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Biomedical subjects

R Torres

Publications and source records attributed to R Torres.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of the expression of P-selectin, ICAM-1, and TNF-alpha in bacteria-free lesional skin of atopic dogs with low-to-mild inflammation.

Canine atopic dermatitis (AD) is a pruritic skin condition that shares many clinical and pathophysiological features with its human counterpart. A major therapeutic challenge of AD is the control of the skin inflammatory process. A detailed knowledge of the pro-inflammatory molecules involved in cell recruitment in AD would allow for a better control of the disease. We thus have studied the protein expression of P-selectin, ICAM-1 and TNF-alpha in the lesional and non-lesional skin of atopic dogs that had been treated for bacterial infections. Despite a low-to-mild inflammatory process, P-selectin protein was clearly upregulated in the lesional skin areas when compared with non-lesional skin (four-fold average increase). This P-selectin upregulation was accompanied by signs of functional changes such as increased cell margination, and membrane-associated protein expression. Although the expression of ICAM-1 and TNF-alpha was not enhanced in the lesional versus the non-lesional skin, there was a trend towards a correlated upregulation of both molecules. Further studies will help elucidate the significance of the substantial overexpression of P-selectin in canine AD, in particular in a scenario where bacterial antigens are not contributing as pro-inflammatory stimuli.

Animals↗
PubMed2006

Thoracoscopic and laparoscopic oesophagectomy improves the quality of extended lymphadenectomy.

BACKGROUND: Oesophagectomy with extended lymphadenectomy carries considerable morbidity due to parietal trauma. It is also technically extremely demanding because the difficult access even through a large thoracotomy requires the use of long instruments to reach the deepest recess in the chest cavity. Since the first thoracoscopic oesophagectomy reported by Cuschieri et al. [1] in 1992, different minimally invasive approaches have been proposed [2-12]. The aim of this video is to show the accurate and relative ease of an entirely thoracoscopic and laparoscopic oesophagectomy with an extended lymph node dissection of mediastinum in prone position (thoracoscopically) and celiac trunk (laparoscopically). METHODS: Oesophagectomy by thoracoscopy, laparoscopy and cervicotomy was proposed in a 63-year-old man with a lower third oesophageal cancer. General anaesthesia was performed with a double-lumen endotracheal tube and the patient was placed in prone position. Surgeons were positioned at the right side of the patient. Only three trocars were needed. A 10 mm 30-degree angled scope was inserted in the 7th intercostal space on the posterior axillary line and the remaining two 5 mm trocars were inserted in the 5th and 9th intercostal spaces on the posterior axillary line. Prone position allows an excellent visibility of the operative field even in an only partially deflated lung. In order to achieve a good exposure, transitory pneumothorax with CO2 (14 mmHg) was performed. The mediastinal pleura overlying the oesophagus was incised and the arch of azygos vein was isolated, ligated and divided. The oesophagus was circumferentially mobilized from the thoracic inlet down to oesophageal hiatus. Para oesophageal and subcarinal lymph nodes were dissected so as to remain in block with the surgical specimen. A 28 F chest tube was inserted in the 8th intercostal space on the anterior axillary line. In the second stage the patient was placed in supine position and pneumoperitoneum was established. Five trocars were placed along an ideal semicircular line, with the concavity facing the subcostal margin and a 30-degree angled laparoscope was used. The lesser omentum was widely opened up the right pillar of the hiatus. Mobilization of the greater curvature of the stomach was performed preserving the right gastroepiploic artery. A wide Kocher maneuver was performed. Celiac lymphadenectomy started with skeletonization of the hepatic artery until the root of left gastric artery was reached. This artery and the left gastric vein were dissected, clipped and sectioned. All fatty tissue and lymph nodes along hepatic artery, left gastric artery and celiac trunk were resected in block with the surgical specimen. Multiple applications of a linear endoscopic stapler were used to create the gastric tube. Finally the distal oesophagus was dissected, until the thoracoscopic dissection field was joined. In the third stage a left lateral cervicotomy was performed and the cervical oesophagus was dissected down to the thoracoscopic dissection plane. Oesophagus and stomach were delivered through the cervical incision and an oesophagogastric anastomosis was created by a linear stapler technique. Cervical and abdominal drainages were installed. RESULTS: The total operative time was 271 minutes (thoracoscopy: 106 minutes, laparoscopy 120 minutes and cervicotomy 45 minutes) and blood loss was about 100 ml. Histological examination demonstrated a squamous cell carcinoma. Both margins of resection were free of tumour and 29 lymph nodes were retrieved. The final stage was IIA (pT3N0Mx). CONCLUSIONS: Thoracoscopic and laparoscopic oesophagectomy with extended lymphadenectomy is technically feasible and safe. Thoracoscopic oesophagectomy in prone position improves the quality of dissection because: The oesophagus and aorto-pulmonary window are reached under excellent visibility, despite a partially deflated lung, which because of gravity will always remain out of harm's way. For the same reason small to moderate bleeding will not obscure the operative field. Dissection with the long endoscopic instruments is more accurate due to the support provided by the entrance site at the parietal level and the ergonomic position of surgeon. This article contains a supplementary video.

