13 research outputs found
Sucrose phosphate synthase activity and the co-ordination of carbon partitioning during sucrose and amino acid accumulation in desiccation-tolerant leaf material of the C4 resurrection plant Sporobolus stapfianus during dehydration.
Both sucrose and amino acids accumulate in desiccation-tolerant leaf material of the C(4) resurrection plant, Sporobolus stapfianus Gandoger (Poaceae). The present investigation was aimed at examining sucrose phosphate synthase (SPS) activity and various metabolic checkpoints involved in the co-ordination of carbon partitioning between these competing pathways during dehydration. In the initial phase of dehydration, photosynthesis and starch content declined to immeasurable levels, whilst significant increases in hexose sugars, sucrose, and amino acids were associated with concomitant significant increases in SPS and pyruvate kinase (PK) activities, and maximal activity levels of phosphoenolpyruvate carboxylase (PEPCase), NADP-dependent isocitrate dehydrogenase (NADP-ICDH), and NADH-dependent glutamate synthase (NADH-GOGAT). The next phase of dehydration was characterized by changes in metabolism coinciding with net hexose sugar phosphorylation. This phase was characterized by a further significant increase in sucrose accumulation, with increased rates of net sucrose accumulation and maximum rates of SPS activity measured under both saturating and limiting (inhibitory) conditions. SPS protein was also increased. The stronger competitive edge of SPS for carbon entering glycolysis during hexose phosphorylation was also demonstrated by the further decrease in respiration and the simultaneous, significant decline in both PEPCase and PK activities. A decreased anabolic demand for 2-oxoglutarate (2OG), which remained constant, was shown by the co-ordinated decrease in GOGAT. It is proposed that the further increase in amino acids in this phase of dehydration may be in part attributable to the breakdown of insoluble proteins
Amino acid pattern and glutamate metabolism during dehydration stress in the 'resurrection' plant Sporobolus stapfianus: a comparison between desiccation-sensitive and desiccation-tolerant leaves
The present study analyses changes in nitrogen compounds, amino acid composition, and glutamate metabolism in the resurrection plant Sporobolus stapfianus during dehydration stress. Results showed that older leaves (OL) were desiccation-sensitive whereas younger leaves (YL) were desiccation-tolerant. OL lost their soluble protein more rapidly, and to a larger extent than YL. Enzymes of primary nitrogen assimilation were affected by desiccation and the decrease in the glutamine synthetase (GS, EC 6.3.1.2) and ferredoxin-dependent GOGAT (Fd-GOGAT, EC 1.4.7.1) activities was higher in OL than in YL, thus suggesting higher sensibility to dehydration. Moreover, YL showed higher total GS enzyme activity at the end of the dehydration stress and was shown to maintain high chloroplastic GS protein content during the entire stress period. Free amino acid content increased in both YL and OL between 88% and 6% relative water content. Interestingly, OL and YL did not accumulate the same amino acids. OL accumulated large amounts of proline and gamma-aminobutyrate whereas YL preferentially accumulated asparagine and arginine. It is concluded (i) that modifications in the nitrogen and amino acid metabolism during dehydration stress were different depending on leaf development and (ii) that proline and gamma-aminobutyrate accumulation in S. stapfianus leaves were not essential for the acquisition of desiccation tolerance. On the contrary, the accumulation of large amounts of asparagine and arginine in the YL during dehydration could be important and serve as essential nitrogen and carbon reservoirs useful during rehydration. In this context, the role of GS for asparagine accumulation in YL is discussed
Apprendimento e cambiamento nelle organizzazioni. Fondamenti, criteri, direzioni. Libellula, Tricase (Le)
Valutazione della contaminazione da policlorobifenili (PCB) in terreni della Valbasento mediante GC-ECD con doppia colonna e GC-MS ad alta risoluzione
Comunicazione ORAL
Relationship between appetite levels and anxiety symptoms in chronic hemodialysis patients
Appetite level evaluated by the appetite and diet assessment tool (ADAT) is associated with several clinical and nutritional variables. Our aim was to expand the study to psychological variables (depression symptoms, anxiety symptoms, and distorted thinking). We studied 96 chronic kidney disease patients treated with hemodialysis three times per week. Representative variables are shown as median (percentile 25âpercentile 75) or absolute values. DRI = daily recommended intake.
