Publications by authors named "Johnson Ho"

Background: Since the initial introduction in 1967 of spinal cord stimulation (SCS) in the field of neuromodulation, SCS has been utilized to treat a multitude of chronic pain disorders refractory to both conservative and surgical management. Although efficacious when indicated, SCS has associated risks.

Objectives: The goals of this study are to explore the trend of rates of SCS complications in 2 approximately equally sized cohorts (1999-2015 and 2016-2021) within a single institution over a 22-year period.

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,,','-Tetramethylchloroformamidinium hexafluorophosphate (TCFH) and -methylimidazole (NMI) enable the facile and practical reaction of carboxylic acids with amines, alcohols, and thiols to form amides, esters, and thioesters. To develop a mild synthesis of ketones with TCFH-NMI directly from carboxylic acids at room temperature, the Mayr nucleophilicity scale was used to compare the values of competent nucleophiles to potential carbon-centered nucleophiles, identifying pyrroles and indoles as successful substrates when ≥ 10.

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Article Synopsis
  • Spinal cord stimulation (SCS) is a treatment used when other options for pain relief haven't worked, but it can have problems and some patients stop following up with their doctors.
  • A study was done to find out why some patients didn't come back for their doctor visits after getting the SCS device, using phone surveys.
  • Out of 49 patients who were lost to follow-up, many said they stopped visiting because their pain got better or they had other health issues, while some just missed their appointments.
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Objectives: The aim of this study was to present key technologic and regulatory milestones in spinal cord stimulation (SCS) for managing chronic pain on a narrative timeline with visual representation, relying on original sources to the extent possible.

Materials And Methods: We identified technical advances in SCS that facilitated and enhanced treatment on the basis of scientific publications and approvals from the United States (US) Food and Drug Administration (FDA). We presented milestones limited to first use in key indications and in the context of new technology validation.

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Background: Complex Regional Pain Syndrome (CRPS) is a chronic debilitating neuropathic pain condition characterized by autonomic and inflammatory features that typically occurs after a traumatic event. Spinal cord stimulation (SCS) has been shown to be effective in the treatment of chronic CRPS refractory to conventional treatment modalities. The collective evidence of novel parameters of SCS for treating CRPS has not been characterized extensively.

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Objectives: To compare medical students' and residents' knowledge retention of assessment, diagnosis and treatment procedures, as well as a learning experience, of patients with spinal trauma after training with either a Virtual Patient case or a video-recorded traditional lecture.

Methods: A total of 170 volunteers (85 medical students and 85 residents in orthopedic surgery) were randomly allocated (stratified for student/resident and gender) to either a video-recorded standard lecture or a Virtual Patient-based training session where they interactively assessed a clinical case portraying a motorcycle accident. The knowledge retention was assessed by a test immediately following the educational intervention and repeated after a minimum of 2 months.

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There are no drugs to manage traumatic brain injury (TBI) presently. A major problem in developing therapeutics is that drugs to manage TBI lack sufficient potency when dosed within a clinically relevant time window. Previous studies have shown that minocycline (MINO, 45 mg/kg) plus N-acetylcysteine (NAC, 150 mg/kg) synergistically improved cognition and memory, modulated inflammation, and prevented loss of oligodendrocytes that remyelinated damaged white matter when first dosed 1 h after controlled cortical impact (CCI) in rats.

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Mild traumatic brain injury afflicts over 2 million people annually and little can be done for the underlying injury. The Food and Drug Administration-approved drugs Minocycline plus N-acetylcysteine (MINO plus NAC) synergistically improved cognition and memory in a rat mild controlled cortical impact (mCCI) model of traumatic brain injury. The underlying cellular and molecular mechanisms of the drug combination are unknown.

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The influence of the falx and tentorium on brain injury biomechanics during impact was studied with finite element (FE) analysis. Three detailed 3D FE head models were created based on the images of a healthy, normal size head. Two of the models contained the addition of falx and tentorium with material properties from previously published experiments.

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This study examined whether peripheral vision reaction time (PVRT) in patients with mild traumatic brain injury (mTBI) correlated with white matter abnormalities in centroaxial structures and impairments in neuropsychological testing. Within 24 h after mTBI, crossed reaction times (CRT), uncrossed reaction times (URT), and crossed-uncrossed difference (CUD) were measured in 23 patients using a laptop computer that displayed visual stimuli predominantly to either the left or the right visual field of the retina. The CUD is a surrogate marker of the interhemispheric transfer time (ITT).

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Background: Yunu-Jian (YJ) is a Chinese medicine (CM) heat purging formula, which is used to reduce wei huo (stomach-heat, SH) and enrich shen yin (kidney-yin, KY). This formula is also commonly used to manage diabetes mellitus and gum/oral inflammation. The activity of YJ can be modified or refined by the addition of other CM herbs and/or minor changes to one of its five key ingredients.

