The return of natural dyes: the case of logwood tree (Haematoxylum campechianum L.).

In recent years, a worldwide reassessment of natural dyes has occurred, driven by the health and environmental issues associated with synthetic dyes. Haematoxylum campechianum L. is a tropical tree from which wood extracts were widely used in the textile industry during the 16th century. The logwood tree extract serves as a contemporary source of hematoxylin, a key dye in the globally prevalent hematoxylin-eosin staining method, a cornerstone in histopathological procedures. This paper will initially explore the re-emergence of natural dyes. Subsequently, it will focus on the historical, conventional, and innovative applications of logwood in the fields of medicine, histopathology, and nanotechnology, along with the status and alternative uses of the hematoxylin-eosin stain. Lastly, this paper will examine the current state of conservation and utilization of Haematoxylum campechianum in Campeche, Mexico, a leading global producer of hematoxylin.

Oleic acid regulates the circadian rhythm of adipose tissue in obesity.

The effect of oleic acid (OA) on the regulation of the circadian rhythm present in human visceral (VAT) and subcutaneous (SAT) adipose tissue from patients with morbid obesity has not been analyzed yet. VAT and SAT explants from patients with morbid obesity were incubated with OA to analyze the circadian regulation of clock and other genes related to lipid metabolism (SREBP-1c, FAS, LPL and CPT1), and their association with baseline variables and the improvement of these patients after bariatric surgery. There were significant differences in amplitude and acrophase in VAT with respect to SAT. In VAT, body weight negatively correlated with BMAL1 and CRY1 amplitude, and REVERBα acrophase; body mass index (BMI) negatively correlated with REVERBα acrophase; and waist circumference negatively correlated with PER3 acrophase. In SAT, BMI negatively correlated with CLOCK amplitude, and CLOCK, REVERBα and CRY2 MESOR; and waist circumference negatively correlated with PER3 amplitude and acrophase. A greater short-term improvement of body weight, BMI and waist circumference in patients with morbid obesity after bariatric surgery was associated with a lower CRY1 and CRY2 amplitude and an earlier PER1 and PER3 acrophase in SAT. OA produced a more relevant circadian rhythm and increased the amplitude of most clock genes and lipid metabolism-related genes. OA regulated the acrophase of most clock genes in VAT and SAT, placing CLOCK/BMAL1 in antiphase with regard to the other genes. OA increased the circadian rhythmicity, although with slight differences between adipose tissues. These differences could determine its different behavior in obesity.

Critical values for automated hemograms and peripheral blood smears / Valores críticos para hemogramas automatizados y frotis de sangre periférica

The report of critical values ​​is considered a necessary practice in clinical pathology laboratories, since its immediate communication determines therapeutic decisions that can save lives. The choice of critical values ​​and the way in which they are reported must be a joint decision between the laboratory specialists and the clinical professionals of each health facility, since they must be integrated into the dynamics of the services involved. Among the critical values ​​that have been chosen for this review, we have included quantitative parameters, whose processing is carried out in automated hematology analyzers, and morphological findings in peripheral blood smears, which are evaluated by trained professionals.

El reporte de valores críticos se considera una práctica necesaria en los laboratorios de patología clínica, pues su comunicación inmediata determina decisiones terapéuticas que pueden salvar vidas. La elección de los valores críticos y el modo en que son reportados debe ser una decisión conjunta entre los especialistas del laboratorio y los profesionales clínicos de cada establecimiento de salud, ya que deben integrarse a la dinámica de los servicios involucrados. Entre los valores críticos que se han escogido para esta revisión hemos incluido parámetros cuantitativos, cuyo procesamiento se ejecuta en analizadores hematológicos automatizados, y hallazgos morfológicos en los frotis de sangre periférica, lo cuales son evaluados por profesionales capacitados.

Transcriptome Mining Provides Insights into Cell Wall Metabolism and Fiber Lignification in Agave tequilana Weber.

