[18F]FDG PET/CT for identifying the causes of fever of unknown origin (FUO).

Fever of unknown origin (FUO) continues to be a challenging diagnosis in clinical medicine. It has more than 200 known causes, including infections, autoimmune diseases, neoplasia, and other miscellaneous disorders. Despite the development of a wide range of diagnostic tools, a specific diagnostic algorithm for FUO is not yet available. However, [18F]FDG PET/CT, which yields information on cellular metabolism, in addition to details of organ anatomy, has been shown to be successful in the FUO investigation. This study highlights the uses of [18F]FDG PET/CT in diagnosing various causes of FUO. [18F]FDG PET/CT has been increasingly used to detect septic infections, sterile inflammatory processes, and malignancies, occupying a significant portion of the known causes of FUO. It has led to a more definitive identification of the etiology of FUO and accurate clinical management. However, more in-depth studies are crucial to understanding if [18F]FDG PET/CT can be used in the work-up of FUO.

Extracellular metallothionein as a therapeutic target in the early progression of type 1 diabetes.

Type 1 diabetes (T1D) is characterized by lymphocyte infiltration into the pancreatic islets of Langerhans, leading to the destruction of insulin-producing beta cells and uncontrolled hyperglycemia. In the nonobese diabetic (NOD) murine model of T1D, the onset of this infiltration starts several weeks before glucose dysregulation and overt diabetes. Recruitment of immune cells to the islets is mediated by several chemotactic cytokines, including CXCL10, while other cytokines, including SDF-1α, can confer protective effects. Global gene expression studies of the pancreas from prediabetic NOD mice and single-cell sequence analysis of human islets from prediabetic, autoantibody-positive patients showed an increased expression of metallothionein (MT), a small molecular weight, cysteine-rich metal-binding stress response protein. We have shown that beta cells can release MT into the extracellular environment, which can subsequently enhance the chemotactic response of Th1 cells to CXCL10 and interfere with the chemotactic response of Th2 cells to SDF-1α. These effects can be blocked in vitro with a monoclonal anti-MT antibody, clone UC1MT. When administered to NOD mice before the onset of diabetes, UC1MT significantly reduces the development of T1D. Manipulation of extracellular MT may be an important approach to preserving beta cell function and preventing the development of T1D.

Role of PET/CT in diagnosing and monitoring disease activity in rheumatoid arthritis: a review.

Rheumatoid Arthritis (RA) is a systemic inflammatory disorder that commonly presents with polyarthritis but can have multisystemic involvement and complications, leading to increased morbidity and mortality. The diagnosis of RA continues to be challenging due to its varied clinical presentations. In this review article, we aim to determine the potential of PET/CT to assist in the diagnosis of RA and its complications, evaluate the therapeutic response to treatment, and predict RA remission. PET/CT has increasingly been used in the last decade to diagnose, monitor treatment response, predict remissions, and diagnose subclinical complications in RA. PET imaging with [18F]-fluorodeoxyglucose ([18F]-FDG) is the most commonly applied radiotracer in RA, but other tracers are also being studied. PET/CT with [18F]-FDG, [18F]-NaF, and other tracers might lead to early identification of RA and timely evidence-based clinical management, decreasing morbidity and mortality. Although PET/CT has been evolving as a promising tool for evaluating and managing RA, more evidence is required before incorporating PET/CT in the standard clinical management of RA.

Chimeric antigen receptor T cell therapy for the treatment of systemic rheumatic diseases: a comprehensive review of recent literature.

