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Biomedical subjects

Y Yamashiro

Publications and source records attributed to Y Yamashiro.

At least 19 recordsLinked to original sources
PubMed2007

Plasma levels of active ghrelin until 8 weeks after birth in preterm infants: relationship with anthropometric and biochemical measures.

This study investigated the relationship between plasma levels of ghrelin and postnatal growth in preterm infants. The levels of active ghrelin in cord blood and in plasma in 25 very low birthweight (VLBW) infants were measured. The results indicate that the levels of circulating active ghrelin markedly increases after birth in VLBW infants, and suggest that the increased levels of ghrelin reflects the maturation of ghrelin production in the stomach and an increased physiological need for ghrelin.

Anthropometry↗
PubMed2006

Independent risk factors for chronic cyclosporine induced nephropathy in children with nephrotic syndrome.

BACKGROUND: Cyclosporine A (CsA) has been widely used in children with steroid dependent and steroid resistant nephrotic syndrome (NS) because of its efficacy in relieving these patients from systemic side effects of steroids. However, its long term use is controversial, since chronic CsA induced nephropathy (CsAN) may develop in a considerable number of patients. AIMS AND METHODS: In order to clarify the risk factors for the development of CsAN, the clinical characteristics of children with steroid dependent or steroid resistant NS taking CsA (target blood trough levels 50-150 ng/ml) for more than six months, managed at a single centre, were retrospectively analysed. RESULTS: Thirteen of 30 children (24 boys and 6 girls) taking CsA (mean duration 43 months, range 6-144) had CsAN defined as the presence of CsA associated arteriopathy with or without striped tubulointerstitial lesions. The multivariate analysis revealed that CsA treatment for more than 36 months and an age younger than 5 years at the start of CsA treatment were independent risk factors for the development of CsAN. The univariate analysis also showed that patients with CsAN had more frequent relapses during CsA treatment than those without CsAN. CONCLUSION: An alternative treatment should be seriously considered after a 36 month administration of CsA in order to prevent CsAN. Data also suggest that CsA treatment in children younger than 5 years should be avoided if possible.

Adolescent↗
PubMed2005

Immunological development of preterm infants in early infancy.

To evaluate the immunological development of preterm infants, especially in early infancy, we examined the serum cytokine levels and the expression of Th2 and Th1 chemokine receptors, CCR4 and CCR5, on days 0, 14 and 28 in 16 low birth weight infants (1720.38 +/- 502.80 g) born at less than 37 (33.63 +/- 3.29) weeks of gestation. Using an enzyme-linked immunosorbent assay (ELISA), serum interleukin (IL)-4 levels exhibited an increase on day 14, but decreased to the initial level on day 28 (P < 0.05). The significant elevation of serum transforming growth factor (TGF)-beta levels was confirmed on day 14 (P < 0.05) but decreased to the initial level on day 28 (P < 0.05). The expression of CCR4 and CCR5 were examined using reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometric analysis. The RT-PCR confirmed the expression of CCR5-mRNA soon after birth, while there was no expression of CCR4-mRNA. Thereafter, the expression of CCR4-mRNA increased significantly and reached the level of CCR5-mRNA expression on day 28 (P < 0.05). Flow cytometric analysis, however, revealed that the expression levels of both CCR4 and CCR5 were low at birth. Thus, CCR4(+) CD4(+) cells were significantly increased from days 0-28 (P < 0.05), while CCR5(+) CD4(+) cells were not. Increased IL-4 and TGF-beta synthesis as well as increased CCR4(+) CD4(+) cells suggest that, under extra-maternal circumstances, there is a shift in bias toward Th2 responses even in preterm infants soon after delivery, while they may be capable of developing Th1 mediated responses soon after birth.

Actins↗
PubMed2004

Cytokines in the gastric mucosa of children with Helicobacter pylori infection.

