Evaluation of a radiographer-provided barium enema service.

AIM: Radiographers performed and reported 5516 double contrast barium enemas (RDCBEs) over 4 years to October 2001. This study was undertaken to assess the accuracy of RDCBE and the sensitivity for diagnosing colorectal cancer (CRC). METHOD: A total of 224 consecutive outpatient RDCBEs were reported; normal (C1), diverticulosis (C2), diverticulosis with filling defect (C3), diverticulosis & other pathology (C4) and abnormal (C5). RDCBEs were then reported by a radiologist (AL, NS) and the two reports compared. Of 450 CRCs, 153 had undergone DCBE; 152 RDCBEs. Reports were analysed to establish concurrence between radiographer and radiologist and final CRC diagnosis. RESULTS: By category: C1 - 37%, C2 - 31%, C3 - 21%, C4 - 11%, C5 - 0%. C4s included polyps (50%), cancer (12.5%), disrupted anastomosis (8%) and colitis (4%). There was no discrepancy between RDCBE and radiologist reports. Radiology and CRC diagnosis agreed in 145 of 152 DCBEs. There were three exclusions: DCBEs occurred outside the study period (2), one only with raised possibility of malignancy. Of eight remaining RDCBEs, seven were false negatives and one false positive. Sensitivity score for RDCBE was 94.5%. Double reporting by a radiologist did not improve sensitivity. CONCLUSION: RDCBEs are as accurate as those performed by radiologists and have a very high sensitivity for CRC. In a time of ever increasing demands for complex staging investigations for CRC and interventional radiology, the ACPGBI needs to reconsider its guidelines on radiographers not only performing but also reporting DCBE.

Role of melanin in mechanical properties of Glycera jaws.

The remarkable mechanical prowess of the jaws of the bloodworm Glycera dibranchiata appears to be a consequence of a robust cross-linked network of organic molecules, notably melanin and proteins, as well as small amounts of unmineralized Cu and a Cu-based mineral. The present study focuses on the role of melanin. Mechanical properties of untreated jaws and the constituent melanin are probed through nanoindentation, both in air and underwater. Complementary information is obtained from density and porosity measurements and attempts at Cu removal from the jaws using EDTA, an effective metal chelator in most biological systems. In near-tip regions of the jaws, mechanical properties attain the highest values and diminish only slightly when wet (by 15-25%), in contrast to the behavior of other organic biomaterials. The melanin constituent contributes significantly to the mechanical integrity of the jaw; its hardness and elastic modulus are about half those of untreated jaws. Although melanin may be the dominant shape-determining component of the structure, it remains to be shown whether jaw assembly is mediated by protein deposition on a melanin scaffold or, conversely, by melanin deposition on a protein scaffold. The inability of EDTA to chelate Cu from the jaws and the relatively high density of the jaws and the melanin support the notion of a highly cross-linked molecular structure. Finally, based on the metric H(3)/E(2) (H being hardness and E the Young's modulus), the results suggest that the abrasion resistance of the jaws is superior to all engineering polymers and competitive with the hardest metallic alloys.

The UK national study of magnetic resonance imaging as a method of screening for breast cancer (MARIBS).

The UK national study of magnetic resonance imaging as a method of screening for breast cancer (MARIBS) is in progress. The study design, accrual to date, and related research projects are described. Revised accrual rates and expected recruitment are given. 15 cancers have been detected to date, from a total of 1236 screening measurements. This event rate and the tumour grades reported are compared with recent reports from other studies in women at high risk of breast cancer.

Structure and structure-function studies of lipid/plasmid DNA complexes.

