Influence of environmental conditions on the production of nutraceuticals in Italian edible plant landraces

Autochthonous plant varieties, also referred to as landraces, represent an important genetic resource, being well-adapted to the environment in which they have been selected. Landraces usually show profiles rich in nutraceuticals, making them an effective and valuable alternative to commercial agri-products, as well as potential candidates for crop improvement programs. Basilicata region is recognized as an Italian hotspot for agrobiodiversity, due to its complex orography. Thus, this work aimed to characterize and monitor, for two successive years, the content of secondary metabolites and related antioxidant properties of seven different species, four officinal (i.e., wild fennel - Feoniculum vulgare Mill.; oregano - Origanum vulgare L.; thyme - Thymus vulgaris L.; valerian - Valeriana officinalis L.) and three fruit species (i.e., fig - Ficus carica L. cv. Dottato; sweet cherry Prunus avium L. cv. Majatica; plum - Prunus domestica L. cv. Cascavella Gialla), collected in three different sites of this region. In detail, spectrophotometric tests were performed to assess the concentration of phenolic compounds, flavonoids, and - for officinal plants - also terpenoids, together with the antiradical activity (FRAP assays). In addition, to better typify the phytocomplexes of these landraces, HPLC-DAD and GC-MS analyses were carried out. In general, officinal plants showed higher values of nutraceutical compounds and related bioactivity with respect to fruit species. The data showed how different accessions of the same species had different phytochemical profiles, according to the sampling area and the year of collection, suggesting a role for both genetic and environmental factors in determining the observed results. Therefore, the final goal of this research was also to find a possible correlation between environmental factors and nutraceutics. The greatest correlation was found in valerian, where a lower water intake seemed to lead to a higher accumulation of antioxidants, and in plum, where the flavonoid content correlated positively with high temperatures. All these outcomes contribute at valorising Basilicata landraces for their aptitude to be high-quality foods and, at the same time, promoting the preservation of the agrobiodiversity for this region.

Factors Affecting Plasma Free Fatty Acids Rise during Hemodialysis

We studied the mechanisms responsible for causing acute changes in plasma lipids during hemodialysis. Dialysis decreased plasma triglycerides to the same extent as when heparin was given without dialysis. Cholesterol increased in proportion to hemoconcentration. Plasma free fatty acids (FFA) levels were also increased, but more so than with heparin alone. Glucose and acetate did not play a role, nor did carnitine loss, and hemofiltration elicited similar effects. The rise in plasma FFA is therefore likely to be caused by other as yet unknown mechanism.

Cost analysis of dialysis modalities in Italy

This study analyses management and costs of dialysis in the Italian National Health Service (NHS). Information on efficacy and health-related quality of life (HRQOL) based on the existing literature also is presented. The clinical differences between the dialysis modalities seem to be related to their appropriateness to specific patient groups. Efficacy rates are similar and the only differences are in complications and HRQOL. Traditional haemodialysis (THD) can be done by Italian patients in dialysis centres or in hospital. High-flux haemodialysis (HFHD) is generally only done in hospital. Peritoneal dialysis (PD) is usually done at home. The cost analysis was performed on a sample of Italian dialysis centres and hospitals, according to the full cost method. As expected, HFHD was more expensive than THD and PD, but no marked differences emerged among the different HFHD modalities. THD modalities in dialysis centres were less costly than in hospitals. Automated PD (APD) was much more expensive (almost twice) than continuous ambulatory PD (CAPD), the cheapest method in absolute terms. This study confirms that dialysis is costly and that it is very difficult to assess the cost-effectiveness of the different approaches. Although this study has limits, it should provide sufficient analytical information to local healthcare managers for more rational allocation of financial resources to dialysis services.

Stability and removal of atorvastatin, rosuvastatin and simvastatin from wastewater

Atorvastatin (ATO), rosuvastatin (RST) and simvastatin (SIM) are commonly used drugs that belong to the statin family (lowering human blood cholesterol levels) and have been detected as contaminants in natural waters. Stability and removal of ATO, RST and SIM from spiked wastewater produced at the Al-Quds University campus were investigated. All three statins were found to undergo degradation in wastewater (activated sludge). The degradation reactions of the three drugs in wastewater at room temperature follow first-order kinetics with rate constants of 2.2 × 10⁻⁷ s⁻¹ (ATO), 1.8 × 10⁻⁷ s⁻¹ (RST) and 1.8 × 10⁻⁶ s⁻¹ (SIM), which are larger than those obtained in pure water under the same conditions, 1.9 × 10⁻⁸ s⁻¹ (ATO), 2.2 × 10⁻⁸ s⁻¹ (RST) and 6.2 × 10⁻⁷ s⁻¹ (SIM). Degradation products were identified by LC-MS and LC/MS/MS. The overall performance of the wastewater treatment plant (WWTP) installed in the Al-Quds University campus towards the removal of these drugs was assessed showing that more than 90% of spiked ATO, RST and SIM were removed. In order to evaluate the efficiency of alternative removal methods to replace ultra-filtration membranes, adsorption isotherms for the three statins were investigated using both activated carbon and clay-micelle complex as adsorbents. The batch adsorption isotherms for the three statins were found to fit the Langmuir equation, with a larger number of adsorption sites and binding affinity for micelle-clay composite compared with activated carbon and filtration experiments of the three statins and their corresponding metabolites demonstrated a more efficient removal by micelle-clay filters.

