Water disinfection by orifice-induced hydrodynamic cavitation.

Hydrodynamic Cavitation (HC) is considered as a promising water-disinfection technique. Due to the enormous complexity of the physical and chemical processes at play, research on HC reactors is usually carried out following an empirical approach. Surprisingly, past experimental studies have never been designed on dimensional-analysis principles, which makes it difficult to identify the key processes controlling the problem, isolate their effects and scale up the results from laboratory to full-scale scenarios. The present paper overcomes this issue and applies the principles of dimensional analysis to identify the major non-dimensional parameters controlling disinfection efficacy in classical HC reactors, namely orifice plates. On the basis of this analysis, it presents results from a new set of experiments, which were designed to isolate mainly the effects of the so-called cavitation number (σv). Experimental data confirm that the disinfection efficacy of orifice plates increases with decreasing σv. Finally, in order to discuss the significance of the results presented herein and frame the scope of future research, the present paper provides an overview of the drawbacks associated with dimensional analysis within the context of HC.

The sensibility and specificity of cerebral oximetry, measured by INVOS - 4100, in patients undergoing carotid endarterectomy compared with awake testing.

BACKGROUND: Selective shunting during carotid endarterectomy (CEA) is advocated to reduce shunt-related stroke. Cerebral monitoring is essential for temporary carotid shunting. Many techniques are available for cerebral monitoring; however, none is superior to monitoring the patient's neurological status (awake testing) while performing the procedure under local anesthesia (LA). Cerebral oximetry (CO) has previously been used to show the adequacy of cerebral circulation in patients undergoing CEA. This investigation was designed to compare the performance of the INVOS-4100 cerebral oximeter and the neurologic functions, by means of detecting cerebral ischemia induced by carotid cross-clamping, in patients undergoing CEA under LA, namely cervical plexus block. METHODS: Patients scheduled for CEA under LA were included. Patients converted to general anesthesia (GA) or other types of operations other than CEA were excluded from this study. We enrolled 100 consecutive patients from January 2009 to December 2010. Bilateral regional cerebrovascular oxygen saturation (rSO(2)) was monitored in all patients, in addition to the awake testing. Changes in rSO(2) following carotid artery clamping were recorded. A drop greater than 20% was considered as an indicator of cerebral ischemia that might predict the need for carotid shunting. Patients were only shunted based on the awake testing. RESULTS: Of the 100 patients undergoing CEA under LA, 9 showed a significant drop in rSO(2) (range: 22.6-32.8%, mean: 26.4%): only three of them required shunting, while the remaining 6 had no changes in consciousness after internal carotid artery (ICA) cross-clamping and it was not necessary to place a shunt (false positive). Compared to the preclamping values, a significant decrease in rSO(2) was found on the hemisphere of the operated side, while no significant change was observed contralaterally. Ninety-one patients had no significant changes of CO values: in 89 of them there was no consciousness deterioration, so we didn't place a shunt (true negative), but 2 patients showing a non-significant post-clamping decline in CO saturation (1.5% and 18.2%) required shunting based on the awake testing (2 false negative). In the current study, the median drop in rSO(2) was 19% (range: 1.5-26.4%) in the 5 patients that required shunting. This represents a sensitivity of 60% and a specificity of 25% for CO in comparison to the awake testing. CONCLUSION: The results of this study suggest that the usefulness of CO in predicting cerebral ischemia is modest. Cerebral monitoring with INVOS-4100 has a high negative predictive value, but the positive predictive value is low.

Endovascular repair of aortic rupture due to Brucella aortitis.

Brucellosis is a zoonosis, caused by bacteria belonging to the genus Brucella. Aortic involvement is a rare complication, often following embolization from infective endocarditis. However, contiguous propagation from vertebral involvement may occur. We report the case of an 81 year old patient abruptly presenting with aortic rupture due to Brucella melitensis infection. The diagnosis of aortic rupture was made by CT. The patient underwent urgent endovascular treatment using endoprosthesis deployment in the abdominal aorta and iliac arteries. Long term antibiotic treatment was given. Resolution of the acute event was obtained without further surgical treatment. 18 months after endovascular treatment, the patient remains in good health.

Early and one-year results of infrainguinal bypass after failure of endovascular therapy.

