The ontogeny of the pancreas in macropodid marsupials

1978 ◽  
Vol 26 (3) ◽  
pp. 487
Author(s):  
AW White ◽  
CJF Harrop
Keyword(s):  
Connective Tissue ◽  
Relative Size ◽  
Pancreatic Tissue ◽  
Pancreatic Development ◽  
Endocrine Tissue ◽  
Red Kangaroo ◽  
Slow Development ◽  
Grey Kangaroo ◽  
Insulin Secreting Cells ◽  
Acinar Tissue

The development of the endocrine pancreas in kangaroos was examined histologically with tissue from three kangaroo species, the red kangaroo Megaleia rufa, the euro Macropus robustus erubescens, and the grey kangaroo Macropus giganteus. The relative size of the pancreas of the pouch young was found not to differ significantly from that of adults. Stages of pancreatic development were described from the frequency of the occurrence of the pancreatic epithelial ducts and the B or insulin-secreting cells, while the development and distribution of the A2 or glucagon-producing cells was also observed. In pouch young of less than 22 days of age the pancreas is dominated by ductular epithelial and undifferentiated pancreatic cells. From days 42 to 97 of pouch life B endocrine cells tend to be concentrated together and ductular tissue encroaches into areas previously dominated by connective tissue. After 120-135 days the first A2 cells are apparent and are usually located at the periphery of the islets, which now take on a distinctive appearance as the acinar tissue expands and separates them. After 135 days of pouch life A2 cells outnumber B cells; the endocrine tissue assumes an adult appearance after 150-160 days. The major difference between the development of pancreatic tissue in foetal sheep and pouch-young kangaroo is the prolonged dominance of connective tissue and the slow development of endocrine tissue in the former.

THE SURVIVAL AND GROWTH OF PANCREATIC TISSUE IN THE ANTERIOR CHAMBER OF THE EYE OF THE ALBINO RAT

1960 ◽  
Vol 20 (1) ◽  
pp. 69-77 ◽  
Author(s):  
R. E. COUPLAND
Keyword(s):  
Anterior Chamber ◽  
Pancreatic Tissue ◽  
Β Cells ◽  
Albino Rat ◽  
Duct Epithelium ◽  
Large Numbers ◽  
Islet Tissue ◽  
Foetal Rat ◽  
Survival And Growth ◽  
Acinar Tissue

SUMMARY Pieces of foetal rat pancreas obtained from specimens of 18–40 mm c.r. length were implanted into the anterior chamber of the mother's eye. The subsequent changes were followed using histological methods. Acinar tissue degenerates and completely disappears during the first 2 weeks after implantation. Duct epithelium proliferates and large numbers of islets of Langerhans are produced which contain both α and β cells. In grafts of 1 year's duration islets form the main bulk of the graft. Methods of staining the islet tissue of the rat are discussed.

scholarly journals Histomorphological changes in the rat pancreas after methionine administration

2020 ◽  
Keyword(s):  
Connective Tissue ◽  
Functional Activity ◽  
Morphological Changes ◽  
Pancreatic Tissue ◽  
European Convention ◽  
Standard Diet ◽  
Cell Nuclei ◽  
Ether Anesthesia ◽  
Rat Pancreas ◽  
Histomorphological Changes

The effectiveness of using various methionine preparations for activating pancreatic function is ambiguous; the reasons may include differences in dosage and duration of methionine administration. The question remains, in what extent the methionine application is efficacious for increasing functional activity of a healthy pancreas. The aim of our study was to investigate morphological changes in pancreas after prolonged administration of methionine. The experiments were carried out on 24 males of Wistar rats at the age of 15 months. During 21 days, the experimental animals received methionine at a daily dose of 250 mg/kg of body weight in addition to the standard diet. Histological preparations were made from pancreatic tissue according to standard method. Morphometry was performed using the computer program «Image J». The rats were taken out of the experiment under ether anesthesia. The studies were carried out in accordance with the provisions of the "European Convention for the Protection of Vertebrate Animals used for Experimental and Other Scientific Purposes" (Strasbourg, 1986). Upon completion of the experiment, histomorphological sings of an increase in functional activity were registered in both exocrine (enlarged acini’s areas and their epithelium height, higher nuclear-cytoplasmic ratio of exocrinocytes, and higher number of nucleoli in cell nuclei) and endocrine (enlarged sizes of the Langerhans islets and increased number of endocrinocytes in the islets) parts of the rat pancreas. In the experimental rats, the relative area of ​​the connective tissue and the stromal-parenchyma index of the pancreas, as well as the width of the interlobular and interacinus layers of connective tissue decreased. A decrease in the mass of connective tissue in the pancreas can be considered as one of the signs of its function activation, an improvement in metabolism between acini, and an increase in regenerative capabilities. Thus, additional administration of prophylactic doses of methionine to healthy animals results in distinct morphological signs of increased pancreatic activity.

