Plasma pharmacokinetics, pulmonary disposition, and safety of subcutaneous gamithromycin in alpacas.

The study objective was to determine the disposition of gamithromycin in plasma, peripheral blood polymorphonuclear cells (PMNs), pulmonary epithelial lining fluid (PELF), and bronchoalveolar lavage (BAL) cells in alpacas. A single subcutaneous injection of gamithromycin (6.6 mg/kg) was administered to six healthy adult alpacas. At various time points after administration, gamithromycin concentrations were analyzed via LC-MS/MS in plasma, PMNs, PELF, and BAL cells until Day 14 post-injection. Plasma gamithromycin concentrations were measured in all six alpacas; the remaining three body compartments were analyzed in four alpacas. Gamithromycin rapidly concentrated in blood PMNs, BAL cells, and PELF. Shorter Tmax , and lower Cmax, and AUC were observed in plasma than in the other three compartments. Cmax was highest in BAL cells (26001.80 ± 12400.00 ng/ml) and PMNs (2573.00 ± 963.30 ng/ml) compared to PELF (660.80 ± 413.70 ng/ml) and plasma (452.30 ± 196.20 ng/ml). Mean terminal half-lives were 72.60 ± 14.10 h in plasma, 56.60 ± 10.60 h in PELF, 62.80 ± 85.30 h in PMNs, and 93.60 ± 124.80 h in BAL cells. No injection site reactions occurred. One alpaca developed colic but no other adverse reactions were noted. Overall, gamithromycin was highly concentrated in white blood cells and pulmonary fluids/cells. Clinical utilization of gamithromycin in alpacas should be done with caution until further investigation of potential for colic.

Pharmacokinetics of diphenhydramine following single-dose intravenous and oral administration in non-fasted adult horses.

Diphenhydramine is an H1 receptor antagonist used to control urticaria and other allergic signs caused by type I hypersensitivity reactions in horses (Equus caballus). Limited studies have been conducted on pharmacokinetics of this drug in horses, with no studies involving oral formulations. Our study investigated pharmacokinetics of an oral diphenhydramine formulation compared to intravenous administration in non-fasted adult horses. Six healthy horses underwent a single administration of three different doses of diphenhydramine (1 mg/kg intravenously, 1 mg/kg intragastrically, and 5 mg/kg intragastrically) with a two-week washout period between doses. Bioavailability of intragastric diphenhydramine was less than one percent and six percent for 1 mg/kg and 5 mg/kg intragastric doses, respectively. This poor bioavailability is similar to what is reported in dogs. Two of six horses experienced transient side effects after intravenous diphenhydramine administration, emphasizing the need for determining therapeutic plasma levels in efforts to determine the lowest effective dose minimizing risk of adverse effects. The main conclusion of our study was that oral diphenhydramine at doses up to 5 mg/kg are unlikely to achieve therapeutic plasma levels in adult horses.

Investigating a method for pharmacologic semen collection in alpacas.

While semen evaluation is standard practice prior to a sale or when infertility is suspected in other species, it is rarely done in camelids due to the difficulties involved in collecting a sample. The reproductive physiology of alpacas differs to that of other domestic animals and is still poorly understood. In the stallion, a technique was developed for semen collection that pharmacologically induces ejaculation without copulation (ex copula). This study investigates whether semen could be reliably collected by ex copula ejaculation in male alpacas. Eleven male Huacaya alpacas were used in this study, and six ex copula treatment protocols were evaluated: (1) saline (control); (2) xylazine only (0.1 mg/kg); (3) xylazine only (0.2 mg/kg); (4) imipramine only (1.0 mg/kg); (5) imipramine (1.0 mg/kg) followed 10 minutes later with xylazine (0.1 mg/kg); and (6) imipramine (2.0 mg/kg) followed 10 minutes later with xylazine (0.1 mg/kg). Each treatment protocol was repeated two to five times. Azoospermic samples obtained from ex copula ejaculation contained numerous epithelial cells but no sperm. A reliable treatment for pharmacologically inducing ejaculation in alpacas remains to be found.

