Cardiovascular Autonomic Dysfunction in Patients with Morbid Obesity

Abstract Background: Morbid obesity is directly related to deterioration in cardiorespiratory capacity, including changes in cardiovascular autonomic modulation. Objective: This study aimed to assess the cardiovascular autonomic function in morbidly obese individuals. Methods: Cross-sectional study, including two groups of participants: Group I, composed by 50 morbidly obese subjects, and Group II, composed by 30 nonobese subjects. The autonomic function was assessed by heart rate variability in the time domain (standard deviation of all normal RR intervals [SDNN]; standard deviation of the normal R-R intervals [SDNN]; square root of the mean squared differences of successive R-R intervals [RMSSD]; and the percentage of interval differences of successive R-R intervals greater than 50 milliseconds [pNN50] than the adjacent interval), and in the frequency domain (high frequency [HF]; low frequency [LF]: integration of power spectral density function in high frequency and low frequency ranges respectively). Between-group comparisons were performed by the Student’s t-test, with a level of significance of 5%. Results: Obese subjects had lower values of SDNN (40.0 ± 18.0 ms vs. 70.0 ± 27.8 ms; p = 0.0004), RMSSD (23.7 ± 13.0 ms vs. 40.3 ± 22.4 ms; p = 0.0030), pNN50 (14.8 ± 10.4 % vs. 25.9 ± 7.2%; p = 0.0061) and HF (30.0 ± 17.5 Hz vs. 51.7 ± 25.5 Hz; p = 0.0023) than controls. Mean LF/HF ratio was higher in Group I (5.0 ± 2.8 vs. 1.0 ± 0.9; p = 0.0189), indicating changes in the sympathovagal balance. No statistical difference in LF was observed between Group I and Group II (50.1 ± 30.2 Hz vs. 40.9 ± 23.9 Hz; p = 0.9013). Conclusion: morbidly obese individuals have increased sympathetic activity and reduced parasympathetic activity, featuring cardiovascular autonomic dysfunction.

Influence of Smoking Consumption and Nicotine Dependence Degree in Cardiac Autonomic Modulation

Abstract Background: Smoking consumption alters cardiac autonomic function. Objective: Assess the influence of the intensity of smoking and the nicotine dependence degree in cardiac autonomic modulation evaluated through index of heart rate variability (HRV). Methods: 83 smokers, of both genders, between 50 and 70 years of age and with normal lung function were divided according to the intensity of smoking consumption (moderate and severe) and the nicotine dependency degree (mild, moderate and severe). The indexes of HRV were analyzed in rest condition, in linear methods in the time domain (TD), the frequency domain (FD) and through the Poincaré plot. For the comparison of smoking consumption, unpaired t test or Mann-Whitney was employed. For the analysis between the nicotine dependency degrees, we used the One-way ANOVA test, followed by Tukey's post test or Kruskal-Wallis followed by Dunn's test. The significance level was p < 0,05. Results: Differences were only found when compared to the different intensities of smoking consumption in the indexes in the FD. LFun (62.89 ± 15.24 vs 75.45 ± 10.28), which corresponds to low frequency spectrum component in normalized units; HFun (37.11 ± 15.24 vs 24.55 ± 10.28), which corresponds to high frequency spectrum component in normalized units and in the LF/HF ratio (2.21 ± 1.47 vs 4.07 ± 2.94). However, in the evaluation of nicotine dependency, significant differences were not observed (p > 0.05). Conclusion: Only the intensity of smoking consumption had an influence over the cardiac autonomic modulation of the assessed tobacco smokers. Tobacco smokers with severe intensity of smoking consumption presented a lower autonomic modulation than those with moderate intensity.

Correlações entre as concentrações de nutrientes, alumínio e sódio nas folhas de "coast cross nº 1" e a análise física e química de um latossol vermelho amarelo: I. Concentrações de nutrientes nas folhas em função das frações granulométricas do solo

Foi realizado um levantamento em 41 áreas de um solo classificado como Latossol Vermelho Amarelo, com amostragens de solo e de folhas da forrageira "Coast Cross nº 1" objetivando o estudo de correlações entre as concentrações de nutrientes, alumínio e sódio nas folhas e as análises físicas do solo. Os autores observaram que a concentração de potássio nas folhas correlaciona-se negativamente com a fração silte do solo. A concentração de cobre nas folhas correlaciona-se negativamente com a fração areia fina e positivamente com argila. Ferro, manganês, zinco, sódio, boro e alumínio não apresentam correlações entre as suas concentrações foliares e os teores de argila no solo.

