Global Distribution of Key Features of Streamer Corona Discharges in Thunderclouds.

We present nighttime worldwide distributions of key features of Blue LUminous Events (BLUEs) detected by the Modular Multispectral Imaging Array of the Atmosphere-Space Interaction Monitor. Around 10% of all detected BLUEs exhibit an impulsive single pulse shape. The rest of BLUEs are unclear (impulsive or not) single, multiple or with ambiguous pulse shapes. BLUEs exhibit two distinct populations with peak power density <25 µWm-2 (common) and ≥25 µWm-2 (rare) with different rise times and durations. The altitude (and depth below cloud tops) zonal distribution of impulsive single pulse BLUEs indicate that they are commonly present between cloud tops and a depth of ≤4 km in the tropics and ≤1 km in mid and higher latitudes. Impulsive single pulse BLUEs in the tropics are the longest (up to ∼4 km height) and have the largest number of streamers (up to ∼3 × 109). Additionally, the analysis of BLUEs has turned out to be particularly complex due to the abundance of radiation belt particles (at high latitudes and in the South Atlantic Anomaly [SAA]) and cosmic rays all over the planet. True BLUEs can not be fully distinguished from radiation belt particles and cosmic rays unless other ground-based measurements associated with the optically detected BLUEs are available. Thus, the search algorithm of BLUEs presented in Soler et al. (2021), https://doi.org/10.1029/2021gl094657 is now completed with a new additional step that, if used, can considerably smooth the SAA shadow but can also underestimate the number of BLUEs worldwide.

Very-high-frequency oscillations in the main peak of a magnetar giant flare.

Magnetars are strongly magnetized, isolated neutron stars1-3 with magnetic fields up to around 1015 gauss, luminosities of approximately 1031-1036 ergs per second and rotation periods of about 0.3-12.0 s. Very energetic giant flares from galactic magnetars (peak luminosities of 1044-1047 ergs per second, lasting approximately 0.1 s) have been detected in hard X-rays and soft γ-rays4, and only one has been detected from outside our galaxy5. During such giant flares, quasi-periodic oscillations (QPOs) with low (less than 150 hertz) and high (greater than 500 hertz) frequencies have been observed6-9, but their statistical significance has been questioned10. High-frequency QPOs have been seen only during the tail phase of the flare9. Here we report the observation of two broad QPOs at approximately 2,132 hertz and 4,250 hertz in the main peak of a giant γ-ray flare11 in the direction of the NGC 253 galaxy12-17, disappearing after 3.5 milliseconds. The flare was detected on 15 April 2020 by the Atmosphere-Space Interactions Monitor instrument18,19 aboard the International Space Station, which was the only instrument that recorded the main burst phase (0.8-3.2 milliseconds) in the full energy range (50 × 103 to 40 × 106 electronvolts) without suffering from saturation effects such as deadtime and pile-up. Along with sudden spectral variations, these extremely high-frequency oscillations in the burst peak are a crucial component that will aid our understanding of magnetar giant flares.

Evaluation of Thin Film Microextraction for trace elemental analysis of liquid samples using LIBS detection.

An analytical methodology based in the combination of Thin Film Microextraction with Laser-induced Breakdown Spectroscopy (TFME-LIBS) was investigated, for the first time, for detection of Cu, Cr, Ni and Pb in aqueous solutions. In this methodology, the analytes were extracted in a thin film of adsorbent material deposited on a solid support, which was introduced in the sample to analyse. After extraction, the analytes retained in the adsorbent were analysed by LIBS. In order to obtain adsorbent films useful for the microextraction step, two different experimental procedures for film generation, denoted as Drop Casting Deposition and Mould Deposition, were evaluated. In both cases, graphene oxide was used as adsorbent material. The mould deposition procedure was found to produce more homogeneous graphene oxide layers, leading to more uniform distribution of the adsorbed analytes on the graphene oxide surface. Experimental parameters affecting the TFME procedure, such as the adsorbent amount and extraction time, were studied. Under optimum microextraction conditions, the analytical figures of merit of the proposed TFME-LIBS method were evaluated, leading to limits of detection ranging from 41 µg kg-1 and 52 µg kg-1. Method trueness, evaluated from the analysis of a real sample of bottle water, led to recovery values about 70%, indicating the existence of strong matrix effects probably due to the presence of major cations in the bottle water. After 50% dilution of the sample with deionized water, recoveries values improved to 100%-108%.

