Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Kinetics and drainage index in function of pH, in the dewatering of arsenic iron sludge

Water for human consumption containing arsenic from natural and anthropogenic sources is a public health problem worldwide. Therefore, different technologies must be used to remove it from the water (coagulation-filtration assisted with ferric chloride, adsorption, membranes, etc.). While these technologies produce water that is free from arsenic, they also produce toxic residuals with high arsenic concentrations, which must be treated in order to decrease their volume and thereby facilitate transport and final disposal. Thus, the main purpose of this investigation was to study the physical and chemical properties of arsenic iron sludge in thickening, chemical conditioning, and dewatering processes, as well as to propose new kinetic criteria for obtaining the drainage index (E_g) based on polymer dose, mesh permeability, specific resistance to filtration, and pH. We found a significant improvement in the physical and chemical properties when thickening the sludge, in particular, floc size increased and specific resistance to filtration and Z-potential decreased due to weakened repulsive forces, resulting in more sedimentation. The polymer AN913VHM (PF2) had the best behavior in the chemical conditioning and dewatering tests, with an optimal dose of 8 mg/L and a mesh permeability of 80-100 ft³/min ft², which made it possible to retain more flocs (60% in 3.74 min). The pH affected the amount of total solids in the cake, with more solids obtained at a pH of 6 (25.93 g/L) and 6.5 (21.81 g/L), and with rapid drainage of surface water (69.28%). Furthermore, new kinetic criteria were obtained for a drainage time of 120 s in order to eliminate 60% of the total volume of the filtrate mass, with E_g of 3.05 at a pH of 6. This value is considered medium drainage for this type of sludge, which is difficult to treat.

Shifts in species interactions and farming contexts mediate net effects of birds in agroecosystems

Some birds are viewed as pests and vectors of foodborne pathogens in farmlands, yet birds also benefit growers by consuming pests. While many growers seek to prevent birds from accessing their farms, few studies have attempted to quantify the net effects of bird services and disservices, let alone how net effects shift across farm management strategies. We quantified the net effect of birds on crop production across 20 California strawberry (Fragaria × ananassa) farms that varied in local management practices and landscape context. We surveyed farms for berry damage and bird droppings (as potential sources of pathogens) and implemented a large-scale exclusion experiment to quantify the impact of birds on production. We found that birds had only a slightly negative overall impact on strawberry production, reducing economic value by 3.6%. Direct bird damage and intraguild predation contributed equally to this net effect, underscoring the importance of indirect trophic interactions that may be less apparent to growers. In simple landscapes (e.g., low proportions of surrounding seminatural habitat), birds provided pest control in the interiors of farm fields, and costs from bird damage to crops peaked at field edges. In complex landscapes (e.g., high proportions of seminatural habitat), birds were more likely to disrupt pest control by feeding as intraguild predators. Nonetheless, seminatural habitat dampened bird services and disservices, and our models predicted that removing habitat around farm fields would increase costs from bird damage to crops by up to 76%. Fecal contamination of crops was extremely rare (0.01%). However, both fecal contamination and bird damage did increase on farms with higher densities of fencing and wires, where birds often perch. Our results demonstrate that maintaining seminatural habitat around farms may enhance bird diversity and mitigate bird damage without increasing food safety risks. We also show that the net effects of birds depend on farming context and vary in complex ways in relation to locations within a farm, local farm attributes, and the surrounding landscape. This context-specific variation must be considered in order to optimize the management of wild birds in agroecosystems.

