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.     

Unusual orthochromatic leukodystrophy with epitheloid cells (Norman-Gullotta): increase of very long chain fatty acids in brain discloses a peroxisomal disorder

Summary Very long chain fatty acids (VLCFA) were found to be markedly increased and phytanic acid was borderline above normal in formalin-fixed brain white matter of case with an unusual type of familial leukodystrophy with epitheloid cells as described previously by Gullotta et al. [Neuropädiatrie (1970) 2: 173–186]. Increased VLCFA in brain clearly demonstrate that the patient had suffered from a peroxisomal disease. This diagnosis is corroborated by ultrastructural findings in brain showing typical lamellar inclusions. The particular type of peroxisomal disorder present in case (heterozygote of X-linked adrenoleukodystrophy?) remains speculative.     

Adult metachromatic leukodystrophy manifested as schizophrenic psychosis (author's transl)

An autopsy case of adult metachromatic leukodystrophy (MLD) manifested clinically as schizophrenic psychosis is reported. A 50-year-old man developed progressive mental changes 10 years before his death, and later manifested a schizophrenic syndrome without neurologic deficits or EEG changes. After his death from uremia neuropathology disclosed MLD with demyelination accentuated in the frontal lobes and abundant metachromatic deposits in the preserved areas of cerebral white matter. Neurochemical examination of the demyelinated frontal area showed reduced concentration of cerebrosides and sulfatides, decreased amounts of total lipids in the tissue, and an increase of sulfatides, and particularly of their cerebron fractions in lipid extract. The problems of adult forms of MLD with prolonged course are discussed with special reference to cases showing mainly psychiatric syndromes.     

Adrenoleukodystrophy in an adult female

Summary A 43-year-old female with adrenoleukodystrophy (ALD) is described, who developed spastic tetraparesis, suffered grand mal seizures, and became stuporous and demented during the last 5 years of her life. Computed tomography revealed symmetrical hypodense lesions in the peritrigonal regions. Adrenal insufficiency was not evident except for skin pigmentation. The ultrastructure of a rectal biopsy specimen showed inclusions with lamellae and interspersed clefts in macrophages of the submucosal layer. At autopsy, the adrenals were found to contain large foam cells filled with similar inclusions. The brain cortex and the spinal cord were histologically normal. However, cerebral white matter exhibited widespread demyelination which spared only the arcuate fibres. In regions of less severe demyelination scattered inflammatory cells were seen. On electron microscopy, aggregates of typical paired leaflets with distinct intermediate lines were demonstrated in perivascular macrophages. Histochemical study showed these cells to contain free as well as esterified cholesterol. Gas chromatographic analysis of very long chain fatty acids (VLFA) from the demyelinated cerebral white matter showed a marked increase of C26:0 fatty acid in cholesterol esters and above-normal values for C24:0 and C24:1 in gangliosides. It is suggested that the condition was a heterozygote form of X-linked ALD. Patients with neurodegenerative symptoms with or without adrenal insufficiency can easily be screened for X-linked ALD by VLFA analysis in blood or cultured fibroblasts.     

Peroxisomal neurologic diseases and Refsum disease: very long chain fatty acids and phytanic acid as diagnostic markers]

Peroxisomal disorders are genetic metabolic diseases with generalized, multiple, or single functional disturbances of the peroxisome. According to the extent of the functional disturbances 3 groups of diseases can be differentiated: disorders with generalized loss of peroxisomal functions (Zellweger syndrome, ZS; neonatal adrenoleukodystrophy, NALD; infantile Refsum's disease), disorders with multiple enzymatic defects (e.g. rhizomelic chondrodysplasia punctata), and disorders with a single enzymatic defect in the peroxisome, the most important being adrenoleukodystrophy/adrenomyeloneuropathy (ALD/AMN). Adult Refsum's disease, a genetic neurological disorder with phytanic acid accumulation, is due to a mitochondrial enzyme deficiency, but is often considered together with peroxisomal diseases because of phytanic acid (PHYT) accumulation in most peroxisomal diseases. The main clinical and pathological criteria of the major disorders and the biochemical parameters of their differentiation are presented. Elevated levels of very long chain fatty acids (VLCFA) and/or PHYT are the primary diagnostic markers for all peroxisomal disorders and adult Refsum's disease, respectively. Our investigations disclosed 30 ALD/AMN hemizygotes, 16 ALD/AMN heterozygotes, 8 cases of ZS/NALD and 7 patients with adult Refsum's disease. In addition, 15 cases of peroxisomal disorders were confirmed by biochemical investigations in autopsy material. With regard to peroxisomal disorders, therapeutic concepts exist only for ALD/AMN: corticosteroid substitution for adrenal insufficiency, dietary treatment, and bone marrow transplantation (BMT). Adult Refsum's disease can be treated successfully by dietary therapy. In case of dietary treatment and BMT, assay of VLCFA and/or PHYT is important for the biochemical evaluation of these therapies.     

