The time course of lymph drainage from the peritoneal cavity in beagle dogs

Lymph drainage routes from the abdominal and pelvic cavities in beagle dogs were observed serially by following the time course of India ink administered intraperitoneally. Four systems of lymph drainage routes from the peritoneal cavity were observed in this study. The earliest drainage returned to the cranial mediastinal lymph nodes via the sternal lymph vessels; subsequently, the sternal lymph nodes located along the internal thoracic artery became involved. Then, a drainage route via the lymph vessel along the left vagus nerve was observed. The final drainage route flowed into the lateral lymph vessel through the thoracic duct located on the vertebra. These results show that India ink is absorbed from the peritoneal cavity, and that the lymph drainage first flows mainly towards the cranial mediastinal lymph nodes through the ventral lymphatic channels. Our serial observations suggest that, over time, the lymph drainage routes changed from the ventral abdominal to the dorsal thoracic lymphatic channels in the thorax.     

Comparison of the accessory activity of murine peritoneal cavity macrophage derived dendritic cells and peritoneal cavity macrophages in a mixed lymphocyte reaction.

A detailed comparison of the accessory cell activities was carried out among murine peritoneal cavity macrophages (PEC-Mphi), peritonea] cavity macrophages stimulated with granulocyte-macrophage colony stimulating factor (GM-CSF) plus interleukin 4 (IL-4), the most popular cytokine combination widely used to generate dendritic cells (DC) and peritoneal cavity macrophage-derived DC (PEC-DC) using a two-way mixed lymphocyte reaction (MLR). All the cell types used efficiently induced statistically significant na?ve T cell proliferation at all culture time points and responder:stimulator ratios used. However, marked differences were noted in the magnitude of the proliferative responses. These variations may be attributed to the intensity of expression of MHC class II glycoproteins, as well as the actual numbers of MHC class II+ cells.     

Phenotype and function of murine peritoneal cavity macrophage derived-dendritic cells

The accessory activity was reported in murine peritoneal cavity macrophage derived dendritic cells (PEC-DC) in a mixed lymphocyte reaction (MLR). Here we continue the characterization of the generated PEC-DC using the criteria of morphology, phenotype and other accessory function. We have demonstrated that murine peritoneal cavity macrophages can be induced to differentiate in vitro into cells exhibiting typical dendritic cell (DC) morphology, phenotype and function. The proliferative capacity of the progenitors was amplified in the first step of the culture (day 0-7) using a combination of early cytokines: interleukin 4 and granulocyte-macrophage colony-stimulating factor. The second step of the culture started at day 7 with the removal of early growth factors to allow differentiation and final maturation of DC during 2 days of culture with interferon gamma plus either Toxoplasma lysate antigen (TLA) or lipopolysaccharide (LPS), a bacterial agent as a DC maturing agent. The resulting DC population exhibited typical DC morphology and expressed higher levels of MHC class II and the co-stimulatory molecules CD80 and CD86 compared to the untreated peritoneal cells. The generated DC cells efficiently presented soluble protein antigen to CD3(+) spleen T cells.     

Effect of petrolatum coating on the rate of occlusion of ameroid constrictors in the peritoneal cavity

OBJECTIVE : To document rate of closure and degree of inflammation associated with petrolatum coated (PCA) and non-coated ameroid constrictors (NCA) in the peritoneal cavity. STUDY DESIGN : Experimental study. ANIMALS : 18 Sprague-Dawley rats. METHODS : Thirty-six ameroid constrictors (AC; 5 mm) were digitally scanned and luminal area measured. Rats were anesthetized, and 1 PCA and 1 NCA were inserted in the peritoneal cavity by median celiotomy. Rats were euthanatized at 2 weeks (6 rats), 4 weeks (6), or 6 weeks (6) after surgery. AC were harvested, digitally scanned, and luminal area determined. Inflammation associated with the AC was subjectively graded (1-5). The effects of petrolatum coating on luminal area measurements and inflammatory score were statistically analyzed. RESULTS : Closure of AC occurred most rapidly during the first 2 weeks, but luminal area decreased only 32% at 6 weeks after implantation. There was no significant difference in rate of closure for PCA compared to NCA at 2, 4, or 6 weeks. Inflammation scores were not significantly different between PCA and NCA. CONCLUSIONS : Petrolatum coating did not slow the rate of closure of AC in the peritoneal cavity. CLINICAL RELEVANCE : The lack of closure of AC supports the conclusion that vascular attenuation is not dependent on luminal constriction alone. Petrolatum coating did not slow the rate of casein expansion and is unlikely to be clinically useful.     

