Muscle oxygenation and glycolysis in females with trapezius myalgia during stress and repetitive work using microdialysis and NIRS

The aim of this investigation was to study female workers active in the labour market for differences between those with trapezius myalgia (MYA) and without (CON) during repetitive pegboard (PEG) and stress (STR) tasks regarding (1) relative muscle load, (2) trapezius muscle blood flow, (3) metabolite accumulation, (4) oxygenation, and (5) pain development. Among 812 female employees (age 30–60 years) at 7 companies with high prevalence of neck/shoulder complaints, clinical examination identified 43 MYA and 19 CON. At rest, during PEG, and STR the trapezius muscle was measured using (1) EMG and MMG, (2) microdialysis, and (3) NIRS. Further, subjective pain ratings were scored (VAS). EMGrms in %MVE (Maximal Voluntary EMG-activity), was significantly higher among MYA than CON during PEG (11.74 ± 9.09 vs. 7.42 ± 5.56%MVE) and STR (5.47 ± 5.00 vs. 3.28 ± 1.94%MVE). MANOVA showed a group and time effect regarding data from the microdialysis: for MYA versus CON group differences demonstrated lower muscle blood flow and higher lactate and pyruvate concentrations. Potassium and glucose only showed time effects. NIRS showed similar initial decreases in oxygenation with PEG in both groups, but only in CON a significant increase back to baseline during PEG. VAS score at rest was highest among MYA and increased during PEG, but not for CON. The results showed significant differences between CON and MYA regarding muscle metabolism at rest and with PEG and STR. Higher relative muscle load during PEG and STR, insufficient muscle blood flow and oxygenation may account for the higher lactate, pyruvate and pain responses among MYA versus CON.     

The effect of irradiation, annealing temperature, and artificial aging on the oxidation, mechanical properties, and fracture mechanisms of UHMWPE

UHMWPE crosslinked using Gamma radiation is believed to have improved wear properties, and this has been extensively studied during the past 10 years. Mechanical properties, oxidation, and wear properties of UHMWPE materials subjected to various thermal treatments have been investigated immediately after irradiation as well as after several years of aging. Nevertheless, the relationship between all these parameters is not yet fully understood. The aim of this study was to investigate the relationship between the thermal treatments that could be applied to irradiated UHMWPE [lower (gamma 60) or higher (gamma 150) than 140 degrees C, the melting temperature of the polymer] and the mechanical properties, the oxidation and the fracture behavior of the material. The effect of artificial aging on these properties was also investigated. This study concludes that immediately after the annealing, the mechanical properties (UTS and epsilon) of the irradiated and annealed material are improved compared with those of nonirradiated material. Although nonirradiated material has higher fracture toughness than irradiated and annealed materials, the materials break according to the same mechanism of fracture. After aging, no changes could be observed in any of the measured properties for nonirradiated material. On the other hand, important changes could be seen in both irradiated and annealed material after aging. Both UTS and epsilon decreased, much more so in the case of gamma 60. Furthermore, the aging induced a subsurface peak of oxidation in both irradiated and annealed materials, twice as intense for gamma 60 than for gamma 150. The mechanism of fracture of these materials changed drastically after aging, probably due to the presence of the oxidation peak, which seems to occur at a location where cracks initiate easily compared with the nonoxidized bulk of the material. In the case of gamma 60, it seems clear that a correlation between mechanical property, oxidation, and fracture mechanism exists. Such a relationship could not be found for gamma 150.     

Elevated serum 8-oxo-dG in hemodialysis patients: a marker of systemic inflammation?

Does inflammation, as assessed by high sensitivity C-reactive protein (hs-CRP), in patients with end-stage renal disease (ESRD) tightly associate with increased serum levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8- oxo-dG)? Increased oxidative stress and inflammation have both been highlighted among several nontraditional risk factors for cardiovascular disease, which is the main cause of mortality in ESRD patients. In contrast to oxidative stress effects on proteins and lipids, DNA base damage has not been well demonstrated in ESRD. Two groups of hemodialysis patients were studied, one group with persistent inflammation (n = 13, with constant elevation of CRP > 10 mg/L for 6 months) and one group of noninflamed patients (n = 19, with constant CRP < 10 mg/L for 6 months). Serum 8-oxo-dG was significantly elevated in persistent inflammation in comparison to noninflamed patients. At an individual level, a significant correlation was found between serum 8-oxo-dG and hsCRP. Extracellular 8-oxo-dG leads to intracellular oxidative damage on the nucleotide pool, thus providing a sensitive marker for inflammatory response. Serum levels of 8-oxo-dG, in combination with other inflammatory markers, serve as useful diagnostic tools for identification of patients in risk for inflammatory complications.     