Systemic rheumatoid diseases (SRDs) are autoimmune and inflammatory disorders that affect multiple organ systems, impacting patients' quality of life, and survival rates. Standard treatment requires continuous drug therapy and immunosuppression. Chimeric antigen receptor (CAR) T cell therapy has the potential to target and eliminate pathologically activated immune cells and re-establish tolerance in organs affected by dysregulated immunity, making them a promising treatment option for autoimmune diseases. In autoimmune diseases, CAR T cells have the advantage of being able to kill B cells effectively without the need for an accessory cell type. Additionally, CAR T cells targeting CD19 have shown promise in comprehensive B cell aplasia, preserving pre-existing humoral immunity, and specifically eliminating pathogenic B cells. CAR T cell therapy's limited use in SRDs is due to its inability to effectively target the various autoreactive lymphocytes present. Researchers are developing a universal CAR T cell therapy that detects and targets autoreactive lymphocytes using major epitope peptides, though further studies are required. Moreover, adoptive transfer of CAR-Tregs has shown promise for effectively reducing inflammation and treating autoimmunity. Through this exploration, the authors hope to provide a comprehensive understanding of the current state of research on this topic, identify areas for further study, and promote the advancement of CAR T cell therapy as a treatment option for SRDs.

Progesterone-stimulated endometrial cell conditioned media increases in vitro produced bovine embryo blastocyst formation.

The early bovine embryo is supported by histotroph molecules secreted by endometrial epithelial (EPI) and stroma fibroblast (SF) cells in response to luteal progesterone (P4). We hypothesized that specific histotroph molecule transcript abundance depends on cell type and P4 concentration and that endometrial cell conditioned media (CM) could improve in vitro produced (IVP) embryo development in culture. Primary bovine EPI and SF cells from seven uteri were incubated for 12 h with RPMI medium containing 0 (Control), 1, 15, or 50 ng of P4. RPMI was also incubated without cells (N-CM) and CM from EPI or SF cultures (EPI- or SF-CM) or a combination of the two (1:1; EPI/SF-CM) was used to culture IVP embryos from days 4-8 of development (n = 117). There was an effect of cell type (SLC1A1, SLC5A6, SLC7A1, FGF-2, FGF-7, CTGF, PRSS23 and NID2) and/or P4 concentration (FGF-7 and NID2) on endometrial cell histotroph molecule mRNA (P < 0.05). Compared to N-CM, blastocyst development on day 7 was greater in the EPI or SF-CM (P ≤ 0.05) and tended to be greater in the EPI/SF-CM (P = 0.07). On day 8, blastocyst development was greater only in the EPI-CM (P < 0.05). Further, culturing embryos with endometrial cell CM reduced day 8 blastocyst transcript abundance of cell adhesion molecule LGALS1 (P < 0.01). In conclusion, endometrial cell CM or histotroph molecules may be used to improve IVP embryo development in cattle.

Is Imaging Bacteria with PET a Realistic Option or an Illusion?

The application of [18F]-fluorodeoxyglucose ([18F]FDG) as a radiotracer to detect sites of inflammation (either due to bacterial infection or primary inflammation) has led to exploring the role of PET in visualizing bacteria directly at sites of infection. However, the results from such efforts are controversial and inconclusive so far. We aimed to assess the limitations of PET as an effective modality in the diagnosis of bacterial infections. Inflammation due to bacterial infections can be visualized by using [18F]FDG-PET. However, the non-specificity of [18F]FDG makes it undesirable to visualize bacteria as the underlying cause of inflammation. Hence, more specific radiotracers that possibly bind to or accumulate in bacteria-specific receptors or enzymes are being explored. Several radiotracers, including 2-deoxy-2-[18F]fluorosorbitol ([18F]FDS), 6-[18F]-fluoromaltose, [11C]para-aminobenzoic acid ([11C]PABA), radiolabeled trimethoprim (11C-TMP) and its analog fluoropropyl-trimethoprim (18F-FPTMP), other radiolabeled sugars, and antimicrobial drugs have been used to image microorganisms. Unfortunately, no progress has been made in translating the results to routine human use; feasibility and other factors have constrained their success in clinical settings. In the current article, we discuss the limitations of direct bacterial visualization with PET tracers, but emphasize the important role of [18F]FDG-PET as the only option for detecting evidence of infection.

Anticoagulation failure in pulmonary thromboembolism in COVID-19 pneumonia despite prolonged anticoagulation: A case series.

