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Biomedical subjects

H Sakurai

Publications and source records attributed to H Sakurai.

At least 469 records · Page 26Linked to original sources
PubMed1990

Changes of lymphocyte subpopulations and natural killer cells in mice sensitized with Toxoplasma lysate antigen before and after Babesia infection.

When 8-week-old BALB/c mice were sensitized with two intramuscular injections of Toxoplasma lysate antigen (TLA) at 2 week interval, the numbers of sIg(+), Thy-1,2(+), Lyt-1,2(+) Lyt-2,2(+), and Asialo GM1(ASGM1)(+) cells in the spleen, liver and peripheral blood increased by 2 to 4 times over those found in unsensitized mice of the same age. When TLA-sensitized and unsensitized mice were infected with Babesia, 4 of 10 (40%) of the TLA-sensitized mice survived infection, while none of the unsensitized control mice lived longer than 14 days after Babesia infection. By contrast, sensitization of nude mice with TLA had no effect on survival, and mice did not live more than 12 days. The number of thymic Thy-1,2(+) cells decreased in TLA-sensitized and unsensitized BALB/c mice by almost 80% within 10 days after infection (AI). During the same time, the numbers of B cells, T cells, and NK cells increased in the spleen, liver and peripheral blood of both sensitized and unsensitized mice. Especially notable were increases in numbers of Lyt-2,2(+) cells in the spleen and blood and increases in numbers of NK cells in the spleen, liver and blood in both TLA-sensitized and unsensitized mice. When spleen cells from TLA-sensitized and unsensitized mice were cultured in the presence or absence of TLA for 6 days, assays for cytotoxicity using NK-insensitive P-815 target cells and NK-sensitive YAC-1 target cells demonstrated higher rates of cytotoxicity in cultures of TLA-sensitized spleen cells.

Animals↗
PubMed1990

Insulin-like effect of vanadyl ion on streptozotocin-induced diabetic rats.

Recent studies have indicated that the blood glucose level of rats with streptozotocin (STZ)-induced diabetes (type 1) is normalized without an increase in the plasma insulin level by administration of sodium orthovanadate in the drinking water. The mechanism of this insulin-like effect of vanadate is unknown. In this study, we investigated whether vanadyl ion, which is less toxic than vanadate to rats, also has an insulin-like effect in rats with STZ-induced diabetes. When rats with STZ-induced diabetes were given a daily i.p. injection of vanadyl sulphate (9.3 and 4.6 mg vanadium/kg body weight), their blood glucose level decreased from about 22.2 to about 7.2 mmol glucose/l within 2 days and remained low for at least 12 weeks. This treatment did not affect their low plasma insulin level. Quantitative electron spin resonance (ESR) spectrometry showed that most of the vanadium (about 90%) in their tissues was present as a vanadyl form (VO2+). ESR analysis also showed that the vanadyl ion in tissues was bound endogenously with four oxygen ligands from either water or oxyamino acid residues in proteins. Vanadyl sulphate accelerated glucose incorporation into adipocytes of rats, suggesting that the action of vanadyl ion is peripheral. Interestingly, vanadyl sulphate at a high concentration (about 10 mmol/l) was more effective than insulin in enhancing glucose uptake. This study demonstrated that: (1) vanadyl sulphate (+4 oxidation state), like vanadate ion, normalizes the blood glucose levels of rats with STZ-induced diabetes; (2) the action of vanadyl ion is peripheral; and (3) the active form of vanadium for an insulin-like effect may be a vanadyl form, not vanadate.

Adipose Tissue↗
PubMed1990

[Tooth tapping frequency of young and elderly subjects].

Tooth tapping frequency was measured in young (21-29 years) and elderly (61-67 years) subjects. They were asked to continue the maximal frequent tapping during 1 min., and their mandibular movement were measured with a Mandibular Kinesiograph. The results are as follows: 1. Each phase of closing, occluding, opening and cycle was prolonged at the terminal of the 1 min. tapping. That is, tapping frequency decreased. Young subjects had 4.6 Hz tapping frequency and 2.7 Hz for elderly subjects. 2. Although the opening phase per cycle and the closing were not changed in spite of the tapping continuity, the occluding one increased at the terminal of the 1 min. tapping. 3. No difference existed between the young subjects and elderly in the maximal velocity of the mandibular movement at the opening and closing. Opening velocity was larger than closing velocity at the young subjects.

Adult↗
PubMed1990

[A study on mandibular incisal point movement of TM disorder patients].

In order to establish diagnostic and treatment system for temporomandibular (TM) disorder patients, data were collected on mandibular border and tapping movements at incisive point and compared with those from the subjects without any TM disorders. Significant differences on the ratio of left and right sides of maximum lateral deviation, maximum opening amount and length of pathway of lateral border movement were clearly obtained, the values of maximum speed and acceleration of closing phase in tapping movement obtained from TM disorder patients were also different significantly from those in the control subjects. These findings suggests that those measured indices in this study would be useful for diagnosis of TM disorders.

