High Risk of Acute Kidney Failure in Kidney Transplant Recipients Early after Bariatric Surgery.

Bariatric surgery is routinely proposed to patients suffering from obesity including kidney transplant recipients. In this specific population, bariatric surgery has a positive impact in long-term outcomes in terms of patient and graft survival. We report here the cases of 4 patients with five post-kidney transplantation bariatric surgeries who experimented acute renal injury early after surgery. Creatinine rising occurred between day 14 and day 20 after surgery. In all cases, it was due to dehydration leading to a pre-renal acute renal failure. The specific care of kidney transplanted patients is discussed: single kidney associated with pre-existing altered kidney function associated with concomitant use of nephrotoxic drugs. Specific education intervention before surgery associated with careful early management of hydration after surgery is mandatory for these patients.

A novel pathogenic variant in MRAP2 in an obese patient with successful outcome of bariatric surgery.

Mutations in genes encoding proteins located in the leptin/melanocortin pathway have been identified in the rare cases of genetic obesities. Heterozygous variants of MRAP2, encoding a G coupled-protein receptor accessory protein implicated in energy control notably via the melanocortin-4 receptor, have been recently identified. A 24-year-old patient with early-onset severe obesity (body mass index [BMI]: 64 kg/m2) associated with hypertension, respiratory complications, nonalcoholic fatty liver disease, and type 2 diabetes was referred to our department. Sleeve gastrectomy was successful. A new heterozygous variant in MRAP2 (NM_138409.4: c.154G>C/p.G52R) variant was identified in the patient DNA. Functional assessment confirmed that this new variant was pathogenic. We report a new pathogenic loss-of-function mutation in MRAP2 in a patient suffering from a severe multicomplicated obesity. This confirms the metabolic phenotype in patients with this monogenic form of obesity. Longer follow-up will be necessary. Our finding will allow a personalized medicine.

Co-crystallisation and humanisation of an anti-HER2 single-domain antibody as a theranostic tool.

Human epidermal growth factor receptor-2 (HER2) is a well-recognised biomarker associated with 25% of breast cancers. In most cases, early detection and/or treatment correlates with an increased chance of survival. This study, has identified and characterised a highly specific anti-HER2 single-domain antibody (sdAb), NM-02, as a potential theranostic tool. Complete structural description by X-ray crystallography has revealed a non-overlapping epitope with current anti-HER2 antibodies. To reduce the immunogenicity risk, NM-02 underwent a humanisation process and retained wild type-like binding properties. To further de-risk the progression towards chemistry, manufacturing and control (CMC) we performed full developability profiling revealing favourable thermal and physical biochemical 'drug-like' properties. Finally, the application of the lead humanised NM-02 candidate (variant K) for HER2-specific imaging purposes was demonstrated using breast cancer HER2+/BT474 xenograft mice.

An antagonistic monoclonal anti-Plexin-B1 antibody exerts therapeutic effects in mouse models of postmenopausal osteoporosis and multiple sclerosis.

Osteoporosis and multiple sclerosis are highly prevalent diseases with limited treatment options. In light of these unmet medical needs, novel therapeutic approaches are urgently sought. Previously, the activation of the transmembrane receptor Plexin-B1 by its ligand semaphorin 4D (Sema4D) has been shown to suppress bone formation and promote neuroinflammation in mice. However, it is unclear whether inhibition of this receptor-ligand interaction by an anti-Plexin-B1 antibody could represent a viable strategy against diseases related to these processes. Here, we raised and systematically characterized a monoclonal antibody directed against the extracellular domain of human Plexin-B1, which specifically blocks the binding of Sema4D to Plexin-B1. In vitro, we show that this antibody inhibits the suppressive effects of Sema4D on human osteoblast differentiation and mineralization. To test the therapeutic potential of the antibody in vivo, we generated a humanized mouse line, which expresses transgenic human Plexin-B1 instead of endogenous murine Plexin-B1. Employing these mice, we demonstrate that the anti-Plexin-B1 antibody exhibits beneficial effects in mouse models of postmenopausal osteoporosis and multiple sclerosis in vivo. In summary, our data identify an anti-Plexin-B1 antibody as a potential therapeutic agent for the treatment of osteoporosis and multiple sclerosis.

