Immunization of cats against feline immunodeficiency virus (FIV) infection by using minimalistic immunogenic defined gene expression vector vaccines expressing FIV gp140 alone or with feline interleukin-12 (IL-12), IL-16, or a CpG motif

Four groups of cats, each containing four animals, were immunized at 0, 3, and 6 weeks with minimalistic immunogenic defined gene expression vector (MIDGE) vaccines containing the gene(s) for feline immunodeficiency virus (FIV) gp140, FIV gp140 and feline interleukin-12 (IL-12), FIV gp140 and feline IL-16, or FIV gp140 and a CpG motif. MIDGEs were coated onto gold beads and injected intradermally with a gene gun. A fifth group of four cats were immunized in an identical manner but with blank gold beads. All cats were challenge exposed to virulent FIV 4 weeks following the final immunization, and the course of infection was monitored. The two groups of cats immunized with the FIV gp140 gene alone or with blank gold particles became highly viremic and seroconverted as early as 4 weeks after infection. In contrast, three of four cats immunized with FIV gp140 in combination with feline IL-12 failed to become viremic or seropositive, as has been shown elsewhere (F. S. Boretti, C. M. Leutenegger, C. Mislin, et al., AIDS 14:1749-1757, 2000). Here we show the effect of IL-12 when used as an adjuvant on the viral RNA and DNA load and on the cytokine profile. In addition, the two groups of cats immunized either with gp140 and IL-16 or with gp140 and the CpG had greatly reduced viremia. Protection correlated weakly with cytotoxic T-lymphocyte activity and increased cytokine transcription of IL-12, gamma interferon, and IL-10 by peripheral blood mononuclear cells in the postchallenge period. This study extends the data on IL-12 and provides new results on CpG motifs and IL-16 used as adjuvants in the FIV cat model.

Protection against FIV challenge infection by genetic vaccination using minimalistic DNA constructs for FIV env gene and feline IL-12 expression

OBJECTIVE

To evaluate the efficacy of a genetic vaccination protocol based on minimalistic, immunogenic defined gene expression (MIDGE) vectors coding for domains of the feline immunodeficiency virus (FIV) env gene and feline IL-12.

METHODS

Three groups of four cats each were immunized three times within 6 weeks by the ballistic transfer of gold particles coated with MIDGE vectors. Group 1 received non-coated gold beads, groups 2 and 3 MIDGE vectors expressing FIV surface plus part of the transmembrane protein. In addition, group 3 received feline IL-12 DNA. All cats were challenged by intraperitoneal injection of 25 TCID50 of infectious FIV Z2. The following criteria were monitored: clinical signs, antibodies to transmembrane protein, antibodies to whole FIV, haematological parameters and kinetics of CD4 and CD8 cells, FIV proviral load (determined by quantitative polymerase chain reaction; PCR) and cytotoxic T lymphocyte (CTL) activity (in selected cats).

RESULTS

None of the cats developed a detectable antibody response during immunizations. Four weeks after challenge exposure, all cats in group 1 (control) and group 2 (FIV surface-transmembrane protein) had seroconverted and showed a high proviral load until week 19 (end of experiment). In contrast, only one of four cats in group 3 (surface-transmembrane protein and IL-12) showed antibodies; it was provirus positive at reduced virus load. Short-lived CTL activity was found in two cats in group 3.

CONCLUSION

Genetic vaccination using a MIDGE-based construct for the expression of the surface-transmembrane protein domain of FIV env and feline IL-12 DNA led to protection against homologous virus challenge in three out of four vaccinated cats.

Chest wall implantation of a mediastinal liposarcoma after thoracoscopy

We report a case of mediastinal liposarcoma resected by thoracoscopy. Despite the precautionary measures, chest wall implantations occurred rapidly at the port's sites in the chest wall and led to death within 24 months. We conclude that thoracoscopy is not a good approach for resection of anterior mediastinal masses in view of their possible malignant character.

