Conspicuous visual signals do not coevolve with increased body size in marine sea slugs.

Many taxa use conspicuous colouration to attract mates, signal chemical defences (aposematism) or for thermoregulation. Conspicuousness is a key feature of aposematic signals, and experimental evidence suggests that predators avoid conspicuous prey more readily when they exhibit larger body size and/or pattern elements. Aposematic prey species may therefore evolve a larger body size due to predatory selection pressures, or alternatively, larger prey species may be more likely to evolve aposematic colouration. Therefore, a positive correlation between conspicuousness and body size should exist. Here, we investigated whether there was a phylogenetic correlation between the conspicuousness of animal patterns and body size using an intriguing, understudied model system to examine questions on the evolution of animal signals, namely nudibranchs (opisthobranch molluscs). We also used new ways to compare animal patterns quantitatively with their background habitat in terms of intensity variance and spatial frequency power spectra. In studies of aposematism, conspicuousness is usually quantified using the spectral contrast of animal colour patches against its background; however, other components of visual signals, such as pattern, luminance and spectral sensitivities of potential observers, are largely ignored. Contrary to our prediction, we found that the conspicuousness of body patterns in over 70 nudibranch species decreased as body size increased, indicating that crypsis was not limited to a smaller body size. Therefore, alternative selective pressures on body size and development of colour patterns, other than those inflicted by visual hunting predators, may act more strongly on the evolution of aposematism in nudibranch molluscs.

Conspicuousness is correlated with toxicity in marine opisthobranchs.

Aposematism is defined as the use of conspicuous colouration to warn predators that an individual is chemically or otherwise defended. Mechanisms that drive the evolution of aposematism are complex. Theoretical and empirical studies show that conspicuousness can be either positively or negatively correlated with toxicity as once aposematism is established, species can allocate resources into becoming more conspicuous and/or increase secondary defences. Here, we investigated the evolution of conspicuousness and toxicity in marine opisthobranchs. Conspicuousness of colour signals was assessed using spectral reflectance measurements and theoretical vision models from the perspective of two reef fish signal receivers. The relative toxicity of chemicals extracted from each opisthobranch species was then determined using toxicity assays. Using a phylogenetic comparative analysis, we found a significant correlation between conspicuousness and toxicity, indicating that conspicuousness acts as an honest signal when signifying level of defence and provides evidence for aposematism in opisthobranchs.

Regression versus no regression in the autistic disorder: developmental trajectories.

Developmental regression is a complex phenomenon which occurs in 20-49% of the autistic population. Aim of the study was to assess possible differences in the development of regressed and non-regressed autistic preschoolers. We longitudinally studied 40 autistic children (18 regressed, 22 non-regressed) aged 2-6 years. The following developmental areas were considered fundamental in the first years of life, and were assessed at ages 2, 3, 4, 5, and 6: receptive and expressive language, communicative and request modalities, play activities, and mental age. Children who regressed showed lower mean performances than those who did not regress and, in the time intervals considered, non-regressed children improved their ratings in the above mentioned variables significantly more than regressed children.

An open-label study of controlled-release melatonin in treatment of sleep disorders in children with autism.

Long-term effectiveness of controlled-release melatonin in 25 children, aged 2.6-9.6 years with autism without other coexistent pathologies was evaluated openly. Sleep patterns were studied using Children's Sleep Habits Questionnaire (CSHQ) and sleep diaries at baseline, after 1-3-6 months melatonin treatment and 1 month after discontinuation. Sleep diary and CSHQ showed a more problematic sleep in autistic children compared with controls. During treatment sleep patterns of all children improved. After discontinuation 16 children returned to pre-treatment score, readministration of melatonin was again effective. Treatment gains were maintained at 12 and 24-month follow-ups. No adverse side effects were reported. In conclusion, controlled-release melatonin may provide an effective and well-tolerated treatment for autistic children with chronic sleep disorders.

Sleep characteristics in healthy children from birth to 6 years of age in the urban area of Rome.

The current survey is an attempt to evaluate age-specific sleep characteristics and to identify the presence of sleep problems in Italian normally developing preschool-aged children. A cross-sectional survey by parental interview on sleep behavior was carried out on 2,889 children (from birth to 6 years). Groups were formed based on age level. Results showed a developmental trend of some sleep characteristics, regarding mainly the length of sleep and rating of night wakings. Comparison with other studies showed that the children in this study had a later sleep onset time and slept less than children of the same age living in some other countries. These dissimilarities may be due to sociocultural and climate differences. Sleep problems (sleep latency longer than 30 minutes or disruptive night wakings) were found in 35% of children less than 2 years old, in 23% of 2-3-year-olds and in 14% of 4-6-year-olds. Children with sleep problems slept significantly less (on average 30-40 minutes across all age levels, required parental presence at time of sleep onset and shared their parents' bed more frequently than those without sleeping problems.

