IDH1-mutated Crohn's disease-associated small bowel adenocarcinomas: Distinctive pathological features and association with MGMT methylation and serrated-type dysplasia

AIMS

Patients with Crohn's disease (CrD) have an elevated risk for the development of small bowel adenocarcinomas (SBAs). Actionable isocitrate dehydrogenase 1 (IDH1) mutations have been reported to be more frequent in CrD-SBAs than in sporadic SBAs. The present study aimed to investigate the clinicopathological and immunophenotypical features, as well as methylation profiles, of IDH1-mutated CrD-SBAs.

METHODS AND RESULTS

An international multicentre series of surgically resected CrD-SBAs was tested for IDH1 mutation. Clinicopathological features, immunophenotypical marker expression and O6-methylguanine-DNA methyltransferase (MGMT) and long interspersed nuclear element-1 (LINE-1) methylation were compared between IDH1-mutated and IDH1 wild-type CrD-SBAs. Ten (20%) of the 49 CrD-SBAs examined harboured an IDH1 mutation and all the mutated cancers harboured the R132C variant. Compared to IDH1 wild-type cases, IDH1-mutated CrD-SBAs showed significantly lower rates of cytokeratin 7 expression (P = 0.005) and higher rates of p53 overexpression (P = 0.012) and MGMT methylation (P = 0.012). All three dysplastic growths associated with IDH1-mutated SBAs harboured the same IDH1 variant (R132C) of the corresponding invasive cancer, and all were of non-conventional subtype (two serrated dysplastic lesions and one goblet cell-deficient dysplasia). In particular, non-conventional serrated dysplasia was significantly associated with IDH1-mutated CrD-SBAs (P = 0.029). No significant cancer-specific survival difference between IDH1-mutated CrD-SBA patients and IDH1 wild-type CrD-SBA patients was found (hazard ratio = 0.55, 95% confidence interval = 0.16-1.89; P = 0.313).

CONCLUSIONS

IDH1-mutated CrD-SBAs, which represent approximately one-fifth of total cases, are characterised by distinctive immunophenotypical features and methylation profiles, with potential therapeutic implications. Moreover, IDH1-mutated non-conventional, serrated dysplasia is likely to represent a precursor lesion to such CrD-SBAs.

Prophylactic versus endoscopy-driven treatment of Crohn's postoperative recurrence: A retrospective, multicentric European study (PORCSE study)

BACKGROUND AND AIMS

No consensus exists on optimal strategy to prevent postoperative recurrence (POR) after ileocecal resection (ICR) for Crohn's disease (CD).We compared early medical prophylaxis versus expectant management with treatment driven by findings at elective endoscopy 6-12 months after ICR.

METHODS

A retrospective, multicentric, observational study was performed. CD-patients undergoing first ICR were assigned to cohort1 if a biologic or immunomodulator was (re)started prophylactically after ICR, or to cohort2 if no postoperative prophylaxis was given and treatment was started as reaction to elective endoscopic findings. Primary endpoint was rate of endoscopic POR (Rutgeerts>i1). Secondary endpoints were severe endoscopic POR (Rutgeerts i3/i4), clinical POR, surgical POR and treatment burden during follow-up.

RESULTS

Of 346 included patients, 47.4% received prophylactic postoperative treatment (proactive/cohort1) and 52.6% did not (reactive/cohort2).Endoscopic POR (Rutgeerts>i1) rate was significantly higher in cohort2 (41.5% vs 53.8%, OR1.81, P=0.039) at endoscopy 6-12 months after surgery. No significant difference in severe endoscopic POR was found (OR1.29, P=0.517). Cohort2 had significantly higher clinical POR rates (17.7% vs 35.7%, OR3.05, P=0.002) and numerically higher surgical recurrence rates (6.7% vs 13.2%, OR2.59, P=0.051). Cox proportional hazards regression analysis showed no significant difference in time to surgical POR of proactive versus expectant/reactive approach (HR2.50, P=0.057). Quasi-Poisson regression revealed a significantly lower treatment burden for immunomodulator use in cohort2 (mean ratio 0.53, P=0.002), but no difference in burden of biologics or combination treatment.

CONCLUSIONS

The PORCSE study showed lower rates of endoscopic POR with early postoperative medical treatment compared to expectant management after first ileocecal resection for Crohn's disease.

Mismatch repair deficiency as prognostic factor for stage III small bowel adenocarcinoma: A multicentric international study

BACKGROUND

Small bowel adenocarcinoma (SBA) is a rare cancer with an aggressive behavior. No study has specifically addressed the putative prognostic role of mismatch repair status in stage III SBAs.

AIMS

We aimed to investigate whether mismatch repair deficiency is associated with cancer-specific survival in a Western cohort of patients with stage III SBAs.