Computationally designed prodrugs of statins based on Kirby's enzyme model

DFT calculations at B3LYP/6-31G(d,p) for intramolecular proton transfer in Kirby's enzyme models 1-7 demonstrated that the reaction rate is dependent on the distance between the two reacting centers, rGM, and the hydrogen bonding angle, α, and the rate of the reaction is linearly correlated with rGM and α. Based on these calculation results three simvastatin prodrugs were designed with the potential to provide simvastatin with higher bioavailability. For example, based on the calculated log EM for the three proposed prodrugs, the interconversion of simvastatin prodrug ProD 3 to simvastatin is predicted to be about 10 times faster than that of either simvastatin prodrug ProD 1 or simvastatin ProD 2. Hence, the rate by which the prodrug releases the statin drug can be determined according to the structural features of the promoiety (Kirby's enzyme model).

Efficiency of membrane technology, activated charcoal, and a micelle-clay complex for removal of the acidic pharmaceutical mefenamic acid

The efficiency of sequential advanced membrane technology wastewater treatment plant towards removal of a widely used non-steroid anti-inflammatory drug (NSAID) mefenamic acid was investigated. The sequential system included activated sludge, ultrafiltration by hollow fibre membranes with 100 kDa cutoff, and spiral wound membranes with 20 kDa cutoff, activated carbon and a reverse osmosis (RO) unit. The performance of the integrated plant showed complete removal of mefenamic acid from spiked wastewater samples. The activated carbon column was the most effective component in removing mefenamic acid with a removal efficiency of 97.2%. Stability study of mefenamic acid in pure water and Al-Quds activated sludge revealed that the anti-inflammatory drug was resistant to degradation in both environments. Batch adsorption of mefenamic acid by activated charcoal and a composite micelle (otadecyltrimethylammonium (ODTMA)-clay (montmorillonite) was determined at 25.0°C. Langmuir isotherm was found to fit the data with Qmax of 90.9 mg g(-1) and 100.0 mg g(-1) for activated carbon and micelle-clay complex, respectively. Filtration experiment by micelle-clay columns mixed with sand in the mg L(-1) range revealed complete removal of the drug with much larger capacity than activated carbon column. The combined results demonstrated that an integration of a micelle-clay column in the plant system has a good potential to improve the removal efficiency of the plant towards NSAID drugs such as mefenamic acid.

Cost analysis of dialysis modalities in Italy

This study analyses management and costs of dialysis in the Italian National Health Service (NHS). Information on efficacy and health-related quality of life (HRQOL) based on the existing literature also is presented. The clinical differences between the dialysis modalities seem to be related to their appropriateness to specific patient groups. Efficacy rates are similar and the only differences are in complications and HRQOL. Traditional haemodialysis (THD) can be done by Italian patients in dialysis centres or in hospital. Highflux haemodialysis (HFHD) is generally only done in hospital. Peritoneal dialysis (PD) is usually done at home. The cost analysis was performed on a sample of Italian dialysis centres and hospitals, according to the full cost method. As expected, HFHD was more expensive than THD and PD, but no marked differences emerged among the different HFHD modalities. THD modalities in dialysis centres were less costly than in hospitals. Automated PD (APD) was much more expensive (almost twice) than continuous ambulatory PD (CAPD), the cheapest method in absolute terms. This study confirms that dialysis is costly and that it is very difficult to assess the cost-effectiveness of the different approaches. Although this study has limits, it should provide sufficient analytical information to local healthcare managers for more rational allocation of financial resources to dialysis services.

Individualized anticoagulation with dermatan sulphate for haemodialysis in chronic renal failure

BACKGROUND

Dermatan sulphate (DS) is a selective thrombin inhibitor with antithrombotic properties and low bleeding potential. In preliminary studies it was reported to be effective for preventing clot formation in the haemodialysis circuit.

METHODS

Ten patients on maintenance haemodialysis for chronic renal failure underwent three consecutive investigation phases. In phase 1 (individual dose titration), repeated dialyses were performed with increasing doses of DS until successful dialysis was obtained in two sessions at the same dose. In phase 2, individualized DS doses were validated by a randomized crossover comparison with the individual heparin dose of each patient. In phase 3, each patient underwent 24 consecutive dialyses with DS over 8 weeks. Successful dialysis was defined as completion of the procedure without visible clot formation in the bubble traps and lines or a greater than 20% decrease in dialyser capacity. Dialysis efficiency (decrease in serum urea and creatinine, Kt/V), APTT prolongation, bleeding time, and DS plasma concentrations were also assessed.

RESULTS

Phase 1: successful dialysis was achieved in nine patients with 4 mg/kg DS as a predialysis intravenous bolus followed by continuous infusion of 0.65 mg/kg/h. One patient required 5 mg/kg plus 1.3 mg/kg/h. Phase 2: no statistically significant differences were found between DS and heparin in any of the investigated variables. Residual dialyser capacity and dialysis efficiency indexes indicated equivalent efficacy. Phase 3: residual dialyser capacity and dialysis efficiency did not change with time. There was no accumulation of DS in plasma. No bleeding or thrombocytopenia were observed.

