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1.
Cureus ; 16(1): e52196, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38347985

RESUMEN

Aims A prospective observational study was performed to assess the feasibility and safety of three-port laparoscopic cholecystectomy. Parameters comprising age, sex, number of cases in which intra-operative difficulty were encountered, and outcomes such as number of cases that required conversion to four-port laparoscopic cholecystectomy, postoperative pain on the visual analog scale (VAS), and postoperative hospital stay were assessed. We also documented difficult cases that were operated successfully with three ports, and the number of cases that needed conversion to four ports along with the reason for the conversion. Material and methods The patients were operated upon in the supine position in all cases. A pre-emptive analgesia with 1% lignocaine was administered in all cases prior to making the incision. The first port was 10-mm supraumbilical and inserted by the open technique. After insertion of the umbilical port, pneumoperitoneum was created by maintaining a maximum pressure of 12 mmHg and a flow rate of 8 L/minute. A camera head with a 30° telescope was introduced in the peritoneal cavity, and diagnostic laparoscopy was performed. A 10-mm subxiphoid port and a 5-mm subcostal port were placed under vision, with the latter placed more lateral and inferior to the conventional port position for better triangulation and ergonomics. The outcomes measured were operative time, the number of cases requiring a fourth port, postoperative pain (VAS), and postoperative hospital stay (number of days patients stayed in the hospital post-surgery until discharge). Data were collected using MS Excel, and an analysis was performed using SPSS Version 21.0. Results Data of 102 patients were analyzed prospectively. The mean age of the patients was 50.98 years, with an SD of 16.88, and the gender ratio was 73:29 (female: male). The mean operative time was 52.68 ± 20.84 minutes, with an SD of 20.84. Difficulty was encountered in 18.6% of cases in the form of pericholecystic adhesions, aberrant Calot's anatomy, empyema or mucocele of the gallbladder, or bleeding from the liver bed or cystic artery stump. Postoperative pain was less in our study due to the reduced number of ports and the use of a pre-emptive analgesia, with a mean VAS score of 1.22 and an SD of 0.56. The mean postoperative hospital stay was 1.08 days, with an SD of 0.31. We needed to convert to a four-port procedure for safety in 2.9% cases. The operative time and postoperative hospital stay in our study were similar to those of other studies, but our average pain score was less due to the use of the pre-emptive analgesia. Only three cases required conversion to four ports, and 99 cases were successfully managed with three ports without compromising safety. No bile duct injury occurred in any of our 102 cases. Conclusion From this study, we conclude that three-port cholecystectomy is feasible, and it can be performed even in difficult cases without compromising safety. The surgical time is similar to that of four-port cholecystectomy, and the postoperative stay is shorter. The decreased number of ports and the pre-emptive analgesia reduced postoperative pain, cosmesis was better, and the incidence of bile duct injury did not increase. The procedure can also be converted to four-port cholecystectomy at any time if safety is compromised. Therefore, three-port cholecystectomy is a viable and safe option in the treatment of gallstone disease.

2.
Cureus ; 15(4): e38354, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37266051

RESUMEN

Congenital diaphragmatic hernia (CDH) is a known cause of secondary gastric volvulus (GV). Both entities are life-threatening, either alone or in exceedingly rare instances when they occur in combination. Here, we describe one such rare combination of CDH and secondary GV in a nine-year-old boy, who presented to us with recurrent episodes of abdominal pain. Urgent laparotomy was done after radiological evaluation (X-ray of chest and abdomen and contrast-enhanced CT chest and abdomen), which revealed mesenterico-axial volvulus of the stomach, secondary to an underlying diaphragmatic defect in the left hemidiaphragm, thus establishing the cause (diaphragmatic defect) and effect (GV), and resulting in a favourable outcome.

