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Biomedical subjects

N Yamaguchi

Publications and source records attributed to N Yamaguchi.

At least 199 records · Page 11Linked to original sources

Japan Clinical Oncology Group (JCOG).

The Japan Clinical Oncology Group (JCOG) is a cooperative oncology group with the aims of conducting, developing, coordinating and stimulating clinical research in Japan on the treatment of cancer and related problems. The purpose of JCOG is to establish and improve the standard of cancer treatment, mainly in solid cancer, through the testing of new therapeutic regimens or combined modalities, using drugs that are newly-approved or already commercially available. Research sponsored by JCOG is accomplished mainly through the execution of large, prospective, randomized, multicenter, clinical trials. In this way, JCOG facilitates the passage of new clinical trial discoveries into state-of-the-art treatment.

Clinical Trials as Topic↗

Identification and characterization of families with aggregation of lung cancer.

BACKGROUND: To clarify genetic factors involved in the susceptibility to lung cancer, it is essential to identify families with lung cancer clustering and to characterize the mode of clustering. Since somatic mutations of the p53, RB and p16 genes occur frequently in lung cancer and the replication error phenotype is seen in a subset of lung cancer, it is possible that germ-line mutations of the p53, RB, p16 and mismatch repair genes influence the susceptibility to lung cancer. METHODS: In this work, cases with familial clustering of lung cancer were selected from 1068 families with primary lung cancer cases in analogy with the criteria for hereditary non-polyposis colorectal cancer (HNPCC). Cases with Li-Fraumeni syndrome, familial retinoblastoma, familial melanoma and HNPCC were also searched among these 1068 families. RESULTS: There were only four families (0.4%) in which more than three relatives were affected by lung cancer. Two successive generations were affected in 36 families (3.4%). Patients with lung cancer before the age of 50 were present in 165 families (15.5%). However, no family conformed to all three criteria. There was only one family with Li-Fraumeni syndrome and no family with familial retinoblastoma, familial melanoma and HNPCC. CONCLUSION: Familial aggregation of lung cancer is rare and germ-line mutations of the p53, RB, p16 and mismatch repair genes may not contribute greatly to susceptibility to lung cancer.

Colorectal Neoplasms, Hereditary Nonpolyposis↗

Effects of FK506 on experimental membranous glomerulonephritis induced by cationized bovine serum albumin in rats.

BACKGROUND: There have been no reports on the effect of FK5 06, a new immunosuppressive agent, on experimental membranous glomerulonephritis (MN) induced by an exogenous antigen. Therefore we investigated the effects of FK506 on MN induced by cationized bovine serum albumin (C-BSA) in rats. METHODS: Two weeks after the rats were immunized with 1 mg of C-BSA and Freund's complete adjuvant, they received intravenous injections of 3 mg/kg of C-BSA 3 times weekly for 4 weeks. Rats were divided into four groups: group A (n = 5) received intramuscular injections of 3 mg/kg of FK506 daily for 5 days beginning 2 days before the first immunization; group B (n =4) received 1 mg/kg of FK506 daily for 2 weeks beginning 2 weeks after the first immunization; and group C (n =4) received 1 mg/kg of FK506 daily for 2 weeks beginning 4 weeks after the first immunization. Group D (n = 5) received no FK506 and served as the control group. Rats were sacrificed 8 weeks after the first immunization. RESULTS: Administration of FK506 in the preimmunization stage almost completely suppressed the development of MN in group A. Histological findings in groups B and C were similar to those in group D, the control group. However, urinary protein excretion was significantly lower in group B (24+/-46 mg/day) and C (220+/-44 mg/day) than in group D (330+/-61 mg/day). Expression of intracellular adhesion molecule-1 in glomeruli and the number of leukocyte functioning-associated molecules-1 were significantly decreased in groups A, B, and C compared with the control group. Administration of FK506 was not associated with any significant side-effects or histological abnormalities. The whole-blood trough levels of FK506 in groups B and C were 9.1 ng/ml and 9.2 ng/ml respectively. CONCLUSIONS: The efficacy of FK506 was significantly increased when the drug was administered in the early phase of immunization in this model. The present study suggests that FK506 may be useful in patients with intractable nephrotic syndrome such as MN.

