Early onset metastatic colorectal cancer in Australia.

BACKGROUND: Colorectal cancer (CRC) incidence and mortality rates have been increasing among young patients (YP), for uncertain reasons. It is unclear whether YP have a distinct tumor biology or merit a different treatment approach to older patients (OP). METHODS: We reviewed prospectively collected data from consecutive patients with metastatic CRC (MCRC) enrolled in the multi-site Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) Australian registry. Clinicopathological features, treatment and survival outcomes were compared between YP (<50 years) and OP (≥50 years). RESULTS: Of 3692 patients diagnosed August 2009 - March 2023, 14 % (513) were YP. YP were more likely than OP to be female (52% vs. 40 %, P < 0.0001), have ECOG performance status 0-1 (94% vs. 81 %, P < 0.0001), to have a left-sided primary (72% vs. 63 %, P = 0.0008) and to have fewer comorbidities (90% vs. 60 % Charleston score 0, P < 0.0001). There were no differences in the available molecular status, which was more complete in YP. YP were more likely to have de novo metastatic disease (71% vs. 57 %, P < 0.0001). YP were more likely to undergo curative hepatic resection (27% vs. 17 %, P < 0.0001), to receive any chemotherapy (93% vs. 78 % (P < 0.0001), and to receive 3+ lines of chemotherapy (30% vs. 24 % (P < 0.0034)). Median first-line progression free survival (10.2 versus 10.6 months) was similar for YP vs OP, but overall survival (32.1 versus 25.4 months, HR = 0.745, P < 0.0001) was longer in YP. CONCLUSION: Known prognostic variables mostly favored YP versus OP with newly diagnosed mCRC, who were also more heavily treated. Consistent with this, overall survival outcomes were improved. This data does not support that CRC in YP represent a distinct subset of mCRC patients, or that a modified treatment approach is warranted.

Prediction of peritoneal soiling in acute appendicitis with simple clinical and laboratory data. Prospective, multicenter, cohort study of 2,645 adult patients nationwide.

BACKGROUND AND AIMS: In order to facilitate the preoperative prediction of complicated appendicitis, we propose a complementary approach by selecting an endpoint defined by the intraoperative finding of peritoneal soiling (PS). METHODS: Over a 6-month period, 38 centers (5% of all public hospitals) attending emergency general surgery patients on a 24-h, 7-days a week basis, enrolled consecutive adult patients requiring appendectomy. Patients were stratified according to the absence or the finding of PS during the surgical procedure. RESULTS: A total of 2645 patients were included; median age (IQR) was 35 (22-51) years, 44.3% were female. The laparoscopic approach was used in 70.8% of appendectomies. In a third of patients (31.7%), there was PS with pus around the appendix, or bowel contents, free pus, or blood in the peritoneal cavity. To develop the prediction model, 1764 patients were randomly selected for the derivation cohort and the remaining 881 patients were assigned to the validation cohort. On multivariable logistic regression analysis of all patients, two clinical variables (age, and pulse) and three laboratory variables (serum urea, serum sodium, and white blood cell count) were individually associated (P < .05) with a greater probability of having PS (Hosmer-Lemeshow chi, 1.63; P = .99; C-statistic, 0.7). Based on the multivariable regression model, both static and dynamic nomograms were developed for the prediction of PS in patients with acute appendicitis. CONCLUSIONS: The entry of simple clinical and laboratory variables in the dynamic nomogram may be useful in guiding the initial management of patients with acute appendicitis in resource-limited settings.

Initial experience of TAS-102 chemotherapy in Australian patients with Chemo-refractory metastatic colorectal cancer.