Assessment of the effects of diet and physical rehabilitation on radiographic findings and markers of synovial inflammation in dogs following tibial plateau leveling osteotomy.

OBJECTIVE To determine the effects of an omega-3 fatty acid and protein-enriched diet, physical rehabilitation, or both on radiographic findings and markers of synovial inflammation in dogs following tibial plateau leveling osteotomy and arthroscopic surgery for treatment of cranial cruciate ligament disease. DESIGN Randomized, prospective clinical trial. ANIMALS 48 dogs with unilateral cranial cruciate ligament disease. PROCEDURES Dogs were randomly assigned to receive a dry omega-3 fatty acid and protein-enriched dog food formulated to support joint health (test food [TF]), a dry food formulated for adult canine maintenance (control food [CF]), TF plus rehabilitation, or CF plus rehabilitation after surgery. Synovial fluid prostaglandin (PG) E2 and interleukin-1ß concentrations, radiographic osteoarthritis scores, osteotomy site healing, and patellar ligament thickness were assessed at predetermined time points up to 6 months after surgery. RESULTS Dogs that received CF had significantly higher PGE2 concentrations over time following surgery than did dogs that received TF, regardless of rehabilitation status. Synovial fluid interleukin-1ß concentrations did not change over time in any groups. Diet and rehabilitation were both associated with osteoarthritis scores, with significantly lower scores over time for dogs that received TF versus CF and for dogs that underwent rehabilitation versus those that did not. Proportions of dogs with complete osteotomy healing 8 and 24 weeks after surgery were significantly lower for dogs that received TF than for dogs that received CF, regardless of rehabilitation status. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that feeding the TF can result in lower synovial fluid PGE2 concentrations and that both the TF and rehabilitation can reduce progression of osteoarthritis in the 6 months following tibial plateau leveling osteotomy; clinical relevance of slower osteotomy healing in dogs fed the TF was unclear.

Pharmacokinetic evaluation and safety of topical 1% morphine sulfate application on the healthy equine eye.

OBJECTIVE: To determine if corneal epithelial cell integrity is detrimentally affected by short-term administration of 1.0% morphine sulfate. Additionally, we sought to determine if topical 1.0% morphine applied to the equine cornea would result in ocular or systemic absorption. ANIMAL STUDIED: Six healthy horses. PROCEDURE: Morphine sulfate (1.0%) was applied topically to one eye every four hours for 72 h before horses were euthanized. Serum samples were collected at varying time points during the study and aqueous and vitreous humor were collected immediately after euthanasia. Morphine quantification in serum, aqueous, and vitreous humor was performed by ELISA. Treated and control corneas were submitted for histopathology. Horses were monitored for adverse ocular and systemic effects throughout the study period. RESULTS: All horses developed mild mucoid ocular discharge in the treated eye. One horse developed a fever during treatment. Morphine was detected in the aqueous humor of the treated eye for all horses with mean ± standard deviation of 165.18 ng/mL ± 87.69 ng/mL. Morphine was detected in vitreous humor of the treated eye of 5 of 6 horses with mean ± standard deviation of 4.87 ± 4.46 ng/mL. Morphine was detected in the serum of 5 of 6 horses at varying time points. Maximum systemic concentration reached in a single horse was 6.98 ng/mL. Corneal histopathology revealed no difference in microscopic appearance between morphine-treated and control corneas. CONCLUSIONS: Topical administration of 1.0% morphine sulfate did not appear to cause any significant ocular or systemic adverse effects. Topical ophthalmic morphine application resulted in both ocular and systemic absorption.

Expression of serotonin, chromogranin-A, serotonin receptor-2B, tryptophan hydroxylase-1, and serotonin reuptake transporter in the intestine of dogs with chronic enteropathy.

