Effect of Lurasidone on Social Functioning in Schizophrenia: Post Hoc Analysis of the JEWEL Study

Objective: To evaluate the effects of lurasidone on social functioning in schizophrenia over the course of a 6-week, double-blind, placebo-controlled study and a subsequent 12-week open-label extension study.

Methods: A total of 478 patients with schizophrenia (per DSM-IV-TR criteria) randomized to either lurasidone 40 mg/d (n = 245) or placebo (n = 233) in the initial 6-week double-blind study (initiated May 2016, completed November 2018) were included in the analysis. Longer-term changes were examined in a sample of 146 patients who received lurasidone, and 141 who received placebo, during the 6-week study and received flexibly dosed (40-80 mg/d) lurasidone during the 12-week extension phase. The 4-item Positive and Negative Syndrome Scale (PANSS) prosocial subscale was used to examine changes in social functioning.

Results: At week 6 of the double-blind phase, lurasidone-treated patients had significantly greater improvement on the PANSS prosocial subscale compared to placebo-treated patients (P < .01, effect size at week 6 = 0.33). Significant differences from placebo were also evident at week 2 (P < .05), week 4 (P < .001), and week 5 (P < .01). Across the 12-week extension phase, patients who received lurasidone during both the 6-week double-blind phase and the 12-week open-label phase continued to show successive decreases in scores on the 4-item PANSS prosocial subscale (score change of -3.0 from double-blind baseline to week 6; mean score change of -4.2 from double-blind baseline to week 12 of the extension phase).

Conclusions: In patients with schizophrenia treated with lurasidone, social functioning improved relative to placebo during a 6-week double-blind study and continued to improve over the course of 12 weeks of extension treatment with lurasidone. Effects of lurasidone on social functioning appear to be comparable to what has been reported for other atypical antipsychotics.

Trial Registration: EudraCT Numbers: 2016-000060-42 and 2016-000061-23.

Photoactive carbon monoxide-releasing coordination polymer particles

We report the synthesis of photoactive carbon monoxide-releasing coordination polymer particles through the assembly of Mn(I) carbonyl complexes with bis(imidazole) ligands. The use of Mn(I) carbonyl complexes as metallic nodes in the coordination network avoids the potential for aggregation-induced self-quenching, favouring their use in the solid state.

A two-step screening to optimize the signal response of an auto-fluorescent protein-based biosensor

Auto-fluorescent protein (AFP)-based biosensors transduce the structural change in their embedded recognition modules induced by recognition/reaction events to fluorescence signal changes of AFP. The lack of detailed structural information on the recognition module often makes it difficult to optimize AFP-based biosensors. To enhance the signal response derived from detecting the putative structural change in the nitric oxide (NO)-sensing segment of transient receptor potential canonical 5 (TRPC5) fused to enhanced green fluorescent protein (EGFP), EGFP-TRPC5, a facile two-step screening strategy, in silico first and in vitro second, was applied to variants of EGFP-TRPC5 deletion-mutated within the recognition module. In in silico screening, the structural changes of the recognition modules were evaluated as root-mean-square-deviation (RMSD) values, and 10 candidates were efficiently selected from 47 derivatives. Through in vitro screening, four mutants were identified that showed a larger change in signal response than the parent EGFP-TRPC5. One mutant in particular, 551-575, showed four times larger change upon reaction with NO and H₂O₂. Furthermore, mutant 551-575 also showed a signal response upon reaction with H₂O₂ in mammalian HEK293 cells, indicating that the mutant has the potential to be applied as a biosensor for cell measurement. Therefore, this two-step screening method effectively allows the selection of AFP-based biosensors with sufficiently enhanced signal responses for application in mammalian cells.

A two-step screening procedure allows optimization of the optical response of an auto-fluorescent protein-based biosensor for nitric oxide without structural information.

Cell-autonomous control of intracellular temperature by unsaturation of phospholipid acyl chains

Intracellular temperature affects a wide range of cellular functions in living organisms. However, it remains unclear whether temperature in individual animal cells is controlled autonomously as a response to fluctuations in environmental temperature. Using two distinct intracellular thermometers, we find that the intracellular temperature of steady-state Drosophila S2 cells is maintained in a manner dependent on Δ9-fatty acid desaturase DESAT1, which introduces a double bond at the Δ9 position of the acyl moiety of acyl-CoA. The DESAT1-mediated increase of intracellular temperature is caused by the enhancement of F₁F_o-ATPase-dependent mitochondrial respiration, which is coupled with thermogenesis. We also reveal that F₁F_o-ATPase-dependent mitochondrial respiration is potentiated by cold exposure through the remodeling of mitochondrial cristae structures via DESAT1-dependent unsaturation of mitochondrial phospholipid acyl chains. Based on these findings, we propose a cell-autonomous mechanism for intracellular temperature control during environmental temperature changes.

