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Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 811 records · Page 45Linked to original sources
PubMed1994

Development of hemopoietic bone marrow within the ectopic bone induced by bone morphogenetic protein.

Neogenesis of hemopoietic bone marrow was observed in the ectopic bone induced by implantation of bone morphogenetic protein (BMP) into the muscle of mice. A bone rudiment-like cartilage was formed first, which was then replaced by bone through an endochondral ossification process. Bone marrow formation occurred after the invasion of blood vessels into the cartilage, with accumulations of small lymphocyte-like cells and the appearance of large hemopoietic stem cells around the blood vessels. The stem cells proliferated and differentiated to form hemopoietic bone marrow. This process was similar to the embryogenesis of bone and bone marrow, but the hemopoietic activity of the BMP-induced bone was transient. The bone marrow was converted to fatty tissue within 2 weeks of its appearance. This study showed that implantation of BMP in the ectopic sites offers a useful model to investigate the neogenesis of ectopic bone marrow and the regulation of its activity.

Adipose Tissue↗
PubMed1994

[A study of complement fixation test by trinitrophenyl-cap-liposome: application of viral antibody test].

The complement fixation (CF) test is used as one of the diagnostic laboratory procedures for viral infections. The liposome is employed in the immunological method for basic research and we used the trinitrophenyl-cap-liposome (TNP-L) instead of sensitized erythrocyte for CF test. "TNP-L" consists of a plasma membrane of trinitrophenyl bases sensitized with antibody and is dissolved easily by animal complements. Carboxyfluorescein enclosed in liposome is released in fixed quantities according to liposome dissolution. Therefore, as our conclusion, the above CF method has a good agreement to that of sensitized erythrocyte. TNP-L method has advantages to be able to eliminate the individual differences and shorter storage-term of red blood cells and is also satisfactory for utilization with high reproducibility and intra day precision.

Animals↗
PubMed1994

[Two cases of replacement lipomatosis of the kidney].

Two cases of replacement lipomatosis of the kidney are reported. One patient was a 64-year-old woman who presented with pain caused by a subcutaneous abscess in the back as the chief complaint. Replacement lipomatosis of the kidney associated with staghorn calculi was diagnosed by computerized tomography (CT) and magnetic resonance imaging (MRI), and nephrectomy was performed. The other patient was a 71-year-old woman whose chief complaint was repeated episodes of pyelonephritis. Staghorn calculi and severe renal dysfunction were diagnosed, and nephrectomy was performed. In both patients, pathological examination revealed marked hyperplasia of adipose tissue in the renal sinus which consisted of mature fat cells, and replacement lipomatosis of the kidney was diagnosed. CT is useful in the diagnosis of this disease, and MRI provides further confirmation.

Adipose Tissue↗
PubMed1994

How extensive should lymph node dissection be for cancer of the thoracic esophagus?

From 1985 to 1992, 171 patients with cancer of the thoracic esophagus underwent esophagectomy with systematic dissection of regional lymph nodes including cervical nodes. The hospital mortality rate was 5.3%. The dissected nodes were classified into four groups: the deep cervical (C), upper mediastinal and cervical paratracheal (U), middle and lower mediastinal (L), and upper perigastric (G) groups. The U group mainly consisted of nodes beside the recurrent laryngeal nerves. The phase of cancer infiltration of lymph nodes was evaluated by the total number and the distribution of involved nodes. Of cases with nodal involvement, only 37% were in the late phase, in which more than seven nodes or in which the U, L, and G groups were all involved. Of cases in the earliest phase in which only one node was involved, 93% had either the U or G group involved. The C group of nodes was infrequently involved until the late phase. Cancer had metastasized to the U and G groups across a considerable anatomic distance even in earlier phases. Outcomes of the cases with nodal involvement not in the late phase were satisfactory; the cumulative survival was 60% at 3 years and 54% at 5 years. Systematic nodal dissection would benefit even cases with nodal involvement, unless the disease is in the late phase. Nodes beside the recurrent nerves and upper perigastric nodes should be dissected with higher priority, though they are located anatomically distant.

Carcinoma, Squamous Cell↗
PubMed1994

[Conservative therapy for retinoblastoma--effect of melphalan on in vitro electroretinogram].

The effect of melphalan (an alkylic anti-cancer drug) on rabbit and human in vitro ERGs was studied to establish the non-toxic concentration of melphalan in chemo-thermotherapy for retinoblastoma. The ERGs were recorded before and 15 min after the perfusate was changed from the control solution to a melphalan-containing solution. Melphalan 10 micrograms/ml and 40 micrograms/ml caused no significant effect on the a-wave, the b-wave, or the oscillatory potential in either the rabbit or the human in vitro ERG. Melphalan 50 micrograms/ml significantly reduced the b-wave, but the change was reversible. Considering the minimum inhibitory concentration of melphalan against retinoblastoma cells on colony assay (4 micrograms/ml), melphalan is one of the most effective drugs for the conservative treatment of retinoblastoma.

