PubMed Health⌕ Search

Biomedical subjects

N Avenia

Publications and source records attributed to N Avenia.

At least 19 recordsLinked to original sources
PubMed2007

Epidemiology of non-gastroenteropancreatic (neuro)endocrine tumours.

The widespread availability and reliability of immunohistochemical techniques in the last three decades have allowed researchers to identify cells with common neuroendocrine markers in virtually every organ. As a whole, these neuroendocrine cells form the so-called diffuse neuroendocrine system. Tumours arising from the cells of the diffuse neuroendocrine system are defined as (neuro)endocrine tumours (NETs). NETs have been increasingly described in recent years. However, despite the increase in the number of published papers focused on NET, we still lack adequate epidemiological data, particularly for non-gastroenteropancreatic (GEP) NETs. Furthermore, the real incidence of neuroendocrine differentiation for most sites is not completely known and is probably underestimated. As a consequence, data on the clinical features of many NET subgroups are not well known or confusing. For all of these reasons, we have attempted to evaluate the epidemiology of non-GEP NETs, reviewing the limited data available in the literature.

Carcinoid Tumor↗
PubMed2006

Biochemical and molecular characterization of the novel BRAF(V599Ins) mutation detected in a classic papillary thyroid carcinoma.

Activating mutations of the BRAF gene are the most common genetic alterations in papillary thyroid carcinomas (PTCs) and the T1799A transversion, resulting in BRAFV600E, appeared virtually unique in this cancer type. Here, we report on the identification in a classic PTC of a novel BRAF mutation, namely a 1795GTT insertion, resulting in BRAFV599Ins, and describe its biochemical and molecular characterization. Kinase assays carried out on BRAFV599Ins and BRAFV600E revealed a three- to five-fold increase in the enzymatic activity of both mutants with respect to BRAFWT. Similarly, evaluation of BRAF-induced phosphorylation of MEK, MAPK and RSK revealed a significant MAPK cascade activation in cells expressing BRAFV599Ins or BRAFV600E, but not in cells expressing BRAFWT. Molecular dynamic simulations showed a destabilization of the inactive conformation of the enzyme in both BRAFV599Ins and BRAFV600E mutants, but not in BRAFWT. The analysis of the interaction energies inside the catalytic site allowed to demonstrate the presence of repulsive electrostatic forces acting on the activation loop and moving from inward to outward of the mutant enzymes. Finally, focus assays in NIH-3T3 cells confirmed a high transformation rate in the cells transfected either with BRAFV599Ins or BRAFV600E. In conclusion, this study demonstrated that BRAFV599Ins, as BRAFV600E, is a 'gain of function' mutation, characterized by a constitutive catalytic activation, which accounts for its causative role in the studied PTC.

Aged↗
PubMed2006

A randomized controlled trial to evaluate the efficacy of ultrasound-guided laser photocoagulation for treatment of benign thyroid nodules.

This randomized controlled study was designed to test the efficacy and safety of percutaneous ultrasound (US)-guided laser photocoagulation (PLP) for treatment of subjects with compressive symptoms due to benign thyroid nodules and/or at high surgical risk. Twenty six subjects were randomized to the intervention (no. 13, age 68+/-3 yr, mean+/-SEM) or observation (no. 13, age 71+/-2 yr) groups. In the control group, the volume of nodules did not significantly change over the 30 week period of observation. In the intervention group, median nodule volume at baseline was 8.2 ml (range 2.8-26.9) and was not significantly different from that of the control group. Nodules decreased significantly (p<0.0001) by 22% after 2 weeks (6.5 ml; range 2.4-16.7) and by 44% after 30 weeks (4.6 ml; range 0.69-14.2). Energy given was correlated (p<0.05) with the reduction of thyroid nodule volume. All patients tolerated the treatment well and reported relief from compressive and cosmetic complaints (p<0.05). At the time of enrolment 7/13 (54%) and 6/13 (46%) of patients in the intervention and control groups, respectively, had sub clinical hyperthyroidism. PLP normalized thyroid function at 6 and 30 weeks after treatment. In conclusion, PLP is a promising safe and effective procedure for treatment of benign thyroid nodules in patients at high surgical risk.

