Outcome determinants of urethroplasty in the management of inflammatory anterior urethral strictures.

BACKGROUND: Limited data are available on outcomes of the surgical management of inflammatory urethral strictures secondary to infection, a major cause of stricture. Several shortcomings that need to be addressed have been identified in the past. OBJECTIVE: To determine the impact of stricture length, position and degree of obliterative urethral lumen on the surgical outcomes of corrective procedures for inflammatory anterior urethral strictures. METHODS: This retrospective analysis used the records of patients who presented with proven infective anterior urethral strictures at an academic hospital from 2007 to 2010. All patients were followed up after 48 months. Urethroplasty outcomes were analysed according to stricture location and length and effect of urethral obliteration. RESULTS: The median age of the 174 patients in the study was 47 (range 21 - 86) years. Anastomotic urethroplasty was successful in 59/99 (59.6%) patients. Augmented anastomotic urethroplasty was successful in 11/15 (73.3%) patients. Dorsal onlay buccal mucosa graft urethroplasty was successful in 23/32 (71.9%) patients, significantly higher than in 2/9 (22.2%) patients who underwent ventral onlay buccal mucosa graft urethroplasty (p=0.017; hazard ratio 3.4; 95% confidence interval 1.29 - 9.40). The one-stage circular pedicled penile skin-flap urethroplasty was successful in 1/12 (8.3%) patients. Two-stage urethroplasty was successful in 5/7 (71.4%) patients. A primary component analysis of the 73 failed procedures showed that stricture length was the main contributor to failure (eigenvalue 1.79; 45%). CONCLUSIONS: Urethroplasty remains a challenge in inflammatory urethral strictures, where stricture length was the main reason for treatment failure.

Acute effects of cigarette smoking on pulmonary function.

INTRODUCTION: Chronic smoking related changes in pulmonary function are reflected as accelerated decrease in FEV1 although histologic changes occur in the peripheral bronchi earlier. More sensitive pulmonary function parameters might mirror those early changes and might show a dose response. METHODS: In a randomized three-period cross-over design 57 male adult conventional cigarette (CC)-smokers (age: 45.1+/-7.1 years) smoked either CC (tar:11 mg, nicotine:0.8 mg, carbon monoxide:11 mg [Federal Trade Commission (FTC)]), or used as a potential reduced-exposure product the electrically heated smoking system (EHCSS) (tar:5 mg, nicotine:0.3 mg, carbon monoxide:0.45 mg (FTC)) or did not smoke (NS). After each 3-day exposure period, hematology and exposure parameters were determined preceding body plethysmography. RESULTS: Cigarette smoke exposure was significantly (p<0.0001) higher in CC than in EHCSS and in NS: (carboxyhemoglobin: CC: 6.4+/-1.9%; EHCSS: 1.3+/-0.6%; NS: 0.5+/-0.3%; serum nicotine: CC: 18.9+/-7.4 ng/ml; EHCSS: 8.4+/-4.3 ng/ml; NS: 1.2+/-1.6 ng/ml). Significantly lower in CC than in EHCSS and NS were specific airway conductance (0.22+/-0.09; 0.25+/-0.12; 0.25+/-0.1 1/cmH(2)O x s; CC vs EHCSS: p<0.05; CC vs NS: p<0.01), forced expiratory flow 25% (7.6+/-1.7; 7.8+/-1.7; 7.9+/-1.7 L/s; CC vs EHCSS or NS: p<0.01). Thoracic gas volume (5.1+/-1; 5+/-1.1; 5+/-1.1L/min) changed insignificantly. CONCLUSION: The data indicate acute and reversible effects of cigarette smoke exposures and no-smoking on mid to small size pulmonary airways in a dose dependent manner.

Ovine progressive pneumonia (Maedi-Visna): an emerging respiratory disease of sheep in Ethiopia.

A serological study was done to assess the role of Maedi-Visna (MV) infection in sheep from flocks with high respiratory tract disease morbidity in Ethiopia. Of 105 sheep examined from central Ethiopia 78 (74%) were positive for MV-infection. However, antibodies to the virus were not detected in 48 sheep and 70 goats from elsewhere in Ethiopia. The infection was detected in all breeds of sheep examined (Awassi, Hampshire, Corriedale, indigenous Menz breeds and their crosses) but with a significant breed difference (chi 2 = 20, p < 0.001) varying from 48% in imported Awassi sheep to 92% in the indigenous Menz sheep. This suggests that Menz sheep are more susceptible to infection, which may support the observation of a higher incidence of clinical disease in these sheep compared to exotic breeds and their crosses. It also supports recent studies indicating that MV is becoming one of the most important respiratory tract diseases in sheep in central Ethiopia. Our findings indicate that MV was introduced into Ethiopia via sheep imported into the central highlands and that it now constitutes an important emerging disease is discussed. Measures to control the disease are suggested.

