At the front of the NVQ.
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Certification↗
Biomedical subjects
C McMahon
Publications and source records attributed to C McMahon.
Possible evidence for genomic imprinting in childhood acute myeloblastic leukaemia associated with monosomy for chromosome 7.
Monosomy or deletion of chromosome 7 is a frequent finding in both de novo and secondary acute myeloid leukaemia (AML) and myelodysplastic syndromes (MDS). Based on analysis of deletions of chromosome 7 in such patients, it has been suggested that there is a critical region of the chromosome lying within bands q21-q31. We have examined bone marrow and peripheral blood samples from 10 patients with MDS, AML and biphenotypic acute leukaemia who had monosomy for or rearrangement of chromosome 7, seeking evidence of non-random allele loss that might suggest the presence of imprinted genes on the chromosome. Bone marrow cells from one patient with the infant monosomy 7 syndrome had loss of maternal alleles as did two patients with biphenotypic leukaemia. Five out of five patients with MDS and both patients with de novo AML had loss of paternal alleles. One of the latter patients had a del(7) (q31q36) rather than monosomy 7. These findings suggest that imprinting of a gene(s) on chromosome 7, within the bands q31-q36, may be of importance in MDS and AML. Despite the reported increased incidence of AML amongst relatives of patients with cystic fibrosis (CF) the gene for which lies in chromosome region 7q31, none of the patients nor parents studied here appeared to be carriers of the most common gene mutation seen in patients with CF, the delta F508.
Acute Disease↗
The effect of a city-wide mass media campaign on the public awareness of diabetes.
The aim of this study was to determine whether a mass media campaign about diabetes would increase public awareness and knowledge of diabetes, leading to an increased rate of detection of previously undiagnosed cases. A telephone questionnaire was administered to two groups of randomly selected members of the public before and after a 1-week mass media campaign. Cases of newly diagnosed diabetes were monitored by general practitioners. The median knowledge score rose from 5 (range 0-10) before the campaign to 6 (0-10) afterwards, p < 0.001. The knowledge score for a control group, questioned post-campaign only, was also 6 (1-10). The increase in the median knowledge score was mainly as a result of more people being able to define diabetes and give two presenting symptoms. This increased awareness did not however result in an increase in detection of new cases.
Adolescent↗
Gadobenate dimeglumine--a new contrast agent for MR imaging: preliminary evaluation in healthy volunteers.
Gadobenate dimeglumine (formerly known as Gd-BOPTA) is a recently developed paramagnetic contrast agent that undergoes biliary as well as renal excretion. It may, therefore, be useful in MR imaging of the liver. Its safety, tolerance, and usefulness in visualizing hepatobiliary structures were studied in eight healthy subjects. Axial abdominal images were obtained with T1-weighted spin-echo and gradient-echo sequences at 1.5 T before and after IV administration of gadobenate dimeglumine in doses of 0.005, 0.05, 0.1, and 0.2 mmol/kg body weight. Two subjects received each dose. Administration of 0.1 mmol/kg resulted in a maximum liver enhancement of 149% on the gradient-echo sequence and of 90% on the T1-weighted spin-echo sequence 60 min after injection. The contrast enhancement of the liver remained virtually constant for 2 hr. The signal-to-noise ratio of the biliary tract increased from 38 to 121 after 2 hr on gradient-echo images. In addition, there was significant contrast enhancement of the kidneys. Optimal visualization of the liver parenchyma was achieved with doses of 0.05 and 0.1 mmol gadobenate dimeglumine/kg. Mild to moderate side effects such as nausea and retching, a sense of warmth at the infusion site, and transient pruritus lasting 1 min were reported by three (38%) of the subjects. The initial results of the first application of gadobenate dimeglumine in humans are encouraging because the contrast agent appears to be reasonably well tolerated at the doses appropriate for hepatobiliary imaging. Further clinical studies of this contrast agent are warranted to assess its effect on liver lesion conspicuity and the frequency with which side effects occur.
Acetates↗
Primary structure of a human arginine-rich nuclear protein that colocalizes with spliceosome components.
The cDNA for a 54-kDa nuclear protein (p54) has been cloned from a human hepatoma expression library. Contained within p54 is an arginine/serine-rich region similar to segments of several proteins that participate in pre-mRNA splicing including the 70-kDa component of U1 small nuclear and "suppressor-of-white-apricot" proteins. The arginine/serine-rich region is dominated by a series of 8-amino acid imperfect repetitive motifs (consensus sequence, Arg-Arg-Ser-Arg-Ser-Arg-Ser-Arg). Antibodies raised against synthetic peptides of p54 react with an approximately 70-kDa protein on immunoblots of HeLa cell and rat liver nuclear proteins. This apparent discrepancy in mass is also observed when p54 mRNA is translated in vitro. Indirect immunofluorescence studies in HeLa cells show that p54 is distributed throughout the nucleus in a speckled pattern, with an additional diffuse labeling of the nucleus excluding the nucleoli. Double immunofluorescence experiments indicate that these punctate regions are coincident with the speckles seen in cells stained with antibodies against several constituents of the pre-mRNA splicing machinery. Sedimentation analysis of HeLa cell extracts on sucrose gradients showed that p54 migrates at 4-6 S, indicating that the protein is not a tightly associated component of snRNPs. Although the function of p54 is not yet known, our structure and immunolocalization data suggest that this protein may have a role in pre-mRNA processing.
