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Biomedical subjects

J Coleman

Publications and source records attributed to J Coleman.

At least 19 recordsLinked to original sources
PubMed2006

The impact of computer display height and desk design on 3D posture during information technology work by young adults.

Computer display height and desk design to allow forearm support are two critical design features of workstations for information technology tasks. However there is currently no 3D description of head and neck posture with different computer display heights and no direct comparison to paper based information technology tasks. There is also inconsistent evidence on the effect of forearm support on posture and no evidence on whether these features interact. This study compared the 3D head, neck and upper limb postures of 18 male and 18 female young adults whilst working with different display and desk design conditions. There was no substantial interaction between display height and desk design. Lower display heights increased head and neck flexion with more spinal asymmetry when working with paper. The curved desk, designed to provide forearm support, increased scapula elevation/protraction and shoulder flexion/abduction.

Adolescent↗
PubMed2005

Drift compression of an intense neutralized ion beam.

Longitudinal compression of a velocity-tailored, intense neutralized beam at 300 keV, 25 mA has been demonstrated. The compression takes place in a 1-2 m drift section filled with plasma to provide space-charge neutralization. An induction cell produces a head-to-tail velocity ramp that longitudinally compresses the neutralized beam, enhancing the beam peak current by a factor of 50 and producing a pulse duration of about 3 ns. This measurement has been confirmed independently with two different diagnostic systems.

Journal Article↗
PubMed2005

Loudness predicts prominence: fundamental frequency lends little.

We explored a database covering seven dialects of British and Irish English and three different styles of speech to find acoustic correlates of prominence. We built classifiers, trained the classifiers on human prominence/nonprominence judgments, and then evaluated how well they behaved. The classifiers operate on 452 ms windows centered on syllables, using different acoustic measures. By comparing the performance of classifiers based on different measures, we can learn how prominence is expressed in speech. Contrary to textbooks and common assumption, fundamental frequency (f0) played a minor role in distinguishing prominent syllables from the rest of the utterance. Instead, speakers primarily marked prominence with patterns of loudness and duration. Two other acoustic measures that we examined also played a minor role, comparable to f0. All dialects and speaking styles studied here share a common definition of prominence. The result is robust to differences in labeling practice and the dialect of the labeler.

Acoustic Stimulation↗
PubMed2004

The role of repeat uterine evacuation in the management of persistent gestational trophoblastic disease.

OBJECTIVE: To evaluate the role of second (and third) uterine evacuation in the management of persistent gestational trophoblastic disease (GTD). METHODS: This was an observational study of all cases registered over a 10-year period at the Trophoblastic Disease Centre at Weston Park Hospital, Sheffield. Five hundred and forty-four of 4050 women registered during 1991-2000 underwent a second uterine evacuation following a presumptive diagnosis of persistent GTD. The reason for evacuation, hCG level prior to the procedure, histological appearances of evacuated products and the clinical outcome (in terms of the need for chemotherapy) were determined. RESULTS: After a second uterine evacuation 368 patients (68%) completed the follow-up programme without further evidence of persistent disease or need for chemotherapy. If the diagnosis of persistent GTD was confirmed solely on the basis of elevated hCG levels then 171 of 282 (60%) patients did not require chemotherapy. Chemotherapy was more likely where there was histological evidence of persistent trophoblastic disease and where the urinary hCG was >1500 IU/L at the time of the repeat evacuation. Twenty-eight of 60 patients (46%) undergoing a third evacuation required chemotherapy. CONCLUSION: Second uterine evacuation can be a useful therapeutic option for patients with presumed persistent trophoblastic disease not mandating immediate chemotherapy, particularly where the hCG level is <1500 IU/L. Patients with documented persistent trophoblastic disease on histological examination of the second evacuation sample are more likely to require chemotherapy. Third evacuation is not now recommended.

Adolescent↗
PubMed2002

Beta-galactosidase from a cold-adapted bacterium: purification, characterization and application for lactose hydrolysis.

