Groups Of Infected Animals Research Articles

The effect of triterpene glycoside on survival and changes in the cytokine profile in the spleen of BALB/c mice under conditions of lethal influenza infection A/WSN/1/33(H1N1)

BACKGROUND: Currently, the search and development of compounds, including herbal ones, with anti-influenza activity are relevant.
 AIM: To study the effect of oral administration of the triterpene glycoside saponin tauroside Sx1 on survival and changes in the cytokine profile of the spleen of mice under conditions of lethal influenza infection.
 MATERIAL AND METHODS: 78 male BALB/c mice aged 4–6 weeks, weighing 16–18 g, were used. They were divided into groups: first — control group; the second was a group of animals infected with influenza virus A/WSN/1/33(H1N1); the third was a group of infected animals that received saponin tauroside Sx1, isolated from the Crimean ivy Hedera taurica (Hibberd) Carrière at a dose of 11.8 mg/kg per day against the background of a viral infection for 3 days. The survival and expression of interleukins-1β and -10 in the spleen of mice on the 4th and 14th days of the experiment were studied. Spleen fragments were stained with hematoxylin and eosin. Microscopic analysis was performed using a video microscopy system. Immunohistochemical study was performed according to a standard protocol. Intergroup differences were assessed using the Kruskal–Wallis test and the Mann–Whitney U test using MS Office (Excel 2010) and Statistica 10.0.
 RESULTS: Administration of saponin tauroside Sx1 significantly increased the average life expectancy of animals by 4.6 days compared to the group without correction; survival rate was 30.0% (p=0.0233). Against the background of influenza infection, an increase in the number of cells secreting interleukin-1β was detected in the spleen of mice. In the mantle zone of the second group, the level of cytokine expression exceeded the control values by 3.41 times (p=0.0001), and the values of the third group — by 3.38 times (p=0.0001). By the 14th day of the experiment in the mantle zone, expression in the group with saponin administration increased, exceeding the indicators of the group without correction by 34.78% (p=0.0482). By the 4th day of the experiment, in both experimental groups, the number of cells positive for interleukin-10 increased in the mantle zone and decreased compensatoryly in the marginal zone. By the 14th day, in the group without correction, a decrease in expression by 24.86% (p=0.0487) was recorded; after the administration of saponin, the number of immunopositive cells was practically no different from the control (p=0.0443).
 CONCLUSION: Therapeutic administration of saponin tauroside Sx1 stabilizes the cytokine profile of the spleen of mice and promotes their better survival in conditions of lethal influenza infection.

Monophasic Variant of Salmonella Typhimurium Infection Affects the Serum Metabolome in Swine.

Salmonella is the most relevant foodborne zoonotic agent found in swine, and its presence in French herds is significant. Its carriage is asymptomatic, which makes it difficult to detect during rearing, thus increasing the risk of its presence on pork meat. Studies have shown that enteric infection in animals could be associated with changes in the serum metabolome composition, through the immune response or changes in the digestive microbiota composition. We hypothesized that these changes in the serum metabolome composition could be used as markers for the detection of asymptomatic animals infected by Salmonella. Using untargeted analysis by liquid chromatography coupled with mass spectrometry, we showed that significant differences in the composition of the serum metabolome could be detected between infected or noninfected animals both 1 and 21 days after experimental infection. This serum metabolome composition significantly changed during the 21 days postinfection in the infected animal groups, suggesting an evolution of the impact of infection with time. Despite this evolution, differences in the serum metabolome composition persisted between infected and noninfected animals 21 days after the initial infection. We also showed a possible difference between high-shedding and low-shedding animals 21 days postinfection. Finally, some of the variations in the metabolome were found to be significantly associated with variations of specific members of the fecal microbiota. Thus, excreting and asymptomatic animals, but also high-shedding animals, could be identified on the basis of their serum metabolome composition.

