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Open Access Publications from the University of California

Scholarly Works (43 results)

  • Article
  • Peer Reviewed
UC Irvine Previously Published Works (2005)
This commentary offers a future health care provider's perspective on the role of complementary and alternative medicine ( CAM) in Western ( namely, in US) medical education and practice. As a student of both public health and medicine in the United States, Jeffrey Ghassemi is interested in CAM's contribution to improving medical practice and teaching. The commentary highlights the ambiguous definitions of CAM to Westerners despite the rising popularity of and expenditures for alternative modalities of care. It then argues for collaboration between alternative and established medical communities to ascertain the scientific merits of CAM. It concludes by calling for a new medical paradigm that embraces the philosophies of both communities to advance education and patient care.
    Cover page: Finding the Evidence in CAM: a Student's Perspective
    • Article
    Contemporary Music Score Collection (2020)
    This music score was submitted for the Kaleidoscope 2020 Call for Scores, an open access collaboration with the UCLA Music Library.
      Cover page: ///^^}}]>>[^"" ::;, Guitar Piece no. 1Creative Commons 'BY-NC-SA' version 4.0 license
      • Thesis
      • Peer Reviewed
      UCLA Electronic Theses and Dissertations (2023)

      The advancement of the humanoid robotics field shows significant potential and progress, however humanoids still have many limitations. This is due to the complexities, cost, danger, and the functional limitations associated with the current state of this technology. This dissertation presents a new type of humanoid bipedal robot. It includes the invention, detailed design, software modeling, fabrication, testing, control, and motion analysis done on the robotic platform BALLU. Buoyancy Assisted Lightweight Legged Unit, or BALLU, is a safe, low cost, simple bipedal robot that uses a helium filled upper body, along with two thin carbon fiber legs. Due to the new architecture and buoyancy force, this robotic platform never falls down and is intrinsically stable. The main prototype version discussed is comparable in size to an adult human, and uses cable driven actuated knee joints for locomotion. The actuation components and the majority of the robot’s weight are located on the feet. Even though each leg has only one active degree of freedom, BALLU can walk forwards and backwards, jump, turn, climb and descend stairs, and go over obstacles and rough terrain. Understanding its non-intuitive dynamics, along with correct actuation and timing and control of the knee joints is the key factor for these types of locomotion. Although BALLU’s leg architecture is inspired and is reminiscent of traditional humanoids and human legs, this novel approach to humanoid design behaves drastically differently and is not modeled using traditional robotic locomotion methods. This dissertation includes the foundational understanding and categorization of this platform's behavior. The platform's physics, control, and locomotion strategies are specifically analyzed and explained in detail. This robotic platform is not intended to replace traditional humanoid robots, rather to introduce new possibilities and present an ultra-safe, low-cost, light-weight alternative tuned for specific applications. The main contribution of this thesis is organization and classification of behavior understanding, and proposing novel unique methods of movement and locomotion for a buoyancy assisted biped robot.

        Cover page: Design, fabrication, and dynamic gait control for a novel buoyancy assisted bipedal robot
        • Article
        • Peer Reviewed
        UCLA Previously Published Works (2016)
        With mortality due to gastrointestinal (GI) bleeding remaining stable, the focus on endoscopic hemostasis has been on improving other outcomes such as rebleeding rate, need for transfusions, and need for angiographic embolization or surgery. Over the past few years, a number of devices have emerged to help endoscopically assess and treat bleeding GI lesions. These include the Doppler endoscopic probe, hemostatic powder, and over-the-scope clip. Also, new applications have been described for radiofrequency ablation. In this article, we will discuss these evolving tools and techniques that have been developed, including an analysis of their efficacy and limitations.
          Cover page: Evolving techniques for gastrointestinal endoscopic hemostasis treatment
          • Article
          • Peer Reviewed
          LBL Publications (2016)
            Cover page: Preface
            • Article
            • Peer Reviewed
            UCLA Previously Published Works (2017)

            Introduction

            The role of EUS-guided FNA as a highly sensitive modality in the diagnosis of pancreatic adenocarcinoma is well documented. However, there is little published data on the role of EUS-FNA in diagnosing pancreatic neuroendocrine tumors (NETs).

