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T Imai

Publications and source records attributed to T Imai.

At least 379 records · Page 21Linked to original sources
PubMed1997

Retroperitoneal laparoscopic adrenalectomy for functioning adrenal tumors: comparison with conventional transperitoneal laparoscopic adrenalectomy.

PURPOSE: We attempted to confirm the possibility and feasibility of laparoscopic adrenalectomy via the retroperitoneal approach, and to compare results of the transperitoneal and retroperitoneal approaches. MATERIALS AND METHODS: Three men and 8 women (mean age 39.6 years) with functioning adrenocortical tumors (primary aldosteronism in 5 and Cushing's syndrome in 6) underwent laparoscopic adrenalectomy via the retroperitoneal approach using a balloon dissection technique and a newly developed ultrasonic aspirator. Results were compared to those of 27 cases of transperitoneal laparoscopic adrenalectomy. RESULTS: Although the retroperitoneal approach was successful in all 5 patients with primary aldosteronism, it succeeded in only 2 of the 6 cases of Cushing's syndrome. In 3 Cushing's syndrome cases the retroperitoneal approach was changed to the transperitoneal laparoscopic approach due to difficulty in exploration. Open laparotomy was required in 1 case of left Cushing's syndrome because of an inadvertent pancreatic injury. Subcutaneous emphysema developed in 6 patients without hypercapnia or prolonged postoperative symptoms. Mean operative time and blood loss, and time to oral intake and ambulation were 248.3 minutes, 151.4 ml., and 1.55 and 2 days, respectively. There was no difference between retroperitoneal and conventional transperitoneal laparoscopic adrenalectomy in regard to these factors or to convalescence. CONCLUSIONS: Retroperitoneal laparoscopic adrenalectomy is feasible for primary aldosteronism. However, Cushing's syndrome is presently a much more difficult indication than primary aldosteronism for this new operative technique.

Adrenal Cortex Neoplasms↗
PubMed1997

[Hereditary progressive dystonia with marked diurnal fluctuation--clinical features and GTP cyclohydrolase I gene mutations].

Hereditary progressive dystonia with marked diurnal fluctuation (HPD) is a disorder characterized by childhood-onset dystonia and a dramatic and sustained response to low doses of levodopa. Recently the GTP cyclohydrolase I(GCH-I) gene was isolated as the first causative gene for HPD. We analyzed the GCH-I gene in 8 clinically diagnosed HPD patients and found different point mutations in GCH-I gene in 3 subjects. The clinical features of these patients considerably resembled each other. Our results imply that although clinically diagnosed HPD subjects could present diverse symptoms, patients with a mutant GCH-I gene might share homogeneous clinical manifestations.

Adolescent↗
PubMed1997

[Effects of theophylline and doxofylline on airway responsiveness in beagles].

We examined the effects of doxofylline, which is a new methylxanthine analog, on heart rate, respiratory rate, respiratory resistance and airway responsiveness in five beagles, and compared with those effects of theophylline. Airway responsiveness to inhaled methacholine was determined by modified Astograph (7Hz oscillation method). Theophylline (10 mg/kg, 20 mg/kg, 40 mg/kg) was orally administered one hour prior to the determination of airway responsiveness and doxofylline (20 mg/kg, 40 mg/kg, 80 mg/kg) was orally administered thirty minutes prior to determination of airway responsiveness at intervals of about one week. Heart rate increased significantly by all dose of theophylline in a dose-dependent manner and by 80 mg/kg of doxofylline. Respiratory rate increased significantly only by 40 mg/ kg of theophylline. Respiratory resistance decreased significantly after administration of 40 mg/kg of theophylline. Airway responsiveness decreased significantly by 40 mg/kg of theophylline and 40 mg/kg, 80 mg/kg of doxofylline in a dose-dependent manner. These results suggest that doxofylline decreased airway responsiveness at the dosage which dose not affect the heart rate and respiratory rate compared with theophylline.

Airway Resistance↗
PubMed1997

[Effects of long-term ethanol administration (1). Effects of long-term ethanol administration on kidney studied at several periods of time during the administration].