108 Use of seminal plasma as ovulation inductor in alpacas (Vicugna pacos) embryo recipient and its effect on pregnancy rate

Alpacas, like other camelids, are classified as induced ovulators because an external stimulus is required for the occurrence of ovulation. Recent studies have identified the β-nerve growth factor (β-NGF), a protein present in the seminal plasma (SP), as responsible for inducing ovulation in this species and having potent luteotropic function. We speculate that SP can be used in reproductive biotechnologies, such as embryo transfer (ET), to increase the number of genetically superior animals produced in breeding programs. The objective of this study was to evaluate the effect of inducing ovulation with SP or a gonadotrophin-releasing hormone (GnRH) analogue on pregnancy rate in recipients of an alpaca ET program. Semen from 5 adult male alpacas was collected with an artificial vagina and diluted 1:1 (v/v) with phosphate-buffered saline (PBS; Gibco-BRL). The diluted semen was centrifuged for 30min at 1200g, and the supernatant or SP was decanted and examined for absence of sperm. Then, the SP was centrifuged again for 20min at 1200×g. The SP was stored at −80°C until the use. Female alpacas (n=38; 6-8 years) with a body condition score of 2.5-3.5 (scale 1-5) were used for the experiment. Animals were evaluated daily by transrectal ultrasonography to determine the presence of a dominant follicle ≥7mm and randomly assigned to one of two groups: (1) GnRH (n=20), 0.04mg of Buserelin acetate IM, or (2) SP (n=18): 1.0mL of seminal plasma IM. Seven days after GnRH or SP treatment (Day 0) the recipients received a fresh embryo. Alpaca donors (n=18) were given GnRH (0.04mg IM) and treated 36h later with 700IU of equine chorionic gonadotropin (ECG). Donors were mated with fertile males 5 days after ECG (Day 0 of recipients), and embryos were recovered 7 days later. Embryos of similar quality were assigned to both groups and transferred nonsurgically to the uterine horn ipsilateral to the corpus luteum. Ultrasonography examinations were performed on Day 2 to confirm ovulation and Day 25 to determine pregnancy in all of the recipients. Data was analysed by chi-squared test. Ovulation rate was not different between groups (100% each). Pregnancy rate was 45% (9 out of 20) and 44% (8 of 18) in GnRH and SP groups, respectively (P=0.77). In conclusion, SP was effective to induce ovulation in alpacas and was able to produce a pregnancy rate similar to that of GnRH as an ovulation-inducing treatment. Thus, SP can be used as an alternative for ET programs in alpacas. Research was funded by the project Role of Seminal Plasma in Reproductive Physiology and Application of Biotechnologies in Camelids (149-2017-CIENCIACTIVA).

Flow Cytometric Assays to Quantify fHbp Expression and Detect Serotype Specific Capsular Polysaccharides on Neisseria meningitidis

Flow cytometry provides an automated analysis of bacteria passing in fluid suspension through a laser light beam. Bacteria are first treated with antibodies that bind to a specific target. These antibodies are tagged to fluorophores that fluoresce when passed through a laser beam. As the bacteria pass sequentially through the laser beam, they absorb and scatter the light in forward and side (90°) angles. The forward angle scatter is proportional to the size of the bacteria and the 90° angle side scatter is proportional to the internal structure (granularity). In addition, the tagged antibodies bound specifically to each bacteria, emit fluorescent light at defined wavelengths that can be collected and measured.Here we describe two flow cytometry based assays to measure expression levels of protein and polysaccharide on the surface of Neisseria meningitidis.

HcTOK1 participates in the maintenance of K+ homeostasis in the ectomycorrhizal fungus Hebeloma cylindrosporum, which is essential for the symbiotic K+ nutrition of Pinus pinaster

Most land plants rely on root symbioses to complement or improve their mineral nutrition. Recent researches have put forward that mycorrhizal fungi efficiently absorb and transfer potassium (K⁺) from the soil to host plant roots, but the molecular mechanisms involved are not completely elucidated yet. We have recently revealed that K⁺ is likely released from the fungal Hartig net to the plant by TOK channels in the ectomycorrhizal model Hebeloma cylindrosporum - Pinus pinaster. H. cylindrosporum harbours three TOK members. Herein, we report that one of them, HcTOK1, has similar features than the yeast ScTOK1. Moreover, we propose a role for this channel in the transport of K⁺ from the medium to ectomycorrhizal roots under K⁺ starvation.

