CDKL5-mediated developmental tuning of neuronal excitability and concomitant regulation of transcriptome.

Cyclin-dependent kinase-like 5 (CDKL5) is a serine-threonine kinase enriched in the forebrain to regulate neuronal development and function. Patients with CDKL5 deficiency disorder (CDD), a severe neurodevelopmental condition caused by mutations of CDKL5 gene, present early-onset epilepsy as the most prominent feature. However, spontaneous seizures have not been reported in mouse models of CDD, raising vital questions on the human-mouse differences and the roles of CDKL5 in early postnatal brains. Here, we firstly measured electroencephalographic (EEG) activities via a wireless telemetry system coupled with video-recording in neonatal mice. We found that mice lacking CDKL5 exhibited spontaneous epileptic EEG discharges, accompanied with increased burst activities and ictal behaviors, specifically at postnatal day 12 (P12). Intriguingly, those epileptic spikes disappeared after P14. We next performed an unbiased transcriptome profiling in the dorsal hippocampus and motor cortex of Cdkl5 null mice at different developmental timepoints, uncovering a set of age-dependent and brain region-specific alterations of gene expression in parallel with the transient display of epileptic activities. Finally, we validated multiple differentially expressed genes, such as glycine receptor alpha 2 and cholecystokinin, at the transcript or protein levels, supporting the relevance of these genes to CDKL5-regulated excitability. Our findings reveal early-onset neuronal hyperexcitability in mouse model of CDD, providing new insights into CDD etiology and potential molecular targets to ameliorate intractable neonatal epilepsy.

Preclinical studies of gene replacement therapy for CDKL5 deficiency disorder.

Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is a rare neurodevelopmental disorder caused by a mutation in the X-linked CDKL5 gene. CDKL5 is a serine/threonine kinase that is critical for axon outgrowth and dendritic morphogenesis as well as synapse formation, maturation, and maintenance. This disorder is characterized by early-onset epilepsy, hypotonia, and failure to reach cognitive and motor developmental milestones. Because the disease is monogenic, delivery of the CDKL5 gene to the brain of patients should provide clinical benefit. To this end, we designed a gene therapy vector, adeno-associated virus (AAV)9.Syn.hCDKL5, in which human CDKL5 gene expression is driven by the synapsin promoter. In biodistribution studies conducted in mice, intracerebroventricular (i.c.v.) injection resulted in broader, more optimal biodistribution than did intra-cisterna magna (i.c.m.) delivery. AAV9.Syn.hCDKL5 treatment increased phosphorylation of EB2, a bona fide CDKL5 substrate, demonstrating biological activity in vivo. Our data provide proof of concept that i.c.v. delivery of AAV9.Syn.hCDKL5 to neonatal male Cdkl5 knockout mice reduces pathology and reduces aberrant behavior. Functional improvements were seen at doses of 3e11 to 5e11 vector genomes/g brain, which resulted in transfection of ≥50% of the neurons. Functional improvements were not seen at lower doses, suggesting a requirement for broad distribution for efficacy.

Communication of individuals with CDKL5 deficiency disorder as observed by caregivers: A descriptive qualitative study.

CDKL5 deficiency disorder (CDD) is a genetically caused developmental epileptic encephalopathy that causes severe communication impairments. Communication of individuals with CDD is not well understood in the literature and currently available measures are not well validated in this population. Accurate and sensitive measurement of the communication of individuals with CDD is important for understanding this condition, clinical practice, and upcoming interventional trials. The aim of this descriptive qualitative study was to understand how individuals with CDD communicate, as observed by caregivers. Participants were identified through the International CDKL5 Disorder Database and invited to take part if their child had a pathogenic variant of the CDKL5 gene and they had previously completed the Communication and Symbolic Behavior Checklist (CSBS-DP ITC). The sample comprised caregivers of 23 individuals with CDD, whose ages ranged from 2 to 30 years (median 13 years), 15 were female, and most did not use words. Semistructured interviews were conducted via videoconference and analyzed using a conventional content analysis. Three overarching categories were identified: mode, purpose and meaning, and reciprocal exchanges. These categories described the purposes and mechanism of how some individuals with CDD communicate, including underpinning influential factors. Novel categories included expressing a range of emotions, and reciprocal exchanges (two-way interactions that varied in complexity). Caregivers observed many communication modes for multiple purposes. Understanding how individuals with CDD communicate improves understanding of the condition and will guide research to develop accurate measurement for clinical practice and upcoming medication trials.

