Diagnostic utility, disease activity, and disease phenotype correlation of serum ASCA, pANCA, and PR3-ANCA in pediatric inflammatory bowel disease

Abstract Objective: This study aimed to evaluate the diagnostic utility, disease activity, and phenotypic association of serum anti-Saccharomyces cerevisiae antibody (ASCA), perinuclear anti-neutrophil cytoplasmic antibody (pANCA), PR3-ANCA, and MPO-ANCA in pediatric patients with inflammatory bowel disease (IBD). Methods: Pediatric patients diagnosed with IBD were recruited and classified as Crohn's disease (CD), ulcerative colitis (UC), and IBD-unclassified (IBD-U) through full investigation. The Paris classification was used to evaluate disease phenotypes of pediatric CD and UC. Results: In all, 229 pediatric patients with IBD (CD 147, UC 53, IBD-U 29) were included. The ASCA IgG seropositivity significantly differed among the three groups (CD 75.4%, UC 17.5%, and IBD-U 60.0%; p < 0.001). PR3-ANCA positive rates were the highest in UC (24.0%), followed by IBD-U (17.6%), and none in CD (p = 0.002); pANCA-positive rates were higher in IBD-U (33.6%), followed by UC (28.0%) than in CD (1.4%) (p < 0.001). Regarding disease phenotype, perianal disease revealed higher serum ASCA IgG titers (median 36.7 U/mL in P1 vs. 25.2 U/mL in P0, p = 0.019). Serum ASCA IgG and IgA cutoff values to distinguish CD were 32.7 (U/mL) and 11.9 (U/mL), respectively, with a specificity of 80.0%. Conclusion: Serological biomarkers of ASCA IgG and IgA were effective for differentiating CD in pediatric IBD patients, and serum pANCA and PR3-ANCA, but not MPO-ANCA, were effective in distinguishing UC and IBD-U. Furthermore, measuring serological titers of ASCA IgG and IgA may help differentiate CD and evaluate the disease activity and phenotype of pediatric IBD in practice.

Diagnostic utility, disease activity, and disease phenotype correlation of serum ASCA, pANCA, and PR3-ANCA in pediatric inflammatory bowel disease.

OBJECTIVE: This study aimed to evaluate the diagnostic utility, disease activity, and phenotypic association of serum anti-Saccharomyces cerevisiae antibody (ASCA), perinuclear anti-neutrophil cytoplasmic antibody (pANCA), PR3-ANCA, and MPO-ANCA in pediatric patients with inflammatory bowel disease (IBD). METHODS: Pediatric patients diagnosed with IBD were recruited and classified as Crohn's disease (CD), ulcerative colitis (UC), and IBD-unclassified (IBD-U) through full investigation. The Paris classification was used to evaluate disease phenotypes of pediatric CD and UC. RESULTS: In all, 229 pediatric patients with IBD (CD 147, UC 53, IBD-U 29) were included. The ASCA IgG seropositivity significantly differed among the three groups (CD 75.4%, UC 17.5%, and IBD-U 60.0%; p < 0.001). PR3-ANCA positive rates were the highest in UC (24.0%), followed by IBD-U (17.6%), and none in CD (p = 0.002); pANCA-positive rates were higher in IBD-U (33.6%), followed by UC (28.0%) than in CD (1.4%) (p < 0.001). Regarding disease phenotype, perianal disease revealed higher serum ASCA IgG titers (median 36.7 U/mL in P1 vs. 25.2 U/mL in P0, p = 0.019). Serum ASCA IgG and IgA cutoff values to distinguish CD were 32.7 (U/mL) and 11.9 (U/mL), respectively, with a specificity of 80.0%. CONCLUSION: Serological biomarkers of ASCA IgG and IgA were effective for differentiating CD in pediatric IBD patients, and serum pANCA and PR3-ANCA, but not MPO-ANCA, were effective in distinguishing UC and IBD-U. Furthermore, measuring serological titers of ASCA IgG and IgA may help differentiate CD and evaluate the disease activity and phenotype of pediatric IBD in practice.

