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Biomedical subjects

Y Ichikawa

Publications and source records attributed to Y Ichikawa.

At least 235 records · Page 13Linked to original sources
PubMed1996

Mutation analysis of gonadotropin receptor and G protein genes in various types of human ovarian tumors.

The heterotrimeric guanine-nucleotide-binding proteins (G proteins) and G protein-coupled hormone receptors including gonadotropin receptors have been suggested to play a role in ovarian tumorigenesis. However, no functional significance of gonadotropin receptors and G proteins in this process has been demonstrated. To investigate this issue, we examined point mutations in these genes in various types of ovarian tumors by polymerase chain reaction-single strand conformation polymorphism analysis and direct sequencing. Among 37 tumors (20 epitherial, 8 sex cord-stromal, and 9 germ cell tumors) and 5 carcinoma cell lines examined, no mutational sequence of G protein-interaction domains of luteinizing hormone receptor and follicle-stimulating hormone receptor, or "hot spots" of the alpha subunit of adenylyl cyclase-stimulating G protein and -inhibitory G protein was observed. Although this analysis was performed on only a limited number of tumors and cell lines, and on limited gene loci, the results suggest that mutational activation in gonadotropin receptors and G proteins is not crucial for ovarian tumorigenesis.

Female↗
PubMed1996

Comparative studies of thrombolysis with single-chain and two-chain recombinant tissue-type plasminogen activators in canine coronary thrombosis.

Tissue-type plasminogen activator (t-PA) can occur in two different forms, single- and two-chain t-PA. Such a difference in structure of the t-PA molecule may induce different biological functions. We compared the thrombolytic efficacy of single-chain t-PA with that of two-chain t-PA and urokinase in a canine thrombosis model. The thrombolytic properties of single- and two-chain recombinant t-PA and urokinase with equivalent activity in vitro after intravenous infusion were examined in 24 anesthetized, open-chest dogs with intracoronary thrombi. Repeated coronary angiography showed that the time to reperfusion was 29.0 +/- 4.8, 32.5 +/- 6.3, and 39.2 +/- 6.8 min, respectively. One dog in the single-chain t-PA group and all dogs in the vehicle group showed no recanalization. Plasma t-PA antigen reached similar plateau levels within 15. min in both the single- and two-chain t-PA groups. The infusion of single- and two-chain t-PA was not associated with systemic fibrinolytic activation, except for a decrease in alpha 2-plasmin inhibitor in single-chain t-PA. However, the infusion of urokinase was associated with significant depletion of fibrinogen. These findings suggest that single-chain t-PA has potent thrombolytic effect without systemic fibrinolytic activity similar to that of two-chain t-PA in a canine coronary artery thrombosis model.

Animals↗
PubMed1996

Three-times-daily monotherapy with tacrolimus (FK 506) in kidney transplantation.

BACKGROUND: Tacrolimus (FK 506) was introduced into organ transplantation as a powerful immunosuppressive but with several adverse effects. In fact, an appropriate protocol for using this agent has not yet been established. On the basis of pharmacokinetic studies and the reports of its administration as a continuous intravenous infusion, we designed the regimen of every eight hours in order to reduce the daily dosage. METHODS: Tacrolimus was given to nine patients in the Japanese FK506 study. Although it was discontinued in two patients within two months because of adverse effects and acute rejection, seven other patients tolerated the agent for a long period and received the drug three times a day. Concomitant prednisolone was gradually tapered and finally withdrawn in these patients. RESULTS: The smaller dosage of tacrolimus led to a higher trough concentration of 14.1 +/- 1.6 ng/mL in the three-times-a-day regimen compared with 12.7 +/- 1.9 ng/ml in twice-a-day therapy (P < 0.01). The daily dosage of tacrolimus proved to be reducible even further. Our target trough concentration was decreased finally to < 5 ng/mL. Concomitant prednisolone was withdrawn in all of the seven patients. The course of these patients has been uneventful for a year after withdrawal of prednisolone. CONCLUSION: Our regimen of three-times-a-day oral administration of tacrolimus is a likely protocol for reduction of its daily dosage, which lowers its adverse effects while maintaining its immunosuppressive action at a lower trough concentration without concomitant prednisolone.

