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Biomedical subjects

G Di Guardo

Publications and source records attributed to G Di Guardo.

At least 37 records · Page 2Linked to original sources

[Usefulness of atrial vulnerability in predicting atrial fibrillation in patients with sick sinus syndrome treated with DDD pacemaker].

BACKGROUND: Atrial fibrillation (AF) is common in patients with sick sinus syndrome (SSS) treated with dual-chamber pacing and it may complicate their management. This study was undertaken to establish the usefulness of atrial vulnerability (AV), determined by means of transesophageal electrophysiological study (TES), in predicting the risk of developing AF and in deciding the type and program of pacemaker (PM) to be implanted in patients with SSS. METHOD: AV was assessed preoperatively using TES in 81 consecutive patients with SSS. AV (AF > 1 min) was divided into "low threshold" (induction with burst < or = 300/min) and "high threshold" (induction with burst > or = 350 min or with incremental ramp). The PM was programmed to ensure constant atrial capture in all patients. Follow-up lasted three years. No patients received antiarrhythmic drugs. RESULT: AV was positive in 52% of patients (Group A) and negative in 48% of patients (Group B). A history of paroxysmal AF was present in 52% of patients in Group A and in 12% of patients in Group B. At follow-up, 38% of Group A and 2% of Group B patients had chronic AF. AV had sensitivity, specificity, positive predictive value (ppv) and negative predictive value (npv) of 94, 59, 38 and 97%, respectively. Thirty-eight percent of patients showed low threshold vulnerability, with sensitivity, specificity, ppv and npv of 87, 92, 87 and 93%, respectively. Sensitivity, specificity, ppv and pnv for history of AF were 93, 100, 98 and 84%, respectively. When the vulnerability threshold and the history of paroxysmal AF were considered together, the sensitivity, specificity, ppv and npv was 94, 100, 100 and 83%, respectively. Multivariate analysis was shown to be an independent predictive value only for history of AF (p = 0.0002). CONCLUSION: AV determined by means of TES, especially with a low induction threshold, shows excellent sensitivity and specificity in evaluating the risk of chronic AF. It could be useful in patients with SSS undergoing cardiac pacing who have never had AF, thus allowing a more accurate choice of the type and program of PM to be implanted. Case histories of paroxysmal AF could represent useful criteria for selecting patients at a high risk of developing chronic AF.

Aged↗

Presence of papillomavirus-like DNA sequences in cutaneous fibropapillomas of the goat udder.

Papillomatous lesions were isolated from the mammary skin of goats and examined for evidence of papillomavirus (PV) infection by various criteria, including gross morphology, histology and DNA hybridization. Although some lesions showed gross papillomatous morphological and histological features similar to those caused by papillomavirus in other species, no viral particles were detected. Reverse slot hybridization revealed cross-hybridization between DNA extracted from goat mammary papillomas and human papillomaviruses (HPV). Southern blot, using ovine papillomavirus (OPV) and bovine papillomavirus type 5 (BPV 5) DNA probes under conditions of reduced stringency (Tm -40 degrees C), detected homologous sequences in 40% of the biopsies. DNA fragments corresponding probably to a monomeric form (7000-8000 bp) of an unknown papillomavirus genome were detected. This study provides evidence for the existence of papillomavirus-like sequences in caprine mammary papillomas and suggests that a papillomavirus is likely to be involved in the development of precancerous lesions of goat mammary skin.

Animals↗

Embryonic and neonatal mortality from salmonellosis in captive bred raptors.

In a captive breeding center near Rome (Italy), cases of embryonic and neonatal death were recorded during the breeding seasons in the European eagle owl (Bubo bubo), peregrine falcon (Falco peregrinus), buzzard (Buteo buteo), and lanner falcon. (Falco biarmicus). Salmonella havana and S. virchow were isolated. Three pulli, clinically infected with S. havana, were successfully treated with enrofloxacin. From two groups of healthy 3- to 4-wk-old eagle owls, Salmonella sp. group 61 (61:r:-) and S. havana were collected. A strain of S. paratyphi B was detected in a pharyngeal swab and a fecal sample from an adult female goshawk (Accipiter gentilis), affected with pharyngeal trichomoniasis. A S. hadar strain was collected from a healthy 1-yr-old female eagle owl and S. livingstone was isolated from a 1-mo-old female peregrine, dead of an acute respiratory syndrome. Lesions of fibrinous polyserositis and multivisceral congestion were observed. From frozen 1-day-old chicks, on which adult and young raptors were fed, S. havana and S. livingstone isolates with similar biochemical and drug susceptibility patterns to those isolated from raptors were identified. A surveillance program on infectious diseases reduced embryonic and neonatal death rates in the following breeding seasons.

Animals↗

Pathology of Serratia marcescens mastitis in cattle.

