Host Status of Graminaceous Cover Crops for Pratylenchus brachyurus.

Taking into account that information about the host status of cover crops for Pratylenchus brachyurus is scarce or contradictory, this study was undertaken to assess the host status of selected graminaceous cover crops by estimating nematode reproduction and their ability to decrease the nematode density in glasshouse conditions. Furthermore, the reproductive fitness of three P. brachyurus populations was assessed for Brachiaria grasses. Silage and forage sorghum proved to be good hosts for P. brachyurus; consequently, they should be avoided in fields infested with this lesion nematode, mainly before susceptible crop such as soybean, common bean, cowpea, and cotton. Dictyoneura grass, the pearl millet cv. ADR 300, and black oat were poor hosts for P. brachyurus but may increase densities of this nematode over time. Consequently, these cover crops might be used in infested fields for only short periods, because they could increase the P. brachyurus population density slowly but progressively.

Efficacy, tolerability, and safety of lanthanum carbonate in hyperphosphatemia: a 6-month, randomized, comparative trial versus calcium carbonate.

BACKGROUND/AIMS: Hyperphosphatemia is an important clinical consequence of renal failure, and its multiple adverse systemic effects are associated with significantly increased risks of morbidity and mortality in dialysis patients. Existing oral phosphate binders have not permitted control of serum phosphate within currently accepted guidelines. This study compares lanthanum carbonate with calcium carbonate for control of serum phosphate in hemodialysis patients. METHODS: In this European multicentre study, 800 patients were randomised to receive either lanthanum or calcium carbonate and the dose titrated over 5 weeks to achieve control of serum phosphate. Serum levels of phosphate, calcium and parathryoid hormone were followed over the following 20 weeks. RESULTS: Around 65% of patients in each group achieved phosphate control, but in the calcium carbonate group this was at the expense of significant hypercalcemia (20.2% of patients vs. 0.4%). Consequently, calcium x phosphate product tended to be better controlled in the lanthanum group. CONCLUSION: This 6-month study demonstrates that serum phosphate control with lanthanum carbonate (750-3,000 mg/day) is similar to that seen with calcium carbonate (1,500-9,000 mg/day), but with a significantly reduced incidence of hypercalcemia. Lanthanum carbonate is well tolerated and may be more effective in reducing calcium x phosphate product than calcium carbonate.

The elderly dialysis patient: management of the hospital stay.

Our data show that survival times in elderly patients can be achieved, which justify the strain of the therapy on the patient, the medical effort and financial expense. It is therefore not justifiable to withhold dialysis from a person who requires it on the basis of age. It is also wrong to reduce the therapeutic endeavours to a minimum and describe these then as 'kinder' to the patient. It is to be feared that such a treatment regimen leads to a shorter survival time and simultaneously to a decreased quality of life. Particularly in view of the person's advanced age, it would seem that we are obligated to treat them with the highest quality care so that the remaining time is not only extended, but is filled with life.

Bone fracture history and prospective bone fracture risk of hemodialysis patients are related to apolipoprotein E genotype.

This investigation of 219 hemodialysis patients relates the history and prospective risk of bone fractures to apolipoprotein E (apoE) genotype. A greater percentage of the 41 patients with the E3/4 and E4/4 genotypes than of the 38 patients with the E2/3 and E2/2 genotypes had a history of bone fractures at the time of recruitment (44% versus 16%, P < 0.005). During the 4 years following recruitment, more of the patients with apoE genotypes E3/4 and E4/4 than with apoE genotypes E2/3 and E2/2 suffered bone fractures, but this difference was not statistically significant (17.1 versus 5.3%, P < 0.1). ApoE genotype appears to be an important genetic risk factor for bone fracture, possibly due to its previously reported influence on vitamin K concentrations in blood.

Bone health of adult hemodialysis patients is related to vitamin K status.

