Transient repolarization alterations dominate the initial phase of an acute anterior infarction — a vectorcardiography study

Objective

To study effects of ischemia-reperfusion on ventricular electrophysiology in humans by three-dimensional electrocardiography.

Methods

Fifty-seven patients with first-time acute anterior ST elevation myocardial infarction were monitored from admission and > 24 h after symptom onset with continuous vectorcardiography (VCG; modified Frank orthogonal leads). Global ventricular depolarization and repolarization (VR) measures were compared at maximum vs. minimum ST vector magnitude (STVM) (median 208; 111–303 vs. 362; 165–1359 min after symptom onset).

Results

At maximum vs. minimum STVM the Tarea (overall VR dispersion) almost tripled (118 vs. 41 μVs; p < 0.0001), the T-loop bulginess was 90% greater (Tavplan 0.91 vs 0.48 μV; p < 0.0001), and Tpeak-end/QT was 39% larger (0.32 vs 0.23; p < 0.0001). QRSarea (overall dispersion of depolarization) was 12% larger at maximum STVM, while QRS duration was 10% longer at minimum STVM.

Conclusions

Ischemia-reperfusion was accompanied by profound and transient alterations of VR dispersion, while changes in depolarization were modest and delayed.     

Formation of Pseudomonas aeruginosa inhibition zone during tobramycin disk diffusion is due to transition from planktonic to biofilm mode of growth

Pseudomonas aeruginosa PAO1 (tobramycin MIC?=?0.064 µg/mL) was used to perform agar diffusion tests employing tobramycin-containing tablets. Bacterial growth and formation of inhibition zones were studied by stereomicroscopy and by blotting with microscope slides and staining with methylene blue, Alcian blue and a fluorescent lectin for the P. aeruginosa PSL, which was studied by confocal laser scanning microscopy. Diffusion of tobramycin from the deposit was modelled using a 3D geometric version of Fick's second law of diffusion. The time-dependent gradual increase in the minimum biofilm eradication concentration (MBEC) was studied using a Calgary Biofilm Device. The early inhibition zone was visible after 5 h of incubation. The corresponding calculated tobramycin concentration at the border was 1.9 µg/mL, which increased to 3.2 µg/mL and 6.3 µg/mL after 7 h and 24 h, respectively. The inhibition zone increased to the stable final zone after 7 h of incubation. Bacterial growth and small aggregate formation (young biofilms) took place inside the inhibition zone until the small aggregates contained less than ca. 64 cells and production of polysaccharide matrix including PSL had begun; thereafter, the small bacterial aggregates were killed by tobramycin. Bacteria at the border of the stable inhibition zone and beyond continued to grow to a mature biofilm and produced large amount of polysaccharide-containing matrix. Formation of the inhibition zone during agar diffusion antimicrobial susceptibility testing is due to a switch from a planktonic to biofilm mode of growth and gives clinically important information about the increased antimicrobial tolerance of biofilms.     

Elucidating the Mechanism of Absorption of Fast-Acting Insulin Aspart: The Role of Niacinamide

Pharmaceutical Research - The aim of this work is to investigate the roles of solute carrier family 22 member 18 (SLC22A18) in lipid metabolism and in establishing the tumor phenotype of HepG2...     

Biomarker Investigations in Adult Female Perch (Perca fluviatilis) From Industrialised Areas in Northern Sweden in 2003

Since the new millennium, a notion has developed in certain parts of society that environmental pollutants and their associated effects are under control. The primary objective of this investigation, performed in 2003, was to test whether this was actually the case in an industrialised region in the County of Västernorrland in northern Sweden with well-documented environmental pollution from past and present activities. This was performed by measuring a moderate battery of simple biomarkers in adult female perch at several stations. The point sources included sewage-treatment plants, pulp and paper mills, as well as other industries. The biomarkers included growth, somatic indices, gonad maturation status, gonad pigmentation, fin erosion, skin ulcers, and ethoxyresorufin-O-deethylase (EROD) activity in the liver. The results showed that the environmental pollutants and their associated effects were not under control. In fact, the health of the perch was impaired at all of the polluted stations. Many responses were unspecific with respect to underlying cause, whereas some effects on EROD activity and gonad maturation status were attributed to historical creosote pollution and current kraft pulp mill effluents, respectively. The data presented may also be used as reference values for future investigations of health effects in perch.     

