[C-reactive protein and homocysteinemia in patients undergoing on-line hemodiafiltration]. / Proteina C-reattiva e omocisteinemia in emodiafiltrazione on-line.

PURPOSE: In renal disease therapy (RDT) patients, high plasma homocysteine (tHcy) is common and high C-reactive protein(CRP) levels can be observed, attributed to the inflammatory process caused by the dialysis itself. Hyperhomocysteinemia and bioincompatibility are considered independent vascular risk factors. This study evaluated the behavior of these parameters in patients undergoing on-line hemodiafiltration (OL-HDF). METHODS: In 56 patients, HDF was performed using high permeability polyamide membranes, exchanging in the post-dilution mode 16-18 L/session of a reinfusate obtained by the on-line system (triple filtration AK200, Gambro). CRP was measured by an immunological method at the start and the end of the session in patients without comorbidities (group 1, n=30)and with inflammatory diseases (group 2, n=26). In 23 of the 56 patients, tHCY was measured (by high performance liquid chromatography (HPLC)) before and after the mid-week session on different schedule of folinic acid, vitamin B12 and vitamin B6. RESULTS: Pre-dialytic CRP was in the normal range in group 1 patients, whereas it was higher in group 2 patients; dialysis did not induce a significant change in either group. The intradialytic percentage tHcy decrease was approximately 50% regardless of the pre-dialytic value, which was significantly different according to the vitamin supplements administered. CONCLUSIONS: HDF, as performed in this study, demonstrated biocompatibility and efficient Hcy removal; therefore, it can prevent cardiovascular disease (CVD) in patients on regular extracorporeal dialysis.

Hidrobiología del Embalse La Quebrada (Córdoba), Argentina : bacteriología y fitoplancton

El Embalse La Quebrada, localizado en Río Ceballos, a 32 Km al Noroeste de la ciudad de Córdoba, es el único reservorio para provisión de agua potable de aproximadamente 30.000 personas que viven en los alrededores, en las localidades de Río Ceballos, Unquillo y Mendiolaza. Desde 1997 se ha detectado un incremento en el proceso de eutroficación del lago, manifestándose principalmente en florecimientos de algas. En la actualidad el lago tiene periódicamente importantes blooms de Ceratium hirundinella (Dinofíceae), que se ven en la superficie del agua como manchones rojizos. También ha habido en los últimos años una interesante variación en dominancia entre Cianobacterias indicadoras de eutroficación, tales como las especies pertenecientes a los géneros Anabaena y Microcystis. En esta contribución se presentan datos varios correspondientes a muestreos efectuados no solamente en el Embalse sino además en sus dos tributarios.Los parámetros estudiados incluyen las más importantes características físico-químicas, microbiológicas y fitoplanctónicas que sirven para estimar calidad de aguaLos resultados indican que el Embalse podría ubicarse en un estadio mesotrófico, con marcada tendencia a eutrófico. Sus aguas se caracterizan por abundante productividad primaria, baja transparencia, procesos anaeróbicos en el hipolimnion que generan gases odoríferos, y recirculación de nutrientes con una alta carga de materia orgánica.Todas estas condiciones son indeseables en un ambiente utilizado como recurso turístico y para provisión de agua potable

Hidrobiología del Embalse La Quebrada (Córdoba), Argentina: bacteriología y fitoplancton

El Embalse La Quebrada, localizado en Río Ceballos, a 32 Km al Noroeste de la ciudad de Córdoba, es el único reservorio para provisión de agua potable de aproximadamente 30.000 personas que viven en los alrededores, en las localidades de Río Ceballos, Unquillo y Mendiolaza. Desde 1997 se ha detectado un incremento en el proceso de eutroficación del lago, manifestándose principalmente en florecimientos de algas. En la actualidad el lago tiene periódicamente importantes blooms de Ceratium hirundinella (Dinofíceae), que se ven en la superficie del agua como manchones rojizos. También ha habido en los últimos años una interesante variación en dominancia entre Cianobacterias indicadoras de eutroficación, tales como las especies pertenecientes a los géneros Anabaena y Microcystis. En esta contribución se presentan datos varios correspondientes a muestreos efectuados no solamente en el Embalse sino además en sus dos tributarios.Los parámetros estudiados incluyen las más importantes características físico-químicas, microbiológicas y fitoplanctónicas que sirven para estimar calidad de aguaLos resultados indican que el Embalse podría ubicarse en un estadio mesotrófico, con marcada tendencia a eutrófico. Sus aguas se caracterizan por abundante productividad primaria, baja transparencia, procesos anaeróbicos en el hipolimnion que generan gases odoríferos, y recirculación de nutrientes con una alta carga de materia orgánica.Todas estas condiciones son indeseables en un ambiente utilizado como recurso turístico y para provisión de agua potable

[Optimization of extracorporeal dialytic treatment: on-line hemodiafiltration]. / Ottimizzazione del trattamento dialitico extracorporeo: l'emodiafiltrazione on-line.