Serotonin regulates many intestinal motor and sensory functions. Altered serotonergic metabolism has been described in human gastrointestinal diseases. The objective of our study was to compare expression of several components of the serotonergic system [serotonin (5-HT), serotonin reuptake transporter protein (SERT), tryptophan hydroxylase-1 (TPH-1), 5-HT receptor2B (5-HT2B)] and the enterochromaffin cell marker chromogranin-A (CgA) in the intestinal mucosa between dogs with chronic enteropathy and healthy controls. Serotonin and CgA expression were determined by immunohistochemistry using banked and prospectively obtained, paraffin-embedded canine gastrointestinal biopsies (n = 11), and compared to a control group of canine small intestinal sections (n = 10). Expression of SERT, TPH-1, and 5-HT2B were determined via real-time reverse transcription (qRT)-PCR using prospectively collected endoscopic duodenal biopsies (n = 10) and compared to an additional control group of control duodenal biopsies (n = 8, control group 2) showing no evidence of intestinal inflammation. Dogs with chronic enteropathies showed strong staining for both 5-HT and CgA. Mean positive cells per high power field (HPF) were significantly increased for both compounds in dogs with chronic enteropathies (p < 0.001 for 5-HT; p < 0.05 for CgA). The number of 5-HT-positive and CgA-positive cells/HPF showed significant correlation in the entire group of dogs, including both diseased and healthy individuals (Pearson r(2) = 0.2433, p = 0.016). No significant differences were observed for SERT, TPH-1, or 5-HT2B expression; however, dogs with chronic enteropathy showed greater variability in expression of TPH-1 and 5-HT2B We conclude that components of the neuroendocrine system show altered expression in the intestinal mucosa of dogs with chronic enteropathy. These changes may contribute to nociception and clinical signs in these patients.

Morphine Synovial Fluid Concentrations After Intravenous Regional Limb Perfusion in Standing Horses.

OBJECTIVE: To determine synovial concentrations of morphine after intravenous regional limb perfusion (IVRLP) with morphine or morphine in combination with gentamicin in clinically healthy, standing sedated horses. STUDY DESIGN: Experimental. ANIMALS: Adult horses (n = 6). METHODS: IVRLP was performed using 0.1 mg/kg morphine (M) in standing sedated horses. After a 3-week washout period, IVRLP was performed on the same forelimb with a combination of 0.1 mg/kg morphine and 1 g gentamicin (M/G). Synovial fluid from the middle carpal joint of the perfused limb and jugular blood samples were collected immediately before each perfusion and 20 minutes, and 2, 8, and 24 hours after IVRLP. Morphine and gentamicin concentrations were determined by ELISA. Data were assessed using 2-way repeated measures ANOVA with significance set at P ≤ .05. RESULTS: Synovial fluid morphine concentrations were greatest 20 minutes after perfusion. Mean ± SD peak synovial morphine concentrations over 12 perfusions were 3903 ± 4881 ng/mL. There was no significant difference in morphine synovial concentrations after M or M/G. Plasma morphine concentrations peaked within 2 hours of perfusion (range, 11-63 ng/mL). Mean peak gentamicin concentrations in synovial fluid were 76,315 ± 39,809 ng/mL. IVRLP morphine did not cause clinically apparent adverse effects. CONCLUSIONS: IVRLP in standing sedated horses results in measurable levels of morphine in synovial fluid and synovial concentrations of gentamicin after perfusion in combination with morphine are equivalent to those previously reported.

Identification of Mycobacterium avium genes expressed during in vivo infection and the role of the oligopeptide transporter OppA in virulence.

Mycobacterium avium causes disseminated disease in patients with AIDS and other immunosuppressive conditions and pulmonary infections in individuals with chronic lung diseases. Much still need to be learn about the mechanisms of M. avium pathogenesis. Using a mouse model of disseminated M. avium disease, we applied an in vivo expression technology system and identified M. avium genes up-regulated in different organs of mice during early stage of infection. The M. avium oppA gene, involved in an active transport of oligopeptides across the cell membrane, was found highly expressed in lung, liver and spleen of mice. Mutation in the transport domain of the oppA gene resulted in bacterial attenuation in both macrophages and in mice. Using protein-protein interaction assay, it was determined that two hypothetical small proteins, MAV_2941 (73aa) and MAV_4320 (45aa), interact with OppA. MAV_2941 was shown to be secreted by the bacterium into the macrophage cytoplasm. Mutations in MAV_2941 was associated with significant impairment of growth in macrophages. Understanding the mechanisms involved in the functions of MAV_2941 and MAV_4320 is warranted.