A transmission electron microscope study of Néel skyrmion magnetic textures in multilayer thin film systems with large interfacial chiral interaction

Skyrmions in ultrathin ferromagnetic metal (FM)/heavy metal (HM) multilayer systems produced by conventional sputtering methods have recently generated huge interest due to their applications in the field of spintronics. The sandwich structure with two correctly-chosen heavy metal layers provides an additive interfacial exchange interaction which promotes domain wall or skyrmion spin textures that are Néel in character and with a fixed chirality. Lorentz transmission electron microscopy (TEM) is a high resolution method ideally suited to quantitatively image such chiral magnetic configurations. When allied with physical and chemical TEM analysis of both planar and cross-sectional samples, key length scales such as grain size and the chiral variation of the magnetisation variation have been identified and measured. We present data showing the importance of the grain size (mostly < 10 nm) measured from direct imaging and its potential role in describing observed behaviour of isolated skyrmions (diameter < 100 nm). In the latter the region in which the magnetization rotates is measured to be around 30 nm. Such quantitative information on the multiscale magnetisation variations in the system is key to understanding and exploiting the behaviour of skyrmions for future applications in information storage and logic devices.

Abstract P3-05-21: An integrative approach to the discovery of triple-negative breast cancer markers derived from extracellular vesicles

Triple-negative breast cancer (TNBC) is an aggressive subtype accounting for nearly 20% of all breast cancer (BC) cases with disproportionally poor prognosis. Treatment options are limited by the lack of expression of common BC receptors targeted by FDA-approved small molecule inhibitors, resulting in an unmet need for efficient and cost effective treatments. Immunotherapies are emerging as a powerful alternative to standard chemo- and radiation therapy. Our objectives are to generate vaccines targeting TNBC and to identify circulating biomarkers capable of monitoring their therapeutic efficacy in a human transgenic mouse model (C57BL/6) compatible with EO771.LMB, a murine cell line of TNBC with a reported basal-like phenotype.

Our current study characterized the cancer-related proteomic and metabolic signatures derived from extracellular vesicles isolated from EO771.LMB. It has been shown that extracellular vesicles (EV) shed by tumors carry complex cargos comprised of proteins, metabolites and nucleic acids and may exhibit cancer-specific signatures with a potential as prognostic markers or predictors of therapy response. EVs released by TNBC tumors into circulation might provide non-invasive and highly actionable insight into the tumor biology of this aggressive cancer.

To further our understanding of cancer-specific EV proteomes, we used mass-spectrometry based proteomics and identified a total of 2265 unique proteins from EVs isolated from conditioned media from EO771.LMB. Our survey across the EV proteome, the expression proteome (5096) and phosphoproteome (2728) identified 6461 unique proteins overall. Within EV sub-fractions, microvesicles and apoptotic bodies were characterized by proteomic cargos different from exosomes. Over 90% of proteins identified in EVs shed by cultured EO771.LMB mapped with proteins curated in ExoCarta. Of interest, exploration of the EV proteome identified 47 GPI-anchored surface proteins. These candidate membrane proteins included Glypican-1 and CD109, previously reported as highly specific to cancer, as well as potential TNBC-specific markers. Our multipronged strategy for deep proteomic profiling of EO771.LMB enhanced identification by ˜25% compared to global whole cell proteomics alone. We also identified ˜3150 metabolites corresponding to lysophosphatidyl choline (35%), fatty-acids, -esters, -amides, -alcohols (30%), glycerophospholipids and sphingolipids (16%), sugar (1%), amino acids and biogenic amines (4%), organic acids and derivatives, cyclic alcohols, aromatic compounds and steroids (13%). Of these, 1450 metabolites were shared between cell line and EVs.

A proteogenomic approach expanded identification to onco-proteoforms and tumor-specific peptides not represented in canonical databases. Custom, cell-specific protein databases derived from whole transcriptome sequencing of EO771.LMB elucidated novel protein variants and mutations. Pan-cancer markers vs. TNBC-specific markers will be verified in other murine cell lines, across multiple cancer types and fibroblast controls. Optimal membrane markers for downstream immune-affinity purification from plasma will be proposed, and their ability to diagnose disease or monitor tumor load during treatment will be discussed.

