Comparative mutagenicity of two chemosterilants, tepa and hempa, in sperm of Bracon hebetor.

In an assessment of the mutagenic efficiency of the alkylating agent, tepa, and its nonalkylating analog, hempa, both chemicals induced a high frequency of recessive lethal mutations in the sperm of the parasitic wasp, Bracon hebetor Say (Habrobracon), although tepa was the more efficient mutagen.

Chromosomal fragments transmitted through three generations in Oncopeltus (Hemiptera).

Chromosomal fragments and translocations induced by x-rays in the sperm of adult milkweed bugs, Oncopeltus fasciatus (Dallas), were detected in the meiotic cells of F(1), F(2), and F(3), males and caused high levels of sterility in lintreated progeny. The persistence of these fragments through numerous generations of cells confirmed the holokinetic nature of the milkweed bug chromosomes.

Surveillance for Lyme disease in Canada: 2009-2015.

OBJECTIVE: To summarize seven years of surveillance data for Lyme disease cases reported in Canada from 2009 to 2015. METHODS: We describe the incidence over time, seasonal and geographic distribution, demographic and clinical characteristics of reported Lyme disease cases. Logistic regression was used to explore differences between age groups, sex and year to better understand potential demographic risk factors for the occurrence of Lyme disease. RESULTS: The number of reported Lyme disease cases increased more than six-fold, from 144 in 2009 to 917 in 2015, mainly due to an increase in infections acquired in Canada. Most locally acquired cases were reported between May and November. An increase in incidence of Lyme disease was observed in provinces from Manitoba eastwards. This is consistent with our knowledge of range expansion of the tick vectors in this region. In the western provinces the incidence has remained low and stable. All cases reported by Alberta, Saskatchewan and Newfoundland and Labrador were acquired outside of the province, either elsewhere in Canada or abroad. There was a bimodal distribution for Lyme disease by age with peaks at 5-9 and 45-74 years of age. The most common presenting symptom was a single erythema migrans rash (74.2%) and arthritis (35.7%). Variations in the frequency of reported clinical manifestations were observed among age groups and years of study. CONCLUSION: Lyme disease incidence continues to increase in Canada as does the geographic range of ticks that carry the Lyme disease bacteria. Ongoing surveillance, preventive strategies as well as early disease recognition and treatment will continue to minimize the impact of Lyme disease in Canada.

Embryonic development in house fly eggs fertilized with genetically deficient sperm.

In house flies, Musca domestica L., eggs fertilized with sperm that have chromosome deficiencies and duplications do not hatch, but develop to a stage where a fully differentiated, prehatch larva is formed. Fifteen different chromosome translocations involving most of the 10 arms of the 5 autosomes were studied by crossing male translocation heterozygotes to normal females. Egg hatch was reduced to 36-66% depending on the translocation used. Eggs that did not hatch after 24 hours were fixed, stained, and examined for stage of development. Several translocations involving the right arm of chromosome 4 indicate that the region closest to the centromere contains genes that affect the process of syngamy or early cleavage divisions, but do not reduce the ability of the sperm to compete for egg fertilization. Approximately 70% of the autosomal genes can be absent from sperm (not simultaneously but in different crosses) without inhibiting embryonic development.

Surveillance for Lyme disease in Canada, 2009 to 2012.

OBJECTIVES: To summarize the first four years of national surveillance for Lyme disease in Canada from 2009 to 2012 and to conduct a preliminary comparison of presenting clinical manifestations in Canada and the United States. METHODS: The numbers and incidence of reported cases by province, month, year, age and sex were calculated. Logistic regression was used to examine trends over time. Acquisition locations were mapped and presenting clinical manifestations reported for jurisdictions where data was available. Variations by province, year, age and sex as well as presenting clinical symptoms were explored by logistic regression. An initial comparative analysis was made of presenting symptoms in Canada and the United States. RESULTS: The numbers of reported cases rose significantly from 144 in 2009 to 338 in 2012 (coefficient = 0.34, standard error = 0.07, P <0.05), mostly due to an increased incidence of infections acquired in Canada. More cases were classified as 'confirmed' (71.5%) than 'probable' (28.5%). Most cases occurred in locations where vector tick populations were known to be present. More men than women were affected (53.4% versus 46.6%), incidence was highest in adults aged 55 to 74 years and in children aged five to 14 years. Most cases (95%) were acquired from April to November. Of cases acquired in endemic areas, 39.7% presented with manifestations of early Lyme disease, while 60.3% had manifestations of disseminated Lyme disease. There were significant differences among age groups, sexes and provinces in the frequencies of reported clinical manifestations. The proportion of cases acquired in endemic areas presenting with early Lyme disease was lower than that reported in the US. CONCLUSION: Lyme disease incidence is increasing in Canada. Most cases are acquired where vector tick populations are spreading and this varies geographically within and among provinces. There is also variation in the frequency of age, season and presenting manifestations. The lower proportion of cases presenting with early Lyme disease in Canada compared with the US suggests lower awareness of early Lyme disease in Canada, but this requires further study.

