Role of primate basal ganglia and frontal cortex in the internal generation of movements

The purpose of these studies was to investigate neuronal activity in the basal ganglia and frontal cortex in relation to the internal generation of goal-directed movements. Monkeys performed goal-directed arm movements at a self-chosen moment in the absence of phasic stimuli providing external temporal reference. They were rewarded with a small morsel of food for each movement, although automatic or repetitive behavior was not reinforced. For reasons of comparison, animals were also trained in a delayed go no-go task in which visual cues instructed them to perform or refrain from an arm movement reaction to a subsequent trigger stimulus. This report describes the activity of neurons in the head of the caudate nucleus and rostral putamen preceding self-initiated arm movements and compares it with instruction-induced preparatory activity preceding movements in the delay task. A total of 497 caudate and 354 putamen neurons were tested in the delay task. Two types of preparatory activity were observed: (1) transient responses to the instruction cue, and (2) sustained activity preceding the trigger stimulus or movement onset. Transient responses were found in 48 caudate and 50 putamen neurons, occurring twice as often in movement ('go') as compared to no-movement ('no-go') trials, but rarely in both. These responses may code the information contained in the instruction relative to the forthcoming behavioral reaction. Sustained activity began after instruction onset and lasted until the trigger stimulus or the arm movement occurred, this being for periods of 2-7 s, 12-35 s, or up to 80 s, depending on the task requirements. This activity was seen in 47 caudate and 45 putamen neurons, was largely confined to go trials, and was unrelated to the preparation of saccadic eye movements. In some cases, this activity began as direct responses to the instruction stimulus, but in the majority of cases developed more gradually before the movement. Thus, both transient and sustained activations appear to be related to the preparation of movements. A total of 390 caudate and 293 putamen neurons were tested during self-initiated movements. Activity preceding earliest movement-related muscle activity was found in 32 caudate and 42 putamen neurons. This premovement activity began 0.5-5.0 s before movement onset (median 1160 ms), increased slowly, reached its peak close to movement onset, and subsided rapidly thereafter. It was unrelated to the preparation of saccadic eye movements. Comparisons between the two tasks were made on 53 neurons.(ABSTRACT TRUNCATED AT 400 WORDS)     

Distribution of Met-enkephalin immunoreactive fibres in the thalamus of the cat

The Met-enkephalin-like immunoreactivity was studied in the thalamus of the cat using an indirect immunoperoxidase method. The densest network of immunoreactive fibres and terminals was observed in the epithalamus and the intralaminar nuclei, particularly those located along the midline nuclei interanteromedialis, submedius, rhomboidens and reuniens. The nuclei parafascicularis and centrum medianum contained also numerous immunoreactive fibres and terminals, whereas the lamina medullaris externa had a lower density of immunoreactive terminals. Enkephalin fibres were almost totally absent in the lateral nuclei of the thalamus, and in the posterior group only the magnocellular part of the corpus geniculatum mediale contained some immunoreactive fibres.     

Validation française d’une échelle de mesure de l’utilisation problématique des jeux vidéo en ligne : l’Internet Gaming Disorder-20

Background:

The study aims to validate an online video game problematic use (Internet Gaming Disorder or IGD) scale in French language: the IGD-20. IGD-20 has been elaborated considering the discussion about the etiology of the IGD, which was included in the section III of the DSM-5. The IGD-20 is composed of 20 items split in six components based on the six components model of addiction from Griffiths.

Methods:

A total of 166 online video game players were recruited on specialized forums, playing 21.9 hours per week. The French version of the IGD-20 was validated through a confirmatory factor analysis via structural equation modeling (SEM).

Result:

The French version of the IGD-20 showed a good validity and a six-factor structure (salience, mood modification, tolerance, withdrawal symptoms, conflict and relapse) (RMSEA = 0.063 [0.049; 0,077], CFI = 0.912, TLI = 0.909).

Conclusion:

The validation of a French scale such as the IGD-20 shows some interest for the French-speaking population, including therapists who could use this scale to investigate the IGD-20 more precisely and for people with IGD-20 who could benefit from a more refined support.     