Form, weight, and indole content of pineal organs of red and grey kangaroos.

1965 ◽  
Vol 13 (5) ◽  
pp. 727 ◽  
Author(s):  
WB Quay ◽  
PC Baker
Keyword(s):  
Acetic Acid ◽  
Functional Status ◽  
Pineal Organ ◽  
Red Kangaroo ◽  
Grey Kangaroo ◽  
Available Information

The pineal organ of the red kangaroo (Megaleia rufa) is shown to be distinguishable from that of the grey kangaroo (Macropus canguru) by being symmetrically bilobate instead of rounded distally. Pineal weights in the two species were similar. At least in M. rufa pineal size appeared to increase with age - from 6.4-15.6 mg in animals aged about 1 yr to 40.1 mg in a female 6+ years old. In comparison with the nocturnal indole contents of the pineal in rats, those of kangaroos have similar levels of 5- methoxy-N-acetyltryptamine (melatonin) and 5-hydroxyindole-3-acetic acid to the nocturnal values recorded in the literature for rats, but a lower level of 5-hydroxytryptamine (serotonin). Available information on vertebrate pineal weights and indoles does not provide evidence for any obviously distinctive evolutionary or functional status for the marsupial pineal organ as compared with that of some eutherian mammals or of some birds and reptiles.

scholarly journals VISTA: VIsual Semantic Tissue Analysis for pancreatic disease quantification in murine cohorts

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Luke Ternes ◽  
Ge Huang ◽  
Christian Lanciault ◽  
Guillaume Thibault ◽  
Rachelle Riggers ◽  
...  
Keyword(s):  
Animal Studies ◽  
Structural Similarity ◽  
Semantic Segmentation ◽  
Pancreatic Disease ◽  
Pancreatic Tissue ◽  
Investigator Bias ◽  
Acinar To Ductal Metaplasia ◽  
Staining Methods ◽  
Acinar Tissue ◽  
Disease Quantification

AbstractMechanistic disease progression studies using animal models require objective and quantifiable assessment of tissue pathology. Currently quantification relies heavily on staining methods which can be expensive, labor/time-intensive, inconsistent across laboratories and batch, and produce uneven staining that is prone to misinterpretation and investigator bias. We developed an automated semantic segmentation tool utilizing deep learning for rapid and objective quantification of histologic features relying solely on hematoxylin and eosin stained pancreatic tissue sections. The tool segments normal acinar structures, the ductal phenotype of acinar-to-ductal metaplasia (ADM), and dysplasia with Dice coefficients of 0.79, 0.70, and 0.79, respectively. To deal with inaccurate pixelwise manual annotations, prediction accuracy was also evaluated against biological truth using immunostaining mean structural similarity indexes (SSIM) of 0.925 and 0.920 for amylase and pan-keratin respectively. Our tool’s disease area quantifications were correlated to the quantifications of immunostaining markers (DAPI, amylase, and cytokeratins; Spearman correlation score = 0.86, 0.97, and 0.92) in unseen dataset (n = 25). Moreover, our tool distinguishes ADM from dysplasia, which are not reliably distinguished with immunostaining, and demonstrates generalizability across murine cohorts with pancreatic disease. We quantified the changes in histologic feature abundance for murine cohorts with oncogenic Kras-driven disease, and the predictions fit biological expectations, showing stromal expansion, a reduction of normal acinar tissue, and an increase in both ADM and dysplasia as disease progresses. Our tool promises to accelerate and improve the quantification of pancreatic disease in animal studies and become a unifying quantification tool across laboratories.

scholarly journals Immunohistochemical Localization of Somatostatin Receptor sst2A in Human Pancreatic Islets

1998 ◽  
Vol 83 (10) ◽  
pp. 3746-3749 ◽  
Author(s):  
J. C. Reubi ◽  
A. Kappeler ◽  
B. Waser ◽  
A. Schonbrunn ◽  
J. Laissue
Keyword(s):  
Pancreatic Islets ◽  
Islet Cells ◽  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Exocrine Secretion ◽  
Pancreatic Tissue ◽  
Receptor Subtype ◽  
Human Pancreas ◽  
Specific Staining ◽  
Acinar Tissue