Guideline compliance in bariatric surgery: a French nationwide study.

BACKGROUND: Strict adherence to guidelines with a comprehensive preoperative assessment and rigorous follow-up are essential to improve postoperative and long-term outcomes of bariatric surgery (BS). OBJECTIVES: To investigate the trends in BS in France and to assess the compliance to guidelines in people with obesity before and after BS. SETTING: University Hospital of Bordeaux, France. METHODS: Data on patients who were admitted for a primary BS procedure in France between January 1 and April 1, 2014, were extracted from the French national health insurance system database. Data on patients' characteristics, preoperative assessment, hospitalization, and postoperative follow-up, including medical consultations, laboratory tests, and drug consumption, during the year preceding and the 2 years after BS were collected. RESULTS: Most of the 11,824 patients (60.4%) had sleeve gastrectomy. Rates of reimbursement for preoperative consultations with general practitioners, digestive surgeons, and endocrinologists or internists were 94.5%, 89.2%, and 63%, respectively. Laboratory tests for nutritional and obesity-related co-morbidity evaluations were performed in 94.3% and 91.4%, respectively. Rates of consultation with general practitioners, digestive surgeons, and endocrinologists or internists dropped from 93.1%, 91.2%, and 29.2%, respectively, the first year to 88.4%, 50.3%, and 20%, respectively, the second year after BS (P < .001). Reimbursements for vitamin, iron, and calcium supplementation dropped from 66.6%, 24.9%, and 21%, respectively, the first year to 52.1%, 19.3%, and 11.7%, respectively, the second year after BS (P < .001). CONCLUSION: Overall compliance with guidelines is improving. While preoperative medical assessment is nearly optimal, efforts still should be made in order to improve long-term follow-up in general and patient adherence to micronutrient supplementation in particular.

A series of severe neurologic complications after bariatric surgery in France: the NEUROBAR Study.

BACKGROUND: Neurologic complications after bariatric surgery are rare, but can have dramatic consequences. Little data are available on this topic. OBJECTIVES: The aim of the Neurologic complications after BARiatric surgery (NEUROBAR) study was to define, which factors (anthropometric, nutritional, surgical, etc.) were frequently associated with neurologic complications after bariatric surgery. SETTINGS: Data were collected by the French Centers of Obesity Care Management hosted in University Hospitals. METHODS: An online standardized questionnaire was designed and submitted to the 37 French Centers of Obesity Management. This questionnaire included items about patient characteristics, bariatric surgery, neurologic complications, nutritional status, and management. Patients were retrospectively included from January 2010 to November 2018. RESULTS: Thirteen centers included 38 patients (34 females and 4 males) with neurologic complications after bariatric surgery. The 2 main bariatric procedures were gastric bypass and sleeve gastrectomy. More than half of the patients with neurologic complications had a surgical complication after bariatric surgery (53%) and gastrointestinal symptoms, including vomiting (53%). Vitamin B deficiencies were frequent (74%) including at least 47% of cases with deficiency in Vitamin B1. CONCLUSION: Early identification of patients with surgical complications and gastrointestinal symptoms after bariatric surgery could help prevent neurologic complications related to nutritional deficiencies.

Oral Hydration, Food Intake, and Nutritional Status Before and After Bariatric Surgery.

BACKGROUND AND AIMS: Bariatric surgery is considered to be the most effective treatment of morbid obesity. Sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGBP) are the most popular procedures. We evaluated nutritional status, micro- and macronutrient intake, and oral hydration in patients before and regularly during 1 year after RYGBP and SG. METHODS: All patients that had been through bariatric surgery with at least 1-year post-surgery were retrospectively included in the study. All participants were evaluated once during the 2 months before the surgery and at 1, 3, 6, and 12 months after surgery. Clinical and biological evaluations as well as dietary investigations were performed. RESULTS: Fifty-seven patients were included in this study (28 RYGBP and 29 SG). Patients in the RYGBP group had significantly higher body weight (132.3 ± 22 versus 122.2 ± 22.2 kg, p = 0.039) than patients in the SG group. Before surgery, total energy intake, oral hydration, and vitamin and mineral intakes were not different between the two groups. RYGBP and SG induced significant similar excess weight loss 1 year after surgery, 48.6 29.8% and 57.6 27.6% of body weight respectively. Energy intake significantly decreased 1 month after surgery and slightly increased from 1 to 12 months without reaching baseline intake levels. Macronutrient repartition did not change during follow-up. Oral hydration significantly decreased after RYGBP (- 58%) and showed a trend to be decreased after SG (- 49%). Sixty-five percent of patients still had vitamin D deficiency 1 year after surgery. Whatever the type of surgery, more than 20% had some vitamin deficiency 1 month after surgery. CONCLUSIONS: Calories intake decreases after bariatric surgery, whatever the type of procedure. In addition, the prevalence of vitamin deficiency is high after bariatric surgery. Lastly, oral hydration is importantly decreased after bariatric surgery, especially after RYGBP.

