Efficient quantum algorithms for set operations.

Analyzing the relations between Boolean functions has many applications in many fields, such as database systems, cryptography, and collision problems. This paper proposes four quantum algorithms that use amplitude amplification techniques to perform set operations, including Intersection, Difference, and Union, on two Boolean functions in O ( N ) time complexity. The proposed algorithms employ two quantum amplitude amplification techniques divided into two stages. The first stage uses the Younes et al. algorithm for quantum searching via entanglement and partial diffusion to prepare incomplete superpositions of the truth set of the first Boolean function. In the second stage, a modified version of Arima's algorithm, along with an oracle that represent the second Boolean function, is employed to handle the set operations. The proposed algorithms have a higher probability of success in more general and comprehensive applications when compared with relevant techniques in literature.

Flavonoids from Barnebydendron riedelii leaf extract mitigate thioacetamide-induced hepatic encephalopathy in rats: The interplay of NF-κB/IL-6 and Nrf2/HO-1 signaling pathways.

Phytochemical investigation of the butanol fraction (BUF) derived from the 70% aqueous methanolic leaf extract of Barnebydendron riedelii led to the isolation of three flavonoid glycosides; kaempferol-3-O-α-l-rhamnopyranosyl-(1 â†’ 6)-ß-d-glucopyranoside, quercetin-3-O-α-l-rhamnopyranosyl-(1 â†’ 6)-ß-d-galactopyranoside and quercetin-3-O-α-l-rhamnopyranosyl-(1 â†’ 6)-ß-d-glucopyranoside. Docking studies were fulfilled to validate the possible bio-properties of BUF toward nuclear factorkappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2). The protective role of BUF against behavioral, biochemical, molecular, histopathological and immunohistochemical alterations in thioacetamide (TAA)-induced hepatic encephalopathy in rats was investigated. The toxicological studies indicated that BUF was safe up to 2000 mg/kg bw. Prior to TAA intoxication, rats were orally treated with either BUF at multiple doses (70, 140 and 280 mg/kg bw) or lactulose (8 mL/kg bw) for 14 consecutive days. On the 13th and the 14th day, TAA (200 mg/kg bw/day) was intraperitoneally injected. The BUF significantly improved motor impairment, ameliorated cognitive deficits and attenuated TAA-induced hepatotoxicity. Moreover, BUF controlled the inflammatory processes by suppressing the hepatic inflammatory cytokine; interleukin-6 (IL-6) as well as its pro-inflammatory mediator; NF-κB supporting the molecular docking assessment. The brain neurotransmitters; dopamine, serotonin and noradrenaline, as well as ammonia levels were improved in BUF-treated TAA-intoxicated animals in a dose-dependent manner. Furthermore, BUF administration to TAA-intoxicated rats modulated the Nrf2 and heme oxygenase 1 (HO-1) genes expression in liver and brain tissues. The histological evaluation showed that pretreatment of TAA-intoxicated rats with BUF ameliorated the degenerative effects of TAA on liver and brain tissues as well as reduced the activation of cellular apoptotic marker; caspase-3 and glial fibrillary acidic protein (GFAP+) astrocytes. In conclusion, the observed hepato-neuroprotective effect of BUF is attributed to its flavonoidal content through its modulatory effects on of NF-κB/IL-6 and Nrf2/HO-1 signaling pathways.

Image Reconstruction Based on Novel Sets of Generalized Orthogonal Moments.

In this work, we have presented a general framework for reconstruction of intensity images based on new sets of Generalized Fractional order of Chebyshev orthogonal Moments (GFCMs), a novel set of Fractional order orthogonal Laguerre Moments (FLMs) and Generalized Fractional order orthogonal Laguerre Moments (GFLMs). The fractional and generalized recurrence relations of fractional order Chebyshev functions are defined. The fractional and generalized fractional order Laguerre recurrence formulas are given. The new presented generalized fractional order moments are tested with the existing orthogonal moments classical Chebyshev moments, Laguerre moments, and Fractional order Chebyshev Moments (FCMs). The numerical results show that the importance of our general framework which gives a very comprehensive study on intensity image representation based GFCMs, FLMs, and GFLMs. In addition, the fractional parameters give a flexibility of studying global features of images at different positions and scales of the given moments.

LC-ESI-MS/MS profiling of alkaloids and antiproliferative activity of Pachypoduim lamerei drake leaves.

