EPR detection of paramagnetic chromium in liver of fish (Anguilla anguilla) treated with dichromate(VI) and associated oxidative stress responses-contribution to elucidation of toxicity mechanisms

The impact of chromium (Cr) on fish health has been the subject of numerous investigations, establishing a wide spectrum of toxicity, attributed particularly to the hexavalent form [Cr(VI)]. However, reports on the simultaneous assessment of Cr toxicity in fish and its toxico-kinetics, namely involving metal speciation, are scarce. Therefore, keeping in view the understanding of the mechanisms of Cr(VI) toxicity, this work intended to detect the formation of paramagnetic Cr species in liver of Anguilla anguilla following short-term dichromate(VI) intraperitoneal treatment (up to 180 min), assessing simultaneously the pro-oxidant properties. The formation of Cr(V) and Cr(III) was examined by electron paramagnetic resonance (EPR), as an innovative approach in the context of fish toxicology, and related with the levels of total Cr. Cr(V) was successfully detected and quantified by EPR spectrometry, showing a transient occurrence, mostly between 15 and 90 min post-injection, with a peak at 30 min. The limitations of EPR methodology towards the detection and quantification of Cr(III) were confirmed. Although Cr(VI) exposure induced the antioxidant system in the eel's liver, the oxidative deterioration of lipids was not prevented. Overall, the results suggested that Cr(V), as a short-lived species, did not appear to be directly and primarily responsible for the cellular damaging effects observed, since stress responses persisted up to the end of exposure regardless Cr(V) drastic decay. Though further research is needed, ROS mediated pathways (suggested by superoxide dismutase and catalase activity induction) and formation of Cr(III) complexes emerged as the most plausible mechanisms involved in Cr(VI) toxicity.

Methylglyoxal causes structural and functional alterations in adipose tissue independently of obesity

CONTEXT

Adipose tissue is one of the first organs to develop insulin resistance even with moderate BMI. However, the contribution of developing hyperglycaemia and concomitant methylglyoxal increment to tissue dysfunction during type 2 diabetes progression was not addressed before.

METHODS

Young and aged Wistar and Goto-Kakizaki rats (non-obese model of type 2 diabetes) and a group of MG-treated W rats were used to investigate the chronic effects of hyperglycaemia and ageing and specifically MG-induced mechanisms.

RESULTS

Diabetic and aged rats showed decreased adipose tissue irrigation and interstitial hypoxia. Hyperglycaemia of diabetic rats leaded to fibrosis and accumulation of PAS-positive components, exacerbated in aged animals, which also showed decreased hipoadiponectinemia, increased MCP-1 expression and macrophage infiltration to glycated fibrotic regions. MG leaded to increased free fatty acids, hipoadiponectinemia, decreased irrigation, hypoxia and macrophage recruitment for glycated fibrotic regions.

CONCLUSIONS

MG contributes to dysfunction of adipose tissue during type 2 diabetes progression.

A comparative study between fluoroscopic and endoscopic guidance in palliative esophageal stent placement

Self-expanding metallic stents (SEMS) are the treatment of choice for incurable obstructive malignant esophageal strictures. Although the placement of SEMS is usually performed with fluoroscopic control (FC), recently several authors have shown the feasibility of placing SEMS under endoscopic control alone (EC). However, studies comparing the two techniques are lacking. The objective of this study was to compare the feasibility and safety of SEMS insertion under fluoroscopic control and endoscopic control. The study was performed through the retrospective analysis of patients who underwent SEMS insertion for malignant dysphagia between January 2005 and January 2010. Data concerning early and late complications and survival were retrieved. Early complications were defined as pain, vomiting, bleeding, malposition/migration, perforation, and/or dysphagia occurring until 30 days of SEMS insertion; and late complications as tumor ingrowth and overgrowth, migration, hemorrhage, fistulae, food impaction, and/or esophagitis occurring after 30 days. We placed 126 SEMS of which 87% for esophageal stricture, 8% for esophagus-respiratory fistula, and 5% for extrinsic compression. The mean age of the patients was 62 years, and 93 were male. SEMS insertion was performed with FC in 66 patients and EC in 60. Early complications occurred in 34 patients (52%) in the FC group and 28 (47%) in the EC group (P=0.71), including: pain in 22 patients of the FC group and 15 of the EC group (P=0.31); vomiting in 15 of the FC group and nine of the EC group (P=0.27); malposition/migration in three of the FC group and four of the EC group (P=0.60); hemorrhage in one of the FC group and two of the EC group (P=0.27); and dysphagia in two of the FC group and three of the EC group (P=0.57). Late complications occurred in 20 patients (30%) in the FC group and 22 (37%) in the EC group (P=0.44), including: tumor in/overgrowth in 13 patients of the FC group and 10 of the EC group (P=0.66); prostheses migration in five of the FC group and eight of the EC group (P=0.28); hemorrhage in two of the FC group and two of the EC group (P=0.54); appearance of esophageal fistulae in seven of the FC group and four of the EC group (P=0.43); food impaction in nine of the FC group and eight of the EC group (P=0.96); esophagitis in 12 of the FC group and 15 of the EC group (P=0.35). Median survival was 107 days (95% confidence interval [CI]=6-369 days) with no difference between the two groups. There were no statistical significant differences in the incidence of complications and in survival between patients undergoing SEMS placement under fluoroscopic control or endoscopic control.

