Functional recovery following musculoskeletal injury in hospital workers

BACKGROUND

Hospital workers are at high risk of work-related musculoskeletal disorders (WRMSDs), but outcomes following such injuries have not been well studied longitudinally.

AIMS

To ascertain functional recovery in hospital workers following incident WRMSDs and identify predictors of functional status.

METHODS

Cases (incident WRMSD) and matched referents from two hospitals were studied at baseline and at 2 year follow-up for health status [SF-12 physical component summary (PCS)], lost workdays, self-rated work effectiveness and work status change (job change or work cessation). Predictors included WRMSD and baseline demographics, socio-economic status (SES), job-related strain and effort-reward imbalance. Logistic regression analysis tested longitudinal predictors of adverse functional status.

RESULTS

The WRMSD-associated risk of poor (lowest quartile) PCS was attenuated from a baseline odds ratio (OR) of 5.2 [95% confidence interval (CI) 3.5-7.5] to a follow-up OR of 1.5 (95% CI 1.0-2.3) and was reduced further in multivariate modelling (OR = 1.4; 95% CI 0.9-2.2). At follow-up, WRMSD status did not predict significantly increased likelihood of lost workdays, decreased effectiveness or work status change. In multivariate modelling, lowest quintile SES predicted poor PCS (OR = 2.0; 95% CI 1.0-4.0) and work status change (OR = 2.5; 95% CI 1.1-5.8). High combined baseline job strain/effort-reward imbalance predicted poor PCS (OR = 1.7; 95% CI 1.1-2.7) and reduced work effectiveness (OR = 2.6; 95% CI 1.6-4.2) at follow-up.

CONCLUSIONS

Baseline functional deficits associated with incident WRMSDs were largely resolved by 2 year follow-up. Nonetheless, lower SES and higher combined job strain/effort-reward imbalance predicted adverse outcomes, controlling for WRMSDs.

Structure of the Channels in the Outer Mitochondrial Membrane: Electron Microscopic Studies of the Periodic Arrays Induced by Phospholipase a(2) Treatment of the Neurospora membrane

The channel proteins in outer membranes of Neurospora crassa mitochondria spontaneously organize into periodic arrays when the membranes are dialyzed in the presence of soluble phospholipase A(2). Electron microscopic images have been recorded at different electron doses from channel arrays in a variety of negative stains, as well as in vitreous ice. Fourier or correlation averages are formed from image fields containing a few hundred unit cells. These averages can be subsequently classified by correspondence analysis and summed to form representative averages over thousands of unit cells. In averages of negatively stained arrays, the stain-filled channel openings are bounded by smaller stain-excluding maxima. The projections of the channel openings are smaller and the subsidiary maxima are more pronounced for channel arrays contrasted with dilute (0.1%) uranyl acetate or aurothioglucose than for arrays embedded in 1% uranyl acetate. Projection images of unstained, ice-embedded membranes provide direct information about distribution of protein and lipid in the VDAC arrays. First experiments have yielded density maps with an apparent Fourier resolution of approximately 1/(2 nm).

Microcyclospora and Microcyclosporella: novel genera accommodating epiphytic fungi causing sooty blotch on apple

Recent studies have found a wide range of ascomycetes to be associated with sooty blotch and flyspeck (SBFS) blemishes on the surfaces of pomaceous fruits, specifically apples. Based on collections of such fungi from apple orchards in Germany and Slovenia we introduce two novel genera according to analyses of morphological characters and nuclear ribosomal DNA sequences (large subunit and internal transcribed spacer regions). Microcyclosporella is represented by a single species, M. mali, and is presently known from Germany and Slovenia. Microcyclosporella is Pseudocercosporella-like in morphology, but genetically and morphologically distinct from Pseudocercosporella s.str., for which an epitype is designated based on a fresh collection of P. bakeri from Laos. Furthermore, Pseudocercosporella is shown to be paraphyletic within the Capnodiales. Microcyclospora gen. nov. is Pseudocercospora-like in morphology, but is genetically and morphologically distinct from Pseudocercospora s.str., which is based on P. vitis. Three species, Microcyclospora malicola, M. pomicola (both collected in Germany), and M. tardicrescens (collected in Slovenia) are described. Finally, a new species of Devriesia, D. pseudoamericana, is described from pome fruit surfaces collected in Germany. Devriesia is shown to be paraphyletic, and to represent several lineages of which only Devriesia s.str. is thermotolerant. Further collections are required, however, before the latter generic complex can be resolved.

