Direct observation of depth-dependent atomic displacements associated with dislocations in gallium nitride

We demonstrate that the aberration-corrected scanning transmission electron microscope has a sufficiently small depth of field to observe depth-dependent atomic displacements in a crystal. The depth-dependent displacements associated with the Eshelby twist of dislocations in GaN normal to the foil with a screw component of the Burgers vector are directly imaged. We show that these displacements are observed as a rotation of the lattice between images taken in a focal series. From the sense of the rotation, the sign of the screw component can be determined.

Evidence of PCDD/Fs and PCBs contamination in trees grown in forests far from their production and contamination-free areas

Polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in trees grown in pathless forests were analyzed to investigate their dispersal patterns in the atmosphere. The pg/g levels of 23 PCCD, 22 PCDF, and 54 PCB congeners were identified. The total amount of PCDDs in the red pine tree sample (95.8 pg/g) was approximately 7 times that in the beech tree sample (13.2 pg/g). The total amount of PCDFs in the red pine tree sample (71.1 pg/g) was also approximately 7 times that in the beech tree sample (11.1 pg/g). The total amounts of PCBs in the red pine tree and beech tree samples were 1,380 and 1,150 pg/g, respectively. The (Cl1-Cl3)-PCBs comprised 63.1 % and 67.6 % of total PCBs in the red pine and in the beech, respectively. The results of the present study indicate that PCDD/Fs and PCBs are transferred over long distances in the atmosphere and accumulated in the contamination-free areas.

Significance of the non-oxidative route of the pentose phosphate pathway for supplying carbon to the purine-nucleotide pathway in Corynebacterium ammoniagenes

To evaluate the strategy of supplying ribose 5-phosphate to the purine-nucleotide pathway exclusively via the nonoxidative route, the glucose 6-phosphate dehydrogenase gene zwf was disrupted in inosine- and 5'-xanthylic acid-producers of Corynebacterium ammoniagenes. In both producers, interruption of the oxidative route caused a decrease in production yields of about 50%. Attempts to increase the capacity of the nonoxidative route through overexpression of the transketolase or transaldolase gene in the zwf mutants led to no discernable effects on production, indicating that, in C. ammoniagenes, the nonoxidative route alone cannot provide sufficient ribose 5-phosphate for high-level production, although nonoxidative synthesis of the precursor is possible.

Music therapy for children with Rett syndrome

The Rett syndrome is good reactivity for sound and music. We enforced active music therapy (MT) individual session to patients with Rett syndrome. The patients were 4, 5 and 6-year-old. The active music therapy and individual session of 30 min/week were performed. It was recorded in video and description, and using the original evaluation list, six items of fact. On largest problem that is hand operation with purpose in childhood of Rett syndrome, we recorded the longest duration and frequency of hand grasping time in one session. There was the improvement of 35.0% of listening music, 33.3% play music, 13.3% singing music, 11.7% minute motion, 11.7% language, and 20.0% personal relation and sociality. The longest duration of hand grasping time was improved from 2 to 12 s in case 2 and from 7 to 80 s in case 3. Grasp frequency which showed the volition rapidly increased from 3 to 41 times, though the elongation for the duration of grasping was little for case 2. Rett syndrome is the disease in which the psychomotor performance regresses with the age, but the aspect that surely developed in the session could be evaluated. Rett syndrome has the ability understanding the music, and music therapy is suitable for them.

Contrasting fates for 6-alpha-methylpenicillin N upon oxidation by deacetoxycephalosporin C synthase (DAOCS) and deacetoxy/deacetylcephalosporin C synthase (DAOC/DACS)

6-alpha-methylpenicillin N was synthesised via known routes from 6-aminopenicillanic acid, and tested as a substrate for recombinant DAOCS and DAOC/DACS. Incubation with DAOCS resulted in conversion of 2-oxoglutarate without oxidation of the penicillin substrate ('uncoupled turnover'). Incubation with DAOC/DACS resulted in oxidation to the cephem aldehyde. This is the first example of substrate-induced 'uncoupled turnover', which has been proposed to be an editing mechanism for these enzymes.

