In vitro elution of gentamicin, amikacin, and ceftiofur from polymethylmethacrylate and hydroxyapatite cement

OBJECTIVE: To compare the elution characteristics of ceftiofur and liquid and powdered gentamicin and amikacin from polymethylmethacrylate (PMMA) and from hydroxyapatite cement (HAC). METHODS: PMMA and HAC beads in triplicate were impregnated with various amounts and formulations of antibiotics. Beads were immersed in 5 mL of phosphate buffered saline that was replaced at 1, 3, 6, and 12 hours, and 1, 2, 3, 5, 7, 10, 14, 18, 22, 26, and 30 days. The eluent was stored at -70 degrees C until assayed within 2 weeks by microbiological assay (gentamicin and amikacin) or capillary electrophoresis (ceftiofur). RESULTS: Rate of elution for all beads was greatest within the first 24 hours. Cumulative release of total antibiotic dose from beads over 30 days was significantly greater from HAC than PMMA. Antibiotic elution was directly related to the amount of antibiotic incorporated into the cement. Powdered and liquid forms of gentamicin had similar elution rates from PMMA. Elution of amikacin from PMMA beads was greater when the powdered form was used compared with liquid amikacin. Eluent concentrations of ceftiofur were similar to those of the aminoglycosides during the first 3 to 7 days but then decreased precipitously by comparison. CONCLUSIONS: Elution of antibiotics from HAC was greater than from PMMA. Gentamicin- and amikacin-impregnated PMMA and HAC released bactericidal concentrations of antibiotic for at least 30 days. Ceftiofur-impregnated PMMA or HAC is unlikely to provide long-term bactericidal concentrations. CLINICAL RELEVANCE: Gentamicin and amikacin elute effectively from PMMA and HAC.     

Esophageal obstruction caused by a left aortic arch and an anomalous right patent ductus arteriosus in two German Shepherd littermates

OBJECTIVE: To present details of surgical management of an unusual vascular ring anomaly in two German Shepherd littermates. STUDY DESIGN: Clinical case report. STUDY POPULATION: Three-month-old intact male and female German Shepherd littermates. RESULTS: In each dog, the esophagus was obstructed by a vascular ring comprised of the left aortic arch, an anomalous patent right ductus arteriosus, and the pulmonary artery ventrally. Surgical treatment consisted of dividing and oversewing the patent right ductus arteriosus. Neither dog has clinical signs of esophageal disease one year after treatment. CONCLUSION AND CLINICAL RELEVANCE: This vascular ring anomaly should be considered a possibility in any young dog with esophageal obstruction and a machinery murmur.     

Expression and characterisation of equine interleukin 2 and interleukin 4

In the present study, we describe the expression of equine IL2 and IL4. The cDNA of equine IL2 or IL4 was cloned in a mammalian expression vector, containing c-terminal myc- and six histidines His(6)-epitopes for recognition and purification of equine cytokines. The vector constructs were used for transfection of chinese hamster ovary (CHO) cells. Purified equine cytokines were characterised by western blotting. Equine IL2 was secreted with a molecular weight of approximately 17.1kDa, whereas IL4 was expressed in three different sizes of 17.1, 19.6 and 22.1kDa, probably due to different glycosylation modifications. The biological activities of both cytokines were tested by proliferation assays using leukoagglutinin (LAG) prestimulated equine PBMC. Both, equine IL2 and IL4 induced dose-dependent lymphocyte proliferation. In contrast to IL4, IL2 supported the proliferation of B cells.     

Tacrolimus-FK506 induced immunosuppression in gnotobiotic piglets

Tacrolimus (FK506), an inhibitor of calcineurin, is an immunosuppressive agent used in clinical trials of transplant patients. Although FK506 targets Ca(2+)-mediated T-cell signaling, phenotype(s) of the specific target cells and the corresponding cytokine pathways are not well known. In this study, the impact of FK506 on number and characteristic of T-cells in selected lymphoid tissues of gnotobiotic (GB) piglets was determined. FK506-treated GB piglets were compared with untreated GB and conventional piglets. The T-helper, cytotoxic, natural killer, double-positive, and activated T-cell populations were analyzed in suspensions of mononuclear cells isolated from thymus, mesenteric lymph nodes and peripheral blood. In vitro secretion of interleukin-8 and interferon-gamma in concanavalin A-stimulated lymphoid cell-cultures was measured by ELISA. Daily intramuscular treatment of GB piglets with 1mg/kg of FK506 from birth for 4 weeks resulted in lowered (P<0.05) in vitro secretion of interferon-gamma and interleukin-8. Moreover, depletions of MNC in systemic and mucosa-associated lymphoid tissues were observed in piglets treated with FK506. The depletions of mononuclear cells and low levels of interferon-gamma and interleukin-8 in piglets treated with FK506 were accompanied by lower proportion of CD3+, CD2+CD4+ and CD2+CD8+ T-cell phenotypes in peripheral blood but not in thymus and mesenteric lymph nodes. These results indicate that FK506-treatment causes immunosuppression in GB piglet, and this effect could be exploited further to study opportunistic pathogens in pig model.     

