Dialysis and the elderly: an underestimated problem

In developed countries, the incidence of end-stage renal failure is constantly increasing, and uremia will soon be a disease typically found in mature and elderly adults. Almost invariably, the physical condition of the elderly patient with terminal uremia is extremely poor, and therapeutic approach complex. Frequent co-morbidity, treatment with many different drugs, the high risk of iatrogenic damage, advanced age and socio-environmental conditions further complicate the management of these patients. While replacement therapy may become necessary, peritoneal dialysis may have advantages over hemodialysis. Peritoneal dialysis causes less hemodynamic stress, does not necessitate vascular access and allows mobility, although it incurs a high incidence of peritonitis and vascular disease. Where hemodialysis is the only feasible treatment, procedures used for vascular access are frequently followed by several complications, representing an important cause of morbidity and hospitalization. In addition, even if it may improve the patient's quality of life, vascular condition, intradialytic hypotension, heart disease, intestinal bleeding and amyloidotic arthropathy are critical aspects of dialysis in the elderly patient. Therefore, particular attention from clinicians and administrators is required and the best possible strategies must be identified in order to provide effective and appropriate services to address these special patients' needs.     

A one-year exercise intervention program in pre-pubertal girls does not influence hip structure

Background

Glucosamine (GlcN) used by patients with osteoarthritis was demonstrated to reduce pain, but the working mechanism is still not clear. Viscosupplementation with hyaluronic acid (HA) is also described to reduce pain in osteoarthritis. The synthesis of HA requires GlcN as one of its main building blocks. We therefore hypothesized that addition of GlcN might increase HA production by synovium tissue.

Methods

Human osteoarthritic synovium explants were obtained at total knee surgery and pre-cultured for 1 day. The experimental conditions consisted of a 2 days continuation of the culture with addition of N-Acetyl-glucosamine (GlcN-Ac; 5 mM), glucosamine-hydrochloride (GlcN-HCl; 0.5 and 5 mM), glucose (Gluc; 0.5 and 5 mM). Hereafter HA production was measured in culture medium supernatant using an enzyme-linked binding protein assay. Real time RT-PCR was performed for hyaluronic acid synthase (HAS) 1, 2 and 3 on RNA isolated from the explants.

Results

0.5 mM and 5 mM GlcN-HCl significantly increased HA production compared to control (approximately 2 – 4-fold), whereas GlcN-Ac had no significant effect. Addition of 5 mM Gluc also increased HA production (approximately 2-fold), but 0.5 mM Gluc did not. Gene expression of the HA forming enzymes HAS 1, 2 and 3 was not altered by the addition of GlcN or Gluc.

Conclusion

Our data suggest that exogenous GlcN can increase HA production by synovium tissue and is more effective at lower concentrations than Gluc. This might indicate that GlcN exerts its potential analgesic properties through stimulation of synovial HA production.     

Microsurgery for treatment of peripheral lymphedema: long-term outcome and future perspectives

Authors report over 30 years of their own clinical experience in the treatment of chronic peripheral lymphedemas by microsurgical techniques performed at the Center of Lymphatic Surgery of the University of Genoa, Italy. Over 1,500 lymphedema patients were treated with microsurgical techniques. Derivative lymphatic-venous techniques were most often used. For those cases where a venous disease was associated to lymphedema, reconstructive lymphatic microsurgery techniques were performed (lymphatic-venous-lymphatic-plasty). Objective assessment was undertaken by water volumetry and lymphoscintigraphy. Volume changes showed a significant improvement in over 83%, with an average follow-up of more than 10 years. There was an 87% reduction in the incidence of cellulitic attacks after microsurgery. Microsurgical lymphatic-venous anastomoses have a place in the treatment of peripheral lymphedema and should be the therapy of choice in patients who are not sufficiently responsive to nonoperative treatment. Improved results can be expected with operations performed at earlier lymphedema stages.     

