Cerebellar mutism syndrome: the importance of preoperative language assessment

Children undergoing surgical removal of tumors in the posterior cranial fossa can encounter a varied and complex constellation of neurological symptoms, called cerebellar mutism, defined as a disturbance in the planning and programming of motor language with preserved understanding, behavioral disorders such as inattention, visual-spatial disorganization, personality change, as well as ataxia and dysmetria. In the last years, several groups have been trying to establish risk factors or even predictive scores in order to be able at least in part to predict the appearance of speech disorders before surgery. We report on a child with pilocytic astrocytoma of the cerebellar vermis who had already been diagnosed with developmental linguistic delay two years earlier. This disorder initially worsened after surgery and later improved in the following 12 months. The aim of this paper is to emphasize the importance of preoperative neuropsychological evaluation. The present case, along with those reported in the literature, suggests that the risk of long-term cerebellar mutism is higher in children with preoperative speech disorders. In these patients a thorough assessment of cognitive and linguistic functions is therefore necessary to better evaluate the risk of cerebellar mutism after surgery.

Degenerative cervical myelopathy: Neuroradiological, neurophysiological and clinical correlations in 27 consecutive cases

•

New insight into prognostic factors for recovery of clinical function following posterior decompression for degenerative cervical myelopathy.

•

An increase of IOM amplitude of at least 50% coupled with preoperative T2-only and diffuse T2 signal changes on MRI is a positive prognostic factors for clinical improvement 6 months after surgery.

•

Clinical improvement at 6 months follow-up can be expected in patients with T1 hypo intensity if a diffuse border of the lesion on T2 images is present.

Intramedullary spinal cord metastasis from an adenoid cystic carcinoma of the external auditory canal: case report

BACKGROUND AND IMPORTANCE

Intramedullary spinal cord metastases (ISCMs) are rare and no cases of ISCM from an adenoid cystic carcinoma (ACC) of the external auditory canal (EAC) have been reported.

CLINICAL PRESENTATION

We report a 54-year old man complaining backpain and worsening myelopathy. He had an ACC of the EAC resected years prior. A spinal MRI demonstrated a contrast-enhancing intramedullary lesion within the conus medullaris. The histopathological diagnosis of the patient was consistent with the patient's primary cancer. At 3 months follow-up, the neurological condition of the patient was unchanged.

CONCLUSIONS

This is the first reported case of ISCM from a primary ACC of the EAC.

A snapshot of European neurosurgery December 2019 vs. March 2020: just before and during the Covid-19 pandemic

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or Covid-19), which began as an epidemic in China and spread globally as a pandemic, has necessitated resource management to meet emergency needs of Covid-19 patients and other emergent cases. We have conducted a survey to analyze caseload and measures to adapt indications for a perception of crisis.

Methods

We constructed a questionnaire to survey a snapshot of neurosurgical activity, resources, and indications during 1 week with usual activity in December 2019 and 1 week during SARS-CoV-2 pandemic in March 2020. The questionnaire was sent to 34 neurosurgical departments in Europe; 25 departments returned responses within 5 days.

Results

We found unexpectedly large differences in resources and indications already before the pandemic. Differences were also large in how much practice and resources changed during the pandemic. Neurosurgical beds and neuro-intensive care beds were significantly decreased from December 2019 to March 2020. The utilization of resources decreased via less demand for care of brain injuries and subarachnoid hemorrhage, postponing surgery and changed surgical indications as a method of rationing resources. Twenty departments (80%) reduced activity extensively, and the same proportion stated that they were no longer able to provide care according to legitimate medical needs.

Conclusion

Neurosurgical centers responded swiftly and effectively to a sudden decrease of neurosurgical capacity due to relocation of resources to pandemic care. The pandemic led to rationing of neurosurgical care in 80% of responding centers. We saw a relation between resources before the pandemic and ability to uphold neurosurgical services. The observation of extensive differences of available beds provided an opportunity to show how resources that had been restricted already under normal conditions translated to rationing of care that may not be acceptable to the public of seemingly affluent European countries.