Blood Loss, Surgical↗
PubMed2006

Losartan improves resistance artery lesions and prevents CTGF and TGF-beta production in mild hypertensive patients.

Although structural and functional changes of resistance arteries have been proposed to participate in arterial hypertension (HTA) outcome, not all therapies may correct these alterations, even if they normalize the blood pressure (BP). The aim of this study was to investigate the mechanisms of the protection afforded by the angiotensin receptor antagonist losartan in resistance arteries from patients with essential HTA. In all, 22 untreated hypertensive patients were randomized to receive losartan or amlodipine for 1 year and the morphological characteristics of resistance vessels from subcutaneous biopsies were evaluated. Protein expression of connective tissue growth factor (CTGF), transforming growth factor beta (TGF-beta), and collagens III and IV was detected by immunohistochemistry. In comparison with normotensive subjects, resistance arteries from hypertensive patients showed a significant media:lumen (M/L) ratio increment and a higher protein expression of CTGF, TGF-beta, and collagens. After 1 year of treatment, both losartan and amlodipine similarly controlled BP. However, M/L only decreased in patients under losartan treatment, whereas in the amlodipine-treated group this ratio continued to increase significantly. The administration of losartan prevented significant increments in CTGF, TGF-beta, and collagens in resistance arteries. By contrast, amlodipine-treated patients showed a higher vascular CTGF, TGF-beta, and collagen IV staining than before treatment. Our results show that the administration of losartan, but not amlodipine, to hypertensive patients improves structural abnormalities and prevents the production of CTGF and TGF-beta in small arteries, despite similar BP lowering. These data may explain the molecular mechanisms of the better vascular protection afforded by drugs interfering with the renin-angiotensin system.

Adult↗
PubMed2006

Sensitization of naive beagles by intradermal injection of an ascaris antigen: induction of a model of skin allergy.

Ascaris suum-hypersensitive beagles represent a unique model of skin allergy. Despite its suitability, the need to test numerous dogs prior to the selection of natural positive responders causes many complications. We hypothesized that the model could be induced in adult beagles by primary sensitization. Ten dogs were included in an intradermal sensitization program using ascaris antigen and were thereafter tested for cutaneous reaction. After 2 weeks, 60% developed a positive reaction that lasted for months. We therefore present a straightforward method to establish the Ascaris canine model of allergy that will extend its availability for research in cutaneous allergy immunomodulation.

Animals↗
PubMed2006

The role of mast cells in atopy: what can we learn from canine models? A thorough review of the biology of mast cells in canine and human systems.

Mast cell research has largely focused on the role of these cells in the early phase of allergic reactions. However, their involvement may well extend beyond this stage, and even reach across nonallergic conditions. Mast cells from different sources have helped advance our knowledge of their biology. Although in vitro and in vivo research in this area has mainly focused on humans, such studies are limited by the extent to which cells from certain human tissues and/or human patients can be collected or studied. While rodents also provide valuable models with which to further our understanding of the behaviour of mast cells and their contribution to allergy, reported differences between human and murine mast cells, and, in some instances, the limitations of in vivo rodent models of mast cell-mediated allergic conditions, preclude their use. In this review, we introduce a relatively unknown mast cell population, that of the dog. Canine mast cells display many phenotypic and functional similarities with their human counterparts, and dogs develop spontaneous and induced allergic diseases that share clinical and pathophysiological features with the human condition. Therefore, the use of canine cells can shed light on the general role of mast cells, particularly in relation to allergic diseases given the potential of in vivo dog models within this field. Here we provide a detailed review of the data reported from in vitro and in vivo studies of canine mast cells, and compare them with results obtained in human systems. We also highlight direct evidence of the mast cell contribution to canine atopy. We conclude that the dog offers useful in vitro and in vivo models in which to investigate mast cell behaviour, and that its use should be considered when undertaking studies aimed either at elucidating the role of mast cells in health and disease, or at prescreening novel therapies prior to entry into man.

