Publications by authors named "Mauricio Sierra"

Introduction: Recurrence of papillary thyroid carcinoma after initial treatment is challenging. Surgical reintervention is recommended, but cure after surgery in uncertain and surgical morbidity may be high. This study evaluates the effect of compartment-oriented lymph node dissection (LND) on clinical and biochemical cure rate as well as the related complications.

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Background: Laparoscopic Roux-en-Y Gastric Bypass (LRYGB) is one of the most commonly performed bariatric procedures. Considering significant differences between populations around the world, surgical outcomes may vary widely. The aim of the study was to develop an educational patient-specific interactive application that may estimate the potential outcomes of LRYGB in the Mexican population.

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Article Synopsis
  • - Total thyroidectomy, a surgery for thyroid diseases, often leads to complications like hypocalcemia and hypoparathyroidism, with a study analyzing data from 1018 patients to assess these risks and outcomes over 16 years.
  • - The study found postoperative hypocalcemia occurred in 32.8% of cases, with 3.9% resulting in permanent hypoparathyroidism, significantly linked to the number of parathyroid glands preserved during surgery.
  • - Key risk factors for permanent hypoparathyroidism included having fewer parathyroid glands left intact, obesity, level VI lymph node dissection, and incidental removal of parathyroid glands without subsequent autotransplantation.
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Aim: The aim of this study is to compare the differences in body composition in patients with obesity with successful weight loss (SWL) and unsuccessful (USWL) 1 year after Roux-en-Y gastric bypass (RYGB).

Methods: We included 36 women and 22 men. After stratifying patients according with SWL (defined as ≥ 50% of excess weight loss), fat-free mass (FFM) and fat mass (FM) trajectories were analyzed in each group.

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Introduction: Body contour surgery (BCS) is a combination of soft tissue resections that have proven to be an effective treatment for the aesthetic and functional problems related to massive weight loss (MWL). There are no studies analyzing the metabolic effect of large volume adipose tissue flap resection in patients with MWL after bariatric surgery.

Methods: This study was a retrospective review of adults who underwent BCS after gastric bypass.

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Background: Advanced bipolar and ultrasonic energy have demonstrated reduction of operating time and blood loss in thyroidectomy. However, these devices generate heat and thermal dispersion that may damage adjacent structures such as the recurrent laryngeal nerve (RLN). This study was designed to evaluate the safety profile of the Harmonic Focus+ (HF+) device through the evaluation of thermal injury to the RLN using different algorithms of distance and time with state of the art technology.

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Intraoperative continuous neural monitoring (C-IONM) during thyroid surgery has been recognized as a useful tool to identify and confirm recurrent laryngeal nerve integrity. The aim of the present study is to analyze electromyographic features and thresholds for normal vocal fold function in our initial experience with C-IONM in thyroid surgery. C-IONM was utilized in 57 patients who underwent thyroid surgery between July 2012 and December 2015.

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Background: Advanced bipolar and ultrasonic devices have shown significant reduction in the surgical time of thyroid operations. This randomized, controlled trial assessed if operative time and other relevant outcomes are different for thyroidectomies performed either with a second-generation advanced bipolar device or traditional tie and suture technique.

Methods: Forty-one patients were randomized into 2 groups (advanced bipolar device and traditional tie and suture).

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This paper presents functional MRI work on emotional processing in depersonalization disorder (DPD). This relatively neglected disorder is hallmarked by a disturbing change in the quality of first-person experience, almost invariably encompassing a diminished sense of self and an alteration in emotional experience such that the sufferer feels less emotionally reactive, with emotions experienced as decreased or "damped down," so that emotional life seems to lack spontaneity and subjective validity. Here we explored responses to emotive visual stimuli to examine the functional neuroanatomy of emotional processing in DPD before and after pharmacological treatment.

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Case reports and an open trial have reported promising responses to repetitive transcranial magnetic stimulation (rTMS) to prefrontal and temporo-parietal sites in patients with depersonalization disorder (DPD). We recently showed that a single session of rTMS to the ventrolateral prefrontal cortex (VLPFC) was associated with a reduction in symptoms and increase in physiological arousal. Seven patients with medication-resistant DSM-IV DPD received up to 20 sessions of right-sided rTMS to the VLPFC for 10 weeks.

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Background: Depersonalization disorder (DPD) entails distressing alterations in self-experiencing. However, it has long been recognized that depersonalisation symptoms occur in other disorders, particularly anxiety and panic. One strand of research proposes that depersonalization phenomenology arises through altered autonomic arousal in response to stress.

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Depersonalisation disorder (DPD) is characterised by a sense of unreality about the self and the world. Research suggests altered autonomic responsivity and dysfunction in prefrontal and temporal lobe areas in this condition. We report the first structural magnetic resonance imaging study of 20 patients with DPD and 21 controls using the FreeSurfer analysis tool employing both region-of-interest and vertex-based methods.

