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PubMed2005

[The influenza season 2004/'05 in the Netherlands with the largest epidemic of the last 5 years caused by the virus variant A/California and the composition of the vaccine for the season 2005/'06].

In the Netherlands, the influenza epidemic of the 2004/'05 season started late. The background value of 3 cases of an influenza-like illness per 10,000 inhabitants per week was exceeded from week 1 until week 14 of 2005. The magnitude of the epidemic was the largest of the last 5 years, namely 104 per 10,000 inhabitants. As usual, the epidemic was caused mainly by influenza-A viruses of subtype H3N2 and to a lesser degree by A/H1N1 and B viruses. The H3N2-virus isolates belonged to the newly emerged variant A/California/7/04, which deviated slightly from the vaccine strain used for the 2004/'05 season. The influenza-B and H1N1 viruses matched the corresponding vaccine viruses well. For the 2005/'06 season, the World Health Organization has recommended the following vaccine composition: A/California/7/04 (H3N2), A/New Caledonia/20/99 (HiNI), and B/Shanghai/361/02.

Global Health↗
PubMed1991

Seasonal changes in avian song nuclei without seasonal changes in song repertoire.

Seasonal variation in the size of song nuclei in the brains of male songbirds may be related to the ability to learn to sing new songs as adults. This hypothesis was tested with the rufous-sided towhee (Pipilo erythrophthalmus), a species in which song repertoires are stable after 1 yr of life. Towhees were hand raised in the laboratory and tutored with normal towhee songs. After song repertoires were recorded at 1 yr of age, photoperiods were manipulated so that 10 male towhees experienced short days and 10 males experienced long days. Circulating hormone concentrations and anatomical attributes of song nuclei were then measured. Photoperiod-related differences in the song nuclei of these towhees were as large as those seen in "open-ended learners" (i.e., species that continue to learn new songs as adults). Seasonal changes of the adult song system may thus occur without disrupting existing song repertoires and without the development of new songs. The synaptic plasticity provided by such seasonal variation, however, may enable song learning by adult birds.

Animals↗
PubMed1979

Seasonal migration and seasonal variation in fecundability: effects on birth rates and birth intervals.

Seasonal patterns in conception rates have been documented in several recent studies. In this paper, a mathematical model of the reproductive process is developed through which the impact of such variation in conception rates is assessed. It is found that the effect on fertility can be quite substantial, but that the birth rate when seasonal variation is occurring is approximated well by the birth rate calculated when conception rates are constant at their mean. These results indicate that further documentation of seasonality in conception rates and exploration of the causes of these patterns and their change is an important area for demographic research.

Birth Rate↗
PubMed1983

[Circadian, infradian and seasonal changes in neural conduction velocity with reference to the effects of temperature. II: Infradian and seasonal changes].

Using the longitudinal study it was shown that a number of sensory neurographic parameters changed systematically throughout the 4-day investigation. In particular the sensory NCV of the n. medianus of the hand increased significantly. Possible causes i.e. the activation of the metabolism are discussed. Should this assumption prove to be true repetitive stimulation of a nerve could have a therapeutic effect. The seasonal influences are displayed using the results of a cross-sectional study. Six out of 21 neurographic parameters showed significant seasonal variations. In the NCVs of the n. medianus and the n. ulnaris maxima were present in summer and autumn while the NCVs of the lower extremities had minima. In winter and spring differences between the NCVs of the lower and upper arm and leg were lowest. These differences may be caused by seasonal changes of the metabolism which modifies the coefficient of the temperature of the neurographic parameters.

Circadian Rhythm↗
PubMedDate not supplied

Seasonal branch and fine root growth of juvenile loblolly pine five growing seasons after fertilization.

