Glycated bovine serum albumin for use in feeding trials with animal models - In vitro methodology and characterization of a glycated substrate for modifying feed pellets

This study investigated different methods to produce N^ε-carboxymethyl-lysine (CML)-enriched bovine serum albumin (BSA) as alternatives to the classical approach using glyoxylic acid (GA) and sodium cyanoborohydride (NaBH₃CN) which results in toxic hydrogen cyanide (HCN). The reaction of GA (6 mmol/L) and NaBH₃CN (21 mmol/L) to produce CML remained the most effective with CML yields of 24-35%, followed by 13-24% using 300 mmol/L glyoxal (GO). GA promoted specific modification of lysine to CML, and fewer structural modifications of the BSA molecule compared with GO, as evidenced by fluorescence and proteomic analyses. GO promoted greater arginine modification compared with GA (76 vs 23%). Despite structural changes to BSA with GO, murine fecal clearance of CML was similar to literature values. Hence, BSA glycation with 300 mmol/L glyoxal is a suitable alternative to GA and NaBH₃CN for generating CML-enriched protein free of HCN, but a CML-only fortification model remains to be described.

Exposure to Contaminated River Water is Associated with Early Hatching and Dysregulation of Gene Expression in Early Life Stages of the Endangered Copper Redhorse (Moxostoma hubbsi)

The copper redhorse (Moxostoma hubbsi) is an endangered fish that spawns exclusively in the Richelieu River (Quebec, Canada). Tributaries of the Richelieu are contaminated with high levels of current-use pesticides, which may impact early-life stage (ELS) copper redhorse and other native fishes. We assessed the effects of exposure to contaminated river water on ELS copper redhorse and river redhorse (Moxostoma carinatum), a related fish that shares the copper redhorse's spawning grounds and nursery habitat. A riverside flow-through system was used to expose copper and river redhorse embryos (1000 each) to Richelieu River water or laboratory water as a control. Fish were maintained until 14 days posthatch, and water samples were taken daily for chemical analysis. Following a heavy rain event, concentrations of two neonicotinoid pesticides, clothianidin and thiamethoxam, exceeded water quality guidelines for aquatic life (20 ng/L). Using nontargeted screening, we tentatively identified an additional 24 pharmaceutical and personal care products and 23 pesticides in river water. Effects of river water on ELS fish were observed in both species, but the copper redhorse appeared to be more sensitive. Fish exposed to river water hatched 10.7 (copper redhorse) and 2.4 (river redhorse) cumulative degree days earlier than controls. Copper redhorse survival was significantly lower in river water (73 ± 16%) compared to laboratory water (93 ± 3%), whereas river redhorse survival was similar between treatments (84 ± 6% and 89 ± 4%, respectively). Sequencing of copper redhorse larvae RNA revealed 18 differentially expressed genes (DEGs) following 14 days of exposure to river water. Eight up-regulated DEGs were linked to immune function and injury response, and seven down-regulated DEGs were involved with digestion and nutrient absorption. The present study provided valuable data on the effects of ELS exposure to a real-world mixture of contaminants in two fish species of concern. Environ Toxicol Chem 2022;41:1950-1966. © 2022 SETAC.

Normal ageing of the brain: Histological and biological aspects

All the hallmarks of ageing are observed in the brain, and its cells, especially neurons, are characterized by their remarkably long lifetime. Like any organ or system, the brain is exposed to ageing processes which affect molecules, cells, blood vessels, gross morphology and, uniquely for this organ, cognition. The preponderant cerebral structures are characterized by the cellular processes of neurons and glial cells and while the quantity of cerebral interstitial fluid is limited, it is now recognized as playing a crucial role in maintaining cerebral homeostasis. Most of our current knowledge of the ageing brain derives from studies of neurodegenerative disorders. It is interesting to note that common features of these disorders, like Tau, phosphoTau and amyloid peptide accumulation, can begin relatively early in life as a result of physiological ageing and are present in subclinical cases while also being used as early-stage markers of neurodegenerative diseases in progression. In this article, we review tissue and cellular modifications in the ageing brain. Commonly described macroscopic, microscopic and vascular changes that in the ageing brain are contrasted with those seen in neurodegenerative contexts. We also review the molecular changes that occur with age in the brain, such as modifications in gene expression, insulin/insulin-like growth factor 1 signalling dysfunction, post-translational protein modifications, mitochondrial dysfunction, autophagy and calcium conductance changes.

