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Il ruolo dello stress ossidativo nei tumori della tiroide, valutato attraverso la spettroscopia di risonanza paramagnetica elettronica e di risonanza magnetica nucleare: la nostra esperienza in chirurgia tiroidea
Full text linkIn molti casi , nelle cellule tumorali tiroidee è stato evidenziato un aumento dello stress ossidativo ed un deficit nel sistema antiossidante, ma gli effetti dello stress ossidativo sulla funzione cellulare rimangono ancora in gran parte sconosciuti. In questo studio abbiamo approfondito il ruolo di alcuni enzimi antiossidanti contenenti selenio, come glutatione perossidasi (GPx1) e tioredossina reduttasi (TrxR1), nei tumori della tiroide, valutando anche, mediante la spettroscopia di Risonanza Paramagnetica Elettronica (EPR), la formazione diretta dei radicali liberi nelle cellule tumorali. Inoltre, utilizzando la spettroscopia di risonanza magnetica nucleare ad alta risoluzione (HR-NMR), abbiamo identificato alcuni metaboliti nelle cellule tumorali della tiroide, che potrebbero essere l’espressione di un cambiamento del metabolismo cellulare in questo tipo di tumore. Campioni di carcinoma tiroideo e tessuto tiroideo sano sono stati raccolti da pazienti sottoposti a tiroidectomia totale per tumore tiroideo ed utilizzati per eseguire sia le analisi spettroscopiche con EPR e NMR, sia la valutazione dell’espressione degli enzimi antiossidanti. Nei nostri campioni abbiamo riscontrato un aumento significativo della formazione dei radicali liberi, mediante spettroscopia EPR, ed una riduzione sia dell’espressione degli enzimi antiossidanti GPx1 e TrxR1. L'analisi metabolomica, condotta mediante spettroscopia NMR, ha dimostrato, inoltre, una differenza significativa nell’espressione di alcuni metaboliti nel tessuto sano, rispetto al tessuto tumorale, evidenziando, in quest’ultimo, una riduzione di succinato, aspartato, mioinositolo, Cho, citrato e glutatione e un aumento di glutammato e acetato. Questi cambiamenti nel metabolismo cellulare riflettono una riduzione dell'attività del ciclo di Krebs a favore della glicolisi nei tumori tiroidei, in presenza di un significativo aumento dello stress ossidativo. I nostri risultati evidenziano che le cellule tumorali tiroidee sono in grado di riprogrammare la loro attività metabolica per sopravvivere in condizioni di elevato stress ossidativo e con un sistema antiossidante compromesso, evidenziando per la prima volta, una connessione tra stress ossidativo e l'alterazione del profilo metabolico nei tumori della tiroide
Peroxynitrite signaling in human erythrocytes: Synergistic role of hemoglobin oxidation and band 3 tyrosine phosphorylation
No full textThe effect of sleeve gastrectomy on oxidative stress in obesity
Full text linkHigh concentrations of free radicals are present in the blood of obese patients. Free radicals are associated with endothelial dysfunction, diabetes, and neoplastic transformation, all conditions that are closely related to obesity. The purpose of our study was to determine whether bariatric surgery modifies the production of free radicals in obese patients. In total, 20 patients with morbid obesity, who were candidates for laparoscopic sleeve gastrectomy (SG), and 18 controls were enrolled in the study. Oxidative stress was studied in obese subjects before and after sleeve gastrectomy. The evaluation of oxidative stress was carried out on blood samples using electron paramagnetic resonance, a refined spectroscopic technique used to identify and quantify the major free radicals, such as •OH, O2•, ONOO-, and NO. Oxidative stress was higher in subjects with morbid obesity prior to surgery, compared to the controls (CP• 9.9 ± 0.3 μM vs. 5.8 ± 0.2 μM). After SG, values decreased to levels comparable to those of controls (CP• 5.4 ± 0.2 μM). Further analysis identified O2• as the main free radical responsible for the oxidative stress. Obesity is associated with an increased blood concentration of free radicals. The normalization of free radicals after sleeve gastrectomy highlights another important benefit of this bariatric surgery technique
Carbon monoxide signaling in human red blood cells: evidence for pentose phosphate pathway activation and protein deglutathionylation
No full textThe biochemistry underlying the physiological, adaptive, and toxic effects of carbon monoxide (CO) is linked to its affinity for reduced transition metals. We investigated CO signaling in the vasculature, where hemoglobin (Hb), the CO most important metal-containing carrier is highly concentrated inside red blood cells (RBCs)
Role of Virtual Reality Simulators in the certification of bariatric surgeons
No full textAIMS: Several studies showed construct validity of virtual laparoscopic simulators for basic laparoscopic skills, however it is not yet clear whether the simulators can identify the actual experience of surgeons in more complex procedures such as laparoscopic Roux-en-Y gastric bypass. Our study tested the ability of the Lap Mentor simulator (SimbionixTM) to recognize the experience in advanced laparoscopic procedures assessing its role in the certification of bariatric surgeons.
