Students' foundational understanding of chemical reaction in the forensic science bachelor's degree program at the National Autonomous University of Mexico.

OBJECTIVE: To compare the understanding of the concept of chemical reaction-as operationalized by Bloom's taxonomy of cognitive levels-of students in forensic science bachelor's degree with that achieved by students majoring in chemistry, as a prerequisite for future professional collaboration and communication. MATERIALS AND METHODS: Using previously validated and published tests developed to assess students' knowledge, comprehension, and application of the concept of chemical reaction, we explored how conceptual understanding developed in students enrolled in (a) a forensic science degree program in a Mexican public university and in (b) chemistry undergraduate programs offered by the same university, and whether both groups achieved comparable attainment levels. FINDINGS AND IMPLICATIONS: Despite receiving considerably less chemical instruction, forensic science students achieved comparable levels of conceptual understanding of chemical reaction to those exhibited by chemistry students. This finding is encouraging because it might mean that future forensic scientists could graduate with a solid foundation of chemical knowledge. More research, particularly on the learning of other key concepts, will be needed to verify these initial findings.

Efficacy and Safety of Erenumab, Galcanezumab, and Fremanezumab in the Treatment of Drug-Resistant Chronic Migraine: Experience in Real Clinical Practice.

BACKGROUND: Due to the recent introduction of new biologic drugs for chronic migraine, a global evaluation in real clinical practice is necessary. OBJECTIVE: The objective was to evaluate the effectiveness and safety in real clinical practice of drugs targeting the calcitonin gene-related peptide receptor (CGRPr) in patients with chronic migraine. METHODS: Single-center, restrospective study (2019-2022), including patients with chronic migraine treated with erenumab, galcanezumab, or fremanezumab. Effectiveness variables were recorded, namely, number of migraine headache days per month (MHD), Migraine Disability Assessment Scale (MIDAS) score, and Headache Impact Test-6 (HIT-6) score, assessing changes at week 12, 24 from baseline. Toxicity was recorded following the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 criteria. RESULTS: In all, 104 patients were included (46.2% erenumab, 41.3% galcanezumab, 12.5% fremanezumab). A reduction in MHD, MIDAS, and HIT-6 was achieved at weeks 12 and 24 with erenumab (p75% at week 24 than those intensified; P = 0.041). There was no difference in efficacy (P = 0.154) or improvement in quality of life (P = 0.783, P = 0.150), but there was greater toxicity (P < 0.001) among nonresponders with erenumab 70 mg versus erenumab 140 mg. CONCLUSIONS: The results confirm the effectiveness and safety of anticalcitonin gene-related peptide (CGRP) drugs in real clinical practice. However, the study shows little benefit from erenumab intensification, with similar effectiveness and worse tolerability than the standard dose.

Simultaneous rupture of two renal artery aneurysms in a patient with tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is an autosomal dominant multisystem neurocutaneous genetic condition. It is characterized by TSC-associated neuropsychiatric disorders, epilepsy, tumors, and angiomyolipoma in multiple organs, such as the skin, lungs, and kidneys. TSC is also associated with the development of aneurysms of the medium and large arteries, including the renal arteries. This condition will usually be diagnosed early in life, and active surveillance is required of tumor and aneurysm growth to prevent life-threatening events. We have presented the case of a 41-year-old patient with TSC that had not been previously diagnosed. The patient had presented with retroperitoneal hematoma secondary to the rupture of two left renal artery branch aneurysms that had likely developed within the angiomyolipoma.

Gaseous emissions during the solid state fermentation of different wastes for enzyme production at pilot scale.

The emissions of volatile organic compounds (VOC), CH4, N2O and NH3 during the solid state fermentation process of some selected wastes to obtain different enzymes have been determined at pilot scale. Orange peel+compost (OP), hair wastes+raw sludge (HW) and winterization residue+raw sludge (WR) have been processed in duplicate in 50 L reactors to provide emission factors and to identify the different VOC families present in exhaust gaseous emissions. Ammonia emission from HW fermentation (3.2±0.5 kg Mg(-1) dry matter) and VOC emission during OP processes (18±6 kg Mg(-1) dry matter) should be considered in an industrial application of these processes. Terpenes have been the most emitted VOC family during all the processes although the emission of sulphide molecules during HW SSF is notable. The most emitted compound was dimethyl disulfide in HW and WR processes, and limonene in the SSF of OP.