Animals↗
PubMed1994

[A case of chronic herpes encephalitis with myelodysplastic syndrome (MDS)].

A 72-year-old male suffering with MDS was admitted to our hospital because of slowly progressive dementia, convulsions and consciousness disturbance. A CT scan of the brain showed a low density area in the right temporal to parietal lobe and T2-weighted MRI of the brain revealed a high intensity signal in the same area. Herpes simplex virus DNA was detected in CSF by PCR method. He was diagnosed as having herpes simplex encephalitis but his clinical course was prolonged and considered atypical as herpetic infection in CNS. However, after administration of aciclovir, progression of his symptoms stopped, and a CT scan still revealed abnormal findings with the same area after more than four months. We thought his chronic course of herpes encephalitis was caused by incomplete immune function suppressed by MDS.

Aged↗
PubMed1994

Correlation between bleeding time and antithrombotic effect of platelet-suppressive agents in rat experimental model.

To examine whether the dosage of a platelet-suppressive agent at which an antithrombotic effect is adequate and bleeding tendency is not increased can be found, the antithrombotic effects, antiplatelet effects and bleeding times of ticlopidine and aspirin were investigated in the rat experimental thrombus formation model. Thrombus formation was determined by measuring the change in wet weight of a silk thread placed in a carotid arteriovenous shunt. Ticlopidine inhibited thrombus formation and platelet aggregation at rather low doses (50-100 mg/kg) without prolonging bleeding time. However, aspirin did not inhibit thrombus formation at even the highest examined dose (200 mg/kg), while bleeding time was prolonged at even the lowest dose (50 mg/kg). These results suggest that a dosage of antithrombotic agent that does not increase bleeding tendency can be easily established using ticlopidine, although it is relatively difficult using aspirin.

Animals↗
PubMed1994

Pathophysiologic role of endothelin-1 in renal function in rats with endotoxin shock.

BACKGROUND: We hypothesized that endothelin-1 (ET-1) is an important mediator in renal dysfunction under septic conditions. This study clarified the pathophysiologic role of ET-1 in renal function under conditions of surgical stress, especially sepsis. METHODS: We investigated the correlation between ET-1 levels and renal function and the effect of anti-ET-1 antibody (AwET-1N40) on renal function in a septic shock rat model. RESULTS: The plasma ET-1 level increased significantly at 30 minutes and remained significantly elevated for 24 hours, reaching a peak (195 +/- 24.4 pg/ml) 3 hours after the endotoxin (lipopolysaccharide derived from Escherichia coli) injection. Increases in plasma creatinine concentration and blood urea nitrogen (BUN) level and decreases in urine volume and urinary sodium excretion were also observed in the early phase after endotoxin injection. The plasma creatinine concentration and the plasma ET-1 level increased significantly at 30 minutes, reached a peak at 3 hours, and then decreased. Anti-ET-1 antibody administration (5 nmol/kg body, four times intravenously) decreased plasma creatinine concentration and BUN level and increased urine volume and urinary sodium excretion 3 hours after endotoxin injection (creatinine, p = 0.07; BUN, p < 0.05; urine volume, p < 0.01; urinary sodium excretion, p < 0.01; anti-ET-1 vs shams). CONCLUSIONS: These results suggest that the increase in endogenous ET-1 induced by sepsis plays an important role in renal dysfunction in the septic state.

Animals↗
PubMed1993

Inhibitory effect of staphylokinase on platelet aggregation.

We investigated the effect of staphylokinase (SAK), which has specific thrombolytic properties, on human platelet aggregation. Platelet aggregation induced with collagen was observed following preincubation of platelets in platelet-rich plasma (PRP) or washed platelet suspension (WP) with SAK at 37 degrees C for 30 min. SAK inhibited platelet aggregation in PRP only at the highest examined concentration (1 x 10(-4) g/ml). Although SAK did not inhibit platelet aggregation in WP which contained fibrinogen, it did when the platelets had been preincubated with SAK and plasminogen. The most effective concentration in WP was 1 x 10(-6) g/ml. The effect could be inhibited by adding aprotinin or alpha 2-antiplasmin. The highest generation of plasmin in the same preincubation fluid was detected at 1 x 10(-6) g/ml SAK. We concluded that SAK can inhibit platelet aggregation in WP by generating plasmin and/or fibrinogen degradation products, but is only partially effective in PRP because of the existence of alpha 2-antiplasmin.

Amino Acid Sequence↗
PubMed1993

Presence of carnitine acetyltransferase in peroxisomes and in mitochondria of oleic acid-grown Saccharomyces cerevisiae.