Introduction: Moderate to severely ill patients diagnosed with Coronavirus disease 2019 (COVID-19) pneumonia develop a series of complications and less frequently, we might witness cases of Pulmonary Thromboembolism (PE)-refractory to the standard treatment with Low Molecular Weight Heparin (LMWH). The aim of this case series is to report the presentation and management of pulmonary thromboembolism secondary to COVID-19 pneumonia. Method: We report a case series of seven cases aged 40-70 who were presented in Dhulikhel Hospital with COVID-19 symptoms in different stages. The case details were extracted from their medical reports of the hospital. The written informed ethical consents were obtained from all the cases and their voluntary participation was assured. Outcome: The cases in the case series admitted with COVID-19 pneumonia, after diagnostic investigation (Chest x-ray, HRCT, CTPA) were suggestive of COVID-19 Pneumonia with ARDS and pulmonary thromboembolism. The cases received rivaroxaban, a newer anticoagulant-15 mg twice daily for 21 days and after discharge, they were asked to continue once daily doses for 9 weeks. Significant improvement was witnessed, with the presence of additional intervention including rehabilitative chest exercises. Conclusion: Pulmonary thromboembolism secondary to COVID-19 pneumonia is a life-threatening condition. Rivaroxaban is seen to be very effective in the management of this condition when an anticoagulation failure occurs even after the therapeutic dose of low molecular weight heparin. Future studies may require more scientific investigations to prevent complications even in the early stages of COVID-19.

Autoimmune gastritis in a male adolescent with cerebellar involvement: A case report.

Introduction: Autoimmune gastritis is an immune mediated disorder characterized as anti-intrinsic factor and anti-parietal cell autoantibodies directed against intrinsic factor and parietal cells of the stomach respectively, leading to vitamin B12 deficiency. When the disease remains undiagnosed and untreated, it may lead to neurological complications and even fatal anemia. Case study: We exemplify a non-vegetarian male adolescent case with the neurological symptoms such as bilateral leg weakness, unsteady gait, slurred speech, vertigo, slowed movement, lethargy, and impaired joint sensation. None of his family members had such illness. His hemoglobin was normal with serum vitamin B12 level 105 pg/mL and anti-intrinsic factor antibody titer positive. A presumed diagnosis of cobalamin deficiency with involvement of the cerebellum, dorsal column and peripheral nerves was made. His symptoms recovered gradually and later completely (after 6 months) after the intramuscular vitamin B12 therapy. Clinical discussion: The indexed rare adolescent case had auto immune gastritis showing neurological manifestation with more pronounced cerebellar features and vitamin B12 deficiency under the non-vegetarian diet consumption. Previous studies had reflected auto immune among adolescents but contrasted some of the clinical features. Conclusion: For the prompt and precise diagnosis of the autoimmune gastritis and to prevent further complications, some of the rare conditions such as deficiency with a non-vegetarian diet, neurological manifestation including cerebellar involvement without anemia should also be considered along with other relevant symptoms. The heightened awareness for timely surveillance and treatment will contribute in reduction of such unusual cases.

Meningeal Signs and Cerebellar Involvement in Scrub Typhus: A Case Report.

Scrub typhus is an arthropod-borne fever that follows the bite of the larval form of Leptotrombidium mite carrying Orientia tsutsugamushi. It remains a serious health problem in the Asia-Pacific region. While it commonly presents as an undifferentiated fever with chills and an eschar, complications like pneumonitis, acute respiratory distress syndrome, disseminated intravascular coagulation, and meningoencephalitis may cause scrub typhus to be fatal. However, regardless of the dramatic presentation, treatment with antibiotics, preferably doxycycline or even azithromycin, is effective in recovery.  In this case report, we present a case of meningitis and cerebellar involvement in an adolescent with positive scrub typhus serology in the absence of an eschar. This brought forward a diagnostic delay as other infections including tuberculosis were considered before scrub typhus due to unusual presenting symptoms and the lack of an eschar. Thus, in cases like these, it becomes imperative to be aware of the unusual manifestations to initiate antibiotics on time and prevent further complications.

Drug-Induced Gum Overgrowth With Low-Dose Amlodipine: A Case Report.

