Biomedical subjects

S Miyazaki

Publications and source records attributed to S Miyazaki.

At least 307 records · Page 17Linked to original sources

PubMed1997

[Ocular complications after renal transplantation].

Seventy-two post-renal transplant patients were studied for ocular complications. Of 72 patients, 56 (77.8%) showed some ocular abnormality. Steroid cataract was the most common complication, occurring in 45 patients (62.5%). Eleven patients (18 eyes) had undergone operations for cataract. The average of their ages was 39.7 years and the period from renal transplantation to cataract operation was 3.3 years. Postoperative visual acuity was over 20/20 in most cases. Increased intraocular pressure was encountered in 9 patients (12.5%), cytomegalovirus ocular infection in 2 (2.8%), hypertensive retinopathy in 2 (2.8%), branch retinal vein occlusion in 1 (1.4%), and subconjunctival hemorrhage in 15 (20.8%). A new immunosuppressant, cyclosporine, increased renal graft survival more than azathioprine. However, ocular complications such as steroid cataract occurred frequently in spite of the use of cyclosporine, as in the azathioprine era. In conclusion, it is necessary for renal transplant patients to receive a periodical ophthalmological check-up.

Adolescent↗

PubMed1997

Renal parenchymal malakoplakia in a four-week-old infant.

We describe a four-week-old male infant with bilateral renal parenchymal malakoplakia who presented with low grade fever, convulsions and lethargy. The patient had profound anemia, hepatosplenomegaly and bilateral nephromegaly with reduced renal function. Both blood and urine cultures grew Escherichia coli, and antibiotic therapy was started. A kidney biopsy obtained on the 20th hospital day confirmed the diagnosis of renal parenchymal malakoplakia. Following treatment with an intravenous methylprednisolone pulse therapy, the infant made significant clinical improvement. He has grown and developed normally in the three years following this episode. We suggest that the steroid therapy was useful in ameliorating renal parenchymal malakoplakia in a patient without an underlying systemic disease. This report describes the youngest patient to have malakoplakia.

Anti-Infective Agents, Urinary↗

PubMed1997

Evaluation of plasma (1-->3)-beta-D-glucan measurement by the kinetic turbidimetric Limulus test, for the clinical diagnosis of mycotic infections.

The present multicentre clinical study was conducted to assess the clinical utility of a new diagnostic method for deep mycosis in which (1-->3)-beta-D-glucan, a fungal cell wall component existing in plasma, was quantitatively measured by the kinetic turbidimetric Limulus test (WB003). Plasma (1-->3)-beta-D-glucan concentrations were 0.57 +/- 0.10 microgram/l in 92 healthy subjects and 0.62 +/- 0.32 microgram/l in 26 patients with non-mycotic diseases (disease control group). In comparison with these healthy subjects and patients with non-mycotic diseases, patients with mycosis had significantly higher plasma (1-->3)-beta-D-glucan concentrations: 19.63 +/- 73.28 micrograms/l in 12 patients with candidaemia, 11.28 +/- 21.42 micrograms/l in 7 patients with urinary Candida infection, 4.84 +/- 12.71 micrograms/l in 5 patients with pulmonary candidiasis, and 12.21 +/- 31.31 micrograms/l in 4 patients with invasive pulmonary aspergillosis. On the statistical analysis of these data, a cut-off value was set at 1.0 microgram/l. Using this cut-off value, 3 patients with pulmonary cryptococcosis and 4 patients (4/6) with pulmonary aspergilloma were all negative with low plasma (1-->3-beta-D-glucan levels. The test WB003 provided equivalent or higher efficiency of diagnosis of candidiasis and aspergillosis, in comparison with commercially available antigen detection kits, demonstrating its utility as a diagnostic reagent. It may also be useful in assessing therapeutic effectiveness when used periodically after treatment.

Adolescent↗

PubMed1997

Preventive effects of polysaccharides extracted from human tubercle bacilli (specific substance of Maruyama) on colonic carcinogenesis in rats.

