27 research outputs found
Scanning electron microscopy of the mucosal surface of the forestomachs and abomasa of grey, white and black Karakul lambs
Homozygous grey and white Karakul lambs suffer from a lethal genetic factor causing death after weaning. Previous studies revealed large milk-filled rumens in the grey and white lambs which was attributed to a significant decrease in the number of myenteric ganglia and neurons in the rumen wall.
This study was undertaken to determine the effect of milk on the epithelial lining of the forestomachs of affected grey and white lambs. In the forestomachs of the black lambs the polygonal epithelial cells were tightly packed, seemed to overlie one another and cytoplasmic projections occurred on the cell surfaces. In the grey and white lambs the epithelium had an eroded appearance due to sloughing of the surface cells and the cytoplasmic projections were lower and had a weathered appearance compared to the black lambs. No obvious differences could be detected in the abomasa of grey, white and black lambs. It is concluded that the milk in the forestomachs of the grey and white lambs is responsible for the epithelial changes.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Neuropeptides in the myenteric ganglia and nerve fibres of the forestomach and abomasum of grey, white and black Karakul lambs
Previous studies indicated large, thin-walled, milk-filled rumens in lethal grey and white Karakul lambs.
There was also a significant decrease in the number and size of the myenteric plexuses and the number
of ganglion cells in these lambs. The purpose of this study was to determine whether the myenteric
ganglia of the affected lambs are functional, by testing for the presence of vaso-active intestinal peptide,
somatostatin, neurotensin, neuropeptide Y, met-enkephalin, calcitonin gene-related peptide and substance
P in the myenteric ganglia and nerve fibres in the forestomach and abomasum of grey, white and black
Karakul lambs.
Four 1-cm² samples were taken from analogous areas of the wall of the rumen, reticulum, omasum and
abomasum of five grey, five white and five black newborn Karakul lambs. They were pinned to wax
squares, fixed for 18 h in Zamboni's fixative, dehydrated and rehydrated through graded alcohols and
stored in phosphate-buffered saline. The outer longitudinal muscle layer of each sample of the rumen,
reticulum, omasum and abomasum was separated from the rest of the tissue layers, stained for each
of the seven neuropeptides by employment of the immunofluorescence technique, and studied with a
Leitz Orthoplan fluorescent microscope.
All the material studied tested positive for all the neuropeptides.
It is concluded that all the peptides tested for were present in all the lambs and that the myenteric ganglia
are therefore functional in the lethal lambs.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Ultrastructure of the myenteric ganglia in the rumen, reticulum, omasum and abomasum of grey, white and black Karakul lambs
Homozygous grey and white Karakul lambs die after they have reached weaning age. This is due to a
lethal gene causing digestive disturbances. Previous studies revealed that grey and white lambs have
large, milk-filled rumens; the phenomenon was attributed to a significant decrease in the number of myenteric
ganglia and neurons in the rumen wall. This study was undertaken to determine whether any morphological
differences exist in the ultrastructure of the myenteric ganglia in the forestomach and abomasum
of grey, white and black Karakul lambs. Samples of the forestomach and abomasum of grey, white
and black Karakul lambs were prepared routinely for electron microscopy and studied with a Phillips electron
microscope. No morphological differences could be detected in the structure of the components of
the myenteric ganglia in the forestomachs and abomasums of grey, white and black Karakul lambs. It was
therefore concluded that the lethal gene in grey and white Karakul lambs results in a paucity of the myenteric
ganglia, but does not affect the ultrastructure of these structures.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Ultrastructure of the epithelium of the rumen, reticulum and omasum of grey, white and black Karakul lambs
Mortalities due to digestive disturbances occur in homozygous grey and white lambs after they have
reached weaning age. Milk-filled, distended rumens, due to malfunctioning of the oesophageal groove,
are found 24 h after birth. Scanning electron microscopical studies revealed that milk caused sloughing
of the luminal cells in the forestomachs of the affected lambs, while no sloughing of cells was apparent
in control black lambs. The purpose of this study was to compare the ultrastructure of the forestomach
mucosa of grey, white and black Karakul lambs; to determine whether the sloughing of luminal cells was
evident in sections; and, if possible, to find a reason for the desquamation of the cells. Samples of the
forestomach of grey, white and black Karakul lambs were prepared routinely for electron microscopy and
studied with a Phillips electron microscope. In all the lambs the mucosa of the forestomach was a
stratified squamous epithelium consisting of a stratum basale, stratum spinosum and stratum corneum.