Replacing fish meal by mealworm (Tenebrio molitor) on the growth performance and immunologic responses of white shrimp (Litopenaeus vannamei) / Farinha de peixe com larvas do bicho-da farinha (Tenebrio molitor) no desempenho de crescimento e respostas imunológicas do camarão branco (Litopenaeus vannamei)

The objective of this study was to determine the effect of replacing FM with mealworm (Tenebrio molitor) on the growth performance and immunologic responses of white shrimp. In addition, the toxicity of such replacement to white shrimp was measured. Mealworm was incorporated to partially or totally replace fish meal in diets for white shrimp. Experimental groups of shrimp with an average initial body weight of 2.39 ± 0.49 g were fed each of 4 isonitrogeneous diets formulated to include 0, 25, 50 and 100% (control, MW25, MW50 and MW100 respectively) of mealworm substituted for fish meal. After eight weeks of feeding trials, shrimp fed diets MW25, MW50 and MW100 had higher live weight gain (10.05 ± 3.06, 11.41 ± 2.08, and 10.36 ± 1.57, respectively), higher specific growth rate (2.56 ± 0.11, 2.79 ± 0.09, and 2.61 ± 0.07, respectively), and better feed conversion ratio (2.89 ± 0.08, 2.69 ± 0.09, and 2.72 ± 0.19, respectively) compared to those of shrimp fed control diet. Survival rate was 98% in all treatments. No toxicity was found in post-mortem pathophysiologic examinations. The levels of immune markers such as beta -glucan binding protein, prophenoloxidase and crustin associated with shrimps cellular and humoral immunity were found to be higher in 25 and 50% mealworm replacement groups. These results clearly indicated that replacement of fish meal with 50% mealworm for shrimp diet was optimal in promoting the growth performance of shrimp without any adverse effect.(AU)

O objetivo deste estudo foi determinar o efeito da substituição do FM por larva de farinha (Tenebrio molitor) sobre o desempenho de crescimento e respostas imunológicas do camarão branco. Além disso, a toxicidade dessa substituição ao camarão branco foi medida. As larvas foram inseridas para substituir parcialmente ou totalmente a farinha de peixe em dietas do camarão branco. Grupos experimentais de camarão com a média de peso inicial de 2.39 ± 0.49g, foram alimentados com quatro dietas isonitrogênicas elaboradas para incluir 0, 25, 50 e 100% (control, MW25, MW50 e MW100 respectivamente) de larvas substituído por farinha de peixe. Após oito semanas de experiencia, os camarões alimentados pelas dietas MW25, MW50 e MW100 tiveram um maior ganho de peso (10.05 ± 3.06, 11.41 ± 2.08 e 10.36 ± 1.57, respectivamente), e uma taxa de crescimento especifico mais alta (2.56 ± 0.11, 2.79 ± 0.09, e2.61 ± 0.07 respectivamente), comparados a aqueles que tiveram a dieta de controle. A taxa de sobrevivência foi de 98% em todos os tratamentos. Nenhuma toxina foi encontrada após a morte, nas quais foram feitos exames fisiopatológicos. Os níveis de marcadores imunológicos como as ligações de proteína betaglucanos, prophenoloxidase, crustinas associadas à imunidade celular e humoral do camarão, foram encontrados maiores que 25 e 50% dos grupos substituídos pelas larvas. Esses resultados indicaram que a troca da farinha de peixe com 50% de larvas para a dieta dos camarões foi ideal para promover o desempenho de crescimento do camarão sem qualquer efeito adverso.(AU)

Replacing fish meal by mealworm (Tenebrio molitor) on the growth performance and immunologic responses of white shrimp (Litopenaeus vannamei) / Farinha de peixe com larvas do bicho-da farinha (Tenebrio molitor) no desempenho de crescimento e respostas imunológicas do camarão branco (Litopenaeus vannamei)

