Heart-rate variability during nocturnal sleep in mentally retarded children

Heart-rate variability in four normal and 30 mentally retarded children was investigated during nocturnal sleep. In four normal and 25 mentally retarded subjects, a high frequency component defined as spectral activity between 0.15 and 0.5 Hz was found in the compressed spectral array of the power spectra. A periodic change was seen in the high frequency component which corresponded precisely to the sleep cycle. However, four children with mental retardation did not show normally expected changes in the high frequency components specific to the sleep stages: a quantity of the high frequency component in only one sleep cycle (n=2; 6 mo. and 3 yr., 8 mo.), a decreased quantity and discontinuity of the high frequency component in only the second sleep cycle (n=1; 1 yr., 2 mo.), and no high frequency component in any sleep cycle (n=1; 3 mo.) These findings suggest that some mentally retarded children have an abnormal parasympathetic nervous activity.

Cambial reactivation in locally heated stems of the evergreen conifer Abies sachalinensis (Schmidt) masters

A study was made of cambial activity, the localization of storage starch around the cambium, and the localization and occurrence of microtubules in cambial cells from dormancy to reactivation in locally heated (22-26 degrees C) stems of the evergreen conifer Abies sachalinensis. Heating induced localized reactivation of the cambium in the heated portions of the stem. Erect ray cambial cells resumed cell division 1 d prior to the reactivation of fusiform cambial cells and procumbent ray cambial cells. The re-initiation of the division of fusiform cambial cells occurred first on the phloem side. During the heat treatment, the amount of storage starch decreased in procumbent ray cambial cells and in the phloem parenchyma adjacent to the cambium but increased in fusiform cambial cells. Preprophase bands of microtubules, spindle microtubules and phragmoplast microtubules were observed both in erect ray cambial cells and in procumbent ray cambial cells. By contrast, no evidence of the presence of such preprophase bands of microtubules was detected in fusiform cambial cells. The results suggest that the localized heating of stems of evergreen conifers might provide a useful experimental model system for studies of the dynamics of cambial reactivation in intact trees.

Baseline respiratory sinus arrhythmia and heart-rate responses during auditory stimulation of children with attention-deficit hyperactivity disorder

During passive and active listening tasks baseline respiratory sinus arrhythmia and heart-rate responses were studied of 18 children with Attention-Deficit Hyperactivity Disorder (ADHD) and 49 healthy school children. The experimental procedure included baseline recording (no task), a passive listening task, instructions, and both simple and discriminative active-listening tasks. ADHD subjects showed less respiratory sinus arrhythmia than normal children but were similarly responsive to tone stimuli.

Age differences in characteristics of the attention process of electrodermal activity during auditory stimulation

Age differences in characteristics of the attention process of electrodermal activity during passive and active listening tasks were studied with 43 nursery and 49 primary school children and 38 university students. The procedure included baseline recording, a passive listening task, instruction, and an active listening task. Significant differences in skin conductance response (SCR) were found among the three age groups. The SCR became smaller for the groups of increasing ages only for the active listening task. As the trials progressed, there was a trend in the three age groups for decreasing SCR amplitude during the passive listening task.

Use of running exercises for preschoolers with mental retardation as a means of improving play or school activity

Various physical training programs have been devised to achieve greater physical fitness for handicapped children who otherwise exercise insufficiently. Such training may also facilitate socializing and play at school. Running exercises were conducted with 4 handicapped preschoolers and 3 age-matched normal preschoolers for 3 30-min. sessions per week for 11 weeks. Measures were seconds taken to run 25 meters and ratings of play behavior. Analysis showed that children who reluctantly joined the exercise made little progress in running. The quality of movement and play activities in nursery school and interactive behavior improved significantly for participants who also improved in running.

Attention state in electrodermal activity during auditory stimulation of children with attention-deficit hyperactivity disorder

Electrodermal activity during passive and active listening tasks of 18 children with Attention-Deficit Hyperactivity Disorder (ADHD) and 49 healthy school children was studied. The procedure included baseline recording, a passive listening task, instructions, and both simple and discriminative active-listening tasks. ADHD subjects tended to exhibit lower arousal as indicated by the decrease in amplitude of the skin conductance response. Present findings confirm classical observation that ADHD children have shorter attention spans.

