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Biomedical subjects

A Morikawa

Publications and source records attributed to A Morikawa.

At least 37 records · Page 2Linked to original sources
PubMed2001

Living-related liver transplantation for type II citrullinemia using a graft from heterozygote donor.

BACKGROUND: Type II citrullinemia (CTLN2) characterized by a liver-specific argininosuccinate synthetase deficiency is an adult onset genetical disorder caused by the mutation of SLC25A13 gene, which results in fulminant hyperammonemia often with poor prognosis. METHODS: A 16-year-old Japanese boy presented fulminant hyperammonemia and encephalopathy and recovered after aggressive medical treatment. The patient was diagnosed as CTLN2 by plasma amino acid pattern and detection of the mutated SLC25A13 gene. We performed living-related liver transplantation (LRLT) using a graft from the genetically proven heterozygote father. RESULTS: Serum amino acid concentration was normalized within a day after transplantation without protein restriction and medication. The patient's postoperative course was natural. The patient is back in school 6 months after surgery. CONCLUSIONS: Living-related liver transplantation using a graft from genetically proven heterozygote donors might be a permissible treatment modality for CTLN2. Long-term observation may be necessary to make a definite conclusion possible.

Adolescent↗
PubMed2001

Relationship between bronchial hyperresponsiveness and development of asthma in children with chronic cough.

To evaluate the relationship between bronchial hyperresponsiveness (BHR) and the development of asthma in children with chronic cough, we performed methacholine inhalation challenges and transcutaneous oxygen pressure (tcPO2) measurements in 92 children with chronic cough aged from 1-13 years (55 boys and 37 girls; mean, 5.3 years) and followed them for > or = 10 years. Forty-four age-matched children with asthma (24 males and 20 females; mean, 6.5 years) and 44 age-matched children without cough or asthma served as controls (18 males and 26 females; mean, 4.6 years). Consecutive doubling doses of methacholine were inhaled until a 10% decrease in tcPO2 from baseline was observed. The cumulative dose of methacholine at the inflection point of the tcPO2 record (Dmin-PO2) was considered to represent hyperresponsiveness to inhaled methacholine. After 10 years or more of follow-up, 60 of the 92 subjects with cough answered our questionnaire, and 27/60 had been diagnosed with asthma. There was a statistical difference in Dmin-PO2 between the children who presented with chronic cough originally and who developed asthma (asthma-developed group) and those who did not develop asthma (asthma-free group). There was no difference in the value of Dmin-PO2 between the asthma-developed group and the asthma group, or between the asthma-free group and the age-matched control group. Among the children with chronic cough, there was no difference in Dmin-PO2 between girls and boys, either in the asthma-developed group or in the asthma-group. We conclude that 45% of the children with a chronic cough in early life developed asthma, and that BHR in children with chronic cough during the childhood period is a strong risk factor for the development of asthma.

Administration, Inhalation↗
PubMed2001

Production of experimental autoimmune sialadenitis in mice immunized with homologous salivary gland extract and Klebsiella O3 lipopolysaccharide.

An experimental murine model for autoimmune sialadenitis was produced by repeated immunization of homologous salivary gland extract together with Klebsiella O3 lipopolysaccharides as an immunological adjuvant. The cell infiltration was observed in the salivary glands of mice immunized more than twice. Inflammatory cells consisting mainly of CD4+ T cells and CD8+ T cells accumulated at the perivascular regions. There was hyperplasia and enlargement of ductal epithelial cells in the secretory acinar units in salivary glands of repeatedly immunized mice. The repeated immunization developed delayed-type hypersensitivity and autoantibody production to the homologous salivary gland extract. The immunohistochemical analysis showed positive staining on the cuboidal cells in the intercalated ducts, and the columnar pseudostratified cells in the striated ducts. Organ-specific antigens with molecular weights ranging from 20 to 90 kDa were recognized by the sera from immunized mice. Therefore, it was suggested that the sialadenitis was produced by the autoimmune mechanism and might be a new experimental model for characterization of the pathogenesis of autoimmune sialadenitis.

Adjuvants, Immunologic↗
PubMed2001

Developmental changes in cyclooxygenase mRNA expression in the kidney of rats.

