Surgical Stoma

The impression approach was used to determine leaf stomatal density, which was expressed as the number of stomata per unit leaf area (Radoglou and Jarvis, 1990 ). The leaves selected were those for which gas exchange was measured. The abaxial epidermis of the leaf was cleaned first using a degreased cotton ball, and then carefully smeared with nail varnish in the mid-area between the central vein and the leaf edge, for approximately 20 min. The thin film (approximately 5 mm×15 mm) was peeled off from the leaf surface, mounted on a glass slide, immediately covered with a cover slip, and then lightly pressured with fine-point tweezers. Numbers of stomata (s) and epidermal cells (e) for each film strip were counted under a photomicroscope system with a computer attachment (MPS 60, Leica, Wetzlar, Germany). Impressions were taken from the six youngest, fully expanded leaves for each treatment. The leaf stomatal index was estimated using the formula [s/(e + s)]×100. The number of guard cells was estimated by doubling the number of counted stomata in the same leaf area (Radoglou and Jarvis, 1990 ). Stomatal size was defined as the length in micrometres between the junctions of the guard cells at each end of the stoma, and may indicate the maximum potential opening of the stomatal pore, but not the aperture of opening that actually occurs (Malone et al., 1993 ; Maherali et al., 2002 ).

The prospective validation study recruited patients at the investigating centre, a university hospital serving a population of approximately 330 000 people with an established secondary care IBD service providing outpatient and inpatient medical and surgical care.23 (link) Patients were recruited during routine visits to the outpatient clinics prior to consultation with the doctor or specialist nurse, during other treatment-related visits (eg, azathioprine monitoring clinic or infusion visit for biologics) or at the time of admission for inpatient care. Inclusion criteria specified a confirmed diagnosis of IBD on the basis of clinical, endoscopic, radiological and/or histological criteria with disease duration of at least 6 months. Exclusion criteria specified non-English speaking subjects, cognitive impairment or serious active psychiatric disease.
After informed consent, the patients completed the IBD-Control questionnaire and were then asked to complete a questionnaire pack comprising a disease-specific QoL questionnaire (the UK-IBD-QoL),16 (link)
17 (link) a generic health status instrument (EuroQol, EQ-5D-3L),24 (link) and the Hospital Anxiety and Depression Scale.25 (link) The research team undertook a simultaneous assessment of current disease activity, using the Harvey-Bradshaw Index (HBI) for CD 5 (link) and the Simple Clinical Colitis Activity Index (SCCAI) for UC.6 (link) The research team and clinicians were blinded to the results of patient-completed questionnaires.
Where the study visit was taking place at a scheduled clinical review (eg, outpatient attendance), the treating clinician or specialist nurse was asked to complete a questionnaire at the end of the consultation to indicate the current state of IBD (Global Physician Assessment) using a categorical scale (remission, mild, moderate or severe), blinded to patient surveys. All treatment decisions were recorded, capturing whether new therapies were started, existing drug doses changed, therapies discontinued or surgery recommended. The research team reviewed the hospital case records and clinical information systems to extract background clinical information regarding diagnosis, duration of disease, previous hospitalisation and surgery, disease extent, presence of stoma or perianal fistulae, major comorbid illness and current therapy for their IBD.