Vitamin K concentrations in the maternal milk of Japanese women.

AIM: To determine the concentration of vitamin K including K1 (phylloquinone) and K2 (menaquinone-n; MK-n) in the maternal milk of Japanese women. METHODS: We collected human milk samples from more than 4000 mothers living throughout Japan from December 1998 to September 1999, and analysed the contents of vitamin K1 and K2 in 834 of the samples. We defined as group A the 555 samples among them that met the following conditions: breast milk of mothers who were under 40 y old, not in the habit of smoking and/or using vitamin supplements, and whose babies showed no symptoms of atopy and whose birthweights were 2.5 kg or more. Vitamins extracted from the enzymatic hydrolysates of the human milk were purified with a Sep-Pak Plus silica cartridge, and then measured by a method based on high-performance liquid chromatography (HPLC) combined with coulometric reduction and fluorometric detection. RESULTS: The mean concentration of vitamin K (K1 + K2) of mothers of group A and all groups were 0.434 +/- 0.293 and 0.517 +/- 1.521 microg/100 ml (average +/- SD), respectively, and menaquinones containing 4, 6 and 7 isoprenoid residues could be detected in the milk samples. Vitamins K1 and MK-4 were found to be predominant in the milk samples, and the concentration of MK-4 in colostrum was higher than that of MK-4 in mature milk. We also found that the MK-7 concentration in the milk of mothers living in eastern Japan was higher than that of mothers living in western Japan. CONCLUSION: The different features of vitamin K1 and MK-7 concentrations in the milk of Japanese women may be due to differences in dietary foods.

CYP3A activity in European American and Japanese men using midazolam as an in vivo probe.

OBJECTIVE: To investigate putative differences in CYP3A activity between European American and Japanese subjects using midazolam as an in vivo probe. METHODS: Midazolam was administered orally (2 mg) to 22 young healthy Japanese men and, on a separate occasion, to 19 of these by the intravenous route (1 mg). The disposition of the drug and its 1'-hydroxy metabolite were determined and compared with data collected in a similar fashion in 20 young healthy European American men. RESULTS: Plasma concentrations of midazolam, especially those attained soon after drug administration, were higher after intravenous injection in Japanese subjects than those in European American men. This observation was associated with smaller initial (2.5-fold) and steady-state (1.8-fold) volumes of distribution for the drug; normalization for body weight only modestly reduced these differences. The systemic clearance value of midazolam was 25% lower (P < .03) in Japanese subjects, but this difference was not apparent after accounting for the smaller body weights of that group. No statistical differences were noted in the elimination half-life (t 1/2) of midazolam between European American and Japanese subjects. Much greater interindividual variability was observed after oral administration compared with intravenous administration, but significant differences were not found between the 2 groups with respect to the maximum midazolam plasma level or its oral clearance. Absolute oral bioavailability and its associated gastrointestinal and hepatic extraction ratios also showed no statistically significant interracial differences. CONCLUSIONS: On average, hepatic CYP3A, as measured by the metabolism of midazolam, is lower in young healthy Japanese men compared with similar European Americans. However, there is considerable interindividual variability, and body size appears to be an important determinant. After oral administration, even greater variability in the plasma level-time profile of midazolam is present, and no statistically significant or clinically important interracial/ethnic difference is present. Possibly because of smaller body mass and differences in body composition, midazolam has a smaller distribution volume(s) in Japanese men than in European American men that might be an important factor when drugs are administered intravenously.

[Clinical features of children with athetotic cerebral palsy in relation to their gestational age at birth].

We present here 38 patients with athetotic cerebral palsy who has trained in our clinic in recent 5 years. The mean age was 4 years and 4 months. In preterm cases, their gestational ages ranged from 27 weeks to 36 weeks, less than 31 weeks in 74%. MRI showed periventricular leukomalacia in 75%. Their clinical picture was mixed quadriplegia with athetosis and spasticity. Half of the cases were profoundly handicapped in motor ability. Fifteen cases had been born in term. Sixty percent of them had a non-mixed type of cerebral palsy. Five cases had no remarkable risk factor during the perinatal period. Six cases were able to walk with or without support. Hypoxic-ischemic encephalopathy was the main cause of athetotic cerebral palsy in recent years. Twin pregnancy was also an important risk factor, especially in preterm infants. MRI could detect lesions in the thalamus or the basal ganglia in only 17% of the 36 cases examined.