Prevalence and aetiology of mastitis in cows from two major Ethiopian dairies.

The study was undertaken to determine the aetiology and prevalence of mastitis in hand-milked cows (n = 186) in two major Ethiopian dairies. The California Mastitis Test and culturing for bacteria revealed that 21.5% of the cows were clinically infected and 38.2% had subclinical mastitis. Most mastitis pathogens isolated from milk samples testing positive by the California Mastitis Test were Gram-positive cocci. Staphylococci constituted 57% of the isolates, of which the predominant cause of bovine mastitis was Staphylococcus aureus (40.5%). Other mastitis pathogens isolated include streptococci (16.5%), coliforms (9%) and corynebacteria (5%). Retrospective analysis of farm records indicated that mastitis was the second most important cause of culling and accounted for 27% of the cows removed from these two dairies.

The ovine respiratory syncytial virus F gene sequence and its diagnostic application.

Ruminant respiratory syncytial viruses (RSVs) are classified into 2 subgroups, ovine RSV and bovine RSV. Although ovine RSV infects cattle, its contribution to bovine respiratory tract disease has not been established, which is an important issue for vaccine development in cattle. Diagnosis by virus isolation or serology has low or variable sensitivity and/or specificity and polymerase chain reaction (PCR) has been recommended as a rapid and sensitive technique for RSV detection. A simple procedure has been developed to detect and identify bovine and ovine RSVs. First, the nucleotide sequence of the ovine RSV fusion (F) gene was determined and compared with representative strains of bovine RSV and human RSV subgroups A and B. The ovine RSV F gene has 85 and 72-73% nucleotide identity with those of bovine RSV and human RSV, respectively. The predicted amino acid sequence of the ovine RSV F gene has 94 and 83-84% amino acid identity with those of bovine RSV and human RSV, respectively. Then PCR primers targeting a specific F gene fragment of bovine and ovine RSV were designed. The primers represented bases 85-103 and the complementary sequence to bases 510-493 of the ovine RSV F gene. A similar PCR product (426 bp) was obtained on agarose gel electrophoresis from bovine RSV and from ovine RSV. The products, however, were unique to the parent virus and could be distinguished by EcoRI or MspI restriction endonuclease cleavage. EcoRI cleaved the ovine product into 2 bands (285 and 141 bp) but failed to affect the bovine RSV PCR product. However, MspI cleaved the bovine product into 2 bands (229 and 197 bp) but had no effect on the ovine product. Also, this assay did not amplify any PCR product with human RSV. The reverse transcription-polymerase chain reaction (RT-PCR) followed by restriction enzyme digestion is a useful and practical approach for detection and differentiation of ruminant respiratory syncytial viruses.

Detection of shared magnetic antigenic determinants on whole Moraxella bovis pili by use of antisera to cyanogen bromide-cleaved M. bovis pilus protein.

OBJECTIVE: To determine the ability of antisera against cyanogen bromide-cleaved pili from 4 strains of Moraxella bovis to react with whole or nondenatured pili. SAMPLE POPULATION: Antisera to 4 strains of M. bovis produced by New Zealand White rabbits. PROCEDURE: Pili from 4 strains of M. bovis were collected and purified. Pilus proteins (pilin) were cleaved, using cyanogen bromide. Whole pilus and cyanogen bromide-cleaved pilin were injected into rabbits. Antisera were serially diluted, reacted with 4 strains of M. bovis, and examined by immunoelectron microscopy and indirect immunofluorescence. RESULTS: Antisera to whole pili aggregated and distorted pili from homologous strains, but pili from heterologous strains were unaffected. Antisera to cleaved pilin fragments resulted in partial aggregation and thickening of homologous and heterologous pili, suggestive of heterospecific antibodies. Attachment of antibodies to pili was detected by indirect immunofluorescence, indicating a strong reaction of antisera to whole pili with homologous pili. Weak cross-reactions were evident with certain heterologous strains. In contrast, antisera to cleaved pilin fragments reacted strongly with pili from homologous and heterologous strains. CONCLUSIONS AND CLINICAL RELEVANCE: We detected shared antigenic determinants on pili from various strains of M. bovis that were not immunogenic in intact pili. These sites were immunogenic after cleavage of pilus protein with cyanogen bromide, and antisera produced to protein fragments reacted with whole pili from heterologous strains of the organism. Vaccines produced from cyanogen bromide-treated pili may induce broader immunity against infectious bovine keratoconjuctivitis than that provided by currently available vaccines.