Factors Generating Glucose Degradation Products In Sterile Glucose Solutions For Infusion: Statistical Relevance Determination Of Their Impacts

Sterilising glucose solutions by heat promotes the generation of a large number of glucose degradation products (GDPs). It has been shown that high levels of GDPs may result in Advanced Glycation End products that have an impact on cellular homeostasis and health in general. If data is available for peritoneal dialysis solutions, little has been published for glucose infusion fluids. It is essential to identify the parameters causing the formation of GDPs and so limit the risk of exposing patients to them. After quantifying both 5-hydroxymethyl-2-furfural, considered as an important indicator of degradation, and 2-furaldehyde, an ultimate GDP of one degradation pathway, in marketed solutions, the aim of this work is to build a model integrating all the parameters involved in the formation rates of these two GDPs: supplier, glucose amount, container material, oxygen permeability coefficient and time-lapse since manufacture. Our results show a good logarithmic relationship between GDP formation rates and time-lapse since manufacture for both GDPs. The amount of GDPs in the glucose solutions for infusion depends on the initial glucose amount, the polymer of the container, the time elapsed since manufacturing and the supplier.

Glycation: the angiogenic paradox in aging and age-related disorders and diseases

Angiogenesis is generally a quiescent process which, however, may be modified by different physiological and pathological conditions. The "angiogenic paradox" has been described in diabetes because this disease impairs the angiogenic response in a manner that differs depending on the organs involved and disease evolution. Aging is also associated with pro- and antiangiogenic processes. Glycation, the post-translational modification of proteins, increases with aging and the progression of diabetes. The effect of glycation on angiogenesis depends on the type of glycated proteins and cells involved. This complex link could be responsible for the "angiogenic paradox" in aging and age-related disorders and diseases. Using diabetes as a model, the present work has attempted to review the age-related angiogenic paradox, in particular the effects of glycation on angiogenesis during aging.

[Pneumatic tube system for blood products transport]

Blood product transport from blood bank to the patient care areas of hospitals is a key step in the transfusion process. The pneumatic tube system is now widely used in hospitals. Strict performance specifications must be respected to guarantee blood safety: robustness, easy to use and respect the constraints imposed to blood products. To secure the disposal of blood products ordered to a carrier (delivery step), a security device must be deployed (video camera, barcode reading, fax, chip), allowing in particular to limit the risk of addressing error when sending (in the case of device with several arrival stations) or picked up by the wrong carrier.

Advanced glycation end products regulate extracellular matrix protein and protease expression by human glomerular mesangial cells

Advanced glycation end products (AGEs) may play a role in the pathogenesis of diabetic nephropathy, by modulating extracellular matrix turnover. AGEs are known to activate specific membrane receptors, including the receptor for AGE (RAGE). In the present study, we analyzed the various receptors for AGEs expressed by human mesangial cells and we studied the effects of glycated albumin and of carboxymethyl lysine on matrix protein and remodelling enzyme synthesis. Membrane RAGE expression was confirmed by FACS analysis. Microarray methods, RT-PCR, and Northern blot analysis were used to detect and confirm specific gene induction. Zymographic analysis and ELISA were used to measure the induction of tPA and PAI-1. We show herein that cultured human mesangial cells express AGE receptor type 1, type 2 and type 3 and RAGE. AGEs (200 microg/ml) induced at least a 2-fold increase in mRNA for 10 genes involved in ECM remodelling, including tPA, PAI-1 and TIMP-3. The increase in tPA synthesis was confirmed by fibrin zymography. The stimulation of PAI-1 synthesis was confirmed by ELISA. AGEs increased PAI-1 mRNA through a signalling pathway involving reactive oxygen species, the MAP kinases ERK-1/ERK-2 and the nuclear transcription factor NF-kappaB, but not AP-1. Carboxymethyl lysine (CML, 5 microM), which is a RAGE ligand, also stimulated PAI-1 synthesis by mesangial cells. In addition, a blocking anti-RAGE antibody partially inhibited the AGE-stimulated gene expression and decreased the PAI-1 accumulation induced by AGEs and by CML. Inhibition of AGE receptors or neutralization of the protease inhibitors TIMP-3 and PAI-1 could represent an important new therapeutic strategy for diabetic nephropathy.

