Morphological evaluation of combined effects of cyclosporin and nifedipine on gingival overgrowth in rats

It has previously been shown that, while cyclosporin A (CsA) and nifedipine both cause gingival overgrowth in the rat. the combined use of these drugs increases the severity of overgrowth. The aim of this study was to describe the histometry and densities of fibroblasts, collagen fibers and vessels in the gingival tissue of rats that were treated with CsA and nifedipine, either alone or in combination. Rats were treated for 60 days with a daily subcutaneous injection of 10 mg/kg body weight of CsA and/or with 50 mg/kg body weight of nifedipine added to the chow. The results confirmed that CsA causes a more severe overgrowth than nifedipine, and that the combined use of these drugs increases the overgrowth severity. All the rat groups that were studied showed that, as the severity of overgrowth increased, there was a parallel increase in fibroblasts and collagen, and a decrease in vessel content. Therefore, independently of whether the gingival overgrowth was caused by CsA alone, nifedipine alone, or both treatments in combination, the fibroblast and collagen density increased in parallel with the severity of the overgrowth. © Blackwell Munksgaard, 2002.

Electrodeposition of amorphous Fe-Cr-P-Ni-C alloys. Morphological and structural characteristics

The effect of bath composition and electroplating conditions on structure, morphology and composition of amorphous Fe-Cr-P-Ni-C deposits on Cu substrate was investigated. The deposition efficiency of Fe-Ni-P-C alloy increased significantly with the addition of formic acid, but decreased with the addition of Cr to the plating bath. The increase of charge density activates the inclusion of Cr in the deposit. However, above a specific value of charge density, which depends on deposition current density, the Cr content in the deposit decreases. SEM analysis showed that the increase of Ni, Cr or charge deposition promotes susceptibility to microcracking.

Morphological aspects of the capybara stomach (Hydrochaeris hydrochaeris): Gross and microscopic structure

The digestive system of the capybara has been investigated because of its coprofagia habits, important for their absorptive activity. These species present differences in terms of gastrointestinal morphological characters when compared with other rodents. Macroscopiclly, the stomach of the capybara is constituted of the following parts: cardiac, pyloric, body, fundic and gastric diverticulum. It presents two curvatures, one big and another small. Externally, the presence of gastric bands (tenias) is observed. With regards to the volumetric view, the gastric capacity varies from 850 to 2010 ml, with an average of 1498.57 ml. So, the stomach of this animal can be classified as a simple stomach, in the format of a curved sack and similar to an inverted letter 'J'. The gastric mucous membrane presents a surface filled by numerous tortuous gastric folds and longitudinally distributed along all its extension. The mucous tunic also possesses recesses located among the successive gastric folds, which were denoted as gastric parts with numerous openings described as gastric pits. In the cardiac part, a glandular epithelium with cardiac glands is noticed containing a lot of parietal and mucous neck cells. The fundic part, body and gastric diverticulum contain proper gastric glands with main, parietal and mucous neck cells. Finally, the pyloric part has pyloric glands with two cellular types, mucous neck and parietal cells.

Blue-greenish acrochaetioid algae in freshwater habitats are Chantransia stages of Batrachospermales sensu lato (Rhodophyta)

Fourteen culture isolates of freshwater acrochaetioid algae from distinct regions around the world were analysed, including the reddish species Audouinella hermannii, the dubious blue-greenish species A. pygmaea, and Chantransia stages from distinct taxonomic origins in the Batrachospermales sensu lato (Batrachospermaceae, Lemaneaceae and Thoreaceae). Four isolates (two 'Chantransia' stages and two species of Audouinella, A. hermannii and A. pygmaea) were tested under experimental conditions of temperature (10-25°C), irradiance (65 and 300 μmol photons m-2 s-1) and photoperiod (16:8 h and 8:16 h light/dark cycles). Plant colour is proposed as the only vegetative character that can be unequivocally applied to distinguish Audouinella from 'Chantransia', blue-greenish representing Chantransia stages and reddish applying to true Audouinella species (also forming reproductive structures other than monosporangia, e.g. tetrasporangia). Some isolates of A. pygmaea were proven to be unequivocally 'Chantransia stages owing either to production of juvenile gametophytes or to derivation from carpospores. No association of the morphology of A. pygmaea was found with any particular species, thus it should be regarded as a complex involving many species of the Batrachospermales sensu lato, as is also the case with A. macrospora. We therefore recommend that all blue-greenish acrochaetioid algae in freshwater habitats be considered as Chantransia stages of members of the Batrachospermales, and that the informal descriptors pygmaea and macrospora be used to distinguish the two discernable morphologies. Induction of gametophytes occurred under much wider conditions than previously reported, reinforcing the conclusion that requirements are probably species-specific. Although phenotypic plasticity was in evidence, with temperature, irradiance and photoperiod affecting morphology, no alga showed variation outside the limits based on traditional taxonomic studies. No overall trend was observed for vegetative or reproductive characters in response to temperature, irradiance and photoperiod for all the algae tested, only for specific algae or characters. Effects of temperature and irradiance on morphological characters were more evident, as well as strong interactions between these variables, whereas few differences were generally found in response to photoperiod and irradiance.