Electronic supplementary material

The online version of this article (10.1007/s00701-020-04482-8) contains supplementary material, which is available to authorized users.

Combined circular external fixation and flexible intramedullary nailing for pediatric bilateral open tibia fractures in blast injury

Management of blast injuries with open fractures and extensive soft tissue damage in pediatric patients is a challenging task even in experienced hands. This article reports the case of an 8-year-old boy with bilateral open tibia fractures and soft tissue loss due to the accidental explosion of a skyrocket. After the emergency procedures with lavage, debridement and temporary bone stabilization, we performed the definitive reconstruction surgery using a combined circular external fixation and flexible intramedullary nailing technique on both legs. This technique allowed easy access to the wounds for plastic surgery procedures and early bilateral weight bearing. All implants were removed within 6 months, the fractures healed with good axial alignment and the patient returned to his preinjury activities one year after the trauma. In this case, the combined use of circular external fixation and flexible intramedullary nailing ensured optimal fractures stabilization, minimizing the damage to the soft tissues and the obstruction for plastic surgeons. We believe that this technique should be considered in pediatric patients with open fractures of the lower limbs and extensive soft tissue injuries.

Biomarkers in Psychiatry: Concept, Definition, Types and Relevance to the Clinical Reality

During the last years, an extraordinary effort has been made to identify biomarkers as potential tools for improving prevention, diagnosis, drug response and drug development in psychiatric disorders. Contrary to other diseases, mental illnesses are classified by diagnostic categories with a broad variety list of symptoms. Consequently, patients diagnosed from the same psychiatric illness present a great heterogeneity in their clinical presentation. This fact together with the incomplete knowledge of the neurochemical alterations underlying mental disorders, contribute to the limited efficacy of current pharmacological options. In this respect, the identification of biomarkers in psychiatry is becoming essential to facilitate diagnosis through the developing of markers that allow to stratify groups within the syndrome, which in turn may lead to more focused treatment options. In order to shed light on this issue, this review summarizes the concept and types of biomarkers including an operational definition for therapeutic development. Besides, the advances in this field were summarized and sorted into five categories, which include genetics, transcriptomics, proteomics, metabolomics, and epigenetics. While promising results were achieved, there is a lack of biomarker investigations especially related to treatment response to psychiatric conditions. This review includes a final conclusion remarking the future challenges required to reach the goal of developing valid, reliable and broadly-usable biomarkers for psychiatric disorders and their treatment. The identification of factors predicting treatment response will reduce trial-and-error switches of medications facilitating the discovery of new effective treatments, being a crucial step towards the establishment of greater personalized medicine.

1-(2',5'-Dihydroxyphenyl)-3-(2-fluoro-4-hydroxyphenyl)-1-propanone (RGM079): A Positive Allosteric Modulator of α7 Nicotinic Receptors with Analgesic and Neuroprotective Activity

Acetylcholine α7 nicotinic receptors are widely expressed in the brain, where they are involved in the central processing of pain as well as in neuropsychiatric, neurodegenerative, and inflammatory processes. Positive allosteric modulators (PAMs) show the advantage of allowing the selective regulation of different subtypes of acetylcholine receptors without directly interacting with the agonist binding site. Here, we report the preparation and biological activity of a fluoro-containing compound, 1-(2',5'-dihydroxyphenyl)-3-(2-fluoro-4-hydroxyphenyl)-1-propanone (8, RGM079), that behaves as a potent PAM of the α7 receptors and has a balanced pharmacokinetic profile and antioxidant properties comparable or even higher than well-known natural polyphenols. In addition, compound RGM079 shows neuroprotective properties in Alzheimer's disease (AD)-toxicity related models. Thus, it causes a concentration-dependent neuroprotective effect against the toxicity induced by okadaic acid (OA) in the human neuroblastoma cell line SH-SY5Y. Similarly, in primary cultures of rat cortical neurons, RGM079 is able to restore the cellular viability after exposure to OA and amyloid peptide Aβ_1-42, with cell death almost completely prevented at 10 and 30 μM, respectively. Finally, compound RGM079 shows in vivo analgesic activity in the complete Freund's adjuvant (CFA)-induced paw inflammation model after intraperitoneal administration.

