Secretory activity and endocrine regulation of male accessory glands in the blood-sucking bug Panstrongylus megistus (Hemiptera: Reduviidae)

The epithelial cells of Panstrongylus megistus male accessory glands (MAG) present ultrastructural characteristics of a secretory cell. Their secretory products are accumulated in the lumen of the four MAG lobes. During the first 8 days of adult life a strong secretion activity occurs, accumulating enough material to produce the first spermatophore. Cerebral neurosecretions as well as juvenile hormone are both involved in MAG secretory activity regulation. Juvenile hormone seems to be the responsible for the stimulation of most protein synthesis in male accessory glands. Cerebral neurosecretion seems to be necessary to stimulate juvenile hormone production and release by the corpus allatum. Furthermore, neurosecretion is required for some polypeptides synthesis by MAG. Although topic application of precocene II to adult males does not reproduce the same effects on MAG as does allatectomy, this compound causes strong reduction on male reproductive capacity.

Histogical and ultrastructural aspects of the brindley's glands of pantrongylus megistus (Burmeister, 1835) (Hemiptera: Reduviidae)

The Brindley's glands of Panstrongylus megistus were studied under the antomic, histologic and ultrastructural point of view. These glands located in the insect's methatorax are paired and have an opening near the third parir of the feet. Beside this aperture, ther are evaporation areas. Shape, sixe and aspect of the gland vary according to the feeding status. The glands are composed by a tubular part corresponding to the duct and a sack-like portion corrsponding to the secretory part. By electron microscopy we observed that the basal part of the epithelium has many interdigitations associated with mitochondria. On the apical surface where epicuticular foldings are located an electonlucent space is often seen. The glands are composed of the following elements: 1) superficial epithelial cells, located just below the apical surface foldings; 2) secretory cells; which are long and have an intracellular canalicule which changes according to the functional state of the cell; 3) a collecting duct to the secretory cells and covered with an epicuticle, reaching up to the gland's lumen; and 4) cells around the duct.

Epithelial effects of proteinase-activated receptors in the gastrointestinal tract

The intestinal epithelium plays a crucial role in providing a barrier between the external environment and the internal milieu of the body. A compromised mucosal barrier is characteristic of mucosal inflammation and is a key determinant of the development of intestinal diseases such as Crohn's disease and ulcerative colitis. The intestinal epithelium is regularly exposed to serine proteinases and this exposure is enhanced in numerous disease states. Thus, it is important to understand how proteinase-activated receptors (PARs), which are activated by serine proteinases, can affect intestinal epithelial function. This review surveys the data which demonstrate the wide distribution of PARs, particularly PAR-1 and PAR-2, in the gastrointestinal tract and accessory organs, focusing on the epithelium and those cells which communicate with the epithelium to affect its function. PARs have a role in regulating secretion by epithelia of the salivary glands, stomach, pancreas and intestine. In addition, PARs located on subepithelial nerves, fibroblasts and mast cells have important implications for epithelial function. Recent data outline the importance of the cellular site of PAR expression, as PARs expressed on epithelia may have effects that are countered by PARs expressed on other cell types. Finally, PARs and their ability to promote epithelial cell proliferation are discussed in terms of colon cancer.

Does the Ingestion of Isoxaflutole Herbicide Affect the Midgut and Salivary Glands of Pentatomidae Predators?

Podisus nigrispinus is a generalist predator naturally occurring in agricultural and forestry systems that effectively contributes to the population balance of phytophagous insects, especially defoliating caterpillars. Histological changes were evaluated in the salivary glands and midgut of P. nigrispinus caused by ingestion of systemic herbicide isoxaflutole. These predator females were fed with leaves of eucalyptus plants, Tenebrio molitor pupae or water, contaminated or not by herbicide. Salivary glands and midguts were dissected, processed and analyzed under a light microscope. Activity level and cell morphology of the salivary glands and midgut showed differences among insects fed on plants, contaminated water or pupae. The epithelia of the salivary gland and midgut of individuals which had no contact with the herbicide showed homogeneous cytoplasm, nucleus with predominance of decondensed chromatin and evident nucleoli, intense cell activity features. As for the insects in contact with contaminated food, they presented undeveloped nucleus and condensed chromatin. The luminal contents of the salivary glands in the contaminated insects had become more acidophilus than in insects without poisoning, as well as having heterogeneous and granular secretion, being more evident in the bioassay in which the insects fed on contaminated water. There was a marked morphological change in the midgut cells in contaminated insects. High degree of apoptosis, disorganization and secretory vacuoles in the epithelial cytoplasm were observed. The apical portion of the midgut cells proved undeveloped, irregular and partially destroyed. It is concluded that isoxaflutole causes morphological changes in the digestive system of the predator P. nigrispinus.