Lifestyle intervention program in deprived obese adult patients and their non-deprived counterparts.

INTRODUCTION: Although it is known that the prevalence of obesity is high in deprived patients, the link between deprivation and obesity, and the impact of deprivation on compliance and efficacy of a lifestyle intervention program are not known. MATERIALS AND METHODS: Deprivation was assessed in 40 patients (23 Females, mean±SD age: 49±17 years) from the diabetology department and 140 patients (101 Females, age: 50±15 years) from the nutrition department of Bordeaux University hospital. Eighty-seven patients suffering from obesity were evaluated before and after a tailored, multidisciplinary lifestyle intervention. Deprivation was assessed using EPICES scores. Deprivation was defined with an EPICES score > 30. RESULTS: Deprived patients suffering from obesity had significantly higher current (43.8 ±8.4 versus 40.9 ± 5.5 kg/m2, p = 0,02) and maximal BMI (46.1± 8.6 versus 42.3± 5.2 kg/m2, p = 0.002) compared to non-deprived obese. Percentage of body weight loss was not different according to deprivation (4.74 ± 0.75 versus 4.65 ± 1.04%, p = 0.9). EPICES scores were not different according to adherence to lifestyle intervention program (20.5 ± 8.5 versus 29.9 ± 3.9 versus 29.0 ±2.5, no follow up versus partial follow up versus total follow up, p = 0,58). CONCLUSION: Deprived patients suffering from obesity have a more serious disease than non-deprived patients. However, neither compliance to the lifestyle intervention program nor body weight loss differed between deprived patients with obesity and non-deprived ones. Deprivation should not be a limitation when enrolling patients with obesity in lifestyle intervention programs.

Structural basis of Toxoplasma gondii MIC2-associated protein interaction with MIC2.

Toxoplasma gondii parasites must actively invade host cells to propagate. Secretory microneme proteins have been shown to be important for both gliding motility and active invasion. MIC2-M2AP is a protein complex that is essential for productive motility and rapid invasion by binding to host cell surface receptors. To investigate the architecture of the MIC2 and M2AP complex, we identified the minimal domains sufficient for interaction and solved the NMR solution structure of the globular domain of M2AP. We found that M2AP adopts a modified galectin fold similar to the C-terminal domain of another microneme protein, MIC1. NMR and immunoprecipitation analyses implicated hydrophobic residues on one face of the M2AP galectin fold in binding to the membrane proximal sixth thrombospondin type I repeat domain of MIC2. Our findings provide a second example of a galectin fold adapted for microneme protein-protein interactions and suggest a conserved strategy for the assembly and folding of diverse protein complexes.

Microneme protein 5 regulates the activity of Toxoplasma subtilisin 1 by mimicking a subtilisin prodomain.

Toxoplasma gondii is the model parasite of the phylum Apicomplexa, which contains obligate intracellular parasites of medical and veterinary importance. Apicomplexans invade host cells by a multistep process involving the secretion of adhesive microneme protein (MIC) complexes. The subtilisin protease TgSUB1 trims several MICs on the parasite surface to activate gliding motility and host invasion. Although a previous study showed that expression of the secretory protein TgMIC5 suppresses TgSUB1 activity, the mechanism was unknown. Here, we solve the three-dimensional structure of TgMIC5 by nuclear magnetic resonance (NMR), revealing that it mimics a subtilisin prodomain including a flexible C-terminal peptide that may insert into the subtilisin active site. We show that TgMIC5 is an almost 50-fold more potent inhibitor of TgSUB1 activity than the small molecule inhibitor N-[N-(N-acetyl-L-leucyl)-L-leucyl]-L-norleucine (ALLN). Moreover, we demonstrate that TgMIC5 is retained on the parasite plasma membrane via its physical interaction with the membrane-anchored TgSUB1.