METHODS

In this retrospective multicentric international cohort study, we enrolled 70 patients who underwent surgically resection for stage III SBAs and we analyzed the frequency of mismatch repair deficiency, tested by immunohistochemistry for mismatch repair proteins and by polymerase chain reaction for microsatellite instability, and its association with cancer-specific survival and other clinic-pathologic factors.

RESULTS

We found sixteen (23%) patients with mismatch repair deficient adenocarcinoma, without discordance between immunohistochemical and polymerase chain reaction for microsatellite instability analyses. Mismatch repair deficiency proved to be associated with a better outcome both at univariable analysis (hazard ratio: 0.28, 95% confidence interval: 0.08-0.91, p: 0.035) and in bivariable models adjusted for patient age or gender, tumor site, pT4 stage, tumor budding, and perineural invasion.

CONCLUSION

This study highlights the importance of testing mismatch repair status to improve prognostic stratification in stage III SBAs.

Pneumocystis jirovecii pneumonia in patients with inflammatory bowel disease - A case series

BACKGROUND AND AIM

Pneumocystis jirovecii pneumonia (PJP) is a very rare, potentially life-threatening pulmonary fungal infection that occurs in immunocompromised individuals including patients with inflammatory bowel disease (IBD). Our aim was to describe immunosuppressive treatment exposure as well as the outcome in IBD patients with PJP.

METHODS

PJP cases were retrospectively collected through the COllaborative Network For Exceptionally Rare case reports of the European Crohn's and Colitis Organization. Clinical data were provided through a case report form.

RESULTS

18 PJP episodes were reported in 17 IBD patients (10 ulcerative colitis and 7 Crohn's disease). The median age on PJP diagnosis was 55 years (IQR, 40-68 years). Two PJP (11.1%) occurred in patients on triple immunosuppression, 10 patients (55.6%) had double immunosuppressive treatment, 4 patients (22.2%) had monotherapy and 2 PJP occurred in absence of immunosuppressive treatment (one in a human immunodeficiency virus patient and one in a patient with a history of autologous stem cell transplantation). Immunosuppressive therapies included steroids (n=12), thiopurines (n=10), infliximab (n=4), ciclosporin (n=2), methotrexate (n=1) and tacrolimus (n=1). None of the patients diagnosed with PJP had received prophylaxis. All patients were treated by trimethoprim/sulfamethoxazole or atovaquone and an ICU stay was required in 7 cases. Two patients (aged 71 and 32 years) died, and one patient had a recurrent episode 16 months after initial treatment. Evolution was favourable for the others.

CONCLUSION

This case series reporting potentially fatal PJP highlights the need for adjusted prophylactic therapy in patients with IBD on immunosuppressive therapy.

Surgery due to Inflammatory Bowel Disease During Pregnancy: Mothers and Offspring Outcomes From an ECCO Confer Multicentre Case Series [Scar Study]

AIMS

i] To evaluate the evolution of pregnancies and offspring after inflammatory bowel disease [IBD] surgery during pregnancy; and ii] to describe the indications, the surgical techniques, and the frequency of caesarean section concomitant with surgery.

METHODS

Patients operated on due to IBD during pregnancy after 1998 were included. Participating clinicians were asked to review their databases to identify cases. Data on patients' demographics, IBD characteristics, medical treatments, IBD activity, pregnancy outcomes, surgery, delivery, and foetal and maternal outcomes, were recorded.

RESULTS

In all, 44 IBD patients were included, of whom 75% had Crohn's disease; 18% of the surgeries were performed in the first trimester, 55% in the second, and 27% in the third trimester. One patient had complications during surgery, and 27% had postsurgical complications. No patient died. Of deliveries, 70% were carried out by caesarean section. There were 40 newborns alive. There were four miscarriages/stillbirths [one in the first, two in the second, and one in the third trimester]; two occurred during surgery, and another two occurred 2 weeks after surgery; 14% of the surgeries during the second trimester and 64% of those in the third trimester ended up with a simultaneous caesarean section or vaginal delivery. Of the 40 newborns, 61% were premature and 47% had low birth weight; 42% of newborns needed hospitalisation [25% in the intensive care unit].

CONCLUSIONS

IBD surgery during pregnancy remains an extremely serious situation. Therefore, surgical management should be performed in a multidisciplinary team, involving gastroenterologists, colorectal surgeons, obstetricians, and neonatal specialists.

Translating Results from VARSITY to Real World: Adalimumab vs Vedolizumab as First-line Biological in Moderate to Severe IBD

BACKGROUND

Selecting a first-line therapy remains challenging in IBD. Adalimumab (ADM) and vedolizumab (VDZ) effectively lead to endoscopic remission in moderate to severe IBD. The VARSITY trial showed superiority of VDZ over ADM in ulcerative colitis (UC) regarding clinical remission and endoscopic improvement at week 52. We explored these results in a real-world setting of UC and Crohn's disease (CD).

