Identification of enteric Helicobacter in avian species.

The presence of enteric Helicobacter species was investigated in poultry (n=130) and in pet and ornamental birds (n=50) using a PCR sequencing method which permits the differentiation of many Helicobhacter species derived from animal tissues. All samples were of Italian origin, except for 21 Guinea fowl from a French flock. About 80% of poultry (chickens, laying hens, Guinea fowl) were positive to Helicobacter DNA. H. pullorum was most frequently (62.1%) identified whereas H. pylori and 3 H. sp. hamster B strains were seen in only 3 cases each. Pet and ornamental birds were all negative. H. canadensis was found in all Guinea fowl from a French farm. This is the first report on the occurrence of this bacterium in poultry.

Isolation of Acinetobacter lwoffii from a lovebird (Agapornis roseicollis) with severe respiratory symptoms.

Although Acinetobacter lwoffii is generally considered an ubiquitous and opportunistic bacterium, this germ has been isolated from the pulmonary and abdominal air sac swabs obtained from a Lovebird (Agapornis roseicollis), which died of a severe respiratory disease. Bacteriological tests (phenotypic and genotypic) led to the identification of A. lwoffii in pure culture. All the other parrots in the breeding centre were treated orally with oxytetracycline for 14 days and 3 months later no bird showed any signs of respiratory symptoms.

[Diseases in animals associated with exposure to electric and magnetic fields of 50/60 Hz: report of a case]. / Patologie animali associate all'esposizione a campi elettrici e magnetici a 50/60 Hz: descrizione di un caso.

Symptoms of diseases and mortality observed in animals bred near two high-voltage electric transmission lines in the district of Aosta are described. Preliminarily the international scientific literature on this subject is considered. The goal of the present paper is to determine the value of the animals with spontaneously occurring diseases as comparative model for risk assessment associated with 50 Hz magnetic fields.

Histological changes caused by the rc mutation in chickens.

The rc gene represents a recessive mutation in chickens, known to cause retinal degeneration and blindness, as well as abnormal sarcolemmal membranes of cardiac myocytes associated with reduced choline transport. In this study, the visceral organs from "old" (aged 12 months) and "young" (aged 5 months) homozygous blind (rc/rc), heterozygous (Rc+/rc) and normal (Rc+/Rc+) chickens were examined histologically to investigate whether the primary effect of the mutation was on cellular structure. Homozygous birds showed enlarged thyroids with acidophilic colloids in enlarged and often ruptured follicles, macrovesicular lipid accumulation in the liver, increased numbers of nuclei in the myocardial fibres, hypertrophy of the lobular structure of the medullary portion of the thymus, cloudy swelling of the tubular epithelium of the kidney and slow maturation (in young birds) and degeneration (in old birds) of the gonads. All lesions, except for those of the thymus, were more severe in old than in young birds. Some heterozygous chickens were mildly affected and none of the normal (Rc+/Rc+) birds exhibited these abnormalities.

Efficacy of maduramicin against turkey coccidiosis in battery: a clinical and pathological study.

Two groups of 24 three-day-old turkeys each were inoculated with Eimeria meleagrimitis sporulated oocytes and fed a diet containing respectively 5 and 6 ppm of maduramicin ammonium. Clinical signs, mortality rates, weight gain, intestinal lesions and replication of the parasite were compared to the data obtained from a group of infected, untreated birds kept in the same experimental conditions over a period of 17 days. The treated birds showed better performances and less severe intestinal damages; the replication and the development of the parasite in the intestinal mucosa were impaired and delayed by the drug. All the data were dose dependent.

Amiloride inhibition of human cytomegalovirus replication.

