Heterogeneous response of adipose tissue to cancer cachexia

Cancer cachexia causes disruption of lipid metabolism. Since it has been well established that the various adipose tissue depots demonstrate different responses to stimuli, we assessed the effect of cachexia on some biochemical and morphological parameters of adipocytes obtained from the mesenteric (MES), retroperitoneal (RPAT), and epididymal (EAT) adipose tissues of rats bearing Walker 256 carcinosarcoma, compared with controls. Relative weight and total fat content of tissues did not differ between tumor-bearing rats and controls, but fatty acid composition was modified by cachexia. Adipocyte dimensions were increased in MES and RPAT from tumor-bearing rats, but not in EAT, in relation to control. Ultrastructural alterations were observed in the adipocytes of tumor-bearing rat RPAT (membrane projections) and EAT (nuclear bodies).

Quantitative analysis of cardiac lesions in chronic canine chagasic cardiomyopathy

Lesions observed in chronic chagasic cardiopathy frequently produce electrocardiographic alterations and affect cardiac function. Through a computerized morphometrical analysis we quantified the areas occupied by cardiac muscle, connective and adipose tissues in the right atrium of dogs experimentally infected with Trypanosoma cruzi. All of the infected dogs showed chronic myocarditis with variable reduction levels of cardiac muscle, fibrosis and adipose tissue replacement. In the atrial myocardium of dogs infected with Be78 and Be62 cardiac muscle represented 34 and 50%, fibrosis 28 and 32% and adipose tissue 38 and 18%, respectively. The fibrosis observed was both diffuse and focal and mostly intrafascicular, either partially or completely interrupting the path of muscle bundles. Such histological alterations probably contributed to the appearance of electrocardiographic disturbances verified in 10 out 11 dogs which are also common in human chronic chagasic cardiopathy. Fibrosis was the most important microscopic occurrence found since it produces rearrangements of collagen fibers in relation to myocardiocytes which causes changes in anatomical physiognomy and mechanical behavior of the myocardium. These abnormalities can contribute to the appearance of cardiac malfunction, arrythmias and congestive cardiac insufficiency as observed in two of the analyzed dogs. Strain Be78 caused destruction of atrial cardiac muscle higher than that induced by strain Be62.

Correlation of serum leptin and insulin levels of pregnant protein-restricted rats with predictive obesity variables

During pregnancy and protein restriction, changes in serum insulin and leptin levels, food intake and several metabolic parameters normally result in enhanced adiposity. We evaluated serum leptin and insulin levels and their correlations with some predictive obesity variables in Wistar rats (90 days), up to the 14th day of pregnancy: control non-pregnant (N = 5) and pregnant (N = 7) groups (control diet: 17% protein), and low-protein non-pregnant (N = 5) and pregnant (N = 6) groups (low-protein diet: 6%). Independent of the protein content of the diet, pregnancy increased total (F1,19 = 22.28, P < 0.001) and relative (F1,19 = 5.57, P < 0.03) food intake, the variation of weight (F1,19 = 49.79, P < 0.000) and final body weight (F1,19 = 19.52, P < 0.001), but glycemia (F1,19 = 9.02, P = 0.01) and the relative weight of gonadal adipose tissue (F1,19 = 17.11, P < 0.001) were decreased. Pregnancy (F1,19 = 18.13, P < 0.001) and low-protein diet (F1,19 = 20.35, P < 0.001) increased the absolute weight of brown adipose tissue. However, the relative weight of this tissue was increased only by protein restriction (F1,19 = 15.20, P < 0.001) and the relative lipid in carcass was decreased in low-protein groups (F1,19 = 4.34, P = 0.05). Serum insulin and leptin levels were similar among groups and did not correlate with food intake. However, there was a positive relationship between serum insulin levels and carcass fat depots in low-protein groups (r = 0.37, P < 0.05), while in pregnancy serum leptin correlated with weight of gonadal (r = 0.39, P < 0.02) and retroperitoneal (r = 0.41, P < 0.01) adipose tissues. Unexpectedly, protein restriction during 14 days of pregnancy did not alter the serum profile of adiposity signals and their effects on food intake and adiposity, probably due to the short term of exposure to low-protein diet.

Biochemical and morpho-anatomical analyses of strawberry vitroplants hyperhydric tissues affected by BA and gelling agents

In vitro propagation has become an effective practice for large-scale production of strawberry plants. The objective of this study was to evaluate the hyperhydricity and the multiplication capacity of two strawberry varieties (Fragaria x ananassa Duch. 'Dover' and 'Burkley') propagated in vitro. Plants maintained in MS medium supplemented with 1.0 mg L-1 BA were individualized and transferred to the same medium solidified with Agar (6.5 g L-1) or Phytagel® (2.5 g L-1) and BA at different concentrations (0; 0.5; 1.0; 2.0 and 3.0 mg L-1). Biochemical and anatomical analyses were carried out, as well as the analysis of the morphological hyperhydricity characteristics. The analysis of data showed: a) the increase in cytokinin concentration increased hyperhydricity frequency in both varieties; b) at concentrations up to 2.0 mg L-1 BA, the replacement of Agar by Phytagel® induced a higher formation of hyperhydric shoots; and c) the addition of BA induced oxidative stress, which is characterized by increased antioxidant activity and lipid peroxidation, as well as alterations at the cellular level, such as malformation of stomata and epidermal cells. In conclusion, the culture medium containing 0.5 mg L-1 BA solidified with Agar provided lower hyperhydricity percentages in association with higher rates of shoot proliferation in strawberry.