METHODS

This retrospective study followed a cohort of biologic-naïve patients starting ADM or VDZ from 2015-2019. Patients had moderate to severe disease (endoscopic Mayo score ≥2 for UC, presence of ulcerations for CD) prior to therapy initiation. For UC, endoscopic remission (endoscopic Mayo score 0) and improvement (endoscopic Mayo score ≤1) at week 52 were assessed. For CD, endoscopic remission (absence of ulcerations) and improvement (markedly better endoscopy despite ulcerations) at weeks 26-52 were studied. Treatment persistence was also evaluated.

RESULTS

In total, 195 biologic-naïve patients (109 UC; 86 CD) were included. In UC, VDZ was superior to ADM regarding endoscopic remission (29% vs 11%, P = .03), endoscopic improvement (51% vs 26%, P = .01) at week 52, and treatment persistence (P = .04). In CD, no differences in endoscopic remission (VDZ 48% vs ADM 60%; P=0.37), improvement (VDZ 76% vs ADM 77%; P = 1.00), or treatment persistence (P=0.43) at weeks 26-52 were seen. Safety profiles were similar in UC and CD.

CONCLUSIONS

This real-world cohort study of biologic-naïve IBD patients found VDZ to be superior to ADM as first-line treatment for patients with UC-but not CD-regarding endoscopic remission at week 52 and treatment persistence.

Safety of sequential biological therapy in inflammatory bowel disease: results from a tertiary referral centre

BACKGROUND

Biologicals represent the cornerstone of treatment for moderate-to-severe inflammatory bowel diseases (IBD). Many patients cycle between biologicals when encountering loss of response or adverse events.

AIM

To assess the occurrence of serious infections and malignancies with exposure to several (classes of) biologicals.

METHODS

We performed a retrospective cohort study in a tertiary referral centre including consecutive IBD patients exposed to adalimumab, infliximab, ustekinumab or vedolizumab between 1996 and 2019. All serious infections and malignancies, as well as potential confounders, were accounted for.

RESULTS

In total, 1575 patients were included with a median (interquartile range) follow-up of 10 (6-16) years and a duration of biological therapy of 71 (39-112) months. Incidence rates of serious infections were 3.4 per 100 patients' years (PY) in the post-biological setting. Serious infections after biological exposure were associated with systemic steroids in monotherapy (hazard ratio 2.96 [95% confidence interval 1.78-4.93], p < 0.0001), combination therapy of systemic steroids and a biological (2.44 [1.37-4.34], p = 0.002), female gender (1.25 [1.04-1.51], p = 0.02), and prior serious infections in the pre-biological setting (1.42 [1.03-1.96], p = 0.03). Malignancy rates were 1.06 per 100PY in the post-biological setting and increased with older age at biological initiation (1.04 [1.02-1.05], p < 0.0001). The risk for serious infections or malignancies was independent of type and number of biologicals to which the patient was exposed.

CONCLUSION

This study shows that the sequential use of biological therapy in IBD does not seem to convey an overall higher risk of serious infections or malignancies, but that underlying more refractory disease seems to increase this risk.

Update on the Management of Inflammatory Bowel Disease during Pregnancy and Breastfeeding

Inflammatory bowel disease (IBD) affects patients during their peak reproductive years. This raises important questions, in both patients and healthcare providers, regarding conception, pregnancy, and breastfeeding. Lack of information and insufficient communication among healthcare providers can leave patients with limited information and even contradictory advice. Given the fact that pregnant and/or breastfeeding IBD patients are excluded from clinical studies the evidence on many questions related to pregnancy and postpartum period is limited. However, there exists increasing data from case series and cohort studies that allows to provide clinical guidance. The overarching concept is that optimizing the mother's health is critical for optimizing the health of the unborn child and benefit of continuing medical therapy in IBD during pregnancy outweighs possible risks in most instances. This paper provides an up-to-date systematic review of the literature on IBD in pregnancy and proposes guidance to questions frequently encountered by healthcare professionals.

Long-term outcomes of patients with ulcerative proctitis: Analysis from a large referral centre cohort

INTRODUCTION

Long-term outcomes of patients with ulcerative proctitis (UP) have been poorly investigated, since these patients are excluded from participation in randomized controlled clinical trials.

OBJECTIVE

The aim of this study was to investigate the prognostic and therapeutic long-term outcomes of patients with UP.

METHODS

A retrospective study of patients with UP followed at our referral centre between 1 January 1998 and 1 January 2019 was performed. Treatment success was defined as clinical response (significant improvement in UP-related symptoms) and endoscopic response (mayo endoscopic sub-score of 0 or 1) if available at last follow-up.

