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Biomedical subjects

M Toda

Publications and source records attributed to M Toda.

At least 145 records · Page 8Linked to original sources
PubMed1991

Inhibition of rotavirus and enterovirus infections by tea extracts.

Epigallocatechin gallate from green tea and theaflavin digallate from black tea inhibited infections of cultured rhesus monkey kidney MA 104 cells with rotaviruses and enteroviruses. Their antiviral effects were maximally induced when directly added to virus, and their pre- and post-treatment of the cells produced much weak antiviral activity. Antiviral activity of the extracts therefore seems to be attributable to interference with virus adsorption.

Animals↗
PubMed1991

[Clinical and physiological features of chronic pulmonary emphysema with paroxysmal dyspnea attacks masquerading as bronchial asthma--improvement of respiratory function after combination therapy of intravenous aminophylline and subcutaneous epinephrine following daily oral administration of prednisolone].

Cases of chronic pulmonary emphysema accompanied with paroxysmal dyspnea attacks are often misdiagnosed as bronchial asthma. These patients repeatedly fall into a state of life-threatening respiratory failure. We must make an accurate diagnosis of emphysema to provide care of them. To clarify the possibility of doing this, we investigated the clinical and physiological features (primarily respiratory function) of emphysema. We observed twenty-five patients with chronic pulmonary emphysema and with chronic bronchial asthma, previously confirmed by selective alveolo-bronchogram (SAB); this technique reliably diagnoses emphysema, but often induces dyspnea attacks due to the stimulation resulting from intratracheal and intrabronchial procedures. In eight patients, chronic pulmonary emphysema was accompanied by an attack of paroxysmal wheezing and dyspnea; chronic pulmonary emphysema with wheezing (WPE). In eight other patients, chronic pulmonary emphysema was present without such attacks; usual pulmonary emphysema (UPE). In the final nine patients, chronic bronchial asthma (CBA) was present, while emphysema was ruled out by means of SAB. In all patients, we measured respiratory function before and after the combination therapy of intravenous aminophylline and subcutaneous epinephrine, which followed daily oral administration of prednisolone (PAE-treatment). In the WPE group, significant increases in measurement of various respiratory functions, including VC, RV, RV/TLC%, FVC, FEV1.0, PFR and V75 (p less than .05 excluded in FEV1.0 and PFR were p less than .01), were found after the PAE-treatment, compared with the values revealed before the treatment. In the UPE group, there were few changes PAE-treatment, compared with the values revealed before the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1991

[Effect of total biliary diversion (cholecysto-jejuno-cystostomy) on gut hormone release and pancreatic structure in dogs].

In order to elucidate the effect to total biliary diversion (TBD) on gut hormone release and pancreatic structure, we performed cholecysto-jejuno-cystostomy (CJC) in 6 mongrel dogs using a small interposed intestinal segment between the gallbladder and the urinary bladder with ligation of the common bile duct. Twelve weeks after CJC, CJC was converted into cholecysto-jejuno-duodenostomy (CJD) to normalize luminal bile flow. Fat rich meal loading tests were carried out before and after these procedures. Plasma concentrations of GI hormones (CCK, PP, GIP) were measured by radioimmunoassay and morphological changes of the pancreas were evaluated by light and electron microscopic study. CJC significantly enhanced the basal levels and fat-stimulated release of both CCK and PP, however after CJD, these changes returned to the normal levels. Following CJC, fat-stimulated GIP release was completely inhibited, but recovered after CJD. Following CJC, hypertrophy of pancreatic acinar cells with profuse and dilated rough endoplasmic reticulum was observed, while after CJD this change returned to the pre-operative state. These results suggest that a feedback regulation may exist between luminal bile flow and CCK secretion, and pancreatic hypertrophy after TBD is, at least partly, due to the increased plasma CCK levels.

Animals↗
PubMed1990

[Antibacterial and anti-hemolysin activities of tea catechins and their structural relatives].