Drug-induced gingival overgrowth is an adverse effect of certain drugs, including amlodipine, in genetically susceptible individuals. Although the exact mechanism of gingival hypertrophy remains unclear, a unifying multifactorial hypothesis has been constructed. Gingival hypertrophy causes difficulty in speech and mastication, poor oral hygiene, and poor aesthetic appearance. Here, we present the case of a 49-year-old woman who developed gum hypertrophy following amlodipine use for two years. Maintenance of oral hygiene and substitution of offending agent is commonly the first step in management.

Concurrent Measurement of Mitochondrial DNA Copy Number and ATP Concentration in Single Bovine Oocytes.

To sustain energy-demanding developmental processes, oocytes must accumulate adequate stores of metabolic substrates and mitochondrial numbers prior to the initiation of maturation. In the past, researchers have utilized pooled samples to study oocyte metabolism, and studies that related multiple metabolic outcomes in single oocytes, such as ATP concentration and mitochondrial DNA copy number, were not possible. Such scenarios decreased sensitivity to intraoocyte metabolic relationships and made it difficult to obtain adequate sample numbers during studies with limited oocyte availability. Therefore, we developed and validated procedures to measure both mitochondrial DNA (mtDNA) copy number and ATP quantity in single oocytes. Validation of our procedures revealed that we could successfully divide oocyte lysates into quarters and measure consistent results from each of the aliquots for both ATP and mtDNA copy number. Coefficient of variation between the values retrieved for mtDNA copy number and ATP quantity quadruplicates were 4.72 ± 0.98 and 1.61 ± 1.19, respectively. We then utilized our methodology to concurrently measure mtDNA copy number and ATP quantity in germinal vesicle (GV) and metaphase two (MII) stage oocytes. Our methods revealed a significant increase in ATP levels (GV = 628.02 ± 199.53 pg, MII = 1326.24 ± 199.86 pg, p < 0.001) and mtDNA copy number (GV = 490,799.4 ± 544,745.9 copies, MII = 1,087,126.9 ± 902,202.8 copies, p = 0.035) in MII compared to GV stage oocytes. This finding is consistent with published literature and provides further validation of the accuracy of our methods. The ability to produce consistent readings and expected results from aliquots of the lysate from a single oocyte reveals the sensitivity and feasibility of using this method.

Detection and Manipulation of the Stress Response Protein Metallothionein.

Metallothioneins (MTs) are small molecular weight stress response proteins that play a central role as reservoir of essential divalent heavy metal cations such as zinc and copper, and also can diminish the effects of toxic heavy metals such as mercury and cadmium. Historically, MT has been considered to be an intracellular protein with roles to play in the management of heavy metals, as a regulator of cellular redox potential, and as a buffer of free radicals. Our recent studies have highlighted immunomodulatory role of MT in inflammatory diseases and also in the progression of metastatic cell movement. Hence, manipulation and detection of MT is essential for its possible use as a diagnostic and in therapeutic interventions of chronic inflammation. This review describes procedures used to detect MT using techniques such as western immunoblot, competition ELISA, flow cytometry and immunohistochemistry. Additionally, it also describes the use of a colorimetric cell proliferation assay (CellTiter 96 AQueous One Solution/MTS) to study the proliferative effect of MT. © 2017 by John Wiley & Sons, Inc.

In vitro assays of chemotaxis as a window into mechanisms of toxicant-induced immunomodulation.

Dysregulated cell movement can lead to developmental abnormalities, neoplasia, and immune system disorders, and there are a variety of contexts in which xenobiotics (and biologic) effects on this movement are of interest. Many toxins and toxicants have been shown to disrupt controlled cell movement. Identification of compounds that affect cell movement is crucial to drug discovery. Drug components may have unexpected consequences with respect to cell motility, which would exclude these compounds in drug development. Finally, the development of drugs that target chemotactic pathways may be useful in the treatment of tumors, which often reprogram chemotactic pathways to become metastatic. The effects of these agents on cell movement can be measured using several different in vitro chemotactic assays. This review details the procedures of three in vitro measurements of chemotaxis: the Boyden chamber, the under-agarose assay, and the automated, real-time, ECIS/Taxis assay, and discusses the inferences that can be drawn from the results of such studies.