Age-, region-, and day/night-related variation of the chloride reversal potential in the rat suprachiasmatic nucleus.

The master control of mammalian circadian rhythms is the suprachiasmatic nucleus (SCN), which is formed by the ventral and dorsal regions. In SCN neurons, GABA has an important function and even excitatory actions in adulthood. However, the physiological role of this neurotransmitter in the developing SCN is unknown. Here, we recorded GABAergic postsynaptic currents (in the perforated-patch configuration using gramicidin) to determine the chloride reversal potential (ECl) and also assessed the immunological expression of the Na-K-Cl cotransporter 1 (NKCC1) at early ages of the rat (postnatal days (P) 3 to 25), during the day and night, in the two SCN regions. We detected that ECl greatly varied with age and depending on the SCN region and time of day. Broadly speaking, ECl was more hyperpolarized with age, except for the oldest age studied (P20-25) in both day and night in the ventral SCN, where it was less negative. Likewise, ECl was more hyperpolarized in the dorsal SCN both during the day and at night; while ECl was more negative at night both in the ventral and the dorsal SCN. Moreover, the total NKCC1 fluorescent expression was higher during the day than at night. These results imply that NKCC1 regulates the circadian and developmental fluctuations in the [Cl-]i to fine-tune ECl, which is crucial for either excitatory or inhibitory GABAergic actions to occur in the SCN.

Human gut microbiota analysis of cystic fibrosis infants using metaproteomics.

We report a metaproteomic analysis of the gut microbiota of eight infants with cystic fibrosis, during the first year of life. This is the first study in this disease that uses metaproteomics to analyze stool samples from patients at such a young age.

Selection versus transmission: Quantitative and organismic biology in antibiotic resistance.

We aimed to determine the importance of selection (mostly dependent on the anthropogenic use of antimicrobials) and transmission (mostly dependent on hygiene and sanitation) as drivers of the spread of antibiotic-resistant bacterial populations. The first obstacle to estimating the relative weight of both independent variables is the lack of detailed quantitative data concerning the number of bacterial cells, potentially either pathogenic or harmless, and bacterial species exposed to antimicrobial action in the microbiotas of specific environments. The second obstacle is the difficulty of considering the relative importance of the transmission and selection exerting their combined effects on antibiotic resistance across eco-biological levels. As a consequence, advances are urgently required in quantitative biology and organismic biology of antimicrobial resistance. The absolute number of humans exposed to antibiotics and the absolute number of potentially pathogenic and commensal bacteria in their microbiomes should influence both the selection and transmission of resistant bacterial populations. The "whole Earth" microbiome, with astonishingly high numbers of bacterial cells and species, which are also exposed to anthropogenic antimicrobials in various biogeographical spaces, shapes the antibiotic resistance landscape. These biogeographical spaces influence various intensities of selection and transmission of potentially pathogenic bacteria. While waiting for more precise data, biostatistics analysis and mathematical or computational modeling can provide proxies to compare the influence of selection and transmission in resistant bacteria. In European countries with lower sanitation levels, antibiotic consumption plays a major role in increasing antibiotic resistance; however, this is not the case in countries with high sanitation levels. Although both independent variables are linked, their relative influence on the level of antibiotic resistance varies according to the particular location. Therefore, interventions directed to decrease antibiotic resistance should be designed "a la carte" for specific locations with particular ecological conditions, including sanitation facilities.

Increased glutamatergic neurotransmission between the retinohypothalamic tract and the suprachiasmatic nucleus of old mice.

Circadian rhythms synchronize to light through the retinohypothalamic tract (RHT), which is a bundle of axons coming from melanopsin retinal ganglion cells, whose synaptic terminals release glutamate to the ventral suprachiasmatic nucleus (SCN). Activation of AMPA-kainate and NMDA postsynaptic receptors elicits the increase in intracellular calcium required for triggering the signaling cascade that ends in phase shifts. During aging, there is a decline in the synchronization of circadian rhythms to light. With electrophysiological (whole-cell patch-clamp) and immunohistochemical assays, in this work, we studied pre- and postsynaptic properties between the RHT and ventral SCN neurons in young adult (P90-120) and old (P540-650) C57BL/6J mice. Incremental stimulation intensities (applied on the optic chiasm) induced much lesser AMPA-kainate postsynaptic responses in old animals, implying a lower recruitment of RHT fibers. Conversely, a higher proportion of old SCN neurons exhibited synaptic facilitation, and variance-mean analysis indicated an increase in the probability of release in RHT terminals. Moreover, both spontaneous and miniature postsynaptic events displayed larger amplitudes in neurons from aged mice, whereas analysis of the NMDA and AMPA-kainate components (evoked by RHT electrical stimulation) disclosed no difference between the two ages studied. Immunohistochemistry revealed a bigger size in the puncta of vGluT2, GluN2B, and GluN2A of elderly animals, and the number of immunopositive particles was increased, but that of PSD-95 was reduced. All these synaptic adaptations could be part of compensatory mechanisms in the glutamatergic signaling to ameliorate the loss of RHT terminals in old animals.

