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Biomedical subjects

M Miyairi

Publications and source records attributed to M Miyairi.

At least 19 recordsLinked to original sources

High prevalence rate of Helicobacter pylori resistance to clarithromycin during long-term multiple antibiotic therapy for chronic respiratory disease caused by non-tuberculous mycobacteria.

BACKGROUND: Helicobacter pylori resistance to clarithromycin, probably due to the frequent use of this antibiotic for the treatment of other diseases, is the greatest obstacle against its eradication. AIM: To clarify the prevalence of clarithromycin-resistant H. pylori in patients with non-tuberculous mycobacterial lung disease receiving multiple antibiotic treatment, including clarithromycin. METHODS: We enrolled 88 patients with non-tuberculous mycobacterial lung disease; 29 underwent upper gastrointestinal endoscopy for the diagnosis of H. pylori infection prior to treatment, and 60 underwent it during treatment. The diagnosis of H. pylori infection was confirmed by histological examination, urease test and microaerobic bacterial culture. The minimum inhibitory concentration of clarithromycin was determined and the DNA was analysed for each of the isolated H. pylori strains. RESULTS: Patients during the treatment had a high prevalence rate of clarithromycin-resistant H. pylori (100%). Analysis of DNA of the clarithromycin-resistant H. pylori isolates revealed point mutations at A2142G or A2143G. Moreover, a linear correlation was found between the total cumulative dose of clarithromycin and the minimum inhibitory concentration. CONCLUSION: All patients with non-tuberculous mycobacterial lung disease being treated long-term with multiple antibiotics, including clarithromycin, harboured clarithromycin-resistant H. pylori in the stomach. Therefore, eradication of H. pylori before commencement of long-term therapy including clarithromycin should be recommended.

Anti-Bacterial Agents↗

Differences in hemostasis among sclerosing agents in endoscopic injection sclerotherapy.

Endoscopic injection sclerotherapy is useful in stopping bleeding from esophageal varices. We compared the in vivo effects of sclerosants on thrombogenesis, hemostasis, and endothelial injury. We injected aethoxysclerol (AS) of ethanolamine oleate (EO) into the small veins of the rat intestine. The maximum thrombogenic index with AS was 30.7 and with EO was 9.2. The venous flow stopped sooner with EO than with AS. The thrombi caused by EO were mixed with red blood cells. Heparin pretreatment decreased the thrombogenic index with AS by 96.7%, but not that with EO. The area of the fluorescein-albumin conjugate that permeated from veins with AS was larger than that with EO. The fluorescent intensity with AS was lower than that with EO. We thus conclude that: (1) the size of thrombi is not necessarily proportional to the hemostatic efficacy; (2) change in a patient's coagulation may affect the potential of sclerosants; (3) the excellent hemostatic efficacy of EO is based on localized injury to the endothelium and the involvement of red blood cells aggregation; and (4) in vivo microscopy is useful in determining the rational selection of sclerosants.

Animals↗

An autopsy case of pseudosarcoma of the common bile duct.

An autopsy case of pseudosarcoma in the common bile duct is reported. An 82-year-old Japanese male complaining of jaundice was admitted to our hospital; he was examined by abdominal ultrasonography (US), revealing biliary calculus, dilatation of the common bile duct, and choledocholithiasis, considered to be the possible cause of the obstructive jaundice. Endoscopic retrograde biliary drainage (ERBD) and cholangioscopy were performed concurrently, revealing a vaguely whitish tumor near the papilla of Vater. Two months later, the patient died from complications of the liver, infection, and disseminated intravascular coagulation (DIC). An autopsy study revealed tumor cells with extreme pleomorphic changes, growing diffusely, very like sarcoma. Further examination revealed epithelioid arrangements in the metastatic lymph node. Twelve kinds of immunohistochemical examination showed a positive reaction, reflecting the presence of an epithelioid cytoskeleton. Of 28 cases of true and pseudosarcoma of the biliary system reported in the Japanese literature, only 1 case was reported, in 1990, to involve the common bile duct. We therefore report the present case of pseudosarcoma of the common bile duct.

Aged↗

In vivo visualization of lymphatic microvessels and lymphocyte migration through rat Peyer's patches.

