PubMed Health⌕ Search

Biomedical subjects

P Barnes

Publications and source records attributed to P Barnes.

At least 19 recordsLinked to original sources
PubMed2000

The use of a task-based exposure assessment model (T-BEAM) for assessment of metal fume exposures during welding and thermal cutting.

Elevated disease rates have been documented among construction workers for cancer, pneumonoconiosis, asbestosis, and silicosis. However, methodologies for exposure assessment in construction are not well described in the U.S. literature. Working through a cooperative agreement with the National Institute for Occupational Safety and Health (NIOSH), the Center to Protect Workers' Rights--a research arm of the Building and Construction Trades Department, AFL-CIO--has developed and used a "Task-Based Exposure Assessment Model (T-BEAM)" for construction. The characteristic elements of T-BEAM are: (1) an emphasis on the identification, implementation, and evaluation of engineering and work practice controls; and (2) use of experienced, specially trained construction workers (construction safety and health specialists) in the exposure assessment process. A task-based approach was used because tasks, or specialized skills, form the single greatest thread of continuity in the dynamic environment of construction. Workers in the construction industry come from several crafts and are typically employed by a large number of contractors throughout their career. Project types (e.g., residential or industrial rehabilitation) are also highly variable and present unique health risks. Finally, because construction involves building, renovating, or dismantling physical surroundings, the work site is constantly changing. Between 1995 and 1996, T-BEAM was applied to the collection of approximately 200 personal exposure measurements associated with "hot work tasks"--welding and thermal cutting. Data were collected with the assistance of specially trained, journeyman ironworkers, pipe fitters, and boilermakers on nine construction sites located throughout the United States. Portable local exhaust ventilation was provided to participating contractors with the intent of measuring its impact on exposure. Results indicate that data collected in a standardized, systematic fashion from multiple work sites can be used to characterize exposures among sampled trades. Comparison of results to American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLVs) demonstrate a significant health hazard among sampled trades posed by welding and thermal cutting fume, manganese, nickel, and chromium VI. Direct estimates of the probability of exceeding the ACGIH TLV for respirable particulate suggests that boilermakers (100%) and ironworkers (71%) are at greatest risk. Other task variables evaluated with respect to exposure include task, whether work was performed indoors or outdoors, intermittency of work, and use of ventilation. Use of local or mechanical ventilation reduced mean exposures to fumes significantly.

Adult↗
PubMed2000

Clinical evaluation of a new, point-of-care hemocytometer.

OBJECTIVE: This study was designed to compare results obtained with a new point-of-care hemocytometer with those of two established (point-of-care and laboratory-based) instruments. DESIGN: To compare CBC values between established laboratory-based and point-of-care instruments, measurements were performed on routinely obtained blood specimens for CBC analysis in our institutional laboratory (phase I) and on specimens from cardiac surgical patients before initiation of cardiopulmonary bypass and after discontinuation of cardiopulmonary bypass in phase II. SETTING: Surgical and hospitalized patients at a tertiary care center. PATIENTS: Measurements were obtained by using blood specimens obtained from 141 hospitalized patients from different services (phase I) or from a consecutive series of 204 patients undergoing cardiac operations (phase II). MEASUREMENTS AND MAIN RESULTS: Hemoglobin (HGB), platelet count (PLT), red blood cell count, and white blood cell count (WBC) were measured with two on-site and one laboratory-based instruments. Hematocrit (HCT) was calculated by using measured variables. Linear regression demonstrated good correlations between Ichor and T540 HGB (r2 = .95), HCT (r2 = .95), PLT (r2 = .94), and WBC (r2 = .95) results (n = 408); similarly, good correlations were observed with Coulter STKS HGB (r2 = .92), HCT (r2 = .91), and PLT (r2 = .94) results (n = 141). The relationship between Ichor and Coulter STKS WBC (r2 = .27) was poor; however, when two Ichor-derived outlier values (>50) were excluded, the relationship was very good (r2 = .99). Bias analysis (mean +/- SD) demonstrated similar results between Ichor and T540 HGB (0.003+/-0.5), HCT (-0.21+/-1.5), WBC (0.79+/-1.3), and PLT values (-9.2+/-16.6) as well as STKS HGB (-0.08+/-0.7), HCT (-0.69+/-2.3), WBC (-0.62+/-5.8), and PLT values (-10.2+/-21.4). CONCLUSIONS: The Ichor hemocytometer provides accurate hematologic results that can facilitate rapid quantitative assessment of CBC variables and thus may be clinically useful, especially in critically ill patients.

Bias↗
PubMed2000

The nurse clinician in surgical services.

Nurses are able to undertake some of the tasks previously performed by junior doctors. The nurse clinician role allows nurses to apply their nursing skills within a medically oriented framework. Managerial support and ongoing training are needed to ensure the continued success of this role.

Education, Nursing, Graduate↗
PubMed1999

Quality-of-life outcomes for men treated with cryosurgery for localized prostate carcinoma.

