Rete testis mucinous adenocarcinoma in a dog.

A bilateral testicular neoplasm from an 11-year-old mixed-breed male dog was removed surgically and examined histologically. The neoplasm was nonencapsulated and composed of acinar and tubular structures lined by one or more layers of neoplastic polyhedral epithelial cells with an abundant mucinous secretion. On histochemistry, all neoplastic cells and associated secretions were periodic acid-Schiff positive. Some neoplastic cells and all associated secretions were positive on mucicarmine stain, and some neoplastic cells, all the stroma, and associated secretions were positive on alcian blue stain. On immunohistochemistry, the neoplastic cells had strong diffuse cytoplasmic immunoreactivity for cytokeratin and vimentin, weak scattered cytoplasmic immunoreactivity for carcinoembryonic antigen and neuron-specific enolase, and no immunoreactivity for S-100. On the basis of histopathology, histochemistry, and immunohistochemical findings, a diagnosis of mucinous adenocarcinoma of rete testis was made. Rete testis adenocarcinoma is a well known but very rare neoplasm in humans. To our knowledge, this is the first report of the mucinous variant of adenocarcinoma of the rete testis in a dog.

Endometritis in postparturient cattle associated with bovine herpesvirus-4 infection: 15 cases.

Suppurative, ulcerative endometritis associated with bovine herpesvirus-4 (BHV-4) infection was identified in 15 postparturient dairy cows from 5 separate dairies. Characteristic eosinophilic to amphophilic intranuclear viral inclusion bodies were identified within degenerate endometrial lining epithelium and endothelial cells. Bovine herpesvirus-4 was confirmed as the etiology by a combination of fluorescent antibody assays, viral isolation, heminested PCR, ultrastructural examination of the uterus and inoculated tissue culture cells, and negative-stain electron microscopy of tissue culture supernatant. Viral particles measuring 70-95 nm were demonstrated in uterine epithelial and endothelial cells by electron microscopy. Bacteria including Arcanobacterium pyogenes, Escherichia coli, and an alpha-Streptococcus isolate were isolated from all uteri. Bovine herpesvirus-4-associated endometritis has been previously reported in sporadic cases in Europe but has not been previously reported in the United States. Endometritis associated with BHV-4 appears to be an emerging syndrome in Georgia dairy herds.

Expression of inflammatory cytokine mRNA in lymphoid tissue from swine experimentally infected with Mycobacterium avium serovar 2.

OBJECTIVE: To evaluate in situ expression of inflammatory cytokine mRNA in lymphoid tissue of swine experimentally infected with Mycobacterium avium serovar 2. ANIMALS: 7 noninfected pigs and 7 pigs infected with M. avium serovar 2. PROCEDURE: Expression of mRNA of inflammatory cytokines such as tumor necrosis factor alpha (TNFalpha), interleukin (IL)-1beta IL-6, and IL-8 in formalin-fixed paraffin-embedded blocks of lymphoid tissue (lymph nodes and tonsil) of swine experimentally infected with M. avium serovar 2 was compared with that of noninfected pigs. Tissues were evaluated by use of morphologic localization of cytokine mRNA, using in situ hybridization at 160 days after inoculation. RESULTS: A noticeable increase in mRNA expression for TNFalpha and mild increases in mRNA expression of IL-8 and IL-1beta were detected in mandibular lymph nodes from infected swine, compared with noninfected swine. Mild increase in mRNA expression for 1L-6 also was observed in tonsils from infected swine. Cytokine mRNA was detected in macrophages and lymphocytes, primarily within cortical follicles and adjacent mantle zones. CONCLUSIONS AND CLINICAL RELEVANCE: Expression of mRNA for inflammatory cytokines was increased in lymphoid tissue of infected swine, possibly resulting from local factors on, or secreted by, M. avium. These results suggest that alterations in cytokine mRNA expression are important in the pathogenesis and clinical course of mycobacteriosis in swine. Modulation of the immune response by vaccines that selectively target cytokine expression and secretion in response to mycobacterial challenge may be effective in prevention of mycobacteriosis in swine.

Mercury biogeochemistry in the Idrija river, Slovenia, from above the mine into the Gulf of Trieste.

