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.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Fc-GDF15 glyco-engineering and receptor binding affinity optimization for body weight regulation

GDF15 is a distant TGF-β family member that induces anorexia and weight loss. Due to its function, GDF15 has attracted attention as a potential therapeutic for the treatment of obesity and its associated metabolic diseases. However, the pharmacokinetic and physicochemical properties of GDF15 present several challenges for its development as a therapeutic, including a short half-life, high aggregation propensity, and protease susceptibility in serum. Here, we report the design, characterization and optimization of GDF15 in an Fc-fusion protein format with improved therapeutic properties. Using a structure-based engineering approach, we combined knob-into-hole Fc technology and N-linked glycosylation site mutagenesis for half-life extension, improved solubility and protease resistance. In addition, we identified a set of mutations at the receptor binding site of GDF15 that show increased GFRAL binding affinity and led to significant half-life extension. We also identified a single point mutation that increases p-ERK signaling activity and results in improved weight loss efficacy in vivo. Taken together, our findings allowed us to develop GDF15 in a new therapeutic format that demonstrates better efficacy and potential for improved manufacturability.

Elevated GDF-15 levels may indicate malnutrition in chronic compensated heart failure with or without diabetes mellitus

Background/Introduction

Malnutrition is common in chronic heart failure (HF) and is associated with adverse outcomes. Elevated NT-proBNP may indicate increased cardiac stress, whereas growth differentiation factor 15 (GDF-15) is increased in response to tissue injury, inflammation and in diabetes mellitus (DM). GDF-15 also negatively regulates appetite, body weight and skeletal muscle homeostasis.

Purpose

We aim to assess the nutritional status of HF patients with or without DM, and determine if GDF-15 is associated with malnutrition.

Methods

We did a cross-sectional analysis on chronic HF patients in a prospective cohort study, forecAsting Heart Failure decompensation (AHF). Chronic compensated HF was defined as a state following hospital discharge for &gt;30 days, or where there had not been hospitalisation for 30 days preceding phenotyping. Patients with a history of HF decompensation were included. Geriatric Nutritional Risk Index (GNRI), including body mass index (BMI) and serum albumin, was used to assess and categorise nutritional status. Patients were classified as being “malnourished” or “well-nourished” based on GNRI scores of &lt;92 and ≥92, respectively. NT-proBNP and GDF-15 levels were measured and echocardiography was done. The study was approved by institutional review board and complied with Declaration of Helsinki.

Results

Among 73 patients (mean age 66 y, 58.9% male), 32.7% exhibited malnutrition as determined by GNRI. There was no difference in age, sex ratio and NYHA functional class between the malnourished and the well-nourished. BMI (22.1 vs 25.6, P&lt;0.001) and levels of GDF-15 (7216.0 vs 2469.0, P&lt;0.001) and NT-proBNP (7158.0 vs 1321.0, P=0.01) were different between the malnourished and well-nourished. Both GDF-15 and NT-proBNP were inversely correlated with GNRI (GDF-15, r=−0.39, P&lt;0.001; NT-proBNP, r=−0.46, P&lt;0.0001). As expected, DM HF patients had significantly higher levels of GDF-15 than non-DM HF patients. In subgroup analysis of DM HF patients, GDF-15 and NT-proBNP levels were higher in the malnourished than well-nourished (median log-[GDF-15], 9.15 vs 8.10, P&lt;0.01; median log-[NT-proBNP], 9.44 vs 7.00, P&lt;0.01). Whereas in non-DM HF, NT-proBNP levels were not different between the malnourished and well-nourished. Age- and sex-adjusted logistic regression model determined that per log increment in GDF-15 level there was a 5.8-fold increased risk of malnutrition (OR 5.81 [2.43–17.62], P&lt;0.001), and for every log increment in NT-proBNP level there was a 1.8-fold increase in the risk of malnutrition (OR 1.82 [1.23–2.88], P&lt;0.01).

Conclusion(s)

Malnutrition is common in chronic compensated HF patients with a history of hospitalisation, and is associated with elevated NT-proBNP and GDF-15 levels. Elevated GDF-15 levels independently predicted poor nutritional status, and with NT-proBNP may indicate a particularly high-risk HF subgroup

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): 1) Health and Medical Research Fund, Food and Health Bureau, 2) Direct Grant, Faculty of Medicine, CUHK

Cardiac Manifestations of Sarcopenia

OBJECTIVES

Screening questions for sarcopenia used in the community (SARC-F) may be regarded as indicators of exercise tolerance.

DESIGN

Observational study.

SETTING

We tested the hypothesis that community-living older people who are screened positive for sarcopenia using the SARC-F tool but without a history of heart failure (HF) have a higher prevalence of cardiac abnormalities compared with those who are SARC-F negative.

PARTICIPANTS

Participants were recruited from a territory-wide primary care needs assessment for older people based in community centres, and from non-acute hospitals in the same region as the study centre.

