Effects of the Natural β-Carboline Alkaloid Harmine,a Main Constituent of Ayahuasca,in Memory and in the Hippocampus: A Systematic Literature Review of Preclinical Studies

Harmine is a natural β-carboline alkaloid found in several botanical species, such as the Banisteriopsis caapi vine used in the preparation of the hallucinogenic beverage ayahuasca and the seeds of Syrian rue (Peganum harmala). Preclinical studies suggest that harmine may have neuroprotective and cognitive-enhancing effects, and retrospective/observational investigations of the mental health of long-term ayahuasca users suggest that prolonged use of this harmine-rich hallucinogen is associated with better neuropsychological functioning. Thus, in order to better investigate these possibilities, we performed a systematic literature review of preclinical studies analyzing the effects of harmine on hippocampal neurons and in memory-related behavioral tasks in animal models. We found two studies involving hippocampal cell cultures and nine studies using animal models. Harmine administration was associated with neuroprotective effects such as reduced excitotoxicity, inflammation, and oxidative stress, and increased brain-derived neurotrophic factor (BDNF) levels. Harmine also improved memory/learning in several animal models. These effects seem be mediated by monoamine oxidase or acetylcholinesterase inhibition, upregulation of glutamate transporters, decreases in reactive oxygen species, increases in neurotrophic factors, and anti-inflammatory effects. The neuroprotective and cognitive-enhancing effects of harmine should be further investigated in both preclinical and human studies.     

Molecular epidemiology of spinocerebellar ataxias in Cuba: Insights into SCA2 founder effect in Holguin

The objective of this study was to determine the prevalence of hereditary ataxias in Cuba, with a special focus on the clinical and molecular features of SCA2. Clinical assessments were performed by neurological examinations and application of the SARA scale. Molecular analyses of genes SCA1–3, SCA6, SCA17 and DRPLA identified 753 patients with SCA and 7173 asymptomatic relatives, belonging to 200 unrelated families. 86.79% of all SCA patients were affected with SCA2. In the Holguin province, the average population prevalence of SCA2 is 40.18 × 10⁵ inhabitants, with the remarkable figure of 141.66 × 10⁵ in the Baguanos municipality. The high prevalence of the SCA2 mutation in Holguin reflects most likely a founder effect. The stabilization of the prevalence along time suggests the existence of premutated chromosomes with pure CAG, acting as reservoir for further expansions. CAG repeat length correlated inversely with age at onset, accounting for 80% of the variability. Genetic anticipation was observed in the 80% of transmissions. Repeat instability was greater in paternal transmissions whereas CAG expansions without anticipation was observed in 10.97% suggesting the effect of CAA interruptions in the CAG segment, which decrease the toxicity of the abnormal ataxin-2, and/or other protective factors.     

Innovative moments and change pathways: A good outcome case of narrative therapy

Objectives. Our aim was to explore the development of innovative moments (i‐moments) in therapeutic conversation and to study how they match our heuristic model that accounts for the development of change, drawn from previous empirical research. Design. In this therapeutic process research, we analysed a good outcome case of narrative therapy with a woman victim of intimate violence. Methods. This case, composed of 12 sessions, was analysed with the Innovative Moments Coding System: Version 1. This coding system allowed the identification of five different types of innovations (i‐moments) that appeared during the therapeutic process: action, reflection, protest, re‐conceptualization, and performing change. For each session, an index of temporal salience was computed, as the percentage of the time in the session that client and therapist spent talking about each i‐moment. Our analysis procedures provided a quantitative and also a complementary qualitative approach. Results. Data showed that the types of i‐moments emerged differently throughout the process. Early sessions were characterized mainly by action and reflection (low temporal salience), middle sessions were found to have mainly protest i‐moments (low or middle temporal salience), and final sessions were characterized by the combination of high salient re‐conceptualization and performing change i‐moments. Conclusions. Findings suggested that narrative change seems to develop in a cyclical way, in which different types of i‐moments contribute to the development of a new self‐narrative in different phases.     

Longitudinal growth in chronic hypokalemic disorders

Growth retardation remains a major complication in children with primary tubular disorders, despite adequate supplemental treatment with electrolytes, water and bicarbonate. Chronic hypokalemia, characteristic of some tubulopathies, impairs growth by mechanisms that are not well known. Association with growth hormone deficiency has been reported in patients with Bartter’s or Gitelman’s syndrome. Tissue-specific alterations of growth hormone and insulin-like growth factor I axis have been described in experimental models of potassium depletion. Hypokalemic rats gain less body length and weight than pair-fed normokalemic animals and, by contrast, develop renal hypertrophy. These rats have low circulating concentrations of insulin-like growth factor I, depressed messenger ribonucleic acid (mRNA) levels of this peptide in the tibial growth plate, and they are resistant to the longitudinal growth-promoting effects of exogenous growth hormone. The reason for this resistance remains to be defined. No alterations in the intracellular signaling for growth hormone have been found in the liver of hypokalemic rats. However, treatment with high doses of growth hormone is unable to normalize hypertrophy of the epiphyseal cartilage chondrocytes, which are severely disturbed in potassium depletion and likely play an important role in the pathogenia of growth impairment in this condition.     

Asociación entre el hydrops endolinfático y vértigo posicional paroxístico benigno: ¿casualidad o causalidad?

IntroductionThe aim of this study was to determine the prevalence of benign paroxysmal positional vertigo (BPPV) in patients diagnosed with endolymphatic hydrops (EH) and to analyze whether this association is a factor for poor prognosis in these patients.Material and methodsA retrospective study was carried out in our department among the patients definitively diagnosed as having Ménière's disease according to the criteria of the American Academy of Otolaryngology and BPPV by the usual triggering manoeuvres.ResultsThe prevalence of BPPV in our patients with EH was 5.1%. The rate of cure with the repositioning manoeuvres is 90.9%, however success with the first manoeuvre was only 63.36%. Recurrences occurred in up to 22.22%. We found a lower success rate with the first manoeuvre in relation to the rest of the patients with BPPV without EH. This difference is statistically significant (P=0.042).DiscussionWe did not find that these patients to have a lower rate of cure with the repositioning manoeuvres or a higher rate of recurrence. But in our protocol the first manoeuvre had a lower success rate than in the rest of the patients.