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Biomedical subjects

Y Mochizuki

Publications and source records attributed to Y Mochizuki.

At least 19 recordsLinked to original sources
PubMed1995

Growth and maturation of small hepatocytes isolated from adult rat liver.

Small hepatocytes existed in the supernatant following low-speed centrifugation of the cell suspension after collagenase liver perfusion. The cells proliferated for more than 2 months and formed colonies in the Dulbecco's modified Eagle's medium supplemented with 10 mM nicotinamide, 10% fetal bovine serum, 1 mM ascorbic 2-phosphate, and 10 ng/ml epidermal growth factor. One small cell finally proliferated to several hundred cells. In addition, some cells in the colonies were shown to differentiate into mature hepatocytes that had a large cytoplasm and sometimes two nuclei. The secretion of albumin in the medium by the hepatocytes increased with time in culture, and the cells possessed connexin 32 in their cell membrane and many peroxisomes. Thus, the small hepatocytes may be "committed progenitor cells" which can further differentiate into mature hepatocytes.

Animals↗
PubMed1995

Amyotrophic lateral sclerosis with marked neurological asymmetry: clinicopathological study.

We attempted to correlate the marked neurological asymmetry observed in two amyotrophic lateral sclerosis patients with their histopathological lesions. Patient 1, a 52-year-old man, developed dysarthria and dysphagia, followed by muscle weakness in the left arm and then of the left leg. Patient 2, a 44-year-old man, developed muscle weakness in the left hand, left leg, tongue with left-sided predominance, right hand and right leg in that order of progression. Both patients exhibited moderate to marked left-sided predominant involvement of the lower motor neuron system, accompanied by retained or hyperactive deep tendon reflexes on the left side in the early stage of their illness. Most of the asymmetry in the lower motor neuron system involvement persisted until the death of the patients. Histopathological examinations, including semiquantitative analysis, revealed that both patients exhibited left-sided predominant degeneration of the lower motor neuron system at those spinal cord levels where the neurological asymmetry was of a moderate to marked degree. In addition left-sided predominant degeneration of the lateral corticospinal tracts was seen in both patients and right-sided predominant involvement of Betz cells in the leg area of the motor cortex of patient 1. This pattern of both the neurological and histopathological asymmetry suggested the probable existence of an intimate somatotopically related linkage between the upper motor neuron system degeneration and lower motor neuron system degeneration in both patients.

Amyotrophic Lateral Sclerosis↗
PubMed1995

Contingent negative variation and movement-related cortical potentials in parkinsonism.

The contingent negative variation (CNV) and movement-related cortical potentials (MRCPs) were recorded in 10 cases of Parkinson's disease, 10 cases of vascular parkinsonism and 10 age-matched healthy controls. The amplitude of the early CNV was smaller in the Parkinson's disease group and the vascular parkinsonism group than in the healthy control group. The latencies of Bereitschaftspotential (BP) and negative slope (NS') were longer and the amplitude of BP was smaller in the Parkinson's disease group and the vascular parkinsonism group than in the healthy control group. These abnormalities in CNV and MRCPs were improved by intravenous injection of L-DOPA.

Aged↗
PubMed1995

Reappearance and long-term maintenance of connexin32 in proliferated adult rat hepatocytes: use of serum-free L-15 medium supplemented with EGF and DMSO.

Intercellular communication, especially gap junctional communication, is thought to be one of the highly differentiated functions of hepatocytes. In primary cultures of rat hepatocytes, it has been considered that the maintenance and the reinduction of differentiated functions is very difficult. In the present study, we succeeded in inducing the gap junctional protein connexin32 (Cx32) in adult rat hepatocytes cultured in serum-free L-15 medium supplemented with epidermal growth factor (EGF) and dimethylsulfoxide (DMSO). When the hepatocytes were cultured in L-15 medium supplemented with 20 mM NaHCO3 and 10 ng/ml EGF in a 5% CO2:95% air incubator, the cells proliferated. Fluorescence immunocytochemistry showed spots immunoreactive to Cx32 on the cell membranes between adjacent cells until day 3, but only a few Cx32-positive spots were found after day 4. Western and northern blot analyses also showed that the amounts of both the protein and mRNA of Cx32 in the cells decreased with time in culture. However, when the cells were treated with 2% DMSO from day 4, the immunoreactive spots reappeared on the cell membranes from day 6 and both their number and intensity gradually increased. The reappearance of Cx32 was accompanied by increases in both the protein and mRNA of Cx32. Furthermore, the expression of Cx32 was well maintained, together with extensive gap junctional intercellular communication, for more than 4 weeks. In addition, ultrastructurally, many gap junctional structures were observed between the hepatocytes, and the antibodies to Cx32 were shown to bind to those structures. This culture system may be useful for studies of the reconstruction of the gap junctional structure, the intracellular pathways of the proteins, and the regulation of synthesis and processing in differentiated hepatocytes.