The process of nutrient analysis for controlled feeding trials: a comparative study of two South African nutrient databases with chemical analysis

BackgroundThere is an increased tendency in the field of nutrition research to conduct more outpatient controlled feeding trials. The formulation of accurate diets is essential in order to assemble valid scientific data, which will substantiate hypothesised relationships between a nutrient variable and an outcome. Research dieticians rely on the accuracy of computerised nutrient databases when designing the menu.ObjectiveThe reliability of the two computerised nutrient databases available in South Africa containing foods from different food sources were investigated, comparing them with each other and with the reference standard of chemical analysis.MethodsA seven day Westernised menu providing an energy level of 7500 kJ/day was entered into FoodFinder3® (2002) and Dietary Manager (modified 2006 version) Software programmes. Food prepared according to this menu was chemically analysed for the macronutrient profiles (carbohydrate, fat and protein), fatty acid distribution (saturated fatty acids, mono-unsaturated fatty acids and poly-unsaturated fatty acids) and total fibre, insoluble and soluble fibre in order to compare data.ResultsThe two nutrient databases' values did not differ significantly from each other despite using different food sources, however, there were differences between the chemically analysed values and the databases' calculated values for selected nutrients. There were no significant differences between the amount of total energy, protein, carbohydrate, poly-unsaturated fatty acids and total fibre. The total fat, saturated fatty acid and mono-unsaturated fatty acid content using both FoodFinder3® and Dietary Manager were statistically and practically significantly higher than the chemical analysis (p < 0.05). FoodFinder3® produced significantly lower levels of insoluble and soluble fibre compared to the chemical analysis.ConclusionThe use of computerised nutrient databases in menu design for controlled feeding trials is functional and assists the research dietician with this challenging task. However, computer nutrient databases are not reliable enough to exclude the step of menu validation by chemical analysis before the start of the intervention.     

Hand bone densitometry: a more sensitive standard for the assessment of early bone damage in rheumatoid arthritis

OBJECTIVE: To examine the role of hand dual-energy x ray absorptiometry (DEXA) compared with radiography in the assessment of bone involvement in patients with early rheumatoid arthritis (RA) who have active disease. METHODS: The study population (n = 79) had RA of <12 months' duration and were selected for poor prognostic features. Clinical data and bone mineral density (BMD) data were collected at baseline, 24 and 48 weeks. Hand radiographs were performed at baseline and 48 weeks. Bone damage analyses were performed for the group and individuals using the smallest detectable change (SDC) method. RESULTS: At baseline, mean disease duration was 8.5 months, erythrocyte sedimentation rate was 34.3 mm/hour, C-reactive protein was 40.2 mg/l, Health Assessment Questionnaire score was 1.35 and 81% of patients were positive for rheumatoid factor. Mean (95% CI) hand BMD loss was 2.5% (-3.5 to -1.5) at 24 weeks and 2.6% (-3.8 to -1.5) at 48 weeks. Individual hand bone loss exceeding the SDC was seen in 46.8% at 24 weeks and in 58.2% at 48 weeks. In the subgroup of 58 patients who had undergone radiography, radiographic joint damage score evaluated by the Sharp-van der Heijde method increased from 4.8 to 10.6 (p = 0.001). Individual hand bone loss in this subgroup exceeding the SDC was seen in 50.0% at 24 weeks and in 56.9% at 48 weeks, whereas at 48 weeks only 22.4% had deteriorated in modified Sharp score. CONCLUSION: The study results indicate that hand DEXA is a more sensitive tool than radiology (radiographic joint-damage scores), for measuring disease-related bone damage in early RA.     

