Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “VACATIONS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 487 records · Page 27Linked to original sources
PubMed2000

DNA repair capacity in healthy medical students during and after exam stress.

There has been extensive research into the effects of stress on immune function but little on the effects of stress on DNA repair capacity (DRC), a process central to maintaining a normal cell cycle. Defective DRC is one of the factors responsible for carcinogenesis. In the present study we assessed DRC in healthy medical students during times of high and low stress. Sixteen medical students were evaluated during the third day of a 5-day exam period and then again 3 weeks later, after vacation. At both time points, participants underwent a brief physical examination, had venous blood drawn, and completed questionnaires to identify subjective stress levels. The DRC was assessed by the host-cell reaction assay, which measures nucleotide excision repair capacity. Participants reported significantly higher levels of subjective stress during the exam period than after vacation. DRC was also significantly higher during the exam period than after vacation, suggesting a positive association between subject stress levels and DRC. The results are discussed in relation to previous findings and implications for cancer research.

Adult↗
PubMedDate not supplied

Terminal Schwann cells guide the reinnervation of muscle after nerve injury.

Schwann cells and axons labeled by transgene-encoded, fluorescent proteins can be repeatedly imaged in living mice to observe the reinnervation of neuromuscular junctions. Axons typically return to denervated junctions by growing along Schwann cells contained in the old nerve sheaths or "Schwann cell tubes". These axons then commonly "escape" the synaptic sites by growing along the Schwann cell processes extended during the period of denervation. These "escaped fibers" grow to innervate adjacent synaptic sites along Schwann cells bridging these sites. Within the synaptic site, Schwann cells, originally positioned above the synaptic site continue to cover the acetylcholine receptors (AChRs) immediately following denervation, but gradually vacate portions of this site. When regenerating axons return, they first deploy along the Schwann cells and ignore sites of AChRs vacated by Schwann cells. In many cases these vacated sites are never reinnervated and are ultimately lost. Following partial denervation, Schwann cells grow in an apparently tropic fashion from denervated to nearby innervated synaptic sites and serve as the substrates for nerve sprouting. These experiments show that Schwann cells provide pathways that stimulate axon growth and insure the rapid reinnervation of denervated or partially denervated muscles.

Animals↗
PubMed2006

Sexual risk and HIV acquisition among men who have sex with men travelers to Key West, Florida: a mathematical modeling analysis.

The present study investigated the sexual risk behaviors of men who have sex with men (MSM) traveling to a popular gay tourist destination in the United States. In 2004, a brief survey was administered to 247 MSM tourists recruited from gay-oriented venues in Key West, Florida. Data collected included demographics, HIV status, length of stay, substance use, and sexual risk behaviors. A probabilistic model of HIV transmission was used to translate participants' reports of their sexual behaviors while in Key West into estimates of their risk of acquiring HIV. Twenty-two percent of participants reported anal sex with multiple partners over a relatively brief period (M = 4.1 days), and approximately one third reported having sex with a partner met during the vacation period. Modeling analyses suggested that sexual activity among vacationing MSM would account for approximately 201 new HIV infections among MSM visitors to Key West each year. Although previous studies have documented sexual risk behavior in travelers, quantitative estimates of the impact of these behaviors on the spread of HIV are lacking. Findings suggest that the risk-taking behavior of MSM on vacation may play an important role in the dissemination of HIV and other sexually transmitted diseases (STDs). Future research should assess additional factors (e.g., use of highly active antiretroviral therapy) that may affect HIV transmission in MSM travelers. In addition, efforts are needed to develop effective risk-reduction interventions for this population.

Adult↗
PubMed2002

Seasonal variation in myopia progression and ocular elongation.

