Modeling vaccination campaigns and the Fall/Winter 2009 activity of the new A(H1N1) influenza in the Northern Hemisphere.

The unfolding of pandemic influenza A(H1N1) for Fall 2009 in the Northern Hemisphere is still uncertain. Plans for vaccination campaigns and vaccine trials are underway, with the first batches expected to be available early October. Several studies point to the possibility of an anticipated pandemic peak that could undermine the effectiveness of vaccination strategies. Here, we use a structured global epidemic and mobility metapopulation model to assess the effectiveness of massive vaccination campaigns for the Fall/Winter 2009. Mitigation effects are explored depending on the interplay between the predicted pandemic evolution and the expected delivery of vaccines. The model is calibrated using recent estimates on the transmissibility of the new A(H1N1) influenza. Results show that if additional intervention strategies were not used to delay the time of pandemic peak, vaccination may not be able to considerably reduce the cumulative number of cases, even when the mass vaccination campaign is started as early as mid-October. Prioritized vaccination would be crucial in slowing down the pandemic evolution and reducing its burden.

Knowledge of the anomalies of the big central veins reduces the morbidity during the cannulation for hemodialysis: Description of a case of persistent left superior vena cava and revision of literature.

The persistence of a left superior vena cava is the result of a lack of an embryological involution of the left anterior cardinal vein. This anomaly is very rare: about 0.3% of the general population. Its incidence increases remarkably from 3-10% in those patients affected with congenital heart disease. Described herein is a case of persistent left superior vena cava, discovered by chance, following the placement of a central venous catheter for hemodialysis. A chest X-ray in projection back-forward showed the central venous catheter along the left sternal margin simulating a placement in the aorta artery. This clinical picture, as described in the literature, is often accompanied by other anatomical anomalies, in our case, by the congenital agenesis of a solitary pelvic kidney. In agreement with the literature and in contrast with what has been reported recently, we sustain that a central venous catheter placed, for any reason, in the persistent left superior vena cava must be removed immediately because it can induce hyperkinetic arrhythmia and cardiac arrest as in our case. Our case report should be a warning that lack of awareness of the anomalies of the big central veins can cause a rise in morbidity.

Verapamil versus amlodipine in proteinuric non-diabetic nephropathies treated with trandolapril (VVANNTT study): design of a prospective randomized multicenter trial.

Angiotensin converting enzyme inhibitors (ACEI) are the most effective antiproteinuric agents and should be used as first-line drugs in both diabetic and non-diabetic proteinuric nephropathies. The role of calcium channel blockers (CCB) is much more controversial. In diabetic patients verapamil and diltiazem seem more effective than dihydropyridines in reducing urinary protein excretion, and have additive effects with ACEI, but little is available on chronic treatment of non-diabetic nephropathies for non-dihydropyridine CCBs. To test whether the combination of verapamil 180 mg or amlodipine 5 mg with trandolapril 2 mg reduces urinary protein excretion more than trandolapril 2 mg alone, we planned a prospective, randomized, double-blind, multicenter trial. The secondary aims are to evaluate the effects of both treatments on the selectivity of proteinuria and check their safety. Consecutive patients aged between 18 and 70 years with non-diabetic proteinuria > or =2 g/24 h and plasma creatinine < 3 mg/dl or creatinine clearance > or = 20 ml/min are asked to participate. After a four-week run-in during which previous antihypertensive therapy is withdrawn, a single dose of trandolapril 2 mg is given once a day in open conditions for four weeks. At the end of this period patients are randomly assigned to receive once a day, in a double blind fashion, either trandolapril 2 mg and verapamil 180 mg [plus a placebo], or trandolapril 2 mg plus amlodipine 5 mg. They are monitored after one, two, five and eight months.

The placement of central venous catheters in hemodialysis: role of the endocavitary electrocardiographic trace. Case reports and literature review.