This investigation of 68 hemodialysis patients (ages 33 to 91) analyzed the association of biochemical indicators of vitamin K nutriture and bone metabolism, and related both to past bone fracture history and prospective bone fracture risk. Phylloquinone concentrations were significantly lower in the 23 patients with previous fractures compared to those without (0.93 vs. 1.50 nmol/liter, P < 0.003) and a smaller percentage of their serum osteocalcin was carboxylated (48.8 vs. 53.6%, P < 0.03). The 41 patients who never had fractures had nearly three times higher phylloquinone concentrations than the nine patients with fractures during a four-year follow-up period (1.59 vs. 0.55 nmol/liter, P < 0.002) and more carboxylated serum osteocalcin (55.2 vs. 42.0%, P < 0.01). None of the patients with phylloquinone concentrations over 2.2 nmol/liter had elevated intact parathyroid hormone (iPTH) concentrations, and only patients with less than 1 nmol/liter phylloquinone had severe hyperparathyroidism (iPTH > 300 ng/liter). Our data thus indicate that suboptimal vitamin K nutriture in hemodialysis patients is associated both with increased bone fracture risk and with a high prevalence of hyperparathyroidism.

Significant reduction of factor D and immunosuppressive complement fragment Ba by hemofiltration.

Because of their effect on the immune response, especially in patients with chronic or acute renal failure, factor D (FD) and the immunosuppressive complement fragment Ba are substances which may be important for the immunological status. Since they cannot be eliminated by conventional Cuprophan hemodialysis because of their high molecular weight (24,000 and 33,000 D, respectively), the effect of hemofiltration (HF) on the plasma concentration of both components was tested. It was shown that plasma levels of FD can be lowered by 43.5% during an HF treatment and the plasma concentration of Ba by 30.6%. Moreover, the two substances could be detected in the hemofiltrate. Up to 75 mg FD and up to 37 mg Ba could be eliminated per treatment, depending on the plasma concentrations and the filtration volume. A convective method such as chronic HF is therefore clearly superior to diffusive methods of blood purification when substances with such a high molecular weight have to be eliminated. It has still to be established whether the elimination of FD and Ba by chronic intermittent HF results in a sustained improvement in the immunological status of patients treated in this way.

The treatment of uraemic hyperphosphataemia with calcium acetate and calcium carbonate: a comparative study.

A comparative study of long-term haemodialysis patients investigated the effects of calcium acetate and calcium carbonate on concentrations of serum phosphate, calcium, and parathyroid hormone. It was demonstrated that both substances led to a significant decrease in phosphate and serum parathyroid hormone. Administration of calcium acetate reduced the serum phosphate concentration in 7 weeks from an initial value of 2.08 +/- 0.53 mmol/l to 1.51 +/- 0.39 mmol/l (P less than 0.01). Following a 1-week wash-out period, calcium carbonate reduced the serum phosphate concentration in the same patients from 1.99 +/- 0.62 mmol/l to 1.34 +/- 0.40 mmol/l (P less than 0.01). Of particular significance, however, is the fact that in relation to daily elementary calcium intake, calcium acetate was a considerably more effective binder of intestinal phosphate than calcium carbonate. During administration of calcium acetate only 1.02 g of elementary calcium were required daily in order to reduce the serum phosphate concentration. The same patients, however, required 1.88 g of elementary calcium during calcium carbonate therapy. Complementary studies investigated the influence of an accompanying calcitriol medication. In this instance, too, calcium acetate was shown to be more effective; although the patients developed hypercalcaemia with calcium acetate, this happened more often with calcium carbonate. In summary it can be said that daily calcium loading of the uraemic organism under calcium acetate therapy is reduced by nearly half as compared to calcium carbonate therapy, and that this can be achieved with the same effective decrease of the serum phosphate concentration.

Soluble interleukin 2 receptor and tissue polypeptide antigen serum concentrations in end-stage renal failure.