The objective of this study was to determine the effect of replacing FM with mealworm (Tenebrio molitor) on the growth performance and immunologic responses of white shrimp. In addition, the toxicity of such replacement to white shrimp was measured. Mealworm was incorporated to partially or totally replace fish meal in diets for white shrimp. Experimental groups of shrimp with an average initial body weight of 2.39 ± 0.49 g were fed each of 4 isonitrogeneous diets formulated to include 0, 25, 50 and 100% (control, MW25, MW50 and MW100 respectively) of mealworm substituted for fish meal. After eight weeks of feeding trials, shrimp fed diets MW25, MW50 and MW100 had higher live weight gain (10.05 ± 3.06, 11.41 ± 2.08, and 10.36 ± 1.57, respectively), higher specific growth rate (2.56 ± 0.11, 2.79 ± 0.09, and 2.61 ± 0.07, respectively), and better feed conversion ratio (2.89 ± 0.08, 2.69 ± 0.09, and 2.72 ± 0.19, respectively) compared to those of shrimp fed control diet. Survival rate was 98% in all treatments. No toxicity was found in post-mortem pathophysiologic examinations. The levels of immune markers such as beta -glucan binding protein, prophenoloxidase and crustin associated with shrimp’s cellular and humoral immunity were found to be higher in 25 and 50% mealworm replacement groups. These results clearly indicated that replacement of fish meal with 50% mealworm for shrimp diet was optimal in promoting the growth performance of shrimp without any adverse effect.

O objetivo deste estudo foi determinar o efeito da substituição do FM por larva de farinha (Tenebrio molitor) sobre o desempenho de crescimento e respostas imunológicas do camarão branco. Além disso, a toxicidade dessa substituição ao camarão branco foi medida. As larvas foram inseridas para substituir parcialmente ou totalmente a farinha de peixe em dietas do camarão branco. Grupos experimentais de camarão com a média de peso inicial de 2.39 ± 0.49g, foram alimentados com quatro dietas isonitrogênicas elaboradas para incluir 0, 25, 50 e 100% (control, MW25, MW50 e MW100 respectivamente) de larvas substituído por farinha de peixe. Após oito semanas de experiencia, os camarões alimentados pelas dietas MW25, MW50 e MW100 tiveram um maior ganho de peso (10.05 ± 3.06, 11.41 ± 2.08 e 10.36 ± 1.57, respectivamente), e uma taxa de crescimento especifico mais alta (2.56 ± 0.11, 2.79 ± 0.09, e2.61 ± 0.07 respectivamente), comparados a aqueles que tiveram a dieta de controle. A taxa de sobrevivência foi de 98% em todos os tratamentos. Nenhuma toxina foi encontrada após a morte, nas quais foram feitos exames fisiopatológicos. Os níveis de marcadores imunológicos como as ligações de proteína betaglucanos, prophenoloxidase, crustinas associadas à imunidade celular e humoral do camarão, foram encontrados maiores que 25 e 50% dos grupos substituídos pelas larvas. Esses resultados indicaram que a troca da farinha de peixe com 50% de larvas para a dieta dos camarões foi ideal para promover o desempenho de crescimento do camarão sem qualquer efeito adverso.

Predicting the presence of an accessory hepatic vein using abdominal computed tomography / Predicción de la presencia de una vena hepática accesoria mediante tomografía computarizada abdominal

The incidence of detection of accessory hepatic vein (AHV) using MRI or CT has been reported. However, previous studies had a small sample size or only reported on the incidence of hepatic vein variants. To the best of our knowledge, there has been no previous report evaluating the factors predictive of the presence of an AHV. To evaluate the incidence and morphology of the accessory hepatic vein (AHV) using multidetector row computed tomography (MDCT) and to investigate the factors which may be helpful in predicting the presence of an AHV. We enrolled 360 patients who underwent abdominal MDCT. We investigated whether the AHV was present and evaluated the frequency of AHVs greater than 5 mm in diameter. We classified the morphology of the AHV entering the inferior vena cava (IVC). We also examined the factors that predicted the presence of an AHV by comparing the diameter of the middle hepatic vein (MHV) and the right hepatic vein (RHV). We identified an AHV in 164 of the 360 patients (45.6 %). Among the 164 AHVs, 56.7 % were larger than 5 mm in diameter. The most common morphologies of the inferior RHV were a single main trunk (58.5 %), followed by two main trunks with a V-shape (19.5 %) and two trunks entering the IVC separately (17.0 %). The possibility that an AHV will be present was significantly higher when the diameter of the RHV was smaller than that of the MHV. MDCT can provide important information regarding AHV incidence and morphology. The possibility of an AHV being present was significantly higher when the diameter of the RHV was smaller than that of the MHV.

