Biomedical subjects

Toru Kato

Publications and source records attributed to Toru Kato.

36 records · Page 2Linked to original sources

PubMed2005

Popliteal angle in preterm infants with periventricular leukomalacia.

The aim of this study is to clarify the usefulness of popliteal angle in infants with periventricular leukomalacia. The popliteal angle was measured at 1, 4, 8, and 12 months of corrected age in 47 infants with periventricular leukomalacia and in 103 control infants with normal development. The popliteal angle was categorized into two groups; tight, when it was < or =120 degrees , and wide, when it was >120 degrees . The severity of diplegia was defined at 2 years as follows: mild, when an infant could walk; moderate, when an infant could sit but could not walk; severe, when an infant could not sit. Tight popliteal angle was more often observed in infants with periventricular leukomalacia than in normal infants at any corrected age. The rate of tight popliteal angle was significantly lower in infants with mild diplegia than in those with moderate or severe diplegia at 8 and 12 months of corrected age. Specificity and positive predictive value were high at 8 and 12 months of corrected age, whereas sensitivity was relatively low. The results of this study suggest that evaluation of popliteal angle is useful for detection of infants with periventricular leukomalacia, although false-negative rate is high during late infancy.

Case-Control Studies↗

PubMed2005

[Subacute encephalitis/encephalopathy with residual cognitive deficit].

We studied clinical features of 5 patients with subacute encephalitis/encephalopathy with residual cognitive deficit. In all patients, impairment of consciousness was mild at the onset, progressed between 4 and 15 days after the onset, and reached its peak at 6-18 days after the onset. Neuroradiological or electrophysiological examinations at the onset showed normal or mildly abnormal findings. In accordance with the clinical deterioration, brain atrophy was detected on cranial magetic resonance imaging (MRI) in 3 patients, and electroencephalogram revealed slowing of the background activities in all patients. Single photon emission computed tomography (SPECT) showed hypoperfusion in the fronto-temporal areas in all patients at the recovery stage. Three patients had severe mental deficits, and the other two had mild cognitive deficit. Motor impairment was observed in one patient.

Atrophy↗

PubMed2004

The evolutionary change of flash visual evoked potentials in preterm infants with periventricular leukomalacia.

OBJECTIVE: The aim of this study was to prospectively investigate flash visual evoked potential (VEP) findings and their chronological changes in preterm infants with cystic periventricular leukomalacia (PVL) during the early neonatal period. METHODS: The subjects of this study were 14 preterm infants with cystic PVL. The patients underwent serial cranial ultrasonography and diagnosed as having cystic PVL. Flash VEPs were diagnosed at least twice within the first 3 weeks of life. RESULTS: All infants had at least one or more flash VEP abnormalities. The most common finding was 'absent VEP', which was seen in 13 infants (93%). 'Delayed latency' was seen in two infants and 'abnormal waveform' was seen in one infant. Concerning the chronological changes, all records were abnormal in 4 infants, and the other 10 had transient normal VEP findings. Among them, flash VEPs changed from normal to abnormal within 10 days after birth in most cases. CONCLUSIONS: Almost all infants with cystic PVL had abnormal flash VEPs within the first 3 weeks of life, but chronological changes of flash VEP findings were seen during the period. SIGNIFICANCE: This manuscript may be useful as a reference to the flash VEPs in preterm infants with cystic PVL.

Cerebral Cortex↗

PubMed2004

Enantioselective reactions of alpha-lithiated allyl aryl sulfides using chiral bis(oxazoline)s.

The reaction of alpha-lithio allyl aryl sulfides, generated by treatment with n-BuLi and chiral ligands at -78 degrees C, with ketones was examined. The alpha-addition products were formed in preference to the gamma-addition products. The enantioselectivity of the alpha-addition products varied depending on the chiral ligand, and bis(oxazoline)-(t)Bu showed the highest enantioselectivity. Chirality 16:86-89, 2004.

Journal Article↗

PubMed2004

Non-epileptic pedaling-like movement induced by triclofos.

We reported an otherwise healthy infant with non-epileptic pedaling-like movement induced by triclofos. For the purpose of sedation for head computed tomography, 80 mg/kg of triclofos was administered. Fifteen minutes after the use of triclofos, the infant exhibited pedaling-like movement accompanied by slight upper eye deviations. This movement could be arrested by manual restraint. The pedaling-like movement lasted for about 2 h intermittently. Electroencephalography during this movement revealed physiological activities with semirhythmic theta waves without paroxysmal activities.

Brain↗

PubMed2004

A pilot study on lidocaine tape therapy for convulsions with mild gastroenteritis.

