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Biomedical subjects

G V Pelagalli

Publications and source records attributed to G V Pelagalli.

At least 19 recordsLinked to original sources
PubMed2001

Anatomical distribution of NPY-like immunoreactivity in the domestic chick brain (Gallus domesticus).

Neuropeptide Y-immunoreactive (NPY-ir) fibers and neurons in the brain of the domestic chick (Gallus domesticus) were described using an immunohistochemical technique. NPY-ir neurons were seen in the lobus parolfactorius; hyperstriatum, neostriatum, paleostriatum, and archistriatum; hippocampal and parahippocampal areas; dorsolateral corticoid area; piriform cortex; two thalamic areas contiguous to the n. rotundus; n. dorsolateralis anterior thalami, pars lateralis, and pars magnocellularis; n. periventricularis hypothalami; n. paraventricularis magnocellularis; regio lateralis hypothalami; n. infundibuli; inner zone of the median eminence; dorsal and lateral portions of the n. opticus basalis; n. raphes; and n. reticularis paramedianus. NPY-ir fibers were seen throughout the entire chick brain, but were more abundant in the hypothalamus where they formed networks and pathways. They were also observed in some circumventricular organs. The anatomical data of the present study regarding the distribution of NPY ir in the chick brain, together with the physiological findings of other studies, suggest that NPY plays a key role in the regulation of the neuroendocrine, vegetative, and sensory systems of birds by acting as a neuromodulator and/or neurotransmitter.

Animals↗
PubMed2001

Morphostructural changes of the kidney microvasculature during the prenatal period in Bubalus bubalis.

The microcirculation of the foetal kidney was studied in the buffalo using light (LM) and scanning electron microscopy (SEM). The primordial glomerules originated from the peripheral zone of the metanephros at the stage of 8 cm CRT. The glomerular capillaries started to differentiate at the stage of 10-15 cm CRT. They were sparse and showed a few primordial pores. In addition, they began to make contacts with primordial podocytes. At the stage of 40-60 cm CRT, the renal microcirculation showed a complex and almost completely organized morphology.

Animals↗
PubMed1999

The innervation of the ureter in the duck (Anas platyrhynchos). A morphological and quantitative study.

The morphology and distribution of the innervation in the duck ureter were studied using AChE histochemistry and PGP 9.5 immunohistochemistry. The density of AChE positive ganglia and neurons was calculated in the adventitial and muscular layers both in young and adult birds. Moreover, in order to investigate regional differences in neuronal density, separate neuron counts and neuron density calculations were performed for the upper, intermediate and lower parts of the ureter, and the data were statistically evaluated. Three nerve plexuses located in the tunica adventitia, in the tunica muscularis and in the lamina propria respectively, were observed. Both in young and adult ducks, the density of adventitial neurons was significantly greater in the lower tract than in the upper and intermediate tracts. The findings of the present study suggest that, in birds, the innervation may play a role in ureteric functions such as epithelial mucosecretion, muscular motility, and closure and/or opening of the ureteric papilla.

Acetylcholinesterase↗
PubMed1998

The morphology of the ureter in the duck (Anas platyrhynchos).

The morphology of the ureter of the duck was investigated, using histological, SEM and TEM techniques. The inner perimeter, the total thickness of the ureteral wall and the thickness of each uretral layer were measured. The epithelium was tall columnar and pseudostratified along all the tracts of the ureter and showed a high muco-secretive activity. The lamina propria contained numerous capillaries and aggregates of leucocytes and macrophages. Throughout the lamina propria there was a dense plexus of nerves. Some denuded single nerve fibres were observed between the epithelial basal cells. A plexus of nerves was also observed in the tunica muscularis. The ostium cloacale ureteris opened on a well-developed papilla in the dorsal region of the urodeum. The total thickness of the ureteral wall, the thickness of the lamina propria and the tunica muscularis, and the inner perimeter progressively increased towards the ostium. The above observations suggest that the avian ureter plays an important role in the modification of the urine coming from medullary cones, and in emission of the urine into the cloaca.

Animals↗
PubMed1996

The valva portalis renalis in the duck (Anas platyrhynchos).