The kidney is an important organ having not only excreting function but also other functions such as production of the substances that activates a living body, enzymatic reaction, immunization etc. For several years we have carried out experiments of ethanol administration to rats and involved observations of various organs including the kidney. Thus we have recognized no small effect of ethanol on the kidney. After ethanol administration, the ethanol and its metabolites go through kidneys and are excreted into urine, and their content of the urine is higher than that of the blood. Their content of the kidney is higher than that of the liver. In view of all these facts, the ethanol effect on kidney is easily assumed. In this study a comparison between effect of ethanol on kidney and that of the liver was made at several periods of time during the administration. Under short, a week ethanol administration, the direct action that exerts on cells is as follows: in the kidney swelling of glomerula and tubules, proliferation of mesangial cells, and hyaline drop in tubular epithelial cells are seen; in the liver storing of small fat drops and enlargement of Kupffer cells are observed. Under long, two month administration, products like ethanol metabolites-protein adducts and hyaline in tubular epithelial cells as their removal reaction are observed in the kidney; in the liver, enlargement of Kupffer cells in shown. Under long administration of six and eleven months, kidney shows atrophy of tubular epithelial cells, urinary casts, and cell infiltration to interstitial tissue; liver shows fat storing and bile duct proliferation. These changes found through the effects of age appear in the experimented rats earlier than the control. In addition thickening of basement membrane of glomerulus, PAS positive deposits in glomerulus, and proliferation of mesangial cell are observed in the kidney. It was apparently observed that effects of ethanol on the kidney appeared earlier than those on the liver.

Administration, Oral↗
PubMed1997

[Effect of long-term ethanol administration (2). Free type and bound type ethanol and related substances contents of the urine from ethanol administrated rats, indices in the serum, and renal tissues].

Histological effects of ethanol on the kidney were published in our previous report. In the present paper, results of the following measurement will be reported: contents of ethanol and related substances in the urine, both free and bound types, collected during the periods from 30 minutes to 11 hours after ethanol administration to rats, and ACE, alpha-GST, LPO, 25(OH)-D3, 1 alpha-25(OH)2-D3, 24, 25(OH)2-D3 in the serum of rats which had ethanol every day for a month. These will be reported together with histological observation of the kidney excised immediately after the blood sample was collected. The measurement of free and bound types ethanol, acetaldehyde, acetone and methanol in the urine was made up to 11 hours after administration of 4 g/kg b.w./day, p.o. and its results showed the highest contents at 9 hours after the administration. Bound type acetic acid showed the high contents at both 90 minutes and 9 hours after the administration. In 11 hours free type ethanol and acetaldehyde recovered their pre-administration value but as to the bound type only acetic acid recovered it. In the serum of the rats which were ethanol 4 g/kg b.w./day, oral administrated for a mouth, ACE showed significantly high value and 1 alpha, 25(OH)2-D3 and 24, 25(OH)2-D3 showed significantly low value relative to the control. Also alpha-GST showed a low value. In the kidney of the same rats the following changes were observed: swelling of glomerulus, thickening of basement membrane of glomerulus, PAS positive deposits in glomerulus, proliferation of mesangial cell, proliferation of juxtaglomenular cell, dilation of tubular lumen, swelling of tubular epithelial cell, its falling, hyaline droplet in tubular epithelial cell, cell infiltration to interstitial tissue, and basophilic tubule. There was not only difference between findings in the control and those in the liver and the brain of the rats which showed changes above-mentioned. As described above, changes were seen in the renal tissue caused by ethanol administration and in this connection changes in indices related to renal function were observed, too. Furthermore, urinary ethanol and related substances, not only free type but also bound type, that went through the kidney were observed for a long period time. The bound type, in particular, was observed for longer duration and hence effects of ethanol on the kidney were surely assumed. Presently longer term experiments are proceeding and other indices connected with renal functions are being studied.

Administration, Oral↗
PubMed1997

[Excision of a chronic expanding hematoma developing after thoracoplasty: a case report].