Serum concentrations of soluble interleukin 2 receptor (IL-2R) were measured in 65 hemodialysis patients and compared with serum levels of beta 2-microglobulin and tissue polypeptide antigen (TPA). Elevated IL-2R levels, found in 85% of examined patients, correlated with elevated TPA serum concentrations (p less than 0.05). Patients with high IL-2R levels were significantly younger (p less than 0.05) than patients with low levels. Primary renal disease and residual renal function had no significant influence on TPA or IL-2R serum concentrations. In 16 patients with carpal tunnel syndrome, increased serum concentrations of IL-2R (p less than 0.005) and TPA (p less than 0.001) were found. We conclude that a non-specific dialysis-induced activation of epithelial and lymphoid cells rather than a specific immune response could explain the concomitant elevation of IL-2R and TPA serum concentrations in hemodialyzed patients. Patients with pronounced cell turnover, reflected by elevated IL-2R and TPA levels, may show an increased susceptibility to dialysis-associated amyloidosis.

Calcium ketovaline as new therapy for uremic hyperphosphatemia.

Since treatment of uremic hyperphosphatemia still represents a major problem and phosphate-binding agents carry the well-known risk of aluminum intoxication, we carried out a study to determine whether calcium ketovaline, a keto acid containing calcium, would show phosphate-binding effects comparable to those obtained with a mixture of amino acids and calcium salts of ketoanalogues tested previously. In vitro as well as in vivo studies show convincingly that calcium ketovaline is a valuable intestinal phosphate binder. Dialysis patients treated for 6 weeks showed a significant (p less than 0.05) decrease in serum phosphate from 2.36 +/- 0.19 to 1.81 +/- 0.16 mmol/l.

The beneficial effect of ketoacids on serum phosphate and parathyroid hormone in patients with chronic uremia.

Hyperphosphatemia and secondary hyperparathyroidism are regular complications in patients suffering from advanced renal failure. As aluminum-containing drugs carry the well-known risk of aluminum intoxication, we were interested in testing in a prospective study a mixture of ketoanalogues and amino acids which have been shown to lower the serum phosphate and parathyroid hormone in uremic patients. For 3 months, in addition to their diet, 17 uremic patients and 12 hemodialysis patients received a daily supplement of this mixture. Although no additional phosphate binders were administered, serum phosphate decreased significantly in the former group and was slightly lower in the latter. The serum parathyroid hormone level was consistently lowered when the initial concentration was not higher than 20 times normal.

Unintentional weight loss in chronic hemodialysis patients--a diagnostic dilemma.

Reasons for an unintentional weight loss were investigated in a retrospective study of 26 (13.5%) patients who, out of 192 patients, had revealed a continuous linear weight loss of more than 4 kg since commencing hemodialysis treatment. The investigated serum parameters were not indicative, nor were the regularly performed tuberculin tests and the computer tomography helpful for the diagnosis. However, from the analysis of the causes for hospital admission it appears that hemodialysis patients with wasting suffer especially frequently from a sepsis. Physicians should be aware of this complication which induces further body weight loss.

Renal osteodystrophy in asymptomatic hemodialysis patients: evidence of a sex-dependent distribution and predictive value of serum aluminum measurements.

Bone histologies and serum concentrations of calcium, phosphate, alkaline phosphatase, iPTH, 25 OHD, 1,25(OH)2D3, and aluminum were obtained from 113 chronically hemodialyzed patients free of symptoms and signs of renal osteodystrophy. All patients had a pathologic bone histology; in 69.0%, a mixed form with predominant osteitis fibrosa and concomitant osteoidosis. In 30.1%, we found pure hyperosteoidosis, nearly half of these cases showing osseous aluminum deposits. Hyperosteoidosis was much more frequent in women (35.7%) than in men (20.9%), although the prescribed intake of aluminum-containing phosphate binders was the same. It is possible that female hemodialysis patients were more prone to aluminum accumulation or that they had a better compliance in taking the aluminum hydroxide. Serum parameters alone were not very helpful in predicting the underlying bone disease. Mean iPTH concentrations tended to be lower in the patients with hyperosteoidosis than in those with the mixed lesion, but there was wide variation. Serum aluminum was only predictive for aluminum deposits in the bone when concentrations exceeded 100 micrograms/L.

