[Regional differences of in vivo proton MR spectroscopy in developing human brain]

The purpose of this study was to clarify regional differences in proton MR spectroscopy (1H-MRS) in the developing human brain. Proton MR spectra were obtained from 24 infants aged 0 to 24 months old. Proton MR spectroscopy was performed on a 1.5 Tesla clinical MR unit using a 3D-chemical shift imaging sequence (3D-CSI). MR spectra obtained from voxels in frontal white matter and those in parietal white matter were compared. The NAA/Cho ratios of the frontal region were lower than those of the parietal region at birth but increased rapidly during the first six months of life. The rate of increase was reduced in the second year of life. In contrast, NAA/Cho ratios in paracentral areas were already high at birth but increased slowly through the first two years of life. Cho/Cr ratios of the frontal region were stable during the first year of life and started to decrease in the second year of life. In the parietal region, Cho/Cr ratios were decreased throughout infancy. Regional differences in 1H-MRS spectra were apparent during infancy, and these differences were suggested to reflect regional differences in the maturation of the developing human brain.

Dependence of sonochemical luminescence on various sound fields

To understand the effect of the sound field on sonochemical luminescence, the exact sound pressure must be determined in each field. In this study it was determined by the Shlieren method, which measures the sound pressure without mixing the sound fields. We compared the efficiency of the sonochemical luminescence in three different ways: changing the diameter of the transducer, combining two transducers to obtain crossed propagating directions and surrounding the sound field by a glass cylinder. In the last case cylinders with various sizes were studied. We found that (i) at the same sound pressure, the larger transducer induces stronger luminescence per unit volume, (ii) driving two transducers produces stronger luminescence than the sum of each transducer and (iii) a glass cylinder surrounding the sound field induces stronger luminescence.

[A nevoid basal cell carcinoma syndrome with chromosomal aberration]

We reported a boy with nevoid basal cell carcinoma syndrome (NBCCS) with chromosomal aberration. He showed multiple jaw cysts, basal cell carcinomas, hypertelorism, macrocephaly and mental retardation. Cranial CT revealed calcification of the falx cerebri and tentorium cerebelli, and dilatation of the lateral ventricles. MRI showed a thin corpus callosum. A chromosomal study revealed a deletion of 9q21.31-q22.31. He had generalized tonic-clonic seizures, which were well controlled. Since the gene for NBCCS was recently mapped to chromosome 9q22.3, we suspected that the deletion site in this patient was responsible for his symptoms of NBCCS.

The nonpeptide alpha-eudexp6l from Juniperus virginiana Linn. (Cupressaceae) inhibits omega-agatoxin IVA-sensitive Ca2+ currents and synaptosomal 45Ca2+ uptake

Recently, the omega-agatoxin IVA (omega-Aga-IVA)-sensitive Ca2+ channel has been demonstrated to play an important role in the physiological neurotransmitter release in mammalian nerve terminals. In this study, we demonstrate that alpha-eudesmol from Juniperus virginiana Linn. (Cupressaceae) inhibits omega-Aga-IVA-sensitive Ca2+ channels in rat brain synaptosomes and cerebellar Purkinje cells. Thirty millimolar KCl-induced 45Ca2+ uptake into the synaptosomes was inhibited by omega-Aga-IVA but insensitive to omega-conotoxin GVIA (omega-CTX-GVIA, N-type Ca2+ channel blocker) and nicardipine (L-type Ca2+ channel blocker). We found that alpha-eudesmol concentration-dependently inhibited the above synaptosomal 45Ca2+ uptake with an IC50 value of 2.6 microM. Co-treatment with alpha-eudesmol and omega-Aga-IVA did not cause any additive inhibitory effect against the synaptosomal 45Ca2+ uptake. Using the whole-cell patch clamp electrophysiological technique, we further demonstrated that alpha-eudesmol concentration-dependently inhibited omega-Aga-IVA-sensitive Ca2+ channel currents recorded from Purkinje cells with an IC50 value of 3.6 microM. The current-voltage relationship of the omega-Aga-IVA-sensitive Ca2+ channel currents was not changed by alpha-eudesmol. On the other hand, alpha-eudesmol also displayed an inhibitory effect on N-type Ca2+ channel currents recorded from differentiated NG108-15 cells with an IC50 value of 6.6 microM. However, alpha-eudesmol had little inhibitory effect on L-type Ca2+ channel currents. Thus, the present data indicated that alpha-eudesmol is a potent nonpeptidergic compound which blocks the presynaptic omega-Aga-IVA-sensitive Ca2+ channel with relative selectivity.