Amino Acid Sequence↗
Attitudes and intentions of UK general practitioners to diabetes care at the time of implementation of their new contract.
Prior to the introduction of their new contract, the intentions of general practitioners in Leeds (UK) towards diabetes care were assessed. All general practices in one Health District (n = 74) were contacted. Assessment was made of 46 (62%), while 28 expressed lack of interest. Of the 46 assessed, 2 (4%) were single-handed, and 44 (96%) were group practices, and list size was 700-15,500. Practice nurses were employed in 44 (96%) practices. There were 35 (76%) practices which expressed an interest in starting a diabetic clinic, while 6 (13%) had established a clinic. Practice facilities necessary to establish and run a clinic were surveyed. Those available were: register of diabetic patients in 12 (26%) (six of which were incomplete); blood sampling facilities in 45 (98%); blood glucose reagent strips in 45 (98%); glucose meters in 21 (46%) (but five with inappropriate test strips). All practices could check urine, blood pressure, and fundi (dark room available in 40 (87%) practices). Access to dietetic and chiropody services on the premises was available in 19 (41%) and 17 (37%) practices, respectively. Some expertise in diabetes was claimed by only 10 (22%) doctors. Staff at all practices desired further training in diabetes. In conclusion, despite the interest of most practices in starting a diabetic clinic, access to dietetic and chiropody services was inadequate. Expertise was generally lacking, but enthusiasm and desire for training were strong.
Attitude to Health↗
Applications of a sequential alternating treatment design.
We propose the use of a combined version of the alternating treatments and multiple baseline designs in situations in which a traditional baseline (no treatment) condition either does not provide an adequate contrast condition or is not feasible or practical due to clinical constraints. We refer to this design as a sequential alternating treatments design because two treatments are initially implemented in a random or counterbalanced fashion and are followed by a sequential change in one or both treatments across settings, subjects, or tasks. The effects of the independent variables are assessed first by analyzing the two series of data points representing the different treatments (relative effects) and then by assessing changes in one or both series, as application of the alternative treatment is introduced sequentially. The sequential application of treatment provides an analysis of control in the same manner as the multiple baseline design; the initial alternating treatments phase provides a contrast condition in much the same manner as a baseline condition. Applications of this design to the assessment of peer training and self-injurious behavior are described.
Behavior Therapy↗
DNA content of rectal scrapings from individuals at low and high risk for the development of colorectal cancer. A feasibility study.
Scrapings of superficial rectal mucosa were collected from 31 patients with colorectal carcinoma, 66 patients with sporadic adenoma, and 53 control subjects with no personal or family history of colorectal cancer. The DNA ploidy level and proliferative patterns of each specimen were analyzed by flow cytometry (FCM). A GMS index, calculated as the ratio of G2 + M:S, was found to be significantly lower in control subjects than in any of the high-risk groups studied. Aneuploidy was more prevalent in rectal scrapings from cancer patients and adenoma patients than in those from control subjects. Aneuploid cell populations were detected in apparently normal rectal scrapings from two control subjects. Some high-risk individuals (i.e., cancer patients and patients with adenomas and a family history of cancer) exhibited higher proportions of tetraploid (designated G2/M) cells and a higher G2/M:S phase ratio than control subjects. The results accumulated thus far show that the rectal scraping procedure is safe and easy to perform. Our limited findings give hope that the DNA content analysis of cells obtained by rectal scraping may eventually prove useful in mass screening for colorectal cancer risk. However, definitive evaluation will require further refinement and elaboration of analytic technique and testing on more patients at various levels of predetermined risk.
Adenoma↗
An evaluation of labeling-then-doing with moderately handicapped persons: acquisition and generalization with complex tasks.
We conducted two experiments in which moderately mentally retarded persons were trained first to label and then to enter characters into a computer, calculator, or checkbook (label-then-do) within a multiple baseline design. In Experiment 1, 5 young adults were trained to enter statistical programs into computers in an office setting. Following training, all subjects' use of verbal labels and key-entry skills generalized across tasks (programs) and settings (offices and computer terminals). In Experiment 2, 3 junior high school students were trained with self-labeling procedures to complete a key-entry task and to balance a checkbook. The performance of all students generalized across tasks and settings, and the use of labels generalized for 2 of the students. Results are discussed relative to mediated generalization and to establishing verbal control over behavior.
Adolescent↗
IgA kappa multiple myeloma and lymphadenopathy syndrome associated with AIDS virus infection.
A 29 year old homosexual male presented with acute renal failure caused by acute myeloma. Subsequent investigation demonstrated antibody to the AIDS-associated virus human T-cell lymphotropic virus III, (HTLV-III/LAV/ARV). The association between lymphadenopathy syndrome and multiple myeloma is discussed.
AIDS-Related Complex↗
Periosteal chondroma with atypical behavior in a 9-year-old black female: case report.
