Search PubMed⌕ Search

Biomedical subjects

M Mohri

Publications and source records attributed to M Mohri.

At least 109 records · Page 6Linked to original sources
PubMed1994

[Chest disease and embolization].

Bronchial artery embolization has become an established technique in the management of massive or recurrent hemoptysis, especially in treating patients who are poor candidates for lung surgical intervention. Nonbronchial systemic collateral arteries and pulmonary arteries may contribute significantly to pulmonary hemorrhage. In recent literature, the former embolization is widely accepted, but embolization of the latter has not been stressed, excluding the patients of AV malformation or pulmonary aneurysm. The recognitions of the precice bronchial artery anatomy and numerous collateral vessels are essential for successful embolotherapy. The much more attention should be given to the character of embolizing material. The clinical background, methods, and results of this procedure are discussed, as are the potential complications and their prevention.

Bronchial Arteries↗
PubMed1994

[A case of aortic regurgitation combined with obstruction of the left coronary ostium caused by adhesion of left coronary cusp].

A case, 31-year-old female with aortic regurgitation and ostial obstruction of left coronary artery, was reported. Her chief complaint was effort angina. The coronary angiography showed obstruction of left coronary ostium with intact main stem and its branches, perfused from right coronary artery and the aortogram revealed aortic regurgitation of grade 3-4. Left Valsalva sinus was obstructed by adhesion of left coronary cusp. Each coronary cusps were resected, and aortic valve replacement with 23 mm SJM valve and coronary arterial bypass by means of in-situ graft of left internal thoracic artery underwent successfully. The pathological findings of aortic cusps were healed valvulitis without specific inflammation as syphilis or aortitis syndrome.

Adult↗
PubMed1993

Antithrombotic effect of recombinant human soluble thrombomodulin on endotoxin-induced disseminated intravascular coagulation in rats.

Thrombomodulin (TM) is an endothelial cell membrane glycoprotein which neutralizes thrombin procoagulant activity and accelerates the thrombin-catalyzed activation of protein C. We expressed recombinant human soluble TM (rhs-TM) in Chinese hamster ovary cells and compared the effects of rhs-TM and heparin on endotoxin-induced experimental disseminated intravascular coagulation (DIC) in rats. Experimental DIC was induced by a continuous intravenous infusion of endotoxin for four hours. rhs-TM or heparin was infused simultaneously with endotoxin. Treatment with rhs-TM significantly reversed the endotoxin-induced changes in significantly reversed the endotoxin-induced changes in following parameters: platelet count, fibrinogen level and fibrinogen and fibrin degradation products. Furthermore, glomerular fibrin deposits elevated by endotoxin treatment were reduced by the rhs-TM administration. Heparin showed the similar effects to rhs-TM. Activated partial thromboplastin time (APTT) in rats receiving rhs-TM were slightly longer than APTT in endotoxin-treated rats, but rats receiving heparin had much more prolonged APTT. From these results, we concluded that rhs-TM may be useful for the clinical treatment of DIC while having only minor adverse effects on APTT.

Animals↗
PubMed1993

Ischaemic preconditioning--time course of renewal in the pig.

OBJECTIVE: The aim was to examine whether ischaemic preconditioning can be renewed by a second cycle of brief coronary occlusions in pigs subjected to two different reperfusion intervals (1 h or 4 d). METHODS: Ischaemic preconditioning was induced by a cycle of two 10 min occlusions of the left anterior descending coronary artery separated by 30 min of reperfusion. Infarction was induced with a subsequent 1 h occlusion and a 2 h reperfusion period. There were four experimental groups: in group I (n = 5), a 30 min reperfusion was interposed after the preconditioning cycle prior to the sustained occlusion; in group II (n = 5), this time frame was extended to 1 h; in group III (n = 5), the preconditioning cycle was renewed 1 h after the first cycle; in group IV (n = 5), the second cycle was performed 4 d later. Control pigs (n = 5) were subjected to 1 h coronary occlusion and 2 h reperfusion without previous short occlusions. Infarct size was measured with p-nitro blue tetrazolium and was expressed as a percent of area at risk. RESULTS: The percent of the risk region infarcted was 69.9 (SEM 3.8)% for controls, 22.9 (3.5)% in group I (p < 0.001 v controls), 67.3 (5.2)% in group II, 66.3 (4.2)% in group III, and 17.9 (3.9)% in group IV (p < 0.001 v controls). Regional wall function measured with ultrasonic crystals deteriorated through the reperfusion intervals, indicating different underlying mechanisms for ischaemic preconditioning and myocardial stunning. CONCLUSIONS: Ischaemic preconditioning with two 10 min occlusions reduced infarct size resulting from a 60 min coronary occlusion when that was performed 30 min after the last short occlusion. This effect was lost after 1 h. Preconditioning could be renewed by a second cycle of brief coronary occlusion and reperfusion 4 d but not 1 h after the first cycle. These results suggest the release of a mediator from an exhaustible pool.