Effect of Ganoderma Fungi and Spirulina Alga in The Liver Tissue of Diabetic Mice Developed with Aloxane and Lead-Induced Anemia

The study was conducted on male mice (Albino mice), which ranged in age from (2-3) months and weights (25 - 30) g. The experiment was conducted in the General Company for the manufacture of medicines and medical supplies - Samarra. And for the period from the beginning of October 2017 to the end of March 2018, Used 42 animals were distributed in seven groups, each containing 6 animals, to determine the effects of both gannoderma and spirulina in laboratory mice induced by diabetes mellitus with a Aloxan at 150 mg / kg Bw. In laboratory mice with anemia with lead acetate of 50 mg / Kg body weight for 30 days (except control group) At the end of the 30-day feeding period.
 
 control group on the regular diet.
 control group infected diabetes and drugs on the regular diet.
 The group of diabetic animals treated with ganoderma fungi powder (47 mg / kg body weight).
 The group of diabetic animals and the treatment of spirulina algae powder (33 mg / kg body weight).
 group of animals infected with anemia and spores on the regular diet and water containing lead acetate
 Group of infected animals and treated with lead acetate + Ganoderma fungi powder (47 mg / kg body weight).
 Group of infected animals and treated with lead acetate + Spirulina algae powder (33 mg / kg body weight).
 
 Histological changes were observed in the Livre tissue: The results of the study of tissues in the group of animals treated with Alloxnesan damage to the overall liver tissue in the form of hepatocytes and hydrolysis and the expansion of the Sinusiod. In the treatment of diabetic animals with ganoderma and spirulina algae, there was improvement in the overall liver tissue in terms of normal hepatocytes, absence of congestion, and normal Sinusiod. the group treated with anemia and treated with lead acetate, we also notice significant damage to the liver tissue. When treated with lead acetate + gannoderma, and spirulina, we did not notice any improvement in liver tissue.

Some of Biochemical Tests for Blood Serum and Some of Hematological Variants of the Blood for Iraqi Camels Infected with Blood Parasites

This study was conducted to measure some biochemical tests of blood serum and some hematological variables of Iraqi camels infected with blood parasites.We collected randomly (70) blood samples for the period of time from the beginning of 1/6/2018 to 30/6/2019 with an age ranging (less than one year - 14 years) (For both sexes), (20) samples of which, with a percentage (28.57%) from camels who were in good health condition for approval as a control group to compare the results of their chemical and blood tests with the results of the tests for camels infected with blood parasites, and a number (50) samples, at a rate (71.43%) from camels, who was suffering from anemia, pall and yellowish of the mucous membranes, combined with areas of edema in the neck, chest, genitals and limbs. The first work of the study is to do clinical examination of all the animals used for research then make blood smears, and biochemical tests of blood plasma was performed, then a statistical analysis of the results obtained was performed using the (SPSS) program. The results of the research showed that number (14) at (28%), had babesia, number (15) at 30%, had anaplasma while (9) at (18%) had trypanosoma, and number (12) at 24%, had thalaria. The results of the clinical examination, after comparing them with the control group, showed there was a statistically significant difference at a level of (p is less than 0.05) between healthy and infected camels. As for the results of the blood tests, it was noted there was a decrease in the values of the tests for the blood samples of animals infected with blood parasites than in the animals of the control group, thus, a statistically significant difference at a level of (p is less than 0.05) was recorded between the two groups, but there was no statistically significant difference at a level of (p is less than 0.05) between animals that infected with blood parasites between them. The results for the values of MCV, MCH, and MCHC, we found that they did not show any statistically significant difference at a level of (p is less than 0.05) between the control group and the group of infected animals also between the infected animals between them. The results of the total number of white blood cells and the differential count for each type of leukocytes in the control and infected group showed a significant statistical difference at a level of (p is less than 0.05) between the two groups and between the types of leukocytes between them and the results of the biochemical tests, the presence of a statistically significant difference at a level of (p is less than 0.05) between the control group and the infected camel group.

