***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE To determine whether clinical trials originating in certain countries always have positive results . DATA SOURCES Abstract s of trials from Medline ( January 1966-June 1995 ) . STUDY SELECTION Two separate studies were conducted . The first included trials in which the clinical outcome of a group of subjects receiving acupuncture  was compared to that of a group receiving placebo , no treatment , or a nonacupuncture intervention . In the second study , r and omized or controlled trials of interventions other than  acupuncture  that were published in China , Japan , Russia/USSR , or Taiwan were compared to those published in Engl and . DATA EXTRACTION Blinded review ers determined inclusion and outcome and separately classified each trial by country of origin . DATA SYNTHESIS In the study of acupuncture  trials , 252 of 1085 abstract s met the inclusion criteria . Research conducted in certain countries was uniformly favorable to acupuncture ; all trials originating in China , Japan , Hong Kong , and Taiwan were positive , as were 10 out of 11 of those published in Russia/USSR . In studies that examined interventions other than acupuncture , 405 of 1100 abstract s met the inclusion criteria . Of trials published in Engl and , 75 % gave the test treatment as superior to control . The results for China , Japan , Russia/USSR , and Taiwan were 99 % , 89 % , 97 % , and 95 % , respectively . No trial published in China or Russia/USSR found a test treatment to be ineffective . CONCLUSIONS Some countries publish unusually high proportions of positive results . Publication bias is a possible explanation . Research ers undertaking systematic review s should consider carefully how to manage data from these countries OBJECTIVES The purpose of this study was to investigate whether lavender oil aromatherapy can reduce the bispectral index ( BIS ) values and stress and decrease the pain of needle insertion in 30 volunteers . SUBJECTS AND METHODS Thirty ( 30 ) healthy volunteers were r and omly allocated to 2 groups : the experimental group received oxygen with a face mask coated with lavender oil for 5 minutes , and the control group received oxygen through a face mask with no lavender oil for 5 minutes . The stress level ( 0=no stress , 10=maximum stress ) , BIS value , and pain intensity of needle insertion ( 0=no pain , 10=worst pain imaginable ) were measured . RESULTS There were no significant differences in age , sex , height , and weight between the two groups .  Stress level , BIS value , and pain intensity of needle insertion before aromatherapy were similar between the two groups . However , the stress values ( p<0.001 ) and BIS value ( p<0.001 ) after aromatherapy were significantly reduced compared with the control . In addition , the pain intensity of needle insertion was significantly decreased after aromatherapy compared with the control ( p<0.001 ) . CONCLUSIONS Lavender aromatherapy in volunteers provided a significant decrease in the stress levels and in the BIS values . In addition , it significantly reduced the pain intensity of needle insertion Changes in the autonomic nervous activity can be induced by various sensory and emotional stimuli . The authors examined whether the power spectral analysis of heart rate variability ( HRV ) could detect changes in autonomic tone following a lavender aroma treatment or not . Healthy young women ( n=10 , 23+/-3 years old ) underwent continuous electrocardiographic ( ECG ) monitoring before and after ( 10 , 20 , 30 minutes ) the lavender fragrance stimuli .  HRV was expressed by three indices : low ( 0.04 - 0.15 Hz ) and high ( 0.15 - 0.40 Hz ) frequency components ( nLF and nHF , respectively ) as well as LF/HF ratio . Increases in the parasympathetic tone were observed after the lavender fragrance stimulus as seen as increases in the HF component and decreases in the LF/HF . Additional measurement with positron emission tomography ( PET ) demonstrated the regional metabolic activation in the orbitofrontal , posterior cingulate gyrus , brainstem , thalamus and cerebellum , as well as the reductions in the pre/post- central gyrus and frontal eye field . These results suggested that lavender aromatic treatment induced not only relaxation but also increased arousal level in these subjects Objectives : To assess a possible relationship between perceived stress and first-time incidence of primary endometrial cancer .  Psychological stress may affect the synthesis and metabolism of estrogens and thereby be related to risk of endometrial cancer . Methods : The 6760 women participating in the Copenhagen City Heart Study were asked about their stress level at baseline from 1981 to 1983 . These women were prospect ively followed up in the Danish nationwide cancer registry until 2000 and < 0.1 % were lost to follow-up . Cox proportional hazard models were used to analyze data . Results : During follow-up , 72 women were diagnosed with endometrial cancer . For each increase in stress level on a 7-point stress scale , there was a lower risk of primary endometrial cancer ( hazard ratio ( HR ) = 0.88 ; 95 % confidence interval ( CI ) , 0.76–1.01 ) . This inverse association was particularly strong in women who received hormone therapy ( HR = 0.77 ; 95 % CI , 0.61–0.96 ) and in normal-weight women ( HR = 0.73 ; 95 % CI , 0.58–0.91 ) . Conclusions : Stress may affect gonadal synthesis of estrogens and alter the sensitivity of the uterus toward estrogen stimulation . These mechanisms may explain the lower risk of endometrial cancer observed among stressed women in this study . Despite these results , stress may still be a risk factor for a range of other diseases and should therefore not be considered a healthy response . HR = hazard ratio ; CI = confidence interval ; HPG = hypothalamic-pituitary-gonadal ; HPA = hypothalamic-pituitary-adrenal ; BMI = body mass Objective : Large-artery stiffness and arterial wave reflections have been identified as independent markers and prognosticators of cardiovascular risk . Mental stress is a novel risk factor for coronary artery disease and has been associated with left ventricular dysfunction , myocardial ischemia and infa rct ion , and sudden cardiac death . The purpose of this study was to assess the effect of acute mental stress on aortic stiffness and wave reflections . Methods : The effect of a mental arithmetic test was assessed in 19 healthy individuals using a r and omized , sham-procedure-controlled , crossover design . Carotid-femoral pulse wave velocity and augmentation index were measured as indices of aortic stiffness and wave reflections , respectively . Results : Mental stress induced a sustained increase in central systolic and pulse pressure throughout the whole study ( systolic : by 7.5 mm Hg , p < .05 ; pulse : by 5.7 mm Hg , p < .01 ) . The increase in peripheral systolic and pulse pressure was not significant throughout the study , but only when their peak values were compared with baseline ( systolic : by 6.2 mm Hg , peak at 0 minutes ; pulse : by 6.6 mm Hg , peak at 5 minutes , p < .05 for both ) . There was a sustained increase in pulse wave velocity ( by 0.57 m/s , p < .005 ) throughout the study denoting a sustained increase in aortic stiffness . Similarly , augmentation index showed a sustained increase with mental stress ( by 6.16 % , p < .05 ) denoting increased wave reflections from the periphery . Conclusion : Acute mental stress results in a prolonged increase in aortic stiffness and wave reflections . Given the important pathophysiologic and prognostic role of these parameters , our results provide important mechanistic links between acute mental stress and increased cardiovascular risk . Tr = timing of the reflected wave ; ANOVA = analysis of variance The effect of the lavender odorant on a Japanese version of Cox and Mackay 's stress/arousal adjective checklist for three groups was studied . One group of 14 was placed into a ( 2- x 2- x 3-m ) sound-protected room for 20 min . without the presentation of an odor , an analogous group of 15 received the odor oil , and one group of 13 received a nonstressful condition . Analysis suggested that lavender odorants were associated with reduced mental stress and increased arousal rate 
    Output:
    
In conclusion , there is limited evidence suggesting that aroma inhalation may be effective in controlling stress .