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Biomedical subjects

M Toba

Publications and source records attributed to M Toba.

54 records · Page 3Linked to original sources
PubMed1986

Ultrastructural studies of experimental endotoxin shock in the liver and spleen: therapeutic effects of low-dose heparin on reticuloendothelial disturbances.

To determine the effects of low-dose heparin on the reticuloendothelial system in shock, rats were subjected to intraperitoneal administration of E coli endotoxin. Alterations such as degeneration and necrosis of the Kupffer cells and sinusoidal endothelial cells were observed in the livers of the non-heparin-treated animals 4 hours after the administration of the endotoxin. These changes progressed with time. Kupffer cells in the heparin-treated rats appeared undisturbed up to 8-12 hours post endotoxin challenge. Phagocytosis of cell remained slight in the heparin-treated rats. The mortality rate of the heparin-treated group was 10% with LD50 endotoxin (7.6 mg/kg). The mortality rate of the untreated control group 24 hours after administration was 50%. However, when endotoxin was administered in a dosage of 30 mg/kg (MLD), the mortality rate of the heparin-treated rats was 60%--10% greater than that of controls (P less than 0.05).

Animals↗
PubMed1985

Structure and expression of the ColE2-P9 immunity gene.

The primary structure and expression of the ColE2-P9 immunity gene (imm) were investigated. The imm gene is located behind the colicin gene (col) in the same orientation with an intergenic space of two base pairs. Although the imm gene was transcribed primarily in response to the SOS function of the host cell as well as the col gene, the immunity phenotype also appeared to be expressed by only a slight level of leaky transcription without an evident promoter. On comparing the ColE2-P9 sequence with those of relevant plasmids, a highly homologous sequence with the immE2 gene was found downstream of the immE3 gene of ColE3-CA38, and thus, an evolutional relationships could be deduced among some E-group Col plasmids.

Amino Acid Sequence↗
PubMed1984

Seroepidemiological study of rotavirus infection in rural Ghana.

Children in a village in rural Ghana were found to have acquired antibody to rotavirus by the age of two years. The results of our study suggest that primary infection takes place early in infancy. Fifty-six per cent of the three to 20-months-old had a four-fold rise in antibody levels during the six months follow-up period and 72.2% of them had one or more episodes of diarrhoea compared with 42.8% of those whose antibody levels stayed the same or decreased. The major epidemic season is considered to be the dry season.

Antibodies, Viral↗
PubMed1984

[An ultrastructural study of the changes of the liver and spleen induced by experimental E. coli endotoxin shock--with special reference to effects of the low-dose heparin therapy].

Firstly, the author has investigated how low-dose heparin had influence on reticuloendothelial system of the normal Wistar rats. Secondly, the effect of the low-dose heparin therapy on E. coli endotoxin shock was investigated as to the ultrastructural changes of the liver and spleen of rats. Activation of the phagocytosis which was substantiated by increased uptake of the carbon was observed in heparin administered rats. In this group, abundant development of intra-cellular organellae was noted in the cytoplasm of the hepatic Kupffer cells, macrophages and reticulum cells of the spleen. The E.coli endotoxin administration resulted in formation of micro-thrombi in sinusoidal spaces of the liver at 4 hours after administration. The Kupffer cells also involved in striking disintegration and necrosis. Similarly the sinusoidal lining cells were denudated with disintegration and necrosis. The above-mentioned changes persisted for long term, while the changes less in heparin administered group. The active phagocytic process was discernible in the latter group. Cellular preservation was also excellent in the spleen. The mortality was lower in initial heparin-treated group in comparison with that of untreated control group.

Animals↗
PubMed1979

Absence of interferon production in a newly established human cell line.