For patients with refractory metastatic colorectal cancer (mCRC) treatment with Trifluridine/Tipiracil, also known as TAS-102, improves overall survival. This study aims to investigate the efficacy and safety of TAS-102 in a real-world population from Victoria, Australia. A retrospective analysis of prospectively collected data from the Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) registry was undertaken. The characteristics and outcomes of patients receiving TAS-102 were assessed and compared to those enrolled in the registration study (RECOURSE). Across 13 sites, 107 patients were treated with TAS-102. The median age was 60 years (range: 31-83), compared to 63 for RECOURSE. Comparing registry TAS-102-treated and RECOURSE patients, 75% vs 100% were ECOG performance status 0-1, 74% vs 79% had initiated treatment more than 18 months from diagnosis of metastatic disease and 36% vs 49% were RAS wild-type. Median time on treatment was 10.4 weeks (range: 1.7-32). Median progression-free survival (PFS) was 3.3 months compared to 2 months in RECOURSE, while median overall survival was the same at 7.1 months. Two patients (2.3%) had febrile neutropenia and there were no treatment-related deaths, where TAS-102 dose at treatment initiation was at clinician discretion.TRACC registry patients treated with TAS-102 were younger than those from the RECOURSE trial, with similar overall survival observed. Less strict application of RECIST criteria and less frequent imaging may have contributed to an apparently longer PFS.

Berberine inhibits experimental varicocele-induced cell cycle arrest via regulating cyclin D1, cdk4 and p21 proteins expression in rat testicles.

The aim of this study was to uncover the protective effect of berberine (BBR), an antioxidant chemical, on experimental varicocele (VCL)-induced adverse effects on cell cycle machinery during early germ cells mitosis. To follow-up this study, 30 mature male Wistar rats were divided into control-sham, nontreated VCL, 50 mg kg-1 and 100 mg kg-1 BBR-treated VCL groups. Following 60 days, histological alterations were analysed by haematoxylin and eosin (H and E) staining, and expressions of cyclin-D1, cyclin-dependent kinase-4 (cdk4) and p21 were investigated by immunohistochemical (IHC) staining technique. Finally, DNA ladder test was carried out to examine the testicular DNA fragmentation. Administration of BBR remarkably diminished the percentage of seminiferous tubules with deformed shape, depleted germ cells and germ cells dissociation compared to VCL-sole group. The IHC observations showed that BBR significantly (p < .05) reduced VCL-induced p21 expression increase and up-regulated cyclin-D1 and cdk4 expressions. Moreover, BBR decreased VCL-induced DNA fragmentation. In conclusion, BBR can promote cell cycle through cellular DNA content protection, p21 expression down-regulation and maintaining cyclin-D1 and cdk4 expressions. Thus, BBR could be considered as a novel protective biochemical agent against experimental VCL-induced derangements. However, more studies are needed to uncover BBR-induced effects on cells cycle process and germ cells development.

Social media as an open-learning resource in medical education: current perspectives.

PURPOSE: Numerous studies evaluate the use of social media as an open-learning resource in education, but there is a little published knowledge of empirical evidence that such open-learning resources produce educative outcomes, particularly with regard to student performance. This study undertook a systematic review of the published literature in medical education to determine the state of the evidence as to empirical studies that conduct an evaluation or research regarding social media and open-learning resources. METHODS: The authors searched MEDLINE, ERIC, Embase, PubMed, Scopus, and Google Scholar from 2012 to 2017. This search included using keywords related to social media, medical education, research, and evaluation, while restricting the search to peer reviewed, English language articles only. To meet inclusion criteria, manuscripts had to employ evaluative methods and undertake empirical research. RESULTS: Empirical work designed to evaluate the impact of social media as an open-learning resource in medical education is limited as only 13 studies met inclusion criteria. The majority of these studies used undergraduate medical education as the backdrop to investigate open-learning resources, such as Facebook, Twitter, and YouTube. YouTube appears to have little educational value due to the unsupervised nature of content added on a daily basis. Overall, extant reviews have demonstrated that we know a considerable amount about social media use, although to date, its impacts remain unclear. CONCLUSION: There is a paucity of outcome-based, empirical studies assessing the impact of social media in medical education. The few empirical studies identified tend to focus on evaluating the affective outcomes of social media and medical education as opposed to understanding any linkages between social media and performance outcomes. Given the potential for social media use in medical education, more empirical evaluative studies are required to determine educational value.

