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Biomedical subjects

Kazuyoshi Watanabe

Publications and source records attributed to Kazuyoshi Watanabe.

72 records · Page 4Linked to original sources
PubMed2002

Combination of neonatal electroencephalography and ultrasonography: sensitive means of early diagnosis of periventricular leukomalacia.

This study was performed to assess the predictive value of ultrasonography and electroencephalography (EEG) in order to identify infants with periventricular leukomalacia (PVL) during the early neonatal period, especially non-cystic cases, and to clarify the combination of ultrasonographic and EEG findings that are the most useful. We studied 288 eligible infants, whose gestational ages ranged between 27 and 32 weeks. PVL was observed in 49 infants (26 cystic PVL and 23 non-cystic PVL). On ultrasonography, 31 infants with PVL were detected on the basis of definite periventricular echodensity (PVE). Thirty-seven infants had at least one of equivocal or definite PVE or cystic changes, but the other 12 did not have any of them. The sensitivity and specificity were 0.76 and 0.81, respectively. In EEG findings, acute stage abnormalities (ASA) of grade II or more were recognized in 31 infants with PVL. The sensitivity and specificity were 0.63 and 0.91, respectively. Equivocal or definite chronic stage abnormalities (CSA) were seen in 43 infants, the sensitivity and specificity being 0.88 and 0.84. The sensitivity of CSA was higher than that of ASA, and the specificity of ASA was higher than that of CSA. When these EEG findings were combined, 45 infants with PVL were detected. The sensitivity, specificity, positive predictive value, and negative predictive value were 0.92, 0.77, 0.45, and 0.98, respectively. Moreover, ultrasonographic and EEG findings were combined, 46 out of the 49 infants with PVL were detected with a sensitivity of 0.94 and a specificity of 0.64. The results indicated that EEG may be suitable for detecting infants at risk for development of PVL on the basis of its high sensitivity, and ultrasonography may be useful for confirming the presence of PVL on the grounds of its high specificity. Appropriate use of these measurements will make an early diagnosis of infants with PVL possible, even in non-cystic cases.

Electroencephalography↗
PubMed2002

Cerebral hemodynamics during early neonatal period in preterm infants with periventricular leukomalacia.

We prospectively investigated the relation among cerebral blood flow, periventricular leukomalacia (PVL) and hypocarbia using Doppler ultrasonography in 53 preterm infants with gestational age between 27 and 34 weeks who required mechanical ventilation during the first 72 h of life. Cerebral blood flow of pericallosal artery was assessed by Doppler ultrasonography at the first and the third day of life. Mean velocity (MV) and Resistance index (RI) of anterior cerebral artery were calculated from the data obtained by Doppler ultrasonography. The diagnosis of PVL was made in 12 infants on the basis of the results of ultrasonography and MRI. Hypocarbia was judged as positive when both arterial blood gas analyses before and after the ultrasonography revealed PaCO(2) values < 25 mmHg. On the first day of life, RI was 0.62 +/- 0.022 in infants with PVL and 0.71 +/- 0.014 in those without PVL. On the third day of life, RI was 0.60 +/- 0.032 in infants with PVL and 0.66 +/- 0.013 in those without PVL. There was a significant difference in RI between the two groups at either point. MV was not significantly different between the two groups at either point. There was no significant difference in RI or MV between infants with and without hypocarbia at either point. RI was significantly lower in infants with PVL during the first 72 h of life, which is suggestive of vasoparalysis in such infants at the level of major cerebral arteries. However, RI or MV was no different between infants with and without hypocarbia.

Anterior Cerebral Artery↗
PubMed2002

Clinical features of benign convulsions with mild gastroenteritis.