Role of CYP3A in haloperidol N-dealkylation and pharmacokinetics in rats.

Haloperidol (HP), an antipsychotic drug, is N-dealkylated by cytochrome P450 (CYP) to 4-fluorobenzoylpropionic acid (FBPA). The purpose of this study was to identify whether CYP3A metabolizes HP to FBPA in hepatic microsomes of rats and to investigate whether an inhibitor or an inducer of CYP3A affects HP pharmacokinetics in rats. The rate of FBPA formation was determined in hepatic microsomes from 8-week-old male Sprague-Dawley rats. Among several specific CYP isozyme inhibitors including troleandomycin (TAO), diethyldithiocarbamate, furafylline and quinine, only TAO showed marked inhibition of FBPA formation. Anti-rat CYP3A serum inhibited FBPA formation by 76.4%, while other anti-rat CYP sera (1A1, 1A2, 2B1, 2C11, 2E1) only slightly did. In a pharmacokinetic study, 8-week-old male Sprague-Dawley rats were given 0.5 mg/kg HP intravenously after treatment with 100 mg/kg erythromycin, a CYP3A inhibitor, or 80 mg/kg dexamethasone, a CYP3A inducer, intraperitoneally once a day for 7 days or 2 days, respectively or untreated. HP half-life was prolongated to 171% of the average control value by erythromycin and shortened to 49% of control by dexamethasone. HP clearance was reduced to 63% of control by erythromycin and was increased to 167% of control by dexamethasone. These results suggested that CYP3A mainly catalyzed HP to FBPA in rats, and the modification of this enzyme activity would affect the pharmacokinetics of HP.

Multiple cytochrome P-450 subfamilies are co-induced with P-glycoprotein by both phenothiazine and 2-acetylaminofluorene in rats.

We studied the effects of two P-glycoprotein (P-gp) inducers, 2-acetylaminofluorene (2-AAF) and phenothiazine (PTZ), administered intraperitoneally, on the activities and content of hepatic cytochrome P-450 (CYP) subfamilies in hepatic microsomes of Sprague-Dawley rats. After 4-day administration of 2-AAF or PTZ, the P-gp content was increased. The total CYP content after PTZ treatment was significantly increased compared with that of controls. The CYP1A, CYP2B and CYP3A2 contents were induced, while the CYP2C6, CYP2C11 and CYP2E1 contents remained unaffected. A marked increase in CYP1A1 was found after administration of each compound. Ethoxyresorufin O-deethylase, pentoxyresorufin O-deethylase, and testosterone 6beta hydroxylation activities showed a significant increase after both 2-AAF and PTZ treatments. In particular, ethoxyresorufin O-deethylase exhibited more than ten times greater activity than that of the controls after the treatments. These results suggest that P-gp inducers affect several CYP subfamilies in addition to CYP3A, which is reported to be up-regulated coordinately with P-gp by a CYP3A inducer.

Carbamazepine induces multiple cytochrome P450 subfamilies in rats.

We compared the effect of three different doses (30, 60, and 100 mg/kg) of carbamazepine (CBZ) administered intraperitoneally for 1, 3, and 7 days on the activity and protein content of hepatic cytochrome P450 (CYP) subfamilies in Sprague-Dawley rats. After 3-day- and 7-day administration with CBZ, the total CYP content had increased in a dose-dependent fashion. Among six enzyme activities examined, only aniline hydroxylase activity remained unchanged after 7-day treatment with CBZ. Pentoxyresorufin O-deethylase activity showed the most significant increase and was induced up to 7 days in a time-dependent fashion. Pretreatment of rats with cycloheximide significantly suppressed the pentoxyresorufin O-deethylase induction by one dose of 100 mg/day CBZ. Immunoblot analysis showed a significant correlation between the protein content of each isoenzyme examined and its activity except CYP2E1 after 7-day treatment with CBZ. Similar results were obtained in the mRNA levels of CYP subfamilies. These results suggested that CBZ may induce multiple CYP subfamilies, except CYP2E1, and the activity and the protein content of CYP2B showed the greatest increase with increased CYP2B mRNA.

Induction of hepatic CYP2B in foetal and neonatal rats after maternal administration of phenobarbital.