HTLV-III antibodies in hemodialysis patients--a consequence of blood transfusions?

An investigation for HTLV-III antibodies in chronic hemodialysis patients revealed in four out of 276 patients a positive result using the ELISA and western blot techniques. All HTLV-III positive patients had received blood transfusions. As it has been shown that a needle stick could transmit the HTLV-III, it is suggested that hemodialysis patients who have received frequent blood transfusions should be screened.

Optimum dialysis treatment for patients over 60 years with primary renal disease. Survival data and clinical results from 242 patients treated either by haemodialysis or haemofiltration.

An analysis of the data of 180 haemodialysis patients and 62 haemofiltration patients over 60 years of age when commencing treatment, clearly shows that this age group of patients (when suffering from primary renal disease) has a very good chance of surviving many years when treated with either haemodialysis or haemofiltration. This refers also to patients being older than 75 or 80 years, who have survival rates of 50 per cent after five years and three years respectively. The presented data further indicate that chronic haemofiltration seems to be the superior treatment when compared with acetate haemodialysis for the treatment of elderly renal patients, as the survival rates are at any chosen time interval higher with haemofiltration than with haemodialysis.

Chronic hemofiltration. A critical evaluation of a new method for the treatment of blood.

The experiences which have been compiled in more than 2400 hemofiltrations confirm that this method represents an alternative way of treating uremic patients. The main advantages of chronic hemofiltration are the comfort of the patient and the ease in handling excess overhydration without extending treatment time, which is less than 3 X 3 hours/week if adequate hemofilters are used. With regard to the improvement of such typical uremic complications as severe hypertension, hypertriglyceridemia or neuropathy, hemofiltration does not seem to be superior to hemodialysis. However, since most hemofiltration patients do not require phosphate binders and, additionally, remarkable amounts of parathyroid hormone are removed during one hemofiltration, it appears possible that hemofiltration might be an important therapeutic alternative for those renal patients who suffer from severe hyperphosphatemia and secondary hyperparathyroidism.

Clinical aspects of hemofiltration.

We report on clinical experiences obtained in 7 uremic patients treated since January 1976 3 times weekly by chronic hemofiltration. The observations which we collected in more than 300 treatments suggest that hemofiltration might be superior to conventional hemodialysis. The main advantages of this treatment are characterized by its better control of hypertension, hyperhydration, and possibly of uremic bone disease. Furthermore, the applied acrylonitrile membrane allows the removal of substances with a molecular weight up to 60,000, similar to the glomerular basement membrane. Additionally, we report on methodological problems, on the compatibility of hemofiltration, and finally on its efficiency for removal of different uremic solutes.

The hemofiltration system: variations of the negative pressure.

The physical conditions of the hemofiltration process are briefly discussed to describe the applied system that is characterized by a negative pressure pump which is directly attached behing the filter. A schema is presented that shows the characteristics of a fully automatic hemofiltration apparatus that is presently in development.

Parathyroid hormone-, 25-OH-vitamin D-, and digoxin levels in patients treated by chronic hemofiltration.

Immunoreactive parathyroid hormone (iPTH) was measured in the serum and filtrate before, during and after hemofiltration. iPTH regularly declines during hemofiltration; one patient, investigated for a longer period, showed a normalization of iPTH serum level with this treatment. The iPTH values found in the hemofiltrate were remarkably high, a finding that could be explained by non-specific effects, by the occurrence of hormone fragments or by an increased secretion rate. At any rate, the results suggest a filtration of parathyroid hormone and/or hormone fragments. On the other hand, it was impossible to detect any 25-OH-vitamin D in the hemofiltrate. Finally, digoxin could be found in the filtrate, but only in very low concentrations.