The aim of this study is to reveal the detailed clinical features of benign convulsions with mild gastroenteritis (CwG). We studied 114 consecutive episodes in 105 patients with CwG between January 1995 and March 2000. CwG was defined as when a patient met the following two conditions: (a) seizures accompanied the symptoms of gastroenteritis without clinical signs of dehydration or electrolyte derangement and (b) the body temperature remained less than 38.0 degrees C before and after the seizures. Patients with meningitis, encephalitis/encephalopathy or apparent history of epilepsy were excluded. The age of onset ranged from 8 to 52 months (mean, 21.1 +/- 8.4 months). Six patients (6%) had a family history of afebrile convulsions and seven (7%) had one of febrile convulsions. The average interval between the onset of gastroenteritis and that of seizures was 2.3 +/- 1.1 days (range, 1-6 days). The average number of seizures during a single episode was 2.6 +/- 1.5 (range, 1-7). Two or more seizures occurred in 86 (75%) of the 114 episodes. Seizures induced by pain and/or crying were seen in 35 (43%) of 82 episodes. Antiepileptic drugs were administered for 96 episodes. Seizures did not cease after the administration of one kind of antiepileptic drug in 56 episodes (58%). Epilepsy developed in none of the patients. All patients exhibited normal psychomotor development. CwG is characterized by a cluster of seizures that are sometimes induced by pain and/or crying. The seizures are rather refractory to antiepileptic treatment, although the seizure and development outcomes are good.

Age of Onset↗
PubMed2002

Prognostic value of positron emission tomography in cryptogenic West syndrome.

The relationship between positron emission tomography (PET) findings and developmental or seizure outcome was examined in 17 infants (11 males, six females; mean age at onset of spasms 7 months, range 3 to 26 months) with newly diagnosed cryptogenic West syndrome. The predictive value of PET in these infants was assessed. PET was performed in the infants at the onset of spasms and 3 months after initial therapy using 18F-labelled 2-deoxy-2-fluoro-D-glucose. A third PET was performed at 18 months of age if the second scan was abnormal. All infants were followed up until at least 3 years of age. Cortical hypometabolism was detected in 11 infants on the first PET and in five infants on the second. Rate of developmental delay at the last follow-up was significantly higher in infants with hypometabolism on the second PET than in those without PET abnormalities (p<0.05). Rate of seizure occurrence after initial treatment was higher in infants with cortical hypometabolism on the second PET, but the difference was not statistically significant. Results suggest that when PET after the initial treatment shows no abnormalities, even though the first PET shows hypometabolism, infants with cryptogenic West syndrome may have a favourable developmental or seizure outcome. PET may be a useful tool in evaluating the prognosis in infants with cryptogenic West syndrome.

Cerebral Cortex↗
PubMed2002

Developmental outcome and types of chronic-stage EEG abnormalities in preterm infants.

The aims of this study were to determine the types of chronic-stage EEG abnormalities that exist and to clarify their relation to neurodevelopmental outcome in preterm infants. We evaluated 183 preterm infants with gestational ages of less than 33 weeks (mean age 29.2 weeks) and weighing less than 2000 g (mean weight 1275 g). The first EEG was performed within 72 hours of life; thereafter, EEG was performed once every 1 to 4 weeks until the infant reached a post-conceptional age of 40 to 42 weeks. Two kinds of EEG abnormalities, acute- and chronic-stage abnormalities, were evaluated and we assessed mainly the latter. Chronic-stage EEG abnormalities were divided into two patterns: disorganized and dysmature. Periventricular leukomalacia (PVL) and intraventricular haemorrhage (IVH) were diagnosed on the basis of ultrasound findings. Psychomotor development was examined every 3 months after discharge until at least 18 months of the infants' corrected age. Disorganized and dysmature patterns were observed in 52 and 28 infants respectively. Among the 52 infants with disorganized patterns, PVL was observed in 31 and IVH in seven infants. Thirty-nine infants had cerebral palsy (CP). Twenty-six achieved normal cognitive development. Of the 28 infants with dysmature patterns, PVL was seen in one and IVH in 11 infants. CP was seen in five infants. Only eight infants achieved normal cognitive development. Gestational age and birthweight were significantly lower in infants with dysmature patterns than in those with disorganized ones. Results indicate that types of chronic-stage EEG abnormalities are related to types of neurological sequelae and are useful for assessing the mode of brain injury in preterm infants.