Among catechins tested, (-)epigallocatechin (EGC), (-)epicatechin gallate (ECg), (-) epigallocatechin gallate (EGCg) inhibited the growth of Staphylococcus aureus, Vibrio cholerae O1 classical Inaba 569B and El Tor Inaba V86. S. aureus was more sensitive than V. cholerae O1 to these compounds. EGCg showed also a bactericidal activity against V. cholerae O1 569B. Pyrogallol showed a stronger antibacterial activity against S. aureus and V. cholerae O1 than tannic and gallic acid. Rutin or caffein had no effect on them. ECg and EGCg showed the most potent anti-hemolysin activity against S. aureus alpha-toxin, Vibrio parahaemolyticus thermostable direct hemolysin (Vp-TDH) and cholera hemolysin. Among catechin relatives, only tannic acid had a potent anti-hemolysin activity against alpha-toxin. These results suggest that the catechol and pyrogallol groups are responsible for the antibacterial and bactericidal activities, while the conformation of catechins might play an important role in the anti-hemolysin activity.

Antitoxins↗
PubMed1990

[Relationship between the anti-hemolysin activity and the structure of catechins and theaflavins].

We examined the corresponding isomers of catechins and theaflavins for anti-hemolysin activities against Staphylococcus aureus alpha-toxin and Vibrio cholerae O1 hemolysin. Catechins and theaflavins showed anti-hemolysin activities in a dose-dependent manner. Among the catechins tested, (-)catechin gallate, (-)epicatechin gallate and (-)epigallocatechin gallate having galloyl groups in their molecules showed more potent anti-hemolysin activities against both toxins. On the other hand, free catechins, i. e. (-)catechin, (-)gallocatechin, (-) epicatechin and (-)epigallocatechin had low anti-hemolysin activities against alpha-toxin. Although (-)catechin or (-)gallocatechin had no effect on cholera hemolysin, (-) epicatechin and (-)epigallocatechin were slightly inhibitory. Among dextrocatechins, (+) epicatechin and (+)epigallocatechin proved to be more effective than (+)catechin and (+) gallocatechin. The anti-hemolysin activities of theaflavins against alpha-toxin and cholera hemolysin were dependent on the number of the galloyl group in their structure. These results suggest that the tertiary structure of the catechin or theaflavin and the active site of hemolysin, that affects the interaction between them, plays an important role in the anti-hemolysin activity.

Biflavonoids↗
PubMed1990

[Myxomatous stromal changes in bone marrow following chemotherapy of acute leukemia--immunohistochemical characteristics of matrix components].

Although fibrosis and gelatinous transformation of bone marrow stroma are well known, there have been few histopathological descriptions in the literature. We studied 16 cases of acute leukemia, and describe the myxomatous changes of bone marrow stroma observed at 2 or 3 weeks following chemotherapy. We analyzed the extracellular matrix components immunohistochemically, using monoclonal or polyclonal antibodies raised against collagens, proteoglycans (PG), fibronectin and laminin. We found that the major components of the myxomatous matrix were chondroitin 6-sulfate PG and large PG. The stainability resembles that of extracellular matrix components in long-term bone marrow culture. We suppose that the myxomatous matrix provides favorable conditions for hematopoiesis, because hematopoietic cells proliferate and differentiate as soon as such stromal changes occur.

Adolescent↗
PubMed1990

[Effect of ileo-jejunal transposition on intestinal structure, plasma enteroglucagon level and evoked potential difference in dogs].

The effects of ileo-jejunal transposition (IJT) on intestinal structure, gastro-intestinal hormones and D-glucose- and L-glycine-evoked potential difference (PD) were studied in dogs. IJT was performed by isoperistaltic interposition of the distal fourth of the small bowel into the proximal jejunum, 15cm distal from the ligament of Treitz. 1) Following IJT, hyperenteroglucagonemia and an increase of mucosal thickness in the whole small intestine were observed. 2) The D-glucose-evoked PD in the mucosa of the transposed ileum was much lower than that in the preoperative ileal mucosa. On the other hand, L-glycine-evoked PD showed no difference between before and after IJT. These results suggest that both morphological and functional intestinal adaptation will simultaneously occur after IJT. This study also suggests that the mechanism of the intestinal adaptation after IJT may be, at least partly, mediated through the increased release of enteroglucagon.