The Idrija Mine is the second largest Hg mine in the world which operated for 500 years. Mercury (Hg)-laden tailings still line the banks, and the system is a threat to the Idrija River and water bodies downstream including the Soca/Isonzo River and the Gulf of Trieste in the northern Adriatic Sea. A multidisciplinary study was conducted in June 1998 on water samples collected throughout the Idrija and Soca River systems and waters and sediments in the Gulf. Total Hg in the Idrija River increased >20-fold downstream of the mine from <3 to >60 ng liter(-1) with methyl mercury (MeHg) accounting for approximately 0.5%. Concentrations increased again downstream and into the estuary with MeHg accounting for nearly 1.5% of the total. While bacteria upstream of the mine did not contain mercury detoxification genes (mer), such genes were detected in bacteria collected downstream. Benthic macroinvertebrate diversity decreased downstream of the mine. Gulf waters near the river mouth contained up to 65 ng liter(-1) total Hg with approximately 0.05 ng liter(-1) MeHg. Gulf sediments near the river mouth contained 40 microgram g(-1) total Hg with MeHg concentrations of about 3 ng g(-1). Hg in sediment pore waters varied between 1 and 8 ng liter(-1), with MeHg accounting for up to 85%. Hg methylation and MeHg demethylation were active in Gulf sediments with highest activities near the surface. MeHg was degraded by an oxidative pathway with >97% C released from MeHg as CO(2). Hg methylation depth profiles resembled profiles of dissolved MeHg. Hg-laden waters still strongly impact the riverine, estuarine, and marine systems. Macroinvertebrates and bacteria in the Idrija River responded to Hg stress, and high Hg levels persist into the Gulf. Increases in total Hg and MeHg in the estuary demonstrate the remobilization of Hg, presumably as HgS dissolution and recycling. Gulf sediments actively produce MeHg, which enters bottom waters and presumably the marine food chain.

Epidemiological study of paratuberculosis in wild rabbits in Scotland.

A survey of 22 farms confirmed the presence of paratuberculosis in wild rabbits in Scotland. Regional differences were apparent in the prevalence of the disease in rabbits, with a significantly higher incidence occurring in the Tayside region. Statistical analysis showed a significant relationship between a previous history or current problem of paratuberculosis in cattle and the presence of paratuberculosis in rabbits on the farms. Molecular genetic typing techniques could not discriminate between selected rabbit and cattle isolates from the same or different farms, suggesting that the same strain may infect and cause disease in both species and that interspecies transmission may occur. The possibility of interspecies transmission and the involvement of wildlife in the epidemiology of paratuberculosis have important implications for the control of the disease.

Effects of macrophage inhibitory factor-A3 (MIF-A3) on cytokine secretion and phagolysosome fusion in murine macrophages.

Macrophage inhibitory factor-A3 (MIF-A3) is a fraction derived from Mycobacterium avium serovar 2 (Mav2) that consists of a small amine containing compound (peptide), trehalose and two or three short chain fatty acids. MIF-A3 has been shown to inhibit candidacidal activity of murine thioglycolate-elicited peritoneal-derived macrophages and bovine peripheral blood monocytes, and scavenge reactive oxygen intermediates. In this study, MIF-A3 was evaluated for its effect on secretion of IL-1beta, IL-6, IL-10, TNFalpha and GM-CSF in C57BL/6 murine thioglycolate-elicited peritoneal-derived macrophages, with and without pre-incubation with affinity purified goat anti-MIF-A3 IgG, using ELISA cytokine kit analysis. Results of this study suggest that anti-MIF-A3 IgG does not enhance clearance of Mav2, alter phagocytosis or alter phagosome-lysosome interactions as determined by electron microscopy in Mav2 infected macrophages. MIF-A3 does induce secretion of IL-6, but does not induce secretion of TNFalpha, IL-1beta, and GM-CSF. TNFalpha has been previously shown to reduce growth, while IL-6 has been shown to enhance growth of M. avium. Since IL-6 appears to enhance growth of M. avium and MIF-A3 induces IL-6 secretion, MIF-A3 may be responsible for enhanced intracellular growth in M. avium infections and be a factor in the pathogenesis of M. avium infections.

Multiple persistent vitelline duct cysts in a dog.

