Search PubMed⌕ Search

Biomedical subjects

Y Tazawa

Publications and source records attributed to Y Tazawa.

At least 37 records · Page 2Linked to original sources
PubMed1998

Neonatal intrahepatic cholestasis with hepatic siderosis and steatosis.

Neonatal intrahepatic cholestasis is a heterogeneous disease of undetermined cause. There is an unreported subset of idiopathic neonatal intrahepatic cholestasis with an unusual histological combination of hepatic siderosis and macrovesicular steatosis. The patients were a 34-day-old female and a 39-day-old male with normal birth weights. Their mothers had received oral iron supplement 4-6 weeks before delivery. The patients had obstructive jaundice noticed at the well-baby clinic at 1 month of life. They had high levels of serum galactose and tyrosine, hyperferritinemia. Urinary organic acid and bile acid analyses were negative, and galactose-1-phosphate uridyltransferase activity in red cells was normal. Liver biopsies showed diffuse iron deposits and macrovesicular fat. By substituting formula milk with lactose-free milk, the patients responded, and had normal biochemical tests within 5 months of life. Follow-up biopsies, at the age of 12 months, showed mild residual fibrosis without iron or fat deposits. They are both well at 3 and 6 years of age, respectively, without biochemical liver dysfunction and neurologic impairment. Prenatal iron-overload might contribute to the pathogenesis of the disease, but further studies are needed to confirm the assumption.

Cholestasis, Intrahepatic↗
PubMed1998

Experience and clinical usefulness of BACTEC MGIT 960.

Recently, an automatic instrument for culturing acid-fast bacteria in liquid media has been introduced in Japan to accelerate and increase the detection of the bacteria as well as the work e ciency of test lab technicians. We compared the MGIT (Mycobacterium Growth Indicator Tube) method and the two conventional culture methods used in our lab by testing 176 specimens (130 cases) submitted for acid-fast testing between July 27 and September 18, 1998. BACTEC MGIT 960 (Nippon Becton Dickinson) was used in the MGIT method while Ogawa K medium and Kudo PD medium were used for our conventional culture methods. Of the 176 specimens, 26 specimens were MGIT positive, 22 specimens were Ogawa K medium positive, and 21 specimens were Kudo PD medium positive. Among these three culture methods, M. tuberculosis was found in 8 specimens, M. avium was found in 9 specimens, M. intracellulare was found in 4 specimens, and other acid-fast bacteria were found in 5 specimens. It took an average of 13.5 days to detect M. tuberculosis by the MGIT method, 23.0 days by the Ogawa K medium, and 24.3 days by the Kudo PD medium, suggesting that the MGIT method is signi cantly faster than the conventional methods (p < 0.05). The MGIT method took an average of 5.7 days to detect M. avium and M. intracellulare while the two conventional methods required more than 20 days, suggesting that the MGIT method is signi cantly faster than the conventional methods (p < 0.05). The BACTEC MGIT 960 was extremely useful for clinical diagnosis in some of the cases and our results indicated that the MGIT method led to more rapid diagnosis and earlier treatment than the conventional methods.

Adult↗
PubMed1997

Pathology of chronic hepatitis C in children. Child Liver Study Group of Japan.

Limited information is available regarding the histology of hepatitis C virus infection in children. The aim of this study was to determine the histological pattern of chronic hepatitis C (CHC) in children, and liver biopsy specimens from 109 pediatric patients with CHC were examined. Each biopsy specimen was evaluated based on a numerical scoring system for the stage of fibrosis (1-4), the grade of portal/periportal necroinflammation (0-4), the grade of lobular necroinflammation (0-4), and their sum (final grade). The histological lesions considered to be characteristic of chronic hepatitis were also evaluated. None of the children had liver cirrhosis, and 105 cases (97%) were stage 1 or 2. Only 4 children were stage 3. Two of these 4 cases showed hemosiderosis. A significant correlation was observed between the staging score and the final grade in the pediatric patients (r = .59; P < .0001). The histological characteristics of adult CHC, such as lymphoid aggregate, bile duct injury, and fatty changes, were also observed in the children. In conclusion, the majority of children with CHC presented with mild fibrosis, but a few showed CHC with lobular distortion and hemosiderosis. Frequent blood transfusion may aggravate hepatic lesions in pediatric CHC.

