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Biomedical subjects

F Guarda

Publications and source records attributed to F Guarda.

At least 19 recordsLinked to original sources
PubMed2006

Haemorrhagic bowel syndrome in dairy cattle: possible role of Clostridium perfringens type A in the disease complex.

A survey based on clinical, pathological and microbiological investigations was performed on 11 Brown Swiss cattle affected with depression, anorexia, agalaxia, ruminal hypomotility, abdominal pain and melaena. In eight animals, macroscopical lesions consisted in haemorrhagic enteritis in the small intestine. Seven of eight isolates from tissue samples were identified as Clostridum perfringens type A, and four were identified as C. perfringens type A with the beta2 toxin gene. Based on these observations, animals were considered affected with haemorrhagic bowel syndrome.

Animals↗
PubMed2003

Maedi-visna virus detection in ovine third eyelids.

Maedi-visna is a systemic disease of sheep caused by a lentivirus, maedi-visna virus (MVV), which mainly affects the lungs and central nervous system but may also affect the mammary glands, joints and other tissues. The aim of the present study was to determine whether the third eyelid was affected in cases of systemic infection. Third eyelid and lung samples from sheep naturally infected with maedi were used. Total DNA was extracted from paraffin-wax-embedded tissues, and a nested polymerase chain reaction (PCR) was performed to amplify MVV proviral DNA. The samples were also tested by in-situ PCR and immunohistochemical methods specific for the detection of MVV proviral DNA and p25, respectively. All sheep showed moderate to severe chronic lymphoproliferative inflammation in the third eyelids. Products of the expected size were obtained by PCR from both lung and third eyelid tissue. In the nictitating membrane, MVV proviral DNA was detected in situ within macrophages, and glandular, ductal and surface epithelia. Immunohistochemistry demonstrated that the infection was productive. Taken together, these results indicate that the third eyelid may represent a target for natural MVV infection and may play a role in disease transmission.

Animals↗
PubMed2002

Virological and histological findings in goats infected by caprine herpesvirus 1.

Two adult goats seropositive to caprine herpesvirus 1 were treated with dexamethasone for 6 days to reactivate the virus. The goats shed the virus by the nasal and the vaginal routes. After necropsy, the histologic examinations on vaginal and nasal mucosa and ganglia showed general degenerative and flogistic lesions of the tissues. The findings confirm the respiratory and especially genital tropism of the virus.

Animals↗
PubMed2001

Clinical signs and diagnosis of scrapie in Italy: a comparative study in sheep and goats.

This article reports the clinical signs of scrapie occurring in sheep-goat flocks in Italy. The research, carried out on over 500 goats and 550 sheep, yielded an interesting clinical picture, especially of goat scrapie. The affected animals, aged between 2 and 8 years, showed neurological signs that could be classified into three categories: changes in mental status, abnormalities of movement and changes in sensation. Some general clinical signs were also observed. The clinical suspicion was confirmed by histopathological and biochemical investigations.

Animals↗
PubMed2001

Severe enteric disease in an animal shelter associated with dual infections by canine adenovirus type 1 and canine coronavirus.

An outbreak of dual infection in dogs with canine adenovirus type 1 (CAV-1) and canine coronavirus (CCV) infection is reported in an animal shelter that comprised approximately 200 adults stray dogs and 30 puppies. Twenty puppies died 7-8 days after the onset of the clinical signs (severe enteritis, leucopoenia, respiratory distress and dehydration). Both CAV-1 and CCV were isolated from tissue or swab samples. Antibodies to CCV and, at high levels, to CAV-1 also were detected in several puppies. The principal histological findings were atrophy of small intestinal villi, lymphoid depletion, hepatitis and bronchopneumonia. The persistence of CCV in the faeces, observed by the polymerase chain reaction assay, was longer than previously reported. Results demonstrated the serious consequences which may occur with dual infections by CAV-1 and CCV in assembled groups of dogs that are housed in poorly managed kennels with inadequate vaccination programmes.

Adenoviruses, Canine↗
PubMed2000

N-Linked glycans of proteins from mitral valves of normal pigs and pigs affected by endocardiosis.

