Ethephon induced oxidative stress in the olive leaf abscission zone enables development of a selective abscission compound.

BACKGROUND: Table olives (Olea europaea L.), despite their widespread production, are still harvested manually. The low efficiency of manual harvesting and the rising costs of labor have reduced the profitability of this crop. A selective abscission treatment, inducing abscission of fruits but not leaves, is crucial for the adoption of mechanical harvesting of table olives. In the present work we studied the anatomical and molecular differences between the three abscission zones (AZs) of olive fruits and leaves. RESULTS: The fruit abscission zone 3 (FAZ3), located between the fruit and the pedicel, was found to be the active AZ in mature fruits and is sensitive to ethephon, whereas FAZ2, between the pedicel and the rachis, is the flower active AZ as well as functioning as the most ethephon induced fruit AZ. We found anatomical differences between the leaf AZ (LAZ) and the two FAZs. Unlike the FAZs, the LAZ is characterized by small cells with less pectin compared to neighboring cells. In an attempt to differentiate between the fruit and leaf AZs, we examined the effect of treating olive-bearing trees with ethephon, an ethylene-releasing compound, with or without antioxidants, on the detachment force (DF) of fruits and leaves 5 days after the treatment. Ethephon treatment enhanced pectinase activity and reduced DF in all the three olive AZs. A transcriptomic analysis of the three olive AZs after ethephon treatment revealed induction of several genes encoding for hormones (ethylene, auxin and ABA), as well as for several cell wall degrading enzymes. However, up-regulation of cellulase genes was found only in the LAZ. Many genes involved in oxidative stress were induced by the ethephon treatment in the LAZ alone. In addition, we found that reactive oxygen species (ROS) mediated abscission in response to ethephon only in leaves. Thus, adding antioxidants such as ascorbic acid or butyric acid to the ethephon inhibited leaf abscission but enhanced fruit abscission. CONCLUSION: Our findings suggest that treating olive-bearing trees with a combination of ethephon and antioxidants reduces the detachment force (DF) of fruit without weakening that of the leaves. Hence, this selective abscission treatment may be used in turn to promote mechanized harvest of olives.

Consistent high prevalence of Exophiala dermatitidis, a neurotropic opportunist, on railway sleepers.

Environmental isolation of black yeasts potentially causing human disorders is essential for understanding ecology and routes of infection. Several Exophiala species show prevalence for man-made environments rich in monoaromatic compounds, such as creosote-treated or petroleum-stained railway sleepers. Ambient climatic conditions play a role in species composition in suitable habitats. Therefore, the aim of the present study was to establish the composition of Exophiala species in railway stations as a potential source of human infections in a subtropical region with evaluation of their antifungal susceptibility profiles. We examined 150 railway samples using cotton swabs moistened with sterile physiological saline. Black yeasts and relatives were selected on theirs colony morphology and identified based on ITS rDNA sequencing. Overall, 36 (24%) of samples were positive for black yeast-like fungi, i.e., Exophiala dermatitidis (n=20, 55.6%) was predominant, followed by E. phaeomuriformis (n=9, 25%), E. heteromorpha (n=5, 13.9%), and E. xenobiotica (n=2, 5.6%). Massive contaminations of E. dermatitidis were seen on railway sleepers on creosoted oak wood at the region close to the sea level, while in cold climates were primarily contaminated with clinically insignificant or rare human opportunists (E. crusticola). It seems that, high temperature and humidity are significant effect on species diversity. Moreover, the MIC results for all E. dermatitidis and E. phaeomuriformis strains revealed the widest range and the highest MICs to caspofungin (range 1-16mg/L, Geometric mean 4.912mg/L), and the lowest MIC for posaconazole (0.016-0.031mg/L, G mean 0.061mg/L). However, their clinical effectiveness in the treatment of Exophiala infections remains to be determined.

Increased motor activity and recurrent manic episodes: predictors of rapid relapse in remitted bipolar disorder patients after lithium discontinuation.