Sleep disorders in tuberous sclerosis: a polysomnographic study.

Overnight polysomnography was performed in 10 subjects with tuberous sclerosis (TS) and partial epilepsy in order to investigate the relationships between sleep organization, sleep disorders and epilepsy. Sleep architecture abnormalities were observed in 9 cases. Compared with ten healthy age-matched controls, the TS group showed a shorter total sleep time, a reduced sleep efficiency, a higher number of awakenings and stage transitions, an increased wake after sleep onset and stage 1 and a decreased REM sleep. Children with seizures showed a more disrupted sleep architecture compared with seizure-free children. Sleep disorders in TS were mainly due to sleep-related epileptic events and were more evident in children who showed large bifrontal or temporal tubers on MRI.

[Continuous localized EEG discharge during sleep in children without neuropsychological problems]. / Décharges EEG localisées continues pendant le sommeil chez des enfants sans troubles neuropsychiques.

After having reported continuous localized EEG discharge during slow sleep (CLEDS) in six children with congenital encephalopathy, we observed a similar EEG picture in six children free from both neuropsychological and neuroradiological defects. They suffered from partial idiopathic epilepsy; five presented a familial disposition towards febrile seizures. Continuous paroxysmal activity during sleep was observed from 4.8 yrs to 4.11 yrs (mean age: 4.9 yrs). Spontaneous remission of CLEDS was observed in three cases after 2-25 months, but one or more relapses occurred in two cases, and five children are still suffering from CLEDS. Seizures were controlled by drugs in all cases. Deterioration of intelligence level, although not severe, was observed in one case, after 24 months of CLEDS.

Partial childhood epilepsy and reaction time: the effect of interictal EEG discharges.

A study was conducted on seven children (five females and two males, aged 5.7-13.1 years) affected with partial epilepsy which was well controlled by therapy. A computer was connected on-line to a polygraph and during two EEG recordings, the subject had to react to the appearance of a colored rectangle on the display screen by pushing a key on the keyboard: these events were automatically marked on the trace of a polygraphic channel. By means of Anova analysis it was demonstrated that during the same recording, reactions simultaneous to paroxysmal discharges were not significantly slower than those measured during free intervals. However, in the same patient, reaction times were significantly prolonged during recordings characterized by a higher rate of EEG paroxysmal activity.

[Partial splenectomy using a stapler and the role of regeneration of the residual splenic stump]. / Splenectomie parziali con stapler e ruolo della rigenerazione del moncone splenico residuo.

Current evidence indicates that only complete or partial intact spleen can protect the organism against pneumococcal sepsis. What is not clear is the amount of minimal splenic tissue needed to protect the organism against such infection. This study has been carried out on 20 dogs which underwent partial or total splenectomy with stapler. Animals were divided into 8 groups according to the quantity of the remnant splenic tissue: 0% (4 dogs); 5% (4); 15% (1); 25% (1); 35% (2); 50% (2); 75% (2); 100% (4), and were followed up for 6 and 12 months. No mortality or bleeding was registered. Results showed a splenic regeneration, histologically demonstrated as an increased number of germinal follicles, in 12 out of 16 dogs, more evident in the animals sacrificed at one year. In conclusion, even a small amount (5%) of splenic tissue preserved with its blood supply can regenerate and acquire with time enough immunological function to protect the organism against post-splenectomy sepsis.

[Aseptic resection of the intraluminal colon in laparoscopy]. / Resezione di colon intraluminale asettica in laparoscopia.

Laparoscopic surgery is an "old" technique extending to new applications including colon surgery. Basically, even though surgical technique and indications do not differ from traditional surgery, it has the advantage to eliminate most of the complications associated with an abdominal incision. In order to improve also the outcome of intestinal anastomoses, an aseptic technique by intestinal intussusception previously described (3) has been modified and carried out laparoscopically in 3 pigs and 3 dogs successfully. The animals were sacrificed after 2 months. Anastomoses were evaluated endoscopically by barium enema and by gross and microscopic examination. Results indicated no mortality or complications except for a small area of mucosal peri-anastomotic necrosis in one dog, which spontaneously healed. Therefore, it seems that the aseptic resection of the colon is possible with laparoscopy obtaining at the same time a decreased morbidity related to the abdominal incision and colonic anastomosis.

[Towards the standardization of sentinel lymph node analysis in women with breast cancer]. / Verso una standardizzazione dell'analisi del linfonodo sentinella in donne con cancro della mammella.

