Ultramorphology and histology of the venom gland of workers of Apis mellifera (Hymenoptera, Apidae) before and after an electrical shock treatment

This paper describes the ultramorphology and histology of the venom reservoir in 14-day old workers of Apis mellifera, immediately before and after the application of electrical shocks with the object of causing venom elimination and reservoir collapse. The external epithelial surface of the reservoir was differentiated according to its morphological aspects into posterior, median, and proximal or duct regions at the ventral surface and into anterior and posterior regions at the dorsal surface. While the epithelium of the proximal region forms a ventral infolding, a dorsal salience is formed at this region. These structures and the epithelial regions persist both in full and empty reservoirs. The reservoir appeared full and distended before the electrical shocks were applied and became empty and withered afterwards due to the elimination of the secretion, without any reductions in length. Nevertheless, some secretion was kept inside the lumen, thus suggesting a possible role for the reservoir in the modification of the secretion.

Corneal endothelium of the Magellanic penguin (Spheniscus magellanicus) by scanning electron microscopy

The corneal endothelium is essential for the maintenance of the corneal transparency. The aim of this study was to examine the morphology of the endothelial surface and perform morphometric analysis of the normal corneal endothelial cells of the Magellanic penguin (Spheniscus magellanicus) using scanning electron microscopy. The present work demonstrates that the corneal endothelium of the Magellanic penguin is similar to those described in other vertebrates. Copyright 2005 by American Association of Zoo Veterinarians.

Morphology of oesophagus and crop of the partrigde Rhynchotus rufescens (Tiramidae)

Twenty adult partridges Rhynchotus rufescens were used to study the morphology of oesophagus and crop. Materials to the morphologic study were collected and lengths of the oesophagus and of the crop were measured. For histological study, fragments of the oesophagus and of the crop were stained routinely with Masson's trichrome stain. Total oesophagus was larger in females. In the entrance of the thorax, its ventral wall is enlarged broadly, forming the crop, which is larger in males. Oesophagus mucosa is constituted by stratified squamous epithelium, with mucous glands and lymphatic tissues. There are three layers of smooth muscle, involved in serosa. The histological structure of the crop is similar to the oesophagus. The mucous glands are reduced in size and the lymphatic tissues are dispersed in the connective tissue. There is a thin stratum of smooth muscle and other two wider layers of longitudinal and circular musculature.

Lipids in oocytes of ants Neoponera villosa (Hymenoptera: Ponerinae)

Elements of oocyte of Neoponera villosa ants (workers and queen) were analyzed histochemically and ultrastructurally. It was observed that lipids are the first element to be deposited. They appear in oocytes of all stages. Lipids probably arose in the younger oocytes (stages I and II) from mitochondria of their own cytoplasm and from the nurse cells as well. In mature oocytes (stage III) the cells of the follicular epithelium appears with droplets of lipids in their cytoplasm showing that besides the other sites, this epithelium can also be active in lipid synthesis.

Quantitative cell-cycle protein expression in oral cancer assessed by computer-assisted system

The knowledge of cell-cycle control has shown that the capacity of malignant growth is acquired by the stepwise accumulation of defects in specific genes regulating cell growth. Histologic diagnosis might be improved by a quantitative evaluation of more specific diagnosis biomarkers, which could help to precisely identify pre-malignant and malignant oral lesions. The aim of the present study is to evaluate whether computer-based quantitative assessment of p53, PCNA and Ki-67 immunohistochemical expression, could be used clinically to foresee the risk of oral malignant transformation. This retrospective study was carried out in ninety-five oral biopsies, 27 were classified as fibrous inflammatory hyperplasia, 40 as leukoplakia and 28 as oral squamous cell carcinoma. Sixteen out of the 40 leukoplakia were diagnosed as non-dysplastic leukoplakia, the other 24 being dysplastic leukoplakia, of which 50.0% were classified as moderate to severe dysplasia. Comparison of the four groups of oral tissues showed significant rises in p53 and Ki-67 positivity index, which increased steadily in the order benign, pre-malignant, and malignant. In contrast, it was not possible to relate higher PCNA levels with pre-malignant and malignant oral lesions. We therefore conclude that PCNA immunohistochemistry expression is probably an inappropriate marker to identify oral carcinogenesis, whereas joint quantitative evaluation of p53 and Ki-67, appears to be useful as a tumor marker, providing a pre-diagnostic estimate of the potential for cell-cycle deregulation of the oral proliferate status.

Morphological alterations on the prostate of Calomys callosus submitted to chronic ethanol ingestion

The objective of the present study was to assess the possible toxic effects of chronic alcohol ingestion on the ultrastructure of the glandular epithelium of the prostate of the rodent Calomys callosus, in order to contribute to the understanding of the consequences of alcohol abuse for the morphology of the male reproductive apparatus. Sixteen adult animals aged three months were divided into two experimental groups. The control group received a solid diet and tap water, and the alcoholic group received the same solid diet and ethanol P.A. diluted 20% in water (v/v). After 120 days of treatment, all animals were anesthetized, weighed and sacrificed. At the end of treatment, mean body weight did not differ between control and alcoholic animals. The prostate epithelial cells of the alcoholic group showed intense atrophy and ultrastructural alterations such as the presence of lipid droplets, altered nuclei, ruptured mitochondrial cristae, and intense dilatation of the cisterns of the granular endoplasmic reticulum. It was concluded that 20% ethanol provokes marked lesions on the epithelium of the prostate probably interfering on the glandular secretion.