Ten patients with remitted bipolar illness on lithium maintenance therapy underwent placebo-controlled lithium discontinuation. Clinical ratings and recording of sleep-wake activity using wrist-worn actigraphs were carried out before and after lithium discontinuation. Seven patients experienced relapse into mania or hypomania within the first 3 months after lithium discontinuation. Actigraphic recordings revealed that patients who relapsed had higher baseline levels of daytime motor activity than patients without relapse. This may suggest that motor activity can be a sensitive marker of subclinical manic tendencies and early relapse following lithium discontinuation.

Actigraphic home-monitoring sleep-disturbed and control infants and young children: a new method for pediatric assessment of sleep-wake patterns.

Two studies were conducted to evaluate actigraphic home-monitoring for the assessment of infants' and children's sleep patterns. In the first study, 11 children (aged 12 to 48 months) were monitored in the laboratory by traditional polysomnography and by actigraphy for one night. Actigraphic automatic sleep-wake scorings were compared with those of the polysomnograph; total agreement rate was 85.3%. In the second study, sleep patterns of 63 sleep-disturbed and 34 control healthy children (aged 9 to 27 months) were compared. These children were home-monitored by actigraph for a mean of 4.45 nights (total 482 nights). Actigraphic data were analyzed by an automated scoring procedure. Sleep quality of the sleep-disturbed children, measured by actigraphically derived sleep percent and number of longer-than-5-minute wakings, was significantly lower than that of the control subjects (P less than .0001). Sleep measures showed significant night-to-night stability in both groups. The stability of specific measures and their age trends were different between the groups. Actigraphic sleep measures alone could discriminate between sleep-disturbed and control children with a highly correct assignment rate of 79.4% and 91.2%, respectively.

Sleep and melatonin in infants: a preliminary study.

Sleep-wake patterns of 20 normal, healthy infants (16 girls and four boys; age range: 26-37 weeks) were recorded for a period of 1 week with a miniature activity monitor. Urine samples were extracted from the infants' disposable diapers that were collected during a 60-hour period to determine the levels of 6-sulphatoxymelatonin (aMT6s, a melatonin metabolite) using a radioimmunoassay test. Infants with "mature" secretion patterns (i.e. with an adult-like circadian rhythm) had a significantly delayed sleep-wake cycle in comparison to those with "immature" patterns. The onset of their nocturnal-sleep episode was delayed by almost 1 hour (22.1 vs. 21.2 hours; p < 0.05). Higher secretion rates of aMT6s during the evening hours (6:00-10:00 p.m.) were associated with earlier onset of nocturnal sleep (r = 0.51; p < 0.05). A delayed peak of melatonin was associated with more fragmented sleep during the night (e.g. r = 0.49; p < 0.05; for lower sleep percent). These findings suggest that melatonin plays an important role in the evolution of the sleep-wake system.

Evaluating night wakings in sleep-disturbed infants: a methodological study of parental reports and actigraphy.

The aim of this study was to investigate the use of objective and subjective sleep measures in diagnostic assessment of night-waking problems during infancy. Infant sleep-wake measures obtained from parental daily logs were compared with objective sleep measures derived from activity monitoring during a week-long period in 66 referred infants. Reported sleep measures were significantly correlated with objective sleep measures and showed a significant level of day-to-day stability. Parents were accurate reporters of sleep-schedule measures (e.g. sleep onset, r = 0.88; sleep duration, r = 0.74; p < 0.0001). However, parents were less accurate in assessing sleep quality measures, significantly overestimating the time that their infants spent in actual sleep and underestimating the number of their night-wakings (r = 0.41 and r = 0.60, respectively; P < 0.001). It is suggested that subjective and objective measures should play a complementary role in the clinical assessment of night-waking problems in early childhood.

Activity-based sleep-wake identification: an empirical test of methodological issues.

The effects of actigraph placement and device sensitivity on actigraphic automatic sleep-wake scoring were assessed using concomitant polysomnographic and wrist actigraphic data from dominant and nondominant hands of 20 adults and 16 adolescents during 1 laboratory night. Although activity levels differed between dominant and nondominant wrists during periods of sleep (F = 4.57; p < 0.05) and wake (F = 15.5; p < 0.0005), resulting sleep-wake scoring algorithms were essentially the same and were equally explanatory (R2 = 0.64; p < 0.0001). When the sleep-wake scoring algorithm derived from the nondominant hand was used to score the nondominant data for sleep-wake, overall agreement rates with polysomnography scoring ranged between 91 and 93% for the calibration and validation samples. Results obtained with the same algorithm for the dominant-wrist data were within the same range. Agreement for sleep scoring was consistently higher than for wake scoring. Statistical manipulation of activity levels before applying the scoring algorithm indicated that this algorithm is quite robust toward moderate changes in activity level. Use of "twin-wrist actigraphy" enables identification of artifacts that may result from breathing-related motions.

