Crayfish Procambarus clarkii retina and nervous system exhibit antioxidant circadian rhythms coupled with metabolic and luminous daily cycles.

Based on previous work in which we proposed midgut as a putative peripheral oscillator responsible for circadian reduced glutathione (GSH) crayfish status, herein we investigated the retina and optic lobe-brain (OL-B) circadian GSH system and its ability to deal with reactive oxygen species (ROS) produced as a consequence of metabolic rhythms and light variations. We characterized daily and antioxidant circadian variations of the different parameters of the glutathione system, including GSH, oxidized glutathione (GSSG), glutathione reductase (GR) and glutathione peroxidase (GPx), as well as metabolic and lipoperoxidative circadian oscillations in retina and OL-B, determining internal and external GSH-system synchrony. The results demonstrate statistically significant bi- and unimodal daily and circadian rhythms in all GSH-cycle parameters, substrates and enzymes in OL-B and retina, as well as an apparent direct effect of light on these rhythms, especially in the retina. The luminous condition appears to stimulate the GSH system to antagonize ROS and lipid peroxidation (LPO) daily and circadian rhythms occurring in both structures, oscillating with higher LPO under dark conditions. We suggest that the difference in the effect of light on GSH rhythmic mechanisms of both structures for antagonizing ROS could be due to differences in glutathione-system coupling strength with the circadian clock.

Out-of-hospital cardiac arrest: first documented experience in a Mexican urban setting.

OBJECTIVE: Out-of-hospital cardiac arrest is one of the leading causes of death in Mexico, but many survival and prognostic factors are unknown. The aim of this study was to assess out-of-hospital cardiac arrest in a Mexican city. METHODS: This was a prospective, cohort study that evaluated the records of the major ambulance services in the city of Queretaro, Mexico. Means, standard deviation, and percentages for the categorical variables were obtained. Logistic regression was performed to determine the effects between interventions, times, and return of spontaneous circulation (ROSC). RESULTS: For an 11-month period, 148 out-of-hospital cardiac arrest cases were recorded. The mean age of the victims was 54 +/- 22.6 years and 90 (65.3%) were males. Forty-nine cases were related to cardiac disease, 46 to other disease, 27 to trauma, 18 to terminal illnesses, and three to drowning. Twelve (8.6%) patients had a pulse upon hospital arrival, but none survived to discharge. No victims were defibrillated prior to ambulance arrival. The collapse-assessment interval was 22.5 +/- 19:1 minutes, the mean value for the ambulance response times was 13:6 +/-10:4 minutes. Basic emergency medical technicians applied chest compressions to 40 victims (27.2%), controlled the airway in 32 (21.8%), and defibrillated seven (4.8%). Chest compressions and airway control showed an OR of 8 and 12 respectively for ROSC. CONCLUSIONS: The poor survival rate in this study emphasizes the need to improve efforts in provider training and public education. Authorities must promote actions to enhance prehospital emergency services capabilities, shorten response times, and provide community education to increase the chances of survival for out-of-hospital cardiac arrest victims in Mexico.

[Syncope in the elderly: findings of diagnostic complementary tests in a University Hospital]. / Séncope en el anciano: Hallazgos de pruebas complementarias en un Centro Hospitalario Universitario.

UNLABELLED: Syncope is a common symptom among older adults. Its aetiologic diagnosis is mainly clinical, but when it has an unknown origin, complementary studies are necessary. We present the experience of a single center in diagnosing Unknown Origin Syncope (UOS). METHODS: We performed a transversal retrolective study to assess the different tests done to patients studied because of USO. RESULTS: The mean age of the older group was 77.6 +/- 6.9 years. The 24-hour Hotter were abnormal in 77.9% of patients, but diagnostic in only 16.3%. Age older than 65 years was associated with a 1.9 increase (CI 95% 0.9-4) in the possibilities of having a diagnosis, while age lesser than 65 was associated with a 0.5 risk CI 95% 0.2-1.08 of having a diagnosis. The 48-hour holter showed similar results. Older age was associated with a 1.69 OR, CI 95% 0.6-4.4 to have a positive Tilt test (91% of older patients). They had mainly the vasodepressor variety of neurally-mediated syncope. (57.1% Vs 40.1%, p = 0.01). Of the 6 electrophysiologic studies performed in people older than 65 years, 3 where diagnostic (50% Vs 33.3%, p = 0.6). CONCLUSIONS: Complimentary tests in people elder than 65 years are diagnostic in a higher proportion than in their younger counterparts. Nevertheless there is a higher risk of false-positive results, so tests such as head-up tilt test should be more carefully interpreted.

The circadian system of crayfish: a developmental approach.