CDKL5 deficiency disorder: progressive brain atrophy may be part of the syndrome.

The clinical phenotype of Cyclin-Dependent Kinase-Like 5 (CDKL5) deficiency disorder (CDD) has been delineated but neuroimaging features have not been systematically analyzed. We studied brain magnetic resonance imaging (MRI) scans in a cohort of CDD patients and reviewed age at seizure onset, seizure semiology, head circumference. Thirty-five brain MRI from 22 unrelated patients were included. The median age at study entry was 13.4 years. In 14/22 patients (85.7%), MRI in the first year of life was unremarkable in all but two. In 11/22, we performed MRI after 24 months of age (range 2.5-23 years). In 8 out of 11 (72.7%), MRI showed supratentorial atrophy and in six cerebellar atrophy. Quantitative analysis detected volumetric reduction of the whole brain (-17.7%, P-value = 0.014), including both white matter (-25.7%, P-value = 0.005) and cortical gray matter (-9.1%, P-value = 0.098), with a reduction of surface area (-18.0%, P-value = 0.032), mainly involving the temporal regions, correlated with the head circumference (ρ = 0.79, P-value = 0.109). Both the qualitative structural assessment and the quantitative analysis detected brain volume reduction involving the gray and white matter. These neuroimaging findings may be related to either progressive changes due to CDD pathogenesis, or to the extreme severity of epilepsy, or both. Larger prospective studies are needed to clarify the bases for the structural changes we observed.

A Case of CDKL5 Deficiency Due to an X Chromosome Pericentric Inversion: Delineation of Structural Rearrangements as an Overlooked Recurrent Pathological Mechanism.

CDKL5 deficiency disorder (CDD) is an X-linked dominant epileptic encephalopathy, characterized by early-onset and drug-resistant seizures, psychomotor delay, and slight facial features. Genomic variants inactivating CDKL5 or impairing its protein product kinase activity have been reported, making next-generation sequencing (NGS) and chromosomal microarray analysis (CMA) the standard diagnostic tests. We report a suspicious case of CDD in a female child who tested negative upon NGS and CMA and harbored an X chromosome de novo pericentric inversion. The use of recently developed genomic techniques (optical genome mapping and whole-genome sequencing) allowed us to finely characterize the breakpoints, with one of them interrupting CDKL5 at intron 1. This is the fifth case of CDD reported in the scientific literature harboring a structural rearrangement on the X chromosome, providing evidence for the hypothesis that this type of anomaly can represent a recurrent pathogenic mechanism, whose frequency is likely underestimated, with it being overlooked by standard techniques. The identification of the molecular etiology of the disorder is extremely important in evaluating the pathological outcome and to better investigate the mechanisms associated with drug resistance, paving the way for the development of specific therapies. Karyotype and genomic techniques should be considered in all cases presenting with CDD without molecular confirmation.

Analysis of electrocardiograms in individuals with CDKL5 deficiency disorder.

CDKL5 deficiency disorder (CDD) is an epileptic encephalopathy associated with medically refractory epilepsy. We sought to determine whether prolonged corrected QT interval (QTc) or other cardiac conduction abnormalities were seen in CDD in a clinical cohort. A cohort of individuals with CDD was evaluated in the Children's Hospital Colorado's International Foundation for CDKL5 Research designated Center of Excellence clinic with routine electrocardiograms obtained as part of routine clinical care. Retrospective review of electrocardiograms was completed. ECGs from 44 individuals (7 male, 37 female, age range 0-34.5 years) with pathogenic mutations and findings consistent with CDD were evaluated. Multiple ECGs were available from the 44 individuals obtained from 1996 to 2020. Prolonged QTc was found in two individuals (4.5%) and either resolved or was not confirmed on Holter monitor; no additional interventions were performed. A total of 11 individuals had echocardiograms for a variety of indications including unexplained tachycardia and ECG abnormalities; all were normal. Two individuals in the cohort died during the study with no abnormal findings on ECG. The incidence of prolonged QTc or other significant actionable cardiac abnormalities was rare in a cohort of individuals with CDD though was higher than the prevalence seen within the general population. Further studies in a larger, confirmatory cohort over a longer period are needed.