Se ha informado de la incidencia de la detección de la vena hepática accesoria (VHA) mediante RM o TC. Sin embargo, estudios previos tenían un tamaño muestral pequeño o solo informaban sobre la incidencia de variantes de las venas hepáticas. Hasta donde sabemos, no ha habido ningún informe previo que evalúe los factores predictivos de la presencia de una VHA. El objetivo del estudio fue evaluar la incidencia y morfología de la vena hepática accesoria (VHA) mediante tomografía computarizada multidetector (TCMD) e investigar los factores que pueden ser útiles para predecir la presencia de un VHA. Se evaluaron 360 pacientes que se sometieron a TCMD abdominal. Se investigó si la VHA estaba presente y se evaluó la frecuencia de VHA mayores de 5 mm de diámetro. Se clasificó la morfología del VHA que drenaba en la vena cava inferior (VCI). Además, se examinaron los factores que predijeron la presencia de una VHA mediante la comparación del diámetro de la vena hepática media (VHM) y la vena hepática derecha (VHD). Se identificó un VHA en 164 de los 360 pacientes (45,6%). Entre las 164 VHA, el 56,7% tenía más de 5 mm de diámetro. Las morfologías más frecuentes del VHD inferior fueron un tronco principal único (58,5%), seguido por dos troncos principales con forma de V (19,5%) y dos troncos que drenaban en la VCI por separado (17,0%). La posibilidad de que una VHA esté presente fue significativamente mayor cuando el diámetro de la VHD era menor que la de la VHM. La MDCT puede proporcionar información importante sobre la incidencia de la VHA y su morfología. La posibilidad de que un VHA estuviera presente era significativamente mayor cuando el diámetro del VHD era menor que la VHM.

Bone mineral density and content are differentially impacted by aerobic and resistance training in the colon-26 mouse model of cancer cachexia

Background: Cancer cachexia is a debilitating paraneoplastic syndrome featuring unintended weight loss and skeletal muscle atrophy. Evidence suggests that bone health may also be compromised, further limiting mobility and quality of life. Aerobic and resistance training was recently reported to differentially affect skeletal muscle adaptations in cancer cachectic mice. The purpose of this investigation was to assess the effects of aerobic and resistance training on bone mineral density (BMD) and bone mineral content (BMC) in mice with colon-26 (C26) tumor-induced cachexia. Methods: Twelve-month old Balb/c mice were aerobic-trained (wheel running 5 days/week) or resistance-trained (weighted ladder climbing 3days/week) for 8 weeks prior to C26 cell injection, followed by an additional three weeks of exercise. BMD and BMC were assessed pre- and post-training by dual-energy x-ray absorptiometry. Results: Resistance-trained C26 mice lost total BMD by 7% (p = 0.06), which did not occur in aerobic-trained C26 mice. In terms of pelvic bone, both resistance- and aerobic-trained C26 mice had significantly lower BMD values (−12%, p = 0.01 and −6%, p = 0.04, respectively), albeit to a lesser degree in aerobic-trained C26 mice. Furthermore, resistance-trained C26 mice tended to lose total BMC (−12%), whereas aerobic-trained C26 mice maintained total BMC. In mice without C26 tumors, resistance training significantly increased total BMD (+13%, p = 0.001). Conclusions: Aerobic and resistance training may differentially affect bone status in C26 cancer cachexia, with high resistance loading possibly being detrimental to total and pelvis BMD, a region expected to bear significant loading stress and contribute substantially to overall mobility. Because resistance training improved BMD in tumor-free mice, the C26 tumor burden appeared to impair the beneficial effect of resistance training on bone mass (AU)