In vitro activity of Proveblue (methylene blue) on Plasmodium falciparum strains resistant to standard antimalarial drugs.

The geometric mean 50% inhibitory concentration (IC50) for Proveblue, a methylene blue complying with the European Pharmacopoeia, was more active on 23 P. falciparum strains than chloroquine, quinine, mefloquine, monodesethylamodiaquine, and lumefantrine. We did not find significant associations between the Proveblue IC50 and polymorphisms in the pfcrt, pfmdr1, pfmdr2, pfmrp, and pfnhe-1 genes or the copy numbers of the pfmdr1 and pfmdr2 genes, all of which are involved in antimalarial resistance.

Absence of association between pyronaridine in vitro responses and polymorphisms in genes involved in quinoline resistance in Plasmodium falciparum.

BACKGROUND: The aim of the present work was to assess the in vitro cross-resistance of pyronaridine with other quinoline drugs, artesunate and several other commonly used anti-malarials and to evaluate whether decreased susceptibility to pyronaridine could be associated with genetic polymorphisms in genes involved in reduced quinoline susceptibility, such as pfcrt, pfmdr1, pfmrp and pfnhe. METHODS: The in vitro chemosusceptibility profiles of 23 strains of Plasmodium falciparum were analysed by the standard 42-hour 3H-hypoxanthine uptake inhibition method for pyronaridine, artesunate, chloroquine, monodesethylamodiaquine, quinine, mefloquine, lumefantrine, atovaquone, pyrimethamine and doxycycline. Genotypes were assessed for pfcrt, pfmdr1, pfnhe-1 and pfmrp genes. RESULTS: The IC50 values for pyronaridine ranged from 15 to 49 nM (geometric mean = 23.1 nM). A significant positive correlation was found between responses to pyronaridine and responses to artesunate (r2 = 0.20; P = 0.0317) but too low to suggest cross-resistance. No significant correlation was found between pyronaridine IC50 and responses to other anti-malarials. Significant associations were not found between pyronaridine IC50 and polymorphisms in pfcrt, pfmdr1, pfmrp or pfnhe-1. CONCLUSION: There was an absence of cross-resistance between pyronaridine and quinolines, and the IC50 values for pyronaridine were found to be unrelated to mutations in the transport protein genes pfcrt, pfmdr1, pfmrp or pfnhe-1, known to be involved in quinoline resistance. These results confirm the interest and the efficacy of the use of a combination of pyronaridine and artesunate in areas in which parasites are resistant to quinolines.

Absence of association between piperaquine in vitro responses and polymorphisms in the pfcrt, pfmdr1, pfmrp, and pfnhe genes in Plasmodium falciparum.

We have analyzed the profiles of 23 of Plasmodium falciparum strains for their in vitro chemosusceptibilities to piperaquine (PPQ), dihydroartemisinin (DHA), chloroquine, monodesethylamodiaquine, quinine, mefloquine, lumefantrine, atovaquone, pyrimethamine, and doxycycline (DOX) in association with polymorphisms in genes involved in quinoline resistance (Plasmodium falciparum crt [pfcrt], pfmdr1, pfmrp, and pfnhe). The 50% inhibitory concentrations (IC(50)s) for PPQ ranged from 29 to 98 nM (geometric mean = 57.8 nM, 95% confidence interval [CI] = 51 to 65) and from 0.4 to 5.8 nM for DHA (geometric mean = 1.8 nM, 95% CI = 1.4 to 2.3). We found a significant positive correlation between the responses to PPQ and DHA (r(2) = 0.17; P = 0.0495) and between the responses to PPQ and DOX (r(2) = 0.41; P = 0.001). We did not find a significant association between the PPQ IC(50) (0.0525 < P < 0.9247) or the DHA IC(50) (0.0138 < P < 0.9018) and polymorphisms in the pfcrt, pfmdr1, pfmrp, and pfnhe-1 genes. There was an absence of cross-resistance with quinolines, and the IC(50)s for PPQ and DHA were found to be unrelated to mutations in the pfcrt, pfmdr1, pfmrp, and pfnhe-1 transport protein genes, which are involved in quinoline antimalarial drug resistance. These results confirm the interest in and the efficacy of the combination of PPQ and DHA for areas in which parasites are resistant to chloroquine or other quinolines.