Assessment of the therapeutic efficacy of various drugs against cryptosporidiosis in calves

The purpose of the research is studying the spread of cryptosporidiosis in calves and assessment of the extenseeffectiveness of antiprotozoal drugs.Materials and methods. The spread, seasonal and age-specific trends of cryptosporidiosis was studied on 395 spontaneously infected animals of five age groups. The first group was formed of calves up to 10 days of age, the second group of calves aged from 11 days to 2 months, the third group of calves from 2 to 4 months, the fourth group of calves from 4 to 6 months of age, and the fifth group of young animals from 6 months up to 1 year. To assess the efficacy of various drugs against cryptosporidiosis in calves, 5 groups of infected animals (4 experimental and 1 control), 10 animals each, were formed according to the principle of analogous pairs. The infection rate in cattle was determined by generally accepted coprological flotation methods, as well as by native smears with further staining according to Ziehl-Nielsen. We also considered clinical signs of cryptosporidiosis (diarrhea, dehydration).Results and discussion. We established the widespread occurrence of cryptosporidiosis in cattle on the farms of the Igrinsky, Uvinsky, Zavyalovsky Districts of the Udmurt Republic. The infection rate ranged from 20.25 to 80.0%. The largest percentage of infected calves was observed in the winter-spring period which was associated with the synchronization of the reproductive cycles of cows and a decrease in the resistance of the animal organism. Toltarox 5% and Galokur drugs in work environments showed 100% extense-effectiveness. It is not recommended to apply Amprolium 25% on these farms due to the low efficacy and the development of parasite resistance to this drug.

Aggregation state of Mycobacterium tuberculosis impacts host immunity and augments pulmonary disease pathology

In vitro phagocytosis of Mycobacterium tuberculosis (Mtb) aggregates (Mtb-AG), rather than similar numbers of single bacilli (Mtb-SC), induces host macrophage death and favors bacterial growth. Here, we examined whether aggregation contributes to enhanced Mtb pathogenicity in vivo in rabbit lungs. Rabbits were exposed to infectious aerosols containing mainly Mtb-AG or Mtb-SC. The lung bacterial load, systemic immune response, histology, and immune cell composition were investigated over time. Genome-wide transcriptome analysis, cellular and tissue-level assays, and immunofluorescent imaging were performed on lung tissue to define and compare immune activation and pathogenesis between Mtb-AG and Mtb-SC infection. Lung bacillary loads, disease scores, lesion size, and structure were significantly higher in Mtb-AG than Mtb-SC infected animals. Differences in immune cell distribution and activation were noted in the lungs of the two groups of infected animals. Consistently larger lung granulomas with large aggregates of Mtb, extensive necrotic foci, and elevated matrix metalloproteases expression were observed in Mtb-AG infected rabbits. Our findings suggest that bacillary aggregation increases Mtb fitness for improved growth and accelerates lung inflammation and infected host cell death, thereby exacerbating disease pathology in the lungs.

Blood Morphology in Dogs with Dirofilariasis

The article addresses the results of a study of blood morphology parameters in healthy dogs vs. dogs diagnosed with dirofilariasis. In the group of infected animals, the most significant difference was 4.9 higher granulocytes. Another significant contribution is eosinophils and, to a lesser extent, neutrophils and monocytes. In blood of infected and healthy animals, no difference was found in terms of the count of red blood cells, haemoglobin, and haematocrit. Anisocytosis value in red blood cells is probably related to the compensated processes, and differs insignificantly between healthy and infected animal groups. Blood morphology of infected animals is characterized by mild reticulocytosis, not exceeding 20% of physiological norm. In the group of infected dogs, platelet count corresponds to the lower boundary of physiological norm. In healthy animals’ group, platelets and platelet crit is physiologically normal. Leukopenia, lymphocytopenia are detected. Apparently, the reason behind the findings is age of the animals and degree of their adaptation to the progress of the invasive process.

