Psilocybin induces acute anxiety and changes in amygdalar phosphopeptides independently from the 5-HT2A receptor

Psilocybin, and its metabolite psilocin, induces psychedelic effects through activation of the 5-HT2A receptor. Psilocybin has been proposed as a treatment for depression and anxiety but sometimes induces anxiety in humans. An understanding of mechanisms underlying the anxiety response will help to better develop therapeutic prospects of psychedelics. In the current study, psilocybin induced an acute increase in anxiety in behavioral paradigms in mice. Importantly, pharmacological blocking of the 5-HT2A receptor attenuates psilocybin-induced head twitch response, a behavioral proxy for the psychedelic response, but does not rescue psilocybin's effect on anxiety-related behavior. Phosphopeptide analysis in the amygdala uncovered signal transduction pathways that are dependent or independent of the 5-HT2A receptor. Furthermore, presynaptic proteins are specifically involved in psilocybin-induced acute anxiety. These insights into how psilocybin may induce short-term anxiety are important for understanding how psilocybin may best be used in the clinical framework.

CHD8 regulates gut epithelial cell function and affects autism-related behaviors through the gut-brain axis

Autism is a neurodevelopmental disorder characterized by early-onset social behavioral deficits and repetitive behaviors. Chromodomain helicase DNA-binding protein (CHD8) is among the genes most strongly associated with autism. In addition to the core behavioral symptoms of autism, affected individuals frequently present with gastrointestinal symptoms that are also common among individuals harboring mutations in the gene encoding CHD8. However, little is known regarding the mechanisms whereby CHD8 affects gut function. In addition, it remains unknown whether gastrointestinal manifestations contribute to the behavioral phenotypes of autism. The current study found that mice haploinsufficient for the large isoform of Chd8 (Chd8L) exhibited increased intestinal permeability, transcriptomic dysregulation in gut epithelial cells, reduced tuft cell and goblet cell counts in the gut, and an overall increase in microbial load. Gut epithelial cell-specific Chd8 haploinsufficiency was associated with increased anxiety-related behaviors together with a decrease in tuft cell numbers. Antibiotic treatment of Chd8L haploinsufficient mice attenuated social behavioral deficits. Together, these results suggest Chd8 as a key determinant of autism-related gastrointestinal deficits, while also laying the ground for future studies on the link between GI deficits and autism-related behaviors.

Zebrafish mutants reveal unexpected role of Lrp5 in osteoclast regulation

Low-density Lipoprotein Receptor-related Protein 5 (LRP5) functions as a co-receptor for Wnt ligands, controlling expression of genes involved in osteogenesis. In humans, loss-of-function mutations in LRP5 cause Osteoporosis-Pseudoglioma syndrome, a low bone mass disorder, while gain-of-function missense mutations have been observed in individuals with high bone mass. Zebrafish (Danio rerio) is a popular model for human disease research, as genetic determinants that control bone formation are generally conserved between zebrafish and mammals. We generated lrp5- knock-out zebrafish to study its role in skeletogenesis and homeostasis. Loss of lrp5 in zebrafish leads to craniofacial deformities and low bone mineral density (total body and head) at adult ages. To understand the mechanism and consequences of the observed phenotypes, we performed transcriptome analysis of the cranium of adult lrp5 mutants and siblings. Enrichment analysis revealed upregulation of genes significantly associated with hydrolase activity: mmp9, mmp13a, acp5a. acp5a encodes Tartrate-resistant acid phosphatase (TRAP) which is commonly used as an osteoclast marker, while Matrix metalloprotease 9, Mmp9, is known to be secreted by osteoclasts and stimulate bone resorption. These genes point to changes in osteoclast differentiation regulated by lrp5. To analyze these changes functionally, we assessed osteoclast dynamics in mutants and observed increased TRAP staining, significantly larger resorption areas, and developmental skeletal dysmorphologies in the mutant, suggesting higher resorptive activity in the absence of Lrp5 signaling. Our findings support a conserved role of Lrp5 in maintaining bone mineral density and revealed unexpected insights into the function of Lrp5 in bone homeostasis through moderation of osteoclast function.