Endocardiosis, a degenerative and dystrophic process affecting cardiac valves and described in many mammalian species, is characterized by the accumulation of glycosaminoglycans, in particular hyaluronic acid, in the extracellular matrix. The glycoprotein patterns of pig mitral valves in normal animals and animals affected by endocardiosis were investigated. A different N-linked glycosylation pattern of glycoproteins was detected in affected valves compared with normal ones. In either normal or pathological species, the detected N-linked glycans were of the complex type. However, in samples from affected valves, sialic acid showed a prevalence of the alpha2,6 linkage to the galactosyl residue, whereas in normal samples the most frequent linkage was of the alpha2,3 type. In normal valves, the majority of complex oligosaccharides presented two outer branches with different degrees of fucosylation and sialylation, whereas in pathological samples we noted an increased number of glycans having up to four outer branches.

Animals↗
PubMed1999

Pestivirus infection in small ruminants: virological and histopathological findings.

Pestivirus infection was detected in several flocks of sheep and goats located in the south of Italy by means of serological, virological and histopathological investigations. From four animals, two lambs and two kids, showing enteric symptoms which died during the first week of life, four pestivirus strains were isolated and typed as BVDV-like (three isolates) and "tipic" BDV strains (one isolate). The histopathological lesions consisted of areas of hypomyelination in the brain, and a slight depletion of thymic medullary lymphocytes associated with an increase in reticular cells.

Animals↗
PubMed1998

Pathology of mitral valve in regularly slaughtered pigs: an abattoir survey on the occurrence of myxoid degeneration (endocardiosis), fibrosis and valvulitis.

The aim of this study was to report the prevalence of degenerative and early inflammatory lesions and to discuss some histological aspects of normal and pathological mitral valve leaflets in healthy, normally slaughtered pigs. Mitral valves were collected from 112, 6 month-old, pigs reared under different conditions. Histological examination revealed the presence of myxoid degeneration in 29.5% of the valves with no significantly different prevalence according to rearing conditions; fibrosis was present in 12.5%; inflammation (non-vegetative valvulitis) occurred in 20 (17.9%) macroscopically normal valves. No vegetative endocarditis could be observed. A significantly higher degree of inflammation was observed in valves affected by myxoid degeneration (P < 0.05) and Anitschkow cells were prevalent in all the pathological valves (P < 0.01). Capillaries were observed in a wide majority of the valves (86.5%), but small arterioles were related to fibrotic thickening of the leaflets (P < 0.01). The following conclusions are discussed: (1) environmental factors seem not to influence the prevalence of endocardiosis; (2) inflammatory foci in myxoid valves are a reaction to both abnormal friction and products of degraded collagen and extracellular matrix; (3) the authors consider the presence of capillaries in pig valves a normal finding whereas proliferation of the vessels occurs under pathological conditions; (4) non vegetative valvulitis can be related to the presence of vessels in the valve and may have a role in both infectious endocarditis and fibrosis; (5) Anitschkow cells are normally observed in pig valves and are not specifically related to pathological lesions.

Abattoirs↗
PubMed1998

Direct detection of Mycobacterium tuberculosis complex and M. avium complex in tissue specimens from cattle through identification of specific rRNA sequences.

Mycobacterium Tuberculosis Direct test and Accuprobe M. avium Complex test, rely on recognition of specific rRNA sequences. The present investigation included sequentially a pre-evaluation study and a study on non-visible lesion tuberculin reactor cattle. As regards the first study, tests were performed on tissue samples from 14 reactors with tuberculous-like lesions and from as many lesion-free non-reactors, using culture findings as a reference. MTD and Accuprobe M. Avium Complex tests proved positive in 12 and 2 reactors respectively. Both tests proved negative in all non-reactors. Data consisted with culture findings. The aim of the second study was to verify the presence of mycobacteria in lymph node and tonsil homogenates from 32 non-visible lesion cattle. MTD and Accuprobe M. avium Complex test proved positive in 10 and 14 subjects respectively; no overlap was found. Our research demonstrates that low to minimal amounts of the main pathogenic mycobacteria can be reliably identified from cattle tissues by commercially available tests, which give simple, more rapid results than conventional techniques.

