Slug species- and population-specific effects on the end points of the Slug Mucosal Irritation test.

The Slug Mucosal Irritation test seems to be a promising method for the evaluation of the local tolerance of products applied to the mucosa. Furthermore, the Slug Mucosal Irritation test is a reliable method to classify chemicals accurately into three eye irritation categories based on the mucus production and the score for tissue damage. Until now the slug Arion lusitanicus collected in Belgium was always used as test organism. The present study investigated the effects of the slug population and species on the end points of the test and on the eye irritation classification. For this purpose, the eye irritation/damage test procedure and eye reference chemicals were used. Comparison of the results of one Belgian and two Swiss A. lusitanicus populations indicated that the geographic and ecological origins of slug populations did neither influence the mucus production, nor the score for tissue damage. Slug species-specific effects on the test end points were investigated by comparing the data of Belgian Limax flavus with corresponding data of Belgian A. lusitanicus. L. flavus produced more mucus than A. lusitanicus, so that the mucus production cut-off values had to be increased. Therefore, the results indicated that the test procedure and prediction model have to be optimised and validated, if other slug species are used instead of A. lusitanicus.     

Frequent detection of human papillomavirus 16 E2-specific T-helper immunity in healthy subjects.

The incidence of genital human papillomavirus (HPV) infections is high in young, sexually active individuals. Most infections are cleared within 1 year after infection. The targets for the cellular immune response in this process of viral clearance remain to be identified, but the expression pattern of the E2 protein in early infection and low-grade cervical intraepithelial neoplasia renders this early protein a candidate antigen. Therefore, we studied the HPV16 E2-specific T-cell responses in more detail. Very strong proliferative responses against one or more peptide-epitopes derived from this antigen can be found in peripheral blood mononuclear cell cultures of approximately half of the healthy donors. Additional analysis revealed that at least a majority of these responses represent reactivity by memory CD4(+) T-helper (Th) 1-type cells capable of secreting IFN-gamma on antigenic stimulation. Interestingly, all of the E2 peptides against which strong responses were detected are clustered in the key functional domains of the E2 protein, which are conserved to considerable extent between HPV types. This suggests that HPV16 E2-specific Th memory may be installed through encounter with HPV types other than HPV16. Indeed, one HPV16 E2-specific Th clone was found to cross-react against homologuous peptides from other HPV types, but three other Th clones failed to show similar cross-reactivity. Therefore, part of the HPV16 E2-specific Th memory may relate to previous encounter of other HPV types, whereas the majority of the immune repertoire concerned is most likely established through infection with HPV16 itself. Our data are the first to reveal that the T-cell repertoire of healthy donors can contain particularly high frequencies of E2-specific memory Th cells and suggest that boosting of this immunity can be used for preventive and therapeutic vaccination against HPV-induced lesions.     

An evaluation of an integrative care approach for end-stage renal disease patients

Studies analyzing the outcome of integrative care of end-stage renal disease (ESRD) patients, whereby patients are transferred from one renal replacement modality to another according to individual needs, are scant. In this study, we analyzed 417 files of 223 hemodialysis (HD) and 194 peritoneal dialysis (PD) patients starting renal replacement therapy between 1979 and 1996, to evaluate the effect of such an approach. Analysis was done for survival of patients on their first modality, for intention-to-treat survival (counting total time on renal replacement therapy, but with exclusion of time on transplantation), and for total survival. Log rank analysis was used and correction for risk factors was performed by Cox proportional hazards regression. Intention-to-treat survival and total survival were not different between PD and HD patients (log rank, P > 0.05). Technique success was higher in HD patients compared to PD patients (log rank, P = 0.01), with a success rate after 3 yr of 61 and 48%, respectively. Thirty-five patients were transferred from HD to PD and 32 from PD to HD. Transfer of PD patients to HD was accompanied by an increase in survival compared to those remaining on PD (log rank, P = 0.001), whereas, in contrast, transfer of patients from HD to PD was not (log rank, P = 0.17). Survival of patients remaining more than 48 mo on their initial modality was lower for PD patients (log rank, P < 0.01). A matched-pair analysis between patients who started on PD and who were transferred to HD later (by definition called integrative care patients), and patients who started and remained on HD, showed a survival advantage for the integrative care patients. These results indicate that patient outcome is not jeopardized by starting patients on PD, at least if patients are transferred in a timely manner to HD when PD-related problems arise.     

