Handgrip Strength in People With Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

The purpose of this study was to systematically review the association between handgrip strength (HGS) and mortality, morbidity, and health-related quality of life (HRQL) in individuals with chronic obstructive pulmonary disease (COPD).

METHODS

The following databases were used: CENTRAL, CINAHL, EMBASE, MEDLINE Ovid, SPORTDiscus, and PsycINFO. Studies published between 2000 and 2020 in English, Portuguese, or French that examined the association of HGS with mortality, morbidity, and HRQL in individuals with stable COPD were selected. Two authors independently extracted data and assessed the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework. The study effects were pooled using random effects meta-analysis models after assessing heterogeneity. The search generated 710 studies, and 18 were included in the review. Studies evaluated a total of 12,046 individuals with stable COPD (mean percent of the predicted forced expiratory volume in 1 second = 34%-80%) using over 10 diverse protocols for HGS measurement. Statistically significant, small, and negative relationships were found between HGS and mortality (r = -0.03; 95% CI = -0.05 to -0.02). Independent of the outcome measure used to assess morbidity, the estimate of the overall relationship was small to moderate and negative: Body Mass Index, Airflow Obstruction, Dyspnea, and Exercise Index Updated (r = -0.42; 95% CI = -0.61 to -0.03); exacerbations (r = -0.02; 95% CI = -0.04 to -0.00); and hospitalizations (r = -0.69; 95% CI = -1.70 to 0.32). Similarly, for HRQL, independent of the outcome measure, the estimate of the overall relationship was small to fair and negative: COPD Assessment Test (weighted r = -0.22; 95% CI = -0.32 to -0.12), Chronic Respiratory Disease Questionnaire domains (-0.24 < r < -0.14), EuroQol Five-Dimension Questionnaire (utility score) (r = -0.17; 95% CI = -0.26 to -0.07), EuroQol Five-Dimension Questionnaire domains (-0.32 < r < -0.06), and St George Respiratory Questionnaire total (r = -0.26; 95% CI = -0.33 to -0.17). The quality of the evidence ranged from low to very low across outcomes.

CONCLUSION

Although heterogeneity was present among HGS measurement protocols, small to moderate associations were found, indicating that those with lower HGS have an increased likelihood of death, a higher risk of increased COPD morbidity (as assessed with Body Mass Index, Airflow Obstruction, Dyspnea and Exercise Capacity indexes), and poorer HRQL.

History of safe use as applied to the safety assessment of novel foods and foods derived from genetically modified organisms

Very few traditional foods that are consumed have been subjected to systematic toxicological and nutritional assessment, yet because of their long history and customary preparation and use and absence of evidence of harm, they are generally regarded as safe to eat. This 'history of safe use' of traditional foods forms the benchmark for the comparative safety assessment of novel foods, and of foods derived from genetically modified organisms. However, the concept is hard to define, since it relates to an existing body of information which describes the safety profile of a food, rather than a precise checklist of criteria. The term should be regarded as a working concept used to assist the safety assessment of a food product. Important factors in establishing a history of safe use include: the period over which the traditional food has been consumed; the way in which it has been prepared and used and at what intake levels; its composition and the results of animal studies and observations from human exposure. This paper is aimed to assist food safety professionals in the safety evaluation and regulation of novel foods and foods derived from genetically modified organisms, by describing the practical application and use of the concept of 'history of safe use'.

Evidence for a telomere-independent "clock" limiting RAS oncogene-driven proliferation of human thyroid epithelial cells

