Experiences of patients enrolled and staff involved in the prehabilitation of elective patients undergoing cardiac surgery trial: a nested qualitative study

The purpose of this study was to understand the views and experiences of patients enrolled and staff involved in the prehabilitation of elective patients undergoing cardiac surgery trial. This sub-study was informed by normalisation process theory, a framework for evaluating complex interventions, and used consecutive sampling to recruit patients assigned to both the intervention and control groups. Patients and all staff involved in delivering the trial were invited to participate in focus groups, which were recorded, transcribed verbatim and subjected to reflexive thematic analysis. Five focus groups were held comprising 24 participants in total (nine patients assigned to the prehabilitation; seven assigned to control; and eight staff). Five themes were identified. First, preparedness for surgery reduced fear, where participants described that knowing what to expect from surgery and preparing the body physically increased feelings of control and subsequently reduced apprehension regarding surgery. Second, staff were concerned but trusted in a safe environment, describing how, despite staff's concerns regarding the risks of exercise in this population, the patients felt safe in their care whilst participating in an exercise programme in hospital. Third, rushing for recovery and the curious carer, where patients from both groups wanted to mobilise quickly postoperatively whilst staff visited patients on the ward to observe their recovery progress. Fourth, to survive and thrive postoperatively, reflecting staff and patients' expectations from the trial and what motivated them to participate. Fifth, benefits are diluted by lengthy waiting periods, reflecting the frustration felt by patients waiting for their surgery after completing the intervention and the fear about continuing exercise at home before they had been 'fixed'. To conclude, functional exercise capacity may not have improved following prehabilitation in people before elective cardiac surgery due to concerns regarding the safety of exercise that may have hindered delivery and receipt of the intervention. Instead, numerous non-physical benefits were elicited. The information from this qualitative study offers valuable recommendations regarding refining a prehabilitation intervention and conducting a subsequent trial.

Cognitive dysfunction and increased phosphorylated tau are associated with reduced O-GlcNAc signaling in an aging mouse model of metabolic syndrome

Metabolic syndrome (MetS), characterized by hyperglycemia, obesity, and hyperlipidemia, can increase the risk of developing late-onset dementia. Recent studies in patients and mouse models suggest a putative link between hyperphosphorylated tau, a component of Alzheimer's disease-related dementia (ADRD) pathology, and cerebral glucose hypometabolism. Impaired glucose metabolism reduces glucose flux through the hexosamine metabolic pathway triggering attenuated O-linked N-acetylglucosamine (O-GlcNAc) protein modification. The goal of the current study was to investigate the link between cognitive function, tau pathology, and O-GlcNAc signaling in an aging mouse model of MetS, agouti KKAy+/- . Male and female C57BL/6, non-agouti KKAy-/- , and agouti KKAy+/- mice were aged 12-18 months on standard chow diet. Body weight, blood glucose, total cholesterol, and triglyceride were measured to confirm the MetS phenotype. Cognition, sensorimotor function, and emotional reactivity were assessed for each genotype followed by plasma and brain tissue collection for biochemical and molecular analyses. Body weight, blood glucose, total cholesterol, and triglyceride levels were significantly elevated in agouti KKAy+/- mice versus C57BL/6 controls and non-agouti KKAy-/- . Behaviorally, agouti KKAy+/- revealed impairments in sensorimotor and cognitive function versus age-matched C57BL/6 and non-agouti KKAy-/- mice. Immunoblotting demonstrated increased phosphorylated tau accompanied with reduced O-GlcNAc protein expression in hippocampal-associated dorsal midbrain of female agouti KKAy+/- versus C57BL/6 control mice. Together, these data demonstrate that impaired cognitive function and AD-related pathology are associated with reduced O-GlcNAc signaling in aging MetS KKAy+/- mice. Overall, our study suggests that interaction of tau pathology with O-GlcNAc signaling may contribute to MetS-induced cognitive dysfunction in aging.

A randomised controlled trial of prehabilitation in patients undergoing elective cardiac surgery

The feasibility, safety and efficacy of prehabilitation in adult patients awaiting elective cardiac surgery are unknown. A total of 180 participants undergoing elective cardiac surgery were allocated randomly to receive either standard pre-operative care or prehabilitation, consisting of pre-operative exercise and inspiratory muscle training. The primary outcome was change in six-minute walk test distance from baseline to pre-operative assessment. Secondary outcomes included change in inspiratory muscle strength (maximal inspiratory pressure); sarcopenia (handgrip strength); quality of life and compliance. Safety outcomes were pre-specified surgical and pulmonary complications and adverse events. All outcomes were assessed at baseline; at pre-operative assessment; and 6 and 12 weeks following surgery. Mean (SD) age was 64.7 (10.2) years; 33/180 (18%) were women. In total, 65/91 (71.4%) participants who were allocated to prehabilitation attended at least four of eight supervised in-hospital exercise classes; participants aged > 50 years were more likely than younger participants to attend (odds ratio (95%CI) of 4.6 (1.0-25.1)). Six-minute walk test was not significantly different between groups (mean difference (95%CI) -7.8 m (-30.6-15.0), p = 0.503) in the intention-to-treat analysis. Subgroup analyses based on tests for interaction indicated improvements in six-minute walk test distance were larger amongst sarcopenic patients in the prehabilitation group (p = 0.004). Change in maximal inspiratory pressure from baseline to all time-points was significantly greater in the prehabilitation group, with the greatest mean difference (95%CI) observed 12 weeks after surgery (10.6 cmH₂ O (4.6-16.6) cmH₂ O, p < 0.001). There were no differences in handgrip strength or quality of life up to 12 weeks after surgery. There was no significant difference in postoperative mortality (one death in each group), surgical or pulmonary complications. Of 71 pre-operative adverse events, six (8.5%) were related to prehabilitation. The combination of exercise and inspiratory muscle training in a prehabilitation intervention before cardiac surgery was not superior to standard care in improving functional exercise capacity measured by six-minute walk test distance pre-operatively. Future trials should target patients living with sarcopenia and include inspiratory muscle strength training.