Prevalence of blastocystis in shelter-resident and client-owned companion animals in the US Pacific Northwest.

Domestic dogs and cats are commonly infected with a variety of protozoan enteric parasites, including Blastocystis spp. In addition, there is growing interest in Blastocystis as a potential enteric pathogen, and the possible role of domestic and in-contact animals as reservoirs for human infection. Domestic animals in shelter environments are commonly recognized to be at higher risk for carriage of enteropathogens. The purpose of this study was to determine the frequency of infection of shelter-resident and client-owned domestic dogs and cats with Blastocystis spp in the Pacific Northwest region of the USA. Fecal samples were collected from 103 shelter-resident dogs, 105 shelter-resident cats, 51 client-owned dogs and 52 client-owned cats. Blastocystis were detected and subtypes assigned using a nested PCR based on small subunit ribosomal DNA sequences. Shelter-resident animals were significantly more likely to test positive for Blastocystis (P<0.05 for dogs, P = 0.009 for cats). Sequence analysis indicated that shelter-resident animals were carrying a variety of Blastocystis subtypes. No relationship was seen between Blastocystis carriage and the presence of gastrointestinal disease signs in either dogs or cats. These data suggest that, as previously reported for other enteric pathogens, shelter-resident companion animals are a higher risk for carriage of Blastocystis spp. The lack of relationship between Blastocystis carriage and intestinal disease in shelter-resident animals suggests that this organism is unlikely to be a major enteric pathogen in these species.

The expression and role of serotonin receptor 5HTR2A in canine osteoblasts and an osteosarcoma cell line.

BACKGROUND: The significance of the serotonergic system in bone physiology and, more specifically, the importance of the five hydroxytryptamine receptor 2A (5HTR2A) in normal osteoblast proliferation have been previously described; however the role of serotonin in osteosarcoma remains unclear. Particularly, the expression and function of 5HTR2A in canine osteosarcoma has not yet been studied, thus we sought to determine if this indoleamine modulates cellular proliferation in vitro. Using real time quantitative reverse transcription PCR and immunoblot analyses, we explored receptor expression and signaling differences between non-neoplastic canine osteoblasts (CnOb) and an osteosarcoma cell line (COS). To elucidate specific serotonergic signaling pathways triggered by 5HTR2A, we performed immunoblots for ERK and CREB. Finally, we compared cell viability and the induction of apoptosis in the presence 5HTR2A agonists and antagonists. RESULTS: 5HTR2A was overexpressed in the malignant cell line in comparison to normal cells. In CnOb cells, ERK phosphorylation (ERK-P) decreased in response to both serotonin and a specific 5HTR2A antagonist, ritanserin. In contrast, ERK-P abundance increased in COS cells following either treatment. While endogenous CREB was undetectable in CnOb, CREB was observed constitutively in COS, with expression and exhibited increased CREB phosphorylation following escalating concentrations of ritanserin. To determine the influence of 5HTR2A signaling on cell viability we challenged cells with ritanserin and serotonin. Our findings confirmed that serotonin treatment promoted cell viability in malignant cells but not in normal osteoblasts. Conversely, ritanserin reduced cell viability in both the normal and osteosarcoma cells. Further, ritanserin induced apoptosis in COS at the same concentrations associated with decreased cell viability. CONCLUSIONS: These findings confirm the existence of a functional 5HTR2A in a canine osteosarcoma cell line. Results indicate that intracellular second messenger signal coupling of 5HTR2A is different between normal and malignant cells, warranting further research to investigate its potential as a novel therapeutic target for canine osteosarcoma.

Anti-glucagon-like peptide-1 immunoreactivity in samples of blood and ileum obtained from neonatal and adult alpacas.