At present, the placement of a central venous catheter is becoming more and more a routine procedure nevertheless it involves different operators in fields such as oncology, nutrition, nephrology, and emergency medicine. It is well known that complications in the placement of CVC may occur in up to 20% of cases. One fifth of the catheters may result to be misplaced either in the internal omolateral jugular vein or in the innominate vein or in the controlateral brachiocephalic veins and usually a chest radiogram is necessary to evaluate its location. On the basis of 10 years of experience including more than 1,000 CVC placements, we now believe that endocavitary electrocardiography EC-ECG, initially studied and applied by Dr. Serafini, constitutes the best technique, more secure and more comfortable for the patient, to verify the position of the tip of a CVC. The technique EC-ECG, very simple and secure, utilizes the CVC as an endocavitary electrode. This is connected to a standard electrocardiograph, the same one to which the patient is connected during the placement of the CVC, and provides, in derivation V 1 or D 3 , an electrocardiographic pattern extremely sensitive to the position of the catheter tip. From December 1991 to December 2000, this technique has been used successfully in our departments of nephrology and applied to 1,139 patients that needed a CVC for hemodialysis. EC-ECG and a standard chest radiogram controlled the first 100 CVC we placed and in the other 1,039 cases, the control was made by EC-ECG alone. Only in 31 patients (2.7% of all cases), due to arrhythmia, the technique EC-ECG was not utilized. According to our experience, the procedure EC-ECG is an extremely reliable technique, sensitive and specific in 100% of cases, easy for the operator to perform, comfortable for patient. It doesn't need additional time to be performed and eliminates the need of taking a chest radiogram that up to now was considered indispensable in order to verify the position of the catheter tip. In this manner serious complications such as pneumothorax, and haemothorax that can complicate the placement of a CVC can also be avoided. Based on our experience, we now believe that this technique, that today has a large application in nephrology, oncology, clinical nutrition and in various branches of general medicine whenever the placement of a CVC is required, should be considered as a possible new guide line in controlling the placement of a CVC together with a chest X-ray when it is necessary.

[Acute kidney failure and losartan: a recently observed event of antagonists of angiotensin II AT1 receptors]. / Insufficienza renale acuta e losartan: una nuova recente segnalazione degli inibitori dei recettori AT1 dell'angiotensina II.

Losartan is the first of a new category of drug that inhibits angiotensin II (ANG II) AT1 receptors antagonists. This drug lowers blood pressure by inhibiting the activity of ANG II and reduces proteinuria and progression of chronic renal failure (CRF). It seems therefore an extremely interesting drug. Aim of this study is to describe 3 cases of acute renal failure (ARF), occurred during therapy with losartan. None of the patients showed renal arteries stenosis or other predisposing factors for the development of ARF. In conclusion, we want pointed out that losartan could affect renal function in a similar way as angiotensin converting enzyme inhibitors (ACEI). We suggested that use of losartan in risk situations, like old age, preexiting CRF, stenosis of renal arteries, solitary kidney and diuretic therapy, should be carefully monitored as well as that of ACE I.

Monitoring of central dual-lumen catheter placement in haemodialysis by endocavitary electrocardiography: a simple and safe technique for the clinical nephrologist.

Complications in the placement of central venous catheter (CVC) may occur in up to 20% of cases. The catheter can be misplaced in the contralateral brachiocephalic vein, the ipsi or controlateral internal jugular vein, and usually a chest X-ray is necessary to evaluate its location. We believe that the best technique, first described by Serafini et al, to establish the position of a CVC is the endocavitary electrocardiography (EC-ECG) and its employment is recommended in all uraemic patients requiring haemodialysis. This technique uses the tip of the CVC as reference lead in a standard electrocardiograph. The best use of this technique has been obtained by echotomographic visualization of the internal jugular vein executed just before transcutaneous puncture of the vessel. From 1991 to December 1999 we have successfully applied this technique in CVC placement in 612 patients requiring haemodialysis. In our opinion, this method is a safe and simple technique that avoids the need for thoracic X-ray controls and time lost waiting for radiographs that prolong the start of the haemodialysis session. According to our experience, we believe that the EC-ECG technique is a method in compliance with Food and Drug Administration guidelines regarding catheter tip location in uraemic patients.

