Cell type-specific expression, regulation and compensation of CDKL5 activity in mouse brain.

CDKL5 is a brain-enriched serine/threonine kinase, associated with a profound developmental and epileptic encephalopathy called CDKL5 deficiency disorder (CDD). To design targeted therapies for CDD, it is essential to determine where CDKL5 is expressed and is active in the brain and test if compensatory mechanisms exist at cellular level. We generated conditional Cdkl5 knockout mice in excitatory neurons, inhibitory neurons and astrocytes. To assess CDKL5 activity, we utilized a phosphospecific antibody for phosphorylated EB2, a well-known substrate of CDKL5. We found that CDKL5 and EB2 pS222 were prominent in excitatory and inhibitory neurons but were not detected in astrocytes. We observed that approximately 15-20% of EB2 pS222 remained in Cdkl5 knockout brains and primary neurons. Surprisingly, the remaining phosphorylation was modulated by NMDA and PP1/PP2A in neuronal CDKL5 knockout cultures, indicating the presence of a compensating kinase. Using a screen of candidate kinases with highest homology to the CDKL5 kinase domain, we found that CDKL2 and ICK can phosphorylate EB2 S222 in HEK293T cells and in primary neurons. We then generated Cdkl5/Cdkl2 dual knockout mice to directly test if CDKL2 phosphorylates EB2 in vivo and found that CDKL2 phosphorylates CDKL5 substrates in the brain. This study is the first indication that CDKL2 could potentially replace CDKL5 functions in the brain, alluding to novel therapeutic possibilities.

Phosphorylation of the novel mTOR substrate Unkempt regulates cellular morphogenesis.

Mechanistic target of rapamycin (mTOR) is a protein kinase that integrates multiple inputs to regulate anabolic cellular processes. For example, mTOR complex 1 (mTORC1) has key functions in growth control, autophagy, and metabolism. However, much less is known about the signaling components that act downstream of mTORC1 to regulate cellular morphogenesis. Here, we show that the RNA-binding protein Unkempt, a key regulator of cellular morphogenesis, is a novel substrate of mTORC1. We show that Unkempt phosphorylation is regulated by nutrient levels and growth factors via mTORC1. To analyze Unkempt phosphorylation, we immunoprecipitated Unkempt from cells in the presence or the absence of the mTORC1 inhibitor rapamycin and used mass spectrometry to identify mTORC1-dependent phosphorylated residues. This analysis showed that mTORC1-dependent phosphorylation is concentrated in a serine-rich intrinsically disordered region in the C-terminal half of Unkempt. We also found that Unkempt physically interacts with and is directly phosphorylated by mTORC1 through binding to the regulatory-associated protein of mTOR, Raptor. Furthermore, analysis in the developing brain of mice lacking TSC1 expression showed that phosphorylation of Unkempt is mTORC1 dependent in vivo. Finally, mutation analysis of key serine/threonine residues in the serine-rich region indicates that phosphorylation inhibits the ability of Unkempt to induce a bipolar morphology. Phosphorylation within this serine-rich region thus profoundly affects the ability of Unkempt to regulate cellular morphogenesis. Taken together, our findings reveal a novel molecular link between mTORC1 signaling and cellular morphogenesis.

Proteomic and cellular localisation studies suggest non-tight junction cytoplasmic and nuclear roles for occludin in astrocytes.

Occludin is a component of tight junctions, which are essential structural components of the blood-brain barrier. However, occludin is expressed in cells without tight junctions, implying additional functions. We determined the expression and localisation of occludin in astrocytes in cell culture and in human brain tissue, and sought novel binding partners using a proteomic approach. Expression was investigated by immunocytochemistry and immunoblotting in the 1321N1 astrocytoma cell line and ScienCell human primary astrocytes, and by immunohistochemistry in human autopsy brain tissue. Recombinant N- and C-terminal occludin was used to pull-down proteins from 1321N1 cell lysates and protein-binding partners identified by mass spectrometry analysis. Occludin was expressed in both the cytoplasm and nucleus of astrocytes in vitro and in vivo. Mass spectrometry identified binding to nuclear and cytoplasmic proteins, particularly those related to RNA metabolism and nuclear function. Occludin is expressed in several subcellular compartments of brain cell-types that do not form tight junctions and the expression patterns in cell culture reflect those in human brain tissue, indicating they are suitable model systems. Proteomic analysis suggests that occludin has novel functions in neuroepithelial cells that are unrelated to tight junction formation. Further research will establish the roles of these functions in both cellular physiology and in disease states.