Cyclosporine A plus low-dose steroid treatment in COVID-19 improves clinical outcomes in patients with moderate to severe disease: A pilot study.

BACKGROUND: COVID-19 pandemic causes high global morbidity and mortality and better medical treatments to reduce mortality are needed. OBJECTIVE: To determine the added benefit of cyclosporine A (CsA), to low-dose steroid treatment, in patients with COVID-19. METHODS: Open-label, non randomized pilot study of patients with confirmed infection of SARS-CoV-2 hospitalized from April to May 2020 at a single centre in Puebla, Mexico. Patients were assigned to receive either steroids or CsA plus steroids. Pneumonia severity was assessed by clinical, laboratory, and lung tomography. The death rate was evaluated at 28 days. RESULTS: A total of 209 adult patients were studied, 105 received CsA plus steroids (age 55.3 ± 13.3; 69% men), and 104 steroids alone (age 54.06 ± 13.8; 61% men). All patients received clarithromycin, enoxaparin and methylprednisolone or prednisone up to 10 days. Patient's death was associated with hypertension (RR = 3.5) and diabetes (RR = 2.3). Mortality was 22 and 35% for CsA and control groups (P = 0.02), respectively, for all patients, and 24 and 48.5% for patients with moderate to severe disease (P = 0.001). Higher cumulative clinical improvement was seen for the CsA group (Nelson Aalen curve, P = 0.001, log-rank test) in moderate to severe patients. The Cox proportional hazard analysis showed the highest HR improvement value of 2.15 (1.39-3.34, 95%CI, P = 0.0005) for CsA treatment in moderate to severe patients, and HR = 1.95 (1.35-2.83, 95%CI, P = 0.0003) for all patients. CONCLUSION: CsA used as an adjuvant to steroid treatment for COVID-19 patients showed to improve outcomes and reduce mortality, mainly in those with moderate to severe disease. Further investigation through controlled clinical trials is warranted.

Urinary Clara Cell Protein in Kidney Transplant Patients: A Preliminary Study.

OBJECTIVE: The aim of this exploratory study was to analyze the urinary excretion of Clara cell protein (CC16), a new marker of proximal tubular dysfunction (PTD), in kidney transplantation (KT). MATERIALS AND METHODS: Urinary concentrations of CC16, ß2-microglobulin (ß2m), and N-acetyl-glucosaminidase (NAG) were measured in 50 KT patients (72% men; mean age 50.4 ± 12.4 years; diabetes in 24%; duration of KT 4.3 ± 3.1 years) and 10 healthy controls (6 men; mean age 33.6 ± 13.4 years). RESULTS: Urinary levels of ß2m, NAG, and CC16 were significantly higher in KT patients than in controls: ß2m: 0.77 (interquartile range [IQ] 0.22 to 4.62) g/g vs 0.069 (IQ 0.05 to 0.10) g/g; NAG: 3.16 (IQ 2.09 to 5.33) U/g vs 1.73 (IQ 1.25 to 2.07) U/g; CC16: 26.01 (IQ 8.62 to 123.3) g/g vs 2.51 (IQ 0.83 to 7.18) g/g (P < .001). Elevated levels of ß2m, NAG, and CC16 were found in 81%, 28%, and 71% of KT patients, respectively. Urinary levels of ß2m, NAG, and CC16 significantly increase as glomerular filtration rate (GFR) decreases. Interestingly, in patients with GFR >60 mL/min, we still found high levels of ß2m, NAG, and CC16 in 77%, 13%, and 52%, respectively. Diabetic subjects had significant higher levels of the 3 markers compared with nondiabetic subjects, without differences in albumin excretion or GFR. CC16 showed a positive correlation with urinary albumin (r = 0.42, P < .001), NAG (r = 0.352, P < .05), and ß2m (r = 0.75, P < .001). CONCLUSION: PTD is highly prevalent in KT patients. This is the first study that analyzes CC16 in KT patients, showing that the urinary excretion of this protein is significantly increased in this population. Further studies are needed to examine the clinical value of CC16 in KT patients.