An initiating role for RAS oncogene mutation in several epithelial cancers is supported by its high incidence in early-stage tumors and its ability to induce proliferation in the corresponding normal cells in vitro. Using retroviral transduction of thyroid epithelial cells as a model we ask here: (i) how mutant RAS can induce long-term proliferation in an epithelial cell in contrast to the premature senescence observed in fibroblasts; and (ii) what is the "clock" which eventually triggers spontaneous growth arrest even in epithelial clones generated by mutant RAS. The early response to RAS activation in thyroid epithelial cells showed two features not seen in fibroblasts: (i) a marked decrease in expression of the cyclin-dependent kinase inhibitor (CDKI) p27(kip1) and (ii) the absence of any induction of p21(waf1). When proliferation eventually ceased (after up to 20 population doublings) this occurred despite undiminished expression of mutant RAS and was tightly correlated with a return to the initial high level of p27(kip1) expression, together with the de novo appearance of p16(ink4a). Importantly, neither the CDKI changes nor the proliferative life span of RAS-induced epithelial clones was altered by induction of telomerase activity through forced expression of the catalytic subunit, hTERT, at levels sufficient to immortalize human fibroblasts. These data provide a basis for cell-type differences in sensitivity to RAS-induced proliferation which may explain the corresponding tumor-type specificity of RAS mutation. They also show for the first time in a primary human cell model that a telomere-independent mechanism can limit not only physiological but also oncogene-driven proliferation, pointing therefore to a tumour suppressor mechanism additional, or alternative, to the telomere clock.

A cautionary note regarding the application of Ki-67 antibodies to paraffin-embedded breast cancers

Immunocytochemical studies examining the Ki-67 proliferation marker in paraffin-embedded material have recently been made possible by the availability of several antibodies, notably MIB-1, which are readily applicable to microwaved sections. Using breast cancer material, the present study examines correlations shown by these new paraffin assays and also by PCNA (proliferating cell nuclear antigen), an existing marker of proliferation, with the established Ki-67 cryosection assay. Paraffin sections were microwaved prior to incubation with Ki-67 or MIB-1 antibodies. Signal detection was carried out with a biotinylated secondary antibody, peroxidase-conjugated streptavidin, and DAB/H2O2 chromogen. The results suggest that caution is required when studying proliferation in paraffin-embedded breast cancers by immunostaining using Ki-67 antibodies. Nuclear staining in wax sections (Ki-Par, MIB-1, PCNA) greatly exceeded that in cryosections (Ki-Froz) and thus correlations were notably absent between Ki-Par or PCNA immunostaining and the routine Ki-Froz assay. Immunostaining with MIB-1 or PCNA may, however, be useful to assess proliferation if cut-offs are applied to eliminate weak immunostaining associated with wax sections. Thus, an approximately linear relationship was seen between MIB-1/Ki-Froz, which was improved if only moderately or moderately/strongly MIB-1-positive cells were scored. Similarly, a significant correlation was also revealed between PCNA/Ki-Froz if such a cut-off was applied.

Identity of some human bladder cancer cell lines

Recent reports on transfection of mouse cells with DNA from the established human urinary bladder cancer cell lines T24, J82 and EJ (MGH-U1), and the presence of an identical genetic modification in T24 and EJ cells have led us to examine the identity of these and other cultures of urothelial origin. By the criteria of HLA-A-B-C typing 7 and isozyme analysis, we conclude that EJ (MGH-U1) and some cultures of J82 are in fact T24 cells. However, five other bladder cancer cell lines, J82 (CO'T), RT4, RT112, TCCSuP and SCaBER, are clearly distinct from T24 by HLA typing (ref. 7) and/or isozyme patterns.

The inhibition of staphylococcal beta-lactamase by clavulanic acid

Clavulanic acid inhibited both the extracellular and cell-extract beta-lactamases of the four Staphylococcus aureus strains tested. The inhibition of S. aureus Russell cell-extract enzyme appeared to be active-site-directed and proceeded in a first-order fashion consistent with the formation of a covalent intermediate. Inhibited enzyme free of excess clavulanic acid was shown to regenerate enzyme activity slowly at pH 7.0, but the rate of reactivation increased at acid pH. When the enzyme was incubated with excess clavulanic acid complete inhibition was rapidly obtained, during further incubation clavulanic acid was shown to disappear slowly and complete loss of clavulanic acid from the reaction mixture coincided with the onset of the return of enzyme activity. A reactive enamine resulting from enzymic hydrolysis of the beta-lactam ring of clavulanic acid has been proposed as a possible intermediate in the inhibitory mechanism.