Microbiological, cytological, histopathological, and immunohistochemical investigations were carried out on four dairy cows affected by Serratia marcescens mastitis. The animals under study were from a herd of 120 lactating cows bred in the province of Rome. In the above herd, S. marcescens mastitis showed a prevalence of 20.8%. S. marcescens was the only bacterial agent isolated, prior to and after slaughter, from the teat milk, the mammary gland and the supramammary lymph nodes of the four cows under study. Cytologically, the four subjects exhibited high cell counts in their milk, with an average of up to 5,570,000 cells/ml in S.marcescens-infected quarters. Macroscopically, nodular lesions were apparent scattered throughout the mammary parenchyma, with enlargement of the regional lymph nodes. Histologically, a chronic, non-purulent mastitis, characterized by a marked fibrous tissue proliferation and the coexistence of corpora amylacea within the glandular alveoli, was observed in association with chronic hyperplastic lymphadenitis involving the supramammary lymph nodes of the four cows. Immunohistochemically, S. marcescens was demonstrated, by means of monoclonal antibodies, both in the mammary gland and in the supramammary lymph nodes from these four animals.

Animals↗

[Study and management of zoonoses transmitted by wild animals].

In the present work the criteria to approach the study, the prophylaxis and the control of wildlife-related zoonoses are discussed, along with the role of veterinarians as responsible for wildlife and public health management. More in detail, the ecological method in approaching the study of wildlife infections is discussed, along with the relationships existing among hosts, parasites and the environment. Finally, the role of man as a host of zoonotic agents is discussed, and the basic principles of prophylaxis and control of infections caused by such agents are also considered.

Animals↗

Post mortem investigations on cetaceans found stranded on the coasts of Italy between 1990 and 1993.

Detailed pathological and virological examinations were carried out on 25 cetaceans found stranded between 1990 and 1993 on the coasts of six Italian regions (Latium, Tuscany, Apulia, Abruzzo, Veneto and Sicily). There were 16 striped dolphins (Stenella coeruleoalba), three bottlenosed dolphins (Tursiops truncatus), three Risso's dolphins (Grampus griseus), one rough-toothed dolphin (Steno bredanensis), one fin whale pup (Balaenoptera physalus), and one minke whale (Balaenoptera acutorostrata). Apart from parasitic diseases (44 per cent), the most frequently detected lesions were pneumonia (68 per cent), enteritis (44 per cent), non-purulent hepatitis (40 per cent), interstitial nephritis (32 per cent) and encephalitis (32 per cent). Morbilivirus infection was diagnosed by immunocytochemistry in four striped dolphins, two stranded on the coasts of Latium in 1991 and two on the coasts of Tuscany in 1993. Despite the presence of lesions consistent with morbilliviral pneumonia in two other striped dolphins stranded on the coast of Apulia in 1991, no morbillivirus antigen was demonstrated in the tissues of these animals. Anticanine distemper virus antibodies were detected in the serum of the adult minke whale found stranded on the coast of Tuscany in 1993. However, no viruses were isolated from the tissues of any of the 25 cetaceans.

Animals↗

Morbilliviruses in aquatic mammals: report on round table discussion.

A workshop was organised to ascertain the current situation with regard to morbillivirus infections in aquatic animals. The great interest generated by the discovery of these new virus infections in 1988 has to some extent abated but much high quality research has continued in this field as the workshop showed. There is some serological evidence that the viruses have continued to circulate in most areas since the initial epizootics. As to their origin, it appears that the most likely source of the European seal morbillivirus (PDV-1) is the North Atlantic and Artic seal populations. As to the origin of the Mediterranean dolphin morbillivirus and the morbilliviruses isolated from porpoises, there is serological evidence that the viruses are widespread in many cetacean species in the Atlantic and 93% of long-finned pilot whales (Globicephala melas) which mass stranded between 1982 and 1993 were morbillivirus seropositive. The epizootic in freshwater seals in Lake Baikal was unrelated to events in the European marine mammal populations. The virus which infected these animals (PDV-2) is indistinguishable from canine distemper field strains. Serological and molecular biological studies provided evidence for the presence of the virus in the seals, at least as late as the Summer of 1992 when the animals were last sampled.

Animals↗

Mast cell tumour destruction in dogs by hypotonic solution.

Distilled water was studied as an hypoosmotic oncolysis agent to prevent mast cell tumour (MCT) recurrence following surgical excision. The results from 118 MCTs excised in 74 dogs were: surgery alone, a recurrence rate of 52.6 per cent (10/19); and surgery followed by distilled water injections into the wound, a 26.2 per cent (26/99) recurrence rate. All of 10 small MCTs (0.03 to 0.25 cm3) injected with distilled water in situ with no surgery, regressed. The present data suggest that distilled water should be considered as an adjunct to surgery for canine MCTs.

Animals↗

Number and size of silver-stained nucleoli (Ag-NOR clusters) in canine seminomas: correlation with histological features and tumour behaviour.