Early and transient cytotoxic response of peritoneal cells from Fasciola hepatica-infected rats

Experimental infection by F. hepatica was performed on rats. Early recruitment of the peritoneal cell population was observed and revealed transient parasite-killing activity, preceded and followed by a state of total unresponsiveness. The activation peaked at seven days post-infection (dpi) and was characterised by a massive peritoneal cell recruitment, a strong superoxide anion and nitric oxide (NO) production, that were coincident with the fasciolicide activity of these cells, as monitored by an in vitro decrease of juvenile fluke viability in a conditioned medium. The addition of L-NG-monomethyl arginine (LNMMA) to cell cultures abrogated both fasciolicide activity and NO production. Parasites started to die when NO production exceeded 25 microM and all juvenile flukes were killed by a 90 microM NO exposition (Lethal Dose 50 between 45.8 and 50.3 microM, 95% fiducial limits). However, when rat peritoneal cells were cultured in the presence of either infected or control rat serum, juvenile flukes were much more resistant to the oxidative burst, despite a massive attachment of rat peritoneal cells to the parasite tegument. These data suggest that a transient control of fasciolosis may take place in the peritoneum following the parasite intrusion but that the parasite efficiently scavenges the host cellular response to avoid destruction.     

Role of immunoglobulin and peritoneal phagocytes in the protection of rats against salmonella infection

Intradermal vaccination of rats with heat-killed Salmonella dublin protected against an intraperitoneal challenge of live S dublin. Serum from vaccinated animals administered intraperitoneally protected normal rats against intraperitoneal challenge with S dublin and four other serotypes. Protection was attributed to opsonic antibodies which promoted phagocytosis by mononuclear phagocytes. The opsonin was identified as IgG2a which prevented lysis of macrophages and enabled them to contain the pathogen at the site of infection. In vitro, mononuclear phagocytes killed S dublin for up to two hours after phagocytosis in the presence of immune rat serum.     

Open peritoneal drainage for treatment of contaminated peritoneal cavity and septic peritonitis in dogs and cats: 24 cases (1980-1986)

The medical records of 22 dogs and 2 cats in which generalized peritonitis had been treated by open peritoneal drainage were reviewed. The age of the affected animals ranged from 5 months to 14 years. The causes of peritonitis were numerous, with the most common being leakage of gastrointestinal contents through spontaneous gastric or intestinal perforations and peritoneal contamination resulting from surgical complications. Bacteria were isolated from 18 (94.7%) of 19 specimens obtained for culturing at the time of diagnosis of peritonitis and from 8 (80%) of 10 specimens obtained for culturing at the time of final abdominal closure. Only 2 (25%) of 8 of the animals in which bacteria were isolated at the time of final abdominal closure died. The overall mortality was 33%. The mortality attributable to peritonitis or its direct complications was 21%. Open peritoneal drainage was tolerated well by all patients.     

Experimental transmission of US scrapie agent by nasal, peritoneal, and conjunctival routes to genetically susceptible sheep

Scrapie is a naturally occurring fatal neurodegenerative disease of sheep and goats. This study documents incubation periods, pathologic findings, and distribution of abnormal prion proteins (PrP(Sc)) by immunohistochemistry in tissues of genetically susceptible sheep inoculated with US sheep scrapie agent. Four-month-old Suffolk lambs (QQ at codon 171) were inoculated by 1 of 3 different routes (nasal, peritoneal, and conjunctival) with an inoculum (No. 13-7) consisting of a pool of scrapie-affected sheep brains. Except for 3 sheep, all inoculated animals were euthanized when advanced clinical signs of scrapie were observed between 19 and 46 months postinoculation (MPI). Spongiform lesions in the brains and labeling of PrP(Sc) in central nervous system and lymphoid tissues were present in these sheep. One intranasally inoculated sheep euthanized at 12 MPI had presence of PrP(Sc) that was confined to the pharyngeal tonsil. These results indicate that the upper respiratory tract, specifically the pharyngeal tonsil, may serve as a portal of entry for prion protein in scrapie-infected environments.     

