scholarly journals Plasma lactate responses during and after submaximal handgrip exercise are not diagnostically helpful in mitochondrial myopathy

Mitochondrion ◽  
2021 ◽  
Author(s):  
Nicoline Løkken ◽  
Sofie Vinther Skriver ◽  
Tahmina Khawajazada ◽  
Jesper Helbo Storgaard ◽  
John Vissing
Author(s):  
Michael P. Dubé ◽  
Douglas W. Kitch ◽  
Robert A. Parker ◽  
Beverly L. Alston-Smith ◽  
Kathleen Mulligan

AbstractPlasma lactate measurements are typically performed in real time, limiting their usefulness in multicenter or longitudinal studies. To determine the stability of lactate specimens, blood was drawn in sodium fluoride/potassium oxalate tubes from 13 volunteers before and after 5min of handgrip exercise to intentionally increase lactate concentrations. Plasma was stored at −70°C. Aliquots were assayed in real time and after 1, 3, 6, 9, 12, 18, and 24months. Real-time lactate concentrations measured at baseline ranged from 0.52 to 2.23mmol/L before and from 2.91 to 11.04mmol/L after handgrip exercise. Using a linear mixed model, the estimated change from baseline at month 24 was 1.67% (95% confidence interval, −0.70% to 4.03%) for pre-exercise samples and 0.39% (95% CI, −1.13% to 1.91%) for post-exercise samples. Stored serial specimens from 232 HIV-infected subjects in a multicenter trial of antiretroviral therapy were also assayed centrally. Among those, median plasma lactate increased from baseline to 64weeks by 0.4mmol/L with zidovudine+lamivudine treatment and by 0.6mmol/L with didanosine+stavudine (each p<0.001 from baseline; p=0.04 for difference between groups over time). When performed as in this study, frozen storage with central batch lactate analysis is appropriate for prospectively collected samples in multicenter trials.


Author(s):  
J. A. Clarke ◽  
D. N. Landon ◽  
P. R. Ward

Intra-mitochondrial crystals have been noted in muscle biopsies from patients in a wide variety of diseased states. As far as we are aware, none of these crystals have been subjected to detailed crystallographic analysis. Recently, similar crystals were observed in a biopsy from a patient with a mitochondrial myopathy, characterised by a deficiency in reducible cytochrome b (Morgan-Hughes, J. A., Darveniza, P., Kahn, S. N., Landon, D. N., Sherratt, R. M., Land, J. M. and Clark, J. B., 1977, Brain, In Press). Aldehyde-fixed, osmicated resin imbedded material was examined using Siemens, JEOL and Phillips electron microscopes with goniometer specimen stages. The crystals generally lay between the outer and inner mitochondrial membranes and measured 1 - 3 μm in length and 0.1 - 0.3 μm in width. Characteristically, these crystals revealed specific periodicities.


Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 229-LB
Author(s):  
NICHOLAS T. BROSKEY ◽  
TERRY E. JONES ◽  
ZHEN YANG ◽  
NKAUJYI KHANG ◽  
DONGHAI ZHENG ◽  
...  

2006 ◽  
Vol 3 (2) ◽  
pp. 83-86
Author(s):  
V. P. Varshney ◽  
Mona Bedi ◽  
Bharti Bhandari ◽  
Jyotsna Bhatnagar

2021 ◽  
Vol 28 (3) ◽  
pp. 328-338
Author(s):  
Ogbutor Udoji Godsday ◽  
Nwangwa Eze Kingsley ◽  
Nwogueze Bartholomew Chukwuebuka ◽  
Chukwuemeka Ephraim ◽  
Ezunu Emmanuel ◽  
...  