The enzyme beta-galactosidase was purified from a cold-adapted organism isolated from Antarctica. The organism was identified as a psychotrophic Pseudoalteromonas sp. The enzyme was purified with high yields by a rapid purification scheme involving extraction in an aqueous two-phase system followed by hydrophobic interaction chromatography and ultrafiltration. The beta-galactosidase was optimally active at pH 9 and at 26 degrees C when assayed with o-nitrophenyl-beta-D-galactopyranoside as substrate for 2 min. The enzyme activity was highly sensitive to temperature above 30 degrees C and was undetectable at 40 degrees C. The cations Na+, K+, Mg2+ and Mn2+ activated the enzyme while Ca2+, Hg2+, Cu2+ and Zn2+ inhibited activity. The shelf life of the pure enzyme at 4 degrees C was significantly enhanced in the presence of 0.1% (w/v) polyethyleneimine. The pure beta-galactosidase was also evaluated for lactose hydrolysis. More than 50% lactose hydrolysis was achieved in 8 h in buffer at an enzyme concentration of 1 U/ml, and was increased to 70% in the presence of 0.1% (w/v) polyethyleneimine. The extent of lactose hydrolysis was 40-50% in milk. The enzyme could be immobilized to Sepharose via different chemistries with 60-70% retention of activity. The immobilized enzyme was more stable and its ability to hydrolyze lactose was similar to that of the soluble enzyme.

Acclimatization↗
PubMed2002

Duplex follow-up of aorto-iliac stents.

OBJECTIVES: to assess the feasibility of duplex follow up of aorto-iliac stents. MATERIAL AND METHODS: in addition to standard clinical and ankle/brachial pressure assessment, 75 patients undergoing aorto-iliac stenting for atherosclerotic disease were prospectively followed up with duplex ultrasound at 3 monthly interval up to 1 year and then annually. We attempted to directly visualise the stents wherever possible using standard 2D imaging, standard and power Doppler, as well as spectral Doppler. Patients had an angiogram at 12 months or sooner if a problem was identified on the duplex scan. RESULTS: mean follow up was 14 months (2-36). Complete visualisation of the pelvic arterial tree was achieved in 94% of scans. All patients had at least one satisfactory scan. Duplex detected 30 lesions in 23 patients. Twenty-seven lesions were confirmed at angiography. There were two false positives. Overall sensitivity, specificity and accuracy were 100%, 93% and 96% for patient undergoing angiography. CONCLUSION: duplex ultrasound follow up is feasible in the majority of patients.

Adult↗
PubMed2001

The major transcription initiation site of the p27Kip1 gene is conserved in human and mouse and produces a long 5'-UTR.

BACKGROUND: The cyclin-dependent kinase inhibitor p27Kip1 is essential for proper control of cell cycle progression. The levels of p27Kip1 are regulated by several mechanisms including transcriptional and translational controls. In order to delineate the molecular details of these regulatory mechanisms it is important to identify the transcription initiation site within the p27Kip1 gene, thereby defining the promoter region of the gene and the 5'-untranslated region of the p27Kip1 mRNA. Although several previous studies have attempted to map p27Kip1 transcription start sites, the results vary widely for both the mouse and human genes. In addition, even though the mouse and human p27Kip1 gene sequences are very highly conserved, the reported start sites are notably different. RESULTS: In this report, using a method that identifies capped ends of mRNA molecules together with RNase protection assays, we demonstrate that p27Kip1 transcription is initiated predominantly from a single site which is conserved in the human and mouse genes. Initiation at this site produces a 5'-untranslated region of 472 nucleotides in the human p27Kip1 mRNA and 502 nucleotides in the mouse p27Kip1 mRNA. In addition, several minor transcription start sites were identified for both the mouse and human genes. CONCLUSIONS: These results demonstrate that the major transcription initiation sites in the mouse and human p27Kip1 genes are conserved and that the 5'-UTR of the p27Kip1 mRNA is much longer than generally believed. It will be important to consider these findings when designing experiments to identify elements that are involved in regulating the cellular levels of p27Kip1.

