Biomedical subjects

J T Soley

Publications and source records attributed to J T Soley.

26 records · Page 2Linked to original sources

PubMed1994

Centriole development and formation of the flagellum during spermiogenesis in the ostrich (Struthio camelus).

The formation and development of the ostrich sperm tail follows the general pattern described for vertebrate sperm but differs in a number of important aspects when compared with other nonpasserine birds. Midpiece formation is characterised by the development of a long (3 microns) distal centriole which determines the length of the midpiece. The distal centriole surrounds a pair of microtubules embedded in a core of dense material. A prominent annulus, which remains stationary during spermiogenesis, demarcates the midpiece/principal piece junction. Ostrich spermatids display similar cytoplasmic densities (chromatoid body, annulus, granulated bodies, reticulated bodies and mitochondria-associated material) to those observed in mammalian spermatids. In the ostrich, however, the chromatoid body is not observed to contribute towards the formation of the annulus while the granulated bodies develop within radial bodies and not in their vicinity as in mammals. Whereas in mammals granulated bodies have been linked to coarse fibre formation they appear to perform a limited function in ostrich spermatids as only rudimentary outer dense fibres are formed. No specific role is attributed to the reticulated bodies but the mitochondria associated material is implicated in the formation of intermitochondrial cement. The formation of the principal piece and end piece of the flagellum is modelled on that of the mammalian spermatid. The axoneme emerges from the free end of the distal centriole and the ribs and longitudinal columns are progressively formed from a layer of amorphous material situated between the axoneme and the plasmalemma. The end piece is formed by an extension of the principal piece consisting of axonemal microtubules closely surrounded by the plasmalemma. The formation of a long distal centriole containing a central pair of microtubules, the stationary nature of the annulus and the presence of a ribbed fibrous sheath around the principal piece distinguishes spermiogenesis in the ostrich and rhea from that of other nonpasserine birds. These features appear to be characteristic of more primitive avian families.

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PubMed1993

Ultrastructure of ostrich (Struthio camelus) spermatozoa: I. Transmission electron microscopy.

The origin and relationships of the tinamous (Order Tinamiformes), ratites (Order Struthioniformes, Rheiformes, Casuariiformes, Apterygiformes) and birds of the order Galliformes and Anseriformes is the subject of much debate and it has been suggested that the ultrastructural analysis of a wide variety of avian sperm may provide information relevant to this problem. This paper describes the fine structure of ostrich sperm and compares the results with published information for other non-passerine birds. Ostrich sperm display a short, conical acrosome which covers the tapered tip of the long, cylindrical nucleus. A nuclear invagination housing an acrosomal rod extends deep within the karyoplasm. A centriolar complex is situated beneath the head and consists of a short proximal centriole and a long (3.0 microns) distal centriole which extends the complete length of the midpiece. The central cavity of the distal centriole contains a pair of microtubules embedded in a rod of electron-dense material. The midpiece is surrounded by a mitochondrial sheath. Concentrations of fine granular material are present between the mitochondria. The principal-piece of the tail is demarcated from the midpiece by a distinct annulus and characterized by a ribbed fibrous sheath enclosing a typical axoneme. Rudimentary coarse fibres are observed between the fibrous sheath and the doublet microtubules of the axoneme in the proximal region of the principal-piece. The end-piece contains a disorganized collection of axonemal microtubules. Ostrich sperm differ in a number of respects from that of other non-passerine birds (the absence of a typical perforatorium; the presence of a ribbed fibrous sheath; a deep nuclear invagination; the structure and length of the distal centriole) but show a close similarity to sperm of the rhea and crested tinamou, both representatives of primitive avian families. These observations add further support to the theory that the ratites and tinamous constitute a monophyletic group. The evidence presented also reinforces the hypothesis that the ratites were the first group to branch off from the main avian stem, to be followed by the Galliformes & Anseriformes. Although it was impossible to determine whether the sperm of the tinamou are more "primitive" than those of the ostrich or rhea, it is clear that ostrich and rhea sperm are closely allied and distinct from tinamou sperm.

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PubMed1992

Specialized veins in the submucosa of the equine ileocecal junction.