Determination of the physiological range of oxygen tension in bone marrow monocytes using two-photon phosphorescence lifetime imaging microscopy

Oxygen is a key regulator of both development and homeostasis. To study the role of oxygen, a variety of in vitro and ex vivo cell and tissue models have been used in biomedical research. However, because of ambiguity surrounding the level of oxygen that cells experience in vivo, the cellular pathway related to oxygenation state and hypoxia have been inadequately studied in many of these models. Here, we devised a method to determine the oxygen tension in bone marrow monocytes using two-photon phosphorescence lifetime imaging microscopy with the cell-penetrating phosphorescent probe, BTPDM1. Phosphorescence lifetime imaging revealed the physiological level of oxygen tension in monocytes to be 5.3% in live mice exposed to normal air. When the mice inhaled hypoxic air, the level of oxygen tension in bone marrow monocytes decreased to 2.4%. By performing in vitro cell culture experiment within the physiological range of oxygen tension, hypoxia changed the molecular phenotype of monocytes, leading to enhanced the expression of CD169 and CD206, which are markers of a unique subset of macrophages in bone marrow, osteal macrophages. This current study enables the determination of the physiological range of oxygen tension in bone marrow with spatial resolution at a cellular level and application of this information on oxygen tension in vivo to in vitro assays. Quantifying oxygen tension in tissues can provide invaluable information on metabolism under physiological and pathophyisological conditions. This method will open new avenues for research on oxygen biology.

Efficacy and Safety of Blonanserin Oral Tablet in Adolescents with Schizophrenia: A 6-Week, Randomized Placebo-Controlled Study

Objectives: To evaluate the short-term efficacy and safety of blonanserin in adolescents with schizophrenia. Methods: This 6-week multicenter, double-blind, randomized, placebo-controlled study investigated fixed-dose blonanserin (8 or 16 mg/day) in patients 12-18 years of age diagnosed with schizophrenia, as indicated by a Positive and Negative Syndrome Scale (PANSS) total score of 60-120 and a Clinical Global Impressions-Severity score of ≥3. The primary endpoint was change from baseline to week 6 in the PANSS total score, using a mixed model for repeated measures analysis. Safety was assessed by the incidence and severity of adverse events (AEs). Results: Among 151 randomized patients, 150 were included in the primary analysis population. Demographic and clinical characteristics were similar across groups at baseline. The rate of study discontinuation was 14.9%, 23.5%, and 28.3% in patients administered with placebo, blonanserin 8 mg/day, and blonanserin 16 mg/day, respectively. The least-squares mean change (95% confidence interval [CI]) from baseline to week 6 in PANSS total score was -10.6 (-16.10 to -5.10), -15.3 (-20.80 to -9.86), and -20.5 (-25.89 to -15.16) in patients administered placebo, 8 mg/day blonanserin, and 16 mg/day blonanserin, respectively. The 16-mg/day blonanserin group showed significantly greater reduction in the PANSS total score than the placebo group (least-squares mean difference [95% CI]: -9.9 [-17.61 to -2.25], p = 0.012, effect size: 0.538), although the 8-mg/day group showed no significant difference. The incidence of AEs such as akathisia, somnolence, and hyperprolactinemia was higher in the blonanserin groups than in the placebo group. AEs associated with blonanserin were generally mild and were consistent with its known profile in adults with schizophrenia. Conclusions: Blonanserin achieved a sufficient efficacy in adolescent patients, and the safety profile was similar to that in adults, which suggests that blonanserin may be a safe treatment option for adolescents with schizophrenia. Study registration number: Japic CTI-111724.