Cerebral Hemorrhage↗
PubMed2002

Effect of candesartan, a type 1 angiotensin II receptor antagonist, on bronchial hyper-responsiveness to methacholine in patients with bronchial asthma.

AIMS: Angiotensin II is a putative mediator in bronchial asthma. There have been very few studies investigating the involvement of angiotensin II receptors in bronchial hyper-responsiveness in asthmatic patients. We examined the effect of candesartan cilexetil, a specific angiotensin II type 1 (AT1) receptor antagonist, on bronchial responsiveness to inhaled methacholine in patients with asthma. METHODS: Bronchial responsiveness to methacholine, assessed as the concentration of methacholine producing a 20% fall in FEV1 (PC20-FEV1), was measured on three occasions 2 weeks apart in 11 stable asthmatic patients. Candesartan cilexetil (8 mg once a day) or a placebo was orally administered for 1 week before the methacholine provocation test in a double-blind, randomized, crossover manner. RESULTS: Although there were no significant differences between treatment periods in FEV1 values at baseline, the geometric mean (95% CI) PC20-FEV1 values increased significantly (P = 0.041) from 0.691 (0.379, 1.259) mg ml-1 with placebo to 0.837 (0.506, 1.384) mg ml-1 with candesartan. Candesartan decreased the mean (95% CI) arterial blood pressure (placebo: 95.6 (89.0, 102.2) mmHg, candesartan: 86.4 (79.8, 93.1) mmHg, P = 0.015). There was no correlation between the change in blood pressure and the change in PC20-FEV1. CONCLUSIONS: We conclude that AT1 receptors are involved in bronchial hyper-responsiveness in asthmatic patients.

Administration, Inhalation↗
PubMed2002

Helicobacter pylori infection in patients with idiopathic short stature.

BACKGROUND: Some investigators have recently described an association between Helicobacter pylori infection and children with short stature. In the present study, we aimed to evaluate children with short stature with different etiologies. METHODS: This study evaluated short patients aged from 1 to 16 years. These patients were divided into a growth hormone deficient short stature group (n = 27) and an idiopathic short stature group (n = 14). A control group included children with normal growth and no abdominal pain (n = 47). Anti-H. pylori antibodies were measured in each group (total of 88). RESULTS: The antibody positivity rates for each group were as follows: growth hormone deficient short stature group, 7.4%; idiopathic short stature group, 28.6%; and control group, 6.4%. The H. pylori antibody positivity rate in the idiopathic short stature group was significantly higher than in the control group. CONCLUSION: Our findings suggest an association between H. pylori infection and idiopathic short stature.

Adolescent↗
PubMed2002

Visual information process in Williams syndrome: intact motion detection accompanied by typical visuospatial dysfunctions.

It has been suggested that visuospatial cognitive disabilities seen in children with Williams syndrome (WMS) are related to a dysfunction of the dorsal stream in the visual information analysis system. We investigated whether visual motion detection is also impaired in WMS because it is one of the main functions of the dorsal stream. Using various psychophysical examinations and magnetoencephalography, we studied a child with WMS who had the typical features of the syndrome. We found profound impairments in the visuospatial cognitions, as previously reported in WMS. In contrast, he had normal ability for the direction discrimination of coherent motion on a background of randomly moving dots, and he perceived apparent motion as do normal children. Furthermore, the latencies of both responses to the coherent and incoherent motions as measured by magnetoencephalography were within the mean +/- 2 SD among normal adults and the estimated origins were near the human homologue of V5/MT (visual area 5/middle temporal area). The results indicate that the visuospatial cognitive deficits in WMS can occur without impairment of the visual motion detection. We consider that the deficits are caused by a restricted dysfunction of the neural groups for position and three-dimensional form perceptions in the dorsal stream of the visual system, though other possibilities are not excluded.

Brain Mapping↗
PubMed2002

[Two cases of infectious mononucleosis-like syndrome associated with human herpes-virus 6].