Resilience of growing in arid and semiarid regions and a high capacity of accumulating sugar-rich biomass with low lignin percentages have placed Agave species as an emerging bioenergy crop. Although transcriptome sequencing of fiber-producing agave species has been explored, molecular bases that control wall cell biogenesis and metabolism in agave species are still poorly understood. Here, through RNAseq data mining, we reconstructed the cellulose biosynthesis pathway and the phenylpropanoid route producing lignin monomers in A. tequilana, and evaluated their expression patterns in silico and experimentally. Most of the orthologs retrieved showed differential expression levels when they were analyzed in different tissues with contrasting cellulose and lignin accumulation. Phylogenetic and structural motif analyses of putative CESA and CAD proteins allowed to identify those potentially involved with secondary cell wall formation. RT-qPCR assays revealed enhanced expression levels of AtqCAD5 and AtqCESA7 in parenchyma cells associated with extraxylary fibers, suggesting a mechanism of formation of sclerenchyma fibers in Agave similar to that reported for xylem cells in model eudicots. Overall, our results provide a framework for understanding molecular bases underlying cell wall biogenesis in Agave species studying mechanisms involving in leaf fiber development in monocots.

Improved method for isolation of high-quality total RNA from Agave tequilana Weber roots.

Together with their undeniable role in the ecology of arid and semiarid ecosystems, Agave species are emerging as a model to dissect the relationships between crassulacean acid metabolism and high efficiency of light and water use, and as an energy crop for bioethanol production. Transcriptome resources from economically valuable Agaves species, such as Agave tequilana and A. salmiana, as well as hybrids for fibers, are now available, and multiple gene expression landscape analyses have been reported. Key components in molecular mechanisms underlying drought tolerance could be uncovered by analyzing gene expression patterns of roots. This study describes an efficient protocol for high-quality total RNA isolation from phenolic compounds-rich Agave roots. Our methodology involves suitable root handling and collecting in the field and using saving-time commercial kits available. RNA isolated from roots free of lignified out-layers and clean cortex showed high values of quality and integrity according to electrophoresis and microfluidics-based platform. Synthesis of long full-length cDNAs and PCR amplification tested the suitability for downstream applications of extracted RNA. The protocol was applied successfully to A. tequilana roots but can be used for other Agave species that also develop lignified epidermis/exodermis in roots.

The Prevalence of Intimate Partner Violence and Association With Depression in University Students: Results of a Cross-Sectional Study.

The purpose of this cross-sectional study was to determine the prevalence of intimate partner violence (IPV) among university students, investigate the potential predictors of IPV in this population, and study the link between IPV and depression. The survey included sociodemographic, relationship quality, and depression-related questions. From 498 respondents, the prevalence of IPV was 4.8%, depression was 30.9%, and suicidal ideation was 20.3%. After adjusting for covariates and confounders, relationship satisfaction (odds ratio [OR], 0.201; 95% confidence interval [CI], 0.101-0.401; p < 0.001) and jealousy (OR, 0.270; 95% CI, 0.094-0.776; p = 0.015) were significant predictors of IPV. Relationship satisfaction predicted depressive disorders (OR, 0.504; 95% CI, 0.365-0.698; p < 0.001). IPV trended toward predicting the presence of a depressive disorder (OR, 0.436; 95% CI, 0.170-1.113; p = 0.083). Relationship satisfaction and jealousy predicted IPV. Although IPV did not predict depression, poor relationship satisfaction increased the odds of depression, implicating the influence of relationship satisfaction on both IPV and depression.

Unravelling Chemical Composition of Agave Spines: News from Agave fourcroydes Lem.

Spines are key plant modifications developed to deal against herbivores; however, its physical structure and chemical composition have been little explored in plant species. Here, we took advantage of high-throughput chromatography to characterize chemical composition of Agave fourcroydes Lem. spines, a species traditionally used for fiber extraction. Analyses of structural carbohydrate showed that spines have lower cellulose content than leaf fibers (52 and 72%, respectively) but contain more than 2-fold the hemicellulose and 1.5-fold pectin. Xylose and galacturonic acid were enriched in spines compared to fibers. The total lignin content in spines was 1.5-fold higher than those found in fibers, with elevated levels of syringyl (S) and guaiacyl (G) subunits but similar S/G ratios within tissues. Metabolomic profiling based on accurate mass spectrometry revealed the presence of phenolic compounds including quercetin, kaempferol, (+)-catechin, and (-)-epicatechin in A. fourcroydes spines, which were also detected in situ in spines tissues and could be implicated in the color of these plants' structures. Abundance of (+)-catechins could also explain proanthocyanidins found in spines. Agave spines may become a plant model to obtain more insights about cellulose and lignin interactions and condensed tannin deposition, which is valuable knowledge for the bioenergy industry and development of naturally dyed fibers, respectively.