Animals↗
PubMed1995

Induction and regulation of connexin26 by glucagon in primary cultures of adult rat hepatocytes.

In the adult rat hepatocyte, the gap junction proteins consist of a major component, connexin32 (Cx32) and a minor component, connexin26 (Cx26). Although we recently reported our success in inducing and maintaining Cx32 in adult rat hepatocytes cultured in serum-free L-15 medium supplemented with epidermal growth factor and 2% dimethyl sulfoxide, it was very difficult to induce Cx26 in the primary hepatocytes. In the present study, we found that the addition of 10(-7) M glucagon into the culture medium could dramatically induce Cx26 mRNA and protein. Although the expression of Cx32 mRNA was also influenced by glucagon, the increase of the expression was small. Immunocytochemically, Cx26-positive spots were observed between most adjacent cells and were co-localized with the Cx32-positive spots. We also examined whether 0.5 mM dibutyl cyclic AMP could induce expression of Cx26 in the cells. The effect of dexamethasone on the expression of Cx26 mRNA compared to that of Cx32 mRNA was examined. For the induction and maintenance of Cx26 mRNA, more than 10(-7) M dexamethasone was necessary in this culture. These results suggest that expression of Cx26 in hepatocytes may be regulated by the concentrations of glucagon and glucocorticoid hormones.

Animals↗
PubMed1995

TGF-beta completely blocks the formation of small-cell colonies: effects of mito-inhibitory factors on the proliferation of primary cultured rat hepatocytes.

The proliferation of primary cultured rat hepatocytes was observed in serum-free modified DMEM supplemented with 10 mM nicotinamide and 10 ng/ml EGF. These proliferating cells were mainly mononucleate and formed small-cell colonies after 4 days of culture. In the present experiment primary cultured hepatocytes were treated with Activin A, IL-1 beta, IL-6, and TGF-beta, which have been shown to be inhibitors of the DNA synthesis of rat hepatocytes, to examine whether these four inhibitors could suppress the formation of small-cell colonies. The initial DNA synthesis of more than 50% of the cells was dose-dependently inhibited by all the factors and the strongest inhibition was demonstrated in the cells treated with TGF-beta. Although Activin A and IL-6 did not block the colony development when the agents were administered at 96 h, just before the time when the cells started to form colonies, TGF-beta and IL-1 beta could inhibit the colony formation completely and partially, respectively. Transient treatment (48-72 h) with TGF-beta was enough to suppress colony development, while Activin A and IL-6 did not block the formation of colonies. IL-1 beta partially suppressed this formation. However, continuous administration (48-144 h) of IL-beta as well as TGF-beta stimulated the detachment of the cells from dishes and the remaining hepatocytes failed to form colonies. In addition, only TGF-beta could inhibit the DNA synthesis of most small cells in the established colonies as well as that of relatively large hepatocytes. Neither Activin A, IL-1 beta nor IL-6 could inhibit the DNA synthesis of the small cells. Thus, only TGF-beta could completely inhibit both the DNA synthesis of any type of hepatocyte and the formation of small-cell colonies.

Activins↗
PubMed1995

The difference in autofluorescence features of lipofuscin between brain and adrenal.

Lipofuscin is the autofluorescent material, which accumulates with aging in the cells of various tissues. However, its autofluorescence characteristics are different among tissues. In the present study, the autofluorescence features of lipofuscin in the brain and adrenal were compared. In 18-21-month-old rats, the brain lipofuscin was granular and its autofluorescence was bright whitish-yellow to bright orange. On the contrary, the adrenal lipofuscin was not demarkated as granules, and its autofluorescence was subdued orange. The emission maximum of the bright whitish-yellow brain lipofuscin was 540 nm to 570 nm and that of the adrenal lipofuscin was 640 nm to 660 nm, when excited at 330 nm to 380 nm. When the spectra were drawn after correcting the wavelength-dependent bias of microspectrofluorometer, the autofluorescence spectra were consistent with microscopically observable tint. To conclude, the present results showed that the autofluorescence features of the bright whitish-yellow brain lipofuscin and the adrenal lipofuscin were quite different.