Citation Format: Igyártó B, Sharma R, Garcia K, David-Dirgo V, Pathak K, Kroll M, Terraf P, Van Keuren-Jensen K, Pirrotte P. An integrative approach to the discovery of triple-negative breast cancer markers derived from extracellular vesicles [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-05-21.

Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmions at room temperature

Facing the ever-growing demand for data storage will most probably require a new paradigm. Nanoscale magnetic skyrmions are anticipated to solve this issue as they are arguably the smallest spin textures in magnetic thin films in nature. We designed cobalt-based multilayered thin films in which the cobalt layer is sandwiched between two heavy metals and so provides additive interfacial Dzyaloshinskii-Moriya interactions (DMIs), which reach a value close to 2 mJ m(-2) in the case of the Ir|Co|Pt asymmetric multilayers. Using a magnetization-sensitive scanning X-ray transmission microscopy technique, we imaged small magnetic domains at very low fields in these multilayers. The study of their behaviour in a perpendicular magnetic field allows us to conclude that they are actually magnetic skyrmions stabilized by the large DMI. This discovery of stable sub-100 nm individual skyrmions at room temperature in a technologically relevant material opens the way for device applications in the near future.

Infecção sistêmica por Mycobacterium avium em cão: relato de caso

Infecções sistêmicas causadas pelo complexo Mycobacterium avium em cães são consideradas raras. Em cães e gatos, a infecção resulta da ingestão de carne ou do contato com solo ou fômites contaminados. As manifestações clínicas de cães infectados por M. avium tendem a ser vagas ou ausentes, logo o diagnóstico in vivo torna-se difícil. A suspeita de infecção sistêmica por micobacteriose ocorreu, neste relato, após a identificação de bacilos álcool-ácido resistentes na amostra de medula óssea, os quais foram identificados como Mycobacterium avium pelo método molecular de reação em cadeia da polimerase com análise de restrição (PCR-PRA). Este animal apresentava uma aplasia de medula óssea em decorrência de Erhlichia canis, corroborando a maioria dos relatos na literatura em que se associa essa infecção a pacientes imunossuprimidos.

Mouse ghrelin-O-acyltransferase (GOAT) plays a critical role in bile acid reabsorption

Ghrelin is a unique peptide gut hormone that requires post-translational modification to stimulate both feeding and growth hormone release. Ghrelin O-acyltransferase (GOAT) was identified as a specific acyl-transferase for ghrelin, and recent genetic deletion studies of the Goat gene (Goat(-/-)) uncovered the role of ghrelin in the regulation of glucose homeostasis. To further understand the physiological functions of the GOAT/ghrelin system, we have conducted a metabolomic and microarray profile of Goat-null mice, as well as determined Goat expression in different tissues using the lacZ reporter gene. Serum metabolite profile analysis revealed that Goat(-/-) mice exhibited increased secondary bile acids >2.5-fold. This was attributed to increased mRNA and protein expression of the ileal sodium-dependent bile acid transporter (ISBT) in the intestinal and biliary tract. Increased expression of additional solute carrier proteins, including Slc5a12 (>10-fold) were also detected in the small intestine and bile duct. Goat staining was consistently observed in the pituitary glands, stomach, and intestines, and to a lesser extent in the gallbladder and pancreatic duct. This is the first report that the GOAT/ghrelin system regulates bile acid metabolism, and these findings suggest a novel function of GOAT in the regulation of intestinal bile acid reabsorption..

Improving cancer control in Canada one case at a time: the "Knowledge Translation in Cancer" casebook

PURPOSE

In-the-field projects aiming to improve quality in cancer control provide a valuable complement to health services and knowledge translation (kt) research studies. The present paper describes the methods used to develop the Knowledge Translation for Cancer Control in Canada: A Casebook and its results.

METHODS

Nominations for in-the-field projects were accepted from individuals and organizations across Canada. The nominations had to demonstrate that a specific cancer control problem was identified; that a deliberate and organized effort was developed and implemented to address the identified problem; and that an evaluation-formal or informal-was used to assess the effort. A selection of nominated cases were chosen for more comprehensive analysis.