Prostaglandins, synthesized by cyclooxygenase (COX), regulate renal hemodynamics and also epithelial water and solute transport. To determine whether COX mRNA expression changes with age, we studied expression in renal medulla and in cortex in developing rats at various ages. We also examined age-related changes in COX mRNA expression induced by lipopolysaccharide (LPS). COX mRNA was quantitatively analyzed in a real-time polymerase chain reaction (PCR) with dual-labeled fluorogenic probes. COX-1 mRNA expression did not change with age in cortex or medulla. COX-2 mRNA expression was highest in 1-week-old rats and lowest in 4- and 8-week-old rats. Lipopolysaccharide treatment did not alter COX-1 mRNA expression in infantile or adult rats. In adults, LPS at 1, 5, and 10 mg/kg induced COX-2 mRNA expression in renal medulla; the higher doses, 5 and 10 mg/kg, induced COX-2 expression in cortex. In infantile rats, COX-2 mRNA, already high in the unmanipulated state, was further increased by only 1 mg/kg LPS in both renal cortex and medulla. Age-related changes in the expression of COX-2 mRNA might be responsible for changing physiologic characteristics of renal function during postnatal development in rats, and may be important in renal cortical development.

Aging↗
PubMed2001

Acute effects of prostaglandin D2 to induce airflow obstruction and airway microvascular leakage in guinea pigs: role of thromboxane A2 receptors.

BACKGROUND: Although prostaglandin D2 (PGD2), a mast cell-derived inflammatory mediator, may trigger allergic airway inflammation, its potency and the mechanism by which it induces airway microvascular leakage, a component of airway inflammation, is not clear. OBJECTIVE: We wanted to evaluate the relative potency of PGD2 to cause microvascular leakage as compared to airflow obstruction, because both responses were shown to occur simultaneously in allergic airway diseases such as asthma. The role of thromboxane A2 receptors (TP receptors) in inducing these airway responses was also examined. METHODS: Anesthetized and mechanically ventilated guinea pigs were given i.v. Evans blue dye (EB dye) and, 1 min later, PGD2 (30, 100, 300 or 1,000 nmol/kg). For comparison, the effect of 150 nmol/kg histamine or 2 nmol/kg leukotriene D4 (LTD4) was also examined. Lung resistance (R(L)) was measured for 6 min (or 25 min for selected animals) and the lungs were removed to calculate the amount of extravasated EB dye into the airways as a marker of leakage. In some of the animals, specific TP receptor antagonists, S-1452 (10 microg/kg) or ONO-3708 (10 mg/kg), or a thromboxane A2 synthase inhibitor, OKY-046 (30 mg/kg), was pretreated before giving PGD2. RESULTS: Injection of PGD2 produced an immediate and dose-dependent increase in RL (peaking within 1 min), which was significant at all doses studied. At 1,000 nmol/kg, PGD2 induced a later increase in R(L), starting at 3 min and reaching a second peak at 8 min. By contrast, only PGD2 at doses of 300 and 1,000 nmol/kg produced a significant increase in EB dye extravasation. The relative potency of 1,000 nmol/kg PGD2 to induce leakage as compared to airflow obstruction was comparable to histamine at most of airway levels, but less than LTD4. Both responses caused by PGD2 were completely abolished by S-1452 and ONO-3708, but not by OKY-046. CONCLUSION: PGD2 may induce airway microvascular leakage by directly stimulating TP receptors without generating TXA2 in guinea pigs. Microvascular leakage may play a role in the development of allergic airway inflammation caused by PGD2.

Airway Obstruction↗
PubMed2001

Plasmapheresis in fulminant acute disseminated encephalomyelitis.

We report an 11-year-old girl with acute disseminated encephalomyelitis (ADEM) who developed respiratory failure and coma despite the use of corticosteroid and intravenous immunoglobulin. We performed plasmapheresis four times, which improved her level of consciousness, hyperesthesia, external ophthalmoplegia and muscle weakness, and led to the normalization of brain and spinal cord MRI. Plasmapheresis might be an effective treatment in cases of fulminant ADEM.

Child↗
PubMed2001

Age-dependent relationship between bronchial hyperresponsiveness to methacholine and total serum IgE level in asthmatic children.