Adult crayfish exhibit a variety of overt circadian rhythms. However, the physiological mechanisms underlying the overt rhythms are controversial. Research has centered on two overt rhythms: the motor activity and the retinal sensitivity rhythms of the genus Procambarus. The present work reviews various studies undertaken to localize pacemakers and mechanisms of entrainment responsible for these two rhythms in adult organisms of this crustacean decapod. It also describes an ontogenetic approach to the problem by means of behavioral, electrophysiological, and neurochemical experiments. The results of this approach confirm previous models proposed for adult crayfish, based on a number of circadian pacemakers distributed in the central nervous system. However, the coupling of rhythmicity between these independent oscillators might be complex and dependent on the interaction between serotonin (5-HT), light, and the crustacean hyperglycemic hormone (CHH). The latter compound has, up until now, not been considered as an agent in the genesis and synchronization of the retinal sensitivity rhythm.

The effect of photoperiod and light irradiance on the antioxidant circadian system of two species of crayfish from different latitudes: Procambarus clarkii and P. digueti.

This work was carried out to study the antioxidant circadian system of two species of crayfish of different latitude origin. We investigated (1) whether both species possess glutathione circadian rhythms and (2) whether both species' rhythms differ in their ability to synchronize to 24 h cycles. Two batches of Procambarus clarkii and P. digueti were kept in (1) light-dark (LD) 12:12 low irradiance (LI) cycles and then exposed to (2) 72 h of complete darkness, (3) LD 12:12 high irradiance (HI), (4) LD 20:4 LI and (5) LD 20:4 HI for 2 weeks. The midgut and hemolymph were sampled and reduced and oxidized glutathione as well as glutathione reductase and glutathione peroxidase were assayed. Cosinor and analysis of variance revealed differences between both species. Procambarus clarkii robust antioxidant circadian rhythms are able to entrain to all conditions resetting to lights on or off. However, the P. digueti weak circadian glutathione system did not entrain to the LD cycles, showing a random distribution of phases. In this species, LD 12:12 and 20:4 HI evidenced significant daily rhythms indicating a damped circadian antioxidative system that is enhanced by the effect of light. This suggests that each species' photoperiodic history determines the adaptive abilities of the circadian antioxidative mechanisms.

Putative pacemakers in the eyestalk and brain of the crayfish Procambarus clarkii show circadian oscillations in levels of mRNA for crustacean hyperglycemic hormone.

Crustacean hyperglycemic hormone (CHH) synthesizing cells in the optic lobe, one of the pacemakers of the circadian system, have been shown to be present in crayfish. However, the presence of CHH in the central brain, another putative pacemaker of the multi-oscillatory circadian system, of this decapod and its circadian transcription in the optic lobe and brain have yet to be explored. Therefore, using qualitative and quantitative PCR, we isolated and cloned a CHH mRNA fragment from two putative pacemakers of the multi-oscillatory circadian system of Procambarus clarkii, the optic lobe and the central brain. This CHH transcript synchronized to daily light-dark cycles and oscillated under dark, constant conditions demonstrating statistically significant daily and circadian rhythms in both structures. Furthermore, to investigate the presence of the peptide in the central brain of this decapod, we used immunohistochemical methods. Confocal microscopy revealed the presence of CHH-IR in fibers and cells of the protocerebral and tritocerebal clusters and neuropiles, particularly in some neurons located in clusters 6, 14, 15 and 17. The presence of CHH positive neurons in structures of P. clarkii where clock proteins have been reported suggests a relationship between the circadian clockwork and CHH. This work provides new insights into the circadian regulation of CHH, a pleiotropic hormone that regulates many physiological processes such as glucose metabolism and osmoregulatory responses to stress.

Asociación de obesidad general y abdominal con hipertensión, dislipemia y presencia de prediabetes en el estudio PREDAPS / Association of general and abdominal obesity with hypertension, dyslipidemia and prediabetes in the PREDAPS study

Introducción y objetivos: Algunas medidas antropométricas muestran mayor capacidad que otras para discriminar la presencia de factores de riesgo cardiovascular. Este trabajo estima la magnitud de la asociación de diversos indicadores antropométricos de obesidad con hipertensión, dislipemia y prediabetes (glucemia basal o glucohemoglobina alteradas). Métodos: Análisis transversal de la información recogida en 2.022 sujetos del estudio PREDAPS (etapa basal). Se definió obesidad general como índice de masa corporal ≥ 30 kg/m2 y obesidad abdominal con 2 criterios: a) perímetro de cintura (PC) ≥ 102 cm en varones/PC ≥ 88 cm en mujeres, y b) índice cintura/estatura (ICE) ≥ 0,55. La magnitud de la asociación se estimó mediante regresión logística. Resultados: La hipertensión arterial mostró la asociación más alta con la obesidad general en mujeres (OR = 3,01; IC95%, 2,24-4,04) y con la obesidad abdominal según el criterio del ICE en varones (OR = 3,65; IC95%, 2,66-5,01). La hipertrigliceridemia y los valores bajos de colesterol unido a lipoproteínas de alta densidad mostraron la asociación más alta con obesidad abdominal según el criterio del ICE en mujeres (OR = 2,49; IC95%, 1,68-3,67 y OR = 2,70; IC95%, 1,89-3,86) y la obesidad general en varones (OR = 2,06; IC95%, 1,56-2,73 y OR = 1,68; IC95%, 1,21-2,33). La prediabetes mostró la asociación más alta con obesidad abdominal según el criterio del ICE en mujeres (OR = 2,48; IC95%, 1,85-3,33) y con obesidad abdominal según el criterio del PC en varones (OR = 2,33; IC95%, 1,75-3,08). Conclusiones: Los indicadores de obesidad abdominal mostraron la mayor asociación con la presencia de prediabetes. La relación de los indicadores antropométricos con hipertensión y con dislipemia mostró resultados heterogéneos (AU)

