In vivo biocompatibility of diamond-like carbon films containing TiO2 nanoparticles for biomedical applications.

Hybrid diamond-like carbon (DLC) with incorporated titanium dioxide (TiO2) nanoparticle coatings have low friction coefficient, high wear resistance, high hardness, biocompatibility, and high chemical stability. They could be employed to modify biomedical alloys surfaces for numerous applications in biomedical engineering. Here we investigate for the first time the in vivo inflammatory process of DLC coatings with incorporated TiO2 nanoparticles. TiO2-DLC films were grown on AISI 316 stainless-steel substrates using plasma-enhanced chemical vapor deposition. The coated substrates were implanted in CF1 mice peritoneum. The in vivo cytotoxicity and biocompatibility of the samples were analyzed from macrophage lavage. Analysis in the first weeks after implantation could be helpful to evaluate the acute cytotoxicity generated after a possible inflammatory process. The in vivo results showed no inflammatory process. A significant increase in nitric oxide production on the uncoated substrates was confirmed through cytometry, and the coated substrates demonstrated biocompatibility. The presence of TiO2 nanoparticles enhanced the wound healing activity, due to their astringent and antimicrobial properties. DLC and TiO2-DLC coatings were considered biocompatible, and the presence of TiO2 nanoparticles reduced the inflammatory reactions, increasing DLC biocompatibility.

Histopathological and Immunohistochemical Characteristics of Thyroid Carcinoma in the Dog.

Thyroid carcinomas are a common form of endocrine neoplasia in dogs. In the present study, we combined histopathology with immunohistochemistry (IHC) to search for the presence of oestrogen receptor alpha (ORα), Cox-2 and Ki67 in canine thyroid carcinomas. Forty-eight thyroid carcinomas were diagnosed throughout the study period. Thyroglobulin and calcitonin IHC distinguished between thyroid tumours with a follicular and medullary (C-cell) origin, respectively. IHC-based diagnosis showed that 42 (87.50%) of the cases were follicular cell carcinoma. In these cases, the follicular-compact pattern was the most frequent (n = 20/42; 47.62%) and six cases (12.5%) were medullary cell (C-cell) carcinomas. Both medullary (C-cell) and follicular carcinomas expressed Ki67 and Cox-2. No differences were observed between medullary and follicular carcinomas with respect to expression of Ki67 (P = 0.34) and Cox-2 (P = 0.9523) markers. A total of 4.17% (n = 2/48) of thyroid carcinomas showed positive nuclear labelling for ORα, suggesting that oestrogen does not directly participate in the pathogenesis of canine thyroid neoplasia.

The lupus patient with positive rheumatoid factor.

Background Patients with systemic lupus erythematosus (SLE) may form clusters with clinical manifestations and autoantibodies. Objective The objective of this report is to study whether SLE patients with positive rheumatoid factor (RF) have a special clinical and/or serological profile. Methods A retrospective study of 467 SLE patients seen at a single rheumatology unit was conducted. Epidemiological data (age, gender, age at disease onset, ethnic background and tobacco use), clinical data (malar rash, photosensitivity, oral ulcers, discoid lesions, serositis, glomerulonephritis, convulsions, psychosis, hemolytic anemia, leukopenia, lymphocytopenia, arthritis and hypothyroidism) and serological profile (anti-dsDNA, anti-Ro/SS-A, anti-La/SS-B, anti-RNP, anti-Sm, IgG aCL, IgM aCL, lupus anticoagulant, direct Coombs and RF) were collected. Patients with positive and negative RF were compared. Results RF was found in 24.9% of the sample. In univariate analysis, RF was positively associated with butterfly rash ( p = 0.04), anti-Ro ( p = 0.03), anti-Sm antibodies ( p = 0.01) and hypothyroidism ( p = 0.01) and negatively associated with glomerulonephritis ( p = 0.003). Logistic regression showed that only glomerulonephritis ( p = 0.03; OR = 0.45; 95% CI = 0.21-0.93) and anti-Ro ( p = 0.009; OR = 2.3; 95% CI = 1.24-4.57) were independent associations. Conclusion In our sample RF was associated with protection from glomerulonephritis and with higher prevalence of anti-Ro antibodies.

Reduction of Toxoplasma gondii Development Due to Inhibition of Parasite Antioxidant Enzymes by a Dinuclear Iron(III) Compound.

Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan that can infect a wide range of vertebrate cells. Here, we describe the cytotoxic effects of the dinuclear iron compound [Fe(HPCINOL)(SO4)]2-µ-oxo, in which HPCINOL is the ligand 1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol, on T. gondii infecting LLC-MK2 host cells. This compound was not toxic to LLC-MK2 cells at concentrations of up to 200 µM but was very active against the parasite, with a 50% inhibitory concentration (IC50) of 3.6 µM after 48 h of treatment. Cyst formation was observed after treatment, as indicated by the appearance of a cyst wall, Dolichos biflorus lectin staining, and scanning and transmission electron microscopy characteristics. Ultrastructural changes were also seen in T. gondii, including membrane blebs and clefts in the cytoplasm, with inclusions similar to amylopectin granules, which are typically found in bradyzoites. An analysis of the cell death pathways in the parasite revealed that the compound caused a combination of apoptosis and autophagy. Fluorescence assays demonstrated that the redox environment in the LLC-MK2 cells becomes oxidant in the presence of the iron compound. Furthermore, a reduction in superoxide dismutase and catalase activities in the treated parasites and the presence of reactive oxygen species within the parasitophorous vacuoles were observed, indicating an impaired protozoan response against these radicals. These findings suggest that this compound disturbs the redox equilibrium of T. gondii, inducing cystogenesis and parasite death.

Participation of alpha-1 and alpha-2 adrenoceptors of the lateral hypothalamic area in water intake, and renal sodium, potassium and urinary volume excretion induced by central administration of angiotensin II.

The circumventricular structures and the lateral hypothalamus (LH) have been shown to be important for the central action of angiotensin II (ANGII) on water and electrolyte regulation. Several anatomical findings have demonstrated neural connection between circumventricular structures and the LH. The present experiments were conducted to investigate the role of the alpha-adrenergic antagonists and agonistic injected into the LH on the water intake, sodium and potassium excretion elicited by injections of ANGII into the lateral ventricle (LV). The water intake was measured every 30 min over a period of 120 min. The sodium, potassium and urinary volume were measured over a period of 120 min in water-loaded rats. The injection of ANGII into the LV increased the water intake, which was reduced by previous injection of clonidine (an alpha-2-adrenergic agonist) into the LH. The injection of yohimbine (an alpha-2-adrenergic antagonist) and prazosin (an alpha-1-adrenergic antagonist) into the LH, which was done before injecting ANGII into the LV, also reduced the water intake induced by ANGII. The injection of ANGII into the LV reduced the sodium, potassium and urinary volume. Previous treatment with clonidine attenuated the action of ANGII in reducing the sodium, potassium and urinary volume, whereas previous treatment with yohimbine attenuated the effects of ANGII but with less intensity than that caused by clonidine. Previous treatment with prazosin increased the inhibitory effects of ANGII in those parameters. The injection of yohimbine and prazosin, which was done before the injection of clonidine, attenuated the effect of clonidine on the ANGII mechanism. The results of this study led us to postulate that when alpha-2-adrenergic receptors are blocked, the clonidine may act on the imidazoline receptors to produce its effects on the ANGII mechanism. We may also conclude that the LH is involved with circumventricular structures, which present excitatory and inhibitory mechanisms. Such mechanisms are responsible for regulating the renal excretion of sodium, potassium and water.

Headache in chagasic women.

The aim of this study was to compare the frequency of headache between Chagasic and Non-chagasic women. The cross-sectional study comprised 647 female > or = 40 years old, Chagasic (n = 362) and Controls (n = 285) at a Brazilian University Hospital. Chagasic were classified as Cardiac (n = 179), Megas (n = 58) or Indeterminate (n = 125) clinical forms. Headache was ascertained according to Headache International Society diagnostic criteria. The age (57.0 +/- 11.3 versus 57.3 +/- 10.4 years), and the percentage of white women (75.8% versus 77.1%) were similar between Chagasic and Controls, respectively. Headache was more prevalent among Chagasic (32.9%) than Controls (16.1%), mainly in Cardiac form (odds ratio, 2.41; 95% confidence interval, 1.38-4.23), phenomenon possibly related to parasympathetic denervation and cerebral vessels changes.

[Frequency of diabetes mellitus and hyperglycemia in chagasic and non-chagasic women]. / Freqüência de diabetes mellitus e hiperglicemia em mulheres chagásicas e não-chagásicas.