Animals↗

Reduced interhemispheric EEG coherence in Alzheimer disease: analysis during rest and photic stimulation.

The present study was conducted to examine interhemispheric electroencephalogram (EEG) coherence at rest and during photic stimulation (5, 10, and 15 Hz) in 10 patients with presenile dementia of the Alzheimer type (AD; mean age at onset, 56 years) and 10 sex- and age-matched control subjects. Compared with the control subjects, the AD patients had significantly lower interhemispheric coherence in the resting EEG for the delta, theta-2, alpha, and beta-1 frequency bands. EEG analysis during photic stimulation also showed that the patients had significantly lower coherence, irrespective of the stimulus frequency. In addition, when we examined the changes in coherence from the resting state to the stimulus condition (i.e., coherence reactivity), significant group differences were found at the brain region primarily involved in visual functioning; the patients had significantly smaller coherence reactivity to photic stimulation at 5 and 15 Hz over the posterior regions. These findings suggest that AD patients have an impairment of interhemispheric functional connectivity in both nonstimulus and stimulus conditions. The findings also suggest a failure of normal stimulation-related brain activation in AD.

Aged↗

Binding of the capsule-like serotype-specific polysaccharide antigen and the lipopolysaccharide from Actinobacillus actinomycetemcomitans to human complement-derived opsonins.

We investigated the molecular mechanism of resistance of Actinobacillus actinomycetemcomitans to complement-dependent chemiluminescence response by human polymorphonuclear leukocytes. Whole cells of serotype b-specific polysaccharide antigen-defective mutants ST2 and ST5 were constructed by inserting transposon Tn916 into A. actinomycetemcomitans strain Y4. These strains induced strong chemiluminescence response by human polymorphonuclear leukocytes and markedly bound to human complement-derived opsonins. In contrast, strain Y4 induced weak chemiluminescence response and weakly bound to complement-derived opsonins. The biosensor analysis revealed that lipopolysaccharide from strain Y4 strongly bound to human C3b, but serotype b-specific polysaccharide antigen did not. The serotype b-specific polysaccharide antigen molecule might sterically hinder the interaction between complement-derived opsonins and lipopolysaccharide to reduce complement-dependent chemiluminescence response by human polymorphonuclear leukocytes.

Adult↗

An attempt of radar chart expression of a self-rating scale for sleep disturbance.

We made an attempt to express a complaint of sleep disturbance by a self-rating scale of radar chart mode. The questionnaire for sleep disturbance is made up of eight items. Each item was scored from grade 1 to 4. The score of each item was projected to the MY radar chart, designed by us. It is noted that this method is useful in following the effect of hypnotics on sleep disturbance.

Adult↗

Apoptotic cell death of high polyploid cells in a cultured sarcoma cell line.

It is well known that DNA-ploidy is useful independent prognosticator of malignancy. However, the biological significance of polyploid cells and the relation between polyploidy and prognosis is not well understood. We analyzed DNA ploidy by flow cytometry in Meth-A cells (a cultured sarcoma cell line) after treatment with K252a, a protein kinase inhibitor, and showed induction of polyploidization. Apoptotic cell death of the high polyploid cells was verified by flow cytometry, morphological observation and gel analysis of DNA integrity. Expression of tumor-suppressor nuclear protein p53 investigated by immunohistochemistry was increased 10-fold or more in cells with 16C (C = haploid DNA content) relative to cells with 2C, suggesting that the overexpression of p53 was involved in the apoptosis. These results may be of clinical relevance since it has been known that both DNA ploidy and p53 expression have prognostic significance.

Animals↗

Saikosaponin b2 induces differentiation without growth inhibition in cultured B16 melanoma cells.