3.
Multimed Tools Appl ; : 1-21, 2023 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-37362719

RESUMEN

Across the world, the seasonal disease influenza is a respiratory illness that impacts all age groups in many ways. Its symptoms are fever, chills, aches, pains, headaches, fatigue, cough, and weakness. Seasonal influenza can cause mild to severe illness and lead to death at times. The task of early detection of influenza is an important research area these days. Various studies show that machine learning techniques have attracted many researchers' attention to the early detection of influenza disease. In this paper, early detection of Influenza disease among all age groups is done using various machine learning techniques. Influenza Research Database and the Human Surveillance Records data sets are used. Data analysis is undertaken, and ensemble-based stacked algorithms are implemented on the whole data set. The performance of different models has been evaluated using different performance metrics. Overall, the study proposes efficient machine learning models that can be implemented to provide a cheaper and quicker diagnostic tool for detecting influenza.

4.
Plant J ; 115(3): 662-677, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37097088

RESUMEN

Plants can retain a memory of previous pathogen infections to mount a more robust defense response during subsequent infections by developing systemic acquired resistance (SAR). However, the mechanism through which plants develop and retain infection memory is not known. Experiments have shown the association of epigenetic modifications of specific defense-related genes with SAR. RSI1/FLD codes for a histone demethylase and is required for the activation of SAR in Arabidopsis. Here we report the identification of RRTF1 as an epigenetic target of RSI1. RRTF1 expression is higher in pathogen-free distal tissues of the rsi1 mutant. Experiments with loss-of-function and overexpression lines suggest RRTF1 is a negative regulator of basal defense against virulent and avirulent pathogens as well as SAR. Enhanced expression of RRTF1 in a wild-type (WT) background specifically impairs SAR without impacting local resistance. RSI1 is recruited at the RRTF1 locus in a SAR-inducible manner and contributes to H3K4me2 and H3K4me3 demethylation. Introduction of the rrtf1 mutation rescues the loss-of-SAR phenotype of rsi1 plants. However, these plants fail to retain infection memory beyond 7 days post-primary inoculation, whereas WT plants retain memory for at least 11 days. Our results demonstrate that RSI1 and RRTF1 form a functional module for retaining infection memory in Arabidopsis.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Enfermedades de las Plantas/genética , Ácido Salicílico/metabolismo , Factores de Transcripción/metabolismo
5.
Sensors (Basel) ; 23(3)2023 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-36772659

RESUMEN

In recent times, much-coveted memristor emulators have found their use in a variety of applications such as neuromorphic computing, analog computations, signal processing, etc. Thus, a 100 MHz flux-controlled memristor emulator is proposed in this research brief. The proposed memristor emulator is designed using a single differential voltage current conveyor (DVCC), three PMOS transistors, and one capacitor. Among three PMOS transistors, two transistors are used to implement an active resistor, and one transistor is used as the multiplier required for the necessary memristive behaviors. Through simple adjustment of the switch, the proposed emulator can be operated in incremental as well as decremental configurations. The simulations are performed using a 180 nm technology node to validate the proposed design and are experimentally verified using AD844AN and CD4007 ICs. The memristor states of the proposed emulator are perfectly retained even in the absence of external stimuli, thereby ascertaining the non-volatility behavior. The robustness of the design is further analyzed using the PVT and Monte Carlo simulations, which suggest that the circuit operation is not hindered by the mismatch and process variations. A simple neuromorphic adaptive learning circuit based on the proposed memristor is also designed as an application.

6.
Gene ; 850: 146926, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36191825

RESUMEN

Arsenic transforming bacterial strains belong to genus Pseudomonas sp.AK9 (KY569424), were isolated from the middle Gangetic plains of Bihar, India. The Pseudomonas sp. AK9 strains were able to transform toxic arsenite to a less toxic arsenate. In the present work, the presence of different arsenic resistance genes (aoxB, arsB, acr3 and aoxAB) were observed in isolated strain. Furthermore, the aoxB gene was amplified from genomic DNA of AK9, cloned in E.coli/DH5αcells, and sequenced. The BLASTn results and phylogenetic study of the aoxB gene showed 95.32 % and 90.07 % identity with the large subunit of aoxB gene of previous reported Thiomonas arsenivorans strain DSM16361 and Thiomonas arsenivorans strain b6, respectively. Further overhang primers were designed for amplifications of full length aoxB gene (∼1200 bp), and cloned in to the expression vector and host E.coli/BL21 cells. The GST-aoxB gene was expressed in BL21 cells, and a profound expression product of âˆ¼ 72 kDa was observed in SDS PAGE. The detection of a large subunit (aoxB) of arsenate oxidase protein in western blotting assay affirmed the expression of aoxB gene in recombinant E.coli/BL21 clone. Further, the recombinant E.coli/BL21cells showed increased growth than the normal E.coli/BL21 cells against As (III). Thus, this study showed the presence of aoxB gene in Pseudomonas sp. AK9 genome which regulates the resistant ability to arsenic toxicity.