Animals↗
PubMed1989

Structural organization of the gene encoding apolipoprotein A-II in an amyloidotic strain of senescence-accelerated mouse.

An inherited polymorphism occurring in the murine apolipoprotein A-II (ApoA-II) transcript seems to be related to the senile amyloidosis which occurs in accelerated-senescence-prone mice (SAM-P). Such being the case, we have determined the entire nucleotide (nt) sequence of the apoA-II gene. The length of the gene is about 1.3 kb and it is interrupted by three introns and the four exons aligned perfectly with the previously sequenced elements of an apoA-II cDNA. Two-nt substitutions [Pro-5(CCA)----Gln(CAG)] in the SAM-P genome were identified in the third exon, hence, we could use a restriction fragment length polymorphism to detect the apoA-II molecular type. Several possible regulatory signals were identified (i) in the 5'-flanking region, including CAAT and TATA boxes, the viral enhancer-like sequence, and the consensus sequences of estrogen response element, and (ii) in the 3'-flanking region, including sequences conserved in the immunoglobulin enhancer, glucocorticoid and estrogen response elements, and a B1 repetitive sequence.

Amino Acid Sequence↗
PubMed1989

Excision products of immunoglobulin gene rearrangements.

We have isolated circular DNAs from splenocytes of euthymic and athymic mice, and prepared the DNA libraries of 1.5 X 10(6) clones. Hundreds of clones homologous to immunoglobulin (Ig) heavy chain segments (DSP2 and DQ52-JH) or light chain segments (J kappa and J lambda) have been identified. Southern hybridization predicted that three of 12 euthymic mouse clones homologous to DQ52-JH and four of 10 athymic mouse clones homologous to DSP2 contained reciprocal recombination products of D-J joining. Some of these clones were characterized by sequencing: two clones contained the precise excision product of the recombination of a DSP2 segment with either JH2 or JH3 segment; two clones showed imprecise ligation of the DSP2-JH2 coding joint and precise ligation of the DFL16.1-JH3 reciprocal joint in the same molecule. They seem to represent a replacement of the pre-existing DSP2-JH2 rearrangement by joining an upstream DFL16 segment to a downstream JH3 segment. The presence in extrachromosomal DNA of a reciprocal recombination product of DH-JH joining is consistent with the view that immunoglobulin genes, like T cell receptor (TCR) genes, can be rearranged in B cell lineage by the looping-out and excision of chromosomal DNA.

Animals↗
PubMed1989

Cholecystokinin antagonism by anthramycin, a benzodiazepine antibiotic, in the central nervous system in mice.

Anthramycin (ATM) which is a product of some streptomyces micro-organisms was shown to antagonize the central effects of cholecystokinin (CCK) such as antinociception and satiety and to displace CCK bound to the slices from the brains of mice. Sulfated octapeptide CCK (CCK8) was administered intracisternally to mice at doses of 1 microgram/mouse for inducing antinociception and 200 ng/mouse for satiety. ATM was administered intraperitoneally to mice at doses such as 0.3 and 0.5 mg/kg. CCK8-induced antinociception and satiety were significantly reversed by ATM in those doses. [125I]CCK8 binding to the brain slices was observed autoradiographically. The autoradiograms from the slices were converted to false color images by using a microcomputer. The radioactivity in the autoradiograms was expressed by color spectra in the false color images. Comparison of the binding of [125I]CCK8 to the brain slices in the presence and the absence of ATM revealed that ATM (10(-6) M) clearly displaced the CCK8 binding in the various regions, especially in the cortex, of the brain. These findings suggest that ATM acts as an potent antagonist of CCK in the central nervous system in mice.

Animals↗
PubMed1989

Excision products of the T cell receptor gene support a progressive rearrangement model of the alpha/delta locus.