Persistent vitelline duct remnants, with the exception of Meckel's diverticulum in pigs and horses, are rare in animals. During an ovariohysterectomy of an 8-month-old Labrador Retriever, multiple fibrous nodules with cystic centers were found attached to the ileal serosa and in a mesodiverticular band attached to the abdominal wall. Histologic and ultrastructural evaluation revealed that the cysts were composed of well-differentiated intestine with mucosa, submucosa, and muscularis layers surrounded by a thick layer of fibrous connective tissue. The morphology and arrangement of lesions were consistent with multiple persistent vitelline duct cysts, a distinct condition related to Meckel's diverticulum. This case in a dog represents a unique presentation of this congenital anomaly in domestic animals.

Efficacy of vaccination for Mycobacterium avium with whole cell and subunit vaccines in experimentally infected swine.

Mycobacterium avium infections are a common problem in large swine producing states and cause substantial financial losses at slaughter inspection due to carcass condemnation. Once the infection is established in a swine herd it is difficult to effectively prevent or eliminate the disease. Previous mouse studies in our laboratory suggested that Macrophage Inhibitory Factor-A3 (MIF-A3) is a virulence factor of M. avium and potential antigen for vaccine development. In this study we evaluated the efficacy of a killed 'whole cell' M. avium serovar 2 bacterin and conjugated MIF-A3 subunit vaccine in preventing infection and disease in swine challenged with virulent M. avium serovar 2. Gross and microscopic pathology, acid-fast staining, culture and polymerase chain reaction (PCR) for the M. avium specific insertion sequence IS902 were utilized in evaluation. Results indicated that neither vaccine prevented infection in challenged animals; however, a 47% reduction in severity of disease was found in swine vaccinated with the 'whole cell' M. avium serovar 2 bacterin. Reduction in severity of disease was not detected in animals vaccinated with the subunit MIF-A3 vaccine.

Phylogenetic and physiological diversity of sulphate-reducing bacteria isolated from a salt marsh sediment.

The phylogenetic and physiological diversity of sulphate-reducing bacteria inhabiting a salt marsh rhizosphere were investigated. Sulphate-reducing bacteria were isolated from a salt marsh rhizosphere using enrichment cultures with electron donors thought to be prevalent in the rhizosphere of Spartina alterniflora. The relationship between phylogeny and nutritional characteristics of 10 strains was investigated. None of the isolates had 16S rRNA sequences identical to other delta subclass sulphate-reducers, sharing 85.3 to 98.1% sequence similarity with 16S rRNA sequences of their respective closest relatives. Phylogenetic analysis placed two isolates, obtained with ethanol as an electron donor, within the Desulfovibrionaceae. Seven isolates, obtained with acetate, butyrate, propionate, or benzoate, were placed within the Desulfobacteriaceae. One isolate, obtained with butyrate, fell within the Desulfobulbus assemblage, which is currently considered part of the Desulfobacteriaceae family. However, due to the phylogenetic breadth and physiological traits of this group, we propose that it be considered a new family, the "Desulfobulbusaceae." The isolates utilised an array of electron donors similar to their closest relatives with a few exceptions. As a whole, the phylogenetic and physiological data indicate isolation of several sulphate-reducing bacteria which might be considered as new species and representative of new genera. Comparison of the Desulfobacteriaceae isolates' 16S rRNA sequences to environmental clones originating from the same study site revealed that none shared more than 86% sequence similarity. The results provide further insight into the diversity of sulphate-reducing bacteria inhabiting the salt marsh ecosystem, as well as supporting general trends in the phylogenetic coherence of physiological traits of delta Proteobacteria sulphate reducers.

Seasonal changes in the relative abundance of uncultivated sulfate-reducing bacteria in a salt marsh sediment and in the rhizosphere of Spartina alterniflora.

Phylogenetic diversity and community composition of sulfate-reducing bacteria in a salt marsh sediment and in the rhizosphere of Spartina alterniflora were investigated. Uncultivated Desulfobacteriaceae family-related phylotypes were studied by selectively amplifying 16S rRNA gene fragments from DNA extracted from salt marsh rhizosphere samples. Two novel phylotypes were retrieved from rhizosphere samples, with A01 having 89.1% sequence similarity with Desulfococcus multivorans and 4D19 having 96.3% sequence similarity with Desulfosarcina variabilis. Additionally, six sequences that were extremely closely related to Desulfococcus multivorans (99% sequence similarity) were found. Reference RNAs containing sequences identical to corresponding cloned regions of A01 or 4D19 16S rRNA were synthesized via in vitro transcription and were used in subsequent quantitative membrane hybridization experiments. Oligonucleotide probes A01-183 and 4D19-189 were designed to specifically target these two novel phylotypes and were tested for target specificity against synthesized RNA and reference RNAs extracted from pure cultures. The newly designed probes were then used, together with eubacterial probes, to determine the relative abundances of the novel phylotypes in the salt marsh sediment and the rhizosphere. Mean relative abundances of A01-183 and 4D19-189 targets were 7.5 and 3.4%, respectively, suggesting that the target organisms of A01-183 and, to a lesser extent, of 4D19-189 play an important role in the salt marsh sediment and the Spartina rhizosphere. A seasonal trend of increased A01 relative abundance during the period of vegetative plant growth was evident, suggesting a close interaction between A01 and S. alterniflora.