Genomic Insight into Mechanisms of Reversion of Antibiotic Resistance in Multidrug Resistant Mycobacterium tuberculosis Induced by a Nanomolecular Iodine-Containing Complex FS-1.

Drug induced reversion of antibiotic resistance is a promising way to combat multidrug resistant infections. However, lacking knowledge of mechanisms of drug resistance reversion impedes employing this approach in medicinal therapies. Induction of antibiotic resistance reversion by a new anti-tuberculosis drug FS-1 has been reported. FS-1 was used in this work in combination with standard anti-tuberculosis antibiotics in an experiment on laboratory guinea pigs infected with an extensively drug resistant (XDR) strain Mycobacterium tuberculosis SCAID 187.0. During the experimental trial, genetic changes in the population were analyzed by sequencing of M. tuberculosis isolates followed by variant calling. In total 11 isolates obtained from different groups of infected animals at different stages of disease development and treatment were sequenced. It was found that despite the selective pressure of antibiotics, FS-1 caused a counter-selection of drug resistant variants that speeded up the recovery of the infected animals from XDR tuberculosis. Drug resistance mutations reported in the genome of the initial strain remained intact in more sensitive isolates obtained in this experiment. Variant calling in the sequenced genomes revealed that the drug resistance reversion could be associated with a general increase in genetic heterogeneity of the population of M. tuberculosis. Accumulation of mutations in PpsA and PpsE subunits of phenolpthiocerol polyketide synthase was observed in the isolates treated with FS-1 that may indicate an increase of persisting variants in the population. It was hypothesized that FS-1 caused an active counter-selection of drug resistant variants from the population by aggravating the cumulated fitness cost of the drug resistance mutations. Action of FS-1 on drug resistant bacteria exemplified the theoretically predicted induced synergy mechanism of drug resistance reversion. An experimental model to study the drug resistance reversion phenomenon is hereby introduced.

Comparative clinico-pathological observations in young Zebu (Bos indicus) cattle experimentally infected with Trypanosoma vivax isolates from tsetse infested and non-tsetse areas of Northwest Ethiopia.

BackgroundThe Northwest region of Ethiopia is affected by both tsetse and non-tsetse transmitted trypanosomosis with a huge impact on livestock productivity. The objective of this experimental study was to determine clinical and pathological findings in young Zebu cattle experimentally infected with Trypanosoma vivax isolates from tsetse infested and non-tsetse infested areas of Northwest Ethiopia. A total of 18 cattle (Bos indicus) aged between 6 and 12 months, purchased from a trypanosome-free and confirmed to be trypanosome negative divided into three groups of six animals were used. Animals in the first two groups (Group TT: tsetse infested isolate infected and Group NT: non-tsetse infested isolate infected) received 2 mL of infected blood from donor animals at 106 trypanosomes/mL, and the remaining group was non-infected control (NIC). Each group was observed for a period of eight consecutive weeks, daily for clinical signs and once per week for parasitaemia. Postmortem examinations were done on euthanized animals, and tissue samples were taken for histopathological analysis.ResultsThe prepatent period of the disease was earlier in the NT group 6 days post infection (dpi) than TT group 12 dpi. The infection was characterized by reduced feed intake, intermittent pyrexia and parasitaemia, enlarged lymph nodes, lacrimation, reduced feed intake and emaciation. Less frequently diarrhea, oedema and nervous signs were observed in both groups of infected animals. At necropsy, infected animals showed enlarged spleen, enlarged lymph nodes, pneumonic and emphysematous lung, enlarged liver, and haemorrhages on the brain and intestine. Histopathological analysis revealed lymphoid hyperplasia of the spleen, necrosis of the liver, encephalitis and hyperplasia of lymph nodes.ConclusionTrpanosoma vivax isolates from both tsetse infested and non-tsetse areas showed a variety of virulence factors leading to the development of acute clinical signs, gross and histopathological lesions. However, the parasitaemia and clinical signs appeared earlier in the NT compared to TT infected groups.

