Publications by authors named "Helene Z Hill"

Article Synopsis
  • Two consecutive maximal cardiopulmonary exercise tests (CPETs) are being used to assess post-exertional malaise (PEM) in individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and potentially other similar conditions like Gulf War Illness (GWI).
  • Researchers evaluated the reliability of this 2-day CPET protocol by analyzing various exercise parameters, focusing on how consistent the results were and what changes might be clinically significant.
  • The study found that while repeatability of CPET results for veterans with GWI was generally strong, no significant differences were observed between veterans and controls, highlighting the need for careful interpretation of the data in these populations.
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Introduction: The components of minute ventilation, respiratory frequency and tidal volume, appear differentially regulated and thereby afford unique insight into the ventilatory response to exercise. However, respiratory frequency and tidal volume are infrequently reported, and have not previously been considered among military veterans with Gulf War Illness. Our purpose was to evaluate respiratory frequency and tidal volume in response to a maximal cardiopulmonary exercise test in individuals with and without Gulf War Illness.

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Gulf War Illness (GWI) is a chronic multi-symptom illness not currently diagnosed by standard medical or laboratory test that affects 30% of veterans who served during the 1990-1991 Gulf War. The clinical presentation of GWI is comparable to that of patients with certain mitochondrial disorders-i.e.

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Chen, Y, Hill, HZ, Lange, G, and Falvo, MJ. Salivary mitochondrial DNA copy number is associated with exercise ventilatory efficiency. J Strength Cond Res 31(7): 2000-2004, 2017-Mitochondrial DNA copy number (mtDNAcn) is an index of mitochondrial content and is responsive to changes in exercise training volume.

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Alpha-melanocyte-stimulating hormone (alpha-MSH) increases melanogenesis and protects from UV-induced DNA damage. However, its effect on mitochondrial DNA (mtDNA) damage is unknown. We have addressed this issue in a pilot study using human epidermal keratinocytes and melanocytes incubated with alpha-MSH and irradiated with UVB.

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Mammalian mitochondria contain full-length genome and a single-stranded 7S DNA. Although the copy number of mitochondrial DNA (mtDNA) varies depending on the cell type and also in response to diverse environmental stresses, our understanding of how mtDNA and 7S DNA are maintained and regulated is limited, partly due to lack of reliable in vitro assay systems that reflect the in vivo functionality of mitochondria. Here we report an in vitro assay system to measure synthesis of both mtDNA and 7S DNA under a controllable in vitro condition.

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Solar radiation can lead to changes affecting DNA metabolism resulting in loss of DNA integrity. Skin specimens obtained from melanoma patients treated at the Memorial Sloan-Kettering Cancer Center were used to study patterns of DNA fragmentation using the comet assay and levels of deletions in mitochondrial DNA (mtDNA) using real-time PCR. Skin specimens were classified according to the glutathione S-transferase M1 (GSTM1) genotype (either wild type [WT] or null) and patient sunburn history.

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A patient is described whose foolish sunbathing practices during adolescence predisposed her to an intense and unpleasant skin reaction during the course of radiation therapy approximately 50 years later. The phenomenon suggests that solar-induced changes in the skin can persist over a very long period of time and emphasizes the need for light-skinned individuals to protect their skin from the intense rays of the sun.

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