Stabilization of Cx43 mRNA via RNA-binding protein HuR regulated by polyamines enhances intestinal epithelial barrier function

Gut barrier dysfunction occurs commonly in patients with critical disorders, leading to the translocation of luminal toxic substances and bacteria to the bloodstream. Connexin 43 (Cx43) acts as a gap junction protein and is crucial for intercellular communication and the diffusion of nutrients. The levels of cellular Cx43 are tightly regulated by multiple factors, including polyamines, but the exact mechanism underlying the control of Cx43 expression remains largely unknown. The RNA-binding protein HuR regulates the stability and translation of target mRNAs and is involved in many aspects of intestinal epithelial pathobiology. Here we show that HuR directly bound to Cx43 mRNA via its 3'-untranslated region in intestinal epithelial cells (IECs) and this interaction enhanced Cx43 expression by stabilizing Cx43 mRNA. Depletion of cellular polyamines inhibited the [HuR/Cx43 mRNA] complex and decreased the level of Cx43 protein by destabilizing its mRNA, but these changes were prevented by ectopic overexpression of HuR. Polyamine depletion caused intestinal epithelial barrier dysfunction, which was reversed by ectopic Cx43 overexpression. Moreover, overexpression of checkpoint kinase 2 in polyamine-deficient cells increased the [HuR/Cx43 mRNA] complex, elevated Cx43 levels, and promoted barrier function. These findings indicate that Cx43 mRNA is a novel target of HuR in IECs and that polyamines regulate Cx43 mRNA stability via HuR, thus playing a critical role in the maintenance of intestinal epithelial barrier function.NEW & NOTEWORTHY The current study shows that polyamines stabilize the Cx43 mRNA via HuR, thus enhancing the function of the Cx43-mediated gap junction. These findings suggest that induced Cx43 by HuR plays a critical role in the process by which polyamines regulate intestinal epithelial barrier.

AB0344 EFFICACY OF SUBCUTANEOUS INFLIXIMAB (CT-P13 SC) COMPARED WITH INTRAVENOUS INFLIXIMAB IN RHEUMATOID ARTHRITIS: A POST-HOC ANALYSIS OF A PHASE 3 RANDOMIZED CONTROLLED TRIAL

Background

Subcutaneous (SC) CT-P13 is the first and only subcutaneous formulation of infliximab (IFX) approved by the EMA.1 In the pivotal study (NCT03147248), non-inferiority of SC IFX to intravenous (IV) was demonstrated in rheumatoid arthritis (RA) patients using 28-joint Disease Activity Score (DAS28) C-reactive protein (CRP) improvement at Week 22, with a statistically significant treatment difference of 0.27 (95% CI 0.02, 0.52) favoring the SC versus the IV arm.2,3 At Week 30, numerical differences in efficacy outcomes were shown between SC and IV IFX favoring SC IFX. IV group patients switched to SC IFX by Week 30, and the difference between the groups was reduced at Week 54.2

Objectives

To investigate whether there was a statistically significant difference between SC and IV IFX at Weeks 30 and 54 in the phase 3 pivotal study of CT-P13 SC using conservative missing imputation methods.

Methods

Patients with active RA who had an inadequate response to MTX received IV IFX 3mg/kg at Weeks 0 and 2 for induction and were randomized at a 1:1 ratio to receive SC IFX 120mg every 2 weeks or IV 3mg/kg every 8 weeks thereafter for maintenance. Patients who were randomized to receive IV IFX switched to SC at Week 30. In this post-hoc analysis, non-responder imputation (NRI) and last observation carried forward (LOCF) methods were used to investigate whether the difference in efficacy outcomes between SC and IV IFX at Weeks 30 and 54 was statistically significant. Assessments included EULAR (CRP/ESR)/ACR response; remission rate and low disease activity (LDA) rate based on DAS28 (CRP/ESR), Clinical Disease Activity Index (CDAI) and Simplified Disease Activity Index (SDAI); Boolean remission rate; and the proportion of patients achieving a minimal clinically important difference (MCID) in Health Assessment Questionnaire (HAQ).