Association of serum gamma-glutamyltransferase and premature coronary artery disease.

BACKGROUND: Serum gamma-glutamyltransferase (GGT) has been introduced as a predictive factor for cardiovascular disease. In this study, we investigated the association of serum GGT and premature coronary artery disease (CAD) in candidates for coronary angiography. METHODS: In this cross-sectional study, we enrolled male subjects aged ≤45 years and female subjects ≤55 years who were candidates for elective coronary angiography due to typical chest pain or a positive non-invasive test. Baseline characteristics were recorded for all the participants and serum levels of blood glucose, lipid profile and GGT were measured. Patients were divided into CAD and non-CAD groups based on angiography for further comparisons. RESULTS: From a total of 367 patients (age 45.1 ± 6.1 years, 161 males [43.9%]), 176 (47.9%) patients had premature CAD. A high level of GGT was significantly associated with the presence of CAD (p < 0.001). A 10-unit increase in GGT could strongly predict the presence of premature coronary artery disease (OR: 13.34, 95% CI: 7.19-24.78; p < 0.001) after adjustment for confounders. The area under the receiver operating characteristic curve for GGT was 80.9% (range 76.5-85.3) and the sensitivity and specificity of GGT at a cut-point of 22.5 IU/l was 80.1% and 70.2%, respectively. Diagnostic accuracy of GGT was 74.9%. The positive predictive value and negative predictive value for GGT was 71.3 and 79.3, respectively. CONCLUSION: We observed that GGT levels in patients with typical chest pain or positive non-invasive tests could predict the presence of premature CAD in young patients.

Hematopoietic SCT in Iranian children 1991-2012.

This study presents the pediatric hematopoietic SCT (HSCT) activity in Iran between 1991 and 2012. Overall, 1105 fifteen-year-old or younger patients have undergone HSCT (975 allogeneic and 130 autologous). Annual HSCTs have been increasing steadily since 2007. HLA-matched siblings and other related donors were the main source of HSCs, although since 2008 a national HLA registry has been established to fill the gap for patients lacking a related donor. Inherited abnormalities of RBCs (45.88%), leukemias (27.6%) and BM failure syndromes (11.94%) constituted the majority of HSCTs during this period. Two-year overall survival and disease-free survival rates for all patients were 74.2% (95% confidence interval (CI): 71.6-77) and 66.3% (95% CI: 63.5-69.3), respectively. Leading cause of death in allogeneic group was TRM (165 deaths) and relapse caused the majority of deaths in the autologous group (39 deaths). All HSCTs from the beginning have been performed exclusively with TBI-free-conditioning regimens, which provides unique data for comparison with activities of other centers. Encouraging survival rates provide a basis for future studies on the extensive applicability of TBI-free-conditioning regimens in pediatric HSCT.

Efficiency of allogeneic hematopoietic SCT from HLA fully-matched non-sibling relatives: a new prospect of exploiting extended family search.

The best donors for hematopoietic SCT (HSCT) are fully-matched siblings. In patients without fully-matched siblings, HLA registries or cord blood banks are alternative strategies with some restrictions. Owing to the high rate of consanguineous marriage in our country, between 2006 and 2013, extended family searches were undertaken in Hematology-Oncology Research Center and Stem Cell Transplantation (HORCSCT), Tehran, Iran, in 523 HSCT candidates with parental consanguinity and no available HLA identical sibling. Fully-matched other-relative donors were found for 109 cases. We retrospectively studied the HSCT outcome in these patients. Median time to neutrophil engraftment was 13 days (range: 9-31days). In 83 patients, full chimerism and in 17 patients, mixed chimerism was achieved. Acute GvHD (aGvHD) grade II-IV appeared in 36 patients (33%). The frequency of aGvHD development in various familial subgroups was NS. Five patients expired before day+100. In the surviving 104 cases, chronic GvHD developed in 20 patients (19.2%). The distantly related subgroup had significantly a higher rate of cGvHD (P=0.04). The 2-year OS and disease-free survival (DFS) were 76.7±4.5% and 71.7±4.7%, respectively. No significant difference in OS (P=0.30) and DFS (P=0.80) was unraveled between various familial relationships. Our considerable rate of fully-matched non-sibling family members and the favorable outcome support the rationale for extended family search in regions where consanguineous marriage is widely practiced.