Animals↗
PubMed2006

Alpha-II-spectrin after controlled cortical impact in the immature rat brain.

Proteolytic processing plays an important role in regulating a wide range of important cellular functions, including processing of cytoskeletal proteins. Loss of cytoskeletal proteins such as spectrin is an important characteristic in a variety of acute central nervous system injuries including ischemia, spinal cord injury and traumatic brain injury (TBI). The literature contains extensive information on the proteolytic degradation of alpha-II-spectrin after TBI in the adult brain. By contrast, there is limited knowledge on the characteristics and relevance of these important processes in the immature brain. The present experiments examine TBI-induced proteolytic processing of alpha-II-spectrin after TBI in the immature rat brain. Distinct proteolytic products resulting from the degradation of the cytoskeletal protein alpha-II-spectrin by calpain and caspase 3 were readily detectable in cortical brain parenchyma and cerebrospinal fluid after TBI in immature rats.

Animals↗
PubMed2006

Efficacy of Candida sake CPA-1 formulation for controlling Penicillium expansum decay on pome fruit from different Mediterranean regions.

The effectiveness of a formulated product of the yeast Candida sake CPA-1 for controlling postharvest diseases on pome fruits was demonstrated in laboratory, semicommercial, and commercial trials carried out in the major pome fruit producing region of the European Union. First, one wettable powder and seven liquid formulations were tested in laboratory trials that involved two varieties of apples and two varieties of pears. In all cases, an efficacy similar to that of fresh cells was demonstrated in the control of artificial Penicillium expansum infection. After these trials, the formulated product chosen for semicommercial and commercial trials was LF1, a liquid formulation that is particularly suitable for commercial applications. In semicommercial trials, LF1 showed a performance similar to fresh cells in most trials, and the population dynamics of both fresh and formulated cells were quite stable throughout the storage period. This indicates the high viability of C. sake CPA-1 in this formulation and the absence of adverse effects during the formulation of the product, which may significantly affect both its ability to grow on fruit and its antagonistic activity. We evaluated the control of natural infection after applying the formulated product in a commercial drencher in different packinghouses. A significant reduction in the incidence of diseases was observed with a recommended dose of around 10(7) CFU/ml when natural infections were greater than 1%. In general, large quantities of yeast were observed on the surface of unwounded fruits of different pome fruit cultivars. Moreover, populations of this biocontrol agent increased rapidly on fruit surfaces and remained quite stable for a long time under commercial storage conditions. Commercial practices used in packinghouses were therefore successfully applied for this formulated product.

Antibiosis↗
PubMed2006

[Preclinical diagnosis of the familial nephropathy associated to hyperuricemia].

We describe one patient with the pre-symptomatic diagnosis of the disease named afamilial nephropathy associated to hyperuricemia)) (OMIM 162000; FJHN). This is a hereditary disease, autosomic dominant, characterized by its progression to renal insufficiency. Several mutations in the gene that codifies uromodulin or Tannn-Horsfall protein (UMOD) have been identified in some families. The clinical presentation is heterogeneous. In some cases the disease appears as juvenile hyperuricemia due to a diminished renal urate excretion, with or without gout, but in some other cases the first manifestation is renal insuffciency. The study of the UMOD gene shows that patient is heterozygous for the mutation C869 --> A, which results in C255Y change, and enabled to establish the diagnosis of FJHN. This patient shows the possibility to identify the genetic alteration associated to FJHN in early stages. This fact implies a clinical follow-up and eventual treatment to reduce the inexorable progression to renal insuffciency.

Child↗
PubMed2005

QTLs for drought escape and tolerance identified in a set of random introgression lines of rice.

A large set of 254 introgression lines in an elite indica genetic background were evaluated for grain yield (GY) and related traits under the irrigated (control) and drought (stress) conditions in two consecutive years for genetic dissection of adaptive strategies of rice to water stress. A total of 36 quantitative trait loci (QTLs) affecting heading date (HD), plant height (PH), GY and yield components were identified and most QTLs showed pronounced differential expression either qualitatively or quantitatively in response to drought. These QTLs could be grouped into three major types based on their behaviors under control and stress conditions. Type I included 12 QTLs that expressed under both the stress and non-stress conditions. Type II comprised 17 QTLs that expressed under irrigation but not under stress. Type III included seven QTLs that were apparently induced by stress. The observation that the Lemont (japonica) alleles at all HD QTLs except QHd5 resulted in early heading under stress appeared to be responsible for the putative adaptation of Lemont to drought by escaping, whereas the Teqing (indica) alleles at most PH/GY QTLs were consistently associated with increased yield potential and trait stability and thus contributed to DT. Our result that most DT QTLs were non-allelic with QTLs for drought escaping suggests that the two adaptive strategies in the parental lines are under possible negative regulation of two largely non-overlapping genetic systems.

