Relation between O3-Inhibition of Photosynthesis and Ethylene in Paddy Rice Grown under Different CO2 Concentrations

This study was conducted to evaluate the role of ethylene in acute ozone (O3: 0, 0.1, and 0.3 cm3 m–3; O0, O0.1 and O0.3, respectively)-induced photosynthetic inhibition of paddy rice leaves grown under different atmospheric carbon dioxide concentrations (CO2: 400 and 800 cm3 m–3; C400 and C800, respectively). Ethephon and silver thiosulfate complex (STS) were applied one day before exposure to O3. Gas exchange, chlorophyll fluorescence, and ascorbic acid were measured immediately before (BE), immediately after (AE-0), and 1 d and 3 d after (AE-1, AE-3) the start of the exposure to O3. In the plants exposed to O3, visible leaf symptoms on the adaxial leaf surface appeared at AE-3. O3 decreased photosynthesis-related parameters, total ascorbic acid content, and redox state of ascorbic acid (RDS), and C800 ameliorated O3-induced damage. STS ameliorated the O3-induced visible leaf symptoms and O3-inhibition of photosynthesis but ethephon worsened slightly or did not affect them. Additionally, we evaluated the effects of O3 and CO2 on ethylene production in rice leaves. Although elevated CO2 did not affect ethylene production, exposure to O3 greatly increased ethylene production at AE-0 and rapidly reduced it at AE-1. These results indicate that ethylene is an important component of signal transduction for the extension of O3 injury in paddy rice

Exogenous ascorbic acid scarcely ameliorates inhibition of photosynthesis in rice leaves by O3

The role of ascorbic acid on acute O3-induced inhibition of photosynthesis in solution-cultured paddy rice was evaluated. As pre-treatment, ascorbic acid (0, 5, and 10 mM) was added to the culture solution for 5 d before 5 h of O3 exposure (0, .1, and .3 cm3 m−3 O3) during daytime. O3 decreased photosynthesis-related parameters, total ascorbic acid content, and the redox state (RDS) of ascorbic acid. Ascorbic acid treatment enhanced the total ascorbic acid contents and its RDS level of rice leaves, but scarcely ameliorated O3-induced inhibition of photosynthesis-related parameters. Inhibition of net photosynthetic rate (PN) by O3 was slightly ameliorated by exogenous ascorbic acid only at 1 d after O3 exposure. These results indicate that ascorbic acid is a component of protection from O3 injury but has a marginal role in the acute inhibition of PN by O3 in rice leaves

Inclination Angle Affects Ozone Injury in the Flag Leaf of Rice

To evaluate the effect of inclination angle of the leaf on the leaf injury of rice by O3, we examined the effect of a 5-hr exposure to 0, 0.1, 0.3 cm3 m-3 O3, abbreviated as O0, O0.1 and O0.3, respectively, of the flag leaf using natural-light gas-exposure chambers. The middle portion of the flag leaf was set horizontally using lead weights (H plant) and it was compared with a non-treated, erect leaf (E plant). Gas exchange and chlorophyll fluorescence were measured immediately before, immediately after, and 1 and 3 d after the start of the exposure. The net photosynthetic rate, stomatal conductance and operating quantum efficiency of photosystem II (Fq’/Fm’) were decreased by the exposure to O3. Furthermore, the inhibitory effects of O0.1 and O0.3 on the H plants were severer than those on the E plants. The maximum quantum efficiency of photosystem II (Fv/Fm) in the leaf of H plants decreased immediately after exposure to O3. These results indicate that the weaker inhibitory effect of O3 on the erect leaf depends on the lower light intensity at the leaf surface, rather than the horizontal leaf position. Key words: Ascorbic acid, Chlorophyll fluorescence, Gas exchange, Leaf inclination angle, Oryza sativa, O3, Quantum efficiency

Przypadek przejściowego bloku przedsionkowo-komorowego z przewodzeniem 2:1, który ustąpił po suplementacji tyroksyną zastosowaną w celu leczenia subklinicznej postaci niedoczynności tarczycy