Animals↗
PubMed1993

Human space experiments in SL-J: preparation and conducted.

This experiment investigated how human beings achieve visual stability during body movements, including fine motion on the ground. When humans are exposed to an environment with different gravity vectors, the programmed behavior on the ground must be changed, that is, it is reprogrammed. This is called habituation or familiarization. This experiment focuses on visual, vestibular and somatosensory perception coordination and how it changes in microgravity as compared to a 1-G environment. We examined these issues under microgravity during the mission Spacelab Japan [correction of Japane] (SL-J) mission with the cooperation of the Japanese Payload Specialist (PS), Dr. Mohri. In this paper we describe how the first human life science experiments were conducted and how the data processed is being.

Adaptation, Physiological↗
PubMed1993

[Clinical features of intestinal tuberculosis].

We had tuberculosis infection cases of gastrointestinal tract diagnosed histopathologically during January 1980 to December 1991 in Tokyo National Chest Hospital. There were 12 cases (male 8, female 4) from 24 y.o. to 88 y.o. (mean 50 y.o.). We got histopathological specimen by operation (6 cases), biopsy (4), and section (2). Pulmonary tuberculosis was complicated in 8 cases, 7 cases had cavity formation and another case was miliary tuberculosis. Distribution of tuberculous lesion was colon (7 cases), small intestines (5), cecum (2), rectum (1) and esophagus (1). First symptom was mainly abdominal symptom such as abdominal pain and diarrhea. There were a perforative peritonitis and a intestinal obstruction during chemotherapy. Three died cases complicated low albuminemia. We suppose that serum albumin is one of the useful marker of patient's prognosis.

Adult↗
PubMed1993

[Clinical studies on ceftriaxone in respiratory tract infections. CTRX Study Group].

We report that the results of clinical studies on ceftriaxone (CTRX) in respiratory tract infections (RTIs). Clinical efficacies and side effects of CTRX were as follows; 1. Clinical efficacies of CTRX in a total of 61 cases with RTIs were excellent in 11 cases, good in 23, fair in 11, poor in 12 and unknown in 4. Thus the overall clinical efficacy rate was 59.6%. In cases of patients with lung cancers, the efficacy rate was 42.9%. 2. Clinical efficacy rates with once daily dosage were 50.0% with a dose level of 1 g CTRX and 54.8% with that of 2 g CTRX. 3. Side effects were observed in 2 cases (3.1%) and laboratory abnormalities were observed in 1 case (1.6%). They were not serious, however. These data suggest that CTRX is one of the useful cephalosporins in treatment of RTIs.

Adult↗
PubMed1992

[Changes in right ventricular function with unilateral pulmonary artery occlusion test for pre-operative evaluation prior to lung resection].

We measured the right ventricular ejection fraction (RVEF) before and during unilateral pulmonary artery occlusion test (UPAO) by thermodilution method. We also measured the right ventricular end-diastolic volume index (RVEDVI), right ventricular end-systolic volume index (RVESVI), and right ventricular stroke volume index (RVSVI). RVEF and RVSVI were significantly decreased by UPAO (p less than 0.05), but there were no obvious changes in RVEDVI and RVESVI. Some cases showed only a small decrease in RVEF by UPAO, even though their total pulmonary vascular resistance indices were over 700 dyne.sec.cm-5/m2 during UPAO. On the other hand, some cases had a decreased in RVEF of more than 10% by UPAO, even though their total pulmonary vascular resistance indices were under 400 dyne.sec.cm-5/m2 during UPAO. We consider that it is important to measure right ventricular functions such as RVEF together with pulmonary vascular hemodynamics in the pre-operative evaluation of cases of lung resection.

Aged↗
PubMed1991

Involvement of a nuclear factor-kappa B-like protein in induction of the macrophage colony-stimulating factor gene by tumor necrosis factor.

The macrophage colony-stimulating factor (M-CSF) is required for the growth and differentiation of mononuclear phagocytes. Previous studies have demonstrated that tumor necrosis factor (TNF) induces transcription of the M-CSF gene in human myeloid cells. The present work examined the effects of TNF on cis-acting elements in the M-CSF promoter. Deleted forms of the M-CSF promoter were linked to the chloramphenicol acetyltransferase (CAT) gene and transfected by electroporation into HL-60 promyelocytic leukemia cells. The results demonstrate that an enhancer responsive to TNF stimulation is located between positions -406 and -344 upstream to the transcription start site. The fragment from positions -419 to -304 was cloned 5' to the heterologous thymidine kinase (TK) promoter and linked to the CAT gene. Both orientations of this fragment enhanced TK-promoter activity in TNF-treated HL-60 cells. The results of gel mobility shift assays with the -419 to -304 fragment demonstrate binding of a constitutive nuclear protein. A TNF-inducible protein also bound to this fragment and resulted in a different mobility pattern. Binding of the TNF-induced nuclear protein to the -419 to -304 fragment was inhibited by an oligonucleotide containing the nuclear factor-kappa B (NF-kappa B) consensus sequence. DNA footprinting demonstrated protection of an NF-kappa B binding site at positions -377 to -368. Methylation interference assays showed that the TNF-induced protein made contact points with guanine residues in the same NF-kappa B sequence. Taken together, the findings provide evidence for involvement of an NF-kappa B-like factor in transcriptional regulation of the M-CSF gene.