[Multidrug-resistant and fluoroquinolone-resistant Salmonella enterica serotype Typhimurium definitive phage type 12 isolated from infantile diarrhea]

A 35-day-old male infant was admitted to our hospital, presenting a high fever, vomiting, and diarrhea. Multidrug-resistant and fluoroquinolon-resistant Salmonella serotype Typhimurium was isolated from his stool. The phage type of the strain was DT12. The strain was resistant to ampicillin, streptomycin, gentamicin, tetracycline, chloramphenicol, sulfamethoxazole-trimethoprim, and fluoroquinolones (levofloxacin; MIC 8 micrograms/ml, norfloxacin; 24 micrograms/ml, ciprofloxacin; 16 micrograms/ml, sparfloxacin; 32 micrograms/ml). He was cured by antibiotic therapy using fosfomycin (< or = 1 microgram/ml). We could not determine a route of infection. Domestic surveillance for fluoroquinolon-resistant Sallmonella is necessary.

Effect of transketolase modifications on carbon flow to the purine-nucleotide pathway in Corynebacterium ammoniagenes

Transketolase, one of the enzymes in the nonoxidative branch of the pentose phosphate pathway, operates to shuttle ribose 5-phosphate and glycolytic intermediates together with transaldolase, and might be involved in the availability of ribose 5-phosphate, a precursor of nucleotide biosynthesis. The tkt and tal genes encoding transketolase and transaldolase, respectively, were cloned from the typical nucleotide- and nucleoside-producing organism Corynebacterium ammoniagenes by a PCR approach using oligonucleotide primers derived from conserved regions of each amino acid sequence from other organisms. Enzymatic and molecular analyses revealed that the two genes were clustered on the genome together with the glucose 6-phosphate dehydrogenase gene (zwf). The effect of transketolase modifications on the production of inosine and 5'-xanthylic acid was investigated in industrial strains of C. ammoniagenes. Multiple copies of plasmid-borne tkt caused about tenfold increases in transketolase activity and resulted in 10-20% decreased yields of products relative to the parents. In contrast, site-specific disruption of tkt enabled both producers to accumulate 10-30% more products concurrently with a complete loss of transketolase activity and the expected phenotype of shikimate auxotrophy. These results indicate that transketolase normally shunts ribose 5-phosphate back into glycolysis in these biosynthetic processes and interception of this shunt allows cells to redirect carbon flux through the oxidative pentose pathway from the intermediate towards the purine-nucleotide pathway.

Seasonal and spatial studies on pesticide residues in surface waters of the Shinano river in Japan

Water samples collected once a week from early April 1996 to the end of August 1996 from four sites on the Shinano River in Japan were analyzed for pesticides and their metabolites using a gas chromatograph-mass spectrometer. Among the total of 53 chemicals found, 22 were herbicides, 15 were insecticides, 11 were fungicides, and 5 were metabolites. The concentrations of chemicals found ranged from 3 ng/L (bromobutide) to 8200 ng/L (isoprothiolane). Herbicides were found primarily during May and June at all four sites. Insecticides and fungicides were found primarily during July and August at all four sites. The presence of pesticides in the river water correlated with the time of pesticide application to the rice fields near the river.

Formation of dioxins during the combustion of newspapers in the presence of sodium chloride and poly(vinyl chloride)