Immunoblot analysis of cyanogen bromide-cleaved Moraxella bovis pilin reveals presence of shared antigenic determinants on pili from heterologous strains.

Moraxella bovis pilus proteins, collected and purified from four strains of M. bovis, were cleaved with cyanogen bromide. Two major fragments were produced. Antisera were produced in rabbits to the pilin protein fragments and to whole uncleaved pili from these strains. Immunoblots of whole and cyanogen bromide-cleaved pilin were reacted with the homologous and heterologous antisera to whole pili and cleaved pilin. Antisera to whole pili reacted strongly with homologous pilin. Weaker and inconsistent reactions were detected with heterologous pilin. Antisera produced to cyanogen bromide-cleaved pilin proteins reacted strongly with homologous and heterologous pilin fragments and uncleaved pilin proteins. These findings demonstrate the presence of conserved antigenic determinants on pili from heterologous strains that are non-immunogenic in the intact pilus but are immunogenic after treatment with cyanogen bromide. Cyanogen bromide-treated pilus preparation might have potential as a vaccine because antibodies are induced against heterologous strains of M. bovis, whether these cross-reactive antibodies are protective remains to be determined.

Validation of synthetic peptide enzyme immunoassays in differentiating two subgroups of ruminant respiratory syncytial virus.

Subgroup-specific peptide-based enzyme immunoassays from each respective G-glycoprotein of the ovine and the bovine respiratory syncytial virus (RSV) were developed to detect RSV-specific IgG responses in cattle. Antigenic peptides from the respective G-glycoprotein were identified from the extracellular central hydrophobic region (amino acids 158-189) located between 2 mucin-rich regions. These antigenic peptides identified by epitope mapping from each G-glycoprotein were synthesized and used to develop the subgroup-specific enzyme immunoassays. The negative cutoff for each enzyme immunoassay was established as the mean optical density of indirect immunofluorescent antibody-negative bovine sera plus 3 SDs. The sensitivity (82.9%) and specificity (100%) of the bovine enzyme immunoassay and the specificity (95.8%) of the ovine enzyme immunoassay were determined by comparison with indirect immunofluorescence (used as the "gold standard"). The negative and positive predictive values were calculated for each assay. The presence of serum antibody to ovine RSV in cattle implies that this virus infects cattle and may contribute to the pathogenesis of bovine respiratory disease.

Prevalence of ovine and bovine respiratory syncytial virus infections in cattle determined with a synthetic peptide-based immunoassay.

Subgroup-specific peptide-based enzyme-linked immunosorbent assays from the G-protein of the ovine and bovine respiratory syncytial virus (RSV), respectively, were used to determine the prevalence of the ovine and bovine subgroup strains of RSV infections in cattle. A total of 1,102 bovine serum samples were obtained from 6 diagnostic laboratories located in the northwestern and the southeastern USA and were tested for antibody to either the bovine or ovine subgroups of RSV. Antibody to viruses from each subgroup was present in samples from each region and all states tested. The Southeast had a higher prevalence of the bovine subgroup strains (69.5%). Then did the Northwest (40.9%). The prevalence of the ovine strain was similar for the two regions (16.7% in the southeast, 14.9% in the northwest). The overall prevalence was 56.6% for the bovine strain and 15.9% for the ovine strain. These results suggest members of the ovine subgroup of RSV circulate in the cattle population but with less frequency than those viruses of the bovine subgroup.

Prevalence of bovine respiratory syncytial virus (BRSV) and bovine herpesvirus-4 (BHV-4) in cattle from Ethiopia.

A serological study was done to establish the occurrence and determine the prevalence of two important respiratory tract pathogens, bovine respiratory syncytial virus (BRSV) and bovine herpesvirus-4 (BHV-4), in cattle in Ethiopia. Prevalence rates for specific antibodies of 92.5% and 22.3% were recorded for BRSV and BHV-4, respectively. The presence of antibodies against these viruses in cattle from Ethiopia is recorded for the first time in this report. Our data suggests diseases caused by these viruses occur in Ethiopia but, perhaps because disease signs are not specific, they have not been recognized in the past.

Prevalence of bluetongue virus antibodies in sheep in central Ethiopia.