Deletion of Smooth Muscle O-GlcNAc Transferase Prevents Development of Atherosclerosis in Western Diet-Fed Hyperglycemic ApoE-/- Mice In Vivo

Accumulating evidence highlights protein O-GlcNAcylation as a putative pathogenic contributor of diabetic vascular complications. We previously reported that elevated protein O-GlcNAcylation correlates with increased atherosclerotic lesion formation and VSMC proliferation in response to hyperglycemia. However, the role of O-GlcNAc transferase (OGT), regulator of O-GlcNAc signaling, in the evolution of diabetic atherosclerosis remains elusive. The goal of this study was to determine whether smooth muscle OGT (smOGT) plays a direct role in hyperglycemia-induced atherosclerotic lesion formation and SMC de-differentiation. Using tamoxifen-inducible Myh11-CreERT2 and Ogtfl/fl mice, we generated smOGTWT and smOGTKO mice, with and without ApoE-null backgrounds. Following STZ-induced hyperglycemia, smOGTWT and smOGTKO mice were kept on a standard laboratory diet for the study duration. In a parallel study, smOGTWTApoE-/- and smOGTKOApoE-/- were initiated on Western diet at 8-wks-age. Animals harvested at 14-16-wks-age were used for plasma and tissue collection. Loss of smOGT augmented SM contractile marker expression in aortic vessels of STZ-induced hyperglycemic smOGTKO mice. Consistently, smOGT deletion attenuated atherosclerotic lesion lipid burden (Oil red O), plaque area (H&E), leukocyte (CD45) and smooth muscle cell (ACTA2) abundance in Western diet-fed hyperglycemic smOGTKOApoE-/- mice. This was accompanied by increased SM contractile markers and reduced inflammatory and proliferative marker expression. Further, smOGT deletion attenuated YY1 and SRF expression (transcriptional regulators of SM contractile genes) in hyperglycemic smOGTKOApoE-/- and smOGTKO mice. These data uncover an athero-protective outcome of smOGT loss-of-function and suggest a direct regulatory role of OGT-mediated O-GlcNAcylation in VSMC de-differentiation in hyperglycemia.

Sex-specific differences in atherosclerosis, thrombospondin-1, and smooth muscle cell differentiation in metabolic syndrome versus non-metabolic syndrome mice

Introduction

Metabolic syndrome (MetS) amplifies the risks of atherosclerosis. Despite well-known sexual dimorphism in atherosclerosis, underlying mechanisms are poorly understood. Our previous findings highlight a proatherogenic protein, thrombospondin-1 (TSP-1), in hyperglycemia- or hyperleptinemia (mimicking obesity)-induced atherosclerosis. However, the role of TSP-1 in the development of atherosclerosis prompted by co-existing hyperglycemia and obesity, characteristic of MetS, is unknown. The goal of this study was to examine sex-specific differences in lesion progression in a model of combined MetS and atherosclerosis (KKAyApoE) and interrogate how these differences relate to TSP-1 expression.

Methods

Male and female KKAy^+/-ApoE^-/- (with ectopic agouti gene expression) and age-matched non-agouti KKAy^-/-ApoE^-/- littermates were placed on a standard laboratory diet from 4 to 24 weeks age followed by blood and tissue harvests for biochemical, molecular, and aortic root morphometric studies.

Results

Metabolic profiling confirmed MetS phenotype of KKAy^+/-ApoE^-/-; however, only male genotypes were glucose intolerant with elevated VLDL-cholesterol and VLDL-triglyceride levels. Aortic root morphometry demonstrated profound lipid-filled lesions, increased plaque area, and augmented inflammatory and SMC abundance in MetS vs non-MetS males. This increase in lesion burden was accompanied with elevated TSP-1 and attenuated LMOD-1 (SM contractile marker) and SRF (transcriptional activator of SM differentiation) expression in male MetS aortic vessels. In contrast, while lipid burden, plaque area, and TSP-1 expression increased in MetS and non-MetS female mice, there was no significant difference between these genotypes. Increased collagen content was noted in MetS and non-MetS genotypes, specific to female mice. Measurement of plasma testosterone revealed a link between the atherogenic phenotype and abnormally high or low testosterone levels. To interrogate whether TSP-1 plays a direct role in SMC de-differentiation in MetS, we generated KKAy^+/- mice with and without global TSP-1 deletion. Immunoblotting showed increased SM contractile markers in male KKAy^+/-TSP-1^-/- aortic vessels vs male KKAy^+/-TSP-1^{+/ +}. In contrast, TSP-1 deletion had no effect on SM contractile marker expression in female genotypes.

Conclusion

Together, the current study implicates a role of plasma testosterone in sex-specific differences in atherosclerosis and TSP-1 expression in MetS vs non-MetS mice. Our data suggest a sex-dependent differential role of TSP-1 on SMC de-differentiation in MetS. Collectively, these findings underscore a fundamental link between TSP-1 and VSMC phenotypic transformation in MetS.

Abstract 135: Sex-specific Differences In The Role Of TSP1 On Metabolic Syndrome-induced Atherosclerosis

Metabolic syndrome (MetS) amplifies risks of atherosclerotic complications. MetS induces abnormal vascular smooth muscle cell (VSMC) migration and proliferation, hallmark of SMC de-differentiation, crucial in the pathogenesis of atherosclerosis. Despite multiple studies revealing sexual dimorphism in atherosclerosis, underlying sex-specific mechanisms are poorly understood. We previously reported a protective role of a potent proatherogenic protein, thrombospondin-1 (TSP1), in hyperglycemia- or hyperleptinemia-induced atherosclerosis. The goal of the present study was to interrogate sex-specific differences in the role of TSP1 on MetS-induced atherosclerosis. We generated a mouse model of combined MetS and atherosclerosis (KKAy +/- ApoE -/- ) by crossing obese hyperglycemic agouti KKAy +/- mice with atherosclerotic ApoE -/- . Male and female age-matched MetS KKAy +/- ApoE -/- and non-MetS KKAy -/- ApoE -/- mice were placed on standard lab diet from 4-24 wks age. After overnight fasting, mice were harvested; plasma, aorta and heart were collected for various studies. In male MetS KKAy +/- ApoE -/- , increased aortic root ORO-positive lipid burden, reduced LMOD (SM contractile marker) and SRF (transcriptional activator of SM differentiation) expression in aortic vessels associated with augmented TSP1 expression vs. non-MetS KKAy -/- ApoE -/- mice. In contrast, no significant differences in lesion lipid burden, TSP1, LMOD and SRF expression were detected between the female genotypes. To delineate whether TSP1 plays a direct role in SMC de-differentiation in MetS, we next crossed KKAy +/- with TSP1 -/- to generate MetS mice with and without global TSP1 deletion. Male and female KKAy +/- TSP1 +/+ (with intact TSP1) and KKAy +/- TSP1 -/- (lacking TSP1) on standard lab diet from 4-18 wks age were harvested at endpoint for aortic tissue collection. In male KKAy +/- TSP1 -/- aortic vessels, SM contractile marker expression (LMOD, calponin) was markedly increased vs. KKAy +/- TSP1 +/+ , suggesting reduced SMC de-differentiation. In contrast, TSP1 deletion had no effect on SM contractile marker expression in female MetS KKAy +/- . Together, these data suggest a sex-specific role of TSP1 on SMC de-differentiation and atherosclerotic lesion formation in MetS.