[Evaluation of urea recirculation and dialysis efficiency of central venous jugular catheters when the venous lumen is used as an arterial lumen]. / Valutazione del ricircolo dell'urea ed efficacia dialitica del catetere giugulare venoso centrale quando il lume venoso è utilizzato come lume arterioso.

BACKGROUND: The dual lumen internal jugular venous catheter has proven to be the most useful temporary vascular access for hemodialysis. According to this evidence it was decided to evaluate urea recirculation rate during hemodialysis performed by dual lumen internal jugular catheter (IJC) under normal condition (R1) and when the arterial lumen of the catheter is used as venous lumen, and the venous lumen as arterial lumen (R2). METHODS: In 71 patients who underwent hemodialysis using a dual lumen IJC, urea recirculation rate was measured during a conventional bicarbonate hemodialysis, under normal condition R1 and during the experimental condition R2. RESULTS: Urea recirculation rate < 5% was achieved for almost all patients under normal condition R1. In the different condition R2, urea recirculation rate increased in all patients, from an average value of 3.7 +/- 1.7 to 5.1 +/- 1.8 p < 0.0001. This increment was expected ut surprisingly low. CONCLUSIONS: In conclusion during hemodialysis with dual lumen IJC efficient treatment can be provided in normal condition and also when the venous lumen is used as arterial lumen.

[Drugs used in the treatment of arterial hypertension in dialysis patients in the Piedmont. What correlations between personal and clinical data can be made from the registry data?]. / I farmaci utilizzati per il trattamento della ipertensione arteriosa nei pazienti in dialisi in Piemonte. Quali correlazioni con i dati anagrafici e clinici sono possibili dai dati del registro?

The therapeutical approach to arterial hypertension in the general population is now relatively well classified, whereas it remains a controversial problem in dialytic patients. The aim of this study was to evaluate the antihypertensive drugs used in dialytic patients in Piedmont and to identify correlations with other personal and clinical data. The authors analysed the data in the Piedmont Dialysis and Transplant Register concerning new patients admitted to dialysis during the period 1990-1995 (2,664 patients at 31/12/1995) and 1,373 patients who began dialysis during the period 1990-1993. A study of the antihypertensive drugs using in single and combined therapy over the five-year period shows major variations in the 45-65 year-old age bracket (increased ACE-inhibitors in single therapy, 15.5-25.6%, increased vasodilators in combined therapy, 15.3-21%). In patients aged > or = 65 years old a slight increase was found in the use of beta-blockers in monotherapy. Antihypertensive drugs at the 1st control (1990-1995 entries) appeared to be stable over the five-year period. From the 1,373 patients who started dialysis in the period 1990-1993, with at least three subsequent controls, the authors selected those hypertensive or normotensive patients receiving ACE-inhibitor therapy (best survival in general population) and compared their survival with that of patients receiving alternative antihypertensive treatment. No significant differences were found. The stability of the antihypertensive drugs taken by these patients over the past 5 years backs the hypothesis of a greater attention paid by nephrologists to the introduction of new drugs, both because of the frequent onset of collateral effects and owing to the special pharmacokinetics present in dialytic patients.

Influence of the hydration state on blood pressure values in a group of patients on regular maintenance hemodialysis.

