Anorexigen (TNF-alpha, cholecystokinin) and orexigen (neuropeptide Y) plasma levels in peritoneal dialysis (PD) patients: their relationship with nutritional parameters.

BACKGROUND: Malnutrition has definitely been related to mortality among dialysis patients. Persistent loss of appetite is one of the major symptoms found in these patients. It is also well recognized that several substances produce anorexia or disorders of the hunger-satiety cycle in several diseases. The aim of this study was to identify the role of anorexigen substances (TNF-alpha and cholecystokinin or CCK) and an orexigen substance (neuropeptide Y or NPY) in anorexia and malnutrition among 55 clinically stable peritoneal dialysis (PD) patients. RESULTS: High TNF-alpha plasma levels were found in 41 of 42 patients (97.6%) with a mean of 70.5+/-32.3 pg/ml. Patients with anorexia (n=11) or anorexia with nausea or vomiting (n=5) had higher TNF-alpha values than patients without these symptoms (75.9+/-34 vs 52.1 +/-24.5 pg/ml, P<0.05). Eight patients with a prior diagnosis of acid pylori disease showed higher TNF-alpha values (87.2+/-24.3) than 30 unaffected patients (63.6+/-30.5, P<0.05). TNF-alpha showed a significant negative linear correlation with retinol binding protein (RBP) (r=-0.37, n=34, P<0.05), and venous pH (r=-0.4, n=42, P<0.01); also, TNF-alpha values higher than 65 pg/ml were inversely associated with transferrin, cholesterol, blood urea nitrogen (BUN) and CCK. Patients with prealbumin levels lower than 30 mg/dl, a BMI lower than 30 kg/m2, nPCR lower than 1.1 g/kg/day and urea KT/V lower than 2.2 showed higher serum TNF-alpha levels. Patients who had been on CAPD treatment for longer periods showed higher TNF-alpha values. High plasma CCK levels were found in 38 of 45 patients (84%), mean 45.9+/-32.3 pg/ml. Patients with anorexia had no difference in CCK values compared with those without. A direct association was found between CCK levels and some nutritional markers (albumin, fibronectin, triglycerides, folic acid and nPCR in non diabetic patients). Although CCK has a recognized anorectic effect, this direct association might be because of an abnormal stimulation of CCK glucose feedback (trypsin) due to continuous peritoneal glucose absorption. This suggests that CCK could be an immediate food intake marker in PD patients. The NPY plasma levels were normal in 33 patients, high in 6 and low in 11. Patients with anorexia showed lower NPY levels than those without. NPY values greater than 50 pg/ml were directly associated with higher transferrin, prealbumin, RBP, nPCR and urea KT/V values. Importantly, a negative linear correlation between NPY and TNF-alpha was found (r=-0.42, n= 41, P<0.01). There was no significant relationship between residual renal clearance and the serum levels of the three peptides. CONCLUSION: In conclusion, our data suggest that high TNF-alpha and low NPY serum levels are associated with anorexia. High TNF-alpha, low CCK and low NPY serum levels are also related to a poor nutritional status. Further research on these circulating substances is required.

[Changes in plasma levels of intestinal regulatory peptides following colonic resection in the rat]. / Evolución de los niveles plasmáticos de péptidos reguladores intestinales tras resección de colon en la rata.

The colon is considered as an endocrine organ producing regulatory peptides. Colon resection exerts an influence on remnant bowel including proliferative adaptive phenomena. The aim of this work was to determine the modifications of several regulatory peptides after colectomy and its relation with the gastrointestinal proliferative changes. 75% proximal colectomy was performed in Wistar rats. Seven groups were used according to sacrifice times: 24 h, 48 h, 72 h, 7 days, 14 days, 21 days and control group without resection. Results show significant decreases in somatostatin, neurotensin and cholecystokinin plasma levels maintained up to 21 days postsurgery. Gastrin is elevated with a highest peak at 72 h achieving basal levels at 21 day. Peptide YY show significant high levels between 72 h and 7 days. Secretin plasma levels are increased 24 h post-surgery, decreasing significantly at day 14. It is suggested that maintained low plasmatic levels of somatostatin, a known mucosal growth inhibitor, after colectomy may help the proliferative adaptation.

[Microbiological control in parenteral nutrition mixtures. Indices of contamination]. / Control microbiológico en mezclas de nutrición parenteral. Indices de contaminación.

Potential contamination of nutritional mixtures during preparation in the Pharmacy Services has led to the need for microbiological controls. In our study, we set out the techniques used in the Son Dureta Hospital between 1986 and 1991. During those six years 11,023 nutritional mixtures were prepared, and 1,714 bacteriological controls were carried out, representing 15.5% of the total. Between January 1986 and June 1989, the simple culture technique was used (culture of 10 ml of the prepared mixture). The contamination rate was 1.27%. Between July 1989 and December 1991, the double sample technique was applied, involving a culture of 10 ml of the mixture, keeping a further 10 ml for subsequent verification culture. With this technique, the contamination rate was fixed at 0.34%. The advantages and drawbacks of the techniques used are described, along with the problem of initial false positives, and a review is made of the 39 germs isolated during the period of study.

[A comparative study of 5 infusion pumps: an evaluation of their suitability for administering parenteral nutrition]. / Estudio comparativo de cinco bombas de infusión: evaluación de su idoneidad para la administración de nutrición parenteral.

To facilitate the control of administering parenteral nutrition (PN), the tendency is to replace traditional infusion equipment with infusion pumps. The aim of this study is to determine the characteristics that a pump should have for infusing PN mixtures and, based on these, to evaluate five models available on the market. The pumps evaluated, all with volumetric programming were: Becton Dickinson VIP II (Prim); Life-Care Pump Model 4 (Abbot-Shaw); Infusomat Secura 1.000 (Braun); Flo-gard (tm) 6,200 (Baxter) and IVAC-591 (Ivac). The following method was used: a) Definition of 16 basic requisites and 7 secondary requisites considered necessary in a PN pump, in accordance with the following criteria: safety, practical usage, comfort and hospital circuits. b) Review and checking of the technical reports on each pump. c) Laboratory tests simulating PN infusion, evaluating the regularity and precision of the infusion speed, and d) Subjective evaluation survey. All the pumps under study complied with the basic requisites. There were differences in the subjective evaluation, although with regard to all concepts and models a score of over 2.5 was reached in a scale of 0 to 5. The highest and lowest values with regard to regularity and precision were within the following ranges: +/- 0.6 ml/h(-)+/- 0.0 ml/h and + 3.4%(-)-1.6% respectively, and no instance of values outside the established ones was detected. The pumps only partly complied with the secondary requisites. Finally, the criteria for defining the most significant requisites was reviewed, based on the services offered by the existing pumps, as well as techniques for determining regularity and precision.(ABSTRACT TRUNCATED AT 250 WORDS)