Rocky Mountain Spotted Fever Mimicking Multisystem Inflammatory Syndrome in Hospitalized Children, Sonora, Mexico.

We describe 5 children who had Rocky Mountain spotted fever (RMSF) and manifested clinical symptoms similar to multisystem inflammatory syndrome in Sonora, Mexico, where RMSF is hyperendemic. Physicians should consider RMSF in differential diagnoses of hospitalized patients with multisystem inflammatory syndrome to prevent illness and death caused by rickettsial disease.

Time after a peak-pesticide use period and neurobehavior among ecuadorian children and adolescents: The ESPINA study.

BACKGROUND: Limited evidence exists regarding transient neurobehavioral alterations associated with episodic pesticide exposures or agricultural pesticide spray periods. We previously observed that children examined soon after a pesticide spray period (the Mother's Day flower harvest [MDH]) had lower neurobehavioral performance than children examined later. The present study builds on our previous work by incorporating longitudinal analyses from childhood through adolescence. METHODS: We examined participants in agricultural communities in Ecuador (ESPINA study) during three periods: July-August 2008 (N = 313, 4-9-year-olds); April 2016 (N = 330, 11-17-year-olds); July-October 2016 (N = 535, 11-17-year-olds). Participants were examined primarily during a period of low floricultural production. Neurobehavior was assessed using the NEPSY-II (domains: Attention/Inhibitory Control, Language, Memory/Learning, Visuospatial Processing, and Social Perception). Linear regression and generalized linear mixed models were used to examine cross-sectional and longitudinal associations between examination date (days) after the MDH and neurobehavioral outcomes, adjusting for demographic, anthropometric, and socio-economic variables. RESULTS: Participants were examined between 63 and 171 days after the MDH. Mean neurobehavioral domain scores ranged from 1.0 to 17.0 (SDrange = 2.1-3.1) in 2008 and 1.0 to 15.5 (SDrange = 2.0-2.3) in 2016. In cross-sectional analyses (2016 only; N = 523), we found significant or borderline positive associations between time after the MDH and Attention/Inhibitory Control (difference/10 days [ß] = 0.22 points [95% CI = 0.03, 0.41]) and Language (ß = 0.16 points [95% CI = -0.03, 0.34]). We also observed positive, longitudinal associations (2008-2016) with Attention/Inhibitory Control (ß = 0.19 points [95% CI = 0.04, 0.34]) through 112 days after the harvest and Visuospatial Processing (ß = 3.56, ß-quadratic = -0.19 [95% CI: -0.29, -0.09]) through 92 days. CONCLUSIONS: Children examined sooner after the harvest had lower neurobehavioral performance compared to children examined later, suggesting that peak pesticide spray seasons may transiently affect neurobehavior followed by recovery during low pesticide-use periods. Reduction of pesticide exposure potential for children during peak pesticide-use periods is advised.

Malignant hyperthermia, environmental heat stress, and intracellular calcium dysregulation in a mouse model expressing the p.G2435R variant of RYR1.

BACKGROUND: The human p.G2434R variant of the RYR1 gene is most frequently associated with malignant hyperthermia (MH) in the UK. We report the phenotype of a knock-in mouse that expresses the RYR1 variant p.G2435R, which is isogenetic with the human variant. METHODS: We observed the general phenotype; determined the sensitivity of myotubes to caffeine-, KCl, and halothane-induced Ca2+ release; determined the in vivo response to halothane or increased ambient temperature; and determined the in vivo myoplasmic intracellular Ca2+ concentration in skeletal muscle before and during exposure to volatile anaesthetics. RESULTS: RYR1 pG2435R/MH normal (MHS-Heterozygous[Het]) or RYR1 pG2435R/pG2435R (MHS-Homozygous[Hom]) mice were fully viable under typical rearing conditions, although some male MHS-Hom mice died spontaneously. The normalised half-maximal effective concentration (95% confidence interval) for intracellular Ca2+ release in myotubes in response to KCl [MH normal, MHN, 21.4 (19.8-23.1) mM; MHS-Het 16.2 (15.2-17.2) mM; MHS-Hom 11.2 (10.2-12.2) mM] and caffeine (MHN, 5.7 (5-6.3) mM; MHS-Het 4.5 (3.9-5.0) mM; MHS-Hom 1.77 (1.5-2.1) mM] exhibited a gene dose-dependent decrease, and there was a gene dose-dependent increase in halothane sensitivity. Intact animals show a gene dose-dependent susceptibility to MH with volatile anaesthetics or to heat stroke. RYR1 p.G2435R mice had elevated skeletal muscle intracellular resting [Ca2+]i, (values are expressed as mean (SD)) (MHN 123 (3) nM; MHS-Het 156 (16) nM; MHS-Hom 265 (32) nM; P<0.001) and [Na+]i (MHN 8 (0.1) mM; MHS-Het 10 (1) mM; MHS-Hom 14 (0.7) mM; P<0.001) that was further increased by exposure to volatile anaesthetics. CONCLUSIONS: RYR1 pG2435R mice demonstrated gene dose-dependent in vitro and in vivo responses to pharmacological and environmental stressors that parallel those seen in patients with the human RYR1 variant p.G2434R.