CONCLUSIONS

The dose of DS can be individually titrated to suppress clot formation during haemodialysis as efficiently as with individualized heparin. Such an individualized DS regimen maintains its anticoagulant efficacy and is safe in prolonged use.

Nitrendipine and enalapril improve albuminuria and glomerular filtration rate in non-insulin dependent diabetes

The effects of 3, 15, and 27 months of treatment with nitrendipine (10 to 40 mg/day) and enalapril (5 to 20 mg/day) on diastolic blood pressure (DBP), overnight urinary albumin excretion (UAE) rate, glomerular filtration rate (GFR), and renal plasma flow (RPF) were studied prospectively in a parallel group design in 13 microalbuminuric non-insulin dependent diabetic patients with mild hypertension and biopsy-proven diabetic glomerulopathy. Throughout the study period DBP decreased in both groups to < 95 mm Hg. At three months UAE, GFR, and RPF did not change significantly. At 15 and 27 months UAE (microgram/min, geometric mean and 95% C.I.) decreased respectively from 47.4 (23.4 to 95.9) to 28.6 (10.3 to 79.4), and to 22.3 (10.9 to 45.2; P = 0.0005) with nitrendipine, and from 58.3 (30.3 to 110.9) to 44.1 (22.9 to 84.8), and to 14.7 (4.4 to 49.3; P = 0.0025) with enalapril. Four patients in each group were normoalbuminuric at 27 months and none became macroalbuminuric. At 15 months the GFR (ml/min/1.73 m2, mean +/- SD) increased from 69.5 +/- 15.2 to 96.6 +/- 22.0 (P < 0.05) with nitrendipine and from 58.9 +/- 10.7 to 78.5 +/- 11.0 (P < 0.05) with enalapril. At 27 months the GFR was still numerically higher that at baseline either with nitrandipine (81.2 +/- 7.8) and with enalapril (79.9 +/- 17.7) (P = 0.7). The RPF (ml/min/1.73 m2, mean +/- SD) at baseline and at 27 months was comparable either with nitrendipine (456.6 +/- 165.3 vs. 400.9 +/- 112.9) and with enalapril (400.3 +/- 81.3 vs. 399.0 +/- 123.7). Both treatments were well tolerated. This is the first evidence that long-term effective control of arterial blood pressure by a calcium channel blocker or by an angiotensin converting enzyme inhibitor, in addition to reducing albuminuria, also improves GFR in incipient nephropathy.

Long-term treatment with either enalapril or nitrendipine stabilizes albuminuria and increases glomerular filtration rate in non-insulin-dependent diabetic patients

The effect of short- (98 days) and long-term (1 year) treatment with nitrendipine (10 to 40 mg/d) and enalapril (5 to 20 mg/d) on kidney function was studied prospectively in a parallel group design in 16 microalbuminuric non-insulin-dependent diabetic patients with mild hypertension and biopsy-proven diabetic glomerulopathy. At the end of the short-term treatment period diastolic blood pressure significantly decreased from 95.4 +/- 2.5 mm Hg to 83.5 +/- 3.5 mm Hg (P < 0.001) in the nitrendipine group and from 96.7 +/- 2.5 to 86.7 +/- 5.6 mm Hg (P < 0.001) in the enalapril group. Both overnight urinary albumin excretion rate and albumin fractional clearance tended to increase in the nitrendipine group and to decrease in the enalapril group, whereas the glomerular filtration rate and the renal plasma flow were similar to baseline in both study groups. At the end of the long-term treatment period diastolic blood pressure significantly decreased from 95.4 +/- 2.5 mm Hg to 86.0 +/- 6 mm Hg (P < 0.005) in the nitrendipine group and from 96.7 +/- 2.1 to 90.8 +/- 4.3 mm Hg (P < 0.05) in the enalapril group. Overnight urinary albumin excretion and albumin fractional clearance were similar to baseline in both study groups. The glomerular filtration rate significantly increased from 70.2 +/- 14.2 to 96.8 +/- 20.4 (P < 0.05) in the nitrendipine group and from 58.9 +/- 10.7 to 78.5 +/- 11.0 (P < 0.05) in the enalapril group. The renal plasma flow also significantly increased from 456.6 +/- 165.3 to 597.2 +/- 178.9 (P < 0.01) in the nitrendipine group.(ABSTRACT TRUNCATED AT 250 WORDS)

Prognosis of untreated patients with idiopathic membranous nephropathy

BACKGROUND

Defining the most appropriate treatment for patients with idiopathic membranous nephropathy is a matter of controversy. The course of the disorder is often benign, and the immunosuppressive regimens used in some patients have uncertain benefits and substantial risks. We studied the natural history of idiopathic membranous nephropathy in patients who received only symptomatic therapy.

METHODS

We prospectively studied 100 consecutive patients (68 men and 32 women; mean [+/- SD] age, 51 +/- 17 years) with biopsy-proved idiopathic membranous nephropathy. The patients received diuretic or antihypertensive drugs as needed, but no glucocorticoid or immunosuppressive drugs. We examined the patients and measured their urinary protein excretion and serum creatinine concentrations every 6 months for a mean of 52 months.