Vitamins and arthritis. The roles of vitamins A, C, D, and E.

There are at least four mechanisms whereby the nutrient vitamins A, C, D, and E may be related to the processes that impede or give rise to OA. These nutrient vitamins have major roles in modulating oxidative stress, participating in immune responses, and contributing to cell differentiation. There is a substantial need to understand the contribution of these nutrients to OA, because they may provide important insight into ameliorating the initiation and progression of the disease. Simultaneously, greater understanding will add rationality to an area of potential intervention that is often based on anecdote. Investigation will be complex; there is the need to select appropriate systems. Typical animal model systems used in the study of OA are inappropriate because most animals can synthesize ascorbic acid. There is the need to disaggregate, as much as possible, the numerous subsets of OA and the plethora of processes that contribute to that heterogeneity. Certainly, there is the need to recognize the interdependency of the actions of each of these nutrients at the cellular level. Furthermore, humans rarely consume these nutrients as independent products. For example, watermelon is a primary source of both ascorbic acid and beta-carotene. Failure to address these complexities denies the scientist the opportunity to advance our understanding of health and disease processes. More importantly, failure to address these complexities denies the person with OA the opportunity to address his or her own health.

Insect radiosensitivity: dose curves and dose-fractionation studies of dominant lethal mutations in the mature sperm of 4 insect species.

Males of 4 species of insects: Musca domestica L. (housefly) (Diptera), Oncopeltus fasciatus (Dallas) ( milkweed bug) (Hemiptera), Anagasta kuhniella ( Zeller ) ( mealmouth ) (Lepidoptera) and Heliothis virescens (Fab.) (tobacco budworm ) (Lepidoptera) were irradiated as adults. Dose--response curves for the induction of dominant lethal mutations in the mature sperm were constructed. The curves were analyzed mathematically and compared with theoretical computer simulated curves requiring 1, 2, 4, 8 and 16 'hits' for the induction of a dominant lethal mutation. The 4 species belonging to 3 different orders of insects showed a wide range in radiation sensitivity and vastly different dose--response curves. The house fly was the most sensitive and displayed a '1-hit' curve. The milkweed bug was intermediate in sensitivity and the curve exhibited '4-hit' kinetics. The mealmoth and tobacco budworm were most radioresistant and the response curves resembled 8-16--hit simulated curves. When the data were analyzed by several mathematical models we found that a logistic response curve gave reasonably good fit with vastly different parameters for the 4 species. Dose-fractionation experiments showed no reduction in the frequency of lethal mutations induced in any species when an acute dose was fractionated into 2 equal exposures separated by an 8-h period. Various reasons for large differences in radiosensitivity are discussed, e.g., (1) differences in repair mechanisms, (2) variation in oxygen concentration, (3) holokinetic versus monokinetic chromosomes and (4) intrinsic differences in mitotic cell cycles which affect the behavior of radiation-induced chromosome breaks.

Social phobia viewed as a problem in social functioning: a pilot study of group behavioral treatment.

Available treatments of social phobia reduce anxiety and avoidance of social situations. Social functioning however, remains relatively unaffected. This study piloted a behavioral group treatment that aimed at improving patients' individual difficulties in social functioning. Five patients fulfilling DSM-IV criteria for social phobia were selected for treatment by a 16-session behavioral group treatment focusing on improving interpersonal functioning both in specific phobic situations as well as in different spheres of social life in general. Four out of 5 patients completed treatment and showed individual patterns of clinically significant improvement. Their individual test-score results and case-histories are presented. Three patients no longer fulfilled to the diagnostic criteria at the end of treatment; the fourth--at 6 month follow-up. This was maintained at a 2 year follow-up.

Is there a difference between family caregiving of institutionalized elders with or without dementia?