Vaccination with feline immunodeficiency virus induces CD4 epitope masking by soluble factors

Soluble factors are important effector mechanisms to control for lentiviral replication. Vaccination of cats with recombinant outer surface proteins (SU) of the FIV envelope protein in combination with complete Freund adjuvant (CFA) and rabies nucleocapsid (NC) protein led to significantly reduced viral loads [Leutenegger, C.M., Hofmann-Lehmann, R., Holznagel, E., Cuisinier, A.M., Wolfensberger, C., Duquesne, V., Cronier, J., Allenspach, K., Aubert, A., Ossent, P. , Lutz, H., 1998. AIDS Res. Hum. Retroviruses, 14(3) 275-283]. Lymphocytes from vaccinated and non-vaccinated cats were stained with two monoclonal antibodies, Fel7 and CAT30A, directed against the feline CD4 antigen. Peripheral blood lymphocytes from cats vaccinated with the SU glycoprotein, CFA and rabies NC protein showed a significantly reduced number of cells after staining with CAT30A, while the number in Fel7 positive lymphocytes remained unchanged. This decreased CAT30A fluorescent staining could be reproduced in vitro by pre-incubating FIV-negative lymphocytes with immune sera from cats in which reduced CAT30A staining was detected. Neither experimental infection nor vaccination with the unglycosylated SU protein alone resulted in this epitope masking. Furthermore, this masking phenomenon was negatively correlated with a decreased susceptibility to activation-induced cell death (AICD). These findings will be discussed based on the current knowledge of CD8(+) T-cell antiviral factors and their involvement in lentiviral infection and/or replication.

Vaccination of Tunisian dogs with the lyophilised SAG2 oral rabies vaccine incorporated into the DBL2 dog bait

The protective effect of the lyophilised SAG2 oral vaccine bait DBL2, already demonstrated on laboratory dogs, needed to be verified on common Tunisian dogs. Seven Tunisian dogs consumed totally or partially one DBL2 bait containing 10(8.3) TCID50 of the highly attenuated rabies vaccine strain, SAG2. Five of the seven vaccinated animals survived a challenge administered 33 days later with a Tunisian canine street rabies virus to which five of the six controls that were not vaccinated and had no specific antibodies succumbed. The partial or total consumption of a single DBL2 bait thus conferred a protective immune response similar to that observed in laboratory dogs to dogs of poor health status. The sero-antibody response was, however, weak: only two vaccinated dogs exhibited a significant neutralising antibody response after vaccination and before the challenge, and four after the challenge.

[Biological diagnosis of the type of liver disease in alcoholic patients with abnormal liver function tests]

OBJECTIVES

The histological diagnosis of the different stages of alcoholic liver disease is not systematic. The aim of this study was to assess whether common biological features were useful in identifying the different stages.

METHODS

One thousand twenty six alcoholic patients with liver histology and without any associated diseases or infections likely to alter serum liver tests were studied. Diagnostic analyses were performed using stepwise discriminant analysis in the entire population and in asymptomatic patients.

RESULTS

a) Serum ASAT activity levels were only normal in 39% of the patients with normal histological liver and in 14% of the patients with steatosis; b) liver failure was already present in patients with fibrosis without cirrhosis; c) betagamma block was the only biochemical parameter which confirmed the diagnosis of cirrhosis without biopsy; d) the diagnostic accuracy of common tests was weak for the diagnosis of alcoholic liver disease without cirrhosis but prothrombin time could be useful in excluding the diagnosis of cirrhosis with and without acute alcoholic hepatitis when liver biopsy is not available.

CONCLUSION

Only a prothrombin time of 80% with a negative predictive value of 94% and the presence of beta-gamma [corrected] block with a positive predictive value of 98% were useful for assessing the diagnosis of cirrhosis in all patients with alcoholic liver disease.

Sickness and behaviour in animals: a motivational perspective

Proinflammatory cytokines, produced by the activated immune system, induce a whole set of non-specific symptoms in the infected individual (i.e. hypophagia, adipsia, reduced social interest). However, evidence summarised in this review shows that behavioural changes induced by cytokines are not merely the consequence of a degraded state but reflect motivational reorganisation. If the set-up of these new priorities is expressed by a general decrease in behavioural activities (e.g. immobility, sleepiness), the sick individual remains nevertheless an open system still able to respond to environmental stimuli. If these cues are evaluated as relevant to the new priorities (e.g. cues from scattered pups or cues from nest material when ambient temperature is low), the sick individual interrupts sickness behaviour in order to respond specifically to the cues (e.g. retrieving of the pups or nest building). Once this is done, there is a return to recuperative behaviour. These findings represent a primary characterisation of biobehavioural action of immune stimuli, and they open new perspectives to facilitate further progress in our understanding of cytokine effects on behaviour.