Cardiomyopathy prognosis after benznidazole treatment in chronic canine Chagas' disease

To evaluate the effects of benznidazole on Chagas' disease cardiac prognosis using an experimental dog model of infection. A total of 28 dogs were divided into three groups: 10 were infected with Trypanosoma cruzi and treated benznidazole during the chronic phase, 10 were infected but untreated, and 8 were non-infected/healthy. The trypanocidal efficacy was measured by parasite kDNA detection in blood and cardiac tissue samples. The effects of benznidazole in ameliorating the cardiac systolic function were evaluated by echodopplercardiogram. The benznidazole initially induced a potent suppression of parasitaemia in treated animals. However, 12 months post-treatment, the parasite kDNA detections were similar between infected groups. In the baseline echocardiographic parameters there was no variation among all animals. Similarly, 1 month post-treatment there was no significant difference among healthy and infected animals with regard to systolic function. At 12 months post-treatment, an increase in cardiac chamber size related to cardiomegaly was detected among treated and untreated animals, but not in the healthy controls. Interestingly, in spite of both groups of infected animals developing a decrease in their systolic cardiac function, this decline was slightly less in the treated animals. We also evaluated levels of tumour necrosis factor-α and interleukin-10 in peripheral blood mononuclear cell culture supernatant. Cytokine profiles were similar between infected animal groups and correlated with alterations in cardiac function. The temporary suppression of the T. cruzi infection induced by benznidazole treatment was efficient in reducing systolic cardiac function alterations, but not in preventing the development of cardiomyopathy.

Altered host response to murine gammaherpesvirus 68 infection in mice lacking the tachykinin 1 gene and the receptor for substance P

The tachykinins are implicated in neurogenic inflammation and the neuropeptide substance P in particular has been shown to be a proinflammatory mediator. A role for the tachykinins in host response to viral infection has been previously demonstrated using either TAC1- or NK1 receptor-deficient transgenic mice. However, due to redundancy in the peptide-receptor complexes we wished determine whether a deficiency in TAC1 and NK1(R) in combination exhibited an enhanced phenotype. TAC1 and NK1(R)-deficient mice were therefore crossed to generate transgenic mice in both (NK1(-/-)×TAC1(-/-)). As expected, after infection with the respiratory pathogen murine gammaherpesvirus (MHV-68), TAC1 and NK1(R)-deficient mice were more susceptible to infection than wild-type C57BL/6 controls. However, unexpectedly, NK1(-/-)×TAC1(-/-) mice were more resistant to infection arguing for a lack of feedback inhibition through alternative receptors in these mice. Histopathological examination did not show any great differences in the inflammatory responses between groups of infected animals, except for the presence of focal perivascular B cell accumulations in lungs of all the knockout mice. These were most pronounced in the NK1(-/-)×TAC1(-/-) mice. These results confirm an important role for TAC1 and NK1(R) in the control of viral infection but reinforce the complex nature of the peptide-receptor interactions.

Studies on the development and role of some cell-mediated immune responses in experimental toxocarosis in mice

AbstractThe studies were undertaken to investigate the development of some cell-mediated immune responses in experimental toxocarosis in mice and to assess the influence of these responses on the course of infection. Mice were infected orally with 350 eggs of Toxocara canis and reinfected with the same dose of parasites after 8 weeks. Groups of infected animals were killed each week of the experiments to obtain spleens, livers and brains for further studies. Lymphocytes from removed spleens were analysed by flow-cytometry for CD4 and CD8 expression and cultured in vitro to measure their responses to Concanavalin A and excretory-secretory (ES) antigen of T. canis in a lymphocyte transformation test. Pieces of livers were used to prepare paraffin sections to be stained later with haematoxylin and eosin, whereas whole brains of the infected animals were examined for the presence of parasite larvae. The results of the studies showed depression of T-cell responses to ConA in early stages of infection and significant increase in the blastogenic responses to the ES antigen from week 4 following infection. The depression of T-cell responses was accompanied by lowered CD4+/CD8+ ratio resulting from increased percentages of CD8+ T cells. Histopathological examination of liver sections revealed trapping of larvae in T. canis reinfected mice. The intensity of infection as measured by larval recoveries from the brains of mice increased gradually up to the 8th week of infection, but did not show significant changes after reinfection, testifying to the development of long-lasting protective immunity during primary infection.