Oil glands in the Neotropical genus Dahlstedtia Malme (Leguminosae, Papilionoideae, Millettieae)

Dahlstedtia pentaphylla (Taub.) Burkart and D. pinnata (Benth.) Malme belong to the Millettieae tribe and are tropical leguminous trees that produce a strong and unpleasant odour. In the present work, we investigated the distribution, development and histochemistry of foliar and floral secretory cavities that could potentially be related to this odour. The ultrastructure of foliar secretory cavities were also studied and compared with histochemical data. These data were compared with observations recorded for other species of Millettieae in order to gain a phylogenetic and taxonomic perspective. Foliar secretory cavities were only recorded for D. pentaphylla. Floral secretory cavities were present in the calyx, wings and keels in both species; in D. pinnata they also were found in bracteoles and vexillum. Such structures were found to originate through a schizogenous process. Epithelial cells revealed a large amount of flattened smooth endoplasmic reticula, well-developed dictyosomes and vacuoles containing myelin-like structures. Cavity lumen secretion stains strongly for lipids. Features of the secretory cavities studied through ultrastructural and histochemical procedures identify these structures as oil glands. Thus, if the odour produced by such plants has any connection with the accumulation of rotenone, as other species belonging to the "timbó" complex, the lipophilic contents of the secretory cavities of Dahlstedtia species take no part in such odour production. The presence, distribution patterns and frequencies of secretory structures in Dahlstedtia are taxonomically significant and may be utilized as a diagnostic character which justifies the separation of this genus into two species.

Morphological changes induced by testosterone in the mammary glands of female Wistar rats

Increased levels of androgens in postmenopausal women are considered to be a risk factor for breast cancer. Testosterone, alone or in combination with estrogen, induces epithelial dysplasia and mammary tumors in Noble rats. Since this model of hormone-induced neoplasia has not been reported in other rat strains, we studied the effect of testosterone on the mammary gland morphology of female Wistar rats. Sixty adult, non-castrated, female Wistar rats were implanted in the dorsum midline with a silicone tube containing 50 mg testosterone (testosterone propionate in 30 animals and non-esterified testosterone in the remaining 30 animals) and 20 additional animals were implanted with empty tubes and used as control. Five animals per group were killed 30, 60, 90, 120, 150, and 180 days after implantation, and the mammary glands were dissected, fixed and embedded in paraffin. Histological sections were then stained with hematoxylin and eosin and picrosyrius red for collagen visualization. Morphological and morphometric analysis demonstrated ductal proliferation and acinotubular differentiation with secretory activity in all treated animals, peaking at 90 days of androgen exposure. After 90 days the proliferation of acinar epithelial cells was evident, but there was a progressive reduction of secretory differentiation and an increase in intralobular collagen fibers. There was no morphological evidence of dysplastic changes or other pre-neoplastic lesions. Testosterone treatment applied to adult, non-castrated female Wistar rats induced a mammary gland hyperplasia resembling the lactating differentiation, with progressive reduction in secretory differentiation.

Tracheal cryopreservation: caspase-3 immunoreactivity in tracheal epithelium and in mixed glands

Cryopreservation has an immunomodulating effect on tracheal tissue as a result of class II antigen depletion due to epithelium exfoliation. However, not all epithelium is detached. We evaluated the role of apoptosis in the remaining epithelium of 30 cryopreserved tracheal grafts. Caspase-3 immunoreactivity of tracheal epithelium was studied in canine tracheal segments cryopreserved with F12K medium, with or without subsequent storage in liquid nitrogen at -196°C for 15 days. Loss of structural integrity of tracheal mixed glands was observed in all cryopreserved tracheal segments. Caspase-3 immunoreactivity in tracheal mucosa and in mixed glands was significantly decreased, in contrast to the control group and to cryopreserved tracheal segments in which it remained high, due to the effect of storage in liquid nitrogen (P < 0.05, ANOVA and Tukey test). We conclude that apoptosis can be triggered in epithelial cells during tracheal graft harvesting even prior to cryopreservation, and although the epithelial caspase-3 immunoreactivity is reduced in tracheal cryopreservation, this could be explained by increased cell death. Apoptosis cannot be stopped during tracheal cryopreservation.

