The Proportion of Self-Reported Asthma Associated with Work in Three States: California,Massachusetts, and Michigan, 2001

Objectives. To assess the proportion of adult asthma at the state level that may be related to work. Design. Work-related asthma questions were added to the 2001 Behavioral Risk Factor Surveillance System (BRFSS) questionnaire in California, Massachusetts, and Michigan. Results. Findings indicate 7.4–9.7% of those with current asthma reported that their asthma may be work related. These results estimate that approximately 137,000 adults in California, 39,000 in Massachusetts, and 63,000 in Michigan have asthma that may be work related. Conclusions. These findings are unique in providing population-based estimates at the state level that illustrate that a substantial portion of adult asthma morbidity is due to exposures in the work environment.     

Antioxidant activity relates to plant part, life form and growing condition in some diabetes remedies

Selection, collection and preparation of 35 plant species used by traditional healers in the boreal regions of Canada for treatment of the symptoms of diabetes were supported empirically by antioxidant activity of the plants. Because antioxidants fluctuate with growth parameters and environmental factors, these remedies were evaluated in relation to the affect of plant part, life form and growing condition on the level of activity. The parts used here more frequently as medicines were roots and bark. Activity (IC(50)) of the bark extracts used medicinally averaged to 21.38+/-3.84 ppm while root extracts used medicinally had an IC(50) of 185.11+/-32.18 ppm in a free radical DPPH assay. In contrast the analysis of extracts of overall parts (medicinal or not) in these species found leaves and bark to have the least activity (112.22+/-30.63 ppm and 123.02+/-21.13 ppm, respectively). The highest activity was found in tree extracts (24.88+/-3.32 ppm) as compared to herbs and shrubs, and increased activity was found in plant extracts from growing conditions of decreased water/fertility. The antioxidant activity of these traditional plant remedies have the potential to be partially deduced through environment signals interpreted by the traditional herbalist.     

Severe Paraneoplastic Hyponatremia and Hypoosmolality in a Patient with Small-Cell Lung Carcinoma: Syndrome of Inappropriate Antidiuretic Hormone Secretion Versus Atrial Natriuretic Peptide or Both?

It is well documented in literature that a majority of small-cell lung cancers are associated with paraneoplastic phenomena. We report the case of a 63-year-old man diagnosed with small-cell lung carcinoma, in whom a severe hyponatremia and renal sodium loss with inappropriate antidiuresis were also found during a routine laboratory testing. Syndrome of inappropriate antidiuretic hormone secretion was first suspected in this patient, but another complex pathogenetic mechanism involving atrial natriuretic peptides could be associated, potentiating the deflation of the plasma sodium level. In our patient, the plasma-atrial natriuretic peptide base level, determined with a sensitive radioimmunoassay, was above the normal range (183 pg/mL; normal range, 50 pg/mL, +/- 10 pg/mL), and the antidiuretic hormone plasma level had an oscillatory pattern, varying between 5.5 pg/mL and 7 pg/mL (normal range, 0-4.7 pg/mL). We discuss the pathogenesis and clinical aspects of this association and the therapeutic options for these types of patients.     

Low somatic K-ras mutation frequency in colorectal cancer diagnosed under the age of 45 years

Somatic mutation of K-ras is known to be a common event in colorectal cancer tumourigenesis however its association with age at onset has not been widely explored. In this study, we have analyzed tumours from a population-based study of colorectal cancer diagnosed before the age of 45 years, in which cases had been previously screened for germ-line mismatch repair gene mutations and for microsatellite instability. We used a micro-dissection and sequencing approach to search for somatic K-ras mutations in codons 12, 13 and 61 in 101 early-onset colorectal cancers. Six (6%) somatic K-ras mutations were detected; five in codon 12 (4 G>T transitions and 1 G>A) and one in codon 13 (G>A transition). All codon 12 mutations were identified in microsatellite stable tumours and the codon 13 mutation was identified in a MSI-high tumour. Four cases with K-ras mutations had no reported family history of colorectal cancer and two had some family history of colorectal cancer. None were known to carry a germ-line mutation in hMSH2, hMLH1, hMSH6 or hPMS2. The role of somatic K-ras mutations in early-onset colorectal cancer carcinogenesis appears to be minor, in contrast to its significant role in colorectal cancer of later age of onset.     