Competitive ELISA was applied to detect antibodies against bluetongue virus in sheep sera collected from different agro-climatic areas in Ethiopia. A total of 90 serum samples were tested and 42 (46.67%) were positive for bluetongue virus antibodies. A prevalence rate ranging from 9.67% for sheep sampled in the highland to 92.85% for sheep sampled in the lowland was recorded. The prevalence correlated with the probable distribution of the Culicoides vector. This is the first report indicating the presence of bluetongue virus infection in animals from Ethiopia.

Analysis of ruminant respiratory syncytial virus isolates by RNAse protection of the G glycoprotein transcripts.

Two different respiratory syncytial virus (RSV) radiolabeled probes were used to characterize the genetic heterogeneity of 25 ruminant RSV isolates by the ribonuclease protection assay. A 32P-radiolabeled antisense RNA probe was transcribed from cloned ovine and bovine RSV G glycoprotein genes and then hybridized with total RNA isolated from infected cells with various ruminant RSV isolates. The results of this study, along with previously published nucleotide sequence data of the ovine RSV G glycoprotein gene, suggest the presence of at least 2 ruminant RSV subgroups. One subgroup is represented by RSV isolated from respiratory disease outbreaks from calves and goats, and the other is represented by RSV isolated from sheep.

Bovine respiratory tract disease caused by bovine viral diarrhea virus.

Although several viruses and bacteria are capable of inducing bovine respiratory tract disease, a pivotal organism in the cause of this complex disease may be bovine viral diarrhea virus (BVDV). Circumstantial evidence has long supported this hypothesis. It is frequently present in diseased respiratory tract tissues often together with other viruses or bacteria. Field observations suggest marked synergism occurs. Researchers have confirmed that, in most instances, the virus itself elicits only a mild respiratory tract disease in susceptible calves, but some strains may be much more pneumo-pathogenic than others. Experimental evidence now supports the hypothesis, that BVDV markedly enhances respiratory tract disease caused by IBRV, BRSV, or Pasteurella haemolytica; that it impairs pulmonary immunity; and that it, by itself, may produce mild respiratory tract disease.

Antibody responses of red wolves to canine distemper virus and canine parvovirus vaccination.

Twenty captive red wolves (Canis rufus), including 16 intended for release into Great Smoky Mountains National Park, Cades Cove, Tennessee (USA), and four housed at Knoxville Zoological Gardens, Inc., Knoxville, Tennessee, were evaluated for immunologic response to vaccination between June 1994 and April 1995. Wolves were vaccinated with modified-live (MLV) canine distemper virus (CDV) and canine parvovirus type-2 (CPV2). Sera were collected, and immunofluorescent staining was performed for determination of immunoglobulin titers (CDV IgM, CDV IgG, and CPV2 IgG). A capture enzyme-linked immunosorbent assay was performed for validation purposes, to confirm the reactivity of our standard diagnostic reagents with red wolf serum. All wolves produced a measurable antibody response to CDV and CPV2 vaccination. Titers against CDV and CPV2 varied widely among individual wolves, but between-litter differences in mean titers were not significant. No consistent response between the degree of response to CDV versus CPV2 vaccination was observed in individual wolves. No differences were seen between IgG responses of pups vaccinated with univalent vaccines given concurrently or during alternating weeks. Pups had an IgG response to CDV and CPV2 vaccination as early as 9 wk of age. Mean post-vaccination IgG titers against CDV were at or above the level normally measured in vaccinated domestic dogs. Mean post-vaccination IgG titers against CPV2 were below the level normally measured in domestic dogs. Adult previously-vaccinated wolves had measurable CDV and CPV2 IgG titers more than 1 yr after vaccination, but did not have significant IgG titer increases after revaccination. We conclude that red wolves are capable of producing an antibody response after vaccination with commercial canine products but that their response to CPV2 vaccination was minimal. This response can be assayed using tests developed for domestic dogs.

Serologic reactivity using conserved envelope epitopes in feline lentivirus-infected felids.