Adaptive Fractional-order Control for Synchronization of Two Coupled Neurons in the External Electrical Stimulation.

This paper addresses synchronizing two coupled chaotic FitzHugh-Nagumo (FHN) neurons with weakly gap junction under external electrical stimulation (EES). To transmit information among coupled neurons, by generalization of the integer-order FHN equations of the coupled system into the fractional-order in frequency domain using Crone approach, the behavior of each coupled neuron relies on its past behavior and the memorized system can be a better fit for the neuron response. An adaptive fractional-order controller based on the Lyaponuv stability theory was designed to synchronize two neurons electrically coupled with gap junction in EES. The proposed controller is also robust to the inevitable random noise such as disturbances of ionic channels. The simulation results demonstrate the effectiveness of the control scheme.

The influence of systemic therapy on the serum levels of IL-6 and IL-8 in pemphigus vulgaris.

BACKGROUND: The place of cell-mediated immunity and cytokines in the immunopathogenesis of pemphigus vulgaris (PV) has not been fully established. OBJECTIVE: To assess the serum levels of pro-inflammatory cytokines, Interleukine-6 (IL-6) and Interleukine-8 (IL-8), in PV patients before and after therapy, to evaluate the influence of therapy on the serum cytokine levels. METHODS: Sixty-six newly diagnosed PV patients enrolled into the study. The serum levels of IL-8 and IL-6 were measured in 66 and 64 patients, respectively. According to the extent of skin and mucosal involvement, the patients were divided into two groups namely mild and severe. The serum levels of cytokines were measured using enzyme-linked immunosorbent assay (ELISA) method before and after 4 weeks of prednisolone plus azathioprine therapy. RESULTS: In 64 patients studied for the serum level of IL-6, the median IL-6 level was significantly decreased from 1.6 to 0.9 pg/mL by therapy (P-value = 0.001). Segregating the patients according to the severity of the disease, the serum level of IL-6 did not differ significantly by therapy in patients with a mild disease. However, in patients with a severe disease the median serum level of IL-6 decreased significantly from 1.8 to 0.9 pg/mL after therapy (P-value = 0.001). No significant changes were found in the IL-8 level by treatment. CONCLUSION: The significant decrease in the IL-6 level after therapy suggests that blocking of IL-6 could have therapeutic benefits for the treatment of PV, particularly in severe forms.

Effect of stage of maturity of grass at harvest on intake, chewing activity and distribution of particle size in faeces from pregnant ewes.