Journal Article↗
PubMed2001

Interferon gamma stabilizes the T helper cell type 1 phenotype.

T helper cell (Th)1-primed CD4 T cells from wild-type donors make little interleukin (IL)-4 when restimulated under Th2 conditions. However, such restimulation of Th1-primed cells from interferon (IFN)-gamma(2/-) or IFN-gamma receptor (IFN-gammaR)(-/-) mice resulted in substantial production of IL-4 and other Th2 cytokines. Adding IFN-gamma to the priming culture markedly diminished the capacity of Th1-primed IFN-gamma(2/-) cells to express IL-4. Even IFN-gamma-producing cells from IFN-gammaR(-/-) mice could acquire IL-4-producing capacity. Thus, IFN-gamma is not required for the development of IFN-gamma-producing capacity, but it plays a critical role in suppressing the IL-4-producing potential of Th1 cells.

Animals↗
PubMed2001

Dual-subtype FIV vaccine protects cats against in vivo swarms of both homologous and heterologous subtype FIV isolates.

OBJECTIVE: To evaluate the immunogenicity and efficacy of an inactivated dual-subtype feline immunodeficiency virus (FIV) vaccine. DESIGN: Specific-pathogen-free cats were immunized with dual-subtype (subtype A FIV(Pet) and subtype D FIV(Shi)) vaccine and challenged with either in vivo- or in vitro-derived FIV inocula. METHODS: Dual-subtype vaccinated, single-subtype vaccinated, and placebo-immunized cats were challenged within vivo-derived heterologous subtype B FIV(Bang) [10--100 50% cat infectious doses (CID(50))], in vivo-derived homologous FIV(Shi)(50 CID(50)), and in vitro- and in vivo-derived homologous FIV(Pet)(20--50 CID(50)). Dual-subtype vaccine immunogenicity and efficacy were evaluated and compared to single-subtype strain vaccines. FIV infection was determined using virus isolation and proviral PCR of peripheral blood mononuclear cells and lymphoid tissues. RESULTS: Four out of five dual-subtype vaccinated cats were protected against low-dose FIV(Bang) (10 CID(50)) and subsequently against in vivo-derived FIV(Pet) (50 CID(50)) challenge, whereas all placebo-immunized cats became infected. Furthermore, dual-subtype vaccine protected two out of five cats against high-dose FIV(Bang) challenge (100 CID(50)) which infected seven out of eight single-subtype vaccinated cats. All dual-subtype vaccinated cats were protected against in vivo-derived FIV(Pet), but only one out of five single-subtype vaccinated cats were protected against in vivo-derived FIV(Pet). Dual-subtype vaccination induced broad-spectrum virus-neutralizing antibodies and FIV-specific interferon-gamma responses along with elevated FIV-specific perforin mRNA levels, suggesting an increase in cytotoxic cell activities. CONCLUSION: Dual-subtype vaccinated cats developed broad-spectrum humoral and cellular immunity which protected cats against in vivo-derived inocula of homologous and heterologous FIV subtypes. Thus, multi-subtype antigen vaccines may be an effective strategy against AIDS viruses.

Animals↗
PubMed2001

Setting system suitability criteria for detectability in high-performance liquid chromatography methods using signal-to-noise ratio statistical tolerance intervals.

For pharmaceutical products, one approach developed to assure that different chromatographic systems are capable of generating valid results is the system suitability test. Typically, a system suitability test involves numerical limits for predefined chromatographic parameters such as theoretical plates, tailing factor, injector reproducibility, etc. An estimation of the ratio of signal compared to baseline is one way to measure system performance, according to a valid method, independent of the instrument. However, since this comparison relates the height of the signal to the height of the noise, it is difficult to relate to the peak area measurements that are typically used for quantification of samples. Additionally, although peak area and peak height may be highly correlated over a wide region, peak area at very low concentrations can be more sensitive to all components of noise due to peak shape. To establish a system suitability criterion, one can use the ratio of the area signal to the baseline noise for replicate injections for samples prepared at concentration equal to the limit of quantitation during the validation studies. A lower limit for this ratio can be derived using statistical tolerance intervals. This lower limit can be applied as a system suitability criterion to measure that any system is performing adequately for measuring low level components in the sample for all future use of the method.

