Evaluation of substantivity of hypochlorous acid as an antiplaque agent: A randomized controlled trial.

BACKGROUND: Hypochlorous acid (HOCl) is a non-antibiotic antimicrobial substance with significant effects on pathogenic oral micro-organisms. The effects of HOCl as an antiplaque agent have not been studied. OBJECTIVE: The aim of this study was to evaluate the substantivity of HOCl mouthwashes compared with chlorhexidine (CHX) rinses and a placebo. MATERIALS AND METHODS: A double-blind randomized controlled trial with 75 participants was conducted. Participants were divided into five groups using block randomization: 0.025% HOCl, 0.05% HOCl, 0.12% CHX, 0.2% CHX, and sterile water as a placebo. Participants were instructed to use each rinse solution for 30 seconds after dental prophylaxis. Samples of saliva were taken at baseline and after 30 seconds, 1, 3, 5 and 7 hours to assess substantivity, and bacterial viability was established by the fluorescence method. Visible plaque in all participants was assessed with the Turesky index at baseline and at 7 hours, and adverse events were also assessed. RESULTS: HOCl led to a 33% reduction in bacterial counts in the saliva after 30 seconds compared with a 58% reduction by CHX. HOCl has no substantivity, and bacterial counts returned to baseline after 1 hour. Placebo treatment led to the highest plaque count after 7 hours compared with the CHX and HOCl groups, although the differences were not significant. HOCl rinsing induced the highest percentages of unpleasant taste and dryness sensations. CONCLUSIONS: HOCl rinses have an initial effect on bacterial viability in saliva but have no substantivity. Other mechanisms may explain its antiplaque effect.

Gastrointestinal Symptoms and Elevated Levels of Anti-Saccharomyces cerevisiae Antibodies Are Associated with Higher Disease Activity in Colombian Patients with Spondyloarthritis.

BACKGROUND: Spondyloarthritis (SpA) is a group of articular inflammatory rheumatic diseases that their gastrointestinal manifestations are around 10% of their extra-articular symptoms, supporting that the inflammatory response of the intestinal mucosa could be associated with the clinical status. OBJECTIVES: To investigate the association between gastrointestinal symptoms and autoantibodies and disease activity between SpA patients, healthy subjects (HS), and patients with inflammatory bowel disease (IBD). METHODS: 102 SpA patients, 29 IBD patients, and 117 HS were included. Autoantibodies as ASCA, ANCA, anti-tTG, anti-DGP, ANA, and IgA were measured. The patients were assessed to evaluate clinical and gastrointestinal symptoms. An association analysis was performed using Chi square test and a logistic regression. RESULTS: Significant differences were found for ASCA levels in SpA (28.2%) compared to IBD (14.2%) and HS (6.0%) (p = 0.029), as well as for ANAS in SpA (49.5%) and IBD (37.9%) (p < 0.001) and abdominal pain (p = 0.012) between SpA (54.3%) and IBD (27.5%). Significant associations were found between BASDAI > 4 and gastrointestinal symptoms (p < 0.05) and IgA (p = 0.007). The association for abdominal bloating was maintained (OR: 3.93, CI-95%, 1.14-13.56; p = 0.030). CONCLUSIONS: Gastrointestinal symptoms, ASCA, ANAS, and IgA levels were associated with high disease activity in SpA compared with IBD and HS.

Is the Treatment with Biological or Non-biological DMARDS a Modifier of Periodontal Condition in Patients with Rheumatoid Arthritis?