Arginine methylation and citrullination of splicing factor proline- and glutamine-rich (SFPQ/PSF) regulates its association with mRNA.

Splicing factor proline- and glutamine-rich (SFPQ) also commonly known as polypyrimidine tract-binding protein-associated-splicing factor (PSF) and its binding partner non-POU domain-containing octamer-binding protein (NONO/p54nrb), are highly abundant, multifunctional nuclear proteins. However, the exact role of this complex is yet to be determined. Following purification of the endogeneous SFPQ/NONO complex, mass spectrometry analysis identified a wide range of interacting proteins, including those involved in RNA processing, RNA splicing, and transcriptional regulation, consistent with a multifunctional role for SFPQ/NONO. In addition, we have identified several sites of arginine methylation in SFPQ/PSF using mass spectrometry and found that several arginines in the N-terminal domain of SFPQ/PSF are asymmetrically dimethylated. Furthermore, we find that the protein arginine N-methyltransferase, PRMT1, catalyzes this methylation in vitro and that this is antagonized by citrullination of SFPQ. Arginine methylation and citrullination of SFPQ/PSF does not affect complex formation with NONO. However, arginine methylation was shown to increase the association with mRNA in mRNP complexes in mammalian cells. Finally we show that the biochemical properties of the endogenous complex from cell lysates are significantly influenced by the ionic strength during purification. At low ionic strength, the SFPQ/NONO complex forms large heterogeneous protein assemblies or aggregates, preventing the purification of the SFPQ/NONO complex. The ability of the SFPQ/NONO complex to form varying protein assemblies, in conjunction with the effect of post-translational modifications of SFPQ modulating mRNA binding, suggests key roles affecting mRNP dynamics within the cell.

Invited review: decoding the pathophysiological mechanisms that underlie RNA dysregulation in neurodegenerative disorders: a review of the current state of the art.

Altered RNA metabolism is a key pathophysiological component causing several neurodegenerative diseases. Genetic mutations causing neurodegeneration occur in coding and noncoding regions of seemingly unrelated genes whose products do not always contribute to the gene expression process. Several pathogenic mechanisms may coexist within a single neuronal cell, including RNA/protein toxic gain-of-function and/or protein loss-of-function. Genetic mutations that cause neurodegenerative disorders disrupt healthy gene expression at diverse levels, from chromatin remodelling, transcription, splicing, through to axonal transport and repeat-associated non-ATG (RAN) translation. We address neurodegeneration in repeat expansion disorders [Huntington's disease, spinocerebellar ataxias, C9ORF72-related amyotrophic lateral sclerosis (ALS)] and in diseases caused by deletions or point mutations (spinal muscular atrophy, most subtypes of familial ALS). Some neurodegenerative disorders exhibit broad dysregulation of gene expression with the synthesis of hundreds to thousands of abnormal messenger RNA (mRNA) molecules. However, the number and identity of aberrant mRNAs that are translated into proteins - and how these lead to neurodegeneration - remain unknown. The field of RNA biology research faces the challenge of identifying pathophysiological events of dysregulated gene expression. In conclusion, we discuss current research limitations and future directions to improve our characterization of pathological mechanisms that trigger disease onset and progression.

Validity and reliability of the Italian version of the short Parkinson's evaluation scale (SPES/SCOPA).