Appetite level
Very poor, poor (N=10)
Fair, Good (N=31)
Very Good (N=55)
Tau
Sex (F/M)
9 / 1
12 / 19*
22 / 33*
--
Age (years)
65 (46â2)
50 (29â65)
47 (33â58)*
â0.18&
Creatinine (mg/dL)
7.4 (6.9â8.6)
11.1 (8.0â13.9)*
11.3 (9.4â13.0)*
Kt/V
1.5 (1.3-1.6)
1.4 (1.2-1.5)
1.4(1.2-1.5)
â0.03
Albumin (g/dL)
3.5 (3.3-3.9)
3.6 (3.5-3.8)
3.6 (3.5-3.8)
0.09
DRI (%)
78 (74â88)
88 (80â99)*
101 (99â103)*
0.54&
Anxiety score
12 (12â20)
9 (4â16)*
5 (3â10)*
â0.26
& â p < 0.05 versus poor or poor appetite, Mann-Whitney or chi2 test.
& p < 0.05, correlation with appetite level (KendallÂŽs Tau coefficient)
Very poor or poor appetite level was associated with female sex, older age, lower creatinine, lower DRI, and higher anxiety symptoms. Intervention of anxiety with cognitive behavioral therapy could improve nutritional treatment among vulnerable patients
Polychlorinated Biphenyls in Contaminated Soil Samples Evaluated by GC-ECD and GC-HRMS
We present
and compare
results obtained from the analyÂsis
of polyÂchlorinated
biphenyls
(PCBs) of a limited
number
of contaminated
soil samples
collected
in three areas of Basilicata
region (south of Italy).
The levels
of PCBs were evaluated
by using two analytical
methods:
(i) parallel
dual-column
gas-chromatography
with dual electron
capture
detectors
(GCâECD) and (ii) gas-chromatography
coupled
to
high-resolution
mass spectrometry
(GCâHRMS) via electron
impact ionization
(EI) in the multiple ion
monitoring
mode (MIM, two ions per compound).
Two extraction
methods
prior to sample
cleanup were
also examined:
microwave-
assisted extraction
(MAE) and ultrasonic-
assisted extraction
(UAE). The MAE
was the extraction
procedure
adopted using acetone/
n-hexane
(1:1, v/v) as it is mainly characterized
by higher sample
throughput
and allowed reduced consumption
of organic solvents.
While extraction
and analyÂsis
of spiked soil samples
showed the applicability
of both methods,
systematic
differences
between the results were obtained for the sum of PCBs as a result of some non-detected congeners
by
GCâECD compared
with GCâHRMS. Indeed, high resolution
MS using EI mode (electron
energy 40 eV)
with a resolving
power of 10,000 provides
additional
information
about the contamination
pattern. The
GCâECD screening
of 11 soil samples
led to just one sample
non-compliant
to as it was close to the guide
value for soils fixed by the Italian
legislation
(i.e., 60 ppb for private
or urban soil). Using GCâHRMS, the
amount of all PCBs found ranged from 5.4 to 127 ppb with five soil samples
non-compliant
to the guide
value. The number
of identified
congeners
ranged from 1 to 9 and 9 to 18 using dual-column
GCâECD and
GCâHRMS, respectively
Laparoscopic Trainers and Surgical Virtual Simulators in Laparoscopic Learning Curve
Robotic Surgery is a current procedure in endosurgery, but literature has not addressed the learning curve for the use of the robotic assisted surgery. The learning curve for robot surgical procedures varies widely. Apart from innate skill, learning curves are composed of at least two fundamentals related to the volume of cases and the incidence rate. Commonly cited reasons include lack of adequate training in residency programs because of the time devoted to abdominal, vaginal, and obstetric procedures, lack of available and adequate training opportunities outside of dedicated fellowships, lack of proctors and mentor surgeons in communities to help to further advance the skills of younger surgeons, and lack of desire to leave established surgical practices to try to develop skills requiring long learning curves to master. Currently, the training involves practice with the surgical robot in either pig or human fresh tissue in a laboratory environment in order to become familiar with the functions of the robot, the attachment of the robotic arms to the robotic trocars, and the overall functions of the robotic console. In this chapter authors reviewed current literature on learning curve in robotic assisted surgery and screened problems linked to robotic surgical skills