Abstract 204: Sex-specific Differences In The Role Of TSP1 On Metabolic Syndrome-induced Atherosclerosis

Metabolic syndrome (MetS) amplifies risks of atherosclerotic complications. MetS induces abnormal vascular smooth muscle cell (VSMC) migration and proliferation, hallmark of SMC de-differentiation, crucial in the pathogenesis of atherosclerosis. Despite multiple studies revealing sexual dimorphism in atherosclerosis, underlying sex-specific mechanisms are poorly understood. We previously reported a protective role of a potent proatherogenic protein, thrombospondin-1 (TSP1), in hyperglycemia- or hyperleptinemia-induced atherosclerosis. The goal of the present study was to interrogate sex-specific differences in the role of TSP1 on MetS-induced atherosclerosis. We generated a mouse model of combined MetS and atherosclerosis (KKAy +/- ApoE -/- ) by crossing obese hyperglycemic agouti KKAy +/- mice with atherosclerotic ApoE -/- . Male and female age-matched MetS KKAy +/- ApoE -/- and non-MetS KKAy -/- ApoE -/- mice were placed on standard lab diet from 4-24 wks age. After overnight fasting, mice were harvested; plasma, aorta and heart were collected for various studies. In male MetS KKAy +/- ApoE -/- , increased aortic root ORO-positive lipid burden, reduced LMOD (SM contractile marker) and SRF (transcriptional activator of SM differentiation) expression in aortic vessels associated with augmented TSP1 expression vs. non-MetS KKAy -/- ApoE -/- mice. In contrast, no significant differences in lesion lipid burden, TSP1, LMOD and SRF expression were detected between the female genotypes. To delineate whether TSP1 plays a direct role in SMC de-differentiation in MetS, we next crossed KKAy +/- with TSP1 -/- to generate MetS mice with and without global TSP1 deletion. Male and female KKAy +/- TSP1 +/+ (with intact TSP1) and KKAy +/- TSP1 -/- (lacking TSP1) on standard lab diet from 4-18 wks age were harvested at endpoint for aortic tissue collection. In male KKAy +/- TSP1 -/- aortic vessels, SM contractile marker expression (LMOD, calponin) was markedly increased vs. KKAy +/- TSP1 +/+ , suggesting reduced SMC de-differentiation. In contrast, TSP1 deletion had no effect on SM contractile marker expression in female MetS KKAy +/- . Together, these data suggest a sex-specific role of TSP1 on SMC de-differentiation and atherosclerotic lesion formation in MetS.

Abstract MP48: Smooth Muscle Cell-Specific Deletion Of O-GlcNAc Transferase Impedes Atherosclerotic Lesion Formation In Western Diet-fed Apoe -/- Mice

Attachment of O-linked N-acetylglucosamine (O-GlcNAc) to nucleocytoplasmic proteins or ‘O-GlcNAcylation’ is a ubiquitous post-translational modification affecting numerous cellular processes. We and others have previously reported that augmented protein O-GlcNAcylation mediates upregulation of numerous genes associated with atherosclerosis. Recent studies suggest the role of O-GlcNAc transferase (OGT), a key regulator of O-GlcNAc signaling, in diabetic vascular calcification and wound healing. However, the role of OGT in the etiology of atherosclerosis is elusive. The goal of the current study was to interrogate whether OGT plays a direct role in the development of atherosclerosis. For this, we crossed tamoxifen-inducible male Myh11-CreERT2;OGT fl/y ;ApoE -/- mice with female OGT fl/+ ;ApoE -/- to generate SMC-specific OGT knockout on ApoE -/- background. To induce Cre recombinase activity, mice genotypes were injected i.p. with 60mg/Kg/day tamoxifen (peanut oil-vehicle control) once daily for 5 consecutive days beginning at 6 wks age. This was followed by a Western diet feeding regimen for additional 6-7 wks. Mice were harvested at 14 wks age after overnight fasting; plasma, aorta, and heart were collected for biochemical, molecular, and lesion studies. Immunoblotting confirmed loss of OGT expression in aortic vessels of tamoxifen-treated Cre tg ;OGT fl/y ;ApoE -/- mice (smOGT KO ;ApoE -/- ) vs. age-matched tamoxifen-treated Cre tg ;OGT +/y ;ApoE -/- littermates (smOGT WT ;ApoE -/- , with intact OGT). Aortic root morphometry revealed a significant reduction (2.5-fold) in lesion lipid burden in smOGT KO ;ApoE -/- mice compared with smOGT WT ;ApoE -/- . This was accompanied by attenuated PCNA (proliferation marker), osteopontin (SM synthetic marker), pERK (SM signaling regulator), YY1 (transcriptional repressor of SM contractile genes), and SRF (transcriptional regulator of SMC proliferation) expression in smOGT KO ;ApoE -/- vs. smOGT WT ;ApoE -/- aortic lysates, shown via immunoblotting. Interestingly, SMC-specific OGT deletion had no effect on plasma total cholesterol and total triglyceride levels. Taken together, these results demonstrate a protective role of SMC-specific loss of OGT on atherosclerotic lesion formation.

Abstract P153: Upregulation Of Thrombospondin-1 Associates With Accelerated Atherosclerosis And Reduced Smooth Muscle Cell Differentiation In Metabolic Syndrome

Hyperglycemia and obesity, characteristic of metabolic syndrome (MetS), are important risk-factors for atherosclerosis. MetS patients manifest increased vascular smooth muscle cell (VSMC) migration and proliferation, hallmark of VSMC phenotypic transition, critical for evolution of atherosclerosis. We previously reported that high glucose and high leptin independently upregulate a potent proatherogenic matricellular protein, Thrombospondin-1 (TSP-1), expression in VSMC. The goal of the present study was to interrogate the role of TSP-1 in SMC de-differentiation and development of atherosclerosis in MetS. We utilized a mouse model of combined MetS and atherosclerosis (KKAy +/- /ApoE -/- ) generated by crossing obese hyperglycemic agouti KKAy +/- mice with atherosclerotic ApoE -/- . Upon weaning (4 wks age), male yellow KKAy +/- /ApoE -/- and age-matched black KKAy -/- /ApoE -/- littermates on standard lab diet were monitored monthly for body weight and blood glucose. At 24 wks age, mice were harvested after overnight fasting; plasma, aorta and heart were collected for biochemical, molecular and lesion studies. Prior to harvest, mice were subjected to treadmill exercise test at an incline with progressively increasing speed until exhaustion. At 16 wks age, yellow KKAy +/- /ApoE -/- mice showed significant increase in body weight and random blood glucose levels (<0.0001) vs. black KKAy -/- /ApoE -/- littermates, validating the MetS phenotype. Peak oxygen consumption (VO 2max ), maximum running speed and total run time until exhaustion were significantly reduced in MetS KKAy +/- /ApoE -/- mice (p<0.003 vs. non-MetS KKAy -/- /ApoE -/- ), suggesting impaired cardiovascular fitness. Aortic root morphometry revealed 4-fold increase in lesion lipid burden in MetS vs non-MetS mice. This was accompanied with reduced LMOD (SM contractile marker) and SRF (transcriptional activator of SM contractile genes) expression in aortic vessels of MetS mice (p<0.04 vs. non-MetS mice). Notably, lesion abundance and reduced SMC differentiation associated with increased TSP-1 expression in the aortic vasculature of MetS mice. Together, our data suggest a putative role of TSP-1 in SMC de-differentiation and atherosclerotic lesion formation in metabolic syndrome.