Recent synchrotron-based X-ray diffraction studies have enabled us to comprehensively solve the self-assembled structures in mixtures of cationic liposomes (CLs) complexed with linear lambda-DNA. In one case the CL-DNA complexes were found to consist of a higher ordered multilamellar structure (labeled L(alpha)C with DNA sandwiched between cationic bilayer membranes. The membrane charge density is found to control the DNA interaxial spacing with high densities leading to high DNA compaction between lipid bilayers. A second self-assembled structure (labeled H(II)C) consists of linear DNA strands coated by cationic lipid monolayers and arranged on a 2D hexagonal lattice. In this paper we report on a combined X-ray diffraction and optical microscopy study of CLs complexed with functional supercoiled plasmid DNA. We describe the self-assembled structures in cell culture medium for both a high transfectant complex (DOTAP/DOPE, phiDOPE = 0.72) and a low transfectant complex (DOTAP/DOPC, (phiDOPC = 0.72). Fluorescence optica microscopy shows two distinct interactions between these two types of complexes and mouse fibroblast L-cells, demonstrating the existence of a correlation between structure and transfection efficiency.

A retrospective 5-year study on the accuracy of the barium enema examination performed by radiographers.

Barium enema examinations have been undertaken by radiographers at the Frenchay Hospital for more than 10 years. We have performed a retrospective study to assess the accuracy of this radiographer service by reviewing those patients who have been examined by both Barium enema and colonoscopy/flexible sigmoidoscopy to determine agreement, and reasons for disagreement. This paper does not attempt to compare the two techniques. In the 5 years between 1992 and 1996, 595 patients had both barium enema and colonoscopy or flexible sigmoidoscopy. In 488 (82%) of these patients the barium enema examination was performed by a radiographer. Comparisons with endoscopy indicate that 96% of polyps >1 cm, and 97% of carcinomas were detected radiologically. We conclude that radiographer performed barium enemas with double reporting produces a very high standard of examination with detection rates for significant lesions comparable with published data.

The influence of polymer molecular weight in lamellar gels based on PEG-lipids.

We report x-ray scattering, rheological, and freeze-fracture and polarizing microscopy studies of a liquid crystalline hydrogel called Lalpha,g. The hydrogel, found in DMPC, pentanol, water, and PEG-DMPE mixtures, differs from traditional hydrogels, which require high MW polymer, are disordered, and gel only at polymer concentrations exceeding an "overlap" concentration. In contrast, the Lalpha,g uses very low-molecular-weight polymer-lipids (1212, 2689, and 5817 g/mole), shows lamellar order, and requires a lower PEG-DMPE concentration to gel as water concentration increases. Significantly, the Lalpha,g contains fluid membranes, unlike Lbeta' gels, which gel via chain ordering. A recent model of gelation in Lalpha phases predicts that polymer-lipids both promote and stabilize defects; these defects, resisting shear in all directions, then produce elasticity. We compare our observations to this model, with particular attention to the dependence of gelation on the PEG MW used. We also use x-ray lineshape analysis of scattering from samples spanning the fluid-gel transition to obtain the elasticity coefficients kappa and B; this analysis demonstrates that although B in particular depends strongly on PEG-DMPE concentration, gelation is uncorrelated to changes in membrane elasticity.

Lamellar biogels: fluid-membrane-based hydrogels containing polymer lipids.

A class of lamellar biological hydrogels comprised of fluid membranes of lipids and surfactants with small amounts of low molecular weight poly(ethylene glycol)-derived polymer lipids (PEG-lipids) were studied by x-ray diffraction, polarized light microscopy, and rheometry. In contrast to isotropic hydrogels of polymer networks, these membrane-based birefringent liquid crystalline biogels, labeled L-alpha,g, form the gel phase when water is added to the liquid-like lamellar L-alpha phase, which reenters a liquid-like mixed phase upon further dilution. Furthermore, gels with larger water content require less PEG-lipid to remain stable. Although concentrated (approximately 50 weight percent) mixtures of free PEG (molecular weight, 5000) and water do not gel, gelation does occur in mixtures containing as little as 0.5 weight percent PEG-lipid. A defining signature of the L-alpha,g regime as it sets in from the fluid lamellar L-alpha phase is the proliferation of layer-dislocation-type defects, which are stabilized by the segregation of PEG-lipids to the defect regions of high membrane curvature that connect the membranes.

