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[en] This paper presents novel design, fabrication, packaging and the first in vitro neural activity recordings of SU-8-based microneedles. The polymer SU-8 was chosen because it provides excellent features for the fabrication of flexible and thin probes. A microprobe was designed in order to allow a clean insertion and to minimize the damage caused to neural tissue during in vitro applications. In addition, a tetrode is patterned at the tip of the needle to obtain fine-scale measurements of small neuronal populations within a radius of 100 µm. Impedance characterization of the electrodes has been carried out to demonstrate their viability for neural recording. Finally, probes are inserted into 400 µm thick hippocampal slices, and simultaneous action potentials with peak-to-peak amplitudes of 200–250 µV are detected.
[en] Epithelioid hemangioendothelioma (EHE) is a rare vascular soft-tissue tumour of intermediate malignancy. Neurofibromatosis type I (NF-1) is a genetic syndrome associated with soft tissue sarcoma and higher risk of developing neoplasia. Lateral meningoceles are uncommon entities, being mostly associated with NF-1. We report a case of a 31-year-old woman, with NF-1 and past history of right thalamic/peduncular astrocytoma WHO grade II, admitted to the Neurosurgery Department in December 2003 due to severe low back pain, irradiating to the left leg without a radicular pattern. Thoraco-lumbar magnetic resonance imaging (MRI) showed a large left posterior paravertebral expansive lesion, bilateral and multiple thoraco-lumbar lateral meningoceles and dural ectasias with scalloping of the vertebral bodies. Biopsy of the paravertebral mass lesion disclosed EHE. We present this case because of the novel association between NF-1 and EHE, and the unusual aggressiveness of the neoplasia. Additionally, we highlight the co-existence of bilateral and multiple lateral meningoceles. (orig.)
[en] Targeted drug delivery to the brain parenchyma, i.e., in brain tumor patients, by means of magnetically supported carrier delivery through the tight vascular endothelium of the blood-brain barrier is of critical biomedical importance. We were interested in delineating the first steps in successful brain drug delivery, which focuses on the interactions between magnetically guided yet freely blood circulating nanoparticles and the blood-brain barrier. We employed an in vivo model to quantitatively determine changes in cerebrovascular flow rate and volume during magnetically guided exposure of circulating nanoparticles.
[en] Collective cell motility is an important aspect of several developmental and pathophysiological processes. Despite its importance, the mechanisms that allow cells to be both motile and adhere to one another are poorly understood. In this study we establish statistical properties of the random streaming behavior of endothelial monolayer cultures. To understand the reported empirical findings, we expand the widely used cellular Potts model to include active cell motility. For spontaneous directed motility we assume a positive feedback between cell displacements and cell polarity. The resulting model is studied with computer simulations and is shown to exhibit behavior compatible with experimental findings. In particular, in monolayer cultures both the speed and persistence of cell motion decreases, transient cell chains move together as groups and velocity correlations extend over several cell diameters. As active cell motility is ubiquitous both in vitro and in vivo, our model is expected to be a generally applicable representation of cellular behavior
[en] Highlights: • We analyze spike trains induced by EA before and after inhibiting SP in PC6 area. • Inhibiting SP leads to an increase of spiking rate of median nerve. • SP may modulate membrane potential to affect the spiking rate. • SP has an influence on long-range correlation of spike train evoked by EA. • SP play an important role in EA-induced neural spiking and encoding. - Abstract: Substance P (SP) participates in the neural signal transmission evoked by electro-acupuncture (EA). This paper investigates the impact of SP on the correlation of spike train in the median nerve evoked by EA at 'Neiguan' acupoint (PC6). It shows that the spiking rate and interspike interval (ISI) distribution change obviously after inhibiting SP. This variation of spiking activity indicates that SP affects the temporal structure of spike train through modulating the action potential on median nerve filaments. Furtherly, the correlation coefficient and scaling exponent are considered to measure the correlation of spike train. Scaled Windowed Variance (SWV) method is applied to calculate scaling exponent which quantifies the long-range correlation of the neural electrical signals. It is found that the correlation coefficients of ISI increase after inhibiting SP released. In addition, the scaling exponents of neuronal spike train have significant differences between before and after inhibiting SP. These findings demonstrate that SP has an influence on the long-range correlation of spike train. Our results indicate that SP may play an important role in EA-induced neural spiking and encoding.