BACKGROUND: Cryosurgery was introduced as an alternative to radiotherapy or radical prostatectomy in the mid-1960s. Although it met the primary objective of achieving local control, it was largely abandoned due to a high incidence of complications. Technologic advances in the areas of imaging and urethral warming have renewed interest in this treatment methodology. The aim of the current study was to determine the quality of life of men enrolled in a Phase II clinical trial of cryosurgery for the treatment of localized prostate carcinoma. METHODS: Men were administered the Functional Assessment of Cancer Treatment-Prostate (FACT-P) prior to their treatment and at 6 weeks and 3, 6, and 12 months posttreatment. RESULTS: By 12 months after cryosurgery, most of the FACT-P subscales had returned to pretreatment levels, following a decline in well-being immediately after cryosurgery. There were two exceptions to this general trend: At 12 months, impairments in social/family well-being and sexual function still remained. The average time to return to work after therapy was 3 weeks. Stay in hospital after treatment was limited to 1 day for 94% of the participants. Compared with men who received the standard treatments of radical prostatectomy and radical radiotherapy, men treated with cryosurgery appeared to have a similar quality of life, with perhaps the exception of decreased sexual function. CONCLUSIONS: The quality-of-life outcomes of this study support the current renewed interest in cryosurgery. The severe impairments reported in other studies were not seen in this sample. In fact, it appeared that all aspects of the participants' well-being had returned to pretreatment levels by 12 months, with the exception of sexual function.

Aged↗
PubMed1999

Reply

Explore the source record for details and available documents.

Journal Article↗
PubMed1999

Leptomeningeal melanoma and Creutzfeldt-Jakob disease in a patient with chronic lymphocytic leukaemia.

A 78-year-old woman with known chronic lymphocytic leukaemia (CLL) was admitted to a psychiatric unit because of rapidly declining cognitive function. Clinical examination also revealed cerebellar signs and she later became akinetic and mute. She deteriorated and died of bronchopneumonia. The histology from the post-mortem confirmed the presence of CLL in the lymph nodes and she was also found to have diffuse leptomeningeal melanoma. In addition, there was extensive prion protein deposition in the cerebral cortex, but without significant spongiosis. The astrocytosis that was present appeared superficial only. Furthermore, prion protein appeared to be co-expressed with betaA4 in the form of plaques. The patient therefore had evidence of sporadic Creutzfeldt-Jakob disease (CJD) in addition to meningeal melanoma and CLL. This case further illustrates the importance of employing prion protein immunohistochemistry in suspected cases of CJD, especially where the histology is atypical.

Aged↗
PubMed1999

Helical CT angiography: dynamic cerebrovascular imaging in children.

BACKGROUND AND PURPOSE: The purpose of this study was to assess the feasibility of helical CT cerebrovascular imaging (CTCVI) in children and to make initial comparisons with MR angiography and digital subtraction angiography (DSA). METHODS: Twenty-six patients, ages 3 days to 17 years, were examined with CTCVI. Patients were scanned with 1-mm collimation and 2:1 pitch 30 seconds after the initiation of a hand injection of 2 mL/kg nonionic contrast material (320 mg/dL iodine) with a maximum dose that did not exceed 80 mL (minimum volume, 5 mL in a 2.5-kg infant). Reconstructions were done using maximum intensity projection and integral rendering algorithms. Four patients had CTCVI, MR angiography, and DSA (42 vessels studied) and nine patients had CTCVI and DSA (136 vessels studied). Scores of 1 (not present) to 3 (present in continuity to the first bifurcation) were assigned independently by two radiologists to 32 vessels in each correlated case for each available technique. RESULTS: There were no technical failures. CTCVI depicted 18 thrombosed dural sinuses, three vascular malformations, one intracranial aneurysm, and four tumors. Ninety-five percent of the vessels seen with DSA were also seen with CTCVI. CTCVI identified all vessels seen on MR angiography. CONCLUSION: Helical CTCVI is an effective technique for assessing the intracranial circulation in children. In this initial comparison, CTCVI showed more vascular detail than MR angiography, and had fewer technical limitations.

Adolescent↗
PubMed1999

Quantitation of nucleolar organizer regions by image analysis in glottic squamous cell carcinoma.

OBJECTIVE: To apply computer image analysis as a quantitative method for analyzing interphase nucleolar organizer regions (NORs) to determine whether this proliferative marker provides useful prognostic information in glottic squamous cell carcinoma. DESIGN: Retrospective testing of biopsy samples and resected tissue. SETTING: Nova Scotia Regional Cancer Centre and regional hospitals in Nova Scotia and Prince Edward Island, Canada. PATIENTS: Patients with primary glottic cancer presenting to the cancer centre between 1984 and 1991. INTERVENTIONS: Semiautomated image analysis was used to measure the nuclear area and the NOR area in formalin-fixed paraffin-embedded tumour samples. OUTCOME MEASURES: Mean nuclear area, mean NOR area and NOR percentage of nuclear area, calculated as the mean NOR area divided by the mean nuclear area, expressed as a percentage. RESULTS: Of 154 cases, 90 samples were received; however, 8 paraffin blocks were exhausted and 29 samples stained poorly due to extent of fixation. Analysis of the remaining 53 cases, all primary squamous cell carcinomas, showed no statistically significant association between, on one hand, mean NOR area or NOR percentage of nuclear area and, on the other hand, tumour grade, tumour stage, tumour recurrence or disease-related death. CONCLUSIONS: This study does not demonstrate a prognostic value of NOR measurement as a proliferative marker in primary glottic squamous carcinoma. However, given the small number of cases in this study, further research should be conducted using a larger number of cases from one centre and comparing NOR measures with other markers of cell proliferation.