Epileptic spasms in CDKL5 deficiency disorder: Delayed treatment and poor response to first-line therapies.

OBJECTIVE: We aimed to assess the treatment response of infantile-onset epileptic spasms (ES) in CDKL5 deficiency disorder (CDD) vs other etiologies. METHODS: We evaluated patients with ES from the CDKL5 Centers of Excellence and the National Infantile Spasms Consortium (NISC), with onset from 2 months to 2 years, treated with adrenocorticotropic hormone (ACTH), oral corticosteroids, vigabatrin, and/or the ketogenic diet. We excluded children with tuberous sclerosis complex, trisomy 21, or unknown etiology with normal development because of known differential treatment responses. We compared the two cohorts for time to treatment and ES remission at 14 days and 3 months. RESULTS: We evaluated 59 individuals with CDD (79% female, median ES onset 6 months) and 232 individuals from the NISC database (46% female, median onset 7 months). In the CDD cohort, seizures prior to ES were common (88%), and hypsarrhythmia and its variants were present at ES onset in 34%. Initial treatment with ACTH, oral corticosteroids, or vigabatrin started within 1 month of ES onset in 27 of 59 (46%) of the CDD cohort and 182 of 232 (78%) of the NISC cohort (p < .0001). Fourteen-day clinical remission of ES was lower for the CDD group (26%, 7/27) than for the NISC cohort (58%, 106/182, p = .0002). Sustained ES remission at 3 months occurred in 1 of 27 (4%) of CDD patients vs 96 of 182 (53%) of the NISC cohort (p < .0001). Comparable results were observed with longer lead time (≥1 month) or prior treatment. Ketogenic diet, used within 3 months of ES onset, resulted in ES remission at 1 month, sustained at 3 months, in at least 2 of 13 (15%) individuals with CDD. SIGNIFICANCE: Compared to the broad group of infants with ES, children with ES in the setting of CDD often experience longer lead time to treatment and respond poorly to standard treatments. Development of alternative treatments for ES in CDD is needed.

Study on Asymmetric Vibrational Coherent Magnetic Transitions and Origin of Fluorescence in Symmetric Structures.

In this work, the physical mechanisms of three highly efficient circularly polarized luminescent materials are introduced. The UV-vis spectra are plotted; the transition properties of their electrons at the excited states are investigated using a combination of the transition density matrix (TDM) and the charge difference density (CDD); combining the distribution of electron clouds, the essence of charge transfer excitation in three structures is explained. The resonance Raman spectrum of the three structures at the S1 and S2 excited states are calculated. The M, M-4 and M, M-5 structures are found to produce novel chirality by electronic circular dichroism (ECD) spectrum, and the reasons for the chirality of the M, M-4 and M, M-5 structures are discussed by analyzing the density of transition electric/magnetic dipole moments (TEDM/TMDMs) in different orientations. Finally, the Raman optical activity (ROA) of M, M-4, and M, M-5 are calculated, and the spectra are plotted. This study will provide guidance for the application of carbon-based nanomaterials in organic electronic devices, solar cells, and optoelectronics.

Neuronal hyperexcitability and ion channel dysfunction in CDKL5-deficiency patient iPSC-derived cortical organoids.