Occurrence,distribution, and phenotype of arylsulfatase A mutations in patients with metachromatic leukodystrophy

Occurrence, distribution, and phenotype of arylsulfatase A (ASA) mutations were investigated in 27 patients with metachromatic leukodystrophy (MLD) from Central Europe, mainly from Austria (n = 15) and Poland (n = 9). Genomic DNA from leukocytes, fibroblasts, or paraffin-embedded, formalin-fixed brain or nerve tissue, respectively, was tested by natural or mutated primer-modulated PCR restriction, fragment length polymorphism for the eight most common European mutations: R84Q, S96F, 459+1G>A, I179S, A212V, 1204+1G>A, P426L, and 1401del11bp. The overall identification rate of unrelated MLD alleles was the highest, in adult (90%), medium in juvenile (50%), and lowest in late infantile (36%) MLD patients. The two common alleles, 459+1G>A and P426L, together accounted for 42% of all 50 unrelated MLD alleles investigated; I179S was observed in 6 of 50 MLD alleles (12%). Thus, I179S was far more frequent than hitherto thought and appears to be a third common mutation in Europe. Moreover, a different allelic distribution between Austrian and Polish juvenile patients was disclosed, indicating genetic heterogeneity of MLD even within Central Europe. The genotype-phenotype correlation suggested by Polten et al. [N Engl J Med 324:18–22, 1991] was not followed by all of our MLD patients. Moreover, some MLD patients with identical ASA mutations presented with different phenotypes. This may be due, at least in some cases, to the presence of an additional mutation on individual mutant alleles. Therefore, prediction of the clinical course from single mutation analysis is not possible. Am. J. Med. Genet. 69:335–340, 1997. © 1997 Wiley-Liss, Inc.     

Rolipram does not normalize very long-chain fatty acid levels in adrenoleukodystrophy protein-deficient fibroblasts and mice

In its severe form, X-linked adrenoleukodystrophy (X-ALD) is a lethal neurodegenerative disorder with inflammatory demyelination, in which defective peroxisomal -oxidation causes accumulation of very long-chain fatty acids (VLCFA) in tissues and plasma, in particular in the nervous system and adrenal glands. Recently, several drugs have been reported to reduce VLCFA in cultured human fibroblasts of X-ALD patients, and therefore to be potential candidates for novel therapeutic treatments in X-ALD. Among the most promising of these substances is the antidepressant rolipram, because of favourable adverse event profile in clinical studies and its additionally reported anti-inflammatory action. To further elucidate the effects of rolipram on peroxisomal -oxidation and VLCFA accumulation, we administered rolipram orally in the diet to ALD protein-deficient mice and ALD protein-deficient cultured human and mouse fibroblasts and assayed the accumulation of VLCFA. In contrast to the previously reported reduction of VLCFA, our data did not demonstrate a decrease in VLCFA content either in vivo or in vitro. NMR spectroscopic analysis verified the structural integrity and purity of the rolipram used here, thus excluding inauthenticity as a reason for the discrepancy. We therefore suggest that rolipram should be excluded from the current list of potential therapeutic agents for X-ALD.     

Mucopolysaccharidosis V (Ullrich-Scheie syndrome) (author's transl)]

Mucopolysaccharidosis V (Scheie's syndrome, MPS-IS) is a very rare, autosomal recessively inherited metabolic disease. The degradation of dermatan sulphate and heparan sulphate is disturbed due to alpha-L-iduronidase deficiency, leading to intracellular storage and excessive urinary secretion of these substances. The characteristic clinical features are contractures (claw-like flexion of the fingers), umbilical and inguinal herniae, corneal opacity, hepatomegaly, myocardiopathy and minor skeletal malformations. A patient with Scheie's syndrome is now reported for the first time in Austria; the results of the clinical, biochemical, chromosomal, dermatoglyphic and electron optical investigations are described and discussed.