Morphological and physiological caste differences in Synoeca cyanea (Hymenoptera, Vespidae, Epiponini) according to the ontogenetic development of the colonies

Morphological caste differences in different stages of the biological cycle in Synoeca cyanea were not distinct. Females presented a gradual sequence in ovarian development from filamentous ovarioles to well developed ones with the presence of intermediates, with shorter ovaries than queens, which can be present or not according to the stage of colonial development. Such data suggest that access to the reproductive status would only be possible in some intervals of colonial development.

Influence of the colony cycle on physiological and morphological caste variation in the perennial neotropical swarm-founding social wasp, Protonectarina sylveirae (Hymenoptera, Vespidae, Epiponini)

This paper describes the influence of the colony cycle on caste differences in Protonectarina sylveirae. Despite invariably keeping the main aspects of the conspicuous dimorphism between the castes, it is shown that: 1- queen-worker differences varied according to the progress of the colony cycle, 2- queens in pre-emergence colonies were smaller than those in male-producing ones, 3- workers were larger in pre-emergence than in other colony stages, 4- at particular steps of the colony cycle, non-inseminated ovary-developed queens and workers were detected. The size of the spermatheca differed between inseminated and non-inseminated queens with the highest values appearing in those bearing the most developed kind of ovary development. Differences between inseminated and non-inseminated queens were found in tergites III and IV, ovarian development and amount of fatty tissues. Because tergite size relates to gaster size, this character may be an important stimulus for selection of larger queens in the course of the colony cycle.

Morphological, mechanical and rheological properties of nylon 6/acrylonitrile-butadiene-styrene blends compatibilized with MMA/MA copolymers

The morphological, mechanical and rheological properties of nylon 6/acrylonitrile-butadiene-styrene blends compatibilized with MMA-MA [poly(methyl methacrylate-comaleic anhydride)] copolymers were studied. A twin screw extruder was used for melt-blended the polymers and the injection moulding process was used to mold the samples. The main focus was on nylon 6/ ABS blends compatibilized with one MMA-MA copolymer. This copolymer has PMMA segments that appear to be miscible with the styrene-acrylonitrile (SAN) phase of ABS and the anhydride groups can react with amine end groups of the nylon 6 (Ny6) to form graft copolymers at the interface between Ny6 and ABS rich phases. Tensile and impact and morphological properties were enhanced by the incorporation of this copolymer. Transmission electron microscopy (TEM) observations revealed that the ABS domains are finely dispersed in nylon 6 matrix and led to the lowest ductile-brittle transition temperatures and highest impact properties. It can be concluded that the MMA-MA copolymer is an efficient alternative for the reactive compatibilization and can be used as a compatibilizer for nylon 6/ABS blends.© 2003 Kluwer Academic Publishers.

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.

Testicular morphological changes during the seasonal reproductive cycle in the bullfrog Rana catesbeiana

Spermatogenesis and steroidogenesis undergo seasonal variations during the reproductive cycle in amphibians. Testicular morphological and morphometric seasonal variations as well as interstitial lipidic inclusions and intralobular glycoconjugates were evaluated during seasonal cycle of Rana catesbeiana. Testes of frogs collected during the annual seasons were weighed for calculation of GSI (Gonadosomatic index). Seminiferous lobule diameters (DSL) and volume densities of seminiferous lobules (VvSL), excretory ducts (VvED), and interstitial tissue (VvIT) were analyzed. Semithin sections were submitted to Periodic Acid-Schiff (PAS) and Alcian Blue (AB) methods for detection of glycoconjugates, while lipidic inclusions were detected by Sudan Black B. GSI showed no significant variations during the year. Since VvED and VvIT increased significantly during summer and were inversely proportional to VvSL, a compensatory effect between the testicular compartments may be related to the maintenance of GSI. During autumn/winter, larger lobular diameters were observed in comparison to spring/summer when spermiogenesis and spermiation were commonly observed. The increased VvIT and the numerous lipidic inclusions in the interstitial cells during summer suggest a relationship between spermiogenesis and steroidogenesis. Besides the structural stability variations occurring in the IT and SL, a possible paracrine interaction between ED and IT should be also involved in the IT development during summer. The presence of PAS and AB-positive globular structures were observed in the seminiferous lobules and excretory ducts. These structures containing acid glycoconjugates appear to be Sertoli cell apical portions, which are accumulated in the lumen of the seminiferous lobules mainly during spermiation. © 2004 Wiley-Liss, Inc.

Morphological aspects of muscle regeneration in the Nile tilapia (Oreochromis niloticus)

The aim of our study was to analyze the morphological events in the skeletal muscle of the Nile tilapia (Oreochromis niloticus) after a traumatic lesion. Thirty-two fish were used, on which a small longitudinal incision was made in the muscle. The fish were sacrificed after 7, 14, 21, and 42 days and muscle samples were collected from the lesion and processed for morphological analysis. Muscle regeneration in the tilapia occurred gradually through the analyzed period, possibly due to the proliferation and differentiation of myosatellite cells, which were more morphologically evident 7 and 14 days after lesion.