RESULTS

Thirty nominations were received. Most tackled problems related to treatment or diagnosis. Challenges related to breast, gastrointestinal, and genitourinary cancer were most common among the disease-specific projects, and most projects were regional in scope, with strategies targeting organizational solutions. Of the 30 nominations, 19 were chosen for further analysis. Of those 19, 5 were influenced by a kt model or theory, and 16 reported formal evaluation strategies. Surveys were the most common evaluation method, and process outcomes and clinical surrogate outcomes were the most frequently cited. Financial and administrative challenges were most often cited as key barriers. The key lessons learned concerned the need for a collaborative high-functioning team, project management, and support.

CONCLUSIONS

The casebook provides tangible examples of in-the-field efforts to improve cancer control and provides practical direction for other individuals and institutions facing similar challenges. We discuss the interface between field projects and research projects in the kt arena and how mutual learning can help to optimize the value of each approach.

Cranberry juice improved antioxidant status without affecting bone quality in orchidectomized male rats

BACKGROUND

We reported that drinking citrus juice improves bone quality in orchidectomized senescent male rats. Because cranberry juice, like citrus, is rich in nutrients and phenolic compounds, beneficial effects of citrus juice might also be seen with cranberry juice. An experiment evaluated effect of drinking cranberry juice on bone quality in orchidectomized rats.

METHODS

Thirty-two 1-year-old male rats were randomized to two groups: a sham-control group (n=8) and an orchidectomized group (n=24). The treatments for the 4 months duration of the study were SHAM, orchidectomy (ORX), ORX+drinking either 27% or 45% cranberry juice concentrate added to drinking water. At the termination of the study, the rats were euthanized, blood was collected for plasma antioxidant status and IGF-I. The femur, tibia and the 4th lumbar were evaluated for bone quality. Total calcium and magnesium concentration in the femurs were also evaluated.

RESULTS

ORX did not affect red blood cell (RBC)-induced hemolysis despite lowering (p<0.05) plasma antioxidant capacity; reduced (p<0.05) plasma IGF-I, femoral density, femoral strength, time-induced femoral fracture, bone mineral content, bone mineral area; numerically (p=0.07) lowered 4th lumbar density; decreased (p<0.05) trabecular connectivity, trabecular number, femoral ash; increased (p<0.05) trabecular separation in comparison to the SHAM group. Drinking cranberry juice increased (p<0.05) plasma antioxidant status, protected RBC against hemolysis, but had no positive effect on bone quality or bone mineral status.

CONCLUSIONS

Cranberry juice increases plasma antioxidant status without affecting bone quality.

Peptide YY regulates bone turnover in rodents

BACKGROUND & AIMS

Peptide YY (PYY) and pancreatic polypeptide (PPY) are members of the neuropeptide Y peptide family. The neuropeptide Y receptor signaling pathway has been implicated in a number of physiologic processes, including the regulation of energy balance and bone mass. To investigate the contribution of endogenous PYY and PPY to these processes, we generated both Pyy- and Ppy-deficient mice.

METHODS

Pyy(-/-) and Ppy(-/-) mice and their respective wild-type littermates were studied from 8 weeks to 9 months of age. Food intake, metabolic parameters, and locomotor activity were monitored using indirect calorimetry. Body composition and bone parameters were analyzed using dual energy x-ray absorptiometry, histomorphometry, and vertebral compression testing.

RESULTS

Studies in these mice showed an osteopenic phenotype specific to the Pyy-deficient line, which included a reduction in trabecular bone mass and a functional deficit in bone strength. Furthermore, female Pyy(-/-) mice showed a greater sensitivity to ovariectomy-induced bone loss compared with wild-type littermates. No food intake or metabolic phenotype was apparent in male or female Pyy(-/-) mice on standard chow. However, female Pyy(-/-) mice on a high-fat diet showed a greater propensity to gain body weight and adiposity. No metabolic or osteopenic phenotype was observed in Ppy-deficient mice.

CONCLUSIONS

These results indicate that endogenous PYY plays a critical role in regulating bone mass. In comparison, its role in regulating body weight is minor and is confined to situations of high-fat feeding.