5-HT2 receptors modulate excitatory neurotransmission to cardiac vagal neurons within the nucleus ambiguus evoked during and after hypoxia

To examine the role of 5-HT2 receptors in the central cardiorespiratory network, and in particular the respiratory modulation of parasympathetic activity to the heart, we used an in vitro medullary slice that allowed simultaneous examination of rhythmic inspiratory-related activity recorded from hypoglossal rootlet and excitatory inspiratory-related neurotransmission to cardioinhibitory vagal neurons (CVNs) within the nucleus ambiguus (NA). Focal application of ketanserin, a 5-HT2 receptor antagonist, did not significantly alter the frequency of spontaneous excitatory postsynaptic excitatory currents (EPSCs) in CVNs in control conditions. However, ketanserin diminished spontaneous excitatory neurotransmission to CVNs during hypoxia. The inhibitory action of ketanserin was on 5-HT3 mediated EPSCs during hypoxia since these responses were blocked by the 5-HT3 receptor antagonist ondansetron. In addition, a robust inspiratory-related excitatory neurotransmission was recruited during recovery from hypoxia. Focal application of ketanserin during this posthypoxia period evoked a significant augmentation of the frequency of inspiratory-related, but not spontaneous EPSCs in CVNs. This excitatory effect of ketanserin was prevented by application of the purinergic receptor blocker pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS). These results demonstrate 5-HT2 receptors differentially modulate excitatory neurotransmission to CVNs during and after hypoxia. Activation of 5-HT2 receptors acts to maintain excitatory neurotransmission to CVNs during hypoxia, likely via presynaptic facilitation of 5-HT3 receptor-mediated neurotransmission to CVNs. However, activation of 5HT2 receptors diminishes the subsequent inspiratory-related excitatory neurotransmission to CVNs that is recruited during the recovery from hypoxia likely exerting an inhibitory action on inspiratory-related purinergic signaling.

Greeen tea extracts lower serum folates in rats at very high dietary concentrations only and do not affect plasma folates in a human pilot study

Green tea catechins (GTC) have been shown to inhibit the activities of enzymes involved in folate uptake. Hence, regular green tea drinkers may be at risk of impaired folate status. The present experiments aimed at studying the impact of dietary GTC on folate concentrations and metabolism. In a human pilot study (parallel design) healthy men consumed for 3 weeks 6 capsules (approximately 670 mg GTC) per day (2 capsules with each principal meal) containing aqueous extracts of the leaves of Camellia sinensis (n=17) or placebo (n=16). No differences in plasma folate concentrations were observed between treatments. We further fed groups of 10 male rats diets fortified with 0, 0.05, 0.5, 1, or 5 g GTC/kg for 6 weeks. Only at the highest intake, GTC significantly decreased serum 5-methyl-tetrahydrofolate concentrations in rats, while mRNA concentrations of reduced folate carrier, proton-coupled folate transporter/heme carrier protein 1, and dihydrofolate reductase (DHFR) remained unchanged in intestinal mucosa. Using an in vitro enzyme activity assay, we observed a time- and dose-dependent inhibition of DHFR activity by epigallocatechin gallate and a green tea extract. Our data suggest that regular green tea consumption is unlikely to impair folate status in healthy males, despite the DHFR inhibitory activity of GTC.

Exclusion of ferrochelatase gene mutations in patients with seasonal palmoplantar keratoderma

Erythropoietic protoporphyria (EPP) is an autosomal dominant disorder that results from a deficiency of ferrochelatase (FECH), the last enzyme in the heme biosynthetic pathway. The characteristic clinical symptoms usually manifest in early childhood on the sun-exposed areas of the body. They are due to protoporphyrin-induced photosensitivity and include pain, burning and stinging of the skin, followed by erythema and edema. Recently, the occurrence of predominantly seasonal palmar and palmoplantar keratoderma in patients with homozygous mutations in the FECH gene has been reported. These data suggested that palmoplantar keratoderma might be a clinical sign of EPP. Palmoplantar keratodermas (PPKs) are a heterogeneous group of genetic skin diseases and include a seasonal variant, erythrokeratolysis hiemalis et estivalis (EH), also known as keratolytic winter erythema. Because the skin symptoms in the latter disorder are similar to those reported for recessive EPP we examined the FECH gene in three unrelated Dutch Caucasian patients with a previous diagnosis of EH in whom mutations in several other genes had been excluded. However, sequencing analysis of the entire coding regions and the adjacent splice sites of the FECH gene in these individuals revealed absence of mutations. Hence, our data largely exclude the possibility that FECH mutations might be responsible for the palmoplantar skin phenotype observed in EH.

Identification and characterization of HMBS gene mutations in Spanish patients with acute intermittent porphyria

Acute intermittent porphyria (AIP), the most common acute hepatic porphyria, is an autosomal dominant disorder with low penetrance that results from a partial deficiency of hydroxymethylbilane synthase (HMBS), the third enzyme in the heme biosynthetic pathway. The disease is clinically characterized by acute neurovisceral attacks that are precipitated by several factors including certain drugs, steroid hormones, alcohol and fasting. Early diagnosis and counselling are essential to prevent attacks, being mutation analysis the most reliable method to identify asymptomatic carriers in AIP families. In this study we have investigated the molecular defect in 15 unrelated Spanish AIP patients. Mutation analysis of the HMBS gene revealed a total of fourteen mutations including six novel ones, two of them were on the same allele in one patient. The novel mutations were three missense (R26L, R173G and D178H), two frameshift (c.749_765dup and c.874insC) and one intronic deletion (IVS12+3_+11delAGGGCCTGT). RT-PCR and sequencing demonstrated that the intronic mutation caused abnormal splicing and exon 12 skipping. Prokaryotic expression of the novel missense mutations showed that only D178H had significant residual activity. These findings will facilitate the accurate identification of presymptomatic AIP carriers in these families and they further emphasize the molecular heterogeneity of AIP in Spain.

