Fat-Free Adipose Tissue Mass: Impact on Peak Oxygen Uptake ( V O 2peak ) in Adolescents with and without Obesity

Abstract

Fat-free body mass (FFM) is a surrogate for skeletal muscle mass and is often used for the normalization of several physiological variables (e.g., oxygen uptake). However, FFM includes non-skeletal muscle components such as the fat-free component of adipose tissue fat cells. As the amount of adipose tissue mass increases, the FFM will also increase and be included in the measurement of FFM. Therefore, FFM may not be an appropriate indicator of muscle mass when targeting individuals with a large amount of body fat. This review aimed (1) to examine the fat-free adipose tissue (FFAT) in adolescents with and without obesity and (2) to investigate the impact of FFAT on peak oxygen uptake (VO_2peak) by comparing VO_2peak expressed relative to FFM and FFM minus FFAT between adolescents with and without obesity. Calculated FFAT was threefold higher in adolescents with obesity compared to those without obesity (mean ± SD; 6.94 ± 1.40 vs. 2.22 ± 0.58 kg). The VO_2peak expressed relative to FFM-FFAT was similar between the two groups (56.5 ± 6.7 vs. 57.4 ± 8.9 ml min⁻¹ kg⁻¹ FFM-FFAT, respectively). On the other hand, VO_2peak expressed relative to FFM was approximately 8% different between groups. When normalizing VO_2peak by FFM, eliminating the FFAT component from FFM may be needed, especially when comparing groups with different body fat mass.

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Kinematic Parameters of Movement at the Shoulder Joint in Normal Gait in Humans

Study objective: to determine the kinematic parameters of the shoulder joint in the normal human gait. Materials and methods. A Vicon programmable system for motion capture and analysis was used to study 10 selected men with near-absolute symmetry of upper limb movements. Results. Quantitative measures of kinematic movement parameters at the shoulder joint in the arm transfer cycle during walking were obtained. Flexion-extension and abduction of the upper limbs during the stepping cycle were symmetrical and coincided with the minimal internal rotation only in the middle of the cycle. Swinging of the arms during walking can be compared with the movements of a pendulum with its center at the shoulder joint with a movement amplitude of 24.6 ± 2.4°. Conclusions. The data obtained here serve as standards and provide for comparative analysis of upper limb movements in patients with arm locomotion disorders, and are also of value in prosthetization and robotics.

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Both Bupivacaine and Levobupivacaine inhibit colon cancer cell growth but not melanoma cells in vitro

Abstract

Background

Retrospective studies indicate that the use of regional anaesthesia causes a reduction in cancer recurrence after oncological surgery, which could be due to anaesthetic's negating effect on immunosuppression related to the surgical stress response. Local anaesthetics may also exert direct suppressive effects on malignant cells, an area where further investigation is urgently needed.

Methods

Human colon cancer cells and human melanoma cells were cultured and then treated with 1 mM bupivacaine or levobupivacaine for up to 24 or 48 h. Their migratory ability was measured by scratch assay, proliferation determined with Ki67 immunofluorescence staining, and apoptosis accessed with annexin V and PI staining on flow cytometry. The effects of bupivacaine and levobupivacaine on cellular signaling and molecular response, specifically, on endoplasmic reticulum stress (ERS), were studied with immunostaining and western blot.

Results

In colon cancer cells, treatment with bupivacaine and levobupivacaine significantly inhibited cell migration (**p < 0.01, ***p < 0.001; n = 4) and proliferation (**p < 0.01; n = 4), while increasing the expression of CHOP (***p < 0.001; n = 4) and decreased the expression of Grp78 (*p < 0.05; n = 4). These effects were not mirrored by melanoma cells, such that no significant increase in apoptosis was seen in either melanoma cell lines following treatment.

Conclusion

These in vitro data suggested that both bupivacaine and levobupivacaine suppress colorectal adenocarcinoma cell proliferation and migration, which are concurrent with increased endoplasmic reticulum stress. Conversely, melanoma cells are more resilient to these two commonly used local anaesthetics. Further in vivo studies or clinical trials are needed.

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Anodal transcranial direct current stimulation does not influence the neural adjustments associated with fatiguing contractions in a hand muscle

Abstract

Purpose

The objective of the current study was to investigate the mechanisms responsible for the briefer time to failure of a submaximal contraction (C2) when performed 60 min after a similar contraction (C1), and the influence of anodal transcranial direct current stimulation (a-tDCS) applied over the motor cortex on these mechanisms.

Methods

In two sessions, ten adults sustained two isometric contractions (35% of maximum) to failure with the abductor pollicis brevis (APB). Before C2, either a-tDCS or sham stimulation was applied over the motor cortex. Fatigue-related changes in Hoffmann (H) and long-latency (LLR) reflexes, motor-evoked potential (MEP) induced by transcranial magnetic stimulation and associated silent period (SP), maximal motor wave (M_max), voluntary activation (VA), electromyographic (EMG) activity and peak force (PT₃) evoked by a 3 pulse-train (100 Hz) were investigated.