Combined Selection System to Lower the Cutoff for Plasma Cell Enrichment Applied to iFISH Analysis in Multiple Myeloma

Multiple myeloma (MM) is a very heterogeneous disease, characterized by multiple cytogenetic aberrations on plasma cells (PC) that have been traditionally used to predict the outcome of the disease. A mayor issue on the analysis of PC is the sometimes low infiltration of these cells in the bone marrow that hampers cytogenetic studies. To solve this problem we have optimized a selection strategy based on PC immunomagnetic isolation that has allowed us to lower to 1% the minimal PC infiltration requirement without loss of purity, enabling to perform genetic analysis. In this study, we have analyzed 153 bone marrow samples of patients suspected of MM, collected from February 2015 to May 2017 by the Genetics service of the Complejo Hospitalario de Navarra. Clinical characteristics of the patients and PC immunophenotyping, conventional cytogenetics and interphase fluorescence in situ hybridization (iFISH) analyses have been assessed on these samples. In our cohort 90% of the samples had cytogenetic abnormalities, among them 50% presented immunoglobulin rearrangements, 41.9% showed 1q gains, 29.7% showed 1p deletions and 33% presented TP53 deletion.

Bbr 2778, an Aza-anthracenedione Endowed with Preclinical Anticancer Activity and Lack of Delayed Cardiotoxicity

With the aim to provide second-generation anthracenedione analogues endowed with reduced side effects and a wider spectrum of action than mitoxantrone and doxorubicin, a large number of new molecules bearing nitrogen atoms in the chromophore was synthesized and screened in vitro and in vivo. From this screening, BBR 2778 (6,9-bis[(2-aminoethyl)amino] benzo[g]isoquinoline-5,10-dione dimaleate) emerged as the most interesting compound. BBR 2778 was tested in vitro on several murine and human tumor cell lines and showed cytotoxic potency lower than that of mitoxantrone and doxorubicin. BBR 2778 was more cytotoxic in leukemia and lymphoma cell lines than in solid tumor cell lines. Although against in vivo models BBR 2778 was less potent than mitoxantrone and doxorubicin, its antitumor activity was equal or superior (in certain tumor models) to that of the above standard compounds. In particular, BBR 2778 was curative against L1210 murine leukemia and YC-8 murine lymphoma. Moreover, it showed an antitumor activity comparable to that of mitoxantrone and doxorubicin on solid tumors. No cardiotoxic effect of BBR 2778 in animals not pretreated with anthracyclines was observed compared to standards. In light of its spectrum of activity and marked efficacy against lymphomas and leukemias over a wide dose range, together with its lack of delayed cardiotoxicity, BBR 2778 has been entered in clinical studies.

N-Benzylpiperidine Derivatives as α7 Nicotinic Receptor Antagonists

A series of multitarget directed propargylamines, as well as other differently susbstituted piperidines have been screened as potential modulators of neuronal nicotinic acetylcholine receptors (nAChRs). Most of them showed antagonist actions on α7 nAChRs. Especially, compounds 13, 26, and 38 displayed submicromolar IC50 values on homomeric α7 nAChRs, whereas they were less effective on heteromeric α3β4 and α4β2 nAChRs (up to 20-fold higher IC50 values in the case of 13). Antagonism was concentration dependent and noncompetitive, suggesting that these compounds behave as negative allosteric modulators of nAChRs. Upon the study of a series of less complex derivatives, the N-benzylpiperidine motif, common to these compounds, was found to be the main pharmacophoric group. Thus, 2-(1-benzylpiperidin-4-yl)-ethylamine (48) showed an inhibitory potency comparable to the one of the previous compounds and also a clear preference for α7 nAChRs. In a neuroblastoma cell line, representative compounds 13 and 48 also inhibited, in a concentration-dependent manner, cytosolic Ca(2+) signals mediated by nAChRs. Finally, compounds 38 and 13 inhibited 5-HT3A serotonin receptors whereas they had no effect on α1 glycine receptors. Given the multifactorial nature of many pathologies in which nAChRs are involved, these piperidine antagonists could have a therapeutic potential in cases where cholinergic activity has to be negatively modulated.