Polysaccharides extracted from human tubercle bacilli (specific substance of Maruyama [SSM]) have been clinically applied with satisfactory results. Thymidylate synthetase (TS) and thymidine kinase (TK) are key enzymes in de novo and salvage pathways for pyrimidine nucleotide synthesis. Well- and moderately well differentiated adenocarcinomas induced with 1,2-dimethylhydrazine (DMH) are widely distributed throughout the colorectal tract with high TK activity, and the poorly differentiated type is mainly restricted in the proximal colon and the cecum with high TS activity in rats. Subcutaneously injecting the rats with SSM reduced TS activity in colonic nontumorous regions, but in the tumorous regions it reduced TK activity compared with that of the DMH-treated rats without SSM treatment. SSM is suggested to reduce the colorectal carcinogenesis induced with DMH by inhibiting DNA synthesis in a de novo pathway, and to suppress the development of the tumors by decreasing DNA synthesis in the salvage pathway in rats.

1,2-Dimethylhydrazine↗

PubMed1997

[Arterial infusion chemotherapy in pelvic space for advanced rectal cancer].

Three rectal cancer patients were treated with arterial infusion chemotherapy through the internal iliac artery. Two patients with pelvic recurrences unresectable after APRA were treated with intensive chemotherapy and the other patient with neoadjuvant chemotherapy. In all cases, 5-FU (500 mg/ body/day) was administered continuously for 5 days or 14 days. We attempted three methods for this procedure which were a bilateral catheterization to the internal iliac artery, a single catheterization with an embolization to the other internal iliac artery and a single catheterization without the embolization. As the result of this treatment, in the resected specimen with neoadjuvant case, histological necrosis was found in 50% in the main tumor and the metastatic lymph nodes. One patient with pelvic recurrence showed a partial response in CT imaging, but died one year later of the recurrence around the external iliac artery. The other patient with pelvic recurrence treated with the bilateral catheterization had no efficacy on CT imaging, but his CEA level has decreased at present. It was concluded that arterial infusion chemotherapy was effective for advanced rectal cancer and the pelvic recurrences. However, the efficacy of this treatment is limited to the area to which the drugs are delivered. Thus, it is important that the method and the location of the catheterization are determined adequately for each case.

Antidotes↗

PubMed1997

Effects of glucagon on superior mesenteric artery and femoral artery haemodynamics in humans.

OBJECTIVE: It remains unclear whether glucagon is a localized splanchnic arterial vasodilator in humans. This study examined this issue by assessing the haemodynamic effect of exogenous glucagon on splanchnic and extrasplanchnic arteries. METHODS: After an overnight fast, flow velocity of superior mesenteric artery and femoral artery was recorded by means of echo-Doppler in 10 controls and 10 patients with cirrhosis. Mean arterial pressure, heart rate and plasma glucagon level were also determined. These measurements were repeated after intramuscular injection of glucagon (1 mg) at 15 min and 30 min. RESULTS: Patients with cirrhosis had much higher glucagon levels than controls (P < 0.01). Plasma glucagon level rose following glucagon administration in controls (P < 0.01) and patients with cirrhosis (P < 0.01). Glucagon administration had no effect on mean arterial pressure, heart rate and femoral artery velocity in controls and patients with cirrhosis. In contrast, superior mesenteric artery velocity significantly increased after glucagon administration in both groups (P < 0.01, P < 0.01), although the effect was less pronounced in patients with cirrhosis than in controls (P < 0.05). CONCLUSION: These data suggest that glucagon might be a localized splanchnic arterial vasodilator. Thus, glucagon may be one of the factors contributing to the pathogenesis of the splanchnic hyperdynamic circulation seen in patients with cirrhosis.

Aged↗

PubMed1996

Lipoprotein analyses in patients with stable angina and acute coronary syndrome.

