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Biomedical subjects

Y Tazawa

Publications and source records attributed to Y Tazawa.

At least 19 recordsLinked to original sources

Urinary organic acids in peroxisomal disorders: a simple screening method.

Using GC-MS, we studied urinary organic acids in 20 Japanese patients with peroxisomal disorders, including Zellweger syndrome (ZS), neonatal adrenoleukodystrophy, and single deficiency of peroxisomal beta-oxidation enzymes. Non-ketotic dicarboxylic aciduria with elevated sebacate/adipate molar ratio was observed in 19 of the 20 patients. Elevation of 2-hydroxysebacate and epoxydicarboxylic acids were seen in 13 and 18, respectively. Tyrosyluria was remarkable in all patients. In two ZS patients, we tracked the time course from birth to infancy, and all the above stated findings were detected, except for one sample. Urinary organic acid analysis is indeed useful for screening subjects with peroxisomal disorders.

Acids↗

Neonatal presentation of adult-onset type II citrullinemia.

Adult-onset type II citrullinemia (CTLN2) is characterized by a liver-specific argininosuccinate synthetase deficiency caused by a deficiency of the citrin protein encoded by the SLC25A13 gene. Until now, however, no SLC25A13 mutations have been reported in children with liver diseases. We described three infants who presented as neonates with intrahepatic cholestasis associated with hypermethioninemia or hypergalactosemia detected by neonatal mass screening. DNA analyses of SLC25A13 revealed that one patient was a compound heterozygote for the 851de14 and IVS11+IG-->A mutations and two patients (siblings) were homozygotes for the IVS11+lG-->A mutation. These results suggested that there may be a variety of liver diseases related to CTLN2 in children.

Adult↗

Urinary bile alcohol profiles in healthy and cholestatic children.

BACKGROUND: Bile alcohols are normal constituents of urine. METHODS: To better understand bile alcohol profile in childhood, urinary specimens from 41 healthy children and 10 children with cholestasis, and 3 healthy adults, were analyzed by GLC and GC-MS. RESULTS: Five bile alcohols, 27-nor-5beta-cholestane-3alpha,7alpha,12alpha,24S,25R-pentol, 5beta-cholestane-3alpha,7alpha,12alpha,24S, 25-pentol, 5beta-cholestane-3alpha,7alpha,12alpha,24S,26-pentol, 5beta-cholestane-3alpha,7alpha, 12alpha,25,26-pentol, and 5beta-cholestane-3alpha,7alpha,12alpha,26,27-pentol were identified in all specimens. C(26)-Pentol was the most abundant constituent, constituting 29.5 to 65% of bile alcohols. Among healthy children (n=41), no significant relationship was seen between proportions of the C(26)-pentol and age, but older children (n=15, 6 to 14 years) showed a significantly greater mean percentage of the C(26)-pentol than young children (n=26, 0 to 5 years; 58.1+/-4.23% vs. 46.0+/-9.24%, p<0.001). In children with cholestatic liver diseases, the percentage of C(26)-pentol in urinary bile alcohols was significantly lower than age-matched controls. CONCLUSIONS: There is an increased composition of C(26)-pentol in older children and relatively decreased composition of C(26)-pentol in children with cholestatic liver diseases.

Adolescent↗

An undescribed subset of neonatal intrahepatic cholestasis associated with multiple hyperaminoacidemia.

Five patients of cholestatic jaundice and multiple hyperaminoacidemias were uncovered during neonatal mass screening for homocystinuria. All five patients had increased plasma levels of methionine, citrulline, tyrosine, threonine, phenylalanine, lysine and arginine. Compared with those of age-matched cholestatic disease controls, idiopathic neonatal hepatitis (n=9) and biliary atresia (n=14), plasma levels of three amino acids, citrulline, methionine, and threonine, were significantly greater, respectively (P<0.01). Liver biopsies examined in four patients uniformly showed diffuse hepatic fatty liver with micro- and macrovesicular droplets without giant cell transformation. Administration of fat-soluble vitamins and formula milk containing middle-chain triglyceride resulted in normalization of amino acid profiles by 6 weeks after the treatment. All liver function tests normalized by 17 months of age.