Base Sequence↗
PubMed1991

Effects of hyperbaric environment on the P300 component of event-related potentials.

Hyperbaric chamber dives at 19 ATA with helium-oxygen were performed at the Japan Marine Science Technology Center, Yokosuka, from January 31 to February 2 in 1990. During simulated underwater experiments, event-related potentials were recorded in 2 divers for assessment of the cognitive function. Although the P300 amplitude of the potentials did not show any significant change, its latency was clearly prolongated and this prolongation continued to when the decompression reached to 70 m below sea level. These findings indicated that the hyperbaric environment corresponding to 180 m below sea level or less must cause some cognitive dysfunctions and that P300 is useful for early detection of those dysfunctions or HPNS.

Cognition↗
PubMed1990

Phospholipase A2 activation and autoinduction of tumor necrosis factor gene expression by tumor necrosis factor.

Tumor necrosis factor (TNF) acts via a cell surface receptor to induce a variety of cellular events including cytolysis, differentiation, and mitogenesis. The mechanisms underlying the cell specific actions of TNF are not known. In the present study, postreceptor events associated with the autoinduction of TNF expression were examined in HL-60 cells. There was no detectable alteration in phospholipase C activity as measured by inositol phosphate generation or release of choline metabolites following TNF stimulation. However, TNF increased the release of arachidonic acid metabolites from HL-60 cells. This increase in arachidonic acid metabolism was associated with a 40% increase in phospholipase A2 activity. Furthermore, the release of arachidonic acid metabolites was blocked by inhibitors of phospholipase A2. Taken together, these findings indicated that TNF stimulates phospholipase A2 and arachidonic acid metabolism in HL-60 cells. The results also demonstrate that TNF expression is induced 15-30 min after stimulation with TNF and that this effect is associated with an increase in the rate of TNF transcription. This autoinduction of TNF mRNA was blocked by inhibitors of phospholipase A2. While the cyclooxygenase inhibitor indomethacin had no detectable effect, ketoconazole and nordihydroguaiaretic acid, inhibitors of lipoxygenase, also blocked the induction of TNF expression by TNF. These findings suggest that phospholipase A2 and lipoxygenase activity are required for the transcriptional activation of TNF gene expression associated with TNF stimulation of HL-60 cells.

Acetophenones↗
PubMed1990

Excitatory and inhibitory effects of adenosine on the neurotransmission in the hippocampal slices of guinea pig.

Postsynaptic potentials (PSPs) were recorded from the granular cell layer of guinea pig hippocampal slices. Application of adenosine at a concentration of more than 10 microM in the incubation medium depressed the amplitude of the PSP, but adenosine at a concentration of 10 nM to 1 microM enhanced the amplitude of the PSP. The dose-response curve of the effect of adenosine showed an excitatory and inhibitory biphasic pattern. Adenosine analogues such as adenosine triphosphate (ATP), adenosine diphosphate (ADP) and nicotinamide adenine dinucleotide (NAD) showed similar biphasic effects, however beta-gamma-methyleneadenosinetriphosphate (beta-gamma-ATP), 5'-N-ethylcarboxamidoadenosine (NECA). N6-cyclohexyladenosine (CHA) and N6-R-phenylisopropyladenosine (RPIA) revealed only inhibitory effects.

Adenosine↗
PubMed1990

Effects of lipopolysaccharide on phospholipase A2 activity and tumor necrosis factor expression in HL-60 cells.