Medical records of > or = 40 years old female seen at University Hospital from June/93 to July/95 were submitted to a cross-sectional study. According to Chagas' disease tests, patients were divided into chagasic (n = 362) and controls (n = 285). Diabetes mellitus was defined on the basis of two fasting blood glucose levels > or = 140 mg/dl and hyperglycemia as fasting blood glucose > 110 mg/dl. Chagasic patients were divided into groups with the cardiac form of the disease (n = 179), with megas (n = 58), and asymptomatic (n = 125). Groups were compared by the chi 2 test, analysis of variance, Student's "t" test, and Kruskal-Wallis and Mann-Whitney tests. A significant difference was assumed when p < 0.05. Chagasic and control groups were matched for age, white color and body mass index. Diabetes mellitus was more prevalent in patients with the cardiac form of Chagas' disease than in controls, or patients with the megas or the asymptomatic form (15.1%, 7.4%, 7.4%, and 5.6%, respectively); the same was observed for hyperglycemia (37.4%, 26.7%, 25.9%, 27.2%), in agreement with the hypothesis that the reduced parasympathetic activity caused by Trypanosoma cruzi leads to relative sympathetic hyperactivity.

[Pancreatic anatomopathologic changes in chronic chagasic women. Preliminary data]. / Alterações anatomo-patológicasdo pâncreas em chagásicas crônicas. Dados preliminares.

The aim of this study was to compare the frequency of pancreas morphologic and morphometric changes in chagasic women (n = 6) aged > or = 40 years, with non-chagasic controls (n = 4), paired concerning to age (59.8 +/- 11.5 versus 59.0 +/- 6.3 years), white color (33.3% versus 50.0%) and body mass index (22.3 +/- 7.0 versus 18.8 +/- 2.1 kg/m2). There were no pancreatic morphometric differences between necropsied chagasic and control groups. However, there was a smaller intrapancreatic neuronal population and a higher frequency of leukocyte perineural infiltrate in the pancreas of chagasic women. This possible intrapancreatic denervation could be associated with changes in carbohydrate metabolism, including hyperglycemia and diabetes mellitus, in some chronic chagasic women.

[Hanseniasis virchowiana in Chagas cardiopathy: an autopsy report]. / Hanseníase virchowiana em cardiopata chagásico: relato de necropsia.

This is a case report of lepromatous infection diagnosed at necropsy, with cardiac alterations directly caused by mycobacteria, in a 34-year-old black male with the cardiac form of Chagas' disease. The possible role of inflammatory mediators on cardiac dysfunction, and the possibility that immune depression may be due to factors associated with heart failure, as congestive splenomegaly and splenic infarctions, are emphasized.

[Frequency of precordialgia in chagasic and non-chagasic women]. / Freqüência de precordialgia em mulheres chagásicas e não-chagásicas.

The aim of this study was to compare the frequency of precordialgia between chagasic and non-chagasic women. A cross-sectional study comprised 647 female aged > or = 40, chagasic (n = 362) and controls (n = 285) was done at a Brazilian university hospital. Chagasic were classified as cardiac (n = 179), megas (n = 58) or indeterminate (n = 125) clinical forms. Chest pain was ascertained by typical or atypical retrosternal pain. Age (57.0 +/- 11.3 vs 57.3 +/- 10.4 years), and percentage of white women (75.8% vs 77.1%) were similar between chagasic and controls, respectively. Chest pain was more prevalent (p < 0.01) among chagasic (14.6%) than controls (5.6%), mainly in the cardiac form (relative risk = 2.41; range: 1.38-4.23), a phenomenon possibly related to cardiac parasympathetic denervation and myocardial microvascular changes.

[Daily and weekly circadian variations in sudden death in Chagas disease]. / Variações circadianas diárias e semanais na morte súbita da doença de Chagas.

PURPOSE: To determinate the circadian daily and weekly variations in the incidence of sudden death due to Chagas' disease. METHODS: In 50 chronic chagasic individuals with sudden death due to Chagas' disease and in 473 individuals with natural, not sudden death, we analyzed both the day of the week and the time of the death. Statistical tests were applied to determine the significance of the difference between proportions and averages. RESULTS: For the chagasic group the values indicated a highly significant excess of lethality for the period between 12 and 6pm. The occurrence of the sudden death was the same in the different days of the week for both groups. CONCLUSION: The observed results suggest that the sudden death associated with Chagas' disease has a circadian pattern with a vespertine peak. Weekly variations in the sudden death of chronic chagasic individuals were not detected.