The Dangerous Middle: Situational Awareness and Worker Perception of Beetle Kill

ABSTRACT

Forest workers, including loggers, foresters, and wildland firefighters, are regularly exposed to some of the most fatal occupational environments in the United States. These hazardous work environments may become even more complex and dynamic when subject to bark beetle outbreaks that have resulted in significant tree mortality. The impacts of tree death from bark beetles are significant, with the cumulative 17-year (2000–2016) footprint for bark beetle caused tree mortality estimated at 54 million acres. However, how workers think about and act in these environments is understudied. This study, therefore, approaches the issue of beetle kill and forest worker safety by examining the perspectives or workers themselves. Its contribution is to leverage ethnographic research to provide insights that can generate new research questions, better inform outreach, and ultimately improve worker safety outcomes. The resulting insights show that beetle kill was understood by workers as a hazard that increased the complexity and dynamism of the work environment, making situational awareness both more necessary and more difficult to maintain. While much research about situational awareness focuses on hazardous situations, it is suggested that building adequate situational awareness should also include broader considerations of organizational communication, as well as training and experience considered over the course of entire careers.     

Expression of P-glycoprotein in normal muscle cells and myogenic tumors.

We have analyzed the expression of the multidrug resistance (mdr-1) gene product, P-glycoprotein, by immunohistochemical staining of frozen tissue sections of human normal muscle fibers and 31 tissue specimens of cases of myogenic sarcomas. The objective of this study was to further characterize what appears to be a variety of responses to therapy in like-appearing but distinct tumors. We have used two mouse monoclonal antibodies that recognize two different epitopes of P-glycoprotein. Mouse monoclonal antibody HYB-241 detects an extracellular epitope of P-glycoprotein, whereas C219 detects a carboxy-terminal intracellular epitope and has recently been reported to cross-react with the mdr-3 gene product. Differential epitope expression was observed among normal muscle fibers with the two antibodies used. Smooth-muscle cells were unreactive for the two antibodies, whereas cardiac and a subgroup of skeletal muscle fibers were intensely stained by C219, but not by HYB-241. P-glycoprotein expression was observed in 23% of the 31 myogenic sarcomas analyzed. Our study was conducted mainly using adult myogenic sarcomas (28 out of 31 cases), with a few cases (three out of 31 cases) of childhood sarcomas. Nineteen tumors were leiomyosarcomas, seven cases were embryonal rhabdomyosarcomas, and five cases were rhabdomyosarcomas. We have considered expression of the mdr-1-coded P-glycoprotein when we observed either HYB-241 and C219 staining, or just HYB-241 immunoreactivities. Although P-glycoprotein expression can now be detected in human sarcomas, further studies are needed, mainly comparing tumor samples before, during, and after therapy, to establish the possible significance of the P-glycoprotein expression in clinical drug resistance.     

EGF enhances the survival of dopamine neurons in rat embryonic mesencephalon primary cell culture.

Epidermal growth factor (EGF) immunoreactive material has been demonstrated to be present in the basal ganglia. In this study, we investigated the effect of EGF on cells cultured from 16-day embryonic rat mesencephalon, which included dopamine neurons that project to the striatum in vivo. EGF receptors were detected in untreated cultures by [125I]-EGF binding. Treatment of the cultures with EGF resulted in up to 50-fold increases in neuronal high-affinity dopamine uptake. Scatchard analysis of uptake kinetics and counting of tyrosine hydroxylase-immunoreactive cells suggest that the effect of EGF on uptake is due to increased survival and maturation of dopaminergic neurons. By contrast, the high-affinity uptake for serotonin was increased only threefold over its controls. There was no significant effect on high-affinity gamma-aminobutyric acid (GABA) uptake. These results suggest that EGF is acting as a neurotrophic agent preferential for dopaminergic neurons in E16 mesencephalic cultures. Immunocytochemistry for glial fibrillary acidic protein demonstrated an increase in astroglia with EGF treatment. Fluorodeoxyuridine, an agent that is toxic to proliferating cells was able to eliminate the effect of EGF on dopamine uptake, suggesting that EGF may be increasing dopaminergic cell survival largely through a population of dividing cells.     

Increased frequency of HLA-DRwl4b(w6)-associated RFLP in Greenlanders of Eskimo origin

HLA-DR typing by the restriction fragment length polymorphism (RFLP) technique of 42 Greenlanders living in northern Jutland, Denmark, revealed a phenotype frequency of 33.3% for HLA-DRw14b(w6), which is significantly different from the frequency of 0.0% observed among 98 Danes of Caucasian origin. When comparing the two populations, the frequency of other HLA-DRB allogenotypes show insignificant variations. Since HLA-DRw14b(w6) is carried by approximately one-third of the Greenlanders tested, this allogenotype may serve as a useful marker in further anthropological and immunogenetic studies.     

Intravenous immunoglobulin may lessen all forms of infection in patients receiving allogeneic bone marrow transplantation for acute lymphoblastic leukemia: a pediatric oncology group study

Fifty patients with refractory acute lymphoblastic leukemia underwent allogeneic bone marrow transplantation after conditioning with high-dose cytosine arabinoside and fractionated total body irradiation. Twenty-nine received intravenous immunoglobulin (i.v.Ig) infusion, primarily to prevent cytomegalovirus infection, and 21 did not. The two groups were biologically comparable. Seven (24.5%) of the i.v.Ig-treated and 14 (66.7%) of the non-i.v.Ig-treated patients developed systemic viral, fungal or bacterial infections and/or interstitial pneumonitis (p less than 0.005), which were fatal in three and 12 cases respectively (p less than 0.001). Currently, 23 (79.3%) of the 29 i.v.Ig-treated and eight (38.1%) of the 21 non-i.v.Ig-treated patients are alive and well (p less than 0.01). We conclude that prophylactic i.v.Ig infusions may reduce the frequency of all forms of serious infection in patients with acute lymphoblastic leukemia undergoing allogeneic marrow transplantation, and thereby improve their survival expectation.     

Further characterization of the pigment in pseudomelanosis duodeni in three patients

Pseudomelanosis duodeni is a rare condition in which dark pigment accumulates in macrophages located in the lamina propria of the duodenal mucosa. Three cases are reported here and the literature is reviewed. No clinical association can be found that points clearly to the underlying etiology. Electron probe x-ray microanalysis was used to study the pigment in macrophage granules in 2 of our patients and demonstrated high iron and sulfur content. Iron accumulation in ferritinlike particles was detected in absorptive cell lysosomes. A possible mechanism for the accumulation of absorbed iron by macrophages is considered.     

Pancreatitis associated with bone marrow transplantation in children.

Vomiting, abdominal pain and distension, common findings in children who receive bone marrow transplants (BMT), are usually attributed to chemo-irradiation and mucositis, universally found in these patients. We report seven children, 3.5% of BMT patients at our institutions, with these symptoms who were found to have mild to severe pancreatitis during conditioning for or after receiving BMT. All patients were receiving drugs known to cause pancreatitis, such as adrenocorticosteroids and sulfonamides as well as numerous putative pancreatotoxins such as cyclosporin A and cytosine arabinoside. Five of the seven patients had suffered from graft-versus-host disease. In patients who have received BMT, upper gastrointestinal symptoms should not be attributed to mucositis or chemo-irradiation without first testing for pancreatitis.