Selective vitamin D receptor activation as anti-inflammatory target in chronic kidney disease.

Paricalcitol, a selective vitamin D receptor (VDR) activator used for treatment of secondary hyperparathyroidism in chronic kidney disease (CKD), has been associated with survival advantages, suggesting that this drug, beyond its ability to suppress parathyroid hormone, may have additional beneficial actions. In this prospective, nonrandomised, open-label, proof-of-concept study, we evaluated the hypothesis that selective vitamin D receptor activation with paricalcitol is an effective target to modulate inflammation in CKD patients. Eight patients with an estimated glomerular filtration rate between 15 and 44 mL/min/1.73 m(2) and an intact parathyroid hormone (PTH) level higher than 110 pg/mL received oral paricalcitol (1 µg/48 hours) as therapy for secondary hyperparathyroidism. Nine patients matched by age, sex, and stage of CKD, but a PTH level <110 pg/mL, were enrolled as a control group. Our results show that five months of paricalcitol administration were associated with a reduction in serum concentrations of hs-CRP (13.9%, P < 0.01), TNF-α (11.9%, P = 0.01), and IL-6 (7%, P < 0.05), with a nonsignificant increase of IL-10 by 16%. In addition, mRNA expression levels of the TNFα and IL-6 genes in peripheral blood mononuclear cells decreased significantly by 30.8% (P = 0.01) and 35.4% (P = 0.01), respectively. In conclusion, selective VDR activation is an effective target to modulate inflammation in CKD.

Relationship between inflammation and microalbuminuria in prehypertension.

Inflammation is a pathogenic factor for target-organ damage (TOD) in hypertension. This study examined the relationship between inflammatory parameters and urinary albumin excretion (UAE) in prehypertension. A total of 65 prehypertensive subjects (blood pressure (BP) 120-139/80-89 mm Hg) and 26 healthy volunteers with BP <120/80 mm Hg were included. High-sensitivity C-reactive protein (hs-CRP), and serum and urinary tumor necrosis factor-α (TNF-α) were measured as inflammatory markers. Prehypertensive individuals had higher levels of inflammatory parameters and UAE than healthy subjects. Analyses carried out in prehypertensive participants showed that BP was similar between individuals with normoalbuminuria or microalbuminuria (MAB) (UAE between 30 and 299 mg per day). However, serum hs-CRP and urinary TNF-α excretion were higher in prehypertensives with MAB. Multiple regression analysis showed that systolic blood pressure (r=0.29, P<0.01), hs-CRP (r=0.20, P<0.001), and urinary TNF-α (r=0.69, P<0.001) were independently correlated with UAE (adjusted R(2)=0.73, P<0.001). Finally, logistic regression analysis performed in the prehypertensive group with the absence or presence of MAB as the dependent variable demonstrated that hs-CRP (3.92 (1.45-10.58), P=0.007) and urinary TNF-α (1.69 (1.20-2.37), P=0.002) were independent risk factors for the presence of MAB. Inflammatory parameters are significantly and independently associated with UAE in prehypertensive subjects, suggesting that inflammation may be a pathogenic factor for the early vascular or TOD in these individuals.

