A short proregion of trialysin, a pore-forming protein of Triatoma infestans salivary glands, controls activity by folding the N-terminal lytic motif

Triatoma infestans (Hemiptera: Reduviidae) is a hematophagous insect that transmits the protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas` disease. Its saliva contains trialysin, a protein that forms pores in membranes. Peptides based on the N-terminus of trialysin lyse cells and fold into alpha-helical amphipathic segments resembling antimicrobial peptides. Using a specific antiserum against trialysin, we show here that trialysin is synthesized as a precursor that is less active than the protein released after saliva secretion. A synthetic peptide flanked by a fluorophore and a quencher including the acidic proregion and the lytic N-terminus of the protein is also less active against cells and liposomes, increasing activity upon proteolysis. Activation changes the peptide conformation as observed by fluorescence increase and CD spectroscopy. This mechanism of activation could provide a way to impair the toxic effects of trialysin inside the salivary glands, thus restricting damaging lytic activity to the bite site.

Biologia alimentar e morfohistologia do tubo digestório do mussum, synbranchus marmoratus, bloch (osteichthyes: synbranchidae) no açude Marechal Dutra Gargalheiras , localizado no semi-árido brasileiro

Food habits and morpho-histology of the digestive tract of marbled swamp eel, Synbranchus marmoratus (Block, 1917) were investigated. The fish samples were captured during August, 2007 to July, 2008 in the Marechal Dutra reservoir, Acari, Rio Grande do Norte. The rain fall data was obtained from EMPARN. The fish captured, were measured, weighed, dissected, eviscerated and individual stomach weights were registered. The stomach contents analyses were carried out based on volumetric method, points, frequency of occurrence and applying the Index of Relative Importance. The degrees of repletion of the stomachs were determined besides the Index of Repletion relating to feeding activity variations and frequency of ingestion during the rainy and dry seasons. The rainfall varied from 0 mm a 335 mm with a mean value of 71.62 mm. Highest rainfall of 335.5 mm was registered in March, 2008 and August to December was the dry period. During the dry period the study species presented high degrees of repletion of the stomachs, with a peak value in the month of September (mean = 4.54; ± SD = 0.56). The minimum mean value of = 3.99 ± SD = 0.25 was registered in the month of May during the rainy period. The stomach contents of S. marmoratus registered show that this fish prefers animals, 78.22% of crustaceans 2.85% of mollusks, 3.25% of fish, 1.4% of insects and 13.5% of semi-digested organic matter, thus characterizing the study species as a carnivore with a preference for crustaceans. The morpho-histological aspects of the digestive tract of S. marmoratus indicate that the mouth is terminal adapted to open widely, thin lips with taste buds, small villiform teeth forming a single series on maxillas, four pairs of branchial arches with short and widely spaced branchial rays. The oesophagus is short and cylindrical with a small diameter. The oesophagus wall is thick with mucas surface and internal parallel folds. The stomach is retilinical in form, presenting cardiac, caecal and pyloric portions. The caecal portion is long and is intermediary in position between the cardiac and pyloric portions. The cardiac portion of the stomach is short and cylindrical formed of simple epithelial cylindrical mucus cells. The caecal portion is long with narrow walls, a big cavity and smaller folds which give rise to gastric glands. The phyloric portion has no glands and primary or secondary mucas folds. The morphohistological aspects of the digestive tract of S. marmoratus indicate its adaptation to a carnivorous feeding habit

Canine lacrimal and third eyelid superficial glands macroscopic and morphometric characteristics

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Morphology of glandular stomach (Ventriculus glandularis) and muscular stomach (Ventriculus muscularis) of the partrigde Rhynchotus rufescens

Vinte perdizes Rhynchotus rufescens adultas foram utilizadas para estudo morfológico do proventrículo e ventrículo gástricos da perdiz Rhynchotus rufescens. Os materiais foram coletados e os comprimentos do proventrículo e do ventrículo gástricos foram avaliados. Para o estudo histológico, fragmentos dos estômagos foram corados pelas técnicas de ácido periódico de Schiff (PAS) e tricromo de Masson. O proventrículo gástrico é alongado, com formato fusiforme direcionado no sentido craniocaudalmente e para a esquerda, e apresenta um comprimento médio 3,20cm nas fêmeas e 3,65cm nos machos. Histologicamente, o proventrículo gástrico é composto por vários lobos e glândulas. A mucosa é formada por epitélio cúbico, sendo bastante pregueada. O ventrículo gástrico tem o formato de uma lente biconvexa, com comprimento médio de 4,30cm nas fêmeas e 4,35cm nos machos. A mucosa é formada por pregas revestidas por células cilíndricas e pelo muco formador da cutícula. Há criptas na base das pregas. em seguida, há uma lâmina própria e uma espessa camada muscular lisa, que se encontra direcionada de acordo com o formato do ventrículo gástrico. A serosa é constituída por uma densa porção de tecido conjuntivo, entremeado por algumas células musculares lisas.

Ticks' response to feeding on host immunized with glandular extracts of Rhipicephalus sanguineus females fed for 2, 4, and 6 days. I. Inactivity or early degeneration of salivary glands?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Secretory process of salivary glands of female Amblyomma cajennense (Acari: Ixodidae) ticks fed on resistant rabbits

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Degenerative process and cell death in salivary glands of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) semi-engorged female exposed to the acaricide permethrin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cell Death in Salivary Glands of Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Acari: Ixodidae) Females at Semi-engorged Feeding Stage

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Lymphatic drainage on healthy and neoplasic mammary glands in female dogs: Can it really be altered?

