Ovarian growth during larval development of queen and worker of Apis mellifera (Hymenoptera: Apidae): a morphometric and histological study.

The present work reports the differences between the ovarian grow in queen and worker larvae of A. mellifera, from the start of differential feeding. The observations made of the growth rates in larvae of both castes showed that the queen and worker larvae have the same rates of cephalic capsule growth from one instar to another but the weight gain is greater in queens. In the same way, the draw areas of ovaries of queens increase more and continuously, while from the 5th instar on the ovaries of workers decrease in size. The decrease is due to a loss of ovariole numbers that starts early in the worker larvae and increases in the 4th-5th instar. The ovarian shape in queens and workers became different in the last larval instars.

Caracterização histológica de folhas de Mentha pulegium x spicata (Lamiaceae)

The glandular hairs of Mentha pulegium x spicata (Lamiaceae) were studied by light microscopy and scanning electron microscopy, Three morphologically distinct types of trichomes are described: two of them are glandulars (peltate and capitate) and one is non-glandular hair (tector). Capitate trichome is of Type I, and consists of a foot cell, a stalk and a unicellular head with elongated format and two lateral depressions, showing the thinnest cuticle. The peltate trichome consists of a foot cell, a stalk cell and a radial cluster of secretory cells, cover by cuticle. The tector trichomes can be simple and forked -format, both multicellular, in which there are ornamentations on cell cuticle. The leaf cross sections, analysed in light microscopy, showed mesophyll organized for unistratification palisade parenchyma and lacurary parenchyma with four to five cell stratum. It was observed the presence of cristal mass agglomerate in mesophyll cells and in epidermical cells.

Ultrastructural and morphometric analysis on the ovary of Wistar rats after chronic ethanol ingestion

In the present study, seventy-two adult rats (Rattus norvegicus albinus) aged three months were used. The animals were divided into two groups (control and alcoholic). The control group received a solid diet (Purina rat chow) and tap water ad libitum. The alcoholic group received the same solid diet and sugar-cane liquid (trade 51, 41° Gay Lussac - GL) diluted 30° GL. At the end or 90, 180 and 270 days of treatment, ten rats of each group were anaesthetized with ethyl ether and sacrificed. The ovaries were collected, fixed, included and submitted to analysis by both light and electron microscopy. The alcoholic group showed increase in the number of corpora lutea at both 180 and 270 days of treatment, atresic follicles at 270 days of treatment, decreased diameter of corpora lutea at 180 and 270 days of treatment, the granulosa layer of the antral follicles at 180 days of treatment, and gradual regression of the theca antral follicles. Furthermore, an increase in diameter and posterior regression of the antral follicle were observed, as well as vacuolation, increased lipid droplets in the granulosa cell at 90 days and in the theca at 180 and 270 days of treatment and gradually in the interstitial cell. The rats showed ovarian alterations after ingestion of alcohol. There was a correlation between exposure time to the drug and the injury observed.

Structure of the pelvic and penile urethra - Relationship with the ducts of the sex accessory glands of the Mongolian gerbil (Meriones unguiculatus)

The urethra is the main place of entry for sexually transmitted pathogens. However, there is little literature on the morphology of the urogenital system, principally the urethra and ducts of the sex accessory glands. The Mongolian gerbil is an insectivorous, herbivorous and monogamous rodent with nocturnal habits; it has been used successfully as a laboratory animal since the 1960s. Therefore, the objective of the present paper was to describe the structure and ultrastructure of the urethra and its relations to the ducts of the accessory sex glands of the Mongolian gerbil (Meriones unguiculatus), contributing to the understanding of the reproductive biology of the rodent and aiming to provide data for future experimental studies. Conventional techniques of light and scanning electron microscopy were utilized. The urethra and ducts of the accessory sex glands are similar to those of the albino rat and the mouse. However, there is variation in drainage type among accessory sex glands for the inner urethra. The ducts of the seminal vesicle, the ductus deferens, drain their contents independently into the ampullary duct that opens in the urethra. The ducts of the prostate, coagulating and bulbourethral glands drain their contents independently into the urethra.

