Slight volume changes in the duck lung do not imply a fundamental change in the structure of the parenchyma.

Slight changes in lung volume have previously been reported in ducks. We studied the functional structure of the lung of the domestic duck using classical anatomical techniques as well as ultrasound monitoring to unravel the causes of such changes. Later dorsal and medioventral secondary bronchi were superficially positioned and covered with a thin transparent and collapsible membrane, internally lined with a cuboidal to squamous epithelium. The lung parenchyma was rigid, with atria well supported by septa containing smooth muscles, interparabronchial septa reinforced by collagen fibres, and blood capillaries supported by epithelial plates. On ultrasound monitoring, an outward and inward movement of the lung surface during inspiration and expiration, respectively, was evident at the region where the airways were covered by the thin membranes. The movements plausibly facilitated air movement in the lung just like the air sacs. We conclude that volume changes in the duck lung occur due to a slight morphological adaptation rather than a change in the archetypical design of the avian lung parenchyma.

Antiulcerogenic effects of selected African nightshades (Solanum nigrum Linn. ) genotypes on the rat stomach: a morphologic and morphometric study / Efectos antiulcerogénicos de genotipos seleccionados de solanáceas Africanas (Solanum nigrum Linn. m) en el estómago de ratas: un estudio morfológico y morfométrico

Solanum nigrum (SLN), commonly known as African nightshade, is used as a vegetable as well as in the management and treatment of various ailments including gastric ulcers. We analyzed, both grossly and microscopically using H&E, Masson's trichrome and PSA staining methods, the protective effects of aqueous leaf extracts of three Kenyan SLN genotypes namely S. scabrum (SSB), S. sarrachoides (SSR) and S. villosum (SVL) on ethanol-induced gastric lesions in rats. There was evidence of gastro-protection by all the three genotypes with the SSB showing the highest ulcer inhibition score (76.37 %) followed by SSR (72.51 %) and SVL (63.30 %). SLN-pretreated rats showed less areas of gastric mucosal surface erosion. Additionally in the pretreated animals, the depth of the ulcers were markedly reduced, reaching only the gastric pit region except in those treated with SVL where the ulcers penetrated slightly more deeply to affect the gastric glands. Compared with controls, the mean microscopic ulcer index decreased 5.07, 3.55 and 2.37-fold in rats pretreated with SSB, SSR and SVL extracts respectively. Results of this work show extracts of the three SLN genotypes to have antiulcerogenic potential but at varied strengths, thus confirming earlier reports that phytoconstituents and hence the efficacy of a medicinal plant may be influenced by genetic factors.

Solanum nigrum (SLN), comúnmente conocida como la solanácea africana, se usa como vegetal, para el tratamiento de diversas dolencias incluyendo las úlceras gástricas. Analizamos de forma macro y microscópica, de forma macroscópica y microscópica, utilizando para ello tinciones de H&E, tricrómico de Masson y PSA los efectos protectores de extractos acuosos de hojas de tres genotipos SLN de Kenia: S. scabrum (SSB), S. sarrachoides (SSR) and S. villosum (SVL) en lesiones gástricas inducidas por etanol en ratas. Hubo evidencia de gastroprotección por parte de los tres genotipos con el SSB mostrando el puntaje más alto de inhibición de la úlcera (76,37 %) seguido de SSR (72,51 %) y SVL (63,30 %). Las ratas tratadas previamente con SLN mostraron menos áreas de erosión de la superficie de la mucosa gástrica. Además, en los animales pretratados, la profundidad de las úlceras se redujo notablemente, llegando solo a la región del fondo gástrico, excepto en aquellos tratados con SVL donde las úlceras penetraron un poco más profundamente para afectar las glándulas gástricas. En comparación con los controles, el índice medio de úlcera microscópica disminuyó 5,07, 3,55 y 2,37 veces en ratas pretratadas con extractos de SSB, SSR y SVL, respectivamente. Los resultados de este trabajo muestran que los extractos de los tres genotipos de SLN tienen potencial antiulcerogénico en diferentes concentraciones, lo que confirma informes anteriores que los fitoconstituyentes y la eficacia de una planta medicinal pueden estar influenciados por factores genéticos.