The study evaluates the potential of high ultrafiltration on-line hemodialfiltration (HDF) as a means of achieving the goals of extracorporeal RDT: the removal of small and medium-sized molecules, vascular stability and biocompatibility. The removal of small molecules was correlated with the UF rate and therefore with reinfusate volume. Medium-sized molecules were only removed from high permeability synthetic membranes in HD, but to a greater extent in HDF because of higher absorption. Vascular stability during the dialytic session is improved by convective processes, as is confirmed by a low prevalence of arterial hypertension in HDF patients. This suggests that HDF facilitates the achievement of dry body weight and therefore an improved correction of hydrosaline retention which is the main cause of hypertension in RDT patients. The biocompatibility of the dialytic system depends on the membrane and the dialysate. Synthetic membranes were shown to be much less toxic than cellulosic membranes and ultrapure dialysate was a useful aid to reduce the risk of inflammatory stimuli. On-line HDF associated the value of low-cost sterile dialysate-reinfu sate with a highly efficient and well tolerated technique.

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.

[Plasma levels of homocysteine in patients on hemodiafiltration]. / Livelli plasmatici di omocisteina in pazienti in emodiafiltrazione.

BACKGROUND: Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases, and is a common finding in patients on regular dialysis treatment. Hemodialysis lowers homocysteine plasma levels in variable amounts, and it was also suggested that folic acid and vitamin B12 supplements can reduce such levels. The purpose of the present study was to evaluate homocysteine plasma levels in patients on hemodiafiltration who received vit. B12 and folate supplements such as to keep their plasma levels in the normal range. METHODS: A retrospective study was carried out in a group of 36 patients on hemodiafiltration, who received routinely folate and vit. B12 supplements i.v. Pre-dialysis plasma levels of folate and vit. B12 and pre-postdialysis homocysteine concentration were evaluated. The latter was correlated with other parameters. RESULTS: The present study confirmed high homocysteine levels in patients on RDT and their reduction due to dialysis, demonstrated a weak negative correlation of pre-dialysis homocysteine with vit. B12 plasma level, but no correlation with folic acid. CONCLUSIONS: This study showed a good efficiency of hemodiafiltration using high permeability membranes on homocysteine removal, whereas the negative correlation between folate and homocysteine plasma level was not confirmed.

[Magnesium hydroxide in idiopathic calcium nephrolithiasis]. / Idrossido di magnesio nella nefrolitiasi calcica idiopatica.

BACKGROUND: While in vitro the protective effect of magnesium on calcium oxalate crystallization is well known, its clinical relevance in calcium nephrolithiasis is still debated. Therefore, the clinical and metabolic effects of magnesium hydroxide therapy were evaluated in calcium stone formers. METHODS: Nine patients (7 M, 2 F), selected for a low urinary magnesium excretion (uMg 56 +/- 12 mg/day), were given Mg hydroxide (500 mg/day), with clinical and metabolic controls at 3, 12 and 18 months. RESULTS: Urinary Mg/uCreat increased throughout the study; uOx/uCreat decreased significantly; uCa/uCreat increased but not significantly. The stone recurrence rate decreased from 0.75 to 0.11 stones/year/patient, throughout the study period. The decrease of uOx is considered a more important risk factor in calcium stone patients than a similar uCa change; it may be due to a reduced intestinal Ox absorption, for the formation of insoluble and not absorbed Mg oxalate. CONCLUSION: In conclusion, Mg hydroxide therapy was encouraging in patients with calcium nephrolithiasis and low uMg; nevertheless a longer period of treatment is needed to confirm these data.

Dialysis in the elderly: improvement of survival results in the eighties.