Exhaust gases from the combustion of newspaper alone, from branches of London plane tree alone, and from newspapers mixed with sodium chloride (NaCl), polyethylene, or poly(vinyl chloride) (PVC) were collected. The samples were analyzed for dioxins by gas chromatography/mass spectrometry. Total amounts of dioxins found in the samples were 0.186 ng/g from newspapers alone, 1.42 ng/g from the branches of London plane, 102 ng/g from newspapers impregnated with sodium chloride (CI wt % = 3.1), 101 ng/g from newspapers impregnated with sodium chloride mixed with PVC (Cl wt % = 2.6), and 146 ng/g from newspapers mixed with PVC (Cl wt % = 5.1). Samples with a higher chloride content produced more dioxins, and there is a clear correlation between dioxin formation and chloride content. The amount of dioxins formed in the samples according to the number of chlorides was Cl5 > Cl4 > Cl6 > Cl7 > Cl8 in PCDD isomers and Cl4 > Cl5 > Cl6 > Cl7 > Cl8 in PCDF isomers, except in the case of newspapers alone. Benzofurans composed 78-92% of the total dioxins formed in the exhaust gases. The higher the number of the chlorides, the lower the production of benzofuran observed. NaCl vaporized at the temperature of the flame used for combustion of the samples (760-1080 degrees C). The results indicate that NaCl and PVC contribute significantly to dioxin formation from waste materials combusted in incinerators.

Gas chromatographic-mass spectrometric determination of hydrophilic compounds in environmental water by solid-phase extraction with activated carbon fiber felt

Simple gas chromatographic-mass spectrometric determination of hydrophilic organic compounds in environmental water was developed. A cartridge containing activated carbon fiber felt was made by way of trial and was evaluated for solid-phase extraction of the compounds in water. The hydrophilic compounds investigated were acrylamide, N,N-dimethylacetamide, N,N-dimethylformamide, 1,4-dioxane, furfural, furfuryl alcohol, N-nitrosodiethylamine and N-nitrosodimethylamine. Overall recoveries were good (80-100%) from groundwater and river water. The relative standard deviations ranged from 4.5 to 16% for the target compounds. The minimum detectable concentrations were 0.02 to 0.03 microg/l. This method was successfully applied to several river water samples.

Bisphenol A in hazardous waste landfill leachates

The levels of bisphenol A in hazardous waste landfill leachates collected in Japan in 1996 were determined by gas chromatograph/mass spectrometer (GC/MS). Bisphenol A was found in seven of 10 sites investigated. All the hazardous waste landfills with leachates contaminated by bisphenol A were controlled. The concentrations of bisphenol A ranged from 1.3 to 17,200 microg/l with a median concentration of 269 microg/l. The source of bisphenol A in landfill leachates may be the waste plastics in waste landfill. The concentrations of bisphenol A in some samples exceeded the EC50 or LC50 levels for aquatic biota. Landfill leachates may be a significant source of bisphenol A found in the environment.

Dechlorination of hexachlorobiphenyl by using potassium-sodium alloy

2,2',4,4',5,5'-Hexachlorobiphenyl (HCB) was dechlorinated with potassium-sodium (K-Na) alloy under an inert gas atmosphere. Solvent effect was observed in the reaction. Dechlorination yields in benzene and cyclohexane were 99.9998%, and 99.99996%, respectively. The reaction was exothermic and proceeded at room temperature. In benzene, trace amounts of polychlorinated biphenyls (PCBs) as products by stepwise dechlorination and polychlorinated quarterphenyls as product of Wurtz-Fittig reaction were detected as reaction intermediate. Reaction products were biphenyl, cyclohexylbenzene, and dicyclohexyl. In cyclohexane, there were no products of Wurtz-Fittig reaction. Dechlorination at para-position preferred to that at ortho-position, judging from analysis of PCBs as intermediates of stepwise dechlorination.

Migration of organophosphorus insecticides cyanophos and prothiofos residues from impregnated paper bags to Japanese apple-pears (Pyrus pyrifolia nakai cv. Nijisseiki)

Bags impregnated with the organophosphorus pesticides prothiofos and cyanophos in three levels were used to cover Japanese apple-pears to protect them from insects. The amounts of prothiofos residue in the bags collected 4 months after application ranged from 0 to 34% of the amounts (81, 148, and 333 microg) found in the bags prior to a bagging. The amounts of cyanophos residue in bags collected 4 months after application ranged from 11 to 29% of the amounts (335, 2860, and 3740 microg) present prior to a bagging. Amounts of prothiofos found in fruits after 4 months ranged from 0 to 0.076 ppm. Amounts of cyanophos found in fruits after 4 months ranged from 0 to 0.011 ppm. Results of the present study indicate that these two pesticides migrated from pesticide-impregnated bags to fruits during the growing season.