Animals↗
PubMed1995

[Examination of the brains of slaughtered cattle for the occurrence of BSE in Italy with attention to non-specific neuronal vacuoles].

In order to find out whether BSE exists in Italy 378 brains of normally slaughtered 2-10 years old cattle submitted from slaughterhouses all over the country were examined histologically. None showed the typical lesions of BSE. About 11.5% of the brains contained large vacuoles in the neurons of brain stem nuclei, in particular the red nucleus in the midbrain. They were considered non specific.

Abattoirs↗
PubMed1994

[Pathology of cardiac ventricular aneurysms in the horse].

The authors describe pathologic and histopathologic findings of three cardiac aneurysms in horses, two of which in the left ventricle and one in the right ventricle. The aneurysms were always associated with multiple foci of myocardiac fibrosis. A hypothesis concerning histogenesis of the lesion is formulated.

Animals↗
PubMed1993

[Malformations of the heart and endocardiosis in swine].

The authors describe in 321 of 170,000 examined slaughter pigs certain cardiac malformations which were associated with endocardiosis of the mitral valve. Aortic stenosis was associated with endocardiosis of the aortic valve. It is assumed that in certain breeds of swine a congenital predisposition for impairment of the collagen metabolism may support the development of endocardiosis.

Animals↗
PubMed1992

Ultrastructural observations on autolytic changes of atrial specific granules in pig heart.

The progressive autolytic changes of atrial specific granules (ASGS) up to 24 hours after death were studied electron microscopically. Tissue samples taken from the left auricular myocardium of four pig hearts at 0, 0.5, 1.5, 3.5, 6, 12 and 24 hours post mortem were fixed for 24 hours by immersion in 2.5 per cent cacodylate buffered glutaraldehyde (pH 7.4). Two pig hearts were kept at 20 degrees C and two at 4 degrees C. Although typical autolytic changes were seen in many organelles, no remarkable modifications in aspect, distribution, content and diameter of ASGS were observed in all samples. The results of this study indicate that ASGS are not morphologically affected by the autolytic processes, at least during the first 24 hours. Hence, the electron microscopic evaluation of ASGS does not need a particular fixation method such as perfusion. This may eliminate technical problems when slaughterhouse material is used.

Animals↗
PubMed1991

The morphology and location of atrial specific granules and the demonstration of atrial natriuretic factor in porcine, lapine and bovine heart by immunoelectronmicroscopy.

The atrial specific granules (ASGs) were studied in samples collected from the right and left auricles of conventionally slaughtered cows (10), pigs (16) and rabbits (8). In addition, the presence of atrial natriuretic factor (ANF) was detected by immunocytochemistry. Mature ASGs, characterized by the presence of highly osmiophilic and electron-dense material surrounded by a membrane, were present in all atrial myoendocrine cells and their diameters ranged from 100 to 470 nm in pigs, from 100 to 235 nm in cattle, and from 125 to 275 nm in rabbits. Immunoelectronmicroscopical studies revealed the presence of ANF in the ASGs of pigs and cattle, whereas anti-ANF polyclonal serum failed to detect any significative reaction in lapine ASGs. The ultrastructural features of the ASGs of pigs, cattle and rabbits described may be useful in comparing the morphological picture of several cardiac endocrine pathological conditions.

Animals↗
PubMed1990

[Pathologico-anatomic findings in thymus gland and female sex organs of slaughtered calves after treatment with anabolically effective substances].

The authors describe the pathomorphological findings in the thymus, female genital organs and Bartholin's glands in 413 slaughter calves with white skeletal musculature. Anabolic substances like oestrogens, androgens, and corticosteroids had most likely been administered to a total of 302 of these animals. In all cases thymic atrophy was present. Microcysts of the ovaries were seen in 17% of the cases, mucometra of the uterus in 49%, hydrometra in 23%, and squamous metaplasia in Bartholin's glands in 15%.

Anabolic Agents↗