BACKGROUND AND OBJECTIVE: Experimental models suggest the use of different therapy protocols in rheumatoid arthritis (RA) as modulators on periodontal condition. This study evaluated the effects of conventional drug treatment and anti-TNF therapy in patients with RA on microbiological and periodontal condition, establishing the association of markers of periodontal infection with indexes of rheumatic activity. MATERIALS AND METHODS: One hundred seventy nine individuals with RA were evaluated (62 with anti-TNF-. and 115 with only DMARDs). The periodontal evaluation included plaque and gingival indexes, bleeding on probing (BOP), clinical attachment loss (CAL), pocket depth (PD) and subgingival plaque samples for microbiological analysis. Rheumatologic evaluations included a clinical examination, rheumatoid factor (RF), antibodies against cyclic-citrullinated peptides (ACPAs), and activity markers (DAS28-ERS), high sensitive C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR). RESULTS: Anti-TNF-alpha therapy influenced periodontal microbiota with a higher frequency of T. denticola (p=0.01). Methotrexate combined with leflunomide exhibited a higher extension of CAL (p=0.005), and anti-TNF-alpha therapy with methotrexate was associated with a lower extension of CAL (p=0.05). The use of corticosteroids exerted a protective effect on the number of teeth (p=0.027). The type of DMARD affected P. gingivalis, T. forsythia and E. nodatum presence. Elevated ACPAs titers were associated with the presence of red complex periodontal pathogens (p=0.025). Bleeding on probing was associated with elevated CPR levels (p=0.05), and ESR was associated with a greater PD (p=0.044) and presence of red complex (p=0.030). CONCLUSION: Different pharmacological treatments for RA affect the clinical condition and subgingival microbiota.

Diode laser surgery versus scalpel surgery in the treatment of fibrous hyperplasia: a randomized clinical trial.

Fibrous hyperplasia is treated by surgical incision using a scalpel, together with removal of the source of chronic trauma. However, scalpel techniques do not provide the haemostasis that is necessary when dealing with highly vascular tissues. Diode laser surgery can be used in the management of oral tissues due to its high absorption by water and haemoglobin, and has provided good results in both periodontal surgery and oral lesions. The aim of the present study was to compare the effects of diode laser surgery to those of the conventional technique in patients with fibrous hyperplasia. A randomized clinical trial was performed in which surgical and postoperative evaluations were analyzed. On comparison of the laser-treated (study group) patients to those treated with a scalpel (control group), significant differences were observed in the duration of surgery and the use of analgesic medications. Over a 3-week period, clinical healing of the postoperative wound was significantly faster in the control group as compared to the study group. In conclusion, diode laser surgery proved to be more effective and less invasive when compared to scalpel surgery in the management of fibrous hyperplasia. However, wound healing proved to be faster when using scalpel surgery.

MÉTODOS PARA LA IDENTIFICACIÓN DEL ANTÍGENO DE HISTOCOMPATIBILIDAD HLA-B27: COMPARACIÓN DE CUATRO PROTOCOLOS TÉCNICOS / METHODS FOR IDENTIFICATION OF ANTIGEN HLA-B27 HISTOCOMPATIBILITY: FOUR TECHNICAL COMPARISONS OF PROTOCOLS / MÉTODOS PARA A IDENTIFICAÇÃO DO ANTIGÉNIO DE HISTOCOMPATIBILIDADE HLA-B27: CAMPARAÇAO DE QUATRO PROTOCOLOS TÉCNICOS

Introducción: La asociación del HLA-B27 y las Espondiloartritis, ha hecho evidente que la tipificación del HLA-B27 sea considerada como un apoyo en el diagnóstico de estas enfermedades. Los métodos más empleados para la determinación del antígeno HLA-B27 en los laboratorios clínicos y en investigación son: la microlinfocitotoxicidad (MCTX), la citometría de flujo digital (CMFd), la citometría de flujo análoga (CMFa) y la reacción en cadena de la polimerasa con primers de secuencia específicos (PCR-SSP). Objetivo: Comparar MCTX con la CMFd, la CMFa con la CMFd, y la técnica de CMFd frente a PCR-SSP. Métodos: Se analizaron 4109 solicitudes de HLA-B27 en población con manifestaciones sugestivas de EAS remitidas entre 2009 y 2012 al Hospital Militar Central y al Instituto de Referencia Andino. Se evaluaron las frecuencias obtenidas por Chi cuadrado (X2); para estimar la concordancia metodológica se utilizó el Coeficiente de Correlación Intraclase (CCI). Los análisis se realizaron con el paquete estadístico SPSS V18. Resultados: Al evaluar 467 datos por la técnica de CMFa frente a PCR-SSP, la CMFa mostró 239 resultados entre positivos y en rango indeterminado, de los cuales, luego de ser confirmados PCRSSP, solo 213 demostraron la expresión de HLA-B27 (p<0.05). Se obtuvieron 208 resultados realizados por CMFd y PCR-SSP simultáneamente, observándose una alta correspondencia entre estas técnicas (p<0.05). Para evaluar la concordancia entre la MCTX y CMFd se analizaron 34 datos, revelando un 100% de correspondencia entre esta dos metodologías (CCI=1,p<0.05). Conclusión: La citometría de flujo digital es un método rápido que presenta un desempeño altamente confiable para la identificación de HLA-B27, resultados que se recomiendan confirmar por PCR SSP.

