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Biomedical subjects

Makiko Osawa

Publications and source records attributed to Makiko Osawa.

At least 19 recordsLinked to original sources

TRH therapy in a patient with juvenile Alexander disease.

Alexander disease is a rare disorder of the central nervous system caused by a de novo mutation in the glial fibrillary acidic protein (GFAP) gene. Unlike the much more common infantile form, the juvenile form is slowly progressive with bulbar, pyramidal and cerebellar signs. Herein, we report a 9-year old Japanese girl suffering from frequent vomiting, slurred speech and truncal ataxia. Juvenile Alexander disease was diagnosed by genetic analysis, which detected a novel GFAP mutation, D360V. We also describe our clinical success in treating this patient with thyrotropin releasing hormone (TRH).

Alexander Disease↗

Cardiac involvement in Fukuyama-type congenital muscular dystrophy.

BACKGROUND: Fukuyama-type congenital muscular dystrophy is an autosomal recessive disorder characterized by generalized skeletal muscle weakness and hypotonia from early infancy and by mental retardation. Little is known about cardiac involvement in patients with Fukuyama-type congenital muscular dystrophy. This study evaluated whether cardiac involvement exists in patients with Fukuyama-type congenital muscular dystrophy. METHODS AND RESULTS: We evaluated left ventricular function using M-mode and Doppler echocardiography in 34 patients with Fukuyama-type congenital muscular dystrophy. The age ranged from 6 months to 30 years (median: 6 years). A total of 64 recordings were analyzed. Left ventricular dimensions and parameters of systolic function measured included left ventricular end-diastolic dimension, left ventricular fractional shortening, left ventricular wall thickness, and the mean velocity of circumferential fiber shortening and end-systolic wall stress relationship. Left ventricular end-diastolic dimension z score >2 was observed in 2 patients (6%). Left ventricular fractional shortening <0.28 and/or reduced mean velocity of circumferential fiber shortening in the mean velocity of circumferential fiber shortening-end-systolic wall stress relationship were observed in 16 patients (47%). A significant correlation between age and left ventricular fractional shortening was observed, and left ventricular fractional shortening decreased with age. Of 12 patients >15 years of age, 10 (83%) showed decreased left ventricular systolic function. Left ventricular fractional shortening was normal in most patients <10 years of age, and it was reduced in most patients >15 years of age. Five patients died of heart failure or respiratory problems, and a histologic examination confirmed the presence of myocardial fibrosis. No patients showed increased left ventricular wall thickness or a conduction abnormality on electrocardiograms. CONCLUSION: Cardiac involvement exists in patients with Fukuyama-type congenital muscular dystrophy and becomes evident in older children in the second decade. A cardiac evaluation, including echocardiograms and subsequent follow-up, is important, especially in patients >10 years of age.

Adolescent↗

Altered glycosylation of alpha-dystroglycan in neurons of Fukuyama congenital muscular dystrophy brains.

To test the hypothesis that the disruption of fukutin protein produces the brain pathology through hypoglycosylation of alpha-dystroglycan (alpha-DG), we immunostained Fukuyama congenital muscular dystrophy (FCMD) brains with an antibody that recognizes the polysaccharide epitope of alpha-DG. Immunoreactivity of the glia-limitans along the cortical surface, as well as that of the glial endfeet around vessel walls, was preserved in the FCMD cerebrum. However, fragmentation of the immunostained glia-limitans was noted in association with parenchymal protrusion and gyral fusion. In the FCMD cerebellum, this fragmentation of alpha-DG labeling was limited to the area of micropolygyria, and immunostaining at the glia-limitans and vessel walls was comparable to that of the control brains, in structurally normal areas. In the hippocampus, neurons of the dentate gyrus and corpus ammonis were immunopositive for alpha-DG in control subjects, but this staining was markedly decreased in FCMD brains. In contrast, immunolabeling of blood vessels and the glia-limitans was preserved in this region. Fukutin antisera clearly labeled hippocampal neurons in control brains, while this labeling was decreased in FCMD brains. Thus, hypoglycosylation of alpha-DG was evident in neurons, but not in the glial cell population of FCMD brains. This suggests that the mechanism of alpha-DG glycosylation may differ between neurons and glial cells, and that a fukutin gene defect may result in functional disruption through hypoglycosylation of both neuronal and glial alpha-DG.

Adolescent↗

Fukutin gene mutations cause dilated cardiomyopathy with minimal muscle weakness.