Antipromoting effects of 5-lipoxygenase inhibitors, 3-nitro-2,4,6- trihydroxybenzamide derivatives, on TPA-promoted transformation in BALB 3T3 cells

In order to discover the role in the promotion process of 5-lipoxygenase (5-LO), a key enzyme in the arachidonate cascade, the antipromoting effects of the 5-LO inhibiting 3-nitro-2,4,6-trihydroxybenzamide (NTB) derivatives were studied in a two-stage transformation assay system using BALB 3T3 cells. All compounds inhibited TPA-promoted transformation in a dose-dependent manner. Most of them achieved a 70-80% inhibition. Good correlations were observed between the inhibition of TPA-promoted transformation and that of 5-LO. These results indicate that 5-LO plays an important role in the promotion stage of the transformation of BALB 3T3 cells.

Inhibitory effects of 3-nitrophloroglucinecarboxylic acid derivatives on Epstein-Barr virus early antigen induction

The inhibitory effects of two series of 3-nitrophloroglucinecarboxylic acid derivatives, 3-nitro-2,4,6-trihydroxythiobenzamides (II) and 3-nitro-phloroglucinecarboxylates (III), on Epstein-Barr virus early antigen (EBV-EA) induction were examined using Raji cells. Some of them strongly inhibited the induction, N-nonyl and O-decyl derivatives being the most potent inhibitors among the thioamides and esters, respectively. These results suggest the possibility that these two 3-nitrophloroglucinecarboxylic acid derivatives may be listed as novel inhibitors of tumor promotion.

Effects of attention state on electrodermal activity during auditory stimulation of children

During passive and active listening tasks electrodermal activity of 49 healthy school children was studied. The procedure included baseline recording, a passive listening task, instructions, and simple and discriminative active-listening tasks. On the passive task from Trials 1 to 10, habituation of the amplitude of the skin conductance response (SCR) occurred. Habituation of SCR amplitude did not occur during the active tasks. The children seemed to pay more attention during the active tasks than during the passive task, since the need to press the key is apt to require and may even increase general attention. As for temporal variables of SCR, the frequency of spontaneous SCRs showed a significant negative correlation with SCR latency and rise time. Reaction time exhibited a significant negative correlation with age. An increase in reaction time was found during the discriminative active-listening task over that for the simple active-listening task during the course of 10 trials. The younger children (6-8 yr.) seemed to require longer to pay attention than the older ones (10-12 yr.). Children seemed to pay more attention during the discriminative than during the simple active-listening task, since the need to press the key for discrimination should require and is likely to increase general attention.

Inhibitory effects of 3-nitro-2,4,6-trihydroxybenzamides on Epstein-Barr virus early antigen induction

Inhibitory effects of a series of 3-nitro-2,4,6-trihydroxybenzamides on Epstein-Barr virus early antigen (EBV-EA) induction were examined using Raji cells. Some of the tested compounds showed highly inhibitory activity, the N-octyl amide derivative being the most active among them. These results suggest the possibility that 3-nitro-2,4,6-trihydroxybenzamides might be listed as novel inhibitors of tumor promotion.

Attention of preschool children: temporal variation of electrodermal activity during auditory stimulation

Temporal variation of electrodermal activity during passive and active listening tasks of 43 healthy preschool children was studied. The procedure included the baseline recording, a passive listening task, instruction, and an active listening task. The frequency of spontaneous skin-conductance responses (SCRs) showed a significant negative correlation with SCR latency and rise time. Mean SCR amplitude, moreover, displayed a significant negative correlation with the SCR latency and rise time. Reaction time exhibited a significant negative correlation with age. A decrease in the SCR latency was noted during the active listening task below that for the passive listening task over 10 trials. The children seemed to pay more attention as SCR latency and rise time decreased, and the younger children seemed to pay attention later than the older ones. Children seemed to pay more attention during the active than during the passive listening tasks, since the need to press the key should require and perhaps increase general attention.