Regulation of hypoxia-inducible factor 1 and the loss of the cellular response to hypoxia in diabetes

Diabetes is frequently associated with hypoxia and is known to impair ischaemia-induced neovascularisation and other forms of adaptive cell and tissue responses to low oxygen levels. Hyperglycaemia appears to be the driving force of such deregulation. Recent data indicate that destabilisation of hypoxia-inducible factor 1 (HIF-1) is most likely the event that transduces hyperglycaemia into the loss of the cellular response to hypoxia in most diabetic complications. HIF-1 is a critical transcription factor involved in oxygen homeostasis that regulates a variety of adaptive responses to hypoxia, including angiogenesis, metabolic reprogramming and survival. Thus, destabilisation of HIF-1 is likely to have a negative impact on cell and tissue adaptation to low oxygen. Indeed, destabilisation of HIF-1 by high glucose levels has serious consequences in various organs and tissues, including myocardial collateralisation, wound healing, renal, neural and retinal function, as a result of poor cell and tissue responses to low oxygen. This review aims to integrate and summarise some of the most recent developments, including new proposed molecular models, on this research topic, particularly in terms of their implications for potential therapeutic approaches for the prevention or treatment of some of the diabetic complications characterised by impaired cellular and tissue responses to hypoxia.

(-)-Linalool, a naturally occurring monoterpene compound, impairs memory acquisition in the object recognition task, inhibitory avoidance test and habituation to a novel environment in rats

It is known that (-)-linalool is a competitive antagonist of NMDA receptors, which play a key role in the learning and memory processes; however, only a few studies have reported a possible interference of (-)-linalool in memory. The purpose of this study was to investigate the (-)-linalool effects on acquisition of short- and long-term memories through the objects recognition task, inhibitory avoidance test and habituation to a novel environment. Furthermore, the open field test was used to investigate the interference of (-)-linalool in motivation, locomotion and exploration by animals. Wistar male adult rats received an intraperitoneal injection (i.p.) of saline (NaCl 0.9%), tween 5% or (-)-linalool (50 or 100 mg/kg) before training in the tasks; MK-801 (0.1 mg/kg), a glutamate antagonist, was used as positive control. Short-term (STM) and long-term (LTM) memories were tested 1.5 and 24 h after training, respectively, in the inhibitory avoidance and recognition objects. The results suggested that (-)-linalool (as 50- and 100-mg/kg doses) impaired LTM acquisition, but not STM acquisition, in the object recognition task. In the inhibitory avoidance test, animals receiving linalool (both doses) showed impairment in acquisition of both memories measured. In the open field test, the animals that received (-)-linalool showed no significant difference in the crossings and latency to start the locomotion in any of the doses tested, although (-)-linalool 100 mg/kg reduced rearing behavior. When re-exposed to open field 24 h after training, the rats that received (-)-linalool 100mg/kg showed no habituation. Taken together, these data suggested that (-)-linalool was able to impair the acquisition of memory in rats, which can be associated to (-)-linalool antagonist capacity as regards NMDA glutamatergic receptors, since other glutamate antagonists also seem to affect memory.

Regulation of hypoxia-inducible factor 1 and the loss of the cellular response to hypoxia in diabetes

Diabetes is frequently associated with hypoxia and is known to impair ischaemia-induced neovascularisation and other forms of adaptive cell and tissue responses to low oxygen levels. Hyperglycaemia appears to be the driving force of such deregulation. Recent data indicate that destabilisation of hypoxia-inducible factor 1 (HIF-1) is most likely the event that transduces hyperglycaemia into the loss of the cellular response to hypoxia in most diabetic complications. HIF-1 is a critical transcription factor involved in oxygen homeostasis that regulates a variety of adaptive responses to hypoxia, including angiogenesis, metabolic reprogramming and survival. Thus, destabilisation of HIF-1 is likely to have a negative impact on cell and tissue adaptation to low oxygen. Indeed, destabilisation of HIF-1 by high glucose levels has serious consequences in various organs and tissues, including myocardial collateralisation, wound healing, renal, neural and retinal function, as a result of poor cell and tissue responses to low oxygen. This review aims to integrate and summarise some of the most recent developments, including new proposed molecular models, on this research topic, particularly in terms of their implications for potential therapeutic approaches for the prevention or treatment of some of the diabetic complications characterised by impaired cellular and tissue responses to hypoxia.