Results

The results indicate that regardless of session, the time to failure was briefer (− 13%, p < 0.05) for C2 than C1, with no a-tDCS effect. During C1, MEP amplitude, SP duration and LLR amplitude increased, H-reflex amplitude did not change, and M_max, VA and PT₃ decreased (p < 0.05). Except for EMG activity that was greater during C2 than C1 (p < 0.001), all variables were similar in C1 and C2 (p > 0.05), and recovered their initial values after the 60-min rest, except PT₃.

Conclusions

The results of the current study indicate that a-tDCS did not influence corticospinal excitability and time to failure of C2 when performed with the APB. These observations may reflect a peripheral origin of the briefer C2 time to failure in the APB.

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Genotype Imputation in Winter Wheat Using First-Generation Haplotype Map SNPs Improves Genome-Wide Association Mapping and Genomic Prediction of Traits

Genome-wide single nucleotide polymorphism (SNP) variation allows for the capture of haplotype structure in populations and prediction of unobserved genotypes based on inferred regions of identity-by-descent (IBD). Here we have used a first-generation wheat haplotype map created by targeted re-sequencing of low-copy genomic regions in the reference panel of 62 lines to impute marker genotypes in a diverse panel of winter wheat cultivars from the U.S. Great Plains. The IBD segments between the reference population and winter wheat cultivars were identified based on SNP genotyped using the 90K iSelect wheat array and genotyping by sequencing (GBS). A genome-wide association study and genomic prediction of resistance to stripe rust in winter wheat cultivars showed that an increase in marker density achieved by imputation improved both the power and precision of trait mapping and prediction. The majority of the most significant marker-trait associations belonged to imputed genotypes. With the vast amount of SNP variation data accumulated for wheat in recent years, the presented imputation framework will greatly improve prediction accuracy in breeding populations and increase resolution of trait mapping hence, facilitate cross-referencing of genotype datasets available across different wheat populations.

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CRISPR/Cas9 Methodology for the Generation of Knockout Deletions in Caenorhabditis elegans

The Caenorhabditis elegans Gene Knockout Consortium is tasked with obtaining null mutations in each of the more than 20,000 open reading frames (ORFs) of this organism. To date, approximately 15,000 ORFs have associated putative null alleles. As there has been substantial success in using CRISPR/Cas9 in C. elegans, this appears to be the most promising technique to complete the task. To enhance the efficiency of using CRISPR/Cas9 to generate gene deletions in C. elegans we provide a web-based interface to access our database of guide RNAs (https://ift.tt/2lH39WK). When coupled with previously developed selection vectors, optimization for homology arm length, and the use of purified Cas9 protein, we demonstrate a robust and effective protocol for generating deletions for this large-scale project. Debate and speculation in the larger scientific community concerning off-target effects due to non-specific Cas9 cutting has prompted us to investigate through whole genome sequencing the occurrence of single nucleotide variants and indels accompanying targeted deletions. We did not detect any off-site variants above the natural spontaneous mutation rate and therefore conclude that this modified protocol does not generate off-target events to any significant degree in C. elegans. We did, however, observe a number of non-specific alterations at the target site itself following the Cas9-induced double-strand break and offer a protocol for best practice quality control for such events.

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Preferences for in‐person disclosure: Patients declining telephone disclosure characteristics and outcomes in the multi‐center COGENT Study

Telephone disclosure of cancer genetic test results is non‐inferior to in‐person disclosure. However, how patients who prefer in‐person communication of results differ from those who agree to telephone disclosure is unclear but important when considering delivery models for genetic medicine. Patients undergoing cancer genetic testing were recruited to a multi‐center, randomized, non‐inferiority trial (NCT01736345) comparing telephone to in‐person disclosure of genetic test results. We evaluated preferences for in‐person disclosure, factors associated with this preference and outcomes compared to those who agreed to randomization. Among 1178 enrolled patients, 208 (18%) declined randomization, largely given a preference for in‐person disclosure. These patients were more likely to be older (p=0.007) and to have had multi‐gene panel testing (p<0.001). General anxiety (p=0.007), state anxiety (p=0.008), depression (p=0.011), cancer‐specific distress (p=0.021) and uncertainty (p=0.03) were higher after pre‐test counseling. After disclosure of results, they also had higher general anxiety (p=0.003), depression (p=0.002) and cancer‐specific distress (p=0.043). While telephone disclosure is a reasonable alternative to in‐person disclosure in most patients, some patients have a strong preference for in‐person communication. Patient age, distress and complexity of testing are important factors to consider and requests for in‐person disclosure should be honored when possible.

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