Early epilepsy is a prominent feature in patients with CDKL5-deficiency disorder (CDD). The underlying mechanism for excessive excitability in CDD is largely unknown. The brain organoid model has been recently developed to resemble many critical features of early human brain development. Here, we used a brain organoid model to investigate the cellular electrophysiological basis for hyper-excitability in CDD patients. Our study employed cortical organoids derived from two CDD patients harboring the same CDKL5 mutation (R59X) and two controls from their healthy parents. Whole-cell patch-clamp recordings revealed higher action potential (AP) firing rate and lower rheobase in both CDD organoids, indicating increased intrinsic neuronal excitability. We further found dysfunction of voltage-gated ion channels in CDD neurons that leads to hyperexcitability, including higher Na+ and K+ current densities and a negative shift in Na+ channel activation. In contrast to neuronal properties, we found that glutamatergic neurotransmission and the electrophysiological properties of glial cells were not altered in CDD organoids. In support of our CDD findings, we further discovered similar electrophysiologic properties in cortical organoids derived from a Rett syndrome (RTT) patient, including alterations in AP firings and Na+ and K+ channel function suggesting a convergent mechanism. Together, our study suggests a critical role of intrinsic neuronal hyperexcitability and ion channel dysfunction, seen in early brain development in both CDD and RTT disorders. This investigation provides potential novel drug targets for developing treatments of early epilepsy in such disorders.

Later onset of Childhood Disintegrative Disorder (CDD): a case report.

Childhood Disintegrative Disorder (CDD) is a rare condition characterized by regression of developmental and behavioral functioning after a period of apparently normal development, with an age of onset around 4 years. CDD is not included within the latest edition of the Diagnostic and Statistical Manual of Mental Disorders. We present a case report of an 11-year-old male who achieved normal development for up to 7 years followed by a deterioration of previously acquired linguistic, intellectual, and social skills. Following treatment with lithium carbonate combined with risperidone, the patient experienced a reduction in irritability and aggression. CDD is a rare condition; therefore, the data presented may be useful to investigate its characteristics of the onset, to improve the understanding of the aspects of differentiation from the Autism Spectrum Disorder and finally to propose the possibility of treatment.

Early elective versus elective sigmoid resection in diverticular disease: not only timing matters-a single institutional retrospective review of 133 patients.

PURPOSE: The optimal timing of elective surgery in patients with the colonic diverticular disease remains controversial. We aimed to analyze the timing of sigmoidectomy in patients with diverticular disease and its influence on postoperative course with respect to the classification of diverticular disease (CDD). METHODS: Patients who underwent elective laparoscopic sigmoidectomy were retrospectively enrolled and subdivided into two groups based on the time interval between the last attack and surgery: group A, early elective (≤ 6 weeks), and group B, elective (> 6 weeks). Multivariate regression models were used to identify factors which predict conversion to laparotomy, postoperative course, and length of hospital stay. RESULTS: A total of 133 patients (group A (n = 88), group B (n = 45)) were included. Basic demographic data did not differ between groups except for a higher rate of diabetes in group B (p = 0.009). The conversion rate was significantly higher in group A in comparison to group B (group A vs. group B: n = 23 (26.1%) vs. n = 3 (6.7%), p = 0.007). Logistic regression analysis revealed the timing of surgery and CDD stage as significant predictors for intraoperative conversion. Moreover, the postoperative course was influenced by high age as well as intraoperative conversion and length of hospital stay by conversion, preoperative CRP levels, and elective surgery. CONCLUSIONS: Both, timing of surgery and the disease stage, influence the conversion rates in laparoscopic sigmoidectomy for diverticular disease. Accordingly, patients with complicated acute or chronic sigmoid diverticulitis should be operated in the inflammation-free interval.

Lockdown impacts on residential electricity demand in India: A data-driven and non-intrusive load monitoring study using Gaussian mixture models.

This study evaluates the effect of complete nationwide lockdown in 2020 on residential electricity demand across 13 Indian cities and the role of digitalisation using a public smart meter dataset. We undertake a data-driven approach to explore the energy impacts of work-from-home norms across five dwelling typologies. Our methodology includes climate correction, dimensionality reduction and machine learning-based clustering using Gaussian Mixture Models of daily load curves. Results show that during the lockdown, maximum daily peak demand increased by 150-200% as compared to 2018 and 2019 levels for one room-units (RM1), one bedroom-units (BR1) and two bedroom-units (BR2) which are typical for low- and middle-income families. While the upper-middle- and higher-income dwelling units (i.e., three (3BR) and more-than-three bedroom-units (M3BR)) saw night-time demand rise by almost 44% in 2020, as compared to 2018 and 2019 levels. Our results also showed that new peak demand emerged for the lockdown period for RM1, BR1 and BR2 dwelling typologies. We found that the lack of supporting socioeconomic and climatic data can restrict a comprehensive analysis of demand shocks using similar public datasets, which informed policy implications for India's digitalisation. We further emphasised improving the data quality and reliability for effective data-centric policymaking.