Background: In the medical and rehabilitative field, it is essential to employ tools such as evaluation scales and performance tests to assess the impact of Parkinson's disease on QoL of affected individuals. The Short Parkinson's Evaluation Scale (SPES) is a reliable and valid tool, applicable both in research and clinical practices, useful in assessing motor damage, activities of daily living, and motor complications in patients with Parkinson's disease. The aim of the study is to investigate validity and reliability of the Italian version of the SPES-SCOPA scale. Methods: Translation and cultural adaptation were performed. Included patients had diagnosis of Parkinson's disease, no concurrent pathologies, MiniMental test score above 2 and signed informed consent; they were recruited at the Department of Human Neurosciences in Sapienza University of Rome, from February 2023 to November 2023. Test-retest reliability was evaluated through Intraclass Correlation Coefficient (ICC), internal consistency was assessed using Cronbach's Alpha and construct validity using Pearson's correlation between SPES-SCOPA and the gold standard PDQ-39. Results: 101 patients were recruited. Inter-rater evaluation was conducted on 62 patients, while 39 underwent an intra-rater assessment. The analysis showed statistically significant data with a Cronbach's Alpha value of 0.89 for the entire scale; test-retest reliability results are statistically significant for all subscales. Correlation between PDQ-39 domains and SPES/SCOPA subscales were statistically significant for most measurements. Conclusion: This research shows that the Italian version of SPES-SCOPA scale has excellent psychometric properties.

Occupational Therapy Task Observation Scale (OTTOS) and Comprehensive Occupational Therapy Evaluation Scale (CO-TES): Italian translation, adaptation, and validation.

Background: In literature there is a lack of specific evaluation tools for behavior in intellectual disabilities in general and during an activity, this is one of the most important field of the Occupational Therapy intervention. Objective: Authors developed an Italian version of the Occupational Therapy Task Observation Scale (OTTOS) and an Italian version of the Comprehensive Occupational Therapy Evaluation Scale (COTES) and examined their reliability and validity. Methods: The original scales were translated from English to Italian using the "Translation and Cultural Adaptation of Patient Reported Outcomes Measures-Principles of Good Practice" guidelines. Both scales were administered to adults with mild and moderate intellectual disabilities. People under eighteen years, with severe and profound intellectual disabilities and deaf people were excluded from the study. Their reliability and validity have been examined. Relia-bility was analyzed via internal consistency (Cronbach's alpha) and stability (intra/inter-rater coefficient), while validity was investigated via construct validity (p-value) and criterion validity using Pearson's correlation coefficients between them and with the Mini Mental State Examination and the Barthel Index Scale. Results: The OTTOS and the COTES were administered to 30 subjects. Cronbach's α for the COTES was 0,91 and Cronbach's α for the OTTOS was 0,92. Regarding the criterion of validity, the two scales have numerous statistically positive correlations, particularly with the Mini Mental State Examination in the Orientation and total part. Furthermore, the correlation with the Barthel scale is present in the total scores, the COTES's third subscale, and the OTTOS's first. Conclusions: The OTTOS and the COTES were reliable and valid outcome measures for assessing behavior in the Italian population.

Mutations in the postsynaptic density signaling hub TNIK disrupt PSD signaling in human models of neurodevelopmental disorders.

A large number of synaptic proteins have been recurrently associated with complex brain disorders. One of these proteins, the Traf and Nck interacting kinase (TNIK), is a postsynaptic density (PSD) signaling hub, with many variants reported in neurodevelopmental disorder (NDD) and psychiatric disease. While rodent models of TNIK dysfunction have abnormal spontaneous synaptic activity and cognitive impairment, the role of mutations found in patients with TNIK protein deficiency and TNIK protein kinase activity during early stages of neuronal and synapse development has not been characterized. Here, using hiPSC-derived excitatory neurons, we show that TNIK mutations dysregulate neuronal activity in human immature synapses. Moreover, the lack of TNIK protein kinase activity impairs MAPK signaling and protein phosphorylation in structural components of the PSD. We show that the TNIK interactome is enriched in NDD risk factors and TNIK lack of function disrupts signaling networks and protein interactors associated with NDD that only partially overlap to mature mouse synapses, suggesting a differential role of TNIK in immature synapsis in NDD.

Loss of NDR1/2 kinases impairs endomembrane trafficking and autophagy leading to neurodegeneration.