In 1989, we established two replications of two fertilization treatments in a 10-year-old loblolly pine (Pinus taeda L.) plantation. Between March and September 1993, branch internode and needle fascicle expansion in the upper and lower third of crowns were measured weekly on three south-facing branches of each of four trees, and new root initiation and elongation were measured at 10-day intervals in three vertical rhizotrons per plot. In one replication, soil water content was measured daily. Fertilization significantly increased the expansion of first flush internodes in the upper crown and first flush needle fascicles in the upper and lower crown. New root growth was stimulated by fertilization in the second half of the growing season. The timing of root growth responses to fertilization corresponded to branch phenologies in the upper and lower crown that were conducive to increased basipetal transport of photosynthate. We conclude, therefore, that new root growth was linked to source-sink activities in the crown. Root initiation was greater in the upper than in the lower part of the soil profile; however, as the growing season progressed and water deficit increased, this relationship was reversed. The effect of soil depth on seasonal root growth was closely associated with water availability, suggesting that root initiation deep in the soil profile is critical for the continued production of new roots in environments subjected to short-term, but relatively severe, water deficits.

Journal Article↗
PubMed2002

[The 2001/2002 influenza season and the vaccine composition for the 2002/2003 season].

The epidemic in the influenza season 2001/2002 was of moderate activity just like in 2000/2001. The influenza epidemic started in week 2 of 2002 when the clinical influenza activity reported by the general practitioner network of the Netherlands Institute of Primary Health Care (NIVEL) increased. This was caused by influenza A viruses of the H3N2 subtype in particular. All influenza A viruses of this subtype were closely related to the vaccine strain for this subtype, A/Moscow/10/99. Influenza B viruses and influenza A/H1 viruses isolated this season had surprising features. The influenza B viruses originated from two lineages. Viruses of the B/Yamagata/16/88 lineage have been circulating for more than twelve years. The vaccine reference strain B/Sichuan/379/99 belongs to this lineage. The B/Victoria/2/87 lineage reappeared again after an absence in Europe of more than ten years and accounted for 50% of the influenza B viruses that were isolated in the Netherlands. Therefore the vaccine will have provided only partial protection against influenza B. The only influenza A/H1 virus that was isolated appeared to be of a new subtype H1N2. The H1 hemagglutinin of this virus was closely related to that of the vaccine strain A/New Caledonia/20/99. The N2 neuraminidase originated from recent human influenza A/H3N2 viruses. Therefore the vaccine probably provided good protection against the new H1N2 subtype. Based in part on these data, the World Health Organization has advised that the vaccines for the season 2002/2003 should contain the following or comparable influenza-virus strains: A/Moscow/10/99 (H3N2), A/New Caledonia/20/99 (H1N1) and B/Hong Kong/330/01, the latter being an influenza B virus of the B/Victoria/2/87 lineage.

Global Health↗
PubMed2005

Seasonality and seasonal affective disorder (SAD): an evolutionary viewpoint tied to energy conservation and reproductive cycles.

The characteristic symptoms of SAD, including hypersomnia and weight gain, might reflect a genetically programmed attempt to conserve energy during historically predictable periods of dwindling food supply. While this basic hypothesis has obvious conceptual appeal, few authors have considered the specific positive selection pressures that might have contributed to such a process. The goal of the current paper is to further develop an evolutionary model of SAD with a focus on energy conservation in the context of seasonal reproductive cycles. To accomplish this, seasonal data on birth rates are considered from an evolutionary viewpoint. There is considerable indirect evidence that in temperate climates, the symptoms of SAD reflect a predisposition for conception to occur in late spring/early summer to ensure a peak of births in the late winter/early spring. The adaptive value of such a pattern, and its putative role in natural selection in humans, is also discussed.

Adaptation, Physiological↗
PubMed1999

The prevalence of seasonal affective disorder in The Netherlands: a prospective and retrospective study of seasonal mood variation in the general population.

BACKGROUND: The aim of the present study was to assess the prevalence of seasonal affective disorder (SAD) in The Netherlands. METHODS: The subjects (n = 5356), randomly selected from community registers, were given the Seasonal Pattern Assessment Questionnaire and the Centre for Epidemiological Studies Depression Scale over a period of 13 months. The response rate was 52.6%. RESULTS: Three percent of the respondents met the criteria for winter SAD, 0.1% for summer SAD. The criteria for subsyndromal SAD, a milder form of SAD, were met by 8.5%, 0.3% of whom showed a summer pattern. Younger women received a diagnosis of SAD more often than men or older women. CONCLUSIONS: SAD subjects were significantly more often unemployed or on sick leave than other subjects. Respondents who met winter SAD criteria were significantly more depressed than healthy subjects, in both winter and summer. Finally, month of completion had no influence on the number of subjects meeting the SAD criteria.