Human herpesvirus-8 (HHV-8)-associated primary effusion lymphoma in two renal transplant recipients receiving rapamycin

The Akt/mammalian target of rapamycin (mTOR) signaling cascade has been demonstrated to be constitutively activated in several malignancies, including Kaposi sarcoma (KS) and human herpesvirus-8 (HHV-8)-associated primary effusion lymphoma (PEL). In organ transplant recipients, therapeutic change from cyclosporin to the mTOR inhibitor rapamycin can lead to regression of KS lesions. Recent experiments using PEL cell lines and murine xenograft PEL models suggested that rapamycin could inhibit the growth of PEL cells. In the present report, we describe the cases of two HIV-1-negative males of African origin who underwent renal transplantation and developed PEL while receiving rapamycin as immunosuppressive treatment. Both patients were retrospectively found to be HHV-8 seropositive before renal transplantation. The present case report suggests that rapamycin may not protect HHV-8-infected renal transplant recipients from occurrence of PEL or progression of pre-existing PEL.

Peritoneal aging during PD: implication of RAGE, the receptor for AGEs

During last years, the number of patients who have been continuously treated by peritoneal dialysis (PD) for over 5 or 10 years has markedly increased. Sclerosing syndromes and membrane failure are the most common complications that are now currently observed in long-term PD patients. Exposure to conventional PD fluids (PDFs) with poor biocompatibility induces a kind of <<chemical peritonitis>> in response of bad <<biotolerance>>. Theperitoneal fibroblasts, mesothelial cells and especially endothelial cells function as a filtration barrier, but also control intraperitoneal inflammation as well as leukocytes and macrophages.Peritoneal exposure to conventional poorly biocompatible PDFs which combine non-physiological pH, high glucose concentrations,and high levels of glucose degradation products (GDPs), is associated with an accelerated peritoneal aging. Heat sterilization of PDFs induces the formation of GDPs which are involved in the formation of advanced glycation end-products (AGEs).Glucose, GDPs and AGEs participate to the peritoneal membrane failure and aging. AGEs via RAGE (receptor for AGEs) are involved in human peritoneal mesothelial cell (HPMC) activation.In the present work, we summarize our previous in vitro works regarding mesothelial RAGE implication in the peritoneal membrane aging. Two periods of aging are distinguished: i) early peritoneal changes related to mesothelial cell activation and loss, ii)late membrane alteration correlated to submesothelial fibrosis and neovascularization.

Vieillissement: rôle et contrôle de la glycation

PURPOSE

Advanced glycation end-products (AGEs) accumulate in aging tissues and organs during rheumatoid arthritis and Alzheimer disease. These aging toxins are especially involved in cell alteration during diabetes mellitus (glycotoxin) and renal failure (uremic toxin). AGEs participate to the endothelial dysfunction leading to diabetic macro but also micro-angiopathy. AGEs binding to cell receptors are critical steps in the deleterious consequences of AGE excess. AGE-receptor activation altered cell and organ functions by a pro-inflammatory, pro-coagulant and pro-fibrosis factors cell response.

CURRENT KNOWLEDGE AND KEY POINTS

Non-enzymatic glycation and glycoxidation with glucose auto-oxidation represent the two main pathways resulting in AGE formation. No exclusive AGE classification is actually available. Pathophysiological mechanisms are described to explain AGE toxicity. AGEs bind to cell receptors inducing deleterious consequences such as endothelial dysfunction after endothelial RAGE activation. AGEs can also have deleterious effects through glycated protein accumulation or in situ protein glycation.

FUTURE PROSPECTS AND PROJECTS

Many in vitro or animal studies demonstrated that AGE deleterious effects can be prevented by glycation inhibitors, AGE cross-link breakers or AGE-RAGE interaction inhibition. New molecules are actually studied as new strategy to prevent or treat the deleterious effects of these aging toxins.