LPS has been identified as a potent activator of mononuclear phagocytes. This activation is associated with TNF gene expression. The intracellular signaling mechanisms responsible for this effect, however, are unknown. The present studies demonstrate that LPS induces TNF transcripts in HL-60 promyelocytic leukemia cells. Because previous studies have demonstrated that eicosanoids are involved in the regulation of TNF gene expression in these cells, we examined the effects of LPS on activation of the arachidonic acid cascade. The results demonstrate that LPS stimulates phospholipase A2 activity and the hydrolysis of both 1,2-dipalmitoyl phosphatidylcholine and 1-steroyl 2-arachidonoyl phosphatidylcholine. In contrast, there was no detectable effect of LPS on activation of protein kinase C. We also demonstrate that inhibition of phospholipase A2 activity with bromophenacyl bromide or quinacrine blocks the induction of TNF transcripts by LPS. These findings suggested that LPS induces TNF gene expression through formation of arachidonic acid metabolites. Indeed, similar results were obtained with mellitin, a known activator of phospholipase A2 and eicosanoid production. Previous studies have also suggested that TNF mRNA levels are increased in HL-60 cells by the 5-lipoxygenase pathway and, in the present work inhibitors of this enzyme blocked LPS-induced TNF expression. Moreover, the cyclooxygenase metabolite, PGE2, as well as dibutyryl cAMP, inhibited the induction of TNF transcripts by LPS. Taken together, these results suggest that LPS induces TNF gene expression through activation of phospholipase A2 and that the level of this induction is regulated by activity of the 5-lipoxygenase and cyclooxygenase pathways.

Acetophenones↗
PubMed1990

Epithelial migration in the healing process of tympanic membrane perforations.

The healing process in 10 human tympanic membrane perforations after trauma and 20 myringotomies was observed under the microscope and was photographed. The movement of the healing process was from the central portion of the perforation to the periphery and followed the same direction as the drum's epithelial migration. At the central portion of the perforation's margin, the keratin layer proceeded to the periphery and was followed by the epidermal cell layer. Only slight movement was observed at the peripheral portion of the perforation. Histopathological examination confirmed these observations. These findings demonstrate that epithelial migration on the tympanic membrane plays a great role in the healing of a perforation.

Cell Movement↗
PubMed1990

Splenic contraction during breath-hold diving in the Korean ama.

Major increases of hemoglobin concentration and hematocrit, possibly secondary to splenic contraction, have been noted during diving in the Weddell seal. We sought to learn whether this component of the diving response could be present in professional human breath-hold divers. Splenic size was measured ultrasonically before and after repetitive breath-hold dives to approximately 6-m depth in ten Korean ama (diving women) and in three Japanese male divers who did not routinely practice breath-hold diving. Venous hemoglobin concentration and hematocrit were measured in nine of the ama and all Japanese divers. In the ama, splenic length and width were reduced after diving (P = 0.0007 and 0.0005, respectively) and calculated splenic volume decreased 19.5 +/- 8.7% (mean +/- SD, P = 0.0002). Hemoglobin concentration and hematocrit increased 9.5 +/- 5.9% (P = 0.0009) and 10.5 +/- 4% (P = 0.0001), respectively. In Japanese male divers, splenic size and hematocrit were unaffected by repetitive breath-hold diving and hemoglobin concentration increased only slightly over baseline (3.0 +/- 0.6%, P = 0.0198). Splenic contraction and increased hematocrit occur during breath-hold diving in the Korean ama.

Adult↗
PubMed1990

[Fatigue and performance of divers during a simulated, non-saturated oxygen-helium dive to 180 meters].

A non-saturated mixed-gas dive to 180 meters depth was carried out at JAMSTEC, using diving simulator (hyperbaric chamber) facilities. Compression started at 10:00 h with helium and oxygen and was carried out at a rate of 12 m/min. Decompression started at 11:15 h using the Comex Helox 180 Diving Manual. Decompression to 1 ATA required 49.2 h. A survey of subjective symptoms, sleep feelings and ball-bearing tests were performed. All night electrophysiological recording of subjects' sleep was performed and polygraphic analysis of nocturnal sleep was done with visual scoring. The results were as follows: Arriving at 180 meters, the complaint rate was 39.2% and fatigue was greater. The type of fatigue that was based on the composition + ratio of symptoms was that of mental fatigue. During the decompression it was recovery. The performance in the ball-bearing test decreased about 20% at a depth of 180 meters because of tremors and disturbance of attention as well as other factors showing symptoms of high-pressure nervous syndrome. The sleep feelings were different in experienced persons and non-experienced persons. The non-experienced persons had markedly decreased REM stages and slept badly all night. Based on these results, fatigue and the performance of divers were discussed.

Adult↗
PubMed1990

[Working ability between air and trimix breathing gas under 8 ATA air condition].

Pneumatic caisson work in Japan has come into operation since 1924. Afterward, this technique of compressed air work has been widely utilized in the construction of foundation basements, shafts of the bottom tunnel shields for subway and so forth. While using this technique of compressed air work means that workers have to be exposed to hyperbaric environment, this technique has risks of not only decompression sickness (DCS) but also toxicity of poisonous gas and/or oxygen deficiency. However, this technique is independent of city construction work and the operation of compressed air work higher than 5ATA (4.0 kg/cm2G) is actually been planning recently. Accordingly unmanned caisson work is considered as a better technique for such higher pressurized work, even though workers must enter into hyperbaric working fields for maintenance or repair of unmanned operated machinery and materials. This research is to establish the safe work under hyperbaric air environment at 8ATA.

Adult↗