Attention of hyperactive preschool children--electrodermal activity during auditory stimulation

Electrodermal activity during passive and active listening tasks for 4 hyperactive (from 3 yr., 9 mo. to 6 yr., 2 mo.) and 43 healthy preschool children (from 4 yr., 8 mo. to 6 yr., 5 mo.) was studied. The procedure consisted of the following phases: baseline recordings (3 min.), a passive listening task, instructions, and an active listening task. The hyperactive subjects tended to exhibit lower levels of arousal, as indicated by the frequency of spontaneous responses, and more marked habituation with repeated stimuli. Also, they tended not to show the increased responsivity expected when attention is active rather than passive. Hyperactive preschool children, moreover, are believed to have shorter attention spans.

Attention of preschool children: electrodermal activity during auditory stimulation

Electrodermal activity during passive and active listening tasks of 43 healthy preschool children (aged 4 yr., 8 mo. to 6 yr., 5 mo.) was studied. The procedure included the following phases: baseline recording (3 min.), a passive listening task, instructions, and an active listening task. An increase in mean amplitude of skin conductance response (SCR) was found during the active listening task over the level for the passive listening task over 10 trials. On the passive listening task from Trial 1 to Trial 10, habituation of mean SCR amplitude occurred. The younger children, moreover, exhibited significantly greater habituation than the older children. Habituation of mean SCR amplitude did not occur during the active listening task. No significant difference was found in mean SCR amplitude during the active listening task for the two age groups. The children seemed to pay more attention during the active listening task than during the passive listening task. The younger children, moreover, are believed to have shorter attention spans.

The three different phases of reticuloendothelial system phagocytic function in rats with liver injury

In the present study, reticuloendothelial system (RES) phagocytic function of rats with partial hepatectomy or experimentally induced liver cirrhosis was investigated by determining the phagocytic index, the opsonic index, and uptake rate in liver, spleen, and lung of a 51Cr-labeled endotoxin-injected rat. In both the partially hepatectomized and the cirrhotic rats, all three indicators varied markedly according to the elapsed period since liver injury. The changes in RES phagocytic function were classified into three different phases: compromised, compensatory, and enhanced. The compromised phase, consisting of a decrease in the phagocytic index, was observed during the first 24 hr after 67% hepatectomy and in advanced liver cirrhosis. This represented the failure of RES phagocytic function. The compensatory phase, in which the phagocytic index was maintained at nearly normal levels mainly by a compensatory enhancement in the opsonic index, was seen during the first to second postoperative day and in moderate liver cirrhosis. The enhanced phase, with a high phagocytic index, was observed from Day 4 to approximately Day 14 after surgery, and in the cases of mild liver damage. In the compromised and compensatory phases, the liver uptake rate was significantly decreased compared with the control. However, the uptake in the spleen and lung were markedly increased. In conclusion, the phagocytic function of the RES was significantly affected to a degree which changed with the extent of liver damage.

Developmental disorders of skin potential responses in mentally retarded children during nocturnal sleep

Skin potential responses (SPRs) of 89 mentally retarded children were studied during their nocturnal sleep. Forty-three out of the 89 subjects showed more SPRs (type A) during NREM sleep than in REM sleep. The opposite was observed in 10 cases (type C), and 4 had evenly distributed SPRs during both sleep phases (type B). The remaining 32 subjects had mixed types AB (n = 19), AC (n = 6) or BC (n = 7). Types B and C (including the mixed type) were observed more frequently for subjects with low developmental quotient (DQ) and abnormal clinical EEGs than for those with high DQ and normal clinical EEGs. Since it has been well established that normal subjects of 3 months and over exhibit exclusively type A, SPRs may be used as an additional tool for the diagnostic assessment of mental retardation in early infancy.

REM sleep latency during nocturnal sleep in mentally retarded infants

REM sleep latency observed in 61 mentally retarded infants (4-13 months of age) was studied throughout nocturnal sleep. Mentally retarded infants revealed a J distribution of short (less than 8 min) and long (more than 8 min) REM sleep latencies. This feature of distribution was similar to that obtained by other authors from normal infants under 3 months of age. REM sleep latency did not depend on the duration of prior wakefulness. Long REM sleep latencies were no more often preceded by long episodes of wakefulness than were short REM sleep latencies. No correlation was found between REM sleep latency and age, developmental quotient or daytime clinical EEG abnormalities.

