Influence of the scan time point when assessing hypoxia in 18F-fluoromisonidazole PET: 2 vs. 4 h

European Journal of Nuclear Medicine and Molecular Imaging - 18F-fluoromisonidazole (18F-FMISO) is the most widely used positron emission tomography (PET) tracer for imaging tumor hypoxia. Previous...     

A Low Serum CCL4/MIP-1β Level May Predict a Severe Asthmatic Responsiveness to Mepolizumab

Objective Mepolizumab, a humanized anti-interleukin-5 monoclonal antibody, is effective for treating eosinophilic severe asthma. However, there is a need for more biomarkers that can predict the patient response to mepolizumab before starting therapy. This study aimed to identify a new biomarker in the serum that is able to accurately predict the responsiveness to mepolizumab. Methods This study enrolled 11 patients who had all been diagnosed with severe eosinophilic asthma and were then administered mepolizumab every 4 weeks for at least 4 months. Blood samples were collected, and pulmonary function tests and questionnaires were administered at baseline and after 4, 8 and 16 weeks of treatment. The response to mepolizumab was then assessed based on the difference in the Asthma Quality of Life Questionnaire (AQLQ) score after 16 weeks of mepolizumab therapy compared with that at baseline. Patients with an increase in the AQLQ score of more than 0.5 were defined as responders. The cytokine levels in the blood were measured by LUMINEX 200 and ELISA. Results There were 6 responders and 5 non-responders. The responders showed a significantly lower serum level of chemokine (C-C motif) ligand 4/macrophage inflammatory protein-1β (CCL4/MIP-1β) at baseline compared to the non-responders. Receiver operating characteristic curves to distinguish responders from non-responders using the baseline serum CCL4/MIP-1β level showed a good area under the curve of 0.9. The non-responders showed a significant increase in the level of CCL4/MIP-1β after 4 weeks compared to the baseline. Conclusion A low baseline serum CCL4/MIP-1β level may be useful for predicting a good mepolizumab response in severe eosinophilic asthma.     

Methotrexate myelopathy with extensive transverse necrosis: Report of an autopsy case

The patient was a 70‐year‐old woman with lymphoplasmacytic lymphoma which showed a predominantly diffuse involvement of the bone marrow and kidney. Because atypical lymphocytes appeared in the cerebrospinal fluid, the intrathecal administration of methotrexate (MTX) and cytosine arabinoside (Ara‐C) was repeated several times. The patient developed flaccid paraplegia 8 months after the beginning of intrathecal administration, and died 4 months later. Autopsy demonstrated extensive transverse necrosis involving the lower thoracic cord and marked vacuolar degeneration of the white matter of the cervical, upper thoracic and lumbo‐sacral cord. Focal vacuolar degeneration of the white matter was also noted in the left parietal lobe. Although vacuolar degeneration of the white matter is a common feature in MTX myelopathy, extensive transverse necrosis is rare. In the present case, an overlapping of two mechanisms, that is, injury of vascular endothelial cells and the direct toxic effect of MTX and Ara‐C on the white matter, probably played a crucial role in the pathogenesis of severe myelopathy. Because severe myelopathy occurs infrequently, considering the large number of patients receiving the intrathecal administration of MTX, it is possible that a constitutional predisposition or abnormal sensitivity to MTX was involved in the pathogenesis in the present patient.     

Mutations in the FHA-domain of ectopically expressed NBS1 lead to radiosensitization and to no increase in somatic mutation rates via a partial suppression of homologous recombination

Ionizing radiation induces DNA double-strand breaks (DSBs). Mammalian cells repair DSBs through multiple pathways, and the repair pathway that is utilized may affect cellular radiation sensitivity. In this study, we examined effects on cellular radiosensitivity resulting from functional alterations in homologous recombination (HR). HR was inhibited by overexpression of the forkhead-associated (FHA) domain-mutated NBS1 (G27D/R28D: FHA-2D) protein in HeLa cells or in hamster cells carrying a human X-chromosome. Cells expressing FHA-2D presented partially (but significantly) HR-deficient phenotypes, which were assayed by the reduction of gene conversion frequencies measured with a reporter assay, a decrease in radiation-induced Mre11 foci formation, and hypersensitivity to camptothecin treatments. Interestingly, ectopic expression of FHA-2D did not increase the frequency of radiation-induced somatic mutations at the HPRT locus, suggesting that a partial reduction of HR efficiency has only a slight effect on genomic stability. The expression of FHA-2D rendered the exponentially growing cell population slightly (but significantly) more sensitive to ionizing radiation. This radiosensitization effect due to the expression of FHA-2D was enhanced when the cells were irradiated with split doses delivered at 24-h intervals. Furthermore, enhancement of radiation sensitivity by split dose irradiation was not seen in contact-inhibited G0/G1 populations, even though the cells expressed FHA-2D. These results suggest that the FHA domain of NBS1 might be an effective molecular target that can be used to induce radiosensitization using low molecular weight chemicals, and that partial inhibition of HR might improve the effectiveness of cancer radiotherapy.     