Absenteeism↗
PubMed2005

Influence of sociodemographic factors on quality of life during pollen season in seasonal allergic rhinitis patients.

BACKGROUND: Quality of life (QOL) is an important outcome in asthma and seasonal allergic rhinitis (SAR), and its determinants are imperfectly understood. More specifically, the influence of sociodemographic factors on QOL in patients with SAR has been so far little investigated. OBJECTIVE: To examine the changes of QOL during the pollen season in patients with isolated SAR or SAR associated with asthma. METHODS: A prospective cohort study was conducted in southern France. Outpatients aged 18 to 60 years and regularly treated by respiratory physicians for SAR (with or without associated asthma) were identified. Patients were recruited before the grass or ragweed pollination period. At peak pollination, patients completed the French versions of the Mini Rhino-conjunctivitis Quality of Life Questionnaire (mini-RQLQ) and the 12-item Short-Form Health Survey (SF-12) physical component summary (PCS) and mental component summary (MCS). RESULTS: A total of 135 patients was included, 83 with isolated SAR and 52 with associated asthma (mean age, 35.4 years; SD, 10.6 years; 56% female). At pollen peak, QOL scores were lower in women for all instruments, with significant effects on SF-12 MCS and PCS scores in multivariate analyses. Likewise, a university-level education was an independent predictor of higher SF-12 PCS and MCS scores. Patients who lived in rural areas had significantly poorer QOL at pollen peak, as measured by the mini-RQLQ (P = .002) and SF-12 PCS (P = .008). No influence of age, presence of an animal at home, or smoking status could be identified on any QOL scores. CONCLUSIONS: Being a woman, living in the countryside, and having a lower education level were all independent predictors of poorer QOL of SAR patients. These factors must be taken into account when interpreting QOL of patients with SAR. Further studies are needed to confirm these results.

Adolescent↗
PubMedDate not supplied

Application of ARIMA model in adjustment of seasonal and non-seasonal variations in births of Ontario.

"The objective of this paper is to justify the use of Autoregressive Integrated Moving Average (ARIMA) models for birth time series data of the province of Ontario [Canada]." The results show that the model provides satisfactory short-term forecasts. "It shows that along with seasonal varations, non-seasonal variations due to reporting etc. must be taken into account for interpreting similar time series data." (summary in FRE, ITA)

Americas↗
PubMedDate not supplied

Tolerability of retreatment with omalizumab, a recombinant humanized monoclonal anti-IgE antibody, during a second ragweed pollen season in patients with seasonal allergic rhinitis.

Two randomized, placebo-controlled, double-blind studies have shown clinical benefit with omalizumab (Xolair), a recombinant humanized monoclonal anti-immunoglobulin E (IgE) antibody, at a dose of 300 mg every 3 or 4 weeks in patients with seasonal allergic rhinitis. The present open-label, 12-week study was designed to assess the safety and tolerability of retreatment with omalizumab in 287 patients previously treated with this agent in one of the latter studies. Omalizumab, 300 mg, was administered subcutaneously every 4 weeks (three injections) to patients with IgE levels < or = 150 IU/mL (n = 182) and every 3 weeks (four injections) to patients with IgE levels > 150 IU/mL (n = 105) at screening before retreatment. Reported adverse events were monitored and blood samples were analyzed for laboratory safety (hematology and serum chemistry) and IgE levels. Urinalysis also was completed as part of the laboratory safety evaluation. The overall incidence and pattern of adverse events were similar to those reported in the primary study. There were no severe or serious adverse events related to omalizumab treatment and no anti-omalizumab antibodies were detected in any patient. Two patients withdrew from treatment because of adverse events (skin rash and nausea; facial erythema and edema) related to study treatment. Free IgE levels decreased to the levels associated with symptom reduction in the core study. In summary, retreatment during a second pollen season with omalizumab, 300 mg every 3 or 4 weeks, was well tolerated and was not associated with any significant immunologic reactions.