Quality assurance and standardization: summary of the satellite meeting, Turku, Finland, 11-12 June 1999

The Quality Assurance (QA) and Standardization satellite meeting addressed five major issues in newborn screening: (i) Pre- and post-analytical phases are important in the overall quality of screening, and quality assurance programs should include these aspects. (ii) It is possible to run a single screening program using laboratories on more than one site, as is done in Europe, California and Cuba. Special quality assurance procedures are necessary for success. (iii) It is possible to achieve improved analytical quality and international comparison of results by use of common reference materials such as the amino acid materials developed in Europe and the US. It will be important to use tested paper with defined performance characteristics. (iv) It is appropriate for newborn screening programs to be accredited, but it will also be important to develop criteria for pre- and post-analytic phases of screening. (v) A new QA program is being developed for Latin America. The Australasian QA program now includes amino acids and acylcarnitines in a form suitable for tandem mass spectrometry blind QA. The European Society for Paediatric Endocrinology has developed guidelines for CAH screening.     

The haematopoietic effect of recombinant human erythropoietin in haemodialysis is independent of the mode of administration (i.v. or s.c.)

Background: Previous studies comparing intravenous (i.v.) and subcutaneous (s.c.) administration of recombinant human erythropoietin (rHuEpo) often did not achieve optimal iron reserve, were restricted to a limited follow-up period (not allowing equilibration) and/or did not exclude the role of other confounding factors. In addition all papers focused on the conversion from i.v. to s.c. Methods: In this study, 30 equilibrated patients on s.c. rHuEpo were randomized into two groups, one converting to i.v. after 6 months of follow-up and one remaining on s.c. rHuEpo. In both groups rHuEpo was administered three times weekly. Only patients completing a further 6 months follow-up were considered for statistical evaluation. Serum ferritin was targeted at 200 ng/ml and haematocrits between 28 and 35% were pursued. Results: The average haematocrit levels before conversion were 31.9±1.1% in the conversion group and 31.4±1.6% at the same time point in the non-conversion group (P-NS). After 6 months haematocrits were 31.5±0.5% in the conversion group and 31.1±0.9% in the non-conversion group (P=NS). Ferritin concentration in the conversion group was 219±49 ng/ml before and 230±83 mg/ml after the conversion. For the non-conversion group ferritin was 224±25 ng/ml and 236±52 ng/ml respectively (P=NS). The weight-standardized average rHuEpo dose per injection remained the same in the conversion group before and after conversion (44.0±1.8 U/kg/injection vs 45.4±4.7 U/kg/injection) P=NS). In the non-conversion group the corresponding rHuEpo doses were 32.9±4.2 U/kg/injection and 39.6±7.0 U/kg/injection respectively (P=NS). There were no differences in serum PTH, aluminium, vitamin B12, folic-acid levels, and intake of co-trimoxazole, ACE inhibitors or theophylline. Conclusion: No changes in rHuEpo dose wee observed after conversion from s.c. to i.v. There were no significant differences between the conversion and non-conversion group. These results are in contrast to some earlier studies suggesting lower rHuEpo requirements in case of s.c. administration. Key words: anaemia; erythropoietin; intravenous erythropoietin; iron; subcutaneous erythropoietin      

Diagnosis of variants of hyperphenylalaninemia by determination of pterins in urine

Assessment of urinary pterins is proposed as a rapid method for recognition of the variants of hyperphenylalaninemia. This is achieved by means of oxidation of pterins by iodine in acidic and alkaline solutions and then by high performance liquid chromatography on a cation-exchange column with fluorimetric detection.

