Comparison between hydrographically conditioned digital elevation models in the morphometric charaterization of watersheds

The aim of this study was to compare the hydrographically conditioned digital elevation models (HCDEMs) generated from data of VNIR (Visible Near Infrared) sensor of ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), of SRTM (Shuttle Radar Topography Mission) and topographical maps from IBGE in a scale of 1:50,000, processed in the Geographical Information System (GIS), aiming the morphometric characterization of watersheds. It was taken as basis the Sub-basin of São Bartolomeu River, obtaining morphometric characteristics from HCDEMs. Root Mean Square Error (RMSE) and cross validation were the statistics indexes used to evaluate the quality of HCDEMs. The percentage differences in the morphometric parameters obtained from these three different data sets were less than 10%, except for the mean slope (21%). In general, it was observed a good agreement between HCDEMs generated from remote sensing data and IBGE maps. The result of HCDEM ASTER was slightly higher than that from HCDEM SRTM. The HCDEM ASTER was more accurate than the HCDEM SRTM in basins with high altitudes and rugged terrain, by presenting frequency altimetry nearest to HCDEM IBGE, considered standard in this study.

Iliac artery myointimal hyperplasia in rabbits submitted to angioplasty and treated with Moringa oleifera

Objective: to assess post-angioplasty myointimal hyperplasia in iliac artery of rabbits treated with extract of Moringa oleifera leaves. Methods : we conducted a randomized trial in laboratory animals for five weeks of follow-up, developed in the Vivarium of Pharmaceutical Technology Laboratory of the Universidade Federal da Paraíba. We used rabbits from the New Zealand breed, subjected to a hypercholesterolemic diet and angioplasty of the external iliac artery, randomized into two groups: M200 Group (n=10) - rabbits treated with 200mg/kg/day of Moringa oleifera leaves extract orally; SF group (n=10) - rabbits treated with 0.9% saline orally. After five weeks, the animals were euthanized and the iliac arteries prepared for histology. Histological sections were analyzed by digital morphometry. Statistical analysis was performed using the Student's t test. The significance level was 0.05. Results : there was no significant difference in myointimal hyperplasia between M200 and SF groups when comparing the iliac arteries submitted to angioplasty. Conclusion : there was no difference of myointimal hyperplasia between groups treated with saline and Moringa oleifera after angioplasty.

Arterial diffuse intimal thickening associated with enzootic calcinosis of sheep

Morphometric, immunohistochemical and ultrastructural studies were carried out on the diffuse intimal thickening (DIT) in arteries of 7 sheep with clinical signs of naturally occurring enzootic calcinosis due to ingestion of the plant Nierembergia veitchii. Arterial lesions consisted of medial deposition of calcium salts and DIT. Calcification of the intima was rare, mild and located near the elastic lamina. By immunohistochemistry a-actin was detected in cells of the media and in cells forming the intimal thickening. Receptors for 1,25(OH)2 vitamin D3 were detected in nuclei of intimal, medial and endothelial cells. DIT was irregularly distributed and was neither proportionally related to the intensity of the underlying mineralization area nor to the thickening of the remaining media. Ultrastructural morphometry in smooth muscle cells (SMCs) of the media and thickened intima revealed, in the latter, an increase of 318% in the volumetric fraction of those organelles involved in synthesis and a proportional decrease in contractile elements when compared to normal values of media cells. There were histological and ultrastructural evidences of modification of SMCs and their migration to the intima, where they proliferated causing DIT. It was concluded that DIT is a consistent component of arteriosclerotic lesions in N. veitchii induced calcinosis of sheep and that the predominant cell in this process is the SMCs originated from its predecessors of the media. It is suggested that the inducing factor for the arterial changes is 1,25(OH)2 D3 present in N. veitchii.

Mycoplasma suis in naturally infected pigs: an ultrastructural and morphometric study

Swine eperythrozoonosis is a haemotrophic disease caused by Eperythrozoon suis, actually called Mycoplasma suis, an extracellular bacterial organism that apparently adheres to pig erythrocyte membrane, inducing its deformation and damage. Since little is known about the ultrastructural and morphometrical aspects of this microorganism, the present work aimed to deal with these issues. The ultrastructural study revealed the presence of structures corresponding to tubules disseminated throughout the soma of M. suis. A variable separation between the microorganism membrane and that of the erythrocyte was also observed. The structural and positional attitude of M. suis could allow speculation about its mechanism of action.