We examined hepatic cytochrome P450 (CYP) induction in rat foetuses and neonates by phenobarbital administered through placenta or breast feeding. In an intraperitoneal study, phenobarbital was administered intraperitoneally to mother rats once a day for 7 consecutive days before delivery. The livers were removed from foetuses, neonates, and mothers just before and 5 and 10 days after delivery. In oral administration study, water containing phenobarbital was given orally ad libitum from day 13 of pregnancy to 3 weeks after delivery (end of lactation). The livers were removed from neonates and mothers just before and one week after delactation. Phenobarbital administered intraperitoneally increased both the activity and the protein expression of CYP2B in 5-day-old neonates, even though the administration ended before delivery. This increase had disappeared in 10-day-old neonates. In mother rats, phenobarbital increased CYP2B just before and 5 days after delivery, while no increase was detected 10 days after delivery. Phenobarbital administered orally also increased both the activity and the protein expression of CYP2B of neonates and mothers during lactation and this increase also disappeared 1 week after delactation. Neither activity nor protein expression of CYP3A were induced in perinates at any age examined in either administration route. In mother rats, increase in CYP3A was found only just before delivery in the peritoneal administration study. Our results suggest that phenobarbital administered through placenta or breast milk transiently induces hepatic CYP2B in newborn rats but that the influence of phenobarbital does not last long.

Developmental changes in urinary elimination of theophylline and its metabolites in pediatric patients.

We investigated the developmental changes in the pattern of urinary metabolites of theophylline, a substrate for CYP1A2, to study when CYP1A2, which is absent in the perinatal period, fully develops during childhood. The urinary ratios of three metabolites (1-methyluric acid, 3-methylxanthine, and 1,3-dimethyluric acid) to theophylline in patients over 3 y of age show a much larger interindividual variation compared with those under 3 y of age, and the mean values of the ratios in patients over 3 y of age were greater than those in patients under 1 y of age. The urinary ratio of 1,3-dimethyluric acid (a metabolite generated by several cytochrome P450s) to 3-methylxanthine or 1-methyluric acid (metabolites generated by CYP1A2 exclusively) seemed to be relatively constant over 3 y of age; in patients under 3 y of age, these ratios were much higher than those in patients over 3 y of age. The urinary ratio of 1-methyluric acid to 3-methylxanthine or 3-methylxanthine to 1-methyluric acid seemed to be relatively invariable in all patients except those less than 1 y of age. These findings suggest that CYP1A2 activity may be programmed to mature by around 3 y of age and that CYP1A2 probably plays a major role in theophylline 8-hydroxylation at a therapeutic concentration after the full development of CYP1A2 activity.

Effects of glucocorticoids on pharmacokinetics and pharmacodynamics of midazolam in rats.

We investigated the effect of dexamethasone (80 mg/kg per day for 2 days) and prednisolone (600 mg/kg per day for 2 days, equivalent to dexamethasone for glucocorticoid (GC) potency) on both pharmacokinetics and pharmacodynamics of midazolam (MDZ), a substrate for cytochrome P450 (CYP) 3A, in 8-week-old male Sprague-Dawley rats. Animals received a single injection of MDZ (pharmacokinetic study, 10 mg/kg; pharmacodynamic study, 55.5 mg/kg) in the tail vein 24 h after the last dose of GC or placebo. The elimination half-life (t(1/2)) and the area under the concentration-time curve of MDZ were significantly reduced by pretreatment with dexamethasone to 58.9% and 44.7% of the control value, respectively, and the clearance of MDZ was significantly increased by dexamethasone. Similar changes observed by prednisolone pretreatment did not reach significance. The t(1/2) of the dexamethasone pretreatment group (14.4+/-0.7 min) was significantly shorter than that of the prednisolone group (20.9+/-1.5 min). The amount of CYP3A2 protein and the activity of erythromycin N-demethylase were significantly increased by dexamethasone and prednisolone pretreatments, but dexamethasone showed a greater effect than prednisolone. Sleeping time was significantly shortened by dexamethasone and prednisolone pretreatment to 38.7% and 57.1% of control value, respectively. The current study demonstrates that the anesthetic effect of MDZ would be reduced in patients treated with dexamethasone or prednisolone, and that the CYP3A induction was greater by dexamethasone than by prednisolone, implying that the potency of CYP3A induction may differ among GCs even when GC activity is the same.

Effects of anti-androgen treatment on the catecholamine synthetic pathway in the adrenal medulla of spontaneously hypertensive rats.