Chromatography, High Pressure Liquid↗
PubMed2001

Novel allogeneic granulocyte-macrophage colony-stimulating factor-secreting tumor vaccine for pancreatic cancer: a phase I trial of safety and immune activation.

PURPOSE: Allogeneic granulocyte-macrophage colony-stimulating factor (GM-CSF)-secreting tumor vaccines can cure established tumors in the mouse, but their efficacy against human tumors is uncertain. We have developed a novel GM-CSF-secreting pancreatic tumor vaccine. To determine its safety and ability to induce antitumor immune responses, we conducted a phase I trial in patients with surgically resected adenocarcinoma of the pancreas. PATIENTS AND METHODS: Fourteen patients with stage 1, 2, or 3 pancreatic adenocarcinoma were enrolled. Eight weeks after pancreaticoduodenectomy, three patients received 1 x 10(7) vaccine cells, three patients received 5 x 10(7) vaccine cells, three patients received 10 x 10(7) vaccine cells, and five patients received 50 x 10(7) vaccine cells. Twelve of 14 patients then went on to receive a 6-month course of adjuvant radiation and chemotherapy. One month after completing adjuvant treatment, six patients still in remission received up to three additional monthly vaccinations with the same vaccine dose that they had received originally. RESULTS: No dose-limiting toxicities were encountered. Vaccination induced increased delayed-type hypersensitivity (DTH) responses to autologous tumor cells in three patients who had received >or= 10 x 10(7) vaccine cells. These three patients also seemed to have had an increased disease-free survival time, remaining disease-free at least 25 months after diagnosis. CONCLUSION: Allogeneic GM-CSF-secreting tumor vaccines are safe in patients with pancreatic adenocarcinoma. This vaccine approach seems to induce dose-dependent systemic antitumor immunity as measured by increased postvaccination DTH responses against autologous tumors. Further clinical evaluation of this approach in patients with pancreatic cancer is warranted.

Adenocarcinoma↗
PubMed2000

Heavy metals in wild rice from northern Wisconsin.

Wild rice grain samples from various parts of the world have been found to have elevated concentrations of heavy metals, raising concern for potential effects on human health. It was hypothesized that wild rice from north-central Wisconsin could potentially have elevated concentrations of some heavy metals because of possible exposure to these elements from the atmosphere or from water and sediments. In addition, no studies of heavy metals in wild rice from Wisconsin had been performed, and a baseline study was needed for future comparisons. Wild rice plants were collected from four areas in Bayfield, Forest, Langlade, Oneida, Sawyer and Wood Counties in September, 1997 and 1998 and divided into four plant parts for elemental analyses: roots, stems, leaves and seeds. A total of 194 samples from 51 plants were analyzed across the localities, with an average of 49 samples per part depending on the element. Samples were cleaned of soil, wet digested, and analyzed by ICP for Ag, As, Cd, Cr, Cu, Hg, Mg, Pb, Se and Zn. Roots contained the highest concentrations of Ag, As, Cd, Cr, Hg, Pb, and Se. Copper was highest in both roots and seeds, while Zn was highest just in seeds. Magnesium was highest in leaves. Seed baseline ranges for the 10 elements were established using the 95% confidence intervals of the medians. Wild rice plants from northern Wisconsin had normal levels of the nutritional elements Cu, Mg and Zn in the seeds. Silver, Cd, Hg, Cr, and Se were very low in concentration or within normal limits for food plants. Arsenic and Pb, however, were elevated and could pose a problem for human health. The pathway for As, Hg and Pb to the plants could be atmospheric.