The aim of this study was to clarify the efficacy and safety of lidocaine tape therapy (LDT) in patients with convulsions with mild gastroenteritis (CwG). Twenty-one consecutive episodes of CwG were treated with LDT therapy. The dose of LDT was 36 mg in patients with body weights of <15 kg, 54 mg in those with body weights between 15 and 20 kg, and 72 mg in those with body weights of >20 kg. LDT was attached on the back of each patient every 12 h. Application of LDT was continued for 48 h. The serum levels of lidocaine (LD) were measured 4 h after the first attachment of LDT. The seizures completely ceased in 13 episodes (62%) after the application of LDT, while a recurrence of seizures was observed in the other 8 episodes. Drip infusion of LD was performed in 4 of these 8 episodes. The serum LD levels were only measurable in 6 infants (average, 0.4 microg/ml; range, 0.2-0.5 microg/ml). In the other patients, the serum LD levels were below the lower limit of measurement. Adverse effects of LDT were not observed in any patients. LDT therapy was safe and effective in patients with CwG.

Administration, Cutaneous↗

PubMed2004

Popliteal angle of low birth weight infants during the first year of life.

The aim of this study is to clarify the evolutional changes of the popliteal angle in low birth weight infants during the first year of life. The popliteal angle was measured at 1, 4, 8, and 12 months of corrected age on routine physical examination of 204 appropriate-for-date infants who had achieved normal psychomotor development. The popliteal angle was visually determined and categorized into two groups; tight, when it was 120 degrees or less, and wide, when it was more than 120 degrees. The infants were divided into five groups according to their birth weights; Group E, birth weight or=2500 gm. At 4 months of corrected age, the rate of a tight popliteal angle was significantly higher in Groups E + V + L1 than in Groups L2 + N. A tight popliteal angle was rare in all groups at 8 or 12 months of age. The results of this study indicate that the physiologic muscle tone of lower extremities is higher in infants with birth weights of <2000 gm at 4 months of corrected age. One should carefully interpret a tight popliteal angle in low birth weight infants during early infancy. Serial assessment of the popliteal angle is necessary before judging that a low birth weight infant has spastic cerebral palsy.

Biological Evolution↗

PubMed2004

Alleles responsible for ABO phenotype-genotype discrepancy and alleles in individuals with a weak expression of A or B antigens.

ABO types obtained from evidentiary samples have been used effectively to obtain the initial information leading to the apprehension of culprits in Japanese criminal investigations. A simple ABO genotyping method using multiplex sequence-specific PCR and capillary electrophoresis was developed as a supplement to serological ABO typing. Limitations in predicting a phenotype based on genotype were evaluated using 1134 randomly selected Japanese peripheral blood samples. A concordance rate of 99.82% (1132/1134 samples) was found between genotypes and phenotypes defined as Groups A, B, AB, and O. Sequencing analysis revealed that one discrepant sample contained an O allele having a previously unreported point mutation at the primer binding site in exon 6, and another discrepant sample contained an O allele lacking the guanine deletion at nt 261 (the O301 allele). Therefore, the existence of such alleles must be given some consideration when predicting phenotype based on genotype.

ABO Blood-Group System↗

PubMed2003

Circulating matrix metalloproteinase-1 and -3 in patients with an acute coronary syndrome.

To elucidate the diagnostic value of serum matrix metalloproteinase (MMP) levels, we measured MMP-1 and MMP-3 by a 1-step sandwich enzyme immunoassay. The transcardiac gradients of both MMPs were greater in patients with unstable angina and acute myocardial infarction than in patients with stable effort angina or control patients. Serum MMP levels appear to be a marker of plaque instability in patients with acute coronary syndrome.

Angina Pectoris↗

PubMed2003

Abnormal sharp transients on electroencephalograms in preterm infants with periventricular leukomalacia.

OBJECTIVE: To determine the clinical significance of abnormal sharp transients other than positive rolandic sharp waves (PRS), electroencephalograms were used for the diagnosis of periventricular leukomalacia (PVL). STUDY DESIGN: We evaluated 126 electroencephalograms from 93 preterm infants; 31 infants had PVL, and 62 were control infants. Frontal sharp waves (FS) were defined as sharp transients of positive polarity with an amplitude >100 microV. Occipital sharp waves (OS) were defined as those of negative polarity with an amplitude >150 microV. FS, OS, or PRS were considered to be present when there were >0.1 per minute. RESULTS: The number of FS per minute was significantly higher in the PVL group than in the control group during days 0 to 4 and 5 to 7. The number of OS per minute was also significantly higher in the PVL group than in the control group during days 0 to 4, 5 to 7, and 8 to 14. The sensitivity of FS or OS was relatively high but that of PRS was low. The presence of two or more types of abnormal sharp transients was correlated with a poor outcome. CONCLUSIONS: FS or OS may be useful for predicting which infant will have PVL.

Cerebral Palsy↗

PubMed2003

Hypoxic ischemic encephalopathy associated with neonatal seizures without other neurological abnormalities.