We investigated the effects of the antiandrogen flutamide on the activity of tyrosine hydroxylase, the levels of its encoding mRNA, and catecholamine levels in the adrenal medulla of male spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Flutamide (30 mg/kg) was administered subcutaneously daily (between 9 and 15 weeks of age). The systolic blood pressure of flutamide-treated SHR rats was lower than that of control SHR. Epinephrine and norepinephrine levels, tyrosine hydroxylase activity, and the levels of encoding mRNA in the adrenal medulla were significantly lower in flutamide-treated SHR rats than in paired controls. Systolic blood pressure, epinephrine and norepinephrine levels, tyrosine hydroxylase activity, and encoding mRNA in the adrenal medulla of WKY rats showed no significant differences between flutamide-treated and control groups. These findings suggested that flutamide may have cardiovascular effects through alteration of the catecholamine synthetic pathway caused by removal of androgen receptor stimulation on the expression of tyrosine hydroxylase in the adrenal medulla of male SHR rats.

Effects of sodium nitroprusside on the catecholamine synthetic pathway in the adrenal medulla of rats.

We studied the effect of sodium nitroprusside (SNP), a nitric oxide (NO) donor, on tyrosine hydroxylase (TH) activity and epinephrine and norepinephrine levels in the adrenal medulla of rats. TH activity and the levels of epinephrine and norepinephrine in the adrenal medulla of the SNP+nicotine (Nic)-treated group were increased significantly compared to those in the control, Nic-treated and SNP-treated groups. Furthermore, methylene blue inhibited this increase in TH activity. The data suggest that the NO derived from SNP may increase TH through the guanylyl cyclase pathway in the presence of Nic.

Liposteroid (dexamethasone palmitate) therapy for West syndrome: a comparative study with ACTH therapy.

Dexamethasone palmitate (liposteroid) was used for the treatment of West syndrome and compared with adrenocorticotropic hormone (ACTH) therapy. A single intravenous injection of liposteroid (0.25 mg/kg) was administered seven times in 3 months (total dosage = 1.75 mg/kg) to five symptomatic patients with West syndrome, aged 4-11 months. ACTH (0.025 mg/kg/day) was administered intramuscularly for 6 weeks according to the conventional therapy in Japan (total dosage = 0.625 mg/kg) to five symptomatic patients with West syndrome, aged 6-10 months. Nodding spasm and hypsarrhythmia on EEG disappeared in all patients in the liposteroid therapy group within four doses; however, partial seizures and focal spikes on EEG reappeared in three patients 2 months after the end of liposteroid therapy. In the ACTH therapy group, nodding spasm and hypsarrhythmia on EEG similarly disappeared during treatment in all patients, but nodding spasm reappeared 2 months after therapy in two patients and partial seizures reappeared in one patient 3 months after therapy. No notable adverse reactions occurred in the liposteroid group, but transient dysfunction of the thyroid and anterior pituitary gland and increased levels of serum cortisol were experienced in the ACTH group. These results suggest that glucocorticoid incorporated in a lipid emulsion is useful for the treatment of West syndrome.

Effect of hypoalbuminemia on the disposition of theophylline. Comparative study with Sprague-Dawley rats and a mutant Sprague-Dawley hyperlipidemic strain with hypoalbuminemia.

We demonstrated the effect of hypoalbuminemia on theophylline disposition in rats. The pharmacokinetic parameters in Sprague-Dawley rats (SDRs) were compared with those in spontaneously hyperlipidemic rats (HLRs), which had approximately one half the serum albumin concentration of the SDRs, after a single 10 mg/kg injection (iv) of theophylline. Theophylline clearance (CL) in the HLRs was increased 1.6-fold, and the AUC was decreased by 36%. Although the elimination t1/2 was not significantly different between the two types of rats, the distribution volume (Vd) was increased significantly in the HLRs, compared with the SDRs. The free theophylline concentration in the SDRs was one half of the total concentration. In contrast, the free theophylline concentration in the HLRs was approximately equal to the total concentration. The enzymatic activities and apoprotein expression levels of CYP1A were decreased significantly in the HLRs, compared with the SDRs. The total theophylline CL was increased in HLRs with hypoalbuminemia, even though they exhibited lower enzymatic activity and CYP1A expression than did the SDRs. Because the unbound fraction and Vd of theophylline in HLRs were much larger than those in SDRs, we conclude that hypoalbuminemia may contribute to an increase in the Vd and a decrease in the CL for theophylline.

