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Combined effect of nitrate and salt concentrations on growth and nitrogen metabolism on durum wheat seedlings kept in hydroponics
No full text
Determinants of hospitalization in a cohort of chronic dialysis patients in central Italy
No full textBackground: Few studies linking hospital discharge records with the population register of chronic dialysis (CD) patients are available. This study aimed to evaluate the frequency and the determinants of hospitalization, taking into account the demographic, clinical and biochemical data. Methods: We conducted a retrospective cohort study in 3411 patients starting dialysis from 1996-2000, reported to the Lazio Dialysis Registry (RDL) (Italy). These patients were linked with the hospital information system from 1996-2002. Hospital admission probability was calculated using the Kaplan-Meier method. To evaluate the determinants of hospitalization risk we used Cox's proportional hazards for the first admission and a marginal model considering competitive effect of mortality, the Wei-Lin-Weissfeld model, for any admission. Results: We found 7530 hospital admissions, referring to 1711 patients (50.7%), with a rate of 63/100 person-years. The most prevalent diagnoses were "diseases of the genitourinary system", (37.4%), and "diseases of the circulatory system", among secondary diagnoses (46.6%). Hospitalization probability was 34.4% at 1 yr after starting dialysis. The risk of first and any hospital admission was higher (p<0.05) for patients having more than one comorbid disease, hematocrit (Hct) level <30%, serum albumin level <3.5 g/dL, and a low degree of self-sufficiency. Conclusions: Hospitalization frequency, mainly during the first months of dialysis, suggests the need to improve the early management of chronic renal failure and indicates the importance of preventing complications and maximizing functional status among the dialysis population
GLYCINE BETAINE IN DURUM WHEAT SEEDLINGS SUBMITTED TO SALT STRESS BY A ROOT SPLIT SYSTEM
No full textCARATTERIZZAZIONE DI ACCESSIONI DI CILIEGIO DELLA REGIONE CAMPANIA ATTRAVERSO L'ANALISI DEL PROFILO DI METABOLITI
No full textNitrate reductase in durum wheat seedlings as affected by nitrate nutrition and salinity
No full textThe combined effects of nitrate (0, 0.1, 1, 10 mM) and salt (0, 100 mM
NaCl) on nitrogen metabolism in durum wheat seedlings were investigated
by analysis of nitrate reductase (NR) expression and activity, and
metabolite content. High salinity (100 mM NaCl) reduced shoot growth
more than root growth. The effect was independent of nitrate
concentration. NR mRNA was present at a low level in both leaves and
roots of plants grown in a nitrogen-free medium. NaCl increased NR mRNA
at low nitrate, suggesting that chloride can mimic nitrate as a signal
molecule to induce transcription in both roots and leaves. However, the
level of NR protein remained low in salt-stressed plants, indicating an
inhibitory effect of salt on translation of NR mRNA or an increase in
protein degradation. The lower activity of nitrate reductase in leaves
of high-nitrate treated plants under salinity suggested a restriction of
NO3- transport to the shoot under salinity. Salt treatment promoted
photorespiration, inhibiting carbohydrate accumulation in plants grown
on low nitrate media. Under salinity free amino acids, in particular
proline and asparagine, and glycine betaine could function as osmolytes
to balance water potential within the cell, especially when nitrogen
availability exceeded the need for growth.The combined effects of nitrate (0, 0.1, 1, 10 mM) and salt (0, 100 mM NaCl) on nitrogen metabolism in durum wheat seedlings were investigated by analysis of nitrate reductase (NR) expression and activity, and metabolite content. High salinity (100 mM NaCl) reduced shoot growth more than root growth. The effect was independent of nitrate concentration. NR mRNA was present at a low level in both leaves and roots of plants grown in a nitrogen-free medium. NaCl increased NR mRNA at low nitrate, suggesting that chloride can mimic nitrate as a signal molecule to induce transcription in both roots and leaves. However, the level of NR protein remained low in salt-stressed plants, indicating an inhibitory effect of salt on translation of NR mRNA or an increase in protein degradation. The lower activity of nitrate reductase in leaves of high-nitrate treated plants under salinity suggested a restriction of NO3- transport to the shoot under salinity. Salt treatment promoted photorespiration, inhibiting carbohydrate accumulation in plants grown on low nitrate media. Under salinity free amino acids, in particular proline and asparagine, and glycine betaine could function as osmolytes to balance water potential within the cell, especially when nitrogen availability exceeded the need for growth
Nitrate reductase and glutamate synthase in the metabolism of compatible compounds in durum wheat under salt stress
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