The pathophysiology of hypertension in patients on renal replacement therapy is not yet clear, and the role of extracellular fluid overload is still a matter of debate. The main problem is the lack of techniques to determine the fluid state. Recently new noninvasive techniques have become available which make it possible to accurately determine the hydration state in these patients. We have studied the influence of the hydration state on interdialytic blood pressure in 45 patients: 21 (46.6%) using antihypertensive medication and 24 (53.4%) without antihypertensive medication. Total body water (TBW) was determined by bioelectrical impedance analysis performed just before a hemodialysis session. The TBW was then related to the fat-free mass calculated by the anthropometric method (aFFM) of Durnin. The hydration state was defined using the following formula: TBW/aFFM 100. Furthermore, for each patient the ideal TBW was calculated according to the Watson formula. The difference between TBW and ideal TBW was considered a further index of the hydration state. Ambulatory blood pressure monitoring was performed by using a Takeda 24200 recorder according to the Korotkoff method during the 24 h before the midweek hemodialysis session. Blood pressure monitoring showed a significant correlation with the hydration state of these patients. In conclusion, the hydration state seems to play a major role in interdialytic blood pressure control.

[Epidemiology and clinical course in hepatitis C-positive patients treated with dialysis in Piemonte. Work group of the RPDT]. / Epidemiologia e comportamento clinico nei pazienti epatite C positivi in dialisi in Piemonte. Gruppo di lavoro dell' RPDT.

The high prevalence of HCV positivity in dialysis patients has recently prompted several studies on this controversial subject. The aim of the study was an evaluation of HCV positivity and of influence on clinical outcome in 2,404 patients on dialysis in Piedmont (Northern Italy Region, about 4,400,000 inhab., 20 Dialysis Centers) at December 1993 (32.7% HCV-positive according to the Regional Registry of Dialysis and Transplantation). As expected, a strong correlation was found with time on dialysis (94.4% in patients with treatment follow-up > or = 20 years) and blood transfusions (41.3% HCV positivity in transfused patients versus 22.6% in not transfused ones; p < 0.0001). Dialysis in a hospital setting is confirmed as at high risk of infection, since HCV positivity was 19.6% in patients always treated by bicarbonate dialysis in hospital versus 8.9% in those treated only by CAPD (start of dialysis in 1992-1993). Despite the high prevalence of HCV positivity, however, death rates for liver disease and for all gastrointestinal causes are very low, regardless of HCV antibody status (1.2% in HCV positive versus 2.3% in HCV negative, NS). Whether this depends upon different clinical features of HCV infection in dialysis patients or merely deflects a relatively short follow-up will be matter of discussion in the future.

Recurrent secondary hyperparathyroidism due to parathyroid carcinoma: usefulness of Ki-67 immunostaining in the diagnosis of a malignant parathyroid tumor.

Parathyroid carcinoma is a very rare disease occurring in less than 2-3% of all the cases showing clinical features of primary hyperparathyroidism. Several histological markers have been used for distinguishing between benign and malignant tumors of the parathyroid glands. However, most of these markers are not easily applicable and clinical prognosis cannot be predicted by histopathological criteria alone. A recent study has drawn attention to the role of the cell cycle associated antigen Ki-67 detected by MIB-1 monoclonal immunocytochemistry in parathyroid tumors: in fact, Ki-67 seems to be a valuable marker of malignancy in such tumors since it permits an easy detection of proliferating and dividing cells. Here we report in detail a case of severe recurrent hyperparathyroidism in a 51-year-old female patient undergoing regular hemodialysis treatment. In the surgical specimens of the parathyroid glands, the tumor proliferative fraction of 56, expressed as the number of Ki-67-positive nuclei per thousand cells, and the mean mitosis count of 0.5, expressed as the percentage of the total amount of Ki-67 positive nuclei, support the diagnosis of parathyroid carcinoma despite the scanty amount of microscopical signs considered characteristic of malignancy, i.e. extensive thick fibrous bands or prominent nucleoli. To our knowledge this paper is the first clinical report that supports the diagnostic role of the cell cycle associated antigen Ki-67 in parathyroid carcinoma in a case of secondary hyperparathyroidism in a patient undergoing hemodialysis.