Aged↗
PubMed2006

Correlation between B-RAFV600E mutation and clinico-pathologic parameters in papillary thyroid carcinoma: data from a multicentric Italian study and review of the literature.

Recently, a somatic point mutation of the B-RAF gene (V600E) has been identified as the most common genetic event in papillary thyroid carcinoma (PTC), with a prevalence variable among different series. Since discordant data on the clinico-pathologic features of B-RAF mutated PTC are present in the literature, the aim of the present co-operative study was to establish the prevalence of this genetic alteration and to perform a genotype-phenotype correlation in a large cohort of patients with PTC. To this purpose, a series of 260 sporadic PTCs with different histological variants were included in the study. The mutational analysis of the B-RAF gene was performed either by RT-PCR followed by single-stranded conformational polymorphism or by PCR and direct sequencing. Statistical analyses were obtained by means of chi2/Fisher's exact test and t-test. Overall, a heterozygous T > A transversion at nucleotide 1799 (V600E) was found in 99 out of 260 PTCs (38%). According to the histological type of the tumor, the B-RAF (V600E) mutation was present in 48.3% of cases of classic PTCs (85 out of 176), in 17.6% (nine out of 51) of follicular variants of PTCs, in 21.7% (five out of 23) in other PTC variants and in none of the ten poorly differentiated tumors. B-RAF (V600E) was significantly associated with the classic variant of PTC (P = 0.0001) and with an older age at diagnosis (P = 0.01). No statistically significant correlation was found among the presence of B-RAF (V600E) and gender, tumor node metastasis (TNM), multicentricity of the tumor, stage at diagnosis and outcome. In conclusion, the present study reports the prevalence of B-RAF (V600E) (38%) in the largest series of sporadic PTCs, including 260 cases from three different Italian referring centers. This prevalence is similar to that calculated by pooling together all data previously reported, 39.6% (759 out of 1914 cases), thus indicating that the prevalence of this genetic event lies around 38-40%. Furthermore, B-RAF (V600E) was confirmed to be associated with the papillary growth pattern, but not with poorer differentiated PTC variants. A significant association of B-RAF mutation was also found with an older age at diagnosis, the mutation being very rare in childhood and adolescent PTCs. Finally, no correlation was found with a poorer prognosis and a worse outcome after a median follow-up of 72 months.

Adolescent↗
PubMed2006

Breast surgery and sentinel node biopsy. Our experience.

Massive campaigns of screening of breast pathologies improved early diagnosis of breast cancers. Most of these cancers are small-sized (T1) and seldom show intraoperative nodal involvement. Sentinel node biopsy is the elective choice in the above mentioned cases because, if negative, it avoids axillary dissection. International literature reports rates of false negative sentinel node biopsy ranging among 4.5 and 12%; results in our experience account for almost 6%. As a consequence, there is the definite risk of potentially positive axilla that will not be dissected with subsequent risk of axillary recurrence within 24 months. The reason of that could be related to the fact that in Referral Centers this technique is performed in strictly selected patients, so as to gain a diagnostic accuracy of 98%. The rate of axillary recurrences does not justify the routine axillary dissection, since this is just a staging, not a therapeutic procedure. In case of doubt, it can be recommended a close and careful follow-up of the axilla.

Axilla↗
PubMed2006

[Thyroid microcarcinoma: our experience].

