Is Borg’s perceived exertion scale a useful indicator of muscular and cardiovascular load in blue-collar workers with lifting tasks? A cross-sectional workplace study

Purpose

To investigate associations between perceived exertion and objectively assessed muscular and cardiovascular load during a full working day among workers with manual lifting tasks.

Methods

A total of 159 men and 41 women from 14 workplaces with manual lifting tasks participated. Participants reported perceived exertion (BORG-CR10) at midday and after work. Surface electromyography of the thigh, lower back and neck muscles were normalized to isometric voluntary contractions (MVC) to express relative muscle load during the day. Cardiovascular load was measured with electrocardiography and calculated as the average percentage of the heart rate reserve capacity (((heart rate during work – resting heart rate) / (maximum heart rate ? resting heart rate)) * 100) during the day.

Results

Using linear regression, significant but weak associations (β < 0.23) were observed between perceived exertion and (1) high muscle activity (>60 % of MVC) of the neck muscles and (2) inactivity (<1 % of MVC) of the thigh muscles and (3) cardiovascular load, respectively. Using logistic regression, perceived exertion ≥4 (high exertion), referencing <4 (low-to-moderate exertion), was related to high activity of the trapezius muscle [OR 18 (95 % CI 2–143)], i.e., the odds for experiencing high exertion during work increased 18-fold for each percentage increase in time above 60 % MVC.

Conclusions

During a full working day among blue-collar workers with lifting tasks, high neck muscle activity increases the odds for experiencing high perceived physical exertion. Perceived exertion of at least 4 on the BORG CR10 scale appears to be a good indicator that high muscular loading occurs.     

Satisfaction levels of paediatric surgeons in Canada

BACKGROUND:

Surgeons’ satisfaction levels may affect patient care and the stability of the surgical workforce.

METHODS:

A detailed Internet-based satisfaction survey was administered to paediatric surgeons in Canada in 2005 and 2012. Satisfaction was rated 1 (most) to 5 (least), in five areas: quality of life, financial compensation, work environment, academics and patient care.

RESULTS:

Responses were received from 21 surgeons in 2005 and 61 in 2012, representing 43% and 98% of practicing paediatric surgeons in Canada, respectively. Satisfaction levels were generally moderate to high in most areas during both years. In academics, surgeons were more satisfied in 2012 with the amount of teaching they provided (1.8 versus 2.2; P=0.02), and clinical research they performed (2.5 versus 3.0; P=0.04). In patient care, there was higher satisfaction with the ability to provide elective services without impediment (2.5 versus 3.0; P=0.02). Over the seven-year period, surgeons increasingly preferred the Canadian health care system over that of the United States (1.7 versus 2.2; P=0.02). In the 2012 survey, no differences in levels of satisfaction were found between male and female surgeons.

CONCLUSIONS:

During the recent seven-year period, satisfaction levels of paediatric surgeons in Canada have been stable with regard to quality of life, compensation and work environment, and improving in areas of academics and patient care. Male and female surgeons are equally satisfied. The Canadian health care system is preferred over that of the United States.     

A metastatic neuroblastoma model in SCID mice

Neuroblastoma (NB), a neural crest derived tumor in children, shows a characteristic pattern of dissemination that includes adrenal glands, local lymph nodes, bone, liver, skin, and bone marrow. We have reconstructed a similar metastatic pattern in SCID mice following tail vein injection of human NB cells. HTLA230, an NB cell line isolated from a patient with advanced disease, and its NGF receptor (trkA) expressing derivative (18–10) cells, consistently disseminated to the liver, the adrenal gland, and the bone marrow, but not the lungs. Metastases in the different organs showed a characteristic hemorrhagic histopathology, and tumors in the bone marrow presented as syncytia-like cell aggregates, typically seen in patients. Cell lines reestablished from 18–10 derived liver and bone marrow metastases maintained their cellular morphology, growth behavior, N-myc overexpression, trkA expression, and functionally responded to NGF treatment, leading to growth arrest and neurite outgrowth. Hence, circulating human NB cells in SCID mice show a similar organ-specific metastatic potential as seen in patients, independent of trkA expression. © 1996 Wiley-Liss, Inc.     