Isosporoid Coccidia (Apicomplexa: Eimeriidae) parasites of tanagers (Passeriformes: Thraupidae) from the Marambaia Island, Brazil

In recent years some coccidian parasites of birds were recorded in Marambaia Island, which is a protected environment with a great biodiversity of birds, mainly tanagers. In this current study Isospora tiesangui, I. sepetibensis, I. ramphoceli, I. navarroi, I. cadimi and I. marambaiensis were identified according to their respective thraupid hosts of the Marambaia Island. These species were characterized with histograms, linear regression and analysis of variance (ANOVA). The main feature of identification was the morphology of the sporocyst, mainly Stieda and substieda bodies, since the morphometry did not provide sufficient differentiation. Besides, Dacnis cayana and Thraupis palmarum were reported as new hosts to I. sepetibensis and I. navarroi respectively.

Sperm morphological and morphometric evaluation in captive collared peccaries (Pecari tajacu)

The aim of this study was to compare different staining methods for the evaluation of sperm morphology by light microscopy and also to describe the morphometry of the entire sperm in collared peccaries (Pecari tajacu). Semen from 10 males was obtained by electroejaculation and evaluated for sperm motility, vigor, and concentration. Semen smears were prepared through three different staining methods: Bengal rose, brome-phenol blue, and eosin-nigrosin. Smears were evaluated under light microscopy and sperm morphologic alterations were determined in percentage. In addition, sperm morphometric analysis was conducted by light microscopy coupled to image analyzer software. The smears stained with Bengal Rose provide the best results for the visualization of the sperm tail, midpiece, and head. The use of eosin-nigrosin stain did not allow an adequate impregnation, and some sperm presented a few contrasts with the background. A higher incidence of bent coiled tails was verified in the use of brome-phenol blue staining (P<0.05). Through morphometric evaluation, it was observed that the tail occupies the greatest proportion (89%) of the sperm which presents a discretely elongated head. According to the results, the use of the Bengal Rose stain is recommended for the morphologic evaluation of the collared peccary sperm.

Porcine follicular fluid concentration of free insulin-like growth factor-I collected from different diameter ovarian follicles

The study aimed to quantify the concentrations of free IGF-I in serum and fluid of ovarian follicles in pre-pubertal gilts and describe the ovarian morphology by measuring the size of the ovaries and counting the number of surface follicles. Ovaries (n=1,000) from pre-pubertal gilts were obtained immediately after slaughter. A total of 10 samplings were performed, with ovaries obtained from 50 females for each collection. The follicles situated on the surface of each ovary were classified as small (SFs, 2 to 5mm in diameter) or large (LFs 6 to 10mm in diameter) and the follicular fluid was obtained by follicle aspiration. The collection of serum samples was performed after the gilts exsanguination using sterile tubes. From the pool of serum and follicular fluid obtained from 50 females, the concentration of free IGF-I was determined in each sample using an enzyme immunoassay kit (ELISA). The description of ovarian morphometry was performed in 100 ovaries from randomly selected gilts. The larger and smaller lengths of ovaries were measured, and the total number of SFs and LFs present on the surface of each ovary were also counted. The IGF-I concentration was greater (P<0.05) in LFs (170.92±88.29 ng/mL) compared with SFs (67.39±49.90ng/mL) and serum (73.48±34.63ng/mL). The largest and smallest length of the ovaries was 26.0±3.0 and 19.0mm ±2.0mm, respectively. The number of SFs (70.86±25.76) was greater (P<0.01) than LFs (6.54±5.26). The study concluded that LFs present greater levels of IGF-I when compared with SFs and blood, which is related to increased activity of the LFs and its differentiation to ovulation. In addition, ovaries of pre-pubertal gilts have a higher number of SFs compared to LFs. Therefore, our study demonstrated unique data regarding the physiological concentration of free IGF-I in ovarian follicles, that can be used in future research to evaluate the addition of this hormone in the in vitro production media of porcine embryos with the goal to improve the technique efficiency.