Dysplasia surveillance in an ulcerative colitis patient: successful detection with narrow band imaging and magnification

One of the contemporary challenges gastroenterologists face is cancer screening and surveillance in long-term colitis patients. The search for a consensually practical and effective method to routinely detect dysplastic mucosa persists. In recent years, publications demonstrating the applicability of narrow band imaging (NBI) in this setting have sparked further research. We present a case report where NBI with magnification played a fundamental role in the detection of dysplasia in an ulcerative colitis patient. This case reinforces the potential widespread applicability of NBI as a surveillance tool in distinguishing dysplastic from nondysplastic colorectal lesions in ulcerative colitis.

[Lumbar tuberculous spondylodiscitis: a minimally invasive surgical approach]

INTRODUCTION

Tuberculous spondylodiscitis is the most frequent and severe manifestation of extra-pulmonary tuberculosis, accounting for 40 to 50 percent of the cases with osteoarticular involvement. Although antituberculous drugs remain the cornerstone of therapy, surgical treatment still has an important role in the management of some situations. Classical approaches of radical debridement have been gradually replaced by minimally invasive surgical procedures.

CASE REPORT

The authors describe a case of an 86-year-old male, diagnosed with a L2-L3 tuberculous spondylodiscitis complicated by an anterior epidural abscess, bilateral psoas muscle abscesses and meningoencephalitis. The patient underwent surgery by minimally invasive posterior paramedian approaches with tubular retractors. A L2-L3 discectomy, drainage of the abscesses and L2-L3 percutaneous transpedicular fixation were performed. The procedure and postoperative period were uneventful and the patient had a favourable outcome.

DISCUSSION

A minimally invasive posterior approach allows adequate access to the spinal canal for neural decompression in cases of spinal infection. Combined with percutaneous internal fixation the procedure prevents the loss of vertebral alignment and facilitates an early mobilization of the patient.

Methylglyoxal-induced imbalance in the ratio of vascular endothelial growth factor to angiopoietin 2 secreted by retinal pigment epithelial cells leads to endothelial dysfunction

Progressive microvascular complications are a main feature of diabetes and are associated with impairment of the angiogenic response. Methylglyoxal (MGO) has been implicated in the molecular events that lead to endothelial dysfunction in diabetes. In this study, we hypothesize that increased levels of MGO disrupt the ratio of vascular endothelial growth factor (VEGF) to angiopoietin 2 (Ang 2) secreted by retinal pigment epithelial (RPE) cells, which provides a key destabilizing signal that leads to apoptosis and decreased proliferation of retinal endothelial cells. Indeed, we show that MGO increases the levels of Ang 2 and dramatically decreases the levels of VEGF secreted by RPE cells in response to hypoxia. Downregulation of VEGF is likely to be related to decreased hypoxia-inducible factor-1alpha (HIF-1alpha) protein levels and HIF-1 transcriptional activity. Data further show that MGO-induced imbalance in the VEGF/Ang II ratio significantly changes the levels of BAX and Bcl-2 in endothelial cells. Moreover, this imbalance is accompanied by an increase in the activity of caspase-3 and decreased proliferation of endothelial cells. Data obtained in cell culture systems are consistent with observations in retinas of diabetic animals, where increased availability of MGO is associated with changes in distribution and levels of HIF-1alpha, VEGF and Ang 2 and increased microvascular permeability. In conclusion, the MGO-induced imbalance in the VEGF/Ang 2 ratio secreted by retinal epithelial cells activates apoptosis and decreases proliferation of retinal endothelial cells, which are likely to contribute to endothelial dysfunction in diabetic retinopathy.

Treatment of BK virus-associated nephropathy with Cidofovir in renal transplantation

BK virus-associated nephropathy (BKVN) has become recognized as an important cause of allograft dysfunction among transplant recipients. Despite reduction in immunosuppression, 30%-40% of recipients progress to allograft loss. Cidofovir is an antiviral agent that has been proposed for treatment of BKVN. We describe the clinical course, renal function, and blood viral measurement in 6 renal transplant recipients with BKVN who were treated with low doses of cidofovir. Administration of cidofovir was associated with clearance of BK virus DNA from blood and stabilization of renal function in 5 cases. These data suggest that cidofovir may be useful as adjuvant therapy for BKVN.

Transarterial chemoembolization of liver metastases in patients with uveal melanoma

Metastases from uveal melanoma are often confined to the liver. Palliative hepatic chemoembolization has been considered to be a reasonable treatment approach. We enrolled 14 patients with hepatic metastases from uveal melanoma into a pilot trial of transarterial chemoembolization (TACE). All patients received additional systemic immuno-chemotherapy or best supportive care. In 31 procedures 100mg/m(2) of cisplatine was continuously infused by means of a power injector preceding embolization by manual injection of polyvinyl alcohol particles. In three procedures cisplatine was replaced by 200mg/m(2) carboplatine because of increased serum creatinine levels. Tumor response was evaluated using RECIST criteria. Fourteen patients received 34 TACE's (mean: 2.4 treatments). Eight patients (57%) achieved partial response (PR), four patients (29%) had stable disease and two patients (14%) tumor progression. Median time to progression was 8.5 months (5-35 months). Median survival after first TACE was 14.5 months in responders compared to 10 months in non-responders (p=0.18, not significant) and 11.5 months (3-69 months) in all patients. In seven patients with metastases occupying less than 25% of liver volume median survival was 17 months compared to 11 months in seven patients with tumor involvement of more than 25% (p=0.02) with partial response rate of 86% and 29%, respectively. TACE of liver metastases from uveal melanoma is well tolerated and may prolong survival in patients with limited tumor extension.