Establishment of a pheasant (Phasianus colchicus) spermatogonial stem cell line for the production of interspecies germ line chimeras

Background Spermatogonial stem cells (SSCs) are important for the production of interspecies germ line chimeras. The interspecies germ cell transfer technique has been suggested as a way to conserve endangered birds. Our objective was to develop a technique for restoring endangered birds by developing interspecies germ line chimeras between pheasant (Phasianus colchicus) and chicken (Gallus gallus) with SSCs. Results SSCs were isolated from the surgically removed testis of a pheasant. Growth conditions for pheasant SSCs were established by co-culturing STO (SIM mouse embryo-derived thioguanine and ouabain resistant) cells and pheasant SSCs. The colony-forming cells divided and proliferated stably to yield an established SSC line. Pheasant SSCs showed strong reactivity for GDNF family receptor alpha1 (GFRa1) marker. Finally, production of germ line chimeras was attempted by transferring pheasant SSCs into recipient embryos. Although final embryo survival was 5.6% (20/354), the initial survival rate was 88% (312/354). To measure the percent transfer of donor SSC to gonads, the pheasant SSCs were labeled with PKH 26 fluorescent dye. We observed 30% donor cells and 9.48% c-kit/CD117-positive cells in the gonads of recipient chickens. Donor SSCs were thus stably engrafted in the recipient gonads. Conclusions This study showed that SSCs can be used as a tool for the conservation of endangered birds and the production of germ line chimeras. Our findings yield insights into how we may use the pheasant spermatogonial stem cell line for efficient production of interspecies germ line chimeras and ultimately, to the restoration of endangered birds.

New additions to the shallow-water hydroids (Cnidaria: Hydrozoa) of the French Lesser Antilles: Martinique.

The present report provides the first general account of the shallow-water hydroids (excluding Eudendriidae) of Martinique, French Lesser Antilles. Of a total of 92 species recorded, 10 athecates and 31 thecates are discussed here, with the remaining species having been the subject of earlier accounts. Six hydroids, namely Halecium discoidum, H. xanthellatum, Sertularella calderi, Antennellapeculiaris, A. similis, and A. tubitheca, are new. Previously unreported data on the nematocyst complement of Heterocoryne caribbensis Wedler & Larson, 1986, Ectopleura mayeri Petersen, 1990, Ralpharia gorgoniae Petersen, 1990, and seven hebellid species are provided.'The gonotheca and the gonophore of Hebellopsis communis Calder, 1991 are described for the first time, allowing a genus transfer to Anthohebella Boero et al., 1997. Thyroscyphus longicaulis Splettstbsser, 1929, a species whose gonosome remained unknown until now, is redescribed based on new, fertile material of both sexes. The occurrence of Antennella quadriaurita Ritchie, 1909 in the Caribbean is questioned upon comparison of its cnidome with that of specimens from Tristan da Cunha, the type locality of this species. An unexpectedly wide morphological variation is noted for Aglaophenia rhynchocarpa Allman, 1877. Specimens corresponding to the Caribbean Gymnangium longicaudum (Nutting, 1900), are shown to be indistinguishable morphologically from a taxon described earlier from Brazil, Gymnangium allmani (Marktanner-Turneretscher, 1890), the latter having priority. Thorough descriptions are provided for the new, lesser known or unidentifiable species, while the common taxa are accompanied by brief remarks and/or distributional data. Illustrations are provided for each species discussed in order to justify their identification, and to facilitate identification by others. A checklist at the end of this work incorporates records of 101 species of hydroids reported from Martinique, both occurring in the present collection and cited in the literature.

Brazilin inhibits UVB-induced MMP-1/3 expressions and secretions by suppressing the NF-κB pathway in human dermal fibroblasts.