MEASUREMENTS

Participants with a total score of >=4 and who did not have any history of HF were invited to attend for further cardiac assessment. Grip strength, walking speed, and the 6-minute walk test and echocardiography were carried out. Patients with frailty and at least Grade II diastolic dysfunction were considered to have heart failure with preserved ejection fraction (HFpEF) if they also had concomitant elevated N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) of at least 300 pg/ml.

RESULTS

Diastolic dysfunction (DD) was significantly associated with SARC-F score >=4 and higher circulating NT-proBNP levels. ROC curves evaluating the predictive values of SARC-F, HGS and gait speed for DD showed that a combination of SARC-F and HGS or gait speed provided significant incremental value in predicting DD.

CONCLUSIONS

Community living older people with sarcopenia detected using a simple questionnaire have a higher prevalence of DD accompanied by elevated NT proBNP. Addition of hand grip strength or walking speed improve the magnitude of the association. SARC-F may be used as a tool to detect early cardiac dysfunction in the community.

P39 Cross-sectional analysis of 6-minute walk distance and diastolic function in a Hong Kong cohort of community-living older adults

Funding Acknowledgements

CUHK Direct Grant, CUHK Lui Che Woo Institute of Innovative Medicine, Food and Health Bureau of HKSAR (EF); Hong Kong Jockey Club Charities Trust (JW)

Background/Introduction

6-min walk distance (6MWD) can indicate frailty extent, cardiac dysfunction, and heart failure (HF) trajectory. Association of 6MWD with diastolic dysfunction (DD) or cardiac biomarker in community-living elderly without a history of HF remains underexplored.

Purpose

This study aims to determine the association between 6MWD, serum N-terminal prohormone of B-type natriuretic peptide (NT-proBNP), and DD in a community-living elderly population without known HF.

Methods

Between Nov 2017 and Aug 2018, 302 Hong Kong Chinese aged ≥60 y and without known HF were recruited into the Undiagnosed heart Failure in Older individuals (UFO) study consisting of robust, pre-frail and frail older adults stratified by FRAIL scale in a ratio of 1:1:1. 6MWD was divided into tertiles. Transthoracic echocardiography and serum NT-proBNP were used to assess cardiac dysfunction. Diastolic function was classified according to international guidelines and NT-proBNP &gt;300 pg/ml was considered elevated.

Results

The ages of participants in the bottom, middle and top tertiles were 80.3 ± 7.4, 73.9 ± 6.3 and 70.0 ± 5.7 years (P &lt; 0.01), respectively, corresponding to a female preponderance of 85.0%, 75.2%, 46.5% (P &lt; 0.01). The highest prevalence rates of hypertension (HT, 76.0% vs 68.3% vs 51.5%, P &lt; 0.01), diabetes mellitus (DM, 41.0% vs 30.7% vs 12.9%, P &lt; 0.01), and ischaemic heart disease (IHD, 14.0% vs 4.0% vs 2.0%, P &lt; 0.01) were observed in the bottom tertile of 6MWD. However, the prevalence of atrial fibrillation (AF) was distributed equally across tertiles (2.0% vs 2.0% vs 2.0%). Frail (63.0% vs 25.7% vs 3.0%, P &lt; 0.01) and pre-frail (36.5% vs 44.6% vs 24.8%, P &lt; 0.01) individuals were most frequently seen in the bottom and middle tertiles of 6MWD.

Using multiple linear regression analysis, S’ velocity, E:E’ ratio and E’ velocity were associated with 6MWD independent of age and sex. Associations between 6MWD and S’, left atrial volume index, E’ and E:E’ remained statistically significant even after adjusting for HT, DM, IHD, AF, stroke, chronic pulmonary disease and arthritis. No correlation was observed between 6MWD and left ventricular ejection fraction. 

Compared with the top tertile of 6MWD, the bottom tertile was associated with increased risks for grade II–IV DD (odds ratio (OR) 3.47, 95% confidence interval (CI) 1.52–7.96, P &lt; 0.01) and NT-proBNP &gt;300pg/ml (OR 10.20, CI 3.74–27.85, P &lt; 0.01, respectively, after adjusting for co-morbidities. The association between reduced 6MWD and elevated NT-proBNP, but not between 6MWD and DD, remained significant (OR 6.00, CI 2.06–17.46) after adjusting for age and sex. The middle tertile was not significantly associated with an increased risk for grade II–IV DD or elevated NT-proBNP.

Conclusion(s)

In this cohort of community-living Hong Kong Chinese elderly recruited equally by frailty status, performance of 6MWD in the bottom and top tertiles was inversely associated with NT-proBNP levels but not with DD.

