Publications by authors named "Detlef Ritter"

Next-generation risk assessment relies on mechanistic data from new approach methods, including transcriptome data. Various technologies, such as high-throughput targeted sequencing methods and microarray technologies based on hybridization with complementary probes, are used to determine differentially expressed genes (DEGs). The integration of data from different technologies requires a good understanding of the differences arising from the use of various technologies.

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In the United States, rural populations comprise 60 million individuals and suffered from high COVID-19 disease burdens. Despite this, surveillance efforts are biased toward urban centers. Consequently, how rurally circulating SARS-CoV-2 viruses contribute toward emerging variants remains poorly understood.

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Objectives: An integrated inhalation approach was outlined to estimate potential adverse acute inhalation effects of aerosols from commercial nebulizer applications used for purposeful room conditioning such as disinfection, scenting or others. Aerosol characterization, exposure estimation and evaluation of acute biological effects by inhalation were included to generate dose-response data, allowing for determination of lowest observable adverse effect levels (LOAELs). Correlation of these to estimates of human lung deposition was included for quantitative to extrapolation approach (QIVIVE) for acute effects during human exposure.

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This case study explores the applicability of transcriptome data to characterize a common mechanism of action within groups of short-chain aliphatic α-, β-, and γ-diketones. Human reference data indicate that the α-diketone diacetyl induces bronchiolitis obliterans in workers involved in the preparation of microwave popcorn. The other three α-diketones induced inflammatory responses in preclinical animal studies, whereas beta and gamma diketones in addition caused neuronal effects.

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As SARS-CoV-2 and influenza viruses co-circulate, co-infections with these viruses generate an increasing concern to public health. To evaluate the prevalence and clinical impacts of SARS-CoV-2 and influenza A virus co-infections during the 2021-2022 influenza season, SARS-CoV-2-positive samples from 462 individuals were collected from October 2021 to January 2022. Of these individuals, 152 tested positive for influenza, and the monthly co-infection rate ranged from 7.

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Inpatient coronavirus disease 2019 (COVID-19) cases present enormous costs to patients and health systems in the United States. Many hospitalized patients may continue testing COVID-19 positive even after the resolution of symptoms. Thus, a pressing concern for clinicians is the safety of discharging these asymptomatic patients if they have any remaining infectivity.

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The long-lasting global COVID-19 pandemic demands timely genomic investigation of SARS-CoV-2 viruses. Here, we report a simple and efficient workflow for whole-genome sequencing utilizing one-step reverse transcription-PCR (RT-PCR) amplification on a microfluidic platform, followed by MiSeq amplicon sequencing. The method uses Fluidigm integrated fluidic circuit (IFC) and instruments to amplify 48 samples with 39 pairs of primers, including 35 custom-designed primer pairs and four additional primer pairs from the ARTIC network protocol v3.

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The severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) Spike glycoprotein is solely responsible for binding to the host cell receptor and facilitating fusion between the viral and host membranes. The ability to generate viral particles pseudotyped with SARS-COV-2 Spike is useful for many types of studies, such as characterization of neutralizing antibodies or development of fusion-inhibiting small molecules. Here, we characterized the use of a codon-optimized SARS-COV-2 Spike glycoprotein for the generation of pseudotyped HIV-1, murine leukemia virus (MLV), and vesicular stomatitis virus (VSV) particles.

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Diagnostic tests for the coronavirus infection 2019 (COVID-19) are critical for prompt diagnosis, treatment and isolation to break the cycle of transmission. A positive real-time reverse-transcriptase polymerase chain reaction (RT-PCR), in conjunction with clinical and epidemiologic data, is the current standard for diagnosis, but several challenges still exist. Serological assays help to understand epidemiology better and to evaluate vaccine responses but they are unreliable for diagnosis in the acute phase of illness or assuming protective immunity.

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Due to the increasing need of new treatment options against bacterial lung infections, novel antimicrobial peptides (AMPs) are under development. Local bioavailability and less systemic exposure lead to the inhalation route of administration. Combining AMPs with nanocarriers (NCs) into nanosystems (NSs) might be a technique for improved results.

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air-liquid interface (ALI) cell culture models can potentially be used to assess inhalation toxicology endpoints and are usually considered, in terms of relevancy, between classic (i.e., submerged) models and animal-based models.

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Higher throughput methods, high content analysis and automated screening methods are of highest demand in drug development today. In toxicology, these strategies are becoming increasingly important, as well. Therefore, an integrated higher throughput method for the comet assay is addressed by the development presented here.

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Although aspirin is cardioprotective in high-risk populations, many with diabetes mellitus (DM) are unresponsive to these benefits. We questioned whether cardiovascular unresponsiveness might be demonstrated by lack of aspirin sensitivity to in vitro platelet functions especially in subjects with poorly controlled diabetes. Six women and 4 men (48+/-8 years [mean+/-S.

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Three cigarette types were compared using an experimental approach for quantifying selected toxicological effects of diluted fresh whole cigarette mainstream smoke in vitro. The test procedure involved automatic smoking of cigarettes according to the FTC/ISO standard, online monitoring of generated smoke aerosols with respect to particulate and gas-phase components, and direct exposure of a human type II-like lung cell line (A549) using exposure conditions relevant to human smoking. Test specimens were the K1R4F standard research cigarettes (9.

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Background: Testing for troponin has important clinical value for patients who present with typical symptoms of acute coronary syndromes (ACS) such as chest pain (CP). Much less is known about the value of troponin testing for patients who present with other symptoms of ACS (anginal equivalent symptoms).

Methods: The utilization and prognostic value of cardiac troponin I (cTnI) were evaluated at a Veterans Affairs Acute Care Facility.

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Numerous approaches have been employed for testing the biological activity of cigarette smoke in vitro. None of them has managed to expose cultured lung cells in a realistic manner to the complex gaseous and particulate mixture that constitutes cigarette smoke. We have devised a system that makes this possible.

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An experimental approach was established for the validation of an in vitro test system for complex environmental test atmospheres consisting of both gaseous substances and particulates. Smoke from two different cigarette types (generated by an automatic cigarette-smoking machine) was employed to assess both the sensitivity and the specificity of the system. The smoke was diluted with synthetic air and used to expose human lung cells grown on microporous membranes.

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Persistent elevation of aspartate aminotransferase (AST) activity in serum due to the presence of a macroenzyme form of AST (macro-AST) may lead to diagnostic confusion in many clinical conditions, particularly those associated with chronic liver disease. We describe a case of macro-AST arising in an adult female with a false-positive hepatitis C virus (HCV) RNA test result that was not accompanied by other biochemical or histologic evidence of liver disease. The presence of macro-AST in serum was confirmed utilizing size-exclusion, high performance liquid chromatography (HPLC) and Protein G-agarose beads to precipitate immune complexes of AST and immunoglobulin G followed by centrifugation and AST activity measurements in the supernatant.

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The application of in vitro methods to the analysis of the effects of airborne materials is still limited, because there are no generally accepted concepts and technologies for efficiently exposing adherent growing cells to test atmospheres, especially those comprising complex mixtures of gaseous and particulate phases. The introduction of in vitro research into the field of inhalation toxicology offers a unique possibility for using human cells and tissues for pre-screening studies, thus reducing the necessity for animal experiments, and cutting the numbers of animals used in toxicological testing. We therefore developed a novel experimental concept that uses an exposure device based on the cell cultivation system CULTEX (Patent No.

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