Adolescent↗
PubMed1997

Heterogeneity of liver disorder in type B Niemann-Pick disease.

Patients with type B Niemann-Pick disease (NPD) are known to be complicated with varying degrees of prognosis-determining liver dysfunction. To see heterogeneity of the dysfunction histologically, we performed liver biopsies on three NPD patients from three different families, who were diagnosed by enzyme assay of acid sphingomyelinase (ASM) and analysis of the ASM gene. In a severe case, of a female patient in her childhood, the liver showed definite fibrosis despite her age. In contrast, in a very mild case, of an adult male patient, the liver showed little fibrosis, though the ballooning of hepatocytes and infiltration of foamy histiocytes were observed in the tissue. Three homo-allelic mutations (S436R, A599T, and S231P) were identified in the patients. Thus, various hepatic phenotypes in type B NPD were shown to be caused by the heterogeneity of liver lesions originating from different ASM gene mutations.

Adult↗
PubMed1997

Effect of weight changes on serum transaminase activities in obese children.

To examine the effect of weight changes on serum transaminase activities, glutamic oxaloacetic and pyruvic transaminases (GOT/GPT), a 3-month observation of 110 obese outpatients treated by a mild regimen for obesity was carried out. Patients were divided into two major groups, group I (n = 73) and group II (n = 37), with or without persistent elevation of serum GOT/GPT (> 30 IU/L), and retrospectively classified into four subgroups according to weight changes: group A, weight loss > 5%; group B, weight loss of < 5%; group C, an increase of < 5%; group D, an increase > 5%. In group IA, the incidence of cases with normalization of serum GOT/GPT was 70% and was significantly greater than those of the other three subgroups, respectively (P < 0.01). The incidences of decreased serum GOT/GPT activities were observed corresponding to the degree of weight changes not only in group I (100-27%) but also in group II (100-33%). These facts indicate that a mild regimen for obese outpatients for 3 months, significantly improves serum transaminase activities in patients not only with weight reduction but also weight gain, and that fatty liver may be present even in obese children with normal serum transaminase levels. The normalization of serum GPT activity in patients with weight gain suggests the presence of another factor contributing hypertransaminasemia in pediatric obese patients.

Adolescent↗
PubMed1997

Serum alanine aminotransferase activity in obese children.

To confirm the significance of the serum alanine aminotransferase (ALT) test for the diagnosis of fatty liver and to clarify the relationship between serum ALT activity and the duration of obesity, we analysed 310 obese young school children (195M, 115F), who were classified into three duration groups (1-3 y, 4-6 y, 7 + y), three age groups (6-7 y, 8-9 y, 10-11 y), and four obesity groups (weight excess: mild, 20-29%; moderate, 30-39%; severe, 40-49%; very severe, 50%). Seventy-seven patients with abnormal ALT test, > 30 IU/l, and 27 patients with normal ALT test were examined by ultrasound study to identify the fatty-fibrotic pattern of the liver. Abnormal results of the serum ALT test were found in 24% of all patients. The fatty-fibrotic pattern was identified in 64/77 (83%) patients with abnormal ALT test and in 5/27 (18%) patients with normal ALT test. The serum ALT test has a sensitivity of 0.92 for detecting the fatty-fibrotic pattern proven by ultrasound study. Frequencies of cases with abnormal serum ALT levels increased with the duration of obesity. In the shortest duration group, however, the frequencies of abnormal results in serum ALT test did not increase with advanced ages or the grades of obesity. In conclusion, the present study confirmed the usefulness of the serum ALT test for screening fatty liver, and showed that a longer duration of obesity is generally associated with the occurrence of fatty liver in a paediatric obese population. In young patients with mild obesity or a short duration of obesity, however, fatty liver or fatty fibrosis may develop. Early intervention should be made in the case of obese children.