Asunto(s)
Arsénico , Arsenitos , Oxidorreductasas , Arseniatos/metabolismo , Arsénico/toxicidad , Arsenitos/metabolismo , Clonación Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Oxidorreductasas/genética , Oxidorreductasas/metabolismo , Filogenia , Pseudomonas/genética , Pseudomonas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo
7.
Transfus Clin Biol ; 29(3): 209-212, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35750196

RESUMEN

Blood transfusion is an integral component of the health Service system and it becomes imperative that its benefits, risks as well as prospective and viable alternatives of this common medical intervention are explained explicitly to the patients. Appropriate compliance to bedside blood transfusion practices can also help in avoiding adverse transfusion outcomes. At the same time, it is also crucial to document a patient's valid consent based on their decision after evaluation of the risk to benefit ratio. This audit aims to assess the compliance and adherence to bedside blood transfusion practices in a tertiary care hospital and role of Continuous Medical education (CME) on it. The study involved collection of data for blood transfusion services and practices in two periods, for adults and children, who received transfusion from the month of June 2021 to October 2021 and a re-audit beginning from November 2021 to February 2022 following few CMEs in between involving doctors and nurses. A total of 3240 transfusion procedures were assessed in this duration. In them 1500 (46.3%) took place before CME and remaining 1740 (53.7%) procedures took place after CME. There were statistically significant differences between pre-CME and post-CME bedside transfusion practices. During CME/training session, pre-training and post training knowledge has been evaluated by test which also showed statistically significant difference in knowledge of transfusion medicine & bedside transfusion practices. Our study recommends that there is a need of frequent audit on bedside transfusion practices to check the quality and standards associated with it and also points out the need of continuous medical education on this issue.


Asunto(s)
Transfusión Sanguínea , Educación Médica Continua , Niño , Humanos , Estudios Prospectivos , Centros de Atención Terciaria
8.
Transfus Apher Sci ; 61(5): 103436, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35361543

RESUMEN

INTRODUCTION: Granulocyte transfusion (GT) is a therapeutic option for prolonged neutropenic patients with severe bacterial or fungal infections. Efficient apheresis based granulocyte collection may be better achieved by infusion of high-molecular-weight (HMW) hydroxyethyl starch (HES). But multiple adverse incidents have been reported with HMW-HES. Due to availability issues and adverse incidents related to it, use of HMW-HES has become limited. Few studies have mentioned about medium molecular weight HES (MMW-HES) (130 kDa) as efficient for this purpose with minimal adverse incidents. So, the aim was to assess the impact of the use of MMW-HES in granulocyte apheresis when using Spectra Optia. METHODOLOGY: In this observational study, donors who received MMW-HES during granulocyte harvest were included in HES group and another group who did not receive HES were grouped as non-HES. Injection G-CSF 10 microgram/kg and tablet dexamethasone 8 mg given 12 h before for non-HES group and 6 - 8 h in case of HES group blood donors. Number of adverse incidents observed were noted. Donor/procedure parameters were compared using Mann-Whitney U test / unpaired t test. RESULTS: Granulocyte yield was significantly higher in the HES group (2.5 × 1010 vs. 1.75 × 1010, p < 0.01) and was attributed to the difference in collection efficiency (22.61% vs. 10.15%, p < 0.01). There were no significant differences in occurrence of adverse events between HES and non-HES groups. CONCLUSION: Our results clearly indicate that sufficient number of granulocytes can be harvested by using MMW-HES in Spectra Optia apheresis system even after short interval between mobilization to harvest.


