Bronchial hyperresponsiveness, airway inflammation, and airflow limitation in endurance athletes

BACKGROUND: Whereas a high prevalence of bronchial abnormalities has been reported in endurance athletes, its underlying mechanisms and consequences during exercise are still unclear. STUDY OBJECTIVES: The purpose of this study was to assess the following: (1) bronchial responsiveness to methacholine and to exercise; (2) airway inflammation; and (3) airflow limitation during intense exercise in endurance athletes with respiratory symptoms. DESIGN: Cross-sectional observational study. SETTING: Lung function and exercise laboratory at a university hospital. PATIENTS AND MEASUREMENTS: Thirty-nine endurance athletes and 13 sedentary control subjects were explored for the following: (1) self-reported respiratory symptoms; (2) bronchial hyperresponsiveness (BHR) to methacholine and exercise; (3) airflow limitation during intense exercise; and (4) bronchial inflammation using induced sputum and nitric oxide (NO) exhalation. RESULTS: Fifteen athletes (38%) showed BHR to methacholine and/or exercise in association with bronchial eosinophilia (mean [+/- SD] eosinophil count, 4.1 +/- 8.5% vs 0.3 +/- 0.9% vs 0%, respectively), higher NO concentrations (19 +/- 10 vs 14 +/- 4 vs 13 +/- 4 parts per billion, respectively), a higher prevalence of atopy, and more exercise-induced symptoms compared with non-hyperresponsive athletes and control subjects (p < 0.05). Furthermore, airflow limitation during intense exercise was observed in eight athletes, among whom five had BHR. Athletes with airflow limitation reported more symptoms and had FEV1, FEV1/FVC ratio, and forced expiratory flow at midexpiratory phase values of 14%, 9%, and 29%, respectively, lower compared with those of nonlimited athletes (p < 0.05). CONCLUSION: BHR in endurance athletes was associated with the criteria of eosinophilic airway inflammation and atopy, whereas airflow limitation during exercise was primarily a consequence of decreased resting spirometric values. Both BHR and bronchial obstruction at rest with subsequent expiratory flow limitation during exercise may promote respiratory symptoms during exercise in athletes.     

Dopamine receptor subtypes contribution to Homer1a induction: Insights into antipsychotic molecular action

The inducible gene Homer1a has been considered a candidate gene for schizophrenia. Drugs efficacious in schizophrenia and acting as dopamine receptor antagonists induce Homer1a expression, although the specific role of the different dopamine receptors in its induction is not completely known.     

Reproducibility of ultrasound-derived muscle thickness and echo-intensity for the entire quadriceps femoris muscle

IntroductionMuscle thickness (MT) and muscle echo-intensity (EI) allow the study of skeletal muscle adaptive changes with ultrasound. This study investigates the intra- and inter-session reliability and agreement of MT and EI measurements for each of the four heads of the quadriceps femoris in transverse and longitudinal scans, using two sizes for the region of interest (ROI); EI measurements only.MethodsThree B-mode images from two views were acquired from each head of quadriceps femoris from twenty participants (10 females) in two sessions, 7 days apart. EI was measured using a large and a small ROI. Reliability was examined with the mixed two-way intra-class correlation coefficient (ICC), the standard error of mean (SEM) and the smallest detectable change (SDC). Bland–Altman's plots were used to study agreement.ResultsHigh to very high inter-session ICC values were found for MT for all muscle heads, particularly for measurements from transverse scans. For EI measurement, ICC values ranged from low to high, with higher ICC values seen with the largest ROI. SDC values ranged between 0.19 and 0.53 cm for MT and between 3.73 and 18.56 arbitrary units (a.u.) for two ROIs. Good agreement existed between MT measurements made in both scans. A small bias and larger 95% limits of agreement were seen for EI measurements collected with the two ROI sizes.ConclusionUltrasound measures of MT and EI show moderate to very high reliability. The reliability and agreement of MT and EI measurements are improved in transverse scans and with larger ROIs.     

An ethnomedicinal, phytochemical and pharmacological profile of Desmodium gangeticum (L.) DC. and Desmodium adscendens (Sw.) DC

Ethnopharmacological relevance

Desmodium gangeticum (L.) DC. and Desmodium adscendens (Sw.) DC. are two important and well explored species of genus Desmodium (Fabaceae (alt. Leguminosae) subfamily: Faboideae). Desmodium gangeticum is used as a tonic, febrifuge, digestive, anticatarrhal, antiemitic, in inflammatory conditions of chest and in various other inflammatory conditions in the Ayurvedic System of Medicine while Desmodium adscendens is widely used for the treatment of asthma in Ghana, Africa.

Aim of the review

The aim of this review is to provide comprehensive information on the botany, traditional uses, phytochemistry, pharmacological research and toxicology of Desmodium gangeticum and Desmodium adscendens to explore their therapeutic potential and future research opportunities.

Materials and methods

All the available information on Desmodium gangeticum and Desmodium adscendens was collected via electronic search (using Pubmed, SciFinder, Scirus, Google Scholar, JCCC@INSTIRC and Web of Science) and a library search for articles published in peer-reviewed journals.