            Objective

            The aim of this study is to compare the sensitivity of EUS-FNA to that of CT-FNA for diagnosing pancreatic NETs.

            Methods

            This is a single institution retrospective analysis of the operating characteristics of EUS-FNA and CT-FNA in detecting pancreatic NETs. Only patients with a final diagnosis of pancreatic NET were selected for this study. Procedure related data, including tumor size and location, and presence of a cytotechnologist were recorded. The results of each FNA were compared to the final clinico-pathological diagnosis to calculate sensitivity.

            Results

            Twenty-eight patients undergoing FNA (19 by EUS, 9 by CT) were analyzed. NETs diagnosed by EUS-FNA were smaller compared with CT-FNA (2.7 ± 0.9cm vs. 6.5 ± 2.1cm, p = 0.009) and were more often found in the pancreatic head (47.4% vs. 11.1%, p = 0.035). There were no significant differences in sensitivity between EUS-FNA and CT-FNA specimens (73.7% vs. 88.9%, p = 0.33).

            Conclusion

            EUS-guided FNA is as sensitive as CT-guided FNA in diagnosing pancreatic NETs, but its main advantage is in the diagnosis of smaller pancreatic NETs in the head of the pancreas. It may also be the preferred approach in the diagnosis of multifocal pancreatic NETs in the setting of MEN I Syndrome.
              Cover page: Endoscopic Ultrasound-Guided Fine Needle Aspiration Accurately Diagnoses Smaller Pancreatic Neuroendocrine Tumors Compared To Computer Tomography-Guided Fine Needle Aspiration.
              • Article
              • Peer Reviewed
              UC San Diego Previously Published Works (2015)

              Context

              During puberty, reactivation of the reproductive axis occurs during sleep, with LH pulses specifically tied to deep sleep. This association suggests that deep sleep may stimulate LH secretion, but there have been no interventional studies to determine the characteristics of deep sleep required for LH pulse initiation.

              Objective

              The objective of this study was to determine the effect of deep sleep fragmentation on LH secretion in pubertal children.

              Design and setting

              Studies were performed in a clinical research center.

              Subjects

              Fourteen healthy pubertal children (11.3-14.1 y) participated in the study.

              Interventions

              Subjects were randomized to two overnight studies with polysomnography and frequent blood sampling, with or without deep sleep disruption via auditory stimuli.

              Results

              An average of 68.1 ±10.7 (± SE) auditory stimuli were delivered to interrupt deep sleep during the disruption night, limiting deep sleep to only brief episodes (average length disrupted 1.3 ± 0.2 min vs normal 7.1 ± 0.8 min, P < .001), and increasing the number of transitions between non-rapid eye movement (NREM), REM, and wake (disrupted 274.5 ± 33.4 vs normal 131.2 ± 8.1, P = .001). There were no differences in mean LH (normal: 3.2 ± 0.4 vs disrupted: 3.2 ± 0.5 IU/L), LH pulse frequency (0.6 ± 0.06 vs 0.6 ± 0.07 pulses/h), or LH pulse amplitude (2.8 ± 0.4 vs 2.8 ± 0.4 IU/L) between the two nights. Poisson process modeling demonstrated that the accumulation of deep sleep in the 20 minutes before an LH pulse, whether consolidated or fragmented, was a significant predictor of LH pulse onset (P < .001).

              Conclusion

              In pubertal children, nocturnal LH augmentation and pulse patterning are resistant to deep sleep fragmentation. These data suggest that, even when fragmented, deep sleep is strongly related to activation of the GnRH pulse generator.
                Cover page: Accumulated Deep Sleep Is a Powerful Predictor of LH Pulse Onset in Pubertal Children
                • Article
                • Peer Reviewed
                UCLA Previously Published Works (2021)

                Background and aims

                No prior randomized controlled trial (RCT) has reported patient outcomes of large over-the-scope clip (OTSC) compared to standard hemostasis as initial endoscopic treatment of severe NVUGIB. This was our study aim.