Results

Of the 343 randomized patients, 165 patients who received SC IFX and 174 patients who received IV IFX from the efficacy population were included in the analysis. There was a statistically significant difference in SC IFX compared to IV treated patients at Week 30 using both NRI and LOCF methods in almost all the clinical variables. However, the difference in efficacy outcomes between SC IFX and IV was reduced at Week 54 after the IV group switched to SC. This supports the improved efficacy of SC IFX at Week 30. Some of the key results (EULAR [CRP] responses, LDA rates based on DAS28 [CRP], CDAI, and SDAI) were presented in Figure 1. Analysis using LOCF and NRI methods yielded consistent results across most of the efficacy outcomes.

Figure 1.

Comparison of clinical outcomes between SC IFX and IV IFX in patients with active rheumatoid arthritis.

*P<0.05.

P-value for difference in proportion between SC and IV treatment group was obtained by asymptotic Wald test.

Low disease activity based on DAS28 (CRP) (< 3.2), CDAI (eatment group AI (≤ 11.0).

Conclusion

Statistical analyses using conservative missing imputation methods showed significantly greater improvements in clinical outcomes with SC IFX compared to IV at Week 30 in patients with RA. Between-group differences was reduced at Week 54, suggesting improved responses after switching from IV to SC.

References

[1]Remsima summary of product characteristics. https://www.ema.europa.eu/en/documents/product-information/remsima-epar-product-information_en.pdf. Published 2021. Accessed 10 January 2022.

[2]Westhovens R, Wiland P, Zawadzki M, et al. Efficacy, pharmacokinetics and safety of subcutaneous versus intravenous CT-P13 in rheumatoid arthritis: a randomized phase I/III trial. Rheumatology (Oxford). 2021;60(5):2277-2287.

[3]Combe B, Allanore Y, Alten R, et al. Comparative efficacy of subcutaneous (CT-P13) and intravenous infliximab in adult patients with rheumatoid arthritis: a network meta-regression of individual patient data from two randomised trials. Arthritis Res Ther. 2021;23(1):119.

Disclosure of Interests

Arnaud Constantin Speakers bureau: Abbvie, Amgen, Boehringer, Celltrion, Galapagos, Janssen, Lilly, Novartis, Sanofi, UCB, Consultant of: Abbvie, Amgen, Boehringer, Celltrion, Galapagos, Janssen, Lilly, Novartis, Sanofi, UCB, Roberto Caporali Speakers bureau: Abbvie, Amgen, BMS, Celltrion, Galapagos, Lilly, Pfizer, Fresenius-Kabi, MSD, UCB, Roche,Janssen, Novartis, Sandoz, Consultant of: Abbvie, Amgen, BMS, Celltrion, Galapagos, Lilly, Pfizer, MSD, UCB, Janssen, Novartis, Sandoz, Christopher John Edwards Speakers bureau: Abbvie, Astra Zeneca, Celltrion, Chugai, Fresenius, Galapagos, Gilead, GSK, Lilly, Janssen, Pfizer, Roche, Consultant of: Abbvie, Astra Zeneca, Chugai, Galapagos, Gilead, GSK, Lilly, Janssen, Pfizer, Roche, Grant/research support from: Celltrion, Pfizer, Abbvie, Joao Eurico Fonseca Speakers bureau: Abbvie, Ache, Janssen, Lilly, Medac, Novartis, Pfizer, Consultant of: Abbvie, Celltrion, Janssen, Lilly, Pfizer, Grant/research support from: Abbvie, Janssen, Lilly, MSD, Novartis, Pfizer, Roche, Florenzo Iannone Speakers bureau: Abbvie, BMS, Celltrion, Galapagos, MSD, Eli-Lilly, Janssen, Novartis, Pfizer, UCB, Consultant of: Abbvie, BMS, Celltrion, Galapagos, MSD, Eli-Lilly, Janssen, Pfizer, Grant/research support from: BMS, MSD, Edward Keystone Speakers bureau: Amgen, AbbVie, Celltrion, F. Hoffmann-La Roche Inc., Janssen Inc., Merck, Pfizer Pharmaceuticals, Sandoz, Sanofi Genzyme, Consultant of: AbbVie, Amgen, Celltrion, Myriad Autoimmune, F. Hoffmann-La Roche Inc, Janssen Inc, Lilly Pharmaceuticals, Merck, Pfizer Pharmaceuticals, Sandoz, Sanofi-Genzyme, Samsung Bioepsis, Grant/research support from: Amgen, Merck, Pfizer Pharmaceuticals, Hendrik Schulze-Koops Consultant of: Celltrion, Taeksang Kwon Employee of: Celltrion Healthcare, Seungmin Kim Employee of: Celltrion Healthcare, Sangwook Yoon Employee of: Celltrion Healthcare, Dong-Hyeon Kim Employee of: Celltrion Healthcare, Gahee Park Employee of: Celltrion Inc., DaeHyun Yoo Speakers bureau: Celltrion, Celltrion Healthcare