Amiloride, an inhibitor of Na+/H+ exchange, interfered with cytomegalovirus (CMV) DNA synthesis, blocked the formation of nuclear inclusions, and reduced CMV infectious yields. The reduction of CMV infectious yields was concentration dependent with an ED90 of 46 microM. Amiloride at a concentration of 150 microM reduced CMV yields by about 100-fold. Reduction of infectious yields appeared to be related to interference with the formation of nuclear inclusions and to inhibition of CMV DNA synthesis. Nuclear inclusions were much reduced in size and demonstrated poorly defined cellulae in the amiloride-treated cells. CMV DNA synthesis was inhibited by approximately 70% when cells were treated with 150 microM amiloride. The reduction in CMV yields could not be related to the reported inhibitory effect of amiloride on protein synthesis. In amiloride (150 microM)-treated, CMV-infected cells, late, yet not immediate-early or early, protein synthesis was markedly decreased relative to untreated, CMV-infected cells. Accordingly, CMV DNA synthesis and the replication of CMV may be related to Na+ entry through an amiloride-sensitive pathway.

Biodistribution of tritiated benzoporphyrin derivative (3H-BPD-MA), a new potent photosensitizer, in normal and tumor-bearing mice.

The biodistribution of a new and very potent photosensitizer, benzoporphyrin derivative-monoacid, ring A (BPD-MA), was determined in normal and P815 (mastocytoma) or M1 (rhabdomyosarcoma) tumor-bearing DBA/2J mice. A dose of 80 micrograms of 3H-BPD-MA was determined at 3, 24, 48, 72, 96 and 168 h post injection. The following tissues were tested: blood, brain, heart, intestine, kidney, lung, liver, muscle, skin, stomach, spleen, thymus and tumor. The biodistribution of 3H-BPD-MA in normal and tumor-bearing mice was comparable overall. 3H-BPD-MA localized in tumors better than in other tissues except kidney, liver and spleen. The tumor to tissue ratios were in the range 1.5-3 at 24 h post injection and increased further during the next 72 h. The highest levels of 3H-BPD-MA were observed in all tissues at 3 h post injection and decreased rapidly during the first 24 h. After 24 h the clearance from tissues was rather slow. The preliminary clearance data obtained in a group of five normal mice indicated that the majority of the injected dose (60%) cleared from the body via the bile and feces, while only about 4% cleared via kidneys and urine. Studies in which 3H-BPD-MA was extracted from tumor, kidney and liver 3 and 24 h after injection showed that, at 3 h, all the photosensitizing activity in tumor was retained. At 24 h only 39% of the activity was retained and considerably less active material was present in liver and kidney.

Effect of prolonged administration of low doses of dietary retinoids on cell-mediated immunity and the growth of transplantable tumors in mice.

A study was conducted on the activity exerted by prolonged dietary supplementation with progressive amounts of retinoids on cell-mediated immune responses and the growth of transplantable tumors in mice. A few groups of BALB/c mice received 0 (group C), 50 (group A 50), 200 (group A 200), 500 (group A 500), and 1,000 (group A 1000) IU retinol palmitate/mouse/day in drinking water for 150 days. At progressive intervals mice from each group were tested for proliferative responses to concanavalin A (Con A), Escherichia coli lipopolysaccharide, interleukin-2, and interferon-gamma release to Con A. Ten mice from each group were also challenged with the 90-100% tumor-inducing dose of 3 distinct transplantable tumors. At the end of the experiment the principal organs were histologically examined, and the accumulation of vitamin A was evaluated. In groups A 200, A 500, and A 1000, an increase in the proliferative responses and production of lymphokines as compared to those in group C occurred after 60-90 days, but vanished after 150 days. The takes of the 3 tumors were impaired when the challenges were performed on days 75 and 150. This enhancement of distinct functions of cellular reactivity and resistance to transplantable tumors showed a linear relationship with the amount of supplemental retinol palmitate for the first 60-90 days. After 150 days, however, these enhancement effects vanished or tended to decrease.

Modulation of natural killer activity in mice by prolonged administration of various doses of dietary retinoids.