Impact of two bacterial biocontrol agents on bacterial and fungal culturable groups associated with the roots of field-grown maize

AIMS

To assess the impact of Bacillus amyloliquefaciens and Microbacterium oleovorans on bacterial and fungal groups associated to the roots of field-grown maize.

METHODS AND RESULTS

Identification and count of bacterial and fungal culturable populations associated to the roots of maize seedlings, changes in culturable community structure according to the richness and diversity indexes concept and shifts in microbial activity through analysis of cellulolytic, ammonification and nitrification potentials were determined, in relation to kernel treatment with biological control agents. Following the treatment of maize kernels with B. amyloliquefaciens at 10(7) CFU ml(-1), an increase in bacterial diversity was observed at the rhizoplane of resultant seedlings. Bacterial richness was significantly increased at the root inner tissues of seedlings treated with Mic. oleovorans. Fusarium, Aspergillus, Penicillium and Trichoderma were the main fungal genera isolated and there population sizes were unequally affected by the addition of biocontrol agents.

CONCLUSIONS

Numbers and types of isolated bacteria and fungi changed in response to the addition of biocontrol agents, while microbial activity remained unchanged with respect to control.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides an insight of the effects of proven biocontrol agents on micro-organisms naturally associated to the target crop.

Hyperattenuating bone marrow abnormalities in myeloma patients using whole-body non-enhanced low-dose MDCT: correlation with haematological parameters

We aimed to establish the role of hyperattenuating medullary abnormalities detected by whole-body non-enhanced low-dose multidetector CT (WBLD-MDCT) in multiple myeloma (MM) patients referred for primary evaluation. 50 consecutive patients with untreated Stage I (n(I) = 11), Stage II (n(II) = 10) and Stage III (n(III) = 29) MM underwent WBLD-MDCT for staging. The number and size of osteolysis, as well as haematologic parameters including paraprotein and beta2-microglobulin levels, were assessed and related to the number, size and density of medullary abnormalities assumed to represent myeloma involvement. Bone marrow abnormalities were found in 2/11 (18%) Stage I, 6/10 (60%) Stage II and 20/29 (69%) Stage III myeloma patients, and did not parallel the incidence of osteolysis. Patients with medullary lesions had higher levels of immunoglobulin A (median, 4730 mg dl(-1) vs 1520 mg dl(-1)), light-chain proteinuria (median, 690 mg dl(-1) vs 214 mg dl(-1)) and IgG paraprotein (median, 3270 mg dl(-1) vs 2610 mg dl(-1)) compared with patients without medullary lesions. In patients with medullary abnormalities, levels of serum beta2-microglobulin were significantly higher than in patients without detectable marrow infiltrates (median, 4.3 mg dl(-1) vs 2.4 mg dl(-1); p = 0.0015). In conclusion, medullary abnormalities visualized by WBLD-MDCT are encountered in all stages of myeloma, including cases without osteolysis. They are associated with significantly elevated serum levels of paraprotein (reflecting tumour mass) and beta2-microglobulin, a prospective prognostic marker for myeloma. The nature and possible prognostic significance of medullary abnormalities detected by WBLD-MDCT therefore warrants further investigation.

Expression of K6W-ubiquitin in lens epithelial cells leads to upregulation of a broad spectrum of molecular chaperones

PURPOSE

Accumulation and precipitation of abnormal proteins are associated with many age-related diseases. The ubiquitin-proteasome pathway (UPP) is one of the protein quality control mechanisms that selectively degrade damaged or obsolete proteins. The other arm of the protein quality control mechanism is molecular chaperones, which bind to and help refold unfolded or misfolded proteins. We previously showed that the molecular chaperones and the UPP work in a competitive manner in eliminating the denatured proteins. To further investigate the interaction between the two protein quality control mechanisms, we determined the effects of the impairment of the UPP on the expression of molecular chaperones in human lens epithelial cells (HLEC).

METHODS

K6W-ubiquitin, a dominant negative inhibitor of the UPP, was expressed in confluent HLEC via an adenoviral vector. The mRNA levels of cytoplasmic and endoplasmic reticulum (ER) chaperones were determined by real-time reverse transcription polymerase chain reaction (RT-PCR). Protein levels for these chaperones were determined by western blotting.

