3,022 research outputs found
Effects of calcium availability on calmodulin level and on metabolic reactivation in early germination phases of radish seeds : ninth international workshop on plant membrane biology
No full textEFFECT' OF CALCIUM AVAILABILITY ON CALMODULIN LEVEL AND ON
METABOLIC REACTIVATION IN EARLY GERMINATION PHASES OF
RADISH SEEDS.
Cocucci. M. and Negrini. N.
Dipartimento di Fisiologia delle Piante coltivate e Chimica agraria. Facolta di agraria. Universita di
Milano. via Celoria 2. 20133 Milano. Italy.
Calcium and Calmodulin (CaM) control many physiological processes in plants. The
level of Ca2+-CaM complex can be modulated by the level of intracellular Ca2+ and also by the level
of CaM. CaM level appears to play an important role in the metabolic reactivation which characterizes
seed germination (1. 2. 3). In radish seeds Ca2+-CaM active complex is also modulated by the
presence of a proteinaceous inhibitor (1). Seed germination is also characterized by the reactivation of
membrane functions suggesting a precocious recovery of the control of ionic homeostasis. The fact that
Ca2+ in early germination was released into the medium (1) sugge~ts a high level of cytosolic Ca2+.
The reduction of Ca2+ availability during radish seed germination was obtained by
incubating the seeds in the presence of the Ca2+ chelator EGTA. The presence of EGTA inhibited
germination (measured as increase in fr. wt.) at concentrations higher than 1 mM. When Ca2+ was
administered together with EGTA. the inhibition was removed suggesting that the EGTA effect is due
to the reduction of Ca2+ availability. EGTA treatment decreased the level of free Ca2+ in the medium.
but the cation bound to EGTA increased; parallelly Ca2+ in the embryo axes decreased. At 1 mM
EGTA. the reduction of Ca2+ availability only slightly affected metabolic reactivation (measured as
RNA and DNA increases) and had no effect on membrane reactivation.
The level and specific activity of CaM in the soluble fraction of radish embryos strongly
increased in early germination phases (ca. +450%). 1 mM EGTA greatly reduced (ca.-50%) the
increases in level and specific activity of CaM. When the soluble fraction was analyzed on Sephadex
G75 column. CaM was eluted in several peaks at MW higher than 30 ill and in particular. at 36 kD.
CaM was co-eluted with the proteinaceus CaM inhibitor present in ungerminated seeds. CaM eluted in
this zone decreased in the seeds germinated in the presence of EGT A.
The decrease in ]eve] and specific activity of CaM was not accompanied by a decrease in
germination and metabolic reactivation when the seed germinate at Jow Ca2+ suggesting that the level
of the cation might control CaM increase and level. that the level of CaM could contribute to control
the level of cytosolic Ca2+ and that the Ca2+-CaM dependent activities could also be also controlled
by the presence of the CaM inhibitor.
1.
2.
3.
Cocucci. M. and Negrini. N. (1988) Plallt Physinl. 88.910- 914.
Cocucci. M. and Negrini. N. (1989) Plalll Membrane trallsport. Dainty 1. et al. eds. pp
355- 360.
Cocucci, M. and Negrini. N. (1991)Physiol. Plalll. 82.143- 149.