Adrenal Glands↗
PubMed1995

[Cerebral blood flow increase and P300 latency prolongation by intravenous injection of acetazolamide--investigation in lacunar cerebral infarction and healthy subjects].

The cerebral blood flow and the P300 were measured before and 20 minutes after intravenous injection of 17 mg/kg acetazolamide in 15 cases of lacunar cerebral infarction and 10 healthy subjects. In cerebral infarction, the study was performed within 2 weeks after the onset. The cerebral blood flow except the infarcted area was increased significantly by the intravenous injection of acetazolamide in the lacunar cerebral infarction group and the healthy subject group. The blood flow decrease around the infarcted area (intracerebral steal phenomenon) by the intravenous injection of acetazolamide was not observed in any case. The N200 latency and the P300 latency were prolonged significantly by the intravenous injection of acetazolamide in the lacunar cerebral infarction group and in the healthy subject group but the N100 latency and the P200 latency did not show any significant changes. Despite the increase in cerebral blood flow, cerebral function may be decreased by intravenous injection of acetazolamide.

Acetazolamide↗
PubMed1995

[Coronary artery bypass grafting in a patient with a single coronary artery].

Coronary artery bypass grafting in a patient with a single coronary artery is reported. A 61-year-old male who had chest pain and palpitation was transferred to our hospital. His ECG showed ischemic change, and CPK rose to a high level. Emergency coronary angiography revealed a type L II A (Lipton's criteria) single coronary artery and atherosclerotic stenosis on three major branches. He underwent CABG of LAD using LITA, #3 and #14 using saphenous vein grafts. Post operative angiography confirmed patent grafts, and the patient was free from symptoms.

Coronary Angiography↗
PubMed1995

[MMIP chemotherapy for the treatment of the relapsed and refractory non-Hodgkin's lymphoma].

For salvage chemotherapy, 30 cases of relapsed or refractory non-Hodgkin's lymphoma (NHL) were treated with MMIP regimen (mitoxantrone 15 mg/m2, methotrexate 400 mg/m2, and ifosfamide 2 g/m2 intravenously in day 1, respectively, and prednisolone 20 mg/m2 orally from day 1 to 5). The overall complete response rate (CR rate) was 20% and the median survival duration was 153 days. In patients with favorable performance status (PS), the CR rate and survival duration were 30% and 407 days, respectively. These results were almost equivalent to previously proposed salvage regimens. The overall disease free survival rate of CR cases at 4 years was 62%, which was excellent as compared with the other salvage regimens. Five of 8 (62.5%) patients previously treated with etoposide-non-containing regimens achieved CR, and the CR rate was significantly superior to that of patients previously treated with etoposide-containing ones. These results indicate that MMIP is a useful salvage regimen for relapsed or refractory NHL, while it seems to be difficult to salvage patients previously treated with etoposide-containing regimens.

Adult↗
PubMed1994

Kinetic studies on the removal of extracellular hydrogen peroxide by cultured fibroblasts.

To investigate the function of antioxidant enzymes in intact cells, we examined the removal of extracellular H2O2 by cultured fibroblasts (IMR-90). H2O2 concentration dependence of the reaction rate was interpreted as that the process involves two kinetically different reactions (referred to as reactions 1 and 2). Reaction 1 was characterized by a relatively low Km value (about 40 microM), and reaction 2 by linear dependence of the rate up to 500 microM H2O2. The magnitude of reaction 1 was reduced by treatment of the cells with diethyl maleate or 6-amino-nicotinamide, while reaction 2 was inhibited by 3-amino-1,2,4-triazole treatment. It was concluded that reactions 1 and 2 are principally due to GSH peroxidase and catalase, respectively. The values of kinetic parameters were estimated by curve-fitting, and it was inferred that 80 to 90% of H2O2 is decomposed by GSH peroxidase at H2O2 concentrations lower than 10 microM. The contribution of catalase increases with the increase in H2O2 concentration. The intact cells showed a low catalase activity (about 15%), as compared with the activity found in the solubilized cells. The low catalase activity was ascribed to the latency of the enzyme caused by localization in peroxisomes. Fibroblasts also removed intracellular H2O2 generated by menadione. Treatment with diethyl maleate greatly impaired the H2O2-removing capability and caused H2O2 efflux into the medium.

