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Biomedical subjects

F Hayakawa

Publications and source records attributed to F Hayakawa.

At least 55 records · Page 3Linked to original sources

Variation of the total amount of fluoride in blood of young women during the menstrual cycle.

We have previously reported the distribution and the forms of fluorides in the blood of men. This study is concerned with the distribution of fluorides in the blood of young women and sex-related differences in the fluoride metabolism related to the calcium metabolism keeping the postmenopausal osteoporosis in mind. The present study shows that women, aged 18 to 20 years, retain more fluorides in blood compared with men and that the nonionic fluoride level in blood varies during a menstrual cycle, whereas the ionic fluoride level is constant. Since fluoride has strong affinity for calcium, behavior of fluoride may reflect that of calcium balance during the menstrual cycle. However, fluoride which binds to calcium is believed to be ionic. Therefore, there must be a transformation between ionic fluoride and nonionic fluoride in order to keep the homeostasis.

Adult↗

[The relationship of a neonatal care center, a pediatric neurology division and a rehabilitation center for disabled children].

We investigated the relationship of the infants admitted to the neonatal intensive care unit (NICU) of Anjo Kosei Hospital, the outpatients of the pediatric neurology division of the same hospital and the patients in Daini-Aoitori Gakuen, Aichi prefectural hospital and Rehabilitation Center for Disabled Children. Eighty-six infants (2.9%) disclosed perinatal brain injury, and seventy infants (2.3%) had cerebral palsy in a total of 2,985 patients who were admitted to the NICU in Anjo Kosei Hospital. Forty seven percent of the outpatients of pediatric neurology division had been admitted to NICU. Eighty-four percent of the in fants with cerebral palsy had been referred to the Rehabilitation Center for Disabled Children. MRI disclosed perinatal brain injury in 72% of patients with cerebral palsy. We stress the importance of an information network among NICUs, pediatric neurology divisions and rehabilitation centers for disabled children.

Cerebral Palsy↗

[Laboratory and clinical studies on tazobactam/piperacillin in the field of pediatrics].

Laboratory and clinical studies on tazobactam/piperacillin (TAZ/PIPC), a combination drug of piperacillin (PIPC) with the new beta-lactamase inhibitor tazobactam (TAZ), were carried out in the field of pediatrics. 1. After intravenous administration of TAZ/PIPC at a dose of 25 mg/kg to one child, the peak plasma levels of TAZ and PIPC were 24.4 micrograms/ml and 119 micrograms/ml respectively after 5 min. The half-lives of TAZ and PIPC were 0.48 and 0.60 hours respectively. Same as 50 mg/kg to two children, the peak plasma levels of TAZ and PIPC were 17.5, 32.2 micrograms/ml and 92.8, 163 micrograms/ml after 5 min. The half-lives of TAZ and PIPC were 0.37, 0.50 hours and 0.51, 0.59 hours. A ratio of TAZ to PIPC was about 1 to 4 in plasma levels. The cumulative urinary recovery rates of TAZ and PIPC in the first 6 hours after intravenous administration were 15.8, 64.9% and 39.8, 53.4%. 2. The antibacterial activity of TAZ/PIPC against clinically isolated organisms was determined. The MICs of TAZ/PIPC were < or = 0.05 microgram/ml against Haemophilus influenzae and Streptococcus pneumoniae and > or = 1.56 micrograms/ml against Escherichia coli, Staphylococcus aureus and Haemophilus parainfluenzae. 3. The clinical efficacy of TAZ/PIPC could be evaluated in 14 patients with various bacterial infections, and was evaluated as "excellent" in 9 patients and as "good" in 5. The overall clinical efficacy rate in 14 cases was 100% and excellent was 64.3%. Bacteriological efficacy rate was 91.7% (10/11). 4. As a side effect, loose stool was observed in one case, no abnormal laboratory test values were observed. It has been concluded that TAZ/PIPC was a useful drug in the field of pediatrics.

Bacterial Infections↗

DNA cleavage reaction and linoleic acid peroxidation induced by tea catechins in the presence of cupric ion.