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Correction to: The “Risser+” grade: a new grading system to classify skeletal maturity in idiopathic scoliosis (European Spine Journal, (2019), 28, 3, (559-566), 10.1007/s00586-018-5821-8)
No full textUnfortunately, the affiliation of the author Negrini S has been incorrectly published in the original version. The complete correct affiliation of this author should read as follows
Scoliosis-Specific exercises can reduce the progression of severe curves in adult idiopathic scoliosis: A long-term cohort study
No full textBackground: Scoliosis fusion surgery is generally considered the only means to stop the progression of adult idiopathic scoliosis (ADIS), but for patients refusing surgery there is lack of evidence in favour of conservative treatment. The aim of the present study was to verify the possible effectiveness of scoliosis-specific exercises when facing ADIS progression. Methods: We designed a retrospective cohort study. Instrumentation: SEAS exercises are scoliosis-specific exercises. In adult patients they are aimed to recover postural collapse, postural control and vertebral stability through an active self-correction. Postural integration is a key element, including the neuromotor integration of correct postures and an ergonomic education program. Therapy includes at least two weekly exercise sessions each lasting 45 min. Outcome measures: Radiographic progression was the main outcome and it was analysed as a continuous variable. Statistics: One way ANOVA and paired t-test were applied for continuous data, while chi-square test was applied for categorical data. Alpha was set at 0.05. Results: The mean Cobb angle of the patients included into the present study, was 55.8 ± 13.2 °. Fifteen patients had previous x-rays testifying scoliosis progression: the average curve progression (worsening) was 9.8 ± 6.6 ° at a median of 25 (range 17-48) years. The remaining were characterized by more severe curves, exceeding 40 ° Cobb (mean curvature 50.9 ± 13.6) but it was not possible to prove that the curves had progressed in these cases. After an average period of 2 years of treatment (range 1-18y), 68 % of the patients experienced an improvement in their scoliosis. However in one patient (3 %) the scoliosis worsened by 5 ° in 18 years (progression rate reduced from 0.5 ° to 0.27 ° per year). Patients improved 4.6 ± 5.0 ° Cobb (P < 0.05), with no differences based on the localization of the curve, gender, age, length of treatment, Cobb degrees at the start of observation or treatment. Conclusions: Scoliosis Specific SEAS Exercises proved to be superior to natural history in ADIS, at least in individual cases and should be considered as a first line treatment especially in patients refusing scoliosis surgery. © 2015 Negrini et al
Fluid exchanges across the parietal peritoneal and pleural mesothelia
No full textIn 31 anesthetized rabbits, after removal of superficial tissues, glass micropipettes filled with 0.5 M NaCl solution and connected to an electrohydraulic servo-null system were used to measure extraperitoneal interstitial fluid pressure (Pi,per) and peritoneal liquid pressure (Pliq,per) at various heights. Linear regressions relating pressure to recording height (H) were Pi,per = 1.07 - 0.27H and Pliq,per = 0.9 - 0.64H, respectively. Protein concentration (Cp;g/dl) and colloid osmotic pressure (II; cmH2O) of plasma and of peritoneal and pleural liquids were 5.48 +/- 0.38 and 24.61 +/- 3.23, 3.07 +/- 0.5 and 13.29 +/- 1.87, and 1.76 +/- 0.42 and 8.45 +/- 2, respectively. The equation relating II to Cp was II = 4.64Cp + 0.0027Cp2. Tissue fluid samples were collected with saline-soaked wicks implanted in vivo or dry wicks inserted postmortem in extraperitoneal and extrapleural interstitial spaces. After 60 and 15 min, respectively, wicks were withdrawn and centrifuged; wick fluid was analyzed in colloid osmometer for small samples. Average extraperitoneal and extrapleural II values were 14.2 +/- 2.49 and 11.94 +/- 1.52 cmH2O, corresponding to Cp of 3.07 and 2.57 g/dl, respectively. The average net pressure gradient, assuming reflection coefficient and hydraulic conductivity (Negrini et al. J. Appl. Physiol. 69: 625-630, 1990; 71: 2543-2547, 1991), was 1.18 and 0.98 cmH2O for parietal peritoneal and pleural mesothelia, respectively, favoring filtration from the extraserosal interstitia into the serosal cavities. Total parietal peritoneal filtration was 1.49 ml.kg-1.h-1, approximately 15-fold higher than that for pleural mesothelium
Calmodulin levels in radish (Raphanus sativus L.) seeds germinating at low calcium availability, induced by EGTA treatments
No full textIncubation of radish (Raphanus sativus L.) seeds in the presence of 1 or 5 mol m(-3) Ca-EGTA, which increased Ca2+ activity in the incubation medium (c. 0.24 or 0.37 mol m-3 at 24 h with respect to c. 0.13 mol m(-3) in the control), did not affect germination, the restoration of K+ net influx, the increase in DNA and RNA levels or protein synthesis. Incubation in 1 mol m(-3) Na-EGTA, which reduced Ca2+ activity in the incubation medium (20 mmol m(-3) at 24 h), decreased the total Ca2+ level in embryo axes (-21%), but only slightly inhibited the increase in fresh weight without affecting the restoration of K+ net influx, the increase in DNA and RNA levels or protein synthesis. In the presence of 5 mol m(-3) Na-EGTA (Ca2+ activity in the incubation medium was 0.6 mmol m(-3)), the decrease in the total Ca2+ level was greater (c. -27%) and the increases in fresh weight, DNA and RNA were inhibited by about 50, 39 and 40%, respectively. These results indicate that increased Ca2+ availability does not affect germination and suggest that the effect of Na-EGTA, at least up to 5 mol m(-3), is a result of an induction of Ca2+ deficiency. The amount and specific activity of calmodulin (CaM) present in the soluble fraction (100 000 g) of radish embryo axes greatly increased during the first 24 h of incubation (c. 5-fold and 7-fold, respectively). This increase was very similar in the Ca-EGTA-treated seeds but was inhibited (c. -38%) by 1 mol m(-3) Na-EGTA, even if the increases in DNA and RNA levels and protein synthesis were not significantly reduced. The lower amount of CaM after 24 h of incubation in 1 mol m(-3) Na-EGTA (c. -30%) was due to a reduction in the fraction of CaM bound to a proteinaceous CaM inhibitor present in radish seeds [M. Cocucci and N. Negrini (1988) Plant Physiology 88, 910-914] and not involved in the metabolic reactivation of the seed. These results suggest that the level of CaM is controlled by Ca2+ availability and that the CaM inhibitor has a role in controlling the amount of Ca-CaM available for the Ca-CaM-dependent enzymes
Physical exercises in the treatment of adolescent idiopathic scoliosis: an updated systematic review.
