Development of a roof bolter canopy air curtain for respirable dust control.

Testing of the roof bolter canopy air curtain (CAC) designed by the U.S. National Institute for Occupational Safety and Health (NIOSH) has gone through many iterations, demonstrating successful dust control performance under controlled laboratory conditions. J.H. Fletcher & Co., an original equipment manufacturer of mining equipment, further developed the concept by incorporating it into the design of its roof bolting machines. In the present work, laboratory testing was conducted, showing dust control efficiencies ranging from 17.2 to 24.5 percent. Subsequent computational fluid dynamics (CFD) analysis revealed limitations in the design, and a potential improvement was analyzed and recommended. As a result, a new CAC design is being developed, incorporating the results of the testing and CFD analysis.

Helmet-Cam: tool for assessing miners' respirable dust exposure.

Video technology coupled with datalogging exposure monitors have been used to evaluate worker exposure to different types of contaminants. However, previous application of this technology used a stationary video camera to record the worker's activity while the worker wore some type of contaminant monitor. These techniques are not applicable to mobile workers in the mining industry because of their need to move around the operation while performing their duties. The Helmet-Cam is a recently developed exposure assessment tool that integrates a person-wearable video recorder with a datalogging dust monitor. These are worn by the miner in a backpack, safety belt or safety vest to identify areas or job tasks of elevated exposure. After a miner performs his or her job while wearing the unit, the video and dust exposure data files are downloaded to a computer and then merged together through a NIOSH-developed computer software program called Enhanced Video Analysis of Dust Exposure (EVADE). By providing synchronized playback of the merged video footage and dust exposure data, the EVADE software allows for the assessment and identification of key work areas and processes, as well as work tasks that significantly impact a worker's personal respirable dust exposure. The Helmet-Cam technology has been tested at a number of metal/nonmetal mining operations and has proven to be a valuable assessment tool. Mining companies wishing to use this technique can purchase a commercially available video camera and an instantaneous dust monitor to obtain the necessary data, and the NIOSH-developed EVADE software will be available for download at no cost on the NIOSH website.

Rebreathing potential of infant mattresses and bedcovers.

OBJECTIVE: To establish the CO2 dispersion and retention properties of some mattresses and bed coverings commercially available in Australia. METHODS: Five mattresses were studied in (i) an in vivo model in which an infant's head was covered by a headbox, rebreathing was allowed to occur, and the final steady state CO2 concentration was measured; and (ii) an in vitro model in which 5% CO2 in a headbox was allowed to disperse, and the time taken for the concentration to reach 1% was measured. Five types of bedcover were studied in (i) an in vivo model in which an infant's head was covered by a bedcover and the final steady state CO2 concentration was measured; and (ii) an in vitro model in which 5% CO2 under a bedcover was allowed to disperse, and the time taken for the concentration to reach 1% was measured. RESULTS: The steady state CO2 concentrations ranged from 0.6% to 3.0% for the mattresses (P < 0.05). The time for CO2 to disperse ranged from 5.5 min to 30.4 min (P < 0.05). Steady state CO2 concentrations ranged from 2.5% to 3.6% for the bedcoverings (P > 0.05). The time for CO2 to disperse ranged from 5.4 min to 7.7 min (P > 0.05). CONCLUSIONS: Some commercial cot mattresses and bedcoverings allow high concentrations of CO2 to accumulate in rebreathing environments. Some mattress types studied were more diffusive to CO2, whereas there was no difference between the bedcovers studied. This may have implications for vulnerable infants at risk of sudden infant death syndrome.

Anetoderma of prematurity in association with electrocardiographic electrodes.

Anetoderma in premature infants is an uncommon lesion that may be associated with the use of various types of monitoring leads. In 2 infants multiple papules of anetoderma occurred on the forehead in association with the use of gel electrocardiographic electrodes. It is postulated that the cause of these papules was a local hypoxemia caused by pressure from the electrodes. Growth-restricted infants may be particularly predisposed to iatrogenic anetoderma.

CA15-3, CASA, MSA, and TPS as diagnostic serum markers in breast cancer.

