Temporal and spatial visualization of water uptake into human hair studied by infrared microscopy.

Real-time examination of water behavior in cuticle, cortex, and medulla of untreated and bleached hair was performed by Fourier-transform infrared (FT-IR) microscopy. Penetration of heavy water from the cuticle to the medulla was visualized and quantified by monitoring the O-D stretching band located at 2500 cm-1. The medulla of untreated hair had a significantly higher peak O-D intensity from 20 min after the heavy water penetration to 20 min after drying than that of bleached hair. Furthermore, heavy water evaporated 1 h slower in untreated hair than in bleached hair in any part. These differences may be due to the increase of S=O stretching of sulfonic acid caused to breaking of the disulfide and thioester bonds by bleach treatment. The method proposed in this study revealed potential application in visualizing and quantifying real-time water behavior in hair.

HLA loci predisposing to immune TTP in Japanese: potential role of the shared ADAMTS13 peptide bound to different HLA-DR.

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare autoimmune disorder caused by neutralizing anti-ADAMTS13 autoantibodies. In white individuals, HLA allele DRB1*11 is a predisposing factor for iTTP, whereas DRB1*04 is a protective factor. However, the role of HLA in Asians is unclear. In this study, we analyzed 10 HLA loci using next-generation sequencing in 52 Japanese patients with iTTP, and the allele frequency in the iTTP group was compared with that in a Japanese control group. We identified the following HLA alleles as predisposing factors for iTTP in the Japanese population: DRB1*08:03 (odds ratio [OR], 3.06; corrected P [Pc] = .005), DRB3/4/5*blank (OR, 2.3; Pc = .007), DQA1*01:03 (OR, 2.25; Pc = .006), and DQB1*06:01 (OR,: 2.41; Pc = .003). The estimated haplotype consisting of these 4 alleles was significantly more frequent in the iTTP group than in the control group (30.8% vs 6.0%; Pc < .001). DRB1*15:01 and DRB5*01:01 were weak protective factors for iTTP (OR, 0.23; Pc = .076; and OR, 0.23, Pc = .034, respectively). On the other hand, DRB1*11 and DRB1*04 were not associated with iTTP in the Japanese. These findings indicated that predisposing and protective factors for iTTP differ between Japanese and white individuals. HLA-DR molecules encoded by DRB1*08:03 and DRB1*11:01 have different peptide-binding motifs, but interestingly, bound to the shared ADAMTS13 peptide in an in silico prediction model.

[Essential thrombocythemia accompanied by adrenal infarction].

A 64-year-old man presented to the emergency department with sudden-onset upper abdominal pain and pain in the left chest area. His platelet count was 121.7×104/µl. Computed tomography (CT) showed bilateral adrenal swelling and inflammation of the adjacent tissue. Diffusion-weighted magnetic resonance imaging (MRI) showed hyperintensity in the bilateral adrenal glands. The patient was diagnosed with bilateral adrenal infarction. A bone marrow biopsy yielded a diagnosis of essential thrombocythemia, and a positive JAK2 V617F mutation was detected. He presented with recurrent adrenal infarction and developed aortic mural thrombosis and splenic infarction. We administered aspirin and performed cytoreductive therapy with hydroxyurea and anagrelide; however, the patient then went into heart failure resulting from coronary artery stenosis. We then added prasugrel to the list of medicines administered to manage his condition. Bilateral adrenal infarction is a very rare thrombotic event of essential thrombocythemia. CT and MRI were useful for making the diagnosis; however, we also had to rule out acute coronary syndrome or intestinal ischemia. Our patient presented with strong thrombotic diathesis, which prompted us to use dual antiplatelet therapy; however, further studies are needed to confirm the efficacy and safety of this treatment.

Successful engraftment after cord blood transplantation from an HLA-homozygous donor (homo-to-hetero cord blood transplantation) in a primary myelofibrosis patient with broad HLA antibodies.

BACKGROUND: Donor-specific human leukocyte antigen (HLA) antibodies are a significant risk factor for graft failure in cord blood transplantation (CBT). Although there are several treatments to decrease HLA antibodies, such as platelet transfusion, plasma exchange, rituximab, and bortezomib, their effectiveness has not been established. STUDY DESIGN AND METHODS: We herein report the case of a primary myelofibrosis (PMF) patient with broad HLA antibodies who underwent CBT from an HLA-homozygous donor in which the alleles were matched only in the host-versus-graft direction (homo-to-hetero CBT). RESULTS: The cord blood was killer cell immunoglobulin-like receptor (KIR) ligand matched. She received a reduced-intensity conditioning regimen. We used tacrolimus and mycophenolate mofetil as prophylaxis against graft-versus-host disease (GVHD). The neutrophils engrafted on Day 31. A chimerism analysis with fluorescence in situ hybridization of peripheral blood cells showed 99.9% donor type on Day 33. She developed only mild acute skin GVHD and chronic skin GVHD. CONCLUSION: This case indicates the usefulness of homo-to-hetero CBT in a patient with broad HLA antibodies with a strong mean fluorescence intensity, which is a significant risk factor for graft failure. Further studies are necessary to determine the risk of GVHD and to elucidate the association between KIR ligand incompatibility and graft failure in homo-to-hetero CBT.

