Targeted Radiotherapy Using Contact X-ray Brachytherapy 50 kV.

Rectal adenocarcinoma is a quite radioresistant tumor. In order to achieve non-operative management (NOM) radiotherapy plays a major role. Targeted radiotherapy aiming at high precision 3D radiotherapy uses stereotactic image-guided external beam radiotherapy machines. To further safely increase the tumor dose, endocavitary brachytherapy (ECB) is an original approach. There are two different ways to perform such an ECB: contact X-ray brachytherapy (CXB) using a 50 kV X-ray generator with an X-ray tube positioned under eye guidance into the rectal cavity and high-dose-rate brachytherapy (HDRB) using iridium-192 sources positioned into the rectal cavity under image guidance. This study focused on CXB. CXB uses a small mobile generator that produces 50 kV X-rays with limited penetration. This technique is well adapted to accessible tumors of limited size and especially needs a high dose rate (≥15 Gy/minutes) for rectal tumors. It is performed on an ambulatory basis. A total dose between 80−110 Gy is delivered in 3−4 fractions over 3 to 6 weeks into a small volume (5 cm3). CXB was pioneered in the 1970s by Papillon using the Philips RT 50TM. Since 2009, the Papillon P50TM has been used in 11 institutions in Europe. The OPERA Phase III trial tested the hypothesis that a CXB boost (90 Gy/3 fr) compared to an EBRT boost (9 Gy/5 fr) for T2−T3 ab < 5 cm and N0−N1 < 8 mm will increase the 3-year organ preservation (OP) rate when combined with 45 Gy/5 weeks with concomitant capecitabine. Out of more than 300 patients with tumors < 3 cm (1962−1992), Papillon reported a long-term local control close to 85%. Similar results were published in Europe and USA at that time. The Lyon R96-2 Phase III trial (2004) demonstrated that, when combined with preoperative EBRT, a CXB boost (90 Gy/3 fr) significantly increased the rate of clinical complete response (cCR) and sphincter preservation, with some patients having OP at 10 years. With more than 2000 patients treated in Europe (2010−2020) using the Papillon 50TM, organ preservation appears possible in close to 80% of cases in selected early T2−T3. The OPERA trial closed after 141 inclusions (2015−2020) after an independent data monitoring committee recommendation because of promising results. At the 2-year follow-up (blinded data), the rate of cCR and OP were 77% and 72%, respectively, for the 141 tumors, and for T < 3 cm (61 pts), they were 86% and 85%, respectively, with good bowel function. The final results should be available in 2022. Organ preservation using NOM appears to be a promising approach for rectal cancer. A CXB boost with chemoradiotherapy in selected early T2−T3 could become an attractive option to achieve a planned OP. This approach should be proposed to well-informed patients after discussion in an MDT.

Propensity score analysis of radical proctectomy versus organ preservation using contact X-ray brachytherapy for rectal cancer.

INTRODUCTION: Radical proctectomy (RP-TME) with neo adjuvant chemoradiotherapy (nCRT) remains the standard treatment for T2-T3 rectal cancer. Organ preservation (OP) using CRT and a "watch and wait" strategy (W&W) is a field of research. Planned organ preservation can be proposed for early T1-T3 using contact X-ray brachytherapy (CXB). We compared the oncological outcomes of both approaches using a propensity score matched-cohort analysis. MATERIAL AND METHODS: For comparative analyses between patients with nCRT + RP-TME and patients with CXB + CRT, propensity scores were calculated with logistic regression and multiple imputations for missing data. The variables included in the propensity score model were PS status, T-N stage and rectal circumference extension. Patients were matched 1:1 using the nearest neighbor method with a 0.1 caliper restriction. The 5-year Cancer Specific survival was the primary end point. RESULTS: The Accord 12 phase III trial included 584 patients who treated with nCRT + RP-TME. The CXB cohort included 71 patients with a planned OP. To select OP patient candidate, T4, tumor with extension >66% circumference were eliminated and only patients treated with CXB + CRT were analyzed in the CXB cohort resulting in a total of 374 patients. A one to one paired cohort with 36 patients in each group was derived. These two cohorts were well matched for all confounding factors except for age. The 5-year cancer specific rate showed no significant difference between the two groups (89% in Accord 12 vs 82% in CXB; p = 0.84). At 5 years, rate of metastasis (15% vs 22%, p = 0.54) showed no significant difference. In the CXB group 33/36 patients preserved their rectum. CONCLUSION: The organ preservation strategy using CXB boost yielded a 5-year cancer specific survival rate similar to patients treated with RP-TME. In selected early T2-3 rectal adenocarcinoma an organ preservation strategy could be offered as a reasonable option.