AIM: The aim of this study was to retrospectively compare early and one-year results of open surgery (OS) for critical limb ischemia (CLI) in patients who underwent primary surgery and in patients operated after a previous failure of endovascular treatment (EV). METHODS: Between January 2004 and December 2007, 460 patients (304 males, 156 females) aged between 46 and 95 (average age 72) underwent OS or EV for CLI. We performed 273 EV (47%) and 307 OS (53%) procedures. In 98 patients (21.3%) the procedures were bilateral. EV procedures were intraluminal, subintimal or both, with selective stenting. OS procedures were distal bypass grafts. OS involved 34 dialysed patients, 159 patients with CLI non-dialysed and not previously submitted to EV treatment (group 1, control group) and 114 patients with failure of previous EV treatment (group 2), frequently performed in different and non surgical centers, 8% of EV failure in our series in this time. We retrospectively compared the early and one-year results in the last two groups of patients in terms of level of revascularization, primary patency, amputation and mortality. RESULTS: By-pass grafts were autologous vein in 94% and PTFE in 6%. Revascularizations have been directed to the tibial or to the plantar arteries at the ankle or foot. Those directed to the plantars were respectively 54% (52% dorsalis pedis, 36% retromalleolar posterior tibial, 12% medial plantar artery) in the control group and 76% (66% dorsalis pedis, 18% retromalleolar posterior tibial, 16% medial plantar artery) in patients with previous failed PTA (P<0.001). Early primary patency, mortality and amputation free survival were respectively in the control group and in patients with previous failure of PTA: 93.7% vs. 76.3% (P<0.001), 2.5% vs. 3.5% (P>0.5), 95% vs. 93% (P>0.5). One-year primary patency, mortality and amputation free survival were respectively in the control group and patients with previous failure of PTA: 86.03% vs. 70.87% (P>0.25), 14.93% vs. 17.56% (P>0.5), 78.1% vs. 68.5% (P>0.1). CONCLUSION: After failure of EV therapy, the subsequent open surgery was more distal and technically demanding. Its results were significantly worse when compared with standard CLI patients, with an increase rate of redo. Our data suggest that EV should not be attempted as the first choice in every patient affected by CLI, and we believe that OS still is the primary treatment for the most advanced clinical situations.

A novel frame-shift deletion causing analbuminaemia in an Italian paediatric patient.

BACKGROUND: Analbuminaemia (OMIM #103600) is a rare autosomal recessive disorder manifested by the absence or severe reduction of circulating serum albumin in homozygous or compound heterozygous subjects. The trait is caused by a variety of mutations within the albumin gene. DESIGN: We report here the clinical and molecular characterization of a new case of congenital analbuminaemia in a 4-year-old Italian girl diagnosed on the basis of the low level of circulating albumin (= 10.0 g L(-1)). The albumin gene was screened by single-strand conformation polymorphism and heteroduplex analysis and the mutated region submitted to DNA sequencing. RESULTS: The proband was found to be homozygous, and both parents heterozygous, for a novel deletion in exon 8 (c.920delT). The subsequent frame-shift should have given rise to a putative polypeptide chain of 304 amino acid residues, which we could not identify in the proband's serum. CONCLUSIONS: A novel analbuminaemia causing mutation was identified and characterized at the clinical level in a child. The molecular diagnosis of the trait is based on the rapid localization of the mutation within the albumin gene by single-strand conformation polymorphism and heteroduplex analysis, followed by DNA sequencing of the mutated region.

Bypass surgery for the treatment of upper limb chronic ischaemia.

OBJECTIVES: This study aims to evaluate the results and complications of surgical arterial revascularisation of the upper limb for treatment of chronic ischaemia using infrabrachial bypass. Results of limb salvage and follow-up with graft patency are analysed. DESIGN: This study is a retrospective analysis of 23 patients affected by chronic upper limb ischaemia and treated by surgical bypass. MATERIALS AND METHODS: We retrospectively analysed 23 patients with upper limb ischaemia treated between January 1998 and January 2008, by means of bypass graft revascularisation. After surgical revascularisation, eight patients (35%) with digital gangrene underwent minor amputations during the same surgical session, or within the following few days. Postoperatively, patients were followed up at regular intervals of 1, 3 and 6 months, and every 6 months thereafter, both clinically and with a duplex ultrasound scan. RESULTS: The mean 34 months' follow-up was 96% complete. Life table analysis revealed a primary patency of 82.6% and secondary patency of 91.3%. Limb salvage was 100%. During the follow-up period, four patients sustained graft occlusion and, of these, two underwent re-do revascularisation with success. CONCLUSIONS: We believe upper limb bypass surgery represents a valid treatment in this clinical setting, both for limb salvage and for relief of symptoms.