Dental Occlusion↗
PubMed1990

No adverse effects of lead on renal function in lead-exposed workers.

A cross-sectional study was performed on 165 male lead-exposed workers to clarify the quantitative relationships between less severe exposure to lead and its effects on renal function in 1985. Mean and range of blood lead concentration (Pb-B) were 36.5 micrograms/dl and 6-73 micrograms/dl, respectively. Duration of lead exposure was 0.1 to 26.3 years. No lead-related changes were detected in serum creatinine concentration, beta-2 microglobulin in urine, creatinine clearance, beta-2 microglobulin clearance, and uric acid clearance. Twenty of the 165 workers had been exposed to lead for more than 10 years with mean duration of 21.0 years. Average concentrations of Pb-B in each individual during 1972 to 1984 were 26.1-66.6 micrograms/dl. Renal function indices of these 20 workers were not different from those of remaining lead-exposed workers whose lead exposure duration were 10 years or less. These results suggest that long-term less severe exposure to lead up to 70 micrograms/dl of Pb-B may not cause adverse effects on renal glomerular function and proximal tubular function.

Adult↗
PubMed1990

Successful retrieval of fractured tracheostomy cannula by flexible fiberoptic bronchoscopy.

The fracture and aspiration of tracheostomy tubing is not rare. It may go unnoticed by the patient. The equipment is prone to shearing at the flange and fracture along its body. Its integrity should be routinely tested, and a policy instituted for the discarding of old equipment. Fiberoptic bronchoscopy is advantageous in that it can be performed quickly and easily, it avoids general anesthesia, and it is more adaptable to foreign body retrieval than the nasopharyngoscope because of its forceps channel, through which varied retrieval instruments can be passed.

Bronchoscopy↗
PubMed1990

[A study of low-dose intermittent intra-arterial infusion chemotherapy for liver metastasis in colorectal cancer].

Since 1985 we have performed low-dose intermittent intra-arterial infusion chemotherapy using an implantable device for inoperable liver metastasis derived from colorectal cancer. We estimated the efficiency of this treatment in terms of effective rates and survival period. We classified subjects into intra-arterial infusion group and general administration group for comparison. The former group was comprised of 54 cases (37 synchronia, 17 heterochronia) treated with low-dose intermittent intra-arterial infusion (FAM ia) from July 1985 to June 1989. The latter comprised 32 cases (17 synchronia, 15 heterochronia) treated with general chemotherapy (general administration of 5-FU and MMC) for three years before December 1986. Of the 37 cases (23 synchronia, 14 heterochronia) evaluated in the intra-arterial infusion group, we recognized 9 PR cases (24.3%; including 5 synchronia, 4 heterochronia). On the other hand, we found only 1 PR case in the general administration group. The 50% survival period in the intra-arterial infusion group was 370 days (380 days synchronia, 340 days heterochronia), against 260 days (270 days synchronia, 250 days heterochronia) in the general administration group. There were no statistically significant differences between the two groups. Although it was not possible for us to obtain satisfactory results in terms of the efficiency of intermittent low-dose intra-arterial infusion treatment, we have been conducting a randomized study considering drug types, drug administration methods, and background of patients to further investigate the efficiency of arterial infusion treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Variations in manganese effect on 6-phosphogluconate dehydrogenases from the thyroid and liver of the mouse and an evidence for non-interchangeability of manganese and magnesium.

Both manganese (Mn) and magnesium (Mg) are known to activate 6-phosphogluconate dehydrogenase (6-PGDH). Yet in the present study none of the metal ions stimulated 6-PGDH from the thyroid of mice, but Mn alone stimulated the enzyme from the liver. Such a stimulatory effect of Mn on the liver enzyme was seen regardless of the presence of Mg, This suggests that the reaction sites for the two ions must be apart from one another or that the affinity of Mn is stronger than that of Mg. The enzyme preparations from livers of those mice which had been administered intraperitoneally with excess of Mn for 1 - 14 days were greatly stimulated by further in vitro addition of Mn, whereas the enzyme sources from the thyroids thus treated were almost insensitive to Mn in vitro. The results indicate that cellular Mn hardly reaches the levels for maximal stimulation of the enzyme in the liver. In addition, some sex difference was observed in the Mn effect on 6-PGDH from the liver.

Animals↗
PubMed1989

Generation of alloxan free radicals in chemical and biological systems: implication in the diabetogenic action of alloxan.

