Abnormally Elevated Blood Tacrolimus Level Following the Concomitant Use of Nirmatrelvir/Ritonavir With Extended-Release Tacrolimus in a Post-lung Transplant Patient: A Case Report and a Literature Review.

Although nirmatrelvir/ritonavir (NMV/r) reportedly increases blood levels of tacrolimus (TAC) due to CYP3A4 inhibition and other factors, reports on the use of NMV/r in combination with tacrolimus hydrate extended-release capsules (TAC-ER) in lung transplant patients are limited. Herein, we present a case with post-lung transplantation of elevated blood trough levels of TAC after concomitant use of NMV/r. A woman in her 60s had undergone lung transplantation. She had coronavirus disease 2019 (COVID-19) and was co-administered NMV/r and TAC-ER, with the trough level controlled at approximately 4 µg/mL. Upon the co-administration of NMV/r and TAC-ER, the patient developed diarrhea and vomiting and was hospitalized. TAC-ER was discontinued on day 6, and TAC level was measured on day 8 and had risen above 100 ng/mL. This level gradually decreased to 17.8 ng/mL on day 11 and 2.4 ng/mL on day 15; therefore, TAC-ER was resumed at 2.5 mg/day. On day 18, the TAC level was 5.2 ng/mL, which was within the target range, and the patient was discharged on day 19. This is the first report of a post-lung transplant patient co-administered TAC-ER with NMV/r, who showed abnormally high blood TAC levels above the detection limit. In patients using TAC-ER after lung transplantation, it may be useful to confirm that the TAC blood level is below the effective therapeutic range before resuming TAC-ER safely.

Atypical Peripheral Retinal Necrosis Without Ocular Inflammation and Retinal Whitening in a Patient With Acute Myelogenous Leukemia: A Case Report.

Retinal necrosis is a severe condition that threatens visual function. It is caused by viruses that are known to cause acute retinal necrosis (ARN) and progressive outer retinal necrosis (PORN), which are called necrotizing herpetic retinopathies (NHR). ARN causes severe intraocular inflammation, including anterior chamber intravitreal cells, keratic precipitate, vitreous opacity, and retinal vasculitis, whereas intraocular inflammation in PORN is considered mild or virtually absent. In addition, PORN is a disease that manifests in immunosuppressive patients, such as those with acquired immunodeficiency syndrome. Here, we present a case of unilateral retinal necrosis after chemotherapy, allogeneic peripheral blood stem cell transplantation, and cord blood transplantation for acute myelogenous leukemia (AML) in a 31-year-old male patient. AML treatment resulted in metabolic remission, and oral steroids and tacrolimus were continued. After two days, the patient visited an ophthalmologist because he noticed a sudden onset of floaters and visual field disturbance in the left eye. The peripheral retina was already necrotic in all layers, causing total retinal detachment. Intraocular inflammation, retinal opacity, or hemorrhagic spots in the fundus were not observed. His previous CD4 count was 43 cells/µL. A polymerase chain reaction test of the anterior chamber fluid revealed varicella-zoster virus (VZV), and vitrectomy was performed four days after disease onset. The excised vitreous demonstrated minimal opacity. The peripheral necrotic retina was excised, photocoagulation was performed on the residual retinal limbus, and silicone oil was injected to maintain retinal attachment. The retinal restoration was maintained under silicone oil tamponade, and corrected visual acuity improved to 20/32 without strong inflammation after vitrectomy. However, two months postoperatively, he contracted coronavirus disease 2019 (COVID-19), his general condition rapidly deteriorated, and he died. This case of retinal necrosis without inflammatory results in an immunocompromised patient and VZV detection in an intraocular sample led us to suspect PORN. However, the patchy or spread retinal whitening characteristic of PORN was completely absent, whereas the well-defined, peripheral, full-layer retinal necrosis characteristic of ARN was present. Thus, this is a rare case of VZV-induced NHR with partial features of PORN and ARN that progressed very silently.

Dysregulation of MAP Kinase Signaling Pathways Including p38MAPK, SAPK/JNK, and ERK1/2 in Cultured Rat Cerebellar Astrocytes Exposed to Diphenylarsinic Acid.