The role of actigraphy in the evaluation of sleep disorders.

This paper, which has been reviewed and approved by the Board of Directors of the American Sleep Disorders Association, provides the background for the Standards of Practice Committee's parameters for the practice of sleep medicine in North America. The growing use of activity-based monitoring (actigraphy) in sleep medicine and sleep research has enriched and challenged traditional sleep-monitoring techniques. This review summarizes the empirical data on the validity of actigraphy in assessing sleep-wake patterns and assessing clinical and control groups ranging in age from infancy to elderly. An overview of sleep-related actigraphic studies is also included. Actigraphy provides useful measures of sleep-wake schedule and sleep quality. The data also suggest that actigraphy, despite its limitations, may be a useful, cost-effective method for assessing specific sleep disorders, such as insomnia and schedule disorders, and for monitoring their treatment process. Methodological issues such as the proper use of actigraphy and possible artifacts have not been systematically addressed in clinical research and practice.

Sleep and pulmonary function in children with well-controlled, stable asthma.

The aim of this study was to assess sleep and pulmonary function in asthmatic and control children. Forty children with well-controlled, stable asthma, and 34 controls (age range: 8.2 to 15.4 years) were monitored with wrist actigraphs and peak-flow meters for 3 consecutive days. In addition, asthma severity was assessed by subjective parental and self-rating scale and symptom checklist. Asthmatic children had poorer sleep quality in comparison to their controls, as manifested in lower percentages of quiet sleep (p < .05) and increased activity level during sleep (p < .05). As expected, asthmatic children had reduced morning peak expiratory flow measures (p < .01) and a higher evening-to-morning drop in peak expiratory flow (p < .005). Peak-flow measures were significantly correlated with subjective and objective sleep measures. In the asthmatic group, sleep measures were also correlated with subjective asthma severity indices and symptom checklists. We conclude that poorer sleep is associated with reduced pulmonary function. The reduced sleep quality, coupled with subjective reports of increased fatigue and reduced alertness found in asthmatic children, suggest that these children are at risk for developing neurobehavioral deficits associated with chronic sleep loss.

Estimating sleep patterns with activity monitoring in children and adolescents: how many nights are necessary for reliable measures?

STUDY OBJECTIVES: This study provides estimates of reliability for aggregated values from 1 to 7 recording nights for five commonly used actigraphic measures of sleep patterns, reliability as a function of night type (weeknight or weekend night), and stability of measures over several months. DESIGN AND SETTING: Data are from three studies that obtained 7 nights of actigraph data (using Mini Motionlogger actigraphs and associated validated algorithms [ASA]) on children and adolescents living at home on self-selected sleep-wake schedules. PARTICIPANTS: Participants were 169 children aged 12-60 months, and 55 adolescents aged 11-16 years. MEASUREMENTS AND RESULTS: Up to 28% of weekly recordings may be unacceptable for analysis in young participants because of illness, technical problems, and participant noncompliance; studies aiming to collect 5 nights of actigraph data should record for at least 1 full week. Reliability estimates for values aggregated over any 5 nights were adequate (> or = .70) for sleep start time, wake minutes, and sleep efficiency. Measures of sleep minutes and sleep period were less reliable and may require 7 or more nights for estimates of stable individual differences. Reliability for 1- or 2-night aggregates were poor for all measures. We found significant and high correlations between summer and fall session measures for all five variables when weekend nights were included. CONCLUSIONS: Five or more nights of usable recordings are required to obtain reliable actigraph measures of sleep for children and adolescents.

Infant-parent co-sleeping in an evolutionary perspective: implications for understanding infant sleep development and the sudden infant death syndrome.