OBJECTIVE: To compare numbers of L cells in intestinal samples and blood concentrations of glucagon-like peptide (GLP)-1 between neonatal and mature alpacas. SAMPLE: Intestinal samples from carcasses of 4 suckling crias and 4 postweaning alpacas for immunohistochemical analysis and blood samples from 32 suckling crias and 19 healthy adult alpacas for an ELISA. PROCEDURES: Immunohistochemical staining was conducted in accordance with Oregon State University Veterinary Diagnostic Laboratory standard procedures with a rabbit polyclonal anti-GLP-1 primary antibody. Stained cells with staining results in ileal tissue were counted in 20 fields by 2 investigators, and the mean value was calculated. For quantification of GLP-1 concentrations, blood samples were collected into tubes containing a dipeptidyl peptidase-4 inhibitor. Plasma samples were tested in duplicate with a commercial GLP-1 ELISA validated for use in alpacas. RESULTS: Counts of stained cells (mean ± SD, 50 ± 18 cells) and plasma GLP-1 concentrations (median, 0.086 ng/mL; interquartile range, 0.061 to 0.144 ng/mL) were higher for suckling alpacas than for postsuckling alpacas (stained cells, 26 ± 4 cells; plasma GLP-1 concentration, median, 0.034 ng/mL; interquartile range, 0.015 to 0.048 ng/mL). CONCLUSIONS AND CLINICAL RELEVANCE: Older alpacas had lower numbers of L cells in intestinal tissues and lower blood concentrations of GLP-1 than those in neonates. These findings suggested that there may be a decrease in the contribution of GLP-1 to insulin production in adult alpacas, compared with the contribution in neonates.

The effect of agility exercise on eicosanoid excretion, oxidant status, and plasma lactate in dogs.

BACKGROUND: The objective was to determine the effects of agility exercise on dogs of different skill levels with respect to urinary eicosanoids, urinary 15F2t-isoprostane (lipid peroxidation marker) and hematological/biochemical changes in plasma. Fifteen adult dogs had blood and urine samples obtained prior to, immediately and 4-hours following an agility exercise. RESULTS: Hematocrit, red blood cells (RBC), albumin, and hemoglobin increased following exercise, with greatest increases correlating to increased skill group (novice, intermediate, masters); at 4-hours post-exercise, hematocrit, RBC, and hemoglobin were decreased. Phosphorus increased following exercise with the greatest increase in novice and intermediates. Plasma lactate increased 3.6-fold in masters, 3.2-fold in intermediates, and 1.2-fold in novice dogs. Urine thromboxane B2 (TXB2) more than tripled 4-hours post-exercise while 6-keto prostaglandin F1α (PGF1α, prostacyclin metabolite), prostaglandin E2 metabolites (13,14-dihydro-15-keto-prostaglandin A2 and 13,14-dihydro-15-keto-prostaglandin E2), and 13,14-dihydro-15-keto prostaglandin F2α were unaffected as determined by a competitive enzyme immunoassay and standardized by division with urine creatinine. Urine 15F2t-isoprostane increased insignificantly. CONCLUSIONS: Alterations in the plasma post-exercise were likely due to hemoconcentration from insensible water loss, splenic contraction and sympathetic stimulation while 4-hours later autohemodilution reduced RBC parameters. Elevations in plasma lactate and urinary TXB2 correlated with advanced skill level/speed of the dogs.

Development of a nested polymerase chain reaction assay for the detection of Eimeria macusaniensis in camelid feces.

OBJECTIVE: To test the ability of a nested PCR assay to detect Eimeria macusaniensis at various stages of infection in alpacas. ANIMALS: 4 healthy adult alpacas with no detectable E. macusaniensis. PROCEDURES: Alpacas were inoculated with 2 × 10(4) sporulated oocysts. Serial fecal samples collected during the next 38 days were tested via sucrose flotation and PCR assay. RESULTS: Oocyst passage was detected via fecal flotation in all 4 alpacas 31 to 35 days after inoculation. Three had positive results for PCR assays on samples obtained 7 to 14 days after inoculation. One alpaca subsequently was removed from the study because of weight loss and inappetence. Two remaining alpacas had positive PCR reactions 28 and 31 days after inoculation, up to 7 days before oocysts appeared in the feces. All fecal samples with positive results for flotation also had positive results for PCR assay. CONCLUSIONS AND CLINICAL RELEVANCE: The PCR assay was able to detect early (7 to 14 days) and late (28 to 31 days) prepatent infection. These positive results suggested that the assay could have been detecting DNA unassociated with oocysts or detecting shedding earlier than has been previously recognized. The gap between the early and late detection periods may not be evident in alpacas receiving a larger or continuous inoculum, as might occur with natural infection. Use of a PCR assay for analysis of fecal samples may be valuable for detection of E. macusaniensis during the prepatent period, thus aiding in the identification and control of infected animals.