A cell line established from human embryonic lung, HEL-R66, was demonstrated to be highly susceptible to herpes simplex virus types 1 and 2, vaccinia virus, Newcastle disease virus (NDV), Japanese encephalitis virus (JEV), western equine encephalitis (WEE) virus, Sindbis virus, vesicular stomatitis virus (VSV), and rabies virus. The maximal yields of NDV, JEV, WEE virus, and rabies virus in this cell line exceeded by 2--4 logs those in control human embryonic lung cells. Inability of this cell line to produce interferon upon treatment with native and UV-irradiated forms of virogenic and lentogenic strains of NDV and with poly I:C was revealed. A refractory state to challenging VSV did not develop in HEL-R66 cells treated with the inducers. Furthermore, pretreatment of HEL-R66 cells with interferon did not potentiate the capacity to produce interferon in response to the addition of poly I:C, whereas the same treatment enhanced the production of interferon in normal human embryonic lung cells.

Cell Line↗
PubMed1977

An analysis of factors influencing the isolation rate of herpes simplex virus.

Attempts were made to improve the rate of isolation of herpes simplex virus (HSV) from clinical specimens by minimizing loss of virus infectivity during transportation and employing the most sensitive cells for isolation. Basical analyses using standard strains of type 1 and type 2 HSV indicated that virus titer decrease was marked even at low temperatures in environments free of proteinous stabilizer such as normal serum or tissue extract, negating the generally held concept that HSV is stable in distilled water. YLE (Earle-lactalbumin HYDROLYSATE-YEAST EXTRACT) medium containing 20% inactivated calf serum was determined to be a transport medium of choice, because degradation of suspended virus during storage and freeze-thawing was negligible and loss of virus during Millipore filtration was minimal. Special coating of the membrane could also be obviated by the use of this solution. In a cell susceptibility test using clinical specimens, secondary rabbit kidney (SRK) cells were the most sensitive, showing a quick development of cytopathic effect. Vero and RK-13 cells were the second best, whereas monkey kidney, HeLa and L cells were far less sensitive. A total of 136 specimens from suspected cases, sent by dermatologists, were tested using SRK cells, and 99 strains of type 1 and 15 strains of type 2 HSV were isolated. Excluding one case from which vaccinia virus was isolated, the isolation rate of HSV was 84.4%.

Animals↗
PubMedDate not supplied

Induction of host DNA synthesis in senescent human diploid fibroblasts by infection with human cytomegalovirus.

A human diploid fibroblast strain, TIG -1, ceased to proliferate at about 60-62 population doubling level. The percentage of nuclei incorporating [3H]thymidine during 24-h culture in fresh medium containing 10% fetal bovine serum was less than 2% in the senescent cells used in this study. Infection of these cells with human cytomegalovirus (HCMV), strain AD-169, increased the percentage of [3H]thymidine-labeled cells by about ten-fold. Equilibrium density gradient centrifugation analysis of purified DNA from infected cells showed that cellular DNA synthesis was stimulated preceded by the viral DNA synthesis. Ultraviolet irradiation of HCMV reduced the ability to induce DNA synthesis. Equilibrium density gradient centrifugation analysis of DNA which was labeled with 5-bromodeoxyuridine indicated semiconservative replication rather than repair synthesis. These results suggested that in a considerable fraction of human senescent cells host DNA replication could be reinitiated by infection with HCMV, but not by the addition of fetal bovine serum.

Autoradiography↗
PubMedDate not supplied

Serial assessment of left ventricular function during dobutamine stress by means of electrocardiography-gated myocardial SPECT: combination with dual-isotope myocardial perfusion SPECT for detection of ischemic heart disease.