OBJECTIVE: The fukutin gene (FKTN) is the causative gene for Fukuyama-type congenital muscular dystrophy, characterized by rather homogeneous clinical features of severe muscle wasting and hypotonia from early infancy with mental retardation. In contrast with the severe dystrophic involvement of skeletal muscle, cardiac insufficiency is quite rare. Fukuyama-type congenital muscular dystrophy is one of the disorders associated with glycosylation defects of alpha-dystroglycan, an indispensable molecule for intra-extra cell membrane linkage. METHODS: Protein and functional analyses of alpha-dystroglycan and mutation screening of FKTN and other associated genes were performed. RESULTS: Surprisingly, we identified six patients in four families showing dilated cardiomyopathy with no or minimal limb girdle muscle involvement and normal intelligence, associated with a compound heterozygous FKTN mutation. One patient died by rapid progressive dilated cardiomyopathy at 12 years old, and the other patient received cardiac implantation at 18 years old. Skeletal muscles from the patients showed minimal dystrophic features but have altered glycosylation of alpha-dystroglycan and reduced laminin binding ability. One cardiac muscle that underwent biopsy showed altered glycosylation of alpha-dystroglycan similar to that observed in a Fukuyama-type congenital muscular dystrophy patient. INTERPRETATION: FKTN mutations could cause much wider spectrum of clinical features than previously perceived, including familial dilated cardiomyopathy and mildest limb girdle muscular dystrophy.

Adult↗

Beta-blocker therapy for cardiac dysfunction in patients with muscular dystrophy.

BACKGROUND: In muscular dystrophy, cardiac function deteriorates with time and heart failure is one of the major causes of death. Although the combination of angiotensin-converting enzyme inhibitors (ACEI) and beta-blockers improves cardiac function in adults, little is known about the efficacy of those drugs in patients with muscular dystrophy. METHODS AND RESULTS: The effect of the beta-blocker, carvedilol, and/or ACEI on ventricular function in patients with muscular dystrophy was studied. Carvedilol and an ACEI were given to 13 patients (ACEI group; mean age 18 years, range 7-27 years), and an ACEI only to 15 patients (carvedilol group; mean age 15 years, range 8-29 years). Diagnoses included Duchenne muscular dystrophy (n=25), Fukuyama muscular dystrophy (n=2), and Emery-Dreifuss muscular dystrophy (n=1). Echocardiographic parameters of the left ventricle were measured during the 2-3 years of follow-up. In the carvedilol group, combination therapy of carvedilol and an ACEI for 2 years resulted in a significant increase in left ventricular fractional shortening (LVFS). In the ACEI group, there was no significant change in LVFS. Left ventricular end-diastolic dimension increased in the ACEI group, but not in the carvedilol group. CONCLUSION: Carvedilol plus an ACEI improves left ventricular systolic function in patients with muscular dystrophy.

Adolescent↗

Platelet mitochondrial evaluation during cytochrome c and dichloroacetate treatments of MELAS.

We hypothesized that serial changes in platelet (PLT) mitochondrial enzyme (ME) activities might correspond to the effects of medications for mitochondrial encephalomyopathy and stroke-like episodes (MELAS). Cytochrome c and sodium dichloroacetate (DCA) were given to a 7-year-old girl with MELAS who had an A3243G mitochondrial DNA mutation. The effects were evaluated with whole PLT-ME assays, developed by our group, using a microplate-reader. During cytochrome c treatment, complex II+III (II+III), complex IV (IV) and citrate synthase (CS) activities showed gradual but statistically significant decrease. II+III activity dropped below normal. II+III/CS activity was initially below normal, followed by a transient improvement, then decreased again before the appearance of central nervous system symptoms. II+III, IV, II+III/CS and IV/CS activities reached their lowest levels in association with a stroke-like episode, then increased with DCA treatment. Our results suggest that progressive mitochondrial dysfunction may occur before the stroke-like episodes in MELAS and that DCA treatment may increase mitochondrial activities. Our whole PLT-ME assay system may be useful for serially evaluating mitochondrial functions in relation to clinical symptoms.

Blood Platelets↗

High bone turnover of type I collagen depends on fetal growth.

The bone metabolic processes of proliferation and differentiation in preterm and term newborns have yet to be fully elucidated. Seventy-four umbilical cord blood samples were collected from preterm and term newborns delivered at 27 to 42 gestational weeks (GWs). Carboxy-terminal propeptide of type I procollagen (PICP), pyridinoline cross-linked telopeptide domain of type I collagen (ICTP), alkaline phosphatase (ALP), and bone-specific alkaline phosphatase (BAP) were measured. Calcitonin (CT), estrogen (E2), intact parathyroid hormone, and insulin-like growth factor-I (IGF-I) were also examined in 20 or 23 randomly selected samples. We conducted cross-sectional regression analyses for bone metabolic markers, fetal growth markers including GWs, birth weight (BW), height (BH) and head circumference (HC), and bone related hormones. PICP and ICTP activities were very high, but decreased significantly with fetal growth based on GWs, BW, BH, and HC changes (GWs, BW, and BH to both PICP and ICTP, P < 0.0001; HC to ICTP, P < 0.0001; HC to PICP, P < 0.05), while BAP and ALP did not change significantly. E2 and CT both showed a significant positive correlation with Ca (P < 0.05), but neither hormone had any apparent correlation with PICP, ALP, BAP, or ICTP. These results suggest very active bone formation and resorption of type I collagen to be dependent on fetal growth and that fetal osteoblasts dominate the proliferation phase of development rather than the maturation phase. However, factors contributing to high bone turnover in the fetus remain to be elucidated.