Mężczyznę w wieku 42 lat przyjęto do szpitala, w którym pracują autorzy niniejszego doniesienia, z powodu napadów kołatania serca. W holterowskim badaniu EKG wykazano blok przedsionkowo-komorowy (AV) z przewodzeniem 2:1 oraz bradykardię z minimalną częstością akcji serca wynoszącą 44 uderzenia/min. Stwierdzono obecność wskazań do przeprowadzenia dalszych badań elektrofizjologicznych oraz do wszczepienia rozrusznika serca. Wyniki badań laboratoryjnych wykonanych w dniu przyjęcia wykazały podwyższone stężenie tyreotropiny przy prawidłowym stężeniu tyroksyny. W celu wykluczenia czynnościowego bloku AV przez 2 tygodnie podawano pacjentowi tyroksynę, zaś w holterowskim badaniu EKG wykonanym po tym okresie wykazano znaczącą poprawę częstości akcji serca bez obecności bloku AV lub długotrwałych przerw w przewodzeniu. Na tej podstawie uznano, że ciężka bradykardia oraz blok AV z przewodzeniem 2:1 wynikały z subklinicznej postaci niedoczynności tarczycy, a przyjmowanie tyroksyny całkowicie wyeliminowało istniejące objawy. (Folia Cardiologica Excerpta 2006; 1: 448-451

Novel Photodynamic Therapy for Esophageal Squamous Cell Carcinoma following Radiotherapy

Radiotherapy (RT) or chemoradiotherapy (CRT) are frequently selected as treatments for esophageal squamous cell carcinoma (ESCC). However, salvage treatment remains challenging when endoscopic resection is not indicated for residual or recurrent ESCC following RT or CRT. Recently, owing to the emergence of second-generation photodynamic therapy (PDT) using talaporfin sodium, PDT can be performed with less phototoxicity and therefore has regained popularity in the treatment of ESCC. In this study, the effectiveness and safety of second-generation PDT in patients with residual or recurrent ESCC following RT or CRT were examined. Local complete response (L-CR) rates, procedure-related adverse events, and prognosis were evaluated. In 12 patients with 20 ESCC lesions, the L-CR rates were 95.0%. Perforation, postoperative bleeding, and photosensitivity were not observed. Esophageal stricture following PDT developed in one patient, but this could be addressed using balloon dilation. During a median follow-up period of 12 (range, 3–42) months, the 3-year cause-specific survival rate was 85.7%. Even in patients with a Charlson comorbidity index score ≥ 3, the 2-year overall survival rates were 100%. In conclusion, PDT was an efficacious and a safe salvage treatment in patients with local residual or recurrent ESCC following RT or CRT

Efficacy and Safety of Peroral Endoscopic Myotomy for Esophageal Achalasia and Achalasia-Related Diseases in Patients Aged 75 Years and Over

Peroral endoscopic myotomy (POEM) has become a popular treatment for esophageal achalasia and other esophageal motility disorders. However, its efficacy and safety in elderly patients are unclear. To clarify that, we reviewed the medical records of patients who underwent POEM in our hospital. A total of 11 patients who underwent POEM for esophageal achalasia (n = 10) and jackhammer esophagus (n = 1) were included. Procedural success, defined as the completion of an esophageal and gastric myotomy, was 100%. Clinical success, defined as an Eckardt score of 3 or less, without the use of additional treatments at 2 months, was 100%. The median Eckardt score significantly decreased after the POEM (baseline vs. 2 months after POEM; 7 (2–8) vs. 0 (0–1), p < 0.01). In the second and third years, the cumulative treatment effect maintenance rate was 88.9%. All patients taking antithrombotic agents had safe operations with the temporary discontinuation of these agents. There were four adverse events (two pneumoperitoneum, one mucosal injury, and one pneumonia), all of which improved with fasting or antibiotics. In conclusion, POEM is an effective and safe treatment for esophageal achalasia and achalasia-related diseases in patients aged 75 years and over