Tea catechins with cupric ion promoted extensive DNA cleavage and fatty acid peroxidation in vitro under aerobic conditions. Neither cupric ions nor polyphenolic compounds including catechins alone induced DNA cleavage. While catalase significantly inhibited the DNA cleavage induced by catechins-Cu2+, superoxide dismutase (SOD) did not, indicating that H2O2 is probably involved in the DNA cleavage. These results suggest that the pro-oxidant property of catechins, which are generally considered to be anti-oxidants and anticarcinogens, is responsible for the O2 reducing ability of catechins catalyzed by cupric ion.

Aerobiosis↗

Fetal heart rate patterns associated with periventricular leukomalacia.

OBJECTIVE: Our purpose was to assess the applicability of fetal heart rate (FHR) monitoring to detect fetuses at risk of developing periventricular leukomalacia (PVL). METHODS: FHR tracings obtained for babies delivered under 33 weeks' gestation and with a birth weight under 2000 g were assessed for baseline heart rate, variability, deceleration and "flip flap' (an oscillatory tracing pattern). RESULTS: PVL developed in 19 of the 103 infants studied. All of these infants were among the fetuses who exhibited average and increased variability. In addition, PVL was detected in 10 (47.6%) of the 21 flip flap positive fetuses, and in 9 (11.0%) of the 82 flip flap negative fetuses. The incidence of PVL was significantly higher in the flip flap positive fetuses (P < 0.005). CONCLUSION: The possibility that an unstable intrauterine environment, reflected by a flip flap pattern, is related to the subsequent development of PVL is indicated.

Female↗

Timing of insults causing abnormal outcome in preterm infants 1989-1992.

OBJECTIVE: The purpose of this study was to clarify the influence of timing of brain insults causing abnormal outcome in preterm infants. METHODS: One hundred and thirty-one preterm infants were examined. The timing of brain insult was estimated from EEG or clinical findings. Development was assessed until a corrected age of 48 months. RESULTS: 39% and 4% of infants, respectively, born before and after the 28-week time point subsequently died (P < 0.05). Abnormal development was observed in 16% of the first group and 13% of the second (N.S.). None of those born before 28 weeks showed intrauterine injuries while nine of the infants which were born after this time showed intrauterine injuries (P < 0.05). Fetal distress was noted in all infants suffering neonatal death born after 28 weeks. CONCLUSION: Intrauterine brain insult was concluded to be the cause of neonatal death or abnormal development in many infants born after 28 weeks.

Brain Injuries↗

Dysmature EEG pattern in EEGs of preterm infants with cognitive impairment: maturation arrest caused by prolonged mild CNS depression.

The significance of mild sustained brain injury in the pathogenesis of perinatal brain damage was investigated using serial EEG recordings performed on 102 early preterm infants surviving beyond 2 years of age. Sixteen infants (16%) elicited mild depression of background EEG activities in the neonatal period. Of nine infants with mild depression of prolonged duration (more than 3 weeks), five (56%) were diagnosed as having cognitive impairment in the follow up study. Four showed no signs of cerebral palsy, while one had cerebral palsy. The infants with cognitive impairment showed mild prolonged depressions in background EEG activities in the early neonatal period and dysmature EEG patterns in the late neonatal period. They also showed maturation arrest in EEG patterns during prolonged mild depression of background EEG activities. In addition to strong sudden depression of CNS causing deep white matter injury and motor impairment, prolonged mild depression is another mode of brain injury in early preterm infants which can induce future cognitive impairment.

Brain Ischemia↗

Disorganized patterns: chronic-stage EEG abnormality of the late neonatal period following severely depressed EEG activities in early preterm infants.

EEG recordings were performed within 72 hours following the birth of 55 preterm infants with a gestational age of less than 29 weeks. Seventeen infants (31%) manifested moderately to severely depressed EEG activities during this period. Eight of the infants died within a few days after birth, and 9 survived. We recorded EEGs from the surviving infants serially throughout the neonatal period, and evaluated EEG findings in the recovery phase following depressed EEG activities. At 1 to 3 weeks after birth, EEGs revealed an abnormal morphology of background activities in 8 of 9 cases; this was also true of the EEGs of 6 cases at 4 weeks or more of postnatal age. The latter 6 cases demonstrated deep white matter injury on cranial ultrasonography, and all of them later developed cerebral palsy. Based on the foregoing, EEG findings of early preterm infants in the late neonatal period are considered a useful means to detect deep white-matter injury and to allow neurological prognosis.