Monitoring of central venous dual-lumen catheter placement in haemodialysis: improvement of a technique for the practising nephrologist.

Mismanagement in the placement of central venous catheter (CVC) may occur in up to 20% of cases. The catheter can be inadvertently placed in the contralateral brachiocephalic vein, the ipsi or contralateral internal jugular vein, and usually a thoracic radiograph is necessary to evaluate its location. We propose a technique first described by Serafini et al. to establish the position of a CVC by endocavitary electrocardiography (EC-ECG) and its employment in a large number of uraemic patients requiring haemodialysis. This technique uses the tip of the CVC as reference lead in a standard electrocardiograph. The best employment of this technique has been obtained by echotomographic visualization of the internal jugular vein executed just before transcutaneous puncture of the vessel. For 13 months we have successfully applied this technique in CVC placement in 81 patients requiring haemodialysis. In our opinion this method is a safe and simple technique that avoids the need for thoracic radiographs and time lost waiting for radiographs that prolong the start of the haemodialysis session. According to our experience, we confirm that the EC-ECG technique provides a method for ensuring compliance with Food and Drug Administration guidelines regarding catheter tip location in uraemic patients.

Monitoring of central venous dual-lumen catheter placement in haemodialysis: improvement of a technique for the practising nephrologist.

Mismanagement in the placement of central venous catheter (CVC) may occur in up to 20% of cases. The catheter can be inadvertently placed in the contralateral brachiocephalic vein, the ipsi or contralateral internal jugular vein, and usually a thoracic radiograph is necessary to evaluate its location. We propose a technique first described by Serafini et al. to establish the position of a CVC by endocavitary electrocardiography (EC-ECG) and its employment in a large number of uraemic patients requiring haemodialysis. This technique uses the tip of the CVC as reference lead in a standard electrocardiograph. The best employment of this technique has been obtained by echotomographic visualization of the internal jugular vein executed just before transcutaneous puncture of the vessel. For 13 months we have successfully applied this technique in CVC placement in 81 patients requiring haemodialysis. In our opinion this method is a safe and simple technique that avoids the need for thoracic radiographs and time lost waiting for radiographs that prolong the start of the haemodialysis session. According to our experience, we confirm that the EC-ECG technique provides a method for ensuring compliance with Food and Drug Administration guidelines regarding catheter tip location in uraemic patients.

Percutaneous renal biopsy utilizing ultrasonic guidance and a semiautomated device.

Percutaneous renal biopsy is a fundamental diagnostic technique in urology and nephrology, recently refined by real-time ultrasonic guidance. The technique described in this article is a biopsy method employing real-time ultrasonic guidance and a semiautomated device. The new device has been constructed to improve percutaneous biopsy technique and to obtain more perfect specimens. This technique was successfully performed in 20 patients undergoing renal biopsy. Diagnostically satisfactory material containing an average of ten glomeruli per specimen was obtained. The results obtained with the new device Biopty Bard have been compared with the results obtained from the same number of biopsies performed with the traditional technique.

Longitudinal assessment of body composition in continuous ambulatory peritoneal dialysis patients using bioelectric impedance and anthropometric measurements.

We assessed the utility of bioelectric impedance analysis (BIA) and anthropometry for longitudinal evaluation of body composition in continuous ambulatory peritoneal dialysis (CAPD) patients. Eleven subjects were studied at the beginning of CAPD and again at regular intervals during the first 6 months of treatment. The significant weight gain that occurs in our patients is mainly due to a rise in total body water (TBW), as measured by BIA, during the first weeks of CAPD, and later on due to a body fat increase. Anthropometry seems more reliable than BIA in the evaluation of body mass, because the latter is derived from TBW in BIA. Therefore, any change in TBW that occurs in a CAPD patient necessarily causes a similar change in the fat-free mass. In our experience, only the combined use of both anthropometry and BIA allows a proper assessment of body composition in patients on CAPD.