The SMYD3 methyltransferase promotes myogenesis by activating the myogenin regulatory network

The coordinated expression of myogenic regulatory factors, including MyoD and myogenin, orchestrates the steps of skeletal muscle development, from myoblast proliferation and cell-cycle exit, to myoblast fusion and myotubes maturation. Yet, it remains unclear how key transcription factors and epigenetic enzymes cooperate to guide myogenic differentiation. Proteins of the SMYD (SET and MYND domain-containing) methyltransferase family participate in cardiac and skeletal myogenesis during development in zebrafish, Drosophila and mice. Here, we show that the mammalian SMYD3 methyltransferase coordinates skeletal muscle differentiation in vitro. Overexpression of SMYD3 in myoblasts promoted muscle differentiation and myoblasts fusion. Conversely, silencing of endogenous SMYD3 or its pharmacological inhibition impaired muscle differentiation. Genome-wide transcriptomic analysis of murine myoblasts, with silenced or overexpressed SMYD3, revealed that SMYD3 impacts skeletal muscle differentiation by targeting the key muscle regulatory factor myogenin. The role of SMYD3 in the regulation of skeletal muscle differentiation and myotube formation, partially via the myogenin transcriptional network, highlights the importance of methyltransferases in mammalian myogenesis.

Utility of the FRAIL Questionnaire in Detecting Heart Failure with Preserved Ejection Fraction

OBJECTIVE

To test the utility of the FRAIL questionnaire as a screening tool for heart failure.

DESIGN

Cross sectional study.

SETTING

Chinese older people in Hong Kong.

PARTICIPANTS

Participants aged 60 years and over were recruited from a territory-wide primary care needs assessment for older people based in community centers as well as two nonacute hospitals.

MEASUREMENTS

Questionnaire administered included the five-item FRAIL scale, and information regarding sociodemographic data, smoking and alcohol use, history of cardiovascular disease and diabetes, and heart failure symptoms. Handgrip strength, walking speed and 6 minute walk distance were recorded. Cardiac assessment included electrocardiogram, echocardiography, and blood assay for N-terminal prohormone of B-type natriuretic peptide (NT-proBNP).

RESULTS

The prevalence of diastolic dysfunction was high, being 52% in the robust group, increasing to 65% in the pre-frail and 85% in the frail group. This finding is accompanied by a corresponding increase in NT-proBNP from 64.18 pg/ml in the robust group, to 118.57 pg/ml in the pre-frail and 167.98 pg/ml in the frail group. Three of the five components of the FRAIL scale, fatigue, resistance and ambulation, were associated with increased odds ratios of diastolic dysfunction among those aged 75 years and older, while resistance alone was associated with increased odds ratio among those less than 75 years old.

CONCLUSION

Frailty is associated with heart failure with preserved ejection fraction (HFpEF), and frailty screening may be used to detect undiagnosed HFpEF. The findings support the proposal that HFpEF be considered a geriatric syndrome.

FBXL13 directs the proteolysis of CEP192 to regulate centrosome homeostasis and cell migration

Aberrant centrosome organisation with ensuing alterations of microtubule nucleation capacity enables tumour cells to proliferate and invade despite increased genomic instability. CEP192 is a key factor in the initiation process of centrosome duplication and in the control of centrosome microtubule nucleation. However, regulatory means of CEP192 have remained unknown. Here, we report that FBXL13, a binding determinant of SCF (SKP1-CUL1-F-box)-family E3 ubiquitin ligases, is enriched at centrosomes and interacts with the centrosomal proteins Centrin-2, Centrin-3, CEP152 and CEP192. Among these, CEP192 is specifically targeted for proteasomal degradation by FBXL13. Accordingly, induced FBXL13 expression downregulates centrosomal γ-tubulin and disrupts centrosomal microtubule arrays. In addition, depletion of FBXL13 induces high levels of CEP192 and γ-tubulin at the centrosomes with the consequence of defects in cell motility. Together, we characterise FBXL13 as a novel regulator of microtubule nucleation activity and highlight a role in promoting cell motility with potential tumour-promoting implications.

Outcome of a Knowledge Contact-based Anti-stigma Programme in Adolescents and Adults in the Chinese Population

A lack of knowledge about mental health and stigma of the mentally ill are barriers to the treatment of mental disorders. To reduce these barriers, anti-stigma campaigns using a knowledge contact approach were launched to raise public mental health knowledge by education and to reduce stigma by encouraging contact with individuals with mental disorders. The current study attempted to investigate the outcome of a knowledge contact-based programme in adolescents and adults in the Hong Kong Chinese population. Matched background individuals served as controls. Results from the 149 adolescents and 98 adults who participated in our programme showed that they had superior mental health literacy to the control group. Although both adolescents and adults showed a positive outcome on most measures of stigma, the former showed positive outcome on more measures of stigma than the latter. Our results support the initiative of using a knowledge contact-based anti-stigma campaign in Chinese societies. The results of this study provide preliminary data that will help inform and guide future research and development of effective mental health awareness programmes specific to people of various age-groups in the Chinese community.