Journal Article↗

The DSL domain in mutant JAG1 ligand is essential for the severity of the liver defect in Alagille syndrome.

Alagille syndrome (AGS) is a congenital multi-system anomaly mainly characterized by paucity of intrahepatic bile ducts caused by haploinsufficiency of the Jagged 1 gene (JAG1). To explore the relationship between genotype and phenotype, we analyzed the JAG1 gene in 25 Japanese AGS families at the genomic DNA level and identified 15 point mutations and one large deletion. Analysis of the genotype and phenotype strongly indicated that the Delta/Serrate/Lag-2 (DSL) domain in JAG1 protein played an essential role in determining the severity of the liver disorder. In four sporadic cases, missing an entire DSL domain in mutant JAG1 resulted in progressive liver failure and all 4 patients needed a liver transplant at a very young age. This correlation was further confirmed by statistical analysis (chi2=9.143, p<0.001). Our finding demonstrated that the DSL domain in JAG1 appears to be essential for normal liver development and function.

Alagille Syndrome↗

Effect of lactational exposure to 1,2,3,4- tetrachlorodibenzo-p-dioxin on cytochrome P-450 1A1 mRNA in the neonatal rat liver: quantitative analysis by the competitive RT-PCR method.

BACKGROUND AND METHODS: The aim of this study was to assess the effect of lactational exposure to dioxins in neonates on the cytochrome P450 1A1 (CYP1A1) induction in the level of gene expression. Maternal rats were treated with a single dose of 50 or 100 micromol/kg 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TCDD), a low potent congener of dioxins, on the first day post-partum (day 1). Induction of CYP1A1 mRNA expression was quantitatively analyzed by the competitive reverse transcription-polymerase chain reaction (RT-PCR) method. RESULTS: The CYP1A1 mRNA was detectable at extremely low amounts in the liver of control neonates and mothers. The mRNA ratios of CYP1A1 to beta-actin in neonates were dose-dependently increased by the treatment of 1,2,3,4-TCDD of their mothers. Its peak occurred on day 6 and was sustained at the same level on day 10. Increases of the ratio with 100 micromol/kg 1,2,3,4-TCDD on day 2, 6 and 10 were 26-, 40- and 40-fold of the appropriate controls, respectively. These levels paralleled the activity of ethoxyresorufin-o-deethylase, representing CYP1A mediated monooxygenase. In the mother, the mRNA ratio was increased only to threefold of the control, 10 days after treatment. CONCLUSION: Current RT-PCR procedure enabled to assess both constitutive and induced levels of CYP1A1 mRNA in the neonatal rat livers. Although the dose of 1,2,3,4-TCDD selected in this study was about 5000 times higher than the daily intake of dioxins in breast-fed infants, CYP1A1 mRNA was highly induced for a longer period of time in neonatal rats receiving 1,2,3,4-TCDD via lactation than the treated maternal rats.

Actins↗

Physical signs associated with excessive television-game playing and sleep deprivation.