We have cloned extrachromosomal circular DNAs containing T cell receptor (TCR) delta gene segments in adult mouse thymocytes and splenocytes. We find that the frequency of circular DNA clones carrying germline delta sequences is lower than that of J alpha probe-positive clones, possibly related to increasing 5' distance from the most upstream J alpha segment. This suggests that the TCR alpha/delta locus is successively rearranged from within and that the delta-containing excision products are progressively diluted out by the subsequent cell division which includes further alpha gene rearrangements. In addition, examination of delta gene excision products revealed newly identified V delta subfamilies, the reciprocal joining of two D delta elements, J delta 2 usage in thymocytes and novel sequences homologous to the human delta-gene deleting elements.

Amino Acid Sequence↗
PubMed1989

A cytotoxic serine proteinase isolated from mouse submandibular gland.

We have isolated a novel cytotoxic factor from the submandibular glands of male BALB/c mice by Sephadex G-50 gel filtration chromatography and reverse-phase HPLC. The cytotoxic factor is a serine proteinase, which belongs to the mouse glandular kallikrein (mGK) family, with an Mr of approximately 27,000. The purified serine proteinase showed cytotoxic activity against mouse thymocytes in a dose-dependent manner, and a serine proteinase inhibitor, diisopropyl fluorophosphate, blocked its cytotoxic activity.

Animals↗
PubMed1989

Response of gut glucagon-like immunoreactivity to hypoglycemia in dogs.

Previous studies demonstrated that insulin-induced hypoglycemia enhances glicentin secretion in piglets and prompted us to investigate the response of glucagon-like immunoreactivity (GLI) to hypoglycemia in dogs. Insulin hypoglycemia did not induce any rise of plasma total immunoreactive glucagon (IRG) measured by nonspecific antiserum to glucagon in normal or pancreatectomized dogs under anesthesia. In contrast, insulin-induced hypoglycemia clearly increased plasma total IRG in both normal and pancreatectomized dogs in a conscious state. Administration of acetylcholine resulted in an elevation of plasma total IRG, whereas epinephrine induced a slight increase in plasma total IRG. The infusion of alpha- or beta-adrenergic blockers did not affect the response of plasma total IRG to hypoglycemia, whereas atropine completely blunted the increase in plasma total IRG during insulin hypoglycemia. Similarly atropine abolished the rise of plasma total IRG during intravenous administration of 2-deoxy-D-glucose. It is concluded that hypoglycemia clearly enhances the secretion of GLI from the gut in dogs and that GLI secretion during hypoglycemia is modulated, at least in part, by the autonomic nervous system.

Acetylcholine↗
PubMed1989

Intestinal absorption of dolichol from emulsions and liposomes in rats.

The intestinal absorption of dolichol from various dosage forms was investigated using the intestinal loop and everted sac methods in the rat. The in situ loop experiments showed that the absorption of dolichol from a triglyceride emulsion was dependent on the chain-length of the triglyceride; the absorption from a tri-n-butyrin emulsion in 1 h was 18.0% of the dose; and the absorption from an HCO-60 suspension was 4.3%. The liposomal preparation enhanced the absorption up to 39.1% of the dose. In in vitro experiments, 25.0% and 13.2% of dolichol were taken up by everted sacs of the jejunum and the ileum, respectively. On the other hand, phospholipids composing liposomes were not absorbed under these conditions. The above results suggest that the absorption mechanism from liposomal preparations may be as follows: dolichol is released from the liposomes into the aqueous phase adjacent to the surface of the intestine and is subsequently partitioned into the intestinal tissue.

Animals↗
PubMed1989

[Antibacterial and bactericidal activities of Japanese green tea].

We found that extracts of Japanese green tea leaves inhibited the growth of various bacteria causing diarrheal diseases. All tea samples tested showed antibacterial activity against Staphylococcus aureus, S. epidermidis, Vibrio cholerae O1, V. cholerae non O1. V. parahaemolyticus, V. mimicus, Campylobacter jejuni and Plesiomonas shigelloides. None of the tea samples had any effect on the growth of V. fluvialis, Aeromonas sobria, A. hydrophila, Pseudomonas aeruginosa, Salmonella enteritidis, enteroinvasive Escherichia coli, enterohemorrhagic E. coli, enteropathogenic E. coli, enterotoxigenic E. coli, Enterobacter cloacae or Yersinia enterocolitica. Salmonella and Shigella showed susceptibilities different depending on the kind of Japanese green tea. Japanese green tea showed also bactericidal activity over S. aureus, V. parahaemolyticus and even enteropathogenic E. coli which was not sensitive when tested by cup method. The bactericidal activity was shown even at the drinking concentration in daily life.