[Occupational exposure to fungicides in floriculture in Ecuador]

Floriculture represents one of the major sources of income in the Ecuadorian Andean Region that can be carried out either in open fields as in greenhouses by using chemical compounds, growing hormones and xenobiotics. Among pesticides, ethylenbisdithiocarbamate (EBDTCs) fungicides represent the most extensively used. The aim of the study was the assessment of exposure to EBDTCs in Ecuadorian floricultural workers by the determination of the urinary excretion of the main metabolite of these compounds, ethylenethiourea (ETU). For this purpose, thirty-six floriculture workers and 7 unexposed healthy subjects were recruited for the study. Median level of ETU excretion in agricultural workers before the work shift was 3.2 micrograms/g creatinine, ranging from 0.4 to 34.5 micrograms/g creatinine. After pesticide application, urinary ETU increased to 6.2 micrograms/g creatinine (1.5-26.5) microgram/g creatinine. Urinary ETU resulted significantly higher in overall workers, taken as pre- and post-shift samples, when compared to controls (0.7, 0.4-2.1 micrograms/g creatinine, p < 0.01). According to jobs, applicators showed the highest levels of ETU excretion whereas growing, post-harvesting and maintenance workers showed similar levels of exposure. Higher level ETU excretion was observed in greenhouse compared to open field workers.

Unacceptable "occupational" exposure to toxic agents among children in Ecuador

To document the problem of child labor as a health issue, we report here three case-studies in Ecuador: exposure to mercury among gold washers, exposure to organophosphates and carbamates in the fruit-growing industry, and exposure to solvents among shoe cleaners. We measured the relevant biological indicators of exposure (mercury in urine, urinary levels of phenols, and acetylcholine esterase in erythrocytes) among selected samples of 10 children for each working place. In all the case studies, the values of the biological indicators showed elevated exposure to well-known toxicants, which are now rare in developed countries, even among adult workers. The findings meld with a previously reported case study of intoxication from inorganic lead among children employed in the manufacture of roof tiles in Ecuador. This study highlights the need to properly evaluate and control the potential health effects due to exposure to toxic substances among children employed in different occupations in several parts of the world.

Occupational Health Research in Developing Countries: The Experience in Ecuador

There has been a growing volume of research regarding occupational hazards in developing countries during the past decade. Results of this work are increasingly appearing in established journals and forming part of the international database on the health effects of working conditions. However, despite many similarities to research conducted in economically advanced countries, research performed in developing countries are often quite different in their motivations, methodologies, and outcomes. To investigate these differences, the recent occupational health research experience in Ecuador was examined. Based on 15 reports that could be identified since 1980 as having sufficient information to analyze, the authors identified certain persistent themes: the preponderance of cross-sectional study designs; the limited availability of quantitative exposure measures, and the utilization of nonstandard clinical measures of outcome. Each of these limitations could be related to obvious conditions under which investigators were working, and each underscores the potential value of strategic alliances between local investigators and collaborators from developed countries. The review also documented the high importance in Ecuador to studies of "established" relationships between well-known toxicants and health. While such studies could be viewed as unoriginal or uninteresting by outsiders, they may form the basis of the domestic or regional research agenda, which cannot be overlooked or misunderstood if international collaborations are not to be exploitative.

Impaired renal acidification following acute renal ischemia in the dog

Transient renal tubular acidosis may complicate acute renal failure (ARF). To clarify this phenomenon, the present study examined tubular H+ ion secretory capacity in an ischemic model of ARF. Clearance studies were performed in dogs subjected to 60 minutes, unilateral renal artery clamping. The contralateral kidney served as control. One hour after release of clamp, mean glomerular filtration rate (GFR) was reduced by 50 to 70 percent in the ischemic kidney. Bicarbonate reclamation (mEq/liter GFR) was comparable in both kidneys. However, ischemia resulted in impaired distal acidification as judged by three separate maneuvers: minimal urinary pH following sulphate infusion was higher in ischemic than in control kidney (6.61 +/- 0.39 vs. 5.39 +/- 0.26, P less than 0.01), mean urine to blood PCO2 difference (U-B PCO2) was significantly lower during phosphate infusion (ischemic: 13.8 +/- 4.1 mm Hg, control: 37.2 +/- 6.8 mm Hg, P less than 0.01) and was completely abolished during isotonic NaHCO3 infusion in the ischemic kidney (-1.9 +/- 3.4 mm Hg) compared to control (40.1 +/- 14.8 mm Hg, P less than 0.05). Urinary potassium excretion was intact following ischemia and was appropriately suppressed by amiloride. Administration of 0.7 M NaHCO3 solution at a rate sufficient to produce maximally alkaline urine resulted in a similar U-B PCO2/UHCO3 relationship in both kidneys in the face of impaired distal acidification in the ischemic kidney. This suggests either that the defect may be reversed by massive bicarbonate infusion or, alternatively, that U-B PCO2 difference may be related to other factors in addition to distal H+ secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Auditory brain-stem evoked potentials in patients undergoing dialysis