PURPOSE: To evaluate possible seasonal variations in myopia progression and ocular elongation in school children. METHODS: Seventy-one children who were enrolled in a clinical trial of bifocals were examined every 6 months for 30 months. Three 6-month intervals ("winters") included none of the summer vacation from school, and two intervals ("summers") included all of the summer vacation. Myopia was evaluated, after cycloplegia with 2 drops of 1% tropicamide, by automated refractor, and changes in axial length and in vitreous chamber depth were measured by A-scan ultrasonography. Data from left and right eyes were averaged because there was no evidence of a significant eye-visit interaction. Analysis of variance with a planned contrast was used to evaluate differences between the observed rates of change over the two summers compared with expected rates assuming no seasonal effect. RESULTS: For 37 children in single-vision lenses, myopia progression rates over the two summers averaged 0.15 D compared with 0.32 D over the three winters. For 34 children in bifocal glasses, summer rates averaged 0.07 D compared with 0.30 D for winters. Analysis of variance showed that seasonal effects on myopia progression were significant (p < 0.025) for both groups for the first summer and approached significance for the second summer. Increases in vitreous chamber depth were also slower during the summer, significantly so (p < 0.01) for both summers in the single-vision group and for the second summer only in the bifocal group. Changes in axial length were somewhat slower in the summer, but the effect of season reached statistical significance in that variable only for the second summer in the bifocal group (p = 0.031). CONCLUSION: Myopia progression rates were slower during the 6-month periods that included all of the summer vacation than would be expected assuming no seasonal effect. Ocular growth was also slower in the summer; but that trend, in most cases, was statistically significant only for changes in vitreous chamber depth and not for axial length.

Child↗
PubMed2003

Risk factors for cutaneous malignant melanoma among aircrews and a random sample of the population.

AIMS: To evaluate whether a difference in the prevalence of risk factors for malignant melanoma in a random sample of the population and among pilots and cabin attendants could explain the increased incidence of malignant melanoma which had been found in previous studies of aircrews. METHODS: A questionnaire was used to collect information on hair colour, eye colour, freckles, number of naevi, family history of skin cancer and naevi, skin type, history of sunburn, sunbed, all sunscreen use, and number of sunny vacations. RESULTS: The 239 pilots were all males and there were 856 female cabin attendants, which were compared with 454 males and 1464 females of the same age drawn randomly from the general population. The difference in constitutional and behavioural risk factors for malignant melanoma between the aircrews and the population sample was not substantial. The aircrews had more often used sunscreen and had taken more sunny vacations than the other men and women. The predictive values for use of sunscreen were 0.88 for pilots and 0.85 for cabin attendants and the predictive values for sunny vacation were 1.36 and 1.34 respectively. CONCLUSION: There was no substantial difference between the aircrew and the random sample of the population with respect to prevalence of risk factors for malignant melanoma. Thus it is unlikely that the increased incidence of malignant melanoma found in previous studies of pilots and cabin attendants can be solely explained by excessive sun exposure.

Adult↗
PubMed2005

Elimination and reinvasion studies with Coptotermes formosanus (Isoptera: Rhinotermitidae) in Louisiana.

Three Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), colonies located inside the 12.75-ha Louis Armstrong Park, New Orleans, were selected for elimination by using the chitin synthesis inhibitor hexaflumuron. Once eliminated, each vacated foraging territory was monitored for reinvasion by neighboring C. formosanus colonies, Reticulitermnes flavipes (Kollar) (Isoptera: Rhinotermitidae) colonies, or both. Each selected colony was eliminated in approximately 3 mo by using baits containing hexaflumuron. Overall activity of each untreated colony in the park remained unchanged during the same period. New C. formosanus and R. flavipes activity was detected in two of the three vacated territories, and in both areas, within days of selected colony elimination. The third vacated territory was completely reoccupied by a new C. formosanus colony approximately 7 mo later. Mark-recapture studies and DNA fingerprinting confirmed the distinctness of the reinvaders from eliminated and neighboring colonies.

Animals↗
PubMedDate not supplied

[Application of transcranial magnetic stimulation for monitoring of the motor cortex condition in dynamics in healthy subjects].