RESULTS

From a total of 1561 patients with ulcerative colitis, 118 patients with UP were identified. A total of 36 (31%) patients were refractory to rectal and oral therapy with 5-ASA and corticosteroids, necessitating azathioprine as monotherapy in 19 (16%) patients and/or biological therapies in 33 (28%) patients. After a median follow-up of 71 months (interquartile range 29-149 months), treatment success was observed in 103/118 (87%) UP patients and in 25/36 (69%) patients with refractory UP. Clinical response rates were significantly higher for refractory UP patients treated with biologicals (23/33; 70%) compared to ones treated with azathioprine (2/19; 11%; p  =  0.001).

CONCLUSION

Good clinical outcomes were recorded in UP, with treatment success in 87% of patients. Nevertheless, 28% needed escalation to biologicals. Long-term outcome in patients on biologicals was superior to azathioprine.

Evaluating Efficacy, Safety, and Pharmacokinetics After Switching From Infliximab Originator to Biosimilar CT-P13: Experience From a Large Tertiary Referral Center

BACKGROUND

The use of infliximab biosimilar CT-P13 has increased in patients with inflammatory bowel disease. Nevertheless, doubts about switching from infliximab originator to biosimilar still exist among patients and health care professionals.

METHODS

Our tertiary referral center underwent a mandatory switch from infliximab originator to CT-P13 in 2017. We investigated pharmacokinetics, efficacy, and safety of this switch. The primary endpoint was infliximab discontinuation within 6 months of switching. Secondary endpoints included loss of clinical remission, need for treatment optimization, adverse events, evolution of patient-reported outcome, C-reactive protein, infliximab trough levels, and antidrug-antibodies.

RESULTS

A total of 361 patients (54.0% male, 70.0% Crohn's disease, 55.6% in clinical remission) were enrolled. Infliximab discontinuation within 6 months was observed in 4%. Loss of clinical remission, adverse events, and antidrug-antibodies were identified in only 2.0%, 2.2%, and 1.1% of patients, respectively. C-reactive protein concentrations and infliximab trough levels remained stable. Independent factors associated with remission at 6 months were lower PRO2 at switch (HR 6.024; 95% CI, 4.878-8.000; P < 0.0001) and higher hemoglobin levels (HR 1.383; 95% CI, 1.044-2.299; P = 0.018).

CONCLUSIONS

Switching from infliximab originator to CT-P13 was not associated with an increased risk of treatment discontinuation, loss of clinical remission, or adverse events. No significant changes in infliximab trough levels or immunogenicity could be identified.

Pregnancy outcomes in inflammatory bowel disease patients treated with vedolizumab, anti-TNF or conventional therapy: results of the European CONCEIVE study

BACKGROUND

Women with inflammatory bowel diseases (IBD) often receive biologicals during pregnancy to maintain disease remission. Data on outcome of vedolizumab-exposed pregnancies (VDZE) are sparse.

AIMS

To assess pregnancy and child outcomes of VDZE pregnancies and to compare these results to anti-TNF exposed (TNFE) or both immunomodulatory and biologic unexposed (CON IBD) pregnancies.

METHODS

A retrospective multicentre case-control observational study was performed.

RESULTS

VDZE group included 79 pregnancies in 73 IBD women. The TNFE and CON IBD group included 186 pregnancies (162 live births) in 164 IBD women and 184 pregnancies (163 live births) in 155 IBD women, respectively. At conception, cases more often had active disease ([VDZE: 36% vs TNFE: 17%, P = .002] and [VDZE: 36% vs CON IBD: 24%, P = .063]). No significant difference in miscarriage rates were found between groups (VDZE and TNFE: 16% vs 13%, P = .567; VDZE and CON IBD: 16% vs 10%, P = .216). In live-born infants, median gestational age and birthweight were similar between groups. Median Apgar score at birth was numerically equal. Prematurity was similar in the VDZE group compared to the control groups, even when correcting for disease activity during pregnancy. The frequency of congenital anomalies was comparable between groups as were the percentages of breastfed babies. During the first year of life, no malignancies were reported and infants' infection risk did not significantly differ between groups.

CONCLUSION

No new safety signal was detected in VDZE pregnancies although larger, prospective studies are required for confirmation.

Clostridium difficile infection in inflammatory bowel disease: epidemiology over two decades

BACKGROUND

The incidence of Clostridium difficile infection (CDI) has been rising in the overall population as well as in patients with inflammatory bowel disease (IBD). However, the incidence of CDI in IBD may be changing owing to alterations in medical therapies.

OBJECTIVE

The aim of this study was to establish the incidence of CDI in IBD over the past two decades and compare risk factors, disease characteristics and outcomes between IBD and non-IBD patients.