Groups of BALB/C mice received a diet supplement of 0 (group C), 200 (group A 200), 500 (group A 500), and 1,000 (group A 1,000) IU retinol palmitate (RP)/mouse/day in drinking water for 450 days. At progressive time intervals, mice from each group were tested for natural killer (NK) activity and for the percentage of large granular lymphocytes (LGL) in the spleen. In groups A 200, A 500 and A 1,000, a dose-dependent increase in NK activity was evident 50 days after the beginning of RP supplementation and was accompanied by a parallel increase of LGL number in the spleen. In group A 1,000, the increase of spontaneous or Poly I:C-induced cytotoxicity persisted until day 160. By contrast, inhibition of Poly I:C-induced NK cytotoxicity was found in this group at day 450.

The roles of vitamin A in the prevention of neoplastic diseases: a critical assessment.

The role of vitamin A and its analogs (retinoids) in the prevention and therapy of neoplastic diseases is discussed. Epidemiological data showing a relationship between vitamin A deficiency and increased frequency of tumors in man and animals are examined and the experimental models demonstrating the protective action of retinoids in the respect of both spontaneous and induced neoplasias of animals are reviewed. Among the possible mechanisms responsible of the antineoplastic activity, the immunopotentiating effect is underlined. Some toxicological aspects of retinoids administration and the consequent application of the experimental results in human medicine are finally discussed.

Interleukin 1- and 2-like activities in the dog.

Canine adherent and non-adherent peripheral blood leukocytes and spleen cells were examined for their ability to produce soluble factors with Interleukin 1- and 2- (IL-1 and IL-2) like activities. For this purpose, three conventional assay systems were used: (a) proliferation on an IL-2-dependent murine cytotoxic T-lymphocyte cell line, (b) enhancement of PHA-induced murine thymocyte proliferation and (c) proliferation of lectin-primed canine peripheral blood lymphocytes (PBL). Only the latter two types of cells respond to IL-1, whereas all three types respond to IL-2. Both types of factors were produced and the kinetics of their release/production were found to be identical to those of human PBL. Results suggested that species-related differences existed. Canine interleukin-containing supernatants had higher titers than murine interleukin-containing supernatants when analyzed on canine lymphocytes, and the reverse was found if murine target cells were used.

Lymphocyte responsiveness to lectin and myelin antigens in canine distemper infection in relation to the development of demyelinating lesions.

Eleven dogs were experimentally infected with canine distemper virus and studied for periods of up to 63 days post-inoculation. The responsiveness of lymphocytes in vitro toward phytohemagglutinin, myelin basic protein and galactocerebroside was tested at regular intervals during the course of infection by means of [3H]thymidine incorporation and flow cytometry. All dogs developed a marked decrease of lymphocyte responsiveness toward phytohemagglutinin. Four dogs recovered rapidly from the immunosuppression and did not develop demyelination or had only mild lesions, while two others failed to recover at all and developed severe non-inflammatory demyelinating lesions. The remaining dogs exhibited a slow or partial immune recovery and had various degrees of inflammatory demyelination. Lymphocytes from 2 dogs with demyelination and 2 dogs without myelin lesions responded to myelin antigens. The findings indicate that the degree of immunosuppression in canine distemper virus infection may determine the type of demyelination and autoimmune reactions that occur during the inflammatory stage of demyelination may be epiphenomena.

Glial proteins in canine distemper virus-induced demyelination. A sequential immunocytochemical study.

A temporal series of demyelinating lesions in experimental canine distemper virus (CDV) infection was examined with immunohistological techniques demonstrating myelin basic protein (MBP), myelin-associated glycoprotein (MAG), and glial fibrillary acidic protein (GFAP) on serial sections. The earliest lesions were characterized by decreased MBP and MAG and increased GFAP. During the further progression of the disease, MBP and MAG losses continued to match each other. There was no indication of MAG loss preceding the disappearance of MBP. In the more advanced lesions there was a marked decrease of GFAP positive cells. Since these findings differed considerably from similar immunohistochemical studies in progressive multifocal leukoencephalopathy (PML) where demyelination results from oligodendroglial infection, it was concluded that the oligodendroglial cell body is not the primary target of CDV. The marked astroglial changes were also considered to contribute to demyelination in CDV infection but the mechanism by which this happens remains unknown.