BACKGROUND: To elucidate significance of physical signs seen in excessive television-game (TVG) players complaining of unexplained persistent symptoms, a cross-sectional cohort study was designed. METHODS: A total of 1143 school children, aged between 6 and 11-years-old, and their parents were included in the study. Questionnaires were sent to guardians asking the number of hours that their children watched TV, TVG, and slept. All children were examined to check for three physical signs, black rings in the skin under the eye (BR), muscle stiffness in the shoulder (MS), and displacement of the scapula associated with muscle stiffness in the shoulder (DS/MS) by inspection and palpitation. RESULTS: The three signs, BR, MS and DS/MS, were present in 165 (14.4%), 229 (20.0%) and 72 (6.2%) children, respectively. Boys had greater frequencies of two signs than girls (BR, 19.6% vs 8.9%, P<0.01; MS, 26.1% vs 13.6%, P<0.01), respectively. Boys spent more time on TVG playing than girls (1.1+/-0.7 h/day vs 0.4+/-0.6 h/day, P<0.0001), respectively. Excessive TVG players, who spent > or = 1 h/day for TVG had greater frequencies of two signs, BR and MS, than those of non-TVG-players (18.9% vs 13.0%, P<0.05; 25.6% vs 14.4%, P<0.01), respectively. The TVG playing time correlated with two signs, BR (P=0.0143) and MS (P=0.0048). Furthermore, sleep deprivation related to three signs, BR (P=0.0078), MS (P<0.0001) and DS/MS (P=0.0290). CONCLUSIONS: Excessive TVG playing links to the occurrence of BR and MS. Other factors, which cause sleep deprivation, may underlie in the occurrence of the three signs. The amount of time spent on TVG playing should be regulated to < 1.0 h/day.

Child↗

Infantile cholestatic jaundice associated with adult-onset type II citrullinemia.

Adult-onset type II citrullinemia, characterized by a liver-specific argininosuccinate synthetase deficiency, is caused by a deficiency of citrin that is encoded by the SLC25A13 gene. Three patients with infantile cholestatic jaundice were found to have mutations of the SLC25A13 gene. Adult-onset type II citrullinemia may be associated with infantile cholestatic disease.

Biopsy↗

[Effects of stimulus intensity on multifocal electroretinograms].

PURPOSE: To investigate origins of responses of the second order kernel components of multifocal electroretinograms (m-ERGs), the influence of stimulus intensities on the waveform were studied. SUBJECTS AND METHODS: M-ERGs were recorded from 20 normal eyes of 14 normal adults using a Visual Evoked Response Imaging System with 19 hexagonal stimulus elements with light intensities of 6.3, 20, 63, 200, or 331 cd/m2. The response densities and implicit times of the first (N1, P1, N2) and the second order kernel components (P1, N1, P2, N2, P3, N3) of the m-ERGs were measured. RESULTS: The components were divided into two groups based on the behavior of the each component to the stimulus intensity change. The first group consisted of all the first order kernel components and P1 and N1 of the second order kernel components whose response densities were significantly larger (p < 0.05) than those of components elicited by stimulus of one grade lower intensity. The second group consisted of N2, P3, and N3 of the second order kernel components whose response densities did not increase when the stimulus intensity was increased from 200 to 331 cd/m2. CONCLUSION: It is probable that in the second order kernel components, the origin of P1, N1, and P2 is different from N2, P3, and N3 because the response to stimulus intensity of the two groups of components was different.

Adult↗

[Is open heart surgery clean: bacteriologic analysis of salvaged blood].

In this prospective study, we evaluated contamination of surgical fields in open heart operations by salvaged blood culture used in autologous transfusions device (Cell Saver 5, Heamonetics Corp., Braintree, MA, USA). And also, we prospectively investigated an efficacy of pre- and intra-operative prophylactic antibiotics administrations (cefazolin). Thirty patients undergone open heart surgeries with median sternotomy enrolled in this study. The patients were divided into two groups, group A (n = 15); without prophylactic antibiotics administration, group B (n = 15); with pre- and intra-operative prophylactic antibiotics administrations. Blood samples were drawn through the right atrium after the discontinuation of CPB and from salvaged blood bags. Bacterial growth was detected in 80.0% of salvaged blood samples in group A, 86.7% in group B (p = 0.62). Whereas no bacterial growth detection in blood samples though the right atrium. Quantitative estimates of contaminations showed 1.06 +/- 1.41, 0.90 +/- 1.24 cfu/ml, respectively (p = 0.22). Although bacterial growth rate were not statistically significant difference between groups, detective rate of Staphylococci was remarkably decreased (p = 0.005) in group B. Pre- and intra-operative prophylactic antibiotics administrations were effective for Staphylococci, but not whole microorganisms. In conclusion, salvaged blood used in autologous transfusions was highly contaminated and it suggests that surgical fields were not clear. Prophylactic antibiotics administrations were effective especially for Staphylococci.