An audit of a radiographer based ultrasound service.

A general ultrasound service has evolved over several years. Radiographers undertake the general ultrasound lists, and show the request card and the hard copy films to a radiologist prior to the patient leaving the department. Whilst it is generally accepted for radiographers to carry the burden of obstetric scanning, this is less so for general work. This audit is of a sample of 100 patients out of the general ultrasound lists. These patients underwent the standard service examination by a radiographer and subsequent report by the radiologist. They also had a separate examination and report by an independent radiologist. 42 patients were agreed to have normal findings. 75 diagnoses or observations were made in the remaining 58 patients. Discrepancies arose between the two limbs of the audit in 20 of the observations. Review of the hard copy films and repeat scanning of patients where necessary identified one relevant error by the auditing radiologist and three relevant errors by the standard service. Whilst errors are made both by radiologists and radiographers, it is concluded that the existing radiographer based ultrasound service provides a satisfactory level of accuracy.

The diagnosis of intra-abdominal abscesses in patients with severe Crohn's disease.

A series of 24 patients with severe relapses of Crohn's disease responding poorly to conventional treatment with corticosteroids was studied to determine the incidence of intra-abdominal abscesses and the best means to detect them. Ultrasound scans proved to be difficult to interpret and unreliable. Computed tomography demonstrated abnormal bowel thickening in most cases, and showed seven of the eight intraabdominal abscesses. 111In leucocyte scintigraphy always demonstrated inflamed areas of bowel, but underestimated the extent of disease in three patients and overestimated it in five. All eight abdominal abscesses were detected, and there were no false-positive results. It was always possible to distinguish the abscess from inflamed bowel wall. Intra-abdominal abscess is not uncommon in patients with severe relapses of Crohn's disease which are not responsive to corticosteroid therapy, being present in about one-third of patients. 111In leucocyte scintigraphy is a simple and helpful test for differentiating between active inflammatory bowel disease and complicating abscesses, contributing significantly to the management of patients with severe Crohn's disease.

Intrathecal administration of 131I radiolabelled monoclonal antibody as a treatment for neoplastic meningitis.

Fifteen patients with neoplastic meningitis received a single intrathecal injection of between 11 and 60 mCi of a 131I radiolabelled monoclonal antibody (MoAb), chosen for its immunoreactivity to tumour. Major toxicity was manifest as nausea, vomiting and headache (7/15 patients), reversible bone marrow suppression (3/8 patients) and seizures (2/15 patients). Nine patients were evaluable for either a tumour or clinical response. Six of these demonstrated an event-free response that was maintained for periods of between 7 and 26 months.

99Tcm-nanocolloid imaging in inflammatory bowel disease.

We have used 99Tcm-labelled nanocolloid in an attempt to locate areas of inflamed bowel wall or abscesses in five patients with ulcerative colitis and nine with Crohn's disease. The scintigraphic findings were evaluated by comparison with those of recent barium studies and, in three patients, with surgical findings at laparotomy. It proved difficult to localize segments of inflamed bowel accurately with 99Tcm-nanocolloid because of the accumulation of radioactivity in the gut lumen, especially 2 or more hours after injection. However, there was little uptake of the labelled nanocolloid by areas of inflamed gut wall in the period before 2 h. When 99Tcm-nanocolloid scans were compared with 111In-WBC scans in eight patients who had both investigations, 99Tcm-nanocolloid scintigraphy was considerably less sensitive than 111In-WBC scintigraphy. One abscess was located correctly; the other was obscured by nearby bladder and bone marrow radioactivity. We conclude that 99Tcm-nanocolloid scanning is neither sensitive nor reliable enough for assessing the location of inflamed bowel wall or the presence of abscess in patients with inflammatory bowel disease.

