Three years of routine vitrification of human zygotes: is it still fair to advocate slow-rate freezing?

Cryopreservation of human oocytes and embryos is a necessary tool in assisted reproduction treatment that leads to an increased cumulative outcome while decreasing costs. Vitrification is a cryopreservation technique that leads to a glass-like solidification, with rapid cooling of cells or tissues. Nowadays vitrification is claimed to be the future of cryopreservation of human embryos due to improved survival rates and clinical outcomes. This study was conducted at a university clinic to assess the safety and efficiency of vitrification of human zygotes as a routine procedure. A total of 849 pronuclear-stage (PN) zygotes were vitrified between March 2004 and July 2006. During this period, 103 cycles of cryopreserved embryo transfer were completed. In total, 339 PN zygotes were thawed resulting in an 89% survival rate (302 PN zygotes). The mean number of embryos per transfer was 2.2. The pregnancy rate obtained was three times higher (36.9%) than that obtained with the slow-rate freezing method (10.2%) used previously in the same centre. In conclusion, vitrification of human zygotes at the pronuclear stage seems to be a successful and reliable method with favourable outcomes and can be recommended as a routine technique for cryopreservation of human embryos.     

Impact of the longitudinal quantitative assessment of juvenile systemic lupus erythematosus severity on the disease outcome

Clinical Rheumatology - This study on juvenile SLE patients aimed to evaluate retrospectively the impact of a tertiary center’s management policy of the disease severity on its long-term...     

Management of Anemia in Children Receiving Chronic Peritoneal Dialysis

Little information exists regarding the efficacy, modifiers, and outcomes of anemia management in children with CKD or ESRD. We assessed practices, effectors, and outcomes of anemia management in 1394 pediatric patients undergoing peritoneal dialysis (PD) who were prospectively followed in 30 countries. We noted that 25% of patients had hemoglobin levels below target (<10 g/dl or <9.5 g/dl in children older or younger than 2 years, respectively), with significant regional variation; levels were highest in North America and Europe and lowest in Asia and Turkey. Low hemoglobin levels were associated with low urine output, low serum albumin, high parathyroid hormone, high ferritin, and the use of bioincompatible PD fluid. Erythropoiesis-stimulating agents (ESAs) were prescribed to 92% of patients, and neither the type of ESA nor the dosing interval appeared to affect efficacy. The weekly ESA dose inversely correlated with age when scaled to weight but did not correlate with age when normalized to body surface area. ESA sensitivity was positively associated with residual diuresis and serum albumin and inversely associated with serum parathyroid hormone and ferritin. The prevalence of hypertension and left ventricular hypertrophy increased with the degree of anemia. Patient survival was positively associated with achieved hemoglobin and serum albumin and was inversely associated with ESA dose. In conclusion, control of anemia in children receiving long-term PD varies by region. ESA requirements are independent of age when dose is scaled to body surface area, and ESA resistance is associated with inflammation, fluid retention, and hyperparathyroidism. Anemia and high ESA dose requirements independently predict mortality.Almost three decades after the advent of recombinant erythropoietin, the management of renal anemia has become a recent focus of attention and changing paradigms. Whereas correction of hemoglobin (Hb) levels to near-normal has previously been recommended on the basis of association studies linking more severe anemia to morbidity and mortality with dialysis,^1–3 interventional clinical trials consistently demonstrate that near-normalization of Hb increases the risk of vascular events and mortality in adults receiving maintenance hemodialysis and in those with CKD who are not undergoing dialysis.^4–6 This has prompted ongoing reevaluation and revisions of treatment targets in patients exposed to erythropoiesis-stimulating agents (ESAs).⁷The appropriateness of applying treatment recommendations established in adult hemodialysis populations at high cardiovascular risk and adults with CKD to children undergoing dialysis is questionable because cardiovascular events are far less common in children with CKD. Furthermore, two thirds of children requiring dialysis initially opt for peritoneal dialysis (PD), and there are no systematic studies in the adult PD population to inform the optimal Hb target range in these patients. The risk profile of patients receiving PD may differ from that of the hemodialysis setting because of the absence of dialysis-induced intermittent hemoconcentration and lack of contact activation of the complement and coagulation systems.Further aspects to consider in pediatric anemia management are the greater physical activity of children and the need for optimal cognitive functioning at school.^8,9 The significant physiologic variation of the normal Hb range with age¹⁰ and the relative ESA sensitivity that reportedly increases with age during early childhood are also noteworthy.¹¹The registry of the International Pediatric Peritoneal Dialysis Network (IPPN) prospectively collects detailed clinical, biochemical, dialysis, and medication-related information (including ESA types and doses and modalities of iron supplementation) from a substantial number of children undergoing long-term PD around the world. In-depth analysis of this unique database has allowed us to (1) gain insight into the demographic characteristics of renal anemia and its treatment in the pediatric PD population worldwide, (2) explore the relationship between ESA dose requirements and body dimensions, (3) identify factors contributing to ESA resistance in children, and (4) associate anemia control with patient outcomes.     