BACKGROUND: Technetium-labeled myocardial perfusion tracers allow simultaneous assessment of myocardial perfusion and left ventricular function by electrocardiography (ECG)-gated myocardial single photon emission computed tomography (SPECT). The purpose of this study was to evaluate left ventricular performance during dobutamine stress by means of ECG-gated myocardial perfusion SPECT with short-time data collection. METHODS AND RESULTS: After administration of Tc-99m sestamibi or tetrofosmin (600-740 MBq), 67 patients with ischemic heart disease, including 35 with prior myocardial infarction, were examined by ECG-gated myocardial perfusion SPECT at rest and during dobutamine stress (at dosages of 4, 8, 12, 16, and 20 microg/kg/min, with increments every 8 minutes). The ECG-gated data collection time was 5 minutes for each dobutamine dosage. After acquisition of gated SPECT data at the highest dose, thallium 201 chloride (111 MBq) was injected, and dual-isotope SPECT was also performed to assess the myocardial ischemia. In 32 patients without prior myocardial infarction, the sensitivity of individual stenosed-vessel detection with dual-isotope perfusion SPECT, with wall motion abnormality obtained from gated SPECT, and with the combined method was 55.9%, 52.9%, and 73.5%, respectively, based on coronary angiography. ECG-gated SPECT during dobutamine infusion revealed regional wall motion abnormalities (worsening or biphasic response) in 19 (57.6%) of 33 infarcted areas with culprit coronary arterial stenosis. The prevalence of reversible perfusion defects on dual-isotope SPECT was higher in segments with wall motion abnormalities than in segments with normal wall motion response (89.5% vs 42.9%, P <.02). CONCLUSIONS: Myocardial perfusion and left ventricular function during dobutamine infusion were analyzed in a single examination by means of the combined method. This procedure has the potential to provide comprehensive information with which to evaluate patients with ischemic heart disease.

Blood Pressure↗
PubMedDate not supplied

Assessment of left ventricular diastolic function with electrocardiography-gated myocardial perfusion SPECT: comparison with multigated equilibrium radionuclide angiography.

BACKGROUND: Technetium-labeled myocardial perfusion tracers allow the simultaneous assessment of myocardial perfusion and left ventricular function by electrocardiography (ECG)-gated myocardial perfusion single photon emission computed tomography (SPECT). This study evaluates left ventricular systolic and diastolic function by ECG-gated SPECT with the use of higher framing (32 frames per cardiac cycle) data acquisition. METHODS AND RESULTS: After receiving an injection of technetium 99m tetrofosmin, 48 patients with cardiac diseases were examined by ECG-gated myocardial perfusion SPECT with a 3-headed gamma camera. During gated data collection, 32 frames per cardiac cycle were acquired over 360 degrees in 60 steps, each of which consisted of 60 beats. Immediately thereafter, the 32 frames taken at each projection angle were combined into 16-frame and 8-frame data sets. Left ventricular end-diastolic volume (LVEDV, in milliliters), left ventricular end-systolic volume (LVESV, in milliliters), and left ventricular ejection fraction (LVEF, percentage) were automatically calculated from the 32-frame, 16-frame, and 8-frame gated data sets. Left ventricular time-volume curves from the 3 data sets were generated by Fourier curve fitting analysis with the use of 3 harmonics, and then peak filling rate (PFR, per second) was measured. Twenty-nine patients also underwent multigated equilibrium radionuclide angiography (ERNA) to determine the LVEF and PFR. Combining the 32-frame data into 16-frame and 8-frame data sets from the 48 patients generated a smaller LVEDV and a larger LVESV, and LVEF was significantly lower in accordance with the decreasing number of frames. Compared with ERNA studies (n = 29), the Bland-Altman method showed underestimated LVEFs and larger 95% limits of agreement in lower framing gated SPECT. CONCLUSIONS: Left ventricular functional parameters obtained from 32-frame gated SPECT correlated closely with those determined by ERNA studies. ECG-gated SPECT with 32-frame data can provide comprehensive information with which to evaluate many types of cardiac diseases.

Adult↗
PubMedDate not supplied

Growth inhibition of herpes simplex virus-1 in the cells expressing abundant 2.0-kilobase latency-associated transcripts.