Morphological aspects of Culex quinquefasciatus salivary glands

The salivary glands of Culex quinquefasciatus female mosquitoes are paired organs composed of two lateral lobes with proximal and distal secretory portions, and a medial lobe. All portions comprise a simple epithelium that surrounds a salivary duct. In the apical portion of the medial lobe, non-secretory cells strongly resemble cells involved in ion and water transport. The general architecture of the secretory portions is similar between lobes. The appearance of the secretory material and the morphological aspect of the apical cell membrane are the most distinctive features among the three secretory portions. Cells in the lateral proximal lobe display thin membrane projections extending into a translucent and finely filamentous secretory product. At the lateral distal portion, the apical cell membrane forms an intricate meshwork that encloses a dark secretory product. Medial lobe secretory cells also contain secretory cavities surrounded by intracytoplasmic vesicles, all containing a very dark and uniform product. Scattered cells holding numerous vacuoles, some of them containing a small and electron-dense granule eccentrically located and resembling those of the diffuse endocrine system, are frequently observed in the periphery of all secretory portions. Immunofluorescence assays revealed that the distal portion of the lateral lobes contains apyrase, an enzyme putatively responsible for platelet aggregation inhibition, diffusely distributed in the cell cytoplasm. © 2003 Elsevier Ltd. All rights reserved.

Effectiveness of EDTA and EDTA-T brushing on the removal of root surface smear layer.

The purpose of this study was to compare the removal of root surface smear layer following active application of EDTA gel and EDTA-T (texapon) gel in different concentrations (5%, 10%, 15%, 20% and 24%), using scanning electron microscopy. A total of 220 dentin blocks obtained from the root surfaces of extracted teeth were divided into 3 groups: Group I - (control) application of saline solution (n = 20); Group II - EDTA gel (pH 7.0) was applied in the following concentrations: 5%, 10%, 15%, 20% and 24% (n = 100); Group III - EDTA-T gel (pH 7.0) applied in the same concentrations described above (n = 100). The photomicrographs were evaluated by one calibrated examiner using a smear layer removal index and following statistical analysis (Kruskal-Wallis test). The results demonstrated that the specimens treated with EDTA and EDTA-T gel presented a better smear layer removal than the control group (p < 0.01); no statistically significant differences were observed between the EDTA and EDTA-T groups and between the concentrations tested (Mann-Whitney, p > 0.05). Within the limits of this study, it can be concluded that all treatment modalities effectively removed the smear layer from the root surface. The addition of texapon into the EDTA gel formulation did not increase its effectiveness.

Smear layer removal capacity of disinfectant solutions used with and without EDTA for the irrigation of canals: a SEM study.

The purpose of this study was to carry out a scanning electron microscopic (SEM) analysis of the cleaning qualities and smear layer removal from root canal walls, instrumented and irrigated with 2.5% NaOCl, 2.0% chlorhexidine and saline solutions. Fifty extracted teeth were used in this study. All teeth were radiographed to determine the existence of a single canal. The crowns were cut at the cervical limit and the root canals were instrumented with K-type files up to size 45. During root canal preparation, irrigations were made with the different solutions being evaluated: Group 1: 2.5% NaOCl (10 roots); Group 2: 2.5% NaOCl and 17% EDTA for 2 minute (10 roots); Group 3: 2.0% chlorhexidine (10 roots); Group 4: 2.0% chlorhexidine and 17% EDTA for 2 minutes (10 roots); Group 5: saline solution (5 roots); Group 6: saline solution and 17% EDTA for 2 minutes (5 roots). After instrumentation, the canals were irrigated with each one of the solutions and the roots were cut in the buccolingual direction for SEM analysis, at the cervical, middle and apical thirds, to ascertain the presence or absence of smear layer and debris. SEM analysis was performed by three calibrated examiners and scores were submitted to Kruskal-Wallis test at the significance level of p = 5%. Results showed that the use of 17% EDTA decreased the smear layer significantly (p < 0.05) for all evaluated solutions in all thirds. When EDTA was not used, a significantly higher quantity of smear layer on the apical third was observed only in the NaOCl groups. The use of 17% EDTA was significant for debris removal except for the chlorhexidine groups. The following conclusion could be drawn: the use of 17% EDTA was necessary to enhance cleanness of the root canals.