Evaluation of Levothyroxine Bioavailability after Oral Administration of a Fixed Combination of Soy Isoflavones in Post-menopausal Female Volunteers

BACKGROUND

Post-menopausal women under treatment with levothyroxine for their medical conditions may take concomitantly dietary supplements containing soy isoflavones in combination to treat their post-menopausal symptoms. The aim of this study was to investigate the effect of a fixed combination of soy isoflavones on the oral bioavailability of levothyroxine in post-menopausal female volunteers.

METHODS

12 healthy post-menopausal female, who were on stable oral levothyroxine as replacement/supplementation therapy for hypothyroidism, received a single recommended oral dose of a food supplement containing 60 mg of soy isoflavones (>19% genistin and daidzin) concomitantly with (test) and 6 h later (reference) the administration of levothyroxine in a randomized, open label, crossover fashion. Plasma concentrations of levothyroxine and soy isoflavones (daidzin, daidzein, genistin, genistein, S-equol) were determined by LC-MS/MS. Pharmacokinetic (PK) parameters were determined by non-compartmental analysis. No effect of soy isoflavones was assumed if the 90% confidence intervals (CIs) for the estimated ratio test/reference was included in the acceptance limits 0.80-1.25 for PK parameters Cmax and AUCt.

RESULTS

The test/reference ratios Cmax and AUCt of levothyroxine were very close to unity (1.02 and 0.99, respectively) and the corresponding 90% CIs (0.99-1.04 and 0.88-1.12, respectively) fell entirely within the acceptance bioequivalence limits.

CONCLUSION

The combination of soy isoflavones used in the present investigation does not affect the rate and extent of levothyroxine absorption when administered concomitantly in post-menopausal women.

Intraoperative neurophysiological monitoring for the resection of brain tumors in pediatric patients

Intraoperative neurophysiology (ION) is the gold standard to map and monitor brain functions during supratentorial surgery in critical areas. This is of great value for the surgery of brain gliomas in adults, but the same ION techniques can be used in the pediatric population with respect to both epilepsy and brain tumor surgery. While the principles of most ION techniques are the same for adults and children, the developing nervous system has peculiar characteristics in terms of anatomical and physiological maturation of afferent and efferent pathways within the brain and the spinal cord. Accordingly, some adjustments, particularly with regards to stimulation parameters, are needed in younger children. This paper will review current ION techniques to assist during the resection of brain tumors in children, focusing on the aspects peculiar to mapping and monitoring of sensori-motor functions in the pediatric population. On the other hand, awake surgery, of common use in adult patients when aiming to identify cortical and subcortical cognitive functions, is of very limited use in children and will not be discussed here.

The Italian validation of the Anosognosia Questionnaire for Dementia in Alzheimer's disease

Although the Anosognosia Questionnaire-Dementia (AQ-D) is one of the main instruments for assessing awareness in Alzheimer's disease (AD), the normative data were until now limited to people from Argentina and Japan. This study aims to validate this instrument in an European context, in particular in an Italian sample. In a multicenter project (Verona, Padova, and Trapani), 130 patients with AD and their caregivers participated in the study. Psychometric characteristics of AQ-D are confirmed indicating that the scale permits the early identification of anosognosia and the correct care management of patients. Indeed, anosognosia results to be present also in patients with very mild AD (moderate: 44.44%; mild: 47.17%; and very mild: 23.73%). Moreover, the results indicate that deficits in awareness may vary in severity and that different types of anosognosia may be identified.