Administration, Oral↗
PubMed1996

Characteristics of Japanese alcoholics with the atypical aldehyde dehydrogenase 2*2. I. A comparison of the genotypes of ALDH2, ADH2, ADH3, and cytochrome P-4502E1 between alcoholics and nonalcoholics.

We examined the genotypes of the aldehyde dehydrogenase (ALDH)-2, alcohol dehydrogenase (ADH)-2, ADH3, and P-4502E1 loci of 53 alcoholics and 97 nonalcoholics. All of the subjects fulfilled the DSM-III-R criteria for alcohol dependence. The control group consisted of 97 subjects who were either hospital staff or students. We also compared the frequencies of homozygous ALDH2*1/1 and heterozygous ALDH2*1/2 genotypes in alcoholics. Our study revealed differences in the allelic frequencies of the ALDH2, ADH2, and ADH3 loci between alcoholics and nonalcoholics. For alcoholics with both homozygous ALDH2*1/1 and heterozygous ALDH2*1/2 genotypes, it was found that ADH2 and ADH3 played important rates. Alcoholics with the heterozygous ALDH2*1/2 genotype showed a significantly higher frequency of ADH2*1/1 than ones with the homozygous ALDH2*1/1 genotype. We assume ADH2*1 plays an important role in the development of alcoholism in alcoholics with the heterozygous ALDH2*1/2 genotype.

Adult↗
PubMed1996

Induction of cytochrome P-450-linked monooxygenase system in rat liver microsomes by xiao-chaihu-tang.

The administration of Xiao-Chaihu-Tang (TJ-9) for 2 weeks induced a 25% increase in the content of cytochrome P-450 in female rat liver microsomes, while the content in male rats remained unchanged. The enzymatic activities toward various xenobiotics were stimulated in female rats, the levels being in the range of 125-250% of those in the control rats. Among these xenobiotics, the metabolic rates for substrates of cytochrome P-450 2E1 were significantly enhanced in female rats. On the other hand, the activities toward various xenobiotics in male rats were unchanged. When 3-methylcholanthrene was given to rats for a week, the augmentation of cytochrome P-450 content and the stimulation of xenobiotic metabolism were observed. However, co-administration of TJ-9 did not alter the effect of 3-methylcholanthrene described above.

Administration, Oral↗
PubMed1996

Haloperidol inhibits neuronal nitric oxide synthase activity by preventing electron transfer.

The effect of a neuroleptic, haloperidol (HP), on nitric oxide formation catalyzed by neuronal nitric oxide synthase (n-NOS) in the porcine brain was investigated. HP inhibited n-NOS activity noncompetitively versus L-arginine as a substrate, decreasing the maximal velocity (Ki value for HP = 31 microM). HP also inhibited the CaM-dependent NADPH consumption by n-NOS (IC50 = 221 microM). These data demonstrate the possibility that HP may mediate some neuronal functions through inhibiting NO release by preventing either the electron transfer through n-NOS or the formation of the activated reduced species of oxygen necessary for the formation of citrulline. And an interaction of HP with CaM may possibly affect the consumption of NADPH and n-NOS enzyme activity.

Animals↗
PubMed1996

Abnormal prostanoid metabolism in lupus nephritis and the effects of a thromboxane A2 synthetase inhibitor, DP-1904.