Brain Damage, Chronic↗

MRI findings in patients with spastic cerebral palsy. I: Correlation with gestational age at birth.

The authors studied MR images of the brain in 152 patients, aged 1 to 19 years (mean 3.3), who had spastic cerebral palsy (CP) and were attending two hospitals in Japan in 1993 and 1994. The relation was studied between the patients' gestational age at birth and their MRI findings, including the severity of periventricular leukomalacia (PVL) seen on MRI. In 119 of these patients, the CP was thought to be due to acquired, destructive brain injury. PVL was seen in 90 and posthemorrhagic porencephaly in 11. These preterm-type brain injuries were observed often in patients who had been born preterm but were also seen in those born at term. Fullterm-type border-zone infarct, bilateral basal ganglia-thalamic lesion, subcortical leukomalacia, and multicystic encephalomalacia were seen in 9, 14, 7, and 3 patients, respectively; these term-type brain injuries were observed only in patients born at or near term. Of the patients with PVL, 90% had been born preterm. Severe PVL was common in the patients whose gestational ages at birth were between 25 and 32 weeks; all patients with PVL who had been born at term had only mild PVL. The authors concluded that MRI findings for patients with spastic CP are closely correlated with gestational age.

Adolescent↗

[Rhythmic alpha/theta bursts in the electroencephalogram of early premature infants: (1). The features in normal early premature infants].

Rhythmic alpha/theta bursts were studied on forty-nine electroencephalographic records of early premature infants, ranging from 25 to 30 weeks of conceptional ages. Frontal alpha bursts and occipital theta bursts were prominent at 25-26 weeks, and temporal theta bursts prominent at 27-28 weeks. Frontal, temporal and occipital alpha/theta bursts were observed unilaterally, when all rhythmic bursts were seen frequently. Frontal and temporal bursts appeared often on the left side and occipital bursts on the right side.

Alpha Rhythm↗

[Rhythmic alpha/theta bursts in the electroencephalogram of early premature infants: (2). Correlation with background EEG activity].

Rhythmic alpha/theta bursts were studied on ninety-five electroencephalographic records of early premature infants, ranging from 25 to 30 weeks of conceptional ages in relation with background EEG activity. When background EEG showed normal, frontal alpha bursts and occipital theta bursts were prominent at 25-26 weeks, and temporal theta bursts at 27-28 weeks. A significant decrease in all rhythmic bursts on the frontal, temporal and occipital areas, was seen in early premature infants showing severe background EEG depression. Incidence of rhythmic alpha/theta bursts varies inversely with depression of background EEG activity.

Alpha Rhythm↗

MRI findings in patients with spastic cerebral palsy. II: Correlation with type of cerebral palsy.

The authors studied MR images of the brain in 152 patients, aged 1 to 19 years (mean 3.3), who had spastic cerebral palsy (CP) and were attending two hospitals in Japan in 1993 and 1994. Eighty-one patients had diplegia, 45 had quadriplegia, and 26 had hemiplegia. Of patients with diplegia, 72 had periventricular leukomalacia (PVL) and very few had other types of lesions. In patients with quadriplegia, three main types of brain lesions were observed: PVL in 12 patients, term-type brain injury in 22, and brain anomaly in 10. In the 26 patients with hemiplegia, 17 had a unilateral lesion (rare in patients with diplegia and quadriplegia), and bilateral lesions were seen in seven others.

Adolescent↗

[Pharmacokinetic and clinical studies with cefluprenam in the pediatric field. Pediatric Study Group of Gefluprenam].