Effect of axillary nodal status on the long-term survival following mastectomy for breast carcinoma: nodal metastases may not always suggest systemic disease.

Records of 215 patients receiving radical mastectomies from 1958 to 1968 at Roswell Park Memorial Institute were reviewed for the significance of axillary nodal status on long-term survival and recurrence. Ten-year disease-free interval rates were 83%, 47%, and 17%, respectively, for patients with negative nodes, 1-3 positive nodes, and greater than or equal to 4 positive nodes. Fifteen-year rates were 80%, 37%, and 8%, respectively. Survival and disease-free interval curves for the 3 nodal status groups were significantly different from each other (P less than 0.0001). Curves for three subclasses of the greater than or equal to 4 positive node group (4-6, 7-12, and greater than or equal to 13) were similar in overall survival, but were significantly (P = 0.04) different for disease-free interval, due to a rapid rate of recurrence in the greater than or equal to 13 positive node group. Hazard rates of treatment failure during each successive 3-year period for 9 years following mastectomy for those with 1-3 positive nodes or greater than or equal to 4 positive nodes decreased with time, whereas the rates for those with negative nodes were low and relatively constant throughout follow-up. These findings support the thesis that a significant proportion of negative nodes patients are cured by mastectomy and that a smaller group of node-positive patients have regional disease with a chance of cure by mastectomy.

Prostatic cancer. Treated at a categorical center, 1980-1983.

This report covers the experience from 537 patients with prostatic cancer seen at Roswell Park Memorial Institute (RPMI) from 1980 through 1983. This is a look at experiences in the early 1980s and is a continuation of the series covering the decades of the 1950s, 1960s, and 1970s. Referrals continue to dominate the series (85% of cases) but are now only slightly younger (65 years) than in-house diagnoses (66 years), of which one third were diagnosed at autopsy. Survival rates in this series, although limited in follow-up, were similar at two years to those in the 1970s and in the extensive series collected by the survey of the American College of Surgeons. Multiple primary tumors were observed in 22 per cent of this series, most frequently involving the bladder in addition to the prostate. Treatments continue to involve chemotherapy earlier in the course of disease as part of a succession of therapeutic modalities that include transurethral resection of prostate (TURP) or prostatectomy, lymph node dissection, external irradiation, castration, and hormones.

Focal sparing in fatty infiltration of the liver.

Four cases of focal sparing in otherwise diffuse fatty infiltration of the liver are reported. The characteristic features are described as shown at sonography, computed tomography (CT) and scintigraphy. It is emphasised that, with ultrasound, if the increased echogenicity of the majority of the liver is not appreciated, then the area of normal hepatic parenchyma may be misinterpreted as a pathological hypoechoic lesion.

Prognostic importance of prostate-specific antigen for monitoring patients with stages B2 to D1 prostate cancer.

To evaluate the prognostic value of prostate-specific antigen (PA) for detection of tumor growth after definitive therapy, 602 sera from 70 patients with stages B2 to D1 prostate cancer (26 of whom recurred) were analyzed in a blind study. Using Cox's proportional-hazards model, a highly significant association was found between serially measured PA and disease-free survival time (p = 0.0002). A positive predictive value of 100% was found for some markedly elevated PA levels and confirmed recurrence of disease. In fact, this study suggested that once a PA level of 88 ng/ml was reached, there was an average time of less than 2 months before a recurrence was clinically confirmed. Tumor growth in patients who recurred was indicated by a PA elevation before recurrence in 92% (24 of 26) as opposed to 20% (9 of 44) in disease-free patients. Additionally, in these 24 of 26 patients, levels of PA were elevated 12 months (mean lead time) before a confirmed disease recurrence. In patients who were still disease free, serial PA appeared to increase concurrently with putative tumor growth as shown by the initial surgical stage. Generally, the greater the PA level the more advanced was the stage of disease (B2 to D1). These data suggest that PA may be a useful adjuvant marker for monitoring tumor growth in patients with regionally confined prostate cancer.