Morphologic features and development of granulomatous vasculitis in feline infectious peritonitis.

Feline infectious peritonitis (FIP) is a fatal, coronavirus (CoV)-induced systemic disease in cats, characterized by granulomas in organs and granulomatous vasculitis. This study describes the morphologic features of granulomatous vasculitis in FIP as well as its development in the course of monocyte-associated feline CoV (FCoV) viremia in five naturally infected Domestic Shorthair cats with FIP. Monocyte-associated FCoV viremia was demonstrated by immunohistology, RNA in situ hybridization, and electron micropscopy. Granulomatous phlebitis at different stages of development was observed. Vasculitic processes ranged from attachment and emigration of FCoV-infected monocytes to vascular/perivascular granulomatous infiltrates with destruction of the vascular basal lamina. Monocytes as well as perivascular macrophages were activated because they were strongly positive for CD18 and expressed cytokines (tumor necrosis factor-alpha and interleukin-1beta) and matrix metalloproteinase-9. In addition, general activation of endothelial cells, represented by major histocompatibility complex II upregulation, was observed in all cases. These results confirm FIP as a monocyte-triggered systemic disease and demonstrate the central role of activated monocytes in FIP vasculitis.

Fatal gastrointestinal infection with 'Flexispira rappini'-like organisms in a cat.

A 4-month-old male British Blue cat with catarrhal to haemorrhagic enteritis showed massive colonization of the stomach, small intestine and caecum with spiral-shaped bacilli. In the stomach, organisms were located in foveolae and gland lumina and within unaltered and degenerate epithelial cells. Inflammatory infiltration was moderate and T cell dominated. In the intestine, bacilli were found in the gut lumen, berween villi, in crypt lumina and within epithelial cells. Degeneration of crypt epithelial cells as well as crypt dilation and moderate to massive macrophage-dominated infiltration of the mucosa and submucosa were observed. Immunohistochemically, bacilli were positive with an antibody against Helicobacter. Ultrastructurally, the organisms strongly resembled 'Flexispira rappini', a spiral-shaped Helicobacter species known as a normal intestinal colonizer in dogs and mice.

Incidence and morphology of endometrial angiopathies in mares in relationship to age and parity.

The morphology of endometrial blood vessels in uterine biopsy specimens from mares of varying age and reproductive status was examined by light (n = 117) and electron microscopy (n = 13), and additionally after elastase digestion (n = 86). Inflammatory vascular alterations were observed in 20.5% of the specimens. Smaller and larger arterial and venous vessels demonstrated mild to severe degenerative lesions. Unaltered vessels were detected only in maiden mares. Vessels in older maiden mares were frequently affected by angiosclerotic changes, characterized by mild to moderate perivascular and intimal sclerosis. The incidence and severity of angiosis increased with the number of previous pregnancies and with advancing age. Changes in multiparous mares resembled the so-called "pregnancy-sclerosis" of other species, with fraying and disruption of the membrana elastica interna, medial atrophy intimal, medial and adventitial elastosis and fibrosis, and calcification processes within the media. Ultrastructural studies revealed characteristic arterial changes in post-parturient mares, namely, disruption of the membrana elastica interna, as well as activated smooth muscle cells and immature elastic fibres within the intima and inner media, suggesting a pregnancy-induced pathogenesis. Haemodynamic and hormonal alterations during pregnancy and the puerperium possibly induce active vascular remodelling. Cycles of vascular growth during pregnancy and subsequent involution post partum are thought to result in progressive degenerative vascular changes, as seen in multiparous mares. Ageing processes, chronic inflammation and short foaling intervals have to be considered as additional pathogenetic factors. Furthermore, severe angiosis was frequently combined with phlebectasia and lymphangiectasia. This may indicate a reduced ability of the vessels to adapt to the varying demands of uterine circulation, with a decrease of uterine perfusion and lymph drainage. Angiosis in older, multiparous mares might therefore be intimately related to infertility.

Hepatic and renal ultrastructural lesions in experimental Clostridium perfringens type A enterotoxemia in chickens.