Introduction: The association between HLA-B27 and spondyloarthritis has made clear the fact that identification of HLA-B27 antigen is considered as a support in the diagnosis of these diseases. The most commonly used methods for determination of the HLA-B27 antigen in clinical laboratories as well as in their research, are microlymphocytotoxicity (MCTX), digital flow cytometry (CMFd), analogous flow cytometry (CMFa) and the Single Specific Primer-Polymerase Chain Reaction (PCRSSP). Objective: compare the CMFd against MCTX, CMFa against CMFd and CMFd against PCR-SSP. Methods: 4109 requests for HLA-B27 were analyzed with manifestations suggestive of SpA submitted between 2009 and 2012 at Hospital Militar Central and Instituto de Referencia Andino. To analyze the frequencies Chi square (X2) was evaluated; to estimate the methodological concordance the intraclass correlation coefficient (ICC) was used. All proposed analyzes were performed with SPSS V18. Results: 467 data obtained by CMFa versus PCR-SSP evaluated the CMFA showed 239 results between positive and indeterminate range, which, after being confirmed by molecular biology (PCRSSP), only 213 showed the expression of HLA-B27 (p <0.05). PCR-SSP and CMFd performed 208 results simultaneously, showing a high correlation between these techniques (p <0.05). To evaluate the correlation between CMFd and MCTX, 34 data were analyzed, revealing a 100% match on the positive results from these two methodologies (ICC = 1, p <0.05). Conclusion: The digital flow cytometry is a rapid method that presents a highly reliable for the initial identification of HLA-B27; results confirmed by PCR SSP recommend performance.

Introdução: a associação do HLA-B27 e as Espondilartrite, evidenciou que a tipificação do HLAB27 seja considerada como um suporte no diagnóstico dessas doenças. Os métodos mais usados para a determinação do antígeno HLA-B27 nos laboratórios clínicos e no investigação são: a microlinphocitotoxicity (MCTX), a citometria de fluxo digital (CMFd), a citometria de fluxo análoga (CMFa) e a reação em cadeia de a polimerasa com primers de sequência específicos (PCR-SSP). Objetivo: Comparar MCTX com a CMFd, a CMFa com a CMFd, e a técnica de CMFd com PCRSSP. Métodos: 4109 solicitudes de HLA-B27 em população com manifestações sugestivas de EAS remitidas entre 2009 e 2012 ao Hospital Militar e ao Instituto de Referencia Andino, foram analisadas. Avaliaram-se as frequências obtidas por Chi quadrado (X2); para estimar a concordância metodológica foi utilizado o Coeficiente de Correlação Intraclasse (CCI). Os análises estão feitos com o paquete estadístico SPSS V18. Resultados: A CMFa mostrou 239 resultados entre positivos e em rango indeterminado quando avaliou-se 467 dados com a técnica de CMFa com PCR-SSP. Só 213 deles demostraram a expressão de HLA-27 (p<0.05), depois de ser confirmados PCR-SSP. Foram obtidos 208 resultados por CMFd y PCR-SSP em simultâneo, com uma alta correspondência entre estas técnicas (p<0.05). Para avaliar a concordância entre MCTX y CMFd analisaram-se 34 dados, revelando um 100% de correspondência entre as duas metodologias (CCI=, p<0.05). Conclusão: A citometria de fluxo é um método rápido que tem um desempeno muito confiável para a identificação de HLA-B27, resultados recomendados para confirmar por PCR SSP.

Estimation of inbreeding and effective population size of full-blood Wagyu cattle registered with the American Wagyu Cattle Association.

