Brain responses to mechanical rectal stimulation in patients with faecal incontinence: an fMRI study.

AIM: Continence is dependent on anorectal-brain interactions. Consequently, aberrations of the brain-gut axis may be important in the pathophysiology of faecal incontinence (FI) in certain patients. The aim of this study was to assess the feasibility of recording brain responses to rectal mechanical stimulation in patients with FI using functional magnetic resonance imaging (fMRI). METHOD: A prospective, cohort pilot study was performed to assess brain responses during rectal stimulation in 14 patients [four men, mean (SD) age 62 (15) years]. Blood oxygen level dependent (BOLD) signals were measured by fMRI during rest and mechanical distension, involving random repetitions of isobaric phasic rectal distensions at fixed (15 and 45 mmHg) and variable (10% above sensory perception threshold) pressures. RESULTS: Increases in BOLD signals in response to high pressure rectal distension (45 mmHg) and maximum toleration were observed in the cingulate gyrus, thalamus, insular cortex, inferior frontal gyrus, cerebellum, caudate nucleus, supramarginal gyrus, putamen and amygdala. Additionally, activation of the supplementary motor cortex and caudate nucleus with inconsistent activity in the frontal lobe was observed. CONCLUSIONS: This study has demonstrated the feasibility of recording brain responses to rectal mechanical stimulation using fMRI in patients with FI, revealing activity in widespread areas of the brain involved in visceral sensory processing. The observed activity in the supplementary motor cortex and caudate nucleus, with relative paucity of activity in the frontal lobes, warrants investigation in future studies to determine whether aberrations in cerebral processing of rectal stimuli play a role in the pathogenesis of FI.

Synthesis of ligand-free CZTS nanoparticles via a facile hot injection route.

Single-phase, ligand-free Cu2ZnSnS4 (CZTS) nanoparticles that can be dispersed in polar solvents are desirable for thin film solar cell fabrication, since water can be used as the solvent for the nanoparticle ink. In this work, ligand-free nanoparticles were synthesized using a simple hot injection method and the precursor concentration in the reaction medium was tuned to control the final product. The as-synthesized nanoparticles were characterized using various techniques, and were found to have a near-stoichiometric composition and a phase-pure kesterite crystal structure. No secondary phases were detected with Raman spectroscopy or scanning transmission electron microscopy energy dispersive x-ray spectroscopy. Furthermore, high resolution transmission electron microscopy showed large-sized nanoparticles with an average diameter of 23 nm ± 11 nm. This approach avoids all organic materials and toxic solvents that otherwise could hinder grain growth and limit the deposition techniques. In addition the synthesis route presented here results in nanoparticles of a large size compared to other ligand-free CZTS nanoparticles, due to the high boiling point of the solvents selected. Large particle size in CZTS nanoparticle solar cells may lead to a promising device performance. The results obtained demonstrate the suitability of the synthesized nanoparticles for application in low cost thin film solar cells.

Lymph node status as a prognostic indicator after preoperative neoadjuvant chemoradiotherapy of rectal cancer.

AIM: The primary aim of this study was to examine lymph node status after neoadjuvant chemoradiotherapy (CRT) using a novel scoring system describing the pathological lymph node regression grade. The proposed scoring system was based on the percentage of fibrosis and the presence of residual tumour amount. The secondary aim of the study was to assess the oncological impact of this scoring system. METHOD: The project was a retrospective cohort study over a 10-year period. Two hundred and two patients with rectal cancer who had received CRT followed by curative surgery were included. A histopathologist prospectively scored each specimen and the impact of the scoring system on survival and recurrence was analysed. RESULTS: One hundred and ninety patients completed long-course preoperative CRT and formed the basis of the study. Overall, 40 recurrences (local and distant) were observed over a median follow-up of 36 months. The lymph node regression score was a significant predictor of tumour recurrence (hazard ratio 1.273, 95% CI 1.048-1.548; P = 0.015). The overall mortality rate was 21%, and a lower lymph node regression score was correlated with an improved survival curve (P = 0.01). CONCLUSION: The results demonstrate that lymph node response to neoadjuvant CRT based on a nodal regression scoring system is related to recurrence.

Factors predicting stomal wound closure infection rates.

BACKGROUND: Stoma closure is associated with high wound infection rates. The aim of this study was to evaluate risk factors for infection rates in such wounds, with particular emphasis on assessing the importance of the stomal wound closure technique. METHODS: A retrospective analysis of 142 patients who had undergone ileostomy or colostomy closure between 2002 and 2011 was performed. Postoperative outcome as measured by wound infection rate was recorded. Three different closure techniques were identified: primary closure (PC), primary closure with penrose drain (PCP) and purse-string circumferential wound approximation technique (PSC). Other factors such as age, sex, ASA score, type of prophylactic antibiotics used, diabetes, smoking and obesity were also analysed. All other techniques were excluded. RESULTS: Our series consisted of 142 stomal closures (90 ileostomy and 52 colostomy closures). The patients had a median age of 63.5 years with an interquartile range of 50.1-73.2 years. The overall wound infection rate was 10.7%. PC, PCP and PSC were associated with wound infection rates of 17.9, 10.5 and 3.6%, respectively. Compared to PSC, PC and PCP were associated with significantly higher wound infection rates (p = 0.027 and p = 0.068, respectively). Obesity was a significant risk factor for wound infection (p = 0.024). Use of triple-agent antibiotics prophylactically had a protective effect on the infection rate (p = 0.012). CONCLUSIONS: To reduce stomal wound closure infection rates, we recommend institution of closure techniques other than PC with or without a drain. Risk factors such as obesity should be addressed, and prophylactic triple antibiotics should be administered.

Extraosseous osteoblastoma of larynx presenting with acute airway obstruction.

OBJECTIVE: We report the case of an osteoblastoma of the larynx arising from the vocal fold, which presented with acute airway obstruction and cardiopulmonary arrest. METHOD: The histopathological findings, differential diagnoses and a novel method of treating laryngeal osteoblastoma, using transoral laser therapy, are discussed. RESULTS: Benign osteoblastoma is a rare primary bone tumour usually presenting in young patients in the spine and sacrum. Its occurrence in the larynx is very rare, with only three similar case reports in the literature, none involving tumour arising from the vocal fold. Differential diagnoses must be considered and excluded using both histopathological and clinical features. Once the diagnosis is confirmed, successful treatment is achieved with surgical excision. CONCLUSION: Osteoblastoma of the larynx is rare, and the clinical features can vary with the anatomical site of the lesion. The recommended treatment is surgical excision which, if available, may be achieved by transoral laser microsurgery. Due to its potential rapid growth, careful follow up is essential in order to detect recurrence.