RESULTS

Expression of K6W-ubiquitin in HLEC increased the expression of a broad spectrum of molecular chaperones. Among the heat-shock proteins, mRNA for alphaB-crystallin, Hsp70, and Hsp90 increased 27 fold, 21 fold, and twofold, respectively, in response to K6W-ubiquitin expression. Among the ER chaperones and ER stress related factors, mRNA levels of protein disulfide isomerase, Grp75, Grp78, Grp94, and the CAAT/enhancer binding protein homologous protein (CHOP) increased from 1.7 fold to 3.7 fold. The mRNA for Hsp60 also increased 1.6 fold in response to the expression of K6W-ubiquitin. The expression pattern of these chaperones in response to the expression of K6W ubiquitin is similar to that obtained when cells were treated with proteasome inhibitors or heat-shock.

CONCLUSIONS

It appears that the upregulation of these chaperones is related to the elevated levels of abnormal proteins in the cells. These findings support our hypothesis that the molecular chaperones and the UPP may back each other up in the process of protein quality control. The upregulation of molecular chaperones in response to the expression of a dominant negative ubiquitin may compensate for the impairment of the UPP in the degradation of abnormal proteins.

Interdomain mobility and conformational stability of type III fibronectin domain pairs control surface adsorption, desorption and unfolding

The 9th-10th type III fibronectin domain pair (9-10FNIII) has found widespread use as a biomimetic surface for cell adhesion. However, the effect of mutations to 9-10FNIII on its surface adsorption characteristics have not been investigated. Here we address this issue using total internal reflection fluorescence (TIRF) and circular dichroism spectroscopy, comparing two conformationally stable 9-10FNIII mutants against the wild type. Desorption of the 9-10FNIII mutants from the silica surface was minimal in comparison to desorption of 9-10FNIII. The extent and rate of protein desorption from silica was empirically matched by loss of secondary structure upon adsorption, with only the spectrum for 9-10FNIII showing extensive loss of the beta-sandwich fold. For the proteins adsorbed to hydrophobic surfaces, only the CD spectra for the 9-10FNIII mutant constrained via an interdomain disulphide bridge showed similarity with the corresponding solution structure. Since the binding of 9-10FNIII to integrin alpha5beta1 is highly dependent on the relative spatial arrangement of the two domains, we suggest that the observed differences in cell adhesion and spreading on wild type 9-10FNIII and mutants may in part be attributed to the extent of protein desorption and unfolding at the surface.

[Daclizumab in combination with mycophenolate mofetil and a late introduction of Tacrolimus at low doses, as a therapeutic approach in the elderly renal transplant donor-recipients pairs in kidney transplant]

BACKGROUND

Nowadays, it is more frequent the use of kidneys from older donors in the renal transplantation. Moreover, it is also increasing the age of the recipients due to the ageing of the population treated with hemodialysis. This makes that recipients become older more commonly. This situation raises specific problems in the renal graft and in the recipient as well. In this manuscript we present the results of a multicenter study that analyzed an immunosuppressive strategy specifically designed to elderly renal transplant donor-recipients.

METHODS

Patients > or =50 years were transplanted from donors > or =55 years. Immunosuppressive strategy consisted of daclizumab (2 doses of 1mg/Kg) in combination with steroids, mycophenolate mofetil (2g/daily during the first 45 days and then adjusted according to local practice) and Tacrolimus. Tacrolimus was introduced between 5 and 7 day post-transplantation, adjusting the predose levels between 4-8 ng/mL. Mean follow-up was 12 months.

RESULTS

A total of 133 patients were included in the study. Mean age of recipients and donors was 61.3+/-6.2 years and 64.4+/-5.3, respectively. 42.9% of patients needed dialysis during the first week (median 4 days). Between first month and first year, serum creatinine improved from 2.0+/-1.0 mg/dl to 1.5+/-0.4 mg/dl. Similar improvements were observed when creatinine clearance (Cockroft-Gault) was calculated. The survival of patient and renal graft at 12 months was 97.7% and 96.1%, respectively. The acute rejection rate was 13.5%. Security profile was good, as expected.

CONCLUSIONS

The Daclizumab and mycophenolate mofetil regimen with a late introduction of Tacrolimus at low doses is a good alternative in the elderly renal transplant recipients with a low immunologic risk.

Solution formulation and lyophilisation of a recombinant fibronectin fragment

The 9th-10th type III fibronectin domain pair shows promise in tissue engineering and tumour vasculature targeting. Calorimetry and structure-function analysis were used to investigate the effects of solution formulation and lyophilisation of a mutant ((9-10)FNIII-P). A single endothermic transition for (9-10)FNIII-P in solution was observed at pH<8, irrespective of addition of sucrose or PEG. The temperature at the maximum heat capacity (T(m)) and enthalpy (deltaH) of the transition increased for increasing sucrose concentrations but decreased for increasing PEG concentrations. The transition was fitted to a single two-state unfolding mechanism (in contrast to unfolding in guanidine. x HCl) and was partially reversible only at pH 4, with increasing concentrations of sucrose causing a marked fall in deltaH between scans. Circular dichroism spectra for the thermal unfolding of (9-10)FNIII-P at pH 4 showed loss of native beta-sheet structure and loss of aromatic contributions to the peak centred around 226 nm yielding an intermediate conformation, which in the presence of sucrose was more disordered. Despite a glass transition (T(g)') for (9-10)FNIII-P(aq) of -70 degrees C, primary drying at -30 degrees C did not perturb its conformation upon reconstitution or its biological activity following lyophilisation; the addition of sucrose or PEG had no influence on structure or activity. The main consideration in the formulation of (9-10)FNIII-P was therefore pH.