Higher whole-blood selenium is associated with improved immune responses in footrot-affected sheep.

We reported previously that sheep affected with footrot (FR) have lower whole-blood selenium (WB-Se) concentrations and that parenteral Se-supplementation in conjunction with routine control practices accelerates recovery from FR. The purpose of this follow-up study was to investigate the mechanisms by which Se facilitates recovery from FR. Sheep affected with FR (n = 38) were injected monthly for 15 months with either 5 mg Se (FR-Se) or saline (FR-Sal), whereas 19 healthy sheep received no treatment. Adaptive immune function was evaluated after 3 months of Se supplementation by immunizing all sheep with a novel protein, keyhole limpet hemocyanin (KLH). The antibody titer and delayed-type hypersensitivity (DTH) skin test to KLH were used to assess humoral immunity and cell-mediated immunity, respectively. Innate immunity was evaluated after 3 months of Se supplementation by measuring intradermal responses to histamine 30 min after injection compared to KLH and saline, and after 15 months of Se supplementation by isolating neutrophils and measuring their bacterial killing ability and relative abundance of mRNA for genes associated with neutrophil migration. Compared to healthy sheep, immune responses to a novel protein were suppressed in FR-affected sheep with smaller decreases in FR-affected sheep that received Se or had WB-Se concentrations above 250 ng/mL at the time of the immune assays. Neutrophil function was suppressed in FR-affected sheep, but was not changed by Se supplementation or WB-Se status. Sheep FR is associated with depressed immune responses to a novel protein, which may be partly restored by improving WB-Se status (> 250 ng/mL).

Comparison of methods to detect gastrointestinal parasites in llamas and alpacas.

OBJECTIVE: To compare relative sensitivity and overall yields of various methods of fecal examination for gastrointestinal parasites in llamas and alpacas. DESIGN: Prospective study. SAMPLE POPULATION: Fecal samples from 42 alpacas and 62 llamas. PROCEDURES: Fecal samples were analyzed via direct smear, a modified McMaster technique with sucrose solution or saturated saline (approx 36% NaCl) solution, and a centrifugation-flotation procedure. McMaster flotation chambers were examined 15 and 60 minutes after loading. Centrifugation-flotation samples were examined after 10 and 60 minutes of flotation. The proportions of samples with positive results and concentrations of parasites were compared among methods. RESULTS: The centrifugation-flotation technique yielded more positive results than other methods for all parasites except small coccidia. Longer flotation time increased the proportion of positive results and parasite concentrations for all parasites except Nematodirus spp. Longer time in the McMaster chamber made little difference. By use of the modified McMaster technique, sucrose solution yielded more positive results for Trichuris spp, Eimeria macusaniensis, and strongyles, whereas saline solution yielded more positive results for Nematodirus spp and small coccidia. The saline solution McMaster test yielded more positive results for small coccidia than did most other methods, and the sucrose McMaster technique yielded more positive results for Trichuris spp. CONCLUSIONS AND CLINICAL RELEVANCE: The centrifugation-flotation technique appeared to offer clear advantages in detecting infection with E macusaniensis, Trichuris spp, Nematodirus spp, and capillarids. The saline McMaster technique appeared to offer an advantage in detecting small coccidia.

Identification of Mycobacterium avium pathogenicity island important for macrophage and amoeba infection.