Treatment with 5 microM of saikosaponin (SS) b2 for 30 days was found to induce differentiation of B16 melanoma cells, with potentiation of expressions of melanogenesis and tyrosinase. To explore the mechanism of this effect, we observed the cell growth, cell cycle and morphology, and found that SSb2 did not affect any of these parameters. That is, SSb2 induced the differentiation of B16 melanoma cells without growth inhibition or cytotoxicity under conditions of low dose and long-term treatment. Phorbol ester, a protein kinase C (PKC) activator, markedly inhibited the expressions of melanogenesis and tyrosinase in both the control B16 melanoma cells and the long-term treated B16 melanoma cells. Down-regulation of the PKC activity may be involved in the effects of SSb2.

Animals↗

Mortality risks of oesophageal cancer associated with hot tea, alcohol, tobacco and diet in Japan.

To clarify mortality risks of oesophageal cancer associated with hot tea, alcohol, tobacco and diet, further analyses on the data from a large prospective cohort study in Japan were conducted. The subjects for analysis were 220,272 men and women aged 40 to 69 at the baseline of 1965. There were 440 oesophageal cancer deaths during the period from January 1966 to December 1981. Person-years at risk were 3,065,182 in total. Rate ratio and 95% confidence interval adjusted for attained age, prefecture, occupation and sex were (RR (95% CI)): 1.6 (1.2-2.0) for hot tea (drinking green tea at high temperatures) in comparison with not-hot tea (drinking green tea at moderate temperatures); 2.4 (1.8-3.1) for daily (4 times/week or more) alcohol drinking in comparison with non-drinking; and 2.3 (1.7-3.1) for heavy smoking (15 cigarettes/day or more) in comparison with non-smoking. Dose-response relationships were found in alcohol drinking and smoking among men and women (p for trend; p < 0.001). The rate ratios were not significantly associated with the dietary factors except for green-yellow vegetables (1-3 times/month or less in comparison with daily; RR = 2.0, 95% CI: 1.2-3.1), where a no dose-response trend was observed (p = 0.45). In comparison based on the binary variables, the RR for the subjects with daily alcohol drinking and current smoking was 3.9 with 95% CI of 2.7 to 5.4, relative to those exposed to neither habit. The joint effect of alcohol drinking (A) and smoking (S) was more than additive (A*S > A + S: 3.9 > 1 + (1.0-1) + (1.6-1)). Further sub-analysis showed that the RR for the subjects with daily alcohol drinking, current smoking and hot tea was 5.7 with 95% CI of 3.7 to 8.9, when the reference was the subjects with not-daily alcohol drinking, non-smoking and not-hot tea. Similar results were obtained from further adjustment of green-yellow vegetables. It is concluded that mortality risks of oesophageal cancer in the present cohort were substantially associated with thermal effect of hot tea, alcohol drinking, smoking and lower consumption of green-yellow vegetables. This finding suggests that life-style modification for smoking and dietary habits is essential to reduce the risks of oesophageal cancer in Japan.

Adult↗

[Data management for clinical trials at the data center].

Data Management is a series of procedures and a research field which assure the quality control in clinical trials. Poorly performed data management can cause various biases in the results of clinical trials. Data management is important especially in cancer clinical trials because of their multiple endpoints, dealing with multiple therapeutic drugs and modalities. Data checks performed by data center staff and composed of manual and computer checks are the main procedures in data management. It is most important that all participants of clinical trials, physicians, nurses, biostatisticians and data managers, understand the data management processes and collaborate with one other from the earliest stage of conducting clinical trials.

Biometry↗

[Giant platelet-like cell fragments produced from abnormal promyelocytes in acute myelogenous leukemia].

A 38-year old man was transmitted to our hospital because of his pneumonia and disconsciousness. Laboratory data showed leukocytosis (32,500/microliter), mild anemia, and decreased platelet count (6.7 x 10(4)/microliter). The bone marrow aspiration revealed the presence of 40% blastoid cells and cytogenetic study showed abnormal karyotype, 45, X, -Y, t(8; 21) (q22; q22), indicating acute myeloid leukemia (AML, M2). Furthermore, on the microscopic observation, cell fragments resembling giant platelets were observed which were positive for myeloperoxidase, and several fragments connected with abnormal promyelocytes through thin cytoplasm. These results suggested these cell fragments may be produced from abnormal promyelocytes in this case.