Adolescent↗
PubMed1990

Seasonal affective disorder and season-dependent abnormalities of melatonin suppression by light.

Twelve patients with seasonal affective disorder (SAD) and eleven normal controls were exposed to 2000 lux and 300 lux of artificial full-spectrum light on consecutive nights during the winter. Suppression of melatonin secretion under the two light intensities was measured and the difference between their effects was taken as a measure of light sensitivity. The test was repeated in summer in both groups, when the SAD subjects were well. The SAD but not the normal group showed a significant seasonal variation in sensitivity to light. There was evidence of supersensitivity in the winter but also of subsensitivity to light in the summer.

Adult↗
PubMed1993

Anxiety disorders and anxiety symptoms in a clinic sample of seasonal and non-seasonal depressives.

Thirty-eight patients with seasonal affective disorder (SAD) were compared with 33 non-seasonal recurrent major depressives (non-SAD) who presented during the winter months for differences in the prevalence of concurrent anxiety disorders and the impact of anxiety on treatment response. SAD patients received light therapy, whereas non-SAD patients received antidepressant medications. There was no differences in the prevalence of any anxiety disorder, or on scores of anxiety on the Hamilton Rating Scale for Depression between the SAD and non-SAD groups. The presence of any anxiety disorder was associated with a better response rate in SAD patients, and an inferior response rate in non-SAD patients. The findings refute previous suggestions that anxiety is more common in SAD than in non-SAD, but suggest that the presence of anxiety may be associated with differential treatment response rates.

Adult↗
PubMed1996

Seasonal and non-seasonal depression and the five-factor model of personality.

The purpose of this study was to compare the personality characteristics of patients with non-psychotic, major depression, seasonal subtype (SAD) to patients with non-psychotic, major depression, without seasonality (non-SAD). The patients were consecutive referrals to a university-affiliated mood disorders outpatient clinic. The personality characteristics were assessed using the five-factor model of personality (FFM) as measured by the revised NEO Personality Inventory (NEO PI-R). Patients were assessed during the acute depressive episode. Controlling for severity of depression, differences were found on only one of the five dimensions, with the SAD patients (n = 43) scoring significantly higher on the Openness dimension than non-SAD patients (n = 57). Based on these results we infer SAD patients may represent a psychologically distinct subgroup of depressed patients-more imaginative, more emotionally sensitive and likely to entertain unconventional ideas than non-SAD patients. This personality constellation may explain why individuals with SAD are more sensitive to and may amplify the mild dysphoria typically associated with winter months.

Depressive Disorder↗
PubMed1988

Seasonal variations of DNA-synthesis in intestinal epithelial cells of hibernating animals--2. DNA-synthesis in intestinal epithelial cells of ground squirrel (Citellus undulatus) during autumn and late hibernation season.

1. DNA-synthesis was found to be gradually reduced in the intestinal crypt cells of ground squirrel during autumn at the time of preparation for hibernation and gradually rose during late hibernation season in February-March at the time of preparation for arousal. 2. A conclusion is made on the seasonal variations in cell replacement of true hibernators.

Animals↗
PubMed2004

Etiology, pathogenesis, and treatment of seasonal and non-seasonal mood disorders: possible role of circadian rhythm abnormalities related to developmental alcohol exposure.