In the present study, evaluation of the antiproliferative activity of Pachypodium lamerei Drake leaves (family Apocyaceae) against human breast cancer cell lines MDA-MB-231 was done for the total methanolic extract, crude alkaloidal mixture and ursolic acid using the MTT colorimetric assay. The methanolic extract showed the strongest antiproliferative activity followed by ursolic acid and crude alkaloidal fraction with an IC50 equal to 6.2, 14.55 and 56.3 µg/ml respectively compared to oleocanthal. It is the first record for the LC/ESI-MS/MS alkaloidal profiling of the leaves of P. lamerei. Seven alkaloids were tentatively identified according to their fragmentation patterns. Four alkaloids were related to the parent indole class and two alkaloids belong to the quinoline class in addition to one steroidal alkaloid with a pregnan nucleus. Phytochemical investigation of the methanolic extract led to the isolation of three triterpenoidal compounds including ursolic acid, 11,12-didehydroursolic acid lactone and ursolic acid lactone.

Hypoglycemic activity of Gleditsia caspica extract and its saponin-containing fraction in streptozotocin-induced diabetic rats.

The fruits of Gleditsia species (Fabaceae) have been known in traditional medicine as a saponin-rich herbal medicine. The present study aimed to investigate the effects of the total methanolic extract of Gleditsia caspica (MEGC) and its saponin-containing fractions (SFGC) on hyperglycemia in streptozotocin (STZ)-induced diabetic rats. A single intraperitoneal injection of STZ (55 mg/kg body weight) was used to induce hyperglycemia in male albino rats. MEGC (15, 30 and 60 mg/kg, p.o.) and SFGC (15, 30 and 60 mg/kg, p.o.) were administered to the diabetic rats daily for 14 days. The anti-diabetic drug gliclazide (10 mg/kg, p.o.) was used as a positive control. Blood samples were collected from overnight fasted rats for the evaluation of the antihyperglycemic, antihyperlipidemic and antioxidant activities. The levels of glucose, triglycerides (TG), cholesterol (TC) and malondialdehyde (MDA) were increased significantly, whereas the levels of α-amylase, insulin and reduced glutathione (GSH) were decreased in the experimental diabetic rats. Pancreas and liver of the diabetic rats exhibited significant changes in the histopathology, morphology and DNA content. Administration of MEGC or SFGC led to a decrease in the levels of glucose, TG, TC and MDA. In addition, the levels of α-amylase, insulin and GSH were increased in MEGC and SFGC treated diabetic rats. Also, the histopathological and morphological changes, as well the changes in DNA were significantly reversed by the extracts. Thus, MEGC and SFGC exhibited potent hypoglycemic and hypolipidemic activities in STZ- induced diabetic rats.

LC/ESI-MS/MS profiling of Ulmus parvifolia extracts and evaluation of its anti-inflammatory, cytotoxic, and antioxidant activities.

In this study, a comparative liquid chromatography/mass spectroscopy (LC/ESI-MS/MS) profiling of different fractions of Ulmus parvifolia leaves and stems was performed. Identification of compounds was based on comparing the mass spectrometric information obtained including m/z values and individual compound fragmentation pattern to tandem mass spectral library search and literature data. Eleven compounds were tentatively identified in the different analyzed fractions. One of the major constituents of this plant was isolated and identified as Icariside E4 [dihydro-dehydro-diconiferyl alcohol-4-O-α-L-rhamnopyranoside] (5). The evaluation of anti-inflammatory activity of the total methanolic extract using nitric oxide inhibition on LPS-stimulated RAW 264.7 cells model strong anti-inflammatory activity with 17.5% inhibition of nitric oxide production versus 10% inhibition for dexamethasone. The cytotoxic activity of the methanolic extract and Icariside E4 was evaluated against four types of human cell lines using MTT assay. Icariside E4 showed cytotoxic effect against Hep-G2, MCF-7, and CACO-2 cell lines compared to a negligible activity for the total extract. The same extract showed a moderate antioxidant activity with SC50=362.5 µg/mL.

Three further triterpenoid saponins from Gleditsia caspica fruits and protective effect of the total saponin fraction on cyclophosphamide-induced genotoxicity in mice.

