***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 Studies have shown that perceived racial discrimination is a significant predictor of  clinical pain severity among African Americans . It remains unknown whether perceived racial discrimination also alters the nociceptive processing of painful stimuli , which , in turn , could influence clinical pain severity . This study examined associations between perceived racial discrimination and responses to noxious thermal stimuli among African Americans and non-Hispanic Whites . Mistrust of medical research ers was also assessed given its potential to affect responses to the noxious stimuli . METHOD One-hundred and 30 ( 52 % African American , 48 % non-Hispanic White ) community-dwelling older adults with symptomatic knee osteoarthritis completed two study sessions . In session one , individuals provided demographic , socioeconomic , physical and mental health information . They completed question naires related to perceived lifetime frequency of racial discrimination and mistrust of medical research ers . In session two , individuals underwent a series of controlled thermal stimulation procedures to assess heat pain sensitivity , particularly heat pain tolerance . RESULTS African Americans were more sensitive to heat pain and reported greater perceived racial discrimination as well as greater mistrust of medical research ers compared with non-Hispanic Whites . Greater perceived racial discrimination significantly predicted lower heat pain tolerance for African Americans but not non-Hispanic Whites . Mistrust of medical research ers did not significantly predict heat pain tolerance for either racial group . CONCLUSION These results lend support to the idea that perceived racial discrimination may influence the clinical pain severity of African Americans via the nociceptive processing of painful stimuli In Malaysia , it is a common belief among health care workers that females and Indians have lower pain threshold . This experience , although based on anecdotal experience in the healthcare setting , does not allow differentiation between pain tolerance , and pain expression . To determine whether there is a difference in the tolerance to pain between the three main ethnic groups , namely the Malays , Chinese and Indians as well as between males and females . This was a prospect i ve study , using a laboratory pain model ( ischaemic pain tolerance ) to determine the pain tolerance of 152 IMU medical students . The mean age of the students was 21.8 years ( range 18 - 29 years ) . All of them were unmarried . The median of ischaemic pain tolerance for Malays , Chinese and Indians were 639s , 695s and 613s respectively ( p = 0.779 ) . However , statistically significant difference in ischaemic pain tolerance for males and females Indian students were observed . Possible ethnic difference in pain tolerance in casual observation is not verified by this laboratory pain model . Difference in pain tolerance between genders is shown only for Indians Abstract The aim of this study was to examine experimental pain sensitivity in three ethnic groups , African Americans , Hispanic Americans and non‐Hispanic White Americans , and to determine whether ethnic identity is differentially associated with pain sensitivity across ethnic groups . Participants included sixty‐three African American , sixty‐one Hispanic and eighty‐two non‐Hispanic white participants who were assessed using three experimental pain measures : thermal , cold‐pressor and ischemic . Participants ’ ethnic identity was assessed using the Multi‐group Ethnic Identity Measure ( MEIM ) . Ethnic group differences in pain responses were observed , with African American and Hispanic subjects showing lower cold and heat pain tolerances than non‐Hispanic White Americans . In addition , pain range ( i.e. tolerance‐threshold ) was computed for heat , cold and ischemic pain , and the two minority groups again had lower values compared to non‐Hispanic White Americans . Ethnic identity was associated with pain range only for African American and Hispanic groups . Statistically controlling for ethnic identity rendered some of the group differences in pain range non‐significant . These findings indicate that ethnic identity is associated with pain sensitivity in ethnic minority groups , and may partially mediate group differences in pain perception . The results of the present investigation provide evidence of ethnic group differences in responses to experimental pain across multiple noxious stimuli , with both minority groups exhibiting greater sensitivity to laboratory evoked pain compared to non‐Hispanic White Americans & NA ; Ethnic differences in the experience of pain , pain‐related health care utilization and pain‐reducing activities have been reported . Thus , evaluating of such variations is important in clinical and