The purpose of this research was to study the mammary lymphatic drainage under a macroscopic and mesoscopic view, comparing the vascular pattern of healthy and neoplasic mammary glands injected with drawing ink alcoholic and fluorescein solutions, in 46 mongrel female dogs. The results pointed out that the thoracic gland is drained by the axillary lymph centre, but in mammary neoplasia either superficial cervical or ventral thoracic lymph centres can be involved. Cranial and caudal abdominal glands may be drained by the axillary, inguinofemoral and popliteal lymph centres. However, the popliteal drainage is specific for the healthy caudal abdominal mammary gland. The inguinal gland can be drained by both inguinofemoral and popliteal lymph centres in both neoplasic and healthy conditions. Regarding the mammary lymphatic communications, this research demonstrated that neoplasic glands present more types of anastomosis (40.9%), than healthy glands (33.33%), and an increase in contralateral anastomosis (50%) compared with healthy ones (33%). Given the data, the mammary neoplasia can change the lymphatic drainage pattern in terms of lymph centres and vascular arborization, thus forming new drainage channels and recruiting a larger number of lymph nodes. Lastly, some comments were made about the severity of a specific neoplasic mammary gland and conditions to be considered before making a decision in terms of the most adequate operative procedure, and suggestions for further investigations.

Changes in minor salivary glands during 4-nitroquinoline 1-oxide-induced rat tongue carcinogenesis

We investigated the changes of minor salivary glands during 4NQO-induced rat tongue carcinogenesis. Histopathological examinations of serous and mucous tongue salivary glands of 30 male Wistar rats were performed after 4, 12 and 20 weeks of 50 ppm 4NQO chronicle administration in drinking water. Ten rats were used as control. Morphometric results were expressed as volume density (Vv %) of each of the components. Histopathological and morphometric changes in the salivary glands were evident only at 20 weeks following 4NQO administration and they included a significant (P < 0.05) decreased in the mean Vv of the serous acini compared with the control group accompanied by abnormal acini (Vv=14 %). Neither mucous acini nor ducts demonstrated significant changes. In conclusion, minor salivary glands are involved in the progression of 4NQO-induced carcinoma.

Immunohistochemical detection of receptors for oestrogen and progesterone in endometrial glands and stroma during the oestrous cycle in Nelore (Bos taurus indicus) cows

The aim of the present study was to monitor endometrial distribution and concentrations of oestrogen receptors alpha (ER alpha) and progesterone receptors (PR) by immunohistochemistry in Nelore cows (Bos taurus indicus) during the oestrous cycle. Blood samples were collected for progesterone measurement and endometrial samples were taken from the uterine horn contra lateral to the corpus luteum in 16 cows at days 0 (ovulation), 5, 9, 13 and 19 of the oestrous cycle. Immunostaining evaluation for ER alpha and PR in the glandular epithelium and uterine stroma was performed by two methods: positive nuclei counting and staining intensity of the nuclei. Specific positive staining reactions for both receptors were limited to cell nuclei and they were not identified in the cytoplasm. The proportion of ER alpha positive nuclei had a temporal variation throughout the oestrous cycle in both cell types evaluated and was higher in uterine stroma than the glandular epithelium (p < 0.05). The greatest proportion of ER alpha stained nuclei was observed at oestrus and during the initial and mid luteal phase (days 5, 9 and 13) (p < 0.05) in the glandular epithelium and at days 0, 5 and 9 in the uterine stroma (p < 0.01). The proportion of PR positive nuclei remained constant throughout the entire oestrous cycle for both cell types evaluated (p > 0.05). A higher proportion of PR positive nuclei was measured in the uterine stroma compared with the glandular epithelium (p < 0.05). Intensity of staining for ER alpha and PR varied throughout the oestrous cycle (p < 0.01). There was a higher staining intensity at days 0 and 5 in the stroma for ER alpha (p < 0.01) and PR (p < 0.01) and in the glandular epithelium at days 0, 5, 9 and 13 for ER alpha (p < 0.01) and at days 0, 5 and 9 for PR (p < 0.01) when compared with the other evaluated days. These data demonstrate that ER alpha and PR expression varied throughout the oestrous cycle in Nelore cows, in general with highest concentrations at oestrus and the lowest during the luteal phase. This is similar to patterns observed in Bos taurus taurus.

Periacinar Retraction Clefting in Nonneoplastic and Neoplastic Prostatic Glands: Artifact or Molecular Involvement

A space between neoplastic acini and prostatic stroma is not rare and studies have interpreted this as an artifact, considering the absence of endothelial cells indicating vascular invasion. Thus, the aims of this work were to characterize and correlate the occurrence and extent of retraction clefting with the reactivities of alpha and beta dystroglycan (alpha DG, beta DG), laminin, matrix metalloproteinase 2 (MMP-2), p63, insulin-like growth factor 1(IGF-1), vimentin, and fibroblast growth factor 2 (FGF-2). The study was based on nonneoplastic and neoplastic prostatic tissues obtained from necropsies and retropubic radical prostatectomies. The results showed that periacinar retraction clefting was significantly more frequent in prostatic carcinoma samples than in normal prostatic acini. Most of the neoplastic acini (72.0%) showed retraction clefting of more than 50% of circumference, which were significantly more frequent in Gleason score 7 and 6. Decreased collagen and reticular and elastic fibers were verified in the stroma around neoplastic acini. Weak and discontinuous alpha DG, beta DG, and laminin immunoreactivities and intensified MMP-2, vimentin, IGF-1 and FGF-2 immunoreactivities were verified in the neoplastic acini; p63 immunoreactivity was negative in all carcinomas. Thus, these findings showed that the lack of epithelial basal cells, DGs, and laminin and increased MMP-2, IGF-1, and FGF-7 could be considered important pathways in periacinar retraction occurrence. This study demonstrated the origin of and the biological mechanisms responsible for periacinar retraction clefting in prostatic carcinoma.