Structural, cytochemical, immunocytochemical and ultrastructural characterization of blood granulocytes of the roadside hawk Buteo magnirostris (Gmelin, 1788) (Avian, Falconiform)

In the peripheral blood of the roadside hawk, Buteo magnirostris, the following types of granulocytic leucocytes were identified: heterophil, eosinophil and basophil. The heterophils presented acidophilic and spindle shaped granules, the eosinophils possess spherical eosinophilic granules and the basophils showed spherical and basophilic granules. The heterophils and eosinophils presented positive cytochemical reaction to glycogen and basic polyaminoacid, while the eosinophils presented sudanophilic granules, which were also positive for myeloperoxidase. The heterophils, alone, presented positivity for acid phosphatase in some granules and immunoreactivity to TGF-β1 was observed only in the cytoplasm of the eosinophils. Electron microscopy demonstrated the heterophil granules as predominantly spindle shaped, being strongly electron-dense, while the eosinophils had numerous uniformly electron-dense spherical granules and the basophils presented three different types of granules identified according to their electron-density and the aspect of their matrix.

Two Digestive Trypsins Occur in Three Species of Neotropical Anophelines

Trypsin activity increases in the midgut of Anopheles aquasalis, Anopheles albitarsis, and Anopheles darlingi after a bloodmeal. The activity returns to basal levels at the time the blood is completely digested. Affinity chromatography, reversed-phase high performance liquid chromatography (HPLC), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to sequentially purify the mosquito trypsins found in the midguts at 24 h after feeding. Amino-terminal sequencing of the purified trypsins showed the occurrence of two distinct trypsins in the midgut of each of the mosquitoes studied. The sequences obtained are similar to those of the trypsins of other hematophagous insects.

Is the number of antennal plate organs (sensilla placodea) greater in hygienic than in non-hygienic Africanized honey bees?

Hygienic behavior is a desirable trait in honey bees (Apis mellifera L.), as hygienic bees quickly remove diseased brood, intermpting the infectious cycle. Hygienic lines of honey bees appear to be more sensitive to the odors of dead and diseased honey bee brood, and Africanized honey bees are generally more hygienic than are European honey bees. We compared the number of sensilla placodea, antennal sensory structures involved in the perception of odor, in 10 bees from each of six hygienic and four non-hygienic colonies of Africanized honey bees. The sensilla placodea of three of the terminal segments (flagellomeres) of the right antenna of each bee were counted with a scanning electron microscope. There were no significant differences in the mean numbers of sensilla placodea between the hygienic and non-hygienic bees, though the variance was higher in the hygienic group. Flagellomere 4 had significantly more sensilla placodea than flagellomeres 6 and 8. However, there was no significant difference between the other two flagellomeres. As hygienic bees are capable of identifying dead, injured, or infested brood inside a capped brood cell, sensilla placodea probably have an important role in enabling worker bees to sense sick brood. However, we did not find greater numbers of this sensory structure in the antennae of hygienic, compared to non-hygienic Africanized honey bees.

The influence of vinegars on exposure of dentinal tubules: a SEM evaluation.

Dentin hypersensitivity is a common painful condition observed in clinics. Dietary habits have been much associated with its development and persistence during and following periodontal treatment. The aim of this in vitro study was to evaluate the influence of vinegars on the removal of smear layer and exposure of dentinal tubules. Extracted human teeth were submitted to manual scaling with Gracey curettes in order to remove the cementum as well as to form a smear layer. Dentin samples with 3 mm(2) were obtained and distributed into six experimental groups: one control and five types of vinegars (alcohol, apple, rice, white wine and balsamic). Each group included two methods of vinegar application: topical and friction. After routine preparation for SEM analysis, photomicrographs were assessed by a calibrated and blind examiner using an appropriate index system. Kruskal-Wallis test indicated a significant influence of vinegars on smear layer removal. There was a statistically significant difference between groups treated with apple, white and rice vinegars and the control group (p < 0.05). Nevertheless, Mann-Whitney test indicated that removal of smear layer did not vary with the method of application (topical versus friction) for any of the tested substances. We can conclude that the contact of vinegar may remove smear layer and expose dentinal tubules, regardless of the type of application. However, balsamic vinegar was associated with less removal of smear layer after both methods of application.