Assessing the impact of the COVID-19 lockdown on the energy consumption of university buildings.

Exceptional pandemic lockdown measures enabled singular experiments such as analysing the energy consumption of vacant buildings. This paper assesses the impact of the COVID-19 lockdown on the energy use of academic buildings. For this purpose, weather-adjusted energy use was compared before and during the lockdown, including different levels of lockdown restrictions. Results obtained for the 83 academic buildings of Universitat Politècnica de Catalunya - Barcelona Tech (UPC) reveal that the avoided energy consumption amounted to over 4.3 GWh during the post-pandemic year. However, the results indicate that academic buildings were still using approximately 46.9% of their typical energy consumption during strict lockdown. This revelation emphasizes the high environmental burden of buildings, regardless of whether they are occupied.

In vivo magnetic resonance spectroscopy in the brain of Cdkl5 null mice reveals a metabolic profile indicative of mitochondrial dysfunctions.

Mutations in the X-linked CDKL5 gene cause CDKL5 deficiency disorder (CDD), a severe neurodevelopmental condition mainly characterized by infantile epileptic encephalopathy, intellectual disability, and autistic features. The molecular mechanisms underlying the clinical symptoms remain largely unknown and the identification of reliable biomarkers in animal models will certainly contribute to increase our comprehension of CDD as well as to assess the efficacy of therapeutic strategies. Here, we used different Magnetic Resonance (MR) methods to disclose structural, functional, or metabolic signatures of Cdkl5 deficiency in the brain of adult mice. We found that loss of Cdkl5 does not cause cerebral atrophy but affects distinct brain areas, particularly the hippocampus. By in vivo proton-MR spectroscopy (MRS), we revealed in the Cdkl5 null brain a metabolic dysregulation indicative of mitochondrial dysfunctions. Accordingly, we unveiled a significant reduction in ATP levels and a decrease in the expression of complex IV of mitochondrial electron transport chain. Conversely, the number of mitochondria appeared preserved. Importantly, we reported a significant defect in the activation of one of the major regulators of cellular energy balance, the adenosine monophosphate-activated protein kinase (AMPK), that might contribute to the observed metabolic impairment and become an interesting therapeutic target for future preclinical trials. In conclusion, MRS revealed in the Cdkl5 null brain the presence of a metabolic dysregulation suggestive of a mitochondrial dysfunction that permitted to foster our comprehension of Cdkl5 deficiency and brought our interest towards targeting mitochondria as therapeutic strategy for CDD.

Sodium channel blockers for the treatment of epilepsy in CDKL5 deficiency disorder: Findings from a multicenter cohort.

OBJECTIVE: This study was aimed to analyze the effectiveness of sodium channel blockers (SCBs) in CDKL5 deficiency disorder (CDD)-related epilepsy. METHODS: A retrospective, observational study was performed, including patients with CDD diagnosis evaluated between 2016 and 2019 at three tertiary Epilepsy Centers. Demographic, electroclinical and genetic features, as well as ASM treatments and their outcomes were analyzed, with special focus on SCBs. RESULTS: Twenty-one patients evaluated at three tertiary Epilepsy Centers were included, of which 19 presented with epilepsy (90.5%); all had pathogenic mutations of CDKL5. Six patients (31.6%) were classified as SCB responders (more than 50% reduction), four being currently seizure free (mean seizure-free period of 8 years). Most frequent SCB drugs were oxcarbazepine (OXC), carbamazepine (CBZ), and lacosamide (LCM). None of them presented relevant adverse events. In contrast, three patients showed seizure aggravation in the non-responder group. When comparing both groups, responders had statistically significant younger age at SCB treatment and epilepsy onset, higher proportion of focal epileptiform activity and less frequent history of West syndrome. CONCLUSIONS: The results of this study indicate that treatment with SCBs might be effective and safe in a subset of patients with CDD-related epilepsy.