Multigene phylogeny of the order Physarales (Myxomycetes, Amoebozoa): shedding light on the dark-spored clade.

The class Myxomycetes consists of free-living protists characterised by their complex life cycle, which includes both microscopic (amoebae, flagellates and cists) and macroscopic stages (spore-bearing fruiting bodies, sclerotia, and plasmodia). Within it, the order Physarales, with more than 450 recognised species, constitutes the largest group. Although previous studies have shown the polyphyly of some of the traditionally accepted genera, its internal phylogenetic relationships have remained uncertain so far, and together with the lack of data for some key species, it prevented any taxonomic and nomenclatural revisions. We have compiled a substantially expanded dataset in terms of both taxon sampling and molecular data, including most of the genera described to date and four unlinked DNA regions, for which we provide partial sequences: nSSU, EF-1α, α-Tub, and mtSSU, analysed through maximum likelihood and Bayesian methods. Our results confirm that the family Didymiaceae is paraphyletic to the rest of Physarales. Within Didymiaceae s.lat., the recent reinstatement of the genus Polyschismium for most species traditionally ascribed to Lepidoderma, except for the type (Ronikier et al. 2022), is further supported here, as well as the definite inclusion of the genus Mucilago in Didymium and Lepidoderma s.str. (L. tigrinum) in Diderma (Prikhodko et al. 2023). Additionally, the genus Diachea is redefined to include some species previously treated in Physaraceae (Craterium spp. with true columella). Within the monophyletic family Physaraceae, most genera are recovered as polyphyletic, suggesting that they should be no longer accepted as currently defined. However, the lack of resolution of some relationships within Physaraceae prevents us from resuscitating or creating several new genera to mitigate polyphyly. Among the well-defined groups with clear molecular signatures, we propose two taxonomic and nomenclatural changes at generic level: 1) a new genus, Nannengaella, is proposed for a major clade containing Physarum globuliferum and other species with heavily calcified sporophores and, often, a true calcareous columella; 2) Lignydium is resurrected for the clade containing Fuligo muscorum. Additionally, Trichamphora is suggested as the correct name for the clade containing Physarum pezizoideum. The taxonomy and nomenclature of some provisional genera, currently synonymous with Fuligo and Physarum, are disentangled, and we provide a comprehensive and updated nomenclatural conspectus that can be used when better resolved phylogenies are obtained. In total, 22 new combinations are proposed in different genera. A provisional key to the genera of the order is also provided. Citation: García-Martín JM, Zamora JC, Lado C. 2023. Multigene phylogeny of the order Physarales (Myxomycetes, Amoebozoa): shedding light on the dark-spored clade. Persoonia 51: 89-124. doi: 10.3767/persoonia.2023.51.02.

Carcinoma de células no pequeñas de pulmón etapa III-B/IV. Experiencia en el Instituto Nacional de Cancerología, 1988-1992 / Non-small cell lung carcinoma stage IIIB/IV. Experience in the Instituto Nacional de Cancerologia, 1988-1992

Análisis retrospectivo en pacientes con carcinoma de células no pequeñas de pulmón etapa III-B/IV, estudiados en la Consulta Externa del Instituto Nacional de Cancerología durante enero de 1988 a diciembre de 1992. Se atendieron 683 pacientes con diagnóstico de cáncer de pulmón; de éstos, 313 se encontraron en etapa III-B/IV (46 por ciento) en etapa IV. Doscientos diecisiete fueron hombres (69 por ciento) y 96 (31 por ciento) mujeres con predominio de pacientes mayores de 60 años. La relación hombre:mujer aumentó a partir de la cuarta década de la vida. La neoplasia más frecuente fue adenocarcinoma (60 por ciento) seguida por carcinoma epidermoide (38 por ciento) y carcinoma de células grandes (2 por ciento). Las modalidades de tratamiento empleadas fueron radioterapia (25 por ciento), sintomático (25 por ciento) y quimioterapia (21 por ciento). No fueron tratados 18 por ciento por las condiciones físicas al momento del ingreso. La supervivencia observada no mostró diferencias en relación a etapa clínica ni tipo histológico; sin embargo, por esquema terapéutico se identificaron algunas diferencias. De tal forma, la medida de supervivencia en los enfermos que recibieron quimioterapia y radioterapia combinadas fue de 243 días; en cambio, fue 210 días en los sujetos tratados con quimioterapia y de 189 días en pacientes con esquema estándar de radioterapia. En 56 de 113 pacientes que recibieron radioterapia hipofraccionada la supervivencia fue de 133 días. Finalmente, los sujetos que no fueron tratados sobrevivieron apenas 58 días

Ejercicio y actividad enzimática en jóvenes deportistas y sedentarios / Exercise and enzymatic activity in athletic and sedentary youths