Células tronco mesenquimales: definiciones, cultivo y aplicaciones potenciales / Mesenchymal stem cells: definitions, culture and potential applications

RESUMEN En los últimos años, las células troncales mesenquimales (Mesenchymal Stem Cells, MSC) han adquirido mucha importancia debido a su gran plasticidad y su capacidad de liberar factores paracrinos con capacidad de interactuar con diversos tipos celulares, tejidos y órganos. El uso de MSC en medicina regenerativa es importante debido a que, al no expresar las moléculas del complejo mayor de histocompatibilidad (MHC) clase II ni moléculas co-estimuladoras y tener baja expresión del MHC clase I, haría que no sean rechazadas por individuos de la misma especie, es posible utilizarlas no sólo de manera autóloga, sino también, eventualmente, alogénica. Sin embargo, es importante demostrar científicamente muchas de sus propiedades, entre ellas las inmunomoduladoras. Al tener varias fuentes de obtención, se debe estandarizar la que sea la mejor para garantizar la pureza y calidad de las MSC. Finalmente, es importante que cuando se trabaje con estas células se demuestre completamente las características del cultivo celular, la inmunotipificación y su capacidad de diferenciación. Se están ensayando muchas aplicaciones clínicas de las MSC. Dentro de ellas, su capacidad para mejorar la recuperación y potencial curación de úlceras crónicas como las diabéticas, ha atraído la atención por su potencial impacto terapéutico.

ABSTRACT In recent years, mesenchymal stem cells (MSC) have become very important due to their high plasticity and their ability to release paracrine factors able to interact with various cell types, tissues and organs. The use of MSC in regenerative medicine became of vital importance, since they do not express histocompatibility MHC molecules class II nor costimulant molecules, and low expression of MHC class I, will not be rejected by individuals of same species, they could be used in an autologous, and eventually, allogeneic manner. However, it is important to scientifically demonstrate many properties, including immunomodulatory ones. Having several sources of obtaining, it should be standardized the best one to ensure the purity and quality of these cells. Finally, it is important when working with these cells, that characteristics of cell culture, immunophenotyping and differentiation capacity are fully demonstrated. MSC have been applied in several clinical uses. Among them, their ability to improve, and even heal chronic ulcers, as diabetic, has attracted attention for its potential therapeutic impact.

[Determination of the healing effect of Piper aduncum (spiked pepper or matico) on human fibroblasts]. / Determinación del efecto cicatrizante de Piper aduncum (matico) en fibroblastos humanos.

OBJECTIVES.: To evaluate the healing effect of a Piper aduncum ethanol-water extract on an adult human dermal fibroblast cell line (hDFa). MATERIALS AND METHODS.: After obtaining the extract via solid-liquid extraction, concentration, and lyophilization, extract proteins were purified using reverse phase high-performance liquid chromatography, identified using tandem mass spectrometry of tryptic peptides, and analyzed using MALDI-TOF-TOF on an ABSciex4800 mass spectrometer. Half maximum effective concentration values (EC50), half maximum inhibiting concentration (IC50), and percentages of cell proliferation were determined using tetrazolium salt assays. Cell migration was evaluated using a "scratch assay". Growth factor expression in cells was analyzed via quantitative real-time reverse transcription polymerase chain reaction. RESULTS.: Against the hDFa cell line, the extract had an IC50 of 200 µg/mL and EC50 of 103.5 µg/mL. In the proliferation assay, protein K2 (obtained from the extract) exhibited increased proliferative activity relative to other treatments (1 µg/mL); this agent also exhibited increased activity (50 µg/mL) in the fibroblast migration assay.Furthermore, the relative expression of platelet-derived growth factor increased by 8.6-fold in the presence of K2 protein relative to the control. CONCLUSIONS.: The hydroethanolic extract of Piper aduncum and its component proteins increased the proliferation and migration of hDFa and increased the expression of growth factors involved in the healing process.