BACKGROUND: A relationship between nonspecific bronchial hyperresponsiveness and allergic airway inflammation has been reported in children and in adults with asthma, but the relationship in infants with asthma is still unclear. OBJECTIVE: To evaluate the relationship between bronchial hyperresponsiveness and total serum IgE level throughout childhood. Bronchial reactivity to methacholine from the age of 1 to 16 years was studied by methacholine inhalation challenge using transcutaneous oxygen pressure (tcPO2) monitoring. METHODS: Two hundred one asthmatic children (boys:girls = 132:69; 7.3+/-4.0 years of age, mean +/- SD) were enrolled in this study. The tcPO2 was measured using a tcPO2 monitor. Serial doses of methacholine were doubled until a 10% decrease in tcPO2 from the baseline was reached. The cumulative dose of methacholine at the inflection point of tcPO2 was considered to represent the bronchial reactivity to methacholine. RESULTS: There was no relationship between the cumulative dose of methacholine at the inflection point of tcPO2 and total serum IgE level in the group of children aged 1 to 4 years (P = 0.212), but significant correlations were found in the groups aged 5 to 10 years and 11 to 16 years (P = 0.044 and P = 0.014, respectively). CONCLUSIONS: We conclude that there is an age-dependent relationship between bronchial reactivity to methacholine and the total serum IgE level and that inhaled allergens, which were more common allergens in older children, may have some effects on the degree of bronchial reactivity to methacholine in children with asthma.

Administration, Inhalation↗
PubMed2001

Gastric neuropeptides and gastric motor abnormality in streptozotocin-induced diabetic rats: observation for four weeks after streptozotocin.

Alterations of gastric calcitonin gene-related peptide and substance P content and gastric emptying in early stages of streptozotocin-induced diabetic rats were investigated. Diabetes was induced by intravenous injection of streptozotocin (50 mg/kg) in male Wistar rats. Gastric emptying of phenol red solution and calcitonin gene-related peptide and substance P content of gastric walls, measured by radioimmunoassay, was assessed two and four weeks after streptozotocin injection. Gastric emptying two weeks after streptozotocin was delayed (32+/-9%) and that four weeks after was enhanced (73+/-2%) compared with nondiabetic control rats (50+/-3%). Calcitonin gene-related peptide content of the gastric antrum and corpus was increased two weeks after and decreased four weeks after streptozotocin, while gastric substance P content was not changed at any time in diabetic rats. Insulin treatment reversed alterations of gastric emptying and calcitonin gene-related peptide content. The delayed gastric emptying in two-week diabetic rats was reversed by CGRP antagonist and the enhanced gastric emptying in four-week diabetic rats was reversed by CGRP pretreatment. These results suggest a possible relationship between gastric calcitonin gene-related peptide and abnormal gastric motility in diabetic state.

Animals↗
PubMed2001

Effect of vincristine on gastric motility in conscious rats.

We investigated the possible involvement of the upper alimentary tract in vincristine (VCR)-induced dysmotility. Gastric contractions were recorded by a strain-gauge force transducer in conscious rats. Rats were injected with various doses of VCR followed by continuous recording for 12 hr. Additionally, 3-hr recordings to study the later effects were performed one and three days after injection. Gastric motility was dose-dependently increased by VCR. Post- versus preinjection motility index (MI; area under contraction waves) ratios were 0.78+/-0.12 for saline and 1.95+/-0.21 for VCR at 0.75 mg/kg. This increase in MI was completely inhibited by atropine and hexamethonium. MI one day after injection of VCR (0.75 mg/kg) was significantly less than in control (0.32+/-0.10 vs 0.92+/-0.24, respectively). The decrease was reversed by acetylcholine. In conclusion, VCR first increased gastric motility, and this was followed by a gradual decrease in conscious rats. These alterations may involve a presynaptic cholinergic pathway.

Acetylcholine↗
PubMed2001

Novel dinucleotide repeat polymorphism in the first exon of the STAT-6 gene is associated with allergic diseases.

