BackgroundPancreatic ductal adenocarcinoma (PDAC) is the fourth most common cause of cancer related death. It is lethal in nearly all patients, due to an almost complete chemoresistance. Most if not all drugs that pass preclinical tests successfully, fail miserably in the patient. This raises the question whether traditional 2D cell culture is the correct tool for drug screening. The objective of this study is to develop a simple, high-throughput 3D model of human PDAC cell lines, and to explore mechanisms underlying the transition from 2D to 3D that might be responsible for chemoresistance.MethodsSeveral established human PDAC and a KPC mouse cell lines were tested, whereby Panc-1 was studied in more detail. 3D spheroid formation was facilitated with methylcellulose. Spheroids were studied morphologically, electron microscopically and by qRT-PCR for selected matrix genes, related factors and miRNA. Metabolic studies were performed, and a panel of novel drugs was tested against gemcitabine.ResultsComparing 3D to 2D cell culture, matrix proteins were significantly increased as were lumican, SNED1, DARP32, and miR-146a. Cell metabolism in 3D was shifted towards glycolysis. All drugs tested were less effective in 3D, except for allicin, MT100 and AX, which demonstrated effect.ConclusionsWe developed a high-throughput 3D cell culture drug screening system for pancreatic cancer, which displays a strongly increased chemoresistance. Features associated to the 3D cell model are increased expression of matrix proteins and miRNA as well as stromal markers such as PPP1R1B and SNED1. This is supporting the concept of cell adhesion mediated drug resistance.

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Drug-resistant tuberculosis (TB) represents a substantial threat to the global efforts to control this disease. After decades of stagnation, the treatment of drug-resistant TB is undergoing major changes: two drugs with a new mechanism of action, bedaquiline and delamanid, have been approved by stringent regulatory authorities and are recommended by the WHO. This narrative review summarizes the evidence, originating from both observational studies and clinical trials, which is available to support the use of these drugs, with a focus on special populations. Areas of uncertainty, including the use of the two drugs together or for prolonged duration, are discussed. Ongoing clinical trials are aiming to optimize the use of bedaquiline and delamanid to shorten the treatment of drug-resistant TB.

Rationale:Cognitive dysfunction is a common presenting symptom in patients with HIV/AIDS. It is usually directly associated with HIV infection or due to opportunistic infection. Rapidly progressive dementia, however, is rarely observed in acute HIV infection or during immune reconstitution. Recently, a case of Creutzfeld-Jakob disease (CJD) has been reported in a patient with chronic HIV infection. The incidence of CJD is not known to be increased among immunocompromised patients.Patient concerns:We here report the case of a 59-year-old male patient with a recent diagnosis of HIV/AIDS and Pneumocystis jiroveci pneumonia presenting with secondary behavioral changes and disorientation. Over the course of several weeks, progressive dementia developed characterized by apraxia, gait ataxia, and mutism.Diagnoses:After the exclusion of common HIV-associated neurologic conditions, the clinical course as well as findings on electroencephalogram (EEG), magnetic resonance imaging (MRI), and a positive 14-3-3 assay converged into a probable diagnosis of CJD. The diagnosis was later confirmed histopathologically.Outcomes:Palliative care was provided, and the patient passed away within 2 months of symptom onset.Lessons:HIV/AIDS is an important stratifying condition during the work-up of many clinical syndromes including encephalopathy but may prematurely exclude important differential diagnoses. Non-opportunistic etiologies have to be considered as part of a secondary workup as this case of concomitant AIDS and CJD demonstrates. Rapidly progressive dementia should be distinguished from delirium as early as possible in order to be able to choose the correct diagnostic pathway. Despite the common occurrence of neurologic syndromes in the setting of immunodeficiency, an analytical diagnostic approach is advisable to minimize diagnostic bias.

A cute febrile illness after tick bites may be caused by various agents (e.g., Borrelia spp., tick-borne encephalitis virus, Babesia spp., Rickettsia spp., Neoehrlichia mikurensis, Anaplasma phagocytophilum). Spiroplasma ixodetis was initially described as a cause of neonatal cataract and uveitis (1,2). Systemic infections caused by other Spiroplasma spp. have been reported in 3 immunocompromised patients (3-5).Spiroplasma spp. are intracellular organisms that belong to the class Mollicutes, which include Mycoplasma spp. These bacteria have a single-layer cell membrane, cannot be visualized by Gram staining, require special substrates for growth, and can be diagnosed by genetic methods (6). Plants, insects, and ticks are known reservoirs (7). S. ixodetis was initially reported in Ixodes pacificus ticks from Oregon, USA (8), and has since been detected in many arthropod species, including Ixodes ricinus ticks in several countries in Europe, but not yet in Sweden (9,10). We report S. ixodetis infections in an immunocompetent patient and an immunocompromised patient after tick exposure in Sweden. The StudyOral and written informed consent were obtained from the 2 patients. Case-patient 1 was an 81-year-old previously healthy woman who sought care at the emergency department of Kalmar County Hospital (Kalmar, Sweden) in July 2021 because of a 3-day history of fever (temperature up to 39°C) and mild headache. She reported frequent tick exposure in southeastern Sweden but no history of opportunistic infections or immunosuppressive diseases or treatments that would have compromised immune defenses. She was admitted because of clinical suspicion of anaplasmosis.Blood tests showed thrombocytopenia and increased levels of C-reactive protein (CRP) and alanine aminotransferase (ALT) (Table ). Real-time PCR specific for A. phagocytophilum (11) and N. mikurensis (12) on EDTA-anticoagulated whole blood showed negative results. However, 3 days after admission, 16S rRNA PCR and Sanger sequencing analysis (Appendix, https://wwwnc.cdc.gov/EID/article/28/8/21-2524-App1.pdf) identified S. ixodetis that had 99.72% sequence homology with a reference strain of S. ixodetis (GenBank accession no. MN166761) (Figure 1). The S. ixodetis sequence has been deposited in GenBank (accession no. OL636349).