To elucidate the function of the latency-associated transcript (LAT) of herpes simplex virus type 1 (HSV-1) in productive infection and latency, we established a cell line stably expressing LAT (V24 cells). V24 cells expressed 2.0-kilobase RNA that corresponds to the major species of LAT in mouse and human sensory ganglia. When the cells were infected with HSV-1 at a low multiplicity of infection, the amount of the progeny virus was much smaller in V24 cells than in a control cell line not expressing LAT. Inefficient growth of HSV-1 in V24 cells was also observed when viral replication was initiated by transfection with viral DNA.

Animals↗
PubMedDate not supplied

Endoscopic variceal ligation (EVL) combined with partial splenic embolization (PSE).

BACKGROUND/AIMS: The effectiveness of reducing the recurrence rate of esophageal varices by combining partial splenic embolization (PSE) with endoscopic variceal ligation (EVL) was investigated. METHODOLOGY: Patients with complete eradication of esophageal varices were collected as study cases with the following results: 31 cases with PSE and EVL (PSE+EVL group), 25 cases with EVL alone (EVL group), and 33 cases with EIS alone (EIS group). The cumulative recurrence rates were obtained by observing new varices. RESULTS: The cumulative recurrence rates at 6 months were 21.1% in the PSE+EVL group, 58.1% in the EVL group and 32.5% in the EIS group. Those at 1 year were 37.0%, 70.7% and 50.2%, respectively, and those at 2 years were 58.1%, 80.4% and 73.0%, respectively. For all 3 time periods, recurrence rates of the PSE+EVL group were significantly lower than those of the EVL group (p=0.042). Cumulative rates in the PSE+EVL group tended to be lower than those in the EIS group. Further analysis was made on the comparative recurrence rates of the 3 groups, according to Child's classification. The cumulative recurrence rates in Child A cases did not significantly differ between the 3 groups. Cumulative rates in Child B cases were significantly lower in the PSE+EVL group than in the EVL group (p=0.032), and those in the PSE+EVL group tended to be lower than those in the EIS group. These trends were observed between the PSE+EVL group and the EVL group in Child C cases, while cumulative rates did not show differences between the PSE+EVL group and the EIS group. CONCLUSIONS: It was inferred that PSE-combined EVL therapy is a very effective therapy for achieving long-term complete eradication of esophageal varices.

Adult↗
PubMedDate not supplied

Long-term results of modified distal splenorenal shunts for the treatment of esophageal varices.

BACKGROUND/AIMS: Long-term results were compared for 3 types of distal splenorenal shunt for the treatment of esophageal varices. METHODOLOGY: Between July 1983 and December 1997, 45 patients with esophageal varices underwent distal splenorenal shunt. Group 1 underwent standard distal splenorenal shunt (n = 11). Group 2 underwent distal splenorenal shunt with splenopancreatic disconnection (n = 11). Group 3 underwent distal splenorenal shunt with splenopancreatic disconnection and gastric transection (n = 23). RESULTS: Additional treatment for recurrent varices was required in group 1, (n = 1, 9.1%), group 2 (n = 2, 18.2%), and group 3 (n = 1, 4.3%). All of the patients with recurrent varices developed a shunt stenosis within the 1st year after distal splenorenal shunt. The prevalence of hyperammonemia in group 1 was 40.0% at 1, 5, and 10 years. In group 2, the prevalence was 14.3% at 1 year, 31.4% at 5 years, and 54.3% at 10 years. In group 3, the prevalence was 0% at 1 year, and 9.1% at 5 and 10 years. The differences between group 3 and groups 1 and 2 were significant (P < 0.01). The cumulative survival rates at 1 year were 90.9%, 63.6%, and 95.7% for groups 1, 2, and 3, respectively. At 10 years, the cumulative survivals rates were 70.7%, 63.6%, and 69.4% for groups 1, 2, and 3, respectively. There were no significant differences in survival between the 3 groups. CONCLUSIONS: Distal splenorenal shunt with splenopancreatic disconnection and gastric transection may reduce the incidence of postoperative hyperammonemia.

Adult↗