Radiofréquence bipolaire et cimentoplastie dans le traitement des métastases osseuses

Bone metastases are the most common cause of pain in cancer patients. Pain management in cancer patients, often revealing the disease and always present at advanced stages, is an important and difficult task. Pain is not always properly controlled by high doses of specific medication, radiation therapy or chemotherapy. When these therapies do not provide adequate pain relief, percutaneous neurolysis, infiltrations, alcoholizations and cementoplasty may be considered. More recently RF ablation has been proposed. On weight-bearing bones, RF can be combined with acrylic cement injection. The authors present here this very effective new technique which is complementary to classical pain management techniques.

Foraminal L5-S1 disc herniation and conus medullaris syndrome: a vascular etiology?

A 56-year-old man presented with a conus medullaris syndrome lumbar magnetic resonance imaging showed only a right foraminal disc herniation at the L5-S1 level. Operative removal of the protrusion was followed by prompt neurological improvement. We postulate that the discrepancy between extent of compression shown by imaging and the neurological findings may reflect vascular compression of the artery of Desproges-Gotteron, an anatomical variant.

Dopamine D2 receptor polymorphisms in inflammatory bowel disease and the refractory response to treatment

Dopamine and its receptors may be involved in inflammatory reaction. The availability of this molecule depends on its receptors. The DRD2 gene, which codifies for the D2 dopamine receptor, has several polymorphisms. In this study, the DRD2 TaqIA polymorphism, which confers a decreased receptor density, was evaluated in 313 individuals including 220 inflammatory bowel disease patients (143 patients with Crohn's disease and 77 with ulcerative colitis) and in 93 healthy blood donors. The analysis was carried out by PCR-RFLP techniques. The frequencies of A (1) A (1) and A (2) A (2) genotypes were similar among Crohn's disease, ulcerative colitis patients, and health controls. Also, the genotype frequency was similar in different groups of disease localization, behavior, and age of disease onset. However, the Crohn's disease patients carriers of A (2) A (2) genotype showed a lower risk for development refractory Crohn's disease (37 out 65) than A (1) A (1) and A (1) A (2) carriers (28 out of 65) [(OR=0.4, 95% CI 0.21-0.87; p=0.02)]. Our results support an involvement of the dopamine receptor in inflammatory bowel disease and suggest a new potential target for therapy in refractory Crohn's disease patients.

The benefit of whole-body low-dose unenhanced multidetector computer tomography (WBLD-MDCT) for follow up and therapy response monitoring in patients with multiple myeloma: Correlation with hematologic parameters

7607

Background: To assessthe value of whole-body low-dose multidetector computer tomography (WBLD-MDCT) as diagnostic and survey modality in multiple myeloma (MM), and as a one-stop alternative (Horger et al. EJR 2005;54:289–297) to established imaging techniques (e.g. x-ray and MRI). Methods: Between 7/2001 and 2/2005, WBLD-MDCT scans were obtained in 90 consecutive patients with histologically proven stage II-III MM, all patients having 2 or more scans (mean = 3,8; range = 2–6). CT-scans were performed using a standardized low-dose protocol and the number, size and density of focal or diffuse medullary (in the appendicular skeleton and pelvis) and extra-medullary lesions as well as osteolysis were analysed for each examination and at follow up. Results were correlated with current standard MM laboratory data and at follow up in order to assess correct temporal recognition of significant myeloma changes by both methods. Results: Detection and follow up of medullary and extra-medullary MM lesions and osteolysis by WBLD-MDCT resulted in a sensitivity of 92%, a specificity of 93%, a NPV of 95%, a PPV of 85% and a likelihood ratio for patients with CT-abnormalities to present changes in the course of their disease of 12. Results of radiologic and hematologic analysis showed high agreement at follow up (median, 3 mo). However, agreement of both techniques at the time of investigation was only moderate (κ = 0.629), with CT being correct in 60% of mismatching cases. Thus, CT enabled earlier detection of MM changes. WBLD-MDCT assessed correctly the course of disease in all 4 patients with nonsecretory MM. Evaluation of stability was optimal in all patients. Conclusions: WBLD-MD represents a reliable, widespread, quick (75s acquisition time), and cost-effective imaging technique in MM, allowing detection of bone marrow involvement, extra-medullary tumors and lytic bone lesions in different clinical settings (staging, follow up, therapy monitoring, evaluation of stability). WBLD-MDCT repeatedly allowed detection of changes in the course of the disease prior to laboratory data, especially in extramedullary MM relapse and nonsecretory MM.

No significant financial relationships to disclose.