Adaptation, Biological↗
PubMed2005

Cyclical upregulated iNOS and long-term downregulated nNOS are the bases for relapse and quiescent phases in a rat model of IBD.

We previously reported that indomethacin induces a chronic intestinal inflammation in the rat where the cyclical characteristic phases of Crohn's disease are manifested with a few days' interval and lasting for several months: active phase (high inflammation, hypomotility, bacterial translocation) and reactive phase (low inflammation, hypermotility, no bacterial translocation). In this study, we investigated the possible role of both constitutive and inducible isoforms of nitric oxide (NO) synthase (NOS) and cyclooxygenase (COX) in the cyclicity of active and reactive phases in rats with chronic intestinal inflammation. Rats selected at either active or reactive phases and from 2 to 60 days after indomethacin treatment were used. mRNA expression of both constitutive and inducible NOS and COX isoforms in each phase was evaluated by RT-PCR and cellular enzyme localization by immunohistochemistry. The effects of different COX and NOS inhibitors on the intestinal motor activity were tested. mRNA expression of COX-1 was not modified by inflammation, whereas mRNA expression of neuronal NOS was reduced in all indomethacin-treated rats. In contrast, NOS and COX inducible forms showed a cyclical oscillation. mRNA expression and protein of both iNOS and COX-2 increased only during active phases. The intestinal hypomotility associated with active phases was turned into hypermotility after the administration of selective iNOS inhibitors. Sustained downregulation of constitutive NOS caused hypermotility, possibly as a defense mechanism. However, this reaction was masked during the active phases due to the inhibitory effects of NO resulting from the increased levels of the inducible NOS isoform.

Animals↗
PubMed2005

Controlling two-center interference in molecular high harmonic generation.

We experimentally investigate the process of intramolecular quantum interference in high-order harmonic generation in impulsively aligned CO2 molecules. The recombination interference effect is clearly seen through the order dependence of the harmonic yield in an aligned sample. The experimental results can be well modeled assuming that the effective de Broglie wavelength of the returning electron wave is not significantly altered by the Coulomb field of the molecular ion. We demonstrate that such interference effects can be effectively controlled by changing the ellipticity of the driving laser field.

Journal Article↗
PubMed2005

Multimedia article. Entirely thoracoscopic pneumonectomy using the prone position: a new technique.