Based on the stress and coping model of Lazarus and Folkman, the aim of this comparative study was to determine whether the caregiving experience of the caregivers of an institutionalized demented relative is different from the one of the caregivers whose relative does not suffer from dementia. Five dimensions of the caregiving experience were considered: stressors, cognitive appraisal of the stressors, social support, coping strategies and well-being. The sample consisted of primary caregivers of a demented and a nondemented relative. Results revealed that the caregivers of a demented relative were exposed to more stressors than the caregivers of a nondemented relative. Functional impairment as well as depressive behaviors were appraised as more disturbing. According to MANCOVA analysis, formal and informal social support seems to play a protective role in the psychological distress of the caregivers of a demented relative. There was no difference between the two groups with regard to their coping strategies. Overall, the caregivers of a demented relative seemed to experience some dimensions of caregiving in a different way compared with their counterparts, and the nature of dementia in itself helps to explain this difference.

The influence of big brothers on the separation-individuation of adolescents from single-parent families.

The separation-individuation process involving children and their mothers is facilitated by fathers. Divorce complicates this process. This study investigated whether substitute father figures can aid male adolescents from single-parent families with separation-individuation. Twenty-nine adolescents matched to Big Brothers were compared with two control groups (adolescents from single-parent families without Big Brothers and those from intact families) on relevant variables. Findings indicated that the adolescents with Big Brothers were less affected by parental rejection than were adolescents in the two control groups. They also appeared to have healthier narcissism than did adolescents from single-parent families without Big Brothers, but were more anxious when relating to male teachers than were adolescents from intact families.

Empirical testing of a longitudinal model derived from the Roy adaptation model.

This article presents the steps and results of the empirical testing of a theoretical longitudinal model, derived from Roy's nursing conceptual model, of the psychosocial determinants of adaptation in different target groups. The model was elaborated and empirically verified based on the integrated results of four longitudinal studies involving groups vulnerable to mental health problems. By means of structural equation analyses, the cross-sectional model was verified at two points in time. The results showed that the model was relatively stable over time. The model was also tested using longitudinal data. Results showed little consistency in the patterns of relationships across studies. The significant links that emerged from the analyses shed some light on the complexity of the process of adaptation to different types of stressors. They underscore the importance for nursing practice to develop interventions aimed at certain variables: perceived stress, conflicts in the exchange of support, and passive and avoidance coping strategies. The results also highlight the importance of the relationship between perceived stress, passive/avoidance coping strategies and psychological distress.

[Validation of a model of psychosocial determinants of occupational health of geriatric nurses]. / Validation d'un modèle de déterminants psychosociaux de la santé au travail de l'infirmière en gériatrie.

The purpose of this study was to verify a model of relationships between psychosocial factors and health for 8066 francophone nurses working in geriatric care in Québec. A random sample of 1990 subjects was drawn and a participation rate of 77.9% and 55% was obtained for the two-time study taken twelve months apart. Based on the theory of Maddi and Kobasa (1984), the model was reproduced for the two-time periods with the aid of structural equations. The analyses showed that three variables exert a direct influence on psychological distress: professional burnout, occupational stressors and hardiness. Also, variables have a direct effect on burnout: listed in order of importance, these are hardiness, occupational stressors, work support, active strategies of coping and employment status. In dealing with the work stressors, the nurses who are hardy make use of active strategies of coping and look for support form their colleagues. The results of the study help to better understand the psychological and social resources that best favor adaptation of working women in highly demanding work environments. The fallout of the study converges towards the quality of life of helping professionals and towards the cost and quality of health and social services.

[Psychological and physical health of the July 1996 disaster victims: A comparative study between victims and non-victims.]. / L'état de santé psychologique et physique des sinistrés des inondations de juillet 1996 : étude comparative entre sinistrés et non sinistrés.

In July 1996, the Saguenay-Lac-St-Jean region suffered one of the greatest natural disasters in Québec's history. This article presents results of a study aiming at comparing, two years after the flood, the physical and psychological health condition of victims (n=177) to that of non-victims (n=168). The results indicate that victims, - regardless of their gender - present a psychological well-being as well as a post-disaster physical health that is different from non-victims. Disaster victims are much more numerous than non-victims in considering that their health is bad or average and in witnessing new health problems or the exacerbation of existing problems. Victims also present more manifestations of prosttraumatic stress and somatic complaints, have higher levels of depression, anxiety and social dysfunction than non-victims. However, no significant difference between subjects was revealed concerning severe depression. Results obtained corroborated that of other studies. After a natural or technological disaster involving important material damages to individual belongings, victims are more affected than non-victims concerning their psychological and physical health.