This study was conducted to investigate the effect of stage of maturity at harvest on the intake of grass silage, eating and ruminating activity and the distribution of faecal particle size in ewes during late pregnancy. A total of 18 Swedish Finull x Dorset 85 ± 8 kg (mean 6 ± s.d.) ewes bearing twins were randomly assigned to three dietary treatments 6 weeks before lambing. The treatments included ad libitum feeding with early harvested (EH), medium harvested (MH) or late harvested (LH) primary-growth grass silage with 45%, 58% and 63% NDF on a dry matter (DM) basis, respectively. Intake and chewing activity were recorded and faeces were sampled over 4 continuous days for each individual ewe. The faeces samples were washed in nylon bags, freeze dried and sieved with pore sizes from 2.4mm to 0.1 mm; particles less than 0.1mm in size were also collected. Subsamples of each sieving fraction were scanned and the dimensions of the individual particles in each sieving fraction were measured by image analysis. In addition, the number of particles longer than 7 mm was counted from the particles retained on a sieve with a pore size of 2.4mm using a simple wet sieving technique. The time spent eating and ruminating per kg of DM intake was affected by the stage of maturity at harvest; it was shorter in ewes fed EH compared with ewes fed MH and LH ( P < 0.05). In comparison with feeding LH, feeding EH resulted in the retention of a larger proportion of particles in the lower and upper sieve fractions (< 0.2mm and > 1 mm, respectively, P < 0.01), a smaller mean particle size ( P < 0.05) and a smaller mean particle width in faeces ( P < 0.01). The results from the simple wet sieving technique confirmed the results from dry sieving and image analysis, showing a higher number of large particles in faeces from ewes fed the EH compared with the ewes fed the MH and LH (P < 0.001). In conclusion, the distribution of faecal particle size might be considered as a footprint of the characteristics of forage fibre eaten by ewes.

Traumatic dissecting posterior cerebral artery aneurysm. A case report and review of the literature.

Dissecting posterior cerebral artery (PCA) aneurysms are among rare cerebrovascular malformations accounting for 2% to 6% of all aneurysms. Herein we describe a case of pediatric dissecting aneurysm located in the PCA with documentation of aneurysm development. In addition, we discuss its treatment with a new therapeutic method involving glue injection.

Susceptibility to pulmonary tuberculosis in Iranian individuals is not affected by compound KIR/HLA genotype.

Natural killer (NK) cells have distinctive functional capacities that are likely to contribute both to innate and adaptive immunity to Mycobacterium tuberculosis. Killer cell immunoglobulin-like receptors (KIR) and their ligands, i.e. human leukocyte antigen (HLA) class I molecules contribute partly in regulation of NK cell activity. In this study, the impact of compound KIR/HLA genotype on susceptibility to pulmonary tuberculosis (TB) has been evaluated in Iranian individuals. A total of 107 TB patients and 100 matched healthy controls were genotyped for 17 KIR genes and their three major HLA class I ligand groups (-C1, -C2 and -Bw4: -B Bw4(Ile80) , -B Bw4(Thr80) and -A Bw4) by a polymerase chain reaction-sequence-specific primers assay. Various analyses including distribution of KIR and HLA ligand genes and genotypes, frequency of inhibitory and activating KIR+HLA combinations and compound genotype status regarding balance of inhibitory and activating components showed no significant difference between patient and control groups. These findings may suggest that compound KIR/HLA genotype has no major impact on limiting Mycobacterium tuberculosis infection.

A biodistribution study of Hemiscorpius lepturus scorpion venom and available polyclonal antivenom in rats

The purpose of the present study was to investigate the biodistribution profile of the venom of Hemiscorpius lepturus, the most dangerous scorpion in Iran. Blood and tissue samples were taken at various predetermined intervals during a 400-minute period for the venom and a 360-minute period for the antivenom in rats. The radio-iodination was carried out using the chloramine-T method. The results showed that the descending order of venom uptake was skin, kidneys and intestine, respectively. The descending order of polyclonal antivenom uptake was kidneys, intestine, heart and lungs. The calculated pharmacokinetic parameters of the venom were Telimination half-life = 521.5 ± 12.6 minutes; Vd/F (apparent volume of distribution) = 14.9 ± 3.3 mL; clearance (CL/F, apparent total clearance of the drug from plasma) 0.02 ± 0.005 mL/minute and for the antivenom Telimination half-life = 113.7 ± 7.4 minutes; Vd/F = 13 ± 1.2 mL and CL/F 0.08 ± 0.01 mL/minute. The pharmacokinetics profile comparison of the venom with that of the antivenom shows that serotherapy may be more effective if administered within 2-4 hours following envenomation by H. lepturus.(AU)