POS0911 SIMILAR CLINICAL RESPONSES ACHIEVED WITH LOWER VERSUS STANDARD DOSES OF INFLIXIMAB BIOSIMILAR CT-P13 IN PATIENTS WITH ANKYLOSING SPONDYLITIS: REAL-WORLD RESULTS FROM THE RAAS STUDY

Background:

CT-P13, an infliximab biosimilar, is effective for treating ankylosing spondylitis (AS) at a dose of 5 mg/kg infused once every 6–8 weeks. Evidence suggests that patients with AS may benefit from a lower dose, and individualised dose/interval adjustments should be based on treatment response.

Objectives:

To analyse real-world treatment patterns (doses and infusion intervals) and outcomes for CT-P13-treated patients with AS over 5 years.

Methods:

The RAAS study collected medical record data for adults with AS treated with CT-P13 at five referral hospitals in the Republic of Korea (2012–2017). Patients were infliximab naïve at CT-P13 initiation (‘naïve’) or had switched to CT-P13 from reference infliximab (‘switched’). Patients were analysed by baseline dose (BD) (<4 mg/kg; ≥4–<5 mg/kg; ≥5 mg/kg), defined as the third (naïve) or first (switched) infusion dose. Baseline infusion intervals were the average of the three infusion intervals after BD. Over time, patients with both constant dose and infusion interval were compared with those with changes in dose and/or infusion interval. Data were analysed by Kruskal–Wallis test, chi-squared test and one-way analysis of variance, and drug survival by log-rank test.

Results:

Overall, 337 patients (219 naïve; 118 switched) were identified. Of those with BD data, 71, 117 and 82 patients had BDs of <4 mg/kg, ≥4–<5 mg/kg and ≥5 mg/kg, respectively. Most patients were male (74.8%). Patients with higher BDs tended to have higher Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores; switched patients had lower scores than naïve patients. Of 186 evaluable patients (118 naïve; 68 switched), 85 (46 naïve; 39 switched) did not have dose and/or interval changes (‘combined constant’ group). More naïve (n=72; 61.0%) versus switched (n=29; 42.6%) patients had dose and/or interval changes (‘combined changed’ group). Considering dose and interval separately, 18/235 evaluable patients (152 naïve; 83 switched) had dose changes (12 increased; 6 decreased) and 110/224 evaluable patients (140 naïve; 84 switched) had interval changes (79 increased; 31 decreased). Cumulative annual doses were similar between naïve and switched patients; switched patients had longer infusion intervals than naïve patients (Figure 1). There were no significant differences in drug survival between BD groups overall or for naïve and switched patients. BASDAI scores over time showed that disease activity was well controlled (Table 1). Patients in the combined changed versus combined constant group had greater improvements in BASDAI score.

Table 1.

BASDAI scores

GroupStatisticW0W54W102W156W210Combined constantTotal (N=85)n7273574231Mean (SD)5.50 (3.12)2.50 (1.71)2.35 (1.66)2.42 (1.66)2.36 (1.68)Median6.322.602.402.552.60Naïve (n=46)n3939261812Mean (SD)7.86 (1.45)2.49 (1.82)2.41 (1.75)2.34 (1.70)1.94 (1.58)Median7.802.201.751.901.44Switched (n=39)n3334312419Mean (SD)2.71 (2.07)2.50 (1.60)2.31 (1.60)2.48 (1.67)2.63 (1.73)Median2.582.752.502.802.70Combined changedTotal (N=101)n8785765335Mean (SD)5.68 (2.89)1.81 (1.45)1.58 (1.27)1.49 (1.34)1.40 (1.24)Median6.701.321.191.201.00Naïve (n=72)n6360543418Mean (SD)7.18 (1.37)2.01 (1.44)1.65 (1.22)1.54 (1.26)1.52 (0.97)Median7.301.831.351.311.35Switched (n=29)n2425221917Mean (SD)1.74 (1.94)1.33 (1.36)1.42 (1.41)1.39 (1.50)1.28 (1.50)Median0.920.800.850.700.58