Long-Term Safety and Efficacy of Blonanserin Oral Tablet in Adolescents with Schizophrenia: A 52-Week, Multicenter, Open-Label Extension Study

Objectives: To evaluate the long-term efficacy and safety/tolerability of oral blonanserin in adolescents with schizophrenia (Study registration number: JapicCTI-111725). Methods: This 52-week, multicenter, open-label extension study enrolled adolescent patients with schizophrenia who opted to enter in this study after the completion of the preceding placebo-controlled study. Blonanserin tablet was orally administered twice daily, after morning and evening meals, for 52 weeks using dose-titration method within a range between 4 and 24 mg/day. The primary end point was the change from baseline to the end of the study in the Positive and Negative Syndrome Scale (PANSS) total score. Safety/tolerability was assessed by the incidence and severity of adverse events. Results: Of 117 patients who completed the preceding placebo-controlled study, 109 entered this extension study and 43 (39.4%) of them discontinued the study treatment. The safety analysis set comprised 106 patients who received the study drug at least once, including 36 and 70 patients treated with placebo (DB-placebo group) and blonanserin tablet (DB-blonanserin group), respectively, in the placebo-controlled study. At the last assessment, the mean change in PANSS total score overall [mean (standard deviation)] was -24.9 (20.76) from the baseline of the placebo-controlled study, which was similar in the DB-placebo and DB-blonanserin groups. The overall incidence of adverse events was 90.6%, and most of them were mild or moderate in severity, with similar incidence of extrapyramidal symptoms (38.7%) to that in adults receiving long-term blonanserin oral tablet treatment and minimal change in weight and metabolic parameters. Conclusions: This long-term extension study showed that 52 weeks of oral blonanserin treatment improved or stabilized psychiatric symptoms in patients with adolescent schizophrenia. There were no major issues with the safety or tolerability of blonanserin administration in this study. Considering relatively less adverse effects on weight increase and metabolic parameters, blonanserin is expected to be a safe/tolerable treatment option for adolescent schizophrenia that can be used seamlessly from adolescence to adulthood.

Effectiveness of Lurasidone 80 mg in Patients with Schizophrenia: Results of an Open-Label, 12-Week Extension Study

PURPOSE

To evaluate the effectiveness and safety of lurasidone 80 mg/day (versus the 40 mg/day dose) during a 12-week, open-label extension study in patients with an acute exacerbation of schizophrenia who had completed a 6-week double-blind study of lurasidone.

PATIENTS AND METHODS

A total of 289 adult patients with schizophrenia completed the double-blind study and enrolled in the 12-week extension study. Lurasidone was flexibly dosed at 40 or 80 mg/day. Effectiveness measures included the Positive and Negative Syndrome Scale (PANSS) subscale scores, Clinical Global Impression-Severity Scale (CGI-S), and Calgary Depression Scale for Schizophrenia (CDSS), analyzed based on last observation carried forward (LOCF-endpoint). Safety/tolerability assessments included adverse events, body weight, laboratory tests, and discontinuation due to adverse events.

RESULTS

Mean endpoint change was greater for lurasidone in modal doses of 80 mg/d (N=136) vs 40 mg/d (N=153) on the PANSS positive subscale (-3.0 vs -2.3), PANSS negative subscale (-1.9 vs -1.7), PANSS General Psychopathology subscale (-5.1 vs -3.8), the CGI-S score (-0.5 vs -0.4), and the CDSS score (-0.7 vs -0.1). Discontinuation rates due to adverse events on lurasidone modal 80 mg/d vs 40 mg/d were 4.4% vs 7.2%; and the most common adverse events in the modal 80 mg/d group were nasopharyngitis, 7.4% (vs 4.6% on modal 40 mg/d), constipation, 5.9% (vs 2.0%), and headache, 5.9% (vs 2.0%).

CONCLUSION

In patients with acute schizophrenia treated with lurasidone 40 mg/d, increasing the dose to 80 mg/d was well tolerated, and was associated with greater improvement in PANSS subscale scores compared to continued treatment with a dose of 40 mg/d.

Functionally deficient TRPV6 variants contribute to hereditary and familial chronic pancreatitis

The recent discovery of TRPV6 as a pancreatitis susceptibility gene served to identify a novel mechanism of chronic pancreatitis (CP) due to Ca²⁺ dysregulation. Herein, we analyzed TRPV6 in 81 probands with hereditary CP (HCP), 204 probands with familial CP (FCP), and 462 patients with idiopathic CP (ICP) by targeted next-generation sequencing. We identified 25 rare nonsynonymous TRPV6 variants, 18 of which had not been previously reported. All 18 variants were characterized by a Ca²⁺ imaging assay, with 8 being identified as functionally deficient. Evaluation of functionally deficient variants in the three CP cohorts revealed two novel findings: (i) functionally deficient TRPV6 variants appear to occur more frequently in HCP/FCP patients than in ICP patients (3.2% vs. 1.5%) and (ii) functionally deficient TRPV6 variants found in HCP and FCP probands appear to be more frequently coinherited with known risk variants in SPINK1, CTRC, and/or CFTR than those found in ICP patients (66.7% vs 28.6%). Additionally, genetic analysis of available HCP and FCP family members revealed complex patterns of inheritance in some families. Our findings confirm that functionally deficient TRPV6 variants represent an important contributor to CP. Importantly, functionally deficient TRPV6 variants account for a significant proportion of cases of HCP/FCP.