                Methods

                Patients with bleeding ulcers or Dieulafoy's lesions and major stigmata of hemorrhage - SRH (active spurting bleeding, visible vessel, or clot) - or lesser SRH (oozing bleeding or flat spots - with arterial blood flow by Doppler probe) were randomized to OTSC or standard endoscopic hemostasis (with hemoclips or multipolar electrocoagulation - MPEC). Patients and their healthcare providers were blinded to treatments and made all post-randomization management decisions. Ulcer patients received high dose intravenous infusions of proton pump inhibitors (PPI) for 3 days, then 27 days of oral PPI. 30 day outcomes were prospectively recorded; data management was with SAS; and data analysis was by a statistician.

                Results

                53 patients (25 OTSC, 28 Standard) were randomized, with similar baseline risk factors. However, there were significant differences in OTSC vs. Standard groups in rates of rebleeding (4% vs. 28.6%; p = .017; relative risk 0.10, 95% confidence intervals 0.01, 0.91; number needed to treat 4); severe complications (0 % vs. 14.3%); and post-randomization units of red cell transfusions (0.04 vs. 0.68). All rebleeds occurred in patients with major SRH and none with lesser SRH.

                Conclusion

                1. OTSC significantly reduced rates of rebleeding, severe complications, and post-randomization red cell transfusions. 2. Patients with major stigmata benefited significantly from hemostasis with OTSC, but those with lesser stigmata did not. (ClinicalTrials.gov, Number: NCT03065465).
                  Cover page: Randomized Controlled Trial of Over-the-Scope Clip as Initial Treatment of Severe Nonvariceal Upper Gastrointestinal Bleeding
                  • Article
                  • Peer Reviewed
                  UCLA Previously Published Works (2021)

                  Introduction

                  Esophageal cancer (EC) is an aggressive malignancy with poor prognosis. Mortality and disease stage at diagnosis are important indicators of improvements in cancer prevention and control. We examined United States trends in esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC) mortality and stage at diagnosis by race and ethnicity.

                  Methods

                  We used Surveillance, Epidemiology, and End Results (SEER) data to identify individuals with histologically confirmed EAC and ESCC between 1 January 1992 and 31 December 2016. For both EAC and ESCC, we calculated age-adjusted mortality and the proportion presenting at each stage by race/ethnicity, sex, and year. We then calculated the annual percent change (APC) in each indicator by race/ethnicity and examined changes over time.

                  Results

                  The study included 19,257 EAC cases and 15,162 ESCC cases. EAC mortality increased significantly overall and in non-Hispanic Whites from 1993 to 2012 and from 1993 to 2010, respectively. EAC mortality continued to rise among non-Hispanic Blacks (NHB) (APC = 1.60, p = 0.01). NHB experienced the fastest decline in ESCC mortality (APC = - 4.53, p < 0.001) yet maintained the highest mortality at the end of the study period. Proportions of late stage disease increased overall by 18.5 and 24.5 percentage points for EAC and ESCC respectively; trends varied by race/ethnicity.

                  Conclusion

                  We found notable differences in trends in EAC and ESCC mortality and stage at diagnosis by race/ethnicity. Stage migration resulting from improvements in diagnosis and treatment may partially explain recent trends in disease stage at diagnosis. Future efforts should identify factors driving current esophageal cancer disparities.
                    Cover page: Trends in Esophageal Cancer Mortality and Stage at Diagnosis by Race and Ethnicity in the United States
                    • Article
                    • Peer Reviewed
                    UCLA Previously Published Works (2022)
                    Artificial intelligence (AI) and machine learning (ML) systems are increasingly used in medicine to improve clinical decision-making and healthcare delivery. In gastroenterology and hepatology, studies have explored a myriad of opportunities for AI/ML applications which are already making the transition to bedside. Despite these advances, there is a risk that biases and health inequities can be introduced or exacerbated by these technologies. If unrecognised, these technologies could generate or worsen systematic racial, ethnic and sex disparities when deployed on a large scale. There are several mechanisms through which AI/ML could contribute to health inequities in gastroenterology and hepatology, including diagnosis of oesophageal cancer, management of inflammatory bowel disease (IBD), liver transplantation, colorectal cancer screening and many others. This review adapts a framework for ethical AI/ML development and application to gastroenterology and hepatology such that clinical practice is advanced while minimising bias and optimising health equity.
                      Cover page: Artificial intelligence in gastroenterology and hepatology: how to advance clinical practice while ensuring health equity
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