Abnormalities of prostanoid metabolism, which may affect renal function, were studied in lupus nephritis. The subjects were 31 patients with lupus nephritis, ten with non-renal SLE, and four with renal, non-SLE collagen disease. Urinary levels of various prostanoids, thromboxane B2(TXB2), 11-dehydro-TXB2, 6-keto-PGF1 alpha,2,3-dinor-6-keto-PGF1 alpha and PGE2, and plasma level of 11-dehydro-TXB2, were determined. The effects of four days' dosing of a selective thromboxane A2 (TXA2) synthetase inhibitor, DP-1904 (DP), on prostanoid metabolism, were also studied. Urinary excretion of TXB2, which reflects the renal production of TXA2, was significantly increased in patients with lupus nephritis as compared with non-renal SLE (p < 0.05). The urinary TXB2/6-keto-PGF1 alpha ratio was also increased in lupus nephritis as compared with non-renal SLE or healthy controls (p < 0.01), indicating a prostanoid imbalance, which may lead to impaired renal function and subsequent pathology. The urinary TXB2/6-keto-PGF1 alpha ratio in these lupus nephritis patients showed negative correlations with Ccr and positive correlations with anti-DNA antibody titer (p < 0.001). DP was administered orally (400 mg/day, given in two divided doses) for four days to eight lupus nephritis patients. The urinary excretion of TXB2 and urinary TXB2/6-keto-PGF1 alpha ratio were decreased after one to two days of treatment in all patients. An increase in creatinine clearance used as a measure of renal function was observed in four of eight patients. Furthermore, no side effects were elicited during the four days of treatment. The conclusion reached were that the abnormal prostanoid metabolism observed in lupus nephritis could aggravate renal function through hemodynamic mediation, and that the deviated metabolism was reversible and, at least partially, corrected by a TXA2 synthetase inhibitor.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Dentatorubral-pallidoluysian atrophy proteins in lymphoblastoid cells.

The genetic defect responsible for dentatorubral-pallidoluysian atrophy (DRPLA) is an expansion of a CAG trinucleotide repeat. The DRPLA gene is translated into protein in the brain. In this study, we demonstrate that the wild-type and mutant genes are also translated into proteins, p190 and p205, in lymphoblastoid cells. The correlation between the age of onset and the expansion of polyglutamine stretch shown by slower electrophoretic mobility suggests that the polyglutamine stretch is directly involved in the acceleration of the disease process. Moreover, analysis of the protein in lymphoblastoid cells can be used as a diagnostic procedure for DRPLA.

Adult↗
PubMed1996

McArdle's disease with non-insulin-dependent diabetes mellitus: the beneficial effects of hyperglycemia and hyperinsulinemia for exercise intolerance.

A 64-year-old female with McArdle's disease and non-insulin-dependent diabetes mellitus (NIDDM) is reported. She had none of the characteristic symptoms of McArdle's disease such as muscle cramps but her serum creatine kinase level was elevated. Muscle biopsy with negative muscle phosphorylase staining showed McArdle's disease. Modified forearm ischemic exercise test was done at two conditions; fasting and two hours after a meal. When fasting, the level of lactic acid did not elevate after exercise. After a meal, however, the serum lactic acid level rose with the elevation of plasma glucose and IRI. Thus, we suggested that high plasma glucose and insulin due to NIDDM may induce blood-borne glucose uptake with exercise.

Biopsy↗
PubMed1996

Clinical application of a novel DNA fluorescence intercalator, pyrylium dye, for the quantification of PCR products.

Polymerase chain reaction (PCR) is a powerful tool for clinical diagnosis in the field of oncology, infection, and allergy. However, a simple and sensitive method for quantifying PCR products has not been established. We therefore used a novel fluorescence DNA intercalator, pyrylium iodide (P2) to quantify PCR products. A 838-bp fragment of the human beta-actin gene and a 374-bp fragment of the gene for ornithine decarboxylase (ODC) and ODC primer dimers were generated by PCR and quantified using either P2 or another fluorescence DNA intercalator, YOYO-1. In addition, utilizing RT-PCR and the P2 method, the ODC mRNA expression from 10 colonic cancers was quantified. Serially diluted beta-actin and ODC PCR products could be quantified using P2 without having to separate them from primer dimers and other components of the reaction mixture. However, YOYO-1 could not be used to quantify the PCR products because of high background fluorescence from the primer dimers. In the clinical study, ODC mRNA expression as quantified by P2 was significantly higher in cancerous tissue (113.8 +/- 4.1; mean +/- SEM; plate reader units) than in mucosa of normal appearance (68.4 +/- 4.8). P2 is a promising tool for quantifying PCR products.