Symptom patterns in adult patients stung by scorpions with emphasis on coagulopathy and hemoglubinuria

The aim of this retrospective descriptive study was to highlight clinical manifestations 24-48 hours following referral of adult patients stung by scorpions. This study contains clinical records of 290 patients admitted to Razi Hospital due to scorpion stings in Ahvaz, Khuzestan province from 2004 to 2005. The most prevalent patient age range was 15-20 years (30.3%). The most common sting location (41.3%) was the upper extremity; nearly half (49.6%) had been admitted within 6-24 hours following sting, while a large majority (85.5%) were hospitalized for 24-48 hours. A total of 116 (40%) patients presented hemoglobinuria. Contrary to available prior reports, the symptoms in none of the patients were accompanied by neurological manifestations. Kidney manifestations (BUN, creatinine), coagulopathy and transfusion were observed in patients with blood cell lysis and hemoglobinuria. The kidney problems were seen more in patients who had been admitted more than 24 hours after the accident. Overall, the findings demonstrate that coagulation and hemoglobinuria signs produced by scorpion sting in Ahvaz differ significantly from those reported elsewhere.

KIR3DL1+HLA-B Bw4Ile80 and KIR2DS1+HLA-C2 combinations are both associated with ankylosing spondylitis in the Iranian population.

Contribution of killer cell immunoglobulin-like receptors (KIR) and their human leucocyte antigen (HLA) class I ligands in the pathogenesis of autoimmune diseases has been shown in several studies. In this study, the possible association of KIR genes, their known HLA ligands and compound KIR/HLA genotypes with ankylosing spondylitis (AS) was assessed. Combined KIR/HLA ligand genotyping was performed by a polymerase chain reaction-sequence-specific primers assay in 35 Iranian patients with AS, and genotypes were compared to those in 200 healthy individuals. The frequencies of telomeric cluster genes KIR2DL5A, KIR2DS1 and KIR3DS1 were significantly increased in AS patient group (P(c) = 0.0082, P(c) = 0.0195 and P(c) = 0.0328, respectively). Conversely, HLA-Bw4 ligand (the presence of one or more -B Bw4(Ile80) , -B Bw4(Thr80) and -A Bw4 epitopes) (P(c) = 0.0004) and HLA-B Bw4(Ile80) (P(c) = 0.053) were less frequent in these patients. Meanwhile, compound KIR/HLA genotype analyses revealed lower frequency of KIR3DL1+HLA-B Bw4(Ile80) (P(c) = 0.0343) and higher frequency of KIR2DS1+HLA-C2 (P(c) = 0.0308) combinations in patients with AS than in controls. In addition, the genotypes iKIR+HLA > aKIR+HLA (P(c) = .0308) and iKIR+HLA > aKIR (P(c) = 0.0258) were statistically less common, and genotypes iKIR+HLA = aKIR+HLA (P(c) = 0.0081) and iKIR+HLA < aKIR (P(c) = 0.077) were more common in patient group. Our findings suggest a role for excessive or inappropriate NK cell activation through 'KIR/HLA' system in AS disease.

Sequence analysis of lysozyme C from the scorpion mesobuthus eupeus venom glands using semi-nested rt-PCR.