SCF (Fbxl17) ubiquitylation of Sufu regulates Hedgehog signaling and medulloblastoma development

Skp1-Cul1-F-box protein (SCF) ubiquitin ligases direct cell survival decisions by controlling protein ubiquitylation and degradation. Sufu (Suppressor of fused) is a central regulator of Hh (Hedgehog) signaling and acts as a tumor suppressor by maintaining the Gli (Glioma-associated oncogene homolog) transcription factors inactive. Although Sufu has a pivotal role in Hh signaling, the players involved in controlling Sufu levels and their role in tumor growth are unknown. Here, we show that Fbxl17 (F-box and leucine-rich repeat protein 17) targets Sufu for proteolysis in the nucleus. The ubiquitylation of Sufu, mediated by Fbxl17, allows the release of Gli1 from Sufu for proper Hh signal transduction. Depletion of Fbxl17 leads to defective Hh signaling associated with an impaired cancer cell proliferation and medulloblastoma tumor growth. Furthermore, we identify a mutation in Sufu, occurring in medulloblastoma of patients with Gorlin syndrome, which increases Sufu turnover through Fbxl17-mediated polyubiquitylation and leads to a sustained Hh signaling activation. In summary, our findings reveal Fbxl17 as a novel regulator of Hh pathway and highlight the perturbation of the Fbxl17-Sufu axis in the pathogenesis of medulloblastoma.

p53 is required for cisplatin-induced processing of the mitochondrial fusion protein L-Opa1 that is mediated by the mitochondrial metallopeptidase Oma1 in gynecologic cancers

Mitochondria are highly dynamic organelles, and mitochondrial fission is a crucial step of apoptosis. Although Oma1 is believed to be responsible for long form Opa1 (L-Opa1) processing during mitochondrial fragmentation, whether and how Oma1 is involved in L-Opa1 processing and participates in the regulation of chemoresistance is unknown. Chemosensitive and chemoresistant ovarian (OVCA) and cervical (CECA) cancer cells were treated with cisplatin (CDDP). Mitochondrial dynamics and protein contents were assessed by immunofluorescence and Western blot, respectively. The requirements of Oma1 and p53 for CDDP-induced L-Opa1 processing, mitochondrial fragmentation, and apoptosis were examined by siRNA or cDNA. CDDP induces L-Opa1 processing and mitochondrial fragmentation in chemosensitive but not in chemoresistant cells. CDDP induced Oma1 40-kDa form increases in OV2008 cells, not in C13* cells. Oma1 knockdown inhibited L-Opa1 processing, mitochondrial fragmentation, and apoptosis. Silencing p53 expression attenuated the effects of CDDP in Oma1 (40 kDa) increase, L-Opa1 processing, mitochondrial fragmentation, and apoptosis in chemosensitive OVCA cells, whereas reconstitution of p53 in p53 mutant or null chemoresistant OVCA cells induced Oma1 (40 kDa) increase, L-Opa1 processing, mitochondrial fragmentation, and apoptosis irrespective of the presence of CDDP. Prohibitin 1 (Phb1) dissociates from Opa1-Phb1 complex and binds phosphorylated p53 (serine 15) in response to CDDP in chemosensitive but not chemoresistant CECA cells. These findings demonstrate that (a) p53 and Oma1 mediate L-Opa1 processing, (b) mitochondrial fragmentation is involved in CDDP-induced apoptosis in OVCA and CECA cells, and (c) dysregulated mitochondrial dynamics may in part be involved in the pathophysiology of CDDP resistance.

Cognitive-behavioural therapy for the symptoms of schizophrenia: systematic review and meta-analysis with examination of potential bias

BACKGROUND

Cognitive-behavioural therapy (CBT) is considered to be effective for the symptoms of schizophrenia. However, this view is based mainly on meta-analysis, whose findings can be influenced by failure to consider sources of bias.

AIMS

To conduct a systematic review and meta-analysis of the effectiveness of CBT for schizophrenic symptoms that includes an examination of potential sources of bias.

METHOD

Data were pooled from randomised trials providing end-of-study data on overall, positive and negative symptoms. The moderating effects of randomisation, masking of outcome assessments, incompleteness of outcome data and use of a control intervention were examined. Publication bias was also investigated.

RESULTS

Pooled effect sizes were -0.33 (95% CI -0.47 to -0.19) in 34 studies of overall symptoms, -0.25 (95% CI -0.37 to -0.13) in 33 studies of positive symptoms and -0.13 (95% CI -0.25 to -0.01) in 34 studies of negative symptoms. Masking significantly moderated effect size in the meta-analyses of overall symptoms (effect sizes -0.62 (95% CI -0.88 to -0.35) v. -0.15 (95% CI -0.27 to -0.03), P = 0.001) and positive symptoms (effect sizes -0.57 (95% CI -0.76 to -0.39) v. -0.08 (95% CI -0.18 to 0.03), P<0.001). Use of a control intervention did not moderate effect size in any of the analyses. There was no consistent evidence of publication bias across different analyses.

CONCLUSIONS

Cognitive-behavioural therapy has a therapeutic effect on schizophrenic symptoms in the 'small' range. This reduces further when sources of bias, particularly masking, are controlled for.