Effects of age on histological parameters of the sweat glands of Nellore cattle

The sweat glands are important in thermoregulation of cattle in a warm environment as they help dissipate heat through evaporation. Studies on gland histology are important to define its secretion potential and the capacity of perspiration and heat removal. The objective of this study was to determine, by histomorphometry, glandular epithelium height, the depth of the gland, length of the glandular portion and number of glands per cm2 of the sweat glands of the three age groups of Nellore cattle. Thirty females were used in this study. They were equally divided into calves, heifers and cows. Histological sections were obtained and analyzed by digital images in Trinocular BX40 Olympus microscope coupled to an Oly - 200 camera, connected to a computer. The images were obtained with microscope with 2x, 4x, 10x and 40x magnification objectives. The measurements were performed using HL Image 97 program. The height of glandular epithelium, depth of the glands, length and density of the glandular portion per cm2 , were all analyzed. The calves showed greater height of the glandular epithelium than heifers (P = 0.0024), and cows (P = 0.0191). The depth of the gland was not influenced by age. Cows had higher length of secretory portion than heifers (P = 0.0379) and calves (P = 0.0077). Heifers had a greater number of sweat glands per cm2 of skin than cows (P = 0.023). In cattle, the height of glandular epithelium and the density decreases as animals get older. On the other hand, the length of the secretor portion increases but with no changes in the depth of the sweat glands

Hepatobiliary alterations in massive biliary ascariasis: histopathological aspects of an autopsy case

Hepatobiliary alterations found in an autopsy case of massive Biliary Ascariasis, are reported on histological grounds. Severe cholangitis was the main finding, but other changes were also detected, such as pyloric and intestinal metaplasia, hyperplasia of the epithelial lining, with intraductal papillomas and adenomatous proliferation. Remnants of the worm were observed tightly adhered to the epithelium, forming microscopic intrahepatic calculi. Mucopolysaccharides, especially acid, showed to be strongly positive on the luminal border, and in proliferated glands around the ducts. The authors discuss the similarity between such findings and Oriental Cholangiohepatitis, and suggest that inflammation and the presence of the parasitic remnants are responsible for the hyperplastic and metaplastic changes, similarly with what occurs in chlonorchiasis, fascioliasis and schistosomiasis.

Identification of Paracoccidioides brasiliensis in adrenal glands biopsies of two patients with paracoccidioidomycosis and adrenal insufficiency

The authors report two cases of adrenal insufficiency secondary to infiltration of the adrenal glands by Paracoccidioides brasiliensis. The first patient had been treated for a chronic multifocal form of paracoccidiodomycosis 11 years ago. The diagnosis of the mycosis was done simultaneous with that of the adrenal insufficiency in the second patient. In both patients the diagnosis was done by direct visualization of fungus in adrenal biopsies. They were treated with hormonal supplements and itraconazol by 12 and six months, without relapses during the follow-up period.

Detection of immunogenic proteins from Anopheles sundaicussalivary glands in the human serum

AbstractINTRODUCTION:The saliva of mosquitoes has an important role in the transmission of several diseases, including malaria, and contains substances with vasomodulating and immunomodulating effects to counteract the host physiological mechanisms and enhance pathogen transmission. As immunomodulatory components, salivary gland proteins can induce the generation of specific IgG antibodies in the host, which can be used as specific biomarkers of exposure to Anopheles sundaicus . The objective of this study was to identify immunogenic proteins from the salivary glands of Anopheles sundaicus by reaction with sera from individuals living in malaria-endemic areas who are thus exposed to Anopheles mosquitoes.METHODS:IgG antibodies targeting salivary gland proteins in serum samples from individuals living in malaria-endemic areas were measured by enzyme-linked immunosorbent assay (ELISA). Sera from healthy individuals living in non-endemic areas were used as negative controls. Determination of the presence of salivary gland immunogenic proteins was carried out by western blotting.RESULTS:Sixteen bands appeared in sodium dodecyl sulfate polyacrylamide gel electrophoresis, with molecule weights ranging from 22 to 144kDa. Among the exposed individuals, IgG responses to salivary gland proteins were variable. Protein bands with molecular weights of 46, 41, 33, and 31kDa were the most immunogenic. These immunogenic proteins were consistently recognized by pooled serum and individual samples from people living in malaria-endemic areas but not by negative controls.CONCLUSIONS:These results support the potential use of immunogenic proteins from the salivary glands of Anopheles as candidate markers of bite exposure or in malaria vaccines.