Correlation between delta and spindle components in compressed spectral array during nocturnal sleep in mentally retarded children

The correlation between the delta and spindle components in compressed spectral array in 96 mentally retarded children (from 3 months to 12 years of age) was studied throughout nocturnal sleep. In 57 (59.4%, group A) of 96 subjects, periodic changes of delta and spindle rhythm powers were noted in sleep EEG. In 29 subjects (30.2% group B), delta but not spindle rhythm powers were found, and in the remaining 10 subjects (10.4%, group C) neither delta nor spindle rhythm powers were found throughout nocturnal sleep. A significant increase in abnormal clinical EEG was found in groups B and C as compared with group A. A significant decrease in the developmental quotient (DQ) was found in groups B and C as compared with group A. A significant decrease in DQ was also found in group C as compared with group B.

Delta and spindle components in compressed spectral array during nocturnal sleep in infants with cerebral palsy

The correlations between the delta and spindle components in compressed spectral array in 21 mentally retarded children with cerebral palsy (CP) (from 4 months to 5 years of age) and 32 reference mentally retarded children of no abnormality with the exception of psychomotor retardation (from 4 months to 12 years of age) were studied throughout nocturnal sleep. In 11 (52%) out of 21 CP cases and 27 (84%) out of 32 reference cases, periodic changes of delta and spindle rhythm powers were noted in sleep EEG (group A). In 5 (24%) other cases in CP and 5 (16%) reference cases delta but not spindle rhythm powers were found (group B), and in the remaining 5 (24%) CP cases neither delta nor spindle rhythm powers were found throughout nocturnal sleep (groups C). A significant decrease in the developmental quotient (DQ) was found in group C as compared with group A in both CP and reference cases. Moreover, a significant decrease in DQ was also found in group B as compared with group A of reference cases.

Delta and spindle components in compressed spectral array during nocturnal sleep in infants with congenital cerebral malformation

The correlation between the delta and spindle components in compressed spectral array in 18 infants with congenital cerebral malformation (from 4 months to 4 years of age) was studied throughout nocturnal sleep. In 7 (39%, Group A) out of 18 subjects, periodic changes of delta and spindle rhythm powers were noted in the sleep EEG. In 5 subjects (28%, Group B), delta but not spindle rhythm powers were found, and in the remaining 6 subjects (33%, Group C) neither delta nor spindle rhythm powers were found throughout nocturnal sleep. A significant decrease in the developmental quotient was found in group C as compared with group A.

Nocturnal sleep in infants with congenital cerebral malformation

Sleep EEG patterns in 17 infants with cerebral malformations (4 months to 4 years of age) were studied throughout nocturnal sleep and the following results were obtained. Seven cases evidenced normal sleep/wakefulness EEG patterns that could be classified into 6 stages. Ten cases showed abnormal sleep EEG patterns as follows: absence of sleep spindles (n = 7) which included cases of absence of EEG patterns characteristic of wakefulness, NREM sleep and REM sleep (n = 5), no characteristic EEG patterns of stages 1-4 (n = 1) and stages W, 1, 2 and REM (n = 1) and the remaining cases with absence of spindles (n = 1), and spindles with an extremely low incidence (n = 2). Short sleep and long awaking times, and no delta rhythmicity during the night, were noted in 5 out of 17 subjects. A significant decrease of DQ was found in subjects with indistinguishable stages including stages W, 1, 2 and REM, as compared with those patients whose stages were all distinguishable.