Correlações entre as concentrações de nutrientes, alumínio e sódio nas folhas de "Coast Cross nº 1" e a análise física e química de um Latossolo vermelho amarelo II: Concentração de nitrogênio e fósforo

Foi realizado um levantamento em 41 pontos de um Latossolo Vermelho Amarelo, com amostragem de solo e folhas da forrageira "Coast Cross Nº 1", objetivando o estudo de correlações entre as concentrações de nutrientes, alumínio e sódio nas folhas e as análises químicas do solo. As folhas foram secas e analisadas para N, P. As amostras de solo foram secas e analisadas pelos seguintes métodos: índices pH (água e CaCl2 0,01 M), matéria orgânica (digestão úmida) , P, K, B, Cu, Fe, Mn, Zn e Na pelo extrator de Mehlich. P através de resina iônica. Ca, Mg e Al pelo KC1 1 N. As frações granulométricas foram dispersas por NaOH 0,1 Ne separadas pelo método da pipeta. Foram observadas correlações entre as concentrações de elementos nas folhas e as determinações no solo. Nitrogênio nas folhas correlacionou-se negativamente com fósforo do solo e positivamente com manganês e enxofre. Fósforo nas folhas correlacionou-se negativamente com cálcio do solo.

Cross-infection experiments with "isospora" of cats and dogs

Feces of 34 dogs out of 251 (13.5%) from guanabara were positive for Isospora. From these 19 (7.5%) were i. rivolta, 13 (5.2%) were I. canis and 2 (0,7) were i. bigemina. "Free-sporocysts" of I. rivolta were eliminated by 9 dogs (3.5%). A "Caryospora-like" oocyst was seen once. Cross-infection experiments performed with Isospora from dogs and cats failed to produce infection while inoculations of these Isospora in their natural hosts succeeded. The results suggest that the species of Isospora occurring in cats are different from those of dogs.

Cross-suppression of specific immune responses after oral tolerance

Adult normal inbred mice rendered tolerant to OVA by previous oral exposure do not respond to intraperitonela immunization with DNP-OVA in adjuvant. These tolerant mice also form less DNP-specific antibodies to DNP-KLH when immunized with mixtures of DNP-KLH and DNP-OVA, or less HGG-specific antibodies when immunized with cross-linked conjugates of OVA and HGG. These same procedures increased DNP-specific or HGG-specific responses in non-tolerant control mice. The cross-supperssion was ineffective, however, to inhibit already ongoing antibody responses.

Granulomatous hypersensitivity to Schistosoma mansoni egg antigens in human Schistosomiasis: I. Granuloma formation and modulation around polyacrylamide antigen-conjugated beads

We have developed an in vitro model of granuloma formation for the purpose of studying the immunological components of delayed type hypersensitivity granuloma formation in patients infected with Schistosoma mansoni. Our data show that 1) granulomatous hypersensitivity can be studied by examining the cellular reactivity manifested as multiple cell layers surrounding the antigen conjugated beads; 2) this reactivity is a CD4 cell dependent, macrophage dependent, B cell independent response and 3) the in vitro granuloma response is antigenically specific for parasite egg antigens. Studies designed to investigate the immune regulation of granulomatous hypersensitivity using purified populations of either CD4 or CD8 T cells have demonstrated the complexity of cellular interactions in the suppression of granulomatous hypersensitivity. The anti-S. mansoni egg immune responses of individual patients with chronic intestinal schistosomiasis can be classified either as soluble egg antigen (SEA) hypersensitive with maximal granulomatous hypersensitivity or SEA suppressive with activation of the T cell suppressor pathway with effective SEA granuloma modulation. Our data suggest that T cell network interactions are active in the generation of effective granuloma modulation in chronic intestinal schistosomiasis patients.

Immunopathology of american cutaneous leishmaniasis. Modulation of MHC class II gene products by Keratinocytes before and after glucantime therapy

Epidermal changes from 32 cutaneous and 3 mucosal American leishmaniasis (ACL) active lesions were studied for HLA-DR, -DP expression, Lanerhans cells and lymphocyte infiltration. In addition to a DR and DQ positivity at the surface of the cells of the inflammatory infiltrate, a strong reaction for DR antigens was detected on keratinocytes. Hyperplasia of Langerhans cells was present in al cutaneous lesions and epidermis was infiltrated by T lymphocytes. When healed lesions of 14 of these subjects were re-biopsied 1 to 12 months after the end of pentavalent antimonial therapy, MHC class antigens could no longer be seen on keratinocytes. Our data represrn evidence for hhe reversibility of the abnormal HLA-DR expression by keratinocytes in ACL after Glucantime therapy or spontaneous scar formation, demonstrating that this expresion is restricted to the period of active lesions. The present findings can be regarded as an indirect evidence that keratinocytes may be involved in the immunopathology of ACL.