Determinación del efecto cicatrizante de Piper aduncum (matico) en fibroblastos humanos / Determination of the healing effect of Piper aduncum (spiked pepper or matico) on human fibroblasts

RESUMEN Objetivos. Evaluar el efecto cicatrizante del extracto hidroetanólico de Piper aduncum, en una línea celular de fibroblastos Dermales Adultos Humanos (hDFa). Materiales y métodos. El extracto se obtuvo mediante extracción sólido-líquido, fue concentrado y liofilizado. Se purificaron las proteínas del extracto mediante cromatografía líquida de alta eficacia de fase reversa (RP-HPLC); las proteínas fueron identificadas por espectrometría de masas en tándem de péptidos trípticos y se analizaron por MALDI-TOF-TOF en un espectrómetro de masa ABSciex4800. Los valores de concentración efectiva media (EC50), concentración inhibitoria media (IC50), y el porcentaje de proliferación celular; fueron determinados por ensayos con sales de tetrazolio (MTT) . La migración celular se evaluó mediante la "técnica de rayado" . Se analizó la expresión de factores de crecimiento mediante el ensayo de reacción en cadena de la polimerasa con transcriptasa reversa a tiempo real (RT- qPCR). Resultados. La línea hDFa evidenció un IC50 de 200 µg/mL con el extracto, el valor de EC50 fue 103,5 µg/mL. En el ensayo de proliferación, la proteína K2; mostró mayor actividad en la proliferación respecto de otros tratamientos (1 µg/mL). En el ensayo de migración de fibroblastos, la proteína K2 mostró mayor actividad (50 µg/mL). La expresión relativa del factor de crecimiento derivado de plaquetas (PDGF) se incrementó 8,6 veces respecto al control, en presencia de la proteína K2. Conclusiones. El extracto hidroetanólico, de Piper aduncum, así como las proteínas que contiene, incrementaron la proliferación y migración de fibroblastos dermales humanos (hDFa); así mismo, aumentaron la expresión de factores de crecimiento que intervienen en el proceso de cicatrización.

ABSTRACT Objectives. To evaluate the healing effect of a Piper aduncum ethanol-water extract on an adult human dermal fibroblast cell line (hDFa). Materials and Methods. After obtaining the extract via solid-liquid extraction, concentration, and lyophilization, extract proteins were purified using reverse phase high-performance liquid chromatography, identified using tandem mass spectrometry of tryptic peptides, and analyzed using MALDI-TOF-TOF on an ABSciex4800 mass spectrometer. Half maximum effective concentration values (EC50), half maximum inhibiting concentration (IC50), and percentages of cell proliferation were determined using tetrazolium salt assays. Cell migration was evaluated using a "scratch assay". Growth factor expression in cells was analyzed via quantitative real-time reverse transcription polymerase chain reaction. Results. Against the hDFa cell line, the extract had an IC50 of 200 μg/mL and EC50 of 103.5 µg/mL. In the proliferation assay, protein K2 (obtained from the extract) exhibited increased proliferative activity relative to other treatments (1 µg/mL); this agent also exhibited increased activity (50 µg/mL) in the fibroblast migration assay.Furthermore, the relative expression of platelet-derived growth factor increased by 8.6-fold in the presence of K2 protein relative to the control. Conclusions. The hydroethanolic extract of Piper aduncum and its component proteins increased the proliferation and migration of hDFa and increased the expression of growth factors involved in the healing process.

Transcriptional activator TAp63 is upregulated in muscular atrophy during ALS and induces the pro-atrophic ubiquitin ligase Trim63.

Mechanisms of muscle atrophy are complex and their understanding might help finding therapeutic solutions for pathologies such as amyotrophic lateral sclerosis (ALS). We meta-analyzed transcriptomic experiments of muscles of ALS patients and mouse models, uncovering a p53 deregulation as common denominator. We then characterized the induction of several p53 family members (p53, p63, p73) and a correlation between the levels of p53 family target genes and the severity of muscle atrophy in ALS patients and mice. In particular, we observed increased p63 protein levels in the fibers of atrophic muscles via denervation-dependent and -independent mechanisms. At a functional level, we demonstrated that TAp63 and p53 transactivate the promoter and increased the expression of Trim63 (MuRF1), an effector of muscle atrophy. Altogether, these results suggest a novel function for p63 as a contributor to muscular atrophic processes via the regulation of multiple genes, including the muscle atrophy gene Trim63.