Neuromuscular differences between boys with and without intellectual disability during squat jump

The purpose of this study was to identify the differences in vertical squat jump (SJ) between volunteers with and without intellectual disability (ID). Thirteen boys with ID (average intelligence quotient, estimated by Wisk III test: 55.6 ± 11.2) and 13 peers without disabilities performed maximal SJ on a force platform. Kinematic data were captured using a six-camera 3D motion analysis system and electromyographic (EMG) activity was recorded using surface electrodes. Unpaired T-test determined the statistical difference between the two groups. The obtained results indicated that the group with ID, jumped lower, developed lower vertical ground reaction forces, knee power output, knee angular velocity, and take-off velocity, and showed longer propulsion duration, decreased mean to maximum agonist EMG activity and higher antagonist/agonist activity ratio. The deficit in the SJ observed in individuals with ID was attributed to a deficit in the examined mechanical and neuromuscular parameters, and especially to the agonist and antagonist co-contraction.     

Sleep disorders in pediatric chronic kidney disease patients

The prevalence of sleep disorders during childhood has been estimated to range from 25 to 43 %. The aim of this review is to determine the prevalence of sleep disorders and possible associations with chronic kidney disease (CKD)-related factors and health-related quality of life (HRQOL) in children with CKD. An electronic systematic literature search for sleep disorders in children with CKD in Pubmed, Embase and the Cochrane Library Databases identified seven relevant articles for review, all of which reported an increased prevalence of sleep disorders in children with CKD. Five studies included children with CKD undergoing dialysis, and two studies included only non-dialysis patients. In all studies the presence of sleep disturbances was assessed by questionnaires; only one study compared the results of a validated questionnaire with laboratory-based polysomnography. The prevalence of any sleep disorder ranged from 77 to 85 % in dialysis patients, to 32–50 % in transplanted patients and 40–50 % in non-dialysis patients. The most commonly studied disorder was restless legs syndrome, which presented at a prevalence of 10–35 %. Three studies showed significant associations between presence of sleep disorders and HRQOL. We found consistent evidence of an increased prevalence of sleep disturbances in children with CKD, and these seemed to play a critical role in HRQOL.     

Peritonitis in children with automated peritoneal dialysis: a single-center study of a 10-year experience

Peritoneal dialysis (PD) constitutes the preferred dialysis modality for children requiring renal replacement therapy with peritonitis being one of the most common complications of PD. This study was performed to evaluate the epidemiology, microbiology, and outcomes of PD-associated peritonitis in Greek children for a 10-year period. A total of 27 patients (16 males) with a mean age 121.8?±?57.2 months were retrospective analyzed. Patients were on PD therapy for a mean duration of 45.2?±?26.1 months. We found 23 episodes of PD-associated peritonitis occurred in 9 out of 27 patients (0.23 episodes/patient-year), with four patients experienced two or more peritonitis episodes. Gram-positive bacteria were responsible for 15 (65.2%) peritonitis episodes, with Staphylococcus aureus being the predominant specie isolated in 30.4% of cases. A total of seven episodes of exit-site infections (ESIs) were identified in five patients (0.069 episodes/patient-year) with the most common bacteria isolated being S. aureus (57.4%). Initial antibiotic treatment included intraperitoneal vancomycin plus ceftazidime in the majority of cases (82.6%). At the end of study, 12 (44.4%) patients remained on PD, 11 (41.8%) underwent renal transplantation, 2 (7.4%) shifted to hemodialysis and unfortunately, two patients (7.4%) died. Conclusively, our study revealed a noticeable low peritonitis and ESIs rate as compared to international data and represents the first evaluation of the characteristics and outcomes of peritonitis in the Greek pediatric PD population.     

The ryanodine receptor agonist 4-chloro-3-ethylphenol blocks ORAI store-operated channels

BACKGROUND

Depletion of the Ca²⁺ store by ryanodine receptor (RyR) agonists induces store-operated Ca²⁺ entry (SOCE). 4-Chloro-3-ethylphenol (4-CEP) and 4-chloro-m-cresol (4-CmC) are RyR agonists commonly used as research tools and diagnostic reagents for malignant hyperthermia. Here, we investigated the effects of 4-CEP and its analogues on SOCE.

EXPERIMENTAL APPROACH

SOCE and ORAI1-3 currents were recorded by Ca²⁺ imaging and whole-cell patch recordings in rat L6 myoblasts and in HEK293 cells overexpressing STIM1/ORAI1-3.

KEY RESULTS

4-CEP induced a significant release of Ca²⁺ in rat L6 myoblasts, but inhibited SOCE. The inhibitory effect was concentration-dependent and more potent than its analogues 4-CmC and 4-chlorophenol (4-ClP). In the HEK293 T-REx cells overexpressing STIM1/ORAI1-3, 4-CEP inhibited the ORAI1, ORAI2 and ORAI3 currents evoked by thapsigargin. The 2-APB-induced ORAI3 current was also blocked by 4-CEP. This inhibitory effect was reversible and independent of the Ca²⁺ release. The two analogues, 4-CmC and 4-ClP, also inhibited the ORAI1-3 channels. Excised patch and intracellular application of 4-CEP demonstrated that the action site was located extracellularly. Moreover, 4-CEP evoked STIM1 translocation and subplasmalemmal clustering through its Ca²⁺ store-depleting effect via the activation of RyR, but no effect on STIM1 redistribution was observed in cells co-expressing STIM1/ORAI1-3.

CONCLUSION AND IMPLICATIONS

4-CEP not only acts as a RyR agonist to deplete the Ca²⁺ store and trigger STIM1 subplasmalemmal translocation and clustering, but also directly inhibits ORAI1-3 channels. These findings demonstrate a novel pharmacological property for the chlorophenol derivatives that act as RyR agonists.