Quantitative analysis of fibrosis and mast cells in the tongue of chronic chagasic patients: autopsy study

Morphological and Histopathological Study of Autopsied Patients with Atherosclerosis and HIV

BACKGROUND

Chronic infection by HIV evolves with a vascular inflammatory action causing endothelial dysfunction. The action of the virus, as well as the side effects of antiretroviral drugs, contribute to the progression of cardiovascular diseases. The present study aimed to evaluate the percentage of collagen fibers and the density of mast cells, chymase and tryptase, in aortas of patients with and without HIV, and also patients with and without atherosclerosis.

METHODS

Aortic fragments were obtained from autopsied patients aged 22-69 years and selected regardless of the cause of death or underlying disease. The samples were divided into four groups, (1) Group with HIV and with atherosclerosis; (2) Group with HIV and without atherosclerosis; (3) Group without HIV and with atherosclerosis; (4) Group without HIV and without atherosclerosis (Control). The percentage of collagen fibers was analyzed in the intima-media layer and the density of mast cells was analyzed in all aortic layers. Graphpad Prism 5.0^® software was used for statistical analysis.

RESULTS

There were more collagen fibers in HIV patients, with or without atherosclerosis. The group with HIV and atherosclerosis presented a higher density of chymase and tryptase mast cells. The correlation between collagen fibers and age was negative in the non-HIV group and with atherosclerosis.

CONCLUSION

The inflammatory process resulting from HIV infection may be relevant in the alteration of aortic collagen fibers and in triggering or accelerating atherosclerosis. The study is important because HIV patients have increased risks for the development of cardiovascular diseases, and follow-up is necessary to prevent such diseases.

The Recombinant Form of Trypanosoma cruzi P21 Controls Infection by Modulating Host Immune Response

Trypanosoma cruzi P21 protein (P21) is a putative secreted and immunomodulatory molecule with potent bioactive properties such as induction of phagocytosis and actin cytoskeleton polymerization. Despite the bioactive properties described so far, the action of P21 on parasite replication in muscle cell lineage or T. cruzi parasitism during acute experimental infection is unclear. We observed that recombinant P21 (rP21) decreased the multiplication of T. cruzi in C2C12 myoblasts, phenomenon associated with greater actin polymerization and IFN-γ and IL-4 higher expression. During experimental infection, lower cardiac nests, inflammatory infiltrate and fibrosis were observed in mice infected and treated with rP21. These results were correlated with large expression of IFN-γ counterbalanced by high levels of IL-10, which was consistent with the lower cardiac tissue injury found in these mice. We have also observed that upon stress, such as that induced by the presence of the IFN-γ cytokine, T. cruzi produced more P21. The effect of P21 in controlling the replication of T. cruzi, may indicate an evolutionary mechanism of survival developed by the parasite. Thus, when subjected to different stress conditions, the protozoan produces more P21, which induces T. cruzi latency in the host organism, enabling the protozoan to evade the host's immune system.

Overexpression of HIF-1α and Morphological Alterations in the Tongue of Rats Exposed To Secondhand Smoke

Smoking is a risk factor for serious health problems and is associated with several changes in the tissues of the oral cavity. The aim of this study was to evaluate the collagen percentage, mast cells density, intensity of immunolabeled cells by anti-HIF-1α in the musculature lingual of rats exposed to secondhand smoke. Twenty-seven female Wistar albino rats were divided into three groups: rats not exposed to tobacco smoke inhalation (Control group) (n=7); rats exposed to smoke inhalation for 30 days (TAB 30) (n=10); and rats exposed to smoke inhalation for 45 days (TAB 45) (n=10). Subsequently, the animals were submitted to euthanasia and removal of the tongue for histological and immunohistochemistry processing and analysis. In the groups TAB 30 and TAB 45 there were a lower percentage of collagen, a higher density of mast cells and a greater intensity of anti-HIF-1α immunolabeled cells compared to Control group. There was also a positive and significant correlation between the percentage of collagen and mast cell density. There was not significative difference between TAB 30 e TAB 45 in any of the parameters evaluated. Therefore, the exposure of rats to secondhand smoke for 45 days causes decrease in perimysial collagen fibers, increase in the number of mast cells and increase in the immunolabeling for HIF-1α in lingual muscle cells. The present study was the first to evaluate the percentage of collagen, mast cell density and immunostaining for HIF-1α in rat tongues exposed to tobacco smoke.