experimental pain . Since clinical pain is greatly influenced by disease‐specific factors ( severity , duration , type and treatment ) , evaluating ethnic differences in experimental pain models may not only provide some information about underlying mechanisms but also may predict or explain group differences in clinical pain . Migraine prevalence within ethnic population s is varied . Capsaicin injection to the forehead of healthy volunteers induces the state of an experimental trigeminal sensitization , which is one of the proposed mechanisms of migraine . The aim of the present study was to investigate ethnic differences between Caucasians and South Indians in this model of trigeminal sensitization . Thirty‐two healthy male volunteers ( 16 South Indians and 16 Danish Caucasians ) were included .  Capsaicin ( 100 μg/0.1 ml ) was injected intradermally to the right forehead skin . Pain sensitivity , secondary hyperalgesic area , and pressure pain threshold were assessed . Overall , the model showed significant greater pain responses in South Indians ( 8.75±1.25 cm pain intensity and 9.33±2.32 cm2 hyperalgesic area ) compared to Caucasians ( 6.25±1.95 cm pain intensity and 6.25±1.41 cm2 hyperalgesic area ) . The model may provide important information for further clinical research , e.g. migraine or differences in mechanisms underlying trigeminal sensitization OBJECTIVE A growing body of literature suggests ethnic differences in experimental pain . However , these studies largely focus on adults and the comparison between Caucasians and African Americans . The primary aim of this study is to determine ethnic differences in laboratory-induced pain in a multiethnic child sample . METHOD Participants were 214 healthy children ( mean age = 12.7 , SD = 3.0 years ) . Ninety-eight Caucasian , 58 Hispanic , 34 African American , and 24 Asian children were exposed to four trials of pressure and radiant heat pain stimuli .  Pain responses were assessed with self-report measures ( i.e. , pain intensity and unpleasantness ) and behavioral observation ( i.e. , pain tolerance ) . RESULTS Asians demonstrated more pain sensitivity than Caucasians , who evidence d more pain sensitivity than African Americans and Hispanics . The results hold even after controlling for age , sex , SES , and experimenter 's ethnicity . Asians also showed higher anticipatory anxiety compared with other ethnic groups . Anticipatory anxiety accounted for some ethnic differences in pain between Asians , Hispanics , and African Americans . CONCLUSIONS By examining response to laboratory pain stimuli in children representing multiple ethnicities , an understudied sample , the study reveals unique findings compared to the existing literature . These findings have implication s for clinicians who manage acute pain in children from diverse ethnic background s. Future investigations should examine mechanisms that account for ethnic differences in pain during various developmental stages OBJECTIVE Although numerous studies have reported ethnic differences in the prevalence and severity of clinical pain , little is known about how these differences affect the perception of experimental pain . The present experiment examined the effects of ethnicity ( African American vs. white ) on thermal pain responses in a healthy undergraduate population . METHODS Thirty white subjects ( 16 women and 14 men ) and 18 African Americans ( 10 women and 8 men ) participated in the study . Thermal testing included evaluation of the following : warmth thresholds , thermal pain thresholds , thermal pain tolerances , and magnitude estimates of both the intensity and unpleasantness of thermal pain ( at 46 degrees , 47 degrees , 48 degrees , and 49 degrees C ) . RESULTS Although no group differences emerged for warmth thresholds , thermal pain thresholds , or pain intensity ratings , African Americans demonstrated lower thermal pain tolerances than whites . In addition , African Americans had smaller slopes and larger intercepts than whites for ratings of pain unpleasantness . Additional analyses suggested that these findings were a consequence of group differences in thermal pain unpleasantness ratings at the lowest temperatures assessed ( 46 degrees and 47 degrees C ) ; at these temperatures , African Americans rated the stimuli as more unpleasant than whites . Finally , group differences in thermal pain tolerance and thermal pain unpleasantness ratings seemed to partially account for greater self-reported daily pain symptoms among African Americans . CONCLUSIONS Collectively , these findings seem to suggest ethnic differences in the perception of the affective-motivational dimension of thermal pain 
    Output:
    
Racial/ethnic differences in experimental pain sensitivity were more pronounced with suprathreshold than with threshold stimuli , which is important in clinical pain treatment .