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Blunt impact produces a heterogeneous brain injury in people and in animal models of traumatic brain injury. We report that a single closed head impact to adult C57/BL6 mice produced two injury syndromes (CHI-1 and CHI-2). CHI-1 mice spontaneously reinitiated breathing after injury while CHI-2 mice had prolonged apnea and regained breathing only after cardiopulmonary resuscitation and supplementation of 100% O2.

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This RCT study aimed to investigate if VIS-Ed (Visualization through Imaging and Simulation - Education) had the potential to improve medical student education and specialist training in clinical diagnosis and treatment of trauma patients. The participants' general opinion was reported as high in both groups (lecture vs. virtual patient (VP)).

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Transcutaneous electrical stimulation is applied in a range of biomedical applications including transcranial direct current stimulation (tDCS). tDCS is a non-invasive procedure where a weak direct current (<2 mA) is applied across the scalp to modulate brain function. High-definition tDCS (HD-tDCS) is a technique used to increase the spatial focality of tDCS by passing current across the scalp using <12 mm diameter electrodes.

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The influence of sulci in dynamic finite element simulations of the human head has been investigated. First, a detailed 3D FE model was constructed based on an MRI scan of a human head. A second model with a smoothed brain surface was created based on the same MRI scan as the first FE model.

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Excessive loading of sediment and nutrients to rivers is a major problem in many parts of the United States. In this study, we tested the non-parametric Seasonal Kendall (SEAKEN) trend model and the parametric USGS Quality of Water trend program (QWTREND) to quantify trends in water quality of the Minnesota River at Fort Snelling from 1976 to 2003. Both methods indicated decreasing trends in flow-adjusted concentrations of total suspended solids (TSS), total phosphorus (TP), and orthophosphorus (OP) and a generally increasing trend in flow-adjusted nitrate plus nitrite-nitrogen (NO(3)-N) concentration.

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Background & Aims: Lymphocyte recruitment to sites of inflammation requires the sequential engagement of adhesion molecules and chemokine receptors. In the current studies we analyzed the role of CD44 for the development of chronic small-intestinal inflammatory infiltrates in vivo.

Methods: By using a tumor necrosis factor (TNF)-driven model of chronic ileitis (ie, B6.

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Health education can offer a valuable window onto conceptual and behavioral change. In Study 1, we mapped out 3rd-grade Chinese children's beliefs about causes of colds and flu and ways they can be prevented. We also explored older adults' beliefs as a possible source of the children's ideas.

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Recruitment of lymphocytes to sites of inflammation requires the sequential engagement of adhesion molecules and chemokine receptors. Of these, the lectin-like molecule CD44 has been particularly implicated in inflammatory trafficking. Using a TNF-driven model of chronic ileitis (i.

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To date, the influence of the vasculature on the dynamic response of the brain has not been studied with a complete three-dimensional (3D) finite element head model. In this study, short duration rotational (10,000 rad/s(2) with a duration of 5 ms) and translational (100G with a duration of 5 ms) acceleration impulses were applied to the 3D finite element models to study the dynamic response of the brain. The hypothesis of this study was that due to the convoluted organization and non-linear material properties of cerebral vasculature, the difference in maximum principle strain between models with and without vasculature should be minimal.

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Background & Aims: CCL25 mediates the homeostatic recruitment of CCR9-expressing lymphocytes to the small intestine, but the function of this chemokine/receptor pair during chronic small intestinal inflammation has yet to be determined. Furthermore, although clinical trials to evaluate the efficacy of targeting the CCL25/CCR9 axis for the treatment of Crohn's disease are being conducted, preclinical data in animal models of IBD are lacking.

Methods: In the current studies, we investigated the expression of CCL25 and CCR9 as a function of disease progression in a spontaneous murine model of chronic ileitis (SAMP1/YitFc) using flow cytometry, real-time reverse-transcription polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry.

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Although there is evidence of widespread distribution of organic fluorochemicals such as perfluorooctane sulfonate and perfluorooctanoate, in the environment, the versatility of these compounds in industrial and commercial applications complicates characterization of pathways into the environment. A solid-phase extraction method coupled with HPLC-negative-ion electrospray tandem mass spectrometry was developed to quantitatively measure trace levels of organic fluorochemicals in drinking water and surface water. Using this method, certain fluorochemicals can be quantitatively measured in water samples down to 25 ppt, a level well below calculated drinking water advisory levels.

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Since the early 1980s, there has been a steady increase in the use of nonvolatile fluorinated organic compounds for a variety of industrial and commercial applications. The industrial use of these relatively stable compounds has initiated debate over the fate of fluorochemicals in the environment and, ultimately, the bioavailability of these compounds. In this manuscript, we present quantitative results from a study of 65 human sera samples purchased from biological supply companies that provide characterization of specific organic fluorochemicals present in the sera of nonindustrially exposed humans.

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