[Granular cell tumor of the common bile duct. Contribution of endoscopic ultrasonography in 2 cases]

We report two cases of granular cell tumors involving the common bile duct in patients presenting with obstructive jaundice. Pre-operative endoscopic ultrasonography showed short asymmetric stricture with small well delimited hypoechoic mass in the distal common bile duct wall and proximal dilatation. These tumors were misdiagnosed as a bile duct carcinoma in one case and biliary metastasis of a melanoma in the other. Histological examination of the resected specimen showed granular cell tumors. A review of the previously reported cases shows that preoperative diagnosis is uncommon. It should be considered when endoscopic ultrasonography performed for biliary obstruction in a young woman shows a small and well limited hypoechoic mass.

Clearance of infection in cats naturally infected with feline coronaviruses is associated with an anti-S glycoprotein antibody response

We have investigated by Western blotting the antibody responses against the three major structural proteins in cats naturally infected with feline coronaviruses that cleared virus infection (group I), established chronic asymptomatic infection (group II) or were sick (group III). The cats of group I developed an anti-S glycoprotein response that was, relative to the anti-M glycoprotein response, at least 30-fold higher than that of chronically infected cats from groups II and III. These results suggest that the anti-S glycoprotein response against antigenic domains revealed by Western blot is associated with clearance of the virus after natural infection, and is not a risk factor for the establishment of a chronic infection.

Safety evaluation of the SAG2 rabies virus mutant in Tunisian dogs and several non-target species

The safety of the SAG2 rabies virus, a highly attenuated mutant of the SAD strain intended to vaccinate dogs by the oral route, was evaluated in local Tunisian dogs and in five other local species likely to consume vaccine baits. These species were the domestic cat (Felis catus), the jackal (Canis aureus), the jerboa (Jaculus orientalis), the merion (Meriones sp.) and the gerbil (Gerbillus campestris). The vaccine was administered orally to 21 dogs, 11 cats and eight jackals and orally or intramuscularly to 62 wild rodents of the above-mentioned species. Seven dogs, one cat, five jackals all juvenile and with poor health status) and two rodents died for intercurrent causes. The others were observed for 60-180 days. No animal showed any rabies symptom. Seroneutralizing antibodies were observed in all experimental groups, only after vaccination, with the highest rate being observed in jackals and rodents. The rabies virus was detected in the oral cavity of three cats 6 h after oral instillation, but was not isolated later either in saliva or in salivary glands. Tissue samples (brain and salivary glands) from dead or euthanized animals were examined for the rabies virus antigen by a fluorescent antibody test. No rabies antigen was detected. These trials confirm the safety of the SAG2 strain on the Tunisian species already demonstrated by other authors on many other target and non target species.

[Descriptive epidemiology of patients with alcoholic liver disease hospitalized in a hepato-gastroenterology service]

OBJECTIVE

To improve the detection of early stage alcoholic liver disease and to identify the importance of this disease, this study compared epidemiological characteristics, the reasons for and the duration of hospitalization, in-patient mortality and the frequency of multiple hospitalizations in alcoholic patients without cirrhosis and in patients with alcoholic cirrhosis hospitalized in the hepatogastroenterology department of Antoine-Beclere Hospital.

MATERIAL AND METHODS

From January 1982 to December 1995, all patients with a daily alcohol intake in the previous year of at least 50 g per day and all patients with alcoholic cirrhosis whatever their drinking habits were studied.

RESULTS

Three thousand three hundred and forty six patients were included. The daily alcohol intake in the previous five years was 118 +/- 81 g and the duration of alcohol abuse was 22 +/- 13 years. Two thousand one hundred eight patients had liver biopsy; 37% had histologically proven or probable cirrhosis. Forty one percent of the patients without cirrhosis who had liver biopsy already had steatofibrosis and/or acute alcoholic hepatitis. 32.5% of the patients had hepatitis B virus markers. 7.7% of the patients were positive for anti hepatitis C virus antibody. Thirty two percent of the patients with cirrhosis were women versus 22% of the patients without cirrhosis (P < 0.01). Alcoholism was the reason for the first hospitalization in sixty percent of the patients without cirrhosis and in twenty percent of the patients with cirrhosis (P < 0.01). On the other hand, ascites were the first reason for the first hospitalization in patients with cirrhosis (28%). The two main causes for multiple hospitalizations were also ascites and alcoholism.