Synergy of mefloquine activity with atorvastatin, but not chloroquine and monodesethylamodiaquine, and association with the pfmdr1 gene.

OBJECTIVES: The aim of the study was to assess the in vitro potentiating effects of atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, in combination with mefloquine, chloroquine or monodesethylamodiaquine against Plasmodium falciparum and to evaluate whether the effects of atorvastatin could be associated with mutations or gene copy number in multidrug resistance (MDR)-like protein genes. METHODS: The susceptibilities of 21 parasite strains to combinations of atorvastatin with mefloquine, chloroquine or monodesethylamodiaquine were assessed using the in vitro isotopic microtest. Genotypes and gene copy number were assessed for pfmdr1, pfmdr2 and pfmrp genes. RESULTS: Atorvastatin demonstrated synergistic effects in combination with mefloquine. The mefloquine IC(50) (50% inhibitory concentration) was reduced by 7%, 24% and 37% in the presence of atorvastatin at concentrations of 0.1, 0.5 and 1.0 microM, respectively. The synergistic effect of atorvastatin on the response to mefloquine was significantly associated with pfmdr1 copy number. The concentration of atorvastatin that could reduce the IC(50) of mefloquine by 50% was 2.4 +/- 1.3 microM for the 12 strains that contained one copy of pfmdr1 and 5.8 +/- 2.1 microM for the 9 strains that contained two copies or more. The synergistic effect of atorvastatin in combination with mefloquine was found to be significantly unrelated to mutations in pfmdr1, pfmdr2 or pfmrp genes. CONCLUSIONS: The synergy of the effect of mefloquine at concentrations relevant to its achievable plasma concentrations in patients taking 80 mg of atorvastatin daily suggests that atorvastatin will be a good candidate in combination with mefloquine for malaria treatment.

Atorvastatin as a potential anti-malarial drug: in vitro synergy in combinational therapy with quinine against Plasmodium falciparum.

BACKGROUND: Quinine (QN) remains the first line anti-malarial drug for the treatment of complicated malaria in Europe and Africa. The emergence of QN resistance has been documented. QN resistance is not yet a significant problem, but there is an urgent need to discover partners for use in combination with QN. The aim of the study was to assess the in vitro potentiating effects of atorvastatin (AVA), a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, in combination with QN against Plasmodium falciparum and to evaluate whether the effects of AVA could be associated with gene copy number or mutations in genes involved in QN resistance, such as pfcrt, pfmdr1, pfmrp and pfnhe. METHODS: The susceptibilities to combination of AVA with QN were assessed against 21 parasite strains using the in vitro isotopic microtest. Genotypes and gene copy number were assessed for pfcrt, pfmdr1, pfmdr2, pfmrp genes. In addition, the number of DNNND, DDNHNDNHNN repeats in pfnhe-1 ms4760 and the ms4760 profile were determined for each strains of P. falciparum. RESULTS: AVA demonstrated synergistic effects in combination with QN against 21 P. falciparum strains. The QN IC50 was reduced by 5% (0% to 15%; 95%CI: 1%-8%), 10% (3% to 23%; 95%CI: 7%-14%) and 22% (14% to 40%; 95%CI: 19%-25%) in presence of AVA at concentrations of 0.1, 0.5 and 1.0 microM, respectively. These reductions were all significant (p < 0.009). The reduction in the QN IC50 in presence of AVA was not significantly correlated with the QN IC50 (r = 0.22, P = 0.3288) or the AVA IC50 (r = 0.03, P = 0.8946). The synergistic effect of AVA in combination with QN was not significantly associated with polymorphisms in the pfcrt, pfmdr1, pfmrp, and pfnhe-1 genes that could be involved in QN resistance. The synergistic effect of AVA on QN responses was not significantly associated with pfmdr1 copy number (P = 0.0428). CONCLUSION: The synergistic effect of AVA in combination with QN was found to be unrelated to mutations occurring in transport protein genes involved in QN drug resistance. The different mechanisms of drug uptake and/or mode of action for AVA compared to the other anti-malarial drugs, as well as the AVA-mediated synergy of the anti-malarial effect of QN, suggests that AVA will be a good candidate for combinatorial malaria treatment. All of these observations support calls for both an in vivo evaluation with pharmacokinetic component and clinical trials of AVA as an anti-malarial therapy.