[The role of laparoscopic surgery in the treatment of occlusive and abdominal aortic aneurys. Review of the literature]. / Il ruolo della chirurgia laparoscopica nella patologia aneurismatica e occlusiva dell'aorta addominale. Revisione della letteratura.

UNLABELLED: The objective of this systematic review of the literature is to evaluate whether a laparoscopic operation can be performed on patients with occlusive or abdominal aortic aneurysm as a minimally invasive and durable alternative. For this purpose, the literature was reviewed and laparoscopic surgery results were compared with those of conventional and endovascular surgery. All series were included, even when containing also one case. Operative and clamping times, mortality and morbidity and hospital stay were evaluated. Thirty-five studies were identified about conventional (4), minilaparotomy (4), endovascular (4), total (12) and video-assisted (11) laparoscopic surgery. Operative and clamping times were shorter for video-assisted procedures than total-laparoscopic procedures. The mortality rate ranged from 3% to 4.5% for conventional surgery, from 0% to 3% for endovascular surgery, from 0% to 6% for total-laparoscopic surgery and from 0% to 4.2% for video-assisted laparoscopic surgery. A variable morbidity was described for all techniques, with a higher incidence in total-laparoscopic surgery. Mean hospital stay was similar for laparoscopic surgery procedures. The learning curve of a surgical team performing laparoscopic surgery improves the RESULTS: Laparoscopic abdominal aortic surgery is feasible and may offer good postoperative recovery with excellent mid-term patency. Shorter hospital stay and simple mid-term follow-up allow more comfort for the patient and probably monetary savings for the community. A steep learning curve is needed. For these reasons laparoscopic video-assisted technique can be considered a third means of treating severe occlusive and aortic aneurysm, but only new instruments for performing aortoprosthetic anastomoses can diffuse the total laparoscopic technique as a routine approach.

Endovascular repair in atypical traumatic rupture of thoracic aorta.

INTRODUCTION: The traumatic rupture of thoracic aorta is a surgical emergency with high risk of morbidity and mortality. CASE REPORT: We describe the case of an atypical rupture of retro-cardiac thoracic aorta with dissection of brachiocephalic trunk and spleen trauma occurred after a road accident. TC scan and perioperative angiography showed an atypical rupture of thoracic aorta. CONCLUSION: A combined treatment, endovascular for retro-cardiac thoracic aorta and surgical for brachiocephalic artery, has been useful to diminish the hemodynamic and organ ischemic problems associated with open surgery.

Surgical treatment of tumors involving the inferior vena cava. Personal experience.

AIM: Leiomyosarcoma of the inferior vena cava (IVC) is a rare tumor that frequently produces non-specific symptoms. Surgical treatment is complex. In this review of our experience, we highlight replacement modalities of the vena cava or other vessels after complete tumor resection. METHODS: During the last 20 years, we treated 12 patients (6 women and 6 men; age range, 38-72 years) with IVC leiomyosarcoma, all apparently free of distant metastases. Tumor location, graft patency, long-term survival and tumor recurrence were recorded. The tumor arose from the IVC in 8 patients; in 2 cases the intracaval mass reached the right atrium; in 4 patients the tumor arose from the femoroiliac axis. Surgical approach was by sternolaparotomy in 5 cases and by median xyphopubic access in 7. Extracorporeal circulation (ECC) was needed in 2 cases. All tumors were removed by en bloc resection. The IVC was directly sutured in 2 patients and patched in 4; no reconstruction was necessary in 2 patients; the IVC was replaced in the remaining cases. Four patients had an additional arteriovenous fistula. One patient underwent bifurcated Dacron graft replacement of the aortic carrefour involved by tumor. RESULTS: Two patients died postoperatively. One patient developed late stenosis of the polytetrafluoroethylene (PTFE) graft, which was treated by stenting. The mean follow-up period was 35 months. The 4-year survival rate was 51% and survival free of recurrence was 63%. CONCLUSION: Leiomyosarcoma of the IVC is an uncommon tumor that produces non-specific symptoms. In the absence of distant malignancy, an aggressive approach can obtain late survival free of recurrence.

[The chronic renal failure epidemic: an underestimated public health problem]. / L'epidemia d'insufficienza renale cronica. Un sottovalutato problema sanitario di prima grandezza.