AIM: Few studies have looked at the cytokine profile in gastric mucosa in children with Helicobacter pylori infection. This study investigated cytokines and their effects on histological abnormalities in the gastric mucosa of children with H. pylori infection. METHODS: The levels of interferon-gamma (IFN-gamma), interleukin-4 (IL-4) and IL-8 proteins were measured in biopsy specimens from the gastric antrum and corpus of children with H. pylori infection, and related to inflammatory cell infiltrations. RESULTS: The antral and corporal mucosal levels of IFN-gamma and IL-8 proteins were significantly higher in children with H. pylori infection than in uninfected children, but there was no such difference in the levels of IL-4 protein. The antral mucosal level of IL-8 protein was significantly higher than the corporal mucosal level of IL-8 protein in the infected children. Inflammatory cell infiltration was significantly higher in the infected children than in the uninfected children, but there were no significant correlations between mucosal cytokine levels and inflammatory cell infiltrations. CONCLUSION: The results suggest that the predominant Th1 cytokine response and enhanced IL-8 production in the mucosa may be involved in the gastric inflammation seen in children infected with H. pylori, as well as in adult patients.

Adolescent↗
PubMed2004

The ratio of n-6 to n-3 fatty acids in maternal diet influences the induction of neonatal immunological tolerance to ovalbumin.

Prevalence of allergy is increasing in many countries and might be related to changed environmental factors, such as dietary fatty acids (FA). The present study investigates whether dietary ratio of n-6 to n-3 FA influences the induction of immunological tolerance to ovalbumin (OA) in neonatal rats. During late gestation and throughout lactation Sprague-Dawley rats were fed a diet containing 7% linseed oil (n-3 diet), sunflower oil (n-6 diet) or soybean oil (n-6/n-3 diet). At 10-16 days of age the rat offspring were subsequently exposed, or not, to OA via the milk. The offspring were weaned onto the same diets as the mothers and immunized with OA and the bystander antigen human serum albumin (HSA). In the offspring on the n-3 diet exposure to OA via the milk resulted in lower delayed type hypersensitivity reaction (DTH) and antibody responses against both OA and HSA, compared to those in the offspring not exposed to OA, indicating the induction of oral tolerance. In the offspring on the n-6 diet, the exposure to OA led to depressed specific immune responses against only OA, not HSA. In the offspring on the n-6/n-3 diet oral exposure to OA did not influence immune responses against OA, or HSA. The results indicate that the dietary ratio of n-6/n-3 FA is important for the induction of neonatal oral tolerance. Thus nonoptimal feeding may have effects on the development of immunological tolerance to dietary antigen ingested by the mother. The ratio of n-6/n-3 FA in the diet may be considered in the context of increased prevalence of allergy.

Animals↗
PubMed2004

Suppressive effects of breast milk on oxidative DNA damage in very low birthweight infants.

BACKGROUND: Human milk contains many kinds of antioxidant and is considered to prevent diseases mediated by oxygen free radicals in very low birthweight (VLBW) infants. AIMS: To examine the antioxidant effects of breast milk in VLBW infants by determining urinary 8-hydroxydeoxyguanosine (8-OHdG) excretion, which is known to be a non-invasive marker for in vivo oxidative DNA damage. METHODS: Urinary 8-OHdG concentrations were measured in 15 breast fed and 14 formula fed VLBW infants at 2, 7, 14, and 28 days of age. RESULTS: Urinary 8-OHdG excretion at 14 and 28 days of age was significantly lower than at 2 and 7 days of age in the breast fed group, and significantly lower than in the formula fed group. CONCLUSION: This is the first direct evidence of the antioxidant action of human milk in VLBW infants.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2004

Long term prognosis of children born to lupus patients.

OBJECTIVE: To determine the long term prognosis of children of patients with systemic lupus erythematosus (SLE). METHODS: Children of patients with SLE were invited to attend our clinic for physical examination and laboratory tests. A total of 195 children (aged 4 months to 26 years; male = 82, female = 113) were examined in 1991, 1995, 1997, and 1998. RESULTS: Two cases were diagnosed as SLE at the first visit and were excluded from the second visit. A significantly higher percentage (52/195 (27%)) of patients were positive for antinuclear antibodies (ANA) at a cut off serum dilution of 1/40 compared with controls (4/57 (7%)). ANA were detected more frequently in female subjects than in men (p<0.05). Forty four subjects were examined on more than two occasions. Nine of the 10 patients who were positive for ANA at the second visit were girls aged 4-8 years. The incidence of anti-DNA and antiphospholipid antibodies in children of patients with SLE was similar to that in the controls. CONCLUSIONS: The finding that children, especially girls, born to maternal lupus patients had a high positive rate for ANA suggests that a genetic factor is involved in SLE pathogenesis. Longitudinal observation of these patients may provide important clinical information and clues to the pathogenesis of SLE.