Nocturnal sleep in mentally retarded infants with cerebral palsy

Sleep EEG patterns in 23 mentally retarded children with cerebral palsy (CP) (from 4 months to 5 years of age) and 39 reference mentally retarded children of no abnormality with the exception of psychomotor retardation (from 4 months to 12 years of age) were studied throughout nocturnal sleep, and the following results were obtained. Eleven CP cases and 30 reference cases evidenced normal sleep patterns that could be classified into 6 stages. Twelve other cases in CP and 9 reference cases showed some abnormal sleep EEG patterns as follows: (i) in CP cases absence of EEG patterns characteristic of wakefulness, NREM sleep and REM sleep without spindles (n = 3); porencephaly with microcephaly (n = 1) and cytomegalovirus infection (n = 2), no characteristic EEG patterns of stages 1-4 without spindles (n = 2); cardiac arrest (n = 1) and agenesis of corpus callosum with lissencephaly (n = 1), absence of REM sleep (n = 1); kernicterus, spindles with an extremely low incidence (n = 5); perinatal anoxia (n = 2), kernicterus (n = 1), Lesch-Nyhan syndrome (n = 1) and cerebral palsy due to unknown etiologies (n = 1), and extreme spindles (n = 1); cerebral palsy due to unknown etiologies, (ii) in reference cases no spindles (n = 2), spindles with an extremely low incidence (n = 6), and extreme spindles (n = 1). Short sleep and long waking times during the night were noted in 4 out of 23 CP subjects; kernicterus (n = 2), agenesis of corpus callosum with lissencephaly (n = 1), and porencephaly with microcephaly (n = 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Nocturnal sleep of severely mentally retarded children and adolescents: ontogeny of sleep patterns

The development of nocturnal sleep of 79 mentally retarded children and adolescents (from 6 months to 20 years of age) was studied. Polygraphic recordings were carried out while the subject was in bed, and routine sleep parameters were measured. Total sleep time and percentage of Stage REM (rapid eye movements) decreased and awake time tended to increase with age. These values were similar to those previously found for age-matched nonretarded subjects. Results showed that the basic function of the sleep-waking system of retarded children seems to develop normally with age.

Skin potential responses of mentally retarded children during nocturnal sleep

Skin potential responses (SPRs) of 38 mentally retarded children were studied during their nocturnal sleep. One subject exhibited no SPRs; 19 of the 37 subjects showed more SPRs (Type A); 11, no predominant ones (Type B); and 7, fewer SPRs (Type C) during quiet sleep (no rapid eye movements, NREM sleep) than in active sleep (REM sleep). Types B and C tended to be observed more frequently for subjects with abnormal clinical EEGs than for those with normal clinical EEGs. Because investigators have established that nonretarded subjects of 3 months and over exhibit Type A, SPRs may be used as an additional assessment for diagnosis of mental retardation in early infancy.

[Stage-classification of reticuloendothelial function in hepatic injuries in the rat]

The serial changes of RE function were classified into 3 stages according to changes in opsonic activity and phagocytic index in hepatectomized, CCl4-treated cirrhotic rats; enhanced stage, compensating stage and critical stage. The phagocytic index was measured by initial disappearance rate after 4 mg/kg i.v. injection of 51Cr-labelled LPS. An opsonic activity was determined by the bioassay method using cultured RE cells prepared from the normal rat liver. The enhanced stage was characterized by an enhancement in both phagocytic index and opsonic activity--3 to 21 day-70% hepatectomized, 2 to 5 day-40% hepatectomized, 3 week-cirrhotic rats. The compensating stage by increased opsonic activity and normal phagocytic index was 2 day-70% hepatectomized and 9 week-cirrhotic rats. The critical stage by decreased phagocytic index was 5 hour to 1 day-70% hepatectomized, 13 week-cirrhotic rats.

Changes in the reticuloendothelial phagocytic function after partial hepatectomy

The changes in the phagocytic function of the reticuloendothelial (RE) system after 67% hepatectomy in rats were studied by use of 51Cr-endotoxin as the phagocytable material. The humoral opsonic index was significantly increased to approximately 1.2 to 1.8 (control, 1.0 +/- 0.2, mean +/- SD) until the fourteenth postoperative day. In contrast, the phagocytic index was decreased to 0.068 +/- 0.016 (control, 0.103 +/- 0.015) on the first day, then returned to the normal level on the second day. In this early postoperative period, uptake rates of 51Cr-endotoxin in the liver were remarkably decreased to about 50% to 70% of control, whereas those in the spleen and lung were increased two- to threefold of control. From the third to the fourteenth day, the phagocytic index was significantly increased compared with the preoperative level. During this period, the uptake rates in the liver and spleen were within the normal range. These results suggest that the increases in the opsonic index of 67% hepatectomized rats represent the homeostatic response for maintaining or stimulating RE system phagocytic function, and that high or normal phagocytic index, concomitant with the increase in the opsonic index, implies an enhanced or compensatory stage, respectively. The decrease in the phagocytic index despite the high opsonic index is assumed to represent a compromised stage of the RE system.