Developmental alcohol exposure adversely influences the developing brain. Alcohol exposure during rapid brain growth causes cell loss, alters connections between brain regions, and lowers the production of biological substances responsible for the communication among neurons. It is reasonable to suggest that alcohol may adversely affect the development of suprachiasmatic nuclei (SCN), the master circadian pacemaker. Multiple research reports suggest that abnormalities in circadian rhythms are involved in the etiopathogenesis of seasonal affective disorder (SAD), a syndrome in which depression develops during autumn or winter and remits the following spring or summer. Several lines of evidence suggest that changes in the circadian system are also involved in the development of nonseasonal mood disorders, such as major depression and bipolar disorder. Thus, developmental alcohol exposure produces subtle abnormalities in circadian rhythms that may contribute to the development of seasonal and nonseasonal mood disorders. Pharmacological, psychological, and light treatments of mood disorders have multiple effects on circadian function. The state of the circadian system may affect a response to treatment. Circadian rhythms have been reported for neurotransmitters, receptors, enzymes, and the second messenger system in the brain that are involved in the effects of treatments. Some of these rhythms have amplitudes as large as several 100%. Effects of many psychotropic medications depend on the time of administration in relation to body rhythmicity. Therefore, subtle circadian rhythm abnormalities related to developmental alcohol exposure may affect treatment response in patients with mood disorders.

Alcohol Drinking↗
PubMed2004

Seasonal changes in markers of oxidative damage to lipids and DNA; correlations with seasonal variation in diet.

We have addressed the question whether the relatively high incidence of cardiovascular disease and certain cancers in countries of central/eastern Europe might be associated with nutritional imbalance, in particular a lack of fresh fruit and vegetables in the diet in winter months. Nutritional parameters and markers of oxidative stress were studied in three Slovak population groups: 46 survivors of myocardial infarction (MI group) and 48 healthy, normolipidemic subjects (NL), living in or near Bratislava; and 70 rural controls (RC group) living a more traditional life style in a country town. Data were collected in February/March and September/October of two consecutive years, representing times of minimum and maximum local availability of fresh fruits and vegetables. Oxidative stress was monitored using two biomarkers; plasma malondialdehyde (MDA, a product of lipid peroxidation), and oxidation of lymphocyte DNA. Dietary antioxidants, folic acid, homocysteine, total antioxidant status (FRAP) and uric acid were measured in plasma. Food frequency questionnaires were administered. Vegetable consumption in summer/autumn was twice as high as in winter/spring. DNA damage did not vary consistently across the seasons. Mean plasma MDA levels for the MI and NL groups showed a clear pattern, with high levels in winter/spring and low levels in summer/autumn. Folic acid showed a reciprocal pattern, similar to the pattern of vegetable consumption. The RC group had the smallest seasonal variations in vegetable consumption, folic acid levels, and MDA. High winter MDA levels are seen in those individuals with relatively low folic acid; they never occur in subjects with high plasma folic acid, implying that folic acid might directly protect against lipid oxidation. This study illustrates the value of the molecular epidemiological approach, while emphasising the need for well characterised population groups and valid biomarkers.

Antioxidants↗
PubMed1999

Temperament traits in seasonal affective disorder, suicide attempters with non-seasonal major depression and healthy controls.

BACKGROUND: Very few studies have compared the temperament traits in matched suicidal and non-suicidal patients with major depression. METHODS: We compared the temperament traits in two matched groups of patients with major depressive disorder (MDD), MDD with seasonal subtype (SAD) without any suicide attempt (n = 23) and MDD without seasonal variation who attempted suicide (non-SAD SA), and compared the patients to matched healthy controls by using the Karolinska Scales of Personality (KSP) and the Marke-Nyman Temperament (MNT) questionnaires. RESULTS: Both the SAD and non-SAD SA groups showed significantly higher Somatic Anxiety, Muscular Tension, Psychasthenia, Irritability, Suspicion, and lower Socialization and Validity than the controls. The non-SAD SA group also showed significantly higher Psychic Anxiety, Detachment and Guilt as compared to controls. When the SAD and the non-SAD SA were compared, we found significantly higher Somatic Anxiety, Psychic Anxiety and Muscular Tension for the non-SAD SA group. CONCLUSIONS: Both SAD and non-SAD SA patients display different temperament profiles compared to controls and in comparison with each other and the suicide attempters show especially high trait anxiety and hostility. CLINICAL RELEVANCE: The results suggest that trait anxiety and hostility, but not impulsivity, are associated with suicidal behavior in major depression.

Adolescent↗