Brazilin (7, 11b-dihydrobenz[b]indeno[1,2-d]pyran-3,6a,9,10 (6H)-tetrol), the major component of Caesalpinia sappan L., is a natural red pigment used for histological staining. Recent studies have shown that brazilin exhibits distinct biological effects, including anti-hepatotoxicity, antiplatelet activity, and anti-inflammatory activities. In the present study, we evaluated the effects of brazilin on MMP-1 and -3 expressions in human dermal fibroblasts exposed to ultraviolet B (UVB) irradiation. Brazilin showed protective effect on UVB-induced loss of cell viability of fibroblasts. Brazilin also blocked significantly UVB-induced Reactive Oxygen Species generation in fibroblasts. Brazilin inhibited UVB-induced MMP-1/3 expressions and secretions in a dose-dependent manner. Moreover, UVB-induced NF-κB activation was completely blocked by treatment with brazilin. These findings suggest that brazilin inhibits UVB-induced MMP-1/3 expressions and secretions by suppressing of NF-κB activation in human dermal fibroblasts. Thus, brazilin might be used as a potential agent for treatment of UV-induced skin photoaging.

Osmotically-induced genes are controlled by the transcription factor TonEBP in cultured cardiomyocytes.

Changes in cardiac osmolarity occur in myocardial infarction. Osmoregulatory mechanisms may, therefore, play a crucial role in cardiomyocyte survival. Tonicity-responsive enhancer binding protein (TonEBP) is a key transcription factor participating in the adaptation of cells to increases in tonicity. However, it is unknown whether cardiac TonEBP is activated by tonicity. Hypertonicity activated transcriptional activity of TonEBP, increased the amounts of both TonEBP mRNA and protein, and induced both the mRNA and protein of TonEBP target genes (aldose reductase and heat shock protein-70). Hypotonicity decreased the amount of TonEBP protein indicating bidirectional osmoregulation of this transcription factor. Adenoviral expression of a dominant negative TonEBP suppressed the hypertonicity-dependent increase of aldose reductase protein. These results indicated that TonEBP controls osmoregulatory mechanisms in cardiomyocytes.

Salinity reduced growth PS2 photochemistry and chlorophyll content in radish

When plants are grown under saline conditions, photosynthetic activity decreases leading to reduced plant growth, leaf area, chlorophyll content and chlorophyll fluorescence. Seeds and seedlings of radish (Raphanus sativus L.) were grown in NaCl solutions under controlled greenhouse conditions. The NaCl concentrations in complete nutrient solutions were 0 (control), 4.7, 9.4 and 14.1 dS m-1. The salinity reduced germination percentage and also delayed the germination rate as the salt level increased. Lengths and fresh weights of root and shoot decreased with the increasing salt concentration. Furthermore, photochemical efficiency of PS2 (Fv/Fm), photochemical quenching coefficient (qP), non photochemical quenching coefficient (qN), leaf area and chlorophyll content (SPAD value) were also reduced (P 0.001) by salt stress. In contrast, the Fo/Fm ratio increased with increasing salt concentration while salinity showed no effect on the efficiency of excitation captured by open PS2 (Fv'/Fm'), electron transport rate (ETR), and leaf water content. Linear regression shows that the photochemical efficiency of PS2 (Fv/Fm) had a positive relationship with the photochemical quenching coefficient (qP), leaf area and chlorophyll content but had no relation with Fv'/Fm', Fo/Fm, and qN.