Influence of residual disease and extreme drug resistance assays on outcome in patients with epithelial ovarian cancer

5504

Background: Extreme drug resistance (EDR) assays have been used as tools in identifying those agents that are least likely to be of clinical benefit in the treatment of epithelial ovarian cancer (EOC). We sought to examine the effect of obtaining EDR assays on the outcome of patients with EOC in the primary and recurrent setting. Methods: We conducted a retrospective review of demographic, pathologic, EDR assay and outcome data from 377 patients with EOC who had an assay sent at the time of their diagnosis or at recurrence. Univariate followed by multivariate analyses using Cox proportional hazards method were performed to identify and estimate the impact of independent prognostic factors on time to progression (TTP), overall survival (OS) and survival after recurrence (RS). Results: Increasing age was associated with a worse OS and RS (HR = 1.34; 95% CI, 1.14–1.58 and HR = 1.14; 95% CI, 1.00–1.31, for each decade increase in age respectively). Compared with patients with microscopic residual disease, patients who were left with 0.1 to 1.0 cm and >1.0 cm residual disease had an increased risk of recurrence (HR=1.94; 95% CI, 1.33 to 2.84 and HR=3.61; 95% CI; 2.07 to 6.39, respectively) and death (HR = 1.59; 95% CI, 1.03 to 2.45; and HR = 2.14; 95% CI, 1.09 to 4.20, respectively). For patients who recurred, those who did not undergo secondary cytoreductive surgery and patients who were left with >1.0 cm residual had an increased risk of death compared to patients with microscopic residual (HR = 2.13; 95% CI, 1.28 to 3.54; and HR = 2.84; 95% CI, 1.71 to 4.71, respectively). EDR assay results for single agents or combinations did not independently predict patient outcomes. Conclusions: The amount of residual disease continues to be an important prognostic factor, especially when all macroscopic disease is removed both in the primary and recurrent setting. Increasing age is also an independent predictor of OS and RS. EDR assay results do not independently predict or alter the outcomes of patients with EOC who are treated with the current standard of care including optimal cytoreductive surgery followed by platinum and taxane combination chemotherapy in either the primary or recurrent setting.

No significant financial relationships to disclose.

Bone Scintigraphy in Common Tumors With Osteolytic Components

Osteolytic lesions are frequently encountered in clinical practice. Radionuclide bone scans with technetium-99m-labeled diphosphonates are often performed in the evaluation of both solitary and multiple osteolytic lesions. In this pictorial review, we critically evaluate the current role of bone scan in common osteolytic tumors including aneurysmal bone cyst, simple bone cyst, fibrous dysplasia, nonossifying fibroma, giant cell tumor, eosinophilic granuloma, enchondroma, chondrosarcoma, osteosarcoma, Ewing sarcoma, myeloma, and metastases. The merits and limitations of bone scanning are emphasized.

Cervical meningocele with tethered cervical cord in a Chinese infant

Cervical meningocele and myelomeningocele are rare spinal dysraphic lesions. Unlike lumbosacral dysraphic lesions, there is often no neurological deficit in infants with cervical lesions, thus the subtle features of cervical cord tethering may be overlooked on imaging. We report a case of cervical meningocele in an 8-month-old girl. The tethering band, confirmed intra-operatively, was not evident on imaging. Untethering of the cord was performed together with resection of the sac and repair of the dura. Tethered cord should be suspected in the presence of cervical meningocele and intact neurology. It should be carefully looked for using high-resolution magnetic resonance imaging or computed tomography. Treatment aims to prevent future neurological deterioration, and should include careful intradural exploration with untethering of the cord.

Cryptococcosis: clinical and biological aspects

The incidence of cryptococcosis rose dramatically with the advent of the acquired immune deficiency syndrome (AIDS) epidemic in the early 1980s until the early 1990s. The frequency of cryptococcosis has been declining since mid 1990s in Europe and America due to the development of more effective antiretroviral therapy and prophylactic treatment regimens designed to prevent fungal infections. The disease, however, is still recognized as one of the most common life-threatening opportunistic fungal infections in immunocompromised patients, particularly among those infected with human immunodeficiency virus (HIV). For this reason, research interest in clinical and biological aspects of the disease remains high. In addition to previously embarked areas of research, the cryptococcal research community has taken advantage of the current sequencing technology and initiated genome sequencing of Cryptococcus neoformans var. neoformans. This review includes various areas of research interest ranging from pathobiology, biochemistry and immunology, to genomics.