Actins↗
PubMed1996

[Experience of 28 deliveries in 21 kidney transplant recipients].

BACKGROUND: Risk factors to induce graft dysfunction during pregnancy in kidney transplant recipients were studied. METHODS: A total of 28 deliveries from 21 female kidney transplant recipients were analyzed. RESULTS: All recipients were maintained on either azathioprine-based (n = 17) or cyclosporine-based (n = 11) immunosuppressive regimens. Graft dysfunction (creatinine clearance < 40 ml/min) occurred in 8 cases (8 patients) during pregnancy. No acute rejection, however, could be observed. In a case-controlled study comparing a group with graft dysfunction vs. a group with good graft function, there were significantly differences in the incidence of the cases with pre-existing hypertension (62.5% vs. 10.0%), the age of the grafted kidney (58.1 vs 47.6 year), the maternal anemia (Hb: 10.3 vs. 11.8 g/dl) and the creatinine level (1.4 vs. 1.0 mg/dl) at the first trimester. These findings suggested that poorer graft function had been underlying before pregnancy and that additional loading of the pregnancy reduced further graft function, while the deterioration would be recovered after delivery in all cases except one case. CONCLUSION: Risk factors to induce graft dysfunction during pregnancy are as follows. 1) high age of the grafted kidney (> 50 year), 2) pre-existing hypertension, 3) maternal anemia (Hb: < 11 g/dl) and 4) high creatinine level (> 1.3 mg/dl) at the first trimester.

Adult↗
PubMed1996

[Adjuvant chemotherapy with cyclophosphamide, adriamycin, and CDDP (CAP) for high risk endometrial cancer after complete surgery].

One hundred and six patients with endometrial cancer were treated at Tsukuba University Hospital between 1983 and 1992. Sixteen patients who underwent complete resection were at high risk for recurrence and were given adjuvant platinum-based, multiagent chemotherapy instead of adjuvant radiotherapy. Eligibility criteria included outer-third myometrial invasion (group 1; n = 5), pelvic lymph node metastasis (group 2; n = 3) or both myometrial invasion and lymph node metastasis (group 3; n = 8). Of these three groups at high risk for recurrence, each patient in groups 1 and 2 developed recurrence and died. In group 3 two patients developed recurrence and one patient has died. There was one treatment death due to neutropenic sepsis in group 3. The recurrence sites in all four patients were local and no distant recurrence was noted. In other words, of 15 patients (excluding one treatment death) at high risk for recurrence, three of 12 patients (25%) with deep myometrial invasion and three of 10 patients (30%) with positive pelvic lymph nodes developed recurrence and died. The other 12 patients (include one patient with recurrence; 100 months) have survived for a long interval (range, 45-131 months). The survival rates for stage I, II, III, and IV are 92.6, 89.5, 60.0%, respectively. Patients with stage I in this study had a better survival than those with stage I in the 1984 annual report of the Japan Society of Obstetrics and Gynecology (p < 0.05). The findings of this prospective clinical trial supported those of the randomized trial comparing adjuvant CAP with radiation therapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

[Prognostic factors of colorectal cancer concerning metastases].

Four prognostics factors were investigated for colorectal cancer metastases. 1) There were statistically more venous invasions using Victoria blue elastic staining in patients with liver or lymph node metastasis than in those without metastasis. 2) The immunohistochemical expression rate of c-erbB-2 in liver metastasis cases was 27%, which was significantly higher than 3% in no metastasis cases. 3) Sialyl Lewis x (SLex) is related with cell adhesion. SLex positive rates in vessel invasion cancer cells were 71.4% with metastasis and 31.0% without metastasis. 4) Matrilysin is one of MMPs and it was significantly increased with Dukes stage by fluorescence intensity.

Colorectal Neoplasms↗
PubMed1996

[Evaluation of the retrosternal space and the retrocardiac space on normal left lateral radiographs of the chest].