We have performed lipid analyses by using a table-top ultracentrifuge based on the Hatch and Lees' method in 77 subjects (60 men, 17 women: mean age, 63 years) to clarify lipoprotein disorders in coronary artery disease. Sixty-four subjects had coronary artery disease and 13 normal subjects were controls. They were divided into the groups with stable angina pectoris and with unstable angina pectoris or acute myocardial infarction (acute coronary syndromes). In patients with coronary artery disease, there were no significant differences from control in age, body mass index, total cholesterol, however, HDL cholesterol was significantly lower than those in the controls. LDL cholesterol:LDL apoB ratio, which is thought to reflect the size of LDL in coronary artery disease, was significantly smaller than that in the controls; mean values were 1.2 in coronary artery disease and 1.4 in controls. There were no significant differences in those lipoprotein disorders between the patients with stable angina and those with acute coronary syndromes. Though these lipoprotein abnormalities would not play a trigger role in acute coronary syndrome, they are characteristic of the lipid profile of patients with coronary artery disease.

Aged↗

PubMed1996

Involvement of Fas ligand and Fas-mediated pathway in the cytotoxicity of human natural killer cells.

The cytotoxicity of NK cells has been thought to be mediated mainly by the perforin-dependent pathway. We investigated the involvement of Fas-mediated pathway in the killing activity of purified human CD3-, CD16+ NK cells. Fas ligand mRNA was expressed in freshly isolated NK cells. Apoptosis, which was identified by the fragmented chromatin in individual cells, was induced in the cells that expressed high levels of Fas via direct NK-to-target cell interaction or Ab-dependent cell-mediated cytotoxicity, even in Ca(2+)-free medium, in which perforin pores are known not to be formed. Apoptosis in both the presence and absence of external Ca2+ was inhibited by Fab of an anti-Fas mAb. Transfection of the Fas gene in target cells facilitated the induction of apoptosis, compared with the parental cell line. The function of the Fas-mediated pathway in the coexistence of the perforin-dependent pathway was examined in 10 cell lines expressing different levels of Fas by Ca2+ imaging and morphologic observation of single cells. With a certain boundary level, low or high levels of Fas expression in target cells were correlated to a great degree with either acute necrosis due to severe membrane damage after NK-target cell contact or apoptosis at a later period, respectively. We concluded that Fas ligand/Fas interaction is present and plays a significant role in the human NK cell-induced apoptosis.

Antibodies, Monoclonal↗

PubMed1996

Necrosis and apoptosis associated with distinct Ca2+ response patterns in target cells attacked by human natural killer cells.

1. During the process of cell death, rises in cytosolic Ca2+ concentration ([Ca2+]i) together with structural changes were investigated in target cells attacked by purified CD3-,CD16+ human natural killer (NK) cells. 2. In the target cell line K562, a rapid [Ca2+]i rise to 1-2 microM occurred a few minutes after NK cell-target cell contact, immediately followed by leakage of the Ca2+ indicator dye fura-2 from the cell. Cells were permeabilized, but their chromatin was not fragmented. The changes were basically consistent with those seen in necrosis induced by activated complement. 3. In the target cell line MOLT-4, which expressed the apoptosis-inducing surface antigen Fas much more strongly than K562, the majority of attacked cells displayed a [Ca2+]i rise to 0.7-1 microM followed by a slow decline, often associated with diminishing [Ca2+]i oscillations. As a whole, [Ca2+]i remained higher than 150 nM for at least 1.5-3 h (approximately 100 nM in control cells). 4. MOLT-4 cells attacked by NK cells became bubble shaped within 20 min of the main [Ca2+]i rise reaching its peak, and then both the cell and chromatin were fragmented into small pieces. These findings were basically consistent with those in apoptosis induced by a monoclonal antibody against the surface antigen Fas. 5. NK cells induced both necrosis and apoptosis in cell lines insensitive to NK cells in the presence of an antibody against the major histocompatibility complex class I (antibody-dependent cell-mediated cytotoxicity, ADCC). The distinct Ca2+ responses patterns described above corresponded to necrosis or apoptosis in different cells stimulated by the common ADCC pathway. 6. Human NK cells were found to be capable of inducing necrosis (membrane damage) or apoptosis (nuclear damage) depending on the target cell types. The characteristic Ca2+ response profile was a good indicator for distinguishing between the modes of cell death induced by the cytotoxicity of the killer cells.