Adolescent↗
PubMed2003

Effects of n-3 polyunsaturated fatty acids on indomethacin-induced changes in eicosanoid production and blood flow in the gastric mucosa of rats.

We investigated the effects of n-3 polyunsaturated fatty acids (PUFAs) on non-steroidal anti-inflammatory drug (NSAID)-induced changes in microcirculation and eicosanoid production in the gastrointestinal mucosa. We measured gastric mucosal blood flow using laser Doppler flowmetry, assessed the fatty acid composition in the mucosal phospholipids, and quantified the production of prostaglandin E2 (PGE2), leukotriene B4, and leukotriene C4 (LTB4 and C4) from the mucosa with the stimulation of calcium ionophore 20 min after an injection of indomethacin or vehicle in rats fed a diet containing different compositions of alpha-linolenic acid. Four weeks after the initiation of the test diet the arachidonic acid level in gastric mucosal phospholipids was significantly lower in the perilla group than in the other three groups. Conversely, alpha-linolenic acid and eicosapentaenoic acid (EPA) were significantly higher in the perilla group than in the other three groups. The percent of gastric mucosal blood flow in the three groups administered indomethacin were significantly lower than that in the control group injected with vehicle alone. The percent of gastric mucosal blood flow in the perilla group was significantly higher than that in the corn group. LTB4 and LTC4 production from the gastric mucosa in the soybean and corn groups were significantly higher than those in the control group, and the LTC4 production in the perilla group was significantly lower than that in the corn group. There were no significant differences in PGE2 production among the four groups. Our results suggest that alpha-linolenic acid affectively suppressed the indomethacin-induced decreases in gastric mucosal blood flow by increasing EPA and decreasing the levels of arachidonic acid and LTC4 in the gastric mucosa.

Animals↗
PubMed2003

Urine-based enzyme-linked immunosorbent assay for the detection of Helicobacter pylori antibodies in children.

OBJECTIVE: Recent studies of urine-based enzyme-linked immunosorbent assays (ELISA) for detection of antibody to Helicobacter pylori (H. pylori) have already shown high sensitivity and specificity in adults. The diagnostic accuracy of these assays in children was investigated. METHODS: The results of serum and urine-based ELISAs were compared with those of 13C-urea breath tests (13C-UBT) and/or detection of faecal H. pylori antigen in 68 children. The effect of urine total immunoglobulin G (IgG) levels on the ELISA results for anti-H. pylori antibodies in urine was also examined. RESULTS: The sensitivity, specificity and accuracy of the serum ELISA were 72.7%, 96.3%, and 92.3% respectively, while those of the urine-based ELISA were 92.3%, 76.4%, and 79.4% respectively. The level of urine total IgG in children with false-positive results in the urine-based ELISA, was significantly higher than that in children who showed negative results in both the urine-based ELISA and the 13C-UBT and/or faecal H. pylori antigen tests. Human gamma-globulin affected the urine-based ELISA results at final concentrations of 2.0 mg/dL, 3.0 mg/dL, and 4.0 mg/dL; the anti-H. pylori antibody values were significantly higher than the ELISA values without the addition of human gamma-globulin. CONCLUSION: The findings suggested that the specificity of urine-based ELISA for detection of H. pylori antibodies is low in children, since high urinary levels of total IgG increase the likelihood of false-positive results.

Adolescent↗
PubMed2003

Postnatal and postprandial changes in plasma concentrations of glicentin in term and preterm infants.