Physiological response to the weaning in two pig lines divergently selected for residual feed intake.

Breeding efficient pigs is a way to reduce dietary costs and environmental waste. However, optimization of feed efficiency must not be linked to a decrease of the ability of animals to cope with stress, such as the weaning. This study characterizes the response after weaning of pigs from two lines divergently selected for residual feed intake (RFI) during growth. Animals of the low (L) RFI line are more efficient than animals from the high (H) RFI line. Thirty-six piglets from each line weaned at 28 days of age were individually housed and fed a conventional dietary sequence. Their performance, behaviour, health and oxidative status, immune and nutritional parameters were followed during three weeks. Daily feed intake and growth rate of pigs from the LRFI line were 35% and 40% lower compared with HRFI (p < 0.001). Pigs from the LRFI-line had lower total tract apparent digestibility (-6% for OM) and suffered more from undernutrition with a 167 and 55% higher plasmatic concentration of NEFA and urea compared with HRFI (p < 0.01). In the first week after the weaning, they had more diarrhoea and had a higher inflammatory status with concentration of haptoglobin 52% higher (p < 0.001). These piglets then seemed to adapt to the weaning conditions and to recover during the second and third weeks. Both lines had similar zootechnical performance and physiological characteristics at the end of the post-weaning period. To conclude, the physiological responses to the weaning differed between lines. Pigs from the LRFI line, selected for greater feed efficiency, were more sensitive to the weaning stress. They were also more resilient as they finally adapted to the new condition and recovered to show similar performance results as pigs of the HRFI line.

Brachytherapy for oligometastatic prostate cancer to the penis.

The origin of penile metastases is in 70% of cases from primary pelvic cancers (genitourinary and recto-sigmoid primary tumors). The prognosis is poor and it is often associated with synchronous bone metastases at the time of diagnosis. We present the case of a 61-year-old patient who developed a penile induration 7 years after radical prostatectomy followed by adjuvant external beam radiation therapy for high-risk prostatic adenocarcinoma. Biopsies confirmed the metastatic localization and a detailed assessment failed to find any further remote lesions. Faced with this penile oligometastatic prostate cancer, we proposed an ablative treatment based on interstitial multi-catheter high-dose rate brachytherapy. At the six-month follow-up, clinical examination and 68Ga-PSMA-11-PET confirmed a complete response of the penile tumor without new lesion at a distance.

APBI Versus Ultra-APBI in the Elderly With Low-Risk Breast Cancer: A Comparative Analysis of Oncological Outcome and Late Toxicity.

PURPOSE: Accelerated partial breast irradiation (APBI) represents a validated technique for low-risk breast cancer. Recently, ultra-APBI (uAPBI) using fewer than 5 fractions was described in the literature. We compared clinical outcomes and late toxicity after APBI or uAPBI in older patients. METHODS AND MATERIALS: Two cohorts of older patients (aged ≥70 years) with low-risk breast cancer treated with APBI (interstitial brachytherapy) were analyzed retrospectively. A total dose of 34 Gy in10 fractions (APBI) or 16 Gy in 1 fraction (uAPBI) was delivered from 2004 to 2012 and from 2013 to 2018, respectively. Oncologic outcome analyzed the cumulative incidence of local relapse, regional relapse, and distant metastases with disease-free survival, cause-specific survival, and overall survival. Late toxicity and cosmetic results were investigated. RESULTS: One hundred fifty-seven patients (APBI, n = 109 patients; uAPBI, n = 48 patients) underwent APBI according to the same selection criteria. Apart from the median follow-up (97 vs 72 months for APBI and uAPBI; P < .002), no significant difference was noted between the 2 groups. Regarding 6-year oncologic outcome, no significant difference was observed between APBI and uAPBI for local recurrence (1.3% vs 0%; P = .4), regional recurrence (2.5% vs 2.3%; P = .9), distant metastases (4.3% vs. 2.4%; P = .6), disease-free survival (85.2% vs. 82.2%; P = .8), cause-specific survival (96.7% vs. 96.2%; P = .9), and overall survival (86.7% vs. 82.2%; P = .7). Regarding late toxicity, no significant difference was observed between APBI and uAPBI (total complication number, 45 vs 33%; P = .173) with only grade 1 (88.4% vs. 95%) and grade 2 (11.6% vs. 5%) late toxicities (P = .677). Similarly, no significant difference was observed for excellent/good cosmetic results between the 2 cohorts (P = .98). CONCLUSIONS: We report the first study comparing APBI versus uAPBI in a cohort of older patients with low-risk breast cancer. No significant difference was found between the 2 treatment groups regarding oncologic outcome, late toxicity, and cosmetic result. uAPBI based on a single fraction of brachytherapy represents an attractive option for therapeutic de-escalation in older patients with breast cancer.