Ultrastructure and lectin cytochemistry of the cloacal pelvic glands in the male newt Triturus marmoratus marmoratus

The cloacal organ of Salamandridae species contains four glands: pelvic, dorsal, ventral, and Kingsbury's glands. Pelvic glands have been studied only by light microscopy with conventional methods, and consist of multiple tubular serous glands with a prismatic epithelium which contains numerous PAS positive secretory granules. The present report is an ultrastructural and lectin cytochemistry characterization of the pelvic glands of Triturus marmoratus marmoratus throughout the reproductive cycle. Our methods consisted of conventional electron microscopy, and colloidal‐gold lectin cytochemistry of the following lectins: WGA, ConA, LcA, UEA‐I, PNA, SBA, and HPA. In the prereproductive period, the glands showed a tall epithelium which consisted of two cell types, dark and clear cells, surrounded by elongated, myoepithelial cells. Both dark and clear cells showed the ultrastructural characteristics of secretory cells, and exhibited many secretory granules in the apical cytoplasm. Areas showing densely packed, degenerating cell organelles—which were not surrounded by membrane—were observed in the dark cells whereas the clear cells showed large heterolysosomes. In the postreproductive period the number of secretory granules decreased, the rough endoplasmic reticulum was less developed, and areas of degenerating organelles were absent. In addition, small basal cells appeared. The results of the lectin histochemistry study were similar in both reproductive periods. In the epithelial cells, the rough endoplasmic reticulum, the Golgi complex, and secretory granules exclusively labeled to ConA. In all cell types, the nuclei reacted to all lectins while the cytosol only reacted to LcA lectin. The ultrastructural and histochemical characteristics of the pelvic glands of T. marmoratus suggest that these glands could be homologous to the mammalian seminal vesicles and prostate. Anat Rec 254:196–204, 1999. © 1999 Wiley‐Liss, Inc.     

Feasibility study of minimally trained medical students using the Rural Obstetrical Ultrasound Triage Exam (ROUTE) in rural Panama

BACKGROUND: Maternal and infant mortality rates reported in rural Panama are greater than those in urban regions. Bocas del Toro is a region of Panama inhabited by indigenous people at greater risk for pregnancy-related complications and deaths due to geographic isolation and limited access to health care. Portable ultrasound training programs have recently been implemented in low-resource settings to increase access to diagnostic imaging. The goal of this study is to determine the feasibility of teaching first-year medical students the Rural Obstetrical Ultrasound Triage Exam (ROUTE) to help identify pathology in pregnant women of the Bocas del Toro region of Panama.METHODS: Eight first-year medical students completed ROUTE training sessions. After training, the students were compared to professional sonographers to evaluate their accuracy in performing the ROUTE. Students then performed the ROUTE in mobile clinics within Bocas del Toro. They enrolled women pregnant in their 2nd or 3rd trimesters and measured biparietal diameter, head circumference, amniotic fluid index, fetal lie and placental position. Any abnormal measurement would be further analyzed by the lead physician for a potential hospital referral.RESULTS: A total of 60 women were enrolled in the study. Four women were detected as having a possible high-risk pregnancy and thus referred to a hospital for further evaluation.CONCLUSION: Based on our data, first-year medical students with additional training can use the ROUTE to identify complications in pregnancy using ultrasound in rural Panama. Additional studies are required to determine the optimal amount of training required for proficiency.     

Assessment of clinical dehydration using point of care ultrasound for pediatric patients in rural Panama

BACKGROUND: Dehydration and its associated symptoms are among the most common chief complaints of children in rural Panama. Previous studies have shown that intravascular volume correlates to the ratio of the diameters of the inferior vena cava (IVC) to the aorta (Ao). Our study aims to determine if medical students can detect pediatric dehydration using ultrasound on patients in rural Panama. METHODS: This was a prospective, observational study conducted in the Bocas del Toro region of rural Panama. Children between the ages of 1 to 15 years presenting with diarrhea, vomiting, or parasitic infection were enrolled in the study. Ultrasound measurements of the diameters of the IVC and abdominal aorta were taken to assess for dehydration. RESULTS: A total of 59 patients were enrolled in this study. Twenty-four patients were clinically diagnosed with dehydration and 35 were classified to have normal hydration status. Of the 24 patients with dehydration, half (n=12) of these patients had an IVC/Ao ratio below the American threshold of 0.8. Of the remaining asymptomatic subjects, about half (n=18) of these subjects also had an IVC/Ao ratio below the American threshold of 0.8. CONCLUSION: Our study did not support previous literature showing that the IVC/Ao ratio is lower in children with dehydration. It is possible that the American standard for evaluating clinical dehydration is not compatible with the rural pediatric populations of Panama.     

Seco-eremophiladiolides and eremophilane glucosides from Pittocaulon velatum

Two seco-eremophiladiolides, velatumolide and epi-velatumolide, the trihydroxyfuranoeremophilane velatumin, and three eremophilane glucosides were isolated from Pittocaulon velatum, together with several known compounds. The structures of these compounds were elucidated by spectroscopic analysis and chemical reactions. The anti-inflammatory activity of the isolated compounds was investigated using the TPA-induced ear edema model.