Atypical time course of clinical signs in a dog poisoned by strychnine

The general health of a German shepherd dog had deteriorated slightly when it was found after being loose for one hour. After 10 hours of observation, the dog showed signs of pain for the first time and signs of poisoning, such as tenseness of muscles, slight opisthotonus, regurgitation, salivation, mydriasis, dyspnoea and cyanosis, were observed; it died 15 minutes after showing the first clinical signs but it had no seizures or tetanic spasms at any time. A postmortem examination did not reveal any pathological changes. A screening test for alkaloids was positive for strychnine (strychnidin-10-one). The presence of strychnine was confirmed and its concentration was determined by gas chromatography/mass spectrometry in urine (728.5 ng/ml) and in the stomach contents (44.6m microg/g). No strychnine was detected in the dog's serum, but traces of brucine (2,3-dimethoxystrychnidin-10-one), the dimethoxy derivative of strychnine, were detected. This case was compared with other strychnine poisonings recorded in the authors' laboratory over the previous six years, taking into account the species, type of samples, the clinical signs and their duration, the postmortem findings, and the concentrations of strychnine. This was the only case to show such an atypical time course of clinical signs.     

Relationship between Marek's disease and the time course of viral genome proliferation in feather tips

A total of 114 male chickens from three sire families of a commercial cross of White Leghorn chickens were infected with RB-1B Marek's disease (MD) virus at 21 days of age by exposing them to chickens previously inoculated with MD virus. The presence of virus in feather tips, feather pulp, and MD viral antibodies indicated all chickens became infected. The first virus-positive chickens were observed at 12 days postexposure (dpe). The frequency reached a maximum at 27 dpe and then decreased. At 80 dpe, when the experiment was terminated, no viral DNA was detected in the feather pulp of the surviving chickens (82%). Death from MD was first observed at 38 dpe and reached 18% by the end of the experiment, with spleen lesions being the major MD lesion. The viral genome titers in spleen extracts of chickens with MD lesions was negatively correlated with the time of death, and, similar to feather pulp, none of the surviving chickens was virus positive at the end of the experiment. Quantization of the viral genome titers in feather tip extracts at 27 and 38 dpe revealed a positive correlation with the presence of MD lesions, but only in the declining phase (38 dpe) and not at the peak (27 dpe) of the viral titer. Sire effects were significant, indicating the presence of genetic factors that affect viral proliferation. Again, significance was only observed at 38 dpe and not at 27 dpe. The results indicate that, in this commercial line, 1) all chickens were susceptible to infection via contact exposure, 2) all surviving chickens recovered from the viral infection, and 3) it is not sufficient to measure viral titers at a single time point when using viral titers as an endpoint for MD susceptibility.     

训练中的助训员

助训员是指协助带犬民警训练警犬的专业训练员.他们虽不直接掌握警犬,但与带犬民警都是训练的直接参与者,同样是犬的复杂综合刺激者,既能给以兴奋性影响,也能给犬以抑制性影响,对训练的成败负有重要的责任.     

Artificial infection by transplantation of juvenile Fasciola worms into the abdominal cavity of rats

Rats were successfully infected with Japanese Fasciola sp. by transplantation of juvenile worms (JW) or metacercariae (MC) into the abdominal cavity. Moreover, the rat was investigated on its suitability for different experiments with liver flukes. JWs or MCs transplanted intraperitoneally (IP) matured in the bile duct of rats. Moreover, more stable infections were established by inoculation of JWs than MCs. About 3 of 10-15 JWs transplanted into the abdominal cavity of a rat matured and laid eggs in the bile duct. The mean prepatent period was 63.5 days in the JW inoculated group. EPG values were kept constant at a level of 10(2)-10(3) about 100 to 230 days after the transplantation of JWs. The life span of Japanese liver flukes was estimated to be about 400 days in rats. From these results, it was concluded that the rat is suitable for various experiments with Fasciola sp.