Urinary Bisphenol A Levels in Young Men: Association with Reproductive Hormones and Semen Quality

Background: Few human studies have examined bisphenol A (BPA) exposure in relation to semen quality and reproductive hormones in men, and results are divergent.Objectives: We examined associations between urinary BPA concentration and reproductive hormones, as well as semen quality, in young men from the general population.Methods: Our study population consisted of 308 young men from the general population. Urinary BPA concentration was measured by isotope dilution TurboFlow-liquid chromatography–tandem mass spectrometry. We used multiple linear regression analysis to estimate associations between BPA concentration and reproductive hormones and semen quality, adjusting for confounding factors.Results: We found that 98% of the men had detectable urinary levels of BPA. Median (5th–95th percentiles) BPA concentration was 3.25 ng/mL (0.59–14.89 ng/mL). Men with BPA concentrations above the lowest quartile had higher concentrations of serum testosterone, luteinizing hormone (LH), estradiol, and free testosterone compared with the lowest quartile (p_trend ≤ 0.02). Men in the highest quartile of BPA excretion had on average 18% higher total testosterone (95% CI: 8, 28%), 22% higher LH (95% CI: 6, 39%), and 13% higher estradiol (95% CI: 4, 24%) compared with lowest quartile. Men in the highest quartile of BPA also had significantly lower percentage progressive motile spermatozoa compared with men in the lowest quartile (–6.7 percentage points, 95% CI: –11.76, –1.63). BPA was not associated with other semen parameters. Adjusting for dietary patterns did not influence the results.Conclusions: The pattern of associations between BPA and reproductive hormones could indicate an antiandrogenic or antiestrogenic effect, or both, of BPA on the hypothalamic–pituitary–gonadal hormone feedback system, possibly through a competitive inhibition at the receptor level. However, additional research is needed to confirm our findings and to further test the suggested potential mechanisms.Citation: Lassen TH, Frederiksen H, Jensen TK, Petersen JH, Joensen UN, Main KM, Skakkebaek NE, Juul A, Jørgensen N, Andersson AM. 2014. Urinary bisphenol A levels in young men: association with reproductive hormones and semen quality. Environ Health Perspect 122:478–484; http://dx.doi.org/10.1289/ehp.1307309     

The impact of introducing new vaccines on the health system: Case studies from six low- and middle-income countries

Objective

We aimed to explore the impacts of new vaccine introductions on immunization programmes and health systems in low- and middle-income countries.

Methods

We conducted case studies of seven vaccine introductions in six countries (Cameroon, PCV; Ethiopia, PCV; Guatemala, rotavirus; Kenya, PCV; Mali, Meningitis A; Mali, PCV; Rwanda, HPV). Interviews were conducted with 261 national, regional and district key informants and questionnaires were completed with staff from 196 health facilities. Routine data from districts and health facilities were gathered on vaccination and antenatal service use. Data collection and analysis were structured around the World Health Organisation health system building blocks.

Findings

The new vaccines were viewed positively and seemed to integrate well into existing health systems. The introductions were found to have had no impact on many elements within the building blocks framework. Despite many key informants and facility respondents perceiving that the new vaccine introductions had increased coverage of other vaccines, the routine data showed no change. Positive effects perceived included enhanced credibility of the immunisation programme and strengthened health workers’ skills through training. Negative effects reported included an increase in workload and stock outs of the new vaccine, which created a perception in the community that all vaccines were out of stock in a facility. Most effects were found within the vaccination programmes; very few were reported on the broader health systems. Effects were primarily reported to be temporary, around the time of introduction only.

Conclusion

Although the new vaccine introductions were viewed as intrinsically positive, on the whole there was no evidence that they had any major impact, positive or negative, on the broader health systems.     

Remaining connected despite separation – former family caregivers’ experiences of aspects that facilitate and hinder the process of relinquishing the care of a person with dementia to a nursing home

Objectives: This qualitative study aimed to illuminate former family caregivers’ experiences of aspects that facilitate and hinder the process of relinquishing the care of a person with dementia to a nursing home.

Method: Ten narrative interviews with former family caregivers were performed and subjected to qualitative content analysis.

Results: An overall theme showed that family caregivers were remaining connected to the person with dementia despite separation. They experienced being ‘caught by surprise’ when the placement occurred. Negative expectations of dementia care made the separation more difficult. Lacking adequate information increased feelings of insecurity. Despite these hurdles, family caregivers found meaning in the new situation as they felt that they could remain connected to their loved one. Being recognized as partners in care of the person with dementia after placement was a facilitating aspect. Family caregivers regarded a well-functioning interaction with staff and a supportive social network as reassuring since they facilitated staying in touch.