Autophagy is essential for neuronal development and its deregulation contributes to neurodegenerative diseases. NDR1 and NDR2 are highly conserved kinases, implicated in neuronal development, mitochondrial health and autophagy, but how they affect mammalian brain development in vivo is not known. Using single and double Ndr1/2 knockout mouse models, we show that only dual loss of Ndr1/2 in neurons causes neurodegeneration. This phenotype was present when NDR kinases were deleted both during embryonic development, as well as in adult mice. Proteomic and phosphoproteomic comparisons between Ndr1/2 knockout and control brains revealed novel kinase substrates and indicated that endocytosis is significantly affected in the absence of NDR1/2. We validated the endocytic protein Raph1/Lpd1, as a novel NDR1/2 substrate, and showed that both NDR1/2 and Raph1 are critical for endocytosis and membrane recycling. In NDR1/2 knockout brains, we observed prominent accumulation of transferrin receptor, p62 and ubiquitinated proteins, indicative of a major impairment of protein homeostasis. Furthermore, the levels of LC3-positive autophagosomes were reduced in knockout neurons, implying that reduced autophagy efficiency mediates p62 accumulation and neurotoxicity. Mechanistically, pronounced mislocalisation of the transmembrane autophagy protein ATG9A at the neuronal periphery, impaired axonal ATG9A trafficking and increased ATG9A surface levels further confirm defects in membrane trafficking, and could underlie the impairment in autophagy. We provide novel insight into the roles of NDR1/2 kinases in maintaining neuronal health.

Epilepsy-linked kinase CDKL5 phosphorylates voltage-gated calcium channel Cav2.3, altering inactivation kinetics and neuronal excitability.

Developmental and epileptic encephalopathies (DEEs) are a group of rare childhood disorders characterized by severe epilepsy and cognitive deficits. Numerous DEE genes have been discovered thanks to advances in genomic diagnosis, yet putative molecular links between these disorders are unknown. CDKL5 deficiency disorder (CDD, DEE2), one of the most common genetic epilepsies, is caused by loss-of-function mutations in the brain-enriched kinase CDKL5. To elucidate CDKL5 function, we looked for CDKL5 substrates using a SILAC-based phosphoproteomic screen. We identified the voltage-gated Ca2+ channel Cav2.3 (encoded by CACNA1E) as a physiological target of CDKL5 in mice and humans. Recombinant channel electrophysiology and interdisciplinary characterization of Cav2.3 phosphomutant mice revealed that loss of Cav2.3 phosphorylation leads to channel gain-of-function via slower inactivation and enhanced cholinergic stimulation, resulting in increased neuronal excitability. Our results thus show that CDD is partly a channelopathy. The properties of unphosphorylated Cav2.3 closely resemble those described for CACNA1E gain-of-function mutations causing DEE69, a disorder sharing clinical features with CDD. We show that these two single-gene diseases are mechanistically related and could be ameliorated with Cav2.3 inhibitors.

The master energy homeostasis regulator PGC-1α exhibits an mRNA nuclear export function.

PGC-1α plays a central role in maintaining mitochondrial and energy metabolism homeostasis, linking external stimuli to transcriptional co-activation of genes involved in adaptive and age-related pathways. The carboxyl-terminus encodes a serine/arginine-rich (RS) region and an RNA recognition motif, however the RNA-processing function(s) were poorly investigated over the past 20 years. Here, we show that the RS domain of human PGC-1α directly interacts with RNA and the nuclear RNA export receptor NXF1. Inducible depletion of PGC-1α and expression of RNAi-resistant RS-deleted PGC-1α further demonstrate that its RNA/NXF1-binding activity is required for the nuclear export of some canonical mitochondrial-related mRNAs and mitochondrial homeostasis. Genome-wide investigations reveal that the nuclear export function is not strictly linked to promoter-binding, identifying in turn novel regulatory targets of PGC-1α in non-homologous end-joining and nucleocytoplasmic transport. These findings provide new directions to further elucidate the roles of PGC-1α in gene expression, metabolic disorders, aging and neurodegeneration.

The zinc finger/RING domain protein Unkempt regulates cognitive flexibility.

