Improving dose delivery accuracy with EPID in vivo dosimetry: results from a multicenter study.

PURPOSE: To investigate critical aspects and effectiveness of in vivo dosimetry (IVD) tests obtained by an electronic portal imaging device (EPID) in a multicenter and multisystem context. MATERIALS AND METHODS: Eight centers with three commercial systems-SoftDiso (SD, Best Medical Italy, Chianciano, Italy), Dosimetry Check (DC, Math Resolution, LCC), and PerFRACTION (PF, Sun Nuclear Corporation, SNC, Melbourne, FL)-collected IVD results for a total of 2002 patients and 32,276 tests. Data are summarized for IVD software, radiotherapy technique, and anatomical site. Every center reported the number of patients and tests analyzed, and the percentage of tests outside of the tolerance level (OTL%). OTL% was categorized as being due to incorrect patient setup, incorrect use of immobilization devices, incorrect dose computation, anatomical variations, and unknown causes. RESULTS: The three systems use different approaches and customized alert indices, based on local protocols. For Volumetric Modulated Arc Therapy (VMAT) treatments OTL% mean values were up to 8.9% for SD, 18.0% for DC, and 16.0% for PF. Errors due to "anatomical variations" for head and neck were up to 9.0% for SD and DC and 8.0% for PF systems, while for abdomen and pelvis/prostate treatments were up to 9%, 17.0%, and 9.0% for SD, DC, and PF, respectively. The comparison among techniques gave 3% for Stereotactic Body Radiation Therapy, 7.0% (range 4.7-8.9%) for VMAT, 10.4% (range 7.0-12.2%) for Intensity Modulated Radiation Therapy, and 13.2% (range 8.8-21.0%) for 3D Conformal Radiation Therapy. CONCLUSION: The results obtained with different IVD software and among centers were consistent and showed an acceptable homogeneity. EPID IVD was effective in intercepting important errors.

Anatomy of the flexor retinaculum of the wrist and the flexor carpi radialis tunnel.

The flexor retinaculum forms a retinacular bridge over the carpal tunnel extending from ulnar to radial direction. Its main function is to protect the contained without a significant mechanical action in supporting the transverse carpal arch. The osteofibrous tunnel of flexor carpi radialis is independent and presents four sections. The palmaris longus tendon presents a distal insertion forming the superficial layer of the aponeurosis palmaris. The flexor carpi ulnaris tendon has four distal insertions.

[Pseudoaneurysm in pancreatic pseudocysts. Report of a clinical case]. / Pseudoaneurisma in pseudocisti del pancreas. Descrizione di un caso clinico.

Pancreatitis in a percentage of 1.5% in a pseudocyst, 10% of which are represented as formations of the pseudoaneurysmatic type one of the visceral artery. The authors of the following study present the case of an 86 year old woman with positive anamnesis because of a chronic pancreatitis, who is affected by a symptomatology in the epigastric regione together with hematemesis and melena. An ecography shows at the head level a mass of cm 6.5 hypo ecogena, delimitated by a hyper ecogena band. A TAC, with and without contrast means and integrated by some RM and angio-RM sequences, shows that it is a vascular injury, with the characteristic area on enhancement after the infusion of the contrast means. The patients goes under surgical intervention, showing a trough supplied by a branch of the hepatic artery. The intervention is performed with the tying of the artery, with the drainage of the residual cavity plus the creation of a pancreatic, cystic and jejunum derivation.

[AIDS and pregnancy: clinical and medicolegal reflections]. / AIDS e gravidanza: riflessioni cliniche e medico-legali.

The authors discuss the various medicolegal aspects concerning the management of pregnancy in women with AIDS. They report the most recent data on the epidemiology and perinatal transmission of the disease. The effects of pregnancy on the evolution of disease as well as the effects of the disease on the evolution of pregnancy are discussed. A distinction is drawn between the progress of pregnancy in seropositive women and the progress of pregnancy in seronegative women. Lastly, the authors raise a number of questions of a medicolegal nature in the light of the legislation currently in force in Italy.

Singlet oxygen induced mutation spectrum in mammalian cells.

