Radiographic study to assess the reliability of the Gillies approach for biopsy of the superficial temporal artery.

Biopsy of the superficial temporal artery is often used in the diagnosis of giant cell arteritis, but at traditional sites there is a risk of injury to the facial nerve. Recently the Gillies incision has been suggested as an alternative means of access for the biopsy, but the anatomical basis of this has not been fully elucidated. We therefore undertook a radiographic review of 150 patients, and examining 300 vessels, to find out. Our results indicated that there is considerable variability in the position of the bifurcation of the superficial temporal artery, and so a Gillies approach may not be reliable, particularly if access to the bifurcation is required.

Urinary incontinence in 9-16 year olds with cystic fibrosis compared to other respiratory conditions and a normal group.

BACKGROUND: Individuals with cystic fibrosis (CF) are deemed at risk of developing urinary incontinence (UI) due to repeated coughing and other factors causing increased pressure on the pelvic floor. Increased incidence of UI is recognised in women and increasingly in men and children. However, there is little comparison with normal controls and other respiratory conditions with chronic cough. Our aim was to report the incidence, degree and impact of UI in 9-16 year olds related to clinical status in CF, compared to these. METHODS: 9-16 year olds were invited to fill in a self-administered anonymous/confidential questionnaire at clinic. Data recorded were sex, age, height, weight, spirometry expressed as percentage predicted. Normal controls - age and sex only recorded. RESULTS: No significant differences were found between incidence of UI (21% CF; 22% respiratory; and 17% normal controls, P=0.43). No relationship found between respiratory or nutritional status and UI. Laughing, exercise and cough were the most common causes of UI. No difference between groups for age range, physiotherapy, breathlessness, antibiotics, urinary tract infections and menarche. Only 6% reported more than a few drops of UI. CONCLUSION: Incidence of urinary incontinence is no different between 9-16 year old girls and boys with CF, and controls.

Randomized single blind trial of two low-volume bowel preparations for screening computed tomographic colonography.

BACKGROUND: Bowel preparation is an important part of computed tomographic colonography (CTC); we evaluated two small-volume preparations for screening CTC with regard to quality of preparation and patient acceptability. METHODS: Asymptomatic subjects at average risk for colorectal cancer from a community-based CTC screening program were randomized to bowel preparation comprising magnesium/bisacodyl/picolax or polyethylene glycol (PEG)/picolax. CTC images were evaluated by a blinded investigator for residual feces and fluid; subjects completed a questionnaire regarding acceptability of the preparation. RESULTS: In 176 subjects randomized to magnesium/bisacodyl/picolax (n = 82) or PEG/picolax (n = 94), the former preparation was discontinued because of syncope or presyncope in four (5%) subjects. Another 137 subjects received PEG/picolax without a significant adverse event. There were no other major differences in acceptability of the preparations as reported by subjects. The quality of bowel preparations for reporting CTC was similar. CONCLUSION: For subjects having screening CTC, both small-volume bowel preparations are generally well tolerated and result in minimal fluid and fecal residue; however, the magnesium/bisacodyl/picolax preparation was accompanied by an unacceptable incidence of syncope and is no longer used by us.

Extracolonic findings at virtual colonoscopy: implications for screening programs.

OBJECTIVE: Virtual colonoscopy (VC) is an evolving technology proposed as a possible screening tool for colorectal cancer. In contrast to conventional colonoscopy, VC may detect extracolonic abdominal pathology. This may lead to unnecessary investigation of benign lesions, or may benefit the patient by identifying serious pathology at an early stage. The aim of this study was to assess the prevalence and characteristics of extracolonic pathology found in patients undergoing VC. METHODS: A total of 100 patients aged > or = 55 yr, referred for colonoscopy for bowel symptoms or family history of bowel cancer, underwent VC. Axial views of the abdomen were reviewed prospectively by a single radiologist for extracolonic pathology. Patients with extracolonic abnormalities were referred to their local doctor or to a specialist clinic when appropriate. Case records were reviewed and treating doctors contacted to document subsequent investigations and procedures generated. RESULTS: Fifteen patients (15%) had extracolonic abnormalities detected. In four patients, the pathology had been diagnosed previously (umbilical hernia, gallbladder and renal calculi, 3.5-cm aortic aneurysm, ovarian cyst). Eleven patients had new abnormalities detected: ovarian cysts (three), liver cysts (two), uterine fibroids (two), gallstones (one), splenic calcifications (one), aortic aneurysm (one), and renal tumor (one). Two patients with ovarian cysts underwent surgery, and histology showed benign cysts. CONCLUSIONS: Extracolonic abnormalities are common at VC. Most are benign, but may lead to investigative and procedural costs. These data should be carefully evaluated in feasibility and cost-effectiveness studies on colorectal cancer screening using VC.

Virtual colonoscopy compared with conventional colonoscopy: a developing technology.

