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Biomedical subjects

H Yabuuchi

Publications and source records attributed to H Yabuuchi.

At least 55 records · Page 3Linked to original sources

Prognostic value of electrically elicited blink reflex in neonates.

The electrically elicited blink reflex (BR) was evaluated in 80 normal neonates and 12 neonates with neurologic abnormalities. In normal subjects, R1 and bilateral R2 responses were elicited both while awake and in a quiet sleep state. Whereas the R1 response was consistently elicited in the active sleep state, as well as while awake, the ipsilateral R2 response was markedly suppressed and the contralateral R2 response was almost absent. The BR in neonates with neurologic abnormalities showed the following variable results: normal, prolonged latency, or suppressed response at initial recording. Abnormal BRs were detected in most neonates with respiratory or sucking problems. While neonates in whom a suppressed response or prolonged latency persisted for over three months had a poor prognosis, those with normal BRs or early correction of the BR abnormality had almost normal development. The BR appears to be useful not only to evaluate brain-stem function in the neonatal period but also to predict subsequent outcome.

Blinking↗

Characterization of cytomegalovirus isolates recovered during repeated infection in renal transplant recipients.

The sources of cytomegalovirus (CMV) infection in seropositive renal transplant recipients include reactivation of latent endogenous virus in the recipient, reactivation of latent virus in donated kidney, or both. If infection occurs by either source, viruses isolated from the same recipient should be the same strain, whereas if it occurs by both sources, those from the same recipient should be different. In this study, we followed prospectively 25 seropositive recipients who predominantly received a kidney from a seropositive donor to determine whether CMV isolates recovered repeatedly from them are the same or different. During an average 10 month follow-up period, six (24%) patients had excreted the virus more than twice at any site and/or at different times. Restriction enzyme analysis of viral DNA prepared by the Hirt procedure revealed that three or four isolates obtained from each of five patients were same, whereas six isolates from one patient included three different strains. Five of six patients had clinical symptoms at the times when CMV was recovered. Three patients with acute rejection and one patient with hepatitis had been infected with one single strain, and all were successfully treated. One patient with fever and acute rejection had been infected with three different strains, and he failed to recover his renal function. These results suggest that most CMV infections in seropositive recipients may be caused by one single strain. However, multiple infections with different strains can also occur. Such infections are associated with more severe clinical disease.

Adolescent↗

Administration of recombinant IL-2 augments the level of serum IgM in an IL-2 deficient patient.

A patient with ataxia telangiectasia was treated with recombinant interleukin-2 (rIL-2) and the resulting immunological effects evaluated. The patient lacked IL-2 production, and immunoglobulin synthesis was also impaired. Treatment with IL-2 selectively increased serum IgM without any significant side effects. Therapy also restored B-cell function in vitro. IgM production as well as the proliferative response to Staphylococcus aureus strain Cowan I. These results suggest that IL-2 treatment may correct both T-cell and B-cell defects.

Adolescent↗

Cooperation of synthetic insulin-like growth factor I/somatomedin C and 1,25-dihydroxyvitamin D3 on regulation of function in clonal osteoblastic cells.

We investigated the effects of insulin-like growth factor I/somatomedin C (IGF-I/SM-C), and the interaction of IGF-I and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on mouse clonal osteoblasts, MC3T3-E1. IGF-I stimulated [3H]thymidine incorporation into the DNA of the cells at concentrations of 1.3-130 X 10(-9) M. The alkaline phosphatase (ALP) activity in cultures was also raised by the hormone at the same concentrations. The optimal dose of IGF-I was 13 X 10(-9) M. Co-addition of IGF-I (1.3-130 X 10(-9) M) and 1,25(OH)2D3 (10(-11) to 10(-10) M) to the culture of MC3T3-E1 cells caused a synergistic increase in ALP activity. 25(OH)D3 and 24,25(OH)2D3 showed a similar effect with IGF-I at 1000-2000 times higher concentrations than 1,25(OH)2D3. [3H]Proline incorporation into collagenase digestible protein (CDP) in media was stimulated dose-dependently by IGF-I up to 2.2-fold over the control levels at 130 X 10(-9) M. Addition of 1,25(OH)2D3 (5 X 10(-11) M) and IGF-I further elevated the proline incorporation into CDP. However, the increment in CDP synthesis, induced by the two hormones was less than the increment in ALP activity. Thus, we conclude (1) that IGF-I stimulates both cell replication and differentiated functions in cultured murine osteoblasts and (2) that IGF-I and 1,25(OH)2D3 have the synergistic effect on ALP activity and the additive effect on collagen synthesis in MC3T3-E1 cells.

Alkaline Phosphatase↗

Cutis laxa with ultrastructural abnormalities of elastic fiber.