Divergence in mating signals correlates with genetic distance and behavioural responses to playback.

Animals use acoustic signals to defend resources against rivals and attract breeding partners. As with many biological traits, acoustic signals may reflect ancestry; closely related species often produce more similar signals than do distantly related species. Whether this similarity in acoustic signals is biologically relevant to animals is poorly understood. We conducted a playback experiment to measure the physical and vocal responses of male songbirds to the songs of both conspecific and allopatric-congeneric animals that varied in their acoustic and genetic similarity. Our subjects were territorial males of four species of neotropical Troglodytes wrens: Brown-throated Wrens (Troglodytes brunneicollis), Cozumel Wrens (T. beani), Clarion Wrens (T. tanneri) and Socorro Wrens (T. sissonii). Our results indicate that birds respond to playback of both conspecific and allopatric-congeneric animals; that acoustic differences increase with genetic distance; and that genetic divergence predicts the strength of behavioural responses to playback, after removing the effects of acoustic similarity between subjects' songs and playback stimuli. Collectively, these results demonstrate that the most distantly related species have the most divergent songs; that male wrens perceive divergence in fine structural characteristics of songs; and that perceptual differences between species reflect evolutionary history. This study offers novel insight into the importance of acoustic divergence of learned signals and receiver responses in species recognition.

K+ channels expression in hypertension after arterial injury, and effect of selective Kv1.3 blockade with PAP-1 on intimal hyperplasia formation.

INTRODUCTION: K(+) channels are central to vascular pathophysiology. Previous results demonstrated that phenotypic modulation associates with a change in Kv1.3 to Kv1.5 expression, and that Kv1.3 blockade inhibits proliferation of VSMCs cultures. PURPOSE: To explore whether the Kv1.3 to Kv1.5 switch could be a marker of the increased risk of intimal hyperplasia in essential hypertension and whether systemic treatment with Kv1.3 blockers can prevent intimal hyperplasia after endoluminal lesion . METHODS: Morphometric and immunohistochemical analysis were performed in arterial segments following arterial injury and constant infusion of the Kv1.3 blocker PAP-1 during 28 days. Differential expression of K(+) channel genes was studied in VSMC from hypertensive (BPH) and normotensive (BPN) mice, both in control and after endoluminal lesion. Finally, the migration and proliferation rate of BPN and BPH VSMCs was explored in vitro. RESULTS: Changes in mRNA expression led to an increased Kv1.3/Kv1.5 ratio in BPH VSMC. Consistent with this, arterial injury in BPH mice induced a higher degree of luminal stenosis, (84 ± 4% vs. 70 ± 5% in BPN, p < 0.01), although no differences in migration and proliferation rate were observed in cultured VSMCs. The in vivo proliferative lesions were significantly decreased upon PAP-1 systemic infusion (18 ± 6% vs. 58 ± 20% with vehicle, p < 0.05). CONCLUSIONS: Hypertension leads to a higher degree of luminal stenosis in our arterial injury model, that correlates with a decreased expression of Kv1.5 channels. Kv1.3 blockers decreased in vitro VSMCs proliferation, migration, and in vivo intimal hyperplasia formation, pointing to Kv1.3 channels as promising therapeutical targets against restenosis.

Rocky Mountain spotted fever is a neglected tropical disease in Latin America.