Activity of carnitine acetyltransferase was detected in glucose- and oleic acid-grown Saccharomyces cerevisiae. Oleic acid-grown cells showed a ten-fold higher activity than glucose-grown cells. Subcellular fractionation of oleic acid-grown cells showed that carnitine acetyltransferase was present in peroxisomes, mitochondria, and cytosol. The results suggested the plausible presence of an 'acetylcarnitine shuttle' in this yeast, as in the case of an n-alkane-assimilating yeast, Candida tropicalis.

Acetyl Coenzyme A↗
PubMed1993

Detection of capsaicin-evoked release of glutamate from spinal dorsal horn slices of rat with on-line monitoring system.

We examined whether capsaicin evokes the release of glutamate from unmyelinated primary afferent fibers, using a fluorometric on-line monitoring system, in which immobilized glutamate dehydrogenase column was connected to an in vitro superfusion system. In this system, an application of capsaicin (1 microM) resulted in an increased outflow of glutamate from dorsal horn slices in a tetrodotoxin-resistant manner, while capsaicin (3 microM) was without effect on ventral horn slices. This effect of capsaicin on the dorsal horn slices was in a concentration-dependent manner at 0.1-3 microM and the effect at 10 microM was not larger than that at 3 microM. The competitive capsaicin antagonist capsazepine significantly reduced the release of glutamate evoked by 1 microM capsaicin. Twice exposures of dorsal horn slices to capsaicin led a significant decrease in the release of glutamate evoked by the second capsaicin stimulation, indicating desensitization to capsaicin. Thus, using on-line monitoring system, we actually demonstrated that capsaicin induced the release of glutamate from the dorsal horn, probably from capsaicin-sensitive primary afferent terminals.

Animals↗
PubMed1993

Determination of hyaluronic acid by high-performance liquid chromatography of the oligosaccharides derived therefrom as 1-(4-methoxy)phenyl-3-methyl-5-pyrazolone derivatives.

Hyaluronic acid (HA) was digested with various kinds of depolymerizing enzymes and the products were analysed by high-performance liquid chromatography (HPLC) after derivatization with 1-(4-methoxy)phenyl-3-methyl-5-pyrazolone (PMPMP). As hyaluronate 4-glycanohydrolase (EC 3.2.1.35) from sheep testis showed a high efficiency for depolymerization, giving the tetra- and hexasaccharides abundantly, and is inexpensive, a method for the specific determination of HA was established, based on digestion by this enzyme followed by determination of the tetra- or hexasaccharide derived therefrom as the PMPMP derivatives by HPLC with UV detection. This method allowed the determination of HA in the range 0.5-50 micrograms with high reproducibility.

Animals↗
PubMed1993

Parotid swelling. Does it affect serum isoamylase level?

Serum levels of total amylase and P-type, and S-type isoamylase were measured in 57 patients with chronic parotid swelling (41 men and 16 women; mean age 60.4) and the same number of age- and sex-matched control individuals without parotid swelling (41 men and 16 women; mean age 60.3). None of the three enzyme measurements differed significantly between patients with parotid swelling and control subjects. It is concluded that chronic enlargement of parotid glands does not affect serum isoamylase level.

Adult↗
PubMed1993

Is the Watanabe heritable hyperlipidemic rabbit a suitable experimental model for percutaneous transluminal coronary angioplasty in humans? A light microscopic, immunohistochemical and ultrastructural study.

OBJECTIVES: This study was designed to assess an experimental model for the study of mechanisms that underlie restenosis after percutaneous transluminal coronary angioplasty. BACKGROUND: The Watanabe heritable hyperlipidemic (WHHL) rabbit lacks the receptor for low density lipoproteins, produces atherosclerotic lesions very similar to those in humans and, therefore, could serve as a suitable model. METHODS: Percutaneous transluminal angioplasty was performed on the left subclavian artery of 10 homozygous rabbits. The animals were killed at a few hours or 3, 7, 14 or 28 days after the procedure. The artery was fixed by perfusion, and the site of angioplasty was examined by both light and electron microscopy with the use of conventional and immunohistochemical staining techniques. RESULTS: Angioplasty had caused a flap-like or dissecting tear into the media. At day 3, cells within the preexisting media adjacent to the injury had the ultrastructural characteristics of synthetic smooth muscle cells. At day 7, spindle cells at the site of injury stained either negative or very weakly positive with a marker for actin; ultrastructurally, these cells had the synthetic phenotype. At day 14, the spindle cells showed a mix of contractile and synthetic phenotypes. The surface was partially covered by endothelial cells. At day 28, the dominant cell type was the contractile smooth muscle cell and the surface was completely covered by endothelial cells. CONCLUSIONS: Both the injury and the response to injury after percutaneous transluminal angioplasty were almost identical to that seen in humans after coronary angioplasty. Thus, the WHHL rabbit appears to be an appropriate experimental model for use in further studies.

Angioplasty, Balloon, Coronary↗