Biomarkers, Tumor↗
PubMed1998

Altitude training at 2690m does not increase total haemoglobin mass or sea level VO2max in world champion track cyclists.

Haemoglobin mass (Hb mass), maximum oxygen consumption (VO2max), simulated 4000 m individual pursuit cycling performance (IP4000), and haematological markers of red blood cell (RBC) turnover were measured in 8 male cyclists before and after (A) 31 d of altitude training at 2690 m. The dependent variables were measured serially after altitude on d A3-4, A8-9 and A20-21. There was no significant change in Hb mass over the course of the study and VO2max at d A9 was significantly lower than the baseline value (79.3 +/- 0.7 versus 81.4 +/- 0.6 ml x kg(-1) x min(-1), respectively). No increase in Hb mass or VO2max was probably due to initial values being close to the natural physiological limit with little scope for further change. When the IP4000 was analysed as a function of the best score on any of the three test days after altitude training there was a 4% improvement that was not reflected in a corresponding change in VO2max or Hb mass. RBC creatine concentration was significantly reduced after altitude training, suggesting a decrease in the average age of the RBC population. However, measurement of reticulocyte number and serum concentrations of erythropoietin, haptoglobin and bilirubin before and after altitude provided no evidence of increased RBC turnover. The data suggest that for these elite cyclists any benefit of altitude training was not from changes in VO2max or Hb mass, although this does not exclude the possibility of improved anaerobic capacity.

Adult↗
PubMed1998

Treated bacterial endocarditis as a histological mimic of fungal infection.

Histological assessment of cardiac valve tissue contributes to the diagnosis of infective endocarditis and is of particular importance in cases in which no organism is cultured. Antibiotic treatment of bacterial endocarditis may lead to abnormal bacterial morphology and staining characteristics. Although in many cases the presence of some residual bacteria of normal appearance makes the diagnosis straightforward, in some only abnormal bacteria may be seen. Unless the appearances of these are interpreted with caution, the presence of larger spherical organisms with the staining properties of a yeast may lead to an erroneous diagnosis of fungal infection.

Anti-Bacterial Agents↗
PubMed1997

Development and validation of a computerized screening test for personality disorders in DSM-III-R.

The available self-report instruments designed to measure personality disorder (PD) are time-consuming to administer and/or score and can be impractical for routine clinical use. There is a need for a computerized method of personality assessment based on contemporary systems of classification. A computerized DSM-III-R-based questionnaire was developed and validated against the structured clinical interview for DSM-III-R Axis-II disorders on a sample of 60 subjects. The computerized test showed moderate validity as a diagnostic instrument (mean kappa coefficient = 0.47). With adjusted cut-off scores it was valid as a screening instrument (mean sensitivity = 0.87). Antisocial, borderline and avoidant PD scores were strongly correlated across measures and not subject to significant observer bias.

Adult↗
PubMed1997

Prospective study of postoperative magnetic resonance imaging in patients with malignant gliomas.

PURPOSE: We studied the natural history of postoperative enhancement on magnetic resonance (MR) scans in patients with malignant glioma to determine the following: (1) when a postoperative MR scan most accurately shows residual enhancing tumor; and (2) whether repeated doses of the contrast agent gadopentetate dimeglumine (Gd-DTPA) were well tolerated. PATIENTS AND METHODS: Seventeen patients with malignant glioma underwent tumor resection; four (24%) had nonenhancing tumors preoperatively. Serial MR scans were performed on postoperative days 1, 3, 5, 7, 14, and 21 and were analyzed qualitatively and quantitatively. The evolution of enhancement and subacute hemorrhage were described and measured. A uniform schedule of postoperative dexamethasone administration was used in all but four patients (24%) (each required higher doses to maintain neurologic function). RESULTS: Nontumoral, marginal (i.e., postsurgical) enhancement, potentially mimicking residual tumor, developed in eight patients (53%), including tumors that were nonenhancing preoperatively, and was maximal from days 5 to 14. Tumor enhancement was optimally visualized on postoperative days 3 to 5. Nine of 10 patients (90%) with gross residual enhancing tumor showed an increase of enhancing tumor size during the study. Methemoglobin was detected at some time in all patients (100%) and was usually minor, but in six (35%) it interfered with residual tumor assessment. The 97 doses of Gd-DTPA, administered in 17 patients, were well tolerated. CONCLUSION: When accurate assessment of residual enhancing tumor is needed in patients with malignant glioma, an MR scan performed on postoperative days 3 to 5 should minimize the confounding effects of postsurgical enhancement and methemoglobin. The repeated administration of Gd-DTPA over several weeks is well tolerated.

Adolescent↗