A reaction kinetics model of water sonolysis in the presence of a spin-trap

The time development of the concentration of a spin-trapped OH radical was studied by electron spin resonance at various sound intensities and various 5,5-dimethyl-1-pyrroline N-oxide (DMPO) concentrations in water sonolysis. The lifetime of the spin-trapped OH radical was also studied, and factors governing sonolysis are discussed. We found that the production of spin-trapped OH radical increases with increasing ultrasound intensity. The lifetime of a spin-trapped OH radical decreases linearly with increase in sonication time. This result suggests that an unknown scavenger is produced by ultrasound. Based on the above results, we suggested a model of the reaction kinetics and estimated the production rate of OH radical from this model.

[Efficacy of continuous intravenous infusion of midazolam in the treatment of status epilepticus in children]

Midazolam infusion was tried as the treatment for 48 episodes of refractory status epilepticus or a cluster of seizures in 16 children. The mean age of patients was 3.5 years (range, 1 month to 18 years). Nine children had epilepsy, one purulent meningitis, one encephalitis, one acute cerebral infarction, and the remaining four had acute phase of hypoxic ischemic encephalopathy. The type of the seizure was a generalized tonic clonic seizure (including a partial seizure secondarily generalized) in 41 episodes, a tonic seizure in 3, an atypical absence in 1, and a complex partial seizure in 3, respectively. All patients received intravenous midazolam at 0.15 mg/kg as bolus, followed by a continuous infusion at 0.1-0.15 mg/kg/hr initially. The dose was increased gradually up to 0.3 mg/kg/hr until the complete control of seizures was achieved. Fourty-one of the 48 episodes of seizures were controlled within 30 minutes after the initiation of midazolam therapy. The mean infusion rate of midazolam required was 0.22 mg/kg/hr. The mean duration of the treatment was 4.1 days. None of the patients had serious changes in the blood pressure or respiratory status attributable to the use of midazolam. In conclusion, midazolam infusion is an effective and safe therapeutic approach for the management of childhood status epilepticus.

Recognition of DNA sequence utilizing osmium complex by amperometric technique

Recognition of DNA sequence utilizing tris-(bipyridyl)osmium(II/III) complex was studied, because the osmium complex interacted with double strand DNA specifically. In this result, double strand DNA (12-20 mer) could be recognized selectivity.

Interaction between tris(bpyl)osmium(II/III) complex and immobilized DNA on a carbon electrode

Interaction between (bipyridyl) osmium (II/III) complex and immobilized DNA on a carbon paste electrode was studied using cyclic voltammetry and chronocoulometry. The complex specifically interacted with immobilized double strand DNA (20 mer).

Binding position of tolbutamide to human serum albumin

The interaction between drugs (tolbutamide (1), 1-butyl-3-(methylsulfonyl)urea (2)) and human serum albumin (3) was investigated by equilibrium dialysis and NMR spectroscopy. The binding of 1 and 2 to 3 was concluded to be hydrophobic and hydrophilic, respectively, on the basis of the dependence of the binding constants on temperature, ionic strength, and chain length of fatty acid added. In 1H-NMR spectra of 1, there were no significant shifts with change in concentration or addition of 3. The spin-lattice relaxation time (T1) and spin-spin relaxation rate (1/T2) of the respective protons of 1 were independent of concentration, but depended on the concentration of 3 added. The binding position was determined from the ratio of 1/T2 of 1 bound to 3 and free 1. 1 and 2 were found to bind to 3 through the tolyl group and sulfonylurea group, respectively. The binding property of 1 was considered to be governed by the competition between the hydrophobic effect of the tolyl group and the hydrophilic effect of the sulfonylurea group in the molecule.