Correct orchestration of nervous system development is a profound challenge that involves coordination of complex molecular and cellular processes. Mechanistic target of rapamycin (mTOR) signaling is a key regulator of nervous system development and synaptic function. The mTOR kinase is a hub for sensing inputs including growth factor signaling, nutrients and energy levels. Activation of mTOR signaling causes diseases with severe neurological manifestations, such as tuberous sclerosis complex and focal cortical dysplasia. However, the molecular mechanisms by which mTOR signaling regulates nervous system development and function are poorly understood. Unkempt is a conserved zinc finger/RING domain protein that regulates neurogenesis downstream of mTOR signaling in Drosophila. Unkempt also directly interacts with the mTOR complex I component Raptor. Here we describe the generation and characterisation of mice with a conditional knockout of Unkempt (UnkcKO) in the nervous system. Loss of Unkempt reduces Raptor protein levels in the embryonic nervous system but does not affect downstream mTORC1 targets. We also show that nervous system development occurs normally in UnkcKO mice. However, we find that Unkempt is expressed in the adult cerebellum and hippocampus and behavioural analyses show that UnkcKO mice have improved memory formation and cognitive flexibility to re-learn. Further understanding of the role of Unkempt in the nervous system will provide novel mechanistic insight into the role of mTOR signaling in learning and memory.

Pattern of acute myocardial infarction in an African country.

OBJECTIVE: The objective of this study was to describe the pattern of acute myocardial infarction in an African country. These data are important for prevention strategies but are scarce from sub-Saharan African countries and altogether absent from Kenya. METHODS AND RESULTS: This was a retrospective study done at Kenyatta National Hospital, Kenya. Cases of acute myocardial infarction admitted to the hospital between January 2000 and December 2009 were examined for mode of diagnosis, age, gender, risk factors, and outcome. Only those with confirmed diagnosis were included. Results were analysed by SPSS version 13.0 for Windows, and are presented in tables and bar charts. One hundred twenty cases (80 men; 40 women) were analysed. Clinical diagnosis had been confirmed by electrocardiography and cardiac enzymes (87.5%), angiography (8.3%) and echocardiography (4.2%). Mean age was 56.8 years and male:female ratio 2:1. Common risk factors were hypertension (35%), diabetes mellitus (20.8%), smoking and infection 12.5% each and alcohol (10.8%). The majority (50.8%) of the patients recovered, 44.2% developed congestive cardiac failure and only 5% died. CONCLUSION: Acute myocardial infarction is not uncommon in Kenya. Over 30% of the patients are 50 years and younger and it carries a high morbidity from heart failure. Risk factors comprise a combination of non-communicable diseases, namely hypertension and diabetes mellitus, coexisting with infections. Control measures targeting both categories are recommended.

Intracranial aneurysms in an African country.

BACKGROUND: Characteristics of intracranial aneurysms display ethnic variations. Data on this disease from the African continent is scarce and often conflicting. AIM: To describe site, age and gender distribution of intracranial aneurysms among Kenyans. STUDY DESIGN AND SETTING: Retrospective study at Kenyatta National Hospital, Kenya. MATERIALS AND METHODS: All records of black African patients with a diagnosis of intracranial aneurysms seen at Kenyatta National Hospital, the largest referral hospital in the Eastern and Central African region, over the period from January 1998 to December 2007 were examined for site, age and gender distribution. The data gathered were coded, analyzed with SPSS 11.50. RESULTS: Fifty-six cases of intracranial aneurysms were analyzed. The posterior communicating artery was the most affected (35.7%), followed by the anterior communicating artery (26.8%), while the posterior cerebral artery was the least affected (2%). Multiple aneurysms were present in 2%. The mean age at presentation was 50.9 years (range 21-80 years) and the gender distribution was equal. CONCLUSIONS: Intracranial aneurysms among Kenyans occur most commonly on the posterior communicating artery, in young individuals, and without gender bias. The distribution differs from that described in the literature and this requires search for risk factors.

[The female sex is an independent prognostic factor for mortality in the acute phase of myocardial infarction]. / El sexo femenino es un factor pronóstico independiente de mortalidad en la fase aguda del infarto de miocardio.

BACKGROUND: To assess the effect of female gender on mortality after acute myocardial infarction (AMI), we studied a cohort of 876 consecutive patients, being women 253 of them (28.8%), admitted to the intensive Care Unit (ICU) because of a first AMI, from September 1992 to October 1995. PATIENTS AND METHODS: We compared the clinical characteristics, the complications and the treatment in both sexes. We estimated the relative risk using logistic regression, being the sex, the independent variable and dependent variables age, history of hypertension and diabetes, AMI location and thrombolytic treatment. RESULTS: The age was higher and the history of hypertension and diabetes more frequent. The AMI location was less often inferior. Women received fibrinolytic treatment less frequently in women than in men. The mortality in the ICU was higher in the women (29.2 vs. 13.5% in the men) and, after adjusting for the previous factors the relative risk was 1.51 (95% confidence internal of 1.01-2.26). CONCLUSIONS: In the population studied, the female gender is an independent risk factor for early mortality in the AMI.