Asunto(s)
Eliminación de Componentes Sanguíneos , Leucaféresis , Humanos , Leucaféresis/métodos , Proyectos Piloto , Peso Molecular , Granulocitos , Eliminación de Componentes Sanguíneos/métodos , Factor Estimulante de Colonias de Granulocitos , Dexametasona , Almidón , Derivados de Hidroxietil Almidón/uso terapéutico
9.
J Family Med Prim Care ; 11(10): 6564-6567, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36618163

RESUMEN

PNETs (pancreatic neuroendocrine tumors) are a rare sub-type of pancreatic tumors, with the majority of them being insulinomas. The vast majority of insulinomas (90%) are benign and solitary, with only 10% being malignant. It has a wide range of clinical manifestations and requires a high level of suspicion to diagnose. Surgical excision has long been the gold standard for treating localized PNET and is still the therapy of choice. Recurrent hypoglycemia is usual in diabetic patients, but this is a rare finding in non-diabetic individuals. Here, we are presenting a rare case of insulinoma who was non-diabetic and presented with recurrent hypoglycemic episodes. A 61-year-old non-diabetic male presented with multiple episodes of hypoglycemia in the past. On thorough workup, there was an increased fasting insulin level with the fasting blood glucose level ranging from 60 to 90 mg/dl. His C-peptide and proinsulin were markedly elevated. His abdominal ultrasound failed to pick up any abnormality. His DOTANOC scan revealed a 2 × 2 cm sized lesion in the distal pancreas suggestive of neuroendocrine pathology. He subsequently underwent spleen preserving distal pancreatectomy, following which his blood sugar levels remained normal, and continued to be free of symptoms on follow-up. Our instance emphasizes the need for evaluating insulinoma as a cause of recurrent hypoglycemia in people who are not diabetic. A high index of suspicion in hypoglycemic individuals who do not respond to standard treatment or whose symptom pattern changes will lower the likelihood of insulinoma diagnosis being delayed.

10.
Phys Chem Chem Phys ; 24(1): 211-221, 2021 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-34878461

RESUMEN

The enhancement in the thermoelectric figure of merit (ZT) of a material is limited by the interplay between the electronic transport coefficients. Here we report the greatly enhanced thermoelectric performance of the SnS bilayer with the application of isotropic strain, due to the simultaneous increase in the Seebeck coefficient and low lattice thermal conductivities. Based on first-principles calculations combined with Boltzmann transport theory, we predict that the band structure of the SnS bilayer can be effectively tuned using the strain, and the Seebeck coefficient is significantly improved for the tensile strain. The lattice thermal conductivities for the bilayer under the tensile strain are quite low (0.21-1.89 W m-1 K-1 at 300 K) due to the smaller frequencies of the acoustic phonon modes. Along the zigzag (armchair) direction, the room temperature peak ZT value of 4.96 (2.40) is obtained at a strain of 2% (4%), which is 5.3 (2.03) times higher than the peak ZT of the unstrained bilayer along the zigzag (armchair) direction. Thus the strain-tuned SnS bilayer is a good thermoelectric material with low lattice thermal conductivities and promising ZT values at room temperature.

11.
J Phys Condens Matter ; 33(31)2021 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-34038887

RESUMEN

Thermoelectric materials with high values of power factor and thermoelectric figure of merit (ZT) are in great demand to make efficient thermoelectric devices. In this work, we explore the thermoelectric transport properties of layered tin sulphide (SnS) using first-principles method combined with Boltzmann transport theory. Our calculations show that the two-dimensional (2D) SnS materials have exceptionally high charge carrier mobilities and low lattice thermal conductivities as compared to other 2D materials such as graphene, phosphorene, MoS2, etc. Consequently, these 2D SnS materials have high power factor andZTvalues.