Effect of gambierol and its tetracyclic and heptacyclic analogues in cultured cerebellar neurons: a structure-activity relationships study.

The polycyclic ether class of marine natural products has attracted the attention of researchers due to their complex and large chemical structures and diverse biological activities. Gambierol is a marine polycyclic ether toxin, first isolated along with ciguatoxin congeners from the dinoflagellate Gambierdiscus toxicus. The parent compound gambierol and the analogues evaluated in this work share the main crucial elements for biological activity, previously described to be the C28=C29 double bond within the H ring and the unsaturated side chain [Fuwa, H., Kainuma, N., Tachibana, K., Tsukano, C., Satake, M., and Sasaki, M. (2004) Diverted total synthesis and biological evaluation of gambierol analogues: Elucidation of crucial structural elements for potent toxicity. Chem. Eur. J. 10, 4894-4909]. With the aim to gain a deeper understanding of the cellular mechanisms involved in the biological activity of these compounds, we compared its activity in primary cultured neurons. The three compounds inhibited voltage-gated potassium channels (Kv) in a concentration-dependent manner and with similar potency, caused a small inhibition of voltage-gated sodium channels (Nav), and evoked cytosolic calcium oscillations. Moreover, the three compounds elicited a "loss of function" effect on Kv channels at concentrations of 0.1 nM. Additionally, both the tetracyclic and the heptacyclic derivatives of gambierol elicited synchronous calcium oscillations similar to those previously described for gambierol in cultured cerebellar neurons. Neither gambierol nor its tetracyclic derivative elicited cell toxicity, while the heptacyclic analogue caused a time-dependent decrease in cell viability. Neither the tetracyclic nor the heptacyclic analogues of gambierol exhibited lethality in mice after ip injection of 50 or 80 µg/kg of each compound. Altogether, the results presented in this work support an identical mechanism of action for gambierol and its tetracyclic and heptacyclic analogues and indicate a "loss of function" effect on potassium channels even after administration of the three compounds at subnanomolar concentrations. In addition, because gambierol is known to stabilize the closed state of Kv3 channels, the results presented in this paper may have implications for understanding of channel functions and for future development of therapies against ciguatera poisoning and potassium channel-related diseases.

Determination of toxicity equivalent factors for paralytic shellfish toxins by electrophysiological measurements in cultured neurons.

The establishment of toxicity equivalent factors to develop alternative methods to animal bioassays for marine-toxin detection is an urgent need in the field of phycotoxin research. Paralytic shellfish poisoning (PSP) is one of the most severe forms of food poisoning. The toxins responsible for this type of poisoning are highly toxic natural compounds produced by dinoflagellates, which bind to voltage-gated Na(+) channels causing the blockade of action potential propagation. In spite of the fact that several standards of PSP toxins are currently commercially available, there is scarcity of data on the biological activity of these toxins, a fact that limits the calculation of their toxicity equivalent factors. We have evaluated the potency of the commercial PSP toxin standards for their ability to inhibit voltage-dependent sodium currents in cultured neuronal cells by electrophysiological measurements. The in vitro potencies of the PSP toxin standards as indicated by their IC(50) values were in the order Neosaxitoxin (NeoSTX) > decarbamoylsaxitoxin (dcSTX) > saxitoxin (STX) > gonyautoxin 1,4 (GTX1,4) > decarbamoylneosaxitoxin (dcNeoSTX) > gonyautoxin 2,3 (GTX2,3) > decarbamoylgonyautoxin 2,3 (dcGTX2,3) > gonyautoxin 5 (GTX5) > N-sulfocarbamoyl-gonyautoxin-2 and -3 (C1,2). The data obtained in this in vitro analysis correlated well with their previously reported toxicity values.

