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The UMB Digital Archive is a service of the Health Sciences and Human Services Library (HS/HSL) that collects, preserves, and distributes the academic works of the University of Maryland, Baltimore. It is a place that digitally captures the historical record of the campus.
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Pharmacokinetic Effects of -Tetrahydropalmatine on Ketamine in Rat Plasma by Ultraperformance Liquid Chromatography Tandem Mass SpectrometryMale Sprague-Dawley rats (n = 18) were randomly divided into three groups: a saline group (20 mL/kg by gavage), a ketamine (KET) group (100 mg/kg by gavage), and a KET (the same routes and doses) combined with levo-tetrahydropalmatine (l-THP; 40 mg/kg by gavage) group (n = 6). Blood samples were acquired at different time points after drug administration. A simple and sensitive ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established to determine the concentrations of KET and its metabolite, norketamine (NK), in rat plasma. Chromatographic separation was achieved using a BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with chlorpheniramine maleate (Chlor-Trimeton) as an internal standard (IS). The initial mobile phase consisted of acetonitrile-water with 0.1% methanoic acid (80 : 20, v/v). The multiple reaction monitoring (MRM) modes of m/z 238.1→m/z 179.1 for KET, m/z 224.1→m/z 207.1 for NK, and m/z 275→m/z 230 for Chlor-Trimeton (IS) were utilized to conduct a quantitative analysis. Calibration curves of KET and NK in rat plasma demonstrated good linearity in the range of 2.5-500 ng/mL (r > 0.9994), and the lower limit of quantification (LLOQ) was 2.5 ng/mL for both. Moreover, the intra- and interday precision relative standard deviation (RSD) of KET and NK were less than 4.31% and 6.53%, respectively. The accuracies (relative error) of KET and NK were below -1.41% and -6.07%, respectively. The extraction recoveries of KET and NK were more than 81.23 ± 3.45% and 80.42 ± 4.57%, respectively. This sensitive, rapid, and selective UPLC-MS/MS method was successfully applied to study the pharmacokinetic effects of l-THP on KET after gastric gavage. The results demonstrated that l-THP could increase the bioavailability of KET and promote the metabolism of KET. The results showed that l-THP has pharmacokinetics effects on KET in rat plasma.
A prospective, multi-center randomized, controlled, blinded trial of vagus nerve stimulation for difficult to treat depression: A novel design for a novel treatment.Few treatment options exist for patients with difficult-to-treat depression (DTD). One potentially efficacious treatment is vagus nerve stimulation (VNS): chronic stimulation of the vagus nerve using an implanted stimulator. Given a series of recent VNS clinical studies, including a large, five-year naturalistic investigation, the Center for Medicare and Medicaid Services (CMS) reconsidered the previous non coverage determination and announced coverage for patients participating in a “coverage with evidence” trial. This study, entitled, A PRospective, Multi-cEnter, Randomized Controlled Blinded Trial DemOnstrating the Safety and Effectiveness of VNS Therapy® System as AdjunctivE Therapy Versus a No Stimulation Control in Subjects With Treatment-Resistant Depression (RECOVER), includes DTD patients with at least four unsuccessful antidepressant treatments in the current episode and will randomize both unipolar and bipolar DTD participants, each up to 500 evaluable enrollees. Predetermined interim analyses will define the necessary sample size. All participants will be implanted with VNS devices: half receive active stimulation during year one, and half receive delayed stimulation after year one. Participants will be followed for 5 years. This RCT is unique for DTD studies: 1) large sample size and long study duration (one year of controlled comparison); 2) use of a percent time in response as the primary outcome measure, given the chronic illness and its fluctuating course (vis-à-vis meeting a response criteria at a single time point); 3) inclusion of diverse measures of VNS impact on function, including quality of life, degree of disability, health status, and suicidality.
Atypical Skin Manifestations During Immune Checkpoint Blockage in Coronavirus Disease 2019-Infected Patients With Lung Cancer.A new coronavirus, named severe acute respiratory syndrome–coronavirus-2 by the WHO, has rapidly spread around the world since its first reported case in late December of 2019 from Wuhan, the People's Republic of China. As of mid-April 2020, this virus has affected more than 180 countries and territories, infecting more than 1,650,000 individuals and causing over 100,000 deaths. With approximately 20 million new cases globally per year, cancer affects a substantial portion of the population. Individuals affected by cancer are more susceptible to infections owing to coexisting chronic diseases (cardiovascular, pulmonary, and diabetes), overall poor health status, and systemic immunosuppressive states caused by both cancer and the anticancer treatment. As a consequence, patients with malignancies, especially those with lung cancer who develop coronavirus disease 2019, experience more difficult outcomes. A recent multicenter study carried out by the Hubei Anti-Cancer Association has also documented that patients with lung cancer had an increased risk of death, intensive care unit requirement, risk of presenting severe or critical symptoms, and use of invasive mechanical ventilation. Here, we present two representative cases of patients with lung cancer and coronavirus disease 2019 without respiratory compromise and with atypical and severe skin manifestations—findings that could be influenced by the long-term use of anti–programmed cell death protein 1 antibody.
Informing the role of RIFINs in malaria pathogenesis, natural immunity, and design of a severe malaria vaccinePlasmodium falciparum is a eukaryotic parasite that causes severe malaria and contributed to 405,000 deaths worldwide in 2018. Victims of severe malaria are predominantly sub-Saharan African children, who typically present with symptoms of severe anemia or unarousable coma. The pathogenesis of severe malaria is poorly understood but mediated by the expression of adhesive variant surface antigens (VSAs) on infected red blood cells. VSAs are involved in sequestration and rosetting, unique virulence processes that allow the parasite to evade host immune responses and prevent clearance in the spleen. A relatively unstudied family of VSAs, the repetitive interspersed family (RIFIN) proteins, have recently been found to be important in rosetting and host immune suppression. RIFINs also appear to be targets for protective immunity; humoral immune responses against RIFINs have been correlated with asymptomatic infections. In this dissertation, I applied a multi-faceted approach using protein and peptide microarrays, transcriptomics, and reverse vaccinology to identify appealing RIFIN candidates for inclusion in a future severe malaria vaccine. I show that serological responses against epitopes within the semi-conserved domain of RIFINs associated with severe malaria reflected age-related malaria exposure. Sequencing and identifying specific rif genes expressed in clinical infections have not been feasible. I have addressed these challenges by adapting a novel bioinformatic pipeline and developing an HMM-based tool to process, assemble, classify, and subtype RIFIN sequences from peripheral blood samples. This takes advantage of a targeted probe capture method that I determined yields more abundant, full-length RIFIN sequences than other library enrichment approaches. Finally, I performed a comprehensive genomic survey of RIFIN gene repertoires using publicly available whole genome data of sixteen P. falciparum isolates to identify highly conserved, strain-transcendent sequences. Together, these results provide insights and powerful tools that can advance our understanding of the role RIFINs play in severe malaria pathogenesis and the development of naturally-acquired immunity to severe malaria. This work will aid efforts to determine targets for vaccines to protect children from the deadliest consequences of malaria.