AIM: To determine the accuracy of computed tomography colography (virtual colonoscopy) in detecting colorectal polyps and colorectal cancer. DESIGN: Blinded comparison of virtual colonoscopy (initially supine-only scans and later supine plus prone scans) with the criterion standard of conventional colonoscopy. SUBJECTS AND SETTING: 100 patients aged 55 years or over referred to a public teaching hospital for colonoscopy, July 1997 to January 2000, because of colonic symptoms or a family history of bowel cancer. MAIN OUTCOME MEASURES: Presence and size of polyps and other lesions; certainty of polyp identification on virtual colonoscopy (on 100-point visual analogue scale); sensitivity and predictive values of virtual colonoscopy. RESULTS: Conventional colonoscopy identifed 121 polyps in 47 patients; 28 of these polyps, in 19 patients, were identified by virtual colonoscopy. Sensitivity of virtual colonoscopy for detecting polyps (using supine plus prone scans) was 73% for polyps with diameter > or = 10 mm (95% CI, 39%-94%) and 19% for smaller polyps (95% CI, 10%-31%) (P < 0.001); corresponding figures for supine-only scans were 57% (95% CI, 18%-90%) and 11% (95% CI, 4%-24%), respectively. Ten polyps identified at virtual colonoscopy were considered false-positive findings (8%). The value of finding a polyp on virtual colonoscopy (with thresholds of 5 mm for diameter and 30 points for certainty score) was assessed as a predictor of finding a polyp (diameter > 5 mm) on conventional colonoscopy. Positive and negative predictive values were 88% and 89%, respectively, for supine plus prone scans. CONCLUSION: Although virtual colonoscopy shows potential as a diagnostic tool for colorectal neoplasia, it is currently not sufficiently sensitive for widespread use.

Structure-function studies of omega-atracotoxin, a potent antagonist of insect voltage-gated calcium channels.

The omega-atracotoxins are a family of 36 to 37-residue peptide neurotoxins that block insect but not mammalian voltage-gated calcium channels. The high phylogenetic specificity of these toxins recommends them as lead compounds for targeting insects that have developed resistance to chemical pesticides. We have begun to examine structure-function relationships in the omega-atracotoxins in order to explore the molecular basis of their activity and phylogenetic specificity. By probing the venom of the Blue Mountains funnel-web spider, Hadronyche versuta, for insecticidal toxins with masses close to that of omega-atracotoxin-Hv1a (omega-ACTX-Hv1a), we have isolated and sequenced five additional omega-atracotoxins. Five of the six omega-atracotoxins isolated from the venom of H. versuta (omega-ACTX-Hv1a to -Hv1e) differ from one another by only 1-3 residues and have similar insecticidal potencies. In contrast, omega-ACTX-Hv1f differs from the other toxins by up to 10 residues and it has markedly reduced insecticidal potency, thus providing information on key functional residues. The new atracotoxin sequences have revealed that the three N-terminal residues are highly conserved. Despite the fact that these residues are structurally disordered in solution we show here, by a series of N-terminal truncations, that they contribute significantly to insecticidal potency. However, loss of activity does not correlate with deletion of highly conserved residues, which leads us to propose that the disposition of the N-terminal charge, rather than the chemical properties of the N-terminal residues themselves, may be critical for the activity of omega-atracotoxin on insect calcium channels.

The cell wall and membrane of Cryptococcus neoformans possess a mitogen for human T lymphocytes.

The mechanism of human T-lymphocyte activation by the pathogenic yeast Cryptococcus neoformans has not been established. Previous investigations have suggested that C. neoformans contains a mitogen for T lymphocytes, while other investigators have attributed lymphocyte proliferation in vitro to a recall antigen. Because of the potential importance of the mechanism of T-cell activation for our understanding of the immune response to C. neoformans, the present studies were performed to determine whether C. neoformans contains a mitogen for T lymphocytes. C. neoformans stimulates fetal blood lymphocytes to proliferate and stimulates proliferation of CD45RA+ cells from adults, indicating that it stimulates naive T cells. The T-cell response to C. neoformans was dependent upon the presence of accessory cells. However, allogeneic cells were sufficient for accessory cell function, indicating that the response was not major histocompatibility complex restricted. The percentage of T cells in the cell cycle was higher than that with the recall antigen tetanus toxoid but lower than that with the mitogenic lectin phytohemagglutinin A or the superantigen Staphylococcus enterotoxin B. Precursor frequency analysis established that 1 in 7,750 +/- 2, 270 T cells proliferated in response to the cryptococcal cell wall and membrane. Compared to the case for most mitogens or superantigens, the proliferative response is late and the number of T cells that enter the cell cycle and the precursor frequency are low, indicating that the mitogenic effect is modest. However, the mitogenic effect of C. neoformans should be considered when interpreting the immune response to C. neoformans, since even weak mitogens can have profound effects on host defense.

Investigation of hematuria at a printing company.

An investigation was undertaken at a printing company into an apparently high prevalence of trace dipstick hematuria discovered during routine medical examinations. In both the printing employees (n = 225) and a control group (n = 118) from other industries, the prevalence of hematuria exceeded that described in most previous reports (31% and 25%, respectively, using the criterion of > 12 glomerular red cells or > 2 nonglomerular red cells/microliter of urine). No focus of abnormality was identified within the printing plant and no association was identified between reported exposure to potentially toxic substances and the degree of hematuria. An occupational hygiene inspection and medical follow-up of selected workers did not reveal any significant abnormalities. The limitations of available information concerning "normal" urinalysis results suggests that hematuria may not be a useful test for the screening of occupational groups at risk of bladder cancer.

Vasculitis and glomerulonephritis: a subgroup with an antineutrophil cytoplasmic antibody.

Four subjects whose plasma produced positive staining of neutrophil cytoplasm, on testing for antinuclear factor, have been found over eight years (and over 10,000 antinuclear factor studies). All four had evidence of diffuse systemic disease with polyarthralgia and lung involvement. Three of four (at least) had evidence of renal involvement and two of four skin biopsy evidence of vasculitis. Defining such a subgroup may help in defining etiology(s) and treatment regimes in diffuse vasculitic disease.