TSP-1 (Thrombospondin-1) Deficiency Protects ApoE-/- Mice Against Leptin-Induced Atherosclerosis

OBJECTIVE

Hyperleptinemia, hallmark of obesity, is a putative pathophysiologic trigger for atherosclerosis. We previously reported a stimulatory effect of leptin on TSP-1 (thrombospondin-1) expression, a proatherogenic matricellular protein implicated in atherogenesis. However, a causal role of TSP-1 in leptin-driven atherosclerosis remains unknown. Approach and Results: Seventeen-weeks-old ApoE-/- and TSP-1-/-/ApoE-/- double knockout mice, on normocholesterolemic diet, were treated with or without murine recombinant leptin (5 µg/g bwt, IP) once daily for 3 weeks. Using aortic root morphometry and en face lesion assay, we found that TSP-1 deletion abrogated leptin-stimulated lipid-filled lesion burden, plaque area, and collagen accumulation in aortic roots of ApoE-/- mice, shown via Oil red O, hematoxylin and eosin, and Masson trichrome staining, respectively. Immunofluorescence microscopy of aortic roots showed that TSP-1 deficiency blocked leptin-induced inflammatory and smooth muscle cell abundance as well as cellular proliferation in ApoE-/- mice. Moreover, these effects were concomitant to changes in VLDL (very low-density lipoprotein)-triglyceride and HDL (high-density lipoprotein)-cholesterol levels. Immunoblotting further revealed reduced vimentin and pCREB (phospho-cyclic AMP response element-binding protein) accompanied with augmented smooth muscle-myosin heavy chain expression in aortic vessels of leptin-treated double knockout versus leptin-treated ApoE-/-; also confirmed in aortic smooth muscle cells from the mice genotypes, incubated ± leptin in vitro. Finally, TSP-1 deletion impeded plaque burden in leptin-treated ApoE-/- on western diet, independent of plasma lipid alterations.

CONCLUSIONS

The present study provides evidence for a protective effect of TSP-1 deletion on leptin-stimulated atherogenesis. Our findings suggest a regulatory role of TSP-1 on leptin-induced vascular smooth muscle cell phenotypic transition and inflammatory lesion invasion. Collectively, these results underscore TSP-1 as a potential target of leptin-induced vasculopathy.

SAT0149 EXPOSURE-RESPONSE RELATIONSHIPS FOR EFFICACY AND SAFETY OF FILGOTINIB AND ITS METABOLITE GS-829845 IN SUBJECTS WITH RHEUMATOID ARTHRITIS BASED ON PHASE 2 AND PHASE 3 STUDIES

Background:

Filgotinib is an orally administered small molecule that provides selective inhibition of JAK1, a signaling molecule that helps drive inflammatory pathways underlying rheumatoid arthritis (RA).

Objectives:

Exposure-response (ER) analyses were performed for efficacy following completion of Phase 2 studies over a wide range of doses to support evaluation of 200mg and 100 mg once daily in Phase 3 studies. ER analyses were subsequently performed by using Phase 3 efficacy data to support selection of the proposed registrational dose. ER analyses for safety based on pooled Phase 2 and Phase 3 studies were conducted to examine the safety of evaluated doses.

Methods:

Population PK analyses were conducted to estimate plasma exposures of filgotinib and GS-829845 (major circulating active metabolite of filgotinib) in both Phase 2 (DARWIN 1 and DARWIN 2) and Phase 3 studies (FINCH 1, FINCH 2, and FINCH 3) encompassing a dose range of 25 to 100 mg twice daily and 50 to 200 mg once daily. As both filgotinib and GS-829845 contribute to efficacy via JAK1 inhibition, their exposures were combined into single parameters, AUCeff and Ctau-eff (effective area under the curve and effective concentration at trough, by accounting for relative inhibition potency and molecular weight) in the ER analyses for various efficacy endpoints (e.g ACR20/50/70 responses) at Week 12 and Week 24. The ER analyses for safety endpoints (the 5 most frequent treatment-emergent adverse events [TEAEs] and Grade 3 or 4 laboratory abnormalities, serious TEAEs, and serious infections) were performed separately for filgotinib and GS-829845 exposures to characterize the individual safety profile of each analyte. The 5 evaluated TEAEs were nausea, nasopharyngitis, upper respiratory tract infection, headache, and hypertension; the 5 Grade 3/4 laboratory abnormalities included lymphocytes decrease, glucose increase, phosphate decrease, triacylglycerol lipase increase, and creatine kinase increase.

Results:

In the ER analyses for efficacy based on Phase 2 studies, high response rates were demonstrated in ACR20/50/70 across all octile groups in subjects with RA receiving filgotinib and the ER supported further evaluation of both 200 mg and 100 mg once daily doses in Phase 3 clinical studies. Similarly, ER relationships based on pooled Phase 3 studies across various endpoints (e.g ACR20/50/70) consistently revealed high response rates across the exposure range for both the filgotinib 200 mg and 100 mg doses. A trend of increasing response with increasing exposure was observed over the exposure range for multiple secondary efficacy endpoints including ACR50 and ACR70 with the effective exposures at filgotinib 200 mg primarily residing on the plateau of the ER curves.

Filgotinib was generally well-tolerated with no individual TEAE or Grade 3 or 4 laboratory abnormality > 5% in the filgotinib 200 mg once daily group up to Week 12. No relationships were observed between filgotinib and GS-829845 exposures (AUC0-24 and Cmax) and the most frequent TEAEs, Grade 3/4 laboratory abnormalities, serious TEAEs, or serious infections up to Week 52.