Mesothelial RAGE activation by AGEs enhances VEGF release and potentiates capillary tube formation

Advanced glycation end-products (AGEs) inhibit ischemia-induced angiogenesis but are potential triggers of neoangiogenesis that occurs in peritoneal dialysis (PD) patients. We investigated whether the effect of glucose and AGEs on human peritoneal mesothelial cells (HPMCs) might alter the release of vascular endothelial growth factor (VEGF) and subsequently the formation of capillary tubes by human umbilical vein endothelial cells (HUVECs). HPMCs were exposed to glucose and the glycated protein Nvarepsilon-(carboxymethyl)lysine-human serum albumin (CML-HSA) and VEGF production was measured by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. Capillary tube formation by HUVECs in presence of HPMC supernatant or co-cultured with HPMC was investigated. AGE and VEGF levels in PD effluents from 11 patients were measured. CML-HSA stimulated VEGF production by HPMCs, P<0.001. Glucose and AGE inhibited capillary tube formation by HUVECs, P<0.001. HPMC supernatant potentiated capillary tube formation, P<0.001. In co-culture with HPMC capillary tube formation was increased, especially by HPMCs stimulated by CML-HSA, P<0.001. Anti-VEGF antibody limited this effect, P<0.001. Preincubation of HPMCs with anti-receptor for AGEs (RAGE) antibody reduced capillary tube formation, P<0.001. AGE and VEGF levels in PD effluents were increased during long dwell time, P<0.05 and P<0.001, respectively. In a co-culture system, we showed that VEGF production by HPMC favors capillary tube formation through mesothelial RAGE activation and could explain neoangiogenesis in PD patient.

French peritoneal dialysis registry (RDPLF): Outline and main results

The Registre de Dialyse Péritonéale de Langue Française (RDPLF Registry) is a non-profit association that has been set up to assist physicians and nurses in evaluating their practical experience and results regarding peritoneal dialysis (PD). Five French-speaking and two Spanish-speaking countries have participated in this initiative (which includes 21 000 patients). In France, 82% of all PD patients are included in the registry and the main results for the period from 1995 to January 2006 form the basis of this report: of 11 744 incident patients with a median age of 71 years, 21.5% were over 80 years of age and 56% were not able to perform PD treatment at home without assistance. Eighty-six percent of the latter group received external assistance from a private nurse and 14% were aided by their family. The overall average rate of peritonitis was one episode every 29 months. The probability of being peritonitis-free appeared to be better for patients on automated PD (59.4% at 2 year) than for those on continuous ambulatory PD (55.3%), but this finding requires further validation. The average waiting time before transplantation was about 2 years. In patients who had undergone transplantation, the peritonitis rate was one episode per 42 months before transplantation compared to one episode per 29 months for patients who had not received a transplant. Eighty-three percent of patients had a hemoglobin level greater than 11 g%. Catheter survival was 92% at 2 years post-insertion and 85% at 5 years, with 94% being implanted by experienced surgeons. In conclusion, the RDPLF results demonstrate that PD may be successfully prescribed for older patients who receive assistance either from their family or from a nurse. Further, a larger number of younger patients should also be prescribed this technique in France. Patients eligible for transplantation and on short-term PD have the lowest risk of developing peritonitis; PD before transplantation may help prolong residual renal function, and initial treatment by PD may also help to preserve vascular access for the future.

Postprandial hyperglycemia alters inflammatory and hemostatic parameters

Glucose or glucose derived products are increased in blood during the postprandial phase and are, to a certain extent, related to meal composition. Glucose and glucose derived products such as advanced glycation end products (AGEs) can be formed in the intracellular compartment but can also be absorbed as AGEs or AGE precursors present in food. Glucose, glucose metabolites and AGEs alter endothelial cell functions, induce adhesion molecule overexpression (ICAM-1, VCAM), cytokine release (IL-6, MCP-1) and tissue factor production. Tumor necrosis factor alpha systemic level is increased during the postprandial phase as are augmented C reactive protein and fibrinogen level. Hyperglycemia induced an increase in plasminogen activator inhibitor, and shortened fibrinogen half life. Hyperglycemia and AGEs provoked an oxidant stress. The formation of reactive oxygen intermediates perturbates NO (Nitric oxide) formation and are deleterious for cell functions. All the modifications observed in the postprandial phase are not too deleterious but their iterative characteristics may lead to vascular dysfunction.