12.
J Complement Integr Med ; 19(1): 27-36, 2021 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-33977685

RESUMEN

OBJECTIVES: Comparative evaluation of cardioprotective activity of Gala and Fuji apple juice against isoprenaline induced cardiotoxicity in rats. METHODS: Rats (125-150 g) were orally administered Gala (GA) and Fuji (FA) apple juice (3 mL/day, per oral) for 13 days. Myocardial injury was inducted on 14th and 15th day by the administration of Isoprenaline (85 mg/kg/day, subcutaneous). RESULTS: In treated group i.e. GA and FA, aspartate aminotransferase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), creatine kinase (CK), Troponin-I level and malondialdehyde (MDA) content was reduced while glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) level was significantly increased. Marked reduction in cholesterol, triglyceride, phospholipids, low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) was observed while high-density lipoprotein (HDL) level increased significantly. In tissue and serum total serum protein (TSP) level, Albumin, Globulin and A/G ratio increased very significantly in the treated group while the level of white blood corpuscles (WBC), haemoglobin (Hb), erythrocyte sedimentation rate (ESR), total fibrinogen (TF), bleeding time (BT), c-reactive protein (C-rP), red blood corpuscles (RBC), clotting time (CT) and prothrombin time (PT) showed a significant rise in the level. The level of Sialic acid, hexose, fucose and hexosamine was highly significantly increased, there was an increase in the level of K+ and glycogen while a significant reduction in electrolyte and glucose level was observed when all these parameters were compared to Isoprenaline (ISO) group. The above findings were supported by histopathological examination of hearts. Cardioprotective activity was compared with standard drug, metoprolol. On comparative analysis of both juices, GA juices have found more effective when compared to FA juice. CONCLUSIONS: The study was concluded that Gala and Fuji apple possessed significant prophylactic and protective effects against Isoprenaline-induced cardiotoxicity in rats through maintaining inhibiting lipid peroxidation, endogenous antioxidant enzyme activities and cytokine levels.


Asunto(s)
Cardiotoxicidad , Malus , Animales , Antioxidantes/metabolismo , Antioxidantes/farmacología , Isoproterenol/metabolismo , Isoproterenol/toxicidad , Peroxidación de Lípido , Malus/metabolismo , Miocardio/metabolismo , Estrés Oxidativo , Ratas
14.
Cells ; 9(1)2020 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-31940829

RESUMEN

BACKGROUND: Myelin is an essential component of the peripheral and central nervous system, enabling fast axonal conduction and supporting axonal integrity; limited tools exist for analysis of myelin composition in-vivo. OBJECTIVE: To demonstrate that the photophysical properties of myelin-incorporated solvatochromic dyes can be exploited to probe the biochemical composition of living peripheral nerve myelin at high spatial resolution. METHODS: Using the myelin-incorporated fluorescent dye Nile Red we sequentially analyzed the spectral characteristics of remyelinating myelin membranes both in-vitro and in-vivo, including in living rats. RESULTS: We demonstrated a consistent bi-phasic evolution of emission spectra during early remyelination, and visually report the reliable biochemical flux of myelin membrane composition in-vitro and in-vivo. CONCLUSIONS: Solvatochromic spectroscopy enables the analysis of myelin membrane maturity during remyelination, and can be performed in-vivo. As the formation of myelin during early-to-late remyelination likely incorporates fluctuating fractions of lipophilic components and changes in lateral membrane mobility, we propose that our spectrochemical data reflects the observation of these biochemical processes.


Asunto(s)
Envejecimiento/patología , Colorantes Fluorescentes/metabolismo , Vaina de Mielina/metabolismo , Oxazinas/metabolismo , Sistema Nervioso Periférico/lesiones , Solventes/química , Células Madre/metabolismo , Animales , Línea Celular , Proteínas Fluorescentes Verdes/metabolismo , Masculino , Sistema Nervioso Periférico/patología , Ratas Endogámicas Lew , Ratas Sprague-Dawley , Análisis Espectral
15.
Ind Psychiatry J ; 29(2): 205-212, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-34158703

RESUMEN

BACKGROUND: Somatization is the presentation of physical symptoms without an objective and identifiable cause, and the condition is among the most common and challenging problems in primary medical care. Several modal of psychotherapy modal is being practiced but effective treatment in rarely delivered. AIM: The aim of this study is to evaluate the efficacy and durability of multimodal psychotherapy in the management of somatization disorder. MATERIALS AND METHODS: This is a hospital-based study using the pre-post design with control group. Thirty outpatient department patients with somatization disorder were selected and divided into two groups, i.e., intervention group and control group using the purposive sampling method. Intervention group was given 12 sessions of management package, i.e., symptoms monitoring form, scheduling of daily activity, sleep hygiene, diaphragmatic breathing, psycho-social intervention, psychodynamic individual psychotherapy, and cognitive restructuring (approximately 3-4 months). Efficacy and durability were measured by the Bradford somatic inventory, general health questionnaire-28 (GHQ-28), defense mechanism inventory (DMI), and Sack's sentence completion test (SSCT). RESULTS: The results reveal that there are significant differences found among intervention group in comparisons to the control group in the context of somatic complaints (BSI), general health functioning (GHQ-28), life conflict (SSCT), and in defense mechanism (DMI). Significant improvement also found between postintervention and follow-up of the intervention group on different study variables. CONCLUSION: The present study findings indicate that multimodal psychotherapy program is effective in the Indian context in the management of somatization disorder.