Conclusion:

ER analyses demonstrate that both the 200 mg and 100 mg once daily filgotinib doses are efficacious in subjects with moderately to severely active RA without clear dose-dependent effects on safety. The trend towards greater efficacy with higher exposures for some secondary endpoints (ACR50 and ACR70) and a lack of exposure-safety relationship supports a dose of 200 mg once daily over 100 mg once daily since it presents the best benefit/risk ratio among the doses tested.

Disclosure of Interests: :

Amy Meng Shareholder of: Gilead Sciences, Employee of: Gilead, Kacey Anderson Shareholder of: Gilead Sciences, Employee of: Sciences, Cara Nelson Shareholder of: Gilead, Employee of: Gilead, Brian Kirby Shareholder of: Gilead, Employee of: Gilead, Liyun Ni Shareholder of: Gilead, Employee of: Gilead, Shu-Min Chuang Shareholder of: Gilead, Employee of: Gilead, Brian Kearney Shareholder of: Gilead, Employee of: Gilead, Anita Mathias Shareholder of: Gilead, Employee of: Gilead

Abstract 428: Role of Thrombospondin-1 in Atherosclerotic Complications Associated With Metabolic Syndrome

Atherosclerosis is the leading cause of increased morbidity and mortality in metabolic syndrome (MetS), a constellation of risk factors that include hyperglycemia and visceral obesity. Individuals with MetS have increased incidence of vascular smooth muscle cell (VSMC) migration and proliferation, a key characteristic of VSMC phenotypic transition. We previously reported that high glucose and high leptin, mimicking hyperglycemia and obesity, independently upregulate a potent proatherogenic matricellular protein, thrombospondin-1 (TSP-1), expression in VSMCs. The goal of the present study was to investigate the role of TSP-1 in development of atherosclerosis in MetS. We generated a mouse model of combined MetS and atherosclerosis ( KKAy +/- /ApoE -/- ) by crossing obese hyperglycemic agouti yellow KKAy +/- mice with atherosclerotic ApoE -/- mice. Upon weaning, yellow KKAy +/- /ApoE -/- mice and age-matched black KKAy -/- /ApoE -/- littermates were maintained on regular chow diet from 4-18 wks of age. Mice were euthanized after an overnight fasting; blood, aortae and heart were collected for lipid profiling, immunoblotting and atherosclerotic lesion studies. Yellow KKAy +/- /ApoE -/- mice showed significant increase in body weight, blood glucose and plasma lipid levels vs. black KKAy -/- /ApoE -/- littermates. Aortic root morphometry demonstrated increased lesion burden (Oil red O) and neointimal thickening (H & E) in MetS KKAy +/- /ApoE -/- vs. non-MetS KKAy -/- /ApoE -/- mice. Immunohistochemistry further revealed co-localization of α-SMA (SMC marker) and PCNA (proliferation marker) expression in aortic roots of KKAy +/- /ApoE -/- vs. KKAy -/- /ApoE -/- mice. Notably, lesion formation was associated with an increase in TSP-1 expression in aortic vessels. Consistently, TSP-1 and PCNA expression were elevated in aortic SMC (aSMC) primary cultures derived from obese diabetic KKAy +/- mice vs. lean non-diabetic KKAy -/- littermates. Finally, incubation of aSMC with a TSP-1 blocking peptide reduced PCNA and vimentin (SMC synthetic marker) expression coupled with attenuated SMC proliferation in obese diabetic KKAy +/- mice. Together, these results suggest a putative role of TSP-1 in accelerated atherosclerosis and VSMC phenotypic transition in MetS.

A phase 3b study of sofosbuvir plus ribavirin in treatment-naive and treatment-experienced Korean patients chronically infected with genotype 2 hepatitis C virus

In Korea, patients with chronic hepatitis C virus (HCV) infection are typically treated with pegylated interferon-alpha plus ribavirin, but interferons are contraindicated in many patients and are often poorly tolerated, particularly by the elderly and those with advanced liver disease. No interferon-free treatment regimens are approved in Korea. Sofosbuvir is an oral nucleotide analog inhibitor of the HCV nonstructural 5B RNA polymerase. It is approved in the USA, European Union and Japan for treating a number of HCV genotypes, including genotype 2. Genotype 2 has a seroprevalence of 38-46% in Korea. This single-arm, phase 3b study (NCT02021643) examined the efficacy and safety of sofosbuvir plus ribavirin (12-week duration) in chronic genotype 2 HCV-infected treatment-naive and treatment-experienced Korean patients with and without cirrhosis. The proportion of patients with sustained virologic response 12 weeks after treatment discontinuation (SVR12) was 97% (125/129), with 96% (101/105) of treatment-naive and 100% (24/24) of treatment-experienced patients achieving SVR12. Two patients experienced virologic failure (n = 1, on-treatment failure; n = 1, relapse). No patient discontinued study treatment due to an adverse event (AE). The most common treatment-emergent AEs were headache (18%, 23/129) and pruritus (15%, 19/129). Few patients had grade 3 AEs (5%, 6/129) or grade 3 laboratory abnormalities (12%, 15/129). No grade 4 AE was reported. These data suggest that 12 weeks of treatment with the all-oral, interferon-free regimen of sofosbuvir plus ribavirin is effective and well tolerated in Korean patients with chronic genotype 2 HCV infection.

All-oral therapy with nucleotide inhibitors sofosbuvir and GS-0938 for 14 days in treatment-naive genotype 1 hepatitis C (nuclear)

Sofosbuvir and GS-0938 are distinct nucleotide analogues with activity against hepatitis C virus (HCV) in vitro. We evaluated the antiviral activity and safety of sofosbuvir and GS-0938 alone and in combination in HCV genotype 1 patients. In this double-blind study, 40 treatment-naïve patients were randomly assigned to 4 treatment cohorts: (i) GS-0938 for 14 days, (ii) GS-0938 for 7 days followed by GS-0938 plus sofosbuvir for 7 days, (iii) sofosbuvir for 7 days followed by GS-0938 plus sofosbuvir for 7 days and (iv) GS-0938 plus sofosbuvir for 14 days. In each arm, 8 patients received active drug and 2 placebo. After 7 days of dosing, patients in all 4 dose groups experienced substantial reductions in HCV RNA, with median declines (Q1, Q3) of -4.50 (-4.66, -4.24) in Cohort 1, -4.55 (-4.97, -4.13) in Cohort 2, -4.65 (-4.78, -4.17) in Cohort 3 and -4.43 (-4.81, -4.13) in Cohort 4; patients receiving placebo had essentially no change in HCV RNA (+0.07 log(10) IU/mL). Seven days after the end of treatment, the proportions of patients with HCV RNA <15 IU/mL were 4 (50%), 8 (100%), 7 (88%) and 5 (63%) for Cohorts 1-4, respectively, vs 0 for placebo. No viral breakthrough or resistance mutations were observed. No serious adverse events or Grade 3 or 4 adverse events were reported. Sofosbuvir and GS-0938-alone and in combination--were well tolerated and led to substantial reductions in viral load. Sofosbuvir is undergoing further investigation as a possible backbone of an all-oral regimen for chronic HCV.