Electrophysiological studies of a child with presumed botulism

Electrophysiological studies of a child with presumed botulism showed that the amplitude of the serially and electrically elicited blink reflexes Rl, R2 and R2' was reduced during recovery. These findings suggest a conduction block of the facial nerves. Other nerve conduction studies and an incremental response to repetitive stimulation demonstrated a block of the presynaptic neuromuscular transmission. Results of the biological tests were negative, but those of electrodiagnosis and clinical examination favored a diagnosis of botulism. A combination of electrically elicited blink reflexes and rapid repetitive stimulation of the peripheral nerves was found to be a sensitive method of assessing the integrity of neuromuscular junctions and the subclinical impairment of muscle nerves.

Successful control with bromide of two patients with malignant migrating partial seizures in infancy

A 3-month-old male and a 4-month-old female infant with intractable seizures were diagnosed as having malignant migrating partial seizures in infancy (MMPSI) with developmental arrest on the basis of characteristics of symptoms, clinical courses and EEGs. We treated these two patients with potassium bromide (80 mg/kg) after conventional antiepileptic drugs failed to adequately control the seizures. The potassium bromide therapy resulted in complete control of seizures in one patient, and more than 95% reduction in seizure frequency in the other.

New monitoring system for ninety pesticides and related compounds in river water by solid-phase extraction with determination by gas chromatography/mass spectrometry

A new monitoring system was established for the determination of 90 pesticides and 10 pesticide degradation products in river water. The pesticides consisted of 18 fungicides, 30 insecticides, and 42 herbicides. The pesticides were extracted with a solid-phase, styrene-divinylbenzene copolymer, eluted with acetone, hexane, and ethyl acetate, and determined by gas chromatography/mass spectrometry. Overall recoveries ranged from 72 to 118%. The limits of detection were 0.01-0.1 microgram/L. This system determines most of the pesticides used in Japan and was successfully applied to practical monitoring of water polluted with pesticides and related compounds.

[Development and evaluation of a photo-rhinometer for clinical use]

We developed a photo-rhinometer (PRM) which is a modification of the Glatzel nasal mirror, and which can promptly evaluate nasal patency under natural respiration without any facial apparatus. We also investigated the clinical applications of the PRM. In PRM operation, moisture deposits resulting from expiratory nasal flow onto a glass plate are visualized for the right and left nostrils separately with an image analyzing computer at a television scan rate of 1/30 of a second. These visualized moisture deposits are averaged over the initial 1 second and differentiated for the initial 90 milliseconds to obtain an average moisture deposit area (AMDA) and the velocity of the moisture deposit (VMD), respectively. The resulting PRM chart, a graphic presentation of the moisture deposit area versus time was expected to be useful for the visual evaluation of nasal patency. PRM measurements were performed on 100 adult volunteers who were selected without knowing whether they had any nasal symptoms or disorders. Results showed that statistical distributions of both AMDA and VMD were equivalent to the normal distribution. A significant correlation was observed between nasal conductance as determined by a rhinomanometer and AMDA as determined by the PRM, and also between the nasal conductance and the VMD, which is r = 0.66 and r = 0.78 respectively. In addition to the 100 cases, five cases of chronic sinusitis and ten cases of acute sinusitis, which had been conservatively treated, were investigated by using the PRM. In some of these cases where improvements in the nasal conditions and reduction of subjective nasal obstruction were recognized, increases in the AMDA and VMD showed a good correlation with improvements in the nasal disorder.

Quantities of bisphenol a leached from plastic waste samples

To quantify the leaching of bisphenol A into water, various samples of plastic waste were cut into small pieces, soaked in water for two weeks at room temperature in the dark, and the concentration of bisphenol A in the water determined by gas chromatography/mass spectrometry (GC/MS). The amount of bisphenol A leached from the plastic wastes ranged from undetectable to 139 micrograms/g. The detection limit was 2 ng/g when 100 g of plastic waste was used. Polyvinyl chloride products yielded the highest concentrations because bisphenol A is used in its manufacture as a stabilizer.