Three triterpenoidal saponins were isolated from the saponin fraction derived from a Gleditsia caspica Desf. methanolic fruit extract. The isolated saponins were identified as gleditsiosides B, C, and Q based on spectral data. The saponin-containing fraction was evaluated in vivo for genotoxic and antigenotoxic activities. The fraction caused no DNA damage in Swiss albino male mice treated with a dose of 45 mg/kg body weight for 24 h, although it significantly inhibited the number of chromosomal aberrations induced by cyclophosphamide (CP) in bone marrow and germ cells when applied before or after CP administration. The inhibitory indices in chromosomal aberrations were 59% and 41% for bone marrow and 48% and 43% for germ cells, respectively. In addition, the saponin fraction was found to reduce the viability of the human tumor cell line MCF-7 in a dose-dependent manner with an extrapolated IC50 value in the range of 220 µg/mL.

Methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis and Enterococcus faecium active dimeric isobutyrylphloroglucinol from Ivesia gordonii.

Bioassay-guided fractionation of the chloroform soluble fraction of stem, leaf, and flower extracts of the American plant Ivesia gordonii led to the isolation of a new dimeric acylphloroglucinol, 3,3'-diisobutyryl-2,6'-dimethoxy-4,6,2',4'-tetrahydroxy-5,5'dimethyldiphenyl methane (1), to which we have assigned the trivial name ofivesinol (1), together with a known monomeric acylphloroglucinol, 1,5-dihydroxy-2-(2'-methylpropionyl)-3-methoxy-6-methylbenzene (2). The structures of the isolated compounds were characterized using 1D- and 2D- NMR spectroscopy, including COSY, HMQC, HMBC, and ROESYexperiments, as well as mass spectrometry. Ivesinol (1) showed potent activity against Staphylococcus aureus (SA) and methicillin-resistant S. aureus (MRSA) with IC50/MIC/MBC values of 0.10/1.25/>20 microg/mL and 0.05/0.31/>20 microg/mL, respectively (vs. IC50/MIC/MBC 0.13/0.5/1.0 microg/mL and 0.13/0.5/1.0 microg/mL of ciprofloxacin), while the corresponding monomer 2 was found to be less active. Compound 1 also demonstrated strong activity against vancomycin-resistant Enterococcus faecium (VRE) with IC50/MlC/MBC values of 0.22/1.25/>20 microg/mL, whereas the reference standard ciprofloxacin was found to be inactive against this strain. In addition, compound 2 showed moderate activity against two species of Candida and Cryptococcus neoformans, while 1 was inactive against these fungi. In order to evaluate the influence of the acyl group(s) in phloroglucinol (3) as a ligand, the mono- (4) and diacetylphloroglucinol (5) were prepared from 3, and evaluated for their in vitro SA, MRSA, and VRE activities; 2,4-diacetylphloroglucinol (5) showed potent activity, like 1, against SA, MRSA, and VRE (ATCC 700221) with IC50/MIC values of 0.3/2.5, 0.23/2.5, and 0.86/2.5 microg/mL, respectively, while 4 was inactive.

Simultaneous dyeing and antibacterial finishing for cotton cellulose using a new reactive dye.

Simultaneous dyeing and antibacterial finishing for cotton fabric using a new antibacterial reactive dye having a modified chemical structure to the commercial reactive dye CI Reactive Red 198 were studied. This modification was carried out by replacing metanilic acid in the commercial dye with 4-amino-N-(4,6-dimethylpyrimidin-2-yl)benzenesulfonamide (sulfadimidine). Optimum exhaustion and fixation values were achieved at 60 g/l sodium sulphate and 20 g/l sodium carbonate for both dyes. The modified dye exhibited higher substantivity, exhaustion and fixation efficiency compared to the commercial dye. Antibacterial activities of the dyed samples at different concentrations of both dyes were studied against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria. The cotton dyed with the modified dye shows higher antibacterial efficacy compared to the dyed cotton fabric using the commercial dye, especially on gram negative (E. coli) bacteria. All the reactive dyeings also exhibited high fastness properties.

Screening of marine extracts for schistosomicidal activity in vitro. Isolation of the triterpene glycosides echinosides A and B with potential activity from the Sea Cucumbers Actinopyga echinites and Holothuria polii.

