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T Tamai

Publications and source records attributed to T Tamai.

At least 109 records · Page 6Linked to original sources
PubMed1985

Serological analysis of serogroup icterohaemorrhagiae using monoclonal antibodies.

Eighteen serovars (19 strains) of serogroup Icterohaemorrhagiae were serologically analyzed using 18 monoclonal antibodies against serovar copenhageni Shiromizu, M20 and serovar icterohaemorrhagiae RGA strains. The reaction patterns of the serovars against these monoclonal antibodies were different. According to these results, we divided the serovars, except for serovar tonkini, into the following three subgroups: Subgroup 1 reacted to many monoclonal antibodies including serovars icterohaemorrhagiae, copenhageni, hualien, monymusk, mankarso, and budapest. Subgroup 2 fell between subgroups 1 and 3 including serovars dakota, naam, bogvere, birkini, smithi, ndambari, gem, ndahambukuje and mwogolo. Subgroup 3 reacted to only a few monoclonal antibodies: serovars weaveri and sarmin. Serovar tonkini did not react to any of the monoclonal antibodies used. There is a possibility that serovar tonkini does not belong to serogroup Icterohaemorrhagiae. Further studies on the serological reactions of each strain revealed that it was impossible to distinguish the RGA strain from the serovar hualien LT11-31 strain, indicating that they may be identical. It was also observed that serovar copenhageni and monymusk seemed to be closely related. Serovars birkini and smithi, and serovars ndambari and gem were alike in their serological reactivities. Among the 18 monoclonal antibodies, RGAMA-1 was a unique antibody which reacted only to serovar icterohaemorrhagiae and serovar hualien, indicating that it must be the serovar icterohaemorrhagiae specific antibody. On the other hand, SHIRMA-2, 5, 6 reacted to all the serovars except for serovars weaveri, sarmin, and tonkini. These antibodies exhibited a broad reaction spectrum.

Antibodies, Monoclonal↗
PubMed1985

[The responses of isolated uterine arteries from pregnant sows to vasoconstrictive agents].

Isometric contractions of isolated uterine arteries, mesenteric arteries and the thoracic aortae of nonpregnant and pregnant sows were measured in a modified Krebs-Henseleit solution in order to investigate the characteristics of the uterine artery responsiveness to vasopressor substances during pregnancy. Contractile response (delta T) of the uterine artery from pregnant sow to angiotensin II(A II) was significantly smaller than that from nonpregnant animal. On the other hand, delta T of uterine artery from pregnant sow to norepinephrine (NE) was greater than that from nonpregnant animal. NE-induced delta T of preparations from both pregnant and nonpregnant sow were suppressed nearly to the same level following the treatment of phentolamine, or verapamil in the incubation medium of 2.5mM Ca2+. In the Ca2+-free (EDTA 1mM) incubation medium, the responses decreased to the minimum degree. These results imply that conspicuous refractoriness of the uterine artery to A II during pregnancy is due to the changes in the characteristics of the uterine vascular wall, and the enhanced responsiveness to NE of the uterine artery may be due to the increased sensitivity in alpha-adrenergic receptor on the vasculature with the increase in Ca ion influx.

Angiotensin II↗
PubMed1984

Role of sex steroid hormones in relative refractoriness to angiotensin II during pregnancy.

Normal human pregnancy is associated with significant vascular refractoriness to the pressor effects of infused angiotensin II, and in women destined to develop pregnancy-induced hypertension, this refractoriness is lost several weeks before the onset of hypertension. The plasma concentrations of sex steroid hormones gradually increase throughout pregnancy. In the present study, the effect of infusion of 17 beta-estradiol (E2), progesterone, or 5 alpha-dihydroprogesterone on the pressor response to infused angiotensin II (0.002 to 0.1 micrograms X min-1 X kg-1) was evaluated in eight unanesthetized and chronically instrumented nonpregnant ewes. Pressor response to infused angiotensin II (0.02 to 0.1 micrograms X min-1 X kg-1) was significantly suppressed by a 60-minute infusion of E2 (0.8 micrograms X kg-1), whereas infusion of progesterone (4 micrograms X min-1 X kg-1) or 5 alpha-dihydroprogesterone (0.8 micrograms X min-1 X kg-1) did not affect the pressor response. Neither the acid-base status, plasma renin activity, nor serum electrolytes were altered by the administration of E2 or progesterone. These results indicate that E2 may play an important role in the refractoriness to infused angiotensin II during pregnancy, and that this refractoriness by E2 is not mediated by changes in chemoreceptor reflex, renin-angiotensin system, or serum electrolytes, but more likely by the changes in the characteristics of the vascular wall.