Health status of children with moderate to severe cerebral palsy

The aim of the study was to evaluate the health of children with cerebral palsy (CP) using a global assessment of quality of life, condition-specific measures, and assessments of health care use. A multicenter population-based cross-sectional survey of 235 children, aged 2 to 18 years, with moderate to severe impairment, was carried out using Gross Motor Function Classification System (GMFCS) levels III (n = 56), IV (n = 55), and V (n = 122). This study group scored significantly below the mean on the Child Health Questionnaire (CHQ) for Pain, General Health, Physical Functioning, and Impact on Parents. These children used more medications than children without CP from a national sample. Fifty-nine children used feeding tubes. Children in GMFCS level V who used a feeding tube had the lowest estimate of mental age, required the most health care resources, used the most medications, had the most respiratory problems, and had the lowest Global Health scores. Children with the most severe motor disability who have feeding tubes are an especially frail group who require numerous health-related resources and treatments. Also, there is a relationship among measures of health status such as the CHQ, functional abilities, use of resources, and mental age, but each appears to measure different aspects of health and well-being and should be used in combination to reflect children's overall health status.

High-throughput analysis in drug discovery: application of liquid chromatography/ion-trap mass spectrometry for simultaneous cassette analysis of alpha-1a antagonists and their metabolites in mouse plasma

The application of liquid chromatography/ion-trap mass spectrometry for simultaneous quantification of multiple drugs and detection of their metabolites for in vitro experiments was reported recently. In the current study, the use of these techniques was extended to in vivo pharmacokinetic (PK) studies of alpha-1a antagonists. In combination with limited time-point PK, greatly increased throughput was demonstrated for the in vivo screening and investigation of in vivo-in vitro correlation. In addition to quantitative analyses, the technique allowed simultaneous detection of major in vivo metabolites without having to reanalyze the plasma samples. The drugs were individually dosed in mice intravenously via tail vein injection and the blood samples were collected 5 min and 2 h after dosing. After the plasma samples for the different drugs had been prepared separately, they were pooled for cassette analysis. The concentrations of five test compounds in the plasma samples at 2 h ranged from 36-1062 ng/mL, whereas their 5-min plasma levels were similar. From the same cassette analysis, major metabolites in the samples were also detected simultaneously through the interpretation of full-scan mass spectra. The metabolite identification confirmed the results from a previous report that the major sites of metabolism are hydroxylation of the phenyl ring not bearing the alkylsulfonamide substitutent, piperidine N-dealkylation, and N-demethylation of the alkylsulfonamide group.

A twenty strain survey and backcross localization of the erythrocytic GTP concentration determining locus Gtpc on mouse chromosome 9

Erythrocyte nucleotide concentrations were surveyed among 20 inbred strains of mice in order to further assess the variability in GTP concentration. There was no significant difference in erythrocytic ATP concentration (Scheffé's test at P = 0.01), 678-1154 nmol/mL packed cells, among the strains surveyed. Two groups were distinguishable with respect to erythrocytic GTP concentration, 8 strains having high GTP, 215 +/- 44 nmole/mL packed cells, and 12 strains having low GTP, 34 +/- 12 nmole/mL packed cells. The erythrocytic GTP concentration determining trait Gtpc was previously shown to be linked to transferrin, Trf, on chromosome 9. Analysis of 232 [(B6 x WB) F1 x B6] backcross individuals for Gtpc and 8 microsatellite markers restricted the localization of Gtpc to a 5.6 +/- 2.1 cM region. The gene order and genetic distances in cM +/- SE are: (D9Mit14) 0.4 +/- 0.4 (D9Mit24) 1.7 +/- 0.8 (Gtpc, D9Mit51, D9Mit116, D9Mit212) 3.9 +/- 1.3 (D9Mit200) 3.0 +/- 1.1 (D9Mit20) 7.8 +/- 1.8 (D9Mit18). The GTP concentration determining trait appears to be a property of erythrocytes as no differences were observed for GTP/ATP ratios of brain, kidney, liver, and tongue from a low GTP strain, C3H/HeHa x Pgk-la and a high GTP strain, C57BL/6J.

Secondary loss of deoxyguanosine kinase activity in purine nucleoside phosphorylase deficient mice

The T-cell immunodeficiency associated with purine nucleoside phosphorylase (PNP) deficiency in man is believed to be due to the accumulation of dGTP which may be preferentially formed from deoxyguanosine in T-lymphocytes or their precursor cells. We found no evidence for dGTP accumulation in thymocytes or spleen leucocytes, < 1 nmol/10(9) cells, nor in erythrocytes, < 0.05 nmol/10(9) cells, of the B6-NPE- or B6-NPF PNP-deficient mice strains. There were no changes in purine or pyrimidine ribonucleotide pools. As these mice had been previously shown to excrete PNP nucleoside substrates, we examined the metabolism of deoxyguanosine. Deoxyguanosine kinase activity as compared to control mice was 6 to 52% for the B6-NPE mutant, 2 to 22% for the B6-NPF mutant. Fractionation of erythrocyte and liver lysates from the F mutation and the background strain, C57BL/6J, by anion exchange chromatography confirmed the secondary deficiency of deoxyguanosine kinase and demonstrated that this activity was distinct from adenosine kinase and two major peaks of deoxycytidine kinase activity. Mouse PNP, expressed and purified as a fusion protein, did not show evidence of being bifunctional and having deoxyguanosine kinase activity. Metabolic modelling revealed that the ratio of deoxyguanosine phosphorylation versus phosphorolysis was < 0.06 in control mice, and < or = 0.3 in lymphocytes of PNP-deficient mice. Were deoxyguanosine kinase not reduced in the PNP-deficient mice, all tissues of the B6-NPF mutant would preferentially phosphorylate deoxyguanosine at low substrate concentrations.