Substantial Improvement in a Nerve Conduction Study of Lymphoma-associated Demyelinating Neuropathy Treated by Intravenous Immunoglobulin and Chemotherapy.

A 64-year-old woman with lymphoma-associated demyelinating neuropathy was treated by 6 cycles of R-CHOP with intravenous immunoglobulin in the first 2 cycles. We noted substantial improvement in the findings of a nerve conduction study (NCS) after the first cycle, followed by more protracted improvement during the second to sixth cycles. The improvement of the neurological symptoms paralleled the findings of the NCS. Our case provides important information for understanding the etiology and optimization of treatments for lymphoma-associated demyelinating neuropathy.

Small molecules that inhibit Vif-induced degradation of APOBEC3G.

BACKGROUND: HIV-1 Vif is essential for virus replication in natural target cells such as T cells and macrophages. Vif recruits a ubiquitin ligase to degrade restrictive APOBEC3 proteins. APOBEC3G is one of the most potent retroviral restriction factors targeted by Vif and, as such, the Vif-APOBEC3G interaction has emerged as a promising HIV-1 therapeutic target. METHODS: 20,000 small molecules were used in live-cell screens for those that preserve EGFP-APOBEC3G fluorescence and luciferase-APOBEC3G luminescence in the presence of HIV-1 Vif. RESULTS: 2 compounds with similar core structures preserved APOBEC3G levels in the presence of Vif. 10 µM of compound restored APOBEC3G to levels sufficient for incorporation into vif-proficient virus particles and restriction of virus infectivity. Vif-dependent APOBEC3G polyubiquitination and general proteasomal activity were unaffected at the same concentration. CONCLUSIONS: The small molecules described here preserve APOBEC3G levels and activity in the presence of Vif. These molecules are starting points for further development as antiretrovirals.

Prolonged ictal monoparesis with parietal Periodic Lateralised Epileptiform Discharges (PLEDs).

We report a patient with prolonged monoparesis and parietal periodic lateralised epileptiform discharges (PLEDs). The patient was a 73-year-old man with chronic myelomonocytic leukaemia who developed persisting monoparesis of the right arm, sensory aphasia, and finger agnosia, initially associated with focal clonic seizures. These neurological deficits remained for seven days without subsequent focal clonic seizures. The EEG showed left-sided PLEDs, maximal in the left occipito-parietal area. Ten days later, following phenytoin treatment, these symptoms suddenly improved and parietal PLEDs disappeared. Sustained PLEDs in the left parietal region may have been causally associated with ictal paresis in this patient.

APOBEC3B can impair genomic stability by inducing base substitutions in genomic DNA in human cells.

Human APOBEC3 proteins play pivotal roles in intracellular defense against viral infection by catalyzing deamination of cytidine residues, leading to base substitutions in viral DNA. Activation-induced cytidine deaminase (AID), another member of the APOBEC family, is capable of editing immunoglobulin (Ig) and non-Ig genes, and aberrant expression of AID leads to tumorigenesis. However, it remains unclear whether APOBEC3 (A3) proteins affect stability of human genome. Here we demonstrate that both A3A and A3B can induce base substitutions into human genome as AID can. A3B is highly expressed in several lymphoma cells and somatic mutations occur in some oncogenes of the cells highly expressing A3B. Furthermore, transfection of A3B gene into lymphoma cells induces base substitutions in cMYC gene. These data suggest that aberrant expression of A3B can evoke genomic instability by inducing base substitutions into human genome, which might lead to tumorigenesis in human cells.

Acute airway obstruction in a patient with achalasia.

Megaesophagus resulting from achalasia is a rare but serious cause of acute airway obstruction. We treated achalasia in a 52-year-old woman with acute respiratory distress and stridor. Chest X-ray and endoscopy showed a marked dilatation of the cervical esophagus with a large amount of undigested food. Emergency suction of the food through a nasogastric tube led to decompression of the esophagus and the immediate relief of respiratory symptoms. These findings suggest a dysfunction of the upper esophageal sphincter as a possible mechanism. As this exceptional complication of achalasia is fatal, a wider appreciation is required.

HIV-1 viral infectivity factor interacts with TP53 to induce G2 cell cycle arrest and positively regulate viral replication.