In order to characterize the molecular nature of singlet oxygen (1O2) induced mutations in mammalian cells, a SV40-based shuttle vector (pi SVPC13) was treated with singlet oxygen arising from the thermal decomposition of the water-soluble endoperoxide of 3,3'-(1,4-naphthylidene) dipropionate (NDPO2). After the passage of damaged plasmid through monkey COS7 cells, the vector was shuffled into E. coli cells, allowing the screening of supF mutants. The mutation spectrum analysis shows that single and multiple base substitutions arose in 82.5% of the mutants, the others being rearrangements. The distribution of mutations within the supF gene is not random and some hotspots are evident. Most of the point mutations (98.4%) involve G:C base pairs and G:C to T:A transversion was the most frequent mutation (50.8%), followed by G:C to C:G transversion (32.8%). These results indicate that mutagenesis in mammalian cells, mediated by 1O2-induced DNA damage, is targeted selectively at guanine residues.

A rare complication of mitral valve replacement. Intraoperative fracture of the right fibrous trigone following a superior approach to the left atrium. Case report.

A rare complication of mitral valve replacement is reported. Following a superior approach, through the roof of the left atrium the mitral valve was replaced with a Björk-Shiley prosthesis in a 52-year-old female, who had undergone previous closed commissurotomy. Fracture of the right fibrous trigone occurred at surgery, following the completion of mitral valve replacement. The lesion was successfully repaired on cardiopulmonary bypass under cardioplegic arrest, placing sutures, after an oblique aortotomy, from below the noncoronary aortic cusp. The postoperative course was uneventful, without occurrence of a-v block. We believe that a superior approach to the left atrium may be a valid alternative for mitral valve surgery in some selected cases.

In vitro action of some disinfectants on Paracoccidioides brasiliensis yeast forms

Descreveu-se a acao fungicida do hipoclorito de sodio (0,3; 1; 2,5; 5 e 10 por cento); do formaldeido (em solucao aquosa a 2,5 e 10 por cento); e alcool etilico a 70,0 por cento sobre formas leveduriformes de 2 cepas de Paraccoccidioides brasiliensis: Pb 18 e cepa Goiana, recentemente isolada. A incubacao do fungo e desinfetantes foi realizada a temperatura ambiente por periodos de 1, 2, 24, 48 e 72 horas. A viabilidade foi avaliada pelo tratamento com diacetato de fluoresceina-brometo de etideo; pela cultura em meios solidos e liquidos a 36 graus Celsius e 26 graus Celsius; transformacao de levedura em micelio a temperatura ambiente; e estudo radiometrico da atividade metabolica. Todas as concentracoes de todos os desinfetantes estudados foram capazes de inativar ambas as cepas, exceto na incubacao com formaldeido a 2 por cento por 1 hora, em que o tratamento por diacetato de fluoresceina-brometo de etideo revelou 40 por cento e 27 por cento de celulas viaveis, respectivamente, para a cepa Pb 18 e Goiana. A transformacao de levedura em micelio foi considerada um metodo rapido, com resultados semelhantes ao cultivo em meios solidos e liquidos.

In vitro action of some disinfectants on Paracoccidioides brasiliensis yeast forms.

The fungicidal action of sodium hypochlorite (0.3, 1, 2.5, 5 and 10%); formaldehyde (2, 5, and 10%); and ethyl alcohol (70%) on yeast forms of Paracoccidioides brasiliensis Pb 18 and a newly-isolated Goiana strain was described. Contact between the fungus and the disinfectants was maintained for 1, 2, 24, 48 and 72 hours at room temperature. Viability was evaluated by the fluorescein diacetate-ethidium bromide treatment, culture in solid and liquid media (36 degrees C and 26 degrees C); yeast to mycelial germination at room temperature; and radiometric study of metabolic activity. All concentrations of disinfectants were found to be effective in inactivating Pb 18 and Goiana strains, except for the 1-hour contact with 2% formaldehyde, in which fluorescein diacetate-ethidium bromide treatment was found to reveal 40 and 27% of viable cells, respectively. The yeast to mycelial germination method was considered to reveal faster and similar results as compared to culture in solid and liquid media.

Singlet molecular oxygen induced mutagenicity in a mammalian SV40-based shuttle vector.