[The clinical study of the first febrile convulsion in children with brain-damage].

Forty-nine patients with cerebral palsy, mental retardation, or other congenital neurological disorders who had experienced febrile convulsions and had no previous nonfebrile seizures were presented. They were followed for 1.6 years to 15 years (mean: 6.8 years) after the initial febrile convulsion. The incidence of subsequent epilepsy (two or more afebrile seizures) was 39%, and 80% of them developed epilepsy within 2 years after the first febrile convulsion. The paroxysmal discharges on EEG recorded prior to or after the first febrile convulsion did not predict the occurrence of later epilepsy. Also under 3 years of age, EEG findings led to the same result. There was no definite evidence that administration of anticonvulsive drugs prevented later epilepsy. Pre-existing neurological abnormality was identified as a risk factor for epilepsy, and was an indication of persistent medication. There is no clear prophylactic procedure against long-lasting attacks. Accordingly, medical therapy can be started when epilepsy has developed. Patients with very severe brain damage who could not move except lying comprised only 6% of all cases, and 69% of the epilepsy patients were well controlled. They showed a good prognosis as compared with children with brain-damage in general with epilepsy.

A comparison of hepatic cytochrome P450 protein expression between infancy and postinfancy.

We immunochemically measured the contents of 9 different cytochrome P450 (CYP) isoenzymes expressed in the liver and compared them between two groups: one group of 6 infant and 4 perinatal patients and one group of 10 patients after infancy (over 1 year old). CYP protein expressed in human liver can be divided into three groups on the basis of expression pattern: (a) CYP2A6, 2C9, 2D6, 2E1, and 3A were present in all samples and no difference was observed between the two groups; (b) CYP1A2, 2B6, and 2C8 were expressed more after infancy than during infancy; and (c) CYP3A7, which has been considered a major CYP enzyme in fetal liver microsomes, was expressed in all infants as well as the four perinatal patients, whereas it was detected in only 2 patients after infancy. These results implied that CYP2A6, 2C9, 2D6, 2E1, and 3A are already expressed during perinatal and infant period, while CYP1A2, 2B6, and 2C8 are expressed highly in subjects over 1 year old, and CYP3A7 disappeared after infancy.

A Japanese patient with X-linked alpha-thalassemia/mental retardation syndrome: an additional case report.

X-linked alpha-thalassemia/mental retardation syndrome (ATR-X) is characterized by severe mental retardation, wide range of minor abnormalities, and association with an unusual form of alpha-thalassemia. Fifty patients in Caucasian origin have been reported. This is the second report of the syndrome demonstrated in Oriental patients.

[A clinical study on children with cerebral palsy able to walk practically].

Forty patients with cerebral palsy, who had been trained in our clinic and attained to walk in recent 10 years, were presented. Forty-five percent of the patients had a history of preterm delivery, and another 45% had no causes suggestive of cerebral palsy. The mean age of the initiation of practical walk was 2 years and 2 months, and that of spastic hemiplegia was 1 year and 10 months. About 60% of the patients with spastic hemiplegia visited our clinic because of abnormal gait. Their brain CT and EEG showed a higher incidence of abnormality than those in other types of cerebral palsy. The type of cerebral palsy and their IQ (DQ) level had no correlation with presence of epilepsy. About 60% of the cases showed normal IQ (DQ) level. Seventy percent of school-aged children belonged to public school, but they received no special training for their physical handicaps. Therefore it was necessary for our hospital to offer them rehabilitation therapy.

The Costello syndrome: are nasal papillomata essential?

Two patients with the Costello syndrome are presented. One was a 7-year-old girl with a history of infantile hypotonia and feeding difficulties. The other was a 3 5/12-year-old boy with a history of neonatal sepsis and respiratory problems. Both had relative macrocephaly at birth, curly hair, large ear lobes, epicanthic folds, a low nasal bridge, thick lips, a short and wide nose, a short neck, a barrel chest, redundant skin, tight Achilles tendons, and pes equinovarus. Nasal papillomata, as described in Costello's two patients, were absent in both patients. Borochowitz et al. (1992) described five patients with what we interpreted as the Costello syndrome but without nasal papillomata. In view of these findings, nasal papillomata are not likely to be essential in the diagnosis of the Costello syndrome.