An enzyme-linked immunosorbent assay (ELISA) based on synthetic peptides identical to lentivirus envelope protein amino acid sequences was used to study serologic reactivity of lentivirus-infected domestic cats and nondomestic felids. One feline immunodeficiency virus (FIV) peptide, P237, was consistently recognized by antibodies from FIV-infected cats, but 2 other FIV peptide antigens were not. The molecular basis for this serologic reactivity was examined. Lentivirus-infected nondomestic Felis species reacted intensely with a puma lentivirus (PLV) peptide corresponding to the conserved FIV peptide. However, lentivirus-infected Panthera species, from which a different lentivirus has been isolated, did not react with the PLV. FIV-infected domestic felids also did not have significant reactivity with the PLV peptide. The peptide ELISA is comparable in sensitivity and specificity to western blot analysis and a commercial enzyme immunoassay. Unlike the other assays, however, the peptide ELISA is inexpensive, requires a small amount of serum, enables the study of specific isotype reactivity, and discriminates between antibodies to FIV and those to PLV. Antibody tests based upon the FIV and the PLV peptides should be useful for detecting the possible introduction of FIV into exotic felids or of lentiviruses from nondomestic felids into the domestic cat population.

Immunology of bovine viral diarrhea virus.

Often persistent and primary postnatal infections with BVDV result in immunosuppression in cattle, thereby enhancing the vulnerability of the latter to secondary infections. The evidence for and nature of impaired immunity in these animals is reviewed. Our knowledge of the extent and nature of protective immunity induced by natural BVDV infections and vaccines is still in its infancy. Significant new information on the bovine immune response to BVDV antigens, however, has been identified in recent years. These data are reviewed and related to prospects for improved immunoprophylaxis against diseases caused by the virus.

Virucidal efficacy of the newer quaternary ammonium compounds.

The virucidal activity of several disinfectants containing newer generation quaternary ammonium compounds (QACs) as their active ingredients was evaluated. Disinfectants were used at the manufacturers' recommended dilutions with isolates of feline herpesvirus, feline calicivirus, and canine parvovirus, and a contact time of 10 minutes at room temperature. Detoxification of virus/disinfectant solutions was done by dialysis prior to virus assay in cell cultures. Two of four disinfectants completely inactivated feline herpesvirus, and two significantly reduced the titer of this virus. None of the disinfectants that were tested completely inactivated feline calicivirus. Canine parvovirus was not inactivated significantly by any of the QAC disinfectants. Sodium hypochlorite completely inactivated all viruses.

Effects of housing and colostrum feeding on serum immunoglobulins, growth, and fecal scores of Jersey calves.

Ninety-six Jersey calves were used to evaluate the effects of housing and method of colostrum feeding on serum Ig concentrations, incidence and severity of scours, intake, and BW changes from birth to 35 d of age. Calves were separated from the dam and fed 2 L of colostrum in nipple-bottles or allowed to nurse the dam for 3 d. Calves were housed in individual hutches or wooden pens in a barn. Intake of colostrum by calves allowed to nurse the dam was not controlled. Serum IgG and IgM concentrations at 24 h of age were greater for calves that nursed the dam. Scours were less severe when calves were housed in hutches, but number of days scouring was unaffected by treatment. Calves fed colostrum in nipple-bottles and housed in the barn consumed more starter than did other calves from 3 to 5 wk of age. The BW were greater for calves allowed to nurse the dam and housed in hutches. Feed efficiency over the 35-d study was improved when calves nursed the dam. Optimal transfer of passive immunity and housing in hutches appeared to maximize health and growth in this study.

Pestivirus translation initiation occurs by internal ribosome entry.

The role of the 385 nucleotide 5' noncoding region (NCR) in the translation of the pestivirus genome was investigated. In vitro translation of an RNA transcript containing the 5' NCR of the bovine viral diarrhea virus (BVDV) genome followed by the coding sequence of the first gene product (p20) of the BVDV large open reading frame resulted in the synthesis of a 20-kDa polypeptide. Results from hybrid-arrest translation studies identified a region involving a predicted RNA stem-loop structure spanning nucleotides 154-261 within the 5' NCR that was important for p20 synthesis. An additional inhibitory oligonucleotide was complementary to the sequence at the base of this stem-loop and encompassed the initiating AUG at nucleotide 386. Antisense oligonucleotides both upstream and downstream of those that were inhibitory had no effect on p20 translation. RNA from a dicistronic expression vector in which the BVDV 5' NCR was inserted between two reporter genes, CAT and LUC, showed strong expression of the second (LUC) cistron upon in vitro translation. This expression was dramatically reduced in an analogous construct in which nucleotides 173-236 of the 5' NCR were deleted. Similar results were obtained when RNA from these same vectors was evaluated for expression after transfection into BHK cells. These results suggest that the BVDV 5' NCR contains an internal ribosome entry site for translation initiation. This translational mechanism is similar to that shown for hepatitis C virus, further demonstrating the close relationship between viruses of these two genera within the family Flaviviridae.