The patient was a 56-year-old woman who had undergone thoracoplasty for right pulmonary tuberculosis 31 years previously. She consulted her local physician complaining of right shoulder pain. Chest X-rays revealed a mass of the thoracic wall, and the patient was referred to our department. Because of the difficulty in making a diagnosis by needle biopsy and of increased pain, operation was done. The mass was covered by a fibrous capsule, and its center was composed of structure-less material including fibrin and blood cells. A diagnosis of chronic expanding hematoma developing after thoracoplasty was made. Beneath the hematoma, a 5 mm diameter hole communicated with the thoracic cavity. Chronic inflammation at this site appeared to have caused the hematoma.

Chronic Disease↗
PubMed1997

Effects of vesnarinone on the bone marrow stromal cell-dependent proliferation and differentiation of HL60 cells in vitro.

It has been reported that vesnarinone, a new inotropic agent used in the treatment of cardiac failure, causes agranulocytosis as a side effect. To study the mechanisms by which this complication occurs, vesnarinone was introduced into a coculture system of HL60 and bone marrow (BM) stromal cells, in which HL60 cells were able to differentiate into mature granulocytes with no inducible exogenous factors added to the culture. When HL60 cells were cocultured with the human BM-derived stromal cell line LP101, HL60 cells were induced to differentiate into mature granulocytes, and expression of the mature granulocyte-macrophage surface antigen, CD11b was increased. Conditioned medium (CM) obtained from LP101 cells also showed the capacity to induce the maturation of HL60 cells, in a dose- and time-dependent manner. The differentiation of HL60 cells induced by CM was also determined by morphological analysis, expression of myeloperoxidase, and a nitroblue tetrazolium (NBT) reduction test. When HL60 cells were cocultured with LP101 in the presence of vesnarinone, the CD11b expression was greatly suppressed. CM obtained from vesnarinone-treated LP101 (ves-CM) lost the capacity to induce the differentiation of HL60 cells, at a concentration of 1 microg/mL of vesnarinone. Vesnarinone itself did not affect the proliferation of HL60 cells. Furthermore, the addition of vesnarinone or ves-CM to HL60 cultures incubated with CM did not alter the induction of CD11b expression, suggesting that vesnarinone has no effect on HL60 cells, but that it inhibits stromal cells from producing soluble factor(s) required for the differentiation of HL60 cells to mature granulocytes. All these findings indicate that vesnarinone causes the hematopoietic disorder agranulocytosis, via impairment of stromal function.

Bone Marrow↗
PubMed1997

[Effects of SDZ ISQ 844, a cyclic nucleotide phosphodiesterase isozyme type III/IV inhibitor, on the release of histamine from human peripheral leukocytes].

We studied the effects of SDZ ISQ 844, a cyclic nucleotide phosphodiesterase (PDE) isozyme type III/IV inhibitor, and salbutamol on the release of histamine from activated human peripheral leukocytes. We stimulated the leukocyte suspensions with calcium ionophore A23187 (Ca-I, 10(-6 M) accompanied with SDZ ISQ 844 (10(-7) M, 10(-6) M, 10(-5) M), salbutamol (10(-7) M, 10(-6) M, 10(-5) M) and combination of SDZ ISQ 844 and salbutamol (10(-7) M, 10(-6) M, 10(-5) M), and measured the levels of histamine in the supernatant fluid and total cyclic AMP levels in the leukocyte suspensions. The increase of histamine levels induced by Ca-I was significantly inhibited by SDZ ISQ 844 (10(-6) M, 10(-5) M) in a dose-dependent manner (p < 0.05, p < 0.01). Salbutamol at the concentration until 10(-5) M did not inhibit the increase of histamine levels. Combination of SDZ ISQ 844 and salbutamol significantly inhibited the increase of histamine levels (10(-6) M, 10(-5) M) in a dose-dependent manner (p < 0.05, p < 0.01). The inhibition of the histamine release by SDZ ISQ 844 (10(-5) M was enhanced significantly by salbutamol (10(-5) M) (p < 0.05). Total cyclic AMP levels in the leukocytes suspensions increased significantly by SDZ ISQ 844 (10(-5) M) and combination of SDZ ISQ 844 and salbutamol (10(-6) M, 10(-5) M) in a dose-dependent manner (p < 0.05, p < 0.01). The increase of cyclic AMP levels by SDZ ISQ 844 (10(-5) M) was enhanced by salbutamol significantly (p < 0.01). These results suggest that selective inhibition of PDE isozyme type III/IV protects the release of histamine from human activated leukocytes in connection with intracellular cyclic AMP levels and the protection is enhanced by beta-agonist.