RESULTS

Twenty-four (65 percent) of the 37 patients followed for at least five years had complete or partial remission of proteinuria; in 6 others (16 percent), end-stage renal disease developed, and they required dialysis. As calculated by the Kaplan-Meier method, the estimated probability (+/- the standard error of the estimate) of retaining adequate kidney function was 88 +/- 5 percent after five years and 73 +/- 7 percent after eight years. The prognosis was poorer in men and in patients over 50 years of age, but not in patients with the nephrotic syndrome, hypertension, or hypercholesterolemia.

CONCLUSIONS

Most untreated patients with idiopathic membranous nephropathy maintain renal function for prolonged periods and are likely to have spontaneous remission. These results do not support the use of glucocorticoids and immunosuppressive drugs in patients with idiopathic membranous nephropathy.

Heterogeneous nature of renal lesions in type II diabetes

The nature of renal damage in patients with type II diabetes remains unclear. This study was directed to evaluate pathologic changes in 52 patients affected by type II diabetes with overt clinical nephropathy by conventional and morphometric techniques. The duration of diabetes ranged from 6 to 384 months, urinary protein excretion ranged from 0.9 to 9.2 g/24 h, and serum creatinine ranged from 0.9 to 9 mg/dL. Specimens were examined semiquantitatively by light microscopy, immunofluorescence, and electron microscopy. Glomerular tuft cross-sectional area was measured by a versatile computer system. Pathologic examination revealed three distinct patterns arbitrarily defined as Classes 1, 2, and 3. Class 1 included 19 patients with typical changes of diabetic nephropathy characterized by a high score of glomerulosclerosis (mean score, 2.1), marked glomerular hypertrophy (23,632 microns2), and arteriolar hyalinosis (mean score, 2). There was a positive correlation between glomerulosclerosis and arteriolar hyalinosis scores (P < 0.05). Class 2 included 16 patients showing chronic and aspecific changes. As compared with Class 1 patients, these patients had less glomerulosclerosis (mean score, 1.3) and less arteriolar hyalinosis (mean score, 0.8) but more severe ischemic glomerular lesions (mean score, 1.4) and arteriosclerosis (mean score, 2). Class 3 included 17 patients showing glomerular disease superimposed on diabetic glomerulosclerosis. There were no differences in age, mean duration of diabetes, renal function, urinary protein excretion, and mean arterial pressure among the three classes of patients. This study indicates that renal lesions in patients with type II diabetes manifest in a quite heterogeneous fashion.(ABSTRACT TRUNCATED AT 250 WORDS)

Nature and extent of glomerular injury induced by cyclosporine in heart transplant patients

We sought to clarify whether low-dose cyclosporine (5.0 +/- 2.2 mg/kg/day) given for more than two years to prevent cardiac graft rejection induced glomerular injury and to quantify the extent of the lesions. After renal hemodynamic studies, renal biopsy specimens were obtained from 10 patients on cyclosporine and analyzed by a novel morphometric technique consisting of a tridimensional reconstruction of the glomerular tuft. Autopsy kidney specimens from three patients with no clinical history of renal disease, and from four patients who died with dilatative cardiomyopathy served as controls. The glomerular filtration rate and renal plasma flow were significantly depressed below normal values in transplant recipients given cyclosporine, averaging 35 +/- 8 and 325 +/- 94 ml/min/1.73 m2, respectively. Conventional light microscopy of specimens from controls and from patients who died with dilatative cardiomyopathy did not reveal renal structural abnormalities. By contrast kidney specimens from cyclosporine-treated patients had obliterative arteriolopathy and ischemic-type changes, with thickening and wrinkling of glomerular capillary wall. Morphometrical analysis of 28 control glomeruli and 40 glomeruli from patients with dilatative cardiomyopathy showed glomerular capillary tuft volumes (VCT) ranging between 1.2 and 2.3 microns 3 x 10(-6), whereas of 102 glomeruli from cyclosporine-treated patients 42.1% had VCT lower than 1.2 microns 3 x 10(-6) and 24.4% VCT higher than 2.3 microns 3 x 10(-6).(ABSTRACT TRUNCATED AT 250 WORDS)

Recombinant human erythropoietin to correct uremic bleeding

Recombinant human erythropoietin may improve hemostasis of uremic patients by correcting anemia. However, a complete correction of renal anemia carries the risk of hypertension, encephalopathy, thrombosis, and hyperkalemia. Our aim was to establish the minimum level of packed cell volume (PCV) achieved with recombinant human erythropoietin that corrects the prolonged bleeding time in uremia. Twenty patients with chronic renal failure, anemia, and very prolonged bleeding time (greater than or equal to 15 minutes) were randomly allocated to erythropoietin or no specific treatment. The initial dose of erythropoietin was 50 U/kg intravenously (IV) three times a week. Every 4 weeks, the dose was increased by 25 U/kg until a normalization of bleeding time was achieved. Erythropoietin at a dose ranging from 150 to 300 U/kg/wk induced an increase in PCV to a range of 27% to 32% in all patients but one, and normalized bleeding time in all patients. A significant negative correlation (r = 0.898, P less than 0.001) was found between PCV and bleeding time measurements. Erythropoietin also significantly (P less than 0.01) increased values for red blood cell (RBC) distribution width (basal, 11.3 +/- 0.6; 12 weeks, 13.1 +/- 1.3). Platelet count and platelet function parameters did not significantly change. In untreated patients, no changes were recorded in all the parameters considered. These results establish in a controlled fashion that erythropoietin shortens bleeding time of uremic patients and indicate that a partial correction of renal anemia is enough to normalize bleeding time.