Oral-facial-digital syndrome type IX in a patient with Dandy-Walker malformation

We report a girl with oral, facial, and digital anomalies including multiple alveolar frenula, lobulated tongue with nodules, a posterior cleft palate, hypertelorism, a prominent forehead with a large anterior fontanelle, and postaxial polydactyly in both hands and the right foot, features compatible with the oral-facial-digital syndrome (OFDS). In addition, she had bilateral microphthalmia, optic disc coloboma, and retinal degeneration with partial detachment, thus establishing a diagnosis of OFDS type IX. Dandy-Walker malformation and retrobulbar cysts were observed on MRI. These additional malformations have not been reported in OFDS type IX. The frequent apnoeic spells which occurred immediately after birth were relieved after cystoperitoneal shunt implantation for hydrocephalus. Considering our case and previous reports of OFDS type IX, including two male sibs, a boy born to consanguineous parents, and three females, inheritance is probably autosomal recessive.

Effects of maternally administered immunoglobulin on platelet counts of neonates born to mothers with autoimmune thrombocytopenia: re-evaluation

OBJECTIVE

Since immunoglobulin is transported across the placenta, maternal administration of it theoretically seems attractive as an antenatal treatment for a fetus. However, the effects of antenatally administered intravenous immunoglobulin (IVIG) on fetal platelet counts have been controversial. Our series of 11 cases of idiopathic thrombocytopenic purpura (ITP) and a review of previous reports are presented. A combined retrospective analysis to know whether maternal response to IVIG is associated with improvement of fetal thrombocytopenia was conducted.

METHODS

IVIG was given to 11 steroid refractory pregnancies with ITP. Good maternal response to the therapy was defined as an increase in the platelet count to greater than 50 x 10(9)/L after completion of the IVIG infusion. Neonatal platelet counts of the umbilical cord were performed just after birth and followed-up for at least the first week of life.

RESULTS

Seven of the 11 neonates had thrombocytopenia of less than 100 x 10(9)/L, and two of them had severe thrombocytopenia of less than 50 x 10(9)/L. Two out of two neonates born to mothers with a good response to IVIG were thrombocytopenic; whereas five out of nine neonates born to mothers with a poor response were thrombocytopenic. The combined retrospective analysis of our results and published reports have shown that fetal thrombocytopenia was not associated with the maternal response to IVIG but with the level of immunoglobulin G of neonates at birth. Passive thrombocytopenia was more frequently observed in neonates with normal levels of immunoglobulin G than those with elevated levels.

CONCLUSION

This combined analysis confirmed the proposed hypothesis that the lack of effect of maternally administered IVIG on fetal platelet counts may mainly be attributed to the insufficient therapeutic level of transferred immunoglobulin G in the cord blood.

Setting up and features of a database of images of plastinated materials

A database of plastinated materials was set up and distributed with a CD-ROM on the Internet. A total of 197 specimens, prepared at the Medical Museum of the University of Tokyo between 1991 and 1995, were catalogued in the database on a personal computer with commercial and original software. The database was originally designed to catalogue anatomical specimens and drawings for curators and researchers, but it also services as a worldwide digital museum.

Schizostatin, a novel squalene synthase inhibitor produced by the mushroom, Schizophyllum commune. II. Structure elucidation and total synthesis

Schizostatin (1) has been isolated as a potent and selective inhibitor of squalene synthase. Its structure has been determined using spectroscopic methods: the compound is shown to be a diterpenoid which has a trans-dicarboxylic acid moiety. Total synthesis of schizostatin (1) was achieved by the highly regio- and stereoselective coupling reaction of an allylic bromide with a barium reagent. The Z-isomer 16 was also prepared using the stereoselective syn-addition of an organocopper reagent to acetylenedicarboxylate.

Muscle involvement in congenital insensitivity to pain with anhidrosis

A patient with congenital insensitivity to pain with anhidrosis, who had characteristic clinical features and biopsied sural nerve, is presented. Nerve pathology findings indicated a loss of the small myelinated and unmyelinated fibers. Biopsied muscle disclosed a marked variation in fiber size, some small fibers with central nuclei, and a small number of small angulated fibers, consistent with neurogenic and myogenic changes. Many patients with congenital insensitivity to pain with anhidrosis had muscle weakness and absent or decreased deep tendon reflexes with normal nerve conduction velocity. We confirmed that lack of small myelinated fibers in motor neurons resulted in a striking change of muscle in our patient.