Clinical response assessment after contact X-Ray brachytherapy and chemoradiotherapy for organ preservation in rectal cancer T2-T3 M0: The time/dose factor influence.

INTRODUCTION: A neoadjuvant treatment aimed at rectal preservation should achieve a clinical complete response. This study comparing neoadjuvant treatment initiated with Contact X-ray (CXB) or External Beam radiotherapy (EBRT) is evaluating the influence of the time/dose parameter on clinical response during the first six months. MATERIALS AND METHODS: This retrospective consecutive series included T2-3 rectal adenocarcinoma staged using digital examination (DRE), endoscopy, magnetic radiation imaging and/or endorectal ultrasound. All patients were treated with organ preservation intent. Treatment protocol combined CXB (80-110 Gy/3-4 fractions) and EBRT ± concurrent capecitabine. In tumor exceeding 3.5 cm treatment was often initiated using EBRT. Clinical response was assessed (DRE, proctoscopy ± imaging) at very close interval between 2 weeks and 6 months after treatment initiation. RESULTS: Between 2002 and 2017, 61 patients (T2: 31; T3: 30) M0 (median age: 76 years) were treated. Treatment was initiated in 40 patients (T2: 28, T3: 12) with contact X-ray and in 21 (T2: 4, T3: 17) with EBRT. Using contact X-ray or EBRT first treatment, clinical complete (or near complete) response at week 14(±1) was respectively 88% [95CI:74-96] and 33% [95CI:15-57]. In multivariate analysis the treatment chronology was the most significant factor influencing cCR (OR: 7.53). At 6 months, with contact X-ray first all patients were in clinical complete response and five with EBRT remained in partial response. With 61 months median follow-up time, the local recurrence rate was 10% [95% CI: 6-16] at 5 years. T3 and fungating tumors were at higher risk of local recurrence. Organ preservation with good function was achieved in 95% of cases. CONCLUSION: This non randomized study tends to show that in early T2-3 tumors, a strategy using upfront contact therapy, which is reducing the overall treatment time, is an option allowing a more favorable outcome than EBRT first.

Second conservative treatment for second ipsilateral breast tumor event: A systematic review of the different re-irradiation techniques.

AIM: To address the different partial breast re-irradiation techniques available in the context of second conservative treatment (SCT), as an alternative to salvage mastectomy, for 2nd ipsilateral breast tumor event (IBTE) and summarize their respective oncological and toxicity outcomes. MATERIAL AND METHODS: A literature search was made based on MeSH/PubMed, including papers from 1995 to 2019. Each article was described according to the main irradiation technique, fractionation, oncological results and grade 3 toxicities related to the salvage conservative treatment. RESULTS: Twenty-two articles were identified, reporting the outcomes of over 1 000 patients. MIB Brachytherapy was the most used re-irradiation technique in case of SCT, with a median 3rdIBTE-FS rate of 88% and summed up grade 3 toxicities of 6%. As for IORT, the average rate of 3rdIBTE-FS was about Finally, external beam partial re-irradiation was recently tested in this indication with encouraging results in terms of tolerance. CONCLUSION: When presenting a 2ndIBTE, a SCT can safely be proposed to carefully selected and well-informed patients, as an alternative to salvage mastectomy. MIB appears to be the first intention and most robust choice. IORT, external beam radiotherapy and balloon brachytherapy are interesting alternatives but have only been tested in small series. Further investigations are required and their use should be limited to clinical trial only.

Mitomycin and 5-fluorouracil for second-line treatment of metastatic squamous cell carcinomas of the anal canal.

