This study investigated autophagy in 37 cases of nasopharyngeal lymphomas including 23 nasal natural killer (NK)/T-cell lymphomas (NKTCL), 3 cytotoxic T-cell lymphomas (cytotoxic-TML) and 9 B-cell lymphomas (BML) by means of antigen-retrieval immunohistochemistry of beclin-1, LC3, mitochondria (AE-1) and cathepsin D. Peculiar necrosis was noted in EBV+ lymphomas comprising 21 NKTCL, 2 cytotoxic-TML and 1 BML. Lymphomas without peculiar necrosis showed high expression of beclin-1, macrogranular cytoplasmal stain of LC3 with sporadic nuclear stain, a hallmark of autophagic cell death (ACD), some aggregated mitochondria and high expression of cathepsin D, suggesting a state of growth with enhanced autophagy with sporadic ACD. EBV+ NKTCL with the peculiar necrosis, showed significantly low level of macrogranular staining of LC3, aggregated mitochondria and low expression of cathepsin D in the cellular areas when degenerative lymphoma cells showed decreased beclin-1, significantly advanced LC3-labeled autophagy, residual aggregated mitochondria and significantly reduced expression of cathepsin D, suggesting advanced autophagy with regional ACD. Consequently it was suggested that enhanced autophagy and reduced expression of lysosomal enzymes induced regional ACD under EBV infection in NKTCL.
We developed a novel ultrarapid immunohistochemical staining method in which an AC electric field is used to facilitate detection of tumor cells. Frozen sections of non-small cell lung cancer in lymph nodes were fixed in acetone for 2 min, after which they were incubated for 2 min with an anti-pancytokeratin antibody cocktail and then with EnVisionTM complex under an alternating current (AC) electric field. The sections were then incubated with a chromogen (3,3'diaminobenzidine) for 3 min and counterstained with hematoxylin. This method enabled detection of tumor cells in frozen sections in less than 15 min. In addition, we were able to reduce the amount of antibody used by more than 90% when the sections were incubated under the AC electric field for a longer period. This method could be a useful tool for frozen section diagnosis and research. Furthermore, with this method the cost of immunohistochemical staining can be reduced.
The hair erection muscle, arrector pili, is a kind of smooth muscle located in the mammalian dermis. The immunohistochemical study using an antibody against smooth muscle alpha actin (SMA) showed that the arrector pili muscle develops approximately 1–2 weeks after birth in dorsal and ventral skin, but thereafter they degenerate. The arrector pili muscle was not detected in the mystacial pad during any stage of development, even in the neighboring pelage-type hair follicle. A strong signal of SMA in the skin was located in the dermal sheath as well as in some outer root sheath cells in the hair and vibrissal follicles. Positive areas in the dermal and outer root sheaths were restricted to a lower moiety, particularly areas of similar height, where keratinization of the hair shaft occurs. This rule is valid for both pelage hair follicles and vibrissal follicles. At medium heights of the follicle, SMA staining in the dermal sheath was patchy and distant from the boundary between dermis and epidermis. In contrast to SMA, vimentin was expressed over the entire height of the dermal sheath. Unlike the arrector pili muscle, the expression of SMA in the dermal sheath was observed during fetal, neonatal, and adult stages. The presence of actin-myosin and vimentin fibers in supporting cells is thought to be beneficial for the hair follicle to cope with the movement of the hair shaft, which may be caused by physical contacts with outside materials or by the contraction of internal muscles.
Localization of alkaline phosphatase (ALP) and cathepsin D (CAPD) in primary cultures of fetal rat hepatocytes was examined using double immunofluorescent staining in order to investigate the relationship between lysosome movement and the fate of ALP during cell restoration after microtubule disruption by colchicine. At 3 hr and 24 hr after colchicine treatment, numerous coarse dots containing ALP were observed throughout the cytoplasm, and some of these showed colocalization with CAPD. At 48 hr and 72 hr after colchicine treatment, although most of the dots containing ALP in the cytoplasm disappeared, dots containing CAPD remained. The present results suggest that the denatured ALP proteins remaining in the cytoplasm of hepatocytes during cell restoration after colchicine treatment are digested by lysosomes.