Osteoclasts adapt to physioxia perturbation through DNA demethylation

Oxygen plays an important role in diverse biological processes. However, since quantitation of the partial pressure of cellular oxygen in vivo is challenging, the extent of oxygen perturbation in situ and its cellular response remains underexplored. Using two‐photon phosphorescence lifetime imaging microscopy, we determine the physiological range of oxygen tension in osteoclasts of live mice. We find that oxygen tension ranges from 17.4 to 36.4 mmHg, under hypoxic and normoxic conditions, respectively. Physiological normoxia thus corresponds to 5% and hypoxia to 2% oxygen in osteoclasts. Hypoxia in this range severely limits osteoclastogenesis, independent of energy metabolism and hypoxia‐inducible factor activity. We observe that hypoxia decreases ten‐eleven translocation (TET) activity. Tet2/3 cooperatively induces Prdm1 expression via oxygen‐dependent DNA demethylation, which in turn activates NFATc1 required for osteoclastogenesis. Taken together, our results reveal that TET enzymes, acting as functional oxygen sensors, regulate osteoclastogenesis within the physiological range of oxygen tension, thus opening new avenues for research on in vivo response to oxygen perturbation.

Safety and Effectiveness of Lurasidone in Patients with Schizophrenia: A 12-Week, Open-Label Extension Study

PURPOSE

The goal of this study was to evaluate the safety and effectiveness of lurasidone among patients with schizophrenia in a 12-week open-label extension study.

PATIENTS AND METHODS

Patients who completed a 6-week, double-blind, placebo-controlled study were enrolled in a 12-week open-label extension study with flexible dosing of lurasidone at 40 or 80 mg/day. Safety assessments included adverse events, vital signs, laboratory tests, and electrocardiogram (ECG) parameters. Effectiveness measures included the Positive and Negative Syndrome Scale (PANSS) total score, Clinical Global Impression-Severity Scale (CGI-S), Calgary Depression Scale for Schizophrenia (CDSS) and quality of life measure.

RESULTS

A total of 289 patients were enrolled in the open-label extension study. Rates of treatment-emergent adverse events (TEAEs) were low; akathisia was the most common TEAE with an incidence of 6.6%. There were 54 patients (18.7%) who discontinued the extension study, with 17 (5.9%) discontinuing due to adverse events. Minimal or no effects of lurasidone on weight, body mass index, metabolic parameters, prolactin, and ECG parameters were evident. There was continued improvement to week 12 in PANSS and CGI-S scores beyond the initial gains made during the prior 6-week double-blind study. Non-responders to lurasidone 40 mg/day in the prior 6-week study showed a mean (standard deviation) improvement from open-label baseline of 10.7 (13.8) points on the PANSS total score after lurasidone dose was increased to a modal dose of 80 mg/day during the extension study. Changes from double-blind baseline in CDSS and quality of life were maintained in the extension study.

CONCLUSION

Treatment with lurasidone 40 or 80 mg once daily (flexibly dosed) continued to be well tolerated with patients demonstrating further improvement in symptoms over the course of a 12-week open-label extension study in patients with schizophrenia.

Efficacy and safety of lurasidone in acutely psychotic patients with schizophrenia: A 6-week, randomized, double-blind, placebo-controlled study

AIM

The aim of this study was to evaluate the efficacy of lurasidone in acute schizophrenia in Japan and other countries.

METHODS

Subjects (aged 18-74 years) diagnosed with schizophrenia were randomized to lurasidone 40 mg/day or placebo. The primary efficacy endpoint was change from baseline on the Positive and Negative Syndrome Scale (PANSS) total score at Week 6. Secondary efficacy assessments included the Clinical Global Impression-Severity Scale (CGI-S). Safety endpoints included adverse events, and laboratory and electrocardiogram parameters.