A new yeast display vector permitting free scFv amino termini can augment ligand binding affinities

Yeast surface display and sorting by flow cytometry are now widely used to direct the evolution of protein binding such as single-chain antibodies or scFvs. The available commercial yeast display vector pYD1 (Invitrogen) displays the protein of interest flanked on the N-terminus by Aga2, the disulfide of which binds the myristylated surface membrane protein Aga1. We have noted that two anti-CD3epsilon scFvs expressed as fusion proteins suffer a 30- to 100-fold loss of affinity when placed NH(2) terminal to either truncated toxins or human serum albumin. In the course of affinity maturing one of these scFv (FN18) using pYD1 we noted that the affinity towards the ectodomain of monkey CD3epsilongamma was too low to measure. Consequently we rebuilt pYD1 tethering the scFv off the NH(2) terminus of Aga2. This display vector, pYD5, now gave a positive signal displaying FN18 scFv with its ligand, monkey CD3epsilongamma. The apparent equilibrium association constant of the higher affinity scFv directed at human CD3epsilongamma increased approximately 3-fold when displayed on pYD5 compared with pYD1. These data show that for certain yeast-displayed scFvs a carboxy-tethered scFv can result in increased ligand-scFv equilibrium association constants and thereby extend the low range of affinity maturation measurements.

Improved binding of a bivalent single-chain immunotoxin results in increased efficacy for in vivo T-cell depletion

Anti-CD3 immunotoxins exhibit considerable promise for the induction of transplantation tolerance in pre-clinical large animal models. Recently an anti-human anti-CD3epsilon single-chain immunotoxin based on truncated diphtheria toxin has been described that can be expressed in CHO cells that have been mutated to diphtheria toxin resistance. After the two toxin glycosylation sites were removed, the bioactivity of the expressed immunotoxin was nearly equal to that of the chemically conjugated immunotoxin. This immunotoxin, A-dmDT390-sFv, contains diphtheria toxin to residue 390 at the N-terminus followed by VL and VH domains of antibody UCHT1 linked by a (G(4)S)(3) spacer (sFv). Surprisingly, we now report that this immunotoxin is severely compromised in its binding affinity toward CD3(+) cells as compared with the intact parental UCHT1 antibody, the UCHT1 Fab fragment or the engineered UCHT1 sFv domain alone. Binding was increased 7-fold by adding an additional identical sFv domain to the immunotoxin generating a divalent construct, A-dmDT390-bisFv (G(4)S). In vitro potency increased 10-fold over the chemically conjugated immunotoxin, UCHT1-CRM9 and the monovalent A-dmDT390-sFv. The in vivo potency of the genetically engineered immunotoxins was assayed in the transgenic heterozygote mouse, tgepsilon 600, in which the T-cells express human CD3epsilon as well as murine CD3epsilon. T-cell depletion in the spleen and lymph node observed with the divalent construct was increased 9- and 34-fold, respectively, compared with the monovalent construct. The additional sFv domain appears partially to compensate for steric hindrance of immunotoxin binding due to the large N-terminal toxin domain.

Divergent evolution of dispersal in a heterogeneous landscape

The evolution of dispersal is investigated in a landscape of many patches with fluctuating carrying capacities and spatial heterogeneity in temporal fluctuations. Although asynchronous temporal fluctuations select for dispersal, spatial heterogeneity in the distribution of fluctuating environmental variables selects against it. We find evolutionary branching in dispersal rate leading to the evolutionarily stable coexistence of a high- and a low-dispersal phenotype. We study how the opposing forces of selection for and against dispersal change with the relative size and the environmental qualities of the source and sink habitats. Our results suggest that the evolution of dispersal dimorphism could be a first step towards speciation and local adaptation.

Expression of an anti-CD3 single-chain immunotoxin with a truncated diphtheria toxin in a mutant CHO cell line

ADP-ribosylating immunotoxins are generally expressed in Escherichia coli and then refolded in vitro. Because the efficiency of the in vitro refolding process decreases with the number of protein domains and internal disulfide bonds, these immunotoxins have been generally limited to single-chain monovalent structures. We now show that using the hamster cell line CHO K1 RE1.22c (J. M. Moehring and T. J. Moehring, 1979, Somat. Cell Genet. 5, 453-468) that has been mutated to ADP-ribosylation insensitivity, a level of 4 microg/ml of a truncated anti-T cell immunotoxin, DT390-scFvUCHT1, can be secreted into the medium. This immunotoxin is glycosylated at the two potential N-linked glycosylation sites in the toxin moiety: positions 16-18 in the A chain and residues 235-237 in the B chain. The glycosylated immunotoxin is relatively nontoxic (IC(50) 4.8 x 10(-10) M). Removal of the N-linked oligosaccharides by N-glycosidase F treatment or mutations at the two N-linked glycosylation sites results in a highly active immunotoxin with an IC(50) of 4 x 10(-12) M toward CD3(+) Jurkat cells. This is a 12-fold increase in toxicity over the same immunotoxin harvested from E. coli periplasm without refolding. A single Asn(235) Ala mutation that removed the B chain glycosylation was nearly as toxic as the double mutant. This suggests that B chain glycosylation is the major cause for the loss of toxicity.

[Comparison: tinnitus pain]

After having recalled the different physiologic hypothesis of the tinnitus and those more documented of the pain, the authors noted certain parallelious in the therapeutical approaches of these tow subjectives sensations. They put the emphasis on the necessity, like with pain, to treat the tinnitus as fast as possible in order to avoid a centralisation by actionning of neuronal autonomized circuits.

Metabolic stabilization of muscle nicotinic acetylcholine receptor by rapsyn

Although the metabolic half-life of muscle endplate acetylcholine receptor (AChR) changes during development and after denervation in the adult, little is known about the molecular mechanisms that influence receptor stability. We have investigated the effect on AChR turnover of its interaction with rapsyn, a 43 kDa peripheral membrane protein that is closely associated with the AChR in muscle cells and is required for its clustering at endplates. Both in transfected COS cells and in cultured myotubes from rapsyn-negative and rapsyn-positive mice, we have found that the presence of rapsyn slows the turnover of AChRs by as much as twofold. The effect was similar for both embryonic (alpha2betadeltagamma) and adult (alpha2betadeltaepsilon) AChRs and for AChRs whose beta subunit lacked a putative tyrosine phosphorylation site. Neither colchicine nor cytochalasin D altered AChR turnover or prevented the rapsyn effect. Mutant rapsyn proteins whose N-terminal myristoylation signal was eliminated, or whose C terminus or zinc-finger domains were deleted, failed to change the rate of receptor turnover. Each of these mutations affects the association of the AChR with rapsyn, suggesting that AChR stability is altered by interaction between the two proteins. Our results suggest that, in addition to its role in AChR clustering, rapsyn also functions to metabolically stabilize the AChR.