16.
Asian J Neurosurg ; 14(2): 575-577, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31143287

RESUMEN

The term phaeohyphomycosis (PHM) means dark-pigmented fungal hyphae. Cerebral PHM (CPHM) with onychomycosis is extremely rare; very few have been reported so far. The authors report a case of CPHM with onychomycosis in a 37-year-old male from a rural background in Haryana, India, with involvement of the left frontal lobe. The mass was resected and biopsy was sent for histopathological examination. He was given antifungal drugs in the postoperative period. The patient responded very well to the treatment, and there were no signs of recurrence at the 6-month follow-up visit. The clinical features, imaging and histopathological investigations, and management of this rare entity are discussed, and the available literature is also reviewed.

18.
Front Cell Neurosci ; 12: 356, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30364248

RESUMEN

Background: Deciphering avenues to adequately control malignancies in the peripheral nerve will reduce the need for current, largely-ineffective, standards of care which includes the use of invasive, nerve-damaging, resection surgery. By avoiding the need for en bloc resection surgery, the likelihood of retained function or efficient nerve regeneration following the control of tumor growth is greater, which has several implications for long-term health and well-being of cancer survivors. Nerve tumors can arise as malignant peripheral nerve sheath tumors (MPNST) that result in a highly-aggressive form of soft tissue sarcoma. Although the precise cause of MPNST remains unknown, studies suggest that dysregulation of Schwann cells, mediated by the microenvironment, plays a key role in tumor progression. This study aimed to further characterize the role of local microenvironment on tumor progression, with an emphasis on identifying factors within tumor suppressive environments that have potential for therapeutic application. Methods: We created GFP-tagged adult induced tumorigenic Schwann cell lines (iSCs) and transplanted them into various in vivo microenvironments. We used immunohistochemistry to document the response of iSCs and performed proteomics analysis to identify local factors that might modulate divergent iSC behaviors. Results: Following transplant into the skin, spinal cord or epineurial compartment of the nerve, iSCs formed tumors closely resembling MPNST. In contrast, transplantation into the endoneurial compartment of the nerve significantly suppressed iSC proliferation. Proteomics analysis revealed a battery of factors enriched within the endoneurial compartment, of which one growth factor of interest, ciliary neurotrophic factor (CNTF) was capable of preventing iSCs proliferation in vitro. Conclusions: This dataset describes a novel approach for identifying biologically relevant therapeutic targets, such as CNTF, and highlights the complex relationship that tumor cells have with their local microenvironment. This study has significant implications for the development of future therapeutic strategies to fight MPNSTs, and, consequently, improve peripheral nerve regeneration and nerve function.