Evidence suggests that infant-parent co-sleeping represents the species-wide pattern of sleep in which human infant physiology evolved. The hypothesis evaluated in this manuscript is that the co-sleeping environment may foster development of optimal sleep patterning in infants and confer other benefits, including reducing the risk of the sudden infant death syndrome (SIDS). These postulations by McKenna are considered from different perspectives by the coauthors. Using evolutionary, cross-species, crosscultural, physiological and behavioral data, our objective was to present a conceptual framework for assessing the developmental consequences of solitary sleeping and infant-parent co-sleeping.

Instability of sleep patterns in children with attention-deficit/hyperactivity disorder.

OBJECTIVE: To compare the stability of the sleep-wake system of children with attention-deficit/hyperactivity disorder (ADHD) and controls by objective and subjective measures. METHOD: Thirty-eight school-age boys with diagnosed ADHD and 64 control school-age boys were examined using actigraphic monitoring and sleep diaries, over 5 consecutive nights. RESULTS: Increased instability in sleep onset, sleep duration, and true sleep were found in the ADHD group compared with the control group. Discriminant analysis revealed that children's classification (ADHD versus control) could be significantly predicted on the basis of their sleep measures. CONCLUSIONS: The findings support the hypothesis that instability of the sleep-wake system is a characteristic of children with ADHD. Given the potential negative effects of disturbed or unstable sleep on daytime functioning, it is recommended that a thorough sleep assessment be conducted when a sleep disturbance is suspected or when symptoms associated with daytime sleepiness or decreased arousal level are present.

Case study: sleep and aggressive behavior in a blind, retarded adolescent. A concomitant schedule disorder?

Blind people are prone to suffer from sleep-wake schedule disorders. This report describes 2 months of monitoring of sleep patterns and aggressive behaviors in a totally blind, severely retarded adolescent boy, hospitalized in a psychiatric hospital. The documented sleep-wake patterns seem to portray a sleep-wake schedule disorder with a monthly periodicity. Aggressive behaviors seem to echo the same periodicity, suggesting that a common or linked biobehavioral timing mechanism may underlie both sleep and episodic aggressive outbursts. The need to consider sleep schedule disorders as a primary process underlying some psychopathological disorders, and the related risks of misdiagnosis and mistreatment, are highlighted.

Sleep and psychological characteristics of children on a psychiatric inpatient unit.

OBJECTIVE: To assess the association of objective measures of sleep-wake patterns and psychological status and abuse history of children hospitalized in a psychiatric inpatient unit. METHOD: Thirty-nine inpatient children participated in the study. They were monitored for one to three consecutive nights with miniature wrist activity monitors for objective assessment of sleep-wake patterns. In addition, a thorough psychiatric and psychosocial assessment was completed with each child and the parents. RESULTS: Children's self-ratings of depression, hopelessness, and low self-esteem were significantly correlated with objective sleep measures indicating poorer sleep quality. No significant correlations between intelligence scores and sleep measures were found. Nonabused and sexually abused children had better sleep quality than physically abused children. CONCLUSIONS: Sleep quality during hospitalization is strongly associated with self experiences of depression, hopelessness, and low self-esteem in children with severe behavior disorders.

Assessment of intervention for infant night waking: parental reports and activity-based home monitoring.

Sleep patterns of 50 infants (aged 9-24 months) with sleep disturbances were studied by using an activity monitor (actigraph) and parental reports during the baseline and intervention periods. Two behavioral intervention methods were used to treat the multiple or prolonged night-waking problems. Infant sleep significantly improved during the period of intervention as measured by both actigraphic and parental monitoring. The discrepancy between parental and actigraphic measures increased over time, as did the number of omitted items from the parental daily logs. The results highlight some of the advantages as well as some of the limitations of actigraphic and parental monitoring of infant sleep, and they suggest that the two methods may have complementary roles in assessing intervention efficacy in this field.

Newborns' sleep-wake patterns: the role of maternal, delivery and infant factors.