Conclusion: Knowledge of the relinquishing process and adequate information about dementia and its progression may help family caregivers better prepare for and adapt to the situation. Family caregivers need to be recognized as partners in care and a welcoming nursing home environment is of utmost importance.     

Exposure to respirable dust and manganese and prevalence of airways symptoms,among Swedish mild steel welders in the manufacturing industry

Purpose

Welding fume consists of metal fumes, e.g., manganese (Mn) and gases, e.g., ozone. Particles in the respirable dust (RD) size range dominate. Exposure to welding fume could cause short- and long-term respiratory effects. The prevalence of work-related symptoms among mild steel welders was studied, and the occupational exposure to welding fumes was quantified by repeated measurements of RD, respirable Mn, and ozone. Also the variance components were studied.

Method

A questionnaire concerning airway symptoms and occupational history was answered by 79 % of a cohort of 484 welders. A group of welders (N = 108) were selected and surveyed by personal exposure measurements of RD and ozone three times during 1 year.

Results

The welders had a high frequency of work-related symptoms, e.g., stuffy nose (33 %), ocular symptoms (28 %), and dry cough (24 %). The geometric mean exposure to RD and respirable Mn was 1.3 mg/m³ (min–max 0.1–38.3 mg/m³) and 0.08 mg/m³ (min–max <0.01–2.13 mg/m³), respectively. More than 50 % of the Mn concentrations exceeded the Swedish occupational exposure limit (OEL). Mainly, low concentrations of ozone were measured, but 2 % of the samples exceeded the OEL. Of the total variance for RD, 30 and 33 % can be attributed to within-worker variability and between-company variability, respectively.

Conclusions

Welders had a high prevalence of work-related symptom from the airways and eyes. The welders’ exposure to Mn was unacceptably high. To reduce the exposure further, control measures in the welding workshops are needed. Correct use of general mechanical ventilation and local exhaust ventilation can, for example, efficiently reduce the exposure.     

Fatigue in patients with spinal muscular atrophy type II and congenital myopathies: evaluation of the fatigue severity scale

Purpose

The aim of this study was to evaluate whether the fatigue severity scale (FSS) is an appropriate instrument to assess fatigue in patients with spinal muscular atrophy type II (SMA II) and congenital myopathies (CM).

Methods

FSS and visual analog scale (VAS) were administered to 33 SMA II- and 72 CM patients. The psychometric properties of the FSS were evaluated by means of classical test theories for each of the disease groups. If abnormal fatigue was present in the disease group, the construct of fatigue was evaluated by means of focus group interviews.

Results

Fatigue was rare in SMA II patients, but very frequent in patients with CM. The cut-off score designating abnormal fatigue (FSS score ≥ 4) was exceeded by 10 % of the SMA II patients in contrast to 76 % of the CM patients, of whom 52 % suffered from severe fatigue (FSS score ≥ 5). Focus group interviews demonstrated that fatigue had an adverse effect on motor function, level of energy, social relations, and identity, four themes that could be captured by the FSS. The FSS and VAS were strongly correlated in SMA II patients, but only moderately in CM patients. The psychometric properties indicated that the original FSS with nine items measures more than one construct of fatigue, eliminating the first two items improved scale properties.

Conclusion

This study demonstrates that fatigue is characteristic in patients with CM, but not in patients with SMA II, in whom fatigue does not seem to impact daily life. While fatigue in CM and SMA II can be captured by FSS, omitting the first two items of the scale will improve its properties and content validity, along with comprehension of the scale itself.     

Reactive groups on polymer covered electrodes, 4. Lactate-oxidase-biosensor based on electrodes modified by polythiophene

Electrocopolymerization of 3-thiopheneacetic acid ( 1 ) and 3-methylthiophene ( 2 ) under various conditions produces poly{(3-methylthiophene-2,5-diyl)-co-[3-(carboxymethyl)thiophene-2,5-diyl]} ( 3 ). By activation of the carboxy groups with dicyclohexylcarbodiimide (DCC) lactate oxidase (LOD) is covalently bonded to the surface of the electrode. In this way a lactate sensor was formed which is applicable for the determination of lactate in micromolar concentrations.