Somatostatin and octreotide inhibit endocrine pancreatic functions in man, via specific somatostatin receptors. However, the cellular distribution of the different somatostatin receptor subtype proteins has not been determined in the human pancreas. Here, the immunohistochemical distribution of the sst2A receptor was investigated using the sst2A receptor specific anti-peptide antibody R2-88 in cryostat as well as in formalin-fixed paraffin-embedded sections of human pancreatic tissue, and compared with insulin, glucagon and somatostatin immunostaining of adjacent sections. All pancreatic islets were immunostained with R2-88. Most islet cells were labeled: the sst2A receptors were present in insulin as well as glucagon producing cells, but were not detected in intra-islet vessels nor in adjacent acinar tissue. Absorption of the sst2A antibody with 100 nM of the antigen peptide abolished specific staining in tissue sections. Immunohistochemical staining with 125I-Tyr3-octreotide. Therefore, the clinical efficacy of octreotide on glucagon and insulin release can be explained by the presence of sst2A receptors in human A and B pancreatic islet cells. Moreover, absence of sst2A receptors in human acinar tissue suggests that the action of somatostatin on pancreatic exocrine secretion is mediated either indirectly or through a different somatostatin receptor subtype on acinar cells.

The Effect of Temporary Closure of Watering Points on Grazing Intensity of Red and Grey Kangaroos With Related Observations on Feral Goats.

1997 ◽  
Vol 19 (2) ◽  
pp. 157 ◽  
Author(s):  
D Freudenberger ◽  
RB Hacker
Keyword(s):  
Grazing Intensity ◽  
Grazing Pressure ◽  
Red Kangaroo ◽  
Goat Grazing ◽  
Grey Kangaroo ◽  
Eastern Australia ◽  
Arid Rangelands ◽  
A Minor ◽  
Temporary Closure ◽  
Feral Goat

In this study we examined the utility of manipulating artificial waters as a means of managing total grazing pressure in semi-arid rangelands of eastern Australia. We tested the efficacy of 'Finlayson trough' exclosure technology at three locations, over two summers, in paddocks with red kangaroos (Macropus rufirs) and two species of grey kangaroo (M. giganteus and M. fuliginosus). We also examined the effect of closing off five waters on the distribution of feral goat grazing intensity at one study site. Generally, there were no apparent reductions in kangaroo and goat grazing intensity following 6-10 weeks of water exclosure, the exception being a minor reduction in red kangaroo grazing intensity at one location. We concluded that kangaroo and goat grazing pressure cannot be substantially reduced by simply closing off waters in and near paddocks for several months. Key words: kangaroos, water exclosure. feral goats, grazing pressure, paddock spelling

Further Observations on the Plants Eaten by Kangaroos and Sheep Grazing Together in a Paddock in South-Western Queensland

1974 ◽  
Vol 1 (1) ◽  
pp. 27 ◽  
Author(s):  
M Griffiths ◽  
R Barker ◽  
L Maclean
Keyword(s):  
Species Difference ◽  
Severe Drought ◽  
N Content ◽  
Plant Parts ◽  
Red Kangaroo ◽  
Grey Kangaroo ◽  
Faecal Samples ◽  
The Mean ◽  
Good Agreement ◽  
Made In

In 8 periods between February 1967 and June 1968, covering a severe drought and subsequent rain, samples of 66 species of dicotyledons and 50 species of monocotyledons were collected from a large paddock in semiarid 'mulga-box' country in south-western Queensland. The mean N content of the dicotyledons ranged from 1.51 to 2.85 g/100 g DM, and that of the monocotyledons from 0.70 to 1.86 g/100 g DM.Stomach or faecal samples were analysed for plant parts. When known plant mixtures were given to 2 grey kangaroos (Macropus giganteus) and two sheep there was no species difference in the digestibility of the different plants or in the size distribution of faecal particles. Comparison of stomach and rectal samples from 5 shot kangaroos and 7 shot sheep showed quite good agreement. Samples of the faeces of sheep, grey kangaroo and a few red kangaroo (Megaleia rufa) were collected from the ground at the same intervals as the plant samples, dried and analysed for N and for plant parts. Detailed results are given. The grey kangaroos consistently ate more grasses than the sheep. The N content of sheep faeces was higher than that of kangaroo faeces, reflecting the higher protein intake of the sheep. The results confirm those of an earlier study (NAR 38, 1829) made in 1963–4 in a period of average rainfall. The authors conclude that competition between sheep and kangaroos is small.

A comparative study of macroscopic and microscopic dimensions of the intensine in five macropods (Marsupialia: Macropodidae). I. Allometric relationships.

