Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Pediatr Neurosurg ; 58(6): 410-419, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37751730

RESUMEN

INTRODUCTION: The aim of the study was to investigate and identify the predictors associated with the incidence of seizures in patients with encephalocele (EC). METHODS: A retrospective analysis was undertaken of patients treated for EC at a tertiary medical center in Tehran between 2010 and 2021. Data including age at presentation, gender, location, size, and content of EC, ventriculomegaly, hydrocephalus, associated anomalies, and neurodevelopmental delay (NDD) were evaluated for their prognostic value. In addition, univariate and multivariate analyses were performed to identify the correlation between independent predictors and seizure incidence. RESULTS: One hundred and two cases of EC were identified. Seventy-one ECs (69.6%) were posterior ECs, while 31 (30.4%) were anterior. Neural tissue was found in 43 (42.2%) of the ECs. Thirty-three patients (32.4%) had ventriculomegaly, of which 90.9% underwent shunt placement for progressive or symptomatic hydrocephalus. Seizure was found in 26 (25.5%) patients. On univariate analysis, presence of other anomalies, postoperative infections, and NDD were associated with seizures (p < 0.05). When the anomalies were categorized into intracranial and extracranial groups in univariate analysis, none was associated with statistically significant increase in seizure (p values of 0.09 and 0.61, respectively). Although according to multivariate analysis, only the association between other associated anomalies and seizure was near significant (OR: 2.0, 95% CI: 0.95-4.2, p = 0.049). Children with NDD and postoperative infection were, respectively, 3.04 and 1.3 times more at risk to experience seizures compared to other patients. CONCLUSION: We found a rate of 25.5% risk of seizure in patients with EC. This study could not find any significant predictors of seizure in children with EC. However, pediatric patients with postoperative infections including sepsis, wound infection, and NDD require more consideration to reduce the risk of seizure.


Asunto(s)
Encefalocele , Hidrocefalia , Humanos , Niño , Encefalocele/epidemiología , Encefalocele/cirugía , Encefalocele/complicaciones , Estudios Retrospectivos , Centros de Atención Terciaria , Resultado del Tratamiento , Irán/epidemiología , Convulsiones/etiología , Convulsiones/complicaciones , Hidrocefalia/epidemiología , Hidrocefalia/cirugía , Hidrocefalia/complicaciones , Complicaciones Posoperatorias/epidemiología
2.
Childs Nerv Syst ; 39(9): 2479-2485, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37010583

RESUMEN

OBJECTIVE: Children with previous ventriculoperitoneal shunt (VPS) insertion due to hydrocephalus may refer to the hospital with various clinical complaints. Shunt malfunction is frequently diagnosed in these children necessitating shunt revision. Although increased head circumference, setting sun eye in younger children, and headache, nausea/vomiting, loss of consciousness, visual disturbance, and other signs of intracranial hypertension are common clinical manifestations of shunt malfunction, some patients may present with odd or unusual symptoms. Here, we present a series of patients with shunted hydrocephalus who presented with odd and unexpected clinical manifestations of shunt malfunction. METHODS: Eight children with shunt malfunction were enrolled in this series. The age, sex, age of shunting, etiology of hydrocephalus and management, post-shunt insertion symptoms/sign, revision surgery, outcome, and follow-up were evaluated. RESULTS: Patients were aged from 1 to 13 years (mean, 6.38 years). There were 5 males and 3 females. The odd presentation associated with shunt malfunction included facial palsy in three children, ptosis in 3 children, and torticollis and dystonia each in one child. All patients underwent shunt revision except for one patient in whom a new shunt was inserted. Follow-up showed improvement of the symptoms in all patients. CONCLUSION: In this series, we reported eight patients with unusual signs and symptoms following shunt malfunction that were successfully diagnosed and managed.


