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Biomedical subjects

G Takada

Publications and source records attributed to G Takada.

At least 91 records · Page 5Linked to original sources

Probability estimation of final height.

13,707 longitudinal records of individuals (6,749 boys and 6,958 girls) from 6 years to 17 years were fitted by means of a smoothing cubic spline function and the factors influencing the change in height SDS during puberty were analysed. Children are divided into subgroups with 0.2 SD intervals according to height SDS at 6 years. Shorter children in subgroups at 6 years tend to increase their final height SDS by entering puberty later and making their height at onset of pubertal growth spurt (PGS) relatively taller. On the other hand taller children in subgroups at 6 years tend to decrease their final height SDS by entering puberty early and make height at PGS relatively shorter. The percentage distribution of a final height SDS against subgroups at 6 years also shows this tendency. This figure is useful in predicting the probability of final height SDS in the clinical field of growth disorders.

Adolescent↗

Peak systolic stress-rate-corrected mean velocity of fiber shortening in preterm and fullterm infants.

The relation of rate-corrected mean velocity of fiber shortening (mVcfc)-end-systolic wall stress (ESS) is a load-independent index of left ventricular contractility, but involves simultaneous M-mode echocardiography, carotid or axillary pulse tracing and blood pressure determination, which may be impractical in younger infants. We examined whether the relation of the peak systolic wall stress (PSS)-mVcfc could be used as a simpler method of assessing left ventricular contractility in preterm and fullterm infants. In 45 preterm and fullterm infants, mVcfc, ESS, and PSS were determined using echocardiography, axillary pulse tracing and blood pressure measurement. Five patients with left ventricular dysfunction or low cardiac output state were also studied. The relation of PSS and ESS was PSS=5.19+1.04 ESS (r=0.98, p<0.01). The slope of mVcfc=1.58-0.012 ESS (r=-0.78, p<0.01) was nearly identical to that of mVcfc=1.60-0.011 PSS (r=-0.75, p<0.01), with no difference in the regression coefficients. The relationship of PSS and ESS in 5 patients was very close and the slope of the regression line was nearly identical to that of 45 infants. The relation of mVcfc PSS correlates well with the relation using ESS and can be used as a simple method of assessing left ventricular contractility.

Blood Pressure↗

Enzyme therapy in Gaucher disease type 2: an autopsy case.

A Japanese patient with Gaucher disease type 2 was treated with enzyme therapy, alglucerase, from 7 to 22 months of age. Whereas hematologic parameters were normalized and hepatosplenomegaly was alleviated, no improvement in neurologic symptoms occurred, and the patient died of respiratory failure at age 22 months. Postmortem examination revealed massive intra-alveolar infiltration of Gaucher cells in lungs and in the central nervous system, i.e., the presence of Gaucher cells in the perivascular Virchow-Robins spaces in the cortex and deep white matter and extensive lamilar necrosis with reactive proliferation of blood vessels and macrophage infiltration of the cerebral cortex. It is suggested that enzyme therapy, with thus far recommended dose, does not prevent long-term respiratory and central nervous system involvement in severe varients of Gaucher disease.

Brain↗

Short-term fasting alters neonatal rat striatal dopamine levels and serotonin metabolism: an in vivo microdialysis study.

Although frequent feeding is necessary for neonatal brains, rat pups were usually separated from their dams throughout a microdialysis experiment. First, in 5-day-old rats, we examined the effect of probe insertion on initial fluctuation of extracellular striatal monoamines using in vivo microdialysis and subsequent HPLC. Second, fasting effect on monoamine metabolism was examined with or without fasting; the latter was regarded as controls. Extracellular striatal DA in the fasting group decreased promptly to 60% of the basal level in the first 2 h, and reached 50% by the end of the experiment. Dopamine in the fasting group decreased more markedly than in the control group (P < 0.01 by ANOVA) which also decreased to about 80% of the basal level. Extracellular 5-hydroxyindole-3-acetic acid (5-HIAA) continuously increased (P < 0.01), and the serum concentration of tryptophan also increased in the fasting group (P < 0.001). We showed that extracellular striatal monoamine levels fluctuated especially in the first 2 h and fasting altered monoamine metabolism. Therefore, it should take at least 2 h after surgery to stabilize the animals and obtain adequate basal levels. In addition, we should consider that these alterations occur when we use fasting animals as controls in microdialysis studies.