Differentiated thyroid cancer had an excellent prognosis; the diagnosis of sub-centimetric differentiated cancer (microcarcinoma) is more and more frequently. Clinical evolution of microcarcinoma could be various: microcarcinoma can represent an autoptic finding or can evolve with locoregional lymph node involvement or metastasis. Various clinical and genetic factors have been considered to predict the aggressiveness of this neoplasm. From 2001 to 2004, 74 patients with diagnosis of thyroid microcarcinoma underwent surgical treatment. By a retrospective survey we evaluated risk factors and the choice of surgical treatment. The aggressiveness appear to be related mainly to multifocality and size. Our therapeutic strategy is to perform total thyroidectomy for benign pathologies, total thyroidectomy with lymphadenectomy in cases with preoperative diagnosis of microcarcinoma.

Adult↗
PubMed2005

Thymic neuroendocrine carcinoma (carcinoid) in multiple endocrine neoplasia type 1 syndrome: the Italian series.

Neuroendocrine tumors may occur in the setting of multiple endocrine neoplasia type 1 (MEN1) syndrome. Among these, a probably underestimated prevalence of well differentiated neuroendocrine thymic carcinoma (carcinoid), a neoplasm characterized by very aggressive behavior, has been described. We report characterization of the seven Italian cases in which this association occurred among a series of 221 MEN1 patients (41 sporadic and 180 familial cases; prevalence, 3.1%). All of the patients were male, and six of seven (85%) were heavy smokers. No associated hormonal hypersecretion was detected. The first diagnosis was between the second and fifth decades. Familial clusters were present in three of seven (42.8%). No genotype-phenotype correlation was found. All seven cases were associated with hyperparathyroidism. In one patient, prophylactic thymectomy revealed a small nodular lesion suggestive of a thymic carcinoid, providing evidence that preventive thymectomy might prevent additional growth of an occult thymic carcinoid. These findings confirm that thymic carcinoids are associated with a very high lethality, with a near-total prevalence in smoker males. Therefore, prophylactic thymectomy should be considered at neck surgery for primary hyperparathyroidism in MEN1 male patients, especially for smokers, and, due to the frequent familial clusters distribution of this pathology, in subjects with affected relatives presenting this feature. Thus, we recommend screening every patient affected with a neuroendocrine thymic neoplasm for MEN1 syndrome.

Adult↗
PubMed2005

Which therapy to prevent post-thyroidectomy hypocalcemia?

Hypocalcemia is one of the most frequent complications after total extracapsular thyroidectomy (TET). In most of cases it is a transient phenomenon. The aim of this study is to evaluate if and how the oral administration of calcium or calcium combined with D-vitamin could effectively prevent post-thyroidectomy hypocalcemia. A randomized prospective study was performed, recruiting 120 patients who underwent total thyroidectomy. The patients in our series were randomly assigned to one of two groups: group A--patients who received calcium lactogluconate/calcium carbonate (mg 300 per day); group B--patients who received calcium carbonate/cholecalciferol therapy (calcium carbonate: 1500 mg per day; cholecalciferol 400 UI per day). The groups were well matched for age, sex and pathologies. Patients of both A and B groups were divided in two subgroups: those operated on for benign thyroid diseases (A1 and B1) and those operated on for malignancy (A2, B2). Serum calcium assays, performed 24, 48 and 72 hours after surgery, showed mean values of calcemia higher in patients of the B1 and B2 group. Statistical analysis was performed using a Student's t test. Mean serum calcium concentrations on post-operative day one, two and three were higher in patients of the group B (p<<0.01). Early and combined oral administration of both calcium and vitamin D seemed to prove major efficacy in preventing and treating post-operative hypocalcemia, showing mean serum calcium levels higher than those of patients who received only oral calcium administration. Nevertheless, further studies are necessary to validate these data.

Adult↗
PubMed2005

Major complications in thyroid surgery: utility of bipolar vessel sealing (Ligasure Precise).