[Knowledges of foodstuffs in relation to adult diseases in Japanese students--results from Japan Know Your Body Study]

As part of developing the Know Your Body (KYB) program for Japan, a questionnaire survey was administered assessing knowledge, attitudes, and behavior regarding cigarette smoking, alcohol drinking, dietary lifestyle and exercise. The subjects, about 13,000 in total, were students in elementary, junior and senior high schools in 9 prefectures. The main results concerning knowledge of foods that cause or prevent adult diseases are as follows: 1) Correct responses on the relationship of excessive salt intake and hypertension were made by 39% of males and 41% of female in the fifth grade of elementary school. In the third grade of junior high school, the percentage of correct answer for the same question increased to 80% of males and females, and in the third grade of senior high school, it rose to 90% of males and 91% of females. No clear sex difference was seen in all the grades of school. 2) Less than 23% of the students from the first to fourth grade of elementary school knew the word "cholesterol" and could distinguish high cholesterol foods. In the sixth grade of elementary school, more than 50% of students knew the word "cholesterol". In the third grade of junior high school, more than 50% of students could distinguish high cholesterol foods correctly and recognized the relationship of excessive cholesterol intake to heart disease. These results provide a basis for determination of the age for introducing nutrition education. 3) The percentage of correct answers for distinguishing green-yellow vegetables, showed a clear sex differential. The percentage of correct answers concerning dietary fiber was 75% for males and 81% for females in senior high school.

Aquastatin A, an inhibitor of mammalian adenosine triphosphatases from Fusarium aquaeductuum. Taxonomy, fermentation, isolation, structure determination and biological properties

A new inhibitor of mammalian adenosine triphosphatases, designated aquastatin A, has been isolated from a fungus identified as Fusarium aquaeductuum. The structure of this compound has been determined by MS and NMR analyses. It inhibits Na+/K(+)-ATPase with an IC50 value of 7.1 microM, and H+/K(+)-ATPase with an apparent IC50 value of 6.2 microM.

Lithocholate-3-O-glucuronide-induced cholestasis. A study with congenital hyperbilirubinemic rats and effects of ursodeoxycholate conjugates

The mechanism of lithocholate-3-O-glucuronide-induced cholestasis is unknown. In this study, we investigated the cholestatic effects of this agent in a congenital hyperbilirubinemic rat, EHBR. We also studied the effects of ursodeoxycholate-3-O-glucuronide and tauroursodeoxycholate on lithocholate-3-O-glucuronide-induced cholestasis in rats. Lithocholate-3-O-glucuronide, administered at the rate of 0.1 mumol/min/100 g for 40 min, a cholestatic dose in control rats, failed to cause cholestasis in EHBR, and biliary lithocholate-3-O-glucuronide excretion was delayed. Biliary concentrations of this agent did not correlate with the severity of cholestasis. Both tauroursodeoxycholate and ursodeoxycholate-3-O-glucuronide, infused at the rate of 0.2 mumol/min/100 g for 120 min, completely inhibited cholestasis induced by lithocholate-3-O-glucuronide administered at the rate of 0.1 mumol/min/100 g for 40 min. Only tauroursodeoxycholate enhanced biliary lithocholate-3-O-glucuronide excretion. These findings indicate that lithocholate-3-O-glucuronide-induced cholestasis is induced by damage at the level of the bile canalicular membrane. Ursodeoxycholate-3-O-glucuronide inhibits this cholestasis, possibly by inhibiting the access of lithocholate-3-O-glucuronide to the bile canalicular membrane.

Dehatrine, an antimalarial bisbenzylisoquinoline alkaloid from the Indonesian medicinal plant Beilschmiedia madang, isolated as a mixture of two rotational isomers

Through bioassay-guided separations of the chemical constituents of the Indonesian medicinal plant Beilschmiedia madang BL. a bisbenzylisoquinoline alkaloid was obtained as the major antimalarial principle. The physicochemical properties of the alkaloid were consistent with the proposed structure of dehatrine. However, the alkaloid isolated by us was shown to be a mixture of two rotational isomers. The X-ray crystallographic analysis of 1 has shown that two rotamers are incorporated in a single crystal in 1:1 ratio. The complex NMR spectrum of 1 has also been defined as a mixture of two rotamers by extensive use of 2D (COSY and COLOC) techniques. Dehatrine has been shown to significantly inhibit the growth of cultured Plasmodium falciparum K1 strain (cholorquine resistant) with similar activity to quinine.