Adrenergic beta-Agonists↗
PubMed1997

[Chemotactic activity of human peripheral eosinophils toward leukotriene E4].

We studied the chemotactic activity of isolated human peripheral eosinophils toward leukotriene (LT) E4. We obtained eosinophil suspensions by the method of CD16 negative selection. Eosinophil chemotactic activities toward platelet activating factor (PAF, 10(-6) M) and LTE4 (10(-7) M, 10(-6) M, 10(-5) M) were studied using a modified Boyden Chamber method. Eosinophils migrated significantly toward PAF and LTE4 (10(-7) M, 10(-6) M). The chemotactic activity toward LTE, was most potential at 10(-6) M. These results suggest that LTE4 is an eosinophil chemoattractant.

Chemotaxis, Leukocyte↗
PubMed1997

Circadian rhythm estimation by core body temperature filtered with simultaneously recorded physiological data.

In field measurements, monitoring of core body temperature is influenced by physical activities; therefore, the estimation of circadian rhythm from the data may not be exact. The purpose of this study is to design a core body temperature filter in order to reduce artifacts induced by physical activities using simultaneously recorded physiological data such as heart rate data. The effects of physical activities on core body temperature and heart rate are assessed through three experiments. Based on the above knowledge, a core body temperature filter was designed. The filter removes part of rectal temperature data as artifact when heart rate rises above a predetermined threshold. As a result, most of the spike-like noise was removed and the filtered temperature data showed sinusoidal variation more than the unfiltered data. The mesor of the estimated rhythm significantly decreased. This filtering method can provide more precise information about circadian rhythm, especially in field measurements.

Adult↗
PubMed1997

[Relationship between the morphological changes of Japanese cedar (Cryptomeria japonica) pollen grains and the release of major allergens from the pollen].

Release of major allergens (Cry j 1, Cry j 2) from Japanese cedar (C. japonica) pollen grains treated with high pressure was investigated. C. japonica pollen grains crushed by high pressure treatment using FRENCH Pressure Cell Press released greater amounts of major allergens, particularly Cry j 2, compared to those without crush. This suggests that the cytoplasm of C. japonica pollen grains contains more Cry j 2 than previously reported. The effect of nasal fluid on the release of major allergens from C. japonica pollen grains was analyzed in vitro. Nasal fluid from patients with nasal allergy remarkably increased the release of major allergens from pollen grains, compared to controls, and the amount of Cry j 1 was greater than Cry j 2. Further studies revealed that nasal fluid affects the outer wall of pollen grains, where Cry j 1 is located, to a greater extent than its effect on the cytoplasm, where Cry j 2 is located.

Allergens↗
PubMed1997

Stereoselectivity in cutaneous hydrolysis and transdermal transport of propranolol prodrug.

This review is written to evaluate the stereoselectivity in cutaneous hydrolysis and transdermal transport of propranolol prodrug. This discussion will be useful in the development of knowledge about stereoselective cutaneous hydrolysis and its influence on stereoselective transdermal transport of many other chiral prodrugs and drugs. Propranolol prodrugs undergo stereoselective hydrolysis in hairless mouse skin homogenate and in excised skin samples during permeation; the stereoselectivity is markedly biased towards hydrolysis of the (R) isomer. Unlike the liver, the esterase activity of the skin is high in its cytosolic fraction. Most of the lipophilic propranolol prodrugs cause stereoselective permeation across hairless mouse skin. A mechanism of stereoselective permeation of propranolol prodrug across the skin has been proposed, which indicates that the stereoselectivity in permeation is resulted from the stereoselective hydrolysis of lipophilic prodrug during permeation.

