Effects of water deficit and salinity stress on late mandarin trees.

To maintain the viability of citrus farms in a scenario of scarce water supplies for irrigation purposes, such as in south-eastern Spain, it is necessary to detect the maximum threshold of crop water status and vegetative growth, both of which are vulnerable to the combined effect of water and salinity stress. With this aim, adult late mandarin trees were subjected to a gradual increase in salinity of the irrigation water for four consecutive growing seasons, accompanied by a water deficit for the first three seasons, while the fourth season counted as a recovery period. The treatments tested were: i) control (CTL), irrigated at 100% of the ETc in the first season followed by an additional 33% water leaching requirement in the second and third seasons; (ii) a regulated deficit irrigation (RDI100) treatment, irrigated as the CTL except in phase I and until mid-phase II, coinciding with the beginning of the slowdown in trunk growth, where irrigation was set at 65 and 50% CTL in the first and last two seasons, respectively, and 80% in phase III; (iii) RDI50, irrigated as the CTL during the first season, and from the second season onwards, at 50% RDI100 during the deficit period; (iv) FARMER, irrigated in accordance with the farmer's criteria. A moderate saline water stress combined with the application of RDI100 treatment did not reduce crop yield after one growing season, but did reduce plant growth. However, after two consecutive seasons (in both RDI strategies) water stress drastically reduced both yield and plant growth, mainly due to a high accumulation of sodium and chloride in the leaves. Gas exchange parameters were also greatly reduced. Furthermore, it was found that the water deficit could be prolonged until the trunk growth slowed down during the second fruit growth stage in mandarin trees, leading to a substantial increase in water productivity values.

Efficacy of triple therapy with a proton pump inhibitor, levofloxacin, and amoxicillin as first-line treatment to eradicate Helicobacter pylori.

BACKGROUND: Triple therapy including a proton pump inhibitor, clarithromycin, and amoxicillin (PPI-CA) is the first-choice treatment used for H. pylori eradication. The efficacy of this treatment is declining of late, and alternative therapies are currently under evaluation. OBJECTIVES: To evaluate the efficacy, safety and compliance of a triple therapy with a PPI, amoxicillin and levofloxacin (PPI-LA)--replacing clarithromycin--for the eradication of H. pylori. METHODS: The study included 135 patients (65% women), mean age 53 years, with dyspeptic symptoms and H. pylori infection proven by a positive urease rapid test, histological analysis, or C13-urea breath test. DIAGNOSIS: non-investigated dyspepsia 48.9%, functional dyspepsia 36.3%, and ulcerative dyspepsia 14.8%. Treatment was indicated with a proton pump inhibitor at usual doses, amoxicillin 1 g, and levofloxacin 500 mg, administered jointly during breakfast and dinner for 10 days. We studied the performance of this triple therapy and its effects using a questionnaire, and effectiveness by the negativity of the C13-urea breath test after 6-8 weeks after treatment discontinuation. Per protocol, we compared the effectiveness of PPI-LA with a control group of 270 patients treated with PPI-CA for 10 days. RESULTS: 130 patients (96.2%) could complete the treatment and follow-up protocol. Effectiveness (intention to treat) was 71.8% (97/135) and 74.6% (per protocol) (97/130). Sixteen patients (11.8%) had well-tolerated adverse effects, except for 5 subjects (3.7%) who dropped out. PPI-CA was effective (per protocol) in 204 patients out of 270 (75.5%) in the control group. CONCLUSIONS: Triple therapy with a PPI, amoxicillin and levofloxacin for 10 days is a well-tolerated treatment that is easy to comply with; however it has low efficiency - less than 80% - and is not recommended as a first-choice treatment for H. pylori eradication. Similar results were obtained with the classic triple therapy using a PPI, clarithromycin and amoxicillin.

Eficacia de una triple terapia con un inhibidor de la bomba de protones, levofloxacino y amoxicilina, como primer tratamiento, en la erradicación de Helicobacter pylori / Efficacy of triple therapy with a proton pump inhibitor, levofloxacin, and amoxicillin as first-line treatment to eradicate Helicobacter pylori