We have determined the deleterious effects of singlet oxygen (1O2), generated by thermal decomposition of the water-soluble endoperoxide 3,3'-(1,4-naphthylidene)dipropionate (NDPO2), on plasmid DNA. By following the electrophoretic mobility of DNA on agarose gels, we detected single and double strand breaks induced by treatment with NDPO2. The vector employed was a mammalian shuttle vector and the mutagenic consequences of these damages were investigated, using as mutation target the supF suppressor tRNA gene. A high increase of the mutation frequency, over the background, was observed in plasmids transfected in bacteria or after passage through mammalian cells. Trapping agents and quencher effects and other controls confirm the involvement of 1O2 in DNA damage and mutagenicity. These findings indicate that 1O2 can induce DNA lesions which are repaired by an error-prone process in prokaryotic and eukaryotic cells.

[Mitral valve replacement with the Björk-Shiley monostrut prosthesis: a 4-year clinical experience]. / Sostituzione valvolare mitralica con la protesi Björk-Shiley monostrut. Esperienza clinica di 4 anni.

Mitral valve replacement with Björk-Shiley monostrut prostheses was performed in 142 patients, aged 18 to 73 (mean age: 53.8). A group of 101 patients underwent isolated mitral replacement (group A), while both mitral and aortic (in one case tricuspid) valves were replaced in 41 (group B). In 19 of group A patients and in 9 of group B patients a tricuspid annuloplasty was added. Hospital mortality was one case in each group (group A: 1%; group B:2.4%). The cause of death was low output in both cases (i.e. not valve-related). Late mortality occurred in 4 cases (4%) in group A, and in 3 cases (7.3%) in group B (follow-up: 6 to 58 months; mean follow-up: 24 months). Actuarial survival was 93.79% in group A and 89.94% in group B one year after surgery; it was 93.79% in group A and 81.76% in group B after 3 years. All deaths from undetermined causes, as well as any new unexplained neurological deficit or peripheral emboli, were considered to be valve-related: 84.18% of group A patients, as well as 67.90% of group B, were event free after 3 year (actuarial). most valve-related events occurred in the first year after surgery. We observed thromboembolism in 3 cases for each group: one patient in group B had pannus formation over the prosthetic annulus; prosthetic valve endocarditis in 1 case of group A and 2 of group B; significant hemorrhage due to anticoagulant therapy in 1 (group A); one patient in each group died suddenly, 4 and 7 months postoperatively. One group A patient and 2 group B patients were reoperated: a new valve prosthesis was implanted in two patients. Mean transvalvular gradient, as determined by echocardiography, was 3.8 +/- 2.3 (SD) mmHg in the case of isolated mitral replacement. In conclusion, we believe these results are highly encouraging, especially in the isolated mitral replacement group. Björk-Shiley monostrut prosthesis has been demonstrated to be a reliable valve substitute, with an acceptable incidence of complications. No Björk-Shiley monostrut prosthesis structural deterioration was seen, and its hemodynamic behaviour may be considered satisfactory.

[Compliance problems in the oral anticoagulant treatment of patients wearing heart valve prostheses]. / Problemi di "compliance" nel trattamento anticoagulante orale dei portatori di protesi valvolari cardiache.

The need for and the efficacy of oral anticoagulation in patients who have undergone prosthetic valve replacement is widely demonstrated. The aim of this study is to assess how dicumarolic treatment is understood and actually accomplished by patients. A 30-question form was sent to 292 patients discharged following valve replacement, 5 to 45 months (mean: 19 months) after surgery. All of the 220 patients who submitted their answers, were effectively on oral anticoagulants. More than 95% of them knew exactly the suggested optimal prothrombin activity range. About one fifth of the patients has laboratory tests performed weekly, and nearly one half does so every 10-15 days. One fourth of the patients does not consult a physician for decision making about drug dosage. Difficulties in maintaining anticoagulation in the desired range, occurring at least once every month, are reported by 18.6% of patients. Haemorrhage was never experienced by 83.18%; in one single case thromboembolism was apparent. A few patients (2.27%) think of oral anticoagulation as a "difficult" treatment. We conclude that complete information is needed, about the aim, the modality, and the potential hazard of oral anticoagulation, so that a better understanding of the treatment and an improved cooperation between physicians and patients can result in benefits, in terms of the safety and efficacy of life-long antithrombotic therapy.