Capillariid nematodes in Brazilian turkeys, Meleagris gallopavo (Galliformes, Phasianidae): pathology induced by Baruscapillaria obsignata and Eucoleus annulatus (Trichinelloidea, Capillariidae)

The pathology induced in turkeys (Meleagris gallopavo) by two capillariid nematodes, Baruscapillaria obsignata and Eucoleus annulatus is described together with data on prevalences, mean infection and range of worm burdens. B. obsignata occurred with a prevalence of 72.5% in the 40 examined hosts in a range of 2-461 nematodes and a mean intensity of 68.6, whereas E. annulatus was present in 2.5% of the animals, with a total amount of five recovered parasites. Gross lesions were not observed in the parasitized birds. Lesions due to B. obsignata mainly consisted of the thickening of intestinal villi with a mild mixed inflammatory infiltrate with the presence of mononuclear cells and heterophils. The lesions induced by E. annulatus were represented by foci of inflammatory infiltrate with heterophils in the crop epithelium and esophagus of a single infected female. These are the first pathological findings related to the presence of capillariid worms in turkeys to be reported in Brazil so far. Capillaria anatis, although present, was not pathogenic to the investigated turkeys.     

Absence of vacuolar membrane involving Toxoplasma gondii during its intranuclear localization

Tachyzoites of Toxoplasma gondii were located inside the nucleus of both skeletal muscle cells infected in vitro and peritoneal exudate cells collected from infected mouse in vivo. Ultrastructural analysis demonstrated that T. gondii invades the nucleus of host cells by the parasite apical region and with constriction of its body. We noted that the rhoptry, a secretory organelle of the parasite that is involved in the host cell invasion mechanism, was empty in the intranuclear T. gondii. The parasites were found in the nuclear matrix without evidence of the vacuolar membrane. Frequently, new parasites invaded host cell nucleus, which was already infected. The significance of this nuclear invasion could reflect an alternative route of T. gondii for its transitory survival or an escape mechanism from the host immune response during the in vivo infection (or both).     

Differences in the number of hemocytes in the snail host Biomphalaria tenagophila, resistant and susceptible to Schistosoma mansoni infection

The relationships between schistosomiasis and its intermediate host, mollusks of the genus Biomphalaria, have been a concern for decades. It is known that the vector mollusk shows different susceptibility against parasite infection, whose occurrence depends on the interaction between the forms of trematode larvae and the host defense cells. These cells are called amebocytes or hemocytes and are responsible for the recognition of foreign bodies and for phagocytosis and cytotoxic reactions. The defense cells mediate the modulation of the resistant and susceptible phenotypes of the mollusk. Two main types of hemocytes are found in the Biomphalaria hemolymph: the granulocytes and the hyalinocytes. We studied the variation in the number (kinetics) of hemocytes for 24 h after exposing the parasite to genetically selected and non-selected strains of Biomphalaria tenagophila, susceptible or not to infection by Schistosoma mansoni. The differences were analyzed referred to the variations in the number of hemocytes in mollusks susceptible or not to infection by S. mansoni. The hemolymph of the selected and non-selected snails was collected, and hemocytes were counted using a Neubauer chamber at six designated periods: 0 h (control, non-exposed individuals), 2 h, 6 h, 12 h, 18 h and, 24 h after parasite exposure. Samples of hemolymph of five selected mollusks and five non-selected mollusks were separately used at each counting time. There was a significant variation in the number of hemocytes between the strains, which indicates that defense cells have different behaviors in resistant and susceptible mollusks.     

Immunohistochemical distribution of the tetraspanin CD9 in normal porcine tissues

The tetra-membrane-spanning protein, CD9 is a 24–27 kDa cell surface glycoprotein expressed in a wide variety of human cells being involved in a variety of cell processes, including signaling, adhesion, motility, fertilization and tumor cells metastasis. By means of a polyclonal antibody (N1) raised against recombinant swine CD9 protein, we studied the immunohistochemical expression of CD9 on different normal swine tissues. Immunochemistry shows that swine CD9 was distribute in a similar form than in human tissues, being present on epithelial cells of lung, liver, kidney, skin, tonsil, testis (epididymo), gut mucosa, uterus and mama. Furthermore, polyclonal antibody against swine CD9 reacts with white matter from cerebrum and cerebellum, peripheral nerves fibers and Hassal corpuscle from thymus and ovum. Platelets react strongly with our antibody, but monocytes and neutrophils react lightly. These results suggest that CD9 antigen should play a similar functional role in swine and human and therefore studies on CD9 on swine as an animal model would allow new knowledge about its role in adhesion, fertilization and tumor metastasis among other important biomedical processes.     