A comparative study of the effect of ciguatoxins on voltage-dependent Na+ and K+ channels in cerebellar neurons.

Ciguatera is a global disease caused by the consumption of certain warm-water fish (ciguateric fish) that have accumulated orally effective levels of sodium channel activator toxins (ciguatoxins) through the marine food chain. The effect of ciguatoxin standards and contaminated ciguatoxin samples was evaluated by electrophysiological recordings in cultured cerebellar neurons. The toxins affected both voltage-gated sodium (Nav) and potassium channels (Kv) although with different potencies. CTX 3C was the most active toxin blocking the peak inward sodium currents, followed by P-CTX 1B and 51-OH CTX 3C. In contrast, P-CTX 1B was more effective in blocking potassium currents. The analysis of six different samples of contaminated fish, in which a ciguatoxin analogue of mass 1040.6, not identical with the standard 51-OH CTX 3C, was the most prevalent compound, indicated an additive effect of the different ciguatoxins present in the samples. The results presented here constitute the first comparison of the potencies of three different purified ciguatoxins on sodium and potassium channels in the same neuronal preparation and indicate that electrophysiological recordings from cultured cerebellar neurons may provide a valuable tool to detect and quantify ciguatoxins in the very low nanomolar range.

First toxin profile of ciguateric fish in Madeira Arquipelago (Europe).

Ciguatera fish poisoning (CFP) is a human foodborne intoxication caused by ingestion of tropical fishes contaminated with the potent polyether toxins known as ciguatoxins (CTXs). These toxins are issued from Gambierdiscus species of dinoflagellates. Herbivorous fish accumulate these toxins in their musculature and viscera after ingesting dinoflagellates. Epidemiological studies showed that CFP has been present in areas between 35 degrees North and 35 degrees South latitude, mainly, Indo-pacific and Caribbean areas, but not in waters closed to European and African continent. In the present paper, a specimen of Seriola dumerili weighing 70 kg and a smaller Seriola fasciata specimen, captured in waters belonging to Selvagens Islands (Madeira Arquipelago), were analyzed. Fishes from this genus were implicated in previous suspected ciguatera poisoning outbreaks in the Portuguese Madeira Arquipelago in the North Atlantic Ocean. Analysis was performed by two approaches, a functional method using cerebellar granule cells and by ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) method. The study was carried out in one portion of the tail muscle of Seriola fasciata and five parts of the body of Seriola dumerili (tail muscle, head, ventral muscle, mid muscle, and liver). The functional method consisted in the modification of the inward sodium current in cerebellar granule cells and the chemical method was a high resolution chromatography, which allowed elucidating the toxin profile in the samples. In addition, UPLC-MS technique was optimized and used for detecting and quantifying CTXs for the first time. After fish extraction and clean up, the chromatograms revealed the presence of CTX-1B at 1111.6 m/z, CTX-3C at 1023.5 m/z, a CTX analogue at 1040.6 m/z, and a CTX from the Caribbean or Indic waters at 1141.6 m/z. Therefore, the results obtained in the present paper for both methods confirm, for the first time, the presence of CTX in fish from Madeira Arquipelago.

Continuous approach for ultrasound-assisted acid extraction-minicolumn preconcentration of chromium and cobalt from seafood samples prior to flame atomic absorption spectrometry.

A rapid and sensitive method has been proposed for the determination of chromium and cobalt in seafood samples by flame atomic absorption spectrometry combined with a dynamic ultrasound-assisted acid extraction and an on-line minicolumn preconcentration. The use of diluted nitric acid as extractant in a continuous mode at a flow rate of 3.5 mL min(-1) and room temperature was sufficient for quantitative extraction of these trace metals from seafoods. A minicolumn containing a chelating resin was an excellent device for the quantitative preconcentration of chromium and cobalt prior to their detection. A flow-injection manifold was used as interface for coupling all analytical steps, which allowed the automation of the whole analytical process. A Plackett-Burman experimental design was used as a multivariate strategy for the optimization of both sample preparation and preconcentration steps. The method was successfully applied to the determination of chromium and cobalt in seafood samples.