Naturally occurring hypothermia promotes survival in severe anaphylaxis.

Although hypothermia has received substantial attention as an indicator of severity in anaphylaxis, it has been neglected from the perspective of whether it could act as a disease-modifying factor in this condition. Here, the impact of naturally occurring (spontaneous) hypothermia on anaphylaxis was evaluated in a murine model of ovalbumin (OVA)-induced allergy. Nonextreme changes in the ambient temperature (Ta) were used to modulate the magnitude of spontaneous hypothermia. At a Ta of 24°C, challenge with OVA intraperitoneally or intravenously resulted in a rapid, transient fall in body core temperature, which reached its nadir 4-6°C below baseline in 30 min. This hypothermic response was largely attenuated when the mice were kept at a Ta of 34°C. The Ta-dependent attenuation of hypothermia resulted in a survival rate of only 30%, as opposed to survival of 100% in the condition that favored the development of hypothermia. The protective effect of hypothermia did not involve changes in the rate of mast cell degranulation, as assessed by the concentration of mast cell protease-1 in bodily fluids. On the other hand, hypothermia improved oxygenation of the brain and kidneys, as indicated by higher NAD+/NADH ratios. Therefore, it is plausible to propose that naturally occurring hypothermia makes organs more resistant to the anaphylactic insult.

Differential expression of mast cell granules in samples of metastatic and non-metastatic colorectal cancer in patients.

Various cell types participate in the tumor process, in which the mast cells have been described; however, the role they play in colorectal adenocarcinoma has not yet been fully understood. Therefore, the present work aimed to compare employing histochemistry and immunohistochemistry, the number of mast cells and the content of some cytoplasmic granules in moderately differentiated non-metastatic and metastatic colorectal adenocarcinoma, analyzing tissue samples from patients. Histochemical techniques with Toluidine Blue (TBO), Periodic Schiff Acid (PAS), Alcian Blue/Periodic Acid-Schiff (PAB) and Alcian Blue/Safranin (ABS); as well as immunohistochemical reactions with anti-antibodies anti-Tryptase and anti-Chymase were applied to quantify total mast cells and content of some cytoplasmic granules. Statistical analysis was performed using SPSS V22.0 software (p ≤ 0.05). The degree of positivity of the reaction and degranulation of mast cells was reported in percentages. In our results, we observed that there are differences in the quantity and histochemical composition of the granules of mast cells (metastatic group PAS and ABS comparing the TBO reaction), as well as in the immunohistochemical composition between Tryptase and Chymase and the number of degranulated cells in both study groups (74 % degranulated mast cells in the metastatic group, 66 % integrate mast cells in the non-metastatic group). Therefore, we consider that the differences may be some of the probable factors that lead to metastasis of colorectal adenocarcinoma.

Quantification of mast cells in the uterine cervix of women infected with human immunodeficiency virus.

The objective of the study was to identify mastocytosis in the chorionic epithelium of the uterine cervix in HIV-infected and non-HIV-infected women in autopsy specimens using histochemistry and immunohistochemistry techniques. Sixteen cervical tissue specimens were collected, of which 10 (62.50%) were from HIV-infected women. Histochemical and immunohistochemical techniques were used to evaluate mast cell density using Giemsa stain and anti-mast cell tryptase and anti-mast cell chymase antibodies, respectively. The study of the sheets and counting of mast cells with blue (Giemsa) or brown staining (anti-mast cell tryptase or chymase antibodies) were performed by 3 examiners, and 10 consecutive fields were examined under a light microscope at 400× magnification. A significant difference was found in mast cell density in the chorionic epithelium of the cervix in HIV-infected compared with non-HIV-infected women. The present study may contribute to the characterization of genital mucosa abnormalities and help better understand the potential role of mast cells in HIV-infected women.