Acellular dermal tissue study: an ultrastructural evaluation of human and porcine derived tissues in a rat model

The purpose of this study was to evaluate the host response of a human and a porcine derived acellular dermal tissue (ADT) implanted in the subcutaneous tissue of a rat model. Two subcutaneous pockets were surgically created along the dorsal midline of 25 rats (5 rats/group). The human ADT was placed superiorly and the porcine ADT, inferiorly. The animals were sacrificed at 07, 15, 30, 60 and 180 postoperative days (PO) and the ADTs and surrounding soft tissues were assessed for ultrastructural evaluation by transmission electron microscopy. The ultrastructural findings were similar in both materials. Normal collagen and elastic fibers bundles were observed during all experimental moments, as well as macrophages presenting cytoplasmic enlargements digesting cellular portions after 15 PO. From 30 until 180 PO, vacuolar structures filled with an amorphous, electron-transparent substance, were present inside and outside the fibroblasts. Both human and porcine ADT showed similar pattern of ultrastructural response when implanted in the subcutaneous tissue of rats. The porcine ADT appears as a good alternative to be used as a biomaterial.

Influence of natural fruit juices in removing the smear layer from root surfaces - An in vitro study

Certain elements of a patient's diet may be associated with dentin hypersensitivity. The intent of this study was to evaluate the degree of removal of the smear layer from dentin surfaces by various fruit juices. A smear layer was created on extracted human teeth by manual scaling. The roots were reduced and distributed into 8 experimental groups. Distilled water was the negative control. The juices were applied by 2 methods: topical application and topical application with friction. Specimens were photomicrographed and graded according to an index of smear layer removal. With topical application, all but 2 of the tested substances resulted in significantly greater removal of the smear layer and opening of dentinal tubules than was the case with the negative control (p = 0.05); the exceptions were Gala apple and Italian grape juices, which were no different from the control. For the active application (with friction), most substances removed more smear layer than the control (p < 0.05); Gala apple, Italian grape and orange juices were similar to the control. For each of the tested substances, removal of the smear layer did not differ with the method of application (topical vs. friction; p > 0.05). It is concluded that natural fruit juices can remove the smear layer from dentin surfaces, and the efficacy of this removal varies with the type of juice. © J Can Dent Assoc 2004.

Blood cell attachment to root surfaces treated with EDTA gel.

Root debridement generates a smear layer which contains microorganisms and toxins that could interfere in periodontal healing. For this reason, different substances have been used to remove it and to expose collagen fibers at the tooth surface. Blood element adhesion to demineralized roots and clot stabilization by collagen fibers are extremely important for the success of periodontal surgery. The aim of this study was to evaluate the different patterns of blood element adsorption and adhesion to root surfaces only irrigated with distilled water and after application of a manipulated or an industrialized EDTA gel. Thirty samples were planed, equally divided into three groups and treated with distilled water (control), a manipulated EDTA gel or an industrialized one. Immediately after, samples were exposed to fresh blood and prepared for scanning electron microscopy. Untreated planed dentin presented the best results with blood cells entrapped in a thick web of fibrin. In the manipulated EDTA group, the web of fibrin was thick with sparse blood elements. The worst result was seen with the industrialized EDTA group, in which no blood elements could be seen. Statistical difference was obtained between control and industrialized EDTA groups. Surfaces only irrigated presented the most organized fibrin network and cell entrapment.

Avaliação ultraestrutural do colágeno do ligamento colateral medial associado ao ligamento oblíquo da articulaç ão do cotovelo de cão SRD após ensaio de tração

Ultrastructural evaluation of the collagen of the mongrel dog medial collateral ligament associated to the oblique ligament after strain. The present work aimed to observe the disposition of the collagen fibres of the medial collateral ligament of the elbow joint of the dog, when associated to the oblique ligament. Thus, 18 articulations were used, divided in three groups. A group had the medial collateral ligament collected and not stretched, other group had the collateral medial ligament stretched separately and the other group had both ligaments (medial collateral and oblique) stretched associately. The medial collateral ligament examined by scanning electron microscopy presented a wavy and reticular pattern of the collagen fibres when not submitted to strain, which was not totally destroyed when it was associated to the oblique ligament. When stretched separately, the medial collateral ligament after strain totally loses the reticular pattern, demonstrating the waste of the fibres to resist to the tension.