AIM: To examined the changes in basal plasma concentrations of glicentin in developing children and the postnatal and postprandial changes in plasma glicentin levels in infants. METHODS: Glicentin, an active component of enteroglucagon, is considered to have a significant trophic action on the intestinal mucosa. Fasting plasma concentrations of glicentin in healthy children and in term and preterm infants were measured before and 30 min after feeding during the first 14 d of life. RESULTS: Plasma basal concentrations of glicentin in children under 1 y of age were significantly higher than those in children aged 1 to 15 y. Plasma basal concentrations of glicentin at 5 or 6 d (2496 and 2190 pg/ml) and at 14 d (2987 and 2817 pg/ml) after birth were significantly higher than those at 1 or 2 d (1098 and 1240 pg/ml) after birth in normal birthweight (NBW) and low-birthweight (LBW) infants. There was no significant difference in the glicentin level between infants at 1 or 2 d (1864 pg/ml) and at 5 or 6 d (1910 pg/ml) after birth in very-low birthweight (VLBW) infants, but the levels at 14 d (3310 pg/ml) after birth were significantly higher than either of those levels. Plasma glicentin concentrations after feeding were significantly higher than those before feeding at 1 or 2 d and at 5 or 6 d after birth in NBW and LBW infants, but a significant increase in the plasma glicentin level after feeding was first observed at 14 d after birth in VLBW infants. There were no significant differences in the basal plasma (2401 and 2718 pg/ml) and postprandial (3007 and 3912 pg/ml) glicentin levels between breastfed and formula-fed infants. CONCLUSION: The results of the study suggest that glicentin may play an important role in intestinal mucosal growth in the early period of life, although its role in VLBW infants should be further investigated.

Breast Feeding↗
PubMed2003

Urinary 8-hydroxydeoxyguanosine excretion in children before and after therapy for eradication of Helicobacter pylori infection.

AIM: A number of reports have implicated oxygen free radicals in the pathogenesis of Helicobacter pylori (H. pylori)-associated disease. 8-hydroxydeoxyguanosine (8-OHdG) has recently been accepted as a sensitive marker for reflecting the oxidative DNA damage. However, there have been no previous studies comparing the changes in urinary 8-OHdG excretions before and after therapy for eradication of H. pylori infection, or to examine 8-OHdG excretions in children with H. pylori infection. The aim of this study was therefore to examine the DNA damage in gastric mucosal cells in children with H. pylori infection. METHODS: Urinary 8-OHdG excretions were measured before and after therapy for eradication of H. pylori infection in 15 children diagnosed with the H. pylori infection and 13 parents who were also suffering from the same infection. RESULTS: In both the children and their parents, no significant differences were found in urinary 8-OHdG excretions either before or after the eradication therapy. Furthermore, there was no significant difference in urinary 8-OHdG excretions between 8 children with peptic ulcers and 7 children without ulcers, either before or after the therapy. CONCLUSION: These results suggest that measurement of urinary 8-OHdG levels is not useful for evaluation of the DNA damage in H. pylori-infected gastric mucosa in children.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2003

Anemia and iron deficiency among schoolchildren in the Aral Sea region, Kazakhstan.

The objectives of this study were to estimate the prevalence of anemia and iron deficiency among schoolchildren in the Aral Sea region of Kazakhstan and to determine the various factors associated with anemia in this population. We conducted a cross-sectional study of randomly selected schoolchildren. Blood samples were collected for measuring hemoglobin (Hb), serum ferritin (SF), total iron binding capacity (TIBC), and other hematological indices, and subjects were screened for anemia and iron deficiency. Associations between Hb concentration and SF, TIBC, anthropometric, and socioeconomic data were evaluated using regression analysis. The prevalence of anemia was 49.8 per cent although levels were mostly mild. Twenty-two per cent of the children were iron depleted (SF < 12 microg/l). Of the anemic children, 32.4 per cent were found to have iron deficiency anemia (anemia with SF < 12 microg/l). There were significant positive correlations between the levels of Hb and SF, but a negative correlation with serum TIBC. Age, mean corpuscular volume (MCV) and SF were found to be significantly related to Hb by stepwise multiple regression analysis. Multiple logistic regression analysis revealed that anemia was independently related to living district, education of father, and child's age. The results suggest that iron deficiency is an important determinant of anemia in this population; however, whole anemia cannot be solely explained by iron deficiency. Further studies are needed for consideration of micronutrients status, parasite infestation, hereditary disorders, and exposure to environmental pollutants.