Transcranial magnetic stimulation (TMS) is used already for sixteen years for studying human central nervous system. The main objective of this work was to study motor thresholds and their hemispheric asymmetry in healthy subjects during TMS. We examined 31 righthanded healthy students. Their motor thresholds were measured in May (before vacations), September (immediately after vacations), and November (two months after vacations). Magnetic stimulator Neurosoft-MS (Ivanovo, Russia) was used for TNS of the motor cortex. It was shown that in the absence of regular active functional loads on the right hand, the motor thresholds in healthy righthanders significantly increased under the TMS of the left hemisphere, and hemispheric asymmetry disappeared under conditions both of muscle relaxation and voluntary contraction. Motor thresholds under the left-side TMS decreased and hemispheric asymmetry recovered with the restart of the regular active functional loads on the right hand.

Adult↗
PubMed2004

[Osteoarthritis, disability, travel and recreational activities: comments from physicians and travel specialists].

IMPACT OF DISABILITY: A survey of general practitioners, rheumatology specialists, and tourism specialists conducted by NEGMA-LERADS Laboratories demonstrated that subjects with osteoarthritis avoid vacation trips more readily than recreational activities. VACATION TRIPS ARE STILL POSSIBLE: Certain tourism organisms have nevertheless developed specialized services for disabled persons. Special emphasis is placed on adequate preparation before the vacation trip. PROBLEMS WITH WALKING: Many persons disabled by osteoarthritis do not require a wheel chair, yet have difficulty walking long distances. It is important to recognize the specific disabilities related to osteoarthritis and their effects on grip force and/or ambulation.

Activities of Daily Living↗
PubMedDate not supplied

Pilot study of peripheral markers of catecholaminergic systems among workers occupationally exposed to toluene.

In a pilot study, serum dopamine beta-hydroxylase (DBH), platelets monoamine oxidase type B (MAO B) activities and basal plasma prolactin (PRL) were measured, among 10 workers occupationally exposed to toluene and 10 control subjects, preceding and immediately following vacation. Six exposed subjects were employed in an adhesive tape making industry and 4 in a paint making industry. Their median basal levels of urinary hippuric acid were 0.44 mmole/mmole creatinine (cr) (range 0.23-1.97) and 0.18 mmole/mmole cr (range 0.15-0.19) respectively, the second to last morning of the work week, preceding vacation. The level of basal urinary hippuric acid among the control group was 0.26 mmole/mmole cr (range 0.03-0.38). The workers from the adhesive tape plant reported a significantly higher number of symptoms experienced frequently (Kruskal, Wallis, p < 0.05). On a group basis, serum DBH was lowest among the workers from the adhesive tape plant, who had the highest levels of basal urinary hippuric acid. In addition, a negative relation was observed between hippuric acid and serum DBH, preceding and following vacation (Rho = -0.46, p = 0.05; Rho = -0.51, p = 0.03). The observed changes in serum DBH activity are consistent with its decrease in human, following long-term exposure to styrene, another aromatic hydrocarbon. The findings of this pilot study, on a limited number of individuals suggest that DBH may be a sensitive peripheral bioindicator. Further studies of larger groups should be done to confirm the decrease in serum DBH activity with toluene exposure and explore whether this alteration is related to the neurotoxic impairments associated with exposure.

Adult↗
PubMed1997

[Immune response reduced by intense intellectual stress: changes in lymphocyte proliferation in medical students].

BACKGROUND: There is a relationship between stressful situations and the susceptibility towards certain diseases, probably mediated by immune system modifications. AIM: To study T lymphocyte proliferation in medical students during periods of differing academic stress. SUBJECTS AND METHODS: Blood samples were obtained from 42 medical students during a period of moderate academic stress, immediately before a final examination and after their summer vacations. T lymphocyte proliferation in response to 5, 10 and 20 mg/ml phytohemagglutinin was measured by the incorporation of 3H-thymidine, and plasma cortisol was measured by RIA. RESULTS: T lymphocyte stimulation index in response to all phytohemagglutinin concentrations was significatively lower in the period before examination than in the other two periods. There were no differences in the index between the period of moderate stress and after summer vacations. Plasma cortisol levels were 15.6 +/- 4.3, 18.6 +/- 5.8 and 16.7 +/- 5.1 mg/dl during the periods of moderate stress, before the examination and after vacations, respectively (p < 0.05 for the difference between examination and the other two periods). CONCLUSIONS: There is a decrease in lymphocyte proliferation and an increase in cortisol levels during a period of acute academic stress in medical students, suggesting that, the exposure of the healthy subjects to common stressful stimuli, may affect their immunocompetance.