Consultation de pharmacie et niveau de connaissance des patients hospitalisés traits par des médicaments anti-vitamine K

The report published by the French Agency for the Medical Safety of Health Products in 2001 estimated the number of hospital admissions in France for hemorrhagic accidents caused by oral anticoagulants (OA) to be 17,000. For this reason, we have set up pharmaceutical counselling for hospitalized patients treated with OA. The object of this article is to describe this therapeutic education program and to present the level of knowledge that patients have of their OA treatment. Among 68 patients treated prior to their admission, 87% knew the name of the OA, 86% the role of this treatment, 80% the dosing schedule, 57% what to do if a dose had been forgotten, 34% the signs of overdose, 48% the signs of and risks associated with not following the treatment schedule, 94% the advantage of biological follow-up and 68% the principal combinations of drugs that should be avoided. Among 118 patients whose treatment was begun during hospitalization, the level of knowledge for each item were respectively: 41%, 61%, 38%, 37%, 19%, 23%, 34% and 24% at the time of counselling. Newly treated patients acquired their knowledge from contact with nurses. The least known items were the symptoms and risks associated with overdosing or underdosing. This knowledge is therefore fragmentary and does not guarantee the patients' safety, which justifies the proposition of this type of counselling to such hospitalized patients.

Absence of ghrelin protects against early-onset obesity

The gut peptide ghrelin, the endogenous ligand for the growth hormone secretagogue receptor, has been implicated not only in the regulation of pituitary growth hormone (GH) secretion but in a number of endocrine and nonendocrine functions, including appetitive behavior and carbohydrate substrate utilization. Nevertheless, recent genetic studies have failed to show any significant defects in GH levels, food intake, or body weight in adult ghrelin-deficient (Ghrl-/-) mice. Here we demonstrate that male Ghrl-/- mice are protected from the rapid weight gain induced by early exposure to a high-fat diet 3 weeks after weaning (6 weeks of age). This reduced weight gain was associated with decreased adiposity and increased energy expenditure and locomotor activity as the animals aged. Despite the absence of ghrelin, these Ghrl-/- mice showed a paradoxical preservation of the GH/IGF-1 axis, similar to that reported in lean compared with obese humans. These findings suggest an important role for endogenous ghrelin in the metabolic adaptation to nutrient availability.

Absence of the lipid phosphatase SHIP2 confers resistance to dietary obesity

Genetic ablation of Inppl1, which encodes SHIP2 (SH2-domain containing inositol 5-phosphatase 2), was previously reported to induce severe insulin sensitivity, leading to early postnatal death. In the previous study, the targeting construct left the first eighteen exons encoding Inppl1 intact, generating a Inppl1(EX19-28-/-) mouse, and apparently also deleted a second gene, Phox2a. We report a new SHIP2 knockout (Inppl1(-/-)) targeted to the translation-initiating ATG, which is null for Inppl1 mRNA and protein. Inppl1(-/-) mice are viable, have normal glucose and insulin levels, and normal insulin and glucose tolerances. The Inppl1(-/-) mice are, however, highly resistant to weight gain when placed on a high-fat diet. These results suggest that inhibition of SHIP2 would be useful in the effort to ameliorate diet-induced obesity, but call into question a dominant role of SHIP2 in modulating glucose homeostasis.

Genetic deletion of ghrelin does not decrease food intake but influences metabolic fuel preference