BACKGROUND: Reports on video-assisted pneumonectomy have remained scarce, despite early demonstration of its technical feasibility. A totally videothoracoscopic pneumonectomy was first reported by Conlan and Sandor. The patient in this report was positioned in the full lateral position. In this video, we report a totally videothoracoscopic left-side pneumonectomy with the patient in prone position. METHODS: A 49-year-old man was admitted to our hospital for a bifocal cancer of the left lower lung lobe (LLL) and the cervical esophagus. The preoperative workup included a chest computed tomography (CT) scan showing a 3-cm mass of the laterobasal segment of the LLL, with retrotumoral atelectasis, lymph nodes smaller than 1 cm in diameter at the aortopulmonary window and under the carena, and finally posterolateral adherences between the parietal and the visceral pleura. Flexible bronchoscopy confirmed the presence of a bronchial tumor at the offspring of the apical bronchus of the LLL. Biopsy showed invasive adenocarcinoma, and a CT scan of the neck and head was significant for tumoral infiltration of the cervical esophagus and retropharyngeal space. Gastroscopy showed a stenosis of the cervical esophagus and hypopharynx. Biopsy showed spinocellular epithelioma, but CT scan of the abdomen and bone scintigraphy did not show metastatic disease. A position emission tomography (PET) scan confirmed the findings of the CT scan. Pneumonectomy and esophagectomy by thoracoscopy, laparoscopy, and cervicotomy were proposed. The purpose of this video is to show the details of the thoracoscopic technique with the patient in the prone position. RESULTS: After induction of general anesthesia, a double-lumen endotracheal tube was placed. The patient was subsequently placed and strapped in a prone position. The surgical team was placed to the left of the patient. A 10-mm trocar was placed in the seventh intercostal space on the posterior axillary line, and a 30 degrees angled videoscope was introduced. Three additional 5-mm trocars were placed at the same level in the 5th, 9th, and 11th intercostal spaces on the posterior axillary line. The mediastinal pleura was opened just ventral to the aorta. The first structure identified was the left main bronchus, which was dissected free and transected with a linear stapler (blue load). The aortopulmonary window became immediately visible. Clearance of this window's lymphoglandular tissue showed, bottom to top, the inferior pulmonary vein, the superior pulmonary vein, and the pulmonary artery. These vascular structures were carefully dissected free with the cautery hook and transected with a vascular linear stapler (white load). The lung was freed entirely tend placed in a retrieval bag for later transhiatal extraction during the laparoscopic phase of the esophagectomy. The intraoperative time for the pneumonectomy was 146 min, and intraoperative blood loss was 30 ml. The pathology report confirmed the presence of invasive, poorly differentiated adenocarcinoma. The bronchial section was free of tumor. One intrapulmonary lymphnode (N1) was positive, whereas all 10 N2 and N3 nodes harvested were free of disease. The tumor was thus staged as IIB (pT2N1Mx). The esophagetomy specimen showed fairly wide differentiated keratinizing of the spinocellular epithelioma with invasion of both pyriform sinuses and both sides of the glottis. CONCLUSIONS: First described by Cuschieri et al. in 1992, the prone position for thoracoscopy allows for a more direct approach to the aortopulmonary window under excellent visual and ergonomic circumstances. Dissection of the hilar larger vessels and performance of lymphnode sampling appear more straightforward because with this technique, the lung is kept out of harm's way, thanks to gravity.

Humans↗
PubMed2005

Global iron connections between desert dust, ocean biogeochemistry, and climate.

The environmental conditions of Earth, including the climate, are determined by physical, chemical, biological, and human interactions that transform and transport materials and energy. This is the "Earth system": a highly complex entity characterized by multiple nonlinear responses and thresholds, with linkages between disparate components. One important part of this system is the iron cycle, in which iron-containing soil dust is transported from land through the atmosphere to the oceans, affecting ocean biogeochemistry and hence having feedback effects on climate and dust production. Here we review the key components of this cycle, identifying critical uncertainties and priorities for future research.

Atmosphere↗
PubMed2005

Effect of H1- and H2-receptor antagonists on the hemodynamic changes induced by the intravenous administration of ketamine in sevoflurane-anesthetized cats.

OBJECTIVE: The anesthetic ketamine has been reported to cause both an increase of the plasma histamine concentration, notably in cats, and a cardiovascular depression. The latter has been described in humans and in other species. However the relevance of the histamine fluctuation for the ketamine-induced hemodynamic changes has not been determined. SUBJECTS AND TREATMENT: We studied the contribution of histamine to the hemodynamic effects induced by IV ketamine (7 mg/kg) in 12 sevoflurane anesthetized cats, of which half had been pre-treated with combined H(1)- and H(2) -receptor antagonists. METHODS: The mean arterial pressure (MAP) and the heart rate (HR) from both untreated (group C) and pre-treated (group AH) cats were recorded before and after the ketamine administration. The plasma histamine concentration was also measured. RESULTS: Plasma histamine fluctuations in the control and the antihistamine-treated group followed a similar pattern (no statistical differences); an initial rise that peaked 2 min after ketamine injection (from 0.63 +/- 0.11 ng/ml to 2.22 +/- 0.69 ng/ml in the C group, and from 0.71 +/- 0.10 ng/ml to 1.09 +/- 0.28 ng/ml in the AH group) followed by an immediate decrease in plasma concentrations. As for the hemodynamic variables under analysis, in the control group ketamine administration was followed by an early 30.3 +/- 8.1% reduction (p < 0.005) in the MAP with no associated changes in the HR. In the antihistamine pre-treated group, ketamine caused a further decrease of the MAP (41.7 +/- 2.3%), and a significant (p < 0.01) 11.6 +/- 2.9% reduction of the HR. CONCLUSION: Ketamine in anesthetized cats triggers histamine release and induces cardiovascular depression. The depression is more pronounced under the blockade of histamine activity through histamine receptor antagonists.

Anesthetics↗
PubMed2005

Multimedia article: laparoscopic left lateral hepatic lobectomy for metastatic colorectal tumor.