Renal failure is considered a rare disease. However, recent epidemiological surveys like the NHANES III survey in the USA have shown that mild and moderate renal insufficiency is much more common: 31% and 4% of Americans, respectively, are affected by a mild or moderate degree of renal insufficiency. Such an epidemic is of particular concern because of the high cardiovascular risk brought about by kidney failure. Renal insufficiency is now considered a public health priority. Together with diabetes and smoking, the metabolic syndrome is the principal factor responsible for this epidemic. The prevalence of chronic renal insufficiency is in fact strictly proportional to the number of components of the metabolic syndrome being present in individual patients. As renal function deteriorates, other risk factors come into play like those peculiar to renal insufficiency (anemia, hyperparathyroidism) and some so-called emerging risk factors (inflammation, hyperhomocysteinemia and high plasma levels of endogenous inhibitors of NO synthase such as asymmetric dimethylarginine).

Podocin-related mechanisms in posttransplant [corrected] recurrence of focal segmental glomerulosclerosis [corrected].

Posttransplantation recurrence of focal segmental glomerulosclerosis (FSGS) is one of the most disarming events in human pathology with important social and psychological consequences. It usually occurs in 30% to 50% of patients affected by the primary form of the disease with an abrupt onset in the majority of cases occurring within 1 month of the transplantation. Prediction of recurrent cases and early therapy with plasmapheresis are the main goals of the therapy. Although the mechanism of posttransplantation recurrence is still obscure, it has been proposed to be of a multifactorial origin, in which plasma factors determine the shedding of proteins of the slit-diaphragm, such as nephrin and podocin, with structural alterations of the ultra-filtering unit of the glomerulus. Low resynthesis of podocin and/or haplo-insufficiency due to heterozygous mutations should represent significant predisposing factors to proteinuria. In this review, the role of podocin in posttransplantation recurrence will be evaluated focusing on the possibility that resynthesis of the protein could represent a key step also for stable normalization of the renal filter. The recent characterization of the podocin promoter cis- and trans- acting elements and the possibility to characterize low- and high-podocin producer haplotypes offer opportunities to evaluate the capacity for podocin resynthesis in the donor kidney. A review of the literature on posttransplantation recurrence of FSGS in patients originally carrying homozygous and/or heterozygous NPHS2 mutations supports the general idea of a multifactorial origin of the primary disease that can be extended to the pathogenesis of posttransplantation recurrence.

Nephronophthisis type 1 deletion syndrome with neurological symptoms: prevalence and significance of the association.

Type 1 nephronophthisis (NPHP) with homozygous deletions of nephrocystin [NPHP1, DEL] has been considered a pure renal disorder, but co-occurrence of extrarenal symptoms, mainly retinitis pigmentosa, is observed in a subset of patients. Recently, [NPHP1, DEL] has been detected in three patients with Joubert syndrome-related disorders (JSRDs), who associated neurological signs with a peculiar neuroradiological malformation known as the 'molar tooth sign' (MTS). To define the frequency of JSRD spectrum in NPHP1 patients, we re-examined 56 cases with [NPHP1, DEL] and found an overall incidence of 8.9% (five out 56 patients). All had small hyperechoic kidneys and had developed advanced renal failure within 15 years. Two patients presented the complete features of JSRD with cerebello-renal-retinal association and MTS. Two others showed, instead, severe intentional tremor and thick superior cerebellar peduncles on brain magnetic resonance imaging (MRI), and one of them had associated retinopathy. The fifth patient presented with hypotonia, developmental delay, central deafness, and ataxia associated with Leber congenital amaurosis and liver fibrosis but with normal brain MRI. Marked intrafamilial variability of associated extrarenal symptoms was observed in familial cases. Deletion extension did not differ in patients with isolated renal phenotype and in those with associated neurological symptoms. In conclusion, neurological defects varying from subtle involvement of cerebellum with thickened peduncle to both JSRD and diffuse central hypotonia are frequent in [NPHP1, DEL] patients. Prevalence of such association may justify systematic neurological and neuroradiological evaluation.

Cis and trans regulatory elements in NPHS2 promoter: implications in proteinuria and progression of renal diseases.