The effects of stimulus rates on the amplitude of median nerve somatosensory evoked potentials: the developmental change

We examined the effects of stimulus rates on the somatosensory evoked potential (SEP) amplitudes following median nerve stimulation at the wrist in 42 children. We divided these subjects into five groups according to their age (0-6 months, 7-12 months, 1-3 years, 4-6 years and more than 7 years) and measured the peak-to-peak amplitude of every component (N9, P10, N11, P13/14, N18, N20, P23, N30) at stimulus rates of 1.0, 3.5 and 5.5 Hz. From N9 to N18, there was no significant change in amplitude nor latency with stimulus rate change in all groups. The amplitude attenuation was found at the N20 and N30 peaks in the young group (0 months to 3 years) and at P23 in all groups with an increasing stimulus rate. The attenuation rate of P23 amplitude was influenced by the age of subjects, being greater in younger groups and greatest in the youngest group (0-6 months). The differences of amplitude attenuation rate between this group and the rest were statistically significant. The results of this study indicate that the amplitudes of the cortical components of SEP in children are greatly influenced by the stimulus rate. Thus when we discuss the amplitude of cortical waves in childhood, we should also pay attention to the stimulus rates.

[Somatosensory evoked potential (SEP) to posterior tibial nerve stimulation in children with cerebral palsy]

We investigated the possible usefulness of SEP to the posterior tibial nerve in children with cerebral palsy. Sixty-four children with cerebral palsy, aged between 6 months to 20 years, were studied. Twelve patients had hemiplegia (H), 24 spastic diplegia who were able to walk (SDW), 17 spastic diplegia who were impossible to walk (SDNW) and 11 spastic quadriplegia (SQ), respectively. We also studied with 40 normal controls. Informed consent was obtained from subjects and parents. A significant difference was found in an appearance rate of P37 between the control and cerebral palsy groups. Absent and shortening of P37 were recognized in 10 among 18 recordings in the paralytic side of patients with hemiplegia. The central conduction time was shortened gradually with age in the control group. There was difference in the central conduction velocity between SDW, SDNW or SQ. These results suggested that P37 was the first cortical response, and that it was useful for the diagnosis of cause of paralysis.

Infantile spasms associated with a histamine H1 antagonist

Some anti-allergic agents act as histamine H1 antagonists and induce seizure discharges in epileptic patients. Of these agents, ketotifen has an especially potent effect. We have experienced 2 cases of 4-month-old boys who developed infantile spasms 8 to 10 days after ketotifen administration. They showed almost the same clinical course with regard to their age, the interval between ketotifen administration and the onset of seizures, their symptoms and EEG abnormalities. These cases suggest that the administration of ketotifen to young infants may be hazardous with regard to inducing infantile spasms.

Comparison of distortion product otoacoustic emissions with auditory brain-stem response for clinical use in neonatal intensive care unit

OBJECTIVES

This study compares the clinical usefulness of distortion product otoacoustic emissions (DPOAEs) with the auditory brain-stem response (ABR) for neonates in the neonatal intensive care unit for the evaluation of hearing impairment.

METHODS

Both DPOAEs and ABR were performed on 36 neonates (67 ears) on the same day. We defined neonates as having normal hearing when the thresholds of wave V of ABR were < or =45 dB hearing level.

RESULTS

(1) We could not obtain DPOAEs at f2 = 977 Hz in neonates with normal hearing because of high noise floors. DPOAE recording time was 36 min shorter than that of ABR. (2) We defined as normal DPOAEs, the number of frequencies which showed the DPgram-noise floor > or =4 dB was > or =4 at 6 f2 frequencies, from 1416 Hz to 7959 Hz. (3) Normal thresholds of ABR and normal DPOAEs showed the same percentages, i.e. 68.7%, but the percentage of different results between ABR and DPOAEs was 6.0%.

CONCLUSIONS

Our study indicates that DPOAEs represent a simple procedure, which can be easily performed in the NICU to obtain reliable results in high-risk neonates. Results obtained by DPOAEs were comparable to those obtained by the more complex procedure of ABR.