Serum and gene expression profile of tumor necrosis factor-alpha and interleukin-6 in hypertensive diabetic patients: effect of amlodipine administration.

Pro-inflammatory cytokines are critical factors in type 2 diabetes-associated atherosclerosis. We aim to analyze in hypertensive type 2 diabetic patients the serum concentrations and the mRNA expression levels in peripheral blood mononuclear cells (PBMC) of the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), as well as to evaluate the effect of amlodipine administration. Twenty-one hypertensive diabetic patients and 10 healthy non-diabetic controls were included in the study. Serum levels of cytokines were measured by chemiluminescent immunometric assay, and mRNA expression levels by RT-PCR. The mean serum concentrations of TNF-alpha and IL-6 in diabetic patients showed a 6.1-fold and 2.9-fold increase with respect to non-diabetic control subjects, respectively (p less than 0.0001). Likewise, there was a 3.3- and a 4-fold increase in the PBMC mRNA expression level of TNF-alpha and IL-6 (p less than 0.0001) in diabetic subjects. After amlodipine administration, a significant decrease (p less than 0.01) was observed in the serum TNF-alpha and IL-6 levels. In addition, pre-treatment mRNA expression of TNF-alpha and IL-6 also decreased, with a mean percent reduction of 26 percent (p less than0.01) and 25 percent (p less than 0.001), respectively. In conclusion, serum concentrations and PBMC mRNA expression levels of TNF-alpha and IL-6 are significantly elevated in hypertensive type 2 diabetic patients. Administration of amlodipine is associated with a significant reduction of the increased levels of these inflammatory parameters, both at the protein as well as at the transcriptional level. These modulatory effects of amlodipine on proinflammatory cytokine level and expression may be related to its suggested anti-atherosclerotic actions.

[Paraquat poisoning: report of two cases and literature review]. / Intoxicación por paraquat: presentación de dos casos y revisión de la literatura.

Cases of poisoning with pesticides, especially suicidal ones, continue to be an important therapeutic problem. The heribicide paraquat (1.1' dimethyl-4.4' bipyridylium dichloride) is the second cause of pesticide poisoning in our country, which is associated with a high mortality rate. We report two cases of suicidal ingestion of paraquat who developed multiorgan failure with a lethal outcome. We also present a brief review of the literature, mainly focused on the different therapeutic options.

Magnesium in dialysis patients: serum levels and clinical implications.

Magnesium is the fourth most abundant cation in the body and is involved in many cell functions. Serum magnesium concentration is maintained within a narrow range by the kidney and digestive tract. Patients with chronic renal failure have an increased body magnesium content. In subjects on hemodialysis and peritoneal dialysis the serum magnesium concentration parallels the dialysate magnesium level. Hypermagnesemia in these patients is frequent, usually mild (serum magnesium lower than 1.5 mmol/l) and asymptomatic, but severe and symptomatic hypermagnesemia can be induced by exogenous magnesium administration. The last section of this review briefly summarizes the clinical implications of hypermagnesemia in dialysis population with special interest on the influence of magnesium on bone disease and parathyroid gland function.

[Computed tomography and polymerase chain reaction in tuberculosis infection in childhood]. / Tomografía computarizada y reacción en cadena de la polimerasa en la infección tuberculosa de la infancia.

The recognition of children with tuberculous infection without disease is often difficult. Minimal active disease may be present in many cases but unrecognised on chest radiography or by microbiologic methods. We have performed computed tomography in 22 children with tuberculous infection, a normal chest radiograph and negative microbacterial culture. In 16 children we also performed DNA amplification by polymerase chain reaction in gastric aspirates. It was found that 14 of 22 (63%) infected children had enlarged lymph nodes. Adenopathies were more frequent in children less than 8 years-old and in the right paratracheal positions. Polymerase chain reaction was positive in 4 of 8 studied children with abnormal computed tomography and in none of the children with normal computed tomography. The demonstration of unrecognised active disease raises the question of the adequate treatment for the children with tuberculous infection. It is proposed that a two drug regimen would be more appropriate than isoniazid alone in children less than 8 years old.