Twenty spontaneous canine seminomas were examined. A statistically significant difference (P < 0.01) was detected in both the mean silver-stained nucleolar area/cell and the mean silver-stained nucleolar number/cell between (1) two intraductal seminomas with no signs of invasion, and (2) three intraductal ones with signs of invasion and 15 diffuse-type seminomas (two of which metastasized 3 and 12 months after surgical treatment). Furthermore, the metastasizing seminomas showed a mean silver-stained nucleolar area/cell which was significantly greater than that observed in all the other seminomas examined (P < 0.01). It is concluded that quantitative studies of nucleolar changes are useful in evaluating the biological behaviour of spontaneous canine seminomas.

Animals↗

Amyloid, amyloid-inducers, cytokines and heavy metals in scrapie and other human and animal subacute spongiform encephalopathies: some hypotheses.

A number of hypotheses regarding the pathogenesis of scrapie and other human and animal spontaneous and experimental subacute spongiform encephalopathies (SSE) are presented here. In particular, it is speculated that a PrPsc 27-30-induced suppression of host's defense system is responsible, through the existence of the different and synergistically operating mechanisms, for the absence of any documented inflammatory or immunologic response during SSE. This could be therapeutically counterparted by the utilization of cytokines (TNF, IL-1, etc) or cytokine-inducers, provided that synthesis and secretion of the above inflammation mediators on behalf of reticulo-endothelial cells were strongly depressed by PrP 27-30, as suggested. Finally, some hypotheses are also made in relation to the blood-brain-barrier's integrity in susceptible hosts. Similarly to Alzheimer's disease (AD) in man, this could play a role also in SSE pathogenesis, facilitating cerebral localization of metals such as aluminum, lead, or silica, which have already been shown to enhance amyloid fibrils' polymerization and deposition within human brain tissue.

Alzheimer Disease↗

Histological, histochemical and ultrastructural features of hyaline inclusions in hepatocytes of striped dolphins (Stenella coeruleoalba).

Many striped dolphins (Stenella coeruleoalba) which died in the recent morbillivirus epizootic in the Mediterranean Sea had hyaline inclusions in hepatocytes. We investigated the histological, histochemical and ultrastructural features of these inclusions in two affected dolphins. Histochemical tests indicated that they contained glycoprotein but not lipid. Ultrastructurally, they consisted of granular, moderately electron-dense material, bounded by a membrane. A central or eccentric core of highly electron-dense material was usually apparent. The inclusions were probably of lysosomal origin.

Animal Diseases↗

Squamous cell carcinoma of the skin in a Père David's deer (Elaphurus davidianus).

A solitary mass overlying the right carpal joint region's skin in an 18-year-old female Père David's deer (Elaphurus davidianus) was surgically excised and histologically diagnosed as a squamous cell carcinoma (SCC). The tumor was locally infiltrative, showing rather few "horn pearls" and many mitotic figures. This is the first report of a cutaneous SCC in the Père David's deer.

Animals↗

Occurrence of Salmonella in swine in the Latium Region (central Italy) from 1980 to 1989: a retrospective study.

An extensive survey was carried out on 849 biological samples (dead animals, organs and viscera, faeces, and rectal swabs) from pigs in the Latium Region (Central Italy) throughout the years 1980-1989. In total, 46 of the samples (5.4%) were found to be bacteriologically positive for salmonellae. Among dead animals, typical gross lesions were observed in 6 clinically infected animals. As far as serotypes are concerned, 11 different ones were isolated, with a predominance of Salmonella typhimurium (26.1%), S. anatum (21.7%), S. bovis-morbificans (15.2%), and S. heidelberg (10.8%). According to Kauffmann-White's classification scheme, 39.1% of the isolated strains belonged to serogroup B, 13% to serogroup C1, 17.4% tot serogroup C2, 6.5% to serogroup D, and 23.9% to serogroup E1. In conclusion, the authors speculate that the relatively low Salmonella isolation frequency (5.4%) reported in this study was not dependent upon the cultural procedures used, since different enrichment and plating methods were used, but rather upon the great number of rural-type herds which were investigated over the decade compared to industrial-type herds. Other factors such as stress conditions, which are particularly pronounced in industrial-type herds, and overall climatic situations, which tend to be characterised by warm, dry and long summers in the Latium Region, are also considered in this respect.

Animals↗

Bovine spongiform encephalopathy: an overview.

Bovine spongiform encephalopathy (BSE), a novel disease of cattle first described in 1986, has now reached epidemic proportion in Great Britain with about 500 cases a week. The clinical, epidemiological, and pathological characteristics of BSE are described. Moreover, the etiopathogenetic mechanisms of spongiform encephalopathies are reviewed. Legislative measures to prevent the spread of BSE in Italy and in other EEC countries and to minimize the theoretical risk to man are reported.

Animals↗