[Type 2 diabetic nephropathy: clinical course and prevention proposals 2004]. / Diabete di 2 tipo e nefropatie: storia naturale e proposte di prevenzione 2004.

The first clinical evidence of nephropathy is the appearance of low, but abnormal, albumin levels in the urine (>30 mg/day or 20 mg/min), microalbuminuria. Without specific interventions, approximately 80% of type 1 diabetics have their urinary albumin excretion increase at a rate of 10-20%/yr to the stage of overt nephropathy or clinical albuminuria (>300 mg/24h or >200 mg/min) over 10-15 yrs, developing hypertension along the way. Approximately 30% of individuals with type 2 diabetes are found to have microalbuminuria or overt nephropathy shortly after the diagnosis of their illness, because diabetes is actually present for many years previously and because the presence of albuminuria can depend on other concomitant nephropathies, as shown by biopsy studies. Without specific intervention, 20-40% of type 2 diabetic patients with microalbuminuria progress to overt nephropathy, but 20 yrs after onset only 20% progress to end-stage renal failure (ESRD). The rates of decline in glomerular filtration rate (GFR) are highly variable from one individual to another, but they may not be substantially different between patients with type 1 and type 2 diabetes. As therapies and interventions for coronary artery disease continue to improve, more elderly type 2 diabetes patients can be expected to survive long enough to develop renal failure. The recently published Italian Society of Nephrology (SIN) guidelines for diagnosis and therapy of diabetic nephropathy present the route for the best strategies in prevention and therapy, from earlier onset to advanced ESRD.

[Acute renal failure caused by VIP-secreting tumor]. / Una causa rara di insufficienza renale acuta: il VIPoma.

A 74-year-old woman had secretory diarrhea, severe metabolic acidosis, hypokalemia, hypovolemia, and acute renal failure caused by a pancreatic vasoactive intestinal polypeptide (VIP)-secreting tumor. Vipoma is a rare neuroendocrine tumor. Morbidity and mortality are related to long-standing dehydration and electrolyte and acid-base disturbance resulting in acute renal failure. Diagnosis requires the documentation of large volumes of secretory diarrhea, elevated VIP plasma levels, and the localization of the VIP-secreting tumor. Metastases are present in 50% of patients at the time of diagnosis. Treatment includes correction of volume, electrolyte, and metabolic abnormalities; CVVH during ARF; pharmacotherapy to decrease gastrointestinal secretion; and surgical resection of the vipoma.

[Vascular access validity and treatment efficiency in hemodialysis]. / Validita' dell'accesso ed efficienza terapeutica in emodialisi.

The vascular access is the "Achille's heel" of the modern hemodialysis. In order to obtain a good depuration, the blood flow in dialysis must be of 250-300 mL/min, at least. The procedures for the preparation and their complications are cause of the 25% of the hospital admissions in patients with chronic uremia in substitutive therapy. Gold standard is still represented from the distal arteriovenous fistulas of Cimino and Brescia. The alternatives to the native veins as the syntetic graft and the tunneled central venous catheteters or the Dialock system, revealed useful in the patients that have exausted the superficial veins, but are of second choice. The native fistula has an advanced validity, demonstrated from lower risk of mortality in the patients who use it, diabetic or not. These affirmations come just from USA, where the arteriovenous grafts prevail and the percentage of central venous catheters is elevated. Thrombosis, infections and reduced depurative efficiency are the main causes. In the Dialysis Unit of Mantova we adopted an aggressive approach to the construction of distal fistula. Out of 172 patients in chronic hemodialysis, 165 use an arterovenous fistula, 4 an arterovenous grafts (PTFE) and 3 a tunnelled central venous catheters (2 Permcath and 1 Tesio). The surgical activity between 1987 and 2001 included 858 procedures on 516 patients (medium ages 59.1 years): Among these, 815 are created from native veins, 28 by arterovenous graft fistulas and 15 with tunnelled hemodialysis catheters. Our current strategy recommended to candidate to permanent venous catheter only patients on chronic hemodialysis with exhausted periferal vascular bed and only when peritoneal dialisys is'nt possible. Generally, the management of the vascular access must preview one tight collaboration between nephrologists, nurses, patient, vascular surgeons and radiologists.