Detection of parvovirus B19 infection in formalin-fixed and paraffin-embedded placenta and fetal tissues

Parvovirus B19 infection was first discovered in 1975 and it is implicated in fetal death from hydrops fetalis the world over. Diagnosis is usually made through histological identification of the intranuclear inclusion in placenta and fetal organs. However, these cells may be scarce or uncharacteristic, making definitive diagnosis difficult. We analyzed histologically placentas and fetal organs from 34 cases of non-immune hydrops fetalis, stained with Hematoxylin and Eosin (HE) and submitted to immunohistochemistry and polymerase chain reaction (PCR). Of 34 tissue samples, two (5.9%) presented typical intranuclear inclusion in circulating normoblasts seen in Hematoxylin and Eosin stained sections, confirmed by immunohistochemistry and PCR. However, PCR of fetal organs was negative in one case in which the placenta PCR was positive. We concluded that parvovirus B19 infection frequency is similar to the literature and that immunohistochemistry was the best detection method. It is highly specific and sensitive, preserves the morphology and reveals a larger number of positive cells than does HE with the advantage of showing cytoplasmic and nuclear positivity, making it more reliable. Although PCR is more specific and sensitive in fresh or ideally fixed material it is not so in formalin-fixed paraffin-embedded tissues, frequently the only one available in such cases.

Canine visceral leishmaniasis due to Leishmania (L.) infantum chagasi in Amazonian Brazil: comparison of the parasite density from the skin, lymph node and visceral tissues between symptomatic and asymptomatic, seropositive dogs

Canine visceral leishmaniasis (CVL) is recognizable by characteristic signs of disease and is highly lethal. The infection, however, may be quite inapparent in some seropositive dogs, and this has raised the polemic question as to whether or not such animals can be a source of infection for Lutzomyia longipalpis, the vector of American visceral leishmaniasis (AVL). In this study we have examined 51 dogs with acute CVL from an AVL area in Pará State, northern Brazil, and compared the parasite density, amastigotes of Leishmania (L.) infantum chagasi, in the skin, lymph node and viscera of symptomatic with that of nine asymptomatic but seropositive dogs (IFAT-IgG). Post-mortem biopsy fragments of these tissues were processed by immunohistochemistry, using a polyclonal antibody against Leishmania sp. The X² and Mann Whitney tests were used to evaluate the means of infected macrophage density (p < 0.05). There was no difference (p > 0.05) in the skin (10.7/mm² x 15.5/mm²) and lymph node (6.3/mm² x 8.3/mm²), between asymptomatic and symptomatic dogs, respectively. It was higher (p < 0.05), however, in the viscera of symptomatic (5.3/mm²) than it was in asymptomatic (1.4/mm²) dogs. These results strongly suggest that asymptomatic or symptomatic L. (L.) i. chagasi-infected dogs can serve as a source of infection, principally considering the highest (p < 0.05) parasite density from skin (10.7/mm² x 15.5/mm²), the place where the vetor L. longipalpis takes its blood meal, compared with those from lymph node (6.3/mm² x 8.3/mm²) and viscera (1.4/mm²x 5.3/mm²).

HIGH SENSITIVE PCR METHOD FOR DETECTION OF PATHOGENIC Leptospira spp. IN PARAFFIN-EMBEDDED TISSUES

This study describes the development and application of a new PCR assay for the specific detection of pathogenic leptospires and its comparison with a previously reported PCR protocol. New primers were designed for PCR optimization and evaluation in artificially-infected paraffin-embedded tissues. PCR was then applied to post-mortem, paraffin-embedded samples, followed by amplicon sequencing. The PCR was more efficient than the reported protocol, allowing the amplification of expected DNA fragment from the artificially infected samples and from 44% of the post-mortem samples. The sequences of PCR amplicons from different patients showed >99% homology with pathogenic leptospires DNA sequences. The applicability of a highly sensitive and specific tool to screen histological specimens for the detection of pathogenic Leptospira spp. would facilitate a better assessment of the prevalence and epidemiology of leptospirosis, which constitutes a health problem in many countries.

Detection of enteroviral sequence in endomyocardial tissues from patients with cardiac diseases in Northern Brazil

In the present report we describe the results from a pilot study aimed at detecting enterovirus sequence in cardiac tissues, obtained through endomyocardial biopsies, from patients suffering from cardiac diseases in the Amazon region. Six samples that were collected from three patients were analysed by RT-PCR showing 3 positive and 3 negative results. These preliminary findings suggest the participation of enteroviruses in the etiology of cardiac diseases, mainly myocarditis, and warrant further and broader local studies on this subject.