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Background: Laparoscopic splenectomy (LS) is considered the standard treatment for patients with refractory primary immune thrombocytopenia (ITP).

Patients And Methods: All patients with ITP who underwent LS during the last 17 years and who had a minimum follow-up of 1 year were included. Several perioperative variables such as age, platelet count, and duration of preoperative therapy were recorded and analyzed, looking for potential predictive variables of clinical response.

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Background: Depersonalization disorder (DPD) includes changes in subjective experiencing of self, encompassing emotional numbing. Functional magnetic resonance imaging (fMRI) has pointed to ventrolateral prefrontal cortex (VLPFC) inhibition of insula as a neurocognitive correlate of the disorder.

Objective: We hypothesized that inhibition to right VLPFC using repetitive transcranial magnetic stimulation (rTMS) would lead to increased arousal and reduced symptoms.

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Objective: The cerebral mechanisms of traits associated with depersonalization-derealization disorder (DPRD) remain poorly understood.

Method: Happy and sad emotion expressions were presented to DPRD and non-referred control (NC) subjects in an implicit event-related functional magnetic resonance imaging (fMRI) design, and correlated with self report scales reflecting typical co-morbidities of DPRD: depression, dissociation, anxiety, somatization.

Results: Significant differences between the slopes of the two groups were observed for somatization in the right temporal operculum (happy) and ventral striatum, bilaterally (sad).

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It is unclear to what degree depersonalization disorder (DPD) and alexithymia share abnormal brain mechanisms of emotional dysregulation. We compared cerebral processing of facial expressions of emotion in individuals with DPD to normal controls (NC). We presented happy and sad emotion expressions in increasing intensities from neutral (0%) through mild (50%) to intense (100%) to DPD and non-referred NC subjects in an implicit event-related fMRI design, and correlated respective brain activations with responses on the 20-item Toronto Alexithymia Scale (TAS-20) and its three subscales F1-F3.

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Background: Laparoscopic Roux-en-Y gastric bypass (LRYGB) may be a technically challenging surgical technique when features such as thick abdominal wall and increased liver volume are present. Very low calorie diets in the form of liquid meal replacements given 6 weeks prior to surgery have proven to decrease liver volume. The aim of our study was to assess the effect of a 6-week preoperative low calorie/regular diet on liver volume and body weight in morbidly obese patients.

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Background: Primary adrenal malignancies are rare and have a dismal prognosis. We report our experience in both adrenocortical carcinomas and malignant pheochromocytomas who received medical care at our Institution between 1994 and 2009.

Material And Methods: The data bases of hospital discharges, surgery and pathology were reviewed looking for patients with diagnosis of primary adrenal malignant tumors.

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Conditional reasoning premises can be systematically manipulated to elicit specific response patterns. This is useful for investigating the reasoning style of people who report clinical symptoms. We administered a standardized conditional reasoning task to 16 participants with a diagnosis of Asperger's syndrome (AS), 16 participants with a diagnosis of depersonalization disorder (DPD), and 32 intelligence-quotient-matched controls.

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Previous studies investigating depersonalization disorder (DPD) report a lower baseline skin conductance level (SCL) and attenuated skin conductance response (SCR) to emotive stimuli. We hypothesized that increasing physiological arousal levels via electrodermal biofeedback may ameliorate disembodiment and emotional numbing symptomatology. Real-time versus sham biofeedback yielded a significant SCL increase after just 3 real-time biofeedback sessions in healthy volunteers.

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A significant association between anxiety and depersonalization has been found in healthy controls and psychiatric patients irrespective of underlying conditions. Although patients with depersonalization disorder (DPD) often have a history of severe anxiety symptoms, clinical observations suggest that the relation between anxiety and depersonalization is complex and poorly understood. Using relevant rating scales, levels of anxiety and depersonalization were assessed in 291 consecutive DPD cases.

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Depersonalization is characterised by a profound disruption of self-awareness mainly characterised by feelings of disembodiment and subjective emotional numbing. It has been proposed that depersonalization is caused by a fronto-limbic (particularly anterior insula) suppressive mechanism--presumably mediated via attention--which manifests subjectively as emotional numbing, and disables the process by which perception and cognition normally become emotionally coloured, giving rise to a subjective feeling of 'unreality'. Our functional neuroimaging and psychophysiological studies support the above model and indicate that, compared with normal and clinical controls, DPD patients show increased prefrontal activation as well as reduced activation in insula/limbic-related areas to aversive, arousing emotional stimuli.

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Background: Small bowel obstruction (SBO) after laparoscopic Roux-en-Y gastric bypass (LRYGB) may be related to the surgical technique used. The frequency and characteristics of postoperative SBO were studied in two cohorts of patients after LRYGB.

Methods: In a 4-year period, 359 patients underwent LRYGB as an initial bariatric operation at our clinic.

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