The ability to infect macrophages is a common characteristic shared among many mycobacterial species. Mycobacterium avium, Mycobacterium tuberculosis, and Mycobacterium kansasii enter macrophages, using the complement receptors CR1, CR3, CR4, and the mannose receptor. To identify M. avium genes and host cell pathways involved in the bacterial uptake by macrophages, we screened a M. avium transposon mutant library for the inability to enter macrophages. Uptake-impaired clones were selected. Sequence of six M. avium clones identified one gene involved in glycopeptidolipid biosynthesis, one gene encoding the conserved membrane protein homologue to the M. avium subsp. paratuberculosis MAP2446c gene and four others belonging to the same region of the chromosome. Analysis of the chromosome region revealed a pathogenicity island inserted between two tRNA sequences with 58% of G+C content versus 69% in the M. avium genome. The region is unique for M. avium and is not present in M. tuberculosis or M. paratuberculosis. Although the mutants did not differ from the WT bacterium regarding the binding to macrophage cell membrane, analysis of macrophage proteins after 1 h infection revealed a deficiency in the mutant to phosphorylate certain proteins on uptake. To understand M. avium interaction with two evolutionarily distinct hosts, the mutants were evaluated for Acanthamoeba castellanii invasion. The defect in the ability of the mutants to invade both cells was highly similar, suggesting that M. avium might have evolved mechanisms that are used to enter amoebas and human macrophages.

The ability to form biofilm influences Mycobacterium avium invasion and translocation of bronchial epithelial cells.

Organisms of the Mycobacterium avium complex (MAC) are widely distributed in the environment, form biofilms in water pipes and potable water tanks, and cause chronic lung infections in patients with chronic obstructive pulmonary disease and cystic fibrosis. Pathological studies in patients with pulmonary MAC infection revealed granulomatous inflammation around bronchi and bronchioles. BEAS-2B human bronchial epithelial cell line was used to study MAC invasion. MAC strain A5 entered polarized BEAS-2B cells with an efficiency of 0.1 +/- 0.03% in 2 h and 11.3 +/- 4.0% in 24 h. In contrast, biofilm-deficient transposon mutants 5G4, 6H9 and 9B5 showed impaired invasion. Bacteria exposed to BEAS-2B cells for 24 h had greater ability to invade BEAS-2B cells compared with bacteria incubated in broth. M. avium had no impact on the monolayer transmembrane resistance. Scanning electron microscopy showed that MAC A5 forms aggregates on the surface of BEAS-2B cell monolayers, and transmission electron microscopy evidenced MAC within vacuoles in BEAS-2B cells. Cells infected with the 5G4 mutant, however, showed significantly fewer bacteria and no aggregates on the cell surface. Mutants had impaired ability to cause infection in mice, as well. The ability to form biofilm appeared to be associated with the invasiveness of MAC A5.

The relationship between endogenous cortisol, blood micronutrients, and neutrophil function in postparturient Holstein cows.

Neutrophil function, blood micronutrients, and cortisol concentrations were measured in 43 clinically healthy postparturient Holstein cows. Estimated 305-day mature equivalent milk production and neutrophil function were related to results of the blood micronutrient concentrations and neutrophil function tests. Cattle had low to normal zinc concentrations; normal to high selenium, vitamin E, and cortisol concentrations; and normal copper concentrations. Blood selenium (P = .03) and zinc (P = .027) concentrations were both significant predictors of neutrophil adhesion, and selenium (P < .001) was a significant predictor of neutrophil cytochrome C reduction (superoxide production). Fourteen of 20 (70%) cattle with blood selenium concentrations > 300 ng/mL had neutrophil adhesion, and 15 of 20 (75%) had cytochrome C reduction above the mean value for this group. There was also a significant correlation (r = 0.331; P = .037) between cytochrome C reduction and estimated milk production. These findings suggest that neutrophils from postparturient dairy cows with higher blood concentrations of selenium have greater potential to kill microbes, and that cattle with greater superoxide production may have higher milk production.

Investigating the onset of autoimmunity in A.SW mice following treatment with 'toxic oils'.