This is the first comparison of the three mucin based tests CA15-3, CASA, and MSA, and the cytokeratin-related TPS assay in breast cancer. The mucin markers were superior to TPS in receiver-operator analysis, though no marker was of use in the diagnosis of malignancy due to low sensitivity. Using cutpoints that gave 95% specificity in benign disease (n = 83), corresponding sensitivities in pre-treatment breast cancer (n = 123: 13 in situ, 54 stage I, 45 stage II, 4 stage III, 7 stage IV) were 17% (CA15-3), 16% (CASA), 13% (MSA), and 8% (TPS), with a strong relationship between marker levels and disease stage. These assays did not always detect the same patients, and the use of CA15-3 combined with CASA gave the highest sensitivity (23%), though this was not significantly better than the use of CA15-3 alone. Despite detecting similar antigens, these assays can show markedly different responses in some patients, indicating that one mucin-based test cannot be substituted for another.

Circulating tumour-associated mucin concentrations, determined by the CASA assay, in healthy women.

This investigation was undertaken to establish a reference range for tumour-associated MUC1 mucins in the serum of healthy women of the ages at risk for adenocarcinoma of the ovary and breast. Blood samples and clinical information were obtained from 5,000 women attending a breast screening mammography clinic. Data from women diagnosed with breast carcinoma and those subsequently diagnosed with other cancers were omitted from the reference range. Mucin concentrations were measured using the CASA assay which detects the protein core of MUC1 encoded mucins. Multiple linear regression analysis showed no effect on CASA concentrations by non-malignant changes to the breast, menopausal status, presence/absence of the reproductive tract, parity or history of hormone use. However, CASA concentrations were significantly increased in smokers (P < 0.001) and progressively increased with age (P < 0.001). These data show that these factors must be given consideration when setting upper limits of normal using MUC1 protein core binding assays.

Comparative study of mammography and mammary serum antigen estimation for breast cancer screening.

OBJECTIVE: To compare mammary serum antigen (MSA) levels with mammography as a screening test for breast cancer. To determine the value of MSA testing to decrease the need for women to undergo mammography. DESIGN: A blind prospective comparison of MSA levels and mammography to detect breast cancer. SETTING: Royal Women's Hospital Breast Cancer Screening Clinic. Women were mainly self-referred. RESULTS: MSA levels had a wide range in normal women and women with mammography-detected breast cancer. Mean MSA levels in women with breast cancer reflected tumour volume, but a wide range was again seen. At 60% specificity, the sensitivity of an elevated MSA level for breast cancer was 63% for invasive cancer and zero for in-situ disease. MSA levels were modestly but significantly elevated in smokers over non-smokers. CONCLUSION: The MSA level is an insufficiently sensitive or specific marker to have a role in screening for breast cancer.

Preoperative discrimination between ovarian carcinoma, non-ovarian gynecological malignancy and benign adnexal masses using serum levels of CA125 and the polymorphic epithelial mucin antigens CASA, OSA and MSA.

Serum levels of the tumor associated antigens CA125, CASA, OSA and MSA were determined preoperatively in a non-consecutive series of patients with: invasive epithelial ovarian cancer (OC, n = 87), ovarian tumors of low malignant potential (LMP, n = 9), benign adnexal masses (BAM, n = 48) and other peritoneal and pelvic malignancies (n = 48). In addition, serum levels of CASA, OSA, and MSA were determined in 3477 asymptomatic well women. Ninety-eight percent of the asymptomatic women had CASA levels < 6.0 U ml-1, OSA levels < 5.5 U ml-1 and MSA levels < 80.0 U ml-1. Serum CA125 levels were> 35 U ml-1 in 89% of OC, in 44% of LMP, and in 23% of BAM. Serum CASA levels were> 6.0 U ml-1 in 58% of OC, in 0% of LMP, and in 0% of BAM. Serum OSA levels were> 5.5 U ml-1 in 61% of OC in 0% of LMP and in 4% of BAM. Serum MSA levels were> 80.0 U ml-1 in 56% of OC, in 11% of LMP, and in 10% of BAM. When cut-off levels were set to exclude all patients with BAM, the best discrimination from OC using a single assay was achieved using CASA (58%). However, a combination of CASA and CA125 gave positive levels in 69% of OC at levels which precluded BAM. All markers were also elevated in some colon cancers, cervical cancers, uterine cancers and other peritoneal malignancies. A combination of CA125 and CASA levels, obtained preoperatively may assist the general gynecologist in avoiding potentially difficult oncologic surgery.