Effect of dietary proteins and lipids in patients with membranous nephropathy and nephrotic syndrome

Twenty-four patients with idiopathic membranous nephropathy, long-lasting nephrotic syndrome and serum creatinine less than 2 mg/dl ate sequentially, in a randomized cross-over design, a normal protein diet containing 1.1 +/- 0.3 g/kg/day of proteins and a low protein diet containing 0.7 +/- 0.1 g/kg/day of protein, each diet for a period of 3 months. Both diets were low in fat (less than 30% of total calories) and cholesterol (less than 200 mg/day) content and rich in polyunsaturated fatty acids and in linoleic acid (10% of energy). Random assignment to one of the two 3 month diet periods was done after a RUN-IN period of at least one month on the hypolipidic normal protein diet. Glomerular filtration rate (inulin clearance), 24 hour urinary protein loss and serum albumin concentration did not significantly differ at the end of the two diet periods, indicating that long-term restriction of protein intake does not modify GFR or urinary protein loss in nephrotic patients. Serum total and LDL-cholesterol and daily proteinuria were significantly lower at the end of both diet periods than at the beginning and at the end of the RUN-IN period. We suggest that these changes were a consequence of the manipulation of dietary fat intake.

[Acute hepatonephritis in a subject occupationally exposed to chloroform]

We describe a case of acute hepatonephritis in a worker of a pharmaceutical factory, due to sporadic and short exposures to chloroform at levels even 70 times higher than its TLV.

Factors affecting plasma free fatty acids rise during hemodialysis

We studied the mechanisms responsible for causing acute changes in plasma lipids during hemodialysis. Dialysis decreased plasma triglycerides to the same extent as when heparin was given without dialysis. Cholesterol increased in proportion to hemoconcentration. Plasma free fatty acids (FFA) levels were also increased, but more so than with heparin alone. Glucose and acetate did not play a role, nor did carnitine loss, and hemofiltration elicited similar effects. The rise in plasma FFA is therefore likely to be caused by other as yet unknown mechanism.

Management of myeloma kidney: an anti-light-chain approach

This report describes the course of 23 patients with multiple myeloma and severe renal failure treated with a combination of plasmapheresis, chemotherapy, and supportive measures. Eight of ten patients with acute renal failure (ARF) obtained recovery of renal function, and in five of them serum creatinine concentration returned to normal. The remaining two patients died before the effect of treatment could be evaluated. Eleven of 13 patients with chronic renal failure (CRF) had substantial, albeit incomplete, improvement in renal function. The extent of functional recovery appeared to depend on the type of renal lesions, probably related to the duration of exposure to light chains. The median survival of the whole series of patients was 9 months, and five patients lived longer than 3 years. No clear-cut difference in survival was found between the group with ARF and that with CRF, although the latter presented higher values of serum creatinine at the time of diagnosis and residual renal insufficiency after the completion of treatment. Moreover, no significantly different survival times were found when the group with complete recovery of renal function was compared to that with minor improvement. Thus, renal failure, with the availability of effective forms of treatment of uremia, did not play a major prognostic role in our series. In contrast, the response to chemotherapy appeared to be the outstanding factor conditioning the duration of survival in these patients.

Are "routine" clinical and laboratory examinations of any help in the treatment of chronic hemodialysis patients?

The relevance of routine physical examinations, laboratory tests, and x-rays in guiding therapeutic decisions was investigated in 54 patients on hemodialysis. Patients were observed for 1 year, while recording all therapeutic interventions and tracing the procedures that had determined them. In no case did a variation in treatment follow the routine physical examination of a patient who was not symptomatic or already signaled for BP or dialytic problems by the hemodialysis nurses. A number of major therapeutic interventions were conversely necessary for acute illnesses that could not be foreseen during the routine physician-patient encounter. Of the many laboratory tests, only the determination of complete blood cell count, serum electrolytes, and calcium and phosphorus levels were frequently associated with therapeutic decisions. No intervention was directly related with x-ray bone examination. On the whole, a subgroup of 11 "high-risk" patients who required frequent and multiple therapeutic interventions was identified, the remaining 43 needing only rare and minor adjustments. It is concluded that routine physical examinations are probably useless in identifying and treating intercurrent problems of patients with chronic end-stage renal failure and that only very few hematochemical laboratory tests should be regularly performed. On the basis of a benefit/risk and benefit/cost examination, it is suggested that personally tailored follow-up schemes would probably be a more appropriate way of monitoring patients on maintenance hemodialysis.

Biofiltration: an effective and simple method to reduce dialysis time

Biofiltration: an effective and simple method to reduce dialysis time. Six stable anuric patients, on maintenance hemodialysis, were treated for 10 weeks with a parallel flow 1 m2 cuprophan filter, for 20 weeks with a parallel flow 1.2 m2 polyacrylonitrile filter using the biofiltration (BF) technique and again 10 weeks with the cuprophan filter. Usual monitors were used, without automatic control of ultrafiltration. Biochemical and hematological profile, urea kinetic parameters, incidence of hypotensive episodes, body weight and blood pressure did not change throughout the study. We conclude that three hours of BF, at least for 20 weeks, are as effective and well tolerated as four hours standard hemodialysis and could be of value in reducing dialysis time, to permit better utilization of dialysis beds.