Hepatic and renal electron microscopic investigations were carried out in 10 chickens that had experimental intraduodenal infection with Clostridium perfringens Type A. Fourteen days postinfection, there were ultrastructural changes in hepatocytes and renal tubular epithelial cells; these included mitochondrial lesions (swelling, cristolysis, rarefication of the matrix, myelin figures), glycogen loss, and capillary endothelial cell swelling in both organs, as well as thickening of glomerular basement membrane. The findings are discussed with particular reference to the pathogenesis of Clostridium perfringens Type A enterotoxemia.

[The morphology and function of the liver in high performance cows 2 weeks post partum]. / Untersuchungen zur Morphologie und Funktion der Leber von Hochleistungskühen 2 Wochen post partum.

Liver biopsies taken 2 weeks post partum from 213 high-yielding cows (6000-8000 kg FCM per 305 days lactation) were investigated biochemically to liver lipid content (GL) and histologically to degree of lipid infiltration (GdL). Additional in 27 cases electron microscopic studies to liver cell morphology and clinico-chemical investigations (beta-OH-butyrate and acetate in blood; quantity of bilirubin, albumin, protein, activity of ASAT and GLDH in blood plasma) were carried out. 22.5% of liver biopsies were histologically free of lipid infiltration (GL: 2.34%; GdL: 0). 77.5% of liver biopsies showed different lipid quantities (GL: 5.1-24%; GdL: 0.3-5.7%). 27 cases additionally investigated electron-microscopically and clinico-chemically can be summarized in 3 groups (with regard to lipid contents): 1. < 5%, n = 7; 2.5-10%, n = 10; 3. 10-24%, n = 10. Electron microscopic changes concerned occasional nucleus alterations, frequent RER dilation, mitochondria condensation or swelling, occurrence of secondary lysosomes and glycogen decrease. RER dilation and mitochondria swelling showed a statistical relation to liver lipid content. Ketone body (beta-OH-butyrate, acetate) and bilirubin concentration climbed with increasing quantity of liver lipid. Activities of GLDH and ASAT failed any dependence to lipid quantity. The results are discussed under the aspect of pathogenesis and dignity of fatty degeneration of the liver post partum.

[The pathology and pathogenesis of experimental Mycoplasma hyorhinis infection of piglets with and without thermomotor stress. 2. Electron microscopic study results]. / Untersuchungen zur Pathologie und Pathogenese der experimentellen Mycoplasma hyorhinis-Infektion der Ferkel ohne und mit thermomotorischer Belastung. 2. Mitteilung: Elektronenmikroskopische Untersuchungsergebnisse.

Electron microscopic investigations on the respiratory tract of piglets with and without Mycoplasma hyorhinis infection (10th day of life) partly combined with swim stress (15 degrees C water temperature) (n = 20/20) yielded the following results: colonization of Mycoplasma hyorhinis in the ciliary zone of trachea and bronchi in 15 out of 40 piglets (37.5%); the evidence rate of Mycoplasma hyorhinis in pneumonic lungs (8 out of 12 = 66.7%) was significantly higher than in nonpneumonic lungs (7 out of 28 = 25.0%) and highest in experimentally infected piglets with swim stress (9 out of 16 = 56.2%). Ultrastructural lesions: loss of cilia; bleb-formation; hydropic degeneration and desquamation of ciliary cells; the occurrence of cilia-free and immature epithelial cells; alveolar collapse; microatelectasis; oedematous swelling of pneumocyte I; accumulation of surfactant in the alveoli; hyperplasia of pneumocyte II; exudation of mononuclear macrophages and neutrophils with numerous digestion vacuoles; several lymphocytes and plasma cells, only a little lymphohistiocytic interstitial and peribronchial infiltration. Phagocytized mycoplasmas were found within the resorption vacuoles of neutrophils in the tracheobronchial area, for this once in alveoli, not (more) against in alveolar macrophages. The results were discussed with regard to etiology and pathogenicity of enzootic pneumonia in pigs.

[Comparative light and electron microscopic studies of spermiogenesis in the male rabbit, boar and ram]. / Vergleichende licht- und elektroenmikroskopische Untersuchengen zum Ablauf der Spermiogenese beim Rammler (Kaninchen), Eber und Schafbock.