Se estudian los niveles de creatinfosfoquinasa 2.7.3.2 (CK), glutámico-oxaloacética transaminasa 2.6.1.1. (GOT), glutámico pirúvico transaminasa 2.6.1.2. (GPT) y amilasa 3.2.1.1., antes de un ejercicio intenso y 24 horas después de éste, en 15 jóvenes desportistas (D) y 15 jóvens de hábitos sedentarios (S). El Test de Esfuerzo consistió en 52 minutos de ejercicios, tales como: trote, abdominales, salto de cuerda etc., las determinaciones enzimáticas se realizaron según: Reitman-Frankel para Transaminasas, Sociedad Alemana de Química clínica para CK y Roe y Smith para Amilasa. Las actividades de CK mostraron diferencias notorias después del ejercicio en ambos grupos, aunque en D su p fue NS, en S tuvo una notable significancia (p < 0,002); analizando transaminasas, en GOT igualmente, se observó diferencias sólo en grupo S (p < 0,01) D(NS), también en GTP su cambio fue significativo sólo para S (p < 0,05) D (NS), la amilasemia no sufrió alteración en ninguno de los grupos (NS) en ambos casos. De muestros resultados se puede concluir que la actividad de CK es alterada a valores más altos ante un esfuerzo físico vigoroso, sin importar la habituación o no que tenga una persona a la actividad física. Las transaminasas presentan diferentes comportamiento, ya sea, si se trata de un deportista o un sedentario; finalmente, la amilasemia no se ve afecta en ambos grupos, pudiéndose deber a que su concentración en el tejido muscular es ínfima

Septicemia y meningitis por Streptococcus pneumoniae en una paciente esplenectomizada. / Septicemia and meningitis by Streptococcus pneumoniae in a splenectomized patient

Se presenta el caso de una paciente de 33 anos de edad que desarrollo septicemia y meningitis por Streptococcus pneumoniae siete anos despues de haver sido sometida a esplenectomia por presentar anemia hemolitica autoinmunitaria. El curso fulminante y, afortunadamente, reacciono al tratamiento. La esplenectomia aumenta el riesgo de infeccion neumococica grave, motivo por el cual se presenta el caso, ademas de tratarse del primer informe bien comprobado esta combinacion patologica en el Hospital de Infectologia del Centro Medico "La Raza", IMSS

Estudio comparativo entre test de Clements y absorbancia a 650nm como indice de madurez pulmonar fetal. / Comparative study between Clements' test and absorbance at 650 nm 25 index of pulmonary fetal maturity

Se analizan 82 liquidos amnioticos determinandoseles absorbancia a 650 nm y test de Clements. Con 3 y 4 tubos encontramos una correlacion r: 0,63 y r:0,73, respectivamente. En cada caso, estudianos los X y sd para cada punto del Clements y los porcentajes de falsos positivos y negativos segun la absorbancia que se elija para limite de madurez pulmonar. Cuando la O.D.es > 0.100 encontramos 12.1% de falsos negativos y 2.4% de falsos positivos. Los 2 falsos positivos nos mostraron problema respiratorio al nacer, siendo las determinaciones hechas 24 hr antes del parto. El test de la absorbancia a 650 nm es un metodo rapido, objetivo y de bajo costo, que puede reemplazar al test de Clements en nuestro medio

Piperacilina, estudio clinico en infecciones graves. / Piperacillin a clinical trial in severe infections

Se realizo un estudio abierto con piperacilina (nueva penicilina semisintetica de amplio espectro) en veinte enfermos con infecciones graves por bacterias sensibles in vitro a la piperacilina. A pesar de que el 75 por ciento de los casos estaba constituido por enfermos inmunocomprometidos, se obtuvo respuesta clinica y bacteriologica satisfactoria en el 90 por ciento. El 80 por ciento de las cepas aisladas tenian una concentracion inhibitoria minima cinco veces menor que los niveles alcanzados con la dosis utilizada de 35 a 40 mg/kg/dosis. Los efectos colaterales que se presentaron en la mitad de los enfermos fueron minimos y reversibles (elevacion de la fosfatasa alcalina en ocho pacientes, elevacion de transaminasas en uno y fiebre en uno) Durante el tratamiento, dos cepas de gram negativos se hicieron resistentes a piperacilina. El presente estudio demuestra la utilidad de la piperacilina en infecciones graves por germenes sensibles, pero su uso como unico antibiotico debe hacerse en forma racional en vista de la aparicion de resistencia durante el tratamiento especialmente con infecciones por gram negativos

Metamorfosis grasa aguda del embarazo.Informe de tres casos. / Acute fatty metamorphosis of pregnancy.Report of three cases

Se informan tres casos de metamorfosis grasa aguda del embarazo (MGAE), vistos en el Hospital de Infectologica del IMSS.Las pacientes cursaban las ultimas semanas de su primera gestacion cuando iniciaron la sintomatologia.El parto se desencandeno o fue inducido cuando las manigestaciones clinicas de MGAE se encontraban bien establecidas en dos de ellas cuyos productos fallecieron; en la otra paciente la sintomatologia se intensifico despues del parto y el producto nacio vivo.Todas fueron enviadas de hospitales de ginecobstetricia con diagnostico de hepatitis viral.Ninguna de ellas tenia antecedentes de haber recibido tetraciclinas. Se describe el cuadro clinico, que es indistinguible de la hepatitis fulminante y puede confundirse tambien con toxemia, asi como aspectos relacionados a la fisiopatogenia y manejo terapeutico