OPN4 belongs to the photosensitive system of the human skin

The human skin has previously been described to be affected by light; however, the underlying mechanism remains unknown. OPN4 (melanopsin) expression was first identified in the skin of amphibians; however, whether it is also expressed and functioned in the human skin has not yet been identified. Here, we show that OPN4 was expressed in the human skin tissue and cultures of isolated keratinocytes, melanocytes and fibroblasts. Additionally, Ca²⁺ influx in vitro and ex vivo and phosphorylation of extracellular signal‐regulated kinases 1/2 in human fibroblasts were observed by stimulation of blue light irradiation. Notably, our findings showed that this Ca²⁺ influx and phosphorylation of extracellular signal‐regulated kinases 1/2 are promoted in an intensity‐dependent manner, indicating that the light signal is converted to an intracellular signal via OPN4 in the human skin. Overall, in this study we showed that the human skin functions as a photoreceptor by demonstrating that in human skin, the photoreceptive protein was expressed, and photoreception was conducted via photoreceptive protein.     

Hepatic artery reconstruction preserving the pancreaticoduodenal arcade in pediatric liver transplantation with celiac axis compression syndrome: Report of a case

CACS is rare, although it has been reported to be a potential risk factor for hepatic artery thrombosis following LT. We herein present the case of a 14‐yr‐old male with stenosis of the origin of the celiac trunk. Preoperative CT and color ultrasonography showed narrowing of the proximal celiac artery. The patient underwent DDLT with standard arterial reconstruction without dividing the gastroduodenal artery. His postoperative course was uneventful, with an excellent hepatic artery flow on Doppler ultrasonography. Applying a meticulous preoperative evaluation and the appropriate surgical technique is crucial in patients with CACS.     

Central pontine myelinolysis following pediatric living donor liver transplantation: A case report and review of literature

CPM is one of the most serious neurological complications that can occur after OLT and is characterized by symmetrical demyelinization in the basis pontis. The etiology of CPM remains unclear, although the rapid correction of the serum sodium and CNI concentrations may be associated with the development of CPM. With recent advances in MRI technology, early diagnosis of CPM has become possible. Here, we present the case of a five‐yr‐old female who developed CNI‐associated CPM after undergoing LDLT. A decreased level of consciousness and dysphasia was noted one wk after LDLT, and MRI revealed findings compatible with a diagnosis of CPM. The patient fully recovered from the neurological deficits related to CPM following the switch from the CNI to sirolimus. We propose MRI to be promptly considered for patients with abnormal neurological findings, together with the substitution of CNI with an mTOR inhibitor as a management regimen for CNI‐related CPM.     

Comparison of fluid leakage from four different cuffed pediatric endotracheal tubes using a pediatric airway simulation model

This study used an airway model to compare the ability of a pediatric endotracheal tube with a taper‐shaped cuff to prevent microaspiration relative to endotracheal tubes with conventional cuffs. Four different types of 5.0‐mm inner diameter cuffed pediatric endotracheal tubes (taper‐shaped cuff [Taper], high‐volume low‐pressure [Hi‐Lo], middle‐volume low‐pressure [Intermediate], and low‐volume low‐profile [Lo‐Pro]) were fixed within vertically placed acrylic tubes. The cuffs were maintained at 10, 20, or 30 cmH₂O pressure and 3 mL of simulated stomach contents was added to the top of the cuffs. The volume of leakage around the cuffs after 5 min and 4 h was measured. After 5 min, the volume of leakage was significantly lower with the Taper than with the Hi‐Lo, Intermediate, or Lo‐Pro at all pressure settings. After 4 h, leakage was significantly lower with the Taper than with the other three tubes regardless of initial cuff pressure (P < 0.05).