1992 ◽  
Vol 40 (1) ◽  
pp. 91 ◽  
Author(s):  
R Osawa ◽  
PF Woodall
Keyword(s):  
Body Size ◽  
Confidence Limits ◽  
Surface Areas ◽  
Red Kangaroo ◽  
A Value ◽  
Grey Kangaroo ◽  
Macropus Rufus ◽  
Villous Height ◽  
Kleiber’S Law ◽  
Swamp Wallaby

Macroscopic and microscopic dimensions of the intestines in five macropod species (the red kangaroo, Macropus rufus; the eastern grey kangaroo, M. giganteus; the agile wallaby, M. agilis; the swamp wallaby, Wallabia bicolor; and the red-necked pademelon, Thylogale thetis) were investigated allometrically in relation to body mass. In general, the length of the small intestine changed in an area : volume (A:V) compensating manner, but the circumference showed negative allometry such that the overall change in surface areas, both ground and mucosal (including the contribution of villi), were isometric but also included the coefficient derived from 'Kleiber's Law' (0.75) in their 95 and 99% confidence limits, respectively. Villous height and width generally showed no significant correlations with body size, but villous density was lower in large individuals. The allometry coefficient for the length of the large intestine was generally near the A:V compensating value (0.5) in most intraspecific analyses but much higher in the interspecific analysis, suggesting that some factor other than body size might be important (possibly dietary fibre). Caecal length was significantly correlated with body size only in two largest species (M. rufus and M. giganteus) and the interspecific analysis gave a value near A:V compensation).

Distribution and abundance of kangaroos (Marsupialia: Macropodidae) at the time of European contact: South Australia.

1994 ◽  
Vol 17 (1) ◽  
pp. 73
Author(s):  
R.D. Barker ◽  
G. Caughley
Keyword(s):  
South Australia ◽  
The State ◽  
Historical Records ◽  
Apparent Increase ◽  
European Contact ◽  
Red Kangaroo ◽  
Grey Kangaroo ◽  
Historical Distribution ◽  
Aboriginal Languages

Historical records, and the names of animals within Aboriginal languages, were analysed to compare the distribution and density of kangaroos at European contact with those of today. We gave up this attempt for the Eastern Grey Kangaroo, Macropus giganteus, presently restricted to the extreme south-east of the state, because it was never differentiated historically from the Southern Grey Kangaroo, M. fuliginosus, which occurs right across the southern portion of the state. The historical distribution of the latter species, and of the Red Kangaroo, M. rufus, seems to have been similar to their distribution today. Past densities are difficult to extract from historical records and are not sufficiently reliable to justify comparison with present densities. We note however an apparent increase in density of 'kangaroos' in the mid-1800s.

Coccidia in wild populations of the red kangaroo, Megaleia rufa (Desmarest), and the grey kangaroo, Macropus canguru (Müller)

Parasitology ◽  
1964 ◽  
Vol 54 (1) ◽  
pp. 105-115 ◽  
Author(s):  
R. Mykytowycz
Keyword(s):  
New Species ◽  
Wild Populations ◽  
Free Living ◽  
Red Kangaroo ◽  
Grey Kangaroo ◽  
Two New Species ◽  
Tibia Length ◽  
Clinical Cases

The incidence and prevalence of coccidia have been studied in populations of free-living red kangaroos, Megaleia rufa, and grey kangaroos, Macropus canguru, in four geographically distinct areas in Australia.Two new species of Eimeria—E. wilcanniensis and E. toganmainensis—are described from M. rufa, and five—E. cunnamullensis, E. gungahlinensis, E. purchasei, E. kogoni, and E. hestermani—from M. canguru.The incidence of coccidia ranged from 6 to 14% in populations of M. rufa and from 26 to 70% in M. canguru. The susceptibility of the animals to coccidia was analysed in relation to the tibia length. Red kangaroos with tibia approximately 360 mm. long and corresponding to an age of about 12 months were found to be most susceptible. No clinical cases of coccidiosis were seen in the field.Special thanks are due to the owners or managers of the properties on which the kangaroos were sampled; to members of the staff of the Regional Pastoral Laboratory ‘Gilruth Plains’ for their assistance in sampling, and to Messrs E. R. Hesterman, C. Kogon, and D. Purchase, who assisted in the field and the laboratory. Three species of Eimeria have been named after them in acknowledgement of their work. Messrs B. V. Fennessy and J. H. Calaby of this Division kindly read the manuscript.I wish to thank Dr G. B. Sharman for his permission to work with captive kangaroos in Canberra, and Mr E. Slater who took the photographs.

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