RESULTS

A total of 483 subjects were randomized to lurasidone or placebo; 107 subjects were from Japan. Mean changes from baseline at Week 6 endpoint in PANSS total scores were -19.3 in the lurasidone group and -12.7 in the placebo group (treatment difference: P < 0.001, effect size = 0.41). Changes from baseline for Week 6 CGI-S scores were -1.0 for lurasidone and -0.7 for placebo (treatment difference: P < 0.001, effect size = 0.41). All-cause discontinuation during the 6-week, double-blind period was 19.4% for lurasidone and 25.4% for placebo, and discontinuation rates due to adverse event were 5.7% for lurasidone and 6.4% for placebo. The following common treatment-emergent adverse events occurred in more than 2% on lurasidone and at a rate at least twice that of the placebo group: akathisia (4.0%), dizziness (2.8%), somnolence (2.8%), abdominal discomfort (2.0%) and asthenia (2.0%). No significant changes in bodyweight or metabolic parameters were observed.

CONCLUSION

Lurasidone 40 mg once daily dosing demonstrated efficacy in a patient population with acute schizophrenia, including subjects from Japan, and was generally safe and well-tolerated.

Inositol 1,4,5-trisphosphate 3-kinase B promotes Ca2+ mobilization and the inflammatory activity of dendritic cells

Innate immune responses to Gram-negative bacteria depend on the recognition of lipopolysaccharide (LPS) by a receptor complex that includes CD14 and TLR4. In dendritic cells (DCs), CD14 enhances the activation not only of TLR4 but also that of the NFAT family of transcription factors, which suppresses cell survival and promotes the production of inflammatory mediators. NFAT activation requires Ca²⁺ mobilization. In DCs, Ca²⁺ mobilization in response to LPS depends on phospholipase C γ2 (PLCγ2), which produces inositol 1,4,5-trisphosphate (IP₃). Here, we showed that the IP₃ receptor 3 (IP₃R3) and ITPKB, a kinase that converts IP₃ to inositol 1,3,4,5-tetrakisphosphate (IP₄), were both necessary for Ca²⁺ mobilization and NFAT activation in mouse and human DCs. A pool of IP₃R3 was located on the plasma membrane of DCs, where it colocalized with CD14 and ITPKB. Upon LPS binding to CD14, ITPKB was required for Ca²⁺ mobilization through plasma membrane-localized IP₃R3 and for NFAT nuclear translocation. Pharmacological inhibition of ITPKB in mice reduced both LPS-induced tissue swelling and the severity of inflammatory arthritis to a similar extent as that induced by the inhibition of NFAT using nanoparticles that delivered an NFAT-inhibiting peptide specifically to phagocytic cells. Our results suggest that ITPKB may represent a promising target for anti-inflammatory therapies that aim to inhibit specific DC functions.

Terahertz pulse-altered gene networks in human induced pluripotent stem cells

Terahertz (THz) irradiation has been exploited in biomedical applications involving non-invasive manipulation of living cells. We developed an apparatus for studying the effects of THz pulse irradiation on living human induced pluripotent stem cells. The THz pulse of the maximum electric field reached 0.5 MV/cm and was applied for one hour with 1 kHz repetition to the entire cell-culture area, a diameter of 1 mm. RNA sequencing of global gene-expression revealed that many THz-regulated genes were driven by zinc-finger transcription factors. Combined with a consideration of the interactions of metal ions and a THz electric field, these results imply that the local intracellular concentration of metal ions, such as Zn²⁺, was changed by the effective electrical force of our THz pulse.

O2-Dependent Protein Internalization Underlies Astrocytic Sensing of Acute Hypoxia by Restricting Multimodal TRPA1 Channel Responses

Hypoxia sensors are essential for regulating local oxygen (O₂) homeostasis within the body. This is especially pertinent within the CNS, which is particularly vulnerable to O₂ deprivation due to high energetic demand. Here, we reveal hypoxia-monitoring function exerted by astrocytes through an O₂-regulated protein trafficking mechanism within the CNS. Strikingly, cultured mouse astrocytes isolated from the parafacial respiratory group (pFRG) and retrotrapezoid nucleus (RTN) region are capable of rapidly responding to moderate hypoxia via the sensor cation channel transient receptor potential (TRP) A1 but, unlike multimodal sensory neurons, are inert to hyperoxia and other TRPA1 activators (carbon dioxide, electrophiles, and oxidants) in normoxia. Mechanistically, O₂ suppresses TRPA1 channel activity by protein internalization via O₂-dependent proline hydroxylation and subsequent ubiquitination by an E3 ubiquitin ligase, NEDD4-1 (neural precursor cell-expressed developmentally down-regulated protein 4). Hypoxia inhibits this process and instantly accumulates TRPA1 proteins at the plasma membrane, inducing TRPA1-mediated Ca²⁺ influx that triggers ATP release from pFRG/RTN astrocytes, potentiating respiratory center activity. Furthermore, astrocyte-specific Trpa1 disruption in a mouse brainstem-spinal cord preparation impedes the amplitude augmentation of the central autonomic respiratory output during hypoxia. Thus, reversible coupling of the TRPA1 channels with O₂-dependent protein translocation allows astrocytes to act as acute hypoxia sensors in the medullary respiratory center.