We experienced two cases of infectious mononucleosis-like syndrome associated with human herpesvirus 6 (HHV-6). One of the patients had been under medication for depression and the other one for schizophrenia. Both of them were taking carbamazepine for more than a week along with the other drugs. The manifestation of the symptoms of those two were almost same, such as high fever, generalized eruption, liver dysfunction, lymph-adenopathy, and existence of atypical lymphocytes. Serological tests for EB virus, cytomegalovirus and herpes simplex virus showed no significant change while the tests for HHV-6 showed increased titers of IgG antibody during the courses. We also examined HHV-6 DNA by real time quantitative PCR tests for HHV-6, and they appeared significantly high in the peripheral blood samples.

Adult↗
PubMed2002

Mutation analysis in a patient with succinic semialdehyde dehydrogenase deficiency: a compound heterozygote with 103-121del and 1460T > A of the ALDH5A1 gene.

We saw a 17-month-old boy with moderate psychomotor retardation, and enzymatically diagnosed succinic semialdehyde dehydrogenase (SSADH) deficiency. After extracting mRNA and genomic DNA from his cultured lymphoblasts, we analyzed the entire coding region of the ALDH5A1 gene using reverse transcription-polymerase chain reaction (RT-PCR) and genomic PCR followed by sequencing. He was demonstrated to be a compound heterozygote with two novel mutations (103-121 del and 1460T>A). The former leads to a frameshift and premature termination, and the latter is a missense mutation, V487E. Both mutations were also detected in the genomic DNA. Taken together with previous mutation reports, genetic heterogeneity was suspected for SSADH deficiency, and may account for the wide range of its phenotype.

Aldehyde Oxidoreductases↗
PubMed2002

Effect of intranasal administration of CV-11974, a type 1 angiotensin II receptor antagonist, on airway hyperresponsiveness and airway inflammation induced by antigen inhalation in guinea pigs.

BACKGROUND: Angiotensin II is a putative mediator in asthma, but the effect of topical administration of type 1 angiotensin II (AT1) receptor antagonists on allergic airway reactions is not known. OBJECTIVE: To investigate the effect of intranasal administration of CV-11974, an AT1 receptor antagonist, and of PD123319, a type 2 angiotensin II (AT2) receptor antagonist, on antigen-induced airway reactions in guinea pigs. METHODS: Thirty minutes after intranasal topical administration of CV-11974 (0.1 or 1.0 mg/ml) or PD123319 (10 mg/ml) into the airways, the animals were given an antigen challenge. Airway hyperresponsiveness and bronchoalveolar lavage fluid were analyzed 24 h after the antigen challenge. RESULTS: Although these compounds did not inhibit antigen-induced early-phase bronchoconstriction or late-phase airway eosinophilia, intranasal administration of CV-11974 (but not PD123319) inhibited antigen-induced airway hyperresponsiveness in a dose-dependent manner 24 h after the antigen challenge. CONCLUSION: Intranasal administration of an AT1 receptor antagonist reduces antigen-induced airway hyperresponsiveness.

Administration, Inhalation↗
PubMed2002

Midkine expression is associated with postnatal development of the lungs.

A heparin-binding growth factor, midkine, is the product of a retinoic acid-responsive gene. Since retinol plays critical roles in lung development and treatment of bronchopulmonary dysplasia, and midkine has been implicated in the maturation of lung explants and in cytoprotection, we herein examined midkine expression during postnatal development of the lungs and hyperoxic lung injury. Midkine protein transiently increased to a maximum level at around 4 days postnatal. Immunohistochemistry revealed that the amounts of midkine increased in resident alveolar cells, but not in smooth muscle cells or the large airway epithelium. If neonatal mice were exposed to >95% oxygen, lung development was impaired and midkine expression was suppressed. In contrast, when adult mouse lungs as well as in vitro cultured lung adenocarcinoma cells were exposed to hyperoxia, midkine expression was not affected. Furthermore, a pronounced induction of midkine by retinoic acid was observed in neonatal lungs. The results indicate that midkine expression is associated with postnatal lung development, but not necessarily with hyperoxic cell damage.

Animals↗
PubMed2002

Acute eosinophilic pneumonia following cigarette smoking: a case report including cigarette-smoking challenge test.

