Management of native warm-season grasses for beef cattle and biomass production in the Mid-South USA.

Native grasses, such as switchgrass (SG; L.), big bluestem (BB; Vitman), indiangrass (IG; Nash), and eastern gamagrass (EG; [L.] L.

Is 1 Hz rTMS Always Inhibitory in Healthy Individuals?

1 Hz repetitive Transcranial Magnetic Stimulation (rTMS) is considered to have an inhibitory effect in healthy people because it suppresses the excitability of the motor or visual cortex that is expressed as an increase in the motor or the phosphene threshold (PT), respectively. However, the underlying mechanisms and the brain structures involved in the action of rTMS are still unknown. In this study we used two sessions of simultaneous TMS-functional magnetic resonance imaging (fMRI), one before and one after, 15 minutes of 1Hz rTMS to map changes in brain function associated with the reduction in cortical excitability of the primary visual cortex induced by 1 Hz rTMS, when TMS was applied on the occipital area of healthy volunteers.

Cocaine is pharmacologically active in the nonhuman primate fetal brain.

Cocaine use during pregnancy is deleterious to the newborn child, in part via its disruption of placental blood flow. However, the extent to which cocaine can affect the function of the fetal primate brain is still an unresolved question. Here we used PET and MRI and show that in third-trimester pregnant nonhuman primates, cocaine at doses typically used by drug abusers significantly increased brain glucose metabolism to the same extent in the mother as in the fetus (approximately 100%).

Simultaneous TMS-fMRI of the Visual Cortex Reveals Functional Network, Even in Absence of Phosphene Sensation.

Phosphene sensation is commonly used to measure cortical excitability during transcranial magnetic stimulation (TMS) of the occipital cortex. However, some individuals lack this perception, and the reason for it is still unknown. In this work, we used functional magnetic resonance imaging (fMRI) to detect brain activation during local TMS of the occipital cortex in twelve healthy subjects.

Association of body mass and brain activation during gastric distention: implications for obesity.

Background: Gastric distention (GD), as it occurs during meal ingestion, signals a full stomach and it is one of the key mechanisms controlling food intake. Previous studies on GD showed lower activation of the amygdala for subjects with higher body mass index (BMI). Since obese subjects have dopaminergic deficits that correlate negatively with BMI and the amygdala is innervated by dopamine neurons, we hypothesized that BMI would correlate negatively with activation not just in the amygdala but also in other dopaminergic brain regions (midbrain and hypothalamus).

Gastric distention activates satiety circuitry in the human brain.

Gastric distention during meal ingestion activates vagal afferents, which send signals from the stomach to the brain and result in the perception of fullness and satiety. Distention is one of the mechanisms that modulates food intake. We measured regional brain activation during dynamic gastric balloon distention in 18 health subjects using functional magnetic resonance imaging and the blood oxygenation level-dependent (BOLD) responses.

Maternal and fetal 11C-cocaine uptake and kinetics measured in vivo by combined PET and MRI in pregnant nonhuman primates.

Unlabelled: Cocaine use during pregnancy has been shown to be deleterious to the infant. This may reflect reduction of flow to placenta or effects on the fetal brain. Methods to assess pharmacokinetics of drugs of abuse in vivo would be useful to investigate the mechanisms underlying the fetal adverse effects.

Maternal-fetal in vivo imaging: a combined PET and MRI study.

Unlabelled: An understanding of how drugs are transferred between mother and fetus during the gestational period is an important medical issue of relevance to both therapeutic drugs and drugs of abuse. Though there are several in vitro and in vivo methods to examine this issue, all have limitations. Furthermore, ethical and safety considerations generally preclude such studies in pregnant humans.

A comparison of sevoflurance to halothane in paediatric surgical patients: results of a multicentre international study.

Induction, emergence and recovery characteristics were compared during sevoflurane or halothane anaesthetic in a large (428) multicentre, international study of children undergoing elective inpatient surgical procedures. Two hundred and fourteen children in each group underwent inhalation induction with nitrous oxide/oxygen and sevoflurane or halothane. Incremental doses of either study drug were added until loss of eyelash reflex was achieved.

Spirituality of EMTs: a study of the spiritual nature of EMS workers and its effects on perceived happiness and prayers for patients.

Introduction: There is reason to believe that traumatic events experienced on the job make emergency medical services (EMS) workers more skeptical about their spiritual beliefs. Little is known about the spiritual lives and experiences of emergency medical technicians (EMTs). No studies have measured the responses of EMTs to the spiritual needs of their patients.

Postextubation laryngeal spasm in an unanesthetized patient with Parkinson's disease.

We present a patient with Parkinson's disease who experienced laryngeal spasm after tracheal extubation without having been anesthetized. This patient's trachea was intubated because of respiratory arrest. We postulate that her postextubation laryngospasm was related to Parkinson's disease.

False aneurysm of the axillary artery following brachial plexus block.

Brachial plexus blockade is a commonly used technique for providing surgical anesthesia for the upper extremity. Although various approaches have been described, the axillary approach is the safest and most frequently used. Most complications associated with axillary nerve block are related to local or systemic anesthetic toxicity, bleeding, infection, and nerve damage.

Nimodipine decreases the minimum alveolar concentration of isoflurane in dogs.

Nimodipine is a calcium antagonist that binds with high affinity to neuronal membranes. It is a potent cerebrovasodilator and has been demonstrated also to affect neurotransmitter synthesis and release. Because patients undergoing surgery for intracranial aneurysms are frequently receiving nimodipine, the authors determined the MAC of isoflurane in six dogs before and during three infusion doses of nimodipine (0.

Intraoperative pulse oximetry in peripheral revascularization in an infant.

Vascular patency after reimplantation has been evaluated by numerous methods. A patient is described in whom pulse oximetry was used for this purpose. Other techniques of evaluating vascular patency are mentioned, and the physics of pulse oximetry are briefly discussed.

Pharmacokinetics and pharmacodynamics of d-tubocurarine and metocurine in the elderly.

The effects of age (older than 70 yr) on the pharmacokinetics and pharmacodynamics of d-tubocurarine (dTc) and metocurine (MTc) were evaluated in studies of 21 patients aged 70-87 and 21 patients aged 29-59. There was a significant difference in the pharmacokinetic parameters of all elderly patients compared with younger controls. With both dTc and MTc, the elderly exhibited a decreased plasma clearance, decreased initial volume of distribution, decreased volume of distribution, and a prolonged elimination half-life.