METHODS: 30 surgeons were divided into two groups according to their experience in laparoscopic and bariatric surgery: General group included 15 general surgeons performing between 75 and 100 non bariatric laparoscopic procedures; Bariatric group included 15 bariatric surgeons performing between 50 and 100 laparoscopic bariatric procedures. Participants were tested on the laparoscopic simulator in one basic task (Task 1: eye-hand coordination) and in two tasks of the gastric bypass module (Task 2: creation of the gastric pouch, Task 3: gastro-jejunal anastomosis).
RESULTS: Comparing the groups, no significant differences were found in task 1 confirming the homogeneity of the two groups for basic laparoscopic skills. Analyzing the results from the gastric bypass module (bariatric vs. general), in task 2, significant differences (p < 0.05) were found in the median volume of the gastric pouch (22 vs. 48 cm3), in the percentage of fundus included in the pouch (8.8 vs. 30.1 %), in the complete dissection at the angle of His (14 vs. 4), and in safety parameters. In task 3, significant differences were found in the size and position of enterotomies.
CONCLUSIONS: Lap MentorTM simulator is able to recognize specific skills of bariatric surgeons also in technical details that affect long-term results of the procedure such as dissection at the angle of His and gastric pouch volume. Furthermore, the possibility of analyzing in details the performance can help define skills where the surgeon is more lacking. These findings suggest a potential role in tailoring the training to maximize improvement. The Lap Mentor may be proposed as a certification tool for bariatric surgeons
L-NAME reverses quinolinic acid-induced toxicity in rat corticostriatal slices: Involvement of src family kinases
No full textA novel approach to study oxidative stress in thyroid diseases: a preliminary study
No full textBackground and Objectives: Recently, several Authors have emphasized the relationship between oxidative stress and thyroid tumors. Several methods have been proposed in the literature for the measurement of oxidative stress in human tissues, although the high reactivity and short half life of Reactive Oxygen and Nitrogen Species make difficult their direct determination. Here we propose a novel approach for the determination of oxidative stress in human tissues, taking into account the relationship between free radicals and thyroid diseases. Materials and Methods: Our goal in this preliminary study, was to demonstrate the opportunity to use the coupling of the EPA-spin trapping technique with the hydroxylamine 1-hydroxy-3-carboxy-pyrrolidine, to detect oxidative stress in the human blood of patients with thyroid disease. Results: Our preliminary findings confirm that this is a sensible, precise and valid method to study the oxidative stress and encourage us to continue the project. Conclusions: Our next goal will be to enroll patients affected by different thyroid diseases and to study the effect of some antioxidants in the management of the disease. This will allow to better understand the pathological path that binds the formation of reactive oxidizing species to the thyroid cancer and eventually to take into account the antioxidant therapy, as a possible additional "therapeutic weapon"
Perioperative care in elderly patients undergoing thyroid surgery
No full textThe features of western world population are rapidly changing. The increment geriatric population obliges clinicians to implement specific recommendations and guidelines to manage these patients.
In the field of thyroid surgery, when indications are represented by benign conditions, surgeons and endocrinologists tent to avoid surgery for the increased perioperative risks in the over 70 year old population.
We reviewed our experience in thyroid surgery in geriatric patients within the environment of a “week surgery unit”. This unit was conceived to offer a highly specialized setting for thyroid patients needing short stay after surgery.
Results showed that the surgical outcomes were comparable to the ones from third surgery in young patients.
The week surgery approach is the best and safest formula to offer to the geriatric population needing thyroid surgery
Salivary uric acid at the acidic pH of the stomach is the principal defense against nitrite-derived reactive species: Sparing effects of chlorogenic acid and serum albumin
No full textAn unusual subcutaneous breast cancer matastasis in a 86-year-old woman
No full textThe most common metastasis
site of breast cancer are the local and distant
lymph nodes, bone, lungs, liver and brain. We
report a 86-year-old woman with an unusual abdominal
subcutaneous metastasis of breast
cancer. The patient was diagnosed with invasive
lobular breast cancer and had been treated
six months earlier with modified radical mastectomy.
Later she presented a painless mass
on the middle upper abdominal wall. She was
subsequently admitted to the hospital to perform
a whole body CT scan, confirming the
presence of the abdominal mass in epigastric
region, causing a partial compression of the
stomach. Histopathological studies confirmed
that the abdominal mass was a rare subcutaneous
metastatic lesion of breast origin. The patient
underwent a surgical intervention to remove
the metastasis and she recovered fully
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