The objective of this research was to examine the population structure of full-blood (100%) Wagyu cattle registered in the United States with the American Wagyu Association, with the aim of estimating and comparing the levels of inbreeding from both pedigree and genotypic data. A total of 4132 full-blood Wagyu cattle pedigrees were assessed and used to compute the inbreeding coefficients (FIT and FST ) and the effective population size (Ne ) from pedigree data for the period 1994 to 2011. In addition to pedigree analysis, 47 full-blood Wagyu cattle representing eight prominent sire lines in the American Wagyu cattle population were genotyped using the Illumina BovineSNP50 BeadChip. Genotypic data were then used to estimate genomic inbreeding coefficients (FROH ) by calculating runs of homozygosity. The mean inbreeding coefficient based on the pedigree data was estimated at 4.80%. The effective population size averaged 17 between the years 1994 and 2011 with an increase of 42.9 in 2000 and a drop of 1.8 in 2011. Examination of the runs of homozygosity revealed that the 47 Wagyu cattle from the eight prominent sire lines had a mean genomic inbreeding coefficient (FROH ) estimated at 9.08% compared to a mean inbreeding coefficient based on pedigree data of 4.8%. These data suggest that the mean genotype inbreeding coefficient of full-blood Wagyu cattle exceeds the inbreeding coefficient identified by pedigree. Inbreeding has increased slowly at a rate of 0.03% per year over the past 17 years. Wagyu breeders should continue to utilize many sires from divergent lines and consider outcrossing to other breeds to enhance genetic diversity and minimize the adverse effects of inbreeding in Wagyu.

Association of tumor necrosis factor alpha-308 promoter polymorphism with spondyloarthritides patients in Colombia.

The pathogenesis of SpA is considered to be a complex and multi-factorial process and, similar to other autoimmune diseases, includes the activity of proinflammatory cytokines such as TNF alpha. Our study compared the -308 promoter polymorphism of TNF alpha with TNF alpha levels, HLA-B27 status, age at the onset of symptoms, SpA subtype and the clinical degree of activity in Colombian SpA patients and healthy subjects (HS). Comparisons of the TNF alpha-308A genotype among HS and SpA patients (P = 0.004), uSpA patients (P = 0.040), ReA patients (P = 0.001), were significantly different and AS patients (P = 0.110), as were alleles for SpAs (P = 0.007) between patients with SpAs and controls. Initial exploratory analyses demonstrated that the TNF alpha-308 SNP genotype frequencies were different among SpA patients and HS in the Colombian population studied. Furthermore, there was no significant correlation with activity and functional clinical index, serum TNF alpha level or HLA B27 status. Allele frequencies, on the other hand, were correlated with the activity clinical index.

Association between Th-17 cytokine profile and clinical features in patients with spondyloarthritis.

OBJECTIVES: In recent years, a substantial amount of information has become available on the relationship between cytokines associated with the Th-17 profile and the development of spondyloarthritis (SpA). The purpose of this study was to evaluate inflammation markers in serum and synovial fluid (SF) and levels of cytokines related to the Th-17 profile in patients with different subtypes of SpA and healthy subjects. METHODS: We evaluated this cytokine profile in light of the clinical activity of the disease in 62 patients. Serum cytokine levels (IL-17, IL-6, IL-1 alpha, TNF alpha, IFN-gamma) were measured by flow cytometry. IL-23, serum amyloid (SAA) and metalloproteinase 3 (MMP-3) were measured with ELISA. In all patients, clinical evaluation was performed using the activity and function indexes of the disease. RESULTS: A comparison showed that IL-17, IL-23, IL-1 alpha, IL-6, and TNF-alpha levels were significantly higher in the serum of SpA patients than healthy subjects (HS), and there were no differences among SpA subtypes. In SF we found higher concentrations of cytokines, but only IL-23 showed significant differences (p<0.05). We found a relationship between enthesitis and peripheral involvement and serum IL-17 levels (9 to 63 pg / ml). There was a correlation between levels above 63 pg/ml and a history of infection. Higher levels of IL-23 in synovial fluid could suggest local amplification of the Th-17 cytokine profile. CONCLUSIONS: These results suggest a possible relationship between IL-17 and enthesis involvement in SpA.