Prognostic value of inhibitory anti-ADAMTS13 antibodies in adult-acquired thrombotic thrombocytopenic purpura

In order to assess the prognostic value of inhibitory anti-ADAMTS13 antibodies in thrombotic thrombocytopenic purpura (TTP), we performed a multicentre prospective study of 33 adult patients with idiopathic acquired TTP. Patients were treated with high-dose plasma infusion and therapeutic plasma exchange. Patients without (group 1, n = 12) and with (group 2, n = 21) detectable inhibitory anti-ADAMTS13 antibodies were compared for clinical presentation, treatment and outcome. Both groups were comparable for clinical presentation. All patients in group 1 achieved a sustained complete remission within a median of 7 d [95% confidence interval (CI), 4-18], which required a median plasma volume of 235 ml/kg (range, 131-1251). In group 2, 17 patients achieved a durable complete remission within a median of 23 d (95% CI, 11-32) (P = 0.001). Median plasma volume was 718 ml/kg (range, 219-3107) (P = 0.02). In group 2, there was a trend for more episodes of flare-up than in group 1 (13 vs. 3, respectively, P = 0.07). Four patients, all from group 2, died (P = not significant). The relapse rate was comparable between both groups. We suggest that TTP with detectable inhibitory anti-ADAMTS13 antibodies displays a worse prognosis, relative to a delayed platelet count recovery, a higher plasma volume requirement to achieve complete remission, and a trend for more frequent episodes of flare-up.

[Pregnancy and hemodialysis]

Pregnancy is a rare occurrence in patients on chronic hemodialysis (CHD). The rate of successful pregnancies amounts to almost 60%, thanks to modifications of the dialysis schedule and a specifically adapted obstetrical and neonatal management. We report on seven pregnancies occurring between 1995 and 2001 in six women with a mean age of 32 years (22-39 years), on HD for a mean period of 36 months (12-96 months). Maternal and fetal complications, and the long-term outcome of mothers and children are reported, and the collaborative approaches adopted by obstetrician, pediatrician and nephrologist are discussed. The frequency and length of HD was systematically increased. One patient chose to terminate her pregnancy at 20 weeks of gestation. The mean gestational age for the six other pregnancies was 31 weeks (24-34 weeks) with an average weight at birth of 1495 g (660-1920 g). One neonate born at 24 weeks died 2 days following delivery. One patient was treated with uterine artery embolization for post-partum haemorrhage. Pediatric evaluation of the five children, who were followed up for a period ranging between 2.5 to 5.5 years, showed a good long-term outcome. In conclusion, pregnancy needs not be counterindicated or systematically terminated in patients on CHD, particularly if transplantation is not possible, if the patient refuses it, or if she is relatively old and there is a long waiting period before transplantation.

Loss of the ex vivo but not the reinducible CD8+ T-cell response to Tax in human T-cell leukemia virus type 1-infected patients with adult T-cell leukemia/lymphoma

Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy (HAM). In asymptomatic carriers and HAM patients, HTLV-1 infection leads to a vigorous cytotoxic T-cell (CTL) response mainly directed to the regulatory Tax protein. In contrast, initial studies showed that anti-HTLV-1 CTL activities were not reproductively detected in ATLL patients, neither ex vivo, nor after in vitro restimulation. To better understand this discrepancy, we explored the anti-HTLV-1 CD8+ T-cell response of eight ATLL patients by using in vitro restimulated or freshly isolated CD8+ T cells. In all the ATLL patients, we found that mitogenic activation allowed the induction of CD8+ T cells able to lyse autologous HTLV-1-infected cells and/or to produce IFNgamma in response to Tax peptides. In contrast, only a minority of the patients possessed CD8+ cells able to respond ex vivo to the same epitopes. These findings indicate that although a restimulatable anti-HTLV-1 CTL activity persists during ATLL, the specific ex vivo response is not constantly maintained. This provides definitive evidence that the CD8+ T-cell response to HTLV-1 is affected by ATLL development and reveals that a major defect concerns the generation and/or the functionality of CD8+ effectors.

[Advanced glycosylation end products (AGE): new toxins?]