Variants That Affect Function of Calcium Channel TRPV6 Are Associated With Early-Onset Chronic Pancreatitis

BACKGROUND & AIMS

Changes in pancreatic calcium levels affect secretion and might be involved in development of chronic pancreatitis (CP). We investigated the association of CP with the transient receptor potential cation channel subfamily V member 6 gene (TRPV6), which encodes a Ca²⁺-selective ion channel, in an international cohort of patients and in mice.

METHODS

We performed whole-exome DNA sequencing from a patient with idiopathic CP and from his parents, who did not have CP. We validated our findings by sequencing DNA from 300 patients with CP (not associated with alcohol consumption) and 1070 persons from the general population in Japan (control individuals). In replication studies, we sequenced DNA from patients with early-onset CP (20 years or younger) not associated with alcohol consumption from France (n = 470) and Germany (n = 410). We expressed TRPV6 variants in HEK293 cells and measured their activity using Ca²⁺ imaging assays. CP was induced by repeated injections of cerulein in TRPV6^mut/mut mice.

RESULTS

We identified the variants c.629C>T (p.A210V) and c.970G>A (p.D324N) in TRPV6 in the index patient. Variants that affected function of the TRPV6 product were found in 13 of 300 patients (4.3%) and 1 of 1070 control individuals (0.1%) from Japan (odds ratio [OR], 48.4; 95% confidence interval [CI], 6.3-371.7; P = 2.4 × 10^-8). Twelve of 124 patients (9.7%) with early-onset CP had such variants. In the replication set from Europe, 18 patients with CP (2.0%) carried variants that affected the function of the TRPV6 product compared with 0 control individuals (P = 6.2 × 10^-8). Variants that did not affect the function of the TRPV6 product (p.I223T and p.D324N) were overrepresented in Japanese patients vs control individuals (OR, 10.9; 95% CI, 4.5-25.9; P = 7.4 × 10^-9 for p.I223T and P = .01 for p.D324N), whereas the p.L299Q was overrepresented in European patients vs control individuals (OR, 3.0; 95% CI, 1.9-4.8; P = 1.2 × 10^-5). TRPV6^mut/mut mice given cerulein developed more severe pancreatitis than control mice, as shown by increased levels of pancreatic enzymes, histologic alterations, and pancreatic fibrosis.

CONCLUSIONS

We found that patients with early-onset CP not associated with alcohol consumption carry variants in TRPV6 that affect the function of its product, perhaps by altering Ca²⁺ balance in pancreatic cells. TRPV6 regulates Ca²⁺ homeostasis and pancreatic inflammation.

Transient receptor potential (TRP) channels: Biosensors for redox environmental stimuli and cellular status

Transient receptor potential (TRP) channels are a family of cation channels that depolarizes the membrane potential and regulates intracellular concentrations of cations such as Ca²⁺. TRP channels are also known to function as "biosensors" to detect changes of the surrounding environment and cellular status. Lines of evidence have unveiled that numerous proteins are subject to redox modification and subsequent signaling. For example, TRPM2, TRPC5, TRPV1, and TRPA1 are known as redox sensors activated by hydrogen peroxide (H₂O₂), nitric oxide (NO), and electrophiles. Thus, these channels facilitate the influx of cations which in turn triggers the appropriate cellular responses against environmental redox stimuli and cellular redox status. In this review, we focus on the recent findings regarding the functions of TRP channels in relation to other ion channels, and other proteins which also go through redox modification of cysteine (Cys) residues. We aim to understand the structural and molecular basis of the redox-sensing mechanisms of TRP channels in exerting various functions under physiological conditions as well as pathological conditions such as cancer malignancy. Their future potential as drug targets will also be discussed.

Contribution of Coiled-Coil Assembly to Ca2+/Calmodulin-Dependent Inactivation of TRPC6 Channel and its Impacts on FSGS-Associated Phenotypes

BACKGROUND

TRPC6 is a nonselective cation channel, and mutations of this gene are associated with FSGS. These mutations are associated with TRPC6 current amplitude amplification and/or delay of the channel inactivation (gain-of-function phenotype). However, the mechanism of the gain-of-function in TRPC6 activity has not yet been clearly solved.