BACKGROUND: T helper-type 2 cytokines, such as interleukin-4 (IL-4) and IL-13, may play a central role in allergic diseases. The protein known as 'signal transducers and activators of transcription 6' (STAT-6) is a key transcription factor involved in both IL-4- and IL-13-mediated biological responses. OBJECTIVE: The objective of this study was to evaluate the possible role of the STAT-6 gene in modulating atopy in the Japanese population. METHODS: We screened all 23 exons of the STAT-6 gene from 10 subjects for mutations by direct polymerase chain reaction (PCR) sequencing. The STAT-6 gene polymorphisms were genotyped by PCR fragment length polymorphism analysis and PCR-SSCP analysis. The IL-4 receptor Q576R polymorphism was also examined by PCR-SSCP analysis. RESULTS: We found a novel dinucleotide repeat polymorphism in the first exon of the STAT-6 gene. The genotypes were classified into four groups according to the number of GT repeats present, from 13 to 16. The frequency of the A1 allele (326 bp, containing 13 repeats of GT) was higher in children with allergic diseases (bronchial asthma, atopic dermatitis and/or food-related anaphylaxis) than controls, although this was not statistically significant (P = 0.0158). In addition, a strong association between the A1 and A3 allele (containing 15 repeats of GT) heterozygote and allergic diseases was identified (P = 0.0002). However, the levels of IgE were not related to the GT repeat polymorphism in the allergic subjects. The GT repeat polymorphism was not associated with the polymorphism in the IL-4 receptor a chain gene (Q576R) and there was no association between the G2964A variant and allergic diseases. CONCLUSION: This suggests that genetic variation in the STAT-6 gene may be associated with predisposition to allergic diseases.

Alleles↗
PubMed2001

Usefulness of Dennis Colorectal Tube in endoscopic decompression of acute, malignant colonic obstruction.

BACKGROUND: Colonoscopic decompression has been attempted in patients with acute colonic obstruction caused by colon cancer to avoid emergency surgery and multiple subsequent operations but has usually been unsuccessful. This is an evaluation of the usefulness of a new device for endoscopic decompression in these patients. METHODS: Nine consecutive patients (6 men, 3 women; 65 to 89 years of age) with acute colonic obstruction resulting from colon cancer underwent endoscopic decompression with a Dennis Colorectal Tube. RESULTS: In all 9 patients (1 with carcinoma of the sigmoid colon, 3 with carcinoma of descending colon, 2 with carcinoma of the transverse colon, 2 with carcinoma of the ascending colon, and 1 with carcinoma of the cecum), endoscopic decompression was successful. After decompressing and cleansing the colon for several days, a one-stage operation was possible in all patients. CONCLUSION: Dennis Colorectal Tube is an excellent device for endoscopic decompression of acute, malignant colonic obstruction.

Acute Disease↗
PubMed2001

Amatoxin poisoning from ingestion of Japanese Galerina mushrooms.

BACKGROUND: Although some Japanese Galerina species poisonings manifest as gastrointestinal symptoms followed by late-onset hepatorenal failure (phalloides syndrome), the toxin responsible for this has not been determined. CASE REPORT: We report a 6-year-old boy who developed characteristic cholera-like diarrhea and late-onset severe hepatic deterioration after eating mushrooms, later identified as a Galerina species, most likely Galerina fasciculata. A residual mushroom revealed alpha-amanitin. This account is the first known reported case of poisoning by Japanese Galerina species where an amatoxin was demonstrated to be responsible for the toxicity.

Agaricales↗
PubMed2001

Development of bronchial hyperresponsiveness during childhood.

Bronchial hyperresponsiveness (BHR) produces the characteristic pathological abnormalities seen in asthma and clearly plays a central role in the pathophysiology of asthma. The presence of BHR has been demonstrated in infants with asthma, as has the possibility of BHR persisting through the childhood period. The level of BHR may not only reflect the state of the airways, as a marker of airway dysfunction, but may also predict the persistent prognosis of the disease. Thus, measurement of BHR may provide important information about the symptoms and lung function in children with asthma. In view of multiple pathophysiological mechanisms, BHR does not seem to have a single cause. Many potential confounding variables, such as age, gender and genetic status, and some environmental factors, such as allergens, infections, and pollutants, could be responsible for the establishment of childhood BHR. There may be differences between the mechanisms that induce transient BHR and the mechanisms that induce persistent BHR. Also, there may be differences between the causes that induce BHR in the infantile period and the causes that maintain persistent BHR during childhood asthma. There is also disagreement as to the most suitable method to measure BHR in children, especially in infants. The assessment of BHR in young children has not been uniformly successful, and measurements of BHR changes over the childhood period (are associated with a number of problems. To resolve these problems, there may be two ways to study childhood BHR. One is to use age-matched specific techniques to clarify the precise BHR in each age group; the other is to use simple techniques that can be performed over the childhood period on a large number of subjects. In studies of infantile respirator, dysfunction the ultimate goal is to establish a simple, noninvasive method by which measurements of respiratory function may be obtained in infants. Further investigations and acceptable methods will be needed to clarify, the mechanisms involved in the establishment of asthma throughout the childhood period.