Advanced glycation end-products (AGEs) are found in excess during diabetes mellitus, uremia and aging. Non enzymatique glycation, glycoxidation with glucose auto-oxidation and the polyol pathway are involved in the production of AGEs. Tissue accumulation of AGEs and their binding to cell receptors are critical steps in the deleterious consequences of AGE excess. AGE-receptor interaction altered endothelial cells, macrophages, mesangial and mesothelial cell functions. AGEs appear to be involved in the genesis of diabetic micro but also macro-angiopathy. Reduction of AGE clearance and permanent oxidative stress are responsible for AGE excess during uremia. High-flux hemodialysis and peritoneal dialysis reduce AGE level but kidney transplantation is the best treatment to restore homeostasis. New drugs are tested to reduce AGEs or AGE deleterious effects but the best treatment remains the prevention of AGE formation by a strict glycemic control.

N(carboxymethyl)lysine as a biomarker for microvascular complications in type 2 diabetic patients

AIMS

Hyperglycemia is linked to vascular dysfunction in patients with diabetes mellitus, either directly or through advanced glycation end product (AGE) formation. Experimental evidence has indicated the possible involvement of AGEs in the genesis of vascular complications. We investigated whether serum levels of AGEs and of the glycoxidation compound carboxymethyl-lysine (CML) were increased and correlated with vascular complications in type II diabetes mellitus.

METHODS

Serum levels of AGEs and CML-human serum protein (CML-HSP) were measured by a specific immunoassay in 51 men and 26 women aged 58 +/- 6.1 years (mean +/- SD) who had been treated for type II diabetes mellitus for 11 +/- 8 years, and in a non-diabetic control group consisting of 39 men and 21 women aged 55.5 +/- 7.5 years. Patients with macroalbuminuria or abnormal creatinine clearance were excluded from the study.

RESULTS

The serum levels of AGEs were significantly increased in patients with type II diabetes compared to controls (P<0.001). Blood levels of CML-HSP were significantly increased in diabetic patients compared to normal subjects [35.3 +/- 27.4 and 9.3 +/- 7.2 (mean +/- SD) pmol/mg of protein, respectively; P<0.0001]. In diabetic patients with retinopathy or microalbuminuria (urinary albumin excretion: UAE > 30 mg/24 h), CML-HSP levels were significantly higher (P<0.02), and even more elevated in patients with both complications.

CONCLUSION

In patients with type II diabetes, CML-HSP levels that are at variance with the HbA(1c) index for blood glucose may be a biomarker of glycoxidation, and related to the development of microvascular complications.

A clinical, molecular and cytogenetic study of 12 cases of human herpesvirus 8 associated primary effusion lymphoma in HIV-infected patients

INTRODUCTION

Primary effusion lymphoma is a rare type of B-cell lymphoproliferative disorder which is mainly observed in patients with HIV infection. Lymphomatous cells bridge features of immunoblastic and anaplastic cells with a non-B non-T phenotype and are characterized by the presence of the human herpesvirus 8 genome. We report on the retrospective analysis of 12 cases.

PATIENTS AND METHODS

: Twelve HIV-infected patients with serous effusions containing large HHV8(+) lymphomatous cells were extensively evaluated to disclose associated visceral involvement. Clonality was assessed by IgH gene rearrangement PCR analysis (n = 11) or Southern blot (n = 1). EBV and HHV8 DNA sequences were detected by PCR analysis. Cytogenetics studies were performed in seven cases using RHG-banding.

RESULTS

Extraserous localizations of lymphoma were present in six cases (50%): mediastinal (n = 2), mesenteric (n = 2), pancreatic (n = 1), and bone marrow involvement (n = 1). A monoclonal rearrangement of IgH genes was demonstrated in six cases, an oligoclonal pattern in one, whereas no clonality could be detected in five. High HHV8 copy numbers were demonstrated in all effusion fluids, with EBV-co-infection in all cases but one. Cytogenetic analysis displayed a complex karyotype in all cases without recurrent abnormalities. Eight patients have died. Three patients are in complete remission at 28, 53 and 55 months after high-dose chemotherapy (n = 1), cidofovir and alpha-interferon combination therapy (n = 1), and antiretroviral therapy alone (n = 1).

CONCLUSION

The clinical and molecular pattern, as well as the response to therapy suggest that primary effusion lymphoma represents an heterogenous type of virus-induced B-cell lymphoproliferative disorder, sharing pathophysiological features with that induced by the Epstein-Barr virus and occurring in immunocompromised patients.