CONTEXT: Praziquantel (PZQ) is the drug available for the treatment of schistosomiasis. The reported reduced cure rates, the failure of treatment after PZQ administration in patients and the existence of resistant parasite strains, reinforce the need to rapidly discover new effective molecules against Schistosoma parasite. OBJECTIVE: To screen the methanol extracts of 79 marine organisms for their schistosomicidal activities against Schistosoma mansoni adult worms in vitro and perform bio-assay directed chromatography for the most active extracts to isolate the active compounds. MATERIALS AND METHODS: Screening of the marine organisms and bio-assay directed chromatography of the most active extracts together with identification of the active isolates using 1D and 2D NMR analysis, were investigated. RESULTS: RESULTS indicated that the isolates echinosides A and B from the sea cucumbers Actinopyga echinites Jaeger and Holothuria polii Delle Chiaie (Holothuriidae) were highly active. Their LC(50) values were equal to 0.19 µg/ml and 0.27 µg/ml, respectively. Detailed (1)HNMR data for echinosides A and B are reported here for the first time. DISCUSSION AND CONCLUSION: These findings demonstrate that the isolated echinosides possess potential in vitro schistosomicidal activity against S. mansoni adult worms. Therefore, echinosides are promising as lead compounds for the development of new schistosomicidal agents.

Colonoscopy for screening and follow up of patients with a family history of colorectal cancer.

OBJECTIVE: To determine the minimum family history of colorectal cancer (CRC), which justifies colonoscopy and to establish whether further colonic assessment is necessary after a negative screening colonoscopy. METHOD: A retrospective review of every colonoscopy undertaken for family screening at the Royal Berkshire and Battle Hospitals, Reading between October 1996 and July 2004. RESULTS: Four hundred and thirty-two patients (261 women) with an average age of 48 years (range 14-84) were screened. Three cancers in patients over the age of 60 years and 49 adenomas were found in 37 patients. Twenty three of 281 (8%) patients with a 'low-risk' family history (one in 12 or less lifetime risk of developing CRC) had either a cancer or an adenoma. Eighteen of 151 (12%) patients with a 'high-risk' family history (one in 10 or greater) had a similar positive colonoscopy. Thirteen of 15 patients who had an adenoma aged under 45 years had a high-risk family history. Seventy-three patients subsequently underwent two or more follow-up colonoscopies. There were 22 adenomatous polyps found in 12 patients (16%) at the first screening, nine adenomas in seven patients in the second colonoscopy and four adenomas found in four patients in all subsequent colonoscopies. CONCLUSION: Patients with a low-risk family history have a similar adenoma pick-up to that of the general population. These patients need not be screened below the age of 50 unless symptomatic. Follow up of low-risk family history (FH) patients with a negative screening colonoscopy is unlikely to be beneficial.

Intra-operative peritoneal lavage--who does it and why?

INTRODUCTION: Intra-operative peritoneal lavage (IOPL) is widely practised but its benefits are unclear. The frequency and pattern of its use amongst general surgeons is investigated. METHODS: A postal questionnaire was sent to 153 general surgical consultants and registrars enquiring about their use of IOPL. The surgeon was asked the volume and type of lavage fluid used, under various circumstances. RESULTS: 118 (77%) questionnaires were returned. 115 (97%) surgeons used IOPL. The majority of surgeons (61%) lavaged until the fluid was clear, 20% used more than 1 l and 17% used between 500-1000 ml. In the case of the dirty abdomen (i.e. gross pus or faecal peritonitis), 47% used saline as the lavage fluid, 38% aqueous betadine, 9% water and 3% antibiotic lavage. Similar results were found in the case of a contaminated abdomen (i.e. a breached hollow viscus). 34% of surgeons used IOPL during clean cases. 36% used water lavage during intra-abdominal cancer surgery; 21% lavaged with saline and 17% with betadine. More registrars (47%) than consultants (29%) lavaged with water during cancer surgery. Consultants, however, used more aqueous betadine. CONCLUSIONS: The frequency of use and choice of lavage fluid varies widely. The successful management of the septic abdomen rests on at least 3 tenants - systemic antibiotics, control of the source of infection and aspiration of gross contaminants. There is little good evidence in the literature to support IOPL in the management of the septic abdomen. The use of IOPL during cancer surgery is supported by in vitro evidence. The current use of IOPL, as shown by this study, appears not to be evidence based.

The incidence and causes of permanent stoma after anterior resection.