A case of a congenital, autosomal recessive form of generalized cutis laxa is reported. The patient was a 27-month-old boy with generalized flaccid skin and short stature. Radiologic examination revealed that the age of the bones of the wrist was compatible with a chronologic age of only 1 year. Elastic fibers were diminished throughout the dermis, and results of electron microscopic study showed globular and unstained elastin and relatively large amounts of the microfibrillar components of elastic fibers.

Biopsy↗

Clinical and electroencephalographical follow-up study of early myoclonic encephalopathy.

We report a clinico-electroencephalographical follow-up study on a male patient with early myoclonic encephalopathy. Frequent massive and fragmentary myoclonic seizures, and myoclonic-clonic seizures were the initial symptoms at the age of 3 days. EEG revealed a suppression-burst pattern at the onset in which burst phases often coincided with myoclonic seizures. Subsequently, non-epileptic erratic myoclonus, various partial seizures and flexor spasms were observed. The partial seizures ceased at around 4 months of age, while the non-epileptic myoclonus and flexor spasms have persisted beyond the age of 6 months. The EEG pattern evolved into atypical hypsarhythmia at two months of age. No specific biochemical or neuroradiological findings were disclosed. His neuropsychiatric development was arrested from the onset. These observations suggest that early myoclonic encephalopathy is an independent epileptic syndrome and that it might be different from early-infantile epileptic encephalopathy described by Ohtahara.

Anticonvulsants↗

Clonal T-cell lymphoproliferation containing Epstein-Barr (EB) virus DNA in a patient with chronic active EB virus infection.

A 10-year-old boy with chronic active Epstein-Barr virus (EBV) infection developed T-cell lymphoproliferation in the terminal stage of hepatic failure. The phenotypes of the proliferating lymphocytes were CD3+, CD4+ and HLA-DR+. The genomic DNAs from these cells demonstrated two rearranged T-cell receptor beta-chain genes and contained the EBV genome. These findings indicate that EBV can infect T lymphocytes and might cause clonal T-cell lymphoproliferation.

Blotting, Southern↗

Prevention of neonatal HBV infection with the combination of HBIG and HBV vaccine and its long-term efficacy in infants born to HBeAg positive HBV carrier mothers.

Seventy-three infants born to HBeAg positive HBV carrier mothers were protected from neonatal HBV infection with our standard prevention schedule consisting of two doses of HBIG (0,2 mo) and three doses of HBV vaccine (2, 3, 5 mo). In 62 infants who successfully responded to HBV vaccine with a titer of anti-HBs greater than 2(3), anti-HBs titer was monitored for as long as 48 months (25.6 +/- 11.0 mo) and found to decrease as follows: 5.1 +/- 1.7 at 12 mo., 4.5 +/- 1.8 at 18 mo., 4.2 +/- 1.8 at 24 mo., 4.0 +/- 1.6 at 30 mo., 3.7 +/- 1.7 at 36 mo., 3.2 +/- 2.0 at 48 mo. During the follow-up period, eight HBV events (11.9%) were demonstrated: one case showed an increase of anti-HBs, three showed a reappearance of anti-HBc alone, three showed a reappearance of anti-HBc with increase of anti-HBs, and one became a chronic HBV carrier. All infants were further divided into three groups by their maximal response of anti-HBs to HBV vaccine: Group I (greater than or equal to 2(6)), Group II (2(3)-2(5)), and Group III (2(2) greater than or equal to). Group I sustained a higher titer from 12 to 30 months of age and had less HBV events than G-II and G-III. Our study suggests that acquisition of a high titer of anti-HBs is important in long-term prevention of HBV infection as well as in the neonatal period in infants born to HBeAg positive HBV carrier mothers.

Carrier State↗

EEG and CT abnormalities in xeroderma pigmentosum.

Xeroderma pigmentosum associated with neurological abnormalities is a less familiar neurocutaneous disorder. In this report, 35 patients with group A xeroderma pigmentosum were assessed for neurological complications. Of these, 17 showed microcephaly and 24 mental retardation. Of 25 patients over 7 years of age, 22 had sensorineural deafness and 12 showed spinocerebellar signs such as nystagmus, dysarthria, tremor and ataxia, while none below 7 years of age had such neurological complications. Thirty-five EEG studies were performed on 29 patients, and 15 showed intermittent spindles of grouped theta waves with abnormal slow background activity and a poorly developed alpha rhythm, suggesting immature brain development or a regression from normal brain function in many areas including the diencephalon. Twenty-six patients were examined by cranial CT scan, of whom 20 showed abnormal CT findings such as ventricular dilatation, diffuse cortical atrophy, and marked thickening of the calvarial bones. The incidence of abnormal EEG and CT findings increased with advancing age in accordance with the development of neurological complications in the CNS, thus suggesting a chronic progressive degenerative disease.