Adult↗
PubMed2001

Psychological stress perturbs epidermal permeability barrier homeostasis: implications for the pathogenesis of stress-associated skin disorders.

BACKGROUND: A large number of skin diseases, including atopic dermatitis and psoriasis, appear to be precipitated or exacerbated by psychological stress. Nevertheless, the specific pathogenic role of psychological stress remains unknown. In 3 different murine models of psychological stress, it was recently shown that psychological stress negatively impacts cutaneous permeability barrier function and that coadministration of tranquilizers blocks this stress-induced deterioration in barrier function. OBJECTIVES AND METHODS: The relationship between psychological stress and epidermal permeability barrier function was investigated in 27 medical, dental, and pharmacy students without coexistent skin disease. Their psychological state was assessed with 2 well-validated measures: the Perceived Stress Scale and the Profile of Mood States. Barrier function was assessed simultaneously with the stress measures at periods of presumed higher stress (during final examinations) and at 2 assumed, lower stress occasions (after return from winter vacation [approximately 4 weeks before final examinations] and during spring vacation [approximately 4 weeks after final examinations]). RESULTS: The subjects as a group demonstrated a decline in permeability barrier recovery kinetics after barrier disruption by cellophane tape stripping, in parallel with an increase in perceived psychological stress during the higher vs the initial lower stress occasions. During the follow-up, presumed lower stress period, the subjects again displayed lower perceived psychological stress scores and improved permeability barrier recovery kinetics, comparable to those during the initial lower stress period. Moreover, the greatest deterioration in barrier function occurred in those subjects who demonstrated the largest increases in perceived psychological stress. CONCLUSION: These studies provide the first link between psychological status and cutaneous function in humans and suggest a new pathophysiological paradigm, ie, stress-induced derangements in epidermal function as precipitators of inflammatory dermatoses.

Adult↗
PubMedDate not supplied

Monthly distribution of menarche among schoolgirls from a municipality in Southeastern Brazil.

We studied the monthly distribution of menarche among schoolgirls from Barrinha, Brazil, a municipality of rural characteristics in the process of transition to urbanization, economically dependent on sugar cane culture and processing. The association between season of the year, month of the year, and birth month and the occurrence of menarche was evaluated. The schoolgirls who provided the date of menarche (month and year) by the recall method and who had menarche up to 36 months before the interview were selected for analysis (460 girls). The correlations between month of occurrence of menarche and month of birth and between menarche and seasons of the year were determined by the chi-square test and the mean monthly ages at menarche were compared by Student's t-test, with a significance level of 0.05. There was a correlation between month of birth and month at menarche, with a peak of occurrence of menarche in December not affected by the menstruating patterns of maturation, but no correlation between menarche and seasons of the year. The difference between mean age at menarche in December (spring-summer transition) and in June (autumn-winter transition) was not significant. Mean age at menarche during the month following school vacations was lower. We conclude that situations of stress-relaxation transition, such as end of the school year, beginning of school vacation, and, perhaps most important, the socioeconomic factor-the end of the sugar cane harvest, when rural workers receive their final payments-favor the occurrence of the peak of menarche in December.

Adolescent↗
PubMed2003

How important are economic factors in choice of medical specialty?