CONCLUSION

Two thirds of heavy drinkers did not have cirrhosis on admission since alcoholism was the first reason for multiple hospitalizations in these patients, therefore the management of alcoholism in out-patients must be improved.

Efficacy of SAG-2 oral rabies vaccine in two species of jackal (Canis adustus and Canis mesomelas)

Trials were carried out to test the efficacy of SAG-2 oral rabies vaccine in two species of jackals, namely the side-striped jackal (C. adustus) and the black-backed jackal (C. mesomelas). The first trial tested the efficacy of SAG-2 when given by direct oral administration at doses of 6.5 and 7.5 log10 median tissue culture infectious doses (TCID50). One side-striped jackal which had received the higher dose did not seroconvert and succumbed to challenge, while all other jackals seroconverted and resisted a lethal challenge. The second trial tested the efficacy in side-striped jackals only of the SAG-2 vaccine when given within chicken head baits. A volume of 1.8 ml of vaccine fluid with titers of 7.0 or 8.0 log10 TCID50/ml were placed into blisters which were stapled under the skin of the chicken heads. All jackals (5/5) which received 8.0 log10 TCID50/ml and 3 of 5 which received 7.0 log10 TCID50/ml seroconverted and resisted lethal challenge. A third trial tested the rate of vaccine virus titer loss in chicken head baits placed under field conditions. Titer loss was marked in baits which were not protected from direct sunshine, whereas under vegetation cover approximately log10 TCID50/ml was lost every 3 days. Hence, it was concluded that a bait vaccine virus titer of 8.0 log10 TCID50/ml will be sufficient to immunize wild jackal populations if enough baits can be consumed by jackals within 3 days. This conclusion needs to be tested through the use of oral vaccine in field trials.

Attempt to modify the immune response developed against FIV gp120 protein by preliminary FIV DNA injection

Following inactivated virus vaccination trials, the surface glycoprotein gp120 (SU) of the feline immunodeficiency virus (FIV) was considered as one of the determinants for protection. However, several vaccination trials using recombinant Env protein or some Env-derived peptides failed to induce protection. To study the influence of the environment in which the surface protein (SU) is injected. we analyzed the impact of a nucleocapsid (NC) DNA immunization on the presentation of the recSU protein to the immune system. Cats were vaccinated either with the recSU protein alone or with NC DNA followed by the recSU protein. Two routes of nucleocapsid DNA vaccination were tested: intramuscular and mucosal injections. Cats immunized with the recSU protein showed a facilitation of infection, since they presented the earliest and the highest humoral response correlating with the highest proviral load. They also showed an acceleration of the appearance of IL4 mRNA signal. Preliminary injection of the DNA coding for NC protein, regardless the route of inoculation, seemed to inhibit the facilitation induced by vaccination with the recSU protein alone. The previously nucleocapsid DNA immunized cats had infectious status similar to those of the control cats, but with lower proviral load and less developed anti-FIV humoral response. Cat No. 2, belonging to the group vaccinated with NC protein by the mucosal route, had a protected-like status which did not correlate with the humoral response. This cat was the only one to have a persisting IFN mRNA signal after challenge specific for the p10 nucleocapsid and recSU proteins. However, no NC specific cytotoxic cells were observed throughout the experiment in this cat. The role of nucleocapsid DNA vaccination is still unknown nevertheless we did demonstrate that the facilitation observed in vaccination trial with recombinant proteins could be modified and that recombinant proteins could be a component of an effective vaccine.

[Inflammatory fibroid polyps of the colon]

Inflammatory fibroid polyp is an uncommon lesion involving the stomach, the small bowel and occasionally the colon. Inflammatory fibroid polyp is a large polypoid lesion arising from the submucosa. It has no malignant potential although extensive infiltration may occur. The main histological characteristics are diffuse inflammatory infiltrate with eosinophils and highly vascularized fibrocytic stroma. Immunohistochemistry is always positive for vimentine and negative for S 100 and desmin. We report four cases of inflammatory fibroid polyps, 3 of which mimicked carcinoma of the colon. Exploratory laparotomy and histopathological examination of the resected specimen were necessary to confirm definitive diagnosis. In the last case, diagnosis was established by histological examination of an endoscopically-removed colonic polyp.