Auditory brain-stem evoked potentials (ABEPs) and pure-tone audiograms were obtained for 38 patients with renal failure, undergoing dialysis, before and after a dialysis session, and for 40 healthy normal subjects. Blood chemistry was also evaluated for each patient before and after dialysis. ABEP abnormality (using 10/sec click rate) was observed for 24% of the patients, rising to 44% when 55/sec measures were included. Abnormalities included prolongations of peak latencies for both click rates, and prolongation of interpeak latency differences. Pre-dialysis calcium was significantly different between patients with or without ABEP abnormality. In addition to this chronic effect on ABEPs, an acute effect of the dialysis session was found. Blood chemistry data, ABEP latencies and I-III interpeak latency differences were significantly different before, as compared to after dialysis. The acute effect of dialysis on blood calcium levels correlated with its effect on latencies of peaks III and V at 10/sec click rate, and on peaks I and V latency at 55/sec. These results may indicate the types of dysfunction revealed by increased stimulus rate measures.

[Jacques Lacan: The turn of the Obligado or the return of the unavoidable]

"La Vuelta de Obligado" (Obligado bend of Paraná river) is the name of a battle fought by local rebels against the colonial invading navy. The victory was due to a witty device: the patriots stretched a cable across the river and succeded in stopping the foreign float. The event is the paradigm of the everlasting fight of under-developped countries against powerful colonial metropolis. The author examines the conditions of local fight against colonizing cultural and scientific ideas, being his main content that scientific advancement needs not be an instrument of scientific imperialism. He analyzes in detail several factors currently impeding the use of scientific discoveries and improvements, focusing into concrete "obstacles" (in Bachelard's meaning) to betterment of Psychoanalytic knowledge. The obstacles are: 1. All-pervading transference. The rule adapted from Melanie Klein theories emphasizing hic et nunc validity of materials from the patient, neglects the fact that the analyst is also moved by desire, and that the patient's productions are not fragments of behavior able to be reduced to the present situation, but vectorial motions, always open and always re-opening into something defined since the beginning as forever lost. 2. Increasing activity for the analyst. The current hypothesis concerning the possibility of analyzing everything, encouraging the analyst's hyperactivity, does not allow for theoretical evaluation of the means and ways of manifestation of unconscious drives through gaps in the discourse. 3. Pan-counter-transference. The conception of counter-transference as an instrument is against Freud's contention, defining it as a reciprocal transference that must be fought in the same way as the patient's. 4. Belittling of theory. The thesis against theory, on the grounds that Psychoanalysis deals with affects and the affective life of patients, forgets that there is always some system for understanding the world and, for want of a theory, an ideological system is always ready to provide the grid underlying all concepts used. 5. Not-analyzing. The automatic "translation", lacking the search for new links to replace the ones that analysis dismantles, leads to denaturalizing the practice and keeping intact the patient's imaginary consistent universe. 6. Intergrationism. Other theories cannot be integrated to Psychoanalysis as they have different objects and different frameworks. Conversely, Psychoanalitic concepts cannot be formulated in other theories conceptual corpus for the same reason. The exception are the sciences having similar fields and methods of analysis, such as Semiotics or Linguistics. In their case the articulation of concepts becomes possible, but still requires the previous command of Psychoanalytic Theory in its full depth. 7. Communicationalism. The most common of all integrations with other sciences is the one linking Psychoanalysis with Communications Theory...