Remodelación ósea en espondiloartritis / Bone remodeling in spondyloarthritis

Las espondiloartropatías (EAS) corresponden a un grupo de patologías inflamatorias crónicas caracterizadas por proliferación ósea que progresivamente conduce a anquilosis y discapacidad funcional. Las alteraciones radiológicas observadas en dichos pacientes revelan cambios erosivos y sobrecrecimiento de estructuras óseas conocidas como sindesmofitos. Teniendo en cuenta la entesis como órgano primario de la enfermedad, varios procesos tienen lugar en este sitio anatómico: inflamación, destrucción ósea y finalmente nueva formación ósea. El proceso inflamatorio tiene como resultado un exceso de formación ósea, y el impacto neto depende de la localización, tipo celular, citoquinas y factores presentes en el micro ambiente local. Varias moléculas que actúan ya sea como moduladores inmunológicos o reguladores de la homeostasis del hueso, han sido implicadas en la mediación del imbalance entre reabsorción y formación que finalmente resulta en degeneración a nivel de la zona de entesis y/o articular. Modelos animales sugieren que la anquilosis articular que puede llegar a producirse puede ser independiente del Factor de Necrosis Tumoral Alfa; por lo tanto, el proceso de neoformación tisular puede ser considerado un blanco terapéutico adicional. La vía de señalización Wnt, considerada el principal regulador de osteoblastogénesis (Familia de glicoproteína Wnt), teniendo en cuenta su papel en cuanto a regulación del imbalance entre formación y resorción ósea, ha constituido un nuevo campo de investigación de gran interés durante los últimos años.

Spondyloarthritis are a group of chronic inflammatory diseases characterized by progressive new bone formation leading to ankylosis and functional disability. The radiographic changes in these patients may show erosive changes and overgrowth of bony structures called syndesmophytes. Given the enthesis as the primary organ of the disease, several processes take place: inflammation, bone destruction and finally new bone formation. The inflammatory process results in excess of bone formation and the impact depends on the location, cell type, cytokines and factors in the local microenvironment. Several molecules that act either as immune modulators or regulators of bone homeostasis have been implicated in mediating the imbalance between resorption and formation that ultimately results in joint degeneration. Animal models suggest that joint ankylosis may be independent of TNF alfa; therefore the process of new tissue formation can be an additional therapeutic target. The Wnt signaling pathway, considered the primary regulator of osteoblastogenesis and its role in terms of regulating the imbalance between bone formation and resorption, is a new research field of great interest in recent years.

Endocrine regulation of the establishment of spermatogenesis in pigs.

Somatic and germ cell maturation precedes the start of spermatogenesis and is coordinated, so efficient spermatogenesis will occur in the adults. The present study was conducted to evaluate endocrine regulation of germ and somatic cell homeostasis in the neonatal boar testis associated with the establishment of spermatogenesis. Testis tissue obtained from 3-, 5-, 7- and 14-day-old piglets were ectopically xenografted onto castrated, immunodeficient nude mice. Grafts were removed 22 weeks later and evaluated for growth and the establishment of spermatogenesis. Recipient mouse testosterone biosynthesis and follicle-stimulating hormone (FSH) concentrations were also assayed. Testis tissue graft growth was significantly greater in testis grafts from 3-day donor tissue when compared to all other ages; 5-, 7- and 14-day-old donor tissue weights were not significantly different at removal. Follicle-stimulating hormone concentrations in recipient mice supporting testis grafts from 5-, 7- and 14-day-old donor tissues did not differ and were similar to normal physiological levels in age-matched, intact nude mice. Serum FSH levels were significantly lower in recipient mice supporting testis grafts from 3-day-old donor tissue. Radioimmunoassay and biological assay indicated no differences in testosterone production by testis tissue grafts of varying donor age. Porcine testis tissue obtained from 3-, 5-, 7- and 14-day-old neonatal boars were all capable of producing round and elongate spermatids after 22 weeks of grafting, but testis grafts from 14-day-old donors had a significantly greater (eightfold) percentage of seminiferous tubules with spermatids compared to all other donor ages (p < 0.05). Cryopreservation did not affect the ability of testis tissue grafts to grow, produce testosterone or establish spermatogenesis when compared to controls (p < 0.05). Collectively, these data demonstrate intrinsic differences in the biological activity of germ and somatic cell populations during neonatal boar testis development associated with the establishment of spermatogenesis.

Heparin and Ca2+-free medium can enhance release of bull sperm attached to oviductal epithelial cell monolayers.