Asunto(s)
Hidrocefalia , Derivación Ventriculoperitoneal , Niño , Masculino , Femenino , Humanos , Derivación Ventriculoperitoneal/efectos adversos , Hidrocefalia/etiología , Hidrocefalia/cirugía , Cefalea/etiología , Vómitos/etiología , Reoperación , Estudios Retrospectivos
3.
J Neurosurg Pediatr ; 32(1): 44-49, 2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-36964731

RESUMEN

OBJECTIVE: Prenatal ventriculomegaly (VM) is classified as mild, moderate, or severe on the basis of the diameter of the atrium. Neurodevelopmental status in prenatal VM is associated with various factors such as the course of VM, VM type, progression, and associated anomalies. In this study, the authors aimed to evaluate neurodevelopmental outcome in patients with prenatal VM and to detect possible associated risk factors. METHODS: In this study, 73 pregnancies with VM who were referred to Children's Medical Center, Tehran, Iran, between 2019 and 2021 were prospectively followed. They were followed up every 2-4 weeks with ultrasonography (US) before delivery and were then observed for an average time of 14.6 months. The authors collected demographic and ultrasound information, associated abnormalities, pregnancy outcomes, and developmental status according to Centers for Disease Control criteria. RESULTS: The mean gestational age at the time of diagnosis was 28.1 weeks, and 46.6% of fetuses were female. According to the first US, 46.6% had mild, 21.9% had moderate, and 31.5% had severe VM. Serial US scans showed that VM had regressed in 20.5% of patients, remained stable in 35.6%, and progressed in 43.8%. Other cranial abnormalities were detected in 38.4% of fetuses. During follow-up, 62.5% of cases had normal developmental status, 26.6% had mild delay, and 10.9% had severe neurodevelopmental delay. Pregnancy was terminated in 9 (12.3%) cases. Normal neurodevelopment was reported in 75.8% of patients with mild VM versus 50% of those with severe VM (p = 0.19). Neurodevelopmental status was normal in 72.5% of cases without other cranial abnormalities (p = 0.018) and in 86.7% of cases with regression of VM (p = 0.028). CONCLUSIONS: Despite analysis of different factors in prenatal VM, only progression of VM and associated cranial abnormalities had significant relationships with neurodevelopmental prognosis.


Asunto(s)
Hidrocefalia , Malformaciones del Sistema Nervioso , Embarazo , Niño , Humanos , Femenino , Masculino , Estudios Prospectivos , Ultrasonografía Prenatal , Irán , Hidrocefalia/complicaciones , Resultado del Embarazo , Diagnóstico Prenatal
4.
Biotechnol Appl Biochem ; 70(1): 318-329, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35484728

RESUMEN

Testosterone is an anabolic steroid and a major sex hormone in males. It plays vital roles, including developing the testis, penis, and prostate, increasing muscle and bone, and sperm production. In both men and women, testosterone levels should be in normal ranges. Besides, testosterone and its analogs are major global contributors to doping in sport. Due to the importance of testosterone testing, novel, accurate biosensors have been developed. This review summarizes the various methods for testosterone measurement. Also, recent optical and electrochemical approaches for the detection of testosterone and its analogs have been discussed.


Asunto(s)
Técnicas Biosensibles , Semen , Humanos , Masculino , Femenino , Testosterona
5.
Biotechnol Appl Biochem ; 70(3): 1044-1056, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36445196

RESUMEN

The significant role of microRNAs in regulating gene expression and in disease tracking has handed the possibility of robust and accurate diagnosis of various diseases. Measurement of these biomarkers has also had a significant impact on the preparation of natural samples. Discovery of miRNAs is a major challenge due to their small size in the real sample and their short length, which is generally measured by complex and expensive methods. Electrochemical nanobiosensors have made significant progress in this field. Due to the delicate nature of nerve tissue repair and the significance of rapid-fire feature of neurodegenerative conditions, these biosensors can be reliably promising. This review presents advances in the field of neurodegenerative diseases diagnostics. At the same time, there are still numerous openings in this field that are a bright prospect for researchers in the rapid-fire opinion of neurological diseases and indeed nerve tissue repair.