Dual effect of endothelin 1 on angiotensin II-potentiated purinergic neurotransmission in prostatic rat vas deferens

Angiotensin and endothelin are vasoactive peptides with neuromodulatory effect, however their interactions in facilitating neurotransmission are largely unknown. In the present study, effort was made to examine how endothelin 1 modulates angiotensin II-potentiated purinergic neurotransmission in prostatic rat vas deferens. Both peptides facilitated field-stimulated muscle contraction in a concentration-dependent manner with Kd values of 16.97+/-6.47 and 2.46+/-0.83 nM for angiotensin II and endothelin 1, respectively. Hill plot analysis gave Hill constants of 0.91+/-0.15 and 0.97+/-0.26 for angiotensin II and endothelin 1, respectively. Correlation analysis indicated that the extent of potentiation by angiotensin II, but not endothelin 1, was proportional to the basal field-stimulated muscle contraction. In the presence of low concentrations of endothelin 1 (< or = 3 nM), angiotensin II-potentiated field-stimulated contraction was further enhanced by endothelin. However, in the presence of high concentrations of endothelin 1 (> or = 10 nM), a much increased basal field-stimulated contraction was observed, and the addition of angiotensin II did not elicit any further enhancement in the contractile response. Intriguingly, after prolonged exposure of prostatic rat vas deferens to a high concentration of endothelin 1, the addition of angiotensin II induced a refractory response to field-stimulation. Taken together, our result indicated that endothelin 1 augmented angiotensin II-facilitated purinergic neurotransmission in prostatic rat vas deferens at low concentrations, but inhibited gradually at high concentrations.     

Paracetamol inhibits nitric oxide synthesis in murine spinal cord slices

Paracetamol is an effective analgesic but its mechanism of action is unclear. We investigated the effect of paracetamol and the analgesic adjuvant caffeine on the activity of NO synthase in mouse spinal cord and cerebellar slices in vitro, by measuring the conversion of [(3)H]arginine to [(3)H]citrulline. Paracetamol (100 microM) had no effect on NO synthase activity in cerebellum, but in the spinal cord both paracetamol (100 microM) and caffeine (30 microM) attenuated glutamate (5 mM)-induced [(3)H]citrulline production and in combination they abolished it. In conclusion paracetamol inhibits spinal cord NO synthesis and this may be related to its analgesic effects.     

Intraarterial hepatic chemoembolization of liver metastases from colorectal cancer adopting irinotecan-eluting beads: results of a phase II clinical study

Since November 2005 a clinical trial of intraarterial hepatic chemoembolization (TACE) with irinotecan-eluting beads has been ongoing in 20 patients affected by liver metastases from colorectal cancer in a palliative setting. A high response rate (80%), with reduction of lesional contrast enhancement in all responding patients was found. The procedure was well tolerated by most patients, with a median duration of hospitalization of 3 days (range 1-10 days). The most important adverse event was abdominal pain during the injection. Adequate supportive treatment with antibiotic and antiemetic prophylaxis, dexamethasone, and intravenous hydration is strictly necessary until the serum levels of transaminases are stabilized and in order to prevent infections. Major analgesics such as morphine must be used before and after the procedure. Our results suggest that TACE using irinotecan-eluting beads is feasible and active in pretreated patients with liver metastases from CRC.     

New release cell for NMR microimaging of tablets. Swelling and erosion of poly(ethylene oxide)

A small release cell, in the form of a rotating disc, has been constructed to fit into the MRI equipment. The present work show that both qualitative and quantitative information of the swelling and erosion behavior of hydrophilic extended release (ER) matrix tablets may be obtained using this release cell and non-invasive magnetic resonance imaging (MRI) studies at different time-points during matrix dissolution. The tablet size, core size and the gel layer thickness of ER matrix formulations based on poly(ethylene oxide) have been determined. The dimensional changes as a function of time were found to correspond well to observations made with texture analysis (TA) methodology. Most importantly, the results of the present study show that both the erosion (displacement of the gel-dissolution media interface) and the swelling (decrease of dry tablet core size) proceed with a faster rate in radial than in axial direction using the rotating disk set-up. This behavior was attributed to the higher shear forces experienced in the radial direction. The results also indicate that front synchronization (constant gel layer thickness) is associated with the formation of an almost constant polymer concentration profile through the gel layer at different time-points.