Vaccination of cats with recombinant envelope glycoprotein of feline immunodeficiency virus: decreased viral load after challenge infection.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
A Aubert
Publications and source records attributed to A Aubert.
Safety study of the SAG2 rabies virus mutant in several non-target species with a view to its future use for the immunization of foxes in Europe.
The safety of the SAG2 virus, a low virulence mutant of the SAD strain, was investigated in ten species of mammals and seven species of birds liable to consume vaccine baits. These species are the western hedgehog (Erinaceus europaeus), the meadow vole (Microtus arvalis), the bank vole (Clethrionomys glareolus), the water vole (Arvicola terrestris), the field mouse (Apodemus flavicollis or A. sylvaticus), the Norway rat (Rattus norvegicus), the european badger (Meles meles), the domestic ferret (Mustela putorius furo), the wild boar (Sus scrofa), the domestic goat (Capra hircus), the carrion crow (Corvus corone), the rook (Corvus frugilegus), the buzzard (Buteo buteo), the red kite (Milvus milvus), the tawny owl (Strix aluco), the long-eared owl (Asio otus) and the barn owl (Tyto alba). The vaccine was administered orally to each species, by an intramuscular (i.m.) route to the rodents and ferret, and by an intracerebral route to the field mouse. No pathogenicity was observed in the 169 animals vaccinated throughout an observation period of over 30 days. After euthanasia, no rabies virus could be detected either in the brain or in the salivary glands of any of the animals. The SAG2 virus administered orally, triggered a specific seroconversion in the field mouse, wild boar, ferret and most of the raptors. Following administration by the i.m. route, specific antibody titres were observed in most of the rodents, as well as in the ferrets.
Animals↗
[Digestive hemorrhage undiagnosed by conventional endoscopy].
Digestive bleeding undiagnosed by conventional endoscopies occurs in about 5% of the patients with gastro-intestinal bleeding. Vascular ectasias are the most common cause. More than half of these tumors are benign. Meckel's diverticulum is the cause of bleeding in two thirds of men under the age of 30. Hemorrhage from the biliary tree or pancreatic duct occurs more often in patients with a suggestive history. According to the abundance and the cause of hemorrhage numerous investigations can be undertaken and the diagnostic value of new endoscopic methods (enteroscopy, endoscopic ultrasonography) must be assessed.
Adult↗
Pyrogens specifically disrupt the acquisition of a task involving cognitive processing in the rat.
In addition to changes in body temperature and other metabolic and physiological responses corresponding to immune activation, pyrogens can induce profound behavioral changes referred to collectively as sickness behavior. One feature of sickness behavior, sometimes reported in clinical settings, but rarely exposed to experimental analysis, is depressed cognitive functioning. The present series of five experiments sought to demonstrate the existence of specific cognitive deficits in rats, independently of any confounding performance effects of pyrogen injections. The behavioral task used, called autoshaping, consisted of presenting hungry Wistar rats with a stimulus (introduction of a retractable lever) that predicted food delivery. Control rats quickly learned to press the lever, although this response does not influence the probability of food delivery. When pyrogens (250 micrograms/kg lipopolysaccharide, 4 micrograms/rat interleukin-1 beta, or 300 mg/rat yeast) were injected to rats during acquisition of this task, they severely disrupted acquisition while the pyrogen was active. The same treatments were, however, without effect on performance when injected later, when performance had stabilized. It is argued that these results demonstrate specific, performance-independent effects of pyrogens on the cognitive processes needed for the acquisition of this task. The results are discussed in terms of the relationship between these effects and the cytokines induced in the brain by pyrogens, and in terms of the exact nature of the cognitive process likely to be affected.
Animals↗
Compared effects of cold ambient temperature and cytokines on macronutrient intake in rats.
To compare the effects of cold and cytokines on spontaneous dietary self-selection, rats (n = 14) were given free access to carbohydrate, protein and fat diets for 4 hours a day. After a 10-day period of habituation to this regimen, they were injected with physiological saline, IL-1 beta (4 micrograms/rat ip) or LPS (83 micrograms/rat ip) or exposed to cold (5 degrees C), the order of treatments being randomized. LPS- and IL-1 beta-treated rats ate less, but ingested relatively more carbohydrate and less protein whereas relative fat intake remained unchanged. In contrast, cold exposed rats slightly increased their food intake but in a non significant manner. They also increased their relative intake of fat but did not change their relative intake of carbohydrate and protein. These results are discussed with respect to the pyrogenic and metabolic effects of cytokines.