Animals↗
PubMed1996

Pathologic implications of restored positive T waves and persistent negative T waves after Q wave myocardial infarction.

OBJECTIVES: We sought to study the pathologic implications of restored positive T waves and persistent negative T waves in the chronic stage of Q wave myocardial infarction. BACKGROUND: Some inverted T waves (coronary T waves) become positive after acute myocardial infarction; others retain their negative T wave component for a long time. The pathologic implications of the difference between restored positive T waves and persistent negative T waves in leads with Q waves has not, until now, been given much careful study. METHODS: Of 17 patients with anterior or anteroseptal myocardial infarction confirmed by autopsy, 8 (group P) had positive and 9 (group N) had negative T waves in precordial leads with Q waves > or = 1 year after the onset of myocardial infarction. The appearance and extent of the infarct area and the degree of coronary artery stenosis were evaluated in both groups. RESULTS: At autopsy, seven of eight patients in group P had nontransmural fibrotic changes in the anteroseptal or anterior wall. However, seven of nine patients in group N had a transmural myocardial infarction consisting of only a thin fibrotic layer in the anteroseptal or anterior wall. The left anterior descending coronary artery showed 75% stenosis in 1 patient in each group but > 90% stenosis in the remaining 15 patients. CONCLUSIONS: Persistent negative T waves in leads with Q waves in the chronic stage of myocardial infarction indicate the presence of a transmural infarction with a thin fibrotic layer, whereas positive T waves indicate a nontransmural infarct containing viable myocardium within the layer.

Aged↗
PubMed1996

Redox-linked ionization of sulredoxin, an archaeal Rieske-type [2Fe-2S] protein from Sulfolobus sp. strain 7.

"Sulredoxin" of Sulfolobus sp. strain 7 is an archaeal soluble Rieske-type [2Fe-2S] protein and was initially characterized by several spectroscopic techniques (Iwasaki, T., Isogai, T., Iizuka, T. , and Oshima, T. (1995) J. Bacteriol. 177, 2576-2582). It appears to have tightly linked ionization affecting the redox properties of the protein, which is characteristic of the Rieske FeS proteins found as part of the respiratory chain. Sulredoxin had an Em(low pH) value of +188 +/- 9 mV, and the slope of pH dependence of the midpoint redox potential indicated two ionization equilibria in the oxidized form with pKa(ox1) of 6.23 +/- 0.22 and pKa(ox2) of 8.57 +/- 0.20. The absorption, CD, and resonance Raman spectra of oxidized sulredoxin are consistent with the proposed St2FeSb2Fe[N(His)]t2 core structure, and deprotonation of one of the two putative coordinated histidine imidazoles, having the pKa(ox2) of 8.57 +/- 0.20, causes a decrease in the midpoint redox potential, the change in the optical and CD spectra, and the appearance of a new Raman transition at 278 cm-1, without major structural rearrangement of the [2Fe-2S] cluster as well as the overall protein conformation. The redox-linked ionization of sulredoxin is also contributed by local changes involving another ionizable group having the pKa(ox1) of 6.23 +/- 0. 22, which is probably attributed to a certain positively charged amino acid residue that may not be a ligand by itself but located very close to the cluster. We suggest that sulredoxin provides a new tractable model of the membrane-bound homologue of the respiratory chain, the Rieske FeS proteins of the cytochrome bc1-b6f complexes.

Circular Dichroism↗
PubMed1996

Structure and expression of two highly related genes encoding SCM-1/human lymphotactin.