Effects of alpha-fluoromethylhistidine on sleep-waking parameters in rats

Effects of alpha-fluoromethylhistidine (FMH), an irreversible inhibitor of histidine decarboxylase, on the sleep-waking parameters were studied in rats for 24 hours. Intraperitoneal administration of FMH (100 mg/kg) at 11:30 hr resulted in a longer sleep latency compared with the control values. Hour-to-hour analyses revealed that wakefulness (W) time decreased (from 20:00 to 07:00 hr) and slow wave sleep (SS) time increased (from 19:00 to 06:00 hr) in the night. Paradoxical sleep (PS) time did not parallel the SS changes; it was increased significantly from 07:00 to 11:00 hr in the next morning. The influence of FMH seemed to be divided into direct, immediate action (increase of W) and late, prolonged action (decrease of W), and the results obtained support the histamine arousal hypothesis.

Facilitative effects of maternal environmental enrichment on maze learning in rat offspring

Pregnant rats were differentially reared in enriched (EC), impoverished (IC), and standard colony conditions (SC) through the pregnancy. Half of the male offspring were reared by their biological mothers and the remaining half were reared by foster-mothers. After weaning male offspring were tested in the Hebb-Williams maze apparatus. The effect of environment was significant for the total error scores; the EC group had less errors than the IC group. In a second experiment all male offspring (EC, SC and IC) were reared by foster-mothers. The effect of environment was significant for initial, repetitive, and total error scores. Further analysis revealed that the EC-SC and EC-IC differences were significant, whereas the IC-SC difference was not. Thus, the results obtained were the first to reveal that maternal environmental enrichment during pregnancy can exert a facilitatory influence on the postnatal maze learning abilities of the offspring.

Non-linearity of visual evoked potentials in cerveau isolé and midpontine pretrigeminal cats

Characteristics of the visual evoked responses to the flickering flash stimulation were studied in the cerveau isolé and midpontine pretrigeminal cats. The flash stimulation frequency was changed stepwise between 1 and 30 Hz in increasing and decreasing order. In all cases of both preparations, with drawing of fixed sweep speed of 200 msec in whole length, P1 and N1 latencies in the successive response slightly prolonged progressively 1 to about 20 Hz and thereafter shortened about 20-30 Hz stimulus frequencies in the course of the increasing phase, and vice versa in the course of the decreasing phase. Moreover, no difference in each latency (P1, N1, P2, N2) was found at the same stimulus frequency during increasing and decreasing phases. In the amplitude taken from the P1-N1 component, the peak was found in 5-9 Hz frequency bands. This peak was higher during the decreasing phase than during the increasing phase, which indicated a hysteresis phenomenon. A peak of power for the 1st harmonics was found at 3-6 Hz driving frequency bands, and that of the 2nd harmonics at 6-10 Hz. In the state without flash stimulus, no peaks or valleys in the power spectrum were found in specific frequencies, for example 3-10 Hz. The peak in the amplitude and that in the power spectrum at 3-10 Hz stimulus frequency bands suggested an entrainment phenomenon induced by forced oscillation. The phenomena of entrainment and hysteresis suggest the existence of a non-linear structure in the oscillation generating systems of visual evoked response.

Cyclic variation of integrated spindle components during nocturnal sleep in mentally retarded children

The cyclic variation of the integrated spindle component in 77 mentally retarded children (from 3 months to 12 years of age) was studied throughout nocturnal sleep. In 31 out of 77 subjects high integrated spindle rhythm power was noted in the sleep EEG. In 24 subjects, low integrated spindle rhythm power was found, and in the remaining 22 subjects no integrated spindle rhythm power was noted throughout nocturnal sleep. There was a significant increase in abnormal clinical EEGs in subjects with no spindle rhythm power as compared to those with high and low spindle rhythm powers. A significant decrease in DQ was found in the subjects with no spindle rhythm power as compared to those with high and low spindle rhythm powers.

