Contributions of Griffith Pugh to Success on Mt. Everest and His Impact on the Advancement of Altitude and Environmental Physiology.

Griffith Pugh, MD (1909-1994), was a pioneer in altitude physiology. During World War II, he developed training protocols in Lebanon to improve soldier performance at altitude and in the cold. In 1951 he was chosen to join the British Everest team as a scientist.

Centering racial justice for Black/African American and Indigenous American people in commercial tobacco product regulation.

Although overall health in the United States (US) has improved dramatically during the past century, long-standing health inequities, particularly the unequal and unjust burden of tobacco-related disease and death among racialized populations, persist. A considerable gap exists in our understanding of how commercial tobacco product regulations and policies cause and/or exacerbate race-based health inequities among Black/African American (B/AA) and Indigenous American people. The purpose of this paper is to 1) describe how existing US commercial tobacco regulatory policies may contribute to structural racism and undermine the full benefits of tobacco prevention and control efforts among B/AA and Indigenous American groups; and 2) initiate a call to action for researchers and regulators of tobacco products to examine policies using an equity lens.

Spinal and corticospinal excitability in response to reductions in skin and core temperatures via whole-body cooling.

Cold stress impairs fine and gross motor movements. Although peripheral effects of muscle cooling on performance are well understood, less is known about central mechanisms. This study characterized corticospinal and spinal excitability during surface cooling, reducing skin () and esophageal () temperatures.

Differences in Tobacco Use Among a Sample of At-Risk Chinese, Filipino, and Vietnamese Adult Men Living in the SF Bay Area.

Background: Smoking among Asian men has been studied, but differences in tobacco and cigarette use among US- and non-US-born Asian subgroups, especially those at risk for substance use or sexually transmitted diseases, has not been well-studied.

Aims: To learn about the smoking of cigarettes or blunts among Asian ethnic groups, and whether place of birth, age, or primary language spoken at home is associated with smoking.

Methods: Study participants were 125 adult (age > 18 years) Chinese, Filipino, or Vietnamese men living in San Francisco, Daly City, or San Jose, California, who self-reported substance use in the past 30 days.

Effects of training with a neuro-mechano stimulator rehabilitation bicycle on functional recovery and paired-reflex depression of the soleus in individuals with incomplete paralysis: a proof-of-principle study.

The present study describes the training effects of a novel motorized bicycle-like device for individuals with incomplete spinal cord injury. Participants were five individuals with motor incomplete spinal cord injury (56 ± 7 years). Four of five participants received two 30-min sessions of training: one with, and one without, mechanical stimulation on the plantar surface of the foot; soleus paired H-reflex depression was examined before and after each session.

Human Responses to 5 Heated Hypothermia Wrap Systems in a Cold Environment.

Introduction: We compared the effectiveness of 5 heated hypothermia wrap systems.

Methods: Physiologic and subjective responses were determined in 5 normothermic subjects (1 female) for 5 heated hypothermia wraps (with vapor barrier and chemical heat sources) during 60 min of exposure to a temperature of -22°C. The 5 systems were 1) user-assembled; 2) Doctor Down Rescue Wrap; 3) hypothermia prevention and management kit (HPMK); 4) MARSARS Hypothermia Stabilizer Bag; and 5) Wiggy's Victims Casualty Hypothermia Bag.

Chronic Increases in Daily Neuromuscular Activity Promote Changes in Gene Expression in Small and Large Dorsal Root Ganglion Neurons in Rat.

The purpose of this study was to determine the response, in rat, to chronic physical activity in small and large DRG neurons. Rats were cage-confined or underwent 16-18 weeks of daily increased activity, via 2 h of treadmill running per day or free access to voluntary exercise wheels, following which small (≤30 µm) and large (≥40 µm) diameter DRG neurons were harvested by laser capture microdissection from flash-frozen lumbar DRGs. Relative mRNA levels were determined using real-time polymerase chain reaction.

Mechanisms and functional implications of motoneuron adaptations to increased physical activity.

Motoneurons demonstrate adaptations in their physiological properties to alterations in chronic activity levels. The most consistent change that appears to result from endurance-type exercise training is the reduced excitatory current required to initiate and maintain rhythmic firing. While the precise mechanisms through which these neurons adapt to activity are currently unknown, evidence exists that adaptation may involve alterations in the expression of genes that code for membrane receptors, which can influence the responses of neurons to transmitters during activation.