SCM-1/lymphotactin is a chemokine-like molecule produced selectively, if not exclusively, by activated CD8+ T cells. Here we report that there are two highly homologous SCM-1 genes, which we designate as SCM-1alpha and SCM-1beta. Both genes have three exons and two introns. The 1st intron of SCM-1alpha contains a pseudogene of the ribosomal large subunit L7a. In SCM-1beta, a 1.5-kb region including about a quarter of the L7a pseudogene is deleted from the 1st intron. Otherwise, the two genes are highly homologous including the 5' and 3' flanking regions. Both genes were mapped to human chromosome 1q23. The two genes were similarly induced in peripheral blood mononuclear cells by mitogenic stimulation. Primer extension and RNase protection revealed several transcription initiation sites. The biological activities of SCM-1alpha and SCM-1beta, which have two amino acid differences at positions 7 and 8 in the mature proteins, remain to be compared.

Amino Acid Sequence↗
PubMed1996

Molecular cloning of a novel T cell-directed CC chemokine expressed in thymus by signal sequence trap using Epstein-Barr virus vector.

Precursors of most secreted and cell surface molecules carry signal sequences at their amino termini. Here we describe an efficient signal sequence trap method and isolation of a novel CC chemokine. An expression library was constructed by inserting 5' portion-enriched cDNAs from phytohemagglutinin-stimulated peripheral blood mononuclear cells into upstream of signal sequence-deleted CD4 cDNA in an Epstein-Barr virus shuttle vector. After electroporation into Raji cells, CD4 antigen-positive cells were enriched by repeated cell sorting and plasmids were recovered in Escherichia coli. Out of 100 plasmid clones examined, 42 clones directed expression of CD4 antigen on the cell surface. Among them were signal sequences of CD6, beta2-microglobulin, MGC-24, and T cell receptor epsilon-chain, and at least four novel potential signal sequences. A cDNA clone encoding a novel CC chemokine was isolated by using one of the trapped fragments. The gene designated as TARC from Thymus and Activation-Regulated Chemokine was expressed transiently in phytohemagglutinin-stimulated peripheral blood mononuclear cells and constitutively in thymus. Radiolabeled recombinant TARC specifically bound to T cell lines and peripheral T cells but not to monocytes or granulocytes. The binding of radiolabeled TARC to the high-affinity receptor (Kd, 2.1 nM) on Jurkat was displaced by TARC but not by interleukin-8, MIP-1alpha, RANTES, or MCP-1. TARC also bound to the promiscuous chemokine receptor on erythrocytes (Kd, 17 nM). TARC induced chemotaxis in T cell lines Hut78 and Hut102. Pretreatment of Hut78 with pertussis toxin abolished the TARC-induced cell migration. Collectively, T cells express a highly selective receptor for TARC that is coupled to pertussis toxin-sensitive G-protein. TARC may a factor playing important roles in T cell development in thymus as well as in trafficking and activation of mature T cells.

Amino Acid Sequence↗
PubMed1996

Resistance to HIV-1 infection in caucasian individuals bearing mutant alleles of the CCR-5 chemokine receptor gene.

HIV-1 and related viruses require co-receptors, in addition to CD4, to infect target cells. The chemokine receptor CCR-5 (ref.1) was recently demonstrated to be a co-receptor for macrophage-tropic (M-tropic) HIV-1 strains, and the orphan receptor LESTR (also called fusin) allows infection by strains adapted for growth in transformed T-cell lines (T-tropic strains). Here we show that a mutant allele of CCR-5 is present at a high frequency in caucasian populations (allele frequency, 0.092), but is absent in black populations from Western and Central Africa and Japanese populations. A 32-base-pair deletion within the coding region results in a frame shift, and generates a non-functional receptor that does not support membrane fusion or infection by macrophage- and dual-tropic HIV-1 strains. In a cohort of HIV-1 infected caucasian subjects, no individual homozygous for the mutation was found, and the frequency of heterozygotes was 35% lower than in the general population. White blood cells from an individual homozygous for the null allele were found to be highly resistant to infection by M-tropic HIV-1 viruses, confirming that CCR-5 is the major co-receptor for primary HIV-1 strains. The lower frequency of heterozygotes in seropositive patients may indicate partial resistance.

Alleles↗