The immune responses on cattle and buffaloes infected with Fasciola gigantica before and after treatment

The immune responses of cattle and buffaloes against the infection of liver flukes Fasciola gigantica were observed by ELISA. Six cattle and 6 buffaloes were infected orally with 700 metacercariae of F. gigantica, 2 cattle and 2 buffaloes were remained uninfected as control animals. Serum blood samples were collected weekly and the antibody levels were monitored before and after treatment. The results showed that the antibody level on cattle increased after 2 weeks post-infection, then gradually increased until reaching the peak at II weeks after infection. In the contrary, the antibody level on buffaloes appeared slower than on cattle, it increased after 13 weeks of infection and reach the peak at 25 weeks after infection. When the antibodylevels reach the peak, both groups of infected animals were treated with triclabendazole. After treatment, the antibody level oncattle was immediately decreased at one week of treatment, and gradually decreased up to the lowest antibody level at 7 weeks after treatment. The response of the treatment on buffaloes showed almost similar pattern, the antibody level decreased after one week of treatment, then remained constant for about 4 weeks, and reach the lowest antibody level at 7 weeks after treatment. It is concluded that the immune responses against the infection of F. gigantica in cattle and buffaloes are different, but the response of the treatment with triclabendazole are similar. Key words : Fasciola gigantica, cattle, buffaloes, antibody levels, triclabendazole

Pharmacodynamics of fluconazole in a murine model of systemic candidiasis.

In this study we defined the pharmacodynamic parameter that optimizes outcome in deep-seated Candida albicans infections treated with fluconazole. Using a murine model of systemic candidiasis, we conducted single-dose dose-ranging studies with fluconazole to determine the dosage of this drug that resulted in a 50% reduction in fungal densities (50% effective dose [ED50]) in kidneys versus the fungal densities in the kidneys of untreated controls. We found that the ED50 of fluconazole given intraperitoneally was 4.56 mg/kg of body weight/day (95% confidence interval, 3.60 to 5.53 mg/kg/day), and the dose-response relationship was best described by an inhibitory sigmoid maximal effect (Emax) curve. To define the pharmacodynamics of fluconazole, we gave dosages lower than, approximating, and higher than the ED50 of fluconazole (range, 3.5 to 5.5 mg/kg/day, equivalent to the ED16 to the ED75) to various groups of infected animals using three dose-fractionation schedules. For each total dose of fluconazole examined, the dose-fractionation schedules optimized the ratio of the area under the concentration-time curve (AUC) to the MIC (the AUC/MIC ratio), the ratio of the maximum concentration of drug in serum (Cmax) to the MIC, and the time that the drug remained above the MIC for the infecting C. albicans isolate. Similar reductions in fungal densities in kidneys were seen between groups that received the same total dose of fluconazole in one, two, or four equally divided doses. Thus, dose-fractionation studies demonstrated that the pharmacodynamic parameter of fluconazole that best predicted outcome was the AUC/MIC ratio.

Myringotomy: A Prerequisite for the Development of Myringosclerosis?

Streptococcus pneumoniae was inoculated into the left middle-ear cavity in two groups of rats, resulting in purulent otitis media. After 3 days, one group of infected animals and a third group of noninfected animals were subjected to left-sided myringotomy. The tympanic membranes were examined both otomicroscopically and histologically 1 and 3 months later. On otomicroscopic examination the noninfected myringotomized animals had developed extensive myringosclerotic lesions, whereas only minimal sclerotic deposits were noted in the myringotomized animals with acute otitis media (AOM). On histologic examination both the noninfected myringotomized animals and the myringotomized animals with AOM were similar in the frequency and extension of sclerotic lesions in the tympanic membrane. The nonmyringotomized rats with AOM were free of sclerotic lesions, except for minor changes found in one animal.