In the grey and white lambs the luminal cells of the stratum corneum were electron dense, non-nucleated
and vacuolated. Sloughing of luminal cells was observed. In the black lambs no sloughing of cells was
evident and the luminal cells were moderately electron-dense, nucleated elements. Desquamation of the
luminal cells in the affected lambs revealed the underlying layer with its exposed desmosomal attachment
sites. This explained the differences in the appearance of the luminal cells in the three groups of lambs
as revealed by the scanning electron microscope.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Morphological changes associated with the development of the rumino-reticulum in growing lambs fed different rations
Morphological changes associated with rumino-reticular development was
compared in two groups of SA Mutton Merino lambs ( n=12) fed different
diets at 3-5 weeks, 17-19 weeks and 31-33 weeks of age. Diet groups were
identified as MMH or MHH according to the sequence at which the
full-milk replacement (M) or hay (H) diet were fed to the lambs over the
three study phases (phases I, II and III) preceding each age period.
Prominent differences in the morphology (size and volume) and function
(pH, proteolytic activity and microbial population) of the
rumino-reticulum were observed in indicator lambs ( n=2) killed at every
age period and also between milk-fed and hay-fed lambs. The size of the
rumino-reticulum was rudimentary at 3-5 weeks of age and remained
underdeveloped in lambs at 17-19 weeks of age which had received a
full-milk replacement diet during phase II. One lamb, slaughtered at 3
weeks of age, showed a large distended rumen with severe sloughing of
the surface cells of the stratum corneum. The size of the
rumino-reticulum increased in size (2 X) in lambs which were fed hay
relative to the milk-fed lambs during phase II and reached adult
proportions in all lambs at 31-33 weeks of age. Ultrastructural
examination showed that rumen papillae were more developed in lambs fed
hay during phase II when compared to those of milk-fed lambs. Rumen
papillae were best developed in phase III lambs.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Faculty of Veterinary Science, University of Pretoriamn201
Kupffer cell structure in the juvenile Nile crocodile, Crocodylus niloticus
The morphology of Kupffer cells was
examined in the liver of the juvenile Nile crocodile
using light microscopy and transmission electron
microscopy. Pleomorphic Kupffer cells were located in
the sinusoids, in the space of Disse, in the hepatic
parenchyma and often connected adjacent sinusoids.
The cell surfaces were irregular due to the presence of
filopodia and lamelliapodia with phagocytosis of white
blood cells, red blood cells and thrombocytes being evident.
The cells were in close contact with endothelial
cells and pit cells in the sinusoidal lumen and with
stellate cells in the space of Disse. The cytoplasm contained
large phagosomes comprising a combination of
ceroid pigment, melanosomes and siderosomes. The
nuclei were often indented and eccentrically placed due
to the presence of the phagosomes. Conspicuous clusters
of membrane-bound tubular organelles with a filamentous
or crystalline interior were observed in the
cytoplasm. The clusters were sometimes separated into
smaller groups around phagosomes. A clear zone
existed between the limiting membrane and the interior
of these tubular organelles with the electron-dense
interior profiles being, respectively, circular, angular or
divided. The tubular organelles have not previously
been described in Kupffer cells and possibly represent
lysosomes with specialized functions. Mitochondria,
microtubules, Golgi profiles, granular and smooth endoplasmic
reticulum, and a few cytoplasmic lipid droplets
were also present. The presence of the tubular organelles
and the occurrence of the Kupffer cells in different
locations in the liver of the juvenile Nile crocodile are
indicative of particularly active and mobile cells.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-4687hb201
A comparative study of the thickness of the tunica muscularis in the forestomach and abomasum of grey, white and black Karakul lambs
Homozygous grey Karakul lambs are born with a lethal genetic factor responsible for death at weaning age. When put on a high roughage diet under field conditions they develop distended, thinwalled rumens and sand impacted abomasa. Homozygous white Karakul lambs have a similar factor but survive for a longer period. Black Karakul lambs are not affected. The present study was undertaken to compare by image analysis the thickness of the tunica muscularis of the forestomach and abomasum of 24-hour old grey, white and black Karakul lambs. One square centimetre samples were taken from equivalent areas in each case of the rumen, reticulum, omasum and abomasum of 38 embalmed
Karakul lambs. Haematoxylin and eosin stained histological sections of each sample were studied with a Vids 2 Image Analyzer and the thickness of the circular and longitudinal muscle layers was measured.