Conjugated estrogens for the management of bleeding associated with renal failure

Bleeding is a major complication of uremia. Both cryoprecipitate and desmopressin effectively shorten the prolonged bleeding time and favorably influence clinical bleeding, but the former carries the risk of transmitting blood-borne infectious diseases, and both cryoprecipitate and desmopressin have a short duration of action. Preliminary evidence has suggested that estrogens may be useful, and we therefore performed a randomized, double-blind, crossover trial comparing the effect of conjugated estrogens with that of placebo on hemorrhagic tendencies and the bleeding time in six patients with uremia who were on maintenance hemodialysis. Five daily infusions of placebo or conjugated estrogens were administered at the beginning of one-month trial periods. Estrogen shortened the bleeding time in all six patients. The effect was detectable six hours after the first infusion, reached its maximum in all patients between days 5 and 7, and lasted for 14 days. By day 16 after the last infusion, the bleeding time had returned to base line in four of the six patients. No side effects were noted during or after estrogen infusion. Estrogens did not influence the circulating level of von Willebrand factor or change its multimeric structure. Moreover, the defective platelet aggregation and thromboxane formation observed in the patients were not corrected by estrogens. We conclude that conjugated estrogens are an adequate alternative to cryoprecipitate or desmopressin for the treatment of bleeding associated with renal failure, especially when a longer duration of action is needed and immediate onset of the effect is not essential. The mechanism of action of estrogens remains to be clarified.

Superimposed nephritis: a separate entity among glomerular diseases?

The concomitant occurrence of two glomerular diseases in the same patient was diagnosed in seven out of 105 patients undergoing renal biopsy for suspected glomerulopathy. The most frequently associated disease was a membranous type glomerulopathy. The follow-up was characterized by a rapid deterioration of renal function and two patients were required to start a chronic hemodialysis program soon after the diagnosis. It is suggested that the observed coexisting patterns of glomerular injury do not occur on the basis of chance alone and should be considered as a separate entity in glomerular pathology. In all cases, clinical and pathologic findings were strongly suggestive for two consecutive distinct pathologic processes, thus justifying the use of the term superimposed nephritis. It is reasonable to assume that the mechanisms responsible for glomerular damage and for the evolution of the disease in superimposed nephritis are different from those regulating the corresponding glomerulonephritis when occurring alone. The high prevalence of membranous pattern in superimposed nephritis indicates that pre-existing glomerular alterations might favor an immune reaction in the subepithelial space.

Moderate doses of aspirin and risk of bleeding in renal failure

Uraemic patients have a bleeding tendency thought to be due to platelet functional abnormalities, but haemodialysis paradoxically exposes patients to the thrombotic complications of arteriovenous shunts. Possible treatments of the latter have been debated. The effect of 100 mg/m2 aspirin on haemostatic function was studied in 29 uraemic patients on chronic haemodialysis who had normal or only slightly prolonged bleeding times. Aspirin did not significantly affect bleeding time in healthy controls but prolonged it in uraemic patients. In 12 of the 29 uraemic patients, the bleeding time after aspirin was longer than 15 min. Aspirin completely abolished thromboxane A2 generation by both control and uraemic platelets, indicating that its effect in uraemic patients is not due to differential inhibition of platelet cyclo-oxygenase. Products of lipoxygenase enzyme and factor VIII von Willebrand factor did not seem to have a role. A careful risk-benefit evaluation is necessary before giving aspirin to uraemic patients on haemodialysis to prevent thrombosis of the arteriovenous shunt.

Adriamycin-induced glomerulosclerosis in the rat

To evaluate long-term effect of sustained proteinuria induced by a single injection of adriamycin (ADR) on occurrence of focal segmental glomerulosclerosis (FSG), we treated 50 Sprague-Dawley (SD) rats, weighing 250 g with 5 mg/kg body weight of ADR. After six months of heavy proteinuria, 40% of ADR-treated rats did not develop FSG. In the remaining 60% of animals, a mild FSG was observed associated with the presence of large tubular casts and interstitial inflammation. Glomerulosclerosis was never observed in absence of tubulointerstitial lesions. Nine months after ADR, all rats exhibited FSG with renal insufficiency but the severest changes were restricted to the tubulointerstitial level. Our results indicate that chronic proteinuria induced by ADR is a relatively good model of glomerular sclerosis, however, the cause of glomerular sclerosis is probably different from that operating in other experimental models of FSG. Both sclerotic changes and progression of disease seem to be dependent on formation of tubular casts with consequent interstitial changes. This study raises the question of the relative role of tubulointerstitial changes in the subsequent development of FSG.