Electron spin resonance (ESR) studies that on reaction with NADPH, alloxan was reduced forming labile anion radicals giving a 7-line signal with g = 2.005. These radicals were also produced on incubation of alloxan with rat liver subcellular fractions and their production was greatly enhanced by NADPH. Alloxan effectively scavenged superoxide anion generated by a xanthine-xanthine oxidase (XOD) system in association with its reduction to these anion radicals. These radicals were also formed during incubation of alloxan with rat pancreatic beta-cells. These results suggest that the cytotoxicity of alloxan is related to the formation of alloxan anion radicals.

Alloxan↗
PubMed1989

[Healthy worker effect on Japanese industry workers: a commentary from the viewpoint of industrial health management].

Healthy worker effect (HWE), which can be described as a lower death rate within a work force when compared to the general population, has been observed in many epidemiological mortality studies on industrial work populations free of significant life-shortening hazards. The purpose of this report is to evaluate this effect on the active work populations engaged in large scale manufacturing companies in Japan, and to appreciate the possible attributable factors to this phenomenon. Standardized mortality ratios (SMRs) were calculated for workers in the member companies of The Japan Iron and Steel Federation (JISF) and The Japan Chemical Fibers and Textile Association (JCFTA), where mortality surveillance systems have been established. SMRs for all causes of death from 1969 to 1981 were within the range of 50 to 81 in JISF, and 34 to 41 in JCFTA. These results point to the existence of strong HWE, equal to or even lower than the reported values in some industrial populations in the United States. An evident HWE for cancer was also observed in the study populations, but it was reported to be of little significance, if at all, in the United States. HWE can be considered as a composite result of factors such as: (1) selection of healthier work force, (2) risk reduction due to life style modification during employment, and (3) methodological characteristics of the SMR, which are dependent on the percentage of active workers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Structure of the gene for the arylphorin-type storage protein SP 2 of Bombyx mori.

Two forms of storage proteins termed "SP 1" and "SP 2", respectively, accumulate in a stage-dependent fashion in the larval hemolymph of the silkworm Bombyx mori. We have cloned and analyzed the genomic sequence encoding SP 2, an arylphorin-type storage protein. The SP 2 structural gene contains five exons spanning over 5 kilobases of chromosomal DNA. The transcription initiation site of the SP 2 gene was identified at the nucleotide level and a typical TATA box was located 30 base pairs upstream of the transcription initiation site. The 5'-flanking region of the gene contains a sequence homologous to the SV 40 enhancer "core" structure. A region homologous to the Drosophila enhancer sequence predicted for the fat body specificity of gene expression exists in the 5'-upstream region. Developmental profiles of the SP 2 mRNA and its precursor in the fat body indicate that the biosynthesis of SP 2 is developmentally regulated at the level of transcription. The exon/intron composition of the SP 2 gene is remarkably similar to that of the SP 1 gene. Moreover, the deduced primary structures of SP 1 and SP 2 exhibit nearly 30% homology, implying that two storage protein genes of the B. mori silkworm might have evolved from a common ancestor.

Amino Acid Sequence↗
PubMed1989

Radioimmunoassay for endothelin and immunoreactive endothelin in culture medium of bovine endothelial cells.

Using a synthetic 21-residue endothelin as antigen, we have produced an antiserum for endothelin and developed a specific and sensitive radioimmunoassay (RIA) for endothelin. The minimum detection limit of the RIA was 1 pg/tube. Immunoreactive (ir-) endothelin was extracted from the culture medium by Bondelute C8 column. The ir-endothelin in the culture medium of endothelial cells (EC) from bovine pulmonary artery and carotid artery was 1.48 ng/ml and 3.31 ng/ml, respectively. Reverse-phase high performance liquid chromatography coupled with the RIA revealed that ir-endothelin in the culture medium comprised one major component corresponding to synthetic endothelin. In addition, the cultured EC of bovine pulmonary artery were specifically stained by immunohistochemical technique. These results suggest that endothelin could be produced in the EC of the pulmonary and carotid arteries besides the aorta. The RIA presented in this study could be an useful tool to investigate the pathophysiologic significance of endothelin.

Animals↗
PubMed1989

Inhibitory effect of Toxoplasma lysate antigen on the multiplication of transplanted tumor in mice.

Tachyzoites of the RH strain of Toxoplasma gondii were pretreated by a process of freezing and thawing followed by ultrasonication. After ultracentrifugation at 144,000 g for 120 minutes, the resulting supernatant contained a protein (TLA 144), which consisted mainly of a component of protozoan origin with a molecular weight of 10,000-20,000, and additional sugars, peptides, and amino acids. TLA 144 was soluble in water and of very low toxicity. Mice that had been inoculated with allogeneic (S-180) and syngeneic (Meth A) transplantable tumor cells, were injected intramuscularly with 100 micrograms of TLA 144 once a week for some time beginning one week after transplantation. It was found that after TLA treatment the multiplication of tumor cells was more intensely inhibited than following administration of OK-432, one of the biological response modifiers (BRMs).

Animals↗