Protein-DNA associations in a gender-specific gene of Schistosoma mansoni: characterization by UV cross-linking, DNase I footprinting and band shift assays

Protein extracts obtained from male and female shistosomes were incubated with a gender-specific gene, F-10, transcribed only in adult females and encoding a major egg-shell protein. The protein/DNA interaction was measured using the band shift, DNase-I-footprinting and UV cross-linking techniques. The results showed a clear band shift when a 302 bp restriction fragment containing the 3'end of the gene was incubated with either female or male proteins. This fragment also contained a putative steroid hormone regulatory element (HRE). In contrast, only the male proteins produced a shift with the 495 bp fragment corresponding to the middle region of the gene. DNase I footprinting showed that proteins from males and females interacted with the F-10 gene by binding to multiple adjacent sites along the DNA, thus generatingrelatively long protected fragments of approximately 100 bp. This result suggested that the adjacent binding of several moles of proteins occured at the 5'end of the gene. UV cross-linking between schistosome proteins and a 21 bp synthetic oligonucleotide the F-10 HRE, evidence proteins having MWS of 30,45 and 65 kDNA. These proteins are presumably involved in the regulation of transcription of the F-10 gene.

Cross-sectional and evolutive studies of schistosomiasis mansoni in untreated and mass treated endemic areas in the southeast and northeast of Brazil

Cross-sectional and evolutive studies on schistosomiasis mansoni were carried out before and after mass treatment in the endemic areas of Capitao Andrade and Padre Paraíso, state of Minas Gerais, Riachuelo, state of Sergipe, Alhandra, state of Paraíba, and Aliança, Alegre and Coroatá, lowland of the state of Maranhao, Brazil, in the last eighteen years. The studies included clinical and fecal examination by the Kato-Katz quantitative technique, skin testfor Schistosoma mansoni infection, evaluation of man-water contact and other epidemiological investigations such as infection rate and dynamic of the snail population. Results showed: (1) Higher prevalence of S. mansoni infection, greater egg load elimination and higher and earlier morbidity of the chronic froms of the disease in the southeast areas of Capitao Andrade and Padre Paraíso; (2) The incidence of hepatosplenic form is higher in some family clusters, in whites and mullattos in all the endemic areas but develop earlier in the southeast; (3) The prevalence and morbidity of schistosomiasis are decreasing both in the mass treated northeast and in the untreated southeast areas; (4) The mass treatment reduces rapidily the prevalence of the infection and the morbidity of the disease but can not control it because of the frequent reinfections due to the intensity of man-water contact.

Evaluation of spleen cell population and effect of splenectomy on granuloma modulation in BALB/c mice infected with Schistosoma mansoni

A kinetic study of the cells present in the spleen of BALB/c mice infected with Schistosoma mansoni was carried out. The lymphocytes were evaluated phenotypically with monoclonal antibodies and the effect of splenectomy on the modulation of periovular granuloma was also investigated. The infected mice had proportional increases in the numbers of neutophils, plasma cells, macrophages and eosinophils in the spleen. The largest number of neutrophil, plasma cells and macrophage were found between the 8th and the 12th week of infection, while the amount of eosinophils were higher later on, around the 20th week. The lymphocytes phenotipically characterized as Thy 1.2, Lyt 1.2 (CD4) increased mildly in proportional numbers. However, the percentage of lymphocytes with the Lyt 2.2 (CD8) phenotype, which is characteristic of supressor and cytotoxic T cells, increased significantly with the progress of the disease. The numbers of B lymphocytes, which comprise 50% of the mononuclear cells present in the spleen, increased significantly till the 16th week they began to decrease. The mean diameters of periovular granulomas were comparatively similar in both experimental groups (splenectomized and non-splenectomized mice). However, the evolutive types of granuloma (exudative, intermediate and fibrous) in splenectomized mice were proprtionally different from those of non splenectomized mice in the 16th and 24th week of infection. It is inferred that lymphonodes or other secondary lymphoide organs, in the abscence of the spleen, assume a modulating action on periovular granulomas, although the evolution of the granulomas is somehow delayed in splenectomized mice.

Role of Immune Complexes from Pacients with Different Clinical Forms of Schistosomiasis in the Modulation of In Vitro Granuloma Reaction

Schistosomiasis is a disease whose pathology is strongly related to the granulomatous reaction formed around parasite eggs trapped in host tissues. Studies have shown that the chronic intestinal form (INT) of this infection is associated with a variety of immunoregulatory mechanisms which lead to a diminished granulomatous reaction. Using an in vitro model of granuloma reaction, we show that immune complexes (IC) isolated from sera of INT patients are able to reduce granulomatous reaction developed by peripheral blood mononuclear cells (PBMC) from acute (AC), INT and hepatosplenic (HE) patients to soluble egg antigen (SEA)-conjugated polyacrylamide beads (PB-SEA). This inhibitory activity is also observed in cell proliferation assay of PBMC from INT and HE patients stimulated with SEA and adult worm antigen (SWAP). Furthermore, IC isolated from sera of patients with different clinical forms of the disease are also able to suppress INT patients PBMC reactivity. Therefore, our results show that circulating IC present in sera of patients with different clinical forms of schistosomiasis may down-regulate PBMC reactivity to parasite antigens resulting in a diminished granuloma reaction to parasite eggs