Spirally arranged bundles of sub-endothelial smooth muscle enfold the small to medium-sized submucosal veins in the equine ileocecal junction. The muscle bundles, accompanied by the endothelial lining, bulge into the lumen of the vessels, partly occluding the latter. Transmission electron microscopy of the muscle cells reveals features consistent with vascular smooth muscle ultrastructure. It is proposed that the throttling effect of the muscle bundles causes engorgement of the submucosal venous plexus, which then assists in the closing of the ileocecal orifice.

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PubMed1991

Encephalitozoon infection in a still-born foal.

A stud Clydesdale foal was still-born near full term. Macroscopic examination revealed a normal placenta, pulmonary atelectasis and faint white mottling of the kidneys. Microscopically there was severe lymphoplasmacytic interstitial nephritis. Numerous organisms resembling Encephalitozoon cuniculi were present in the affected kidneys. The organisms occurred in the areas of inflammation as well as in the renal glomeruli and intracellular cysts in the renal tubular epithelial cells and exhibited Gram positive staining. Ultrastructurally the organisms possessed a polar vacuole and a spiral filament typical of Microsporidia. The organisms were not detected in sections of the other organs examined.

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PubMed1990

Scanning electron and light microscopy of the mucosa of the equine ileocaecal junction.

The ileocaecal junction mucosal surface morphology of 5 horses and 1 donkey was examined using scanning electron microscopy and light microscopy. Based on differences in surface morphology, the junction could be divided into 4 distinct regions. The distal extremity of the ileum was characterized by the presence of typical finger-like villi followed by a narrow zone displaying short, stubby villi which gradually merged into a 3rd region representing the true transitional zone between the small and large intestine. In this region the villi fused, forming low ridges arranged in circular, semi-circular or S-shaped patterns. Many of the fused villi were indented at the tips giving these structures a doughnut-like appearance. The caecal portion of the ileocaecal junction formed the 4th region and was characterized by the absence of villi and the occurrence of regularly spaced crypt openings each surrounded by a slightly raised circular mound.

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PubMed1986

Ultrastructural changes in the acrosome of human sperm during freezing and thawing: a pilot trial.

As a pilot trial, a semen sample was diluted with a glucose-citrate-egg yolk diluent and frozen in 0.5 ml PVC paillettes in liquid nitrogen vapor. Motility and acrosome integrity of the sample were evaluated before and after freezing, and longevity was monitored up to 6 h postthaw. Acrosome integrity was assessed by comparing Spermac-stained thin smears with TEM. Acrosome damage was found to be progressive, and four main types of acrosome state were identified and illustrated.

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PubMed1985

Infertility in a Maltese poodle as a result of a sperm midpiece defect.

A 2 1/2-year-old Maltese poodle was examined for breeding soundness following a series of unsuccessful matings to fertile bitches. He was found to have only 8% normal sperm in his ejaculate when Spermac-stained smears were examined under the light microscope. The defect most frequently encountered involved the midpiece attachment, and the various manifestations of disintegration found in this region are described and illustrated. Transmission and scanning electron microscopy confirmed light microscopical findings.

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PubMed1983

Intoxication of cattle on kikuyu grass following army worm (Spodoptera exempta) invasion.

Clinical features and pathological and mycological findings in a field outbreak of intoxication in dairy cattle grazing kikuyu grass are reported. The outbreak followed invasion of the grass by the army worm (Spodoptera exempta). Clinical signs included drooling of saliva, depression, apparent inco-ordination, sunken eyes, ruminal distension and atony, recumbency, moderate diarrhoea and "sham drinking". Seventy-seven cows (64%) were clinically affected over a period of 12 days. Of these, 37 died. Necropsies performed on 4 affected cattle revealed necrosis of the epithelium of the forestomach, which was consistently more severe in the omasum. Light microscopy showed extensive necrosis of the epithelium of the forestomach with associated fibrinopurulent inflammation. The stratum spinosum and s. granulosum were selectively involved, but the s. basale was generally preserved. Electron microscopical examination of ruminal and omasal epithelium from 2 of these cattle revealed cytopathological features in the s. spinosum and s. granulosum which were consistent with stages in an acute, anoxic type of injury. Mycological examination of the pastures revealed sparse growth of a mixed fungal population, which included Myrothecium verrucaria. There was no evidence of heavy fungal infestation. Previous evidence that M. verrucaria, or other fungi, may be involved in the aetiology of kikuyu grass poisoning of cattle in New Zealand is addressed. It appears improbable that any of the fungi isolated in this investigation could have played an important role in the aetiology of this outbreak.

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