Rocky Mountain spotted fever (RMSF), a severe and extraordinarily lethal infectious disease, has emerged as a widespread public health crisis among predominantly vulnerable populations in several countries of Latin America, particularly evident in northern Mexico. Historically, RMSF has gained less attention than many other tropical infectious diseases, resulting in insufficient allocations of resources and development of capabilities for its prevention and control in endemic regions. We argue that RMSF fulfills accepted criteria for a neglected tropical disease (NTD). The relative neglect of RMSF in most Latin American countries contributes to disparities in morbidity and mortality witnessed in this region. By recognizing RMSF as an NTD, an increased public policy interest, equitable and more appropriate allocation of resources, scientific interest, and social participation can ameliorate the impact of this potentially treatable disease, particularly in vulnerable populations.

Rocky Mountain Spotted Fever in Mexico: A Call to Action.

Rocky Mountain spotted fever (RMSF) is an ongoing public health crisis in Mexico, particularly in states bordering the United States. The national highest incidence and mortality of RMSF occur in this region, resulting in a case-fatality rate that ranges annually between 10% and 50%, primarily affecting vulnerable groups such as children, elderly adults, and persons living in poverty. Multiple biological, environmental, and social determinants can explain its growing presence throughout the country and how it challenges the health system and society. It is necessary to integrate resources and capacities from health authorities, research centers, and society to succeed in dealing with this problem. Through a scientific symposium, a group of academicians, U.S. health officials, and Mexican health authorities met on November 8-10, 2023, in Hermosillo, Mexico, to discuss the current situation of RMSF across the country and the challenges associated with its occurrence. An urgent call for action to improve national capacity against RMSF in the aspects of epidemiological and acarological surveillance, diagnosis, medical care, case and outbreak prevention, health promotion, and research was urged by the experts. The One Health approach is a proven multidisciplinary strategy to integrate policies and interventions to mitigate and prevent the burden of cases, deaths, and suffering caused by RMSF in Mexico.

A state-of-art-review on emerging contaminants: Environmental chemistry, health effect, and modern treatment methods.

Pollution problems are increasingly becoming e a priority issue from both scientific and technological points of view. The dispersion and frequency of pollutants in the environment are on the rise, leading to the emergence have been increasing, including of a new class of contaminants that not only impact the environment but also pose risks to people's health. Therefore, developing new methods for identifying and quantifying these pollutants classified as emerging contaminants is imperative. These methods enable regulatory actions that effectively minimize their adverse effects to take steps to regulate and reduce their impact. On the other hand, these new contaminants represent a challenge for current technologies to be adapted to control and remove emerging contaminants and involve innovative, eco-friendly, and sustainable remediation technologies. There is a vast amount of information collected in this review on emerging pollutants, comparing the identification and quantification methods, the technologies applied for their control and remediation, and the policies and regulations necessary for their operation and application. In addition, This review will deal with different aspects of emerging contaminants, their origin, nature, detection, and treatment concerning water and wastewater.

The breed and season effects on scrotal circumference and semen characteristics of hair sheep rams under tropical conditions.

The aim of the present work was to evaluate the breed and season effects on scrotal circumference (SC) and semen characteristics of 28 mature hair sheep rams kept under tropical conditions. SCs, sperm concentration (SPC) and abnormal sperm were significantly affected by breed effect (p < 0.001). The season effect was significant in SPC (p < 0.0001) while ejaculate volume, mass motility and SPC were affected by breed × season interaction effect (p < 0.001). It can be concluded that the magnitude of the breed and season effects were not sufficient to affect the reproductive capacity of hair sheep rams throughout the year.

Impact of liver steatosis on the correlation between liver stiffness and fibrosis measured by transient elastography in patients coinfected with human immunodeficiency virus and hepatitis C virus.