[Intracranial and cranial complications of paranasal sinusitis. Report of 4 cases at the Lomé University Hospital Center]

The complications of paranasal sinusitis are rare (only 4 cases have been observed during 5 years). The acute frontal sinusitis is the most frequent cause. The diagnosis of the frontal osteitis and the extradural abscess is made during the course of the surgical intervention. An antibiotherapy combining an ampicillin and a gentamicin is used. The treatment of the complication and the causative sinusitis is a guarantee of recovery.

A retrospective survey of patients with one previous caesarean section delivered at the Port Moresby General Hospital: a comparative study of those delivered vaginally and those delivered by repeat caesarean section

We studied 510 patients in a retrospective, nonrandomized, comparative survey of vaginal births and repeat caesarean section after one primary caesarean section at the Port Moresby General Hospital. 478 (94%) were allowed a trial of scar (TOS). The most common indications for elective caesarean section in the other 32 patients were cephalopelvic disproportion (CPD) 31%, contracted pelvis 19% and preeclampsia 12.5%. In 41% of patients TOS was terminated by emergency caesarean section. Logistic regression analysis showed that the following were significantly associated with repeat caesarean section after TOS: parity of one, no vaginal birth after the primary caesarean section, narrow obstetric conjugate, birthweight of 2500 g or greater, short stature, high level of the head at admission to the labour ward and region of origin.

Differential regulation of protease and extracellular matrix protein expression by transforming growth factor-beta 1 in non-small cell lung cancer cells and normal human bronchial epithelial cells

In addition to autoregulating its own expression, transforming growth factor-beta 1 (TGF-beta1) also regulates the production of proteases, protease inhibitors and extracellular matrix proteins. To investigate the relationship between plasminogen activator (PA), plasminogen activator inhibitor-1 (PAI-1) and the extracellular matrix in malignant and normal lung epithelial cells and to determine whether malignant lung epithelial cells may be more invasive than normal lung epithelial cells because of differences in expression of these proteins in response to TGF-beta, the regulation of PA, PAI-1, fibronectin, laminin and thrombospondin by TGF-beta1 in human non-small cell lung cancer (NSCLC) cells was examined and compared with normal human bronchial epithelial (NHBE) cells. TGF-beta1 caused a persistent increase in expression of the mRNAs for both PA and PAI-1 in NSCLC cells, with the increase in PAI-1 mRNA beginning several hours before that of PA mRNA. By immunoprecipitation analysis, it was shown that TGF-beta1 also induced a corresponding increase in the amount of PAI-1 protein in these NSCLC cells as well. In contrast, while TGF-beta1 also increased expression of PAI-1 mRNA in NHBE cells, expression of PA mRNA decreased simultaneously. Treatment of NSCLC cells with TGF-beta1 resulted in a persistent increase in expression of the mRNAs for fibronectin, laminin and thrombospondin; expression of fibronectin protein also increased after treatment with TGF-beta1 in these cells. When NHBE cells were similarly cultured in the presence of TGF-beta1, expression of fibronectin mRNA also increased in a persistent manner; however, only an early transient increase in the level of the mRNAs for laminin and thrombospondin was detected in these cells. These data show that there is differential regulation of the genes for PA and PAI-1 and the extracellular matrix protein fibronectin in response to TGF-beta1 not only when NSCLC and NHBE cells are compared, but also when different NSCLC cells are compared with each other.

Transforming growth factor-beta isoforms in the developing chicken intestine and spleen: increase in transforming growth factor-beta 4 with coccidia infection

Expression of transforming growth factor-betas 2, 3 and 4 (TGF-beta) in the developing chicken intestine and spleen was investigated using specific cDNA probes and antibodies for the different TGF-beta isoforms. Coordinate expression of the mRNAs for TGF-beta s 2, 3 and 4 was detected in the embryonic intestine by 8 days, with maximal expression of the mRNAs for TGF-beta s 2 and 4 occurring at 12 and 19 days, respectively, while expression of TGF-beta 3 mRNA remained constant during this time. While specific antibodies for TGF-beta s 2, 3 and 4 could detect only weak immunohistochemical staining of the intestinal epithelium in 4-, 12- and 16-day-old embryos, intense staining for TGF-beta s 2, 3 and 4 was detected in the tips of the intestinal villi of 19-day-old embryos. In the spleen, expression of the mRNAs for TGF-beta s 2 and 3 increased in the newly hatched chick compared with the embryo and then decreased in the adult to levels that were lower than in the embryo; expression of TGF-beta 4 mRNA increased progressively with developmental age, with expression in the adult spleen being significantly higher than in the embryonic and hatchling spleen. Immunohistochemical staining of spleens showed a selective increase in the level of reactive TGF-beta 4 with increasing developmental age, while staining for TGF-beta s 2 and 3 was constant during development. After infection of 1-month-old chickens with coccidian parasite, expression of TGF-beta 4 mRNAs increased 5-8-fold in intestinal intra-epithelial lymphocytes and 2.5-fold in spleen cells, while expression of the mRNAs for TGF-beta s 2 and 3 remained constant in these cells. The results of this study suggest that TGF-beta may play a role in development of the intestine and spleen in the chicken and that TGF-beta 4 in particular increases after infection of coccidia in the chicken.

Sclerosing stromal tumour of the ovary

Two cases of sclerosing stromal tumour of the ovary in young Melanesian females are described and the differential diagnosis is discussed. Sclerosing stromal tumour of the ovary is a rare benign tumour of ovarian stromal origin which is associated with endocrine activity in a few cases. One of the patients presented with signs of precocious puberty and the tumour in this patient was considered as a functioning lesion.