Ghrelin is a recently identified growth hormone (GH) secretogogue whose administration not only induces GH release but also stimulates food intake, increases adiposity, and reduces fat utilization in mice. The effect on food intake appears to be independent of GH release and instead due to direct activation of orexigenic neurons in the arcuate nucleus of the hypothalamus. The effects of ghrelin administration on food intake have led to the suggestion that inhibitors of endogenous ghrelin could be useful in curbing appetite and combating obesity. To further study the role of endogenous ghrelin in appetite and body weight regulation, we generated ghrelin-deficient (ghrl(-/-)) mice, in which the ghrelin gene was precisely replaced with a lacZ reporter gene. ghrl(-/-) mice were viable and exhibited normal growth rates as well as normal spontaneous food intake patterns, normal basal levels of hypothalamic orexigenic and anorexigenic neuropeptides, and no impairment of reflexive hyperphagia after fasting. These results indicate that endogenous ghrelin is not an essential regulator of food intake and has, at most, a redundant role in the regulation of appetite. However, analyses of ghrl(-/-) mice demonstrate that endogenous ghrelin plays a prominent role in determining the type of metabolic substrate (i.e., fat vs. carbohydrate) that is used for maintenance of energy balance, particularly under conditions of high fat intake.

Ciliary neurotrophic factor improves diabetic parameters and hepatic steatosis and increases basal metabolic rate in db/db mice

Obesity plays a central role in the development of insulin resistance and type 2 diabetes. We therefore examined the effects of a modified form of ciliary neurotrophic factor [Axokine, which is hereafter referred to as ciliary neurotrophic factor (CNTF)Ax15], which uses a leptin-like mechanism to reduce body weight, in the db/db murine model of type 2 diabetes. In previous studies, weight loss produced by CNTF treatment could largely be attributed to its effects on food intake. In contrast, CNTFAx15 treatment of db/db mice caused significantly greater weight loss and marked improvements in diabetic parameters (e.g., levels of glucose, insulin, triglyceride, cholesterol, and nonesterified free fatty acids) than could be accounted for by reduced caloric intake alone. These beneficial effects, above and beyond those seen in animals controlled for either food restriction or body weight, correlated with the ability of CNTFAx15 to increase metabolic rate and energy expenditure and reduce hepatic steatosis while enhancing hepatic responsiveness to insulin. The hepatic effects were linked to rapid alterations in hepatic gene expression, most notably reduced expression of stearoyl-CoA desaturase 1, a rate-limiting enzyme in the synthesis of complex lipids that is also markedly suppressed by leptin in ob/ob mice. These observations further link the mechanisms of CNTF and leptin action, and they suggest important, beneficial effects for CNTF in diabetes that may be distinct from its ability to decrease food intake; instead, these effects may be more related to its influence on energy expenditure and hepatic gene expression.

Brain-derived neurotrophic factor improves blood glucose control and alleviates fasting hyperglycemia in C57BLKS-Lepr(db)/lepr(db) mice

Systemic administration of brain-derived neurotrophic factor (BDNF) decreases nonfasted blood glucose in obese, non-insulin-dependent diabetic C57BLKS-Lepr(db)/lepr(db) (db/db) mice, with a concomitant decrease in body weight. By measuring percent HbA1c in BDNF-treated and pair-fed animals, we show that the effects of BDNF on nonfasted blood glucose levels are not caused by decreased food intake but reflect a significant improvement in blood glucose control. Furthermore, once established, this effect can persist for weeks after cessation of BDNF treatment. Oral glucose tolerance tests were performed to examine the effects of BDNF on blood glucose control in the fasted state and after an oral glucose challenge. BDNF treatment normalized fasting blood glucose from initially hyperglycemic levels and also showed evidence for beneficial, although less marked, effects on the ability to remove exogenous glucose from blood. One means to lower fasting blood glucose is to reduce the glucose output of peripheral tissues that normally play a part in the maintenance of fasting hyperglycemia. Because the liver is the major endogenous source of glucose in blood during fasting, and because hepatic weight and glucose output are increased in type 2 diabetes, we evaluated the effects of BDNF on liver tissue. BDNF reduced the hepatomegaly present in db/db mice, in association with reduced liver glycogen and reduced liver enzyme activity in serum, supporting the possible involvement of liver tissue in the mechanism of action for BDNF.