SD, standard deviation; W, Week

Conclusion:

These real-world data demonstrate that adjusting dose and infusion interval can improve clinical outcomes for CT-P13-treated patients with AS. Drug survival and BASDAI results show that patients with lower baseline BASDAI receiving low CT-P13 doses can achieve the same outcomes as those dosed with ≥5 mg/kg. Findings support the lack of impact of switching from reference infliximab to CT-P13 on efficacy, underlining conclusions previously drawn for efficacy and safety.1

References:

[1]Kim T-H, et al. Clin Drug Investig 2020;40:541–53.

Acknowledgements:

Funding: This study was supported by Celltrion Healthcare Co., Ltd. (Incheon, Republic of Korea). Medical writing support was provided by Beatrice Tyrrell, DPhil (Aspire Scientific, Bollington, UK), and funded by Celltrion Healthcare Co., Ltd. (Incheon, Republic of Korea).

Disclosure of Interests:

Shin-Seok Lee: None declared, Tae-Hwan Kim: None declared, Won Park Consultant of: Celltrion, Inc., Yeong Wook Song: None declared, Chang-Hee Suh Speakers bureau: AbbVie Inc., Astellas Pharma Inc., Samsung Bioepis Co., Ltd, Consultant of: Celltrion Healthcare Co., Ltd., Eli Lilly and Company, GlaxoSmithKline plc, Janssen Pharmaceuticals, Yungjin Pharmaceutical, Co., Ltd, SooKyoung Kim Shareholder of: Celltrion Healthcare Co., Ltd., Employee of: Celltrion Healthcare Co., Ltd., DaeHyun Yoo Speakers bureau: Celltrion, Consultant of: Celltrion, Grant/research support from: Celltrion

THU0186 CLINICAL EVALUATION OF THE IMMUNOGENICITY TO CT-P13 FOR SUBCUTANEOUS USE IN PATIENTS WITH ACTIVE RHEUMATOID ARTHRITIS: 1-YEAR CLINICAL RESULTS FROM A MULTICENTER, RANDOMIZED CONTROLLED PIVOTAL TRIAL

Background:

Novel subcutaneous infliximab (CT-P13 SC) was developed to augment the flexibility in therapeutic use of infliximab and noninferiority (NI) of CT-P13 SC versus CT-P13 intravenous (IV) was demonstrated for efficacy in patients with rheumatoid arthritis (RA) [1]. CT-P13 SC 120mg biweekly showed consistent higher therapeutic trough levels during the treatment period, which helps in maintaining efficacy over time. Since immunogenicity has clinical importance in patients using anti-TNF alpha agents and there is a general presumption that SC route is more immunogenic than IV route, this needs careful assessment.

Objectives:

Immunogenicity assessment of CT-P13 SC with further impact analysis has been performed on the pivotal data set [1] to determine whether there was any correlation between the magnitude of anti-drug antibody (ADA) positivity and clinical outcomes in RA patients.

Methods:

The immune response against CT-P13 in human serum was detected using an electrochemiluminescence (ECL) platform with an Affinity Capture Elution (ACE) step. An ADA ECL ACE assay showed ability to detect ADA at low levels in all samples regardless of residual drug in serum (25 ng/mL ADA in the presence of 80 μg/mL of CT-P13 in RA serum). To investigate the impact of ADA titer on PK, efficacy and safety, key clinical parameters were assessed by visit based ADA titer quartile. All patients who had ‘Positive’ ADA status result at each visit were included in the analysis and categorized into 4 groups using the 25th, 50th, 75th percentiles of ADA titer result, respectively.

