Back Pain in Outer Space.

Space travel has grown during the past 2 decades, and is expected to surge in the future with the establishment of an American Space Force, businesses specializing in commercial space travel, and National Aeronautics and Space Administration's planned sustained presence on the moon. Accompanying this rise, treating physicians are bracing for a concomitant increase in space-related medical problems, including back pain. Back pain is highly prevalent in astronauts and space travelers, with most cases being transient and self-limiting (space adaptation back pain).

Screening for Complicated Grief in a Military Mental Health Clinic.

Introduction: Bereavement is one of the most common and stressful life experiences one can endure. Typical grief reactions follow a course of recovery in which individuals come to terms with the loss and resume functioning within weeks to months. However, for some, grief remains indefinitely distressing.

Sexual Trauma and Adverse Health and Occupational Outcomes Among Men Serving in the U.S. Military.

Although absolute counts of U.S. service men who experience sexual trauma are comparable to service women, little is known about the impact of sexual trauma on men.

Adults see vision to be more informative than it is.

Humans gain a wide range of knowledge through interacting with the environment. Each aspect of our perceptual experiences offers a unique source of information about the world-colours are seen, sounds heard and textures felt. Understanding how perceptual input provides a basis for knowledge is thus central to understanding one's own and others' epistemic states.

Lung uptake of antibodies to endothelial antigens: key determinants of vascular immunotargeting.

Vascular immunotargeting is a mean for a site-selective delivery of drugs and genes to endothelium. In this study, we compared recognition of pulmonary and systemic vessels in rats by candidate carrier monoclonal antibodies (MAbs) to endothelial antigens platelet endothelial cell adhesion molecule (PECAM)-1 (CD31), intercellular adhesion molecule (ICAM)-1 (CD54), Thy-1.1 (CD90.

A targetable, injectable adenoviral vector for selective gene delivery to pulmonary endothelium in vivo.

Adenoviral (Ad) vectors are promising gene therapy vehicles due to their in vivo stability and efficiency, but their potential utility is compromised by their restricted tropism. Targeting strategies have been devised to improve the efficacy of these agents, but specific targeting following in vivo systemic administration of vector has not previously been demonstrated. The distinct aim of the current study was to determine whether an Ad-targeting strategy could maintain fidelity upon systemic vascular administration.

Chromosomal localization of the genes for human carboxypeptidase D (CPD) and the active 50-kilodalton subunit of human carboxypeptidase N (CPN1).

Human carboxypeptidase N is a 280-kDa tetrameric enzyme consisting of two 83-kDa regulatory subunits and two catalytic 50-kDa subunits. The 83-kDa subunit is a member of the leucine-rich repeat family of proteins and has been localized to chromosome 8p22-p23. The 50-kDa subunit is a member of the regulatory B-type carboxypeptidase family, which includes carboxypeptidases M, E/H, AEBP1, and a newly described member, carboxypeptidase D, which has three tandem active site domains.

The effect of hyperthyroidism on Müller's muscle contractility in rats.

The objective of this study was to determine if hyperthyroidism affects the responses of Müller's muscle to alpha-1 adrenoceptor agonists and consequently, if these responses might explain thyroid eyelid retraction. Sprague-Dawley adult rats (n = 37) were divided into control and treated groups and given either placebo or intraperitoneal triiodothyronine (250 micrograms/kg/d) for 1, 2, or 3 weeks. A suture was passed through their upper eyelid and connected to a force transducer that measured Müller's muscle contractions.

The influence of chronic hypokalemia on myocardial adrenergic receptor densities: enhanced sensitivity to epinephrine-induced arrhythmias.

We studied the effects of a 30-day potassium (K+)-deficient diet on blood [K+] myocardial adrenergic receptor densities, serum catecholamines, and epinephrine arrhythmogenicity in adult laboratory rats (250 +/- 25 g). Within 3 days of beginning the K+-deficient diet, blood [K+] decreased by 50%. After 5 days, the myocardial alpha-1 density increased (62 +/- 2 vs 148 +/- 16 fmols/mg protein), and the total beta receptor increased (95 +/- 5 vs 273 +/- 49) without significant change in receptor affinity.

Prediction of cerebral blood flow in fetal lambs by carotid artery ultrasonic flow transducer.

To determine whether common carotid artery blood flow measured with an ultrasonic flow transducer would predict brain blood flow in fetal sheep, we measured unilateral common carotid artery blood flow and compared this to simultaneous measurements of total brain blood flows made by radioisotope-labelled microsphere techniques. We studied anaesthetized, exteriorized fetal sheep with intact umbilical circulation after ligation of extracranial, extracerebral arteries and placement of a common carotid artery flow transducer; five fetuses at 120 d gestation had 19 total comparison measurements. As measured by microsphere technique, mean basal blood flow during undisturbed conditions to regional brain areas were similar to normal values reported for the exteriorized ovine fetus; these flows were highly correlated to fetal PaCO2 and successfully varied over a wide range (total brain 9.

Analysis of halothane effects on myocardial force-interval relationships at anesthetic concentrations depressing twitches but not tetanic contractions.

Background: Tetanic contractions in rat myocardium depend solely on cellular Ca2+ uptake, whereas twitches depend on Ca2+ release from the sarcoplasmic reticulum. Because halothane may cause loss of sequestered Ca2+, the anesthetic was tested for its differential effects on twitch and tetanic forces. The in vitro effects of halothane on the twitch force-interval relationship were then evaluated, using a mathematical model that relates twitch contractile force to the Ca2+ content of intracellular compartments.