BACKGROUND: Metastatic squamous cell carcinomas (SCC) of the anal canal are rare and there is no international consensus on their second-line management. 5-Fluorouracil (5-FU) and mitomycin in combination with radiotherapy is the standard for locally advanced forms but its efficacy in metastatic stage has never been evaluated. PATIENTS AND METHODS: We report a retrospective analysis of patients treated with 5-FU and mitomycin from 2000 to 2017 in our institution for a metastatic SCC of the anal canal after failure of platinum-based regimen. The main outcome was progression-free survival (PFS) and the secondary outcomes were overall survival (OS), response rate, and toxicity. RESULTS: Nineteen patients, 15 women and four men, with a median age of 57 years were identified (range, 40-79 years). Patients received a median of three cycles (1-7) of mitomycin 5-FU. A dose reduction was necessary in six patients (31.6%), one patient had to discontinue treatment following toxicity and no death was due to treatment toxicity was reported. An objective response was observed in five patients (26.4%, 95% CI 6.6-46.2) including one complete response, six patients (31.6%, 95% CI 10.7-52.5) showed tumor stabilization. Median PFS and OS were 3 months [95% CI 1-5] and 7 months [95% CI 2.2-11.8]. Responder had a median duration of response of 4 months [95% CI 1.8-6.1] and one patient had 23 months duration of response. No significant difference was noted for PFS and OS for patients previously treated with mitomycin and 5-FU at a local stage. CONCLUSION: Mitomycin and 5-FU regimen provides tumor control with acceptable tolerance. It is an option for patients with metastatic SCC of the anal canal after failure of platinum-based chemotherapy. [Correction added on 9 October 2019, after first online publication: '5-FU' was inadvertently removed from the Results and Conclusion and has now been added to the text.].

GEC-ESTRO APBI classification as a decision-making tool for the management of 2nd ipsilateral breast tumor event.

AIM: Second ipsilateral breast tumor event (2ndIBTE) occurring after primary radio-surgical treatment can be treated by either salvage mastectomy or 2nd conservative treatment (2ndCT) including an accelerated partial breast re-irradiation (APBrI). We analyzed the impact of the GEC-ESTRO APBI classification (GAC) on the oncological outcome after APBrI. MATERIALS AND METHODS: Between 2000 and 2016, 159 patients (pts) underwent a 2ndCT. After lumpectomy, APBrI was performed using either low-dose (30-55 Gy reference isodose) or high-dose rate brachytherapy (28-34 Gy). Oncological outcome including 3rdIBTE, regional (RFS) or metastasis-free survival (MFS), specific (SS) and overall survival (OS) was analyzed according to GAC. Univariate (UVA) and multivariate analyses (MVA) were conducted to identify significant prognostic factors for 3rdIBTE. RESULTS: With a median follow-up of 71 months (range 62-85 months), 60 pts (42%), 61 pts (42.7%) and 22 pts (15.4%) were classified as low-risk (LR), intermediate-risk (IR) and high-risk (HR), respectively. For the whole cohort, 6-year 3rdIBTE-free survival, RFS, MFS, SS and OS rates were 97.4, 96.4, 90.3, 92.9 and 91.2%, respectively. Six-year 3rdIBTE-free survival rates for LR, IR and HR were 100, 95.8 and 92.9%, respectively (p = 0.003), while no significant differences were found between the three GAC groups for RFS, MFS, SS. In UVA, lympho-vascular invasion (p = 0.009), positive margins (p = 0.0001) and GAC high-risk group (p = 0.001) were considered as significant prognostic factors for 3rdIBTE, while, in MVA, high-risk group (p = 0.009) was the only prognostic factor. CONCLUSION: In case of 2ndIBTE, GAC could be used as a decision helping tool to discuss conservative or radical treatment options. Patient information remains crucial in order to accurately define the salvage therapy modalities.

Responses to weaning in two pig lines divergently selected for residual feed intake depending on diet.