Identification of a recurrent mutation in the protoporphyrinogen oxidase gene in Swiss patients with variegate porphyria: clinical and genetic implications

Variegate porphyria (VP), one of the acute hepatic porphyrias, results from an autosomal dominantly inherited deficiency of protoporphyrinogen oxidase (PPOX), the seventh enzyme in heme biosynthesis. Affected individuals can develop both cutaneous symptoms and potentially life-threatening neurovisceral attacks. Thirty unrelated VP index patients and families are currently known in the Swiss Porphyrin Reference Laboratory in Zürich. In 16 of a total of 24 genetically tested families, we detected a recurrent mutation in the PPOX gene, designated 1082-1083insC, reflecting a prevalence of 67%. Haplotype analysis revealed that 1082-1083insC arose on a common genetic background and, thus, represents a novel founder mutation in the Swiss population. Knowledge on the carrier status within a family does not only allow for adequate genetic counseling but also for prevention of the potentially life-threatening acute porphyric attacks. Hence, future molecular screening in Swiss VP patients might be facilitated by first seeking for mutation 1082-1083insC.

Utility of routine PET/CT and MRI staging in patients with sentinel lymph node positive melanoma

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Background: The utility of routine radiographic staging in sentinel lymph node (SLN) positive stage III melanoma is unclear. Although body computed tomography (CT) has proven unlikely to identify occult metastasis at the time of diagnosis, there is some suggestion that whole body positron emission tomography combined with computed tomography (PET/CT) may be more sensitive in the detection of clinically unsuspected metastatic melanoma. We evaluated the ability of routine PET/CT and brain MRI to detect occult metastatic disease at the time of diagnosis in patients with SLN positive stage III melanoma. Methods: All clinically node- negative patients with cutaneous melanoma and a positive SLN who completed staging with PET/CT from 2003 through 2008 were identified from a prospective, IRB-approved, single-institution database. Data were analyzed to determine the positive (PPV) and negative (NPV) predictive values of PET/CT in detecting occult metastatic disease. Results: 72 patients had a positive SLN and were staged with PET/CT and 61 with brain MRI. There were 41 men and 31 women. Median age was 55 years. Median Breslow depth was 2.50 mm. 5 patients were T1, 25 T2, 22 T3, and 20 T4. 46 % were ulcerated. MRI was negative in all 61 patients. PET/CT was interpreted as suspicious for metastasis in 8 patients (11%) and negative in 64 (92%). 6 (8%) of the suspicious PET/CT scans were subsequently proven to be negative for malignancy and 1 (1.4%) proven to be an incidental thyroid cancer. Only 1 patient (1.4%) was found to have metastatic melanoma, an in transit metastasis that was previously unrecognized. PPV was 13% and NPV 100% for PET/CT. No patients were found to have occult distant metastases by either brain MRI or PET/CT. Conclusions: Patients with SLN positive stage III melanoma are unlikely to have occult metastatic disease detected by PET/CT or brain MRI and should not have further therapy delayed to obtain imaging. These findings are consistent with prior reports of body CT alone and question the utility of routine staging with current imaging modalities in patients with SLN positive melanoma. Future research should be directed toward improved imaging techniques in order to detect early micrometastatic melanoma.

No significant financial relationships to disclose.

A new experimental setup for in situ infrared reflection absorption spectroscopy studies of atmospheric corrosion on metal surfaces considering the influence of ultraviolet light

The knowledge available regarding the influence of ultraviolet (UV) light on the atmospheric corrosion of materials is very rudimentary. Therefore, a new experimental setup consisting of a cell for studying in situ reactions occurring at the metal/atmosphere interface by simultaneously applying infrared reflection absorption spectroscopy (IRRAS) and quartz crystal microbalance (QCM) measurements was designed and built. The cell presented consists of an acrylic glass body with a UV-light-transparent window mounted in such a way that the sample can be irradiated and weathered under controlled atmospheric conditions under a grazing angle of incidence of the IR beam. This new setup was tested by using a specimen of polycrystalline silver, where the growth of Ag(2)CO(3) and AgOH as basic silver carbonate on the surface could be observed. The weathering tests were carried out in synthetic air containing 90% relative humidity (RH) and 250 ppm CO(2), with and without UV light. The results obtained from the IRRAS spectra could be perfectly correlated with the in situ QCM data.