Periosteal chondroma is an uncommon benign cartilaginous tumor of bone reported most often in children and young adults but is as of yet unreported in a black child. This is a case of periosteal chondroma in a 9-year-old black female with unusual findings of short duration of symptoms; large size; suspicious x-ray appearance and; aggressive behavior. The lesion was histologically benign and has not recurred six years post curettage.
Bone Neoplasms↗
Collection calls: train your receptionist not to be timid.
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Accounting↗
Potential artifacts in scanning electron microscopy of the trabecular meshwork in glaucoma.
We examined the trabecular meshwork surface by scanning electron microscopy to investigate possible artifacts appearing during collection and preparation of trabeculectomy specimens. As controls, trabecular tissue samples from normal and glaucomatous patients were dissected from whole eyes obtained at enucleation or at autopsy. Our results suggest that the major contaminants are released during decompression of the globe at trabeculectomy; these consist of an amorphous substance, a fibrillar material, and, occasionally, red blood cells. Small tissue samples may also abe contaminated by the conducting adhesive used to fasten them to metal stubs. This silver paint may coat the surface of the meshwork and appear to be a smooth substance blocking the outflow of aqueous humor. We were unable to confirm the finding reported by others that an amorphous blocking material is present in the trabecular interstices in patients with open-angle glaucoma.
Adhesives↗
Comparison of A.N.A. and N.L.N.; history and function.
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American Nurses' Association↗
Mn-DPDP enhancement patterns of hepatocellular lesions on MR images.
The recently developed paramagnetic hepatobiliary contrast agent manganese dipyridoxyl diphosphate (DPDP) was evaluated in eight patients. Pathologic diagnoses included five hepatocellular carcinomas, two cirrhoses, and one focal nodular hyperplasia. T1-weighted spin-echo and gradient-echo images were obtained after intravenous injection of 5 or 10 mumol/kg Mn-DPDP; these were compared with unenhanced T1-weighted spin-echo and gradient-echo images and T2-weighted spin-echo images. In all patients with lesions of hepatocellular origin, focal areas of increased enhancement were seen in the lesions after administration of Mn-DPDP. In the cirrhotic livers, these areas corresponded to foci of hepatic regeneration. In all patients, the signal-to-noise ratio in normal liver tissue increased significantly after injection of Mn-DPDP. Signal intensity in the six primary liver tumors was further increased, so that they appeared hyperintense relative to surrounding liver tissue on all T1-weighted images. Conspicuity and demarcation of all lesions were improved on Mn-DPDP-enhanced images.
Adult↗
Three-dimensional MR reconstruction images of skull base tumors.
Forty-eight patients with skull base tumors were evaluated prospectively with T1-weighted spin-echo two-dimensional (2D) magnetic resonance (MR) sequences, a three-dimensional (3D) MR TurboFLASH (fast low-angle shot) sequence, and a 3D reconstruction window technique. All patients underwent surgery with histopathologic correlation, and the three MR imaging techniques were compared to assess representation of tumor margins and the topographic relationship of tumor to surrounding tissue and adjacent vasculature. The best results were obtained with standard 2D spin-echo sequences after administration of the paramagnetic contrast agent gadopentetate dimeglumine. The 2D MR sequences gave the highest contrast-to-noise ratios, with decreasing values for 3D sequences and 3D reconstructions, respectively. Nevertheless, 3D MR imaging, by virtue of its good representation of adjacent structures, aided surgeons in planning surgical intervention. This study presents the technical features of 3D imaging of the skull base, the choices involved in its implementation, and its potential clinical applications.
Brain Neoplasms↗
The increasing prevalence of childhood sickle-cell disease in Ireland.
BACKGROUND: Ireland has been relatively free of sickle-cell disease (SCD) and a care policy for the disease has not been established. AIM: To determine the prevalence of childhood SCD in Ireland and to predict requirements for a comprehensive care and assessment programme. METHODS: We retrospectively analysed the data of children with SCD presenting with sickle-cell crisis to one institution from January 1999 to April 2001. We also determined the nature and severity of the presenting haemoglobinopathy phenotype. RESULTS: Ninety-two patients with haemoglobinopathy have been registered with the Paediatric Haematology Service. The majority are from Nigeria with a smaller number from Angola and the Congo. Sixty have sickle-cell trait, 23 SCD, four haemoglobin SC disease and two haemoglobin E (HbE). There have been 32 sickle-cell crises. The majority were haemolytic or splenic sequestration events with a smaller number of aplastic and vaso-occlusive events and one osteomyelitis. CONCLUSION: The increasing number of children presenting with SCD as a result of the increasing refugee numbers requires a comprehensive care approach similar to that required for paediatric haemophilia to ensure optimum care.
Adolescent↗
Growth of an atrial septal defect: missing the window for transcatheter closure.
We describe a patient diagnosed with a small atrial septal defect (3-4 mm) that had grown to 24 mm in diameter over a six-year period. Timing of transcatheter intervention may be affected by growth of the atrial septal defect and this reports the first case of an atrial septal defect outgrowing the possibility of transcatheter closure.
Cardiac Catheterization↗