Effects of anticancer drug docetaxel on the structure and function of the rabbit olfactory mucosa.

Docetaxel (DCT) is an anticancer drug which acts by disrupting microtubule dynamics in the highly mitotic cancer cells. Thus, this drug has a potential to affect function and organization of tissues exhibiting high cellular turnover. We investigated, in the rabbit, the effects of a single human equivalent dose (6.26 mg/kg, i.v.) of DCT on the olfactory mucosa (OM) through light and electron microscopy, morphometry, Ki-67 immunostaining, TUNEL assay and the buried food test for olfactory sensitivity. On post-exposure days (PED) 5 and 10, there was disarrangement of the normal cell layering in the olfactory epithelium (OE), apoptotic death of cells of the OE, Bowman's glands and axon bundles, and the presence (including on PED 3) of blood vessels in the bundle cores. A decrease in bundle diameters, olfactory cell densities and cilia numbers, which was most significant on PED 10 (49.3%, 63.4% and 50%, respectively), was also evident. Surprisingly by PED 15, the OM regained normal morphology. Furthermore, olfactory sensitivity decreased progressively until PED 10 when olfaction was markedly impaired, and with recovery from the impairment by PED 15. These observations show that DCT transiently alters the structure and function of the OM suggesting a high regenerative potential for this tissue.

Morphofunctional adaptations of the olfactory mucosa in postnatally developing rabbits.

Rabbits are born blind and deaf and receive unusually limited maternal care. Consequently, their suckling young heavily rely on the olfactory cue for nipple attachment. However, the postnatal morphofunctional adaptations of olfactory mucosa (OM) are not fully elucidated. To clarify on the extent and the pattern of refinement of the OM following birth in the rabbit, morphologic and morphometric analysis of the mucosa were done at neonatal (0-1 days), suckling (2 weeks), weanling (4 weeks), and adult (6-8 months) stages of postnatal development. In all the age groups, the basic components of the OM were present. However, proliferative activity of cells of the mucosal epithelium decreased with increasing age as revealed by Ki-67 immunostaining. Diameters of axon bundles, packing densities of olfactory cells, and cilia numbers per olfactory cell knob increased progressively with age being 5.5, 2.1, and 2.6 times, respectively, in the adult as compared with the neonate. Volume fraction values for the bundles increased by 5.3% from birth to suckling age and by 7.4% from weaning to adulthood and the bundle cores were infiltrated with blood capillaries in all ages except in the adult where such vessels were lacking. The pattern of cilia projection from olfactory cell knobs also showed age-related variations, that is, arose as a tuft from the tips of the knobs in neonates and sucklings and in a radial pattern from the knob bases in weanlings and adults. These morphological changes may be attributed to the high olfactory functional demand associated with postnatal development in the rabbit.

Comparative morphometry of the olfactory bulb, tract and stria in the human, dog and goat / Morfometría comparada del bulbo, tracto y estría olfatoria en el humano, perro y cabra

Morphometric parameters of olfactory brain components show species-dependent variations. However, the association of these parameters with olfactory function vis-à-vis ecological and evolutionary behaviors is poorly understood. In this study, a morphometric analysis of the olfactory bulb, tract and stria was carried out in three ecologically diverse animals comprising humans (primate), dogs (carnivore) and goats (herbivore) to elucidate differences in morphometry in relation to olfactory function. Using formalin-fixed brains, volumes and linear measurements of the olfactory structures were determined and correlated with those of cerebrum and the whole brain. The volume of the olfactory bulb was greatest in dogs, followed by goats and humans and constituted 0.31 percent, 0.18 percent and 0.01 percent, respectively, of the brain volume. Similarly, the ratio of volume of the bulb, tract and stria to that of brain was 1.95 percent in the dog, 0.77 percent in the goat and 0.03 percent in the human. The width of the bulb was greatest (p< 0.05) in dogs (10.80 +/- 1.64mm) compared to goats (8.25 +/- 0.96mm) and humans (5.50 +/- 0.71mm), and accounted for a hemisphere breadth of 42.91 percent, 29.73 percent and 8.94 percent respectively. Interestingly though, the total length of the olfactory bulb, tract and striae increased in the order of goat (34.5 +/- 1.30mm), human (36.25 +/- 1.70mm) and dog (48.20 +/- 1.92mm), and constituted 21.47 percent, 51.87 percent and 72.30 percent, respectively, of the hemisphere length. These results suggest that the morphometric adaptations of the olfactory components to olfactory function decline from the dog, to goat, to human, and this may be indicative of the varied olfactory functional needs in regard to the ecological diversity of these species.