Clinical characteristics associated to atrial fibrillation in chronic hemodialysis patients.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained arrhythmia diagnosed in non-uremic patients and its prevalence increases in older subjects, however, information concerning AF in dialysis patients is scarce. Therefore, we carried out a prospective cross-sectional study from September 1996 to December 1996 in order to evaluate the prevalence and some of the clinical characteristics associated to AF in hemodialysis (HD) patients. SUBJECTS AND METHODS: 316 HD patients (age 63 +/- 12 years, dialysis duration 69 +/- 71 months) treated in three different hospital-based units were studied. Standard 12-lead electrocardiograms (ECGs) carried out in the interdialytic day during the study period were reviewed. Data concerning age, history of ischemic heart disease (IHD), cerebrovascular disease (CVD), peripheral vascular disease (PVD), presence of diabetes, smoking history and antihypertensive therapy were collected. Systolic and diastolic blood pressure, fasting cholesterol and triglycerides, albumin and hemoglobin were also derived from the clinical records. Performance status was assessed by Karnofsky index (Ki). RESULTS: 74 patients (23.4%) had persistent AF, i.e. presence of AF in all (at least two) ECGs performed in the study time. Patients with AF were older (age 69 +/- 10 vs 62 +/- 12 years, p < 0.001), had lower Ki (54 +/- 20 vs 68 +/- 17, p < 0.01), cholesterol (182 +/- 46 vs 198 +/- 52 mg/dl, p < 0.01) and albumin (3.9 +/- 0.5 vs 4.1 +/- 0.5 g/dl, p < 0.001) compared to those with no AF. Prevalence of IHD (44.5% vs 19%, p < 0.05) and PVD (23% vs 11%, p < 0.05) was higher among AF patients. Logistic regression analysis showed that IHD (p < 0.001) and Ki (p < 0.01) were independently associated to AF. CONCLUSION: We conclude that AF is a frequent arrhythmia in HD patients treated in hospital-based dialysis units, especially in those with low performance status. It appears to be associated to the atherosclerotic damage of coronary arterial tree. Prospective studies are necessary to assess whether it could contribute to cardiovascular morbidity and mortality in end-stage renal disease.

The effect of metabolic control on development and progression of diabetic nephropathy.

The progressively growing number of patients with end-stage renal failure (ESRF) associated with diabetes mellitus and requiring renal replacement therapy (RRT) stimulated both nephrologists and diabetologists to investigate the mechanisms linking hyperglycaemia to diabetic renal failure and to set up measures to prevent the onset and slow the progression of diabetic nephropathy. Over the last few decades, a large number of studies have investigated both the incidence of diabetic nephropathy and the relationship between metabolic control and the development of diabetic nephropathy. Chronologically, the first type of diabetes and diabetic nephropathy to be studied was type I, and it is only in recent years that metabolic control has been proven to be a contributor to the development of nephropathy in such patients. Recently, the DCCT demonstrated that metabolic control in the prealbuminuric phase was effective in reducing the incidence of microalbuminuria, even if it was unable to reduce the incidence of overt proteinuria in patients with type I diabetes and established proteinuria. On the other hand, in type II diabetes, the number of studies demonstrating a favourable effect of metabolic control on onset and progression of diabetic nephropathy is only slightly greater than those that failed to show a favourable effect. This feature may suggest that in type II patients, genetic and ethnic differences, nutritional aspects, lifestyle and other confounding factors may play a relevant role in the course of the disease. However, the trials performed and the retrospective analyses generally agree that glycated haemoglobin two standard deviations greater than the mean is related to a worsening in progression of diabetic nephropathy and to an enhanced risk of other complications. In general, a glycated haemoglobin < or =8% seems advisable. Moreover, in both type I and type II, greater emphasis should be placed on the major risk factors such as hypertension, smoking habits and hyperlipidaemia.

Fatal sepsis from Vibrio vulnificus in a hemodialyzed patient.

Vibrio vulnificus, a particularly virulent halophilic vibrio, has been isolated from the blood and skin necrotic lesion of a hemodialyzed patient with sepsis. The patient has had exposure of the skin to seawater. Various chronic conditions including renal failure have a great risk for developing septicemia due to V vulnificus. It is necessary to inform persons with liver diseases or immunocompromising conditions of hazards associated with the consumption of undercooked seafood and seawater exposure.