METHODS

We performed electrophysiologic, biochemical, and biophysical experiments to elucidate the molecular mechanism underlying calmodulin (CaM)-mediated Ca²⁺-dependent inactivation (CDI) of TRPC6. To address the pathophysiologic contribution of CDI, we assessed the actin filament organization in cultured mouse podocytes.

RESULTS

Both lobes of CaM helped induce CDI. Moreover, CaM binding to the TRPC6 CaM-binding domain (CBD) was Ca²⁺-dependent and exhibited a 1:2 (CaM/CBD) stoichiometry. The TRPC6 coiled-coil assembly, which brought two CBDs into adequate proximity, was essential for CDI. Deletion of the coiled-coil slowed CDI of TRPC6, indicating that the coiled-coil assembly configures both lobes of CaM binding on two CBDs to induce normal CDI. The FSGS-associated TRPC6 mutations within the coiled-coil severely delayed CDI and often increased TRPC6 current amplitudes. In cultured mouse podocytes, FSGS-associated channels and CaM mutations led to sustained Ca²⁺ elevations and a disorganized cytoskeleton.

CONCLUSIONS

The gain-of-function mechanism found in FSGS-causing mutations in TRPC6 can be explained by impairments of the CDI, caused by disruptions of TRPC's coiled-coil assembly which is essential for CaM binding. The resulting excess Ca²⁺ may contribute to structural damage in the podocytes.

TRPM7 channels mediate spontaneous Ca2+ fluctuations in growth plate chondrocytes that promote bone development

During endochondral ossification of long bones, the proliferation and differentiation of chondrocytes cause them to be arranged into layered structures constituting the epiphyseal growth plate, where they secrete the cartilage matrix that is subsequently converted into trabecular bone. Ca²⁺ signaling has been implicated in chondrogenesis in vitro. Through fluorometric imaging of bone slices from embryonic mice, we demonstrated that live growth plate chondrocytes generated small, cell-autonomous Ca²⁺ fluctuations that were associated with weak and intermittent Ca²⁺ influx. Several genes encoding Ca²⁺-permeable channels were expressed in growth plate chondrocytes, but only pharmacological inhibitors of transient receptor potential cation channel subfamily M member 7 (TRPM7) reduced the spontaneous Ca²⁺ fluctuations. The TRPM7-mediated Ca²⁺ influx was likely activated downstream of basal phospholipase C activity and was potentiated upon cell hyperpolarization induced by big-conductance Ca²⁺-dependent K⁺ channels. Bones from embryos in which Trpm7 was conditionally knocked out during ex vivo culture exhibited reduced outgrowth and displayed histological abnormalities accompanied by insufficient autophosphorylation of Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) in the growth plate. The link between TRPM7-mediated Ca²⁺ fluctuations and CaMKII-dependent chondrogenesis was further supported by experiments with chondrocyte-specific Trpm7 knockout mice. Thus, growth plate chondrocytes generate spontaneous, TRPM7-mediated Ca²⁺ fluctuations that promote self-maturation and bone development.

Intracellular thermometry with fluorescent sensors for thermal biology

Temperature influences the activities of living organisms at various levels. Cells not only detect environmental temperature changes through their unique temperature-sensitive molecular machineries but also muster an appropriate response to the temperature change to maintain their inherent functions. Despite the fundamental involvement of temperature in physiological phenomena, the mechanism by which cells produce and use heat is largely unknown. Recently, fluorescent thermosensors that function as thermometers in live cells have attracted much attention in biology. These new tools, made of various temperature-sensitive molecules, have allowed for intracellular thermometry at the single-cell level. Intriguing spatiotemporal temperature variations, including organelle-specific thermogenesis, have been revealed with these fluorescent thermosensors, which suggest an intrinsic connection between temperature and cell functions. Moreover, fluorescent thermosensors have shown that intracellular temperature changes at the microscopic level are largely different from those assumed for a water environment at the macroscopic level. Thus, the employment of fluorescent thermosensors will uncover novel mechanisms of intracellular temperature-assisted physiological functions.