Analysis of Variance↗

Influence of right ventricular volume and pressure overloads on assessment of left ventricular volume using two-dimensional echocardiography in infants and children with congenital heart diseases.

In patients with right ventricular volume or pressure overload, the biplane Simpson's rule underestimates left ventricular volume more than the modified Simpson's rule. We suggest that the modified Simpson's rule should be used for estimation of left ventricular volumes rather than the biplane Simpson's rule in determining therapy for infants or children with complicated congenital heart disease.

Adolescent↗

Expression and function of murine receptor tyrosine kinases, TIE and TEK, in hematopoietic stem cells.

Two highly related receptor tyrosine kinases, TIE and TEK, comprise a family of endothelial cell-specific kinase. We established monoclonal antibodies against them and performed detailed analyses on their expression and function in murine hematopoietic stem cells (HSCs). TIE and TEK were expressed on 23.7% and 33.3% of lineage marker-negative, c-Kit+ and Sca-1+ (Lin- c-Kit+ Sca-1+) HSCs that contain the majority of day-12 colony-forming units-spleen (CFU-S) and long-term reconstituting cells, but not committed progenitor cells. Lin- c-Kit+ Sca-1+ cells were further divided by the expression of TIE and TEK. TIE+ and TEK+ HSCs as well as each negative counterpart contained high proliferative potential colony-forming cells and differentiated into lymphoid and myeloid progenies both in vitro and in vivo. However, day-12 CFU-S were enriched in TIE+ and TEK+ HSCs. Our findings define TIE and TEK as novel stem cell marker antigens that segregate day-12 CFU-S, and provide evidence of novel signaling pathways that are involved in the functional regulation of HSCs at a specific stage of differentiation, particularly of day-12 CFU-S.

Animals↗

Changes in right ventricular volume in early human neonates.

To evaluate changes in the right ventricular volume in early human neonates, twenty fullterm infants were examined at 2, 24 and 120 h of age by two-dimensional echocardiography. End-diastolic and end-systolic right ventricular volumes (RVEDV and RVESV, respectively) were calculated with a computer system based on the bi-plane Simpson's rule using the apical four chamber and parasternal short axis views. Then right ventricular stroke volume (RVSV), ejection fraction (RVEF), and the mean normalized systolic ejection rate were obtained. The inner diameter of the ductus arteriosus was also measured simultaneously. RVEDV increased significantly by 24 h of age, but remained constant thereafter. RVESV remained virtually unchanged from 2 to 120 h, resulting in a significant increase (36%) of RVSV at 24 h compared with that at 2 h. The mean normalized systolic ejection rate remained unchanged. There was a good correlation between RVEDV and RVSV (r = 0.83). All ductus arteriosus except three narrow ones was closed by 24 h of age. In conclusion, at 24 h of age, the significantly increased RVEDV was closely related to the increased RVSV, which might be induced by increased volume load to the right ventricle because of the closure of the ductus arteriosus.

Ductus Arteriosus↗

Chylothorax in a polysplenia infant with cor triatriatum, pulmonary stenosis and sick sinus syndrome.

An infant with chylothorax and polysplenia is described. Her chylothorax was refractory and related to right-sided heart failure derived from pulmonary stenosis, cor triatriatum, and sick sinus syndrome. In addition to Brock operation and cardiac pacing, thoracic duct ligation was performed, but it resulted in an only transient amelioration of the chylothorax. Eventually, the chylothorax resolved when total cardiac repair was performed for cor triatriatum. We propose that, in a patient with chylothorax and right-sided heart failure caused by compound cardiac malformations, as in this patient early surgical treatment for the underlying disease of right-sided heart failure should be considered.

Chylothorax↗

Active hypothalamic-pituitary-gonadal axis in an infant with X-linked adrenal hypoplasia congenita.

To evaluate the hypothalamic-pituitary-gonadal axis in an infant with adrenal hypoplasia congenita, we measured the serum levels of testosterone and performed a luteinizing hormone-releasing hormone stimulation test. The diagnosis was made because of the presence of a mutation, A300V, in the DAX-1 gene. The results demonstrated an active hypothalamic-pituitary-gonadal axis, with adult-level testosterone of 266 ng/dl on day 0, and maintenance of testosterone concentration in the 100 to 250 ng/dl range for 140 days as expected. The luteinizing hormone-releasing hormone lest was compatible with an active pituitary gland with a luteinizing hormone peak of 13.1 IU/L and a follicle-stimulating hormone of 5.0 IU/L We conclude that the DAX-1 mutation does allow a normal reproductive axis at birth. We speculate that sometime between infancy and puberty this mutation in the DAX-1 gene leads to an inability to activate the reproductive axis from its childhood suppression; thus puberty will not develop in this infant.