Asthma↗
PubMed2001

Novel inactivating missense mutations in the thyrotropin receptor gene in Japanese children with resistance to thyrotropin.

We describe Japanese siblings with resistance to thyrotropin (TSH) who are compound heterozygotes for two novel mutations in the TSH receptor gene. The affected siblings had increased serum TSH, normal serum thyroid hormones, and normal positioned but slightly hypoplastic thyroid glands. The mutated paternal allele has the substitution of His (CAC) in place of Arg (CGC) at codon 450 (R450H) of the TSH receptor. The mutated maternal allele has the substitution of Ser (AGT) in place of Gly (GGT) at codon 498 (G498S) of the TSH receptor. COS-7 cells transfected with the R450H mutant exhibited a slightly decreased TSH binding and a slightly decreased cyclic adenosine monophosphate (cAMP) response to TSH, whereas cells transfected with the G498S mutant exhibited a markedly decreased TSH binding and a markedly decreased cAMP response to TSH. Flow immunocytofluorometry analysis demonstrated that the G498S mutant resulted in extremely low expression at the cell surface as compared with the wild type receptor and the R450H mutant, in spite of a normal intracellular synthesis. The present cases are the first Japanese patients with TSH resistance in whom mutations in the TSH receptor gene have been identified. These novel mutations may contribute to understanding of the struc-ture-function relationship of the TSH receptor.

Adult↗
PubMed2001

Flavonoids protect mice from two types of lethal shock induced by endotoxin.

The protective effect of flavonoids on two types of lethal endotoxic shock was studied. A lethal endotoxic shock was induced by administration of lipopolysaccharide (LPS) into D-galactosamine (D-GalN)-sensitized mice and another one was done by administration of a high dose of LPS into normal mice. Pretreatment with a series of flavonoids protected mice from two types of endotoxin lethality. Flavonoid pretreatment reduced the serum tumor necrosis factor-alpha (TNF-alpha) level in mice injected with D-GalN and LPS, but not in mice injected with a high dose of LPS. TNF-alpha-induced lethal shock in D-GalN-sensitized mice was also protected by pretreatment with flavonoids, suggesting that flavonoids augmented the resistance to TNF-alpha lethality. On the other hand, flavonoids reduced the plasma level of lipid peroxides in mice injected with a high dose of LPS, but not in D-GalN-sensitized mice. Taken together, these results indicated that flavonoids might protect mice from two types of endotoxin lethality. The protective mechanism of flavonoids in each endotoxin lethality is discussed.

Animals↗
PubMed2001

Neonatal thrombocytosis resulting from the maternal use of non-narcotic antischizophrenic drugs during pregnancy.

Neonatal thrombocytosis can result from maternal narcotic drug abuse. The case of a male infant is reported who was born to a woman with schizophrenia treated with non-narcotic psychotropic drugs during pregnancy; he developed severe prolonged thrombocytosis. The platelet count reached 1310 x 10(9)/l on day 15. This thrombocytosis persisted for three months. The patient was treated with dipyridamole. A bone marrow aspirate showed normal myeloid and erythroid precursors with an increased number of megakaryocytes. Plasma concentrations of interleukin 6 and thrombopoietin were suppressed. No obvious complications from the thrombocytosis occurred, and the platelet count fell to within the upper limit of normal after 3 months of age. This case indicates that thrombocytosis may occur in infants born to mothers treated with non-narcotic psychopharmaceutical drugs during pregnancy. The thrombocytosis in this case may have been induced by factors other than interleukin 6 or thrombopoietin.

Dipyridamole↗