Intraoperative mapping and monitoring in supratentorial tumor surgery

With the increasing strive for complete resections of supratentorial low or high-grade gliomas, the necessity for intraoperative electrical stimulation methods to map and monitor functional important cortical or subcortical brain areas increased. While many brain functions can be assessed during awake surgery using electrical stimulation, motor function as well as visual function can be mapped and monitored in the asleep patient, as well. Several different methods reviewed in this article are available which lead to an improved functional outcome while increasing the extent of tumor resection and thereby potentially the oncological outcome of the patient.

Awareness of cognitive deficits and clinical competence in mild to moderate Alzheimer's disease: their relevance in clinical practice

Awareness of cognitive deficits and clinical competence were investigated in 79 mild to moderate Alzheimer's disease patients. Awareness was assessed by the anosognosia questionnaire for dementia, and clinical competence by specific neuropsychological tests such as trail making test-A, Babcock story recall test, semantic and phonemic verbal fluency. The findings show that 66 % of the patients were aware of memory deficits, while the 34 % were unaware. Deficit in awareness correlated with lower scores on the Mini Mental State Examination test that, in the score range from 24.51 to 30 and from 19.50 to 24.50, appeared to be a significant predictor of level of awareness. None of the AD patients had fully preserved clinical competence, only 7 patients (9 %) had partially preserved clinical competence and 72 patients (91 %) had completely lost clinical competence. All the patients with partially preserved clinical competence (9 %) were aware of their memory deficit. The study indicates that neuropsychological tests used for the assessment of executive functions are not suitable for investigating clinical competence. Therefore, additional and specific tools for the evaluation of clinical competence are necessary. Indeed, these might allow clinicians to identify AD patients who, despite their deficits in selected functions, retain their autonomy of choice as well as recognize those patients who should proceed to the nomination of a legal representative.

Cognitive stimulation in a-MCI: an experimental study

Nowadays, preventing the effects of mental decline is an international priority, but there is little research into cognitive training in mild cognitive impairment (MCI). We present the results of a program aimed at teaching memory strategies and improving metacognitive abilities. This was associated with training to ameliorate caregivers' assistance. Two groups (A and B) were compared in a crossover design. After the first evaluation, group A (but not B) participated in a 6-month cognitive stimulation program. After a second assessment, only B received treatment and then a final evaluation was carried out on both the groups. The results show that (1) both the groups improved their performance as an effect of training; (2) improvements are specific to the functions trained; (3) in the interval without intervention, performance of group B worsened; and (4) group A has maintained their results over time. In conclusion, our results show that specific training may reduce memory impairment in MCI.

Characterization of a new trabectedin-resistant myxoid liposarcoma cell line that shows collateral sensitivity to methylating agents

Myxoid Liposarcomas (MLS), characterized by the expression of FUS-CHOP fusion gene are clinically very sensitive to the DNA binding antitumor agent, trabectedin. However, resistance eventually occurs, preventing disease eradication. To investigate the mechanisms of resistance, a trabectedin resistant cell line, 402-91/ET, was developed. The resistance to trabectedin was not related to the expression of MDR related proteins, uptake/efflux of trabectedin or GSH levels that were similar in parental and resistant cells. The 402-91/ET cells were hypersensitive to UV light because of a nucleotide excision repair defect: XPG complementation decreased sensitivity to UV rays, but only partially to trabectedin. 402-91/ET cells showed collateral sensitivity to temozolomide due to the lack of O(6) -methylguanine-DNA-methyltransferase (MGMT) activity, related to the hypermethylation of MGMT promoter. In 402-91 cells chromatin immunoprecipitation (ChIP) assays showed that FUS-CHOP was bound to the PTX3 and FN1 gene promoters, as previously described, and trabectedin caused FUS-CHOP detachment from DNA. Here we report that, in contrast, in 402-91/ET cells, FUS-CHOP was not bound to these promoters. Differences in the modulation of transcription of genes involved in different pathways including signal transduction, apoptosis and stress response between the two cell lines were found. Trabectedin activates the transcription of genes involved in the adipogenic-program such as c/EBPα and β, in 402-91 but not in 402-91/ET cell lines. The collateral sensitivity of 402-91/ET to temozolomide provides the rationale to investigate the potential use of methylating agents in MLS patients resistant to trabectedin.