Animals↗
FIV vaccine studies. I. Immune response to recombinant FIV env gene products and outcome after challenge infection.
We have vaccinated five groups of cats (n = 25) four times with five preparations of recombinant feline immunodeficiency virus (FIV) env gene products; one group (n = 7) served as control. The vaccine formulations were as follows: (1) envelope glycoprotein of FIV Zurich 2 (FIV Z2) expressed in a Baculovirus system and isolated by gel electroelution (denatured form); (2) insect cells expressing FIV Z2 glycoprotein; (3) envelope glycoprotein of a Boston strain (FIV Bangston) expressed in insect cells and isolated by gel electroelution (denatured form); (4) glycosylated Bangston envelope protein made in insect cells and isolated in a native form; (5) non-glycosylated Bangston envelope protein made in Escherichia coli. All cats were challenged with 20 50% cat infective doses (CID50) of FIV Z2 previously titrated in cats. All vaccinated cats developed high enzyme-linked immunosorbent assay (ELISA) antibodies to the homologous antigen; crossreactivity to heterologous antigens was seen at a lower level. Virus neutralizing antibodies (tested with Petaluma virus) reached titers up to 32. After challenge, all cats seroconverted (as judged by anti gag antibodies in Western blot) and became infected (as judged by virus isolation and/or polymerase chain reaction) between 4 and 11 weeks with the exception of one cat. It is concluded that it is relatively easy to induce high ELISA antibody titers using recombinant env gene products, ELISA antibody titers do not correlate with virus neutralization or with protection.
Animals↗
FIV vaccine studies. II. Clinical findings, hematological changes and kinetics of blood lymphocyte subsets.
Five groups of cats were vaccinated with different recombinant feline immunodeficiency virus (FIV) SU vaccines expressed either in Escherichia coli or in the Baculovirus system. In Part I of this series, we described the humoral immune response and outcome of intraperitoneal FIV challenge exposure. Additionally, all cats were monitored for clinical and hematological changes and the course of blood lymphocyte subsets. These results are described in this present paper. A great increase of antibodies was found after vaccination with different recombinant FIV antigens, which did not protect the cats from intraperitoneal FIV challenge infection. This observation was paralleled by an increase of eosinophils during vaccination which was even more pronounced after challenge infection. After FIV challenge, infection lymphadenopathy, gingivitis, pharyngitis, changes in total leukocytes and neutrophils and a decrease in the CD4+:CD8+ ratio were found in cats of all groups and were considered as a sign of the FIV infection taking place, independent of vaccination. The following observations suggest that in these cats a TH2-like immune response was elicited: the high counts of eosinophils, the nature of antigen and adjuvant (aluminium hydroxide) and the high amounts of antigens used for immunization. Clearly, this type of immune response did not protect the animals from intraperitoneal FIV challenge infection.
Animals↗
Recombinant FeLV vaccine: long-term protection and effect on course and outcome of FIV infection.
The efficacy and the long-term protection of a recombinant feline leukemia virus (FeLV) vaccine were determined in 30 specified pathogen free cats for over 3 years. At the same time, in order to specify the effects of feline immunodeficiency virus (FIV) on the immune system, one half of the cats (n = 15) were previously infected with the Swiss isolate FIV Zurich 2. The second half of the animals (n = 15) served as non-infected controls. Eighteen (nine FIV-negative, nine FIV-positive) vaccinated and 12 (six FIV-negative, six FIV-positive) non-vaccinated cats were intraperitoneally challenged with FeLV A. Seventeen of 18 vaccinated cats were protected against persistent viremia, while ten of 12 non-vaccinated controls became infected. An increase of antibodies against FeLV SU was found in all protected cats after the challenge exposure. No difference in vaccine efficacy was found between FIV-negative and FIV-positive animals. The whole group of cats was observed for over 3 years. There were no further vaccinations during this period. CD4+ and CD8+ cell subsets, clinical outcome and time of survival of the cats were recorded. FIV-negative and FIV-positive animals were kept in two different rooms. However, FeLV-negative and FeLV viremic cats were housed together in both rooms in order to imitate a natural FeLV exposure situation. Anti-recombinant FeLV SU antibodies were measured by enzyme-linked immunosorbent assay. Although a continuous decline of antibodies was found in FeLV vaccinated cats, they remained protected against constant FeLV challenge for over 3 years. FIV infection had a stronger effect on the depression of the CD4+:CD8+ ratio than FeLV infection. Within the group of FIV-positive cats, the FeLV-vaccinated animals had significantly better survival rates as well as better clinical and laboratory parameters. FIV- and FeLV-coinfected cats showed the lowest CD4+:CD8+ ratio, mainly caused by decreased CD4+ lymphocyte counts. CD8+ lymphocytes with strong fluorescence (CD8(high)) disappeared and cells with weak fluorescence (CD8(low)) appeared instead. Prevention of coinfection by immunizing FIV-positive cats against FeLV infection improved the clinical outcome and prolonged the cat's life expectancy.