Air Pollution↗
PubMed2000

High levels of sequence polymorphism and linkage disequilibrium at the telomere of 12q: implications for telomere biology and human evolution.

The human Xp/Yp telomere-junction region exhibits high levels of sequence polymorphism and linkage disequilibrium. To determine whether this is a general feature of human telomeres, we have undertaken sequence analysis at the 12q telomere and have extended the analysis at Xp/Yp. A total of 22 single-nucleotide polymorphisms (SNPs) and one 30-bp duplication were detected in the 1,870 bp adjacent to the 12q telomere. Twenty polymorphic positions were in almost complete linkage disequilibrium, creating three common diverged haplotypes accounting for 80% of 12q telomeres in the white population. A further 6% of 12q telomeres contained a 1,439-bp deletion in the DNA flanking the telomere. The remaining 13% of 12q telomeres did not amplify with the primers used (nulls). The distribution of telomere (TTAGGG) and variant repeats within 12q telomeres was hypervariable, but alleles with similar distribution patterns were associated with the same haplotype in the telomere-adjacent DNA. These data suggest that 12q telomeres, like Xp/Yp telomeres, exhibit low levels of homologous recombination and evolve along haploid lineages. In contrast, high levels of homologous recombination occur in the adjacent proterminal regions of human chromosomes. This suggests that there is a localized telomere-mediated suppression of recombination. In addition, the genetic characteristics of these regions may provide a source of deep lineages for the study of early human evolution, unaffected by both natural selection and recombination. To explain the presence of a few diverged haplotypes adjacent to the Xp/Yp and 12q telomeres, we propose a model that involves the hybridization of two archaic hominoid lineages ultimately giving rise to modern Homo sapiens.

Base Sequence↗
PubMed2000

Quality of life and outcomes after pancreaticoduodenectomy.

OBJECTIVE: To assess the quality of life (QOL) and functional outcome of patients after pancreaticoduodenectomy. SUMMARY BACKGROUND DATA: Pancreaticoduodenectomy is gaining acceptance and is being performed in increasing numbers for various malignant and benign diseases of the pancreas and periampullary region. There is a general impression that pancreaticoduodenectomy can severely impair QOL and alter normal activities. Only a few small studies have evaluated QOL after pancreaticoduodenectomy. METHODS: A standard QOL questionnaire was sent to 323 patients surviving pancreaticoduodenectomy who had undergone surgery at The Johns Hopkins Hospital between 1981 and 1997. Thirty items on a visual analog scale were categorized into three domains: physical (15 items), psychological (10 items), and social (5 items). Scores are reported as a percentile, with 100% being the highest possible score. The same QOL questionnaire was also sent to laparoscopic cholecystectomy patients and healthy controls. A separate component of the questionnaire asked about functional outcomes and disabilities. RESULTS: Overall QOL scores for the 192 responding pancreaticoduodenectomy patients in the three domains (physical, psychological, social) were 78%, 79%, and 81%, respectively. These QOL scores were comparable to those of the 37 laparoscopic cholecystectomy patients and the 31 healthy controls. The pancreaticoduodenectomy patients were subgrouped into chronic pancreatitis, other benign disease, pancreatic adenocarcinoma, and other cancers. Patients who underwent resection for chronic pancreatitis and pancreatic adenocarcinoma had significantly lower QOL scores in the physical and psychological domains compared with the laparoscopic cholecystectomy patients and the healthy controls. Common problems after pancreaticoduodenectomy were weight loss, abdominal pain, fatigue, foul stools, and diabetes. CONCLUSIONS: This is the largest single-institution experience assessing QOL after pancreaticoduodenectomy. These data demonstrate that as a group, patients who survive pancreaticoduodenectomy have near-normal QOL scores. Many patients report weight loss and symptoms consistent with pancreatic exocrine and endocrine insufficiency. Most patients have QOL scores comparable to those of control patients and can function independently in daily activities.

Adenocarcinoma↗