Ultrasound measurement of placental thickness to detect pregnancies affected by homozygous alpha-thalassaemia-1

Homozygous alpha-thalassaemia-1, a common cause of hydrops fetalis, is usually diagnosed invasively. We measured placental thickness by ultrasound at 10-21 weeks' gestation in 231 at-risk pregnancies. 60 were affected (by DNA analysis). The sensitivity and specificity in detecting affected pregnancies at cut-off of mean placental thickness plus 2 SD before 12 weeks' gestation were 0.72 (95% CI 0.52-0.93) and 0.97 (0.9-1.0). After 12 weeks sensitivity increased to 0.95 (0.89-1.0) and by 18 weeks reached 1.0 (0.60-0.99) without change in specificity. Selection of pregnancies at risk by measurement of placental thickness will reduce the number of invasive diagnostic procedures.

Chemotherapy-induced lactose intolerance in adults

BACKGROUND

Anorexia and weight loss contribute to the morbidity and mortality from cancer. This study was designed to test the hypothesis that chemotherapy produces lactose intolerance which could have an adverse effect on the nutritional status of patients receiving cytotoxic drugs.

METHODS

Twenty-seven patients were evaluated for the development of lactose intolerance during chemotherapy. Lactose breath hydrogen testing (LBHT) was used to assess lactose malabsorption objectively. This test is based on the principle that in patients with lactase deficiency, lactose is not hydrolyzed in the small intestine and ultimately is degraded by colonic bacteria. This results in the production of hydrogen gas, which is excreted by the lungs and can be quantified with a breath hydrogen analyzer.

RESULTS

Of the 27 patients studied, 8 (30%) had an abnormal postchemotherapy LBHT results, and for the population as a whole, postchemotherapy LBHT values were significantly greater than prechemotherapy values (P = 0.04). However, only three patients (11%) showed clinical symptoms of lactose intolerance during the post-chemotherapy LBHT. Five patients had asymptomatic elevations in breath hydrogen excretion on prechemotherapy testing. One of these patients had a further increase in hydrogen excretion on Day 8 after chemotherapy, which was accompanied by symptoms of lactose intolerance. Twenty-two patients had normal prechemotherapy LBHT results. Two of these patients had abnormal post-chemotherapy LBHT results, which were associated with symptoms of lactose intolerance.

CONCLUSION

Although chemotherapy may interfere with lactose metabolism, the development of symptomatic lactose intolerance is uncommon. Dietary restriction of milk products in patients receiving chemotherapy therefore is not warranted unless clinical symptoms of lactose intolerance are observed.

Assignment of a gene that determines erythrocytic guanosine-5'-triphosphate concentration (Gtpc) to mouse chromosome 9

Nine inbred mouse strains surveyed for erythrocytic guanosine-5'-triphosphate (GTP) concentration were found to segregate into two discrete groups. Strains having low GTP levels between 1.4 and 3.4 nmol/10(9) cells were C3H/HeJ, C3H/HeHa, A/J, and WB/ReJ. Strains having high GTP levels between 11.0 and 14.8 nmol/10(9) cells were AKR/J, DBA/2J, CBA/J, C57BL/6J, and C57L/J. Erythrocytic ATP levels did not vary significantly among these groups. Crosses between low and high GTP strains gave F1 progeny having intermediate levels of GTP, and the progeny of F1's backcrossed to parental strains segregated in a 1:1 ratio for GTP concentration. We designated the GTP concentration determining trait, Gtpc. Typing the C57BL/6J x C3H/HeJ (B x H) recombinant inbred strains for GTP levels revealed 0/12 strain distribution pattern differences for loci on both chromosomes 5 and 9. Backcross analysis did not provide evidence for linkage of Gtpc to W (dominant white spotting) on chromosome 5 with 15/45 recombinants. A test for linkage of Gtpc to transferrin (Trf) on chromosome 9 gave evidence of linkage with an observed recombination frequency of 14.6 +/- 5.5 and a 99% confidence interval of 3.9-33.9 cM.