Asunto(s)
Técnicas Biosensibles , MicroARNs , Enfermedades Neurodegenerativas , Humanos , MicroARNs/genética , Enfermedades Neurodegenerativas/diagnóstico , Enfermedades Neurodegenerativas/genética , Técnicas Electroquímicas , Biomarcadores
6.
Mol Cell Probes ; 66: 101865, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36162597

RESUMEN

Pseudomonas aeruginosa possesses innate antibiotic resistance mechanisms, and carbapenem-resistant Pseudomonas aeruginosa has been considered the number one priority in the 2017 WHO list of antimicrobial-resistant crucial hazards. Early detection of Pseudomonas aeruginosa can circumvent treatment challenges. Various techniques have been developed for the detection of P. aeruginosa detection. Biosensors have recently attracted unprecedented attention in the field of point-of-care diagnostics due to their easy operation, rapid, low cost, high sensitivity, and selectivity. Biosensors can convert the specific interaction between bioreceptors (antibodies, aptamers) and pathogens into optical, electrical, and other signal outputs. Aptamers are novel and promising alternatives to antibodies as biorecognition elements mainly synthesized by systematic evolution of ligands by exponential enrichment and have predictable secondary structures. They have comparable affinity and specificity for binding to their target to antibody recognition. Since 2015, there have been about 2000 journal articles published in the field of aptamer biosensors, of which 30 articles were on the detection of P. aeruginosa. Here, we have focused on outlining the recent progress in the field of aptamer-based biosensors for P. aeruginosa detection based on optical, electrochemical, and piezoelectric signal transduction methods.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Pseudomonas aeruginosa , Aptámeros de Nucleótidos/química , Técnicas Biosensibles/métodos , Anticuerpos
7.
ACS Appl Bio Mater ; 5(8): 3649-3657, 2022 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-35830462

RESUMEN

The in vivo chemogenetic property of mercuric ions (Hg2+) was investigated as a specific hypercalcemia actuator in snail's spinal cord cell manipulation by extracellular field potential biosensing analysis. For this purpose, a three-microelectrode system with working, counter, and pseudo reference electrodes was blindly implanted into the snail's spinal cord to electrically stimulate (triggering) the action potential with a staircase electrical voltage at a very low frequency level, along with measurement of the electrical current, as a detection system. Under optimum conditions, using the one-factor-at-a-time method, a wide linear range between 1.0 × 10-14 and 1.0 × 10-1 mol L-1 with correlation coefficients (R2) >0.98 and a response time (t90) of maximum 10.0 s were approximated. Percentages of relative standard deviation were estimated to be 3.08 (reproducibility, n = 50) and 7.31 (repeatability, n = 15). The detection limit was estimated to be sub 2.1 × 10-16 mol L-1 based on the Xb- + 3Sb definition. The reliability of this phenomenon was evidenced by the estimation of recovery percentages (between 95 and 107%) during spiking Hg2+ standard solutions. The probable mechanism behind this process could be attributed to the following: (i) the neuronal ephaptic coupling during electrical synchronization by a specific brain-triggered wave as a neuronal motor toolkit and (ii) chemical synchronization using a Hg2+ hypercalcemia actuator (biosensor). Linear correlation has been evidenced during interactions between Hg2+ and a calcium ionic channel's protein with a gram molecular weight of 66.2 ± 0.3 KCU. This process, therefore, caused an opening of the Ca2+ channel gates and majorly released the Ca2+ (hypercalcemia) that was detected as the main source of the measured electrical current. At this condition, ultratrace levels of Hg2+ ions not only were considered as nontoxic reagents but also had chemically regulating effects as ephaptic synchronizers to the neuron cells. This report may pave the way for using mercury ions at an ultratrace level for clinical controlling purposes during neuronal spinal cord cell manipulation.