5-alpha-Dihydroprogesterone↗
PubMed1984

Lacrimal gland accumulation of 67Ga-citrate in patients with Sjögren's syndrome.

The extent of 67Ga accumulation in the two lacrimal glands in patients with keratoconjunctivitis sicca (KCS) of Sjögren's syndrome was studied. Of the two main groups one consisted of 69 subjects without ophthalmic complaints (control group), the other consisted of 26 patients with KCS of Sjögren's syndrome. Of the 26 patients with KCS, 7 had been diagnosed as probable KCS (probable sub-group) and the other 19 had been diagnosed definite KCS (definite sub-group). About 3 mCi (111 MBq) 67Ga-citrate was injected IV into each subject and this was followed by scintigraphy at 24, 48, and 72 h after the injection of 67Ga. A positive finding in the lacrimal gland was noted in 64 of 69 subjects (92.7%) in the control group and in 7 of 7 patients (100%) with probable KCS. Three of 19 patients with definite KCS (15.7%) showed positive findings under scintigraphy. When the scintigraphic finding in the lacrimal gland is not positive in patients with suspected KCS of Sjögren's syndrome, they can then be diagnosed with little risk as definite KCS cases. Shirmer's test was performed on subjects in the probable and definite groups. There was statistical significance between the positive and equivocal or negative scintigraphic finding and Schirmer's values. These results suggest a correlation between gallium accumulation in the lacrimal gland and the tear production.

Adolescent↗
PubMed1984

Lipoprotein lipase activities in heart muscle of streptozotocin-induced diabetic rats.

Triglyceride lipase (TGL) activities in the homogenates of the rat heart muscle were studied. TGL activity per mg protein of heart muscle was the highest in heart muscle homogenate utilizing 2.1 M glycine buffer, pH 8.3 among the assays investigated. The effects of NaCl, serum and heparin on TGL activities in heart muscle homogenates indicated the characteristics of lipoprotein lipase (LPL). Twelve-hour fasting increased heart muscle LPL activity, while enzyme activities in 48 hour- and 72 hour-fasted rats were lower than those in fed rats. LPL activities in heart muscle homogenates in streptozotocin (STZ)-induced diabetic rats either 3 days or 4 weeks after STZ injection, were decreased significantly as compared with those of control rats.

Animals↗
PubMed1984

Characterization of monoclonal antibodies against etiological agents of Weil's disease.

Monoclonal antibodies against etiological agents of Weil's disease were produced by cell fusion technology. Twenty hybridomas were produced through the fusion of P3X63Ag8 .653 cells with spleen cells from BALB/c mice immunized against Leptospira interrogans serovar icterohaemorrhagiae RGA strain and serovar copenhageni Shiromizu and M20 strains. Reactivities of the antibodies produced by the hybridomas were determined by the microscopic agglutination test. Among the five hybridoma antibodies to the RGA strain, two reacted specifically to serovar icterohaemorrhagiae, two reacted to serovar icterohaemorrhagiae at a high titer and serovar copenhageni at a low titer, and one reacted to serovars icterohaemorrhagiae, copenhageni, pyrogens, and canicola. Of the ten hybridoma antibodies to the Shiromizu strain, one reacted specifically to serovar copenhageni, seven reacted to both serovars copenhageni and icterohaemorrhagiae at almost the same titer, and two exhibited intermediate properties. Of the five hybridoma antibodies to the M20 strain, three reacted to both serovars copenhageni and icterohaemorrhagiae at almost the same titer, one reacted to serovar copenhageni at a low titer and serovar icterohaemorrhagiae at a high titer, and one reacted to serovars copenhageni, icterohaemorrhagiae, and pyrogens. The results revealed that each serovar has its own antigen(s) and their common antigens. In addition, 20 strains of leptospires were recently isolated and tested with three monoclonal antibodies characterized by different reactivities. Twenty strains were clearly identified by their antibodies, i.e., 16 strains were identified as serovar icterohaemorrhagiae and three strains were identified as serovar copenhageni. The remaining strain, which was not agglutinated by three antibodies, was identified as serovar autumnalis by an agglutination test with immune rabbit sera.

Agglutination↗
PubMed1984

Antigenic analysis of Japanese encephalitis virus by using monoclonal antibodies.