[Videolaparoscopic treatment of paraesophageal hiatal hernia]

STUDY AIM

The aim of this prospective study was to report the results of videolaparoscopic repair in a series of ten patients with paraesophageal hernia.

PATIENTS AND METHODS

From January 1982 to September 1998, ten patients (three men and seven women, mean age: 68 years [range: 42-87]) were operated on for paraesophageal hernia. An intrathoracic gastric volvulus was present in four patients, a severe anemia in four and two were asymptomatic. All interventions were performed laparoscopically and included sac resection, crura closure and realization of a posterior gastric valve on 270 degrees.

RESULTS

There was one irruption of gastric juice in the bronchial tree at the beginning of the anesthesia which required assisted ventilation for 3 days. The mean follow-up was 17.5 months (range: 3-50). There was no postoperative diarrhea and no gas bloat syndrome. Eight patients complained of postoperative dysphagia which disappeared within 6 weeks, except in one patient with esophageal motility disorder postoperatively discovered. None of the patients had postoperative gastroesophageal reflux. A chest X-ray performed after 1 year detected no hernia recurrence in seven patients. There was no recurrent anemia after 6 months.

CONCLUSION

The videolaparoscopic repair of paraesophageal hernias is feasible without any technical difficulties even in aged patients with precarious physical conditions. The results are good with a mean follow-up of 17.5 months.

[Laparoscopic cholecystectomy and lithiasis of the common bile duct: prospective study on the importance of preoperative endoscopic ultrasonography and endoscopic retrograde cholangiography]

OBJECTIVES

Laparoscopic cholecystectomy is the standard treatment of symptomatic gallstones. At present, no consensus has been reached on the diagnostic and therapeutic methods of concomitant common bile duct stones. Systematic preoperative endoscopic ultrasonography followed, if necessary, by endoscopic retrograde cholangiography and sphincterotomy during the same anesthetic procedure could be a diagnostic and therapeutic alternative for common bile duct stones making possible a laparoscopic cholecystectomy without intraoperative investigation of the common bile duct.

METHODS

One hundred and twenty-five patients underwent a prospective endoscopic ultrasonographic evaluation prior to laparoscopic cholecystectomy for symptomatic gallstones. Fourty-four patients (35%) had at least one predictive factor for common bile duct stones. Endoscopic ultrasonography and cholecystectomy were performed on the same day. Endoscopic ultrasonography was followed by endoscopic retrograde cholangiography and sphincterotomy by the same endoscopist in case of common bile duct stones on endoscopic ultrasonography. Patients were routinely followed up between 3 and 6 months and one year after cholecystectomy.

RESULTS

Endoscopic ultrasonography suggested common bile duct stones in 21 patients (17%). Endoscopic ultrasonography identified a stone in 17 of 44 patients (38.6%) with predictor of common bile duct stones and only in 4 of 81 patients (4.9%) without predictor of common bile duct stone. Among these 21 patients, one patient was not investigated with endoscopic retrograde cholangiography because of the high risk of sphincterotomy, 19 patients had a stone removed after sphincterotomy, one patient had no visible stone neither on endoscopic retrograde cholangiography, nor on exploration of the common bile duct after sphincterotomy. Endoscopic ultrasonography was normal in 104 patients (83%). However, two patients in this group were investigated with endoscopic retrograde cholangiography because endoscopic ultrasonography was incomplete in one case and because endoscopic ultrasonography was normal in the second case but a stone in the left hepatic duct was detected by ultrasonography. A stone was removed after endoscopic sphincterotomy in these two patients. In the group of 102 patients without stone, 91 out of 92, continued to be asymptomatic during a median follow-up of 8.5 months. One patient with symptoms one month after cholecystectomy underwent endoscopic sphincterotomy but no stone was found.

CONCLUSIONS

Systematic preoperative endoscopic ultrasonography followed, if necessary with endoscopic retrograde cholangiography and sphincterotomy is a diagnostic and therapeutic alternative for common bile duct stones making possible a laparoscopic cholecystectomy without intraoperative investigation of the common bile duct for all patients. This alternative is only justifiable in patients with predictor of common bile duct stones.