Podocin (NPHS2) expression in podocytes is associated with variable degrees of proteinuria and progression to renal failure in different glomerular diseases that suggests different expression profiles in NPHS2 promoter. Three functional polymorphisms in NPHS2 promoter (-51T, -116T, and -535 insCTTTTTT(3)) were found determining strong downregulation (-73, -59, and -82%, respectively) of the reporter gene expression when transfected in podocytes. Electrophoretic mobility shift assay experiments showed that all wild-type variants (-51G, -116C, and -535 insCTTTTTT(2)) formed specific DNA-protein complexes with podocyte nuclear extracts that were abolished by the presence of the rare forms (-51T, -116T, and -535 insCTTTTTT(3)). In the case of -51G, upstream stimulatory factor-1 (USF1) was identified as the specific trans element in accord to binding inhibition experiments and USF1 RNAi silencing. Haplotype analysis of 204 normal controls and 545 patients with renal diseases (308 immunoglobulin (Ig)A nephropathy and 237 focal segmental glomerulosclerosis) evidenced that -116/-51 and -535/P2OL formed two blocks in strong linkage disequilibrium in both normal and pathological cohorts. The high NPHS2 promoter profile -116C/-51G haplotype was more frequent in patients with IgA nephropathy (P-value=0.005) and was associated with a better clinical outcome in terms of proteinuria and creatinine levels. Overall our study describes functional variants of NPHS2 promoter and characterizes trans-acting elements that modulate podocin expression in the kidney. High producer NPHS2 promoter haplotypes seem protective in patients with chronic glomerular diseases.

Posttransplant recurrence of proteinuria in a case of focal segmental glomerulosclerosis associated with WT1 mutation.

Posttransplant recurrence of inherited focal segmental glomerulosclerosis (FSGS) is still an enigma owing to the evident paradox of the molecular origin of proteinuria. A young girl with FSGS for WT1 mutation (IVS9+4C>T) and Frasier syndrome received a renal transplant at the age of 11 years. After an initial good outcome with recovery of renal function, proteinuria re-appeared after 7 days and steadily increased up to a nephrotic range. Determination of plasma permeability activity showed concomitant high Palb (0.7). At this point, plasmapheresis was started and after nine cycles with 1500 mL exchange and albumin re-infusion, proteinuria decreased to normal range and is still normal after 3 years. This is the first description of posttransplant recurrence of proteinuria in Frasier syndrome that should be included in potential outcome of renal transplant in this category of patients. This observation confirms the concept that recurrence of proteinuria may occur in inherited forms of FSGS so far reported only for patients carrying NPHS2 mutations and reinforces the idea on multifactorial origin of the disease.

[Oscillometric wrist devices: comparison with the standard mercury sphygmomanometer and estimate of the "supine" error]. / La misura oscillometrica della pressione al polso: confronto con il metodo sfigmomanometrico classico e valutazione dell'errore di posizione del polso col paziente supino.

Before introducing a wrist device (NAIS-Matsushita) for blood pressure (BP) measurement in our Unit, we formally tested its validity. Since the wrist position is critical and BP in the clinical setting is often measured with patients lying in bed, we also estimated the error introduced by allowing the wrist to lay flat at the bed level. Ten normal subjects and 20 hypertensive patients took part in two consecutive studies. In the first study the subjects were sitting and the blood pressure was simultaneously taken with the auscultatory mercury sphygmomanometer on the left arm and with the NAIS on the right wrist. The wrist was kept at the heart level. In the second study two NAIS devices were used with the subjects lying in bed; the left wrist was allowed to stay at the bed level, while the right one was kept at the heart level. The diastolic BP was consistently underestimated (P< 0.001) by the wrist device (79 mmHg 95%CI: 75-83) as compared to the values obtained with the standard mercury sphygmomanometer (85 CI: 79-88). No significant difference was found in systolic BP (mercury: 135 CI: 127-143; wrist 134 CI: 126-141). In the second study the BP (systolic and diastolic) was markedly higher (P<0.001) when the wrist was kept at the bed level (systolic bed level: 144 CI: 135-152; systolic heart level: 135 CI:126-141; diastolic bed level: 83 CI:78-88; diastolic heart level: 76 CI:71-79).

Primary aortoduodenal fistula including the afferent loop of a Billroth II anastomosis. A case report.

Primary aortoenteric fistula is a very rare consequence of the evolution of an abdominal aortic aneurysm (AAA). The 3rd and 4th portion of the duodenum are involved in up to 80% of all cases. Frequently, gastrointestinal bleeding represents the first symptom, and diagnosis is difficult because of the aspecific clinical presentation and course, characterized by alternating remission and relapse; this is the reason why surgical treatment is usually delayed and therefore such events are managed as emergencies with a preoperative and intraoperative high death rate. We report the case of a 76-year-old man with a primary aortoduodenal fistula, who was submitted to gastric resection according to Billroth II 20 years before. This case could be interesting for its anatomical peculiarities favourable to the formation of the fistula.