Hybridoma cells were produced by fusing P3X63Ag8.653 mouse myeloma cells with spleen cells from BALB/c mice immunized with Japanese encephalitis (JE) virus, Nakayama-RFVL strain. The resulting 26 clones produced hemagglutination inhibition antibodies against the homologous strain. The hemagglutination inhibition reactivity of each clone was tested against six flaviviruses: JE, Murray Valley encephalitis (MVE), Egypt 101 strain of West Nile (WN), St. Louis encephalitis (SLE), Russian spring summer encephalitis, and dengue type 1. The 26 monoclonal antibodies fell into four groups: 14 JE species-specific antibodies, 6 antibodies reactive to JE and MVE viruses, 3 antibodies to three or four viruses in the JE-MVE-WN-SLE subgroup, and 3 antibodies to all six flaviviruses. Furthermore, antigenic comparison of 27 strains of JE virus was carried out by using five JE species-specific monoclonal antibodies. Of these, 24 strains were isolated in various parts of Japan, and 3 strains came from Southeast Asia. In reactivity, the 27 strains were classified into at least four antigenic groups. The results showed that the Nakayama-Yakken strain is a mutant strain which lacks the Nakayama strain-specific antigen and that the recently isolated strains are immunologically different from Nakayama and JaGAr 01 strains. One clone (NARMA 13) produced a JE species-specific antibody which showed almost the same titer against 26 JE virus strains, whereas one clone (NARMA 5) produced a Nakayama strain-specific antibody which reacted only to the Nakayama-RFVL and Nakayama-Yoken strains.

Animals↗
PubMed1984

[An evaluation of radioactive colloid for measuring the volume of effective liver].

A methods for liver scintigraphy for finding the effective liver volume were developed. Matrix ROI (region of interest) was set on the anterior liver scintigram with 99mTc tin colloid and 198Au colloid, respectively. The various depths of liver under matrix ROI were calculated from the count rate noting the absorption coefficient. The effective liver volume was the sum total of the areas of matrix ROI to the various depths. In order to check the accuracy of this method, the effective liver volume was calculated using the liver phantom and the patient's liver scintigraphy. The volume obtained for the liver phantom was nearly equal to the real volume. The liver volume in 19 patients using 99mTc tin colloid and 198Au colloid showed good correlation with the volume as measured by computed tomography (CT) scan (r = 0.841, r = 0.749).

Aged↗
PubMed1984

[Effect of nicotine on uterine blood flow and antagonistic effect of prostaglandin I2 derivative (OP-41483) in pregnant ewes].

In order to elucidate the mechanism of the detrimental effect of smoking on uteroplacental circulation in pregnant women, and to confirm the protective effect of PGI2 derivative (OP-41483) against the effect, hemodynamic responses to various doses of nicotine infusion (0.25-1.0 mg/min) were measured before and during the OP-41483 infusion in chronically instrumented pregnant ewes. Moreover, the isometric tension responses of spiral strips of sow uterine arteries to the nicotine and norepinephrine perfusion were also measured using an in vitro technique. The results were as follows: Maternal mean arterial blood pressure (MAP) and the cardiac output were increased by the intravenous infusion of various doses of nicotine; however the uterine blood flow (UBF) decreased consistently in a dose-dependent fashion, and it decreased 20.4% from the control level following the infusion of 1.0 mg/min nicotine, suggesting a detrimental effect on the fetus. During the infusion of OP-41483 (25 micrograms/min), nicotine induced MAP increases were suppressed at all test doses and the decrease in UBF was lessened by 22% of control delta UBF on doses of 1.0 mg/min nicotine. In the muscle chamber, the tension increase in uterine artery strips of nonpregnant sows to various nicotine concentrations (10(-7)-10(-4) M) were suppressed by the preliminary treatment with phentolamine (0.1 mg/min), and the responses to norepinephrine were also suppressed by the preliminary treatment with a low concentration of nicotine (10(-6) M) in the buffer bath.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Effect of fatty acids on lipid and apoprotein secretion and association in hepatocyte cultures.