In biopterin-synthetase deficiency, only neopterin accumulated; in dihydropteridine-reductase (DHPR) deficiency and in phenylketonuria, high levels of pterins are found, but BH₄ levels, absent in the former and high in the latter, allow a differential diagnosis. Phenylalanine loads in the controls also lead to increased elimination of pterins, but with a pattern different from that found in phenylketonuria.

This method can be used before dietary treatment and thus can be proposed for all newly detected hyperphenylalaninemic babies.     

Dialysate partitioning in the Genius batch hemodialysis system: effect of temperature and solute concentration

BACKGROUND: The Genius batch system contains a 75-L closed reservoir from which fresh dialysate is extracted at the top, and to which spent dialysate is returned at the bottom. In vivo studies have demonstrated that almost the entire amount of dialysate can be used before contamination of fresh with spent dialysate occurs. The question is raised whether density differences cause this separation, and what the relative contributions of temperature and solute content are. METHODS: As patient substitute, a container filled with dialysate was loaded with various amounts of urea. Temperature differences between spent and fresh dialysate were imposed by not heating the dialysate at the outlet line from the dialyzer (A), heating the outlet to obtain continuously equal temperatures at inlet and outlet (B), or to temperatures as in vivo (C). With a dialysate flow set at 300 mL/min, urea is not expected at the inlet before 250 minutes. RESULTS: With a urea concentration of 33 mg/dL, urea contamination at the dialysate inlet line occurred after 185 +/- 20 (A), 122 +/- 11 (B), and 175 +/- 12 minutes (C) of dialysis, whereas with 67 mg/dL, this happened at 219 +/- 5 (A), 162 +/- 11 (B), and 202 +/- 8 minutes (C). With 100 and 150 mg/dL, urea contamination appeared at 224 +/- 2 (A) and 204 +/- 14 minutes (B), and 227 +/- 5 (A) and 232 +/- 3 minutes (B), respectively. CONCLUSION: Both temperature differences between spent and fresh dialysate and solute content of spent dialysate contribute to dialysate partitioning in the Genius dialysis system.     

Diabetes-related symptoms and negative mood in participants of a targeted population-screening program for type 2 diabetes: The Hoorn Screening study

Objective: To determine the level of diabetes-related symptom distress and its association with negative mood in subjects participating in a targeted population-screening program, comparing those identified as having type 2 diabetes vs. those who did not. Research design and methods: This study was conducted within the framework of a targeted screening project for type 2 diabetes in a general Dutch population (age 50–75 years). The study sample consisted of 246 subjects, pre-selected on the basis of a high-risk profile; 116 of whom were subsequently identified as having type 2 diabetes, and 130 who were non-diabetic subjects. Diabetes-related symptom distress and negative mood was assessed ∼2 weeks, 6 months, and 12 months after the diagnosis of type 2 diabetes, with the Type 2 Diabetes Symptom Checklist and the Negative well-being sub scale of the Well-being Questionnaire (W-BQ12), respectively. Results: Screening-detected diabetic patients reported significantly greater burden of hyperglycemic (F=6.0, df=1, p=0.015) and of fatigue (F=5.3, df=1, p=0.023) symptoms in the first year following diagnosis type 2 diabetes compared to non-diabetic subjects. These outcomes did not change over time. The total symptom distress (range 0–4) was relatively low for both screening-detected diabetic patients (median at ∼2 weeks, 6 months, and 12 months; 0.24, 0.24, 0.29) and non-diabetic subjects (0.15, 0.15, 0.18), and not significantly different. No average difference and change over time in negative well-being was found between screening-detected diabetic patients and non-diabetic subjects. Negative well-being was significantly positive related with the total symptom distress score (regression coefficient β=2.86, 95% CI 2.15–3.58). Conclusions: The screening-detected diabetic patients were bothered more by symptoms of hyperglycemia and fatigue in the first year following diagnosis type 2 diabetes than non-diabetic subjects. More symptom distress is associated with increased negative mood in both screening-detected diabetic patients and non-diabetic subjects.