BACKGROUND/AIMS: In the small intestine, lymphocytes migrate through Peyer's patches. The distribution of lymphatic microvessels in rat Peyer's patches and lymphocyte traffic through them were studied. METHODS: Vital dyes were injected via a micropipette into the Peyer's patches tissue to fill lymphatic microvessels and to stain lymphocytes in lymphatic microvessels. RESULTS: Direct microscopic observation revealed a dense plexus of lymphatic microvessels in the perifollicular and interfollicular areas. Injection of the dyes into the germinal center failed to delineate lymphatic microvessels. The lymphatic microvessels in the perifollicular area were filled with lymphocytes. Most lymphocytes in the perifollicular lymphatics stayed in the lymphatic microvessels. Some lymphocytes became detached and drained into lymphatic microvessels in the interfollicular areas. Lymphocytes then moved toward the submucosal lymphatics beneath the villi around the Peyer's patches. The interfollicular lymphatics did not display contractile activity but had valves. Opening and closing of valves was synchronized with the respiration and the back and forth flow of lymphocytes. CONCLUSIONS: There are numerous lymphocytes in a dense lymphatic network in the perifollicular and interfollicular areas of Peyer's patches. This well-developed lymphatic network has the potential capacity for storage of lymphocytes and modulation of lymphocyte migration.

Animals↗

[Successful therapy with tegafur and lentinan after TAE for hepatocellular carcinoma--a case report].

A 46-year-old male (performance status 1) with hepatocellular carcinoma (HCC), which diffusely involved the anterior segment of the right lobe, occluded the second portal branch and metastased to the left lobe (stage IV-A), was on combined therapy with TAE of lipiodol (LPD), mitomycin C (MMC) 10 mg and gelatin sponge at the time of angiography on March 16, 1987. Immunochemotherapy with tegafur suppository (Teg sp) 1,000 mg/day and OK432 i.m. was performed for one month after TAE. Instead of OK432, lentinan (LNT) 2 mg in 20% glucose sol. 20 ml i.v./wk was combined with Teg sp 1,000 mg/day from May 13, 1987. Teg sp was reduced to 1,000 mg/2 days from June of the same year, and since then the same therapy of Teg + LNT has been continuing even now. Serum AFP values showing 150 X 10(4) ng/ml at maximum were decreased down to less than 20 ng/ml 13 months after this therapy (total doses: Teg ca. 250 g, LNT 108 mg), remaining still normal. Marked reduction in the size of the lesion (PR) by the therapy has also been proved by the body CT. His PS is now in grade 0. Although in this case the initial steep decline in AFP values was possibly brought about by TAE, the successive antitumor effect indicated by persistent low AFP values may have been mainly due to Teg + LNT. Collection of data on the therapy is needed to clarify this point.

Antineoplastic Combined Chemotherapy Protocols↗

Colchicine effect on bile canalicular motility: long-term study using isolated cultured hepatocytes and time-lapse cinephotomicrography.

The effect of colchicine on spontaneous in vitro contractions of bile canaliculi was assessed using time-lapse cinephotomicrography. Colchicine 2.5 microM and/or taurocholate 5 microM were added to the culture medium. The experiment was long-term, lasting for 13 h. Frame-by-frame analysis revealed that colchicine, after a lag period of 4 h, suppressed the number of contractions over the remainder of the 13-h experimental period, even in the presence of taurocholate (p less than 0.001). The number of contractions per hour decreased in both the colchicine and combined colchicine-plus-taurocholate-treated groups compared to untreated and taurocholate-treated controls. These results do not necessarily mean that colchicine has an effect on the contractile process per se, since the contractions, when they occurred, appeared normal. It is likely that the canalicular motility events are related to bile secretion. The reduction in contractions after a lag period likely indicates that secretion is impaired, and hence the need for contractions is reduced. These results support the view that for normal canalicular bile secretory function, microtubules as well as a normal microfilament system are required.

Animals↗

Cell motility of fetal hepatocytes in short-term culture.

The motility of freshly isolated fetal rat hepatocytes using time-lapse cinemicroscopy was documented and the fetal liver was stained by the DACH-HMM method for F-actin. This approach allowed direct correlation of cellular activity with the distribution of cytoplasmic actin filaments. The fetal liver cells were highly active, and showed ruffling, pseudopodia, and random forceful movements which caused the cells to pull apart from each other. The behavior of these cells differed markedly from that of adult liver cells which remain cohesive and show orderly contractions of bile canaliculi. Cytoplasmic actin in fetal hepatocytes lacked the predominantly pericanalicular distribution observed in adult cells. Random spontaneous cellular contraction and locomotion of fetal liver cells give way during maturation to orderly, forceful contractions of bile canaliculi in fully differentiated cells and is accompanied by a redistribution of the cellular actin. These finding collectively suggest a correlation between actin filament distribution, hepatocellular development, and functional maturation.