Adolescent↗
PubMed2003

Renal tubular dysfunction in children living in the Aral Sea Region.

BACKGROUND: The Aral Sea region is a natural area seriously polluted by human activities. Recent surveillance revealed the increased prevalence of diverse chronic diseases in children. AIMS: To investigate the function of renal tubules, which are most at risk of damage as a result of heavy metal intoxication, in children of the Aral Sea region. METHODS: A group of 205 children living in Kazalinsk, close to the Aral Sea, and a group of 187 children living in Zhanakorgan, far from the Aral Sea, were examined by means of random urine samples. Both urinary N-acetyl-beta-D-glucosaminidase (NAG; U/mmol Cr) and beta2 microglobulin (BMG; microg/mmol Cr) were calculated for each subject. RESULTS: Mean urinary NAG and BMG were both significantly higher in Kazalinsk than in Zhanakorgan (NAG: 0.77 (0.58) and 0.62 (0.37) U/mmol Cr; BMG: 41.8 (54.8) and 22.5 (20.4) microg/mmol Cr, respectively; mean (SD), p < 0.01). The number of children with abnormal values of NAG (>1.5 U/mmol Cr) was significantly more prevalent in Kazalinsk than in Zhanakorgan (7.9% and 2.6%, respectively, p < 0.05). CONCLUSION: Renal tubular function of children around the Aral Sea region is profoundly impaired. This should be taken into account when considering the health problems of this area.

Acetylglucosaminidase↗
PubMed2002

Effects of n-3 polyunsaturated fatty acids on dermatitis in NC/Nga mice.

The administration of n-3 polyunsaturated fatty acids (PUFAs) is known to be effective against allergic diseases by suppressing the production of eicosanoids derived from arachidonic acid. To investigate the mechanisms and efficacy of n-3 PUFA treatment in patients with atopic dermatitis (AD), we administered four different formulas of alpha-linolenic acid for 6 weeks in an AD model using NC/Nga mice. According to the doses of alpha-linolenic acid given, the levels of alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid in the red blood cell membranes increased while the levels of linoleic acid and arachidonic acid decreased. However, there was no significant difference among the four dose groups in clinical skin severity score, histopathological findings of skin lesions, or levels of total plasma IgE. Moreover, there was no significant difference in the production of leukotriene B(4) and Leukotriene C(4) from skin lesions after stimulation with A23187 among the groups, although the production of prostaglandin E(2) (PGE(2)) was significantly reduced and skin blood flow in the ear was significantly higher in the group given the highest dose of alpha-linolenic acid. Our results suggest that the administration of alpha-linolenic acid can change the fatty acid composition, PGE(2) production, and skin blood flow but may not prevent the development of dermatitis in NC/Nga mice.

Animals↗
PubMed2002

Extremely high prevalence of hypercalciuria in children living in the Aral Sea region.

UNLABELLED: The Aral Sea region is a natural area seriously polluted by human activities. In addition to the increased prevalence of diverse chronic diseases in children, the risk of developing urolithiasis is reported to be high in this region. This study was undertaken to clarify the prevalence of hypercalciuria in children of the Aral Sea region. A group of 205 children living in Kazalinsk, close to the Aral Sea, and a group of 187 children living in Zhanakorgan, far from the Aral Sea, were screened for hypercalciuria. Urinary sodium excretion (sodium per creatinine, uNa/Cr) in addition to calcium excretion (calcium per creatinine, uCa/Cr) was also calculated for each subject. Mean uCa/Cr (mmol/mmol) and uNa/Cr (mmol/mmol) excretions were significantly higher in Kazalinsk than in Zhanakorgan (uCa/Cr: 0.75 +/- 0.74 and 0.33 +/- 0.30; uNa/Cr: 3.54 +/- 2.27 and 2.89 +/- 1.69, respectively, mean +/- SD, p < 0.01). Hypercalciuria regarded as an uCa/Cr of more than 0.703 was observed in 79 out of 205 Kazalinsk children (38.6%) while this was seen in only 24 out of 187 Zhanakorgan children (12.8%). Linear regression analysis revealed a direct positive correlation between urinary calcium and sodium excretion (p < 0.01) in Kazalinsk children. CONCLUSION: The prevalence of hypercalciuria in children around the Aral Sea region is extremely high. This may be associated with excessive intake of calcium and sodium, or due to impaired renal tubular function caused by toxic chemicals. Therefore, hypercalciuria that may lead to urolithiasis should be taken into account when considering the health problems of this area.