Antibodies, Monoclonal↗

PubMed1996

Spatiotemporal analysis of calcium dynamics in the nucleus of hamster oocytes.

1. Subcellular Ca2+ dynamics inside and around the nucleus of immature hamster oocytes were analysed with confocal Ca2+ imaging. 2. The ratio value between emission intensity of two injected fluorescent Ca2+ indicators, Calcium Green and Fura Red, was almost uniform over the entire oocyte, suggesting that nucleoplasmic Ca2+ concentration ([Ca2+]n) is comparable to cytoplasmic Ca2+ concentration ([Ca2+]c) at the resting state. 3. When Ca2+ was iontophoretically injected into the nucleoplasm or the perinuclear cytoplasm, it diffused across the nuclear envelope (NE), and perinuclear [Ca2+]c and [Ca2+]n reached the same level within 2 s, although the NE worked as a weak but detectable barrier for Ca2+ diffusion. 4. Inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release from the NE through the inner membrane was not detected, even when a large amount of IP3 was delivered in close proximity to the inner nuclear membrane. 5. When an oocyte was uniformly stimulated by photolysis of caged IP3, a Ca2+ rise was initiated in the perinuclear cytoplasm. The [Ca2+]n rise was always delayed with respect to, but rapidly equilibrated with, the [Ca2+]c rise. 6. Clusters of the endoplasmic reticulum were located in the perinuclear cytoplasm and served as the trigger zone of IP3-induced Ca2+ release. 7. The results indicate that the [Ca2+]n rise occurs as the consequence of the influx of Ca2+ which was released in the perinuclear cytoplasm, not Ca2+ release from NE to the nucleoplasm.

Animals↗

PubMed1996

Successful retrieval of unexpanded Palmaz-Schatz stent from left main coronary artery.

A 64-year-old patient with silent myocardial ischemia after anterior myocardial infarction was treated with directional coronary atherectomy, balloon angioplasty, and placement of Palmaz-Schatz stent. An unexpanded Palmaz-Schatz stent was retained in the left main coronary artery and was treated successfully with a nitinol goose-neck snare. After this procedure, another Palmaz-Schatz stent was successfully implanted without any complications.

Angioplasty, Balloon, Coronary↗

PubMed1996

Antiischemic effect of intracoronary diltiazem on myocardial ischemia during PTCA.

To evaluate the effect of intracoronary diltiazem on myocardial ischemia during percutaneous transluminal coronary angioplasty (PTCA), 38 patients were randomly assigned to receive inactive placebo (n = 19; group C) or a low dose (1 mg, n = 10; group D1), or a high dose (2 or 3 mg, n = 9; group D2) of diltiazem in a double-blind manner. The agent was administered directly into the coronary artery via a balloon catheter following a control balloon inflation. Chest pain score (maximum, 10) and the magnitude of ischemic ST elevation on standard and intracoronary electrocardiograms (ECGs) during a balloon inflation were assessed in the control and posttreatment periods. After the administration of diltiazem, the chest pain score was significantly decreased in group D1 (control: 5.1 +/- 3.6, posttreatment: 3.8 +/- 3.1, P < 0.01) and group D2 (3.4 +/- 2.5 vs 2.5 +/- 2.0, P < 0.01), but not in group C (4.1 +/- 3.1 vs 3.7 +/- 3.3, difference not significant). The magnitude of ST elevation relative to the control on standard and intracoronary ECGs was significantly smaller in groups D1 and D2 than in group C (standard ECG; D1: 51.8 +/- 10.6% of control, D2: 41.6 +/- 28.7% vs C: 93.3 +/- 15.6% and intracoronary ECG; D1: 47.1 +/- 11.7% of control, D2: 27.5 +/- 26.9% vs C: 94.6 +/- 29.3%, all P < 0.01). Although systolic blood pressure decreased slightly in groups D1 and D2, there was no significant correlation between the change in ST elevation and the change in the rate-pressure product. Pretreatment with a small dose of intracoronary diltiazem attenuated myocardial ischemia during PTCA and this pretreatment may enable us to perform balloon inflation for a longer period.