Weaning is a stress every piglet has to face. It is a main cause of antibiotic uses due to digestive disorders. In this study, response to weaning was analyzed in pigs from two lines divergently selected for residual feed intake (RFI) during growth. A total of 132 pigs from each line, housed per line and diet in conventional postweaning units of 12 castrated males and 12 females, were fed either a conventional control (two successive diets) or a complex (three successive diets) dietary sequence during the postweaning period (4 to 10 wk of age). BWs were recorded at weaning (days 0 and 28 of age), days 1, 2, 6, 12, 19, 26, and 42 (10 wk of age), and at 23 wk of age. Feces texture was examined before weaning (day -1), at day 1, 2, 6, 12, and 19. Feed intake was recorded at pen level from days 0 to 42 after weaning, and individually thereafter. Plasma was collected after blood samplings at days -1, 6, 19, and 42 on half of the piglets: all piglets of a given sex in each pen were sampled, to achieve a balanced number across factors. Pigs of the low RFI (LRFI) line were heavier at weaning, had greater glucose concentration, and lower levels of diarrhea at days 1 and 2 than pigs from the high RFI (HRFI) line (P < 0.01). At day 42, there was no BW difference between lines, and G:F ratio did not differ between lines (P = 0.40). The LRFI pigs had lower feed intake and growth rate from day 0 to day 19 (P < 0.005), and greater plasma concentration of non-esterified fatty acid (P < 0.001), indicating an increased mobilization of body lipids and proteins immediately after weaning compared with HRFI pigs. They also had greater levels of diarrhea at day 6 (22% for LRFI vs. 14% for HRFI, P = 0.002), but the concentration of plasma haptoglobin did not indicate acute inflammation. The complex diet sequence improved feed intake and growth, and reduced diarrhea, mainly in the LRFI line (P < 0.001). To conclude, pigs from the LRFI line were more negatively affected by weaning stress, but managed to recover afterwards. The complex diet sequence ameliorated some of the negative effects that weaning had on the LRFI pigs, but limited effects of nursery period feeding sequence on growth performance were observed during the growing-finishing period.

Feeding behaviour and pre-prandial status affect post-prandial plasma energy metabolites and insulin kinetics in growing pigs fed diets differing in fibre concentration.

Variations in feeding behaviour between animals result from individual variations in their metabolism as affected by diet composition. The study aimed to link the within-day dynamics of voluntary feed intake and those of blood metabolites and insulin in growing pigs having ad libitum access to feed and receiving diets differing in dietary fibre levels and aleurone supplementation. A total of forty pigs (body weight: 35 kg) had access to diets provided ad libitum, which differed by fibre content (13 or 18 % neutral-detergent fibre) and aleurone supplementation (0, 2 or 4 g/kg). Feeding behaviour was individually recorded for 1 week. The kinetic of plasma metabolites and insulin was followed for 1 h after a voluntary test meal. Dietary fibre level did not affect the daily feed intake but increased meal size and meal duration. Aleurone supplementation (4 g/kg) decreased the daily feed intake and number of meals. Dietary fibre level only decreased insulin concentration measured 15 min after meal beginning. Aleurone supplementation (4 g/kg) decreased glycaemia in the first hour after the meal and insulinaemia 15 min after the meal. Free access to feed led to high variability in pre-prandial metabolites and insulin concentrations, resulting in different test meal size irrespective of diet composition. Animals were then spread over different profiles combining feeding behaviour and fasted status to explain different profiles of regulation of feed intake. Plasma metabolites and insulin kinetics were affected by diet composition but also by animal characteristics. Individual variability should be considered when diet composition is used to modulate feeding behaviour.

Single fraction of accelerated partial breast irradiation in the elderly: early clinical outcome.