Analysis of long-term dialysis results is the cornerstone of renal replacement therapy evaluation. Elderly patients may be considered a crucial cohort, since subtle differences may be enhanced in a population of lower life expectancy. The aim of the study was an analysis, from the Piedmont Registry of Dialysis and Transplantation, of the results obtained in 1981-1992 (northern Italy, about 4,400,000 inhabitants, 21 dialysis centres, open acceptance since mid-1970s) in patients aged > or = 65 years (475 patients started treatment in 1981-1985, 1026 in 1986-1992). As a first treatment, during the 12 years considered acetate haemodialysis decreased sharply; bicarbonate haemodialysis is currently the standard treatment (68%). Peritoneal dialysis is stable (21%), and haemodiafiltration is increasing (8%). Shifts between treatments are frequent: 15% of elderly patients changed treatment at least once in 1991-1992. Nephroangiosclerosis/ischaemic renal disease, undefined causes and diabetes mellitus are the major causes of end-stage renal disease; 57.3% of patients have high risk conditions in addition to age. In this cohort of patients, mean age of new cases starting dialysis significantly increased in 1986-1992 (72.7 +/- 5.4 years) versus 1981-1985 (71.3 +/- 4.5; P < 0.001). Despite this, survival at 2 years increased significantly from 54.6% in the period 1981-1985 to 59% in the period 1986-1992 (P < 0.05). Even in an ageing dialysis population, therefore, choice of an open dialysis system with easy changes among treatments allowed improvement of survival results; further technical advances may help in maintaining present trends.

Calcitriol pulse therapy for severe hyperparathyroidism or calcium salts as phosphate binders in renal dialysis patients?

The concurrent use of calcitriol (CAL) pulse therapy to reduce parathyroid hormone (PTH) secretion and of calcium (Ca) salts as the most appropriate phosphate binders was evaluated for over 1 year in a group of 14 patients with good divalent ion control on CaCO3 therapy but with increasing levels of serum intact PTH. CAL pulse therapy was effective and safe in only 2 patients; in the remaining subjects it resulted in hypercalcemia and/or hyperphosphatemia, not reversed by adjusting the dialysate Ca concentration and or CaCO3 dose, and had to be stopped. Therefore, CAL pulse therapy does not seem to be compatible with Ca salts which, in our opinion, deserve priority in the therapy of renal dialysis patients.

[Can malnutrition be prevented in patients on chronic extracorporeal dialysis?]. / Può essere prevenuta la malnutrizione nei pazienti in dialisi extracorporea cronica?

In the attempt to prevent malnutrition, a seven year longitudinal evaluation was carried out in 24 RDT patients in order to assess the efficacy of the following strategy: 1) Counseling for an adequate physical activity and a high caloric intake limiting dietary restrictions to fluids, salt and fruit. 2) Improvement of anemia by increasing dialysis dose and/or by administering EPO. 3) The use of high UF HDF in order to employ more biocompatible membranes and to improve small and middle molecules removal. Nutritional status was assessed by a biochemical screening and by evaluating the variations of dry body weight (BW), which had to be also confirmed by a normal cardiac volume. Moreover in all patients a 4 consecutive days dietary record was obtained one year before the end of the observation period. During this period the mean dry BW increased significantly except in the two last years, when it remained stable. The increase of BW was associated with a reduced incidence of hypertension, a significant increase of Hb and reduction of BUN and sCr. The remaining biochemical parameters were constantly in the normal range. The dietary record showed a mean caloric-proteic intake similar to that recommended for the general population. These data point out that the above strategy can prevent malnutrition in patients on RDT. It must be confirmed whether the use of more biocompatible membranes and the removal of the middle molecules can play an important role in this setting.

[Vocal function after cordectomy (traditional surgical treatment vs CO2 laser): a comparative objective-instrumental evaluation]. / Valutazione obiettivo-strumentale della funzionalità glottica residua dopo cordectomia tradizionale e cordectomia CO2 laser.

Concerning the wider use of the CO2 laser in the treatment of laryngeal diseases, the Authors, in a comparative study based on an objective-instrumental evaluation, evaluated residual vocal function after traditional surgical treatment (chordectomy) vs. CO2 laser treatment. Forty-one patients treated for T1a glottic carcinoma (U.I.C.C. 1987) in last 8 years were examined Vocal function following CO2 laser surgery was evaluated in 17 patients (16 males and 1 female, aged between 38 and 78, with an average age of 53) and compared to vocal function of 24 patients treated with traditional chordectomy (23 males and 1 female, aged between 51 and 73, with an average age of 58). All patients showed a minimum follow-up of 30 months and none, at the time of evaluation, had undergone phonatory re-education. Glottic functionality evaluation was performed as follows: Evaluation of anatomical and functional results by means of a rigid fiberoptic laryngoscopy and subsequent photographic documentation for successive comparative evaluation. Evaluation of residual voice quality by phoniatricians otorhinolaryngologists and the patients themselves. Recording and electroacoustic analysis of some vocal samples. Laryngeal objectivity of surgical results were constantly related to subjective and instrumental voice evaluation. Phonatory results in patients treated with CO2 laser were better than those found in patients treated with traditional chordectomy.