PCDD, PCDF, planar and other PCB levels in human milk in Japan. off

26 human milk samples in Japan were individually analyzed for PCDDs, planar and other PCB. Mean total concentrations of PCDDs planar and other PCBs were 8.5 pg/g, 8.8 pg/g and 5.5 ng/g of whole milk, respectively. TEQs were calculated using International-TEFs(I-TEFs) for PCDDs/Fs and TEFs proposed by the WHO for planar PCBs. Mean total TEQs of PCDDs and planar PCBs were 0.48, 0.63 and 0.39 pg/g of whole milk, respectively. These values were similar to those of other industrialized countries.

When do brain abnormalities in cerebral palsy occur? An MRI study

The authors used MRI to analyse retrospectively the brain images of patients with cerebral palsy (CP) to evaluate its the role in the assessment of brain abnormalities and injury, and the relationship of pre-, peri- and postnatal events to CP. 70 patients with CP aged two to 16 years who underwent MRI were divided into four groups: group 1 (26 patients) comprised subjects whose CP was considered to have been caused by neuronal migration disorders in the embryonal stage; group 2 (30 patients) contained subjects whose cause was vascular disorders; in group 3 patients (five) the cause was intra-uterine infection; and CP clearly attributable to birth asphyxia (group 4) was noted in only nine patients. The results indicate that CP of term infants is often the result of prenatal factors, and their MRI findings indicated migration and cerebral infarction. Brain MRI is an essential examination in identifying the factors causing brain damage in CP.

[Developmental changes of central conduction time of evoked potentials in infants and children]

We investigated the developmental changes of the central conduction time (CCT) of the median nerve somatosensory evoked potential (SEP) and the auditory evoked potential (ABR): SEP was recorded in 148 children and adults, and ABR in 307 subjects. We determined the rostral CCT (CCT 1:P 14 to N 17) and the caudal CCT (CCT 2:N 17 to N 19), because the central sensory tract was long, and included the spinal tract, brainstem, thalamus and cerebral cortex. The greatest changes in CCT of SEP occurred during early infancy (0 to 6 months of age). The latency of SEP gradually decreased with maturation. CCT 2 showed similar developmental patterns and was longer than CCT 1 during 0 to 4 months of age. Developmental changes in CCT 1 linearly decreased as age increased. The CCT of ABR also decreased as age increased. The maturation of I-III interpeak latency (IPL) (2 years of age) was earlier than the III-V IPL (3 years of age). The maturation of both ABR and SEP was seen from the rostral to caudal direction. The correlation coefficients of CCT, CCT 1 and CCT 2 divided by body height were 0.86, 0.77 and 0.69, respectively. They were higher than non-divided correlation coefficients. CCTs of the short latency SEPs were also related to body height.

Steady-state auditory evoked potentials (SSAEPs) in the rabbit. Contribution of the inferior colliculus

Steady-state auditory evoked potentials (SSAEPs) were recorded in rabbits with both surface and depth electrodes. Surface recording from the bregma provided the largest and most typical SSAEPs as compared to other surface locations when a stimulus rate of 50 Hz was used. The medial geniculate body (MGB) showed no potential corresponding to the surface SSAEP. On the other hand, the latency of SSAEP in the inferior colliculus (IC) corresponded closely to that of the surface potential. Furthermore, the amplitude of the IC potential tended to become large with the stimulus rate of 50 Hz as compared with transient stimuli. Although other auditory nuclei in the brain-stem, the ventral nucleus of the lateral lemniscus, the trapezoid body and the auditory nerve responded to transient stimuli with an amplitude larger than that of the IC, no amplification occurred with 50 Hz stimuli in these nuclei. These findings suggest that the IC contributes to the generation of SSAEP to a great extent.