Animals↗
Successful treatment by mesocaval anastomosis of a common-bile-duct compression by choledochal varices.
Explore the source record for details and available documents.
Adult↗
Indirect evidence for the presence and physiological role of endogenous extracellular ATP in the semicircular canal.
Previous studies have shown that low concentrations of exogenous ATP, added to the perilymphatic fluid, could modify the bioelectrical activity of the isolated semicircular canal of the frog (Rana pipiens). To test the hypothesis that ATP is endogenously present and active in the perilymphatic fluid, the influence of two ATP-purinoceptor antagonists, Reactive Blue 2 and suramin, and of the enzyme, nucleotide pyrophosphatase, were examined. When applied by perilymphatic bath substitution, the three compounds reduced, in a dose-dependent manner, the firing of the afferent fibers monitored in the absence of mechanically-applied stimulation. The response of the afferent fibers, recorded when the sensory cells were mechanically inhibited, was also reduced. No modification of the response of the excitatory phase of the mechanical stimulus was observed in the presence of the two antagonists. In contrast, the signal was significantly reduced by the enzyme. None of the three compounds exhibited an influence on the transepithelial potential, or its variation in response to mechanical stimulation. The ATP-induced modification of the firing rate of the afferent fibers, monitored in the absence of mechanical stimulation, was reduced in the presence of the three drugs. No influence of Reactive Blue 2 and suramin was observed on the increase of the spontaneous firing induced by carbachol. In contrast, the effect of carbachol was decreased by nucleotide pyrophosphatase. The excitatory influence of glutamate on the spontaneous firing was not modified by Reactive Blue 2, while it was slightly increased by suramin and nucleotide pyrophosphatase.(ABSTRACT TRUNCATED AT 250 WORDS)
Adenosine Triphosphate↗
Prevalence of cholelithiasis according to alcoholic liver disease: a possible role of apolipoproteins AI and AII.
Moderate alcohol intakes decreases the risk of gallstones; in contrast, the prevalence of gallstones is increased in patients with alcoholic cirrhosis. The aims of this prospective study were to assess the prevalence of cholelithiasis among drinkers according to the histological severity of liver disease, and to estimate the importance of serum apolipoproteins AI and apolipoprotein AII as risk factors for gallstones. Among the 320 drinkers included, 53 patients had cholelithiasis. The prevalence increased (p < 0.0001) from 5% in patients with normal liver (1 of 22) and 6% in patients with steatosis only (3 of 47) to 13% in patients with fibrosis (7 of 54), reaching 27% among patients with biopsy-proven cirrhosis (28 of 103). Among patients with clinically obvious cirrhosis on whom biopsy was not performed mainly because of the severity of liver disease, the prevalence of cholelithiasis reached a maximum of 46% (6 of 13). Among drinkers with nonsevere liver disease, patients with cholelithiasis were older (59 +/- 9 years, mean +/- SD vs. 45 +/- 11, p = 0.003) with lower apolipoprotein AI (118 +/- 37 vs. 163 +/- 45 mg/dl; p = 0.002) and apolipoprotein AII (30 +/- 12 vs. 53 +/- 20 mg/dl; p = 0.0002) in comparison with patients without cholelithiasis. These differences persisted after considering by multiple logistic regression analysis, sex, and ideal body weight. Alcohol consumption during the last 5 years was lower in patients with cholelithiasis (83 g/day) in comparison with patients without cholelithiasis (142 g/day; p = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Review of the reviewer.
Reviewers can disagree substantially when evaluating the same materials. For papers submitted to an editorial board, the Editor-in-Chief can suggest compromises. However, this is not the case in the normal abstract grading procedures for large meetings. If important discrepancies arise between reviewers, a review committee may propose corrective measures. However, this is only feasible for smaller meetings with a limited number of abstract submissions. In this study, when reviewing the same abstracts, a statistically significant correlation between reviewers was present in 15 instances and absent in 13 others. It would appear that some review of the reviewer is highly desirable and may prevent publication bias.