Influence of the Current Management of Renal Transplant Recipients on the Prevalence of Anemia and Related Costs

The use of mycophenolate mofetil (MMF) and renin-angiotensin system blockers (RAB) to prevent and treat chronic graft nephropathy may affect the incidence of anemia in renal transplant recipients. We compared 2 sets of cadaver-donor recipients, namely those followed at the end of 1995 (group 1; n = 252) versus 2003 (group 2; n = 530) in terms of general characteristics, incidence of anemia (hemoglobin [Hb] < or =13 g/L males, 12 g/L females) or severe anemia (Hb < or =11 g/L males, 10 g/L females) and use cost of treatment with erythropoietin (EPO). Group 2 was significantly older, heavier and longer since grafting. Fifty-seven percent received MMF, 21% received azathioprine, and 5% received rapamycin. In group 1, 83% were given azathioprine. RAB were administered to 35.1% in group 2 versus 14.7% in group 1 (P < .001). Mean blood pressure was identical in the 2 groups, but graft function was worse in group 2 (Cockroft, 62 vs 74 mL/min; P < .001). Mean Hb levels (13.66 + - 3.1 vs 13.82 + - 1.7 g/L) and prevalence of anemia (36.9% vs 34.5%) for groups 1 and 2, respectively, were similar. The rate of severe anemia, however, was lower in group 2 (2.3% vs 8.7%; P < .001). The use of EPO increased from 2.8% (group 1) to 8.7% (group 2; P < .01). In 2003, the cost of EPO was calculated at 1982 Euros/patient-year and 91,150 Euros per year for the whole patient group. Despite accumulation of predisposing factors, the control of anemia in our patients has improved due to the expanded use of EPO. Along with its high cost, EPO therapy has potential positive repercussions on the quality of life and patient prognosis. Therefore, we need to precisely define the optimal use of EPO in renal transplant recipients.

Pharmacokinetics of Mycophenolate Mofetil in Kidney Transplant Patients With Renal Insufficiency

Mycophenolate mofetil (MMF) is an immunosuppressant that is widely used for prophylaxis of rejection in solid organ transplantation. In this study, we examined the effect of renal insufficiency on the pharmacokinetics of MMF, particularly on the free fraction of drug in renal transplant patients. Our study was performed on 10 patients with severe renal insufficiency (creatinine clearance [CrCl] <30 mL/min), and 10 control patients with preserved renal function (CrCl >90 mL/min). All the patients had received a cadaveric donor graft at least 1 year prior and were clinically stable under treatment with MMF and cyclosporine. For each patient, we determined 12-hour areas under the curve (AUC(0-12 h)) for the metabolites: mycophenolic acid (MPA), 7-O-mycophenolic acid glucuronide (MPAG), and the free non-protein-bound fraction of MPA (f-MPA). The two groups were matched for age, sex, and MMF dose. Mean AUC(0-12 h) values for MPA were similar in both groups. The renal insufficiency group showed a significantly increased AUC(0-12 h) for MPAG (1550 +/- 392 vs 3527 +/- 1130 microg.h/mL, P < .001) and increased trough and AUC(0-12 h) values for f-MPA (0.023 +/- 0.02 vs 0.094 +/- 0.07 microg/mL, P = .003, and 0.87 +/- 0.3 vs 1.52 +/- 0.8 microg . h/mL, P = .016, respectively). We proposed that these differences should be taken into account when deciding upon the dose of this drug for the subset of patients with impaired transplant function.

Plasmapheresis for the prophylaxis and treatment of recurrent focal segmental glomerulosclerosis following renal transplant

We evaluated 10 patients with primary focal segmental glomerulosclerosis (FSGS) treated with plasmapheresis (PS) following renal transplantation. Three patients lost their first graft due to FSGS recurrence. In seven patients, PS was indicated as treatment for probable recurrence defined as the onset of proteinuria above 1 g/24 hours. In the remaining three patients, treatment was started in the first week posttransplant as prophylaxis against recurrence. The PS protocol was 17 sessions with the exchange of 2.5 L of plasma for 5% albumin over 10 to 12 weeks. Losartan (25 to 100 mg/d) was given to most patients at the end of PS treatment. The mean follow-up time after PS was 10 months. All patients currently have a functioning graft. A full response to treatment, defined as persistently reduced proteinuria to less than 500 mg/24 hours or the lack of recurrence in prophylactic treatment, was achieved in six patients. Three patients showed a partial decrease in proteinuria (to less than 1 g/24 hours). One patient failed to respond and still has nephrotic range proteinuria. No adverse effects of PS were recorded. A prompt start of PS combined with the use of losartan yields good results in the prophylaxis and treatment of recurrent FSGS following renal transplant in terms of quickly reduced proteinuria. Given the natural course of FSGS, a longer follow-up is needed to estimate the impact of PS on graft survival.