Altered transcription of glutamatergic and glycinergic receptors in spinal cord dorsal horn following spinal cord transection is minimally affected by passive exercise of the hindlimbs.

Gene expression is altered following a spinal transection (STx) in both motor and sensory systems. Exercise has been shown to influence gene expression in both systems post-STx. Gene expression alterations have also been shown in the dorsal root ganglia and nociceptive laminae of the spinal cord following either an incomplete spinal cord injury (SCI) or a contusive SCI.

α-Motoneurons maintain biophysical heterogeneity in obesity and diabetes in Zucker rats.

Small-diameter sensory dysfunction resulting from diabetes has received much attention in the literature, whereas the impact of diabetes on α-motoneurons (MN) has not. In addition, the chance of developing insulin resistance and diabetes is increased in obesity. No study has examined the impact of obesity or diabetes on the biophysical properties of MN.

Serotonin controls initiation of locomotion and afferent modulation of coordination via 5-HT receptors in adult rats.

Key Points: Experiments on neonatal rodent spinal cord showed that serotonin (5-HT), acting via 5-HT receptors, is required for initiation of locomotion and for controlling the action of interneurons responsible for inter- and intralimb coordination, but the importance of the 5-HT system in adult locomotion is not clear. Blockade of spinal 5-HT receptors interfered with voluntary locomotion in adult rats and fictive locomotion in paralysed decerebrate rats with no afferent feedback, consistent with a requirement for activation of descending 5-HT neurons for production of locomotion. The direct control of coordinating interneurons by 5-HT receptors observed in neonatal animals was not found during fictive locomotion, revealing a developmental shift from direct control of locomotor interneurons in neonates to control of afferent input from the moving limb in adults.

The African American Youth Smoking Experience: An Overview.

Introduction: Beginning in the late 1970s, a very sharp decline in cigarette smoking prevalence was observed among African American (AA) high school seniors compared with a more modest decline among whites. This historic decline resulted in a lower prevalence of cigarette smoking among AA youth that has persisted for several decades.

Methods: We synthesized information contained in the research literature and tobacco industry documents to provide an account of past influences on cigarette smoking behavior among AA youth to help understand the reasons for these historically lower rates of cigarette smoking.

Understanding Tobacco Use Behaviors Among African Americans: Progress, Critical Gaps, and Opportunities.

Introduction: Although multiple factors likely influence the differences between African Americans (AAs) and whites in cardiovascular disease and lung cancer mortality rates, historical patterns of tobacco use, particularly cigarette smoking, are the major contributors. This issue of Nicotine & Tobacco Research presents original research, a review, and commentaries that will serve to advance our understanding of several relevant behavioral similarities and differences between AAs and whites.

Behavioral Analysis: Here, we illustrate how the diverging trends in cigarette smoking between AA and white high school seniors observed since the mid-1970s were influenced by patterns of ever use and current use among ever users.

Comparison of Distal Limb Warming With Fluidotherapy and Warm Water Immersion for Mild Hypothermia Rewarming.

Objective: The purpose of the study was to determine the effectiveness of Fluidotherapy rewarming through the distal extremities for mildly hypothermic, vigorously shivering subjects. Fluidotherapy is a dry heat modality in which cellulose particles are suspended by warm air circulation.

Methods: Seven subjects (2 female) were cooled on 3 occasions in 8˚C water for 60 minutes, or to a core temperature of 35°C.

Force regulation and electrical properties of motor units in overloaded muscle.

Introduction: The influence of long-term muscle overload on force regulation and electrical properties of motor units (MUs) was investigated in rats.

Methods: Compensatory overload of the medial gastrocnemius was induced by tenotomy of its synergists. Electrophysiological experiments were performed on functionally isolated MUs 3 months after the surgery.

Serotonin receptor and KCC2 gene expression in lumbar flexor and extensor motoneurons posttransection with and without passive cycling.

Sacrocaudal motoneuron gene expression is altered following a spinal transection. Of interest here is the regulation of serotonin (5-HT) receptors (R), glutamate receptor, metabotropic 1 (mGluR1), and potassium-chloride cotransporter (KCC2), which mediate motoneuron excitability, locomotor recovery, and spasticity posttransection. The examination of these genes in lumbar motoneurons posttransection has not been studied, which is necessary for developing potential pharmacological interventions aimed at restoring locomotion and/or reducing spasticity.