Amyloid bone disease and highly permeable synthetic membranes.

The effect of different highly permeable membranes on amyloid bone disease (ABD) was retrospectively evaluated in patients on renal replacement therapy (RRT) in our Unit with a dialytic age of more than 4 years. A group of 36 patients (age 60 +/- 12 years) after a variable period (28 +/- 29 months) on hemodialysis with cuprophane membrane (CU-HD), were moved to HDF with a reinfusate volume of 22 +/- 1 1/session, for a period of 65 +/- 26 months using the following membranes: AN69 1.6 m2, PAN 1.8, PMMA 2.1, PS 1.3, polyamide (PA) 1.3 and 1.6. Bone x-rays of wrists, hips and shoulders were taken annually and the presence of ABD was evaluated according to generally accepted criteria. ABD occurred in 4 patients after a period of 73 +/- 30 months on CU-HD only; it developed in 4/7 patients an AN69, in 4/6 on PAN, in 3/5 on PMMA, in 3/5 on PS; no patient of the 13 on PA developed ABD. Comparing patients on PA with those on other synthetic membranes, no significant difference was found in dialysis time (73 +/- 19 vs 83 +/- 28 months) as well as in age (59 +/- 13 vs 61 +/- 11 years) at ABD on set, when present. These data strongly encourage prospective studies enrolling more patients for a longer period of observation in order to evaluate possible differences on ABD development among various synthetic membranes.

[Arterial pressure in idiopathic calcium nephrolithiasis]. / Pressione arteriosa nella nefrolitiasi calcica idiopatica.

Hypertension and calcium nephrolithiasis show some common features, such as the high prevalence of hypercalciuria and of elevated urinary sodium excretion. 28 patients with idiopathic calcium stone disease and 17 normals were studied: all the subjects were evaluated for the mean arterial pressure, and for the metabolic risk factors for calcium stone disease. The mean arterial pressure proved to be higher in patients with calcium nephrolithiasis than in normals. In normals the mean arterial pressure showed a direct relationship with the urinary calcium, while in the group of stone patients it had a direct relationship with the urinary sodium excretion. The lack of relationship between the mean arterial pressure and calcium excretion, in patients with calcium stones, suggests an impaired tubular calcium handling in such patients.

New reinfusate composition in high UF haemodiafiltration: electrolyte solution combined with bicarbonate.

When high-permeability membranes are employed, high UF should be used in order to obtain optimal uraemic toxin removal and to avoid backfiltration. A high UF requires the infusion of an electrolyte solution including Ca2+ and Mg2+ which cannot be associated with bicarbonate in prepackaged solutions because of the risk of precipitation; therefore acetate or lactate are used as buffers. This study evaluated whether bicarbonate can be infused together with an electrolyte solution in high UF HDF, and if so, the clinical advantages that could be obtained by substituting acetate with bicarbonate in the reinfusate. In 12 patients on postdilutional high UF (121 +/- 10 ml/min) HDF (Qb 400, Qd 500 ml/min, dialysate containing Na, 141 +/- 2; K, 2.5; Ca, 3.5; Mg, 0.7; Cl, 111 +/- 2; acetate, 3; bicarbonate, 34 mEq/l; TMP 400 mmHg), an acid bag (Na, 128; K, 4; Ca, 7; Mg, 2; Cl, 141; acetate, 8 mEq/l), and a basic bag (Na, 150; HCO3, 80; Cl, 70 mEq/l), each containing 2 litres, were simultaneously infused through a Y connection. The final composition of reinfusate at the drip-chamber, combined with the above dialysate, allowed a negative intradialytic mass balance for Na, K, Mg and a positive one for Ca, acetate, to maintain prepostdialytic plasma values of these ions as well as bicarbonate close to normal limits. Furthermore, in five high-risk patients, clinical data were evaluated on high UF HDF, infusing a solution containing either acetate or bicarbonate, and an improvement of vascular stability was observed with the bicarbonate reinfusate.(ABSTRACT TRUNCATED AT 250 WORDS)

[The diagnosis and treatment of dysphagia]. / Diagnosi e trattamento della disfagia.

The structures in the head and neck are important in respiration, deglutition and communication. The post surgical head and neck cancer patient will probably exhibit a variety of disorders in both speech and swallowing. This study examined swallowing problems in three groups of patients following ablative surgery for pharyngolaryngeal carcinoma: supraglottic laryngectomies, hemilaryngectomies and subtotal laryngectomies. A total of 28 patients were studied. Videofluoroscopic studies with liquid and thick paste were completed one week post initiation of oral feeding following surgery and during the rehabilitation treatment.