Peritonitis due to Staphylococcus sciuri in a patient on continuous ambulatory peritoneal dialysis

Among the coagulase-negative staphylococci, Staphylococcus sciuri has rarely been described as the aetiology of continuous ambulatory peritoneal dialysis (CAPD) peritonitis. It has been reported in 1 case of endocarditis and has been isolated from peritoneal dialysis fluid in 2 patients. The case reported here describes CAPD peritonitis due to S. sciuri shortly after a previous episode due to S. aureus, showing the necessity to identify coagulase-negative staphylococci to find new species that cause CAPD peritonitis.

Diffuse large B-cell non-Hodgkin's lymphoma in a patient with autoimmune lymphoproliferative syndrome

Mutations of Fas or Fas ligand genes result in the autoimmune lymphoproliferative syndrome (ALPS) in humans. We report here a diffuse large B-cell non-Hodgkin's lymphoma occurring in a man with ALPS. Fas-mediated lymphocyte apoptosis was defective in vitro, owing to a mutation within the death domain of the Fas molecule. High-dose methotrexate and doxorubicin-based chemotherapy led to complete remission of lymphoma.

High levels of human herpesvirus 8 viral load, human interleukin-6, interleukin-10, and C reactive protein correlate with exacerbation of multicentric castleman disease in HIV-infected patients

Multicentric Castleman disease (MCD) is a distinct type of lymphoproliferative disorder associated with inflammatory symptoms and interleukin-6 (IL-6) dysregulation. In the context of human immunodeficiency virus (HIV) infection, MCD is associated with human herpesvirus 8 (HHV8) infection. In a prospective study of 23 HIV-infected patients with MCD, clinical symptoms of MCD were present at 45 visits, whereas patients were in chemotherapy-induced clinical remission at 50 visits. Symptoms were associated with a high level of serum C reactive protein, high HHV8 viral load in peripheral blood mononuclear cells, and high plasma human IL-6 and IL-10 levels. Strong correlations between plasma IL-6 and plasma IL-10 with the HHV8 viral load suggest that both cytokines may be involved in the pathogenesis of this virus-associated lymphoproliferative disorder.

[Muscle infarction. An unknown complication of diabetes mellitus]

INTRODUCTION

Diabetic muscle infarction (MI) is a rare and little-known complication of diabetes mellitus.

CASE REPORT

We report a case of relapsing MI in which magnetic resonance imaging (MRI) suggested the diagnosis. A 53-year-old man with multi-complicated type II diabetes mellitus was admitted to our unit for illness and deep tumefaction of the right thigh. Because of unconclusive MRI, a muscular biopsy of the lesion was performed and MI confirmed. Three months after, a left relapse of MI occurred. Immediate treatment with immobilization and heparinotherapy permitted a rapid recovery.

CONCLUSION

About 70 previously reported cases are reviewed. The mean age at presentation was about 40 years. MI was usually seen in patients with long-standing diabetes with multiple end organ microvascular complications. Homo- or heterolateral recurrences are reported in almost half of the patients. MRI is the best imaging technique for suggesting the diagnosis.

[Human herpesvirus 8 (HHV8). II. Pathogenic role and sensitivity to antiviral drugs]

Human herpesvirus 8 (HHV8) has been found to be associated with three different diseases observed in Aids patients: Kaposi's sarcoma, primary effusion lymphoma, which is a rare type of non-Hodgkin lymphomas affecting the body cavities, and multicentric Castleman's disease. The role of this new herpesvirus and other lymphoid proliferations, like angioimmunoblastic lymphadenopathy or multiple myeloma, is much debatable. To date, there are several evidences for a direct role of this virus in the occurrence of the Kaposi's sarcoma, although the hypothesis of a passenger virus hypothesis cannot be totally excluded. In vitro, HHV8 is sensitive to some anti-herpesvirus drugs like foscarnet, cidofovir and adefovir, but the indications of these therapies in the prevention or the treatment of the Kaposi's sarcoma have not been documented so far.