The blink reflex in neonates with a subsequent poor outcome

We examined maturational changes in the electrical blink reflex in 11 handicapped children, i.e., 4 cases of developmental delay, 4 of cerebral palsy, 2 of congenital hydrocephalus, and 1 of congenital cytomegalovirus infection. The developmental delay and cerebral palsy cases were all born at 25-36 weeks' gestation. In all cases, prolonged latency, low amplitude, or the absence of the late component of the blink reflex was observed in the follow-up study. These results indicate that prematurity and some congenital impairment mainly influence the maturation of the long-loop reflex arc in the blink reflex.

Oscillatory potentials of visual evoked potentials using source derivation technique in rabbits

The topographic distribution of epidurally recorded flashed visual evoked potentials (VEPs) in unanesthetized rabbits was studied using 2 montages. VEPs with linked ears reference and source derivation were compared. With the linked-ears reference, N34 of VEPs which consisted of slow potentials and superimposed oscillations were recorded diffusely over the head. When source derivation was used, the slow negative potentials of N34 present on the recordings in P3 and P4 were not obtained in F3, Fz and F4. In a digital filtering study of the oscillatory potentials, N34 in oscillatory potentials which were recorded diffusely over the head were localized to the visual cortex by source derivation. It was concluded that N34 in the oscillatory potentials generated from the visual cortex are enhanced and localized with source derivation.

MRI of the head in the evaluation of microcephaly

Fifty-five patients with microcephaly (head circumference < -2SD) were identified. The 55 patients were divided into two groups, consisting of group 1 (34 cases) in which genetic causes were considered primary, and group 2 (21 cases) in which intrauterine and/or postnatal acquired factors were thought to be responsible. MRI abnormalities were present in 80% of the total series: 68 and 100% in groups 1 and 2, respectively. In group 1, migration abnormalities were the most prominent and mental retardation was the major neurological handicap, while in group 2, hydranencephaly and infarction secondary to brain circulatory derangements were the most frequently observed abnormalities, with severe multiple handicaps such as cerebral palsy, epilepsy and mental retardation seen. Head MRI was considered indispensable in the investigation of the causes of microcephaly and in determining the neurological prognosis of affected patients.

[Statistical analysis on the cases of thyroid papillary carcinoma]

Statistical analysis was performed on the postoperative recurrence of forty four patients with thyroid papillary adenocarcinoma, who underwent radical surgery in the Department of Otolaryngology, Hamamatsu University Hospital from January 1978 to March 1991. In this study, we defined a new factor called "Operative Radicality index (OR index)" and analyzed the data with a multivariate analysis (Cox model). The result showed that the risk of postoperative recurrence was significantly affected by the age, the size of tumor and the OR index. The postoperative five-year cumulative recurrence rate was approximately 10% in the group of patients whose lateral neck regions were systematically dissected only when any metastatic lymph nodes were clinically detected within the region, in addition to the routine anterior neck dissection, and 70% in the group of patients whose metastatic lymph nodes in the lateral neck region were partially removed, but 6% in the group of N0 patients who did not undergo lateral neck dissection because no nodal metastases were detected even in the operative findings. Considering the quality of postoperative life, we concluded that in the primary surgery for the thyroid papillary adenocarcinoma, the lateral neck dissection should be applied to only the regions with metastatic nodes detected preoperatively or during operation, in addition to the routine anterior neck dissection. And the OR index was useful for the statistical analysis with regard to the policies of treatment and the prognosis.

Angelman syndrome in three siblings: characteristic epileptic seizures and EEG abnormalities

Neurologic findings in 3 siblings with Angelman syndrome (AS) with apparently normal karyotype but DNA deletion of 15q11-q12 deriving from their mother are described. Increased auditory brainstem response (ABR) thresholds were noted in all 3. Interictal EEG findings included periodic 2- to 3-Hz high-voltage slow wave bursts bioccipitally and sporadic slow spike wave complexes mainly bifrontally. EEG findings suggestive of minor epileptic status were apparent in the elder brother and may be a characteristic feature in young AS patients. Seizures suggestive of generalized epilepsy have been reported in 90% of AS patients. AS is considered a good model of symptomatic generalized epilepsy associated with chromosomal DNA deletion of the (GABA)A receptor beta 3-subunit gene.