In 1981, over 20,000 people were struck with toxic oil syndrome (TOS). H-2s strains of mice have been shown to develop symptoms of TOS after exposure to toxic oil. We examined the effects of toxic oil on A.SW mice, which are susceptible to chemically-induced autoimmunity, but do not spontaneously develop autoimmune disease. Mice were treated with three types of toxic oil: CO756 (case oil from Spain), RSD99 (rapeseed oil with no 3-(N-phenylamino)-1-2-propanediol (PAP) derivatives) and RSA99 (rapeseed oil supplemented with PAP derivatives). Mercuric chloride treated mice were used as a positive control. After toxic oil treatment, there were no consistent differences in body weight or organ weight (liver, kidney, thymus and spleen) as a percent of body weight at any of these timepoints: 2.5, 5 or 10 weeks. We also found that treatment with toxic oil did not induce autoantibody formation or lead to increased serum levels of IgG1, IgG2a or IgE at these timepoints. Conversely, at all timepoints, there were significant increases in organ weight as a percent of body weight in the mercury treated mice. Additionally, mercuric chloride treated mice had elevated serum levels of IgG1, IgG2a and IgE and developed anti-nuclear and anti-collagen antibodies.

Immunoglobulin and autoantibody responses in MRL/lpr mice treated with 'toxic oils'.

The toxic oil syndrome (TOS) occurred in Spain in 1981 as a result of ingestion of oil mixtures containing aniline-denatured rapeseed oil. The disease afflicted almost 20000 people, resulted in more than 400 deaths, and mimicked an autoimmune disease in all patients. Phenilamine-propanediol (PAP) has been implicated as a possible etiologic agent of TOS but absence of an acceptable animal model to evaluate the autoimmune potential of the 'case oil' has hindered identification of the actual etiologic agent(s). The purpose of this study was twofold; (1) to develop an animal model of human disease to investigate the immunological etiology and pathogenesis of TOS and (2) to determine if the 'case oil' responsible for TOS and/or two synthesized oils either induced or exacerbated the systemic autoimmune disease that occurs spontaneously in the MRL/lpr mouse. The oils tested were a denatured rapeseed oil collected from a family (case oil) who were affected by the TOS (CO756), a rapeseed oil denatured with 2% aniline and enriched with a mixture of diesters of PAP (RSD), and a rapeseed oil denatured with 2% aniline but contained no diesters of PAP (RSA). Female MRL/lpr mice, 7 weeks of age, received orally either an undiluted (neat) or a 1:10 diluted dose of each test oil, canola oil (oil control), water (nai;ve control), or 50-ppm mercury (positive control). Half of each group was sacrificed after 5 weeks of exposure and the remaining mice after 10 weeks of exposure. Serum IgG1, IgG2a, IgE isotypes and antinuclear (ANA), collagen type II, histone, single-stranded DNA (ssDNA), double-stranded DNA (dsDNA) and Sm autoantibody concentrations were determined after 5 and 10 weeks of exposure. The oils did not significantly affect the concentrations of the serum immunoglobulins, although a shift in the IgG1:IgG2a ratio towards IgG1 was noted from 12 to 17 weeks of age (5-10 weeks of treatment). The oils did however stimulate the systemic autoimmune response. The RSD neat treatment resulted in a nonsignificant but noted increase in autoantibodies to collagen (10 weeks), histone (10 weeks) and dsDNA (5 and 10 weeks). CO756 neat increased the serum levels of ANA (5 weeks), collagen (5 weeks) and dsDNA (5 and 10 weeks). The RSA 1:10 dilution increased ssDNA and dsDNA autoantibodies at 5 weeks. The results suggest that PAP is an active principle of these noted responses. These data, coupled with the toxicology and pathology data from this study (Toxicol. Path. 29 (2001) 630), revealed that the three oils incited induction of the lymphoproliferative syndrome and that the two oils containing PAP induced and enhanced the systemic autoimmune response that develops spontaneously at an early age in the MRL/lpr mouse. There was also a positive correlation noted between serum autoantibody concentrations and progression of the idiopathic autoimmune syndrome in the MRL/lpr mouse.