Epidemiology and characterization of animal Salmonella enterica subspecies Enterica serotype typhimurium DT104 in Hungary

Reports on the internationally emerging significance of multiresistant zoonotic Salmonella in animals and man prompted studies to estimate the significance of multiresistant Salmonella enterica subspecies enterica serotype Typhimurium (S. Typhimurium) phage type DT104 of animal origin in Hungary. A collection of 231 strains (primarily of goose, turkey, poultry and porcine origin from the years 1997-1998) was tested for resistance against 7 selected antibiotics (ampicillin, chloramphenicol, enrofloxacin, nalidixic acid, streptomycin, tetracycline and sulphamethoxazole). Strains with resistance against 3 or more were defined as multiresistant. All strains were phage typed using Felix-Callow's S. Typhimurium phage typing system, and 91 of them (suspect DT104) were also typed according to Anderson's definitive typing (DT) system. In this study, 14% of animal strains from 1997-1998 was classified as DT104, for which turkey, pig and duck seemed to be the main carriers, and the multiresistant non-DT104 strains represented a further 6% of this collection. The prevalence of DT104 was highest among strains of turkey origin (50%), followed by strains of pig (29%), chicken (25%), duck (19%), and goose (3%) origin. The other DT104 related phage types (DT12 and U302) were only detected in the case of 4 strains (2 of porcine, and one each of turkey and of goose origin). The DT104 corresponded to the Felix-Callow types 2/3 or 2c/3 in each case, except in the case of 3 turkey strains where they corresponded to type 35/3. Nalidixic acid resistance was detected in all multiresistant turkey strains and in some of other animal origin but none of these strains were resistant to enrofloxacin. A retrospective analysis (based on the above relationship) indicated that S. Typhimurium strains corresponding to DT104 could be present and increase in the Hungarian farm animal population from about 2% to 20% between 1985 and 1990, in a manner similar to the emergence of human DT104, as reported elsewhere (Pászti et al., 2000). The 91 suspect DT104 strains were also tested for plasmid profile and for spvC gene indicating the presence of the large serotype specific plasmid (Ssp). No characteristic plasmid profile could be attributed to S. Typhimurium DT104. The serovar-specific large plasmid was detected by PCR for spvC in 100% of DT104 strains and in 77% of the non-DT104 strains. The virulence of two DT104 strains was tested in orally infected day-old chicks and compared with virulence of 4 non-DT104 strains. Higher colonizing virulence of DT104 strains could be established as compared to the other strains.     

Survey on Myxobolus infection of the bleak (Alburnus alburnus L.) in the river Danube and in Lake Balaton

In a three-year survey of myxosporean infections of the bleak (Alburnus alburnus), involving the examination of 205 fish specimens from the River Danube and 50 from Lake Balaton, four Myxobolus species (two gill parasites, one fin parasite and a species parasitising the skeletal muscles) were detected. Two of the species could be identified as M. alburni and M. obesus. Of the other two species, the gill parasite proved to be a hitherto undescribed species which is described here as a new species by the name of M. margitae. One of the two gill-parasitic species, M. obesus, formed plasmodia in the respiratory lamellae of the gill filaments, while the plasmodia of M. margitae n. sp. were formed in the afferent artery of the primary gill filaments. The plasmodia containing spores morphologically identifiable with the species M. alburni were located in the connective tissue between the fin rays. The less frequently found muscle-parasitic Myxobolus species has not been identified precisely. The plasmodia of M. obesus were found in the fish in May and June, while those of M. alburni and M. margitae n. sp. in July and August. The prevalence of infection in fish examined in these periods was 15.5% for M. obesus, 11.5% for M. margitae and 14.0% for M. alburni.     