A 21-year-old woman presented with acute progressive dyspnea. Chest computed tomography (CT) revealed diffuse bilateral infiltrates. Based on the results of transbronchial lung biopsy (TBLB) and bronchoalveolar lavage fluid (BALF) and her clinical course, she was diagnosed as having acute eosinophilic pneumonia. We suspected that the disease was related to smoking because she had started smoking ten days before the onset of symptoms. Therefore, a cigarette-smoking challenge test was done with the patient's informed consent. After the challenge, eosinophilic pneumonia was documented by BALF and TBLB findings, which were similar to those detected on admission, without significant radiographic findings.

Acute Disease↗
PubMed2002

[A case with frontal lobe epilepsy presenting with absence seizures as cardinal manifestation: ictal EEG findings].

We report here a 9-year-old boy presenting with absence and complex partial seizures. Absence seizures occurred several times a day, with sudden arrest of speech and gesture, alteration of consciousness, myoclonus of unilateral or bilateral angles of the mouth, occasional simple automatism and brisk recovery of consciousness. Complex partial seizures occurred once to three times a month with loss of consciousness, salivation, deviation of the head and eyes toward the left, elevation of upper limbs and tonic convulsion of the left upper and lower limbs. Interictal EEG showed right frontal pole-dominant high-voltage slow waves or spike-and-waves. Ictal simultaneous video-EEG recordings of absence seizures revealed a frontal dominant 3-3.5 Hz spike-wave burst lasting several seconds. A partial seizure never preceded the absence seizure. Transverse topographical analysis revealed that the first spike component of the spike-wave burst of absence seizure always showed phase reversal on the right anterior temporal electrode. The following ones, however, showed phase reversal on the left anterior temporal electrode. Ictal EEG of the complex partial seizure could not be detected because it rarely occurred. There was no abnormal finding on brain MRI. Interictal single photon emission tomography (SPECT) indicated hypoperfusion of the dorsal and medial cortex of the right middle frontal lobe. Interictal positron emission tomography (PET) also indicated hypometabolic areas in the dorsal and medial cortex of the right frontal lobe, together with those in the right temporal and parietal cortex. EEG evolution and neuroimaging studies suggested that the epileptic focus of the absence seizure might have originated at the dorsal cortex of the right middle frontal lobe and immediately spread to the medial cortex. Both the seizures were well controlled by the combination of phenytoin and high dose sodium valproate.

Brain↗
PubMedDate not supplied

Importance of the angiotensin type 1 receptor in angiotensin II-induced bronchoconstriction and bronchial hyperresponsiveness in the guinea pig.

Although angiotensin II (Ang II) causes bronchoconstriction and bronchial hyperresponsiveness to methacholine in mildly asthmatic patients, the responsible mechanisms for these reactions are unclear. The authors examined the effect of intravenous infusion of Ang II on airway constriction in guinea pigs. Furthermore, the effects of subthreshold concentrations of Ang II on bronchial responsiveness to methacholine were investigated. Airway opening pressure (Pao), an index of bronchoconstriction, increased dose dependently after intravenous infusion of 3 and 10 nmol/kg Ang II (72.2 and 236.5 increase above the baseline value, respectively). In another set of experiments, animals received a methacholine inhalation challenge under a constant intravenous infusion of a subthreshold dose of Ang II (2 nmol/kg/min). The Ang II infusion elicited bronchial hyperresponsiveness to methacholine. The provocative concentration of methacholine, which produced a 200% increase above the baseline Pao (PC200), decreased from 306.9 to 156.1 micrograms/mL upon Ang II infusion. Pretreatment with TCV-116, a type 1 Ang II (AT1) receptor antagonist, but not PD123319, a type 2 Ang II (AT2) receptor antagonist, dose dependently prevented both the Ang II-induced bronchoconstriction and bronchial hyperresponsiveness to methacholine. The authors conclude that Ang II caused bronchoconstriction and induced bronchial hyperresponsiveness to methacholine via the AT1 receptors and that this effect did not involve the release of other bronchoactive mediators.

Angiotensin II↗