Quando plantas crescem sob condições de salinidade, sua atividade fotossintética diminui levando a um crescimento reduzido, menor área foliar, conteúdo de clorofila e fluorescência de clorofila. Sementes e plântulas de rabanete (Raphanus sativus L.) foram germinadas e conduzidas em soluções de NaCl sob condições controladas de casa de vegetação. As concentrações de NaCl adicionado a solução nutritiva completa foram 0 (Controle), 4,7; 9,4 e 14,1 dS m-1. A salinidade diminui a percentagem de germinação e também atrasou a taxa de germinação com o aumento do nível de sal. Comprimento e peso fresco da parte aérea e da raiz decresceram com o aumento da concentração salina. Além disso, a eficiência fotoquímica de PS2 (Fv/Fm), o coeficiente fotoquímico de 'quenchin" (q p), o coeficiente não fotoquímico de "quenching" (q n), a área foliar e o teor de clorofila (valor SPAD) também foram reduzidos (P 0,001) por estresse de sal. Ao contrário, a relação Fo/Fm aumentou com a concentração salina, ao passo que a salinidade não teve efeito sobre a eficiência de excitação capturada pelo PS2 aberto (Fv'/Fm'), taxa de transporte eletrônico (ETR) e conteúdo de água na folha. Através de regressão linear mostrou-se que a eficiência fotossintética de PS2 (Fv/Fm) teve uma relação positiva com o coeficiente fotoquímico de "quenching" (q p), área foliar e conteúdo de clorofila, mas nenhuma relação com (Fv/Fm), (Fo/Fm), e q n.

Salinity reduced growth PS2 photochemistry and chlorophyll content in radish

When plants are grown under saline conditions, photosynthetic activity decreases leading to reduced plant growth, leaf area, chlorophyll content and chlorophyll fluorescence. Seeds and seedlings of radish (Raphanus sativus L.) were grown in NaCl solutions under controlled greenhouse conditions. The NaCl concentrations in complete nutrient solutions were 0 (control), 4.7, 9.4 and 14.1 dS m-1. The salinity reduced germination percentage and also delayed the germination rate as the salt level increased. Lengths and fresh weights of root and shoot decreased with the increasing salt concentration. Furthermore, photochemical efficiency of PS2 (Fv/Fm), photochemical quenching coefficient (qP), non photochemical quenching coefficient (qN), leaf area and chlorophyll content (SPAD value) were also reduced (P 0.001) by salt stress. In contrast, the Fo/Fm ratio increased with increasing salt concentration while salinity showed no effect on the efficiency of excitation captured by open PS2 (Fv'/Fm'), electron transport rate (ETR), and leaf water content. Linear regression shows that the photochemical efficiency of PS2 (Fv/Fm) had a positive relationship with the photochemical quenching coefficient (qP), leaf area and chlorophyll content but had no relation with Fv'/Fm', Fo/Fm, and qN.

Quando plantas crescem sob condições de salinidade, sua atividade fotossintética diminui levando a um crescimento reduzido, menor área foliar, conteúdo de clorofila e fluorescência de clorofila. Sementes e plântulas de rabanete (Raphanus sativus L.) foram germinadas e conduzidas em soluções de NaCl sob condições controladas de casa de vegetação. As concentrações de NaCl adicionado a solução nutritiva completa foram 0 (Controle), 4,7; 9,4 e 14,1 dS m-1. A salinidade diminui a percentagem de germinação e também atrasou a taxa de germinação com o aumento do nível de sal. Comprimento e peso fresco da parte aérea e da raiz decresceram com o aumento da concentração salina. Além disso, a eficiência fotoquímica de PS2 (Fv/Fm), o coeficiente fotoquímico de 'quenchin" (q p), o coeficiente não fotoquímico de "quenching" (q n), a área foliar e o teor de clorofila (valor SPAD) também foram reduzidos (P 0,001) por estresse de sal. Ao contrário, a relação Fo/Fm aumentou com a concentração salina, ao passo que a salinidade não teve efeito sobre a eficiência de excitação capturada pelo PS2 aberto (Fv'/Fm'), taxa de transporte eletrônico (ETR) e conteúdo de água na folha. Através de regressão linear mostrou-se que a eficiência fotossintética de PS2 (Fv/Fm) teve uma relação positiva com o coeficiente fotoquímico de "quenching" (q p), área foliar e conteúdo de clorofila, mas nenhuma relação com (Fv/Fm), (Fo/Fm), e q n.