Abstracting and Indexing↗
Corticosterone regulates behavioral effects of lipopolysaccharide and interleukin-1 beta in mice.
The modulatory role of endogenous corticoids in the behavioral effects of lipopolysaccharide (LPS) and recombinant human interleukin-1 beta (IL-1 beta) was studied in mice. Adrenalectomy enhanced the depression of social exploration induced by subcutaneous injection of 200 ng of IL-1 beta or 2 micrograms of LPS. This effect was mimicked by an acute injection of the progesterone antagonist RU-38486 (0.25-1 mg). Chronic replacement with a 15-mg corticosterone pellet abrogated the enhanced susceptibility of adrenalectomized animals to 200 ng of IL-1 beta but had only partial protective effects on their response to 400 ng of IL-1 beta and LPS. These results suggest that the pituitary-adrenal response to cytokines exerts an inhibitory feedback on the cell targets that mediate the behavioral effects of LPS and IL-1 beta.
Adrenalectomy↗
Determinants of left ventricular function two weeks and one year after an acute myocardial infarction.
This study examines possible covariates of left ventricular function two weeks and sixteen months after an acute infarction. It was performed in a group of 312 patients randomized double blindly to recombinant tissue plasminogen activator (rt-PA) (n = 156) or placebo treatment and followed thereafter for at least one year. Two weeks after the infarction, enzymatic infarct size, infarct-related vessel, and number of diseased coronary arteries were significant determinants of the infarct-related regional wall motion (centerline method) (R2 = 0.25 to 0.60, P = 0.0001). Enzymatic infarct size, regional wall motion of both infarct-related and remote areas, reinfarction, and treatment allocation were significant independent correlates of ejection fraction (R2 = 0.76), end-diastolic volume (R2 = 0.20), and end-systolic volume (R2 = 0.69, P < 0.0001). Infarct-related coronary artery and predischarge end-systolic volume were significant independent covariates of ejection fraction at rest (R2 = 0.47) after sixteen months. Age, enzymatic infarct size, and predischarge end-diastolic volume were independent determinants of the maximal (R2 = 0.49, P < 0.0001) and peak exercise ejection fraction (R2 = 0.49, P < 0.0001).
Adult↗
A 270 degree laparoscopic posterior fundoplasty in the treatment of gastroesophageal reflux.
BACKGROUND: The aim of this prospective study was to evaluate the results of laparoscopic treatment of gastroesophageal reflux using a posterior fundoplasty. STUDY DESIGN: Fifty-one patients with gastroesophageal reflux or paraesophageal hernia, or both, documented by fibroscopy, acid reflux monitoring, and manometry were evaluated. The operative technique consisted of abdominal esophagus mobilization, approximation of the crura, and construction of a 270 degree posterior gastric valve, 5 to 7 cm in height. A clinical examination was performed after two weeks, four months, one year, and two years, and fibroscopy, acid reflux monitoring, and manometry were done at four months. RESULTS: One patient required a conversion to laparotomy. One opening of the gastric valve was repaired laparoscopically. There was no perioperative death. Morbidity was limited to one case of pulmonary aspiration of gastric juice. All patients but one who were operated on laparoscopically have been clinically evaluated between four and six months after surgery. There was no dysphagia, diarrhea, or gas bloating reported after two months. Four patients without clinical symptoms refused to go through postoperative explorations. Among the 45 remaining patients, one had a reflux recurrence and another only an abnormality on acid reflux monitoring. There was no degradation of the clinical result among the 26 and 12 patients seen at one and two years, respectively. CONCLUSIONS: A 270 degree posterior fundoplasty can be performed laparoscopically without major morbidity. A short follow-up examination confirms the efficacy of the procedure and the absence of specific morbidity. If these results are confirmed, they could be an argument to broaden the indications of the antireflux procedure as compared to prolonged medical treatment.
Adult↗
Influence of ATP and ATP agonists on the physiology of the isolated semicircular canal of the frog (Rana pipiens).