Effects of experimental dicrocoeliosis on oxidative drug metabolism in hamster liver

The purpose of this investigation was to determine the effects of experimental dicrocoeliosis on the hepatic oxidative drug-metabolizing system in hamsters. Studies were carried out 80 and 120 days after infestation with an oral dose of 40 metacercariae of Dicrocoelium dendriticum. The parasitic pathology was ascertained by detection of the fluke eggs in faeces, increased serum alanine aminotransferase and aspartate aminotransferase activities, and postmortem and histological findings. Cytochrome P-450 concentration, aniline hydroxylase activity and ethoxycoumarin O-deethylase activity were significantly decreased in both groups of infected animals. Aminopyrine N-demethylase activity and erythromycin N-demethylase activity were only reduced 120 days after infection. Effects on drug metabolizing enzymes were unrelated to changes in the physical state of the microsomal membrane, as assessed by measurement of fluorescence polarization. The results of this study indicate that the capacity of the liver for handling drugs and xenobiotics may be impaired as a consequence of dicrocoeliosis.

Experimental studies on the pharmacokinetics and therapeutic effect of cefbuperazone in biliary infection

A study was carried out using an experimental biliary infection model to investigate the pharmacokinetic characteristics and therapeutic effect of cefbuperazone in the rabbit. Thirty rabbits were divided into three equal groups; a control group of normal animals, a group of infected animals receiving no cefbuperazone, and a group of infected animals receiving 50 mg cefbuperazone/kg intramuscularly. The experimental infection was made by direct inoculation of a suspension of E. coli into the common bile duct after ligation. The results showed that extremely high levels of cefbuperazone were achieved in bile and tissues of the biliary tract and were higher than those in the blood. Moreover, the levels were maintained at effective concentrations even after 6 hours. Viable bacterial cells from bile and the gall-bladder were barely detectable 24 and 48 hours after infection in the cefbuperazone-treated group, whilst counts remained high in the other infected group. White blood cell counts were increased at 24 hours after infection but were significantly lower in the cefbuperazone-treated group. Histological examination revealed marked inflammatory changes in the gall-bladder and bile duct of infected, untreated animals but few, mild changes only were seen in cefbuperazone-treated animals. Similarly, total bilirubin and liver enzymes were markedly increased in infected animals, but transaminases and alkaline phosphatase were significantly lower in the treated compared to the untreated group. The findings indicate, therefore, that cefbuperazone can be a useful antibiotic in biliary infection.

Peripheral blood leucocytes subpopulation dynamics during Trypanosoma congolense infection in Boran and N'Dama cattle: an analysis using monoclonal antibodies and flow cytometry.

A panel of monoclonal antibodies (MoAb) with specificities for bovine leucocyte subsets were used in conjunction with routine haematological procedures to analyse sequential changes in peripheral blood leucocyte populations during the course of tsetse fly-transmitted Trypanosoma congolense infection in trypanotolerant N'Dama and trypanosusceptible Boran cattle. Subsequent to the first parasitaemic wave, the N'Dama cattle maintained packed cell volumes (PCV) above 22 and lower levels of parasitaemia than Boran throughout the 160 days of the experiment. In contrast, the Borans developed severe anaemia and required curative drug therapy (i.e., PCV dropped to less than 15) by 55 days (range: 22-55 days) post infection. There were significant (P less than 0.05) decreases in total white blood cells and total lymphocytes from pre-infection levels to the first peak of parasitaemia (day 16 post-infection) in both groups. Flow cytometric analyses using MoABs revealed that this change was due to an absolute decrease in T cells expressing BoT2 and either BoT4 or BoT8, surface immunoglobulin M-positive (sIgM+) B cells, and null cells which did not express T cell, B cell or monocyte markers. During this period there was significant variation over time, but no overall increase or decrease, in the number of cells expressing class II major histocompatibility (MHC) molecules or monocyte markers, or in the number of circulating neutrophils or eosinophils. The BoT4/BoT8 ratios were significantly (P less than 0.01) increased in both groups of infected animals at the first peak of parasitaemia. After day 22 in the infected N'Damas and in the Borans which required drug therapy, there was a leucocytotic response characterized by an increase in the total number of B cells, T cells, and null cells. Prior to infection and throughout the course of the experiment N'Dama cattle had significantly (P less than 0.01) higher numbers of B cells and null cells than Boran.