Physician visits by rheumatoid arthritis patients: A prospective analysis

Obejective. To examine prospectively, using the behavioral model of health service utilization, patient-initiated physician visits, physician-requested visits, and visits for disease flares by 270 patients with rheumatoid arthritis (RA). Methods. Four waves of telephone interviews were conducted over 2 years. Hierarchical regression analyses were used to assess the relative contributions to variance explained by blocks of variables indicating need for care and predisposing and enabling factors. Results. Predisposing and enabling factors accounted for 50–67% of the explained variance in the 3 types of visits, while need accounted only for 33–50%. Conclusions. Studies seeking to identify factors other than need for care that facilitate or inhibit physician visits among RA patients are essential to analyzing the costs of care.     

Temporary loss of perivascular aquaporin-4 in neocortex after transient middle cerebral artery occlusion in mice

The aquaporin-4 (AQP4) pool in the perivascular astrocyte membranes has been shown to be critically involved in the formation and dissolution of brain edema. Cerebral edema is a major cause of morbidity and mortality in stroke. It is therefore essential to know whether the perivascular pool of AQP4 is up- or down-regulated after an ischemic insult, because such changes would determine the time course of edema formation. Here we demonstrate by quantitative immunogold cytochemistry that the ischemic striatum and neocortex show distinct patterns of AQP4 expression in the reperfusion phase after 90 min of middle cerebral artery occlusion. The striatal core displays a loss of perivascular AQP4 at 24 hr of reperfusion with no sign of subsequent recovery. The most affected part of the cortex also exhibits loss of perivascular AQP4. This loss is of magnitude similar to that of the striatal core, but it shows a partial recovery toward 72 hr of reperfusion. By freeze fracture we show that the loss of perivascular AQP4 is associated with the disappearance of the square lattices of particles that normally are distinct features of the perivascular astrocyte membrane. The cortical border zone differs from the central part of the ischemic lesion by showing no loss of perivascular AQP4 at 24 hr of reperfusion but rather a slight increase. These data indicate that the size of the AQP4 pool that controls the exchange of fluid between brain and blood during edema formation and dissolution is subject to large and region-specific changes in the reperfusion phase.     

Bacterial invasion of vascular cell types: vascular infectology and atherogenesis

To portray the chronic inflammation in atherosclerosis, leukocytic cell types involved in the immune response to invading pathogens are often the focus. However, atherogenesis is a complex pathological deterioration of the arterial walls, where vascular cell types are participants with regards to deterioration and disease. Since other recent reviews have detailed the role of both the innate and adaptive immune response in atherosclerosis, herein we will summarize the latest developments regarding the association of bacteria with vascular cell types: infections as a risk factor for atherosclerosis; bacterial invasion of vascular cell types; the atherogenic sequelae of bacterial presence such as endothelial activation and blood clotting; and the identification of the species that are able to colonize this niche. The evidence of a polybacterial infectious component of the atheromatous lesions opens the doors for exploration of the new field of vascular infectology and for the study of atherosclerosis microbiome.     

Ueber die Fettresorption und die Entstehung der Becherzellen

Ohne ZusammenfassungHierzu Taf. XIV.     

Distinguishing Incubation and Acute Disease Stages of Mild-to-Moderate COVID-19

While numerous studies have already compared the immune responses against SARS-CoV-2 in severely and mild-to-moderately ill COVID-19 patients, longitudinal trajectories are still scarce. We therefore set out to analyze serial blood samples from mild-to-moderately ill patients in order to define the immune landscapes for differently progressed disease stages. Twenty-two COVID-19 patients were subjected to consecutive venipuncture within seven days after diagnosis or admittance to hospital. Flow cytometry was performed to analyze peripheral blood immune cell compositions and their activation as were plasma levels of cytokines and SARS-CoV-2 specific immunoglobulins. Healthy donors served as controls. Integrating the kinetics of plasmablasts and SARS-CoV-2 specific antibodies allowed for the definition of three disease stages of early COVID-19. The incubation phase was characterized by a sharp increase in pro-inflammatory monocytes and terminally differentiated cytotoxic T cells. The latter correlated significantly with elevated concentrations of IP-10. Early acute infection featured a peak in PD-1⁺ cytotoxic T cells, plasmablasts and increasing titers of virus specific antibodies. During late acute infection, immature neutrophils were enriched, whereas all other parameters returned to baseline. Our findings will help to define landmarks that are indispensable for the refinement of new anti-viral and anti-inflammatory therapeutics, and may also inform clinicians to optimize treatment and prevent fatal outcomes.