The morphology of the valva portalis renalis of the duck was investigated, using histological, SEM and TEM techniques. The wall thickness of the vena iliaca externa, the vena portalis renalis caudalis, the vena iliaca communis and the vena renalis caudalis was morphometrically evaluated. The blood pressure in these veins was measured using a three-way H2O manometer. The valva portalis renalis was composed primarily of epithelioid cells and lined with endothelium. Throughout the entire valva there was a dense complex of nerve structures made up of fibers and fiber bundles which also extended beneath the endothelium of the valva and around the subendothelial epithelioid cells. The wall thicknesses of the veins supplying the renal portal system (vena iliaca externa and vena portalis renalis caudalis) were greater than those of the vessels collecting the renal refluent venous blood (vena iliaca communis and vena renalis caudalis). In addition, the blood pressure values taken in the vena iliaca externa and the vena portalis renalis caudalis were much higher than those in the vena iliaca communis and the vena renalis caudalis. The above observations suggest that the renal portal system works at higher blood pressure levels than the general venous system and that the valva portalis renalis regulates its aperture in order to maintain a constant blood pressure and a continuous blood flow in the renal portal system vessels, hence avoiding damage to the renal parenchyma caused by pressure overloads.

Animals↗
PubMed1995

[Morphofunctional study of the lingual papillae in cattle (Bos taurus)].

The morpho-functional and topographical features of the lingual papillae situated on the dorsal surface of the bovine tongue, were studied utilizing LM and SEM techniques. In the bovine species, the functional differentiation of the lingual papillae in their gustatory and mechanical modes, seems to be related to the position of the papillae rather than to their morphological features. The gustatory function predominates over the mechanical one on the caudal tract of the tongue body (lateral to the lingual torus and associated with circumvallate papillae). The gustatory function also involves the conical papillae situated on the caudal tract of the tongue body. This gustatory function is aided by additional anatomical structures: 1. The grooves situated on the rostro-lateral side of the conical papillae; 2. The microcraters located on the top of the fungiform papillae; and 3. The furrows of the circumvallatae papillae vallum. The contact between saliva soluble food particles and taste buds is aided and made more efficient by these structures. Furthermore, a large variety of conical papillae were observed, whereas no filiform papillae were noted.

Animals↗
PubMed1995

Morphostructural characteristics of the vallate papillae in Bos taurus.

The Morpho-structural characteristics of the vallate papillae of the bovine tongue were studied utilizing LM, SEM and TEM techniques. In the bovine, the vallate papillae are numerous and different in size. They have a prominent vallum papillae which surrounds a deep sulcus papillae. The sulcus has many elongated taste buds on its inner wall. Nervous fibers enter the taste bud and sometimes have rosary shaped axons. The gustative sensitivity of these animals may be instrumental, in their choice of food and avoidance of noxious plants.

Animals↗
PubMed1994

[The microvascularization of the choroid plexus of the lateral ventricles in the goat (Capra hircus)].

The goat choroid plexus angioarchitecture of the lateral ventricles was studied under the SEM using the method of "microvascular corrosion casts". The whole plexus is semilunar shaped and directed in an antero-posterior, latero-median fashion. In the plexus the lateral extremity is larger than the median one. All the components of the vascular bed (arteries, veins and capillaries) of the choroid plexus have interesting morpho-structural features. In particular, the capillaries are more developed than the other components and they are variously located on both sides of the plexus. The capillary network has a various organization in different zones of each side of the plexus.

Animals↗
PubMed1993

[The innervation of the syrinx of the duck (Anas platyrhynchos)].

The innervation of the Syrinx was studied in 15 female Peking Ducks of 10 to 12 months old by using L.M. and E.M. In this organ a nervous plexiform net is present located in the connective below the epithelium along the membrana tympaniformis medialis. This net-work is made of the nervous trunks which repeatedly anastomise among themselves and display during their course acapsulate ganglions. However, no specialized contact device were encountered at the periphery.

Animals↗
PubMed1993

[Morphostructural study of the lingual papillae in the buffalo (Bubalus bubalus)].