Angina Pectoris↗

PubMed1996

Enhancement of coronary reactive hyperemia in patients with ischemic myocardial tolerance during angioplasty.

The purpose of this study was to elucidate the effect of repeated brief coronary occlusions on reactive hyperemia during percutaneous transluminal coronary angioplasty (PTCA) in patients with or without ischemic tolerance. Seventeen patients undergoing PTCA for chronic stable angina were studied. Patients with well developed collateral vessels were excluded. After successful predilatation, coronary flow velocity was recorded with the use of a Doppler flow guide wire, and reactive hyperemia was assessed immediately after each of two 2-min coronary occlusions followed by 2 mins of reperfusion. The intracoronary electrocardiogram (icECG) was recorded via the flow guide wire placed in the center of the ischemic zone. Patients were divided into two groups: those who showed a reduction of ST elevation in the icECG recorded at the time of the second coronary occlusion (group I), and those who showed no difference in ST elevation between the two occlusions (group II). There were no significant differences in blood pressure, heart rate, or baseline coronary flow velocity between the two groups before the first occlusion, but the ST elevation at the time of the first coronary occlusion was greater in group I than in group II (8.9 +/- 6.2 versus 1.1 +/- 2.0 mm, P < 0.01). Reactive hyperemia was significantly greater after the second coronary occlusion than after the first in group I (22.1 +/- 15.8 versus 30.4 +/- 21.0 cm/s, P < 0.05), but it did not change in group II (25.6 +/- 13.0 versus 23.5 +/- 11.2 cm/s NS). Reactive hyperemia was enhanced in patients with ischemic tolerance who showed a reduction in St elevation in the icECG. These results suggest that observed reactive hyperemia does not necessarily reflect the severity of ischemia.

Aged↗

PubMed1996

Inhibition by dexamethasone of the lipopolysaccharide-induced increase in IL-6 mRNA abundance and IL-6 production in human polymorphonuclear leukocytes.

Interleukin-6 (IL-6) is a key inflammatory cytokine that is produced by various cell types including polymorphonuclear leukocytes (PMNs). However, the pathophysiological roles of IL-6 produced by human PMNs are unclear. Bacterial lipopolysaccharide (LPS) induced marked increase in IL-6 production, determined by enzyme-linked immunosorbent assay, and IL-6 mRNA abundance determined by reverse transcription-polymerase chain reaction analysis, in purified human PMNs. Both effects of LPS were inhibited in a dose-dependent manner by dexamethasone (10(-6) to 10(-8) M). IL-6 receptor mRNA was constitutively present in PMNs and its abundance was not affected by either LPS or dexamethasone. These results indicate that PMNs are an important source of IL-6 in acute inflammatory reactions, and that the anti-inflammatory actions of dexamethasone is attributable in part to inhibition of IL-6 production by these cells. The constitutive presence of IL-6 receptor mRNA in PMNs suggests that IL-6 may exert pathophysiological effects on these cells.

Dexamethasone↗

PubMed1996

Leukotriene B4 and C4 in cerebrospinal fluid from children with meningitis and febrile seizures.

Concentrations of immunoreactive leukotriene C4 (LTC4) and leukotriene B4 (LTB4) in the cerebrospinal fluid from 18 patients with aseptic meningitis, including 2 patients with encephalitis and 4 patients with febrile seizures, were measured by a sensitive and specific radioimmunoassay; these results were compared with those from control subjects. The concentrations of both LTC4 and LTB4 were elevated significantly in patients with meningitis (LTC4: 115.6 +/- 47.7 pg/ml; LTB4: 1,603.0 +/- 273.5 pg/ml; n = 18) compared to controls (LTC4: 83.2 +/- 21.6 pg/ml; LTB4: 1,219.3 +/- 161.5 pg/ml; n = 12; P < .05 and P < .01, respectively). However, there was no significant increase in LT levels in patients with febrile seizures. These findings suggest that LTs may play an important role in the inflammatory response induced by viral infections of the central nervous system.