Seroepidemiology of Brucella abortus infection in bovids in Sri Lanka

From 1992 to 1995, 0.15% (n=3916) of the bovids (cattle and buffalo) in Sri Lanka were sampled, using a multi-stage sampling procedure. Serum antibodies for Brucella abortus were detected using the indirect enzyme-linked immunosorbent assay (ELISA). The age, the agroecological zone and the management system practiced in the farms of the sampled bovids were studied as risk factors for seropositivity.The overall seroprevalence of brucellosis in cattle was 4.7% (n=3076) and 4.2% in buffaloes (n=840). Bovids that were over 3 years of age, from the dry zone (annual rainfall 20-35 in.), and reared under an extensive management system had higher odds of being seropositive. Bovids from the dry zone were at approximately six times higher odds of being seropositive even after controlling for the possible effects of age and management system. Approximately 75% of the seropositive males were from the dry zone. Most bovids (84%) from the dry zone in this study were reared under an extensive management system (free grazing) which allows unrestricted contact between animals. These factors may have contributed to the spread of brucellosis in bovids in the dry zone.This infection might be an important cause of abortion in bovids in Sri Lanka. However, there is also evidence of other causes for abortion, repeat breeding and retained placenta.     

Natural transplacental infection of dairy calves with bovine immunodeficiency virus and estimation of effect on neonatal health

Many experimental infection studies with bovine immunodeficiency virus (BIV) have been conducted, but neither virus transmission under natural conditions nor longitudinal clinical effects of naturally occurring infections in non-experimental populations are well explored. We tested the hypotheses that BIV is transmitted across the placenta during gestation and that intragestionally infected calves are at increased risk of neonatal disease. A cohort of 59 dairy cows on one farm were enrolled at parturition and the BIV serostatus of the cows and their pre-colostral calves determined with an indirect fluorescent-antibody assay. Moreover, the enrolled calves were monitored thrice weekly for specific clinical signs through the duration of the 30 day neonatal period and the occurrence of clinical signs analyzed for association with calf pre-colostral BIV serostatus and dam BIV serostatus. Confounding due to calf passive immunity and season of birth were also explored. Forty percent of seropositive cows (14/35) gave birth to seropositive calves but no seropositive calves (0/19) were born to seronegative dams (estimated relative risk 16, 95% exact confidence interval 2.6–5.8×10²⁹). Calf pre-colostral BIV serostatus was not associated with the occurrence or frequency of clinical signs — but dam BIV serostatus was associated with the odds of occurrence of calf hyperthermia and with the frequency of occurrence of calf hyperthermia and hyperventilatory events. This study is inconclusive about the effects of prenatal BIV infection on neonatal health — but it does provide evidence for the natural occurrence of transplacental BIV infection.     

Bioremediation of olive oil mill wastewater: chemical alterations induced by Azotobacter vinelandii

An environmentally friendly bioremediation system of olive oil mill wastewater (OMWW) is studied with respect to its physicochemical characteristics and degradation efficiency on major characteristic constituents. The method exploits the biochemical versatility of the dinitrogen fixing bacterium Azotobacter vinelandii (strain A) to grow in OMWW at the expense of its constituents and to transform it into an organic liquid fertilizer. The system eliminates the phytotoxic principles from OMWW and concomitantly enriches it with an agriculturally beneficial microbial consortium along with useful metabolites of the latter. The end product, branded "biofertilizer", is used as soil conditioner and liquid organic fertilizer. Growth of A. vinelandii in OMWW results in the decline of content of most of the compounds associated with phytotoxicity, and this is confirmed by the assessment of degradation yields. In parallel, during the process several other compounds noncommittally undergo degradation and biotransformation. More specifically, the biofertilization system is capable of achieving removal yields as high as 90 and 96% after 3 and 7 days of treatment, respectively. Statistical analysis of the results showed that between the periods of operation no significant difference occurs with respect to the degradation yield. Moreover, the degradation yield from 3 to 7 days of continuous operation of the system remains almost unaltered during 2 consecutive years.     

Isolation and partial characterization of thermostable isoperoxidases from potato (Solanum tuberosum L.) tuber sprouts

Peroxidases (POD; EC 1.11.1.7) can cross-link cell wall polymers and may have an impact on the final textural quality of potato tubers. Because heat treatments are important during processing, the thermal properties of isoPODs from soluble and ionically and covalently bound fractions were studied from both potato tubers and sprouts. For both tissues, the ionically bound fraction was the most thermostable; approximately 20% of POD activity remained after a heat treatment of 10 min at 90 degrees C (for sprouts). The temperature profile of the ionically bound sprout fraction appeared to be nonlinear and suggested the presence of a very thermostable POD, which still showed activity after a heat treatment at 100 degrees C. Visualization by using isoelectric focusing confirmed the occurrence of a thermostable isoPOD with an IEP of 9.5, which displayed regeneration of activity after heat inactivation. This cationic POD was further purified by chromatography techniques, and by SDS-PAGE its molecular mass was estimated at 38 kDa.