Bacteria↗
PubMed1989

[Effect of ileo-jejunal transposition (IJT) on gastrointestinal hormones and intestinal structure in dogs].

The effects of ileo-jejunal transposition (IJT) on gastro-intestinal hormones and intestinal structure have been studied in 9 mongrel dogs. IJT was performed by isoperistaltic interposition of the distal fourth of the small bowel in the jejunum 15 cm distal from the ligament of Treitz. A test meal (carbohydrate- and fat-rich) loading was carried out in 5 dogs before and 4 and 12 weeks after the operation. Plasma concentrations of gastrointestinal hormones (GLI, GI, GIP and gastrin) were measured by radioimmunoassay using the antibodies. The six mongrel dogs were used for the histological studies. Following IJT hyperenteroglucagonemia was observed, especially in postprandial state. An increase of the mucosal thickness in the whole intestine was observed after IJT. This suggested the possibility that enteroglucagon stimulates intestinal mucosal growth as a circulating hormone. Postprandial plasma GIP levels after IJT were significantly lower at the 90, 120 and 150 min after the test meal loading than those of the preoperative state. Plasma gastrin levels were no significant differences before and after surgery. These observations lead us to conclude that enteroglucagon may play an important role in intestinal adaptation mechanisms after IJT.

Animals↗
PubMed1989

[Percutaneous transluminal coronary angioplasty for treatment of acute myocardial infarction: comparison with percutaneous transluminal coronary recanalization].

Percutaneous transluminal coronary angioplasty (PTCA) was evaluated as a means of reperfusion of the infarct-related coronary artery, and the results were compared with those of percutaneous transluminal coronary recanalization (PTCR). There were no difference in sex, age, infarct location and time from the onset to start of treatment between 135 patients with evolving acute myocardial infarction treated with PTCA (PTCA group) and 113 patients treated with PTCR alone (PTCR group). Fifty-nine patients in the PTCA group underwent PTCA following PTCR; the remaining 76 patients were without prior PTCR. Successful PTCA, defined as a 20% or more reduction in percent luminal stenosis diameter, was achieved in 123 (90%) of the 135 patients in the PTCA group. The reperfusion rate was 93% in the PTCA group and 77% in the PTCR group (p less than 0.01). Residual stenosis immediately after the treatment was 30 +/- 13% in the PTCA group and 70 +/- 16% in the PTCR group (p less than 0.01). In the PTCA group, three cases developed serious complications which were associated with angioplasty: coronary perforation, side branch occlusion resulting in cardiogenic shock and exacerbation of cardiogenic shock. The latter two patients died, however, there was no difference in hospital mortality rate: 6% in the PTCA group versus 11% in the PTCR group. At follow-up angiography performed four weeks after admission, reocclusion of the successfully recanalized arteries was observed in 3% of the PTCA group and in 14% of the PTCR group (p less than 0.01). Regional wall motion was evaluated by left ventriculography using a wall motion score system which consisted of six grades; from normal counted as 0, to dyskinesis counted as 5. There was no difference in the wall motion score between the successful PTCA group and the successful PTCR group (2.6 +/- 1.4 versus 2.8 +/- 1.4), but the scores of both groups were better than those of the non-recanalized group (3.4 +/- 1.0: p less than 0.01). In conclusion, PTCA and PTCR have the same effect on hospital mortality rate and regional wall motion, but PTCA has a higher reperfusion rate and a lower reocclusion rate than does PTCR. Although PTCA has a potential disadvantage inducing serious complications, it appears to be a useful treatment for acute myocardial infarction.

Aged↗