Los parámetros morfométricos de los componentes del cerebro olfativo presentan variaciones que dependen de las especies. Sin embargo, la asociación de estos parámetros con la función olfativa vis-à-vis los comportamientos ecológicos y evolutivos es poco conocida. En este estudio se llevó a cabo un análisis morfométrico del bulbo, tracto y estría olfatoria en tres animales de diversidad ecológica que abarcan los seres humanos (primates), perros (carnívoros) y cabras (herbívoros) para dilucidar las diferencias en la morfometría en relación con la función olfatoria. El uso de cerebros fijados en formalina, los volúmenes y las medidas lineales de las estructuras olfativas se determinaron y se correlacionaron con el cerebro. El volumen del bulbo olfatorio fue mayor en los perros, seguidos por cabras y seres humanos y constituyeron un 0,31 por ciento, 0,18 por ciento y 0,01 por ciento, respectivamente, del volumen del cerebro. Del mismo modo, la relación entre el volumen del bulbo, vías y estrías al del cerebro fue de 1,95 por ciento en el perro, un 0,77 por ciento en la cabra y 0,03 por ciento en el ser humano. El ancho del bulbo fue mayor (p <0,05) en los perros (10,80 +/- 1.64mm) en comparación con cabras (8,25 +/- 0.96mm) y humanos (5,50 +/- 0.71mm), y representó una total hemisférico de 42,91 por ciento, 29,73 por ciento y 8,94 por ciento respectivamente. Sin embargo, curiosamente la longitud total del bulbo olfatorio, del tracto y estrías aumentaron en la cabra (34,5 +/- 1,30 mm), en humanos (36,25 +/- 1.70mm) y en el perro (48,20 +/- 1,92mm), y constituyeron 21,47 por ciento, 51,87 por ciento y 72,30 por ciento, respectivamente, del largo del hemisferio. Estos resultados sugieren que las adaptaciones morfométricas de los componentes olfativos de la función olfativa se van reduciendo de perro a cabra y al hombre y esto puede ser indicativo de las variadas necesidades funcionales olfativas en lo que respecta a la diversidad ecológica de estas especies.

Spatial and functional relationships between air conduits and blood capillaries in the pulmonary gas exchange tissue of adult and developing chickens.

The documented data regarding the three-dimensional structure of the air capillaries (ACs), the ultimate sites of gas exchange in the avian lung is contradictory. Further, the mode of gas exchange, described as cross-current has not been clearly elucidated. We studied the temporal and spatial arrangement of the terminal air conduits of the chicken lung and their relationship with the blood capillaries (BCs) in embryos as well as the definitive architecture in adults. Several visualization techniques that included corrosion casting, light microscopy as well as scanning and transmission electron microscopy were used. Two to six infundibulae extend from each atrium and give rise to numerous ACs that spread centrifugally. Majority of the ACs are tubular structures that give off branches, which anastomose with their neighboring cognates. Some ACs have globular shapes and a few are blind-ending tapering tubes. During inauguration, the luminal aspects of the ACs are characterized by numerous microvillus-like microplicae, which are formed during the complex processes of cell attenuation and canalization of the ACs. The parabronchial exchange BCs, initially inaugurated as disorganized meshworks, are reoriented via pillar formation to lie predominantly orthogonal to the long axes of the ACs. The remodeling of the retiform meshworks by intussusceptive angiogenesis essentially accomplishes a cross-current system at the gas exchange interface in the adults, where BCs form ring-like patterns around the ACs, thus establishing a cross-current system. Our findings clarify the mode of gas exchange in the parabronchial mantle and illuminate the basis for the functional efficiency of the avian lung.