19.
J Neurosurg ; 130(1): 163-171, 2018 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-29350602

RESUMEN

OBJECTIVE Intravital spectral imaging of the large, deeply situated nerves in the rat peripheral nervous system (PNS) has not been well described. Here, the authors have developed a highly stable platform for performing imaging of the tibial nerve in live rodents, thus allowing the capture of high-resolution, high-magnification spectral images requiring long acquisition times. By further exploiting the qualities of the topically applied myelin dye Nile red, this technique is capable of visualizing the detailed microenvironment of peripheral nerve demyelination injury and recovery, while allowing us to obtain images of exogenous Schwann cell myelination in a living animal. METHODS The authors caused doxorubicin-induced focal demyelination in the tibial nerves of 25 Thy-1 GFP rats, of which 2 subsets (n = 10 each) received either BFP-labeled SKP-SCs or SCs to the zone of injury. Prior to acquiring images of myelin recovery in these nerves, a tibial nerve window was constructed using a silicone hemitube, a fast drying silicone polymer, and a small coverslip. This construct was then affixed to a 3D-printed nerve stage, which in turn was affixed to an external fixation/microscope stage device. Myelin visualization was facilitated by the topical application of Nile red. RESULTS The authors reliably demonstrated intravital peripheral nerve myelin imaging with micron-level resolution and magnification, and minimal movement artifact. The detailed microenvironment of nerve remyelination can be vividly observed, while exogenously applied Schwann cells and skin-derived precursor Schwann cells can be seen myelinating axons. CONCLUSIONS Topically applied Nile red enables intravital study of myelin in the living rat PNS. Furthermore, the use of a tibial nerve window facilitates stable intravital peripheral nerve imaging, making possible high-definition spectral imaging with long acquisition times.


Asunto(s)
Axones/patología , Microscopía Intravital/métodos , Vaina de Mielina/patología , Traumatismos de los Nervios Periféricos/diagnóstico por imagen , Nervio Tibial/diagnóstico por imagen , Nervio Tibial/lesiones , Animales , Modelos Animales de Enfermedad , Colorantes Fluorescentes , Masculino , Oxazinas , Ratas , Ratas Sprague-Dawley , Células de Schwann/patología
20.
Biomed Mater ; 13(3): 034101, 2018 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-29068322

RESUMEN

In this study, GFP+ skin-derived precursor Schwann cells (SKP-SCs) from adult rats were grafted into the injured spinal cord of immunosuppressed rats. Our goal was to improve grafted cell survival in the injured spinal cord, which is typically low. Cells were grafted in hyaluronan-methylcellulose hydrogel (HAMC) or hyaluronan-methylcellulose modified with laminin- and fibronectin-derived peptide sequences (eHAMC). The criteria for selection of hyaluronan was for its shear-thinning properties, making the hydrogel easy to inject, methylcellulose for its inverse thermal gelation, helping to keep grafted cells in situ, and fibronectin and laminin to improve cell attachment and, thus, prevent cell death due to dissociation from substrate molecules (i.e., anoikis). Post-mortem examination revealed large masses of GFP+ SKP-SCs in the spinal cords of rats that received cells in HAMC (5 out of n = 8) and eHAMC (6 out of n = 8). Cell transplantation in eHAMC caused significantly greater spinal lesions compared to lesion and eHAMC only control groups. A parallel study showed similar masses in the contused spinal cord of rats after transplantation of adult GFP+ SKP-SCs without a hydrogel or immunosuppression. These findings suggest that adult GFP+ SKP-SCs, cultured/transplanted under the conditions described here, have a capacity for uncontrolled proliferation. Growth-formation in pre-clinical research has also been documented after transplantation of: human induced pluripotent stem cell-derived neural stem cells (Itakura et al 2015 PLoS One 10 e0116413), embryonic stem cells and embryonic stem cell-derived neurons (Brederlau et al 2006 Stem Cells 24 1433-40; Dressel et al 2008 PLoS One 3 e2622), bone marrow derived mesenchymal stem cells (Jeong et al 2011 Circ. Res. 108 1340-47) and rat nerve-derived SCs following in vitro expansion for >11 passages (Funk et al 2007 Eur. J. Cell Biol. 86 207-19; Langford et al 1988 J. Neurocytology 17 521-9; Morrissey et al 1991 J. Neurosci. 11 2433-42). It is of upmost importance to define the precise culture/transplantation parameters for maintenance of normal cell function and safe and effective use of cell therapy.


Asunto(s)
Células de Schwann/trasplante , Piel/citología , Traumatismos de la Médula Espinal/cirugía , Animales , Axones/fisiología , Supervivencia Celular/efectos de los fármacos , Células Madre Embrionarias/citología , Femenino , Proteínas Fluorescentes Verdes/metabolismo , Ácido Hialurónico/química , Hidrogeles/química , Masculino , Mycoplasma , Regeneración Nerviosa , Células-Madre Neurales/citología , Ratas , Ratas Endogámicas F344 , Resistencia al Corte
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