An analysis of variance indicated a significant difference between the groups in the thickness of the tunica muscularis of the rumen, reticulum and abomasum; the grey group displaying the thinnest and the black group the thickest. The omasa were not affected. The study indicates a reduction in thickness of the tunica muscularis of the homozygous grey and white lambs when compared to normal black lambs.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
A comparative histological study of the number and size of the myenteric ganglia and neurones in the fore-stomach and abomasum of grey, white and black Karakul lambs
Homozygous grey Karakul lambs are born with a lethal genetic factor responsible for death at
weaning age. When put in a high roughage diet under field conditions they develop distended, thin-walled
rumens and sand impacted abomasa. Homozygous white Karakul lambs have a similar factor
but survive for a longer period. Black Karakul lambs are not affected. The present study was undertaken
to compare by image analysis the number and size of the myenteric ganglia, and the number of
myenteric neurones in the walls of the fore-stomach and abomasum of 24-h-old grey, white and black
Karakul lambs. One square centimetre samples were taken from analogous areas of the rumen, reticulum,
omasum and abomasum of 38 embalmed Karakul lambs. Haematoxylin and eosin stained histological
sections of each sample were studied with a Vids 2 Image Analyzer. One way analysis of
variance indicated a significant difference between the groups regarding the number and size of the
myenteric ganglia and in the number of myenteric neurones in the reticulum, rumen and abomasum.
The number and size of the ganglia and the number of neurones was greatest in the black lambs and
decreased progressively in the white and grey lambs. The omasum was not affected. It is suggested
that the paucity of myenteric ganglia and neurones in the regions examined is instrumental in causing
the lethal condition described above.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Medical University of Southern Africamn201
Histomorphometrical and ultrastructural study of the effects of carbendazim on the magnum of the Japanese quail (Coturnix coturnix japonica)
The study investigated the effect of various doses of carbendazim on the morphology of the
magnum of the Japanese quail. No morphological changes were observed in the magnum
in birds treated with carbendazim at doses of 25 mg/kg and 100 mg/kg bodyweight. A
carbendazim dose of 400 mg/kg bodyweight was the lowest dose which caused morphological
changes in the magnum. Histologically, carbendazim caused pyknosis and glandular atrophy
in the magnum mucosa. Carbendazim also caused significant decreases in the height of
the mucosal folds, epithelial height, glandular width and glandular luminal diameter at
400 mg/kg and 800 mg/kg (p < 0.05). At ultrastructural level, dose-dependent deciliation
was observed. Pyknotic nuclei, dilated cisternae of rough endoplasmic reticulum, swollen
mitochondria, numerous vacuoles and lysosomes in the luminal and glandular epithelia were
identified. The observed degenerative changes could be due to cytoskeletal disruption caused
by carbendazim toxicity. Degeneration of the luminal and glandular cells in the magnum pose a
potential threat to the egg production and reproduction of exposed birds.http://www.ojvr.orgam2013ab201
Morphology of the female reproductive organs of the African lion (Panthera leo)
The topography and splanchnology of the reproductive organs of the African lioness were studied and described in situ and after removal. The kidneys were located far caudally in relation to the thirteenth ribs. The suspensory ligament was very well developed, originated in a fan-like manner from the dorsolateral abdominal wall lateral to the kidney and extended up to a few centimetres cranial to the kidney. The proper ligament of the ovary as well as the round ligament was well developed. The round ligament inserted on the medial femoral fascia. The left ovary was bigger than the right. The ovarian bursa had a short mesosalpinx that did not cover any part of the ovary and the fimbriae extended along the entire length. The urethral tuberculum as well as the urethral crest were well developed. The left uterine horn was longer than the right. The uterine tube was found to open directly into the tip of the uterine horn and not onto a papilla. The reproductive organs of the lioness resembled those of the domestic cat and dog but with some major differences.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1463-6395hb201