Morphological and morphometric evaluation of prepubertal gilt ovaries, uterine tubes and uterus at different oestrus cycle stages

Studies are performed in developing techniques/procedures that provide greater reproductive performance in farm animals, including pigs. In this sense, the study of gilts reproductive organs at different oestrus cycle stages for assessing the presence of abnormalities and/or other parameters that may affect the future animal fertility is important. In order to evaluate the morphological, morphometric and histomorphometric features of ovaries, uterus and uterine tubes (UTs) characteristics of prepubertal gilts at different oestrus cycle stages, reproductive tracts from 48 animals immediately after slaughter were obtained. After, the structures were dissected and removed, and the ovaries were used for classification of oestrus cycle stage of each gilt in follicular phase (FP) and luteal phase (FL). Then, morphometric evaluations of ovaries, UTs, uterine horns and uterine body were performed. Besides that, medial segments of UTs and uterus were fixed in Bouin solution, processed and included in paraffin, when histological sections of 5.0 micrometers (µm) were obtained and stained with Hematoxylin and Eosin. Histomorphometric analyzes using image capture system and specific software were performed. Afterwards, data were submitted to Student's t test for assessment the statistical differences (P<0.05) between the two different oestrus cycle stages (FP × LP) and between the placement of reproductive structures (right × left antimer). Among the gilts evaluated, 35 were in the FP and 13 in LP. There was no difference (P>0.05) between morphometric parameters of ovaries, UTs and uterus of gilts in FP and LP. Likewise, in respect to the placement of reproductive structures, both in the oestrus cycle stages, as in the general average, there was no difference (P>0.05). Regarding the histomorphometric variables, gilts classified in FP presented a higher (P<0.05) height of glandular and UT epithelium compared to animals in LP. On the other hand, the diameter of endometrial glands was higher (P<0.05) in gilts at LP compared to FP. Furthermore, gilts in LP presented a higher (P<0.05) proportion of endometrium occupied by glands, whereas animals in FP had a higher (P<0.05) proportion of connective tissue and blood vessels. In conclusion, in prepubertal gilts, the histomorphometric parameters as endometrial glands diameter, the height of glandular epithelium and of UT epithelium and the proportion of endometrium occupied by connective tissue, besides the glands and blood vessels varies through the oestrus cycle, possibly under the influence of ovarian steroids.

Morphometric analysis of the Brasiliorchis picta complex (Orchidaceae)

One of the largest genera of Orchidaceae in the Neotropics with about 450 species, Maxillaria presents several taxonomic uncertainties about its generic circumscription and the delimitation of species groups, mainly due to the large variability of some species. The present study aims at verifying the morphological variation and species delimitation in the Brasiliorchis picta complex, a recent new genus derived from Maxillaria, using morphometric multivariate analysis. A total of 340 specimens belonging to six species (B. chrysantha (Barb. Rodr.) R.B. Singer, S. Koehler & Carnevali, B. gracilis (Lodd.) R.B. Singer, S. Koehler & Carnevali, B. marginata (Lindl.) R.B. Singer, S. Koehler & Carnevali, B. picta (Hook.) R. Singer, S. Koehler & Carnevali, B. porphyrostele (Rchb. f.) R.B. Singer, S. Koehler & Carnevali and B. ubatubana (Hoehne) R.B. Singer, S. Koehler & Carnevali) were analyzed using multivariate methods (PCA, CVA, DA, and Cluster Analysis with UPGMA). B. gracilis shows the largest morphological discontinuity, mainly due to its smaller size. The other species tend to form distinct groups, but intermediate characteristics between pairs of species induce overlaps among the individuals of different species and thus confuse the distinction of each one. Hybridization and geographic distribution can be involved in the differentiation of the species and lineages in this complex. Because the species classified a priori in this work cannot be recognized by the quantitative characters measured here, such other tools as geometric morphometry and molecular data should be employed in future works to clarify species relationships in this complex.