Adrenal Insufficiency↗

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↗

Cranial computed tomography scans of premature babies predict their eventual learning disabilities.

It remains difficult to predict, early enough to intervene effectively, the risk of the development of learning disabilities among extremely low birth weight (ELBW) infants (birth weights less than 1,000 g). We prospectively studied the relationship between dilatations of lateral ventricles of the cranial computed tomography (CT) scan taken at the postconceptional age of 40 weeks and learning disabilities in their school age. Using a computer digitizer, we measured the areas of ventricles on cranial CT scans. The mean area of lateral ventricles of the learning disabilities-suspected group was significantly larger than that of the control group (392.9 and 277.4 mm2, respectively; P < .01). There were no significant differences between the two groups in gestation, birth weight, physical measurements, and developmental quotients at early school age. The dilatation of the lateral ventricles assessed by cranial CT at the corrected term may be one of the first predictors of learning disabilities recognizable at early school age.

Brain↗

Childhood multiple sclerosis treated with plasmapheresis.

We report a case of multiple sclerosis in a 7-year-old boy. He experienced three episodes in 8 months and was repeatedly treated with a high dose of methylprednisolone. During the third episode, to avoid the side effects associated with frequent high doses of steroid, we substituted plasmapheresis for methylprednisolone, initially performing it for 3 days and continuing it every 2 to 3 weeks according to the fluctuating values of antinuclear antibody. The patient improved markedly after initiation of plasmapheresis and has been relapse-free for more than 18 months. The effectiveness of plasmapheresis for treatment of multiple sclerosis in adults is variable and has seldom been reported in children. Our case suggests that plasmapheresis as an alternative therapy is useful for steroid-dependent or severe types of multiple sclerosis even in childhood, especially when its chronic course is assessed by antinuclear antibody titers.

Anti-Inflammatory Agents↗

A case of neonatal choriocarcinoma.

Choriocarcinoma occurring in a placenta and metastasizing to the fetus is quite rare. We describe here a case of such infantile choriocarcinoma, initially appeared as refractory anemia and rapidly metastasized to the liver, lungs, and brain. The placenta looked normal and was not submitted to histological examinations. Neither noninvasive nor invasive diagnostic methods (ultrasonography, computed tomography, magnetic resonance image, scintigraphy, and hepatic arteriography) gave any diagnostic information on the tumor. Liver biopsy was considered too risky due to a possible bleeding. Correct diagnosis was established only after the postmortem examination. Two months after the infant's death, we were informed that the mother was found having hepatic and pulmonary tumors. The importance of the maternal history and measurement of urinary human chorionic gonadotropin is emphasized for a rapid and correct diagnosis of infantile choriocarcinoma.

Anemia, Refractory↗

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↗

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↗

Magnesium attenuates a striatal dopamine increase induced by anoxia in the neonatal rat brain: an in vivo microdialysis study.

We evaluated the effects of magnesium on extracellular dopamine (DA) and its metabolites in the striatum of 5-d-old rats submitted to 16 min of anoxia using microdialysis and HPLC. Rat pups were divided into three groups and received either 1) intrastriatal perfusion (IS) of MgSO4, 2) intraperitoneal injection (IP) of MgSO4, and 3) NaCl and Ringer's solution, respectively in place of MgSO4. After stabilization, Mg2+, saline, and Ringer's solution were administered; then, 114 animals were exposed to 100% nitrogen for 16 min. Anoxia induced a DA surge, an acutely marked increase of DA, in both the control and the IP group. In contrast, the DA surge was significantly suppressed in the IS group (p < 0.01, analysis of variance). During anoxia, the plasma Mg2+ in the IP group, but not in the IS group, maintained a significantly higher level compared with the basal level. On the other hand, Mg2+ in the perfusates in the IS group, but not in the IP group, maintained a significantly high level during anoxia. Alterations induced by anoxia in other metabolites, 3,4-dihydroxyphenylacetic acid, homovanillic acid, norepinephrine, and 5-hydroxyindole-3-acetic acid, did not significantly differ among the three groups. We propose that elevated levels of Mg2+ in the striatum had inhibitory effects on the DA surge during anoxia.

3,4-Dihydroxyphenylacetic Acid↗