Results:

The four subgroups categorized by quartiles at each visit from week 22 to week 54 were: 1st (ADA titer ≤ 3), 2nd (3 < ADA titer ≤ 9), 3rd (9 < ADA titer ≤ 27) and 4th (27 < ADA titer). There was a trend for pre-dose concentration to decrease as ADA titer increases for both CT-P13 SC and CT-P13 IV arms as expected (Figure 1). Patients in the 1st and 2nd subgroup maintained the sufficient therapeutic drug concentration level. Figure 2 shows the correlation between ADA titer and efficacy outcomes where the change from baseline of DAS28 (CRP) and the proportion of patients achieving ACR20 were lower in the 3rd and 4th subgroups. The ADA impact was especially apparent in the 4th subgroup where the mean pre-dose concentration of the patients was below the therapeutic drug concentration level (1 μg/mL), which led to worse efficacy outcomes in both arms, IV as well as SC. Nevertheless, no impact of ADA on safety profile in both arms was observed. A neutralizing antibody (NAb) method with enhanced drug tolerance but limited performance was also developed and clinical consequences of NAb titer in terms of PK, efficacy and safety were not different from the results with ADA.

Conclusion:

The analysis of both ADA positivity and titer is clinically meaningful in the prediction of PK profile and clinical response. CT-P13 SC administration did not result in a greater incidence of ADA compared to the CT-P13 IV and there were no clinical differences depending on the formulation.

References:

[1]Westhovens R, et al. Annals of the Rheumatic Diseases 2019;78:1158-1159.

Disclosure of Interests:

Rene Westhovens Grant/research support from: Celltrion Inc, Galapagos, Gilead, Consultant of: Celltrion Inc, Galapagos, Gilead, Speakers bureau: Celltrion Inc, Galapagos, Gilead, DaeHyun Yoo Grant/research support from: Celltrion, Inc, Consultant of: Celltrion, Inc, Speakers bureau: Celltrion Healthcare, Inc, Piotr Wiland Grant/research support from: Celltrion, Inc, Speakers bureau: Novartis, Pfizer, Abbvie, Gedeon-Richter, Lilly, Roche, Sandoz, Marek Zawadzki Grant/research support from: Celltrion, Inc, Delina Ivanova Grant/research support from: Celltrion, Inc, Alfredo Berrocal Grant/research support from: Celltrion, Inc, Speakers bureau: Pfizer, Elias Chalouhi Grant/research support from: Celltrion, Inc, Éva Balázs Grant/research support from: Celltrion, Inc, Consultant of: Amgen, Sergii Shevchuk Grant/research support from: Celltrion, Inc, Sang Joon Lee Shareholder of: Celltrion, Inc, Employee of: Celltrion, Inc, Sung Hyun Kim Shareholder of: Celltrion, Inc, Employee of: Celltrion, Inc, JeeHye Suh Employee of: Celltrion, Inc, Chankyoung Hwang Employee of: Celltrion, Inc, Dae Seok Choi Shareholder of: Celltrion, Inc, Employee of: Celltrion, Inc

Neutropenia following Perioperative Intraperitoneal Chemotherapy

Introduction

The purpose of this retrospective report was to evaluate clinical features associated with profound neutropenia in patients with peritoneal carcinomatosis who were treated with heated intraoperative intraperitoneal chemotherapy (HIIC) followed by early postoperative intraperitoneal chemotherapy (EPIC). Common clinical denominators for significant neutropenia were analyzed.

Materials and Methods

A retrospective study of all available clinical data of six patients with postoperative neutropenia out of a total of 242 was undertaken. All patients underwent cytoreductive surgery, HIIC with mitomycin C (n = 4) or cisplatin (n = 1) and EPIC with 5-fluorouracil (5-FU) for 4 (n = 1) or 5 (n = 5) days.

Results

All six patients presented with hematologic toxicity of WHO criteria grade 4; four of them died postoperatively. Two of the patients who died, and one who did not die, developed bowel perforations. Five patients had prior chemotherapy with 5-FU; three of them had toxic side effects. All patients were overweight, and three patients were anemic preoperatively. The neutropenia presented with fever, leukopenia and thrombocytopenia on postoperative days 10–15. The leukocyte count courses showed a pattern suggesting the 5-FU as the cause of leukopenia. There was no consistent warning signal for predicting severe neutropenia.

Discussion

Neutropenia following cytoreductive surgery combined with HIIC and EPIC has a high mortality (66%). Patients who are at special risk and should have a dose reduction include patients who had toxicities from prior chemotherapy, who present with obesity and anemia. The groups have an increased risk of developing postoperative profound neutropenia. This condition can result in a prohibitively high mortality and morbidity rate. Therefore, reduced doses of chemotherapy in selected patients are necessary to prevent this condition from developing.