Introducción: la triple terapia con un inhibidor de la bomba de protones, claritromicina y amoxicilina (IBP-CA) es el tratamiento de primera elección más utilizado en la erradicación de H. pylori. La eficacia de este tratamiento está disminuyendo en los últimos años y se están valorando otras alternativas terapéuticas. Objetivos:valorar la eficacia, cumplimiento y seguridad de una triple terapia con un IBP, amoxicilina y levofloxacino, sustituyendo a la claritromicina, en la erradicación de H. pylori. Métodos: periodo de estudio: 2007-2008. Se incluyen 135 pacientes (65% mujeres), edad media de 53 años, con síntomas dispépticos e infección por H. pylori, constatada por positividad del test rápido de la ureasa, histología o prueba del aliento con urea-C13. Diagnósticos: dispepsia no investigada: 48,9%, dispepsia funcional: 36,3% y dispepsia ulcerosa: 14,8%. Se indica tratamiento con un inhibidor de la bomba de protones, a dosis habitual, amoxicilina 1 g y levofloxacino 500 mg (IBP-LA), administrados de forma conjunta en desayuno y cena, durante 10 días. Se valora el cumplimiento de la triple terapia y sus efectos adversos mediante interrogatorio y su eficacia mediante la negatividad de la prueba del aliento con urea-C13 practicada a las 6-8 semanas del término del tratamiento. Se compara la eficacia, por protocolo, del tratamiento con IBP-LA con la observada en un grupo control de 270 pacientes tratados con IBP-CA durante 10 días en los años 2006-2007. Resultados: 130/135 pacientes (96,2) del grupo de estudio completaron el tratamiento y el protocolo del seguimiento. La eficacia por intención de tratar fue del 71,8% (97/135) y por protocolo del 74,6% (97/130). Dieciséis pacientes (11,8%) presentaron efectos adversos bien tolerados, excepto en 5 pacientes (3.7%) que motivan el abandono del tratamiento. El tratamiento con IBP-CA resultó eficaz, por protocolo, en 204/270 (75,5%) pacientes del grupo control...(AU)

Background: triple therapy including a proton pump inhibitor, clarithromycin, and amoxicillin (PPI-CA) is the first-choice treatment used for H. pylori eradication. The efficacy of this treatment is declining of late, and alternative therapies are currently under evaluation. Objectives: to evaluate the efficacy, safety and compliance of a triple therapy with a PPI, amoxicillin and levofloxacin (PPI-LA) - replacing clarithromycin - for the eradication of H. pylori. Methods: the study included 135 patients (65% women), mean age 53 years, with dyspeptic symptoms and H. pylori infection proven by a positive urease rapid test, histological analysis, or C13-urea breath test. Diagnosis: non-investigated dyspepsia 48.9%, functional dyspepsia 36.3%, and ulcerative dyspepsia 14.8%. Treatment was indicated with a proton pump inhibitor at usual doses, amoxicillin 1 g, and levofloxacin 500 mg, administered jointly during breakfast and dinner for 10 days. We studied the performance of this triple therapy and its effects using a questionnaire, and effectiveness by the negativity of the C13-urea breath test after 6-8 weeks after treatment discontinuation. Per protocol, we compared the effectiveness of PPI-LA with a control group of 270 patients treated with PPI-CA for 10 days. Results: 130 patients (96.2%) could complete the treatment and follow-up protocol. Effectiveness (intention to treat) was 71.8% (97/135) and 74.6% (per protocol) (97/130). Sixteen patients (11.8%) had well-tolerated adverse effects, except for 5 subjects (3.7%) who dropped out. PPI-CA was effective (per protocol) in 204 patients out of 270 (75.5%) in the control group...(AU)

Water stress preconditioning to improve drought resistance in young apricot plants.

The effect of water stress preconditioning was studied in 1-year-old apricot plants (Prunus armeniaca L., cv. Búlida). Plants were submitted to different treatments, T-0 (control treatment) and T-1, drip irrigated daily; T-2 and T-3, irrigated daily at 50% and 25% of T-0, respectively; T-4 and T-5, irrigated to field capacity every 3 and 6 days, respectively. After 30 days, irrigation was withheld for 10 days, maintaining the T-0 treatment irrigated daily. After this period, the plants were re-irrigated to run-off and treated as control treatment. The stomatal closure and epinasty observed in response to water stress represented adaptive mechanisms to drought, allowing the plants to regulate water loss more effectively and prevent leaf heating. A substantial reduction in the irrigation water supplied combined with a high frequency of application (T-3 treatment) promoted plant hardening; the plants enduring drought better, due to their greater osmotic adjustment (0.77 MPa), which prevented severe plant dehydration and leaf abscission. Such a preconditioning treatment may be valuable for young apricot plants in the nursery stage in order to improve their subsequent resistance to drought. A 50% reduction in daily irrigation (T-2 treatment) did not significantly affect either gas exchange rates or leaf turgor, which suggests that water should be applied frequently if deficit irrigation is to be implemented.