Asunto(s)
Técnicas Biosensibles , Hipercalcemia , Mercurio , Técnicas Biosensibles/métodos , Humanos , Iones , Mercurio/toxicidad , Reproducibilidad de los Resultados , Médula Espinal/química
8.
Biosens Bioelectron ; 182: 113125, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33773382

RESUMEN

Chemogenetic property of mercuric ion (Hg2+) was investigated as a specific hypercalcemia actuator in the neuronal spinal cord cell manipulation by Zeta-based potentiometric bio-sensing analysis via introducing a novel array-based Hg2+ bio-sensor. For this purpose, the array of a two-electrode system including Ag/AgCl (sat'd Cl-) as reference electrode and a paste nano-composite as the indicator electrode was utilized. The indicator electrode was made of activated multi-walled carbon nanotubes as conductive support, a grounded slice of sheep's spinal cord as natural neuron stem cells (ionophore), and oxalate ion as both the dispersed phase and cationic site. Under optimum conditions by one-at-a-time method, a two-linear range between 1.3 × 10-4- 6.5 × 10-12 and 2.7 × 10-14- 1.4 × 10-21 mol L-1 with correlation coefficients (R2) of 0.96 and 0.99, respectively, and response time (t90) of maximum 5.0 min were approximated. The percentages of relative standard deviation were estimated to be 4.05 (repeatability, n = 10) and 6.14 (reproducibility, n = 12). The detection limit was estimated to be sub 5.3 × 10-22 mol L-1 based on the X̄b+3Sb. The reliability of this phenomenon was evidenced by different analytical techniques. The Zeta-based electrical response was therefore attributed to highly Ca2+ pumping from the stem cells ionic channel gates as the proposed mechanistic behavior of the spinal cord. Actuating (triggering) the stem cells by Hg2+ consequently led to generate significant Zeta potential as the proposed mechanism. The results pointed to the potentiometric responsibility of a protein with gram molecular weight of 66.2 ± 0.3 KCU in the stem cell matrix as a specific hypercalcemia actuator.


Asunto(s)
Técnicas Biosensibles , Hipercalcemia , Mercurio , Nanotubos de Carbono , Electrodos , Humanos , Neuronas , Reproducibilidad de los Resultados , Médula Espinal
9.
J Neurosurg Pediatr ; 27(5): 497-502, 2021 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-33668033

RESUMEN

OBJECTIVE: Prenatal ventriculomegaly is classified as mild, moderate, or severe based on the atrium diameter. The natural course and intrauterine progression of mild and moderate ventriculomegaly associated with the neurodevelopmental status of these children has been widely reported. METHODS: One hundred twenty-two pregnancies with mild and moderate ventriculomegaly referred to the pediatric neurosurgery clinic of Children's Medical Center between 2010 and 2018 were retrospectively studied. The authors collected demographic and first and sequential ultrasonographic information, associated abnormalities, information about pregnancy outcomes, and the latest developmental status of these children according to Centers for Disease Control and Prevention criteria by calling parents at least 1 year after birth. RESULTS: The mean gestational age at the time of diagnosis was 29.1 weeks, and 53% of fetuses were female. The width of the atrium was registered precisely in 106 cases, in which 61% had mild and 39% had moderate ventriculomegaly. Information on serial ultrasound scans was collected in 84 cases in which ventriculomegaly regressed in 5, remained stable in 67, and progressed in 12 patients. Fourteen cases (29.7%) in the mild ventriculomegaly group and 6 cases (16.2%) in the moderate group had associated abnormalities, with corpus callosum agenesis as the most frequent abnormality. The survival rate was 80% in mild and 89.4% in moderate ventriculomegaly. Considering survival to live birth and progression of the ventriculomegaly, the survival rate was 100% in regressed, 97% in stable, and 41.6% in progressed ventricular width groups (p < 0.001). Neurodevelopmental status was evaluated in 73 cases and found to be normal in 69.8% of the cases; 16.4% of children had mild delay, and 5.4% and 8.2% of cases were diagnosed with moderate and severe delays, respectively. CONCLUSIONS: In spite of a high rate of missed data in our retrospective study, most patients with mild or moderate ventriculomegaly had a stable or regressed course. Most cases had near-normal developmental status. Prospective studies with a larger sample size and detailed developmental evaluation tests are needed to answer the questions related to the natural course, survival, and prognosis of prenatal ventriculomegaly.


