Sleep and behavior problems among preschoolers.

This study described the relationship between amount of sleep and behavior problems among preschoolers. Participants were 510 children aged 2 to 5 years who were enrolled through 68 private pediatric practices. Parents reported on the amount of sleep their child obtained at night and in 24-hour periods. With demographic variables controlled, regression models were used to determine whether sleep was associated with behavior problems. The relationship between less sleep at night and the presence of a DSM-III-R psychiatric diagnosis was significant (odds ratio = 1.23, p = .026). Less night sleep (p < .0001) and less sleep in a 24-hour period (p < .004) were associated with increased total behavior problems on the Child Behavior Checklist; less night sleep (p < .0002) and less 24-hour sleep (p < .004) were also associated with more externalizing problems on that measure. Further research is needed to ascertain whether sleep is playing a causal role in the increase of behavior problems.

Naps in children: 6 months-7 years.

A cohort of 172 children was followed from 6 months to 7 years of age to determine how nap patterns change with age and whether there was individual stability of nap patterns. Results showed that there were no differences in nap patterns based on gender, ordinal position, whether naps spontaneously disappeared or were stopped by the parents, and the number of naps at 6 months of age. Total daytime sleep remained a stable individual characteristic between 6 and 18 months of age. Age was associated with hours napping (r = -0.73, p < 0.001) and number of naps (r = -0.52, p < 0.001). A pattern of two naps per day was well established by 9-12 months of age and one afternoon nap by 15-24 months. The modal duration of naps from 2 to 6 years was 2 hours. During the 3rd and 4th year, napping occurred in the majority of children, but at decreasing rates. A minority of children were napping at 5 and 6 years and naps usually disappeared by age 7.

Melatonin increases cyclic guanosine monophosphate: biochemical effects mediated by porphyrins, calcium and nitric oxide. Relationships to infant colic and the Sudden Infant Death Syndrome.

It is hypothesized that melatonin, by its actions on porphyrin and nitric oxide biosynthesis, produces an increase in cyclic guanosine monophosphate.

Sudden infant death syndrome: a genetically determined impaired maturation of the photoneuroendocrine system. A unifying hypothesis.

Sudden Infant Death Syndrome (SIDS) is the unexpected, and after autopsy, unexplained death of an apparently healthy infant. SIDS exhibits circannual, circadian, and ontogenetic features which may reflect an impaired maturation of the photoneuroendocrine system caused by a genetic absence or mutation of the enzyme N-acetyltransferase which is the rate-limiting enzyme for the biosynthesis of the hormone melatonin in the pineal gland. The failure of normal pineal gland development and subsequent impaired production of its main secretory product, melatonin, may cause a lethal imbalance in the chemical interactions among serotonin, progesterone, and catecholamines. The result of this chemical imbalance, culminating in SIDS, involves the neurotoxic and cardiomyotoxic effects of abnormally elevated catecholamines and intracellular calcium ions.

The photo-biochemical basis of infant colic: pineal intracellular calcium concentrations controlled by light, melatonin, and serotonin.

Infant crying during the first 3 months of life exhibits a circadian rhythm with peak crying in the evening hours. Intracellular calcium ion within the pineal gland may be influenced by alternating light and dark, melatonin concentrations, and serotonin concentrations which both exhibit circadian rhythmicity. Differences in light by latitude and differences in the ontogenic development of melatonin and serotonin rhythmicity could combine to effect the pineal intracellular concentrations of calcium and result in high levels of infant crying called colic.

Infant colic: the effect of serotonin and melatonin circadian rhythms on the intestinal smooth muscle.

It is hypothesized that in the evening, peak serotonin concentration causes intestinal cramps associated with colic because serotonin increases intestinal smooth muscle contractions. Melatonin has the opposite effect of relaxing intestinal smooth muscles. Both serotonin and melatonin exhibit a circadian rhythm with peak concentrations in the evening. However, serotonin intestinal contractions are unopposed by melatonin during the first 3 months because only serotonin circadian rhythms are present at birth. Melatonin circadian rhythms appear at 3 months of age. The cramps of colic disappear at 3 months of age.

Colic, sleep inertia, melatonin and circannual rhythms.

Colic is periodic behavior occurring at the end of the day during the first 3 months of life characterized by crying. It is hypothesized that the crying at the end of the day is due to sleep inertia or a state dissociation during which the infant is simultaneously partially awake and partially asleep because of the absence of a melatonin diurnal rhythm. The melatonin timing mechanisms, which codes for day length, is initiated prenatally by the maternal pineal gland, and after 3 months postnatally, the melatonin nocturnal secretion rhythm is maintained by the infant's pineal gland. To record the seasonal variation in day length away from the equator, 12 months are required to complete the melatonin chemical calendar. This circannual process is only 9 months completed at the time of birth, and 3 additional months are needed during which the infant may have difficulty reconciling cues for the timing of evening sleep due to discrepancies between the expected photoperiod derived from the prenatal maternal pineal melatonin circadian rhythm and the postnatally experienced photoperiod. Data is presented showing that the incidence of colic increases with increasing latitude in support of the hypothesis that infant crying at the end of the day during the first 3 months represents the last quarter of a circannual photoperiodic development process.