[Mesenchymal stem cells: definitions, culture and potential applications]. / Células tronco mesenquimales: definiciones, cultivo y aplicaciones potenciales.

In recent years, mesenchymal stem cells (MSC) have become very important due to their high plasticity and their ability to release paracrine factors able to interact with various cell types, tissues and organs. The use of MSC in regenerative medicine became of vital importance, since they do not express histocompatibility MHC molecules class II nor costimulant molecules, and low expression of MHC class I, will not be rejected by individuals of same species, they could be used in an autologous, and eventually, allogeneic manner. However, it is important to scientifically demonstrate many properties, including immunomodulatory ones. Having several sources of obtaining, it should be standardized the best one to ensure the purity and quality of these cells. Finally, it is important when working with these cells, that characteristics of cell culture, immunophenotyping and differentiation capacity are fully demonstrated. MSC have been applied in several clinical uses. Among them, their ability to improve, and even heal chronic ulcers, as diabetic, has attracted attention for its potential therapeutic impact.

Conservative treatment of an epidural abscess after thoracic epidural catheterization.

We describe a case of a thoracic epidural abscess after epidural catheter insertion in a patient undergoing lobar segmentectomy. The patient described a "pulsatile" back pain the sixth day after surgery, and purulent material at the entry site of the catheter was observed. The image of the nuclear magnetic resonance confirmed an epidural abscess that was treated conservatively with antibiotics after a consensus decision among neurosurgery, infectious diseases an anesthesia services. The abscess was reabsorbed completely with no sequelae.

Pattern recognition in neural networks with competing dynamics: coexistence of fixed-point and cyclic attractors.

We study the properties of the dynamical phase transition occurring in neural network models in which a competition between associative memory and sequential pattern recognition exists. This competition occurs through a weighted mixture of the symmetric and asymmetric parts of the synaptic matrix. Through a generating functional formalism, we determine the structure of the parameter space at non-zero temperature and near saturation (i.e., when the number of stored patterns scales with the size of the network), identifying the regions of high and weak pattern correlations, the spin-glass solutions, and the order-disorder transition between these regions. This analysis reveals that, when associative memory is dominant, smooth transitions appear between high correlated regions and spurious states. In contrast when sequential pattern recognition is stronger than associative memory, the transitions are always discontinuous. Additionally, when the symmetric and asymmetric parts of the synaptic matrix are defined in terms of the same set of patterns, there is a discontinuous transition between associative memory and sequential pattern recognition. In contrast, when the symmetric and asymmetric parts of the synaptic matrix are defined in terms of independent sets of patterns, the network is able to perform both associative memory and sequential pattern recognition for a wide range of parameter values.

Paravertebral cervical nerve block in a patient suffering from a Pancoast tumor.

In patients with aggressive tumors resistant to conventional pain treatment, regional anaesthesia frequently becomes an alternative therapy. Cervical paravertebral nerve block among several access options to the brachial plexus is barely ever used. We present a case with severe shoulder and upper extremity pain owing to an expanding Pancoast tumor exhibiting compression upon the brachial plexus. Continuous intrathecal morphine infusion and adjuvant treatment was not sufficient to render the patient pain-free. With the addition of paravertebral nerve blockade the patient's pain improved substantially, however without impacting his longevity.

[Adrenal carcinoma: 7 year disease free survival after complete primary tumor resection and repeated resection of local-regional and distant recurrences. Review after one case with poor initial life expectancy]. / Carcinoma suprarrenal: supervivencia a 7 años libre de enfermedad tras resección completa del tumor primario y resecciones repetidas de recidivas locorregional y a distancia. Revisión a raiz de un caso con una pobre esperanza de vida inicial.