Actins↗

Coordination of the contractile activity of bile canaliculi. Evidence from spontaneous contractions in vitro.

Rat hepatocytes, when isolated and maintained in primary culture, are capable of producing forceful contractions of their bile canaliculi, with contractions occurring on a regular basis once every 5.5 minutes. To determine whether the contraction of one bile canaliculus affected the contraction of a neighboring canaliculus, cinephotomicrographic studies of pairs of contiguous canaliculi were undertaken. The activity of 10 pairs of contiguous canaliculi, and 10 pairs of noncontiguous canaliculi which served as a control group, was recorded for a period of 12.5 hours at the rate of 1 frame every 15 seconds. Using frame-by-frame analysis of this period of observation, we determined the time of contraction of each of the canaliculi in the pairs. Cross-correlations were obtained for the contraction times of each of the 10 pairs of contiguous canaliculi and 10 control pairs. A peak in activity was found, with that peak occurring five frames or 75 seconds from the midline, whereas the noncontiguous controls showed no correlation in contractile activity. This finding indicates that, when one bile canaliculus contracts, a neighboring canaliculus is likely to contract after an interval of 1.25 minutes. That there is coordination of contractile activity of bile canaliculi suggests that, within the intact liver lobule, ordered motility function of the bile canaliculi may facilitate bile flow.

Animals↗

Taurocholate accelerates bile canalicular contractions in isolated rat hepatocytes.

The influence of sodium taurocholate on bile canalicular contractions was examined by time-lapse cinephotomicrography of isolated rat hepatocytes in primary monolayer cultures. Frame-by-frame analyses indicates that as the dose of taurocholate increased, the number of contractions increased in a dose-dependent manner up to 5 microM. Because bile canaliculi are the smallest biliary passages across which bile secretion occurs, and because it is known that taurocholic acid within the dose range used in these studies causes a linear increase in bile secretion, the results suggest that canalicular contractions may be a function of canalicular bile secretion.

Animals↗

Phalloidin alters bile canalicular contractility in primary monolayer cultures of rat liver.

We observed the motility of bile canaliculi in isolated rat hepatocytes obtained from animals that were pretreated with phalloidin (500 micrograms/kg body wt) for 1 and 3 days. Time-lapse cinephotomicrographs were taken in each experiment and in controls for 16.25 h. As we previously reported in normal hepatocytes, active contractions of bile canaliculi were observed. The number of contractions was 127.6 in controls, compared with 58.0 in 1-day phalloidin pretreated and 16.2 in 3-day phalloidin pretreated groups. The contraction process itself was not normal in the experimental groups, the contraction phase being slow and sustained. The altered canalicular motility depended on the dose of phalloidin administered. These results suggest that the integrity of actin filaments is necessary for normal bile canalicular motility. Further, dysfunction of actin microfilaments with altered canalicular motility may be involved in the pathogenesis of canalicular cholestasis.

Animals↗

[Backward flow signal in the left atrium studied by Doppler echocardiography. Differentiation from mitral regurgitation].

A backward flow signal in the left atrium masquerading as mitral regurgitation was studied by a pulsed Doppler method. The subjects consisted of 20 normal volunteers, 12 cases with mitral valve prolapse syndrome, five cases with rheumatic mitral regurgitation, five cases with lone atrial fibrillation, four cases with asymmetric septal hypertrophy and three cases with the Björk-Shiley tilting disc valve in the mitral position. In two-dimensional echocardiography combined with pulsed Doppler method, a Doppler signal was recorded by locating a sample volume in the left atrium. In all of the cases with mitral valve prolapse syndrome and the cases with the prosthetic valve as well as in all of the normal subjects, the backward flow signal was observed in the left atrium. In three cases with mitral valve prolapse syndrome, it was differentiated from a transvalvular regurgitant flow signal. In all cases with rheumatic mitral regurgitation, the backward flow signal was masked by a turbulent flow signal representing regurgitation. In cases with mitral stenosis, the backward flow signal was scarcely recognized. The duration of the backward flow signal had no relationship with heart rate. The histogram of incidence on the scale of R-R interval revealed normal distribution with a mean value of 0.24 sec (+/- 0.09 sec). Therefore, in cases with tachycardia, the backward flow signal was seen throughout systole. The peak backward flow velocity of Doppler signals was correlated (r = 0.71, p less than 0.01) with the peak forward flow velocity in diastole. The faint backward flow signal seen in cases with mitral stenosis and post-extrasystolic potentiation of the backward flow signal were suggestive of the foregoing relationship. The mechanism producing the backward flow was postulated as a water hammer phenomenon caused by closure of the mitral valve.