Analysis of small cell lung cancer cell growth inhibition by 13-cis-retinoic acid: importance of bioavailability

13-cis-Retinoic acid can mediate differentiation of transformed cells and slow the proliferation of malignant cells, suggesting its use as a potential intervention tool. Specific cDNA probes for retinoic acid receptors demonstrated the expression of mRNAs for the different retinoic acid receptor isoforms in small cell lung cancer cell lines. Addition of 13-cis-retinoic acid to small cell lung cancer cells cultured using serum-free, hormonally defined medium resulted in a 5-8-fold increase in the level of the retinoic acid receptor-beta mRNAs; in medium containing serum, the increase in expression of the retinoic acid receptor-beta mRNAs was less pronounced, usually no more than 2-fold. Using an in vitro proliferation assay, addition of 13-cis-retinoic acid resulted in a significant dose-dependent, growth-inhibitory effect on the small cell lung cancer cell lines tested using serum-free conditions. These inhibitory effects decreased when cells were cultured in medium containing serum or serum components. Molecular size exclusion chromatography and native gel electrophoresis showed that the causative serum component eluted and migrated with serum albumin. Preincubating serum with triglycerides restored the inhibitory effects of 13-cis-retinoic acid demonstrated in serum-free systems. These data suggest that 13-cis-retinoic acid preferentially binds to serum albumin, restricting its inhibitory effects on epithelial cell receptors. Blocking retinoic acid-albumin interactions with a fatty acid source may improve the bioavailability of 13-cis-retinoic acid and significantly enhance the inhibitory effect in vivo.

Expression of transforming growth factor beta ligand and receptor messenger RNAs in lung cancer cell lines

Specific cDNA probes for transforming growth factor beta s (TGF-beta s) 1, 2, and 3 and TGF-beta types I, II, and III receptors were used to study expression of the mRNAs of the different TGF-beta ligand and TGF-beta receptor isoforms in cultured non-small cell lung cancer (NSCLC) cells and small cell lung cancer (SCLC) cells. Expression of TGF-beta 1 mRNA was detected in both cell types using Northern blot hybridization, with the level of expression of this mRNA being higher in several NSCLC cell lines. In addition, expression of TGF-beta 2 and TGF-beta 3 mRNAs was also detected in NSCLC and SCLC cells but at levels that were lower than that of TGF-beta 1 mRNA. Besides expression of a 3.4-kilobase (kb) TGF-beta 3 transcript, a smaller 2.8-kb TGF-beta 3 transcript was detected in some NSCLC and SCLC cells. TGF-beta 1 and TGF-beta 2 proteins were detected in the conditioned media of NSCLC and SCLC cells, with the levels being higher in several NSCLC cells than in SCLC cells. Expression of TGF-beta types I and II receptor mRNAs was also detected in most NSCLC and SCLC cells, with expression of a 5.5-kb type I receptor mRNA being higher than that of a 5.5-kb type II receptor mRNA in both cell types. In contrast, a 6-kb TGF-beta type III receptor mRNA was detected in only some NSCLC cells and could not be detected in the SCLC cells examined. Also, there was an inverse relationship between the level of expression of the 5.5-kb TGF-beta type I receptor mRNA and that of the 6-kb TGF-beta type III receptor mRNA. Addition of TGF-beta 1 and TGF-beta 2 proteins resulted in an increase in the mRNAs for TGF-beta s 1 and 2 and an increase in the amount of TGF-beta 1 protein in some NSCLC cells, indicating that these cells are responsive to TGF-beta and its effects. At the same time, a differential change in expression of the 2.8- and 3.4-kb TGF-beta 3 transcripts was detected in some lung cancer cells following the addition of TGF-beta 1 and TGF-beta 2. Also, addition of TGF-beta 1 to NSCLC cells inhibited colony formation of some of these cells in soft agarose in a dose-dependent manner.(ABSTRACT TRUNCATED AT 400 WORDS)

Anti-idiotype antibodies prevent antibody binding to mouse sperm and antibody-mediated inhibition of fertilization

Antibodies to components of sperm can interfere with sperm function and prevent fertilization by blocking specific steps of gamete interaction. It can be proposed that anti-idiotype antibodies (anti-Ids) that recognize determinants located close to or within the antigen-binding site of an anti-sperm antibody could block antibody binding to sperm antigen and antibody-mediated inhibition of fertilization. To test this hypothesis, rabbit polyclonal antibodies to idiotypic determinants of the monoclonal anti-sperm antibody M42.15 were developed and characterized. Previous studies demonstrated that M42.15 monoclonal antibody (mAb) inhibits fertilization in vitro and in vivo by inhibiting sperm-zona pellucida interaction. Anti-idiotype antibodies to M42.15 mAb (anti-Id M42) were isolated by affinity chromatography on immobilized M42.15 mAb. Binding specificity of anti-Id M42.15 was demonstrated in a solid-phase radioimmune binding assay and by specific immunoprecipitation of soluble M42.15 mAb. Anti-Id M42 competitively inhibited M42.15 mAb, but not P220.2 mAb, binding to mouse sperm, confirming that the anti-Id preparation contained antibodies directed against idiotopes within or adjacent to the antigen-binding site of the mAb. At equimolar concentrations, anti-Id M42 inhibited binding of 125I-labeled M42.15 mAb to sperm by greater than 80%. These results showed that anti-Id M42 efficiently blocked antibody binding to sperm and suggested that anti-Id M42 could be used to neutralize the anti-fertility activity of the M42.15 mAb. When tested in in vitro fertilization assays, anti-Id M42, but not rabbit immunoglobulin, prevented M42.15 mAb-induced inhibition of fertilization. Together, these results show that the inhibitory activity of anti-sperm antibodies capable of interfering with gamete interaction can be neutralized by anti-Id that recognize determinants close to the antigen-combining site of the anti-sperm antibody.

Urine mutagenicity of steel workers exposed to coke oven emissions

Urine mutagenicity of 19 individuals was investigated at a steel mill. All the subjects worked on the coal processing unit. Urine samples were collected at the end of a working day. Urine samples of two exposed workers were collected at the end of two periods of rest and two periods of working. Mutagens were extracted on XAD-2 resin and tested by the Salmonella microsomal assay and the SOS spot test. Mutagenic potencies of exposed smokers and exposed non-smokers were 8.62 +/- 6.56 and 1.1 +/- 0.48 revertants/mg creatinine respectively with Salmonella typhimurium strain TA98 + S9. Both values were significantly higher than those of unexposed smokers and non-smokers (5.07 +/- 3.33 and 0.47 +/- 0.72 revertants/mg creatinine respectively). The urinary mutagenic potency of the two exposed individuals increased at the end of periods of working (15.97 +/- 2.57 revertants/mg creatinine) and decreased at the end of periods of rest (12.31 +/- 2.45 revertants/mg creatinine). Urinary mutagens were detected with S. typhimurium strain TA100 + S9 to a lesser extent. No direct-acting mutagens were detected by the SOS spot test. Atmospheric benzo[a]pyrene (BaP) were also measured by h.p.l.c. on the coke battery. BaP concentrations ranged between 0.01 and 0.6 microgram/m3 air at the different working sites. Biological monitoring with short-term tests is discussed.