Intraspecific variation in the venoms of the South American rattlesnake (Crotalus durissus terrificus)

The venom of eight individual Crotalus durissus terrificus snakes from the State of Minas Gerais, Brazil, in addition to pooled venom from Butantan Institute, were compared. Snakes were captured in distinct locations, some of them 600 km apart: Conselheiro Lafaiete, Entre Rios de Minas, Itauna, Itapecerica, Lavras, Patos de Minas, Paracatu, and Santo Antonio do Amparo. The crude venoms were tested for proteolytic, phospholipase A2, platelet aggregating, and hemagglutinating activities. The venoms were also analyzed by polyacrylamide gel electrophoresis (PAGE) and isoelectric focusing (IEF). Chromatographic patterns of venom proteins on both gel-filtration and anion-exchange chromatographies were also performed. All venoms presented high phospholipase A2 and platelet-aggregating activities, but only minimal hemagglutinating or proteolytic activities were found. Gel-filtration chromatography showed a characteristic profile for most venoms where four main peaks were separated, including the typical ones where convulxin and crotoxin were identified; however, peaks with high amounts of lower molecular weight proteins were found in the venoms from the Santo Antonio do Amparo location and Butantan Institute, characterizing these venoms as crotamine positive. Anion-exchange chromatographies presented a similar protein distribution pattern, although the number of peaks (up to ten) distinguished some venom samples. Consistent with these results, polyacrylamide gels that were silver stained after venom separation by PAGE or IEF presented a similar qualitative band distribution, although a quantitative heterogeneity was detected among venoms. Our results suggest that the variability found in venom components of C. d. terrificus venoms captured in Minas Gerais State may be genetically inherited and/or environmentally induced.     

Phenotypic subtypes of acute lymphoblastic leukemia associated with different nuclear chromatin texture

OBJECTIVE: To determine if phenotypic subtypes of acute lymphoblastic leukemia (ALL) are associated with different nuclear textures. STUDY DESIGN: In 49 newly diagnosed patients, diagnostic work-up was made by routinely Giemsa-stained smears and immunophenotyping. B-precursor ALL was further subdivided by European Group for the Immunological Classification of Leukemias criteria. T-ALL was analyzed as a whole group. One hundred nuclear images were acquired; standard morphometric variables and texture features derived from the co-occurrence matrix were calculated. RESULTS: In T-ALL, nuclei presented higher mean and minimal gray levels and higher local homogeneity and angular second moment but lower entropy values, contrast, diagonal moment and cluster prominence than did nuclei in B-derived ALL. In T-ALL, peripheral blood (PB) leukocyte count showed significant positive correlation with minimal gray level and inverse correlation with nuclear area. In B-ALL, peripheral leukocyte count showed positive correlation with mean fluorescence intensity of CD45. In T-ALL but not in B-ALL, inverse correlation existed among age and PB leukocyte count and mean gray levels, and direct correlation existed with nuclear area and mean optical density. CONCLUSION: ALL of B- or T-origin presented significant differences in nuclear texture features, probably reflecting different molecular events associated with cell differentiation, gene methylation pattern, apoptosis, and lineage-specific functional events.     

Exposure of young rats to high estrogen doses leads to degeneration of elongated spermatids

Single high doses of estrogen (35 mg/kg body weight) were administered to young rats aiming to exacerbate its effects on germ cell populations. The short-term (1 week) and medium-term (7 weeks) consequences of this estrogenic treatment (ET) on the testis were evaluated using light and electron microscopies, quantitative methods and TUNEL reaction. Short-term ET led to 50% atrophy of the testis, however, in the medium term the gonado-somatic index was recovered. No histopathological alterations were found at seminiferous epithelium except for short-term severe degeneration of elongated spermatids (EL) and low frequency of these cells in both time intervals. Two morphologically distinct patterns of degeneration were observed: (1) clusters of EL which were TUNEL-negative and exhibited bizarre appearance and nuclear fragmentation, (2) isolated apoptotic EL within the cytoplasm of Sertoli cells (SC). Both degenerative phenomena were more frequent in stages III-VIII of seminiferous cycle, whereas at stages I and II only coiling of flagellum was observed. One week after ET, small amounts of EL were detected in stages IX-XII, suggesting spermiation failure. Signs of functional SC damage such as an accumulation of myelin-like inclusions in their cytoplasm were observed in the short but not medium-term. However, the apoptotic rates still remained five times higher and the number of elongated spermatids was three-fold lower. Our data indicate that exposure to a high dose of estrogen around puberty has stage-specific effects on the testis and causes massive degeneration of elongated spermatids.     

Diagnostic imaging and histologic background of nipple discharge -- our experience with 40 patients

The authors present the diverse etiology of nipple discharge, which background may be a tumor. They discuss the checkup ways of nipple discharge and review in detail the galactographic technique and evaluation. The examination of pathologic nipple discharge is essentially based on contact cytology, x-ray-, and ultrasound mammography. Consequently, galactography is applied by filling the ducts with contrast material. The final diagnosis is rendered by histologic examination, following the operation. The authors demonstrate the application and role of galactography through various cases.