Adolescent↗

Transient infantile hyperthyrotrophinaemia.

Sixteen cases of transient infantile hyperthyrotrophinaemia were followed up for two to seven years. Concentrations of serum triiodothyronine, thyroxine, and free thyroxine were maintained within the normal range in all cases. All but one child, who had a hearing disturbance, showed normal mental development with normal physical and skeletal maturation. Eleven children had normal concentrations of serum thyroid stimulating hormone and no signs or symptoms of thyroid dysfunction; in three children, diffuse small goitres developed and two further children showed relapse with slightly raised concentrations of thyroid stimulating hormone. It is concluded that 'transient infantile hyperthyrotrophinaemia' is a syndrome, which differs from typical transient neonatal hypothyroidism, and that careful follow up is necessary because some children show signs of mild pituitary-thyroid dysfunction in later childhood.

Child Development↗

[Doppler echocardiographic estimates of pressure gradients in various types of stenoses: usefulness and limitations].

UNLABELLED: In the present study, the accuracy of Doppler estimates of pressure gradients in various types of stenoses was clinically and experimentally evaluated. Fifty-seven patients, including 23 with ventricular septal defect, 15 with aortic or pulmonary valvular stenosis, four with infundibular stenosis, and five with supravalvular aortic or pulmonary stenosis were observed. The peak systolic pressure gradient (dP (C] was obtained at the time of catheterization in all patients. Before catheterization, the maximum velocity was measured by pulsed or continuous Doppler echocardiography and the estimated systolic pressure gradient according to Doppler (dP (D] was calculated by the simplified Bernoulli equation. The experimental model was designed to create pulsatile flow through a stenosis model. Nine different stenotic model types were used, including three orifice-like stenoses and six truncated cones with heights of 10 mm and 20 mm distal to the stenosis. The orifices in their stenoses were 3, 4 and 5 mm, respectively. Glycerin solution containing Sephadex with a viscosity similar to that of blood was used as the circulation medium. Its specific gravity was 1.16 g/cm3. In each stenotic model, the maximum velocity and instantaneous systolic peak pressure gradient were measured at various water flow rates. CLINICAL RESULTS: In patients with ventricular septal defect or valvular stenosis, dP (D) correlated very well to dP (C), with the regression equation, y = 0.87x + 2.79 (r = 0.92) or y = 0.96x + 1.02 (r = 0.99). In the other patients except for three with patent ductus arteriosus, dP (D) overestimated dP (C) by 11 to 71 mmHg, and their post-stenotic areas had gradually widened according to angiographic findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Stenosis, Subvalvular↗

[Ultrasonic Doppler assessment of hemodynamics in extra-intracranial arterial anastomosis in children with Moyamoya disease].

Recently the extra-intracranial (EC/IC) arterial bypass operation has been introduced in the treatment of Moyamoya disease and excellent postoperative outcomes have been reported. To assess the cerebral hemodynamic changes after the bypass surgery, ultrasonic Doppler flowmetry was performed in 10 children with Moyamoya disease. Their surgical treatments included superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis or encephalo-duro-arterio-synangiosis. The flow velocity and pattern of the major cerebral arteries and STAs, the donor artery of the bypass, were studied both before and after the operation. The results of Doppler flowmetry were compared with clinical symptoms and angiographical findings. Though the Doppler sonography of the major cerebral arteries showed little change, the flow velocity of the STAs revealed a pronounced and rapid increase after the bypass surgery. The flow pattern of the STAs, which was of the external carotid type preoperatively, changed to the internal carotid type postoperatively. These ultrasonic Doppler findings were thought to be due to a decrease in the peripheral vascular resistance, and suggested a good patency of the bypass arteries. These results of the Doppler flowmetry were in good agreement with clinical and EEG improvement and the findings of the postoperative cerebral angiography. It is suggested that ultrasonic Doppler flowmetry is a noninvasive and reliable method of assessing the function of the EC/IC bypass in children with Moyamoya disease.

Adolescent↗

Impaired cholesterol esterification in cultured skin fibroblasts from patients with I-cell disease and pseudo-Hurler polydystrophy.

Cholesterol esterification was examined in cultured skin fibroblasts from patients with I-cell disease and pseudo-Hurler polydystrophy by incubating cells pretreated without fetal calf serum for 48h, with (14C) cholesterol for 24h. Impaired cholesterol esterification was found in these cells and free cholesterol was accumulated in plasma membrane and Golgi fractions. This impairment was also induced in control cells by adding leupeptin (20 micrograms/ml) or monensin (2 micrograms/ml). These findings suggest the importance of the role of lysosomes for esterification of cholesterol and give a hint as to the basic defect in type C Niemann-Pick disease.

Autoradiography↗