PATIENTS AND METHODS

In this retrospective case-control study, the incidence of CDI in IBD was followed for 18 years. The electronic database of our centre was reviewed for all stool samples received from patients admitted to gastroenterology wards or visiting the outpatient clinic. Diagnosis of CDI was based on diagnostic criteria that evolved throughout the years.

RESULTS

IBD patients (n=44) with CDI were found to be younger (P=0.0001), have less cardiovascular comorbidity (P=0.023), fewer prior hospitalizations (P=0.009) and fewer prior antibiotic use (P=0.005). More IBD patients were on biologic therapy (P=0.0001) or steroids (P=0.001) but less likely taking proton pump inhibitors (P=0.001). The number of stool testing per year increased as well as the median number of positive stool samples for CDI (2% in 2000-2008 to 3% in 2009-2017, P=0.032). Pseudomembranes were only seen in non-IBD patients (28%, P=0.048). There was no difference in the choice of antibiotics between IBD and non-IBD patients [metronidazole (36 vs. 51%) and vancomycin (36 vs. 26%), P=0.090 and 0.190]. The 1-year mortality rate was lower in IBD patients compared with non-IBD patients (0 vs. 32%, P=0.0001).

CONCLUSION

In the past two decades, the incidence of CDI in IBD and non-IBD patients has increased. However, the overall outcome of CDI in IBD patients was favourable compared with non-IBD patients.

Outcome of Pregnancies in Female Patients With Inflammatory Bowel Diseases Treated With Vedolizumab

BACKGROUND AND AIMS

Vedolizumab is an IgG1 anti-α4β7 integrin antibody approved for the treatment of inflammatory bowel diseases [IBD], but without clear safety data during conception, pregnancy and nursing. Animal studies showed that mucosal vascular addressin cell adhesion molecule 1 [MAdCAM-1] is expressed by maternal vessels in the placenta and recruits α4β7-expressing cells that are considered important for maternal/fetal tolerance. Blocking this interaction by vedolizumab might affect this process. We aimed to evaluate pregnancy outcomes in vedolizumab-treated female IBD patients.

METHODS

We conducted a retrospective, multicentre Belgian observational study. Details on disease activity, prenatal complications, delivery and neonatal outcome were collected through a case report form.

RESULTS

Twenty-four pregnancies were reported. Five women had active disease at conception and one patient flared during pregnancy. There were 23 live births. Complications were observed in 25% of pregnancies [premature rupture of membranes, pre-eclampsia, miscarriage, elective termination and stillbirth] and in 35% of infants [prematurity, intra-uterine growth retardation, small for gestational age and congenital malformations including hip dysplasia, pulmonary valve stenosis and Hirschprung's disease]. Vedolizumab was continued throughout pregnancy in two females and stopped in the 1st and 2nd trimester in five and 16 patients, respectively. For live born children, the median [interquartile range] gestational age, weight and Apgar score 5 min after birth were 39 [37-39.6] weeks, 3270 [3080-3585] grams and 10 [9-10], respectively.

CONCLUSIONS

Although several complications were observed, both in mothers and in newborns, no firm conclusions can be drawn. Awaiting prospective and controlled registries, vigilance and strict follow-up of pregnant patients treated with vedolizumab seems mandatory.

Use of active scintillating targets in nuclear physics experiments - Measurement of spontaneous fission

A novel detector has been used, in order to perform measurements of spontaneous fission to α-decay ratios for 240Pu, 242Pu and 252Cf isotopes. The detectors are based on the well-known technique of liquid scintillating counting. The principle and advantages of the use of such detectors in nuclear physics is discussed. The application to the characterization of spontaneous fission is described and it is demonstrated that highly precise measurements are possible, and that the main limit is due to the isotopic content knowledge of the measured samples.

Perioperative Use of Vedolizumab is not Associated with Postoperative Infectious Complications in Patients with Ulcerative Colitis Undergoing Colectomy

BACKGROUND AND AIMS

Preoperative use of vedolizumab has been associated with increased short-term postoperative infectious complications. We assessed this risk in a single-centre cohort of patients with ulcerative colitis undergoing colectomy.

METHODS

Chart review was performed for all colectomies between 2006 and 2016. Short-term postoperative [non]infectious complications were evaluated within 30 days after colectomy. The comprehensive complication index was calculated based on all reported events.

RESULTS

We identified 170 eligible patients [46% female, median age 40 years]. Thirty-four patients [20%] received vedolizumab within 16 weeks, 60 [35%] received anti-tumour necrosis factor [TNF] within 8 weeks, 32 [19%] received a moderate-to-high dose of prednisone and 71 [42%] received other therapies at colectomy. Pouch construction was performed at first stage in 47 patients [28%], and less frequently in patients under vedolizumab, anti-TNF or steroids [all p < 0.01]. Sixty-two short-term infectious and 75 noninfectious complications were reported in, respectively, 49 [29%] and 64 [38%] patients. Only pouch construction at first stage of surgery was independently associated with short-term postoperative infectious (odds ratio 2.40 [95% confidence interval 1.18-4.90], p = 0.016), overall complications (3.11 [1.52-6.40], p = 0.002) and more severe complications (comprehensive complication index 20.9 [0.0-30.8] vs 0.0 [0.0-20.9], p = 0.001). Perioperative medical therapy [including vedolizumab] did not influence short-term outcome, either in the overall population or in the subpopulation of patients with pouch construction at a second stage.