Evaluation of efficacy and safety of cefluprenam (code number: E1077, abbreviation: CFLP), a newly developed injectable cephem antibiotics was conducted on adult patients with various infections, and followed by the study group organized from 39 institutions in pediatric field, as the drug showed no toxicity problems in suckling animals. Informed consents from legal representatives were obtained prior to the study. 1. Clinical efficacy. Two-hundred eighty one cases were included for analysis of clinical efficacy after 40 cases of exclusion or drop-out were subtracted from a total of 321 cases. However, the cumulative number of cases evaluable for analysis was considered to be 289, because 8 cases that had 2 different diseases at the same time were counted in each category of disease. In the cases in which causative organisms were identified (group A), 148 of 154 cases were rated as good or excellent, with an efficacy rate of 96.1%. As for clinical efficacies by disease, efficacy rates were 6/6 for purulent meningitis, 4/5 for sepsis, 95.7% (62/65) for pneumonia, 100.0% (29/29) for urinary tract infections, and 94.1% (16/17) for skin and soft tissue infections. The rate of excellent responses among excellent and good responses was 73.6% (109/148), showing a higher value than any of recent injectable beta-lactams. On 32 cases with S. pneumoniae infection, the efficacy rate of CFLP was 100.0%. In the cases where causative organisms were not identified (group B), 128 of 135 cases were rated as good or excellent, with an efficacy rate of 94.8%. In the all cases including both the group A and the group B, the efficacy rate was 95.2% (276/289) and the rate of excellent responses among excellent and good response was 70.7% (195/276). Against severe infections, CFLP exhibited excellent clinical efficacy, showing an efficacy rate of 8/8 for meningitis, 3/5 for sepsis and 100.0% (22/22) for severe pneumonia. As for bacteriological responses, eradication rates were 95.2% (177/186) in total. Against Gram-positive cocci, the eradication rate was 92.7% (76/82), with eradication rates of 94.3% (33/35) for Staphylococcus aureus, and 93.3% (28/30) for Streptococcus pneumoniae. Against Gram-negative rods, the eradication rate was 97.1% (101/104), and eradication rates were 100.0% (22/22) for Escherichia coli, 97.5% (39/40) for Haemophilus influenzae and 100.0% (19/19) for Molaxella catarrhalis. In cases in which more than 3 days of treatment with previous chemotherapy resulted in no response, the efficacy rate of CFLP was 94.2% (98/104), rated excellent in 68 cases and good in 30 cases. In these cases, the eradication rate was 98.1% (52/53). 2. Pharmacokinetics. CFLP was intravenously administerrd to 12 subjects at doses of 20 to 40 mg (potency)/kg. In 9 subjects aged more than 12 months, maximum serum levels (Cmax), T 1/2 beta and AUC of CFLP were 155.3 +/- 9.8 micrograms/ml, 1.43 +/- 0.18 hours and 111.7 +/- 15.0 micrograms.hr/ml, respectively, when a dose of 20 mg (potency)/kg was used. In 2 subjects aged not more than 12 months, the mean Cmax, T 1/2 beta and AUC were 153 micrograms/ml, 1.6 hour and 81 micrograms.hr/ml, respectively, at a dose of 20 mg(potency)/kg. The mean Cmax, T 1/2 beta and AUC were 332 micrograms/ml, 0.93 hours and 157.3 micrograms.hr/ml, respectively, in 1 subject at a dose of 40 mg (potency)/kg. In 10 subjects dosed 20 mg (potency)/kg, urinary levels were 2413 +/- 512, 1471 +/- 524, and 470 +/- 115 micrograms/ml in 0-2, 2-4, and 4-6 hours after dosing, respectively, showing a cumulative urinary excretion rate of 61.4 +/- 6.3%. In 1 subject dosed 40 mg (potency)/kg, urinary levels were 5700 and 4770 micrograms/ml in 0-2 p3d 2-4 hours after dosing, respectively, showing a cumulative urinary excretion rate of 42.1%. Cerebrospinal fluid concentrations of CFLP, on 10 subjects with purulent meningitis dosed 40-103 mg (potency)/kg were 3.2-32.9 micrograms/ml at 0.5-2 hours after administration within 4 days after the onset of

Bacteria↗

Timing of periventricular leukomalacia using neonatal electroencephalography.