An ongoing debate exists among health care researchers about the mechanism that allocates physicians across medical specialties, and appropriate policy measures to correct imbalances that may arise from time to time. Most researchers believe that choice of residency program by medical school graduates is key to understanding how physicians are distributed across specialties, but there is much disagreement about whether economic or non-economic factors are most influential in determining this choice. We undertake an empirical investigation of two potentially important economic factors: income and leisure. To do so, we specify a two way error component regression model to estimate the effects of expected earnings and available leisure time, and uncertainty of earnings and leisure, on specialty choices of medical residents. Our findings indicate that economic factors are an important influence in the specialty choice process; in particular, medical residents are attracted to specialties that offer the prospect of longer and more certain annual vacations, higher earnings, shorter residency programs, and more certain work schedules. Our results suggest that employment contracts that provide generous annual vacation time and promise regular weekly work schedules may be more effective than increased earnings in correcting the current perceived shortage of primary care physicians.

Career Choice↗
PubMed2004

Sun exposure may protect against non-Hodgkin lymphoma: a case-control study.

Ultraviolet radiation is a hypothesised risk factor for non-Hodgkin lymphoma (NHL) but no epidemiological study has examined this association using direct measures of sun exposure in individuals. Adults aged 20-74 years living in NSW and ACT, Australia, were the study population. Cases (704 of 829 invited to take part, 85%) were diagnosed January 2000 to August 2001. Controls (694 of 1,136 invited to take part, 61%) were randomly selected from state electoral rolls and frequency-matched to cases by age, sex and state of residence. A self-administered questionnaire and telephone interview measured outdoor hours on working and nonworking days and vacations at 10, 20, 30, 40, 50 and 60 years of age. Logistic regression models of NHL and sun exposure contained the 3 matching variables, ethnicity and sun sensitivity measures as covariates. Contrary to expectations, risk of NHL fell with increasing reported sun exposure hours. Relative to 1.0 for the lowest quarter of total sun exposure hours, the odds ratios (ORs) for successively higher quarters were 0.72 (95% CI 0.53-0.98), 0.66 (0.48-0.91) and 0.65 (0.46-0.91) (p(trend)=0.01). The association of sun exposure on nonworking days with NHL was stronger; OR for highest quarter 0.47 (0.34-0.66) (p(trend)=0.0001). Risk also fell with sun exposure on vacations; OR for highest quarter 0.60 (0.43-0.85) (p(trend)=0.003). These associations appeared strongest in women and in childhood. There was little evident trend in risk with exposure on working day. Our results provide strong statistical evidence for an inverse association between sun exposure and NHL. Increasing evidence that vitamin D may protect against cancer makes UV-mediated synthesis of vitamin D a plausible mechanism whereby sun exposure might protect against NHL.

Adolescent↗
PubMed1985

Cutaneous melanoma in relation to intermittent and constant sun exposure--the Western Canada Melanoma Study.

The histories of exposure to sun through occupational, recreational and vacation activities of 595 patients with newly incident cutaneous melanoma excluding lentigo maligna and acral lentiginous melanoma, were compared to those of comparison subjects drawn randomly from the same population and matched for age, sex and province of residence in Western Canada. Significant increases in risk were seen with increasing amount of sun exposure through outdoor activities associated with recreation and vacations; activities likely to involve more intense sun exposure were associated with greater increases in risk. While a moderate amount of occupational exposure was associated with increased risk, greater occupational exposure resulted in no further increase; in men a decrease in risk was seen. These findings were independent of the effects of hair and skin colour, freckles, ethnic origin and socio-economic status. The results suggest that short-term exposure to unusually intense sunlight increases the risk of melanoma, while long-term constant exposure has no effect or may decrease risk. No simple relationship was seen between melanoma risk and total sunlight exposure. This study introduces new methods of assessing different types of sun exposure from retrospective data.

Adult↗
PubMed1992

Urinary excretion of o-cresol and hippuric acid after toluene exposure in rotogravure printing.