[en] Early models of the oculomotor plant only considered the eye globes and the muscles that move them. Recently, connective tissue structures have been found enveloping the extraocular muscles (EOMs) and firmly anchored to the orbital wall. These structures act as pulleys; they determine the functional origin of the EOMs and, in consequence, their effective pulling direction. A three dimensional model of the oculomotor plant, including pulleys, has been developed and simulations in Simulink were performed during saccadic eye movements. Listing's law was implemented based on the supposition that there exists an eye orientation related signal. The inclusion of the pulleys in the model makes this assumption plausible and simplifies the problem of the plant noncommutativity
[en] Acardiac twinning is a severe and rare complication of monochorionic placentation. The acardiac twin does not survive while mortality of the normal twin is about 50-70 % as the normal twin has to provide circulation not only for itself but also for acardiac twin. Proper timing of the delivery is of prime importance to the survival of the normal fetus for which emphasis is placed on close sonographic monitoring for early antenatal diagnosis. This series describes three such cases, which are now termed Twin Reversed Arterial Perfusion (TRAP) sequence. (author)
[en] We report a 73-year-old woman with primary left atrial rhabdomyosarcoma and its 1H MR spectroscopy (MRS) findings. The tumor showed a 2.8 cm sized lesion in the posteroinferior atrial wall on MRI. 1H MR spectra were acquired using a point-resolved spectroscopy (PRESS) sequence with electrocardiographic (ECG) gating and respiratory motion. The use of 1H-MRS allowed the quantification of triglyceride (TG) peak groups at 0.9 and 1.3 ppm, and unsaturated group of lipids at 2.1 ppm, creatine (Cr) at 3.0 ppm, and choline (Cho) at 3.2 ppm. The percentages of the myocardial metabolites based on water-peak in the interventricular septum were TG 18.4%, Cr 1.6%, Cho 3.3% and unsaturated group 4.0%, whereas the rhabdomyosarcoma showed TG 118.8%, unsaturated group 5.1%, Cr 1.3%, Cho 3.5% and the olefinic components of fatty acid at 5.4 ppm 24.5%. This case demonstrates that 1H-MRS is potentially useful to diagnose the rhabdomyosarcoma by quantifying the myocardial metabolites which are important biomarkers for heart function and diseases
[en] To review indications and complications of hysterectomy carried out for benign gynecological conditions at Fauji Foundation Hospital, Rawalpindi, Pakistan and compare with standard guidelines in order to improve patient care. Methodology: All patients who underwent hysterectomy from August 1, 2015 to July 31, 2017 were reviewed. The indications and complications were analyzed. Results: A total 318 hysterectomies were performed during the study period. Out of these, 251 (79%) were performed abdominally and 67(21%) vaginally. Among abdominal hysterectomies, 209(65.7%) were performed for benign condition. The complication rate after abdominal hysterectomy was 9.05% while after vaginal hysterectomy it was 3%. The preoperative blood transfusion rate was 20 %. Conclusion: Overall patient care in terms of diagnostic work up and surgical complication rate was good. The underuse or low acceptance of Levonorgestrel IUS among patients, lack of operative endoscopy and overuse of prophylactic oophorectomy were the flaws identified in our study. (author)
[en] Objective: To determine the effect of neurectomy in reducing the frequency of chronic inguinodynia after mesh hernioplasty in open inguinal hernia repair. Study Design: Single blind randomised controlled-trial. Place and duration of study: Surgical Unit-I, Department of General Surgery, Services Hospital, Lahore, Pakistan from September 2018 to September 2019. Methodology: All male patients undergoing open groin hernia surgery were included in the study. A total of 100 patients were randomly categorised into group A (neurectomy group) and group B (nerve sparing group). Patients were followed up for three months for the development of chronic inguinodynia. Signifiance was determined at p <0.05 using Chi-square and Fisher’s exact tests. Results: Out of 100 patients, 50 patients were enrolled in group A, while 50 were enrolled in group B. Mean age of patients was 42.1 ± 17.5 years. The median (IQR) acute pain score in neurectomy group was 3.0 (2.0-4.0), while median (IQR) acute pain score was 4.0 (3.0-6.0) in nerve sparing group with statistically significant difference (z = -3.256, p = 0.001). The frequency of chronic inguinodynia was significantly less in group A compared to group B [3 (6%) vs. 13 (26%), p = 0.012]. Conclusion: Excision of ilioinguinal and iliohypogastric nerve in inguinal mesh hernioplasty reduces the frequency of chronic inguinodynia. Ilioinguinal neurectomy may be practised routinely in patients undergoing Lichtenstein mesh hernioplasty. (author)