OBJECTIVES: We report the case of a female patient with adrenal carcinoma who had undergone surgery and presented with local-regional and distant recurrences, emphasizing the importance of the aggressive surgical treatment to achieve long-term survival which is unexpected sometimes. Currently, it represents the gold standard and all cases should be reported to stimulate other groups to work in this line. METHODS/RESULTS: We report the case of a 29-year-old female patient who consulted for left flank pain, being diagnosed of an adrenal tumor by radiological tests; she underwent surgical excision of a left adrenal carcinoma (stage II). Later on she presented with local-regional recurrences (2 times) and distant metastases (liver) undergoing excision in three procedures. Currently, the patient is alive and free of disease 7 years after diagnosis. CONCLUSIONS: Adrenal cancer recurrences have been considered lethal in the short-term. Nevertheless, an aggressive surgical approach of local recurrences and metastasic disease may significantly prolong patient's survival and, sometimes, leave the patient disease free several years after the diagnosis of the primary tumor.

Carcinoma suprarenal: supervivencia a 7 años libre de enfermedad tras resección completa del tumor primario y resecciones repetidas de recidivas locorregional y a distancia. Revisión a raíz de un caso con una pobre esperanza de vida inicial / Adrnal carcinoma: 7 year disease free survival after complete primary tumor resection and repeated resection of local-regional and distant recurrences. Review after one case with poor initial life expectancy

OBJETIVO: Comunicamos el caso de unapaciente con un cáncer suprarrenal intervenido que presentóposteriormente recidivas locorregional y a distancia,enfatizando la importancia del tratamiento quirúrgicoagresivo para lograr supervivencias a veces noesperadas a largo plazo. En la actualidad, representael “gold standard” y todos los casos deben comunicarsepara estimular a los distintos grupos a trabajar enesta línea.MÉTODO/RESULTADOS: se presenta el caso de unapaciente de 29 años que consultó por dolor en flancoizquierdo, diagnosticándose en los estudios de imagenun tumor suprarrenal; fue intervenida, realizándoseresección de un carcinoma suprarrenal izquierdo(Estadio II). Posteriormente presentó recidiva locorregional(en dos ocasiones) y a distancia (en hígado), siendoresecada la enfermedad en las tres ocasiones en sutotalidad. En el momento actual, 7 años después deldiagnóstico, está viva y libre de enfermedad.CONCLUSIÓN: la recidiva del cáncer suprarrenal seha considerado letal a corto plazo desde el punto devista pronóstico. Sin embargo, un abordaje quirúrgicoagresivo de la enfermedad recurrente y metastásicapuede prolongar de forma significativa la supervivenciadel paciente y lograr, en ocasiones, “status” de libre deenfermedad varios años después del diagnóstico deltumor primario

OBJECTIVES: We report the case of afemale patient with adrenal carcinoma who had undergonesurgery and presented with local-regional and distantrecurrences, emphasizing the importance of theaggressive surgical treatment to achieve long-term survivalwhich is unexpected sometimes. Currently, it representsthe gold standard and all cases should be reported tostimulate other groups to work in this line.METHODS/RESULTS: We report the case of a 29-yearoldfemale patient who consulted for left flank pain,being diagnosed of an adrenal tumor by radiologicaltests; she underwent surgical excision of a left adrenalcarcinoma (stage II). Later on she presented with localregionalrecurrences (2 times) and distant metastases(liver) undergoing excision in three procedures.Currently, the patient is alive and free of disease 7 yearsafter diagnosis.CONCLUSIONS: Adrenal cancer recurrences havebeen considered lethal in the short-term. Nevertheless,an aggressive surgical approach of local recurrencesand metastasic disease may significantly prolongpatient’s survival and, sometimes, leave the patient diseasefree several years after the diagnosis of the primarytumor

A comparison of lateral popliteal versus lateral midfemoral sciatic nerve blockade using ropivacaine 0.5%.