Left lateral chest radiographs with normal studies were evaluated in 100 Japanese (50 females and 50 males) to compare the radiolucency of the retrosternal space (RSS) with that of the retrocardiac space (RCS) and to measure the RSS. In 56 (56%) cases, the RSS was equally radiolucent to the RCS. In 40 (40%) cases, the RSS was less radiolucent than the RCS (33 of 50 females and 7 of 50 males). The difference between the sexes was statistically significant (p = 0.0001). The RSS was more radiolucent than the RCS in only 4 (4%) males. Frontal chest radiographs of 50 females were classified into one of three groups (Small, Medium, or Large) depending on the size of soft tissue opacity of the breast. The differences between the radiolucency of the RSS and RCS were statistically significant between the Small and Medium and the Small and Large groups (both p < 0.0001). The strength of the relationship between the radiolucency and body-to-fat ratio was statistically significant (p = 0.0028). Results of data comparison between females and males remained significant when adjusted for differences in body-to-fat ratio (p < 0.0001). The distance on the chest radiograph from the sternum to the most anterior aortic border (the distance of RSS) could be measured on only 37 (37%) lateral chest radiographs, and the averages and standard deviations were as follows: 2.2 +/- 0.5 in all cases, 2.0 +/- 0.5 in females, and 2.4 +/- 0.5 in males. The difference between the sexes was statistically significant (p < 0.05). In conclusion, an RSS that is more opaque (less radiolucent) than the RCS is a frequent normal finding because of the opacity of the breast and fat tissue, especially in females, and the length of the RSS is shorter in females than in males.

Adult↗
PubMed1996

A novel mutation in the cytochrome P450(27) (CYP27) gene caused cerebrotendinous xanthomatosis in a Japanese family.

Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive lipid storage disease caused by mutations in the cytochrome P450(27) (CYP27) gene. This disease is characterized by the accumulation of a bile alcohol, cholestanol, in diverse tissues. Accumulation in the central nervous system leads to neurological dysfunction including dementia, spinal cord paresis, and cerebellar ataxia. Accumulation in other tissues causes tendon xanthomas, premature atherosclerosis, and cataracts. In a Japanese family with CTX, we identified two points mutations in the CYP27 gene at different sites. One is a novel transversion, which substitutes G for C at Pro 368 (CCC) to Arg (CGC). The other is a transition, which substitutes A for G at Arg441 (CGG) to Gln (CAG), this being the same mutation that Kim et al. reported (1994. J. Lipid Res. 35: 1031 - 1039). Allele-specific polymerase chain reaction analysis indicated that the father and mother of this family, who themselves had no clinical manifestations of CTX, had the former and latter mutations heterozygously, respectively. On the other hand, the patients each had both mutations heterozygously. These results are highly suggestive, but not conclusive, that the newly identified transversion in the CYP27 gene accounts for the sterol 27-hydroxylase (EC 1.14.13.15) deficiency in these patients.

Alleles↗
PubMed1996

[Abnormal head drooping in facioscapulohumeral muscular dystrophy].

Diagnosis of facioscapulohumeral muscular dystrophy (FSHD) is based on its characteristic pattern of muscle wasting. Initial symptom is usually shoulder girdle and upper arm muscle wasting resulting in difficulty in arm-lifting. Patients are aware of progressive change of facial appearance caused by characteristic facial muscle weakness. Affection of other muscles is usually realized much later, but, there is a considerable variation in pattern and severity between individuals even in the same family so that several clinical subtypes such as jump form or scapuloperoneal syndrome have been proposed. Here we described three patients with FSHD showing conspicuous head-drooping caused by severe wasting of posterior neck muscles. These patients realized abnormal neck posture much earlier than appearance of obvious gait disability, while they show other characteristic FSHD features. Familial occurrence is observed in two cases, other affected members from both families do not show abnormal head drooping. Therefore we regarded this sign as another example of clinical heterogeneity of this genetic disorder.

Aged↗