[Radiotherapy of the breast: changes in the volume of the lung covered in the treatment fields and resulting changes in dose distribution]. / Radioterapia della mammella: variazioni del volume del polmone compreso nei campi del trattamento e conseguenti modificazioni della distribuzione della dose.

In breast cancer adjuvant therapy, respiratory movements continuously modify the irradiated volumes and the anatomical shape of this body region. Fifteen patients were submitted to 3 Computed Tomography (CT) sequences for treatment planning: the first one without any indications to the patient (the standard sequence) and the second and the third one with spontaneous stopped inspiration and expiration, respectively; the patient was always in the same position. The treatment was planned on standard CT images and then applied to the other sequences, maintaining all parameters unvaried, including isocenter position and treatment time. The lung volumes within the fields (and those included in the 95%, 100%, 105% isodoses referred to the prescribed dose) were evaluated with dose/volume histograms. The average irradiated lung was 69 cm3 (DS 28) in standard sequences, 136 cm3 (DS 67) in inspiration and 41 cm3 (DS 25) in expiration. The pulmonary volume within the above isodoses exhibited similar changes. In other words, the lung volume actually irradiated during the whole treatment is smaller than the one which can be calculated on standard CT sequences and it corresponds to expiration volume. The remaining part falls into a wide "twilight zone" relative to dose. Therefore, the true risk of lung toxicity can be similarly lower than the calculable one on standard CT images. Thus, the complication risk (based on dose/volume histograms and normal tissue control probability parameters) could be assessed in new prospective studies, introducing a corrective factor for the irradiated lung volume, because the latter is smaller than that shown by standard CT.

[Volume of the irradiated small intestine during pelvic radiotherapy. Comparison of various calculation methods]. / Il volume dell'intestino tenue irradiato durante la radioterapia pelvica. Confronto tra diverse metodiche di calcolo.

In pelvic irradiation, the small bowel portion included in the planning treatment volume is one of the major factors of acute enteropathy. Three different methods are used to calculate the bowel volume: Gallagher's grid method and two systems based on specific algorithms using CT data. We compared the results of these different methods in a series of nine patients submitted to treatment volume planning simulation for pelvic irradiation, after oral barium administration. The small bowel volumes were calculated with the grid method on orthogonal radiographs. About one hour later, the patients were submitted to CT for radiotherapy planning. The small bowel regions to be irradiated were drawn manually on all CT slices on a Varian Cadplan 2.62 console. Two different algorithms were used to calculate the small bowel volumes: one of them based on polyhedral and the other on cylindric approximation. The average volumes, the variance and the determination coefficient with linear and polynomial regression were in substantial statistical agreement in the three series; the correlation index between the grid and the CT methods ranged 0.84-0.87. Therefore, the authors believe that enteric side-effects can be correlated with the irradiated small bowel volume, independent of the calculation method.

[Assessment of the tumor bed dose in the conservative treatment of breast carcinoma]. / Valutazione della dose al letto tumorale nel trattamento conservativo del carcinoma mammario.

We investigated the variations in the total dose given to primary tumor sites in breast irradiation after conservative surgery. Fifty patients consecutively submitted to CT for radiotherapy treatment planning were entered into this study. Treatment was planned with Varian Cadplan 2.61 for both whole breast irradiation (2 Gy/fraction, up to 50 Gy) and boost (2 Gy/fraction, up to 10 Gy) according to the ICRU 50 report. The doses were calculated localizing the tumor site with preoperative mammography or breast US, surgery description, the possible presence of clips and treatment planning CT. The doses to tumor volumes ranged 46.5 to 53.4 Gy [average: 50.7, standard deviation (SD): 1.47] with the tangential fields. The relative biological effects (RBE) ranged 55.2 to 64.9 Gy (average: 61.05, SD: 2.06). The total doses to tumor beds ranged 57.8 to 65.2 Gy (average: 61.6, SD: 1.63) and the relative RBE from 67.8 Gy to 79.4 Gy (average: 74.3, SD: 2.30). In conclusion, in our opinion, the assessment of radiotherapy efficacy in breast irradiation should be related also to tumor bed dose and not only to the prescribed dose. Indeed, its wide range (and, consequently, the marked differences seen in RBE) might be misleading, especially when the relationship between local relapse and boost usefulness is considered.