Renal biopsy in patients with acute renal failure and prolonged bleeding time: a preliminary report

A significant percentage of acute renal failure patients may benefit from a diagnostic renal biopsy, but this procedure carries an unacceptable risk of hemorrhagic complications. We have previously shown that red cell transfusions and 1-deamino-8-D-arginine vasopressin (DDAVP) are effective in managing uremic bleeding. We now report the results of giving washed red cell transfusions or DDAVP to 9 patients with uremia due to acute renal failure to improve hemostasis and allow a diagnostic renal biopsy. All patients admitted to the study had prolonged bleeding time (BT), ie, more than 10 minutes, and our procedure shortened BT in all cases, though in two patients BT after the therapeutic procedure was still longer than normal. In these two, biopsy was not performed. The seven patients whose BT became normal underwent percutaneous biopsy. Only minor clinical complications were registered. Computerized tomography (CT) revealed an incidence of perirenal hematomas comparable to that usually reported in patients with normal or slightly depressed renal function who undergo renal biopsy. Our findings indicate that red cell transfusions or DDAVP can temporarily restore hemostasis, allowing a diagnostic percutaneous biopsy in patients with acute renal failure.

Inhibition of human platelet aggregation by parathyroid hormone. Is cyclic AMP implicated?

Parathyroid hormone (PTH) is a polypeptide which in different in vitro systems raises intracellular cyclic AMP (cAMP) levels via adenyl cyclase activation and stimulates Ca2+ transport across cell membranes. We tested whether, on the basis of this mechanism, PTH would inhibit human platelet aggregation. The latter was tested in vitro by a photometric technique. Platelet aggregation induced by the calcium ionophore A 23187 was inhibited by PTH at concentrations (0.5-3 USP U/ml) similar to those effective in other in vitro systems. Higher concentrations of PTH were required to prevent aggregation initiated by adenosine-5'-diphosphate, arachidonic acid, or platelet-aggregating factor. The terminal synthetic fragment 1-34 b PTH was ineffective against all aggregation stimuli. The antiaggregating effect of PTH was potentiated by verapamil and theophylline and was additive to that of PGI2. However, PTH did not appear to increase platelet cAMP levels and was not counteracted by an inhibitor of platelet adenyl cyclase. It is therefore unlikely that PTH inhibits platelet aggregation through an adenyl cyclase stimulated increase of cAMP. Since PTH levels are markedly increased in uremic plasma, it might contribute to the defective platelet function and the bleeding tendency frequently occurring in uremic patients.

Heparin for hemodialysis: practical guidelines for administration and monitoring

Anticoagulation of extracorporeal circuit still represents a major problem for hemodialysis units. Uraemic patients are at risk of hemorrhages, so anticoagulant could increase such a risk. On the other hand clotting of extracorporeal circuit may complicate inadequate heparin administration or hemostatic activation by the foreign surfaces. In this article we propose a simple standard for heparin administration and monitoring which allows the theoretical best anticoagulation for extracorporeal circuit. Our data also indicate that the effect of our proposed schedule is not influenced by the type of membrane or dialyser used.

The metabolism of arachidonic acid by platelets in nephrotic syndrome

The production of malondialdehyde (MDA) and thromboxane B2 (TxB2) by platelets following an arachidonic acid (AA) challenge was greater in nephrotic platelet rich plasma (PRP) than in normal PRP. The uptake of 14C-AA, and its subsequent conversion to 14C-TxB2 following a thrombin stimulus, was also greater in nephrotic than normal PRP. Normal plasma diminished the MDA production by nephrotic platelets. The addition of albumin to nephrotic PRP, or, the intravenous infusion of albumin in quantities sufficient to correct hypoalbuminemia also diminished the excessive production of prostaglandin metabolites by nephrotic platelets. The platelet aggregate ratio (PAR), which measures circulating platelet aggregates, was abnormal during the acute phase of nephrotic syndrome but reverted to normal following remission. These data indicate that hypoalbuminemia is associated with increased AA metabolism by platelets and suggest that platelet "hyperactivity" may contribute to the proclivity toward thrombosis observed in nephrotic syndrome.

Immune response to hepatitis B vaccine in staff and patients in renal dialysis units

Anti-HBs response was detected in 96 per cent of staff members in three haemodialysis units after three 20 microgram doses of hepatitis B vaccine and in 82 per cent of adult patients treated with three 40 microgram doses. The percentage of responders and levels of antibody remained unchanged at 12 months from the beginning of the trial. Three out of six children injected with three 20 microgram doses in a paediatric haemodialysis unit remained free from markers of HBV infection and had high levels of anti-HBs after the second dose of vaccine. The other three children who developed serological markers of HBV infection seroconverted to anti-HBc within six months from the first dose and, in one of them, antigenaemia at three and four months was detected.

Deamino-8-D-arginine vasopressin shortens the bleeding time in uremia

In a randomized double-blind cross-over trial we gave either 1-deamino-8-D-arginine vasopressin or placebo to 12 patients with uremia, hemorrhagic tendencies, and prolonged bleeding times. After vasopressin infusion, all patients had shortened bleeding times, with the effect lasting for at least four hours in most cases. Platelet count, platelet cyclic AMP levels, platelet retention on glass beads, plasma fibronectin, serum thromboxane B2 and residual prothrombin, hematocrit, and plasma osmolarity were unchanged after vasopressin. A consistent post-infusion increase in factor VIII coagulant activity and, to a lesser extent, in factor VIII-related antigen and ristocetin cofactor accompanied the shortening of bleeding time. In addition, vasopressin induced the appearance in plasma of larger von Willebrand-factor multimers than those present in the resting state. The compound was given to nine additional patients with acute or chronic renal failure and prolonged bleeding times, before major surgery or renal biopsy. In these patients, shortening of the bleeding time was associated with normal hemostasis. Our findings indicate that 1-deamino-8-D-arginine vasopressin can be used for temporary correction of bleeding time and may prevent surgical bleeding in patients with uremia.

