Mitochondrial respiration and glycolytic activity are the main energy metabolic pathways in cells. Analyzingcellular energy metabolism is important for understanding the state of cells. The extracellular flux analyzer (XF)is a cell metabolism analyzer that measures the oxygen consumption rate (OCR) and the extracellular acidificationrate (ECAR) of cells in extracellular medium to profile the activities of mitochondrial respiration and glycolysis,respectively. This device is a system that can noninvasively measure metabolism over time on 24- to 96-well culture plates. The XF-specific sensor cartridge has a fluorescent dye embedded in the tip that serves as an oxygensensor and pH sensor. The mortar-like shape of the bottom of the cell culture plate creates a microspace of 7 μL orless around the cells. This microscopic space makes it possible to measure minute changes in the culture mediumdue to cellular energy metabolism. By adding various compounds to the drug port attached to a cartridge equippedwith a fluorescent sensor, it becomes possible to measure cellular metabolism in real time. The use of XF to elucidate cellular energy metabolism mechanisms in various research fields, such as cancer, metabolic diseases, andimmunity, may lead to the development of new testing methods and treatments.

A 75-year-old male presented with a 2-week history of persistent fever, sputum, and cough. Infiltrates in theright upper lobe were noted, and bacterial pneumonia was considered; however, antibiotic treatment was ineffective. We doubted a bacterial pneumonia diagnosis and performed bronchoscopy. An increase in the lymphocytecount in the bronchoalveolar lavage fluid, along with high levels of Aspergillus antigen and β-D-glucan, wasobserved, while blood Aspergillus antigen and β-D-glucan were negative. We diagnosed chronic necrotizingpulmonary aspergillosis and initiated treatment with VRCZ, which resulted in defervescence and improved theradiographic findings. To evaluate the treatment effect, we performed another bronchoscopy. The lymphocyte countand β-D-glucan level in the bronchoalveolar lavage fluid decreased, which is consistent with the clinical findings.We report a case that suggests the diagnostic utility of β-D-glucan in bronchoalveolar lavage fluid for chronicnecrotizing pulmonary aspergillosis on the basis of our experience.

A 75-year-old woman presented with gradual memory loss and disorientation during the previous year. Despitescoring 22 points on the MMSE, she remained polite. Brain MRI indicated no abnormalities, however, SPECTrevealed relative hypoperfusion in the posterior cingulate gyrus. She was diagnosed with Alzheimer’s diseaseand began therapy with donepezil. Within four months, rapid cognitive impairment required hospitalization. Twoweeks later, myoclonus developed, resulting in akinetic mutism. Following admission, an MRI revealed hyperintense areas in the right basal ganglia and cerebral cortex, as well as periodic synchronous discharges on EEG. CSFanalysis revealed positive 14-3-3 protein and RT-QUIC results. A prion protein-encoding gene study revealed sporadic Creutzfeldt–Jakob disease with methionine homozygosity at codon 129. Initially, diagnosed with Alzheimer’s disease, rapid symptom development became apparent 16 months later, suggesting concurrent sporadicCreutzfeldt–Jakob disease.

A 44-year-old woman presented to her local doctor with complaints of stomach pain. She was referred to ourhospital following the detection of a hepatic tumor through an abdominal ultrasound and contrast-enhanced CT.Initially, she was diagnosed with a primary liver tumor and subsequently underwent a left hepatectomy. Postoperative pathological examination revealed that the patient had a neuroendocrine tumor (NET). As no other primarylesion was found, the diagnosis was confirmed as a NET originating in the liver. Nine months after surgery, thepatient is currently alive with no recurrence. Primary hepatic neuroendocrine tumors are exceedingly rare and areoften difficult to diagnose before surgery because of the absence of specific imaging findings. Similarly, in thiscase, an accurate preoperative diagnosis of a primary liver neuroendocrine tumor could not be obtained.