Introduction and objectives: Some anthropometric measurements show a greater capacity than others to identify the presence of cardiovascular risk factors. This study estimated the magnitude of the association of different anthropometric indicators of obesity with hypertension, dyslipidemia, and prediabetes (altered fasting plasma glucose and/or glycosylated hemoglobin). Methods: Cross-sectional analysis of information collected from 2022 participants in the PREDAPS study (baseline phase). General obesity was defined as body mass index ≥ 30 kg/m2 and abdominal obesity was defined with 2 criteria: a) waist circumference (WC) ≥ 102 cm in men/WC ≥ 88 cm in women, and b) waist-height ratio (WHtR) ≥ 0.55. The magnitude of the association was estimated by logistic regression. Results: Hypertension showed the strongest association with general obesity in women (OR, 3.01; 95%CI, 2.24-4.04) and with abdominal obesity based on the WHtR criterion in men (OR, 3.65; 95%CI, 2.66-5.01). Hypertriglyceridemia and low levels of high-density lipoprotein cholesterol showed the strongest association with abdominal obesity based on the WHtR criterion in women (OR, 2.49; 95%CI, 1.68-3.67 and OR, 2.70; 95%CI, 1.89-3.86) and with general obesity in men (OR, 2.06; 95%CI, 1.56-2.73 and OR, 1.68; 95%CI, 1.21-2.33). Prediabetes showed the strongest association with abdominal obesity based on the WHtR criterion in women (OR, 2.48; 95%CI, 1.85-3.33) and with abdominal obesity based on the WC criterion in men (OR, 2.33; 95%CI, 1.75-3.08). Conclusions: Abdominal obesity indicators showed the strongest association with the presence of prediabetes. The association of anthropometric indicators with hypertension and dyslipidemia showed heterogeneous results (AU)

Crayfish brain-protocerebrum and retina show serotonergic functional relationship.

The results from various studies have indicated possible functional relationships between crayfish electroretinogram (ERG) rhythmic amplitude changes and the serotonergic pathways projecting from the central brain through the optic neuropils to the eye, but to date, this functional interaction has not been proven. Here, in a set of experiments using an isolated eyestalk-brain preparation, we investigated whether there is a circadian input from the brain to retina that regulates this rhythm. We sought to determine whether the protocerebral bridge (PB) stimulation affects the ERG amplitude in accordance with the zeitgeber time (ZT) and whether 5-HT modulates the associate input. Our results showed that photic stimulation of retina produced changes in both the amplitude and the frequency of spontaneous electrical activity in the protocerebral neuropils. In addition, electrical stimulation of the medial protocerebrum, particularly the PB, produced statistically significant changes in the ERG that depended on both the time of day and the level of serotonin. This suggests that pathways between retina and PB seem to be serotonergic.

Séncope en el anciano: hallazgos de pruebas complementarias en un Centro Hospitalario Universitario / Syncope in the elderly: findings of diagnostic complementary tests in a University Hospital

Syncope is a common symptom among older adults. Its aetiologic diagnosis is mainly clinical, but when it has an unknown origin, complementary studies are necessary. We present the experience of a single center in diagnosing Unknown Origin Syncope (UOS). METHODS: We performed a transversal retrolective study to assess the different tests done to patients studied because of USO. RESULTS: The mean age of the older group was 77.6 +/- 6.9 years. The 24-hour Hotter were abnormal in 77.9% of patients, but diagnostic in only 16.3%. Age older than 65 years was associated with a 1.9 increase (CI 95% 0.9-4) in the possibilities of having a diagnosis, while age lesser than 65 was associated with a 0.5 risk CI 95% 0.2-1.08 of having a diagnosis. The 48-hour holter showed similar results. Older age was associated with a 1.69 OR, CI 95% 0.6-4.4 to have a positive Tilt test (91% of older patients). They had mainly the vasodepressor variety of neurally-mediated syncope. (57.1% Vs 40.1%, p = 0.01). Of the 6 electrophysiologic studies performed in people older than 65 years, 3 where diagnostic (50% Vs 33.3%, p = 0.6). CONCLUSIONS: Complimentary tests in people elder than 65 years are diagnostic in a higher proportion than in their younger counterparts. Nevertheless there is a higher risk of false-positive results, so tests such as head-up tilt test should be more carefully interpreted.