Alanine Transaminase↗
PubMed1997

[Choroidal lesions and surgical treatment of bullous retinal detachment].

To define choroidal lesions of bullous retinal detachment, we performed indocyanine green angiography (IA) on 20 eyes of 10 patients with bullous retinal detachment. Four of these eyes were treated with sclerectomy and sclerostomy (Gass), and the benefit was evaluated. IA showed the following choroidal abnormalities: choroidal filling delay in the macular region (6 of 18 eyes, 33%) and underneath the leaking sites (9 of 18 eyes, 50%), localized (1 eye, 5%) and extended (18 eyes, 90%) choroidal venous dilatation, and intrachoroidal hyperfluorescence (all eyes, 100%). After the surgical treatment, retinal detachments resolved within 9 weeks (mean 5.3 weeks). Since choroidal filling delay, choroidal venous dilatation and intrachoroidal hyperfluorescence were observed, it is suggested that choroidal congestion plays a causative role in bullous retinal detachment. Sclerectomy and sclerostomy seemed to be beneficial in treatment of this condition.

Adult↗
PubMed1996

Cytotoxic activity against tumour cells mediated by intermediate TCR cells in the liver and spleen.

Morphological and phenotypic characterization in previous studies has indicated that intermediate (int) T-cell receptor (TCR) cells or T natural killer (TNK) cells may stand at an intermediate position between NK cells and high TCR cells of thymic origin in phylogenetic development. In this study, a functional study on cytotoxic activity against various tumour targets was performed in each purified subset. When a negative selection method entailing in vivo injection of anti-asialo GM, antibody or anti-interleukin (IL)-2R beta monoclonal antibody (mAb) was applied, IL-2R beta 1 CD3 NK cells were found to have the highest NK activity while IL-2R beta 1 int CD3 (or TCR) cells had a lower level of the NK activity. High CD3 cells (freshly isolated) did not have any such activity. Sorting experiments further revealed that the NK function mediated by int CD3 cells was augmented when they were exposed to anti-CD3 mAb. anti-TCR alpha beta, or anti-TCR-delta mAb. This phenomenon was not observed in NK cells and high CD3 cells. More importantly, when anti-CD3 mAb (or anti-TCR mAb) was added to the assay culture, int CD3 cells became cytotoxic against even NK-resistant tumour (Fc gamma R-. Fas+) targets. Liver mononuclear cells or int CD3 cells exposed to anti-CD3 mAb for 6 hr showed an elevated level of perforin in their cytoplasms. The present results suggest that int CD3 cells are usually non-cytotoxic against various tumours but become functional after being stimulated via the TCR CD3 complex.

Animals↗
PubMed1996

Relationships between clinical and histological profiles of non-familial idiopathic neonatal hepatitis.

Idiopathic neonatal hepatitis (INH) is a syndrome characterized clinically and histologically but there is little information concerning the relationship between the clinical features and histological findings. In the present study, sixty-two patients clinically diagnosed as non-familial INH were histologically classified into four groups according to a provisional definition based on predominant lesions and examination of their clinical features. Patients of cholestasis (n = 23) and giant cell hepatitis (GCH, n = 21) were most frequent (37% and 33%, respectively), and patients of fatty liver (n = 10) and hepatitis (n = 8) were less common (16% and 13%). The GCH group showed a dominance of male, low birthweight, older and breast-fed babies. The cholestasis group demonstrated a dominance of male, low birthweight, younger and bottle-fed babies. The hepatitis group had the highest frequencies of high-grade hepatomegaly and splenomegaly. Fifty six cases completely recovered. Two died of hepatic failure in early infancy and four had chronic liver diseases at the age of 12 months. The fatty liver group had the worst outcome. Histological features in non-familial INH were variable and typical giant cell hepatitis was seen in only one-third of patients. Characteristic clinical features in each histologically classified group may suggest heterogenous etiologies underlying non-familial INH.