Importance of sympathetic innervation in the positive inotropic effects of bradykinin and ramiprilat.

Isolated rat left atria or right ventricular strips were electrically stimulated at a constant frequency. The amplitude of twitch contractions, thus elicited, rose as a function of stimulation intensity because of increases in the evoked release of sympathetic catecholamines. Bradykinin had no effect on contractile force in preparations paced at a minimal intensity (threshold).

Brain alpha 2-adrenergic receptor binding during incomplete cerebral ischemia in the rat.

alpha 2-Adrenergic agonists decrease sympathetic activity and improve outcome from brain ischemia. We evaluated whether changes in alpha 2-adrenergic receptor binding activity may be important in the sympathetic depressant and cerebral protective effects of halothane (1.1% inspired) or isoflurane (1.

Progesterone potentiation of bupivacaine arrhythmogenicity in pentobarbital-anesthetized rats and beating rat heart cell cultures.

The effects of progesterone treatment on bupivacaine arrhythmogenicity in beating rat heart myocyte cultures and on anesthetized rats were determined. After determining the bupivacaine AD50 (the concentration of bupivacaine that caused 50% of all beating rat heart myocyte cultures to become arrhythmic), we determined the effect of 1-hour progesterone HCl exposure on myocyte contractile rhythm. Each concentration of progesterone (6.

Diminished muscarinic receptor-mediated cerebral blood flow response in streptozotocin-treated rats.

Endothelium-dependent vascular relaxation in the brain may be impaired in the streptozotocin-treated chronically hyperglycemic diabetic (D) rat. To study this, we measured regional cerebral blood flow (rCBF) changes induced by intracarotid (ic) or intravenous (iv) infusions of the blood-brain permeant muscarinic receptor (MR) agonist oxotremorine (Oxo). In nondiabetic (ND) rats, both ic and iv Oxo resulted in significant (P less than 0.

Captopril improves neurologic outcome from incomplete cerebral ischemia in rats.

We investigated the effects of the angiotensin-converting enzyme inhibitor captopril on neurologic outcome in a rat model of incomplete cerebral ischemia. Twenty male Sprague-Dawley rats were anesthetized with 70% nitrous oxide in oxygen and fentanyl (10 micrograms x kg-1 i.v.

Postischemic treatment with hypothermia improves outcome from incomplete cerebral ischemia in rats.

It is known that hypothermia can improve outcome when induced during ischemia. We evaluated whether hypothermia can decrease ischemic injury if it is induced after incomplete ischemia. Rats were anesthetized with 1.

Hypothermia versus ethanol: neurologic outcome after incomplete cerebral ischemia in midazolam-anesthetized rats.

We examined neurologic outcome after incomplete cerebral ischemia in rats treated with hypothermia versus ethanol, two techniques that decrease brain metabolism. All animals, including control rats, received a baseline midazolam anesthetic. Ischemia was produced by right carotid artery occlusion combined with hemorrhagic hypotension to a mean arterial pressure of 30 mm Hg for 30 min.

Ganglionic blockade improves neurologic outcome from incomplete ischemia in rats: partial reversal by exogenous catecholamines.

The authors investigated the effects of nitrous oxide (N2O), ganglionic blockade, and combined infusion of epinephrine and norepinephrine (0.1 microgram.kg-1.

Cerebrovascular and cerebral metabolic effects of N2O in unrestrained rats.

There is controversy about whether N2O increases cerebral blood flow and cortical oxygen consumption (CMRO2) in rats. Cortical and subcortical blood flow and CMRO2 were measured in awake, unrestrained rats while awake and during 70% N2O administration using radioactive microspheres. In the awake state, cortical and subcortical blood flow were 126 +/- 10 and 98 +/- 7 ml.

Brain lactate and neurologic outcome following incomplete ischemia in fasted, nonfasted, and glucose-loaded rats.

The neurologic outcomes following incomplete cerebral ischemia in rats treated by fasting, nonfasting, or glucose administration (6 ml/kg of 50% glucose solution intraperitoneal) were compared. Rats were anesthetized with 1.4% inspired isoflurane in air and incomplete ischemia was produced by temporary unilateral carotid occlusion and hypotension of 30 mmHg for 30 min.

Comparison of methohexital and isoflurane on neurologic outcome and histopathology following incomplete ischemia in rats.

Using a rat model of incomplete cerebral ischemia the effects of isoflurane (iso) and methohexital (metho) were compared with those of 70% nitrous oxide controls (N2O). Two levels of incomplete cerebral ischemia were produced by right carotid occlusion plus hypotension for 30 min: moderate = 30 mmHg, FIO2 = 0.30; severe = 25 mmHg, FIO2 = 0.

The effects of magnesium salts on the duration of epinephrine-induced ventricular tachyarrhythmias in anesthetized rats.

The effects of MgSO4 or MgCl2 infusion on the duration of epinephrine-induced cardiac arrhythmia were evaluated in male rats anesthetized with either halothane or pentobarbital. In addition, the duration of epinephrine-induced arrhythmia in pentobarbital (50 mg/kg) anesthetized rats was compared with the duration of arrhythmia in halothane (1.5%) anesthetized rats.