Genome sizes of Desulfovibrio desulfuricans, Desulfovibrio vulgaris, and Desulfobulbus propionicus estimated by pulsed-field gel electrophoresis of linearized chromosomal DNA.

Pulsed-field gel electrophoresis (PFGE) of linearized, full-length chromosomal DNA was used to estimate the genome sizes of three species of sulfate-reducing bacteria. Genome sizes of Desulfovibrio desulfuricans, Desulfovibrio vulgaris, and Desulfobulbus propionicus were estimated to be 3.1, 3.6, and 3.7 Mb, respectively. These values are double the genome sizes previously determined for two Desulfovibrio species by two-dimensional agarose gel electrophoresis of DNA cut with restriction enzymes. PFGE of full-length chromosomal DNA could provide a generally applicable method to rapidly determine bacterial genome size and organization.

Macrophage inhibitory factor-A3 derived from Mycobacterium avium serovar 2 inhibits candidacidal activity of murine peritoneal macrophages.

Macrophage inhibitory factor-A3 (MIF-A3), a fraction derived from Mycobacterium avium serovar 2 inhibited candidacidal activity in macrophages from C57BL/6, C57BL/10, C3H/HeJ and A/J strains of mice. Inhibition of candidacidal activity was demonstrated at MIF-A3 concentrations ranging from 100-400 micrograms/ml in macrophages without additional stimulators (exception C3H/HeJ macrophages) and in macrophages additionally stimulated with 200 U/ml interferon-gamma, 100 ng/ml phorbol myristate acetate and 0.4 ng/ml E. coli lipopolysaccharide from all mouse strains tested. The decreased candidacidal effect produced by MIF-A3 was dose-dependent and appeared greatest in macrophages treated with phorbol myristate acetate and lipopolysaccharide. This effect was neutralized by the addition of goat anti-MIF-A3 antiserum. Macrophages from the Bcgs mouse strains (C57BL/6 and C57Bl/100 were more sensitive to the effect(s) of MIF-A3 than macrophages from the Bcgr mouse strains (C3H/HeJ and A/J).

Episodic symptoms in dysfunctioning children and adolescents following mild and severe traumatic brain injury.

The present investigation examines the phenomenology of episodic symptoms in dysfunctioning children and adolescents following mild (n = 25) or severe (n = 25) traumatic brain injury (TBI). TBI patients in both groups commonly endorsed symptoms such as staring spells, memory gaps, and temper outbursts. Anticonvulsant response in the 27 patients treated, reflected moderate to substantial improvement in 92%. A dose-response relationship between injury severity and number of episodic symptoms was not observed; however, patients in the severe TBI sample did produce significantly more defective performances on a dichotic word-listening task (DWLT) and lower IQ values. Defective DWLT performance was also significantly associated with greater number of episodic symptoms endorsed, but only in the mild TBI sample. Parallels with epilepsy spectrum disorder and clinical implications for paediatric TBI are discussed.

Determination of atmospheric methyl bromide by cryotrapping-gas chromatography and application to soil kinetic studies using a dynamic dilution system.

Methyl bromide (CH(3)Br) is considered to be a major source of stratospheric Br, which contributes to the destruction of ozone. It is therefore necessary to understand the natural sinks of this compound and to accurately measure ambient mixing ratios. Methodology is described for the measurement of atmospheric CH(3)Br by cryotrapping-gas chromatography and its application to soil kinetics. A 2-propanol/dry ice cryotrap was used to preconcentrate CH(3)Br in standard and air samples, with subsequent detection using a gas chromatograph equipped with an O(2)-doped electron capture detector (GC-ECD). The GC-ECD cryotrapping method had a detection limit of 0.23 pmol of CH(3)Br. This is equivalent to the amount of CH(3)Br in a 500 mL sample of ambient air at the estimated northern hemisphere atmospheric mixing ratio of 11 parts per trillion by volume (pptv). A dynamic dilution system was developed to produce mixing ratios of CH(3)Br ranging between 4 and 1000 pptv. Calibrated mixing ratios of CH(3)Br produced with the dilution system were used to determine soil uptake kinetics employing a dynamic soil incubation method.