Substitutions of amino acids in the pore domain of homomeric α7 nicotinic receptors for analogous residues present in heteromeric receptors modify gating, rectification and binding properties

We have studied the role of different amino acids in the M2 transmembrane domain of the α7 neuronal nicotinic receptor by mutating residues that differ from the ones located at the same positions in other α (α2-α10) or β (β2-β4) subunits. Our aim was to investigate the contribution of these amino acids to the peculiar kinetic and inward rectification properties that differentiate the homomeric α7 receptor from other nicotinic receptors. Mutations of several residues strongly modified receptor function. We found that Thr245 had the most profound effect when mutated to serine, an amino acid present in all heteromeric receptors composed of α and β subunits, by dramatically increasing the maximal current, decreasing the decaying rate of the currents and decreasing receptor rectification. Some mutants also showed altered agonist-binding properties as revealed by shifts in the dose-response curves for acetylcholine. We conclude that residues in the M2 segment and flanking regions contribute to the unusual properties of the α7 receptor, especially to its characteristic fast kinetic behavior and strong inward rectification and furthermore to the potency of agonists.

Circumscribed palmar or plantar hypokeratosis: report of an italian case

Circumscribed palmar or plantar hypokeratosis is a rare benign epidermal malformation of the skin. Clinically it shows asymptomatic, well-circumscribed, and depressed erythema persisting for many years on the palms or soles. Its main histopathologic feature shows a characteristic epidermal depression with an abrupt decrement in the thickness of the stratum corneum, with a sharp stair between normal and involved skin. We describe a case of a 68-year-old woman who presented with an erythematous, asymptomatic, well-circumscribed, depressed patch, on the right thenar eminence which had been present for years.

Latency time in cutaneous leishmaniasis

Latency period in cutaneous leishmaniasis was very rarely studied so far. We describe three patients, aged 71, 50 and 32 years, respectively, who contracted cutaneous leishmaniasis in Sicily. In all patients, clinical diagnosis was confirmed by histopathological examination and polymerase chain reaction: the latter was positive for Leishmania infantum in two patients and Leishmania canis in one. All cases were characterized by a very long period of latency, ranging from 11 to 16 months. These cases suggest that latency time of cutaneous leishmaniasis acquired in Sicily may be sometimes very long. The reasons of this latency time are unknown: latency depends neither by the involved species of sandflies and Leishmania nor by the immunological response of the patients: all laboratory tests, including immunological ones, were normal.

Influenza A (H1N1) encephalitis with severe intracranial hypertension

The swine-origin influenza A (H1N1) virus was responsible for the pandemic infection in 2009. We report a case of encephalitis diagnosed as the H1N1 virus infection in a young child. The H1N1 virus infection can be causative of the encephalitis, as with other influenza virus infections. For patients presenting with influenza-like illness accompanied by mental status changes or seizures, high suspicion for unusual presentations of influenza A virus infection and careful monitoring, including EEG and intracranial pressure monitoring, are essential for reducing complications.

Wild grapevine: silvestris, hybrids or cultivars that escaped from vineyards? Molecular evidence in Sardinia

Vitis vinifera ssp. silvestris, the spontaneous subspecies of V. vinifera L., is believed to be the ancestor of present grapevine cultivars. In this work, polymorphism at 13 SSR loci was investigated to answer the following key question: are wild plants (i) true silvestris, (ii) hybrids between wild and cultivated plants or (iii) or 'escapes' from vineyards? In particular, the objective of the present study was to identify truly wild individuals and to search for possible hybridization events. The study was performed in Sardinia, the second largest island in the Mediterranean Sea, which is characterized by a large and well-described number of both grape cultivars and wild populations. This region was ideal for the study because of its spatial isolation and, consequently, limited contamination from outside material. The results of this study show that domesticated and wild grapevine germplasms are genetically divergent and thus are real silvestris. Pure lineages (both domesticated and wild) show very high average posterior probabilities of assignment to their own clusters, with a low level of introgression.