CONCLUSIONS

Perioperative use of vedolizumab was not associated with short-term postoperative [infectious] complications. However, postponing pouch construction to a second stage of surgery is advisable in patients under biological therapy or moderate-to-high doses of steroids.

Preparation of thick uranium layers on aluminium and stainless steel backings

The methods of electrodeposition and "molecular plating" were studied for the production of uranium targets with an areal density up to 0.6 mg cm(-2) on aluminium and up to 1.5 mg cm(-2) on stainless steel backings from aqueous and organic electrolytes. For characterisation of the deposited material, gamma-ray spectrometry, alpha-particle spectrometry, X-ray fluorescence, X-ray powder diffraction, scanning electron microscopy and autoradiography were applied.

Multi-layer ²³⁵UF₄-⁶LiF-Au targets for high-resolution fission fragment measurements

Multi-layer (235)UF4-(6)LiF-Au targets have been produced by vacuum deposition on thin polyimide foils with an areal density, measured by spectrophotometry, of about 33µgcm(-2). The foils were first covered with an Au-layer and then, with a second layer of (6)LiF, both by vapour deposition. The (235)UF4 layer was prepared by fluoride sublimation. Each deposited mass was characterized separately by means of differential weighing for the Au and (6)LiF layers and by low-geometry alpha-particle counting for the (235)UF4 layer. The atomic abundances of the uranium base material have been measured by thermal ionization mass spectrometry. The targets were prepared for measuring fission-fragment emission yields with high mass-resolution.

Impact of adding 5.5 mM glucose to SOF medium on the development, metabolism and quality of in vitro produced bovine embryos from the morula to the blastocyst stage

Although toxic for early stages of embryo development, glucose is a physiological metabolic substrate at the morula and blastocyst stages. We evaluated the effect of adding 5.5 mM glucose from the morula stage on bovine blastocyst development and quality. In vitro matured and fertilised bovine oocytes were cultured in modified Synthetic Oviduct Fluid medium containing 5% fetal calf serum, but without added glucose, up to day 5 post-insemination (pi). Morulae were selected and further cultured in the presence or absence of 5.5 mM glucose. Blastocyst and hatched blastocyst rates were recorded. Oxygen, glucose and pyruvate uptakes as well as lactate release were evaluated. The quality of the resulting blastocysts was evaluated by the cell allocation to the inner cell mass (ICM) and trophectoderm (TE) and by the apoptotic index. Adding glucose increased the blastocyst rate at day 8 pi (80% vs 65%) but had no impact on hatching rate (25% vs 28%). A 22% decrease in oxygen uptake was observed in the presence of glucose, concomitant with an increase in lactate release, although no change was observed in pyruvate uptake. A slight decrease in blastocyst cell number was observed at day 7 in the presence of glucose while neither the ICM/TE cell ratio nor the apoptotic index were affected. In conclusion, adding 5.5 mM glucose from the morula stage has a limited impact on blastocyst rate and quality although important modifications were observed in embryo metabolism. It remains to be determined whether those modifications could influence embryo viability after transfer.

The development and psychometric testing of an instrument to measure diabetes management self-efficacy in adolescents with type 1 diabetes

Adherence to treatment is a major issue for people with diabetes mellitus, and attention has been given to improving self-management in persons with this chronic disease. Most studies show that knowledge alone will not improve self-management behavior. Self-efficacy, a concept introduced by Bandura, has been shown to be an important variable in improving health behaviors. In order to determine whether self-efficacy can influence self-management of diabetes, however, instruments to measure self-efficacy are needed in native languages at an appropriate developmental level, and with good psychometric properties. The study reported here was part of a larger project in the Netherlands, Belgium and the United States in which several instruments, measuring diabetes management self-efficacy, have been developed, both in English and Dutch, for different types of diabetes and different age groups. This article reports on the development and psychometric testing of an instrument measuring self-efficacy in adolescents with type 1 diabetes mellitus. Initially 30 items for the instrument were generated through focus group interviews and their relevance was judged by a team of 10 experts on self-management behavior in adolescents. The final instrument contained 26 items. The sample for psychometric testing consisted of 90 patients with type 1 diabetes who were between 12 and 18 years old. Cronbach's alpha of the instrument was 0.86. An exploratory factor analysis produced two factors which reflect general and more difficult diabetes self-management situations.