Postangioplasty restenosis: a practical model in the porcine carotid artery

Transluminal coronary angioplasty is a routine therapeutic intervention in coronary heart disease. Despite the high rate of primary success, restenosis continues to be its major limitation. Porcine models have been considered to be the most adequate experimental models for studying restenosis. One limitation of porcine models is the need for radiological guidance and the expenses involved. The objective of the present study was to adapt an experimental model of angioplasty in the porcine carotid artery that does not require radiological equipment. Eight animals were used to develop the technique of balloon injury to the common carotid artery by dissection without radiological guidance. This technique was then employed in six other animals. Under anesthesia, the left common carotid artery was dissected and incised at the carotid sinus for insertion of an over-the-wire angioplasty balloon towards the aorta. Overstretch injury of the carotid artery was performed under direct visualization. After 30 days, the arteries were excised and pressure-fixated. Uninjured carotid arteries from 3 additional animals were used as controls. A decreased luminal area associated with intimal hyperplasia and medial reaction was observed in all injured arteries. Immunohistochemistry identified the intimal hyperplastic cells as smooth muscle cells. Computerized morphometry of the ballooned segments revealed the following mean areas: lumen 2.12 mm2 (± 1.09), intima 0.22 mm2 (± 0.08), media 3.47 mm2 (± 0.67), and adventitia 1.11 mm2 (± 0.34). Our experimental model of porcine carotid angioplasty without radiological guidance induced a vascular wall reaction and permitted the quantification of this response. This porcine model may facilitate the study of vascular injury and its response to pharmacological interventions

Studies on the intrinsic nervous system of the wild rodent Calomys callosus digestive tract. II: The submucous plexus

The submucous plexus of the normal small and large intestine of Calomys callosus was studied by NADH and AChE histochemical techniques and by transmission and scanning electron microscopy. The plexus contains (mean ± SD) 7,488 ± 293 neurons/cm2 in the duodenum, 5,611 ± 836 in the jejunum, 2,741 ± 360 in the ileum, 3,067 ± 179 in the cecum, and 3,817 ± 256 in the proximal colon. No ganglia or nerve cell bodies were seen in the esophagus, stomach, distal colon or rectum. The neurons are pear-shaped with a round or oval nucleus and the neuronal cell profile areas were larger in the large intestine than in the small intestine. Most of the neurons display intense AChE activity in the cytoplasm. AChE-positive nerve fibers are present in a primary meshwork of large nerve bundles and in a secondary meshwork of finer nerve bundles. At the ultrastructural level, the ganglia are irregular in shape and covered with fibroblast-like cells. The nucleoplasm of the neurons is finely granular with a few condensations of chromatin attached to the nuclear envelope. In the neuropil numerous varicosities filled with vesicles of different size and electron densities are seen. The pre- and post-synaptic membrane thickenings are asymmetric. Characteristic glial cells with oval nuclei and few organelles are numerous. These data provide a detailed description of this submucosal meshwork.

Probable effect of photoperiod on seasonal variation in the nuclear volume of the adrenal cortex of viscacha (Lagostomus maximus maximus)

The neuroendocrine system regulates several organic functions such as reproduction, metabolism and adaptation to the environment. This system shows seasonal changes linked to the environment. The experimental model used in the present study was Lagostomus maximus maximus (viscacha). The reproduction of males of this species is photoperiod dependent. Twenty-four adult male viscachas were captured in their habitat at different times during one year. The adrenal glands were processed for light microscopy. Serial cuts were stained with hematoxylin-eosin for the morphometric study, and 100 nuclei of each zone of the adrenal cortex were counted per animal. Data were analyzed statistically by ANOVA and the Tukey test. The cells of the glomerulosa zone are arranged in a tube-shaped structure. The fasciculata zone has large cells with central nuclei and clearly visible nucleoli and with a vacuolar cytoplasm. In the reticularis zone there are two of types of cells, one with a nucleus of fine chromatin and a clearly visible nucleolus and the other with nuclear pycnosis. Morphometric analysis showed maximum nuclear volumes during the February-March period with values of 133 ± 7.3 µm3 for the glomerulosa, 286.4 ± 14.72 µm3 for the fasciculata, and 126.3 ± 9.49 µm3 for the reticularis. Minimum nuclear volumes were observed in August with values of 88.24 ± 9.9 µm3 for the glomerulosa, 163.7 ± 7.78 µm3 for the fasciculata and 64.58 ± 4.53 µm3 for the reticularis. The short winter photoperiod to which viscacha is subjected could inhibit the adrenal cortex through a melatonin increase which reduces the nuclear volume as well as the cellular activity.