Partial protection by vaccination with recombinant feline immunodeficiency virus surface glycoproteins

In an effort to induce a strong immune response that might protect against feline immunodeficiency virus (FIV) challenge infection, three groups of five specified pathogen-free (spf) cats each were immunized subcutaneously with different FIV antigen preparations. Immunizations were done at weeks 0, 2, and 4 with 100 microg of recombinant SU from an FIV Zurich 2 (FIV Z2) strain expressed by E. coli (group 1) or the baculovirus expression system (groups 2 and 3) adsorbed on aluminum hydroxyde and administered with QS-21 (groups 1 and 2) or Freund's adjuvant together with the recombinant nucleocapsid protein (protein NC) of rabies virus (group 3). Protein NC was described to act as an exogenous superantigen. Group 3 cats demonstrated the highest detectable antibody response to the vaccine antigen as determined by ELISA and Western blot analysis. All immunized cats together with seven control animals were challenged with 20 CID50 of cat lymphocyte-grown FIV Z2 3 weeks following the last immunization. Whereas virus was readily recovered from peripheral blood lymphocytes of seven of seven nonvaccinated control cats following this challenge dose, virus was not recovered from two cats of groups 1 and 2. All cats in groups 2 and 3 showed a provirus load significantly decreased to 3% of that of controls up to week 8 after challenge infection. Eleven of 15 vaccinated cats and 5 of 7 control cats developed virus-neutralizing antibodies by week 8 after challenge infection. The two cats negative on virus isolation remained seronegative, developed no detectable virus-neutralizing activities, but were repeatedly positive in provirus PCR. Moreover, starting at week 1 after challenge, both cats showed the lowest provirus load in their respective groups. These results indicate that immunization with recombinant FIV SU in conjunction with appropriate adjuvants may lead to partial protection against FIV challenge infection.

[MRI cholangiography with rapid spin-echo technique: prospective evaluation of 20 patients]

PURPOSE

To evaluate a MR cholangiographic technique using a non breath-hold fast spin-echo technique in patients with suspected bile duct obstruction.

MATERIAL AND METHODS

Twenty patients with suspected bile duct obstruction were prospectively investigated with MR cholangiography using a T2-weighted non breath-hold fast spin-echo technique (TR = 8000-9000 mse, effective TE = 120-266 msec, ETL = 16-32, acquisition time = 1-3 min) with a body coil. Results of MR cholangiography were compared to those obtained with endoscopic retrograde cholangiography (n = 20 patients) and endoscopic sonography (n = 12 patients) that were considered as reference.

RESULTS

MR cholangiography provided high-quality images in 19 out of 20 cases (95%). MR cholangiography had 100% sensitivity, 100% specificity and 100% accuracy in the diagnosis of bile duct dilation. MR cholangiography had 73% sensitivity, 75% specificity and 73% accuracy in the diagnosis of bile duct obstruction. MR cholangiography failed to depict small stones (< 3 mm) of the main bile duct in 4 cases in which no bile duct dilatation was found.

CONCLUSION

MR cholangiography using a non breath-hold fast spin-echo technique depicts bile duct dilatation with a degree of accuracy comparable to that achieved with endoscopic examination. In the absence of bile duct dilatation, small stones of the main bile duct may be undetected with MR cholangiography.

Differential effect of lipopolysaccharide on food hoarding behavior and food consumption in rats

Experimental studies assessing the suppressing effect of lipopolysaccharide (LPS) on feeding behavior have focused exclusively on the ingestive component of this behaviour without taking into account its appetitive component. The appetitive sequence of feeding behavior regroups activities animals engage in to gain access to food without necessarily eating it. The objective of the present study was to compare the effects of LPS on food intake and food hoarding. Rats were given the possibility to access food during a 30-min daily session in an apparatus consisting of a cage connected to an alley with free food at its end. Subjects were tested under different motivational levels for food hoarding: a first group (FS) received a food supplement to maintain stable body weight while a second group (noFS) did not receive such a supplement. LPS (250 micrograms/kg i.p.) dramatically decreased total food intake in rats from both groups whereas food hoarding was much less affected in LPS-treated rats from the noFS group. This expression of a still salient secondary motivation in LPS-treated rats which did not receive any food supplement can be interpreted to suggest the expression of an anticipatory feeding behavior along with a reduced immediate appetite. In addition, LPS had no effect, in rats from the noFS group, on the amount of food eaten after transport to the refuge. LPS-treated animals still appear to be able to adjust their defensive behavioral strategies with regard to their needs and capacities. These findings support the adaptive value of the behavioral changes displayed by LPS-treated animals.