Fatigue crack propagation resistance of highly crosslinked polyethylene

A higher degree of cross-linking has been shown to improve wear properties of ultra-high molecular weight polyethylene in laboratory studies. However, cross-linking can also affect the mechanical properties of ultra-high molecular weight polyethylene. Fatigue crack propagation resistance was determined for electron beam cross-linked ultra-high molecular weight polyethylene and compared with gamma irradiation cross-linked and noncross-linked polyethylene fatigue specimens. Crosslinking was done with different dosages of irradiation followed by melting. For one irradiation dose (50 kGy) extrusion and molding processes were compared. A fracture mechanics approach was used to determine how the degree of cross-linking affects resistance to crack propagation in ultra-high molecular weight polyethylene. Fatigue crack propagation resistance was reduced in proportion to the irradiation dose. The type of irradiation (gamma or electron beam) or manufacturing method (extrusion or molding) did not affect fatigue crack propagation resistance. The reduced fatigue strength of highly cross-linked ultra-high molecular weight polyethylene could lead to mechanical failure in conditions that are associated with cyclic local tensile stresses.     

Work-related carpal tunnel syndrome (WR-CTS) in Massachusetts, 1992-1997: source of WR-CTS, outcomes, and employer intervention practices

BACKGROUND: The Massachusetts Sentinel Event Notification System for Occupational Risks (MASS SENSOR) receives reports of work-related carpal tunnel syndrome (WR-CTS) cases from (1) workers' compensation (WC) disability claims for 5 or more lost work days; and (2) physician reports (PR). METHODS: From 1992 through 1997, 1,330 WC cases and 571 PR cases completed follow-back surveys to provide information on industry, occupation, attributed source of WR-CTS, outcomes, and employer intervention practices. RESULTS: Sixty-four percent of the respondents had bilateral CTS and 61% had surgery, both of which were proportionally more frequent among WC cases. Office and business machinery was the leading source of WR-CTS (42% of classifiable sources) in every economic sector except construction, followed by hand tools (20%). Managers and professional specialty workers were the most likely to report employers' interventions and were up to four times more likely to report equipment or work environment changes than higher risk groups. CONCLUSIONS: State-based surveillance data on the source of WR-CTS provided valuable information on how and where to implement interventions. New occurrences of WR-CTS are likely, especially in the highest risk industries where very few cases reported primary prevention measures (e.g., changes to equipment or work environment) implemented by their employers.     

A chronic bile duct and intravenous cannulation model in conscious rabbits for pharmacokinetic studies.

In the development of novel pharmaceutical compounds, pharmacokinetic parameters, such as the extent of biliary excretion, must be characterized. Pharmacokinetic studies in nonrodent species, typically dogs, are generally required for new drug approvals. However, in some cases, rabbits may be a more desirable model. We developed a surgical procedure for the intermittent or continuous collection of bile for long-term use. This surgery involves the removal of the gallbladder and cannulation of the proximal and distal aspects of the common bile duct using a 40 cm flexible surgical-grade cannula. The cannula loop is passed subcutaneously and exteriorized between the scapulae to divert bile flow. During use, the proximal cannula segment is attached to a collection container placed in a nylon torso jacket worn by the animal, and the distal segment of catheter is sealed with a stainless-steel adapter. An auricular catheter, secured by ligatures, is placed aseptically into the lateral ear vein and the tip is advanced to the cranial vena cava for serial blood collection. Daily infusions of a heparinized saline "lock" ensure patency. These procedures have been used in 18 rabbits for up to 1 month without clinical complications. Complete blood counts, biochemical profiles, body weights, and bile flow were monitored weekly and reflected normal enterohepatic circulation.