Passive immune therapy for experimental Pseudomonas aeruginosa pneumonia in the neutropenic host.

Studies were conducted in guinea pigs, myelosuppressed by cyclophosphamide, for determination of whether passive immune therapy for Pseudomonas aeruginosa pneumonia would be useful in the setting of neutropenia. Groups of infected animals (14 per group) were treated with a single intravenous infusion of hyperimmune IgG antibody to P. aeruginosa (PA-IGIV; 500 mg/kg), tobramycin (1.7 mg/kg per 8 hr), ticarcillin (120 mg/kg per 6 hr), or combinations of these regimens. Control groups received intravenous albumin solution. Survival rates were 0% with albumin only, 0% with PA-IGIV, 43% with tobramycin (P less than .05), 86% with tobramycin plus PA-IGIV (P less than .05 vs. tobramycin alone), 7% with ticarcillin, and 43% with ticarcillin plus PA-IGIV (.05 less than P less than .10 vs. ticarcillin alone). Additive intrapulmonary killing of P. aeruginosa and prevention of bacteremia were observed in animals treated with tobramycin plus PA-IGIV compared with either treatment alone. Thus, passive immune therapy for P. aeruginosa pneumonia may be useful in the neutropenic host, but only when used in conjunction with antimicrobial agents.

Time courses of antibody levels in Mastomys natalensis after infections with Litomosoides carinii, Dipetalonema viteae, Brugia malayi or B. pahangi, Determined by ELISA.

Using a Litomosoides carinii adult antigen, time courses of antibody levels were followed by an ELISA in L. carinii, Dipetalonema viteae, Brugia malayi and B. pahangi infected Mastomys natalensis. Using various groups of infected animals, periods up to 400 days after infection were covered. In L. carinii infected Mastomys, antibodies were first detected 11 days p.i. and levels increased rapidly until day 40. Temporarily reduced levels about the beginning of patency were followed by increasing values until about 100 days p.i. Then the antibody content of the sera remained more or less constant until about 250 days p.i. although maximum levels were found at day 170. Thereafter, the antibody concentration in the sera declined slowly but high levels were still observed 390 days p.i. The antibody content was usually higher in animals with high microfilariae densities than in those with low microfilariae counts but relations could not be proven statistically. In D. viteae infected Mastomys, maximum antibody values were reached within the beginning of patency. Levels were not altered markedly until about 110 days p.i. Thereafter they decreased slightly but then remained constant until the end of the investigation period 350 days p.i. B. malayi infected animals showed a rapid increase of the antibody content in the sera; a maximum was reached by 20 days after the infection. Thereafter, somewhat constant levels were found for 4--5 months. After 300 days p.i. the antibody levels declined progressively, accompanied with increasing parasitaemia densities; after 380 days the levels reached about 2/3 of the maximum. However, despite this, no relation was found between the levels of parasitaemia and antibody in individual animals. In B. pahangi infections the main prepatent antibody increase occurred during week 5 p.i., when maximum values were observed. The beginning of patency and the early patency were accompanied with slightly declining antibody levels. From 150 days p.i. until the end of the investigation 400 days p.i., the antibody content of the sera was fairly constant.