, on ozone-induced airway hyperresponsiveness (AHR) with airway inflammation in dogs. Airway responsiveness (AR) to methacholine was measured by modified Astograph (7 Hz oscillation method) before and after ozone exposure, and the numbers of neutrophils in the peripheral blood and total cell counts, differential cell counts and TXB2 in BALF were measured before and after ozone exposure. Ozone exposure was carried out for 2 hr at an ozone level of 3.46 +/- 0.10 ppm (mean +/- SE). There was a significant increase in AR to methacholine after ozone exposure (p less than 0.01), and the numbers of neutrophils in the peripheral blood and the total cell and neutrophil counts in BALF increased significantly (p less than 0.05). Pretreatment with AH 21-132 at an oral dose of 20 mg/kg significantly prevented the ozone-induced AHR to methacholine (p less than 0.01), and also inhibited the increase of neutrophil counts in the peripheral blood, and the total cell counts and the neutrophil counts in BALF after ozone exposure. There was no significant change in the levels of TXB2 in BALF before and after ozone exposure. In dogs not exposed to ozone, AR to methacholine and respiratory resistance to methacholine significantly decreased after administration of AH 21-132 at an oral dose of 20 mg/kg (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1991

[Morphological observation of the mitral annulus fibrosus (II)].

In 1986, Hutchins observed a high incidence of the disjunction of the mitral annulus fibrosus in mitral valve prolapse syndrome. However, we could not prove his view in our previous study using one section in each case. In this study, the types of mitral annulus fibrosus were analyzed in plural sections. Autopsy hearts of nine aged cases were used for examination of the mitral annulus fibrosus in five to eight longitudinal sections from the posterolateral wall. The types of the mitral annulus fibrosus were classified as; Type A (the mitral valve attaches to the left ventricle), Type B (the valve attaches to the left atrium), Type C (the atrialis layer of the valve continues to the left atrium, while the fibrosa layer continues to the left ventricle), and type D (mitral annulus calcification). A1-3 and B1-3 are subtypes. In the nine cases there were no consistent patterns in type distributions. All sections showed Type A1 (Case 2), Type A1 to A3 (Case 5), and Type B1 to B3 (Case 8). In other cases, a combination of Type A and B (Case 4, 6, 7, 9), and inclusion of Type C (Case 1) and Type D (Case 3) were found. The location of the middle scallop of the posterior mitral leaflet corresponded to the section of the previous study. Among three cases of Type A in the middle scallop, two showed Type A in every section. Among five cases of Type B in the middle scallop, only one case showed Type B in every section. Other four cases showed various combinations with the other types. A case of Type D in the middle scallop showed also Type B and Type C. The conclusion of this study was that in 1/3 of the cases, the type of the mitral annulus fibrosus was consistent, but in the other 2/3 they were not consistent. In other words, one section is not necessarily representative of the morphology of the mitral annulus fibrosus in each case.

Aged↗
PubMed1991

[Inhibitory effect of prostaglandin I2 on the increase of airway responsiveness induced by inhaled thromboxane A2 mimetic U-46619 in dogs].

To investigate the effect of prostaglandin I2 (PGI2) on the increase of airway responsiveness induced by inhaled thromboxane A2 (TxA2), we measured the airway responsiveness to inhaled methacholine (Mch) after inhalation of TxA2 mimetic U-46619 alone and after inhalation of U-46619 in combination with PGI2 (U-46619/PGI2) in six dogs. Airway responsiveness to Mch was determined by Astograph (7Hz oscillation method). Inhalation of U-46619 was carried out for five minutes at a half of minimum threshold concentration, and the concentration of PGI2 was double that of U-46619. Inhaled U-46619 significantly increased airway responsiveness to Mch (p less than 0.01). However the airway responsiveness to Mch did not increase following inhalation of U-46619/PGI2, and the increase of airway responsiveness to Mch induced by inhaled U-46619 was inhibited significantly by PGI2 (p less than 0.01). PGI2 inhalation alone did not affect the basal airway responsiveness to Mch. These results indicate that PGI2 protects the hyperresponsiveness induced by TxA2 inhalation in dogs.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1991

[A case of type I hyperprolinemia associated with photogenic epilepsy].

A 9-year-old girl with type I hyperprolinemia, who also had photogenic epilepsy, was reported. She showed epileptic discharges and the regression in speech and motor activities, since 7 years of age. Her plasma proline levels were 3 to 4 times higher than control levels. In urine, iminoglycinuria appeared, when plasma proline value exceeded 0.80 mM. The proline oxidase activity of the liver tissues obtained by biopsy in the patient was about 23.5%, compared to that of controls. In spite of the restriction of proline and protein intake, she showed progressive speech and motor retardation.