BACKGROUND AND OBJECTIVES: The midfemoral approach to the sciatic nerve (MF) is a new technique that has been used for postoperative analgesia after knee surgery. The aim of the present study was to compare efficacy, performance time, and patient acceptance of the midfemoral approach to that of the lateral approach at the level of the popliteal fossa (popliteal block [PB]). METHODS: Sixty-three patients were enrolled in this prospective, randomized study. Thirty-two patients received a lateral sciatic nerve block (group PB) and 31 patients a midfemoral block (group MF). Ropivacaine 0.5% (30 mL) was used in both groups. RESULTS: The quality of nerve blockade was comparable in both groups. Onset of sensory block for peroneal and tibial nerves was significantly shorter in group MF than in group PB, 5 (1-20) minutes and 5 (1-20) minutes versus 10 (1-40) minutes and 10 (1-45) minutes, respectively. Onset of motor block in both territories was also shorter in group MF compared with PB, 6 (2-35) minutes and 5 (2-55) minutes versus 15 (2-60) minutes and 15 (2-60) minutes, respectively (P <.05). There was no difference in duration of sensory and motor blockade, 16 (7-32) hours versus 16 (6-43) hours and 16 (8-32) hours versus 16 (6-25) hours. There was no significant difference between both groups with respect to difficulty of nerve block performance. Patient discomfort during needle puncture was also similar. CONCLUSIONS: The midfemoral approach to the sciatic nerve for ankle and foot surgery resulted in a reliable anesthetic, comparable to that of the lateral popliteal approach. This technique is simple, safe, and provides postoperative analgesia as effective as that obtained with the lateral approach.

Transient neurological syndrome: does it really exist?

PURPOSE OF REVIEW: Subarachnoid injection of local anesthetics has been related to the appearance of transient neurological symptoms (called transient neurologic syndrome), as reflected by a number of clinical reports showing their incidence in clinical practice. However, the etiology of this syndrome is virtually unknown, as is the number of factors implicated in its development. This review will attempt to clarify this entity and its relationship with spinal anesthesia. RECENT FINDINGS: Intrathecal administration of local anesthetics is known to increase glutamate concentration in cerebrospinal fluid and histopathologic changes of motor neurons in the lumbar spinal cord, suggesting damage of dorsal and ventral roots. In-vitro studies of cultured neurons exposed to different concentrations of local anesthetics have shown changes in growth of cones and neurites, which may be related to transient neurologic syndrome. SUMMARY: The latest studies show biochemical and anatomopathologic changes that support the structural basis of the existence of transient neurologic syndrome. In the authors' view, transient neurologic syndrome could represent the lower end of a spectrum of local anesthetic toxicity. Recent findings demonstrate that nerve membrane damage induced by highly concentrated local anesthetics such as lidocaine, tetracaine, dibucaine and procaine may generate irreversible neural injury. Still further studies are needed to establish the relationship between morphological changes induced in vitro and the occurrence of clinical symptoms.

Role of Ca2+ in the secretory and biosynthetic response of porcine gonadotropes to substance P and gonadotropin-releasing hormone.

Substance P has been previously shown to stimulate luteinizing hormone (LH) secretion and synergistically enhance gonadotropin-releasing hormone (GnRH)-evoked LH release from cultured pig pituitary cells. To investigate the mechanisms involved in these responses, the effects of substance P (100 nM; 4 h) and/or GnRH (10 nM, 4 h) on LH release, LH intracellular content, and betaLH mRNA accumulation were evaluated in the absence or presence of extracellular Ca(2+). Likewise, the effects of substance P on the dynamics of cytosolic free Ca(2+) concentration ([Ca(2+)](i)) were examined in single cells. Extracellular Ca(2+) deprivation abolished both substance P- and GnRH-stimulated LH release, as well as their synergistic interaction. The substance P antagonist D-Arg1,D-Phe5,-Trp7,9,Leu11-substance P (100 nM) blocked the stimulatory effect of substance P on LH release and its interaction with GnRH without affecting GnRH-induced LH secretion. Whereas substance P did not modify betaLH transcript levels, GnRH stimulated betaLH mRNA accumulation through a mechanism dependent upon extracellular Ca(2+). Substance P directly increased [Ca(2+)](i) in a 30% of gonadotropes by causing two distinct types of response kinetics with single-peak (predominant, 83.3%) or sustained-plateau profiles. Reduction of external [Ca(2+)] decreased by half the percent of responsive cells, which only showed single-peak profiles. Taken together, our results demonstrate that the ability of substance P to stimulate basal and GnRH-induced LH release is exerted directly upon gonadotropes, is extracellular Ca(2+)-dependent and does not seem to require net increases in betaLH mRNA levels. Moreover, [Ca(2+)](i) measurements revealed that although substance P action in pig gonadotropes is strongly dependent on extracellular Ca(2+) influx, it would also involve intracellular Ca(2+) mobilization. Finally, extracellular Ca(2+) also plays a requisite role to sustain GnRH-stimulated increases in both betaLH mRNA and LH release.