The morphostructural characteristics of lingual papillae in 30 adult buffaloes were studied by SEM. In this species, dorsal lingual surface papillae shows different shape so that their classification is complicated. Topography and morphology of conical and vallate papillae presents significant aspects. Particularly, the conical papillae have a different morphological organization when they are localized over the side of the tongue apex or over dorso-lateral tract of the tongue body. The functional aspects are discussed.

Animals↗
PubMed1991

[The structure of the clavicular air sac of the duck (Anas platyrhinchos)].

The structural organization of the epithelium lining the clavicular air sac in Duck was studied by light and electron microscopic. This epithelium consists of two types of pavement like cells. The first flat types of cells are numerous with large mitochondria containing cytoplasm and elongated nuclei. The second short and dumpy cells are few in number and are after seen near the ostium. They could have long microvilli like pseudopod on their apical surface ready to engulf inhaled foreign particles. Desmosomal bridges too are found between contiguous cells.

Air Sacs↗
PubMed1990

[The structure of the syrinx in the duck (Anas platyrhinchos)].

The morphological and structural aspects of the Membrana tympaniformis medialis of the syrinx were studied with L.M. and E.M. in 32 female and male Peking ducks from 6 to 12 months old. The membrane is covered by pseudostratified prismatic epithelium which shows different regional features. While at level of the proximal and distal third of the tympanic membrane the morphological and structural aspects of the cells resemble that of the adjacent structures (pessulus and primary bronchi), the middle part of the epithelium layer becomes gradually flattered; the epithelium is made up of oblique or horizontal cells which touch each other by means of many lateral interdigitations. At level of the upper parts of the cells there are several types of cell junctions. This particular disposition seem to be well adapted to the contractions of the syringeal muscles.

Animals↗
PubMed1990

Transplantation of Lewis lung carcinoma in mouse uterus.

Earlier studies have shown that pregnant and nonpregnant mammalian uteri respond differently to tumor cell invasion, colonization and metastasis, but the biological basis of such differential uterine response has not been clarified. In the present study we have investigated the role of the metastatic potential of the tumor in the differential response of different stages of mouse uteri, using a highly metastatic tumor. The results obtained were compared with earlier data obtained using low metastatic or nonmetastatic tumors. Lewis lung carcinoma (LLC) cells were infused nonsurgically into nonpregnant uteri of various estrus stages and into pregnant uteri on day 3 postcoitum. Response of the uteri and embryos was studied histologically on days 2, 5 and 18 posttreatment (p.t.). The embryonic development was severely inhibited resulting in extensive resorption. In the tumor cell-treated animals, despite an early and uniform invasion the patterns of tumor cell colonization and metastasis differed remarkably from the pregnant to nonpregnant uteri. On day 5 p.t. 66% of nonpregnant animals showed tumor cells in the endometrium and 40% had tumor metastasis in other organs. Though 40% of the pregnant animals had tumor cells in the uteri, none had metastasis in other organs. By day 18 p.t., despite the absence of tumor cells in the uteri, 75% of nonpregnant animals showed metastasis in lung and liver. In pregnant animals, tumor cells were seen neither in uteri nor in other organs studied. These results indicate the refractory nature of both the pregnant and nonpregnant mouse uteri to the survival and colonization of LLC cells, but the mechanisms by which the tumor cells are eliminated differ between these two types of uteri.

Animals↗
PubMed1989

The vascularization of the Bursa cloacalis (of Fabricius) in the duck.

The morphological and structural features of the vascular component of the bursa of Fabricius in the duck are described. By means of an intravasal perfusion of suitably colored neoprene Latex or Microscopaque, or a perfusion of Indian ink, it was possible to follow visually the routes of arteries, veins and the microcirculation; this last represents a major characteristic of the bursal follicle in the duck. The microcirculation has its origins in several roots arising from the follicular arterioles, which in the region of the cortex constitute an open vascular layer. From these pre-capillary arterioles, adjacent to the limiting layer between cortex and medulla, a dense capillary network is formed. With the aid of an electron microscope the presence of a cortico-medullary barrier of an epithelio-reticular nature was revealed; close to it there are the terminal branches of the intrafollicular network. The barrier appears to be structurally more compact than that of the cortical capillaries of the mammalian thymus.

Animals↗