BACKGROUND: To analyze the clinical outcome of elderly women with early breast cancer who underwent accelerated partial breast irradiation (APBI) based on a post-operative single fraction of multicatheter interstitial high dose-rate brachytherapy (MIB). METHODS: A single institution retrospective cohort study was performed focusing on elderly patients (≥ 65 years old) presenting a low-risk breast carcinoma treated by lumpectomy plus axillary evaluation followed by MIB. A single fraction of 16 Gy was prescribed on the 100% isodose. Clinical outcome at 3 years was reported based on local relapse free survival (3-y LRFS), specific survival (SS) and overall survival (OS). Acute (< 180 days after APBI) and late toxicity were evaluated. Cosmetic results were clinically evaluated by the physician. RESULTS: Between January 2012 and August 2015, 48 women (51 lesions) were treated. Median age was 77.7 years (range: 65-92) with a median tumor size of 12 mm (range: 3-32). Five patients (pts) presented an axillary lymph node involvement (4 Nmic, 1 N1). Invasive ductal carcinoma was the most frequent histology type (86.3%). With a median follow-up of 40 months (range: 36-42), no local relapse occurred while 1 pt. developed axillary relapse (2.1%). The 3-y LRFS, SS and OS rates were 100%, 100% and 93.1% respectively. Forty-five acute events were remained. The most frequent acute toxicity was grade (G) 1 hyperpigmentation (26.7%), 3 pts. (6.3%) presented G3 acute toxicity (2 breast hematomas, 1 breast abscess). No ≥ G3 late toxicity was observed while 15 late toxicities occurred (G1: 13 events - 86.7%) mainly breast fibrosis). The rate of excellent cosmetic outcome was 76.4%. CONCLUSION: We reported promising and encouraging clinical outcome of a post-operative single fraction of MIB ABPI in the elderly. This approach leads to consider a sfAPBI as an attractive alternative to intra-operative radiation therapy while all the patients will be good candidates for APBI in regards to the post-operative pathological report. More mature results (number of patients and follow-up) are needed.

Effects of host genetics and environmental conditions on fecal microbiota composition of pigs.

Since microbiota may influence the physiology of its host including body weight increase, growth rate or feed intake, in this study we determined the microbiota composition in high or low residual feed intake (HRFI and LRFI) pig lines, of different age and/or subjected to sanitary stress by sequencing the V3/V4 variable region of 16S rRNA genes. Allisonella, Megasphaera, Mitsuokella, Acidaminococcus (all belonging to Firmicutes/class Negativicutes), Lactobacillus, Faecalibacterium, Catenibacterium, Butyrivibrio, Erysipelotrichaceae, Holdemania, Olsenella and Collinsella were more abundant in HRFI pigs. On the other hand, 26 genera including Bacteroides, Clostridium sensu stricto, Oscillibacter, Paludibacter, Elusimicrobium, Bilophila, Pyramidobacter and TM7 genera, and Clostridium XI and Clostridium XIVa clusters were more abundant in LRFI than HRFI pigs. Adaptation of microbiota to new diet after weaning was slower in LRFI than in HRFI pigs. Sanitary stress was of relatively minor influence on pig microbiota composition in both tested lines although abundance of Helicobacter increased in LRFI pigs subjected to stress. Selection for residual feed intake thus resulted in a selection of fecal microbiota of different composition. However, we cannot conclude whether residual feed intake was directly affected by different microbiota composition or whether the residual feed intake and microbiota composition are two independent consequences of yet unknown genetic traits differentially selected in the pigs of the two lines.

Digesta transit in different segments of the gastrointestinal tract of pigs as affected by insoluble fibre supplied by wheat bran.

Digestibility is the result of two competing processes: digestion and digesta transit. To develop or parameterise mechanistic models of digestion, both processes have to be quantified. The aim of this study was to determine the effect of insoluble dietary fibre on the transit in the gastrointestinal tract of pigs. Six barrows (33 kg initial body weight and fitted with two simple T-cannulas at the proximal duodenum and distal ileum) were used in a double 3 x 3 Latin square design. Pigs were offered diets differing in total dietary fibre content (170, 220 and 270 g/kg DM) at 4 h intervals. A single meal marked with YbO2 and Cr-EDTA was used to determine the kinetics of markers concentrations of the solid and liquid phases, respectively. The mean retention time (MRT), calculated by the method of the moments, averaged 1, 4 and 38 h in the stomach, small intestine and large intestine, respectively. Increasing the insoluble fibre content in the diet had no effect on MRT in the stomach and decreased the MRT of both phases in the small intestine (P < 0.05). In the large intestine, increasing the insoluble fibre content decreased the MRT of the liquid phase (P = 0.02) and tended to decrease the MRT of the solid phase (P = 0.06). Transit of the solid phase in the large intestine was 4-8 h slower than transit of the liquid phase. Analysis of marker excretion curves indicated that the small and large intestine should be represented mathematically to have both a tubular (propulsion) and compartmental (mixing) structure.

Feeding different types of cooked white rice to piglets after weaning influences starch digestion, digesta and fermentation characteristics and the faecal shedding of beta-haemolytic Escherichia coli.