Amino Acid Metabolism, Inborn Errors↗
PubMed1991

[The role of thromboxane A2 in the development of airway responsiveness after platelet activating factor inhalation in dogs].

To determine whether thromboxane A2 (TxA2) is involved in airway hyperresponsiveness after platelet activating factor (PAF) inhalation, we studied the effect of a specific TxA2 receptor antagonist, AA-2414 on the development of airway responsiveness induced by PAF inhalation in six dogs. Airway resistance and airway responsiveness to inhaled methacholine were determined by modified Astograph (7 Hz oscillation method). PAF inhalation (1000 micrograms/ml, ten minutes) caused a significant increase of airway resistance (p less than 0.01), and the increase of airway resistance was not inhibited by pretreated AA-2414. Airway responsiveness to inhaled methacholine increased significantly 3 hr after PAF inhalation (p less than 0.01). Pretreated AA-2414 inhibited the increase of airway responsiveness significantly (p less than 0.01), but the inhibition was partial. After PAF inhalation, total cell counts, neutrophil counts, eosinophil counts and the levels of TxB2 in bronchoalveolar lavage fluid increased significantly (p less than 0.05), and these increase were not affected by pretreated AA-2414. These results suggest that TxA2 is not involved in the bronchoconstriction induced by PAF inhalation, but TxA2 plays a partial role in the development of airway responsiveness after PAF inhalation in dogs.

Administration, Inhalation↗
PubMed1991

[Castleman's disease associated rheumatoid arthritis recurring 20 years after removal].

A 40-year-old female associated with Rheumatoid Arthritis was treated by extirpation of the mediastinal tumor. Histological examination of the tumor revealed Castleman's disease of Hyaline-Vascular type and histology of the dissected mediastinal lymphnodes was the same appearance as tumor. The present case is unusual in that the tumor recurred in the same site 20 years after removal. The complete removal of tumor with dissection of lymphnodes surrounding tumor is important for the treatment of surgery. The present case is the 1st to be reported in Japan.

Adult↗
PubMed1990

Comparison of the promoter regions of H-2Kb and H-2Kbm1 class I MHC genes.

The 2.0 kb-long nucleotide sequences of the promoter regions of two closely related class I genes of the mouse major histocompatibility complex (H-2Kb and H-2Kbm1) have been determined and compared. The promoter sequence of the H-2Kbm1 gene differs from that of the H-2Kb gene by a single deletion of a 'C' at position -456 in the upstream region of H-2Kbm1 gene. The actual existence of this deletion of a single base in genomic DNA has been verified by genomic DNA hybridization, using oligonucleotide probes specific for H-2Kbm1 or H-2Kb respectively. The effect on the enhancer activity of H-2Kbm1 promoter region of the difference at position -456 has been analyzed by the chloramphenicol acetyltransferase (CAT) assay, using appropriate DdeI fragments (-533 to -408 for H-2Kbm1; -534 to -408 for H-2Kb) cloned downstream of pH-2(367)CAT gene construct. The CAT activity determined by the H-2Kbm1 fragment was about 3-fold higher than that of H-2Kb, a result which probably accounts for the higher level of the H-2Kbm1 transcript and antigen in lymph node cells.

Animals↗
PubMed1990

Production of endothelin-1 by rat cultured mesangial cells.

We investigated whether ET-1 is synthesized by and released from mesangial cells. ET-1-like immunoreactivity (LI) released into medium increased time-dependently under a serum-free condition. The amounts of ET-1-LI released into the medium was augmented in the presence of fetal calf serum. Reverse-phase HPLC profile of the conditioned media revealed a major component coeluting with standard ET-1. Northern blot analysis of poly(A) +RNA extracted from mesangial cells showed a single major band corresponding to the size of preproET-1 mRNA (2.3 kb). These findings demonstrate that ET-1 is synthesized by and released from rat mesangial cells and suggest a possibility that it acts on their own cells as an autocrine factor.

Animals↗
PubMed1990

Cytokine-induced release of endothelin-1 from porcine renal epithelial cell line.