P2X4 activation modulates volume-sensitive outwardly rectifying chloride channels in rat hepatoma cells

Volume-sensitive outwardly rectifying (VSOR) Cl(-) channels are critical for the regulatory volume decrease (RVD) response triggered upon cell swelling. Recent evidence indicates that H(2)O(2) plays an essential role in the activation of these channels and that H(2)O(2) per se activates the channels under isotonic isovolumic conditions. However, a significant difference in the time course for current onset between H(2)O(2)-induced and hypotonicity-mediated VSOR Cl(-) activation is observed. In several cell types, cell swelling induced by hypotonic challenges triggers the release of ATP to the extracellular medium, which in turn, activates purinergic receptors and modulates cell volume regulation. In this study, we have addressed the effect of purinergic receptor activation on H(2)O(2)-induced and hypotonicity-mediated VSOR Cl(-) current activation. Here we show that rat hepatoma cells (HTC) exposed to a 33% hypotonic solution responded by rapidly activating VSOR Cl(-) current and releasing ATP to the extracellular medium. In contrast, cells exposed to 200 microm H(2)O(2) VSOR Cl(-) current onset was significantly slower, and ATP release was not detected. In cells exposed to either 11% hypotonicity or 200 microm H(2)O(2), exogenous addition of ATP in the presence of extracellular Ca(2+) resulted in a decrease in the half-time for VSOR Cl(-) current onset. Conversely, in cells that overexpress a dominant-negative mutant of the ionotropic receptor P2X4 challenged with a 33% hypotonic solution, the half-time for VSOR Cl(-) current onset was significantly slowed down. Our results indicate that, at high hypotonic imbalances, swelling-induced ATP release activates the purinergic receptor P2X4, which in turn modulates the time course of VSOR Cl(-) current onset in a extracellular Ca(2+)-dependent manner.

Role of loop 9 on the function of neuronal nicotinic receptors

We have studied the role of loop 9 in the function of neuronal nicotinic receptors. By systematically mutating the residues in the loop we have determined that the most important amino acids determining the coupling of binding to gating are the ones closer to the transmembrane region. Single mutations at location E173 in homomeric alpha7 receptors destroyed their function by completely abolishing the current while preserving the expression at the membrane. In contrast, heteromeric receptor alpha3beta4 with the same mutations retained some function. We conclude that loop 9 has a different role in the function of homomeric and heteromeric receptors.

Intracranial pressure monitoring in pediatric bacterial meningitis: a fancy or useful tool? A case report

Childhood meningitis is associated with high mortality and morbidity. In selected cases, the prompt institution of invasive intracranial pressure (ICP) monitoring and therapy may improve survival but few studies have evaluated the indications for ICP monitoring in this specific neurological disease. This article examines the case of a five-year-old child who was comatose when admitted to the hospital with unilateral dilated pupil, neck stiffness and fever (T 39 degrees C). The initial brain computed tomography scan was unremarkable. Dexamethasone and empirical antibiotic therapy for suspected meningitis was started and a lumbar puncture (LP) was performed. The LP opening pressure was 45 mmHg. Cerebrospinal fluid microscopy demonstrated Meningococcal meningitis. The likelihood of raised ICP, associated with third nerve palsy, prompted insertion of an intraparenchymal catheter for ICP monitoring. Intracranial hypertension was treated with medical therapy. ICP was controlled within 72 hours. On day nine, the ICP device was removed. On the same day, the child started to obey commands, was rapidly weaned from mechanical ventilation and was extubated. He was discharged from the Department on day 13 and after two weeks went home with residual dysmetria and mild motor impairment. This study indicates that ICP-targeted treatment in children improves the outcome of severe cases of bacterial meningitis. ICP monitoring could particularly be useful to optimize brain perfusion and provide relief from severe neurological impairment, which is associated with the clinical signs of meningitis and increased ICP levels.