Physiological characterization of Taxol-induced large-fiber sensory neuropathy in the rat

The cancer chemotherapeutic agent Taxol (paclitaxel) causes a dose-related peripheral neuropathy in humans. We produced a dose-dependent large-fiber sensory neuropathy, without detrimental effects on general health, in mature rats by using two intravenous injections 3 days apart. Tests of other dosing schedules demonstrated the dependence of the severity of the neuropathy and of animal health on both the dose and the frequency of dosing. Pathologically, severe axonal degeneration and hypomyelination were observed in sections of dorsal roots, whereas ventral roots remained intact. Electrophysiologically, H-wave amplitudes in the hindlimb and amplitudes of predominantly sensory compound nerve action potentials in the tail were reduced. These effects persisted for at least 4 months after treatment. Motor amplitudes were not affected, but both motor and sensory conduction velocities decreased. The ability of rats to remain balanced on a narrow beam was impaired, indicating proprioceptive deficits. Muscle strength, measured by hindlimb and forelimb grip strength, and heat nociception, measured by tail-flick and hindlimb withdrawal tests, were not affected by Taxol. This model of Taxol-induced neuropathy in mature rats, with minimal effects on general health, parallels closely the clinical syndrome observed after Taxol treatment in humans.

Pharmacokinetics and interspecies scaling of recombinant human factor VIII

Recombinant human (rh) factor VIII is a glycoprotein consisting of multiple polypeptides with relative mobilities (M(r)) ranging from 80,000 to 210,000. It is produced in mammalian cells. Single-dose intravenous pharmacokinetic studies were conducted with rh factor VIII (Kogenate rh Antihemophilic Factor, Miles, Inc.) in male mice (21.0-25.8 g) and rats (252.0-254.2 g). Each species received 400 IU/kg, and blood was collected up to 12 hr (mice) or 32.5 hr (rats) post-dose. Immunoreactive factor VIII concentrations in plasma were quantified by a sensitive and specific ELISA. In both species, the disposition profiles were described by the sum of two exponentials. The pharmacokinetics of rh factor VIII in mouse were as follows: clearance, 27.7 ml/hr/kg; initial volume of distribution, 72 ml/kg; steady-state volume of distribution, 148 ml/kg; and terminal half-life, 4.1 hr. In rat, the mean estimates were as follows: clearance, 16.0 ml/hr/kg; initial volume of distribution, 41 ml/kg; steady-state volume of distribution, 125 ml/kg; and terminal half-life, 5.5 hr. These pharmacokinetic parameters for rh factor VIII in animals and human rh factor VIII pharmacokinetic parameters from the literature were evaluated to determine if the parameters can be represented by the allometric relationship, Y = aWb, where Y is the pharmacokinetic parameter, and W is body weight. The following allometric relations were obtained for rh factor VIII: clearance (ml/hr) = 10.4W0.69, half-life (hr) = 7.5 W0.18, initial volume of distribution (ml) = 43.6 W1.04, and steady-state volume of distribution (ml) = 99.1 W0.84. The allometric exponents for each parameter conformed to theory and were within the range of values commonly observed for xenobiotics and therapeutic proteins. These studies suggest that the pharmacokinetics of rh factor VIII in laboratory animals are predictive of the disposition in humans despite the complex nature of its biological interactions and the chemical diversity of the purified material.

Effects of in utero administration of phenobarbital on gamma-glutamyl transpeptidase

The present study was undertaken to determine the effects of the in utero administration of phenobarbital (Pb) on gamma glutamyl transpeptidase (gamma-GTP) in rats. Female Wistar rats were bred to healthy adult males. On day 1 of gestation (evidenced by spermatozoa from vaginal smear) the pregnant rats were given 100 mg/kg phenobarbital (as the sodium salt) daily via the BioServ Liquid diet throughout gestation. Pair-fed controls were given the same volume of food as consumed by the experimental group. The offspring were sacrificed at birth and body, brain and liver weights determined. The pups born to the Pb treated mothers weighed significantly less than those born to the control mothers (4.77 and 6.60 g respectively). The brains and livers were homogenized in Tris buffered saline and assayed for gamma-GTP activity. Brain gamma-GTP activity was found to be 0.00807 u in the Pb group and 0.00670 u in the control group. We also examined the effects of chronic administration of Pb in adult rats and found no apparent effect on liver or brain gamma-GTP activity.