To elucidate the mechanism by which endothelin-1 (ET-1) is released from renal epithelial cells, we have investigated the effects of several compounds on release of ET-1-like immunoreactivity (LI) from LLCPK1 cell line. Thrombin, transforming growth factor-beta, cytokines (tumor necrotizing factor-alpha, interleukin-1 beta), and phorbol ester stimulated ET-1-LI release in a time- and dose-dependent manner. The cytokine-induced ET-1-LI release was not affected by indomethacin. Northern blot analysis using cDNA for porcine preproET-1 as a probe revealed a single major band corresponding to the size of ET-1 mRNA in LLCPK1. These data indicate that the preproET-1 gene is also expressed in renal epithelial cells and the release of ET-1 from renal cells is regulated by the similar mechanism to that from endothelial cells.

Animals↗
PubMed1990

[A clinicopathological analysis of renal cell carcinoma in solitary kidney].

Seven patients with renal cell carcinoma, who had undergone uninephrectomy or who had only one functioning kidney were clinicopathologically studied. They were 5 males and 2 females, with ages ranging from 51 to 74 years (mean: 61 years). Of these cases, 4 had undergone uninephrectomy for renal cell carcinoma, and 1 had received uninephrectomy because of renal calculus. In the remaining 2 cases, one kidney did not function (hypoplastic kidney). Renal cell carcinoma was discovered by macroscopic hematuria in 2 cases, during the follow-up observation after a previous surgical treatment of renal cell carcinoma in 4 cases and by abdominal computed tomography during treatment of abdominal aneurysm in 1 case. Excluding one case with multiple metastases, all cases were surgically treated (3 with partial nephrectomy and 3 with enucleation). During surgery, renal blood vessels were clamped for 24-60 minutes (mean: 38 minutes). After operation, 5 cases showed an elevation in serum creatinine (greater than or equal to 2.0 mg/ml), which, however, was normalized rapidly by conservative treatment. They have been followed up for 6 months to 7 years and 8 months after operation (mean: 2 years and 11 months). The case which had undergone before and recently received enucleation (2 pieces) showed metastasis of cancer to the pancreas 2.5 years after the recent operation. Therefore, this case additionally received partial pancreatectomy. The results of this study suggest that conservative surgical treatments are appropriate for the treatment of renal cell carcinoma in patients with solitary kidney from viewpoint of the quality of life, so long as postoperative management is sufficiently made.

Aged↗
PubMed1990

Mast cell heterogeneity: two-dimensional gel electrophoretic analyses of rat peritoneal and intestinal mucosal mast cells.

Peritoneal mast cells (PMC) and intestinal mucosal mast cells (IMMC) were purified from rats infected with the nematode Nippostrongylus brasiliensis. Overall protein constituents of both mast cell subtypes were analyzed by two-dimensional gel electrophoresis using either nonequilibrium pH gradient electrophoresis (NEPHGE) or isoelectric focusing (IEF) in the first dimension and SDS-PAGE (10%) in the second dimension followed by silver staining. PMC had seven dominant basic proteins (PB2-8; pI 9-9.5) with estimated molecular masses of 26 to 37 kDa, as well as 80 to 90 neutral or acidic proteins, most of which had pI 6 to 7.5 and estimated molecular masses of 20 to 100 kDa. All the basic proteins were granule-associated. Three basic proteins, PB6 (29 kDa), PB7 (28 kDa) and PB8 (RMCP I, 26 kDa), bound [3H]diisopropyl fluorophosphate (DFP), suggesting that they are serine proteases. However, only PB8 was reactive with antibodies to RMCP I. Another basic component (less than 14 kDa), perhaps a degradation product of PB6, PB7 or PB8, also bound [3H]DFP. By comparison, IMMC possessed nine basic proteins (IB1-9) and, in general, they were more acidic (pI about 8.5-9) than those of PMC. Four major basic proteins (IB6-9) were all 24 kDa but were slightly different in isoelectric points. These and another 46-kDa basic component (IB2) were reactive with antibodies to RMCP II and bound [3H]DFP. There were no other DFP-binding proteins in IMMC. In spite of remarkable differences between basic granule-associated proteins in PMC and basic proteins in IMMC, spots in the neutral-acidic range were for the most part similar in the two mast cell subsets, although quantitative differences were evident for some spots. Thus, rat mast cell populations from the peritoneal cavity and intestinal mucosa exhibit marked heterogeneity in their protein constituents with basic pI, including in their granule-associated proteins with serine protease activity.

Animals↗
PubMed1990

An adult-onset case of sporadic motor neuron disease with basophilic inclusions.