Adult↗

[A case of glomerulonephritis with singular high titer of anticardiolipin antibody].

We report here a case of severe membranoproliferative glomerulonephritis with a singular high titer of anticardiolipin antibody (aCL). A 19-year-old Japanese female was admitted to Tsukuba Gakuen Hospital after complaining of general edema for 5 months. She had no past history of thrombosis, thrombocytopenia, or spontaneous abortion. Laboratory findings revealed that she had nephrotic syndrome and moderate renal dysfunction. Immunological test showed a high titer of aCL with a high-normal limit of antinuclear antibody, negativity for anti-beta(2) glycoprotein I antibody and negativity for anti-DNA antibody. In the renal biopsy tissue, most glomeruli showed global sclerosis and the remaining glomeruli revealed membranoproliferative change with crescent formation. Steroid therapy with warfarin and dipyridamole was effective and her renal function improved gradually. This case lacked the typical symptoms of primary antiphospholipid syndrome and did not satisfy the criteria of SLE. In spite of these findings, the singular high titer of aCL with membranoproliferative glomerulonephritis characterized this case.

Adult↗

[A case of systemic AA amyloidosis complicating Crohn's disease].

Although systemic AA amyloidosis complicating Crohn's disease has been found in 0.5 to 6% in America and Europe, it is relatively rare in Japan. We report a case of systemic AA amyloidosis complicating Crohn's disease. In 1979, a 26-year-old Japanese man presented with diarrhea, melena and perianal abscesses, and was diagnosed as having Crohn's disease. He was treated with oral prednisolone, salazosulfapyridine and diet therapy. However, the gastrointestinal symptoms recurred and he was hospitalized several times. In 1991, his thyroid gland was found to be swollen, but with normal thyroid function, and his thyroid gland became larger subsequently. In October 1995, he showed renal dysfunction (blood urea nitrogen 33.2 mg/dl; serum creatinine 1.5 mg/dl) with proteinuria. His renal function had been deteriorating rapidly. On September 13, 1996, he was admitted to the Tsukuba University Hospital. At the time of admission, his renal function showed a blood urea nitrogen of 129.5 mg/dl with a creatinine of 5.4 mg/dl. The urine contained 0.8 g of protein per 24 hours. He presented with diarrhea for several days before admission and was treated with central venous hyperalimentation. Despite supportive care, he developed end-stage renal failure, then hemodialysis was initiated on October 7. His condition was complicated by a complete auriculoventricular block on October 18. He died of hemoperitoneum on October 25. On postmortem examination, extensive amyloid deposits were found in multiple organs including kidneys, intestine, heart, thyroid gland, lungs, liver, spleen, pancreas, gall bladder, adrenal glands, testis, prostate, bone marrow and parathyroid glands. Analysis of amyloid protein in the autopsy specimens showed type AA.

Adult↗

[Relationship of utilization rate of health examination under the Elderly Act to medical expenditure and days of medical care for the elderly].

The aim of this study was to investigate the relationship of utilization rate of health examination to medical expenditure and days of medical care per insured person under the Elderly Act. The factors related with the utilization rate of health examination were also analyzed by multiple regression analysis. The material used in this analysis was the 1993 national health insurance data for all of the 3,252 municipalities of Japan. The main results were as follows: 1. The average medical expenditure and days of medical care among the municipalities declined in the increasing order of the three categories of utilization rate of health examination; municipalities with utilization rate of less than 30% being the highest, and those with 50% or more being the lowest. 2. The average medical expenditure and days of medical care among the municipalities with community health centers were smaller than those without. 3. Multiple regression analysis showed that utilization rate had a positive relationship to percentage of elderly, presence of community health center, public financial power index, and number of public health nurses per resident. It had a negative relationship to the population and the number of clinical beds per resident. The number of public health nurses per resident was the most significant factor related with the utilization rate (standardized partial regression coefficient = 0.32). These results suggest that increasing the utilization rate of health examination and the number of community health centers could serve to lower medical expenditure and days of medical care through the promotion of the health services provided by municipalities.