Intestinal Failure and Aberrant Lipid Metabolism in Patients With DGAT1 Deficiency.

BACKGROUND & AIMS: Congenital diarrheal disorders are rare inherited intestinal disorders characterized by intractable, sometimes life-threatening, diarrhea and nutrient malabsorption; some have been associated with mutations in diacylglycerol-acyltransferase 1 (DGAT1), which catalyzes formation of triacylglycerol from diacylglycerol and acyl-CoA. We investigated the mechanisms by which DGAT1 deficiency contributes to intestinal failure using patient-derived organoids. METHODS: We collected blood samples from 10 patients, from 6 unrelated pedigrees, who presented with early-onset severe diarrhea and/or vomiting, hypoalbuminemia, and/or (fatal) protein-losing enteropathy with intestinal failure; we performed next-generation sequencing analysis of DNA from 8 patients. Organoids were generated from duodenal biopsies from 3 patients and 3 healthy individuals (controls). Caco-2 cells and patient-derived dermal fibroblasts were transfected or transduced with vectors that express full-length or mutant forms of DGAT1 or full-length DGAT2. We performed CRISPR/Cas9-guided disruption of DGAT1 in control intestinal organoids. Cells and organoids were analyzed by immunoblot, immunofluorescence, flow cytometry, chromatography, quantitative real-time polymerase chain reaction, and for the activity of caspases 3 and 7. RESULTS: In the 10 patients, we identified 5 bi-allelic loss-of-function mutations in DGAT1. In patient-derived fibroblasts and organoids, the mutations reduced expression of DGAT1 protein and altered triacylglycerol metabolism, resulting in decreased lipid droplet formation after oleic acid addition. Expression of full-length DGAT2 in patient-derived fibroblasts restored formation of lipid droplets. Organoids derived from patients with DGAT1 mutations were more susceptible to lipid-induced cell death than control organoids. CONCLUSIONS: We identified a large cohort of patients with congenital diarrheal disorders with mutations in DGAT1 that reduced expression of its product; dermal fibroblasts and intestinal organoids derived from these patients had altered lipid metabolism and were susceptible to lipid-induced cell death. Expression of full-length wildtype DGAT1 or DGAT2 restored normal lipid metabolism in these cells. These findings indicate the importance of DGAT1 in fat metabolism and lipotoxicity in the intestinal epithelium. A fat-free diet might serve as the first line of therapy for patients with reduced DGAT1 expression. It is important to identify genetic variants associated with congenital diarrheal disorders for proper diagnosis and selection of treatment strategies.

Arabidopsis DET1 degrades HFR1 but stabilizes PIF1 to precisely regulate seed germination.

Seed is an essential propagation organ and a critical strategy adopted by terrestrial flowering plants to colonize the land. The ability of seeds to accurately respond to light is vital for plant survival. However, the underlying mechanism is largely unknown. In this study, we reveal a circuit of triple feed-forward loops adopted by Arabidopsis seeds to exclusively repress germination in dark conditions and precisely initiate germination under diverse light conditions. We identify that de-etiolated 1 (DET1), an evolutionarily conserved protein, is a central repressor of light-induced seed germination. Genetic analysis demonstrates that DET1 functions upstream of long hypocotyl in far-red 1 (HFR1) and phytochrome interacting factor 1 (PIF1), the key positive and negative transcription regulators in seed germination. We further find that DET1 and constitutive photomorphogenic 10 (COP10) target HFR1 for protein degradation by assembling a COP10-DET1-damaged DNA binding protein 1-cullin4 E3 ligase complex. Moreover, DET1 and COP10 directly interact with and promote the protein stability of PIF1. Computational modeling reveals that phytochrome B (phyB)-DET1-HFR1-PIF1 and phyB-DET1-Protease-PIF1 are new signaling pathways, independent of the previously identified phyB-PIF1 pathway, respectively mediating the rapid and time-lapse responses to light irradiation. The model-simulated results are highly consistent with their experimental validations, suggesting that our mathematical model captures the essence of Arabidopsis seed germination networks. Taken together, this study provides a comprehensive molecular framework for light-regulated seed germination, improving our understanding of how plants respond to changeable environments.