[The Leser-Trélat sign associated with carcinoma of the cervix uteri. Report of a case and review of the literature]. / Sinal de Leser-Trélat associado a carcinoma de colo uterino. Relato de um caso e revisão bibliográfica.

The sign of Leser-Trélat in a patient with squamous cell carcinoma of the cervix is reported. This seems to be the first report of this association. Literature was reviewed, try to correlate this entity with acanthosis nigricans and to link this sign with internal malignancy or other kind of epidermal stimuli.

Home pneumograms in normal infants.

To obtain age-specific normative data, we performed home cardiorespiratory recordings (pneumograms) in 56 normal infants at 1 month of age. A repeat pneumogram was performed at 3 months in 39 infants. Total sleep time was determined and all sleep intervals were summed and analyzed for five respiratory pattern variables: frequency of all apneic episodes greater than or equal to 6 seconds in duration (A6/D%), periodic breathing, longest apneic episode, and number of episodes greater than 11 and greater than 15 seconds. The normal infants at 1 and at 3 months were compared with 66 patients with apnea of infancy. Median A6/D% was 0.1 in the normal infants at 1 and 3 months, compared with 0.64 in those with apnea of infancy (P less than 0.001). Median periodic breathing was 0.4 and 0.2 episodes per 100 minutes in the normal infants at 1 and 3 months, respectively, compared with 1.25 in infants with apnea of infancy (P less than 0.001). Median longest apneic episode was 8.0 seconds in the normal infants at 1 and 3 months, compared with 11 seconds in those with apnea of infancy (P less than 0.001). No normal infant had an apneic episode greater than 15 seconds in duration, whereas the group with apnea of infancy had 0.4 +/- 1.0 episodes of apnea of greater than 15 seconds (P less than 0.01). Despite these significant group differences, use of these respiratory patterns either alone or in combination permitted only about 80% correct classification of normal infants and those with apnea of infancy.

Plasma progesterone concentrations and infant temperament.

Progesterone and its metabolites are potent depressors of the central nervous system. Plasma progesterone concentrations significantly correlated with temperament ratings for approach/withdrawal (r = -0.35, p = 0.01) and intensity (r = -0.28, p = 0.04) among 42 normal infants. The median age at the time of the progesterone sample was 36 days. Easier infants tended to have higher plasma progesterone concentrations compared with more difficult infants (mean +/- SEM: 25 +/- 4 ng/dl versus 17 +/- 3 ng/dl, p = 0.15). Results are consistent with the hypothesis that progesterone or its metabolites may exert a behavioral depressor effect in infancy.

Treatment of infantile colic with dicyclomine hydrochloride.

We performed a prospective, randomized, double-blind, placebo-controlled clinical trial of dicyclomine hydrochloride using specific diagnostic criteria for infantile colic: spells of unexplained irritability, agitation, fussiness or crying lasting greater than or equal to 3 hours/day, occurring greater than or equal to 3 days/week, and continuing for greater than or equal to 3 weeks. Dicyclomine eliminated colic in 15 of 24 (63%) infants, whereas placebo was effective in six of 24 (25%) (corrected X2 = 5.42, P = 0.02). The study also addressed the hypothesis that parental distress caused by infantile colic affects subsequent temperament and sleep patterns. The data fail to document easier temperaments or longer sleep durations at 4 months in infants whose colic ceased during treatment.

Sleep duration, temperament, and Conners' ratings of three-year-old children.

Parental reports of sleep patterns, ratings on the Behavioral Style Questionnaire, and Conners' Abbreviated Parents' Questionnaire were obtained for 60 three-year-old children. Children who were more adaptable, mild, and positive in mood, or children with an easy temperament, had longer total sleep durations and lower Conners' ratings than children with opposite traits. Adaptability was the temperament characteristic most highly correlated with total sleep duration and the only characteristic which correlated with the number of night wakings. In addition, children with low activity ratings had long total sleep durations, low Conners' ratings, and were described as having a quiet sleep pattern. Long sleep durations and low Conners' ratings appear to be features of children with an easy temperament or low motor activity when awake and asleep.

Night waking in 4- to 8-month-old infants.

Parental reports of night waking and sleep patterns were obtained for 141 normal 4- to 8-month-old infants from middle-class families. A group of infants was identified who had a past history of colic and who were perceived to have a current night waking "problem." These infants awoke more often than other infants and also had significantly briefer total sleep duration. Night waking was described as a problem in infant boys more often than in infant girls. A second group of infants who awoke frequently was reported to snore or mouth breathe when asleep. This group of infants did not have a past history of colic, was not perceived to have a night waking problem, and was not overly represented by boys. Ordinal position, father's education level, gender, and method of feeding did not affect reported sleep patterns.