Amitrole↗
PubMed1994

Amoxicillin concentration in pus from abscess caused by odontogenic infection.

1. Amoxicillin concentration in pus from odontogenic infection was assayed and the concentrations were compared with MIC (minimum inhibitory concentration) of alpha-hemolytic streptococci isolated from odontogenic infection. 2. Measurable amoxicillin concentrations in serum and pus were found in all instances (n = 16). 3. The mean peak concentrations in serum and pus were found at identical times, 1.5 hr after administration, which were 5.92 and 0.90 micrograms/ml, respectively. 4. The mean concentration ratio of pus/serum at the peak time was 0.15. 5. All amoxicillin concentrations in pus at the peak time exceeded the MIC for 90% of alpha-hemolytic streptococci (0.25 micrograms/ml).

Administration, Oral↗
PubMed1994

Interaction of interleukin-1 and interferon-gamma on fibroblast growth factor-induced angiogenesis.

The interaction of interleukin-1 (IL-1) and interferon-gamma (IFN-gamma) actions on several aspects of angiogenesis in vitro and in vivo was studied. The proliferation and migration of human umbilical vein endothelial cells cultured with basic fibroblast growth factor (bFGF) were synergistically inhibited by cotreatment with IL-1 and IFN-gamma. Endothelial cell adhesion to collagen was suppressed by IL-1 and the effect was slightly enhanced by the combination of IL-1 and IFN-gamma. Local administration of IL-1 (10,000 U) and IFN-gamma (1,000 U) inhibited bFGF-induced angiogenesis in the skin of mice, and synergistic inhibitory activity of the combination was demonstrated. Expression of FGF receptors was strongly downregulated by the combination, whereas expressions of epidermal growth factor (EGF) receptors, integrin beta 1 and integrin beta 3 were not. EGF partially abrogated the growth-inhibitory effects of IL-1 and IFN-gamma. These findings indicate that IL-1 and IFN-gamma are each able to act an angiogenesis inhibitor in a situation where FGF plays a major role in angiogenesis, and the activity is synergistically enhanced when they are used in combination.

Animals↗
PubMed1994

Progressive encephalopathy in a Crohn's disease patient on long-term total parenteral nutrition: possible relationship to selenium deficiency.

The case of a patient with Crohn's disease complicated by progressive and irreversible encephalopathy, who had been on long-term total parenteral nutrition due to short bowel syndrome, is described. He initially experienced a disturbance of his vision, which was followed by various neurological symptoms during the next 3 years. These symptoms rapidly progressed until he finally developed consciousness disturbance. He also manifested erythrocytic macrocytosis, a low serum level of tri-iodothyronine and a high level of thyroxine. His blood levels of various trace minerals and vitamins were normal, except for selenium, which showed extremely low values. In addition, impaired plasma glutathione peroxidase activity was confirmed. After intravenous supplementation of selenium, macrocytosis, tri-iodothyronine and thyroxine values, and glutathione peroxidase activity all became normalized, yet he improved little neurologically. Our case suggests that long-term selenium deficiency may cause progressive and irreversible encephalopathy, and that careful monitoring of this mineral is necessary when an excessive period of total parenteral nutrition is being considered in the clinical setting.

Adult↗
PubMed1994

Mucosal prolapse syndrome: diagnosis with endoscopic US.

PURPOSE: To determine the value of endoscopic ultrasound (US) in the diagnosis of mucosal prolapse syndrome (MPS), also known as solitary ulcer of the rectum. MATERIALS AND METHODS: Three male and two female patients (age range, 17-66 years) with biopsy-proved MPS underwent endoscopic US. The average rectal wall thicknesses of the affected areas were compared with those of normal-appearing mucosa. RESULTS: The gross appearance of the rectal lesions was classified into three types: polypoid (n = 2), flat (n = 1), and ulcerative (n = 2). In all three types of lesions, endoscopic US demonstrated smooth, diffuse thickening of the third layer of the rectal wall; the other layers had minimal thickening. Neither a solid hypoechoic mass nor a transmural infiltrating lesion was visible, and the five-layer structure of the rectal wall was completely preserved. In the polypoid lesions, the third layer was winding as well as thickened, and microcystic components were occasionally found. CONCLUSION: Endoscopic US enabled differentiation of MPS from other conditions such as malignant neoplasia and Crohn disease.

Adult↗