Efeitos do parasitismo sobre a estrutura branquial de Leporinus macrocephalus Garavello e Britsk, 1988 (Anastomidae) e Piaractus mesopotamicus Holmberg, 1887 (Osteichthyes:Characidae).

This work described the lesions caused in different species of fish by gill parasites from fee-fishing at Guariba, State of São Paulo. The research was developed from april, 1997 to march to 1999, seeking to verified the kind tissues lesions from fish. Of these, forty and seven were Leporinus macrocephalus and fifty and five Piaractus mesopotamicus. About 87.2% of the L. macrocephalus, and 58.1% of the P. mesopotamicus were sponged by several species of parasites. The parasite most abundant in L. macrocephalus was Piscinoodinium pillulare, while monogenean, Trichodina sp and myxosporidian infected P. mesopotamicus. Severe gill lesions have been observed in L. macrocephalus and P. mesopotamicus caused by monogenean, P. pillulare e Trichodina sp. parasitism, such as intersticial hemorrhage, sub-epithelium edema, inflammation, epitelial hiperplasy in filaments and lamina, proliferation of mucosal cells and laminar fusion.

Association between solitary keratoacanthoma and cigarette smoking: A case-control study

Solitary keratoacanthoma (KA) is a common benign epithelial tumor of the skin characterized by rapid growth and a tendency toward spontaneous regression. The exact etiology and classification of KA are a matter of debate. Smokers also seem to be more affected than persons who never smoke. The objective of this study was to evaluate the association between solitary KA and smoking habit. A case-control study involving 78 patients diagnosed with KA and 199 controls from the related community was performed to evaluate the association between cigarette smoking and KA. A higher smoking prevalence was noted in cases (69.2 %) than controls (21.6 %) and the odds ratio adjusted for sex and age was 9.1 (95 % CI 4.9 to 17.1, p< 0.01). The mean tumoral diameter at surgery and the site of involvement was not statistically related to smoking. These findings suggest that cigarette smoking is associated with the development of KA. © 2006 Dermatology Online Journal.

Localização histoquímica de algumas hidrolases no epidídimo do gerbilo

This study mainly showed that alkaline phosphatase expression had been present in the proximal regions of the epididymidis ductus of the gerbil which comprised the initial segment and proximal caput. The reactivities of acid phosphatase and ATPase were strong in the proximal and distal regions of the epididymidis ductus at the level of the apical cytoplasm and epithelium, except at the corpus level, a very thin isthmus located between the caput and cauda epididymidis, and as a general rule a low enzymatic reactive region of the epididymis of gerbil. SDH revealed also low activities in all the regions and regional structures of the duct, except into the luminal content formed by storaged spermatozoa, prior on the cauda level. The enzymes presented in the epididymis were correlated to some histophysiological roles such as the enzymatic mediation of endocytosis, secretion, absorption and active transport concerning to phosphatases and ATPase and a possible mitochondrial role of SDH could occur at the spermatozoa level in which the middle pieces were formed by a great amount of mitochondria.

Estudo morfológico e histomorfométrico sobre variações sazonais do ducto deferente de codorna da variedade italiana

In the autumn the vas deferens of the Italian variety of domestic quail appeared as a single, thin, and straight duct along its total extension. Thus, transversal histologic sections of this duct showed a circular tubular shape. The pseudoestratified columnar epithelium that lined the vas deferens presented longitudinal folds which invaded the lumen frequently empty of spermatozoa. Although in the winter, spring and summer the usual morphological appearance of the quail's vas deferens was seen as a highly coiling duct. So, each transversal histologic section of the vas deferens, in all the segments, showed parallel cut sections of the duct being irregular in shape and variable in number and interconnected by the adventitial loose connective tissue. In these observations, the tubular lumen was totally performed by spermatozoa and seminal fluid. Consequently, with previous base on the testis kinetics of the Italian quail variety, it was concluded that the spermatozoa production, followed by emission, storage and ejaculation of spermatozoa through the vas deferens did not stop during the winter, spring and summer, but ceased in the autumn the quiescent phase of the circannual reproductive cycle in this bird.

Efeito da mitomicina c no epitélio ciliar estudo experimental em coelhos com microscopia eletrônica de varredura e de transmissão

Purpose: To evaluate and correlate in the rabbit the possible changes caused by mitomycin C under the scleral flap in the ciliary epithelium with transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Methods: The eyes of 32 albino rabbits were studied and divided in 4 experimental groups. The right eye (RE) was intended for the experimental groups and the left eye (LE) for the controls. Group I (G1) was formed by 8 eyes that received 0,5 mg/ml of mitomycin C under the scleral flap and were examined after 15 days. Group II (G2) differed from G1 only in the time of the exam, after 30 days. Group III (G3) was formed by 8 eyes that received 0,2 mg/ml of mitomycin C under the scleral flap and were examined after 15 days. Group IV (G4) differed from group 3 just in the time of the exam, after 30 days. In each eye the internal ciliary epithelium were examined with TEM. Results: The following changes in the internal ciliary epithelium were observed in groups G2, G3, and G4 with TEM: discontinuous and irregular basement membrane, more irregular and electron-dense nucleous, enlargement among interdigitation, edematous mitochondria and myelin figures. These alterations were not found in all the animals of the groups. Group G 1 did not present alterations. Roughness in groups G 1, G2, G3 and G4 were observed with SEM. In groups G 1 and G2 continuity solutions were also observed. Conclusion: Mitomycin C in 0,2 mg/ml and 0,5 mg/ml concentrations caused changes in the internal ciliary epithelium 15 and 30 days after, with TEM and SEM. There was no correlation between dosage, time and with TEM and SEM.