Biomarkers↗

Extremely low-dose ACTH step-up protocol for West syndrome: maximum therapeutic effect with minimal side effects.

We studied the effectiveness of our new ACTH treatment strategy for West syndrome (WS), which was based on the results of our previous extremely low-dose ACTH study. The subjects were 31 infants with WS (cryptogenic WS in nine; symptomatic WS in 22). Synthetic ACTH-Z in a dose of 0.005 mg (= 0.2 IU)/kg/day was injected once every morning for at least 2 weeks, up to a maximum of 3 weeks. When this first treatment course achieved full seizure and EEG control, ACTH was tapered to zero over the subsequent 1 or 2 weeks. In the absence of a documented response, the dosage was increased to 0.025 mg (= 1.0 IU)/kg/day for the next 2 weeks (second treatment course). We analyzed the short-term as well as long-term effects, and the incidence of side effects. The first treatment course successfully controlled both spasms and hypsarrhythmia in 17 patients (55%), only spasms in one, and hypsarrhythmia in two. The second treatment course was then introduced in eight of the remaining 14 patients, providing complete suppression of WS in an additional two patients. Regarding the long-term effects, 13 patients (48%), with excellent short-term results and a longer than 1-year follow-up, remained seizure-free. Side effects of a mild degree were seen in 13 patients during ACTH treatment. Our new ACTH step-up method brought 61 and 48% of the patients into short-term and long-term remission, respectively, without significant side effects. The dose of ACTH required to control WS appears to be unexpectedly smaller than the dose we previously used.

Adrenocorticotropic Hormone↗

Usefulness of coadministration of bucolome in warfarin therapy: pharmacokinetic and pharmacodynamic analysis using outpatient prescriptions.

Bucolome, a nonsteroidal anti-inflammatory drug, has often been coadministered to patients who take warfarin as an anticoagulant. This combination increases the anticoagulant effect, which is most likely due to the interaction of bucolome with the pharmacokinetics (PK) or pharmacodynamics (PD) of warfarin. More than 30 years ago the mechanism of this interaction was reported to be inhibition of warfarin protein binding by bucolome, and the inhibition of warfarin metabolism by bucolome was also recently reported. Here, we examined daily doses of warfarin and its anticoagulant effect (thrombo-test, TT) in outpatient prescriptions in five hospitals to elucidate the drug interaction and the usefulness of this drug combination. Among the warfarin prescriptions, 78 were for patients also taking bucolome and 99 were for patients not taking bucolome. The daily dose of warfarin in patients taking bucolome was significantly lower than those without bucolome (ca. 40%). TT in patients taking bucolome was significantly lower as compared to those not taking bucolome. Control of the anticoagulant effect was greater with coadministration of bucolome and warfarin than with warfarin alone. PK and PD analysis of our results suggests that the improved therapeutic effect resulting from coadministration of warfarin with bucolome was due to lower and less patient-to-patient variation of intrinsic hepatic clearance (CL(int)) of warfarin, since bucolome decreased the high CL(int) but did not have a great effect on the low CL(int). In conclusion, administration of bucolome in warfarin therapy is useful to control the anticoagulant effect of warfarin. Attention should also be paid to the enzymatic inhibition by bucolome on the PK of coadministered drugs.

Adult↗

Pathological study of bronchospasms/tracheomalasia in patients with severe motor and intellectual disabilities.

This report concerns two autopsy cases of severe motor and intellectual disabilities (SMID) who died of bronchospasms or tracheomalasia. One case had no anatomical change in the tracheal wall except for an endotracheal granuloma, while the other showed softening of the tracheal wall. Since patients with SMID have risk factors for bronchospasms and tracheomalasia, such as gastro-esophageal reflux, aspiration, and thoracic deformities, it is important that we suspect the possibility of these conditions, when we see the respiratory distress in cases of SMID.

Adult↗

Zonisamide for West syndrome: a comparison of clinical responses among different titration rate.