Change of the higher order structure of DNA induced by the complexation with intercalating synthetic polymer, as is visualized by fluorescence microscopy

The electrophoretic movement and Brownian motion of T4DNA, lambda DNA and their complexes with polyacrylamide (PAAm) via intercalative unit from 5-[(4-acryloylamino)phenyl]-3-amino-7-(dimethylamino)-2-methylp henazinium chloride were observed using fluorescence microscopy. It was found that T4DNA/PAAm complex migrates slower than T4DNA alone in gel electrophoresis, although they exhibit similar conformational change during the migration. Quantitative analyses of the translational diffusion of the lambda DNA and its complex in solution demonstrate that the DNA molecules extend due to intercalative binding of PAAm, suggesting the pseudo-grafting structure of the complex.

Opposite effect between intercalator and minor groove binding drug on the higher order structure of DNA as is visualized by fluorescence microscopy

Fluorescence microscopy is applied to obtain the information on the change of the higher-order structure of giant DNA molecules in an aqueous solution. Using T4 DNA, it becomes clear that ethidium bromide, an intercalator, tends to extend the DNA, whereas minor groove binding drugs such as 4',6-diamidino-2-phenylindole and Hoechst 33258 tend to contract the DNA. These changes of higher-order structure have been quantitatively evaluated as the changes in persistent length together with the change of contour length. It is also confirmed that the persistent length obtained by use of fluorescence microscopy is reliable enough comparing with those reported for the shorter DNA by use of light scattering.

Effects of ursodeoxycholate, its glucuronide and disulfate and beta-muricholate on biliary bicarbonate concentration and biliary lipid excretion

We previously reported that high-dose ursodeoxycholate (UDC) infusion in rats resulted in extensive glucuronidation of UDC, and speculated that the glucuronidation causes bicarbonate-rich hypercholeresis induced by UDC (Takikawa, H., Sano, N., Narita, T. and Yamanaka, M. Hepatology 1990; 11: 743-749). To test this hypothesis, UDC, UDC-3-O-glucuronide, UDC-3,7-disulfate and beta-muricholate were separately and intravenously infused into rats (1 mumol/min per 100 g), and biliary bicarbonate concentration was measured. The effects of these bile acids on biliary lipid secretion were also studied. All four bile acids increased bile flow and biliary bile acid excretion. UDC and beta-muricholate significantly increased biliary bicarbonate concentration, whereas UDC glucuronide and disulfate did not. Independence of UDC glucuronide excretion and biliary bicarbonate concentration was also confirmed in EHBR, a hyperbilirubinemic mutant Sprague-Dawley rat. In this case biliary bicarbonate concentration also increased in spite of the absence of UDC glucuronide in the bile after UDC infusion. Biliary phospholipid secretion was increased with UDC, unchanged with beta-muricholate, and decreased with UDC glucuronide and disulfate. Biliary cholesterol secretion was increased with UDC, unchanged with beta-muricholate and UDC glucuronide, and decreased with UDC disulfate. These data indicate that glucuronidation is not the cause of bicarbonate-rich hypercholeresis induced by UDC but that glucuronidation and sulfation change the effect of UDC on biliary lipid secretion.

Direct observation of the biphasic conformational change of DNA induced by cationic polymers

The interaction between T4 DNA and basic polypeptides was observed using fluorescence microscopy. Free DNA molecules exhibited random Brownian motion accompanying the conformational change. With the addition of polycation, such as histone and polyarginine, DNA molecules tended to shrink to become spherical shapes. The persistent lengths and the distributions of long axis lengths of DNA-polyarginine complexes were determined from the video images at various polyarginine concentrations. It is demonstrated that the conformation of DNA changes in a biphasic manner in the presence of polyarginine.