Molecular phylogenetic and morphological analyses of Oidium heveae, a powdery mildew of rubber tree

Powdery mildew of rubber tree caused by Oidium heveae is an important disease of rubber plantations worldwide. Identification and classification of this fungus is still uncertain because there is no authoritative report of its morphology and no record of its teleomorphic stage. In this study, we compared five specimens of the rubber powdery mildew fungus collected in Malaysia, Thailand, and Brazil based on morphological and molecular characteristics. Morphological results showed that the fungus on rubber tree belongs to Oidium subgen. Pseudoidium. Nucleotide sequence analysis of the ribosomal DNA internal transcribed spacer (ITS) region and the large subunit rRNA gene (28S rDNA) were conducted to determine the relationships of the rubber powdery mildew fungus and to link this anamorphic fungus with its allied teleomorph. The results showed that the rDNA sequences of the two specimens from Malaysia were identical to a specimen from Thailand, whereas they differed by three bases from the two Brazilian isolates: one nucleotide position in the ITS2 and two positions in the 28S sequences. The ITS sequences of the two Brazilian isolates were identical to sequences of Erysiphe sp. on Quercus phillyraeoides collected in Japan, although the 28S sequences differed at one base from sequences of this fungus. Phylogenetic trees of both rDNA regions constructed by the distance and parsimony methods showed that the rubber powdery mildew fungus grouped with Erysiphe sp. on Q. phillyraeoides with 100% bootstrap support. Comparisons of the anamorph of two isolates of Erysiphe sp. from Q. phillyraeoides with the rubber mildew did not reveal any obvious differences between the two powdery mildew taxa, which suggests that O. heveae may be an anamorph of Erysiphe sp. on Q. phillyraeoides. Cross-inoculation tests are required to substantiate this conclusion. © The Mycological Society of Japan and Springer-Verlag 2005.

Morphological, mechanical and thermal properties of nylon 6/ABS blends using glycidyl methacrylate-methyl methacrylate copolymers

Nylon6 is an attractive polymer for engineering applications because it has reactive functionality through amine and carboxyl end groups that are capable of reacting. For this reason, it has been used a lot in polymeric blends. Blends of nylon6/ABS (acrylonitrile-butadiene-styrene) were produced using glycidyl methacrylate-methyl methacrylate (GMA-MMA) copolymers as compatibilizer. The binary blends were immiscible and exhibited poor mechanical properties that stemmed from the unfavorable interactions among their molecular segments. This produced an unstable coarse phase morphology and weak interfaces between the phases in the solid state. The presence of the copolymer in the blends clearly led to a more efficient dispersion of the ABS phase and consequently optimized Izod impact properties. However, the compatibilized blend showed poor toughness at room temperature and failed in a brittle manner at subambient temperatures. © 2005 Springer Science + Business Media, Inc.

Skeletal maturation analysis by morphological evaluation of the cervical vertebrae

The determination of skeletal maturation by morphological evaluation of the cervical vertebrae was evaluated in a 100 cephalograms. The analysis showed that this method was reproducible for assessing the individual's growth curve.

Ecology and morphological characterization of gametophyte and 'Chantransia' stages of Sirodotia huillensis (Batrachospermales, Rhodophyta) from a stream in central Mexico

The morphology and phenology of Sirodotia huillensis was evaluated seasonally in a central Mexican first-order calcareous stream. Water temperature was constant (24-25°C) and pH circumneutral to alkaline (6.7-7.9), and calcium and sulfates were the dominant ions. The gametophyte stages were characterized by the presence of a distinctive mucilaginous layer, a marked difference in phycocyanin to phycoerythrin ratio between female and male plants, and the presence of a carpogonia with a large trichogyne (>60 μm). Occasionally three capogonia were observed on a single basal cell. The 'Chantransia' stages were morphologically similar to those described for the other members of Batrachospermales. A remarkable observation was the formation of dome-shaped structures, consisting of prostrate filaments that are related with the development of new gametophytes. Chromosome numbers were n = 4 for fascicle cells, cortical filament cells and dome-shaped cells, and 2n = 8 for gonimoblast filament cells and 'Chantransia' stage filaments. Gametophytes and 'Chantransia' stages occurred in fast current velocities (60-170 cm/s) and shaded (33.1-121 μmol photons/m2/s) stream segments. The population fluctuated throughout the study period in terms of percentage cover and frequency: the 'Chantransia' stages were most abundant in the rainy season, whereas gametophytic plants had the highest frequency values during the dry season. These results were most likely a result of fluctuations in rainfall and related changes in current velocity. Some characteristics of this population can be viewed as probable adaptations to high current velocities: the mucilaginous layer around plants that reduces drag; potential increase in fertilization by the elongate and plentiful trichogynes and abundant dome-shaped structures producing several gametophytes.

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.