[Human herpesvirus 8 ( HHV-8 ): I. Characteristics and epidemiology]

HHV8 is a new herpesvirus recently identified in the Kaposi's sarcoma lesions, and initially named Kaposi's sarcoma-associated herpesvirus. It is a member of gamma-2 herpesvirus family and it shows a number of homologies with the Epstein-Barr virus and the herpesvirus saimiri. HHV8 genome also codes for several proteins which are homologous to cellular proteins and could disturb the regulation mechanisms of cellular proliferation and apoptosis. This is the case for a viral IL6, an antiapoptotic factor homologous to Bcl2, a viral cyclin, a member of the IRF family (interferon regulatory factors) and a G-protein-coupled receptor homologous to the IL8 receptor. Seroprevalence studies showed that HHV8 infection was not ubiquitous but rather limited to some geographic areas (Italy, Greece, Africa), and to some populations of homosexual and bisexual individuals with sexually transmitted diseases. To date, several lines of epidemiologic evidence suggest that this virus is sexually transmitted, although other routes of transmission cannot be excluded.

[Retinochoroidal involvement of type II membranoproliferative glomerulonephritis. An angiographic study with indocyanine green]

PURPOSE

Type II measangiocapillary glomerulonephritis is related to dense deposits within the glomerular basal membrane and the basal membrane of the pigment epithelium (Bruch's membrane). Being a vasculitis, an angiographic study by indocyanine green (ICG) could possibly enlarge the semiologic features of this disease.

METHODS

The indocyanine green angiographic changes in 3 patients with predialitic renal failure due to type II measangiocapillary glomerulonephritis (MCGN II) (dense deposit disease) are reported. A complete ophthalmologic examination, electroretinography, electro-oculography, fluorescein and indocyanine green angiography (ICG) were performed for each patient.

RESULTS

Abnormal hyperfluorescent dots were seen on the same part of the fundus on both fluorescein and ICG angiography, though these locations were different for each of the three patients. These results seem to link the deposits to vascular changes within the choriocapillaris, which opposes them to drusen encountered in age related macular degeneration (ARMD). It appears that the choriocapillary lesions could be similar to the glomerular disease.

CONCLUSION

Beyond the diagnostic challenges related to the nephrologic disease, it is known that subretinal neovascularization occurs in some cases of MCGN II, although the pathophysiologic mechanism of the deposits is probably not the same as in ARMD. Therefore, ICG angiography should be performed when MCGN II is first known, serving as an initial examination for further follow-up.

Erythrocyte sedimentation rate, an underestimated tool in chronic renal failure

BACKGROUND

Erythrocyte sedimentation rate is widely used in the general population. It has seldom been studied in patients with chronic renal failure. The purpose of this study was to assess its usefulness in haemodialysis patients.

METHODS

Forty-five haemodialysis patients with no evidence of acute or chronic inflammatory illness were studied. Nine were diabetic, and 12 used a non-biocompatible membrane. Erythrocyte sedimentation rate was determined, using a modified Westergren method. Plasma fibrinogen concentration, complete blood count, and serum chemistries were also studied.

RESULTS

Erythrocyte sedimentation rate was normal or mildly elevated in most of our patients, with a median of 30 mm/h. Linear analysis found positive correlation between erythrocyte sedimentation rate and fibrinogen concentration, globulin level, platelet, and white cell counts, and negative correlation with haematocrit. Fibrinogen concentration was normal in 22 patients, and moderately elevated in 14. It was significantly higher in diabetic patients, or those using a non-biocompatible membrane. The same positive correlations were found for fibrinogen concentration as for erythrocyte sedimentation rate.

CONCLUSIONS

We conclude that erythrocyte sedimentation rate can be used in haemodialysis patients much in the same way as in the general population, as it is influenced by the same factors, and its baseline value is lower than previously reported. The lower concentration of fibrinogen, an independent predictor of cardiovascular risk, in patients treated with biocompatible membranes may be of clinical relevance.

[Cutaneous atypical Mycobacterium infection with hematogenic dissemination]

Non-tuberculous mycobacteria are ubiquitous non-pathogens except for subjects with deficient local or general defence systems. Nearly 80% of the cases observed in France occur in HIV+ patients. Lung, lymph node or skin infections usually simulate tuberculosis and diagnosis must be based on precise identification of the infectious strain. Recommended treatment of M. kansasii is now well established but protocols for other mycobacteria are still under evaluation. We observed a case presenting with persistent fever resistant to large spectrum antibiotics. This case occurred in a 75-year-old non-immunodepressed women who presented typical microcalcifications of the skin subsequent to blood stream dissemination.