We administered zonisamide (ZNS) to patients with West syndrome in different titration protocols and compared their short-term therapeutic effects. We designed three protocols to raise the serum ZNS concentration (SZC): (1) increase the dose in three steps, from 3 to 10 mg/kg every 3 days, (2) increase the dose from 5 to 10 mg/kg over 3-7 days, and (3) start with 10 mg/kg and maintain this dosage for 2 weeks. The subjects were 23 infants with West syndrome, 8 of whom comprised the 1st group, 5 the 2nd group, and the remaining 10, the 3rd group. As a result, excellent and good effects were obtained in a total of seven patients (30.4%) and one patient, respectively (1/8 in the 1st step-up group, 3/5 in the 2nd step-up group, and 4/10 in the 3rd group). The maximum SZC was higher in the excellent and good effect groups (n=8; 32.0+/-8.0 microg/ml) than in the ineffective group (n=15; 22.4+/-8.2 microg/ml) (P<0.05). The period of time required for cessation of spasms appeared shorter in the 3rd group (n=4; mean=5.7 days) than in the 1st and 2nd groups (n=4; mean=10.3 days). There were few side effects except for transient hyperthermia and gastrointestinal symptoms. Our new protocol of starting with 10 mg/kg of ZNS can be introduced safely and make a therapeutic judgment feasible within 2 weeks.

Anticonvulsants↗

Effect of ACTH therapy for epileptic spasms without hypsarrhythmia.

PURPOSE: We analyzed the short- and long-term effects of adrenocorticotropic hormone (ACTH) therapy for patients with epileptic spasms (ESs) who did not meet the criteria of West syndrome (WS). METHODS: The subjects were 30 patients, including 13 boys and 17 girls, who had received ACTH therapy between 1970 and 2003. We excluded patients with WS, but included those with a history of WS who no longer showed hypsarrhythmia at the period of ACTH therapy. The age at onset of ESs and at ACTH therapy ranged from 2 to 82 months with a median of 18 months, and from 11 to 86 months with a median of 29 months, respectively. RESULTS: Excellent and poor responses were obtained in 19 (63%) and 11 (37%) patients, respectively, as a short-term effect. Although the patients could be subclassified into five subgroups according to the previous reports, no difference was seen in short- term response to ACTH. Among 17 of the 19 patients with excellent short-term outcomes and a follow-up of >1 year after the ACTH therapy, eight patients have continued to be seizure free (29%; excellent long-term effect), whereas the remaining nine patients had a recurrence of seizures (complex partial seizures, four; generalized tonic seizures, three; ESs, two) at 9 months to 198 months (median, 49 months) after ACTH therapy. In addition, nine of the 17 patients demonstrated a localized frontal EEG focus after the ACTH therapy, although most of these had previously shown diffuse epileptic EEG abnormality. CONCLUSIONS: ACTH therapy is worth trying for patients with resistant ESs, even without features of WS. However, the long-term effect is uncertain because recurrences of various types of seizures, including focal, were frequently observed.

Adolescent↗

[Muscular dystrophy].

The muscular dystrophies are a genetically heterogeneous group of progressive disorders that lead to the breakdown of the integrity of skeletal muscle. Numerous recent advances made in research into the molecular genetics of muscular dystrophy have highlighted the diversity of this family of disorders. Muscle biopsy allows the immunohistochemical analysis of various muscle specific proteins, and can provide important data enabling definitive diagnosis. Muscle biopsy is not always necessary, such as in the case of Duchenne or Fukuyama type dystrophies, which are relatively easy to diagnose by genetic testing; in such cases, however, consideration must given to the ethical implications of testing. The future promises the development of new therapeutic approaches and clinical applications based on genetic diagnostic data.

Genetic Techniques↗

[Clinical and electroencephalogram study of 5 children with hypothalamic hamartoma].

We retrospectively studied 5 children with hypothalamic hamartoma (HH) to elucidate the clinical, neuroimaging and electroencephalogram (EEG) characteristics of this disorder. In all cases, high resolution MRI scans demonstrated an intrahypothalamic mass protruding into the 3rd ventricle. An initial symptom was epileptic attack in 4 cases and precocious puberty in the remaining one. Gelastic seizures developed in 4 of 5 patients at ranging from 2 days to 11 years of age. The ictal EEGs during the gelastic seizures showed diffuse attenuation of background activity, followed by rhythmic slow discharges either diffusely or in the central area. Gamma-knife radiosurgery was performed on 2 cases whose seizures were resistant to available antiepileptic drugs. One of the 2 patients was responded significantly to this treatment, showing the disappearance of combined attacks and a marked reduction of the generalized spike-waves discharges. A more aggressive therapy, including gamma-knife radiosurgery and surgical treatment, should be considered for patients whose seizures are resistant to the medical treatment and causing deterioration of intelligence and behavioral problem.

Adolescent↗