Effect of temperature on phagocytic activity of neutrophils.

The effect of temperature on phagocytic activity of neutrophils has been evaluated. Freshly collected heparinised blood samples from young healthy volunteers were incubated with heat killed Staphylococcus aureus at 37 degrees C, 38 degrees C, 39 degrees C and 40 degrees C for 20 minutes. Some of the neutrophils engulfed some heat killed bacteria. Then the blood smears were prepared and stained by Leishman's stain. Engulfed bacteria within the neutrophils stained intensely were observed and counted to find out the phagocytic index and avidity index of the neutrophils. It was found that phagocytic index increased significantly at 38 degrees C and 39 degrees C in comparison to that of at 37 degrees C but did not show significant increase when incubated at 40 degrees C. It seems that contractile elements responsible for the movement of the neutrophils through the formation of pseudopod is more activated at higher temperature (38 degrees C and 39 degrees C) in comparison to that of at normal body temperature (37 degrees C). Temperature higher than 39 degrees C may cause impairment in enzyme function responsible for assembly and disassembly of actin and myosin filaments in the cell causing decreased movement and decreased rate of formation of psudopod resulting in decreased phagocytic activity.

Phagocytic activities of neutrophilic leukocytes in women in various phases of menstrual cycle, and in pregnancy.

This study evaluated the phagocytic activities of neutrophilic leukocytes in both sexes during reproductive age and in women in different phases of the menstrual cycle and in pregnancy. In this study, 9 male and 12 female medical students, 17 to 20 years of age, 23 pregnant women and 9 women after delivery were evaluated. Heparinized blood was incubated with heat killed bacteria Staphylococcus aureus at 37 degrees C for 20 minutes. The blood films were stained with Leishman stain and the phagocytic index was found out by the number of neutrophilic leukocytes ingested with organisms in 100 cells and the total number of organisms counted therein. At the interval of 14 days, on 3 consecutive occasions, the phagocytic index was studied on the same male and female subject. The phagocytic activities of neutrophilic leukocytes were found slightly higher in females than in males; more so in pregnancy than in non-pregnant women, woman controls and after delivery. During the expected ovulation period, the phagocytic activities were observed more than during the menstrual and premenstrual phases. The phagocytic activities were found more in pregnancy and during the ovulatory period in women.