Viral infectivity factor, an accessory protein encoded in the HIV-1 genome, induces G2 cell cycle arrest; however, the biological significance and mechanism(s) remain totally unclear. Here we demonstrate that the TP53 pathway is involved in Vif-mediated G2 cell cycle arrest. Vif enhances the stability and transcriptional activity of TP53 by blocking the MDM2-mediated ubiquitination and nuclear export of TP53. Furthermore, Vif causes G2 cell cycle arrest in a TP53-dependent manner. HXB2 Vif lacks these activities toward TP53 and cannot induce G2 cell cycle arrest. Using mutagenesis, we demonstrate that the critical residues for this function are located in the N-terminal region of Vif. Finally, we construct a mutant NL4-3 virus with an NL4-3/HXB2 chimeric Vif defective for the ability to induce cell cycle arrest and show that the mutant virus replicates less effectively than the wild-type NL4-3 virus in T cells expressing TP53. These data imply that Vif induces G2 cell cycle arrest through functional interaction with the TP53/MDM2 axis and that the G2 cell cycle arrest induced by Vif has a positive effect on HIV-1 replication. This report demonstrates the molecular mechanisms and the biological significance of Vif-mediated G2 cell cycle arrest for HIV-1 infection.

Mycophenolate mofetil combined with tacrolimus and minidose methotrexate after unrelated donor bone marrow transplantation with reduced-intensity conditioning.

We evaluated the efficacy of a post-grafting immunosuppressive regimen consisting of tacrolimus, methotrexate, and mycophenolate mofetil (MMF) in 21 adults (median age, 55 years) with poor-risk hematologic malignancy who underwent unrelated bone marrow transplantation after fludarabine-based reduced-intensity conditioning (RIC). In combination with intravenous tacrolimus and minidose methotrexate (5 mg/m2 on days 1, 3, and 6), MMF was orally administered at 30 mg/kg daily in three divided doses between days 7 and 27. All patients achieved neutrophil recovery with donor-type chimerism at a median of 19 days (range, 13-35). Cumulative incidences of grades II-IV and III-IV acute graft-versus-host disease (GVHD) were 33% (95% CI, 15-53%) and 5% (95% CI, 0.3-20%), respectively. Five of 20 evaluable patients developed extensive chronic GVHD. Toxicities associated with the use of MMF were acceptable, although one patient experienced intractable GVHD immediately after the cessation of MMF. With a median follow-up of 24 months, overall survival at 3 years was 38% (95% CI, 14-63%). No late graft failure was observed. In conclusion, post-transplant MMF combined with tacrolimus and methotrexate was well tolerated and conferred stable donor cell engraftment, low risk of severe acute GVHD, and encouraging overall survival in unrelated donor marrow transplantation after RIC regimens.

MDM2 is a novel E3 ligase for HIV-1 Vif.

The human immunodeficiency virus type 1 (HIV-1) Vif plays a crucial role in the viral life cycle by antagonizing a host restriction factor APOBEC3G (A3G). Vif interacts with A3G and induces its polyubiquitination and subsequent degradation via the formation of active ubiquitin ligase (E3) complex with Cullin5-ElonginB/C. Although Vif itself is also ubiquitinated and degraded rapidly in infected cells, precise roles and mechanisms of Vif ubiquitination are largely unknown. Here we report that MDM2, known as an E3 ligase for p53, is a novel E3 ligase for Vif and induces polyubiquitination and degradation of Vif. We also show the mechanisms by which MDM2 only targets Vif, but not A3G that binds to Vif. MDM2 reduces cellular Vif levels and reversely increases A3G levels, because the interaction between MDM2 and Vif precludes A3G from binding to Vif. Furthermore, we demonstrate that MDM2 negatively regulates HIV-1 replication in non-permissive target cells through Vif degradation. These data suggest that MDM2 is a regulator of HIV-1 replication and might be a novel therapeutic target for anti-HIV-1 drug.

Phosphorylation of APOBEC3G by protein kinase A regulates its interaction with HIV-1 Vif.

Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G, referred to here as A3G) is a potent antiretroviral host factor against human immunodeficiency virus type 1 (HIV-1). HIV-1 viral infectivity factor (Vif) counteracts A3G by promoting its degradation via the ubiquitin-proteasome pathway. Recent studies demonstrated that protein kinase A (PKA) phosphorylates activation-induced deaminase (AID), another member of the APOBEC3 family. A3G has two putative PKA phosphorylation residues. Here we show that PKA binds and specifically phosphorylates A3G at Thr32 in vitro and in vivo. This phosphorylation event reduces the binding of A3G to Vif and its subsequent ubiquitination and degradation, and thus promotes A3G antiviral activity. Computer-assisted structural modeling and mutagenesis studies suggest that the interaction between A3G Thr32 and Arg24 is crucial for interaction with Vif. These data imply that PKA-mediated phosphorylation of A3G can regulate the interaction between A3G and Vif.