Results

About 25 different species of Desmodium including Desmodium gangeticum and Desmodium adscendens are used ethnomedicinally all over the world. Phytochemical research on Desmodium gangeticum and Desmodium adscendens has led to the isolation of alkaloids, pterocarpans, phospholipids, sterols, flavones and flavonoid glycosides from Desmodium gangeticum and triterpenoid saponins, phenylethylamines and indole-3-alkyl amines from Desmodium adscendens. Crude extracts, fractions and isolated components of Desmodium gangeticum and Desmodium adscendens showed a wide spectrum of in vitro and in vivo pharmacological activities like antileishmanial, immunomodulatory, antiasthmatic, smooth muscle relaxant, anti-inflammatory, anti-ulcer, cardio-protective, antidiabetic, antiamnesic, antiviral, antioxidant and hepatoprotective activities.

Conclusions

Desmodium gangeticum and Desmodium adscendens have emerged as a good source of traditional medicine. Desmodium gangeticum possesses the ability to scavenge the free radicals generated during ischaemia and ischaemia reperfusion thereby preserving the mitochondrial respiratory enzymes that eventually lead to cardio-protection and has potential prophylactic and therapeutic efficacy against Leishmania infection. Desmodium adscendens is useful against chronic bronchitis and asthma. However, there is a need to search for individual secondary metabolites responsible for these actions and study their mode of actions, bioavailability, pharmacokinetics and physiological pathways in sufficient detail. The promising results should be further substantiated by clinical trials.     

Selective blockade of serotonin2C receptor enhances Fos expression specifically in the striatum and the subthalamic nucleus within the basal ganglia

Serotonin_2C (5-HT_2C) receptors are widely expressed in the basal ganglia, a group of brain regions involved in the control of motor behavior. However, it remains unclear whether their tonic influence on neuronal activity is distributed in these regions. We have addressed this question by measuring the product of the proto-oncogene c-Fos in rats after peripheral administration of the non-selective 5-HT antagonist mianserin, the 5-HT_2C/2B antagonist SER-082 or the selective 5-HT_2C antagonist SB 243213. The intraperitoneal administration of 1 mg/kg of SB 243213 or SER-082, but not mianserin, enhanced Fos-immunoreactive cells in the subthalamic nucleus and the striatum, primarily its medial portion. None of these treatments significantly affected Fos expression in the external globus pallidus, the entopeduncular nucleus (the internal globus pallidus in primate) or the substantia nigra pars reticulata. The data suggest that selective blockade of 5-HT_2C receptors is necessary to unmask a tonic regulation of neuronal activity by this receptor in the basal ganglia and that this effect is restricted to the two structures receiving cortical entries, the striatum and the subthalamic nucleus.     

Mast cells accumulate in the anogenital region of somatosensory thalamic nuclei during estrus in female mice

Mast cells are located in the mammalian thalamus where their numbers are sensitive to reproductive hormones. To evaluate whether differences between sexes and over the estrus cycle influence the nuclear distribution of mast cells in mice, we mounted a comprehensive analysis of their distribution in males compared to females and in females over the estrus cycle. Compared to males, mast cells were more numerous in the lateral intralaminar and posterior nuclei of females during estrus and in the ventral posterolateral (VPL) and medial geniculate nuclei during proestrus. During estrus, mast cells were especially concentrated in those regions within the VPL and posterior thalamic nuclei that receive somatosensory information from the anogenital region. Treatment of ovariectomized mice with estrogen increased the number and the percent of mast cells that were degranulated compared to that after ovariectomy alone, an effect that was most apparent in the lateral intralaminar, VPL and posterior nuclei. In estrogen-primed, ovariectomized females, progesterone delivered 5 h before tissue collection counteracted the effects of estrogen. Cromolyn, a mast cell stabilizer, injected centrally 1 h prior to and 24 h after estrogen in ovariectomized mice, prevented the increase in number of mast cells in the whole thalamus and in the intralaminar, VPL and posterior nuclei. This suggests that estrogen induces hyperplasia by a mechanism that involves mast cell degranulation. Based on the discrete anatomical location of mast cells in areas of somatosensory nuclei that receive anogenital input together with the temporal correspondence of these cells with estrus, mast cells are well situated to influence sensory input in females during mating.     

Sensory input to cerebellocerebral relay neurons in the cat thalamus

Intracellular recording techniques were used to study the synaptic responses of feline ventrolateral neurons to dorsal column, spinothalamic and sensory cortex stimulation. More than 75% of the cells responded with short- and long-latency excitatory or inhibitory postsynaptic potentials to the one or/and other stimulation sites. These findings indicate that a considerable amount of somatosensory integration in the cerebellocerebral circuit occurs in the thalamic relay neurons.     

Cholinergic facilitation of thalamic relay transmission in the cat

The effects of intravenously injected atropine and physostigmine were tested on field potentials evoked in ventral anterior and ventral lateral, ventral posterolateral, and lateral geniculate nuclei of the thalamus by electrical stimulation of principal afferent pathways. Postsynaptic components of potentials evoked by stimulation of the brachium conjunctivum, medial lemniscus, and optic tract were usually selectively enhanced by physostigmine and depressed by atropine. Responses evoked in the ventral lateral nucleus by stimulation of the precruciate cortex were similarly altered, but in a smaller proportion of tests. In a small number of tests, the nicotinic blocker, mecamylamine, was also found to depress the postsynaptic responses to stimulation of the three major afferent pathways. Transmission in these pathways and the effects of drug administrations were partly dependent on the anesthetic state of the animal. Halothane and pentobarbital administration depressed the postsynaptic responses. It is possible that depression of thalamic relay transmission by anesthetic agents, by anticholinergic drugs, and during slow-wave sleep may all reflect interaction with a common cholinergic neuronal system.