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Biomedical subjects

H Augsburger

Publications and source records attributed to H Augsburger.

10 recordsLinked to original sources

Investigation of the female canine urethral vascular plexus using light and scanning electron microscopy: a contributing factor to urinary continence.

The vascular system of the female canine urethra was investigated by means of serial histological sections, vascular corrosion casts and scanning electron microscopy. The urethral vascular plexus, located in the proprial connective tissue between the epithelium and the smooth musculature, consisted of sinusoids. It could be divided distally into two parts defined by a constriction in the transitory region between the third and fourth urethral quarters. The proximal segment of the plexus was composed of interconnected longitudinal tubes, whereas the distal part assumed a more net-like form and was continuous with the vestibular plexus. Small arteries usually ran alongside the sinusoidal vessels for a considerable distance before emptying either directly or through branches into the plexus. This vascular arrangement establishes the vascular plexus as a structure similar to an erectile tissue with an arterial inflow, thereby emphasizing the importance of the plexus as a major contributory component guaranteeing urinary continence.

Animals↗

[Muscular dystrophy in a cat].

A case of muscular dystrophy in a 1-year-old male castrated Domestic Shorthair cat is presented. The most striking clinical features were regurgitation, a stiff gait, an increased muscle tone and exercise intolerance. Serum biochemistry panels showed a marked increase in the muscle specific enzyme creatine kinase, and moderately elevated levels of LDH, AST and ALT. Spontaneous electrical activity of skeletal muscles in the form of "bizarre high frequency discharges" and "myotonia-like repetitive discharges" were registered. Gross pathology revealed a marked hypertrophy of the skeletal muscles. The main histopathological changes were myofiber necrosis and calcification, variation in fiber size, hypertrophied muscle fibers of type I and type II and fiber splitting. Indirect immunofluorescence showed dystrophin deficiency. Feline muscular dystrophy resembles the X-linked human Duchenne muscular dystrophy (DMD). Besides the X-linked muscular dystrophy in the mouse and Golden Retriever the feline muscular dystrophy could represent another valuable animal model for the study of DMD.

Alanine Transaminase↗

[Involution and redevelopment of the mammary gland in goats. Histological-histochemical studies after a lactation time of 8-10 months].

7 chamois-coloured mountain goats were used to investigate histologically and histochemically the processes of involution and redevelopment of the mammary gland after a lactation period of 8 to 10 months. Tissue specimens were obtained by incision biopsy at drying-off two months prepartum and afterwards in intervals of 8-16 days up to parturition. The findings of this investigation were compared with results of two former investigations, in which involution and proliferation of the gland were studied separately, thus precluding an overlapping of the two processes. At drying-off, after an 8 to 10 month-lactation, sections indicative of active lactation occurred concomitantly with sections at various stages of involution, as well as early stages of redeveloping alveoli. At 16 days post drying-off, the sections indicating lactation at first examination were in a stage of maximum involution and transformation. Thus, the time required for involution was reduced by half compared to drying-off at peak lactation. At 32 days post drying-off, stages of proliferation predominated with only a few involuting glands. Specimens obtained thereafter contained only redeveloping glands. The histological and histochemical differentiation between areas of involution and those of proliferation may present difficulties during the mid-portion of the dry period. There appears to be an association between the length of the time interval from drying-off to parturition and the rate of tissue transformation in the caprine mammary gland; the rate is increased when the duration of the dry period is reduced.

Animals↗

Ultrastructural alterations in mammalian parathyroid glands induced by fixation.

The influence of fixation methods, buffers and ions on the ultrastructure of parathyroid cells was studied in dogs, cats, rats and mice. Parathyroids fixed by immersion showed 3 chief cell variants referred to as cells in active, intermediate and resting stages, multinucleated syncytial cells, atrophic cells and, only in 1 feline parathyroid, a few oxyphil cells. Parathyroid glands fixed by perfusion, however, consisted only of 1 cell type. Satisfactory preservation was achieved by perfusion with 2.5% glutaraldehyde in 0.1 M Na cacodylate containing 0.25 mM CaCl2 and 0.5 mM MgCl2, and postfixation with 1% OsO4 in 0.1 M s-collidine containing 0.5 mM CaCl2 and 1.0 mM MgCl2. Good preservation was also obtained using Na phosphate during prefixation and postfixation. Other combinations of buffers led to shrinkage, dilation of rough endoplasmic reticulum cisternae, disruption of membranes or loss of matrix and secretory granules. The results demonstrate that the variants of parathyroid chief cells, multinucleated syncytial cells and atrophic cells arise during fixation.

Animals↗