In the present study the Authors tried and assess the advantages of the standard sutureless thyroidectomy performed by the Ligasure Vessel Sealing System, thanks to the use of the dedicated Precise handle. The Authors compared the efficacy of haemostasis and the economical impact of the device, in terms of drug administration and costs. The Authors comparatively analyzed 120 total extracapsular thyroidectomies (TET) performed by the standard operative technique (Group A, control) and 70 TET achieved by the "sutureless technique" (Group B, case). There was a statistically significant decrease of transient postoperative hypocalcemia (5.71% vs 7.5%) and also of mean operative time (about 20 minutes) in patients of the group B. Non significant decrease of other kind of complications (postoperative hemorrhage, transient and permanent inferior laryngeal palsy, stupor of the superior laryngeal nerve, seromas) were also observed. The use of the Ligasure Precise resulted easy, safe and efficient in the Authors' experience. It allowed the decrease of postoperative haemorrhages and mean operative time.

Case-Control Studies↗
PubMed2004

[Surgical treatment of umbilical hernia in children. Our experience].

AIM: To identify the main parameters which, differently correlated, indicate in which case, age and modality umbilical hernia in children should be surgically repaired. METHODS: The authors report personal experience on 319 children with umbilical hernia observed in the last 7 years. In 72 cases, on the basis of the evaluation of some parameters, a surgical correction was performed with the technique described. RESULTS: All the procedures were performed in "day surgery". There were no early complications, neither anesthetic nor surgical. All children showed a good recovery of all functions (feeding, intestinal canalization, walking about) and activities. No middle and long-term complications were observed. CONCLUSIONS: Umbilical hernia needs a surgical repair only in a few cases and after a careful evaluation of some parameters (age, sex, kind of hernia, size and consistency of the hernial porta, protrusion and expansion). The surgical procedure should guarantee either the safe and prompt repair or the cosmetic result; the use of some devices (anesthetic and surgical) allow to obtain excellent results.

Ambulatory Surgical Procedures↗
PubMed2000

The role of silicone stents in the treatment of cicatricial tracheal stenoses.

OBJECTIVE: Tracheal stenting for cicatricial stenoses is reserved for patients whose lesions are deemed inoperable for local or general reasons. The aim of our study was to verify the long-term results of silicone tracheal stents in such a clinical setting. METHODS: Clinical data of 45 patients treated by tracheal silicone stents, between 1987 and 1999, were reviewed. All patients had highly symptomatic cicatricial stenoses; they were selected for stenting rather than for surgery because of local and general conditions. This series has been divided in two groups according to the purpose of stenting: bridge to surgery or definitive treatment. Follow-up ranged between 12 and 83 months. Twenty-seven patients received a Montgomery T tube (Hood Laboratories, Pembroke, Mass), 16 a Dumon stent (Novatech, Plan de Gras, France), and 2 a Dynamic stent (Rusch, Kernen, Germany). RESULTS: No procedure-related mortality was observed. Nine patients underwent curative resection and reconstruction after a variable stenting period; one had a recurrent stenosis and was treated for palliation with a T tube. Tracheal stenting was performed for palliation as a definitive treatment in 37 patients. Among this group, 11 patients died of unrelated causes at a median of 10 months after the endoscopic treatment. The stent was permanently removed in 10 after a median interval of 32 months (range 9-70 months); in 4 others, symptomatic recurrence of the stenosis was observed within 6 weeks of stent removal. None of the patients successfully decannulated had a completely normal tracheal lumen but all remained asymptomatic because the residual stenosis was mild or well tolerated for concomitant limitation of physical activity. CONCLUSIONS: Long-term treatment with a silicone stent was safe and well tolerated in cicatricial tracheal stenoses. This procedure can be considered as a bridge to curative surgery or as a definitive treatment. The latter, generally performed for palliation, may provide satisfactory therapeutic results in selected patients, even in the presence of severe circumferential stenoses.

Adolescent↗
PubMed2000

[Central venous access systems in the oncologic patient].