Polymerase chain reaction-based method for the identification of Leishmania (Viannia) braziliensis and Leishmania (Viannia) guyanensis in mucosal tissues conserved in paraffin

ABSTRACTINTRODUCTION: In the Americas, mucosal leishmaniasis is primarily associated with infection by Leishmania (Viannia) braziliensis. However, Leishmania (Viannia) guyanensis is another important cause of this disease in the Brazilian Amazon. In this study, we aimed at detecting Leishmaniadeoxyribonucleic acid (DNA) within paraffin-embedded fragments of mucosal tissues, and characterizing the infecting parasite species.METHODS: We evaluated samples collected from 114 patients treated at a reference center in the Brazilian Amazon by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses.RESULTS: Direct examination of biopsy imprints detected parasites in 10 of the 114 samples, while evaluation of hematoxylin and eosin-stained slides detected amastigotes in an additional 17 samples. Meanwhile, 31/114 samples (27.2%) were positive for Leishmania spp. kinetoplast deoxyribonucleic acid (kDNA) by PCR analysis. Of these, 17 (54.8%) yielded amplification of the mini-exon PCR target, thereby allowing for PCR-RFLP-based identification. Six of the samples were identified as L. (V.) braziliensis, while the remaining 11 were identified as L. (V.) guyanensis.CONCLUSIONS: The results of this study demonstrate the feasibility of applying molecular techniques for the diagnosis of human parasites within paraffin-embedded tissues. Moreover, our findings confirm that L. (V.) guyanensisis a relevant causative agent of mucosal leishmaniasis in the Brazilian Amazon.

Titanium pigment in tissues of drug addicts: report of 5 necropsied cases

The aim of this report is to describe the anatomic-pathologic findings from necropsies of 5 drug addicts with titanium pigment in several organs after chronic intravenous injection of crushed propoxyphene hydrochloride tablets. Samples from liver, spleen, lungs, lymph nodes, and bone marrow were obtained, and after being grossly studied, they were submitted to evaluation using common light and polarized microscopy. In all 5 cases, a pigment with characteristics of titanium dioxide was found within tissue samples of the organs studied. Our findings suggest that research concerning titanium pigment within body tissues should be enhanced, considering the potential contribution of this morphologic data to forensic pathology.

Detection of viral infection by immunofluorescence in formalin-fixed tissues, pretreated with trypsin

The presence of viral antigen in sections from formalin-fixed and paraffin-embedded human tissues was demonstrated by trypsin digestion followed by direct or indirect immunofluorescence. The specimens may be used for retrospective diagnosis. The immunofluorescence technique has to be adapted to the suspected virus infection on the basis of previous histopathology study. Variations of trypsin concentration time and temperature of incubation, expose different viral antigens and have to be previously tested for each unknown system. For measles virus detection in lung a stronger digestion has to be applied as compared to adenovirus or respiratory disease viruses in the same tisue. Flavivirus in liver tissue needs a weaker digestion. The reproducibility of the method makes it useful as a routine technique in diagnosis of virus infection.

Trypanosoma cruzi strains and autonomic nervous system pathology in experimental chagas disease

Lesions involving the sympathetic (para-vertebral ganglia) and para-sympathetic ganglia of intestines (Auerbach plexus) and heart (right atrial ganglia) were comparatively analyzed in mice infected with either of three different strain types of Trypanosoma cruzi, during acute and chronic infection, in an attempt to understand the influence of parasite strain in causing autonomic nervous system pathology. Ganglionar involvement with neuronal destruction appeared related to inflammation, which most of the times extended from neighboring adipose and cardiac, smooth and striated muscular tissues. Intraganglionic parasitism was exceptional. Inflammation involving peripheral nervous tissue exhibited a focal character and its variability in the several groups examined appeared unpredictable. Although lesions were generally more severe with the Y strain, comparative qualitative study did not allow the conclusion, under the present experimental conditions, that one strain was more pathogenic to the autonomic nervous system than others. No special tropism of the parasites from any strain toward autonomic ganglia was disclosed.

The Growth of Brown Adipose Tissue in Cold-acclimatized Rats after Depletion of Mast Cell Histamine by Compound 48/80

Cold acclimatization (4-5°C) is accompanied by 2-3 fold increase of brown adipose tissue (BAT). This rapid growth of interscapular BAT was studied after histamine depletion. In control rats maintained at room temperature (28 ± 2°C) the BAT histamine content was 23.4 ± 5.9 (mean ± SD) µg/g of tissue and cold acclimatization (5±1°C) produced a significant increase of BAT weight, but reduced the histamine content to 8.4 ± 1.9 µg/g. The total weight of BAT after 20 days of acclimatization was unaffected by depletion of histamine due to compound 48/80. The low level of histamine in BAT of cold acclimatized rats could be due to a fast rate of amine utilization; alternatively an altered synthesis or storage process may occur during acclimatization.