A 36-year-old man developed motor neuron signs consisting of weakness and atrophy of the right upper limb, which progressed to involve the other limbs along with development of upper motor neuron signs including pseudobulbar palsy. He died 8.5 years after onset. Bilateral precentral gyri and putamina were grossly atrophic. In addition to severe degeneration of bilateral pyramidal tracts and marked neuronal cell loss of the precentral gyri and putamina, basophilic inclusions were widely distributed in the motor cortex, putamina, general somatic motor neurons such as the hypoglossal nucleus and spinal anterior horns, and other areas like the red nucleus and inferior olive. The inclusions were clearly shown with Nissl stain to be anilinophilic irregular masses with distinct rims. Ultrastructurally the inclusions appeared to consist of thick filamentous structures of 12-25 nm in diameter studded with electron-dense ribosome-like granules. Thick filamentous profiles were relatively short or occasionally fragmentary, haphazardly mingled with various amounts of granules and other organelles. No prominent accumulation of 10-nm neurofilaments or eosinophilic inclusions like Bunina bodies were found. The inclusions were indistinguishable from those reported in so-called "juvenile" amyotrophic lateral sclerosis.

Adult↗
PubMed1990

Clinicopathological studies and operative results of hepatocellular carcinoma with liver cirrhosis, comparing HB-associated cirrhosis to alcoholic and post-transfusion cirrhosis.

The present study was undertaken to elucidate clinicopathological findings and operative results of HCC with HB-associated cirrhosis, compared with those in HCC patients with alcoholic and post-transfusion cirrhosis. The number of the HBV group was 26 cases, consisting of 17 in sAg(+), 4 in eAg(+) and 5 in eAb(+) subgroups. The number of the post-transfusion group was 7 and that of alcoholic group was 12. A high incidence of hypersplenism and esophageal varix in the eAg(+) subgroup was found. ICG R15 was the highest, KICG and ICG Rmax were the lowest in the eAg(+) subgroup. The mean diameter of tumors was the largest, 6.6 +/- 3.9 cm, in the sAg(+) subgroup and was the smallest, 2.2 +/- 1.7 cm, in the eAg(+) subgroup. The incidence of postoperative jaundice, hyperammoninemia and live dysfunction were the highest in the sAg(+) and eAg(+) subgroup. One and three-year survival rate were 76.9% and 48.1% in the sAg(+) subgroup, 60.0% and 30.0% in the eAb(+) subgroup, and the one-year survival rate in the eAg(+) subgroup was 50.0%. The three-year survival rate could not be calculated because 3 years had not passed since the operation. The prognosis was the poorest in the HBV group among all groups. This study suggests that in HBV-associated cirrhosis, hepatectomy might induce "acute on chronic" changes (acute hepatitis and fulminant hepatitis). Therefore we should select operative procedures by considering surgical risk and the etiology of liver cirrhosis in hepatectomy.

Adult↗
PubMed1990

Second-generation approach to the construction of yeast artificial-chromosome libraries.

We describe an improved method for construction of yeast artificial-chromosome (YAC) libraries that contain large inserts of foreign DNA. The procedure consists of seven steps: (i) preparation of human DNA in agarose beads; (ii) partial digestion of the DNA with EcoRI; (iii) electrophoretic elimination of the smaller partial-digest fragments; (iv) ligation of the EcoRI fragments with vector arms in molten agarose; (v) hydrolysis of agarose with agarase; (vi) fractionation of the recombinant molecules by sucrose-gradient centrifugation; and (vii) transformation of yeast. More than 7000 colonies were obtained starting with 15 micrograms of human DNA, which was fractionated on a single sucrose gradient. The average size of these YACs was approximately 380 kb. It is estimated that the total length of human DNA present in the clones corresponds to 80% of the length of the human haploid genome. The results of screening the clones for a number of single-copy genes indicate that the clones reflect a nearly random sampling of the human genome. The efficiency of the cloning is sufficient to support the construction of multihit libraries for the human genome or for the genomes of other higher organisms.

Base Sequence↗
PubMed1990

Effects of mianserin on negative symptoms in schizophrenia.

The efficacy of mianserin as a supplement in treating chronic schizophrenia was tested in 20 inpatients with schizophrenia who were receiving fixed doses of neuroleptics. Mianserin was given for six weeks with a starting dose of 60 mg/day. A brief psychiatric rating scale (BPRS) was completed before starting mianserin and thereafter BPRS scoring was carried out once weekly. The total BPRS score and the score for negative symptoms were decreased by mianserin treatment as compared to the pre-treatment values. Plasma 5-HIAA concentrations were increased after medication in both responding patients and nonresponding patients. However, the 5-HIAA values of responders were lower than those of nonresponders. Plasma HVA levels were slightly increased by mianserin in the responders. There were no significant changes in MHPG levels. These results suggest that the negative symptoms of schizophrenia may be improved by mianserin treatment.

Adult↗