Respiratory mechanics and morphometric changes during anesthesia with ketamine in normal rats

Ketamine is believed to reduce airway and pulmonary tissue resistance. The aim of the present study was to determine the effects of ketamine on the resistive, elastic and viscoelastic/inhomogeneous mechanical properties of the respiratory system, lungs and chest wall, and to relate the mechanical data to findings from histological lung analysis in normal animals. Fifteen adult male Wistar rats were assigned randomly to two groups: control (N = 7) and ketamine (N = 8). All animals were sedated (diazepam, 5 mg, ip) and anesthetized with pentobarbital sodium (20 mg/kg, ip) or ketamine (30 mg/kg, ip). The rats were paralyzed and ventilated mechanically. Ketamine increased lung viscoelastic/inhomogeneous pressure (26%) compared to the control group. Dynamic and static elastances were similar in both groups, but the difference was greater in the ketamine than in the control group. Lung morphometry demonstrated dilation of alveolar ducts and increased areas of alveolar collapse in the ketamine group. In conclusion, ketamine did not act at the airway level but acted at the lung periphery increasing mechanical inhomogeneities possibly resulting from dilation of distal airways and alveolar collapse.

Morphological changes of carotid bodies in acute respiratory distress syndrome: a morphometric study in humans

Carotid bodies are chemoreceptors sensitive to a fall of partial oxygen pressure in blood (hypoxia). The morphological alterations of these organs in patients with chronic obstructive pulmonary disease (COPD) and in people living at high altitude are well known. However, it is not known whether the histological profile of human carotid bodies is changed in acute clinical conditions such as acute respiratory distress syndrome (ARDS). The objective of the present study was to perform a quantitative analysis of the histology of carotid bodies collected from patients who died of ARDS. A morphometric study of carotid bodies collected during routine autopsies was carried out on three groups: patients that died of non-respiratory diseases (controls, N = 8), patients that presented COPD and died of its complications or associated diseases (N = 7), and patients that died of ARDS (N = 7). Morphometric measurements of the volume fraction of clusters of chief cells were performed in five fields on each slide at 40X magnification. The numerical proportion of the four main histological cell types (light, dark, progenitor and sustentacular cells) was determined analyzing 10 fields on each slide at 400X magnification. The proportion of dark cells was 0.22 in ARDS patients, 0.12 in controls (P<0.001), and 0.08 in the COPD group. The proportion of light cells was 0.33 (ARDS), 0.44 (controls) (P<0.001), and 0.36 (COPD). These findings suggest that chronic and acute hypoxia have different effects on the histology of glomic tissue.

Experimental chronic entrapment of the sciatic nerve in adult hamsters: an ultrastructural and morphometric study

Entrapment neuropathy is a group of clinical disorders involving compression of a peripheral nerve and interference with nerve function mostly through traction injury. We have investigated the chronic compression of peripheral nerves as an experimental procedure for detecting changes in ultrastructural nerve morphology. Adult hamsters (Mesocricetus auratus, N = 30) were anesthetized with a 25% pentobarbital solution and received a cuff around the right sciatic nerve. Left sciatic nerves were not operated (control group). Animals survived for varying times (up to 15 weeks), after which they were sacrificed and both sciatic nerves were immediately fixed with a paraformaldehyde solution. Experimental nerves were divided into segments based upon their distance from the site of compression (proximal, entrapment and distal). Semithin and ultrathin sections were obtained and examined by light and electron microscopy. Ultrastructural changes were qualitatively described and data from semithin sections were morphometrically analyzed both in control and in compressed nerves. We observed endoneurial edema along with both perineurial and endoneurial thickening and also the existence of whorled cell-sparse structures (Renaut bodies) in the subperineurial space of compressed sciatic nerves. Morphometric analyses of myelinated axons at the compression sites displayed a remarkable increase in the number of small axons (up to 60%) in comparison with the control axonal number. The distal segment of compressed nerves presented a distinct decrease in axon number (up to 40%) comparatively to the control group. The present experimental model of nerve entrapment in adult hamsters was shown to promote consistent histopathologic alterations analogous to those found in chronic compressive neuropathies.