Aged↗

[Bacterial contamination of salvaged blood in open heart surgery: is that an airborne contamination or a normal skin flora contamination?].

We investigated sources of bacterial contamination of intraoperative salvaged blood producted by autologous transfusions device (CS; CELL SAVER 5, Heamonetics Corp., Braintree, MA). Eleven patients undergone open heart surgeries including 2 emergency operations with a median sternotomy enrolled in this study. Blood samples were drawn from salvaged blood bags. Airborne contaminants (AB) were collected by a blood agar plate put besides the operation bed for 30 minutes. The median wounds samples were collected by a swab. Bacterial growth was detected in 81.8% of salvaged blood samples. Twenty-nine bacterium were isolated from CS, 72.4% of those were Staphylococci. 9.1% of sample was positive in wound swabs. Forty bacterium were isolated from plate cultures. 65% of them were Staphylococci. Staphylococcus epidermidis and coagulase negative Staphylococcus isolated both CS and AB in the 2 cases had the same identify codes, and incubated from several AB cultures. Corynebacterium sp. is also isolated from both CS and AB cultures in other 2 same cases. In 7 out of 8 cases (87.5%), from which Staphylococci isolated in CS, the Staphylococci were cultured from AB in not the same but the other cases. In conclusion, highly incidence of the identification in identical code of Staphylococci indicated that the main source of CS contamination was highly suspected to AB.

Air Microbiology↗

Prospective reevaluation of risk factors in mother-to-child transmission of hepatitis C virus: high virus load, vaginal delivery, and negative anti-NS4 antibody.

Of 21,791 pregnant women screened in Tottori Prefecture, Japan, 127 (0.58%) were positive for anti-hepatitis C virus (HCV) antibody and 84 (0.39%) were positive for HCV RNA. Of 84 children followed up for at least 6 months, 7 (8%) were infected. All of them were born to 26 mothers with a high virus load (HVL; >/=2.5x106 RNA copies/mL [27%]), compared with 0 of 58 children born to non-HVL mothers (P<.001). Because all the infected children were vaginally delivered, the infection rate among 16 vaginally delivered children born to the HVL mothers was as high as 44%. The prevalence of anti-NS4 antibody in the mothers with an infectious HVL was significantly lower than that in the mothers with a noninfectious HVL (P=.048). Analysis of our results suggests that maternal HVL, vaginal delivery, and negative anti-NS4 antibody are significant risk factors for the mother-to-child transmission of HCV.

Delivery, Obstetric↗

[Activities of antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. Levofloxacin--Surveillance Group].

The surveillance study was conducted to determine the antimicrobial activity of fluoroquinolones (ofloxacin, levofloxacin, ciprofloxacin, tosufloxacin) and other 20 antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. The resistance to fluoroquinolones was remarkable in Enterococci, methicillin-resistant staphylococci and Pseudomonas aeruginosa from UTI. However, many of the common pathogens such as Streptococcus pneumoniae including penicillin-resistant isolates, methicillin-susceptible Stahylococcus aureus, Moraxella catarrhalis, the family of Enterobacteriaceae, Haemophilus influenzae including ampicillin-resistant isolates have been kept to be susceptible to fluoroquinolones. About 90% of P. aeruginosa isolates from RTI were susceptible to fluoroquinolones. In conclusion, the results from this surveillance study suggest that fluoroquinolones are useful in the treatment of various bacterial infections including respiratory infections.

Anti-Infective Agents↗

[Electrical responses from the inner retina of rats with streptozotocin-induced early diabetes mellitus].