BACKGROUND: A safe and dependable venous access is mandatory in order to perform cancer chemotherapy and monitor blood values in the neoplastic patient. Prolonged infusions of medications with sclerosing action may damage the vessel wall, inducing chemical thrombophlebitis. Furthermore, extravasation of necrotizing compounds may be a danger to the patient. The application of totally implantable venous access systems (VAS) started in 1982, in the United States of America, where at present 500,000 devices are implanted annually. In Italy such method has been introduced in a later period, with a constantly growing trend. VAS devices have evolved since their first presentation, and so have application techniques: the original surgical route has been supported by the percutaneous one, considered most appropriate by several Centers. In this study, personal experience concerning application of VAS in cancer patients is presented. METHODS: From July 1994 to February 1998, at the General Thoracic Surgery Dept. of the University of Perugia, 198 VAS have been implanted in 195 patients. During the first period all the systems have been applied by surgical cutdown of the cephalic vein (150 cases). In the last 12 month the percutaneous technique for vein puncture has been adopted in 48 patients. RESULTS: Immediate and late complications have occurred: among the former, pneumothorax, hematoma, malposition; among the latter, infection, subclavian vein thrombosis, catheter rupture. The results are analysed after an extensive review of the international literature; pros and cons of the different implantation techniques and the technical aspects useful for preventing complications are underlined.

Adult↗
PubMed1998

Resection with curative intent after endoscopic treatment of airway obstruction.

BACKGROUND: Endoscopic treatment of malignant central airway obstructions usually is done for palliation. The exact role of such a procedure as preparatory to operation remains controversial. METHODS: From 1987 through 1996, 24 patients at our institution underwent tracheobronchial pulmonary resection after preliminary endoscopic treatment. During the same period, 304 patients underwent 449 operative rigid bronchoscopies for airway obstructions, most involving the use of a neodymium:yttrium-aluminum-garnet laser. The indications for operation were squamous cell carcinoma in 14 patients, bronchial gland tumors in 8 patients, and papillary thyroid cancer infiltrating the trachea in 2 patients. The total resection rate was 9.5% (5% for squamous cell carcinoma, 75% for low-grade malignant bronchial tumors, and 75% for papillary thyroid cancer). The median period between operative rigid bronchoscopy and operation was 18 days. RESULTS: No complications were observed after endoscopic treatment. There were two perioperative deaths (adult respiratory distress syndrome after carinal resection and pulmonary embolism after pneumonectomy) and one major complication (poor postoperative pulmonary function after pneumonectomy). No anastomotic complications were observed in the tracheobronchoplastic procedures. Follow-up was possible in every patient but 1: 6 patients died at a median of 30.5 months after operation (range, 3 to 46 months), 2 patients are alive with disease, and the rest are alive without evidence of disease at a median of 21 months (range, 2 to 61 months). CONCLUSIONS: Most patients who require endoscopic therapy for malignant airway obstructions are not candidates for operative resection. Preliminary endoscopic relief of obstruction can increase operability and improve surgical results in a highly selected group of patients.

Adult↗
PubMed1996

Bone heterograft for chest wall reconstruction after sternal resection.

BACKGROUND: Experimental and clinical results of chest-wall reconstruction with bone heterograft after sternectomy are reported. METHODS: Seven dogs underwent subtotal or total sternectomy and reconstruction by implantation of a cortico-spongy bone heterograft sandwiched between two layers of a reabsorbable mesh. RESULTS: No major postoperative complications were observed. The implant has shown favorable mechanical and biological properties. Six and 9 months after operation all animals were sacrificed and pathologic examination showed good incorporation of the implanted bone with only partial resorption of its spongiosa. Subsequently, 2 patients underwent sternal resection with different indications and reconstruction was achieved by the technique developed experimentally. No complications were observed. Excellent immediate chest-wall stabilization was obtained, persisting for a follow-up period longer than 6 months. CONCLUSIONS: In comparison with autologous bone, sterile bone heterograft seems to offer the same mechanical properties with a significantly reduced surgical trauma.

Adult↗
PubMed1991

[Picotamide: use in chronic obliterative arteriopathies of the lower limbs].

In the present study the authors evaluated treatment efficiency and patient compliance of medium-term therapy with Picotamide, given in doses of 900 mg/die for the first 15 days, and 600 mg/die up to the completion of a three-month period, to 50 patients affected by vaso-occlusive arterial disease of the lower limbs. At follow-up visits the following controls have been carried out: CW Doppler sonography of the lower limbs, Maximum Walking Distance (M.W.D.), Red blood cell count, White blood cell count, Platelet count, Haemoglobin and Fibrinogen levels. At the end of the three-month therapy period the Ankle-Arm parameters remained unchanged.

Aged↗
PubMedDate not supplied

[Conservative surgery in the treatment of rectal tumors. Our experience, 1986-1997].

OBJECTIVE: Our institution's experience with low anterior resection for primary rectal cancer was reviewed to determine cancer treatment results and to identify risk factors for pelvic recurrence. METHODS: Ninety-two patients treated for primary rectal cancer between 1986 and 1997 were studied retrospectively. All cases was classified according to Astler-Coller. Median follow up was 46 months. RESULTS: Actuarial 5-year survival for all patients was 79%. Among 28 patients who relapsed, only 9 pelvic recurrence was detected with an actuarial rate of 15% at 5 years. Lymph nodes involvement were associated with increased risk for pelvic recurrence. DISCUSSION: Low anterior resection permitted by circular stapler provides good treatment for mid-rectal cancers and for some distal rectal cancers. Pelvic recurrence is not correlated with neoplasm localization, T stage and short distal resection margins, but only with the presence of lymph nodes involvement. This result increase the value of the hypothesis that search the pelvic recurrence origin in a extra-parietal disease respect anastomotic disease. CONCLUSION: Fundamental to prevent pelvic recurrence is the surgical technique that have to remove lymph node en bloc with the rectum doing a dissection along the endopelvic fascia to Denonvillers fascia so to take away completely the mesorectum.

Adenocarcinoma↗
PubMedDate not supplied

[Surgical treatment of thyroid cancer in 243 cases].

The incidence of thyroid cancer, which accounts for 1-2% of all malignancies, constantly increasing. Its management requires an integrated approach, in which the surgeon plays a pivotal role, providing the basis for further treatment. At present, the extent of exeresis, the lymph-node dissection technique and the management of upper respiratory-digestive tract infiltration are still debatable issues. The authors report on their experience with 243 surgically treated thyroid malignancies over the period from January 1986 to December 1999. The operations performed were: total thyroidectomy 226 cases, lobo-isthmectomy 3 cases, total thyroidectomy + lung metastasectomy 1 case, total thyroidectomy + SE quadrantectomy 1 case, total thyroidectomy + monolateral modified neck dissection 30 cases, total thyroidectomy + bilateral modified neck dissection 17 cases, total thyroidectomy + radical neck dissection 1 case, total thyroidectomy + tracheal sleeve resection 5 cases. In 9 cases, extensive tracheal involvement (5.5 cm), age or neoplastic histology allowed only palliative treatment (endoscopic recanalization + tracheal endoprosthesis or tracheostomy. Nd-Yag laser endoscopic recanalization was performed in 2 patients as a preliminary stage in subsegmental radical treatment, and in 5 cases for palliation. Recurrent laryngeal nerve palsy occurred in 3 cases, long-term hoarseness in 2, and hypoparathyroidism in 4. The overall mean hospital stay was 4.8 days. Of 299 patients still alive, 215 are free of disease. Surgery is the treatment of choice, with the goal of completely removing the neoplasm, together with any anatomical structures involved in infiltration (muscles, respiratory-digestive tract, lymph nodes). Satisfactory palliation can be achieved by endoprosthesis deployment or tracheostomy in all cases where surgery is ruled out due to extent of disease, patient age or histological type.

Adult↗