We assessed the effect of different hepatic conditions such as fibrosis, steatosis and necroinflammatory activity on liver stiffness as measured by transient elastography in HIV/HCV-coinfected patients. We studied all consecutive HIV/HCV-coinfected patients who underwent liver biopsy and elastography between January 2007 and December 2008. Liver fibrosis was staged following METAVIR Cooperative Study Group criteria. Steatosis was categorized according to the percentage of affected hepatocytes as low (≤10%), moderate (<25%) and severe (≥25%). A total of 110 patients were included. Fibrosis was distributed by stage as follows: F0, n = 13; F1, n = 47; F2, n = 29; F3, n = 18; and F4, n = 3. Liver biopsy revealed the presence of hepatic steatosis in 68 patients (low to moderate, n = 53; and severe n = 15). By univariate regression analysis, fibrosis, necroinflammatory activity, and the degree of steatosis were correlated with liver stiffness. However, in a multiple regression analysis, steatosis and fibrosis were the only independent variables significantly associated with liver stiffness. With a cut-off of 9.5 kPa to distinguish patients with F ≤ 2 from F ≥ 3, elastography led to a significantly higher number of misclassification errors (25%vs 5%; P = 0.014), most of which were false positives for F ≥ 3. Our study suggests that the correlation between liver stiffness and fibrosis as estimated by transient elastography may be affected by the presence of hepatic steatosis in HIV/HCV-coinfected patients.

Effects of Naringin on Cardiomyocytes From a Rodent Model of Type 2 Diabetes.

Diabetic cardiomyopathy (DCM) is a primary disease in diabetic patients characterized by diastolic dysfunction leading to heart failure and death. Unfortunately, even tight glycemic control has not been effective in its prevention. We have found aberrant diastolic Ca2+ concentrations ([Ca2+]d), decreased glucose transport, elevated production of reactive oxygen species (ROS), and increased calpain activity in cardiomyocytes from a murine model (db/db) of type 2 diabetes (T2D). Cardiomyocytes from these mice demonstrate significant cell injury, increased levels of tumor necrosis factor-alpha and interleukin-6 and expression of the transcription nuclear factor-κB (NF-κB). Furthermore, decreased cell viability, and reduced expression of Kir6.2, SUR1, and SUR2 subunits of the ATP-sensitive potassium (KATP) channels. Treatment of T2D mice with the citrus fruit flavonoid naringin for 4 weeks protected cardiomyocytes by reducing diastolic Ca2+ overload, improving glucose transport, lowering reactive oxygen species production, and suppressed myocardial inflammation. In addition, naringin reduced calpain activity, decreased cardiac injury, increased cell viability, and restored the protein expression of Kir6.2, SUR1, and SUR2 subunits of the KATP channels. Administration of the KATP channel inhibitor glibenclamide caused a further increase in [Ca2+]d in T2D cardiomyocytes and abolished the naringin effect on [Ca2+]d. Nicorandil, a KATP channel opener, and nitric oxide donor drug mimic the naringin effect on [Ca2+]d in T2D cardiomyocyte; however, it aggravated the hyperglycemia in T2D mice. These data add new insights into the mechanisms underlying the beneficial effects of naringin in T2D cardiomyopathy, thus suggesting a novel approach to treating this cardiovascular complication.

Effect of supplementation with corn oil on postpartum ovarian activity, pregnancy rate, and serum concentration of progesterone and lipid metabolites in F1 (Bos taurus x Bos indicus) cows.

The aim was to evaluate the effect of corn oil supplementation during postpartum anoestrus on ovarian activity, pregnancy rate, progesterone (P(4)), and lipid metabolites (cholesterol, CHO; low and high density lipoproteins; LDL and HDL, respectively) concentrations in blood of F(1) (Bos taurus x Bos indicus) grazing cows. Cows were randomly assigned to an experimental group, fed with a supplement containing 4% corn oil on dry matter basis (OG, n = 11), and a control group with the same supplement without corn oil (CG, n = 12). Both supplements contained equivalent amounts of crude protein and metabolizable energy and were fed for 34 days continuously. All cows were induced to estrous 12 days after beginning of supplementation by using a synthetic progestagen and artificially inseminated 56 h after retiring the implants. Pregnancy diagnosis was performed by transrectal palpation 45 days after insemination, evaluating simultaneously ovarian activity. P(4) and lipid metabolites (CHO, HDL, LDL) concentrations were determined in blood samples collected at 3-day intervals, from the beginning of corn oil supplementation and up to 10 days after artificial insemination. Ovarian activity was affected by treatment (p < 0.05), finding ovarian structures in 72.7% of OG cows and in 50% of CG cows. Concentration of P(4) and CHO was higher for OG with respect to CG (2.52 +/- 0.65 vs 1.88 +/- 0.62 ng/ml and 117.79 +/- 11.57 vs 85.71 +/- 12.11 mg/dl, respectively), whereas pregnancy rate and blood concentrations of HDL and LDL were not affected by treatment (p > 0.05). Addition of corn oil to the supplement stimulated ovarian activity and increased serum concentrations of progesterone and cholesterol in grazing B. taurus x B. indicus cows with low body condition score showing postpartum anoestrus.