PURPOSE: To evaluate behavior of the scotopic threshold response (STR) and the oscillatory potential (OP) in the electroretinogram (ERG) in streptozotocin (STZ)-induced diabetic rats (DM rats). METHODS: The amplitude of the STR and the OP 3, the implicit time of the STR, and the peak latency of the OP 3 of the DM rats were measured. RESULTS: No significant differences were observed in the mean amplitude or the mean implicit time of the STR between the control and the DM rats. On the other hand, the mean peak latency of OP 3 of the DM rats was significantly prolonged up to 125% of the control rats (p < 0.01), although there were no significant differences between the two groups in the mean OP 3 amplitude. CONCLUSIONS: Although both STR and OP were of inner retinal origin, their behavior was different in DM rats. This result supported some reports describing how dopaminergic amacrine cells generate OP and glycinergic or GABAergic amacrine cells generate STR. In the early stage of diabetic retinopathy, there may be not only minor ischemia but also disorder of neurotransmission of the amacrine cells in the inner retinal layers.

Animals↗

Fine-resolution mapping by haplotype evaluation: the examples of PFIC1 and BRIC.

Loci for two inherited liver diseases, benign recurrent intrahepatic cholestasis (BRIC) and progressive familial intrahepatic cholestasis type 1 (PFIC1), have previously been mapped to 18q21 by a search for shared haplotypes in patients in two isolated populations. This paper describes the use of further haplotype evaluation with a larger sample of patients for both disorders, drawn from several different populations. Our assessment places both loci in the same interval of less than 1 cM and has led to the discovery of the PFIC1/BRIC gene, FIC1; this discovery permits retrospective examination of the general utility of haplotype evaluation and highlights possible caveats regarding this method of genetic mapping.

Cholestasis, Intrahepatic↗

Refractive results of post penetrating keratoplasty photorefractive keratectomy.

BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate the safety, effectiveness, and predictability of photorefractive keratectomy (PRK) for severe myopia and astigmatism following penetrating keratoplasty. PATIENTS AND METHODS: PRK was performed on 42 eyes, and 33 eyes were followed up for at least 6 months. RESULTS: Mean preoperative spherical equivalent was -8.29 +/- 4.01 diopters (D), which decreased to -2.96 +/- 3.26 D in manifest refraction at 6 months. Keratometric power reduced from 48.06 +/- 3.32 D preoperatively to 43.97 +/- 3.40 D. Refractive and keratometric astigmatism attained the reduction of 31.0% and 13.56% in average respectively. Twenty three eyes had improved uncorrected visual acuity. CONCLUSION: PRK was effective in reducing post-keratoplasty myopia and astigmatism, but the predictability was not as good as in the non-grafted eye.

Astigmatism↗

Idiopathic neonatal hepatitis presenting as neonatal hepatic siderosis and steatosis.

Idiopathic neonatal hepatitis (INH) is a heterogeneous disease of undetermined cause. We report a retrospective histologic reevaluation of INH. Sixty patients with INH were reviewed along with 32 biliary atresia (BA) patients. Histologic findings, iron and fat deposits, giant cell transformation, portal fibrosis, and bile duct proliferation were semiquantitatively graded from 0 to 4+. Significant histologic findings were defined as > or =2+. Frequencies of patients with significant histologic findings in the INH group were compared with those of the BA group. Among the patients with significant histologic findings, those in the INH group had significantly less iron deposits (P < 0.01), portal fibrosis (P < 0.01), and bile duct proliferation (P < 0.01) than those of the BA group. A combination of significant hepatic macrovesicular steatosis and siderosis was observed in 10 INH patients but not in any BA patient (10/60 vs 0/32, P < 0.05). Without extensive treatment, the 10 INH patients all recovered, and hepatic abnormalities normalized by the age of 12 months. In conclusion, the present study showed that the recognition of hepatic siderosis is helpful to distinguish BA from INH and that in a subset of INH patients hepatic macrovesicular steatosis and siderosis occurs.

Biliary Atresia↗