We reported three term or near-term infants with parasagittal infarcts. Their Apgar scores were low and the amniotic fluid was meconium-stained. Resuscitation was necessary immediately after birth, but they were not stuporous and no neurological abnormalities were recognized on admission. They showed metabolic acidosis and transient hypoglycemia, and two showed hematoemesis. Seizures were observed between 2 and 15 h of age in all of them. Electroencephalography demonstrated moderate or severe depression, and CT demonstrated bilateral abnormal low densities in the border zones of the middle and posterior cerebral arteries. Two of them had mental retardation and epilepsy, although the other exhibited normal development. Our infants suggest that neonatal seizures can also occur in infants with hypoxic ischemic encephalopathy without apparent neurological abnormalities.

Anticonvulsants↗

PubMed2003

Amplitude spectral analysis of maturational changes of delta waves in preterm infants.

The aim of this study is to clarify the usefulness of amplitude spectral analysis for an evaluation of maturational changes of delta activities in preterm infants. We chose each ten healthy infants without complications who were 29-30, 31-32, and 33-34 weeks of post-conceptional age (PCA) at electroencephalogram (EEG) recordings. Fast Fourier transform algorithm was applied for amplitude spectral analysis. The analyzed data were divided into four frequency bands; D1 0.53-1, D2 1-2, D3 2-3, and D4 3-4Hz. The average amplitude of six segments with high voltage slow waves was calculated in each frequency band. A significant reduction of the amplitude along with PCA was present in all leads in D1 band. On the other hand, a significant negative correlation with PCA was observed only in the occipital leads in D2, D3 or D4 bands. In conclusion, maturational EEG changes assessed by amplitude spectral analysis were prominent in the occipital areas, and in the frequency less than 1Hz.

Algorithms↗

PubMed2003

The predictive value of electroencephalogram during early infancy for later development of West syndrome in infants with cystic periventricular leukomalacia.

PURPOSE: The aim of this study was to elucidate a predictive value of electroencephalogram (EEG) during early infancy for later development of West syndrome (WS) in premature infants with cystic periventricular leukomalacia (PVL). METHODS: The subjects of this study were 19 infants with cystic PVL born between 1992 and 1996. EEGs were recorded at 3 months of corrected age (CA) in all of them. We divided these 19 infants into the following two groups; group A (n = 9), no paroxysmal discharge was recognized; and group B (n = 10), paroxysmal discharges were recognized. RESULTS: In none of the infants in group A did WS develop. Subsequent EEGs were normal in all infants in group A. WS developed in seven of 10 infants in group B. The occurrence of WS is significantly higher in group B than in group A. The mean age at the onset of WS was 6 months of CA. Paroxysmal discharges in infants in group B were observed as irregular spikes-and-waves and polyspikes-and-waves, mainly in bilateral parietooccipital areas. In seven of eight patients with severe MRI findings in group B, WS developed. CONCLUSIONS: Paroxysmal discharges during early infancy were correlated with later development of WS in infants with cystic PVL. The possibility of developing WS had increased in the children with the combination with EEG and MRI findings.

Age of Onset↗

PubMed2003

Ischaemic preconditioning and outcomes after angioplasty: effects of drug therapy.

Ischaemic preconditioning is one of the mechanisms by which human myocardium and human life are protected from ischaemic insults. One of the clinical situations in which we can discuss preconditioning is repetitive coronary occlusions by balloon inflation during elective percutaneous transluminal coronary angioplasty (PTCA) for stable angina pectoris. The severity of myocardial ischaemia assessed by ST-segment elevation or chest pain is less during the second balloon inflation compared with the first, if the duration of the first coronary occlusion is sufficient to precondition the myocardium. Many drugs have been identified that produce a reduction or induction in indices of preconditioning during PTCA. Preconditioning-mimetic drugs include adenosine, bradykinin, nitroglycerin and nicorandil. It is of paramount importance that we investigate and develop preconditioning-mimetic drugs which may enable an increased tolerance to effort angina, limit infarction size in susceptible patients, and decrease the incidence of sudden cardiac death as a result of ventricular tachyarrhythmias.

Adenosine↗

PubMed2002

A pilot study on umbilical venous level of natriuretic peptides in preterm infants and their relation to periventricular leukomalacia and antenatal complications.

The aim of this study was to determine the relation between umbilical venous levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in preterm infants, and the development of periventricular leukomalacia (PVL) and antenatal complications. Umbilical venous blood samples were obtained from 19 preterm infants with gestational age between 27 and 32 weeks. Cystic PVL was seen in four of them on ultrasonography. Several maternal variables were also investigated. There were no significant differences in ANP or BNP level between infants with and without PVL. Both ANP and BNP levels were significantly higher in infants with antenatal magnesium administration than in those without. Umbilical venous levels of natriuretic peptides were not useful to predict neurological outcome in preterm infants.

Atrial Natriuretic Factor↗

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

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↗