Structure and functional relevance of the Slit2 homodimerization domain.

Slit proteins are secreted ligands that interact with the Roundabout (Robo) receptors to provide important guidance cues in neuronal and vascular development. Slit-Robo signalling is mediated by an interaction between the second Slit domain and the first Robo domain, as well as being dependent on heparan sulphate. In an effort to understand the role of the other Slit domains in signalling, we determined the crystal structure of the fourth Slit2 domain (D4) and examined the effects of various Slit2 constructs on chick retinal ganglion cell axons. Slit2 D4 forms a homodimer using the conserved residues on its concave face, and can also bind to heparan sulphate. We observed that Slit2 D4 frequently results in growth cones with collapsed lamellipodia and that this effect can be inhibited by exogenously added heparan sulphate. Our results show that Slit2 D4-heparan sulphate binding contributes to a Slit-Robo signalling mechanism more intricate than previously thought.

Atorvastatin is a promising partner for antimalarial drugs in treatment of Plasmodium falciparum malaria.

Atorvastatin (AVA) is a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor. AVA exposure resulted in the reduced in vitro growth of 22 Plasmodium falciparum strains, with the 50% inhibitory concentrations (IC(50)s) ranging from 2.5 microM to 10.8 microM. A significant positive correlation was found between the strains' responses to AVA and mefloquine (r = 0.553; P = 0.008). We found no correlation between the responses to AVA and to chloroquine, quinine, monodesethylamodiaquine, lumefantrine, dihydroartemisinin, atovaquone, or doxycycline. These data could suggest that the mechanism of AVA uptake and/or the mode of action of AVA is different from those for other antimalarial drugs. The IC(50)s for AVA were unrelated to the occurrence of mutations in the transport protein genes involved in quinoline antimalarial drug resistance, such as the P. falciparum crt, mdr1, mrp, and nhe-1 genes. Therefore, AVA can be ruled out as a substrate for the transport proteins (CRT, Pgh1, and MRP) and is not subject to the pH modification induced by the P. falciparum NHE-1 protein. The absence of in vitro cross-resistance between AVA and chloroquine, quinine, mefloquine, monodesethylamodiaquine, lumefantrine, dihydroartemisinin, atovaquone, and doxycycline argues that these antimalarial drugs could potentially be paired with AVA as a treatment for malaria. In conclusion, the present observations suggest that AVA is a good candidate for further studies on the use of statins in association with drugs known to have activities against the malaria parasite.

Plasmodium falciparum Na+/H+ exchanger 1 transporter is involved in reduced susceptibility to quinine.

Polymorphisms in the Plasmodium falciparum crt (Pfcrt), Pfmdr1, and Pfmrp genes were not significantly associated with quinine (QN) 50% inhibitory concentrations (IC(50)s) in 23 strains of Plasmodium falciparum. An increased number of DNNND repeats in Pfnhe-1 microsatellite ms4760 was associated with an increased IC(50) of QN (P = 0.0007). Strains with only one DNNND repeat were more susceptible to QN (mean IC(50) of 154 nM). Strains with two DNNND repeats had intermediate susceptibility to QN (mean IC(50) of 548 nM). Strains with three DNNND repeats had reduced susceptibility to QN (mean IC(50) of 764 nM). Increased numbers of NHNDNHNNDDD repeats were associated with a decreased IC(50) of QN (P = 0.0020). Strains with profile 7 for Pfnhe-1 ms4760 (ms4760-7) were significantly associated with reduced QN susceptibility (mean IC(50) of 764 nM). The determination of DNNND and NHNDNHNNDDD repeats in Pfnhe-1 ms4760 could be a good marker of QN resistance and provide an attractive surveillance method to monitor temporal trends in P. falciparum susceptibility to QN. The validity of the markers should be further supported by analyzing more isolates.