Effects of lifestyle intervention on dietary intake, physical activity level, and gestational weight gain in pregnant women with different pre-pregnancy Body Mass Index in a randomized control trial.

Background: The objectives of this study were to assess the efficacy of lifestyle intervention on gestational weight gain in pregnant women with normal and above normal body mass index (BMI) in a randomized controlled trial.

Methods: A total of 116 pregnant women (<20 weeks of pregnancy) without diabetes were enrolled and 113 pregnant women completed the program. Participants were randomized into intervention and control groups.

Differential regulation of the fiber type-specific gene expression of the sarcoplasmic reticulum calcium-ATPase isoforms induced by exercise training.

The regulatory role of adenosine monophosphate-activated protein kinase (AMPK)-α2 on sarcoplasmic reticulum calcium-ATPase (SERCA) 1a and SERCA2a in different skeletal muscle fiber types has yet to be elucidated. Sedentary (Sed) or exercise-trained (Ex) wild-type (WT) and AMPKα2-kinase dead (KD) transgenic mice, which overexpress a mutated and inactivated AMPKα2 subunit, were utilized to characterize how genotype or exercise training influenced the regulation of SERCA isoforms in gastrocnemius. As expected, both Sed and Ex KD mice had >40% lower AMPK phosphorylation and 30% lower SERCA1a protein than WT mice (P < 0.

Daily passive cycling attenuates the hyperexcitability and restores the responsiveness of the extensor monosynaptic reflex to quipazine in the chronic spinally transected rat.

Activity-based interventions such as locomotor training or passive cycling have a positive influence on the spinal circuitry and recovery following a spinal cord injury (SCI). The use of quipazine in combination with exercise training has demonstrated a greater functional recovery than has exercise training alone. However, the influence of exercise or training on the responsiveness of the spinal cord to quipazine has not been examined following a chronic spinal transection.

Comparison of heat donation through the head or torso on mild hypothermia rewarming.

Objective: The purpose of the study was to compare the effectiveness of head vs torso warming in rewarming mildly hypothermic, vigorously shivering subjects using a similar source of heat donation.

Methods: Six subjects (1 female) were cooled on 3 occasions in 8 ºC water for 60 minutes or to a core temperature of 35 ºC. They were then dried, insulated, and rewarmed by 1) shivering only; 2) charcoal heater applied to the head; or 3) charcoal heater applied to the torso.

Correlates of HIV and HCV risk and testing among Chinese, Filipino, and Vietnamese men who have sex with men and other at-risk men.

Asian Americans are one of the more under-researched groups in the United States. This holds true with regard to research on risk assessment, screening, and testing for human immunodeficiency virus (HIV) and hepatitis C (HCV). Here, we address that lack by exploring correlates of risk and testing for the two diseases among Chinese, Filipino, and Vietnamese men who have sex with men (MSM) and other at-risk men in the San Francisco Bay Area.

Removal of supraspinal input reveals a difference in the flexor and extensor monosynaptic reflex response to quipazine independent of motoneuron excitation.

The purpose of this study was to determine if quipazine, a serotonergic agonist, differentially modulates flexor and extensor motor output. This was achieved by examining the monosynaptic reflex (MSR) of the tibial (extensor) and peroneal (flexor) nerves, by determining the basic and rhythmic properties of extensor and flexor motoneurons, and by recording extracellular Ia field potentials of the tibial and peroneal nerves in the in vivo adult decerebrate rat in both spinal intact and acute spinalized preparations. In the spinal intact preparation, the tibial and peroneal MSR amplitude significantly increased compared with baseline in response to quipazine, with no difference between nerves (P < 0.

Substance use among Chinese, Filipino, and Vietnamese adult men living in San Jose, Daly City, and San Francisco, and its implications on ATOD prevention services.

This intervention study collected data on Chinese, Filipino, and Vietnamese high-risk adults to ascertain similarities and differences in drug use patterns. Study participants (N = 126) participated in a 5-week intervention study to mitigate substance abuse and the prevalence of hepatitis C and HIV among high-risk adults in San Francisco, San Mateo, and Santa Clara Counties of California. Data reported were collected at baseline.