Diagnosis, Differential↗
PubMed1996

Relationship of feeding modality to clinical features in Japanese infants with idiopathic neonatal hepatitis of the non-familial form.

To clarify the relationship between idiopathic neonatal hepatitis and feeding type, that is, formula-milk feeding and breast-milk feeding, the medical records of 100 patients (68 male and 32 female babies) with idiopathic neonatal hepatitis of non-familial form referred to the medical centers of Akita University and Tohoku University during the past 18 years were reviewed. The patients were divided into two 9 year periods (1975-83 and 1984-92), and their clinical features were analyzed in terms of feeding type and sex. The number of patients enrolled decreased from 69 in the first half to 31 in the second half. The number of male patients dropped from 53 to 15, although the number of female patients (n = 16) remained the same in both 9 year periods. The frequency of formula-milk feeding significantly decreased in the second half (42/69 to 6/31, P < 0.01). Compared with the expected numbers of patients in the second half, calculated on the changes in the live birth population and feeding modality between the two halves, the actually enrolled numbers of patients in the second half were less in both the male and the formula-milk fed groups (x0.35 and x0.22), whereas the numbers of female and breast-milk feeding groups were close to the expected values (x1.26 and x1.08). When sex and feeding modality were combined, the formula-milk fed male group showed the lowest value (x0.10), and the breast-milk fed female group showed the highest value (x2.85). In conclusion, feeding type, especially in combination with gender, might be one causative factor in the occurrence of idiopathic neonatal hepatitis.

Breast Feeding↗
PubMed1996

[The effect of calcium antagonist on ischemia-reperfusion injury of the rabbit retina].

We investigated the effect of nicardipine (NC), a calcium antagonist, on retinal ischemia-reperfusion injury. Electroretinogram (ERG) was recorded from rabbit eyes before and after ischemia produced by increasing intraocular pressure to 140 mmHg for 90 min after giving 0.01% NC (0.1 ml) intravitreally (n = 4). ERGs from intact (non-ischemic) rabbit eyes after injecting NC intravitreally was also recorded (n = 4) (NC group). The recovery rate of b-wave amplitude after reperfusion was significantly higher in the NC group than in the control group which was given saline without NC (p < 0.05). There were no significant differences between the NC and the control groups in a-wave amplitude and implicit time of the b-wave. No significant changes were detected in the a-wave or b-wave amplitude after intravitreal injection of NC into the intact eyes. We suggest that NC can prevent ischemia-reperfusion injury of the rabbit retina and could be considered for clinical use.

Animals↗
PubMed1995

The relationship between serum transaminase activities and fatty liver in children with simple obesity.

To determine hepatic diseases in obese children, biochemically and histologically, 11 obese patients with abnormal serum transaminase activities were subjected to this study. Fat accumulation in the liver was semiquantitatively graded, and histologically the 11 patients were classified into four groups; fatty liver, fatty hepatitis, fatty fibrosis and fatty cirrhosis. All patients had fat deposition in liver specimens, the grade of which did not significantly correlate with the degree of obesity. The grade of fat deposition in the liver specimens also did not significantly correlate with either serum transaminase activities or GOT/GPT ratio. Five patients were grouped into the fatty liver group, three into the fatty hepatitis group, and the remaining three patients into the fatty fibrosis group. However, no significant differences were found among the three histologically classified groups in terms of serum transaminase activities or GOT/GPT ratio. The usefulness of serum transaminase activities and GOT/GPT ratio was limited in predicting the severity of fat deposition or histological abnormality in pediatric obese patients.

Adolescent↗