Severe glomerular epithelial cell damage does not prevent passive Heyman nephritis in rats

Passive Heymann nephritis (PHN) is an experimental model of membranous glomerulopathy in the rat ascribed to in situ formation of immune complexes. Very recently the demonstration that the aminonucleoside of puromycin provides some protection against PHN has highlighted the role of intrinsic properties of the glomerulus in immune complex formation. Adriamycin, a widely employed chemotherapeutic agent, is known to induce a nephrotic syndrome in rats characterized by severe ultrastructural changes of glomerular epithelial cells and by loss of glomerular polyanionic charges. We have studied the effect of pre-treatment with adriamycin on glomerular immune deposits in PHN using immunomorphological and quantitative techniques. In normal rats (group 1) injection of heterologous antibodies to proximal tubular brush border antigen (anti-FxIA), rapidly induces subepithelial immune deposits, as observed by immunofluorescence. Pre-treatment of rats with adriamycin (group 2) 48 hr before injection of anti-FxIA antibodies, when proteinuria is absent, does not alter the immunohistological findings of PHN. Heavily proteinuric rats (group 3) pre-treated with adriamycin 13 days before injection of anti-FxIA did not show any significant difference from groups 1 and 2. Species binding of injected anti-FxIA antibodies, studied by paired label techniques, was similar in normal rats and in proteinuric and non-proteinuric rats treated with adriamycin. The only difference was in the group of proteinuric rats treated with adriamycin, in which at 5 hr binding in the kidney was higher, due to tubular brush border binding as shown by immunofluorescence. This study indicates that local changes of the glomerulus and loss of glomerular histochemical properties do not invariably alter the glomerular deposition of immune complexes.

Haemolytic uraemic syndrome: therapeutic effect of plasma infusion

The therapeutic effect of plasma infusion was evaluated in 10 children and seven adults with haemolytic uraemic syndrome. All but one patient responded to this treatment with rapid disappearance of haematological abnormalities. The patient who apparently failed to respond to plasma infusion obtained complete remission of the disease after plasmapheresis. Although 15 of the 17 patients were anuric or oliguric on admission, renal function recovered completely in eight children and two adults. Seven patients showed residual chronic renal failure and two required long-term maintenance haemodialysis. Treatment with plasma was also successful in patients with relapses or recurrent episodes. Plasma infusion is a promising therapeutic approach for the haemolytic uraemic syndrome and deserves further study in clinical trials.

Platelet function in patients on maintenance hemodialysis: depressed or enhanced?

Uremic patients on long-term hemodialysis show a paradoxical association of hemorrhages on the one hand and thrombotic complications or atherosclerosis on the other. Platelet function has been found to be depressed in some cases but enhanced in others. In 19 patients, both platelet aggregation and prostaglandin formation appeared to be significantly enhanced in response to low concentrations of arachidonic acid but significantly reduced with high concentrations. It is suggested that this double functional abnormality of uremic platelets may contribute to the complex vascular disturbances of hemodialyzed patients.

Adriamycin-induced nephrotic syndrome in rats: sequence of pathologic events

Adriamycin has been suspected of causing experimental nephrotoxicity. We report here that adriamycin induces a nephrotic syndrome in rats, proteinuria beginning 4 to 5 days after a single intravenous injection (7.5 mg. per kg. of body weight). The full expression of the syndrome develops 13 to 15 days later. Minimal alterations at light microscopy, negative immunofluorescence, and only some focal "fusion" of foot processes can be observed by electron microscopy in the early phase after injection (28 hours). At 13 days, loss of foot process architecture, and replacement by flattened epithelial cytoplasm, was invariably found. These ultrastructural findings became extensive at 28 days follow-up. Colloidal iron staining of kidney biopsies revealed loss of glomerular polyanions as early as 3 hours and very marked loss at 28 hours after adriamycin injection. Polyanions were totally absent at 13 days and were still undetectable at 28 days. Thus, the loss of polyanionic charges associated with the sialic acid coat precedes the ultrastructural changes and the onset of proteinuria. These changes appeared similar to those reported in rats treated with daunomycin or puromycin animonucleoside. The present study supports in a different animal model the concept that both morphologic changes and proteinuria are the consequence of a common primary event that is the loss of glomerular fixed negative charges.

Plasmatic regulation of vascular prostacyclin in pregnancy

Activity of prostacyclin-stimulating factor was measured in six normal, non-pregnant women, six women in early normal pregnancy, six in late normal pregnancy, and six in late pregnancy complicated by severe pre-eclampsia. The activity was lower in the women in late pregnancy than in those in early pregnancy and the controls but was about normal in those with severe pre-eclampsia. These results may be relevant to the physiology of pregnancy and the pathogenesis of pre-eclampsia.

Reduced umbilical and placental vascular prostacyclin in severe pre-eclampsia

Prostacyclin production was significantly depressed in foetal and placental vascular tissues from five patients with severe pre-eclampsia in comparison to vascular tissues from women with uncomplicated pregnancy. Such an abnormality may be responsible for a reduced blood flow and defective fetal nutrition thus playing a major role in the pathogenesis of this syndrome.