The success of assisted reproductive techniques, such as IVF, could be enhanced by being able to select the most competent spermatozoa in a sample. Attachment and subsequent release of spermatozoa from oviductal epithelial cells (OEC) could provide populations of functionally superior spermatozoa for use in these protocols. The objective of the present study was to investigate the ability of heparin and Ca2+-free medium to induce spermatozoa release from bovine OEC. Epithelial cells were grown to confluence in 24-well plates and pooled frozen bull semen was added to a final concentration of 1 x 10(6) spermatozoa/well. Spermatozoa were allowed to bind to OEC for 2 h. Medium with unbound spermatozoa was removed and replaced by Sperm-TALP, only (control), with heparin (5, 10, or 15 IU/mL), or Ca2+-free with 2 mM EGTA. Treatments were left on sperm-OEC co-cultures for 0.5, 1, 2, 3, or 5 h. At each time, the media were recovered and spermatozoa from each treatment were counted and evaluated for acrosome integrity and motility. The total number of spermatozoa attached to OEC after 2 h of co-culture was considered 100%. Spermatozoa release is expressed as percentage of the total number of sperm cells bound to OEC after 2 h of co-culture. Data were analyzed by ANOVA and results are expressed as mean +/- SEM from three independent replicates. Beginning at 0.5 h, more sperm cells (P < 0.05) were released from OEC in the heparin groups (10 and 15 IU/mL, 77.3 +/- 6.2% and 84.0 +/- 6.2%, respectively) as compared to the control (46.4 +/- 6.2%). The Ca2+-free medium also induced spermatozoa release when compared with the control, but the effect was not significant until 3 h (38.2 +/- 1.9% vs 59.5 +/- 6.9%; P < 0.05). The percentage of acrosome reacted spermatozoa was not affected by heparin treatment. Heparin at 10 IU/mL increased (P < 0.05) the percentage of motile spermatozoa, whereas Ca2+-free medium caused the opposite effect at 0.5 h after addition of treatments. We conclude that both heparin and Ca2+-free medium are able to promote spermatozoa displacement from OEC attachment. Based on motility and acrosome status data, we predict that released sperm cells may be used for IVF and other assisted reproductive techniques.

Coding sequences of the MHC II beta chain of homozygous rainbow trout (Oncorhynchus mykiss).

Six lines of homozygous rainbow trout (Oncorhynchus mikiss) from different genetic and geographical backgrounds have been produced as aquatic models for biomedical research by the chromosome set manipulation techniques of androgenesis and gynogenesis. Messenger RNA from spleens was extracted. and the MHC II B cDNA sequences, amplified by RT PCR, were cloned into plasmids. Sequences of the MHC II beta2 domains were highly conserved between the different plasmids from the same and different lines of trout. Most of the variability among sequences was found in the amino terminal half of the beta1 domain, which corresponds with the peptide binding region of the MHC II molecule. This diversity suggests that the different lines of trout may exhibit differences in immune response. Rainbow trout MHC II B sequences were similar to the MHC II B sequences of the Pacific salmon (O. gorbuscha, O. tshawytscha, O. nerka, O. miasou, O. kisutch). Southern blot analysis performed on the restricted DNA of the OSU and Hot Creek trout, and the doubled haploid progeny produced by androgenesis from OSU x Hot Creek hybrids indicates that two distinct genes encode the MHC II B sequences and that these genes are unlinked.

Acceptance of skin grafts by isogenic rainbow trout (Oncorhynchus mykiss).

OBJECTIVE: To test the immunocompetence of isogenic families of rainbow trout by measuring their ability to accept or reject skin grafts. ANIMALS: 3 families of isogenic rainbow trout (Oncorhynchus mykiss), produced by mating homozygous females and homozygous males, plus 4 chinook salmon (O tshawytscha) were used in these experiments. PROCEDURE: Grafts (allografts, members of the same family; autografts, donor and recipient were the same fish; and xenografts, O tshawytscha as donor) were exchanged. Grafts were applied on day 0 and removed on day 21, placed in neutral-buffered formalin, and embedded in paraffin. Lymphocytes and nuclei were counted in representative stained sections in the epidermis, dermis, and hypodermis. Results were analyzed by univariate analysis, using the Shapiro-Wilk statistic. RESULTS: Autografts were retained and minimal histologic changes were apparent. Allografts were histologically similar to autografts. Xenografts were rejected. CONCLUSIONS: Results indicate that the immune system of isogenic rainbow trout is unable to distinguish between family members within isogenic families, but that a vigorous response is mounted against chinook salmon xenografts. The isogenic rainbow trout are immunocompetent with respect to the phenomenon of graft rejection.