Immunosuppression Studies

•SAMPLE = 75 FIRST YEAR MEDICAL STUDENTS (49 MALES, 26 FEMALE). ALL HAD VOLUNTEERED

•BLOOD SAMPLES TAKEN 1 MONTH BEFORE FINAL EXAMS AND THEN AGAIN ON THE FIRST DAY OF EXAMS (AFTER TWO EXAMS HAD BEEN TAKEN)

•BLOOD SAMPLES ANALYSED FOR THE AMOUNT OF LEUCOCYTE ACTIVITY, AND THE AMOUNT OF “NATURAL KILLER CELL ACTIVITY”

•STUDENTS WERE ALSO GIVEN A QUESTIONNAIRE TO ASSESS PSYCHOLOGICAL SYMPTONS, LONELINESS AND LIFE EVENTS

- AS PREDICTED NATURAL KILLER CELL ACTIVITY WAS GREATLY REDUCED IN THE SECOND SAMPLE SHOWING REDUCED IMMUNE FUNCTION OR IMMUNOSUPPRESSION

- QUESTIONNAIRE RESULTS SHOWED THE STUDENTS WHO REPORTED FEELING THE MOST LONELY, HAD THE WEAKEST IMMUNE RESPONSE.

Evaluation

- Volunteer sample will not give a wide range of participants, so results are less likely to 
  be generalised

•394 healthy subjects

•Answered a questionnaire to assess their level of stress. This was measured by:
–The number of life changes recently experienced
–How “out of control” individuals felt.

•Then given nasal drops containing one of five types of respiratory viruses.

•An additional 26 were given saline nasal drops (control group)

•Subjects then quarantined and monitored for symptoms of infection

•RATES OF BOTH CLIINICAL COLDS AND RESPIRATORY INFECTION INCREASED WITH INCREASES IN THE DEGREE OF PSYCHOLOGICAL STRESS, IN A DIRECTLY POSITIVE CORRELATION

•THESE EFFECTS WERE NOT ALTERED WHEN AGE, GENDER, EDUCATION, ALLERGIC STATUS, WEIGHT (AND OTHER FACTORS) WERE TAKEN INTO CONSIDERATION

•OTHER “MEDIATORS” SUCH AS SMOKING, ALCOHOL CONSUMPTION, EXERCISE, DIET AND SO ON...DID NOT EXPLAIN THE ASSOCIATION BETWEEN STRESS OR ILLNESS

Evaluation

- By being quaratined it prevented the participants being affected by their environments therefore higher validity in results

A.) •Riley created stress in mice 
       •He placed them on a turntable rotating at 45rpm

B.) Riley implanted cancer cells into two groups of mice:
     Group 1: 10minutes of rotation per hour for 3 days
     Group 2: No rotation.

A.)

FOUND A MARKED DECREASE IN THEIR LYMPHOCYTE COUNT OVER A FIVE HOUR PERIOD

B.) AS HYPOTHESISED;
     GROUP 1 DEVELOPED LARGE TUMOURS
     GROUP 2 SHOWED NO TUMOUR GROWTH

Evaluation

- Can we apply results to humans? Are we that similar?

• It can be considered that those that are long term carers, for example of older or disabled family members, are under chronic stress
  
• Participants: 18 female carers with a control group matched by sex and age
  
• Study focused on the number of T-Cells

• Carers showed a signifigantly lower number of T-Cells
• Carers also showed signififantly higher numbers of T-Suppressor Cells (which reduce immune response)