Lingual salivary gland hypertrophy and decreased acinar density in chagasic patients without megaesophagus

Although the salivary glands present several functions, there are few studies evaluating these glands in Chagas disease (CD). This study aimed to compare the percentage of collagen, the presence of inflammation, the density of chimase and tryptase mast cells, the area and density of lingual salivary gland acini in autopsied individuals with and without (CD). We analyzed 400 autopsy reports performed in a tertiary public hospital from 1999 to 2015 and selected all the cases in which tongue fragments were collected (27 cases), 12 with chronic CD without megaesophagus (CH) and 15 without CD (non-chagasic - NC). The histological sections of the tongue were stained by Picrosirius red for collagen evaluation and Hematoxylin-eosin for morphometric evaluation of salivary gland acini and inflammation. Anti-chimase and anti-tryptase antibodies were used for the immunohistochemical evaluation of mast cells. The chagasic patients presented higher volume and lower density of salivary glands acini. There was no difference in the collagen percentage, inflammation and density of mast cell chymase and tryptase between the groups. Although we did not observe a significant difference between the groups regarding the collagen percentage, inflammatory process and mast cell density, our results suggest that even without megaesophagus, chagasic patients present hypertrophy of the lingual salivary glands and lower acinar density probably due to mechanisms independent of the esophagus-glandular stimulus.

Evaluation of aortic changes in elderly people autopsied with acquired immunodeficiency syndrome

Background

To verify the distribution of the degree of fat deposits and percentage of collagen and elastic fibers in the intimal and medial layers of the aorta of elderly patients autopsied, with and without Acquired Immunodeficiency Syndrome (AIDS).

Methods

Twenty-six fragments of the aorta from elderly patients autopsied in the period from 1982 to 2014, were collected and, divided into two groups, being 13 with AIDS and 13 without AIDS. The intensity of the atherosclerosis was macroscopically evaluated in a semi-quantitative way. To quantify the elastic and collagen fibers, it was used the Leica Qwin Plus® software.

Results

In the comparison of the macroscopic intensity of atherosclerosis, the AIDS group (t = 0.6969, p = 0.4992). Regarding elastic fibers, there was a significant increase in the AIDS group (U = 115,800; p < 0.0001). Comparing the groups, there was a significant increase of the collagen fibers in the aortic layers in the AIDS group (U = 114,100; p < 0.0001).

Conclusion

The infection by the HIV influence in the amount of fibers in the extracellular matrix and the intensity of lipid deposit, demonstrating that it may be a risk factor to be considered for the development of atherosclerosis.

Association between mast cells, tissue remodelation and parasite burden in the skin of dogs with visceral leishmaniasis

Canine visceral leishmaniosis (CVL) is a zoonosis of major public health impact caused by organisms of the genus Leishmania which is transmitted to human and animals by phlebotomine sand flies. The skin is the first point of contact with Leishmania parasites for sandy fly vectors and it is considered an important reservoir compartment in infected dogs. The aim of this study was to determine the main histophatologic alterations in ear skin of dogs naturally infected by Leishmania infantum with different clinical status and different degrees of parasitism. Therefore, thirty-four dogs naturally infected with L. infantum were grouped according to their clinical status in asymptomatic (AD, n=11), oligosymptomatic (OD, n=11) and symptomatic dogs (SD, n=12) as well as their degrees of parasite load in the skin as low (LP, n=11), median (MP, n=11) and high (HP, n=12) parasitism. Additionally, ten dogs were used as control (CD, n=10). At necropsy, skin samples were collected for further histological and parasitological analysis. The OD and SD groups presented higher parasite burden than AD group. The inflammation was higher in SD group when compared to OD and AD. The LP, MP and HP groups showed an increasing inflammatory process, indicating that a great parasite load is accompanied by a major inflammatory process in the skin. The number of mast cells was higher in the OD and LP groups than CD group, suggesting that these cells may be involved in tissue remodeling, since that an increase of type III collagen fibers and decrease type I collagen fibers were observed in these groups. Taken together, our results enable a better understanding of the alterations in skin of CVL dogs and consequently new insights about the pathogenesis of CVL.