Effect of low speed drilling on osseointegration using simplified drilling procedures

Our aim was to find out whether simplified drilling protocols would provide biological responses comparable to those of conventional drilling protocols at the low rotational speed of 400rpm. Seventy-eight root form endosseous implants with diameters of 3.75, 4.2, and 5mm were placed into canine tibias and allowed to heal for 3 and 5 weeks. After the dogs had been killed, the samples of implanted bone were retrieved and processed for non-decalcified histological sectioning. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) analyses were made on the histological sections. Implants treated by the simplified protocol resulted in BIC and BAFO values comparable to those obtained with the conventional drilling protocol, and there were no significant differences in the technique or diameter of the drilling. The results suggest that the simplified procedure gives biological outcomes comparable to those of the conventional procedure.

Evaluation of bone response to various anorganic bovine bone xenografts: an experimental calvaria defect study

This in vivo study investigated the in vivo performance of two newly developed synthetic bone substitutes and compared them to commercially available xenografts (Bio-Oss, Geistlich Pharma AG, Switzerland; OsteoGraf, Dentsply, USA). The materials were tested in a rabbit calvaria model, and the bone forming properties were observed at 4 and 8 weeks after implantation by means of histomorphometry and micro computed tomography (micro-CT). Defects without any graft material were used as negative controls. Micro-CT showed that all materials tested presented new bone formation that filled the defects at both time points, whereas the negative control presented less bone formation, with soft tissue infiltration into the defects. Comparable bone fill percentages were observed for histomorphometric and micro-CT results. Even though no statistically significant difference was found quantitatively between all of the bone graft substitute groups, a higher mean decrease in graft material filling the defects, along with higher remodelling activity, was evident for the experimental materials compared to the commercially available xenografts at 8 weeks. The results indicate that the experimental materials possess high degradability, along with osteoconduction comparable to commercially available xenografts.

[Development of a nested polymerase chain reaction test for the diagnosis of transmissible gastroenteritis of pigs]

The aim of this study was to develop a nested polymerase chain reaction (nested PCR) for the rapid detection of transmissible gastroenteritis virus (TGEV) of pigs. The primers were designed on the basis of highly conserved regions of several TGEV sequences included in the analysis. External primers were used to amplify a fragment of the expected size (441 bp) in all the samples evaluated using reverse transcriptase polymerase chain reaction (RT-PCR), but with very low intensity. In the second amplification (nested PCR), internal primers were used to amplify a fragment of the expected size (168 bp), with good concentration. The performance of the test based on virus isolates in tissue culture and in clinical samples was judged good for the virological diagnosis of transmissible gastroenteritis of pigs.

SU-E-J-23: Prostate Bed Motion Study Using Surgical Clips Based on Daily CBCT

PURPOSE

To study prostate-bed motion after prostatectomy using the surgical clips as a surrogate.

METHODS

On the treatment planning CT, surgical clips within the PTV are identified and contoured. They are also identified and contoured in each daily CBCT. The center of mass (COM) coordinates for each clip within the native reference frame of each image set of CT and CBCT are recorded. Each CBCT (for daily image guidance) is registered to the planning CT based on the pelvic bony structure. The resulted 3D transformation matrix is used to convert the clip coordinates in the CBCT to the planning CT reference frame. Difference between the converted COM coordinates and the one in planning CT is taken as the rigid motion of the prostate bed relative to the pelvic bony structure during the course of radiation therapy. The motion data are then analyzed using statistical error analysis and quantified by the commonly defined M (average over all fractions and all patients), S (stdev of averages per patient, the systematic motion), and s (root mean square of stdev per patient, the random motion). Among a large pool of patients, seven patients were selected for this retrospective study, each with 3 to 11 identifiable clips and 17 to 26 CBCT sets. The total number of clips is 44 and total daily CBCT sets 160.

RESULTS

In the (right-left, anterio-posterior, foot-head) directions, the M values are (0.2 mm, 0.4 mm, -0.6 mm), S (0.2, 2.5, 3.2), and s (1.7, 2.6, 2.1).