Imaging yeast NPCs: from classical electron microscopy to Immuno-SEM.

Electron microscopy (EM) has been used extensively for the study of nuclear transport as well as the structure of the nuclear pore complex (NPC) and nuclear envelope. However, there are specific challenges faced when carrying out EM in one of the main model organisms used: the yeast, Saccharomyces cerevisiae. These are due to the presence of a cell wall, vacuoles, and a densely packed cytoplasm which, for transmission EM (TEM), make fixation, embedding, and imaging difficult. These also present problems for scanning EM (SEM) because cell wall removal and isolation of nuclei can easily damage the relatively fragile NPCs. We present some of the protocols we use to prepare samples for TEM and SEM to provide information about yeast NPC ultrastructure and the location of nucleoporins and transport factors by immunogold labeling within that ultrastructure.

Geometric features of vertebrobasilar arterial system in adult black Kenyans / Características geométricas del sistema arterial vertebrobasilar en kenianos negros adultos

Geometric features of vertebrobasilar system influence occurrence of posterior circulation atherosclerosis, aneurysms, stroke and neuroradiological procedures. These features show ethnic variation, but data from black Africans in Sub Saharan Africa are scarce. This study aimed to describe geometric features of vertebrobasilar system in a black Kenyan population. It was a descriptive cadaveric study at Department of Human Anatomy, University of Nairobi. One hundred and seventy three formalin-fixed adult brains of individuals (99 male; 74 female; Age range 20 - 79) who had died of non cerebrovascular causes were studied. Level and angle of confluence of vertebral artery; diameter, length and bifurcation angles of basilar artery were measured. Data were analysed by SPSS version 21 for windows. The student t - test was used to determine the sex differences at 95 % confidence interval. Data are presented in macrographs, tables and bar charts. Confluence of vertebral arteries occurred at the sulcus bulbopontinus in 79.8 %; rostral to it in 11.5 % and caudal to it in 8.7 % of cases. Mean angle of vertebral artery confluence was 46.7º and 68.9º in males and females respectively (p£0.042). Mean length of the basilar artery was 26.8 mm; 26.3 mm in males and 27.1 mm in females (p=0.465). Mean diameter was 3.52 mm; 3.32 mm in males and 3.72 mm in females (p=0.002). The mean angle of basilar artery bifurcation was 120.3º ± 15.2; 99.3º ± 32.9 in males and 140.3º ± 16.1 in females (p=0.024). It was wider than 90º in 82.9 % of males and 95.9 % females (p=0.032). In 85 (49.1 %) it was wider than 120º. The vertebrobasilar system in the Kenyan population has geometric features that constitute risk factors for atherosclerosis. These features display sex dimorphism which may explain differences in prevalence of atherosclerosis and aneurysms. Neurosurgeons and neurologists should be aware of these differences. Individuals with risk prone geometric features should be followed up for atherosclerosis.