[Repeat consultations in pediatric hospital emergencies]. / Consultas reiterativas en la urgencia hospitalaria pediátrica.

The objectives of this study were to analyze the social and clinical aspects of the infant and child population who excessively utilize the hospital emergency services. To this end, the clinical histories of 130 children admitted to a pediatric hospital have been analyzed. These children were between the ages of 2 months and 10 years and had 10 or more visits to the emergency room or had more than 4 visits during the same year. The control group was arbitrarily composed of 270 children admitted to the same service during the same period of time. We found that in the study group the sociocultural level was low in 71% and 17% had serious social deprivation (significant differences with the control population, p < 0.05). Twenty percent had at least one previous febrile convulsion (p < 0.001) and 33% had more than four hospital admissions. No significant differences in the number of urgent consultations were found between the different days of the week no between the different months. The most frequent diagnosis was upper respiratory tract infections. The number of consultations was higher (p < 0.05) in children with serious social deprivation, chronic pathology, multiple hospital admissions and whose home was near the hospital. We conclude that children with reiterative consultations to the hospital emergency services usually have a social level lower than the control group. Most of these consultations are caused by banal problems and the children are subjected to an excessive number of analytical and radiological tests. Therefore, adequate health education is necessary among these sociocultural level groups in order to avoid using the emergency services as primary attendance consultations.

[Fever and petechial exanthema in children]. / Fiebre y exantema petequial en niños.

In an attempt to determine clinical and analytical predictive parameters of a possible grave disease, we have carried out a retrospective study of 172 children admitted to our hospital with fever and petechiae as initial symptoms. The ages ranged between 1 month and 10 years. Even though we have not found a clinical symptom or analysis sufficiently sensitive as to predict all grave diseases, the general clinical state of the child associated with either a high or low white cell count and an abnormal coagulation study should be alert signals for a serious infectious disease. On the contrary, if the clinical and analytical parameters are within normal limits the risk of a grave disease is low. We emphasize the high incidence of meningococcal disease (26%).

[Peripartum cardiomyopathy with normal endomyocardial biopsy and positive antimyosin-In 111 study for myocarditis]. / Miocardiopatía periparto con biopsia endomiocárdica normal y estudio con antimiosina-In 111 positivo para miocarditis.

Peripartum cardiomyopathy is a rare manifestation of heart disease which accounts for less than 1% of the cardiovascular problems associated to pregnancy, with a variable incidence of myocarditis ranging from 29 to 100%. We present a patient with peripartum cardiomyopathy in whom endomyocardial biopsy was normal, but the studies with anti-myosin antibodies suggested the presence of myocarditis. Clinical signs and controversies between anatomopathologic and isotopic studies are discussed.

[Usefulness of the determination of free erythrocyte protoporphyrin in relation to other hematologic parameters in iron deficiency]. / Utilidad de la determinación de la protoporfirina eritrocitaria libre en relación a otros parámetros hematimétricos en el déficit de hierro.

Hematological parameters and free eythrocyte protoporphyrin (FEP) on a capillary blood sample were measured in 175 apparently healthy children ranging from 6 months to six years of age. Thirty eight children had hematological parameters descended and/or FEP elevated were asked to return for blood counts, FEP, serum ferritin, serum iron, total iron binding, capacity, transferrin saturation and ALA-D activity, on a venous blood sample. Only 34 children returned. Twenty seven, 15.4%, had iron stores descended or iron deficiency, 18 of them with anemia. FEP had significant correlation coefficients with hematologic parameters (p less than 0.001), serum iron and transferrin saturation (p less than 0.01). On iron deficiency anemia detection, the FEP had a sensibility and specificity of 0.94 and 0.75 respectively.