CONCLUSIONS

Relative to the bony pelvic structure, the prostate bed motion characteristics are similar to that of intact prostate, as summarized in Table 2 of Rasch et al 2005 ('Target Definition in Prostate, Head, and Neck.' Semin Radiat Oncol 15:136-145).

Infection with a pathogenic turkey coronavirus isolate negatively affects growth performance and intestinal morphology of young turkey poults in Canada

Turkey coronavirus (TCoV) is an important viral pathogen causing diarrhoea of young turkey poults that is associated with sizeable economic losses for the turkey industry. Using a field isolate that was found to be free from turkey astrovirus and avian reovirus we were able to reproduce the clinical disease associated with TCoV. Clinical signs and weight gain of poults during experimental infections were compared with age-matched, uninfected controls. Poults infected at 2 days of age had 100% morbidity and 10% mortality, and birds infected at 28 days of age showed 75% morbidity and no mortality. Diarrhoea was consistently seen in infected poults at 2 to 3 days post infection (d.p.i.) with a duration of about 3 to 5 days. Mean body weights of birds infected at 2 or 28 days of age were significantly reduced compared with uninfected birds by 7 d.p.i. and remained significantly lower for the duration of the study. At 44 days of age, poults infected at 2 or 28 days of age weighed only 68.1% or 77.7%, respectively, compared with uninfected turkeys of the same age on the same diet, a mean difference in body weights of 683 or 477g, respectively. Infected birds had profound villus atrophy with some compensatory crypt hyperplasia at 5 to 7 d.p.i. Villus heights in the duodenum were significantly reduced at 7 d.p.i. We were able to reproduce enteric disease using only a pathogenic field isolate (MG10) of TCoV that negatively affected growth performance and intestinal morphology of young turkey poults.

Virus shedding and serum antibody responses during experimental turkey coronavirus infections in young turkey poults

The course of turkey coronavirus (TCoV) infection in young turkey poults was examined using a field isolate (TCoV-MG10) from a diarrhoeal disease outbreak on a commercial turkey farm in Ontario, Canada. Two-day-old and 28-day-old poults were inoculated orally with TCoV-MG10 to examine the effect of age on viral shedding and serum antibody responses to the virus. The presence of coronavirus particles measuring 105.8+/-21.8 nm in the cloacal contents was confirmed using transmission electron microscopy. The pattern of cloacal TCoV shedding was examined by reverse-transcription polymerase chain reaction amplification of the nucleocapsid gene fragment. TCoV serum antibody responses were assessed with two recently developed TCoV enzyme-linked immunosorbent assays that used TCoV nucleocapsid and S1 polypeptides as coating antigens. Poults were found equally susceptible to TCoV infection at 2 days of age and at 4 weeks of age, and turkeys of either age shed virus in their faeces starting as early as 1 day post-inoculation and up to 17 days post-inoculation. Poults infected at 2 days of age were immunologically protected against subsequent challenge at 20 days post-inoculation. The protection was associated with measurable serum antibody responses to both the nucleocapsid and S1 structural proteins of TCoV that were detectable as early as 1 week post-infection.

Highly virulent porcine reproductive and respiratory syndrome virus emerged in China

A highly pathogenic pig disease emerged in China in 2006, which was characterized by prolonged high fever, red discoloration of the body, and blue ears associated with high mortality. Porcine reproductive and respiratory syndrome virus (PRRSV) was isolated as the single most prominent virus in the samples collected from affected pigs. The full-length genomic sequence of the virus revealed two distinct deletions in the non-structural protein 2 (NSP2) in comparison to all previously reported North American genotype PRRSV. Through extensive surveys in 14 different provinces, 56 additional PRRSV isolates were obtained from affected farms. All of the isolates were found to contain identical deletions in NSP2. To confirm the etiology, eight 60-day-old PRRSV-free pigs were divided into two groups and the test group was intranasally infected at a titer of 2 x 10(5.0) tissue culture infectious dose 50 per pig. The inoculated pigs all died at 7, 8, 12, 16, or 21 days post-inoculation with their clinical and pathological findings similar to those in the field. The viruses recovered from dead pigs were identical to the inoculated virus in NSP2 and GP5 genes. Our study shows that the recently emerged PRRSV in China is characterized by two discontiguous deletions in NSP2 and is the cause for the current epizootics in China.