No full textTwo years ago we published an update of another of our previous systematic reviews about the effectiveness of physical exercises (PEs), and we found that the evidence on exercises for AIS was of level 1b. Now we have updated these results in the field of exercises for AIS with the final aim to find the strongest evidence as possible about PEs. Our goal was to verify if treatment with specific exercises for AIS has changed in these years. The study design was a systematic review. A bibliographic search with strict inclusion criteria (patients treated exclusively with exercises, outcome Cobb degrees, all study designs) has been performed on the main electronic databases. We found a new paper about active autocorrection (Negrini et al, 2008 b), a prospective controlled cohort observational study on patients never treated before so the number of manuscripts considered in the systematic review was 20. The highest quality study (RCT) compared 2 groups of 40 patients, showing an improvement of the curve in all treated patients after 6 months. All studies confirmed the efficacy of exercises in reducing the progression rate (mainly in early puberty) and/or improving the Cobb angles (around the end of growth). Exercises were also shown to be effective in reducing brace prescription. Appendices of the popular exercise protocols that have been used in the research studies that are examined are included with detailed description and illustrations. This study (like the previously published systematic reviews) showed that PEs can improve the Cobb angles of individuals with AIS and can improve strength, mobility, and balance. The level of evidence remains 1b according to the Oxford Centre for Evidence-based Medicine, as previously documented
Sport improved medium-term results in a prospective cohort of 785 adolescents with idiopathic scoliosis braced full time. SOSORT 2018 award winner
No full textPURPOSE: The association between idiopathic scoliosis (IS) and sports activities remains vague. We aimed to analyse their effect on full-time braced adolescents with IS. METHODS: We retrospectively recruited all the consecutive patients of a tertiary referral Institute of age ≥ 10 (adolescents), with a juvenile (JIS) or adolescent (AIS) IS diagnosis, Risser 0-2, TLSO brace prescription and self-reported adherence ≥ 20 h per day, and follow-up out-of-brace X-rays 18 months after brace prescription. We divided participants into two groups: SPORT (sport twice or more per week) and CONTROL (sport once per week or less). We calculated odds ratio (OR) to compare the outcome of subjects performing to those not performing sport. We ran a logistic regression with covariate adjustment to assess if sports frequency affected the outcomes. RESULTS: Out of 33,311 participants assessed for eligibility, 785 satisfied the inclusion criteria (693 females, age 12.7 ± 1.3 and 40 ± 11° Cobb). The SPORT group consisted of 290 participants and the CONTROL group of 495. The SPORT group showed higher odds of improvement (OR = 1.59, 95%CI = 1.17-2.16, p = 0.0018). The odds of improving increased with the frequency of sports activity (OR = 1.20, 95%CI 1.08-1.34). CONCLUSION: This study shows that sports activities increase the odds of improvement at 18-month follow-up in adolescents with IS treated with a full-time brace. The odds of improvement increase with sports week frequency.sponsorship: This study was supported and funded by the Italian Ministry of Health - Ricerca Corrente 2022. We thank Alberto Negrini and the ISICO software team for the conception, development, and maintenance of the program for data collection and extraction. (Italian Ministry of Health - Ricerca Corrente 2022)status: Publishe
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