69 research outputs found
Increase of free Mg(2+ )in the skeletal muscle of chronic fatigue syndrome patients
In a previous study we evaluated muscle blood flow and muscle metabolism in patients diagnosed with chronic fatigue syndrome (CFS). To better understand muscle metabolism in CFS, we re-evaluated our data to calculate free Magnesium levels in skeletal muscle. Magnesium is an essential cofactor in a number of cell processes. A total of 20 CFS patients and 11 controls were evaluated. Phosphorus magnetic resonance spectroscopy from the medial gastrocnemius muscle was used to calculate free Mg(2+ )from the concentrations and chemical shifts of Pi, PCr, and beta ATP peaks. CFS patients had higher magnesium levels in their muscles relative to controls (0.47 + 0.07 vs 0.36 + 0.06 mM, P < 0.01), although there was no difference in the rate of phosphocreatine recovery in these subjects, as reported earlier. This finding was not associated with abnormal oxidative metabolism as measured by the rate of recovery of phosphocreatine after exercise. In summary, calculation of free Mg(2+ )levels from previous data showed CFS patients had higher resting free Mg(2+ )levels compared to sedentary controls
Free Mg(2+ )concentration in the calf muscle of glycogen phosphorylase and phosphofructokinase deficiency patients assessed in different metabolic conditions by (31)P MRS
BACKGROUND: The increase in cytosolic free Mg(2+ )occurring during exercise and initial recovery in human skeletal muscle is matched by a decrease in cytosolic pH as shown by in vivo phosphorus magnetic resonance spectroscopy ((31)P MRS). To investigate in vivo to what extent the homeostasis of intracellular free Mg(2+ )is linked to pH in human skeletal muscle, we studied patients with metabolic myopathies due to different disorders of glycogen metabolism that share a lack of intracellular acidification during muscle exercise. METHODS: We assessed by (31)P MRS the cytosolic pH and free magnesium concentration ([Mg(2+)]) in calf muscle during exercise and post-exercise recovery in two patients with McArdle's disease with muscle glycogen phosphorylase deficiency (McArdle), and two brothers both affected by Tarui's disease with muscle phosphofructokinase deficiency (PFK). RESULTS: All patients displayed a lack of intracellular acidosis during muscle exercise. At rest only one PFK patient showed a [Mg(2+)] higher than the value found in control subjects. During exercise and recovery the McArdle patients did not show any significant change in free [Mg(2+)], while both PFK patients showed decreased free [Mg(2+)] and a remarkable accumulation of phosphomonoesters (PME). During initial recovery both McArdle patients showed a small increase in free [Mg(2+)] while in PFK patients the pattern of free [Mg(2+)] was related to the rate of PME recovery. CONCLUSION: i) homeostasis of free [Mg(2+)] in human skeletal muscle is strongly linked to pH as shown by patients' [Mg(2+)] pattern during exercise; ii) the pattern of [Mg(2+)] during exercise and post-exercise recovery in both PFK patients suggests that [Mg(2+)] is influenced by the accumulation of the phosphorylated monosaccharide intermediates of glycogenolysis, as shown by the increased PME peak signal. iii) (31)P MRS is a suitable tool for the in vivo assessment of free cytosolic [Mg(2+)] in human skeletal muscle in different metabolic conditions
Severity of Hepatocyte Damage and Prognosis in Cirrhotic Patients Correlate with Hepatocyte Magnesium Depletion
We aimed to evaluate the magnesium content in human cirrhotic liver and its correlation
with serum AST levels, expression of hepatocellular injury, and MELDNa prognostic score. In liver
biopsies obtained at liver transplantation, we measured the magnesium content in liver tissue in
27 cirrhotic patients (CIRs) and 16 deceased donors with healthy liver (CTRLs) by atomic absorption
spectrometry and within hepatocytes of 15 CIRs using synchrotron-based X-ray fluorescence microscopy.
In 31 CIRs and 10 CTRLs, we evaluated the immunohistochemical expression in hepatocytes
of the transient receptor potential melastatin 7 (TRPM7), a magnesium influx chanzyme also involved
in inflammation. CIRs showed a lower hepatic magnesium content (117.2 (IQR 110.5–132.9) vs. 162.8
(IQR 155.9–169.8)  g/g; p < 0.001) and a higher percentage of TRPM7 positive hepatocytes (53.0
(IQR 36.8–62.0) vs. 20.7 (10.7–32.8)%; p < 0.001) than CTRLs. In CIRs, MELDNa and serum AST at
transplant correlated: (a) inversely with the magnesium content both in liver tissue and hepatocytes;
and (b) directly with the percentage of hepatocytes stained intensely for TRPM7. The latter also
directly correlated with the worsening of MELDNa at transplant compared to waitlisting. Magnesium
depletion and overexpression of its influx chanzyme TRPM7 in hepatocytes are associated with
severity of hepatocyte injury and prognosis in cirrhosis. These data represent the pathophysiological
basis for a possible beneficial effect of magnesium supplementation in cirrhotic patients
VINIFICAZIONE IN QVEVRI DI UVE cv ALBANA - Un ritorno all'eta della pietra
I qvevri sono dei vasi vinari in terra cotta dalle straordinarie caratteristiche, che permettono di produrre eccellenti vini con prolungate macerazioni. I qvevri hanno una lunga storia, che oramai dura da più di 7000 anni, affondando le radici nel lontano medio oriente. La storia dei qvevri utilizzati per la vinificazione, macerazione e affinamento dei vini, è legata alla tradizione georgiana, tanto che nel dicembre 2013 l'UNESCO ha elevato la vinificazione tradizionale georgiana in qvevri a Patrimonio culturale immateriale dell'Umanità . Nell’ultimo decennio anche in Italia, come in altri paesi Europei, si è provato ad utilizzare i qvevri per la vinificazione con ottimi risultati, risvegliando la curiosità in diversi viticoltori artigiani ed eno-appassionati. Tuttavia, la letteratura scientifica e le conoscenze sugli effetti della vinificazione in qvevri sono ancora scarse e non esaustive.
In questo contesto, lo scopo del presente lavoro di tesi consiste nello studio degli effetti della vinificazione in qvevri con macerazione del vitigno Albana. I risultati della vinificazione in qvevri sono stati confrontati con quelli di una classica vinificazione in bianco in acciaio della stessa cultivar. L’albana è il più tipico vitigno del territorio romagnolo, grazie alla sua grande tipicità territoriale e alla sua alta concentrazione polifenolica si presta molto bene ad essere utilizzato per questo tipo di vinificazione. In particolare, è stato riscontrato, tramite HPLC-DAD, un elevato contenuto di polifenoli estratti grazie alla macerazione avvenuta sia in fermentazione e sia a qvevri sigillati in post-fermentazione (102 giorni). Inoltre, è stato valutato anche l’impatto di tale metodo di vinificazione sulle molecole volatili, le quali andranno ad influenzare il quadro organolettico del vino ottenuto. In particolare, si è riscontrato un aumento di esteri e chetoni/aldeidi, soprattutto dovuti all’esterificazione dei prodotti della fermentazione malolattica
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