Community Health Services↗

[An enlarging dysembryoplastic neuroepithelial tumor during a 6-year period: a case report].

A 16-year-old boy who had been found at the age of 9 years to have complex partial seizures was referred to our department by a psychiatrist for evaluation for surgical treatment of epilepsy, in 1994. A diagnosis of multiple cerebral infarction accompanied with arachnoid cyst was made when he was 11 years old, in 1988, by computed tomography (CT) and magnetic resonance imaging (MRI) findings. Results of a neurological examination on admission revealed marked mental and speech retardation. MRI and CT studies demonstrated an enlarged Sylvian fissure and a mass lesion in the left frontal lobe which was enlarged, compared to the findings of MRI in 1988. A left fronto-temporal craniotomy with excision of the frontal lesion was performed. Histological examination revealed cortical dysplasia, multi-nodular pattern, and glioneuronal components, whose findings coincide with criteria for diagnosing dysembryoplastic neuroepithelial tumors. MIB1 antibody immunostaining study revealed no positivity, but immunostaining study for PCNA (proliferation of cell nuclear antigen) revealed from 0 to 6.5% positivity in each nodule. PCNA high positivity was observed in the nodules which were composed of packed oligodendrocyte-like cells. Enlargement in the size of the lesion in our case suggests increased cell proliferation activity during a 6-year period.

Adolescent↗

Potentiation of depolarization-induced calcium release from skeletal muscle triads by cyclic ADP-ribose and inositol 1,4,5-trisphosphate.

Two second messengers, cyclic ADP-ribose (cADPR) and inositol 1,4,5-trisphosphate (IP3), potentiated the Ca2+ release from sarcoplasmic reticulum induced by transverse tubular membrane depolarization monitored in a triadic vesicle prepared from skeletal muscle. However, without depolarization they could not trigger the Ca2+ release. On the contrary, only cADPR potentiated caffeine-induced Ca2+ release. Because Ca2+ releases potentiated by cADPR and IP3 were inhibited by 1 microM ruthenium red and 100 microM ryanodine, probably these second messengers potentiated the Ca2+ release through ryanodine receptor Ca2+ channels. These results suggest that in skeletal excitation-contraction coupling, cADPR and IP3 play a role as a potentiator or a modifier in vivo, but both modification pathways are different from each other.

Adenosine Diphosphate Ribose↗

Molecular cloning of a novel brain-specific serine protease with a kringle-like structure and three scavenger receptor cysteine-rich motifs.

In order to find serine proteases specifically expressed in brain, we designed degenerate mixed primers for consensus sequences of serine protease domains. By PCR utilizing the primers, we have cloned a novel sequence from reverse transcripts of total RNA of mouse brain and used it as a probe to screen a mouse brain cDNA library. Overlapping cDNAs encoding a precursor of a novel brain specific serine protease (BSSP-3) were cloned. DNA insert of the longest clone consisted of 2614-bp with an entire open reading frame encoding a secretory/membrane-anchored precursor protein consisting of 761 amino acids (AA) which may be processed to yield an active enzyme of 245 AA. As found in known serine proteases, BSSP-3 enzyme domain contained a catalytic triad which consists of AA residues essential for the enzyme activity. In the upstream region of the enzyme domain that resides at C-terminus of the precursor protein, there are, from N-terminus to downstream, a sequence similar to a kringle structure and three repetitive ones highly similar to the scavenger receptor cysteine-rich (SRCR) motifs. Northern blot analysis demonstrated that mBSSP-3 mRNA was specifically expressed in the mouse brain, lung and kidney. We concluded that a novel brain serine protease, BSSP-3, is a new member of kringle and SRCR superfamilies.

Amino Acid Sequence↗