Two doses of daclizumab with delayed introduction of low-dose tacrolimus in elderly recipients of cadaveric renal transplants from donors >55 years of age

BACKGROUND

Renal transplants from elderly donors have a high incidence of delayed graft function, which can be increased by the initial use of calcineurin inhibitors. Our purpose was to assess the safety and efficacy of an immunosuppressive regimen using anti-IL-2R antibodies and MMF that allows delayed introduction of low-dose tacrolimus using elderly donors to elderly recipients.

METHODS

This observational study involved 13 transplant centers. In total there were 119 patients (age 60.5 +/- 6.6 years, range 50 to 77) who received a kidney from a donor of mean age 64 +/- 5 years (range 55 to 76), 94% of whom died from a CVA. Immunosuppression consisted of daclizumab (1 mg/kg in two doses; preoperatively and on day 14) combined with steroids, mycophenolate mofetil (initial dose of 2 g/d), and tacrolimus (0.1 mg/kg per day). Tacrolimus was introduced before day 7 (mean 5.5 days) and adjusted to a target level of 5 to 8 ng/mL. The mean follow-up was 8 months.

RESULTS

Two grafts were lost due to primary nonfunction and acute rejection and 48 patients (40%) required dialysis due to delayed graft function, although it was generally of short duration (median 4 days; only 2 cases >2 weeks). Acute rejection occurred in 16 patients (13.4%), of whom 13 were biopsy-confirmed (10.9%; Banff 1997 grades I and II). Three patients withdrew from the study, and three died (sepsis, accident, and cardiovascular event). The remaining 111 patients continued follow-up, with a median creatinine value of 1.5 mg/dL at 12-months. Eighty-six percent of patients had at least one episode of infection, half of which were urinary tract infections. There were 16 cases of CMV infection.

CONCLUSIONS

Based on the initial results, our immunosuppressive regimen seems to offer good short-term renal function while maintaining an acceptable rejection rate and a low incidence of serious infections.

Treatment of hepatitis C virus with interferon in hemodialysis patients awaiting kidney transplant

INTRODUCTION

Hepatitis C virus (HCV) infection is associated with worsening disease progression after renal transplant, and to date there is no available treatment for use at this stage. It has therefore been recommended to treat HCV infection with interferon (IFN) during the dialysis period while the patient is on the waiting list for transplantation.

METHODS

We analyzed data from 27 patients on hemodialysis awaiting transplant, who were under IFN treatment for chronic HCV infection (dominant genotype, 1b). The starting regime was IFN alpha-2b, 3 MU x 3/week (n = 20) or pegylated IFN alpha-2a, 135 mg/week (n = 7). If there was clearance of HCV RNA in the first 3 to 6 months, we attempted to prolong IFN treatment for 1 year, although in many patients the dose had to be reduced. A sustained response was defined as viral clearance for at least 12 months after the end of treatment.

RESULTS

Viremia was negative in 13 patients (48.1%) at the end of treatment, but two of these patients relapsed, to give an overall long-term response rate of 11 patients (40.7%) and incomplete follow-up in three patients. Viral clearance was not achieved in 11 patients. In three patients (12%), IFN had to be suspended before finishing the third month of therapy due to side effects (mainly pancytopenia and intolerance of a previous kidney graft). Seven patients showing a sustained response underwent transplant, maintaining a negative viremia result.

CONCLUSIONS

IFN treatment was effective in a high proportion of dialysis patients with HCV infection, with response rates possibly even higher than for the general population. However, its use is restricted by a high incidence of side effects.

Drug coated stents for carotid intervention

Carotid endarterectomy has demonstrated its superiority over medical treatment of symptomatic as well as asymptomatic stenosis of the extracranial carotid artery. Although minimally invasive methods initially failed to produce similar results, stent implantation is becoming an alternative technique for stroke prophylaxis with technical advances, cerebral protection and careful patient selection. Even though restenosis does not seem to be a major limitation compared to coronary interventions, in-stent restenosis might occur more frequently with an increasing number of procedures performed and longer follow-up periods. Drug eluting stents have shown to attenuate this complication. Currently, no clinical data on drug eluting stents in carotid arteries are available. This article discusses the current literature on carotid artery stenting and the potential role of drug eluting stents in this field.

Risk of human exposure to paralytic toxins of algal origin

The most significant neurotoxins produced by harmful algal blooms (HABs) are paralytic shellfish toxins (PSTs) found in shellfish and freshwater. Human exposure to neurotoxins through the food consumption represents a severe hazard to human health and the exposure through contaminated water represents an added risk often difficult to recognize. Furthermore, there is an insufficient knowledge of toxicokinetics of these complex toxins produced by HABs. If human acute exposure occurs, the diagnosis of intoxication is typically based upon symptomatology and analysis of shellfish tissue by mouse bioassay, HPLC-FLD analysis and mouse neuroblastoma assay. However, the health risks due to chronic exposure should also be considered and its prevention could be reached with a better understanding of sub-lethal doses of these toxins. In this context, information required for development of a diagnostic protocol should include knowledge about toxicokinetics and toxicodynamics of these neurotoxins. We emphasise the importance of research on biomarkers to prevent, predict and diagnose acute and chronic human exposure to PST.