Sentinel lymph node biopsy allows enhanced pathology through serial sections and immunohistochemical analysis of the retrieved node, with detection of micrometastases and isolated tumor cells not otherwise recognized. We present our experience with a simple, effective, pathology protocol requiring six couples of sections at three different sentinel lymph node levels. Additional micrometastases or ITC were diagnosed in 51/416 patients (14.6%).

The effect of niaprazine on some common sleep disorders in children. A double-blind clinical trial by means of continuous home-videorecorded sleep.

A placebo-controlled double-blind clinical trial on the effect of niaprazine on children with some common sleep disorders was carried out. Niaprazine at a daily dosage of 1 mg/kg body weight or placebo at random was administered to a selected group of 36 children (aged from 6 months to 6 years) suffering from frequent nighttime waking or inability to fall asleep. The effect of niaprazine (or placebo) on sleep disorders was studied by means of continuous home-videorecorded sleep before and after the trial. A reliable positive effect of niaprazine on the sleep disorders considered was found. No adverse side effects were observed. We conclude that niaprazine seems to represent an effective and safe drug for the therapy of frequent nighttime waking and inability to fall asleep.

Sleep problems and daytime behavior in childhood idiopathic epilepsy.

PURPOSE: To evaluate the presence of sleep problems and their association with behavioral and adjustment problems in children with idiopathic epilepsy. METHODS: A parental questionnaire was used to assess sleep problems in 89 children with idiopathic epilepsy for comparisons with 49 siblings and 321 healthy control children, equally distributed for age and sex. Sleep problems were clustered into five factors: parasomnias, parent/child interaction during the night, sleep fragmentation, daytime drowsiness, and bedtime difficulties. Daytime behavior and psychological adjustment were assessed by means of the Child Behavior Checklist. Maternal distress and disturbance was evaluated by the Malaise Inventory. The better to identify factors associated with sleep problems in the children with epilepsy, multiple regression analysis was performed. RESULTS: Children with epilepsy showed significantly more sleep problems than did both siblings and healthy controls. Within the epileptic group, children with current seizures complained more of sleep problems than did the seizure-free children. Moreover, children with epilepsy showed more behavioral problems and maladjustment. Age, paroxysmal activity density, duration of illness, seizure frequency, and behavioral problems were significantly associated with sleep problems in the epileptic group. CONCLUSIONS: The results of this study in a highly selected sample pointed out the presence of sleep problems, and adjustment and behavioral problems in children with idiopathic epilepsy. The presence of epilepsy, although benign, in childhood is associated with adaptive problems of the child. From this point of view, the alteration of some sleep habits may be a sign of emotional maladjustment. Although parents failed to perceive them as a problem, our findings indicate that attention to sleep and behavioral problems is important in clinical management of children with idiopathic epilepsy.

Effect of benzyladenine on some enzymes of mitochondria and microbodies in excised sunflower cotyledons.

Benzyladenine (BA) increases the rate of expansion of dark-grown sunflower (Helianthus annuus L.) cotyledons. The hormone slightly enhances the development of the two glyoxysomal enzymes, isocitrate lyase and malate synthetase, during the first 3 days of germination and greatly accelerates their decay in the 2 following days. The levels of the peroxisomal enzymes, glycolate oxidase and glyoxylate reductase, are enhanced by BA more than those of the two glyoxysomal enzymes. These effects of BA on microbody enzymes are very similar to those of white light. Mitochondrial enzyme activities are increased to a varying extent by BA: the increase is minimal for fumarase, and maximal for cytochrome oxidase. The level of cytochrome oxidase is enhanced 346% at the 5th day of germination. Also, the rate of O(2) consumption is increased by BA, but the time course of this increased O(2) consumption does not match with that of cytochrome oxidase. Fusicoccin, a fungal toxin, mimics the effect of BA on cotyledon expansion, but fails to duplicate its action on microbody enzymes. This suggests that the effect of BA on microbody enzymes is not closely linked with the mechanism of growth promotion.

Responsiveness of the visual system in childhood migraine studied by means of VEPs.

We have tried to ascertain whether the increased visual evoked potential (VEP) amplitude found in adult migraineurs is present also in children with migraine. We investigated 43 children, 26 male and 17 female, with a mean age of 11.4 years, 24 with common and 19 with classic migraine, and compared them with a control group of 20 children, 11 male and 9 female, with a mean age of 9.7 years. Flash and pattern reversal VEPs were recorded in both groups, and the study was carried out in the pain-free interval between attacks. The children with migraine showed a significant (p less than 0.01) increase in VEP amplitude on flash stimulation but not on pattern reversal. There were no differences between classic and common migraine. The abnormal responsiveness of the visual system seems to be related to variations in light intensity rather than to spatial contrasts.