Diphenylarsinic acid (DPAA) was a major compound found in the arsenic poisoning incident that occurred in Kamisu, Ibaraki, Japan in 2003. People exposed to DPAA via contaminated well water suffered from several neurological disorders, including cerebellar symptoms. We previously reported that DPAA induces cellular activation in cultured rat cerebellar astrocytes, dose-dependent promotion of cell growth (low DPAA), cell death (high DPAA), and increased phosphorylation of mitogen-activated protein (MAP) kinases (p38MAPK, SAPK/JNK, and ERK1/2). Moreover, DPAA induces up-regulation of oxidative stress-counteracting proteins, activation of CREB phosphorylation, increased protein expression of c-Jun and c-Fos, and aberrant secretion of brain-active cytokines (MCP-1, adrenomedullin, FGF2, CXCL1, and IL-6). Here, we explored the role of MAP kinases in DPAA-induced activation of astrocytes using specific MAP kinase signaling inhibitors [SB203580 (p38MAPK), SP600125 (SAPK/JNK), SCH772984 (ERK1/2), and U0126 (MEK1/2, a kinase for ERK1/2)]. DPAA-induced activation of MAP kinases had little contribution to DPAA-induced cell growth and death. On the other hand, a power relationship among MAP kinases was also observed, in which p38MAPK suppressed DPAA-induced SAPK/JNK and ERK1/2 activation, whereas ERK1/2 and MEK1/2 facilitated p38MAPK and SAPK/JNK activation. In addition, SAPK/JNK had minimal effects on the activation of other MAP kinases. DPAA-induced activation of transcription factors and secretion of brain-active cytokines were submissively but intricately dominated by MAP kinases. Collectively, our results indicate that DPAA-induced activation of MAP kinases is neither a cell growth-promoting response nor a cytoprotective one but leads to transcriptional disruption and aberrant secretion of brain-active cytokines in cerebellar astrocytes.

Diphenylarsinic Acid Induced Activation of Cultured Rat Cerebellar Astrocytes: Phosphorylation of Mitogen-Activated Protein Kinases, Upregulation of Transcription Factors, and Release of Brain-Active Cytokines.

Diphenylarsinic acid (DPAA) was detected as the primary compound responsible for the arsenic poisoning that occurred in Kamisu, Ibaraki, Japan, where people using water from a well that was contaminated with a high level of arsenic developed neurological (mostly cerebellar) symptoms and dysregulation of regional cerebral blood flow. To understand the underlying molecular mechanism of DPAA-induced cerebellar symptoms, we focused on astrocytes, which have a brain-protective function. Incubation with 10 µM DPAA for 96 h promoted cell proliferation, increased the expression of antioxidative stress proteins (heme oxygenase-1 and heat shock protein 70), and induced the release of cytokines (MCP-1, adrenomedullin, FGF2, CXCL1, and IL-6). Furthermore, DPAA overpoweringly increased the phosphorylation of three major mitogen-activated protein kinases (MAPKs) (ERK1/2, p38MAPK, and SAPK/JNK), which indicated MAPK activation, and subsequently induced expression and/or phosphorylation of transcription factors (Nrf2, CREB, c-Jun, and c-Fos) in cultured rat cerebellar astrocytes. Structure-activity relationship analyses of DPAA and other related pentavalent organic arsenicals revealed that DPAA at 10 µM activated astrocytes most effective among organic arsenicals tested at the same dose. These results suggest that in a cerebellum exposed to DPAA, abnormal activation of the MAPK-transcription factor pathway and irregular secretion of these neuroactive, glioactive, and/or vasoactive cytokines in astrocytes can be the direct/indirect cause of functional abnormalities in surrounding neurons, glial cells, and vascular cells: This in turn might lead to the onset of cerebellar symptoms and disruption of cerebral blood flow.

BDNF increases the phagocytic activity in cultured iris pigment epithelial cells.

To investigate the effect of brain derived neurotrophic factor (BDNF) on the phagocytic activity in iris pigment epithelial (IPE) cells, purified porcine photoreceptor outer segments (POS) were applied to cultured IPE cells for three hours. To measure phagocytic activities, bound and total POS were differentially stained using a double immunofluorescence staining method. BDNF increased the binding of POS in IPE cells in a dose-dependent manner. Ingestion of POS, however, was not affected throughout the concentrations used in this study. To investigate the signal transduction pathways of BDNF, a phosphatidylinositol 3-kinase (PI3K) inhibitor, LY294002, and MAPK/ERK kinase (MEK) inhibitor, PD98059, were used for this study. LY294002 had no effect on the binding and ingestion of POS in BDNF-treated IPE cells. On the other hand, PD98059 completely inhibited the increase of POS binding in BDNF-treated cells and also decreased the ingestion of POS. These results indicate that increased POS binding activity by BDNF and the decreased ingestion of POS were mediated through the MAPK pathway.

Introduction of the Low Vision Evaluator (LoVE) for children.

PURPOSE: To determine whether the Low Vision Evaluator (LoVE) can grade the visual acuity of young children with light perception and hand movement acuity into finer acuity steps and at what age reliable measurements can be obtained. METHODS: Two hundred twenty children were tested with the LoVE. Each eye was tested separately, and each stimulus magnitude (intensity x duration) was presented three times. Three catch trials per eye also were presented. RESULTS: Scores ranged from -8 to -1 on variable-duration tests and from 22.5 to 37.5 dB on fixed-duration tests for four children with hand movement vision. Scores ranged from -12 to 0 on variable-duration tests and from 12.5 to 40 dB on fixed-duration tests for five children with light perception vision. Reliable measurements were obtained at different times on different days. Mean scores for children with counting finger vision or better were significantly better than scores for eyes with light perception and hand movement (P < .001 and P < .01, respectively). Reliability was less for children younger than age 4 years. CONCLUSIONS: The LoVE is capable of grading the visual function of children with light perception and hand movement vision into finer steps. Reliable measurements can be obtained for children age 4 years and older.