Minimal requirement of the remnant pancreas for protein and DNA synthesis of cultured hepatocytes prepared from pancreatectomized rats

The incorporation of 3H-thymidine and 3H-leucine into the hepatocytes was studied, using cultured hepatocytes prepared from normal and pancreatectomized rats. (1) In the cultured hepatocytes prepared from 80% pancreatectomized rats, the incorporation of 3H-thymidine and 3H-leucine into hepatocytes remained unchanged compared with those of sham-operated controls. In contrast, in those from totally pancreatectomized rats, the incorporation of 3H-thymidine and 3H-leucine decreased to approximately 67% and 37% respectively of sham-operated controls. However, those returned to near normal in the cultured hepatocytes from totally pancreatectomized rats treated by 0.8 IU/kg of insulin. (2) The addition of insulin (10(-4) M) to the culture medium stimulated the incorporation of 3H-thymidine into cultured hepatocytes prepared from normal rats to 148% of controls. The insulin-stimulated incorporation was inhibited by the addition of glucagon to the culture medium. The combined addition of insulin and glucagon did not synergistically act on DNA synthesis. It is suggested that the portal blood insulin in the presence of more than 20% of the pancreas is imperative for maintaining spontaneous regeneration.

Cyclic variation of integrated delta components during nocturnal sleep in mentally retarded children

The cyclic variation of the integrated delta component in 80 mentally retarded children (from 2 months to 12 years of age) was studied throughout nocturnal sleep, and the following results were obtained. In 62 out of 80 subjects the high integrated delta rhythm power was noted in sleep EEG. In 11 out of the 80, low integrated delta rhythm power was found. In the remaining 7 subjects, no integrated delta rhythm power was found throughout nocturnal sleep. A significant increase in abnormal clinical EEG was found in subjects without delta rhythm power as compared to those with high delta rhythm power. A significant decrease in DQ was found in the subjects without delta rhythm power as compared to those with high and low delta rhythm powers.

Respiratory pauses and apnea during nocturnal sleep in mentally retarded infants

Respiratory pauses (ResP), apnea (Ap) and periodic respiration (PerR) observed in 42 mentally retarded infants (from 9 to 50 weeks of age post term) were studied throughout nocturnal sleep. All subjects had ResP in the recordings. The range of ResP rates was 4.1-42.1/h, and the mean was 13.5/h. Ap occurred in 22 out of 42 subjects. The range of Ap occurrence (10-15 sec duration) among subjects was 1-10, with a mean of 4.1. Moreover, in 4 out of 22 subjects, Aps of greater than 15 sec duration were seen. In 30 out of 42 subjects, PerR occurred. The range of occurrence of PerR among subjects was 1-35, and the mean was 9.6.

The first phase of nocturnal sleep in mentally retarded children

The first phase of sleep observed in 104 mentally retarded children (from 3 months to 8 years of age) was studied throughout nocturnal sleep, and the following results were obtained. In 4 out of 104 subjects, REM sleep onset was observed, and in the remaining 100 subjects NREM sleep onset was found at the first wakefulness-sleep transition of the night. Following awakenings (lasting 4 min or more) during the night, 170 (51.7%) out of a total of 329 samples were REM sleep onset, and 159 (48.3%) showed NREM sleep onset. The phases of sleep onset and those following awakenings evidenced no correlation between the frequency of NREM sleep onset and DQ or clinical EEG, whereas a positive correlation was found between the frequency of NREM sleep onset and age.

Effects of environmentally differential rearing upon maze performance in prenatally irradiated microcephalic rats

Pregnant rats received 100 rads of X-irradiation on day 17 of gestation. Control pregnant rats were sham-irradiated on the same gestation day. The male offspring were reared under environmentally enriched, standard colony, and impoverished conditions for 30 days after weaning. Then the Hebb-Williams maze test was carried out. All the prenatally X-irradiated rats were microcephalic: their mean cerebral wet weight was 15.5% less than controls. The effect of X-irradiation was not significant in error scores and running times, whereas the effect of environment was significant in these items; initial and total error scores and running times were decreased in enriched groups compared to impoverished groups in controls as well as in X-irradiated animals.