Las características geométricas del sistema vertebrobasilar influyen en la aparición de aterosclerosis en la circulación posterior, aneurismas, apoplejía, detectados durante procedimientos neurorradiológicos. Estas características muestran variación étnica, pero los datos de los africanos negros en el África Subsahariana son escasos. Este estudio tuvo como objetivo describir las características geométricas del sistema vertebrobasilar en una población negra de Kenia. Fue un estudio descriptivo cadavérico en el Departamento de Anatomía Humana de la Universidad de Nairobi. Se estudiaron 173 cerebros adultos (99 varones, 74 mujeres, rango de edad 20-79), fijados en formalina, de individuos que habían fallecido por causas no cerebrovasculares. Se midieron el nivel y ángulo de confluencia de la arteria vertebral, diámetro, longitud y bifurcación de la arteria basilar. Los datos fueron analizados por SPSS versión 21 para Windows. La prueba t de Student se utilizó para determinar las diferencias de sexo con un intervalo de confianza del 95 %. Los datos se presentan en macrografías, tablas y gráficos de barras. La confluencia de las arterias vertebrales se produjo en el surco bulbopontino en el 79,8 %; rostral al surco en 11,5 % y caudal al surco en 8,7 % de los casos. El ángulo medio de la confluencia de la arteria vertebral fue 46,70 y 68,90 en hombres y mujeres, respectivamente (p£0,042). La longitud media de la arteria basilar fue de 26,8 mm; 26,3 mm en hombres y 27,1 mm en mujeres (p=0,465). El diámetro promedio fue de 3,52 mm; 3,32 mm en hombres y 3,72 mm en mujeres (p=0,002). El ángulo medio de la bifurcación de la arteria basilar fue de 120,30 ± 15,2; 99.30 ± 32,9 en hombres y 140,30 ± 16,1en mujeres (p=0,024). Era más amplio que 90º. En un 82,9 % de los hombres y 95,9 % de las mujeres (p=0,032) se observó un ángulo más amplio que 90°. En 85 (49,1 %) fue más amplio que 120°. El sistema vertebrobasilar en la población de Kenia tiene características geométricas que constituyen factores de riesgo para la aterosclerosis. Estas características muestran dimorfismo sexual que puede explicar las diferencias en la prevalencia de aterosclerosis y aneurismas. Los neurocirujanos y los neurólogos deben tener en cuenta estas diferencias. Las personas con características geométricas propensas al riesgo deben ser seguidas por aterosclerosis.

Variations in branching of the posterior cord of brachial plexus in a Kenyan population.

BACKGROUND: Variations in the branching of posterior cord are important during surgical approaches to the axilla and upper arm, administration of anesthetic blocks, interpreting effects of nervous compressions and in repair of plexus injuries. The patterns of branching show population differences. Data from the African population is scarce. OBJECTIVE: To describe the branching pattern of the posterior cord in a Kenyan population. MATERIALS AND METHODS: Seventy-five brachial plexuses from 68 formalin fixed cadavers were explored by gross dissection. Origin and order of branching of the posterior cord was recorded. Representative photographs were then taken using a digital camera (Sony Cybershot R, W200, 7.2 Megapixels). RESULTS: Only 8 out of 75 (10.7%) posterior cords showed the classical branching pattern. Forty three (57.3%) lower subscapular, 8(10.3%) thoracodorsal and 8(10.3%) upper subscapular nerves came from the axillary nerve instead of directly from posterior cord. A new finding was that in 4(5.3%) and in 3(4%) the medial cutaneous nerves of the arm and forearm respectively originated from the posterior cord in contrast to their usual origin from the medial cord. CONCLUSIONS: Majority of posterior cords in studied population display a wide range of variations. Anesthesiologists administering local anesthetic blocks, clinicians interpreting effects of nerve injuries of the upper limb and surgeons operating in the axilla should be aware of these patterns to avoid inadvertent injury. A wider study of the branching pattern of infraclavicular brachial plexus is recommended.

Coblation turbinate reduction in childhood allergic rhinitis.

INTRODUCTION: Nasal obstruction is the allergic rhinitis symptom least amenable to medical treatment, and inferior turbinectomy may be required. Coblation is a minimally invasive technique that is effective in obstruction secondary to inferior turbinate hypertrophy. The present study assessed efficacy in children presenting with obstructive allergic rhinitis after failure of medical management. PATIENT AND METHODS: This prospective study included nine children with allergic rhinitis. Coblation was performed after assessment of rhinitis. Obstruction was assessed on rhinomanometry and a visual analog scale; other rhinologic functional signs were assessed on interview, and functional impact was assessed on the PRQLQ quality of life questionnaire. RESULTS: After the procedure, all nine children showed reduced nasal obstruction and improved rhinologic function signs, confirmed by the favorable evolution of PRQLQ scores. CONCLUSIONS: The study demonstrated the interest of coblation in controlling nasal obstruction in children with allergic rhinitis refractory to medical treatment, with conserved nasal function. Larger-scale studies with longer follow-up will be needed to confirm these results.