Secretory characteristics and viability of human term placental tissue after overnight cold preservation

Collection of human term placentae for research purposes is generally limited during working hours. Preserving placental tissue overnight might help to postpone experiments and, by extent, to increase material availability. In this study, fragments from normal placentae were incubated at 37 degrees C either immediately after delivery or after preservation at 4 degrees C in a HEPES-buffered solution or in a Roswell Park Memorial Institute (RPMI) 1640 culture medium. Protein, human chorionic gonadotrophin (HCG), human placental lactogen (HPL) and lactate dehydrogenase (LDH) contents within preserved explants were similar to those within freshly delivered ones. In contrast, HCG and HPL amounts released during incubation of preserved tissue were lower than with freshly delivered tissue. Differences were significant only during the first 3 h of incubation. Hormone releases were similarly Ca(2+)-stimulated, and Co(2+)- and low temperature-inhibited in preserved and freshly delivered tissues. After preservation, LDH leakage was also reduced. Furthermore, before and after 37 degrees C incubation during 6 h, preserved tissue was morphologically indistinguishable from freshly delivered tissue and showed neither higher incidence of DNA fragmentation, nor elevated caspase-3 activity, both of which are markers of apoptosis. This study validates an original, useful and rapid method to preserve placental tissue. Consequently, this preservation model may facilitate the study of physiological processes regulating placental hormone secretion in normal and pathological conditions.

Apoptosis in human term placenta is not increased during labor but can be massively induced in vitro

Apoptosis in human placental villi is reported to increase until close to delivery. However, the involvement of the apoptotic process in the initiation of labor, and more particularly in relation to the decrease in placental perfusion during uterine contractions, remains unknown. The purpose of the study was to examine the reactivity of the apoptotic machinery in term placentae obtained before or after the onset of labor and after in vitro incubations. The incidence of apoptotic nuclei (< 1%) as evidenced by the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) method, and the histological distribution of immunoreactive Bcl-2, Bax, and Bcl-x proteins, were similar in placentae collected after delivery and before the onset of labor and in placental explants maintained overnight at 4 degrees C in a minimal salt-Hepes medium. By contrast, 28% of nuclei contained fragmented DNA when placental explants were incubated overnight at 37 degrees C. This marked increase was associated with a decrease in the intensity of the Bcl-2 immunostaining and an increase in the intensity of Bax and Bcl-x immunostaining. In conclusion, the present study clearly evidences the presence of an active apoptotic machinery in term placental cells that is not involved in normal parturition.

Ultrastructural and immunocytochemical analysis of diploid germ cells isolated from fetal rabbit gonads

Germ cells were isolated from rabbit fetal gonads between 18 and 22 days post coitum and examined morphologically, ultrastructurally and for immunocytochemical and cytochemical characteristics. Observations were compared with the information available from the corresponding cells of other mammalian species. The general morphology and ultrastructure of healthy isolated rabbit fetal germ cells were found to be very similar to those of the rabbit and mouse diploid germ cells in situ. Moreover, rabbit fetal germ cells shared common immunocytochemical characteristics with mouse undifferentiated embryonic stem cells or embryonic carcinoma cells, such as the presence of TEC-1 (SSEA-1) antigens, a peripheral network of F-actin, the absence of cytokeratins 8/18 and lamins A/C and an alkaline phosphatase activity. No difference between the sexes was observed. Morphological and physiological similarities with the migrating and cultured primordial germ cells of the mouse also suggest that diploid rabbit germ cells would be good candidates for deriving pluripotential embryonic germ cells (EG cells) if favourable culture conditions could be found. In conclusion, the rabbit may be a suitable model for investigations on EG cells in domestic mammals with delayed meiosis.

Development of bovine nuclear transfer embryos made with oogonia

The pluripotency of embryonic germ cells in the mouse suggests that mitotic bovine fetal germ cells might also be a source of pluripotent cells. To investigate the pluripotency of bovine oogonia, the development in vitro of bovine embryos reconstructed by fusing oogonia with enucleated oocytes was compared with that of embryos made similarly with either blastomeres or granulosa cells. The donor cells (fresh oogonia, cryopreserved oogonia, 16- to 32-cell-stage blastomeres, or granulosa cells) were fused to the enucleated oocytes electrically. The proportions of reconstructed embryos that had cleaved at 40 h after fusion using these types of donor cells were not significantly different (37%, 33%, 56%, and 31%, respectively; p > 0.05). However, the proportions of cleaved reconstructed embryos that developed to the blastocyst stage were 9%, 13%, 36%, and 3%, respectively, significantly higher (p < or = 0.05) with blastomeres than with the other three types of donor cells. After transfer of 3 morulae and 4 blastocysts made with oogonia into three recipient heifers, embryonic and extra-embryonic tissues developed in one animal. On recovery after 43 days gestation, this conceptus was shown to be genetically identical, at 11 microsatellite loci, to the fetus that had provided the oogonia. Cytological analysis of the embryos made with oogonia at 40-44 h after fusion and at the morula and blastocyst stages revealed that aberrant cytokinesis and nucleokinesis had given rise to multinucleated, anucleate, and polyploid cells in the reconstructed embryos. It is concluded that limited pluripotency of bovine oogonia has been demonstrated, warranting further study in this area.