Developmental studies on EEG spectral analysis in mentally retarded children

The EEG developmental characteristics of 36 mentally retarded infants were investigated by auto-power spectrum analysis. A significant positive correlation with age was found in the dominant frequency in all of the three regions, occipital, central, and frontal. A tendency for the generalized component to increase was found in 3- to 5-year-old subjects as compared with those aged 6 months to 1 year and 7 months. Developmental coherence characteristics could not be found. The peak components tended to show higher coherence values in the frontal-central relation than in the central-occipital and occipital-frontal ones.

Spindle evolution in normal and mentally retarded children: a review

In neonates and infants, sleep-wake parameters indicate characteristic ontogenetic features. Sleep spindle activity also changes with maturation in terms of frequency, amplitude, and amount. For this reason, spindles are one of the useful indices of cerebral function in infants. The literature on the development of spindles in normal and mentally retarded children is reviewed.

Concurrent occurrence of rapid eye movement with spindle burst during nocturnal sleep in mentally retarded children

Concurrence of REM and sleep spindle in 45 mentally retarded children (from 4 months to 8 years of age) was studied throughout nocturnal sleep, and the following results were obtained. (1) Twenty-five cases showed a single or burst of REMs during stage NREM with sleep spindles. (2) Twenty-nine cases showed sleep spindles at the beginning or toward the end of stage REM sleep. (3) No significant difference in DQ was found between the subjects with and without REMs during stage NREM sleep. The former subjects, however, had more normal clinical EEGs than the latter. (4) No significant difference in DQ or clinical EEG classification was revealed between the subjects with REMs during stage NREM sleep and those with spindles during stage REM sleep. (5) It was concluded that the concurrence of REM and sleep spindle during stage NREM is a useful sign for early diagnosis of mental retardation.

Nocturnal sleep in severely mentally retarded children: abnormal EEG patterns in sleep cycle

Sleep EEG patterns in 43 mentally retarded children (from 4 months to 80 years of age) were studied throughout nocturnal sleep and the following results were obtained. (1) Twenty-two cases evidenced normal sleep patterns that could be classified into 6 stages. (2) The 21 other cases showed some abnormal sleep EEG patterns as follows: (a) absence of sleep spindles (n = 18) which included cases of high voltage fast activity (n = 2) and cases of low voltage activity throughout nocturnal sleep (n = 3); (b) indistinguishable delta and theta activities (n = 1), extreme spindle-like pattern (n = 1), absence of REM sleep (n = 1). (3) The severely mentally retarded children under 18 months had definitely decreased spindle activity in comparison to the values obtained by other authors from normal children. (4) The majority of the abnormal sleep EEG patterns occurred during light sleep. (5) A significant decrease in DQ was found in children with abnormal sleep patterns throughout NREM sleep as compared with those in whom abnormal EEGs occurred only during stages 1 and 2. (6) It was concluded that the EEG recorded in nocturnal sleep may serve as a useful indicator of abnormality in mentally retarded children.

Sleep-waking cycle in microencephalic rats induced by prenatal methylazoxymethanol application

Sleep-wakefulness cycle of adult microencephalic rats due to prenatal administration of methylazoxymethanol (MAM) acetate at the dose of 20 mg/kg on the 15th day of gestation showed no difference from the normal control group, whereas at the dose of 25 mg/kg, %PS and PS/TS decreased significantly. MAM-induced microencephalic rats revealed a significant increase of spindle bursts during PS, suggesting that their PS is less deep than that of the controls.

The pathogenesis of Bartter's syndrome. Functional and histologic studies

We describe a patient with Bartter's snyndrome. In addition to the well-known characteristic findings by light microscopy, electron micrograms confirmed the presence of juxtaglomerular cell hyperplasia with polymorphous renin secretory granules and dense multivesicular bodies. Volume expansion by albumin infusion decreased plasma renin activity and aldosterone excretion, and improved the pressor response to exogenous angiotensin, suggesting that the renin-angiotensin-aldosterone system was not autonomous but that a decreased extracellular volume might be a major defect in this patient. During hypotonic saline diuresis, moreover, fractional free water clearance per fractional distal sodium delivery, CH2O/CH2O + CNa, was markedly depressed in the patient when compared with the value in the controls. Evidence presented suggests that chronic extracellular volume depletion exists as a consequence of an impaired sodium transport in the ascending limb of Henle's loop.