OBJECTIVE: To estimate the timing of brain damage involved in the onset of periventricular leukomalacia in the perinatal period we recorded and analyzed neonatal electroencephalograms (EEGs). METHODS: Twenty-four preterm birth infants proved by real time ultrasonic examination or MRI to be suffering from periventricular leukomalacia underwent serial electroencephalography from soon after birth. RESULTS: Thirteen (54%) demonstrated intrauterine injury patterns, 2 infants (8%) showed postnatal injury, and in the remaining 9 cases (38%) the time of injury could not be determined by electroencephalography. Antepartum maternal hemorrhage (6), premature rupture of membranes (3), twining (3), chorioamnionitis (2), and perinatal asphyxia (2) were complications encountered in the group with intrauterine injury patterns. CONCLUSIONS: Our observations suggest that more than half of periventricular leukomalacia cases are associated with premature birth infants showing intrauterine injury patterns on electroencephalography, indicating the existence of intrauterine insult.

Brain Injuries↗

Periventricular leukomalacia and West syndrome.

The authors studied the clinical course and electroencephalograms (EEGs) of 27 patients with periventricular leukomalacia (PVL), to investigate the relation between PVL and West syndrome. Seven of the 27 patients with PVL developed WS; in all seven the PVL was severe. Bilateral parieto-occipital dominant irregular polyspike-and-wave (PO-polySpW) bursts were seen in eight of the 21 patients whose EEGs were recorded within the age of one year (corrected for preterm birth). All eight had severe PVL, and in six, bilateral PO-polySpW bursts were followed by hypsarrhythmia and spasms. None of the 12 patients without polyspike-and-wave bursts developed West syndrome, the study shows that West syndrome is a common complication of severe PVL and that it correlates strongly with the occurrence of bilateral PO-polySpW bursts on follow-up EEGs.

Birth Weight↗

Benign partial epilepsy in infancy.

The aim was to examine the occurrence of benign partial epilepsy in infancy (BPEI). BPEI was defined as epilepsies with complex partial seizures (CPS) or secondary generalised seizures (SGS), or both, compatible with the following characteristics: normal development before and after onset, no underlying disorders, normal interictal electroencephalograms (EEGs), and good response to treatment. All 75 patients who developed epilepsy within the first 2 years of age between 1987 and 1993 were evaluated: 22 patients fulfilled the definition completely; eight had CPS only, four SGS only, and 10 had both CPS and SGS; 17 had clusters of seizures. Eight patients had a positive family history. The average age of onset of seizures was 5.9 months. Interictal EEGs were all normal. Response to treatment was excellent and the average period of seizure persistence was 3.0 months. All had normal psychomotor development. Patients with BPEI were more common in this study than previously reported.

Anticonvulsants↗

[Oligohidrosis caused by zonisamide].

We studied 70 patients who took zonisamide (ZNS) in August 1994, to clarify the relation between ZNS and oligohidrosis. Twelve of the 70 patients were revealed to have oligohidrosis by the interview with patients' mothers. Six of these 12 patients were evaluated by heat loading test, which showed a decreased sweat response in all patients. Five of the 12 oligohidrotic patients were evaluated by acetylcholine (Ach) loading test and all of them showed a decreased sweat response. On two patients poor sweat responses to heat loading and Ach loading recovered after discontinuation of ZNS. These results suggest that ZNS causes dysfunction of sweat glands.

Acetylcholine↗

[Perinatal brain injury in infants with depressed EEG activities immediately after birth].

We investigated the developmental outcome and features of brain imaging in 33 infants with moderate or severe depression of background EEG activities immediately after birth. Lesions due to perinatal injury were observed in 25 infants on neonatal ultrasonography and/or childhood MRI. These findings strongly correlated with their gestational age. Periventricular leukomalacia and posthermorrhagic porencephaly were observed in preterm infants. On the other hand, perinatal injury of mature brain type, such as multicystic encephalomalacia, parasagittal infarct, bilateral basal ganglia/thalamic lesion, and subcortical leukomalacia, were observed in full-term infants. Periventricular leukomalacia rather correlated with moderate depression of EEG activities than severe depression like observed in full-term neonates who have brain lesions due to perinatal asphyxia.

Asphyxia Neonatorum↗