Complete genomic sequence of turkey coronavirus

Turkey coronavirus (TCoV), one of the least characterized of all known coronaviruses, was isolated from an outbreak of acute enteritis in young turkeys in Ontario, Canada, and the full-length genomic sequence was determined. The full-length genome was 27,632 nucleotides plus the 3′ poly(A) tail. Two open reading frames, ORFs 1a and 1b, resided in the first two thirds of the genome, and nine additional downstream ORFs were identified. A gene for hemagglutinin-esterase was absent in TCoV. The region between the membrane (M) and nucleocapsid (N) protein genes contained three potential small ORFs: ORF-X, a previously uncharacterized ORF with an associated putative TRS within the M gene (apparently shared among all group III coronaviruses), and previously described ORFs 5a and 5b. The TCoV genome is organized as follows: 5′ UTR – replicase (ORFs 1a, 1b) – spike (S) protein – ORF3 (ORFs 3a, 3b) – small envelop (E or 3c) protein – membrane (M) protein – ORF5 (ORFs X, 5a, 5b) – nucleocapsid (N) protein −3′ UTR – poly(A). TCoV genome structure and sequence was most similar, but distinct from, avian infectious bronchitis virus (IBV). This is the first complete genome sequence for a TCoV and confirms that TCoV belongs to group III coronaviruses.

Avian hepatitis E virus in an outbreak of hepatitis–splenomegaly syndrome and fatty liver haemorrhage syndrome in two flaxseed-fed layer flocks in Ontario

Two commercial layer chicken flocks that were fed a flax-based diet beginning at 28 weeks of age for the production of omega-3 fatty-acid-enriched eggs experienced increased mortality when the birds reached 37 weeks. The average weekly mortality was 0.34% over a 20-week period, with peak mortality of 0.9% for 1 week. Reduced feed consumption, reduced body weight gain and poor peak production were noticed prior to the onset of increased mortality. A total of 245 birds were necropsied and 78% of these had lesions in the liver and spleen, with 44% of those necropsied having changes consistent with hepatitis-splenomegaly syndrome, with lesions ranging from acute periportal lymphoplasmacytic hepatitis to chronic severe cholangiohepatitis with haemorrhage, vasculitis and amyloidosis. A total of 11% of the birds had lesions typical of fatty liver haemorrhagic syndrome, and 22% had lesions found in both hepatitis-splenomegaly syndrome and fatty liver haemorrhagic syndrome. No significant bacteria or viruses were recovered from samples of the liver/bile or spleen but 11 of 21 bile samples contained avian hepatitis E virus RNA detectable with a reverse transcriptase-polymerase chain reaction assay. Comparative sequence analysis found identities of 82 to 92% and 78 to 80% between the helicase and capsid protein genes, respectively, of the virus detected in this outbreak and those of other avian hepatitis E virus isolates, suggesting extensive genetic heterogeneity in avian hepatitis E viruses in Ontario flocks.

Comprehensive management of diffuse malignant peritoneal mesothelioma

AIMS

In the past, diffuse malignant peritoneal mesothelioma (DMPM) has been regarded as a terminal condition. The length of the survival was dependent upon the aggressive versus indolent biology of the neoplasm, nevertheless cure was not considered as a reasonable expectation and the overall median survival was approximately one year.

METHODS

A comprehensive literature review and a collection of pertinent data published on DMPM from the Washington Cancer Institute were used to construct this report.

RESULTS

Recent publications from Bethesda MD, New York, Milan Italy, Lyon France and Washington DC have shown a remarkable prolongation in the median survival of this group of patients with approximately half the patients alive at 5 years. These prolonged survivors were treated with an intensive local-regional treatment strategy that included cytoreductive surgery (CRS) with peritonectomy and hyperthermic intraoperative intraperitoneal chemotherapy (HIIC) and some patients with early postoperative intraperitoneal chemotherapy (EPIC). As larger numbers of patients have been treated, clinical features by which to select patients most likely to benefit from this approach have been identified. Also, as the experience in the management of patients receiving these treatments has increased, the morbidity and mortality associated with their management is being reduced.

CONCLUSIONS

A new standard of care involves surgical removal of large disease deposits combined with perioperative intraperitoneal chemotherapy. Knowledgeable management uses selection criteria and incurs low morbidity and mortality.