OBJECTIVE: The purpose of this study was to assess the sleep-wake patterns of fullterm (> or = 37 weeks) newborns and to evaluate the effects of specific factors including maternal gestational diabetes, infant size and anthropometric measures, gender, gestational age and delivery variables. METHODS: Two-hundred twenty newborns were studied in the hospital nursery for a continuous 24-h period with miniature activity monitors attached to the infants' ankles. The sample consisted of 102 infants of gestational diabetic mothers (IGDM) and 118 controls. Anthropometric measurements were obtained and maternal and infant characteristics were recorded. RESULTS: The newborns had a discernible diurnal sleep pattern and slept twice as much during the nighttime as daytime hours (P < 0.001). Higher skinfold measurements correlated significantly with increased quiet and motionless sleep (P < 0.05) for the IGDM but not for controls. Sleep of infants born at later gestational ages was characterized by increased percent of quiet and motionless sleep (P < 0.0001). No direct gender effects were identified. CONCLUSIONS: Multiple factors were associated with the sleep-wake patterns of the newborns on our study cohort including maternal glucose values during pregnancy, increased measures of adiposity in IGDM, increased gestational age, mode of delivery and delivery Sequence. Investigation of the sleep-wake characteristics of neonates using activity monitors is a noninvasive method for gaining new understanding of the relationships between sleep wake activity patterns and infant characteristics.

Sleep patterns and sleep disruptions in school-age children.

This study assessed the sleep patterns, sleep disruptions, and sleepiness of school-age children. Sleep patterns of 140 children (72 boys and 68 girls; 2nd-, 4th-, and 6th-grade students) were evaluated with activity monitors (actigraphs). In addition, the children and their parents completed complementary sleep questionnaires and daily reports. The findings reflected significant age differences, indicating that older children have more delayed sleep onset times and increased reported daytime sleepiness. Girls were found to spend more time in sleep and to have an increased percentage of motionless sleep. Fragmented sleep was found in 18% of the children. No age differences were found in any of the sleep quality measures. Scores on objective sleep measures were associated with subjective reports of sleepiness. Family stress, parental age, and parental education were related to the child's sleep-wake measures.

[Value of determining prostate specific antigen in follow-up of prostatic cancer].

The value of measuring serum prostate specific antigen (PSA) in monitoring cases of prostatic cancer was studied in 239 patients. 30 patients with benign prostatic hyperplasia served as controls. The patients were treated by radical prostatectomy, radiotherapy or chemotherapy. In the controls PSA levels were elevated in 60%, indicating that PSA measurement is not specific for prostatic cancer. Among 35 patients before and after radical prostatectomy, in those without disease progression, PSA levels were repeatedly low, but were elevated in all with progression. Among 25 patients after radiation and in 28 before and after radiation, low PSA levels were found in all those, without disease progression. High PSA levels, or a rise in levels after irradiation, preceded local growth or metastatic spread. In the 95 patients with metastatic spread who received hormone-and/or chemo-therapy, low PSA levels following initiation of treatment, were a favorable prognostic indicator, with a sensitivity of 100%. High levels, or a rise of levels after initiation of treatment indicated disease progression. The rise in PSA levels preceded clinical evidence of progression by 0 to 30 months. We conclude that serum PSA is a valuable marker for following patients with prostatic cancer.

Effects of prone and supine positions on sleep state and stress responses in preterm infants.

AIM: The purpose of the study is to assess the influence of prone or supine position on sleep states and on withdrawal and approach reactions of preterm infants. METHODS: Thirty-two preterm infants from Meir Medical Center, Israel, mean post menstrual age 30.37±2.57, mean birth weight 1250g±313.86, participated in the study. Infants were studied during 48h. Positions (prone and supine) were alternated every 3-4h after feedings. Sleep states were assessed by Actigraph measurement and by two daily 30-min Naturalistic Observations of Newborn Behavior (NONB) to confirm sleep states and for recording the behavioral reactions (approach and withdrawal). RESULTS: In the prone position there were more approach reactions as compared to withdrawal reactions (p<.001) while in the supine position, the approach and withdrawal reactions were comparable. In the prone position more sleep patterns (deep sleep, light sleep, drowsy) were observed as opposed to more awake patterns (quiet awake, active awake and agitated fussy) that were seen in the supine position. CONCLUSIONS: Clinical implications encourage placing the preterm infant in the prone position while in the NICU. This enables important achievements such as longer periods of quality sleep, and production of adaptive self-regulatory reactions.