BACKGROUND: The growth of experience in laparoscopic surgery, technological improvements in laparoscopic instruments, and the application of laparoscopy to oncology surgery are responsible for the new challenge of laparoscopic liver surgery. Several series of laparoscopic liver resections have been reported, and these series have shown the feasibility of resections. The first anatomical laparoscopic liver resection was a left lateral segmentectomy, reported in 1996 by Azagra et al. due to favorable anatomy of this hepatic segment for a totally laparoscopic approach. METHODS: This video shows a left lateral hepatic lobectomy (bisegmentectomy 2-3) by a total laparoscopic approach in a 56-year-old woman who presented with a metastatic tumor from operated colorectal cancer. A CO(2) pneumoperitoneum was induced with a Veress needle and abdominal pressure was maintained at 12 mmHg. Five trocars were placed along an ideal semicircular line, with the concavity facing the right subcostal margin, and a 30 degrees angled laparoscope was used. A retraction of round ligament with suture was performed to obtain exposure of the inferior face of liver. The left hepatic pedicle was dissected in close vicinity with the portal branch. Segmental vascular structures and bile ducts of segments 3 and 2 were progressively and intraparenchymatously identified, clipped, and sectioned. A Pringle's maneuver was not necessary. The dissection line was demarcated on the liver with monopolar cautery, and liver parenchymal transection was obtained with an ultrasound scalpel (Ultracision, Ethicon Endosurgery). Finally, the left hepatic vein was sectioned with a linear vascular endostapler (Ethicon Endosurgery). Extraction of specimen was performed using a plastic bag through an enlarged trocar site. RESULTS: The operative time was 110 min, and blood loss was zero. The postoperative period was uneventful, the length of hospital stay was 5 days, and the patient returned to normal activity 1 week postoperatively. The surgical margins of specimen were free of disease. CONCLUSIONS: Laparoscopic left lateral lobectomy of the liver is feasible and safe in patients with isolated malignant disease of the left lateral segment. This approach reduces blood loss and postoperative hospital stay, and it has a better cosmetic result.

Colorectal Neoplasms↗
PubMed2005

High-strength apatitic cement by modification with superplasticizers.

This study reports on a novel method to improve the strength of apatitic bone cements. The liquid phase of Biocement-H was modified with commercial superplasticizers. The results showed that small additions, i.e. 0.5 vol%, in the aqueous liquid phase improved the maximum compressive strength of Biocement-H (35 MPa) by 71%, i.e. 60 MPa. Moreover, the addition of high amounts of superplasticizers, i.e. 50 vol.%, allowed for a significant reduction of the liquid-to-powder ratio from 0.32 to 0.256 mL/g, without affecting the maximum strength and/or the workability of the cement. These results open up new ways to develop injectable and high-strength apatitic bone cements for load-bearing applications.

Bone Cements↗
PubMed2005

Deep brain stimulation in intraoperative MRI environment - comparison of imaging techniques and electrode fixation methods.

We performed 118 consecutive DBS cases from November 1999 to June 2002. Intraoperatively there were 10 cases studied with fluoroscopy, 73 with 0.2 Tesla (T) MRI and 35 with 1.5 T MRI. Ten electrodes were secured by Medtronic caps, 25 by methyl methacrylate with titanium miniplates, and 82 by Navigus caps. The 3-dimensional displacement between the planned target and actual electrode position (3DD) was determined by fusing the postoperative MRI with the preoperative imaging. The 3DD for using Medtronic caps, methyl methacrylate with miniplates, and Navigus caps were 4.80 +/- 3.16, 2.64 +/- 1.26 and 2.23 +/- 1.15 mm (mean +/- SD), respectively. Navigus caps had statistically significant accuracy (P = 0.03) in holding the electrode when compared with Medtronic caps, and it facilitated electrode revision. The fixation devices significantly affect the final vertical position of the electrode. The 3DD for fluoroscopy, 0.2 T and 1.5 T MRI cases were 4.80 +/- 3.16, 2.31 +/- 1.21 and 2.34 +/- 1.14 mm (mean +/- SD), respectively. No statistically significant difference (P = 0.91) in 3DD was demonstrated between 0.2 T and 1.5 T MRI cases. The presence of intraoperative 1.5 T MRI allowed near real-time electrode position confirmation and early detection of hemorrhagic complications. Satisfactory microelectrode recording was feasible in low-field 0.2 T and high-field 1.5 T MRI environments. Further studies on performing DBS in real-time intraoperative MRI are warranted.

Adolescent↗