Integrated spatiotemporal trends using TRMM 3B42 data for the Upper São Francisco River basin, Brazil.

Trend analysis is an important issue for the decision-making processes. Thus, trends of rainfall, consecutive dry days (CDD), and consecutive wet days (CWD) in the Upper São Francisco River basin, Brazil, using daily rainfall data from the Tropical Rainfall Measuring Mission (TRMM) for recent 18 years, were analyzed. Instead of analyzing the trend of one average time series for one specific confidence level, a spatiotemporal analysis over the entire area with 169 continuous time series is done by applying the nonparametric Mann-Kendall and Sen tests for simultaneously 13 confidence levels and a new integrated confidence classification is proposed. The results show that the rainfall has increased during the less rainy periods (from June to October) and has decreased in the rainy periods (from November to May), with the highest and lowest confidence levels, respectively. An analysis of CDD and CWD shows that the number of CDD has decreased, while the number of CWD has increased, which revealed that the dry periods are more frequently interrupted for the period studied.

Multilevel cervical arthroplasty: current evidence. A systematic review.

OBJECTIVE Cervical disc arthroplasty (CDA) has been demonstrated to be an effective treatment modality for single-level cervical radiculopathy or myelopathy. Its advantages over an anterior cervical discectomy and fusion (ACDF) include motion preservation and decreased reoperations at the index and adjacent segments up to 7 years postoperatively. Considering the fact that many patients have multilevel cervical disc degeneration (CDD), the authors performed a systematic review of the clinical studies evaluating patients who underwent multilevel CDA (2 or more levels). METHODS A systematic review in the MEDLINE database was performed. Clinical studies including patients who had multilevel CDA were selected and included. Case reports and literature reviews were excluded. Articles were then grouped according to their main study objective: 1) studies comparing multilevel CDA versus ACDF; 2) studies comparing single-level CDA versus multilevel CDA; and 3) multilevel CDA after a previous cervical spine surgery. RESULTS Fourteen articles met all inclusion criteria. The general conclusions were that multilevel CDA was at least as safe and effective as ACDF, with preservation of cervical motion when compared with ACDF and potentially with fewer reoperations expected in most of the studies. Multilevel CDAs are clinically effective as single-level surgeries, with good clinical and radiological outcomes. Some studies reported a higher incidence of heterotopic ossification in multilevel CDA when compared with single-level procedures, but without clinical relevance during the follow-up period. A CDA may be indicated even after a previous cervical surgery in selected cases. CONCLUSIONS The current literature supports the use of multilevel CDA. Caution is necessary regarding the more restrictive indications for CDA when compared with ACDF. Further prospective, controlled, multicenter, and randomized studies not sponsored by the device manufactures are desirable to prove the superiority of CDA surgery over ACDF as the treatment of choice for CDD in selected cases.

Learning experiences with sunitinib continuous daily dosing in patients with pancreatic neuroendocrine tumours.

Molecular strategies to improve outcomes for patients with pancreatic neuroendocrine tumours (nets) have focused on targeting vascular endothelial growth factor, platelet-derived growth factor, and mtor (the mammalian target of rapamycin). This approach has led to the regulatory approval of two molecularly targeted agents for advanced pancreatic nets: sunitinib, a multi-targeted tyrosine kinase inhibitor, and everolimus, an mtor inhibitor. Initial experience with sunitinib in advanced pancreatic net was gained from the phase iii registration trial, which used a continuous daily dosing (cdd) schedule instead of daily drug administration for 4 consecutive weeks every 6 weeks (schedule 4/2), the approved schedule for advanced renal cell carcinoma (rcc) and gastrointestinal stromal tumour (gist). Clinical experience gained with schedule 4/2 in rcc and gist shows that, using a therapy management approach, patients can start and be maintained on the recommended dose and schedule, thus optimizing treatment outcomes. Here, we discuss challenges that can potentially be faced by physicians who use sunitinib on the cdd schedule, and we use clinical data and real-life clinical experience to present therapy management approaches that support cdd in advanced pancreatic net.