In the present study, the influence of extracellular ATP and ATP agonists in the physiology of the vestibular organs was examined, using the in vitro model of the isolated semicircular canal of the frog (Rana pipiens). The firing activity of the afferent nerve, the d.c. nerve potential and the transepithelial potential were measured in the absence and presence of mechanical stimulation of the sensory epithelium. Administration of ATP into the perilymphatic compartment, from 10(-12) to 10(-3) M, increased the firing rate of the afferent fibers recorded in the absence of mechanical stimulation. Recordings of the d.c. nerve potential indicated that the afferent fibers were hyperpolarized. The presence of the purine also modified the transepithelial potential. During mechanical stimulation of the sensory epithelium, both the evoked afferent firing and the evoked variation of the d.c. nerve potential were reduced in the presence of ATP. However, ATP did not effect the evoked modulation of the transepithelial potential, evoked by the mechanical stimulation. Administration of the P2x purinoceptor agonists, alpha, beta-methylene-ATP and beta, gamma-methylene-ATP, at concentrations between 10(-12) and 10(-3) M, did not significantly modify the different bioelectrical activities investigated. In contrast, 2-methylthio-ATP, a P2y purinoceptor agonist, more potent and efficacious than ATP in its effect on the spontaneous firing. Concurrently, no modification of the d.c. nerve potential, the transepithelial potential and their variation during mechanical stimulation was observed. In opposition to the ATP effect, the total amplitude of the evoked firing was increased in the presence of 2-methylthio-ATP. These data suggest that extracellular ATP, present in the perilymphatic compartment, may act as a neuromodulator in the vestibular physiology. The effects of the purine appear to be mediated by the activation of a P2y subtype of purinoceptor. The absence of an effect of ATP and 2-methylthio-ATP on the evoked variation of the transepithelial potential suggest that the purine did not affect the processes responsible for the generation of the receptor potential but more likely modified the mechanisms involved in the release of the neurotransmitter from the hair cells and/or acted on the afferent endings.
Action Potentials↗
Early intravenous administration of metoprolol enhances myocardial salvage by thrombolysis with recombinant tissue-type plasminogen activator after thrombotic coronary artery occlusion in the dog by improvement of the collateral blood flow to the area at risk.
OBJECTIVES: We studied the effects of beta 1-adrenergic blockade preceding thrombolysis on hemodynamic variables, myocardial blood flow and infarct size in a canine model of thrombotic occlusion of the left anterior descending coronary artery. BACKGROUND: Previous work suggested a reduction in infarct size and improvement in left ventricular function by intravenous beta-blockade preceding thrombolysis. METHODS: Experiments were conducted in 34 anesthetized dogs; 17 received 0.975 mg/kg body weight of metoprolol intravenously starting 15 min after occlusion, and thrombolysis was initiated 60 min after occlusion. Seventeen dogs received saline solution followed by thrombolysis. Coronary blood flow was measured by radioactive microspheres, infarct size by a dye method, hemodynamic variables by catheter-tipped pressure transducers and cardiac output by the thermodilution method. RESULTS: Infarct size in metoprolol- and placebo-treated dogs was 23.62 +/- 18.04% and 41.50 +/- 16.03% of area at risk, respectively (p < 0.01). Before occlusion, myocardial blood flow and hemodynamic variables were similar. Sixty minutes after occlusion, cardiac output (1.94 +/- 0.41 vs. 2.32 +/- 0.68 liters/min, p < 0.01) was lower in the metoprolol-treated dogs. Collateral flow to the area at risk (17.27 +/- 7.44 vs. 10.25 +/- 5.33) and to its epicardial (21.68 +/- 8.04 vs. 11.5 +/- 6.10), midmyocardial (14.30 +/- 8.63 vs. 7.35 +/- 4.94) and endocardial (13.18 +/- 8.21 vs. 6.26 +/- 5.34 cm3/min per 100 g) layers was higher (p < or = 0.05) in the metoprolol-treated dogs. The ratio of epicardial flow area at risk/circumflex territory was inversely correlated to infarct size (r = -0.69, p < 0.01). After 5 min of occlusion, collateral flow was comparable in the five dogs of each group; over the next 55 min it remained constant in the metoprolol group but decreased in the placebo dogs. CONCLUSIONS: Intravenous metoprolol, administered before thrombolysis, enhances infarct size limitation, partly by improvement of collateral flow to area at risk.
Animals↗
[Transparietal spontaneous migration: a complication related to the use of a new material of percutaneous endoscopic gastrostomy?].
Explore the source record for details and available documents.
Carcinoma, Squamous Cell↗