Islet autoantibodies in cord blood from patients who developed type 1 diabetes mellitus at 15-30 years of age

Islet cell autoantibodies are early markers for type 1 diabetes. The aim of this study was to determine whether islet autoantibodies were present at birth in young adults who developed type 1 diabetes at 15-30 years of age. Cord blood sera from 30 patients who developed type 1 diabetes between 15 and 25 years of age and sera from 320 randomly selected control children were tested for islet cell antibodies (ICA) by indirect immunofluorescence and autoantibodies against the 65 kD isoform of glutamic acid decarboxylase (GADA), islet cell antigen-2 (IA-2A) and insulin (IAA) by radiobinding assays. The young adults who developed type 1 diabetes did not differ from controls in the cord blood prevalence of any of the four islet autoantibodies. This is in contrast to our previous findings that children who developed type 1 diabetes below 15 years of age had an increased prevalence of cord blood islet autoantibodies. Our present data suggest that, in contrast to children, pre- and perinatal risk factors are less likely to be involved in the development of type 1 diabetes in young adults.     

Role of efflux pumps and mutations in genes for topoisomerases II and IV in fluoroquinolone-resistant Pseudomonas aeruginosa strains

We have investigated the occurrence of mutations in topoisomerase II (DNA gyrase) subunit B(gyrB) and topoisomerase IV subunit E(parE) and the hyperexpression of genes for four efflux pump proteins in 20 previously described, fluoroquinolone-resistant clinical strains of Pseudomonas aeruginosa. Amino acid alterations were found in GyrB in five strains and in ParE in three strains with MIC of norfloxacin > or = 8 mg/L, and it is likely that some of the alterations contribute to the quinolone resistance exhibited by these strains. Seventeen of the 20 strains overproduced mRNA for one or more pump proteins (MexB, MexD, MexF, or MexY), which caused multidrug resistance phenotype in more than half of strains. Two strains were hypermutable and one of them was highly resistant, but the other strain was only moderately resistant.     

Related carbapenemase-producing <Emphasis Type="Italic">Klebsiella</Emphasis> isolates detected in both a hospital and associated aquatic environment in Sweden

Carbapenem antibiotics are one of the last-resort agents against multidrug-resistant (MDR) bacteria. The occurrence of carbapenemase-producing Enterobacteriaceae (CPE) in wastewater and aquatic environments is an indication of MDR bacteria in the community. This study evaluated CPE in aquatic environments and compared them to the local hospital isolates in Sweden. Phenotypic and genotypic analyses of antibiotic resistance of environmental and clinical CPE were performed. The relatedness of the isolates and possible clonal dissemination was evaluated using phylogenetic and phyloproteomic analysis. Klebsiella oxytoca carrying carbapenemase genes (bla_VIM-1, bla_IMP-29) were isolated from wastewater and the recipient river, while K. oxytoca (bla_VIM-1) and Klebsiella pneumoniae (bla_VIM-1, bla_OXA-48, bla_NDM-1, bla_KPC-3) were isolated from patients at the local clinics or hospital. The K. oxytoca classified as sequence type 172 (ST172) isolated from the river was genotypically related to two clinical isolates recovered from patients. The similarity between environmental and clinical isolates suggests the dispersion of bla_VIM-1 producing K. oxytoca ST172 from hospital to aquatic environment and the likelihood of its presence in the community. This is the first report of CPE in aquatic environments in Sweden; therefore, surveillance of aquatic and hospital environments for CPE in other urban areas is important to determine the major transfer routes in order to formulate strategies to prevent the spread of MDR bacteria.     

Neonate characteristics after maternal use of antidepressants in late pregnancy

BACKGROUND: Exposure to antidepressants during the third trimester of pregnancy has been associated with an increased risk for adverse birth outcomes, including preterm birth, respiratory distress, and hypoglycemia. OBJECTIVE: To investigate neonatal outcomes in 997 infants (987 mothers) after maternal use of antidepressants based on prospectively recorded information in antenatal care documents. RESULTS: An increased risk for preterm birth (odds ratio [OR], 1.96) and low birth weight (OR, 1.98) was verified, but the gestational week-specific birth weight was increased notably after exposure to tricyclic antidepressants. An increased risk for a low Apgar score (OR, 2.33), respiratory distress (OR, 2.21), neonatal convulsions (OR,1.90), and hypoglycemia (OR, 1.62) was found, the latter especially after exposure to tricyclic drugs, but no significant effect on the frequency of neonatal jaundice was seen (OR, 1.13). Most effects seemed not to be selective serotonin reuptake inhibitor drug specific, and outcomes after exposure to paroxetine hydrochloride were not worse than after exposure to other selective serotonin reuptake inhibitors. CONCLUSIONS: Neonatal effects after maternal use of antidepressant drugs during late pregnancy were seen. Selective serotonin reuptake inhibitors may be the drugs of choice during pregnancy.