AIMS: Defunctioning stomas are used following anterior resection to guard against the serious consequences of anastomotic leak such as pelvic sepsis and generalized peritonitis. This study aims to determine what proportion of patients undergoing anterior resection have a defunctioning stoma, how many of these patients do not have their stoma closed, and the reasons for this. METHODS: All patients undergoing a resection for rectal cancer in our institution in a five year period (January 1995 to December 1999) are included in the study. Anterior resection was performed on 154 patients, divided into 76 anterior resections (AR) and 78 low anterior resections (defined as the anastomosis within 6 cm of the anal verge). The data from these patients were analysed retrospectively. RESULTS: Of the total of 154 patients undergoing anterior resection, 59 (38%) were defunctioned, divided into 33 with loop ileostomy and 26 with loop colostomy. Five of these patients had not had their stoma closed at a median follow up of four years (range 1.5-6.5 years). The reasons for non closure were anastomotic stricture (2), metastatic disease (2), and patient choice (1). When comparing AR and LAR, 16% of patients had a defunctioning stoma after AR, compared with 60% after LAR (P < 0.01). CONCLUSION: Anterior resection is being performed for very low rectal tumours in order to avoid a permanent stoma. However we have found that 8% of patients who are defunctioned with a stoma at anterior resection will not have their stoma closed, and conclude that patients should be warned of this pre-operatively.

An analysis of the accuracy of P-POSSUM scoring for mortality risk assessment after surgery for colorectal cancer.

OBJECTIVE: To compare predicted vs. observed mortality using P-POSSUM and determine whether this scoring system reflected observed surgical outcomes. PATIENTS AND METHODS: Consecutive patients who underwent a colorectal resection for cancer over a 12-month period were scored using P-POSSUM to estimate mortality risk and POSSUM to calculate predicted morbidity. This was then compared with observed outcomes. The main outcome measurements were 30 day postoperative mortality and postoperative morbidity. RESULTS: 173 patients underwent a colorectal resection for cancer during the study period. The observed mortality rate was 8.7% compared with a P-POSSUM predicted mortality rate of 15.6% (P < 0.01). Observed morbidity was 29% whereas the predicted morbidity rate was 32% (P=0.1). CONCLUSIONS: P-POSSUM allows for standardization of physiological and operative variables. Risk of postoperative mortality may be overestimated by the scoring system however.

Topical diltiazem ointment in the treatment of chronic anal fissure.

BACKGROUND: Chronic anal fissure has traditionally been treated surgically. Initial enthusiasm for chemical sphincterotomy has waned because of poor outcomes with glyceryl trinitrate ointment. In this study the use of topical 2 per cent diltiazem ointment has been investigated as an alternative method of chemical sphincterotomy. METHODS: A prospective assessment of 71 consecutive patients with a chronic anal fissure treated with 2 per cent topical diltiazem ointment for a median duration of 9 (range 2--16) weeks was performed. RESULTS: Fifty-one patients (75 per cent) experienced healing of the fissure after 2--3 months of treatment with topical diltiazem. Seventeen patients who did not heal were treated for a further 8 weeks with topical diltiazem. Eight of these patients subsequently healed with diltiazem. Fifty-nine of 67 patients who completed follow-up therefore healed on diltiazem ointment. Four patients experienced perianal dermatitis and one patient experienced headaches. No other side-effects were recorded. After a median of 32 (range 14--67) weeks' follow-up following completion of treatment, 27 of 41 patients available remain symptom free. Six of seven patients with recurrent fissure were treated successfully by repeat chemical sphincterotomy. CONCLUSION: Topical 2 per cent diltiazem ointment used as an agent for chemical sphincterotomy for chronic anal fissure offers significant healing rates but does not have a significant side-effect profile, which may aid compliance to treatment. Early recurrences are common but usually amenable to further chemical sphincterotomy.

Functional outcomes after ileal pouch-anal anastomosis for chronic ulcerative colitis.

OBJECTIVE: To assess long-term outcomes after ileal pouch-anal anastomosis (IPAA) for chronic ulcerative colitis (CUC) with specific emphasis on patient sex, childbirth, and age. SUMMARY BACKGROUND DATA: Childbirth and the process of aging affect pelvic floor and anal sphincter function independently. Early function after IPAA is good for most patients. Nonetheless, there are concerns about the impact of the aging process as well as pregnancy on long-term functional outcomes after IPAA. METHODS: Functional outcomes using a standardized questionnaire were prospectively assessed for each patient on an annual basis. RESULTS: Of the 1,454 patients who underwent IPAA for CUC between 1981 and 1994, 1,386 were part of this study. Median age was 32 years. Median length of follow-up was 8 years. Pelvic sepsis was the primary cause of pouch failure irrespective of sex or age. Functional outcomes were comparable between men and women. Eighty-five women who became pregnant after IPAA had pouch function, which was comparable with women who did not have a child. Daytime and nocturnal incontinence affected older patients more frequently than younger ones. Incontinence became more common the longer the follow-up in older patients, but this was not found in younger patients. Poor anal function led to pouch excision in only 3 of 204 older patients. CONCLUSIONS: Incontinence rates were significantly higher in older patients after IPAA for CUC compared with younger patients. However, this did not contribute to a greater risk of pouch failure in these older patients. Patient sex and uncomplicated childbirth did not affect long-term functional outcomes.