Microbial formation of dimethyl sulfide in anoxic sphagnum peat.

Peat bogs dominated by Sphagnum spp. have relatively high areal rates of dimethyl sulfide (DMS) emission to the atmosphere. DMS was produced in anoxic slurries of Sphagnum peat with a linear time course and with an average rate of 40.4 (range, 22.0 to 68.6) nmol per liter of slurry (middot) day(sup-1) observed in nine batches of slurry. Methanethiol (MeSH) was produced at roughly similar rates over the typical 4- to 8-day incubations. DMS and MeSH production in these acidic (pH 4.2 to 4.6) peats were biological, as they were stopped completely by autoclaving and inhibited strongly by addition of antibiotics and 500 (mu)M chloroform. Endogenous DMS production may be due to the degradation of S-methyl-methionine, dimethyl sulfoxide, or methoxyaromatic compounds (e.g., syringic acid), each of which stimulated DMS formation when added at 5 to 10 (mu)M concentrations. However, on the basis of the high rates of thiol (MeSH and ethanethiol) methylation activity that we observed and the availability of endogenous MeSH, we suggest that methylation of MeSH is the major pathway leading to DMS formation in anaerobic peat. Solid-phase adsorption of MeSH plays a key role in its availability for biomethylation reactions. Additions of acetate (1.5 mM) or compounds which could cause acetate to accumulate (e.g., glucose, alanine, and 2-bromoethanesulfonate) suppressed DMS formation. It is likely that acetogenic bacteria are involved in DMS formation, but our data are insufficient to allow firm conclusions about the metabolic pathways or organisms involved. Our observations are the first which point to the methylation of MeSH as the major mechanism for endogenous DMS production in any environment. The rates of net DMS production observed are sufficient to explain the relatively high fluxes of DMS emitted to the atmosphere from Sphagnum sp.-dominated wetlands.

Neurobehavioural dysfunction following mild traumatic brain injury in childhood: a case report with positive findings on positron emission tomography (PET).

The present case study describes the neurobehavioural, neurodiagnostic, and positron emission tomography (PET) scan findings in a child who sustained a whiplash-type injury in a motor vehicle accident. Although neck and back pain were reported immediately, neurobehavioural symptoms, such as staring spells, gradually increased in frequency over a 2-year period following the accident. At 4 years after the accident the patient's symptoms persisted, as reported by teachers and parents, and more extensive diagnostic work-up was initiated. Standard EEG was normal while two ambulatory EEGs were abnormal and interpreted as epileptiform. A PET scan showed evidence of marked hypometabolism in both temporal lobes. Neuropsychological findings were consistent with PET findings and reflected verbal and visual memory deficits in the context of high average intelligence. Treatment with carbamazepine, verapamil, and fluoxetine greatly improved the patient's symptoms. The present case illustrates an example of a poor outcome in a paediatric case of mild traumatic brain injury, the importance of PET in demonstrating definitive evidence of brain dysfunction, and the child's positive response to anticonvulsant medication.

Combined adenovirus and rotavirus enteritis with Escherichia coli septicemia in an emu chick (Dromaius novaehollandiae).

A 2-week-old emu chick (Dromaius novaehollandiae) of approximately 200 g body weight was presented for necropsy with a history of weakness, diarrhea, pallor of the head, and acute death. Hemorrhagic enteritis with mild hepatomegaly was noted on gross examination. Microscopic examination revealed necrohemorrhagic enteritis with intralesional intranuclear basophilic viral inclusion bodies in intestinal epithelial cells; splenic lymphoid necrosis and fibrin exudation; hepatocellular vacuolar change; and multiple clusters of small gram-negative bacilli in the liver, spleen, yolk sac, and intestine. Transmission electron microscopy of negatively stained fecal specimens and thin sections of small intestine revealed clusters of viral particles consistent with adenovirus and rotavirus. Attempts at viral isolation from pooled tissue specimens were unsuccessful. Escherichia coli was isolated from specimens of liver and intestine and from an abdominal swab.