Reduction of immunity in HIV-infected individuals: can fibrosis induce hypoplasia in palatine and lingual tonsils of individuals with HIV infection?

The role of tonsils in oral immunity has been described. However, the pathogenesis of HIV infection in these organs is still unclear. The aim of this study is to perform histological and immunohistochemical analysis of the palatine and lingual tonsils of autopsied individuals with or without HIV infection. Twenty-six autopsied individuals with HIV infection (HI) (n=13) and without HIV infection (CO) (n=13) were selected. Palatine and lingual tonsil fragments were collected for histological and immunohistochemical analysis. We found in the HI group a higher frequency of hyaline degeneration in both palatine and lingual tonsils; smaller follicle areas, and a higher percentage of collagen in comparison with the CO group. In the HI group, there was higher density of blood vessels in palatine tonsils than in the CO group. In the HI group, there were significant positive correlations between palatine and lingual tonsils and the area of lymphoid follicles, and between the percentage of blood vessels and collagen in palatine tonsils. In addition, there was a significant negative correlation between the percentage of collagen and lymphoid follicle area in both palatine and lingual tonsils in the HI group. These findings suggest that the immune functions of these tonsils are prejudiced by fibrosis. Therapies to reduce the neoformation of collagen are required to improve immune function of organs against pathogens.

Correlation of lifetime progress of atherosclerosis and morphologic markers of severity in humans: new tools for a more sensitive evaluation

OBJECTIVES

To describe the morphological features of atherosclerosis in the aortas of autopsied patients (ranging from young adults to the elderly), thus providing new tools for a more sensitive morphological evaluation.

METHOD

We collected 141 aorta samples. We assessed the macroscopic degree of atherosclerosis, thickness of the intima and media, lipid and collagen depositions in the intima, and the infiltration of mast cells into the layers of the aorta. We correlated the findings with gender, age, race and cause of death.

RESULTS

The degree of atherosclerosis was significantly higher in the elderly. The aorta was thicker in the elderly and in cases with a cardiovascular cause of death. The thickness of the intima was significantly greater in the elderly, in males and in cases with a cardiovascular cause of death. The lipid content in the intima of the aorta was significantly higher in Caucasians. Older people and men had a significantly higher number of mast cells.

CONCLUSION

A macroscopic evaluation is a good indicator of the severity of atherosclerosis, but a more detailed analysis, namely evaluating the thickness of the layers of the aorta and the number of mast cells, may further elucidate the changes in the constituents of this vessel.

Quantification of fibrosis and mast cells in the tissue response of endodontic sealer irradiated by low-level laser therapy

Low-level laser therapy (LLLT) accelerates tissue repair. Mast cells induce the proliferation of fibroblasts and the development of local fibrosis. The objective of this study was to quantify fibrosis rate and mast cells in connective tissue after endodontic sealer zinc oxide and eugenol (ZOE) was implanted and submitted to LLLT, immediately after implant and again 24 h later. Sixty mice were distributed into three groups: GI, GII, and GIII (n = 20). In GI, the tubes filled with Endofill were implanted in the animals and were not irradiated with LLLT. In GII, the tubes containing Endofill were implanted in the animals and then irradiated with red LLLT (InGaAIP) 685-nm wavelength, D = 72 J/Cm(2), E = 2 J, T = 58 s, P = 35 mW, and in GIII, the tubes with Endofill were implanted and irradiated with infrared LLLT (AsGaAl) 830-nm wavelength, D = 70 J/Cm(2), E = 2 J, T = 40 s, P = 50 mW. After 7 days and 30 days, the animals were killed. A series of 6-µm-thick sections were obtained and stained with Toluidine Blue and Picrosirius and analyzed under a standard light microscope using a polarized light filter for the quantification of fibrosis. The statistics were qualitative and quantitative with a significance of 5%. The irradiation with LLLT did not offer improvement in the fibrosis rate, however, it provided a significant decrease in the concentration of independent mast cells for the period studied.