Forty-eight, 21-d-old pigs were used to examine the effects of different types of cooked white rice on starch digestion, digesta and fermentation characteristics, shedding of beta-haemolytic Escherichia coli and performance after weaning. Pigs received one of three rice-based diets: (i) medium-grain Amaroo (AM), (ii) long-grain Doongara (DOON), and (iii) waxy (WAXY). The remainder of the diet consisted predominantly of animal proteins. A fourth diet contained mainly wheat, barley and lupins (WBL). On days 1, 3, 7 and 9 after weaning, a faecal swab was taken for assessment of beta-haemolytic E. coli and faecal consistency. Apparent digestibility of starch measured in the ileum 14 d after weaning was highest (P = 0.004) in AM and WAXY and lowest, but the same (P>0.05), in DOON and WBL. Starch digestibility in the rectum was highest in all rice diets (P < 0.001). Digesta viscosity was highest in pigs fed WBL in both the ileum (P < 0.001) and caecum (P = 0.027). Pigs fed rice generally had lighter (P < 0.05) gastrointestinal organs than pigs fed WBL. Performance of pigs was similar for all treatments; however, pigs fed rice-based diets had a higher (P < 0.001) carcass percentage than pigs fed WBL. Pigs fed WBL produced more acid (P < 0.05) but had lower molar proportions of acetate (P < 0.05), isobutyrate (P < 0.01) and isovalerate (P < 0.001) and a higher molar proportion of butyrate (P < 0.01) in the large intestine than pigs fed rice. Shedding of E. coli was low; however, pigs fed AM and WBL shed less E. coli than pigs fed other diets.

Main intestinal markers associated with the changes in gut architecture and function in piglets after weaning.

We analysed the spatio-temporal sequence of events concerning the morphology, physiology and ecology of the gut of piglets during the 2 weeks following weaning, in order to provide a limited number of variables that could be relevant markers of the gut post-weaning changes. An experiment was conducted on sixty piglets fasted for 2 d, then administered a weaning diet with a moderate or a high content of wheat using controlled gastric feeding, and slaughtered at different time-points post-weaning. Sixty-nine variables were analysed by principal component analysis. The results showed that the temporal changes induced in the gut by weaning can be divided into two periods: an acute period happening immediately after weaning, followed after day 5 by a more progressive adaptative and maturational phase. The main factors of this adaptation were the refeeding process and the time, while the diet per se had little influence. The villus length, lactose activity, macromolecule fluxes across the jejunum and the plasma cholecystokinin were proposed as markers of the acute phase. Ths mass of the jejunum, the weight of the pancrease, the content of stomach, the trypsin activity and the theophyl-line-induced secretion in jejunum were related to the re-feeding. Markers proposed to follow the gut maturation were the maltase activity, the glucose absorption and the basal resistance in the ileum, the lactobacilli and enterococci in the colon, and the pH of colonic and caecal contents. These markers might be helpful to design suitable diets to limit posts-weaning gut disorders in pigs.

Influence of the Phaseolus vulgaris phaseolin level of incorporation, type and thermal treatment on gut characteristics in rats.

Phaseolus vulgaris phaseolin has been shown to stimulate faecal losses of endogenous N in rats. Experiments with purified phaseolin were carried out in rats to test the hypothesis that these losses reflect intestinal disorders. Phaseolin composition varies depending on its constitutive subunits. Therefore, three phaseolin types (S, T, I) were tested. Phaseolin T was incorporated in varying levels (0, 33, 67 or 100 % of the dietary protein) as raw material in experiment 1. In experiment 2, the three phaseolin types were incorporated at 50 %, with or without previous thermic treatment. Raw casein was the basal protein source and was also heated in experiment 2. Faecal digestibility of phaseolin and gut integrity were evaluated in both experiments. The incorporation level or type of phaseolin had little effect on gross anatomy of gut segments but these factors influenced the weight and pH of fresh contents of the stomach and caecum (P<0.05). Raw phaseolin T incorporated at various levels led to an enlargement of duodenal villi together with a tendency for increased crypt depth in the jejunum (P=0.06). Activities of both alkaline phosphatase in the duodenum and aminopeptidase N in the ileum decreased (P<0.05) after thermal treatment of casein while they increased (P<0.05) for heat-treated phaseolin S and T, respectively. In conclusion, raw phaseolin had no effect on the tissue weight of gut segments and induced limited alterations in the small intestine. Differences due to phaseolin level or type were limited too.