Decline in normal physiological pulmonary function has been attributed to premorbid conditions such as prehypertension. Research evidence suggests that physical activity reduces age-related decline in pulmonary function and improves the efficiency of the lungs in prehypertensive patients. However, there is a scarcity of data evidence relating to isometric exercise and pulmonary function. Furthermore, the interrelationship between the intensity and duration of isometric exercise and pulmonary function in these patients is still uncertain. Therefore, this study was undertaken to investigate the effect of isometric handgrip exercise on pulmonary function capacity in adults with prehypertension. To determine the effectiveness of isometric handgrip exercise on pulmonary function capacity in adults with prehypertension. A quasi experiment using a pre- and post-exercise method was carried out in two out-patients hospital settings. The sample comprised 192 sedentary pre-hypertensive subjects, aged between 30–50 years, that were randomly distributed into three groups of 64 participants each. The subjects performed, for 24 consecutive days, an isometric handgrip exercise at 30% Maximum Voluntary Contraction (M.V.C.). At the end of the 24 days, group one (GP1) discontinued, while group two (GP2) continued the exercise protocol for another 24 consecutive days and group three (GP3) continued with the exercise protocol for another 24 consecutive days but at 50% M.V.C. Determinants of lung function (outcomes) were Forced Expiratory Volume in 1 s (FEV1), Forced Vital Capacity (FVC), FEV1/FVC Ratio and Peak Expiratory Flow Rate (PEFR). The study shows that there was no statistically significant difference in the pre- and post-exercise outcomes for FEV1, FVC, FEV1/FVC Ratio and PEFR after 24 days for group 1. In group 2, there was a statistically significant difference in the FVC [(mean = 0.12 ± 0.12), (p = 0.002)], FEV1 [(mean = 0.15 ± 0.17), (p = 0.003)] and PEF [(mean = 0.85 ± 0.35), (p = 0.001)] after 48 days. In group 3, there was a statistically significant difference (p = 0.001) in all the outcomes assessed after 48 days. There was a between groups difference in favour of group 2 compared with group 1 for outcomes of FEV1 [(mean = 0.142 ± 0.68), (p = 0.005)] and PEF [(mean = 0.83 ± 0.19), (p = 0.0031)]. There was statistically significant difference in favour of group 3 compared to group 2, by increasing the exercise intensity from 30% to 50% M.V.C., for outcomes of FVC [mean change = 0.10 ± 0.052), (p = 0.005)], FEV1/FVC [mean change = 3.18 ± 0.75), (p = 0.017)] and PEF [(mean change = 0.86 ± 0.35), (p = 0.001)] after 48 days. Isometric handgrip exercise (after 48 days at 30% to 50% M.V.C.) improves outcomes of pulmonary function capacity in adults with prehypertension. Meanwhile, duration and/or increase in intensity of the isometric effort significantly contributed to the affects attained.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Seong Taeg Kim ◽  
Yeekyoung Ko ◽  
Jong-Wook Beom ◽  
Ki Yung Boo ◽  
Jae-Geun Lee ◽  
...  

Abstract Background Arterial stiffness is associated with myocardial ischemia and incident coronary artery disease (CAD), and indexes of arterial stiffness are usually increased in patients with CAD. However, these indexes are often increased in elderly without CAD. Arterial stiffness in patients with CAD may become more evident after isometric handgrip exercise which increases systolic pressure and ventricular afterload. We investigated the association of the change of stiffness indexes after isometric handgrip exercise with the lesion extent of CAD and the necessity for coronary revascularization. Methods Patients who were scheduled a routine coronary angiography via a femoral artery were enrolled. Arterial waveforms were traced at aortic root and external iliac artery using coronary catheters at baseline and 3 min after handgrip exercise. Augmentation index (AIx) was measured on the recorded aortic pressure waveform, and pulse wave velocity (PWV) was calculated using the ECG-gated time difference of the upstroke of arterial waveforms and distance between aortic root and external iliac artery. Results Total 37 patients were evaluated. Both PWV and AIx increased after handgrip exercise. ΔPWV was significantly correlated with ΔAIx (r = 0.344, P = 0.037). Patients were divided into higher and lower ΔPWV or ΔAIx groups based on the median values of 0.4 m/sec and 3.3%, respectively. Patients with higher PWV had more 2- or 3-vessel CAD (69% vs. 27%, P = 0.034), and underwent percutaneous coronary intervention (PCI) more frequently (84% vs. 50%, P = 0.038), but higher ΔAIx was not associated with either the lesion extent or PCI. Area under curve (AUC) of ΔPWV in association with PCI by C-statistics was 0.70 (95% confidence interval [CI] 0.51–0.88; P = 0.056). In multiple logistic regression analysis, ΔPWV was significantly associated with PCI (odds ratio 7.78; 95% CI 1.26–48.02; P = 0.027). Conclusions Higher ΔPWV after isometric handgrip exercise was associated with the lesion extent of CAD and the necessity for coronary revascularization, but higher ΔAIx was not.


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