Adult↗

Intrahepatic cholestasis as a canalicular motility disorder. Evidence using cytochalasin.

A rich network of actin-containing microfilaments are associated with the plasma membrane of the liver cells. These filaments are especially numerous in the pericanalicular region. Recently, active contractions of bile canaliculi have been observed in normal coupled isolated hepatocytes. In this report, we document that this motility behavior is abolished by cytochalasins B and D. Other cytoplasmic contractile movements are also reduced or lost after a brief initial period of enhanced surface activity with the formation of zeiotic blebs. The lack of contractile activity of bile canaliculi is accompanied by the gradual dilation of canalicular lumina. Since there is overwhelming evidence that the functional effects of the cytochalasins on cell motility are due to their effects on actin filaments, we propose that the altered canalicular contractility observed is due to the effects of cytochalasin on pericanalicular actin filaments. If bile canalicular contractility is a requirement for normal bile flow, then interference with this mechanism may be a factor in the pathogenesis of some types of intrahepatic cholestasis.

Animals↗

Effect of colchicine on intestinal alkaline phosphatase activity during linoleic acid absorption in rats.

The purpose of this study is to examine whether intestinal alkaline phosphatase (IAP) plays a role in transporting lipoproteins to lymphatics during fat absorption. In control rats, the increased activity of IAP in intestinal lymph was observed parallel with the amount of absorbed linoleic acid. In colchicine-treated rats, lymphatic absorption of intraduodenally administered linoleic acid was decreased and administered lipid was transported slowly to lymphatics, mostly in the form of free fatty acid. However, the equal or slightly larger amount of output of IAP to lymphatics was observed in spite of the decrease in lipid absorption in colchicine-treated rats. Histochemically, prolonged activity of IAP in stroma and submucosal lymphatics was found in colchicine-treated rats fed with fat. These results suggest that microtubules are not involved in IAP transport into lymphatics, and these data do not necessarily rule out that IAP plays a role in lipoprotein transport.

Alkaline Phosphatase↗

Pathological and pathophysiological study on intestinal lymphatic system in fat absorption.

Pathological and pathophysiological study on the intestinal lymphatics was carried out clinically and experimentally. Jejunal biopsy study revealed marked dilatation of intestinal lymphatics in liver cirrhosis with ascites and Behçet's disease as well as protein-losing enteropathy. Lymphangiographic study showed also abnormal findings in above-mentioned diseases. In cases of McKee dogs in which mechanism of blockade of lymphatic flow was already clarified, McKee dogs showed marked malabsorptive of fat. When lymphatic flow was blocked mechanically at the thoracic duct, fat accumulation was seen in the absorptive cells as well as in dilated intestinal lymphatics. In administration of colchicine to rats, fat accumulation was seen in the matrix of absorptive cells as well as in the endoplasmic reticulums and Golgi apparatus. However, amorphous substances instead of chylomicrons were seen in dilated intestinal lymphatics. These studies suggested that a tract of fat transportation from intestinal cells to the thoracic duct should be considered as a functional unit in fat absorption.

Animals↗

Role of plasma histamine in liver injury--clinical and experimental investigations.

Plasma histamine level (PHL) was evaluated by a modified fluorometric assay (Suzuki) in the patients with various forms of liver disease as well as rabbits with liver injury. And the data obtained were compared with liver function tests in assessing the stage and prognosis of hepatic dysfunction. In acute hepatitis, if its prognosis was "good", as was also shown in the animal group with single dose administration of CCl4, the level of plasma histamine attained a peak before that of serum transaminases, and returned to normal prior to that of the latter. In persistent and chronic hepatitis, although correlation between PHL and other liver function tests was poor and variable, PHL remained high. And the estimation of PHL during the course of this state showed that it was elevated prior to that of serum transaminases, in dicating high level of plasma histamine in this state, even in apparent "steady state", worsening of the disease. In liver cirrhosis PHL correlated with the degree of serum transaminases as well as serum gammaglobulin. In "poor prognosis" group (patients with hepatic coma and rabbits treated with consecutive administration of CCl4) PHL increased extremely high, which was contrasted with the lowered levels of transaminases. These results strikingly suggest that histamine is involved in liver injury and estimation of PHL in the course of hepatic disorder is useful for a prediction of prognosis.

Animals↗