Comparative study of wax glands in four Meliponini bees (Hymenoptera, Apidae) producing different quantities of wax

The developmental degree of the wax glands was compared in four Meliponini bees, that produce different quantities of wax. The histological data and height average of the wax epithelium during the time in which the maximum production of wax is expected, are in accordance with the rates of wax produced by the species. In Lestrimelitta limao (Smith, 1863) a species which has cleptobiotic habits, and frequently rob wax from the attacked colonies, the height of wax epithelium was the lowest among the studied species. The cells seem to show an abnormal vacuolated cytoplasm, in the phase in which they would be producing wax.

Aspectos parasitários observados no local inoculado com esporozoitos de Plasmodium Gallinaceum

The following is a summary of the studies made on the development of Plasmodium gallinaceum sporozoites inoculated into normal chicks. Initially large numbers of laboratory reared Aëdes aegypti were fed on pullets heavily infected with gametocytes. Following the infectious meal the mosquitoes were kept on a diet of sugar and water syrup until the appearance of the sporozoites in the salivary glands. Normal chicks kept in hematophagous arthropod proof cages were then inoculated either by bite of the infected mosquitoes or by subcutaneous inoculations of salivary gland suspensions. By the first method ten mosquitoes fed to engorgement on each normal chick and were then sacrificed immediately afterwards to determine the sporozoite count. By the second method five pairs of salivary glands were dissected out at room temperature, triturated in physiological saline and inoculated subcutaneously. The epidermis and dermis at the site of inoculation were excised from six hours after inoculation to forty eight hours after appearance of the parasites in the blood stream and stretched out on filter paper with the epithelial surface downward. The dermis was then curretted. Slides were made of the scrapings consisting of connective tissue and epithelial cells of the basal layers which were fixed by metyl alcohol and stained with Giemsa for examination under the oil immersion lens. Skin fragments removed from normal chicks and from regions other than the site of inoculation in the infected chicks were used as controls. In these, only the normal histological aspect was ever encountered. In the biopsy made at the earliest period following inoculation clearly defined elongated forms with eight or more chromatin granules arranged in rosary formation were found. The author believes these to be products of the sporozoite evolution. Search for transition stages between these forms and sporozoites is planned in biopsies to be taken immediately following inoculation and at given intervals up to the six hour period. 1.) 6 and 12 hour periods. The bodies referred to above found in the first period in great abundance, apparently in proportion to the large numbers of sporozoites inoculated, were perceptibly reduced in numbers in the second period. 2.) 18 hour period. Only one biopsy was examined. This presented a binuclear body shown in Fig. 1, having a more or less hyaline protoplasm staining an intense blue and a narrow vacuole delimiting the cell boundaries. The two chromatin grains were quite large presenting a clearly defined nuclear texture. 3.) 24 hour period. A similar body to that above (Fig. 2) was seen in the only preparation examined. 4.) 60 hour period. The exoerythrocytic schizonts were found more frequently from this period onward. Several such were found no longer to contain the previously described vacuoles (Fig. 3). 5.) 84 hour period. Cells bearing eight or more schizonts were frequently encountered here. That these are apparently not bodies in process of division may be seen in Fig. 4. From this time onward small violet granules similar to volutine grains appeared constantly in the schizont nucleus and protoplasm. These are definitely not hemozoin. The above observations fell within the incubation period as repeated examinations of the peripheral and visceral blood were negative. Exoery-throcytic parasites also were never encountered in the viscera at this time. Exoerythrocytic schizonts searched for at site of inoculation 1, 24 and 48 hours after the incubation period were present in large number at all three times with apparent tendency to diminish as the number within the blood stream increased. Many of them presented the violet granules mentioned above. The appearance of the chromatin and the intensity of staining of the protoplasm varied from body to body which doubtless corresponds to the evolutionary stage of each. This diversity of aspect may frequently be seen in the parasites of the same host cell (Fig. 5.). These findings lend substance to the theory that the exoerythrocytic forms are the link between the sporozoites and the pigmented parasites of the red blood corpuscles. The explanation of their continued presence in the organism after infection of the blood stream takes place and their presence in cases infected by the inoculation blood does not come within the scope of this work. Large scale observations shortly to be undertaken will be reported in more detail particularly observations on the first evolutionary phases of the sporozoite within the organism of the vertebrate host.

Anothor Trypanosoma, distinct from T. cruzi, multiplies in the lumen of the anal glands the opossum Didelphis marsupialis

Epimastigotes were found multiplying in the anal glands and in hemocultures of an opossum; rare metacyclics were seen in the cultures. The flagellate is possibly T. (Megatrypanum) freitasi Rego, Magalhães & Siqueira, 1957, but its final identification is still pending.