In 62 male rotogravure printers, the time-weighted average (TWA) toluene exposure during one workweek ranged from 8 to 496 mg/m3 (median 96). Post-shift urinary excretion of hippuric acid showed a poor correlation with the air toluene concentration. Level of o-cresol excretion ranged from 0.08 to 2.37 mmol/mol creatinine and was associated with the exposure (rS = 0.57, P less than 0.0001), although the variation was considerable. However, this metabolite was significantly influenced by smoking habits, both in the workers (0.34 vs 0.10 mmol/mol creatinine after adjustment to zero exposure for the smokers and non-smokers, respectively; P = 0.03) and in 21 unexposed controls (0.18 vs 0.06 mmol/mol creatinine; P = 0.002). The excretion of these metabolites was followed during vacation, when the workers were unexposed. The shared one-compartment half-time was 44 h (+/- SE 30, 82). After 2-4 weeks of vacation, the concentration of o-cresol was significantly higher for the smokers than the non-smokers (0.14 vs 0.06 mmol/mol creatinine; P = 0.02). No smoking-associated difference was found for the urinary hippuric acid concentration. However, there was an association between alcohol consumption and hippuric acid excretion (P = 0.03); no such difference was shown for o-cresol. These results demonstrate that hippuric acid excretion is unsuitable for biological monitoring of toluene exposure when the exposure level is below 200 mg/m3. Also, in spite of the favourable excretion kinetics, the impact of smoking and the large interindividual variation warrant the same conclusion for o-cresol as a means of monitoring low level exposure in an individual worker.

Adult↗
PubMed1998

Development of endothermy in a Tasmanian marsupial, Bettongia gaimardi and its response to cold and noradrenaline.

Marsupials at birth are ectothermic and gradually attain the ability to change their metabolic heat production during pouch life. How this process occurs in the bettong has been measured on 13 pouch young from week 1 until 3 weeks after pouch vacation (week 18). Oxygen consumption was measured at 35 degrees C (pouch temperature) and at 22 degrees C. The results at 35 degrees C showed an increase in metabolic rate from week 1 until week 12 when there was a decrease to near adult levels after pouch vacation. At 22 degrees C young bettongs had a lower metabolic rate (compared with measurements made at 35 degrees C) until week 9 after which there was an increase above measurements made at 35 degrees C. Noradrenaline had little effect until week 10 after which the metabolic rate (although measured at 35 degrees C) paralleled the levels measured at 22 degrees C. The free thyroxine level was low in early pouch life, increased to a peak at week 12 then decreased. Thermal conductance increased until week 10 after which it decreased, reaching values similar to those of adult bettongs by week 20. The results indicate that non-shivering thermogenesis occurs in this macropodoid marsupial. This phenomenon may be a phylogenetic difference between macropodid and non-macropodid marsupials as also suggested by Nicol et al. (1997).

Age Factors↗
PubMed2006

A case study in resort climatology of Phoenix, Arizona, USA.

Tourists often use weather data as a factor for determining vacation timing and location. Accuracy and perceptions of weather information may impact these decisions. This study: (a) examines air temperature and dew points from seven exclusive resorts in the Phoenix metropolitan area and compares them with official National Weather Service data for the same period, and (b) utilizes a comfort model called OUTCOMES-OUTdoor COMfort Expert System-in a seasonal appraisal of two resorts, one mesic and one xeric, compared with the urban Sky Harbor International Airport first-order weather station site in the central urban area of Phoenix, Arizona, USA (lat. 33.43 degrees N; long. 112.02 degrees W; elevation at 335 m). Temperature and humidity recording devices were placed within or immediately adjacent to common-use areas of the resorts, the prime recreational sites used by guests on most resort properties. Recorded data were compared with that of the official weather information from the airport station, a station most accessible to potential tourists through media and Web sites, to assess predicted weather for vacation planning. For the most part, Sky Harbor's recorded air temperatures and often dew points were higher than those recorded at the resorts. We extrapolate our findings to a year-round estimate of human outdoor comfort for weather-station sites typical of resort landscapes and the Sky Harbor location using the OUTCOMES model to refine ideas on timing of comfortable conditions at resorts on a diurnal and seasonal basis.

Arizona↗