Skeletal muscle: length-dependent effects of potentiating agents.

The ability of vertebrae skeletal muscle to contract more vigorously than normal in the presence of potentiating agents depends on the initial length of a muscle cell. Other factors such as the intracellular calcium ion transient, temperature, chemical nature of the potentiating agent, and the ratio of intrinsic twitch to tetanic force influence the degree of contractile potentiation but cannot account for the length dependence. At least part of a muscle cell seems normally less than fully active during contractions not only at short lengths but also at optimal sarcomere lengths.

Local calcium transients triggered by single L-type calcium channel currents in cardiac cells.

Excitation-contraction coupling was studied in mammalian cardiac cells in which the opening probability of L-type calcium (Ca2+) channels was reduced. Confocal microscopy during voltage-clamp depolarization revealed distinct local transients in the concentration of intracellular calcium ions ([Ca2+]i). When voltage was varied, the latency to occurrence and the relative probability of occurrence of local [Ca2+]i transients varied as predicted if Ca2+ release from the sarcoplasmic reticulum (SR) was linked tightly to Ca2+ flux through L-type Ca2+ channels but not to that through the Na-Ca exchanger or to average [Ca2+]i. Voltage had no effect on the amplitude of local [Ca2+]i transients. Thus, the most efficacious "Ca2+ signal" for activating Ca2+ release from the SR may be a transient microdomain of high [Ca2+]i beneath an individual, open L-type Ca2+ channel.

Chemotransduction in the carotid body: K+ current modulated by PO2 in type I chemoreceptor cells.

The ionic currents of carotid body type I cells and their possible involvement in the detection of oxygen tension (Po2) in arterial blood are unknown. The electrical properties of these cells were studied with the whole-cell patch clamp technique, and the hypothesis that ionic conductances can be altered by changes in PO2 was tested. The results show that type I cells have voltage-dependent sodium, calcium, and potassium channels. Sodium and calcium currents were unaffected by a decrease in PO2 from 150 to 10 millimeters of mercury, whereas, with the same experimental protocol, potassium currents were reversibly reduced by 25 to 50 percent. The effect of hypoxia was independent of internal adenosine triphosphate and calcium. Thus, ionic conductances, and particularly the O2-sensitive potassium current, play a key role in the transduction mechanism of arterial chemoreceptors.

DPPX modifies TEA sensitivity of the Kv4 channels in rabbit carotid body chemoreceptor cells.

Chemoreceptor cells from rabbit carotid body (CB) exhibit transient outward currents reversibly inhibited by low P(o2). Molecular and functional dissection of the components of these outward currents indicates that at least two different channels (Kv4.3 and Kv3.4) contribute to this current. Furthermore, several lines of evidence support the conclusion that Kv4 channel subfamily members (either Kv4.3 alone or Kv4.3/Kv4.1 heteromultimers) are the oxygen sensitive K channels (K(o2)) in rabbit CB chemoreceptor cells. However, the pharmacological characterization of these currents shows that they are almost completely blocked by high external TEA concentrations, while Kv4 channels have been shown to be TEA-insensitive. We hypothesized that the expression of regulatory subunits in chemoreceptor cells could modify TEA sensitivity of Kv4 channels. Here, we explore the presence and functional contribution of DPPX to K(o2) currents in rabbit CB chemoreceptor cells by using DPPX functional knockdown with siRNA. Our data suggest that DPPX proteins are integral components of K(o2) currents, and that their association with Kv4 subunits modulate the pharmacological profile of the heteromultimers.

First isolation of Tenacibaculum maritimum from wedge sole, Dicologoglossa cuneata (Moreau).

The first isolation of Tenacibaculum maritimum from wedge sole, Dicologoglossa cuneata, is reported. The pathogen was recovered from ulcers of cultured fish, from three different outbreaks. The six isolates obtained were biochemically and serologically characterized and diagnosis was confirmed by polymerase chain reaction using specific primers and partial 16S rRNA gene sequencing. The isolates constituted a homogeneous phenotypic group; however, they belong to two of the different serotypes described within this species. A virulence evaluation of the isolates using Wedge sole fry was also performed.