Child↗

PubMed1996

Mass screening for neuroblastoma: quo vadis? A 9-year experience from the Pediatric Oncology Study Group of the Kyushu area in Japan.

Since 1985, a nationwide program of mass screening for neuroblastoma has been available for 6-month-old infants throughout Japan. From 1985 to 1993, the authors studied 285 patients with neuroblastoma among their regional population of 15 million. There was an increase in the total number of patients per year in comparison to the previous 6-year period (1979 to 1984). However, no significant difference was noted in the number of patients older than 1 year or in the incidence of advanced-stage (stages III and IV) unscreened cases. The majority of neuroblastomas in the screened group showed favorable biological factors, even in the advanced stages. However, there was a small group with histologically and/or biologically unfavorable factors; five of 115 had amplified N-myc oncogene, four of 74 showed unfavorable Shimada histological findings, and three of 33 had an unfavorable DNA ploidy pattern. One case from this group with unfavorable factors died of the tumor. 3) Thirty-eight cases were negative at the time of mass screening, but later presented with neuroblastoma. Most of them were diagnosed between 1 and 3 years of age, and 30 of the 38 cases (78.9%) were advanced stage with unfavorable prognostic factors. Thus, the authors conclude that mass screening at 6 months can detect a selected population of infants with neuroblastoma; some of the tumors may represent subclinical masses destined for spontaneous regression. However, some tumors with unfavorable factors have been detected by mass screening before progression and/or dissemination. Infants in this group are considered to benefit most from early diagnosis and treatment.

Adolescent↗

PubMed1996

Production of interleukin-5 and the suppressive effect of cyclosporin A in childhood severe atopic dermatitis.

A child with severe atopic dermatitis had marked improvement with oral cyclosporin A (CyA) therapy. The function of activated T lymphocytes and serum interleukin-5 concentrations were reduced. The expression and production of interleukin-5 were high, but were suppressed during CyA therapy and by CyA in vitro. Oral CyA therapy may be useful for severe atopic dermatitis.

Child, Preschool↗

PubMed1996

Distinct Ca2+ response patterns in human natural killer cells during induction of necrosis or apoptosis of target cells.

Human CD3-, CD16+ natural killer cells (NKs) induced necrosis in the cell line K562 and the minor population of MOLT-4, while induced apoptosis in the majority of MOLT-4, in one-to-one cell interaction. Simultaneous Ca2+ imaging of NK and target cells revealed remarkable differences in changes of cytosolic Ca2+ concentration ([Ca2+]i) during the process of distinct target cell killing. A rapid [Ca2+]i rise in NK was generated within 2 min after contact with any target. For induction of necrosis, the [Ca2+]i rise in NK reached a peak of 580 +/- 195 nM (mean +/- SD, n = 41) and was followed by an abrupt large [Ca2+]i rise in target cells probably due to Ca2+ entry through pores formed by perforin which was released from NK. The interval between onsets of NK and target Ca2+ responses (Tnk-t) was shorter than 3 min in most cases. Target cells were soon permeabilized, and NK Ca2+ responses ceased in 14 +/- 7 min. For induction of apoptosis, NK Ca2+ responses were relatively smaller (405 +/- 125 nM, n = 16), and Tnk-t was widely scattered up to 30 min. NK Ca2+ responses lasted much longer in a form of Ca2+ oscillations (total duration, 66 +/- 33 min) in parallel with target Ca2+ responses, and ceased as apoptotic changes such as cellular and nuclear fragmentation advanced. The difference in Tnk-t suggests that rapid synchronous release of perforin tends to cause necrosis rather than apoptosis. The duration of NK Ca2+ responses suggests that some 'off signals' may be transmitted to NK following recognition of target cell damage.

Apoptosis↗