Increasing digesta viscosity using carboxymethylcellulose in weaned piglets stimulates ileal goblet cell numbers and maturation.

Intestinal mucin, a family of glycoproteins secreted by goblet cells, is the main constituent of the mucus protecting the gastrointestinal tract. For optimal mucosal protection, both the quantitative and qualitative characteristics of mucin are essential. To evaluate how viscosity influences ileal apparent digestibility and mucin biology, a highly viscous nonfermentable soluble polysaccharide, carboxymethylcellulose (CMC), was fed to weaned piglets for 15 d. The ileal crude mucin concentration was determined by ethanol precipitation, and changes in goblet cell subtypes were analyzed by the histochemistry of ileal and colonic tissues. As expected, CMC increased the viscosity of ileal digesta and the moisture of feces (P < 0.001). The crude mucin concentration and output at the ileum were higher (P < 0.05) in pigs fed CMC than those fed the control diet. Increasing intestinal content viscosity in pigs fed CMC had no significant effects on the ileal apparent digestibility of dry matter, organic matter, nitrogen, and minerals. The number of total ileal goblet cells per villus also was higher (+30%, P < 0.05) in pigs fed the CMC diet compared with controls. This increase was essentially accounted for by increased numbers of acidic and acidic sulfated mucin-containing cells (+30%, P < 0.05). Trends (P = 0.06) toward decreased numbers of neutral and acidic mucin-containing cells in ileal crypts were also noted. In conclusion, increasing intestinal content viscosity in weaned piglets fed CMC increased the ileal mucin output and numbers and maturation of goblet cells in ileal villi without effects on the apparent digestibility of the diet.

Estimation of ileal output of gastro-intestinal glycoprotein in weaned piglets using three different methods.

Mucin is the main constituent of gastrointestinal mucus and is responsible for its physicochemical and physiological properties. Previous studies have suggested that this glycoprotein represents a major component of undigested endogenous protein at the ileum. The aim of the study was to estimate the ileal output of this glycoprotein using three methods: direct ELISA, hexosamine-based method and ethanol precipitation. For setting up the ELISA assay, the glycoprotein was isolated from intestinal mucus scraping by cesium chloride density gradient ultracentrifugation and a rabbit hyperimmune plasma was raised against the purified glycoprotein. Ileal outputs of hexosamine and glycoprotein were measured in weaned piglets fed a control diet (C) based on casein or diets which contained 50% crude protein supplied by white (WCP) or black (BCP) chickpea. The hexosamine output was higher (P < 0.05) with the WCP diet (2.3 and 1.5 g x kg(-1) of dry matter intake for glucosamine and galactosamine, respectively) than with diet C (1.1 and 0.7 g x kg(-1) of DMI). The hexosamine-based and ethanol precipitation methods, but not the ELISA, showed significant differences between the diet treatments (P < 0.05). Although hexosamine-based and ethanol precipitation methods for the estimation of ileal glycoprotein appeared to be more satisfactory than the developed ELISA to display diet effects in this study, it remains to be determined whether the higher glycoprotein data variability observed with ELISA reflects the actual biological variability of the phenomenon or not.

Legume grains enhance ileal losses of specific endogenous serine-protease proteins in weaned pigs.

Feeding legume grains to pigs usually increases losses of endogenous proteins at the terminal ileum. However, the identity of such proteins is largely unknown. This study was undertaken to determine the ileal flow and identity of soluble proteins present in large concentrations in ileal digesta of young pigs fed soybean meal (SBM), peas (P), faba beans (FB), or blue lupin (L) in expt. 1, and white (WPC) or black (BPC) chickpeas in expt. 2. Protein in the control diet (C) was provided by casein. Ileal digesta proteins were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis, Coomassie blue staining, densitometry and N-terminal amino acid sequencing. Three protein bands at molecular masses of 25, 27, and 30 kDa had a higher ileal flow (P < 0.05) in the pigs fed the legume-based diets compared to those fed the control diet in expt. 2. This was true for the 25- and 30-kDa proteins (P < 0.05) and the 27-kDa protein (P < 0.10) in pigs fed the legume-containing diets in expt. 1. These proteins shared N-terminal amino acid sequences with enzymes of the serine protease family including pig trypsin (25 kDa) and blood coagulation factor IX or chymotrypsin (27 and 30 kDa).