Primary myocutaneous flap closure following resection of locally advanced pelvic malignancies.

BACKGROUND: Perineal wounds, created at the time of extended resection for locally advanced malignancy and following chemoradiation, are at risk of serious complications. METHODS: To determine whether immediate myocutaneous flap closure prevents complications, 57 patients treated with multimodality therapy and proctectomy (35 perineal wounds) or sacrectomy (22 posterior wounds) were studied. Patients were categorized according to whether they underwent primary skin and pelvic closure (group 1; ,n = 20); primary skin and omental pelvic closure (group 2; n = 24); or immediate myocutaneous flap closure (group 3; n = 13). RESULTS: Groups were similar with respect to age and sex; however, group 1 had more primary tumours and required less radical surgery and chemoirradiation than groups 2 and 3. Groups 1 and 2 experienced more complications overall (eight of 20, nine of 24 and three of 13 patients in groups 1, 2 and 3 respectively), more acute wound complications (seven of 20, nine of 24 and two of 13), delayed wound healing (three of 20, six of 24 and one of 13) and more reoperations for perineal wound problems (five of 20, seven of 24 and zero of 13). Patients in group 2 had a significantly longer hospital stay than those in group 1. Flap closure (group 3) did not increase the length of stay. The routine use of primary flap closure reduced overall wound complications (eight of 31 versus ten of 26 patients) and length of hospitalization (13 versus 17 days). CONCLUSION: Complete wound healing was achieved in all patients; however, immediate myocutaneous flap closure reduced the need for readmission and reoperation.

Preoperative magnetic resonance staging of rectal cancer with an endorectal coil and dynamic gadolinium enhancement.

BACKGROUND: The aim of the study was to assess the value of endorectal coil magnetic resonance imaging (MRI) with gadolinium enhancement in the preoperative staging of rectal cancer. METHODS: In addition to standard evaluation, patients with rectal lesions were assessed by MRI obtained with a pelvic phased-array coil in combination with an endorectal coil. RESULTS: The study group comprised 29 patients with rectal cancer staged with an endorectal coil who had surgery without preoperative adjuvant therapy. In addition to standard T1- and T2-weighted images, dynamic contrast-enhanced images were acquired in all patients. Considerable interobserver variation was noted, particularly for pathological tumour stage pT1 or pT2 (kappa = 0.36). Compared with pathological findings, endorectal MRI correctly staged nine patients, overstaged 16 and understaged four. Whilst lymph node metastases were accurately detected in 70 per cent of patients, the positive predictive value was only 58 per cent. CONCLUSION: MR staging of rectal cancer with an endorectal coil and gadolinium enhancement is inaccurate for early tumours (stage T1 or T2) and is associated with a considerable degree of interobserver variation for individual scan sequences.

A UK training programme for nurse practitioner flexible sigmoidoscopy and a prospective evaluation of the practice of the first UK trained nurse flexible sigmoidoscopist.

BACKGROUND: Flexible sigmoidoscopy is a technical skill that has been successfully performed by suitably trained colorectal nurse practitioners in the USA. However, no recognised training course exists for nurse practitioners in the UK. AIMS: To design and evaluate a training programme for nurse endoscopists. METHODS: A multidisciplinary committee of nurses and clinicians developed a structured programme of study and practice. This involved a staged process of observations, withdrawals, and ultimately, full procedures. Once training had been completed the nurse practitioner was permitted to practice independently. Patients with colorectal symptoms referred for flexible sigmoidoscopy were examined for the final stages of training and independent practice. A prospective evaluation of the training and practice of the first trained nurse flexible sigmoidoscopist was performed. Barium enema, video, clinical follow up, and histology were used to validate the results of the flexible sigmoidoscopies. RESULTS: The training programme required that 35 observations, 35 withdrawals, and 35 supervised full procedures were performed prior to the development of independent practice. Subsequent to the completion of this programme 215 patients have been examined independently by the nurse practitioner. Ninety three per cent of the examinations were judged successful and pathology was identified in 51%. The nurse endoscopist successfully identified all "significant" pathology whereas barium enema failed to identify pathology in 12.5%. There were no complications. CONCLUSION: With suitable training nurse endoscopists are able to perform flexible sigmoidoscopy safely and effectively.