Assessment of nuclear totipotency of fetal bovine diploid germ cells by nuclear transfer

Nuclear transfer was used to study nuclear reprogramming of fetal diploid bovine germ cells collected at two stages of the fetal development. In the first case, germ cells of both sexes were collected during their period of intragonadal mitotic multiplication at 48 days post coïtum (d.p.c.). In the second case, only male germ cells were collected after this period, between 105 and 185 d.p.c. Isolated germ cells were fused with enucleated oocytes. Reconstituted embryos were cultured in vitro and those reaching the compacted morula or blastocyst stage were transferred into synchronous recipient heifers. Of 511 reconstituted embryos with 48 d.p.c. germ cells (309 males and 202 females), 48% (247/511 ) cleaved; 2.7% (14/511 ) reached the compacted morula stage and 8 of them the blastocyst stage (1.6%). No difference was observed between sexes. All 14 compacted morulae/blastocysts were transferred into 6 recipients and one pregnancy was initiated. This recipient was slaughtered at Day 35 and an abnormal conceptus (extended trophectoderm and degenerated embryo) was collected. Its male sex, genetically determined, corresponded to that of donor fetus. Of 380 reconstituted embryos with male 105 to 185 d.p.c. germ cells, 72.1% (274/380 ) cleaved, 2.1% (8 380 ) reached the compact morula stage and 7 of these the blastocyst stage (1.8%). Three blastocysts and one morula were transferred into 4 recipients. Two became pregnant at Day 21 but only one at Day 35 which aborted around Day 40. Our results show that the nucleus of diploid bovine germ cells of both sexes can be reprogrammed. However, in the absence of further development of these reconstituted embryos, nuclear totipotency of bovine diploid germ cells remains to be evidenced.

Differential ability of male and female rabbit fetal germ cell nuclei to be reprogrammed by nuclear transfer

The pluri- or totipotency of gonial cells, isolated from rabbit fetuses at 18-20 days of pregnancy, has been investigated by transferring their nuclei into enucleated oocytes and following the development of the resulting reconstituted embryos both in vitro (in a total of 726 embryos) and in vivo (in 135 embryos). The gonial cells exhibited pseudopodial activity like that of primordial germ cells and ultrastructural studies confirmed that neither male nor female cells had entered meiosis. When the gonial cells were used immediately after isolation, about 37% of the reconstituted embryos of both sexes cleaved, with no significant difference according to sex. However, after a further 4-day culture of the cleaved embryos, the blastocyst formation rate was four times higher in those made with male (16%) than with female (4%) gonial cells. No implantation sites were detected following transfer of reconstituted embryos into recipient females. These results show that the nuclei of male and female rabbit diploid germ cells differ in their capability to be "reprogrammed" and bring about development to the blastocyst stage following nuclear transfer. The origin of this difference, which is evidenced long before the onset of meiosis is discussed.

Low levels of chimerism in rabbit fetuses produced from preimplantation embryos microinjected with fetal gonadal cells

The potential pluripotency of rabbit fetal germ cells has been investigated by using them to make chimeric embryos. Gonial cells, isolated from enzyme-dispersed male and female transgenic fetal rabbit gonads of 18-22 days gestation, were microinjected in groups of about 10 into 640 nontransgenic rabbit embryos between the two-cell and expanded blastocyst stages. Injections were made with primary isolations of gonial cells, within 48 hr of their collection. The injected embryos were transferred, with or without non-injected control embryos, into 49 recipient rabbits. Tissues from 159 resulting fetuses, implantation sites, and a few liveborn young were examined by PCR analysis for the two transgenes used (alpha-1 antitrypsin or luciferase). The overall pregnancy rate (about 80%) was not affected by the stage of development of the embryo injected, nor by co-transfer of control embryos. The survival rate of injected embryos (18% overall, 23.6% in pregnant recipients) was almost identical to that of 243 control embryos. Chimerism was detectable in tissues produced from 4 of 159 (2.5%) of the injected embryos, all four of which had been injected at the 8- to 16-cell stage. This low rate of success indicates that, although passage of rabbit gonial cells is not an absolute requirement for pluripotency, further investigation should pay particular attention to improving culture conditions with a view to deriving EG cell lines.