Significance of phototherapy-induced riboflavin deficiency in the full-term neonate

As a result of impaired fatty acid oxidation, a characteristic urinary dicarboxylic aciduria occurs in the riboflavin deficient animal. We compared the occurrence of riboflavin deficiency induced by phototherapy with changes in urinary organic acid profiles in 8 full-term, breast-fed neonates who received phototherapy for hyperbilirubinemia, and in 10 full-term, breastfed controls. Riboflavin status was assessed by measuring flavin adenine dinucleotide saturation of erythrocyte glutathione reductase. All 8 neonates exposed to phototherapy developed riboflavin deficiency (p less than 0.001). Riboflavin deficiency was progressive with the duration of phototherapy. None of the controls was riboflavin deficient. Urine organic acid profiles indicative of mitochondrial acyl-CoA dehydrogenase activity (fatty acid beta-oxidation, quantitated by gas chromatography mass spectrometry) showed no changes between the study and control groups in mono-, di-, or tricarboxylic acids or other organic acids. The riboflavin deficiency induced by phototherapy in full-term neonates was not of sufficient severity to limit riboflavin-dependent fatty acid oxidation.

Effects of medium-chain triglyceride feeding on energy balance in adult humans

In recent years, the metabolism of triglycerides has attracted much attention. Oxidation of fatty acids is an essential energy supply, especially when glucose supply is limited. In the present study, the effect of a 3-day high medium-chain triglyceride (MCT; 51% of calories), low carbohydrate intake on plasma glucose and amino acid, and urinary organic acid levels, including dicarboxylic and tricarboxylic acid cycle intermediates, was determined in eight normal adult volunteer subjects. Urine was collected at baseline and at 48 to 72 hours for amino acid and organic acid levels, and plasma collected at 0 and 72 hours for glucose and amino acid concentration. The MCT diet increased urinary levels of dicarboxylic acids (adipic 8-, suberic 65-, sebacic 284-fold) and keto acids (acetoacetate and beta-hydroxybutyrate, 67.5-fold); alanine and lactate were decreased 2.5- and 4-fold, respectively, while pyruvate, other amino acids and citric acid intermediates remained unchanged. Plasma amino acid levels were unchanged, while the plasma glucose levels decreased by 8% from baseline. The loss of calories as urinary dicarboxylic acids and keto acids, although increased during the MCT diet, was less than 1% of the daily caloric intake. The data suggest MCT sustain energy expenditure through medium-chain fatty acid (MCFA) oxidation with no decrease in citric acid cycle intermediates, while sparing protein oxidation.

Genetic deficiency of purine nucleoside phosphorylase in the mouse. Characterization of partially and severely enzyme deficient mutants

Two independent mutations of purine nucleoside phosphorylase were identified in the first-generation progeny of male mice that had been treated with the mutagen N-ethylnitrosourea and mated to untreated females. The common allele in inbred strains is Np-1a and the mutants are assigned the gene symbols Np-1e and Np-1f. Heterozygotes had approximately half normal purine nucleoside phosphorylase activity in erythrocytes and activity of homozygotes was 17 and 5% of NP-1A for NP-1E and NP-1F, respectively. The following properties are consistent with both Np-1e and Np-1f being point mutations: the expression of residual but markedly reduced activity with normal Michaelis constants for inosine and phosphate, altered isoelectric points, and increased thermal lability. The reduction in erythrocyte activity was also evident in other tissues. A metabolic consequence of the mutations was increased purine nucleoside excretion. Inosine and guanosine, total 150 +/- 84 microM, and inosine, deoxyinosine, guanosine, and deoxyguanosine, total 1490 +/- 190 microM, were present in urine of Np-1e/Np-1e and Np-1f/Np-1f mice, respectively, but not in normal urine, less than 10 microM.

Increased activity, amount, and altered kinetic properties of IMP dehydrogenase from mycophenolic acid-resistant neuroblastoma cells

Mouse wild-type neuroblastoma cells (NB cells) were stepwise selected for 10,000-fold increased resistance to mycophenolic acid (NB-Myco cells), an inhibitor of IMP dehydrogenase (IMP:NAD+ oxidoreductase, EC 1.1.1.205). IMP dehydrogenase activity was increased 25-fold, from 3.1 to 75 nmol/min.mg of protein; and a 56.7-kDa peptide was increased in abundance 200-500-fold in NB-Myco as compared to NB cells. Purification and sequence analysis confirmed that the abundant protein was IMP dehydrogenase. The stepwise selection, increased activity and protein abundance, and unstable phenotype are indirect evidence for a process of gene amplification. Kinetic findings consistent with an Ordered Bi Bi mechanism were indicative of IMP dehydrogenase having undergone mutation. The Michaelis constants were unchanged for IMP (14 and 13 microM) and increased 4-fold for NAD from 25 to 94 microM for NB and NB-Myco cells, respectively. The Ki for mycophenolic acid was increased 2400-fold from 1.4 nM to 3.4 microM for the enzyme from NB versus NB-Myco cells, and the Ki for XMP was increased 4-fold from 78 to 336 microM. Mycophenolic acid exhibited uncompetitive inhibition with IMP, consistent with the formation of a dead end E-XMP-inhibitor complex. The cellular GTP concentration was increased 2-fold in resistant cells and, upon removal of mycophenolic acid, further increased to 4.5-fold that of NB cells.