Asia, Central↗
PubMed2002

Th1/Th2 balance in childhood idiopathic nephrotic syndrome.

AIMS: In view of the conflicting evidence of helper T cell type 1 (Th1) or type 2 (Th2) pattern of cytokine synthesis in childhood idiopathic nephrotic syndrome (INS) this study examined the balance of Th1 and Th2 which are characterized by intracellular cytokine production of interferon-gamma (IFNgamma) and interleukin-4 (IL-4), respectively. SUBJECTS AND METHODS: Sixteen children with steroid-sensitive INS (mean age 9.0 years) were included in this study, together with 15 healthy normal children (mean age 7.9 years) for the control group. Intracellular production of both IFNgamma and IL-4 in helper T cell (CD4+ cell) was investigated by a 3-color flow cytometry. RESULTS: The cross-sectional data showed no significant differences of percentages of Th0 (IFNgamma+ IL-4+ CD4+ cell), Th1 (IFNgamma+ lL-4- CD4+ cell) and Th2 (IFNgamma- IL-4+ CD4+ cell) in CD4+ cells (p > 0.05). The Th1/Th2 ratio during nephrotic relapse did not differ from those during nephrotic remission and in normal healthy children (p > 0.05). CONCLUSION: We conclude that there is no significant skew of Th1/Th2 balance in childhood INS and that the cardinal immunological abnormality does not lie in helper T cells but in other cells, such as suppressor/cytotoxic T cells, natural killer cells or monocytes/macrophage. To clarify the pathogenesis of INS, comprehensive studies for these cells would be worthwhile.

Case-Control Studies↗
PubMed2001

Structure and expression of human mitochondrial adenylate kinase targeted to the mitochondrial matrix.

The previously isolated cDNA encoding human adenylate kinase (AK) isozyme 3 was recently renamed AK4. Consequently, human AK3 cDNA remains to be identified and we have little information about the functional relationship between human AK3 and AK4. In pursuit of the physiological roles of both the AK3 and AK4 proteins, we first isolated an authentic human AK3 cDNA and compared their expression. Nucleotide sequencing revealed that the cDNA encoded a 227-amino-acid protein, with a deduced molecular mass of 25.6 kDa, that shares greater homology with the AK3 cDNAs isolated from bovine and rat than that from human. We named the isolated cDNA AK3. Northern-blot analysis revealed that AK3 mRNA was present in all tissues examined, and was highly expressed in heart, skeletal muscle and liver, moderately expressed in pancreas and kidney, and weakly expressed in placenta, brain and lung. On the other hand, we found that human AK4 mRNA was highly expressed in kidney, moderately expressed in heart and liver and weakly expressed in brain. Western-blot analysis demonstrated expression profiles of AK3 and AK4 that were similar to their mRNA expression patterns in each tissue. Over expression of AK3, but not AK4, in both Escherichia coli CV2, a temperature-sensitive AK mutant, and a human embryonic kidney-derived cell line, HEK-293, not only produced significant GTP:AMP phosphotransferase (AK3) activity, but also complemented the CV2 cells at 42 degrees C. Subcellular and submitochondrial fractionation analysis demonstrated that both AK3 and AK4 are localized in the mitochondrial matrix.

Adenylate Kinase↗