Increasing availability of free fatty acids (FFA) to liver results in enhanced rates of secretion of triglycerides in lipoproteins. However, as FFA uptake increases, triglyceride secretory rates reach a plateau and esterified fatty acids accumulate intracellularly, suggesting that something is limiting lipid transport out of the liver. One possibility could be the limited availability of apoproteins. To test this hypothesis, primary rat hepatocytes in culture were incubated with increasing amounts of FFA (0-2.1 mumol/dish) and the amounts of lipids and apoproteins inside the cells and in culture media were measured; the latter by specific radioimmunoassays. Media also were fractionated on Sepharose 2B and 6B columns and the elution profiles of apoproteins were obtained. With exposure to increasing amounts of free fatty acids, hepatocytes took up more fatty acids and intracellular levels of triglycerides rose (from 71 to 146 micrograms/mg cell protein). Concomitantly, media triglycerides nearly doubled (31 to 51 micrograms/mg). Incorporation of [3H]glyceride into cellular and media triglyceride also rose. However, levels of apoproteins A-I, B, C-III3, and E in cells and media were unchanged. The increasing amounts of triglycerides in media were present in larger particles, as demonstrated on gel permeation chromatography. The elution profiles of apoproteins B, C-III3, and E were altered in that a greater proportion of the apoproteins eluted with larger particles. Similar results were obtained when hepatocytes were preloaded with increasing amounts of FFA over 12 h and analyses of cells and media were carried out 8 and 22 h after removal of fatty acids from the media. During loading of cells, accumulation of cellular triglycerides was directly related to media FFA concentrations. During unloading, triglyceride secretory rates were related to cellular triglyceride levels. At higher triglyceride secretory rates larger particles were secreted and a greater proportion of apoproteins was associated with the larger particles, but total amounts of apoproteins in the system did not change. These data lead us to suggest that enhanced rates of apoprotein synthesis need not occur in the response to acute changes in hepatic lipid transport, rather, increased secretion of lipid is brought about by augmented intracellular lipid apoprotein association.

Animals↗
PubMed1983

Receptors for homologous plasma lipoproteins on a rat hepatoma cell line.

Hepatocytes express on their surfaces more than one class of receptors capable of mediating the internalization of lipoproteins. However, relatively little is known about the binding characteristics of hepatic receptors for various lipoproteins, about the regulation of the receptors, and about the consequences for intracellular lipid metabolism of uptake of lipoproteins via different classes of receptors. The aim of the present studies was to characterize the binding and degradation of various lipoproteins and their mutual competition for cellular processing. Since these kinds of studies may be more easily carried out in continuous established hepatoma cell lines than in nondividing primary hepatocyte cultures, we examined the lipoprotein receptor functions of a well differentiated rat hepatoma (H-35). Cells were grown to confluence in Eagle's minimal essential medium in 15% newborn calf serum. Medium then was changed to 15% lipoprotein-deficient serum for 44 hr before experiments. External binding of 125I-labeled rat plasma and intestinal lymph lipoproteins was assessed at 4 degrees C. Cellular uptake and degradation were assessed at 37 degrees C. Lipoproteins were isolated by fixed angle or zonal ultracentrifugation or by heparin affinity column chromatography and characterized as to their lipid and apoprotein compositions. Labeled low density (LDL), high density (HDL2), non-apoE-HDL, very low density lipoproteins (VLDL), and chylomicron remnants (CM-R) each manifested specific and saturable binding and degradation by the hepatoma cells. Competition experiments indicated that separate receptors were present for LDL, HDL2, and CM-R. Most of HDL2 appeared to be bound to the non-apoE-HDL receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

[Effects of indomethacin on renal and uterine blood flow and pressor responsiveness to angiotensin II or norepinephrine in pregnant dogs].

Pressor responsiveness to angiotensin II (A II) or norepinephrine (NE) in anesthetized nonpregnant and pregnant dogs, and the changes in renal blood flow (RBF) and uterine blood flow (UBF) elicited by the pressure rise in pregnant dogs were studied. Intervention of prostaglandins (PGs) in these hemodynamic responses was also examined, comparing the responses before and after the administration of indomethacin (IDM). The pressor responsiveness to the pressor substances was diminished in near term pregnant dogs in common with normal human pregnancy, and the refractoriness disappeared after the administration of IDM. RBF decreased following the infusion of A II or NE, and IDM enhanced the responses. A characteristic increase in UBF was observed following the infusion of A II exhibiting the maximum response at a dose of 0.05 microgram/kg, while it decreased following the infusion of NE, and these responses remained almost unchanged after IDM administration, although there was a 24.2% decrease in the base line value of UBF. It seems appropriate to conclude that PGs play a pivotal role in the development of the relative vascular refractoriness to infused pressor substances characterizing normal pregnancy, and also in preservation of RBF and UBF during pregnancy. Moreover, PGs attenuate the response of the renal vascular bed as well as systemic vascular bed to the pressor substances. However, the refractoriness of uterine vascular bed to A II remained almost unchanged regardless of PGs synthesis, suggesting the existence of another competitive factor involved in the effect of A II.

Angiotensin II↗