BACKGROUND: Lysozyme is an antimicrobial protein widely distributed among eukaryotes and prokaryotes and take part in protecting microbial infection. Here, we amplified cDNA of MesoLys-C, a c-type lysozyme from the most common scorpion in Khuzestan Province, Southern Iran. METHODS: Scorpions of Mesobuthus eupeus were collected from the Khuzestan Province. Using RNXTM solution, the total RNA was extracted from the twenty separated venom glands. cDNA was synthesized with extracted total RNA as template and modified oligo(dT) as primer. In order to amplify cDNA encoding a lysozyme C, semi-nested RT-PCR was done with the specific primers. Follow amplification, the fragment was sequenced. RESULTS: Sequence determination of amplified fragment revealed that MesoLys-C cDNA had 438 bp, encoding for 144 aa residues peptide with molecular weight of 16.702 kDa and theoretical pI of 7.54. A putative 22-aminoacids signal peptide was identified. MesoLys-C protein was composed of one domain belonged to c-type lysosyme/ alphalactalbumin. CONCLUSION: Multiple alignment of MesoLys-C protein with the related cDNA sequences from various organisms by ClustalW program revealed that some of the conserved residues of other c-type lysosymes were also seen in MesoLys-C. However, the comparison suggested that Mesobuthus eupeus of Khuzestan and east Mediterranean Mesobuthus eupeus belonged to different subspecies.

In vivo pharmacological study on the effectiveness of available polyclonal antivenom against Hemiscorpius lepturus venom

The available Razi Institute antivenom is still, empirically, used by intramuscular (IM) administration for the treatment of scorpion stings in humans by six medically dangerous species including Hemiscorpius lepturus (H. lepturus). The aim of this study was to assess the neutralizing ability and effectiveness of the antivenom in inhibiting hemoglobinuria, biochemical changes, increased microalbuminuria and urinary lactate dehydrogenase (LDH) following H. lepturus sting. Simultaneous intramuscular administration of 10 μL and 100 μL of antivenom, after 24 hours, had no significant preventive effect on the extent and degree of hemoglobinuria or proteinuria produced in venom-treated rats. After IM administration of antivenom, no significant changes in decreased red blood cell (RBC) count and hemoglobin were observed. Immediate intramuscular administration of 10 μL of antivenom had no significant effects on both LDH and microalbuminuria. The present findings did not present correlation with clinical signs. Therefore, to fully assess the efficacy of the available antivenom and make appropriate recommendations, more in vivo or in vitro investigations including antigen-antibody interaction, enzymatic analysis and route-dependent administration are required.(AU)

Effects of physical form and stage of maturity at harvest of whole-crop barley silage on intake, chewing activity, diet selection and faecal particle size of dairy steers.

This study examined the effects of physical form and stage of maturity at harvest of whole-crop barley silage (WCBS) on feed intake, eating and rumination activity, diet selection and faecal particle size in dairy steers. Whole-crop barley was harvested and ensiled in round bales. Eight dairy steers (live weight (LW): 350 ± 10 kg) in a duplicated 4 × 4 Latin square design were fed WCBS harvested at heading or dough stage of maturity in long form or chopped in a 2 × 2 factorial treatment arrangement. The WCBS was supplemented with soybean meal. Daily dry matter (DM) intake increased by 7% (P < 0.05) due to chopping of dough-stage silage but was unaffected by chopping of heading-stage silage. The steers fed chopped, but not those fed long dough-stage silage, selected for starch in the WCBS (P < 0.001). The neutral detergent fibre (NDF) intake was 5% higher (P < 0.01) for heading than for dough-stage silage and was associated with lower concentration of indigestible NDF (96 v. 170 g/kg DM). Rate of intake of DM and NDF was 37% higher (P < 0.001), daily eating time was 24% shorter (P < 0.001) and daily chewing time was 8% shorter (P < 0.05) for chopped silage compared with long silage but there was no effect of maturity. Daily rumination time was not affected by treatments, whereas rumination and chewing times per kg NDF intake were 15% and 13% higher (P < 0.05), respectively, for dough-stage than for heading-stage silage. The proportion of faecal particles retained on a 1 mm screen was 30% higher (P < 0.001) due to chopping and 45% higher (P < 0.001) due to delayed harvest. Chopping the dough-stage silage reduced the proportion of grain in faeces from 97 to 43 g/kg DM (P < 0.05) indicating higher starch digestibility. In conclusion, chopping increased DM intake of WCBS when harvested at dough stage but not at heading stage of maturity.