Asunto(s)
Hidrocefalia/patología , Preescolar , Progresión de la Enfermedad , Femenino , Enfermedades Fetales , Feto , Humanos , Hidrocefalia/complicaciones , Lactante , Recién Nacido , Masculino , Trastornos del Neurodesarrollo/epidemiología , Trastornos del Neurodesarrollo/etiología , Embarazo , Estudios Retrospectivos
10.
Sci Rep ; 11(1): 3683, 2021 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-33574428

RESUMEN

Probable mechanism behind the neuronal ephaptic coupling is investigated based on the introduction of "Brain"-triggered potential excitation signal smartly with a specific very low frequency (VLF) waves as a neuronal motor toolkit. Detection of this electric motor toolkit is attributed to in-vitro precise analyses of a neural network of snail, along to the disconnected snail's neuronal network as a control. This is achieved via rapid (real-time) electrical signals acquisition by blind patch-clamp method during micro-electrode implanting in the neurons at the gigaseal conditions by the surgery operations. This process is based on its waveform (potential excitation signal) detection by mathematical curve fitting process. The characterized waveform of this electrical signal is "Saw Tooth" that is smartly stimulated, alternatively, by the brain during triggering the action potential's (AP's) hyperpolarization zone at a certain time interval at the several µs levels. Triggering the neuron cells results in (1) observing a positive shift (10.0%, depending on the intensity of the triggering wave), and (2) major promotion in the electrical current from sub nano (n) to micro (µ) amper (nA, µA) levels. Direct tracing the time domain (i.e., electrical signal vs. time) and estimation of the frequency domain (diagram of electrical response vs. the applied electrical frequencies) by the "Discrete Fast Fourier Transform" algorithm approve the presence of bilateral and reversible electrical currents between axon and dendrite. This mechanism therefore opens a novel view about the neuronal motor toolkit mechanism, versus the general knowledge about the unilateral electrical current flow from axon to dendrite operations in as neural network. The reliability of this mechanism is evaluated via (1) sequential modulation and demodulation of the snail's neuron network by a simulation electrical functions and sequentially evaluation of the neuronal current sensitivity between pA and nA (during the promotion of the signal-to-noise ratio, via averaging of 30 ± 1 (n = 15) and recycling the electrical cycles before any neuronal response); and (2) operation of the process on the differentiated stem cells. The interstice behavior is attributed to the effective role of Ca2+ channels (besides Na+ and K+ ionic pumping), during hyper/hypo calcium processes, evidenced by inductively coupled plasma as the selected analytical method. This phenomenon is also modeled during proposing quadrupole well potential levels in the neuron systems. This mechanism therefore points to the microprocessor behavior of neuron networks. Stimulation of the neuronal system based on this mechanism, not only controls the sensitivity of neuron electrical stimulation, but also would open a light window for more efficient operating the neuronal connectivity during providing interruptions by phenomena such as neurolysis as well as an efficient treatment of neuron-based disorders.


Asunto(s)
Axones/fisiología , Encéfalo/fisiología , Neuronas Motoras/fisiología , Neuronas Eferentes/fisiología , Caracoles/fisiología , Potenciales de Acción/efectos de la radiación , Animales , Axones/efectos de la radiación , Encéfalo/efectos de la radiación , Ondas Encefálicas/fisiología , Calcio/metabolismo , Estimulación Eléctrica/efectos adversos , Potenciales de la Membrana/efectos de la radiación , Neuronas Motoras/efectos de la radiación , Red Nerviosa/fisiología , Red Nerviosa/efectos de la radiación , Neuronas Eferentes/efectos de la radiación , Técnicas de Placa-Clamp , Caracoles/efectos de la radiación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA