PubMed Health⌕ Search

Biomedical subjects

V Arena

Publications and source records attributed to V Arena.

At least 91 records · Page 5Linked to original sources

Physical properties and gel electrophoresis behavior of R12-derived plasmid DNAs.

A series of closed circular (I) plasmid DNAs has been derived from drug resistance factor R12, and the nicked circular (II) and linear (III) derivatives of these molecules prepared by irradiation in the presence of ethidium bromide and by treatment with restriction enzyme EcoRI, respectively. These DNAs encompass the molecular weight range 3.6 to 61 megadaltons. The base compositions range from 45% to 51% (GC) as estimated by buoyant density determinations. The smaller plasmids are significantly less supercoiled (9-10%) than are the larger (12-13%). The gel electrophoretic behavior of the three DNA structural forms was determined as a function of molecular weight in agarose gels of concentrations ranging from 0.7% to 1.6% and at electrophoresis salt concentrations from 0.02 M to 0.08 M sodium acetate. The mobilities of DNAs I and III undergo a reversal relative to each other at a molecular weight which decreases with increasing agarose gel concentration. The molecular weight at which DNA II fails to enter a gel depends upon the ionic strength during electrophoresis but not upon the gel concentration.

Centrifugation, Density Gradient↗

[Changes in the plasma magnesium content in patients subjected to cardiopulmonary bypass].

Changes in plasma magnesium content in 17 patients operated in extracorporeal circulation are reported. Values were low at the end of the operation, but rose at the end of the first day to achieve spontaneous resolution of the condition within 3 days. No close relationship between such loss and immediate postoperative arrhythmia could be discerned. Attention is, however, drawn to 3 cases in which ventricular fibrillation was not resolved until electric shock treatment was preceded by the administration of magnesium sulphate.

Arrhythmias, Cardiac↗

Radiolabeled localization of the sentinel lymph node: dosimetric evaluation in personnel involved in the procedure.

AIMS AND BACKGROUND: Peritumoral injection of 99mTc-labeled colloids for lymphoscintigraphy and radioguided surgery does not entail any relevant radiation burden to the patients. The real issue about radiation protection concerns the personnel involved in the procedure besides the nuclear medicine personnel. The aim of our study was to evaluate the cumulative doses to personnel involved during the injection of radiolabeled compounds, under ultrasound or stereotactic guidance and the radiation burden to the personnel involved in the surgical incision of the tumor 24 hours after the administration of 99mTc-labeled colloids. METHODS AND STUDY DESIGN: We performed environmental contamination tests (SMEAR TEST) and exposure evaluation in the operating room. RESULTS: In the operating room the removed activity in the analyzed samples was less than 0.5 Bq/g and exposure to the personnel was less than 6 micro Sv/h. The evaluations made during ultrasound guidance demonstrated an equivalent and effective dose less than 20 microSv. CONCLUSIONS: Our results show that during ultrasound or stereotactic administration of radiolabeled compounds the radiation burden to the personnel involved in the procedure is virtually negligible. The surgeons too are exposed to a negligible radiation dose.

Adult↗

Preliminary study of sentinel node identification with 99mTc colloid and blue dye in patients with endometrial cancer.

AIMS AND BACKGROUND: Intraoperative lymphatic mapping and sentinel node (SLN) biopsy have generated a tremendous amount of interest and are already established as part of the standard practice in the surgical management of breast cancer and melanoma. To reduce extensive radical procedures and decrease the morbidity in the treatment of gynecologic malignancies, much effort is being made to use less aggressive interventions. The purpose of our study was to determine the feasibility of SLN mapping in a group of patients with endometrial cancer at early stages. METHOD AND STUDY DESIGN: Between September 2000 and May 2001 11 patients with endometrial cancer FIGO stage Ib (n = 10) and IIa (n = 1) underwent laparoscopic SNL detection during laparoscopy-assisted vaginal hysterectomy with bilateral salpingo-oophorectomy and bilateral systematic pelvic lymphadenectomy. Radioactive isotope injection was performed 24 hours before surgery and blue dye injection was performed just before surgery in the cervix at 3,6, 9 and 12 hours. A 350 mm laparoscopic gamma scintyprobe MR 100 type 11, 99mTc settled (Pol Hi Tech), was used intraoperatively for SLN detection. RESULTS: Seventeen (17) SLNs were detected with lymphoscintigraphy (six bilateral and five unilateral). At laparoscopic surgery we found the same locations belonging at internal iliac lymph nodes (the so-called Lebeuf-Godard area, lateral to the inferior vesical artery, ventral to the origin of the uterine artery and medial or caudal to the external iliac vein). Fourteen (14) SLNs were negative on histological analysis and three were positive for micrometastases (mean SLN sections = 60). All other pelvic lymph nodes were negative at histological analysis. The same SLN locations detected with the gamma scintyprobe were observed at laparoscopy after patent blue dye injection. CONCLUSIONS: Our preliminary data suggest that combined 99mTc-labeled colloid and vital blue-dye techniques are feasible for SLA detection in endometrial cancer; they represent a very promising tool to transform the management of early-stage endometrial cancer. The clinical validity of this combined technique should be evaluated prospectively.

Adult↗

Sentinel node detection in breast carcinoma.

AIMS AND BACKGROUND: The standard procedure for the evaluation of axillary nodal involvement in patients with breast cancer is still complete lymph node dissection. However, about 70% of patients are found to be free of metastatic disease while axillary node dissection may cause significant morbidity. Lymphatic mapping and sentinel lymph node (SLN) biopsy are changing this situation. METHODS AND STUDY DESIGN: In a period of 18 months we studied 201 patients with breast cancer, excluding patients with palpable axillary nodes, tumors > 2.5 cm in diameter, multifocal or multicentric cancer, pregnant patients and patients over 80 years of age. Before surgery 99mTc-labeled colloid and vital blue dye were injected into the breast to identify the SLN. In lymph nodes dissected during surgery the metastatic status was examined by sections at reduced intervals. Only patients with SLNs that were histologically positive for metastases underwent axillary dissection. RESULTS: We localized one or more SLNs in 194 of 201 (96.5%) patients; when both techniques were utilized the success rate was 100%. Histologically, 21% of patient showed SLN metastases (7.8% micrometastases) and 68% of these had metastases also in other axillary nodes. None of the patients with negative SLNs developed metastases during follow-up. CONCLUSIONS: At present there is no definite evidence that negative SLN biopsy is invariably correlated with negative axillary status; however, our study and those of others demonstrate that SLN biopsy is an accurate method of axillary staging.

Aged↗

[Chronic HCV hepatopathy and cryoglobulinemia. The associated clinical spectrum].

BACKGROUND AND AIM: The hepatitis C infection (HCV) has numerous extrahepatic manifestations owing to the systemic nature of the infection itself. HCV infects the cells that carry a CD 81 receptor and show a marked tropism for hepatocytes, bone marrow staminal cells and circulating lymphomonocytes. One consequence of this tropism is the activation of B lymphocyte clones with the consequent production of autoantibodies and cryoglobulins. The secondary event is the formation of circulating immune complexes which, having precipitated at an intravascular level, may cause part of the extrahepatic manifestations associated with these infections. METHODS: This retrospective study evaluated the manifestations correlated and/or associated with HCV hepatitis and mixed cryoglobulinaemia. RESULTS: This analysis showed that 75% of consecutively studied patients reveal clinically important extrahepatic manifestations. CONCLUSIONS: This underlines the "broad spectrum" action played by the hepatitis C virus in the host organism.

Adult↗

[Fetal pseudohypoaldosteronism: a rare cause of hydramnios].

PHA is a rare cause of hydramnios, characterized by increased amniotic fluid levels of aldosterone and sodium. Two distinct genetic entities (PHA type I and PHA type II) are included. Both are stemmed by a target organ defect with diminished renal tubular responsiveness to aldosterone. The AA present a case in which pregnancy resulted in a preterm infant with severe hydramnios, metabolic acidosis, hyponatriemia, hyperkaliemia. Salt and fluid replacement significantly improved clinical and metabolic condition. However a growth deficiency (-2 SDS) persists at follow-up.

Female↗

[Fetal pseudohypoaldosteronism: rare cause of hydramnios].

PHA is a rare cause of hydramnios, characterized by increased amniotic fluid levels of aldosterone and sodium. Two distinct genetic entities (PHA type I and PHA type II) are included. Both are stemmed by a target organ defect with diminished renal tubular responsiveness to aldosterone. The AA present a case in which pregnancy resulted in a preterm infant with severe hydramnios, metabolic acidosis, hyponatriemia, hyperkaliemia. Salt and fluid replacement significantly improved clinical and metabolic condition. However a growth deficiency (-2 SDS) persists at follow-up.

Adult↗

Surgical treatment of subvalvular aortic stenosis. Long-term results.

From 1966 till May 1988, 53 patients underwent surgery for fixed subaortic stenosis. Subvalvular obstruction was isolated in 27 patients (Group I) and associated with aortic valve lesions in 26 (Group II). A membranous stricture was documented in 5 patients and a fibromuscular ring in 48. Excision of the ring and myectomy were performed in all patients, and an associated aortic valve replacement or reconstruction in 7 and 4 patients respectively. There were no hospital deaths. Follow-up evaluation in 50 patients ranged from 6 months to 22 years. Eight patients had to be reoperated upon (1 from group I, 7 from group II): aorto-ventriculoplasty was performed in 3, aortic valve replacement with redo myectomy in 3 and mitro-aortic valve replacement in 2. One of them had 2 reoperations. Functional status at the time of the last outpatient visit was most satisfactory. Continued evaluation remains necessary as obstruction may reappear despite the absence of symptoms.

Adolescent↗

[Treatment of esophageal achalasia].

4 cases of oesophageal achalasia, 2 primary and 2 recurrences following multiple oesophagomyotomy are reported. The superiority of oesophagomyotomy carried out by the left transthoracic route (according to Ellis) in cases of primary achalasia is stressed. On the basis of the literature and reported experience, it is concluded that this approach is also preferable in recurrences when the previous operation was done by the abdominal route and the recurrence occurred within 6 months. In all other cases, particularly in the presence of an achalasic megaoesophagus, partial oesophagogastric resection with interposition of a jejunal loop (Merendino's operation) is the procedure of choice and the satisfactory results of using it are reported.

Adult↗