Light-microscopic studies were conducted into testicular swabs of male rabbit, boar, and ram and compared to data obtained from electron-microscopic studies into ultramicrotomised specimens of male rabbit and ram, with the view to elucidating the courses of spermiogenesis. Intraspermatic spermatid transformation was found to be largely the same in these species. Spermiogenesis, so far subdivided by four phases, is proposed for subdivision into five phases, Golgi, hood, acrosomal, cuff, and maturation, to incorporate into overall spermatogenesis the process of spermatic maturation, to incorporate into overall spermatogenesis the process of spermatic maturation which takes place in the epididymal ductuli. Plasma transudation, in concomitance with spermiogenesis, is attached to the various phases. Evidence has already been produced to existence of four or five. They were found to be of great relevance to the formation of spermia normal in terms of morphology and physiology. Testicular swabs are easier to prepare than microtomised specimens and, therefore, should be given preference for light-microscopic studies into spermiogenesis. Besides, their informative capability is high, as may be seen from the above results.

[Light and electron microscopic studies of cardiac pathomorphology in swine due to transport fatigue (porcine stress syndrome)]. / Lichtmikroskopische und elektronenmikroskopische Untersuchungen zur Pathomorphologie des Herzens bei Schweinen mit Transportermüdung (porcine stress syndrome).

Optical light microscopy and electron microscopy were used to examine 22 or eleven hearts of pigs which had been killed in a state of extreme fatigue due to transport. Samples were taken and fixed within five minutes from stunning. The following histological findings were obtained: Glycogen depletion of the myocardiac fibres was conspicuous in most cases, usually with high glycogen levels in Purkinje's fibres. Discrete, easily overseeable changes of scattered fibres or groups of fibres in the form of granular or hyaline degeneration were recorded from 73 per cent of the cases, with degeneration having been granular in 59 per cent and hyaline in 54 per cent. Fibre oedema was rare and recordable from only two cases. Changing prestatic hyperaemia was established from terminal vessels, while no visible alterations were found in capillary endothelia by optical light microscopy. The following results were gained by means of electron microscopy: Glycogen depletion was accompanied by differently pronounced expansion of parts of both the sarcoplasmic reticulum and T-system. Unchanged mitochondria were detected together with incipient mitochondrial swelling to different degrees, accompanied by cristolysis, in certain rare instances, as well as by partial or total homogenisation of interior mitochondrial structures, in more frequent cases. Z-strips were widened in eight cases. Limited decomposition of fibrils in some myocardiac cells was observed in samples of three animals. There were signs of usually moderate interfibrillar and perinuclear oedema and of predominantly inconspicuous capillary endothelia. Most of the changes were reversible and less strongly pronounced, and they were likely to suggest the presence of disorders in energy metabolism and impairment of stimulus conduction. They are interpreted as secondary myocardiopathy, caused by haemodynamic-hypoxic factors, following primary insufficiency of peripheral circulation.

[Pathomorphological changes in the skeletal muscles (musculus longissimus dorsi) in swine following varied transport stresses and resting periods prior to slaughter]. / Pathomorphologische Veränderungen an der Skelettmuskulatur (Musculus longissimus dorsi) von Schweinen nach unterschiedlichen Transportbelastungen und Ausruhezeiten vor der Schlachtung.

The M. longissimus dorsi of 171 pigs were histologically examined for pathological signs. Acute hyaline-plaque degenerations and necrosis (hsD/N) in various degrees of manifestation were recorded from 42.7 and hyaline transverse ligaments (hQb) from 22.8 per cent of all cases. The occurrence of hsD/N following container transport was lower with significance (33.3 per cent) than that following lorry transport (50.5 per cent). The form of transport failed to have any substantive effect on the occurrence of hQb, the figures being 20.5 per cent for container and 24.7 per cent for lorry. Short resting periods, between 0.5 and 1.2 hours, were followed with significantly higher occurrence of hsD/N, as compared to longer resting periods, between five and eight or 23 hours. These pathological findings were not further reduced by extending the resting period from something between five and eight to 20 hours. The pathological hsD/N and hQb findings were recordable from both PSE pork (hsD/N = 51.4 per cent, hQb = 25.7 per cent) and from pork without any quality shortcomings (hsD/N = 39.7 per cent, hQb = 22.1 per cent), but the number of hsD/N cases in the context of PSE pork tended to be higher than that in high-quality pork. No sex dependence was established. The results are discussed under the aspect of aetiopathogenesis of stress-borne myopathy.