A genetically encoded fluorescent tRNA is active in live-cell protein synthesis

Transfer RNAs (tRNAs) perform essential tasks for all living cells. They are major components of the ribosomal machinery for protein synthesis and they also serve in non-ribosomal pathways for regulation and signaling metabolism. We describe the development of a genetically encoded fluorescent tRNA fusion with the potential for imaging in live Escherichia coli cells. This tRNA fusion carries a Spinach aptamer that becomes fluorescent upon binding of a cell-permeable and non-toxic fluorophore. We show that, despite having a structural framework significantly larger than any natural tRNA species, this fusion is a viable probe for monitoring tRNA stability in a cellular quality control mechanism that degrades structurally damaged tRNA. Importantly, this fusion is active in E. coli live-cell protein synthesis allowing peptidyl transfer at a rate sufficient to support cell growth, indicating that it is accommodated by translating ribosomes. Imaging analysis shows that this fusion and ribosomes are both excluded from the nucleoid, indicating that the fusion and ribosomes are in the cytosol together possibly engaged in protein synthesis. This fusion methodology has the potential for developing new tools for live-cell imaging of tRNA with the unique advantage of both stoichiometric labeling and broader application to all cells amenable to genetic engineering.

Methyl transfer by substrate signaling from a knotted protein fold

Proteins with knotted configurations, in comparison with unknotted proteins, are restricted in conformational space. Little is known regarding whether knotted proteins have sufficient dynamics to communicate between spatially separated substrate-binding sites. TrmD is a bacterial methyltransferase that uses a knotted protein fold to catalyze methyl transfer from S-adenosyl methionine (AdoMet) to G37-tRNA. The product, m1G37-tRNA, is essential for life and maintains protein-synthesis reading frames. Using an integrated approach of structural, kinetic, and computational analysis, we show that the structurally constrained TrmD knot is required for its catalytic activity. Unexpectedly, the TrmD knot undergoes complex internal movements that respond to AdoMet binding and signaling. Most of the signaling propagates the free energy of AdoMet binding, thereby stabilizing tRNA binding and allowing assembly of the active site. This work demonstrates new principles of knots as organized structures that capture the free energies of substrate binding and facilitate catalysis.

Deciphering Subtype-Selective Modulations in TRPA1 Biosensor Channels

The transient receptor potential (TRP) proteins are a family of ion channels that act as cellular sensors. Several members of the TRP family are sensitive to oxidative stress mediators. Among them, TRPA1 is remarkably susceptible to various oxidants, and is known to mediate neuropathic pain and respiratory, vascular and gastrointestinal functions, making TRPA1 an attractive therapeutic target. Recent studies have revealed a number of modulators (both activators and inhibitors) that act on TRPA1. Endogenous mediators of oxidative stress and exogenous electrophiles activate TRPA1 through oxidative modification of cysteine residues. Non-electrophilic compounds also activate TRPA1. Certain non-electrophilic modulators may act on critical non-cysteine sites in TRPA1. However, a method to achieve selective modulation of TRPA1 by small molecules has not yet been established. More recently, we found that a novel N-nitrosamine compound activates TRPA1 by S-nitrosylation (the addition of a nitric oxide (NO) group to cysteine thiol), and does so with significant selectivity over other NO-sensitive TRP channels. It is proposed that this subtype selectivity is conferred through synergistic effects of electrophilic cysteine transnitrosylation and molecular recognition of the non-electrophilic moiety on the N-nitrosamine. In this review, we describe the molecular pharmacology of these TRPA1 modulators and discuss their modulatory mechanisms.

Different Contribution of Redox-Sensitive Transient Receptor Potential Channels to Acetaminophen-Induced Death of Human Hepatoma Cell Line

Acetaminophen (APAP) is a safe analgesic antipyretic drug at prescribed doses. Its overdose, however, can cause life-threatening liver damage. Though, involvement of oxidative stress is widely acknowledged in APAP-induced hepatocellular death, the mechanism of this increased oxidative stress and the associated alterations in Ca²⁺ homeostasis are still unclear. Among members of transient receptor potential (TRP) channels activated in response to oxidative stress, we here identify that redox-sensitive TRPV1, TRPC1, TRPM2, and TRPM7 channels underlie Ca²⁺ entry and downstream cellular damages induced by APAP in human hepatoma (HepG2) cells. Our data indicate that APAP treatment of HepG2 cells resulted in increased reactive oxygen species (ROS) production, glutathione (GSH) depletion, and Ca²⁺ entry leading to increased apoptotic cell death. These responses were significantly suppressed by pretreatment with the ROS scavengers N-acetyl-L-cysteine (NAC) and 4,5-dihydroxy-1,3-benzene disulfonic acid disodium salt monohydrate (Tiron), and also by preincubation of cells with the glutathione inducer Dimethylfumarate (DMF). TRP subtype-targeted pharmacological blockers and siRNAs strategy revealed that suppression of either TRPV1, TRPC1, TRPM2, or TRPM7 reduced APAP-induced ROS formation, Ca²⁺ influx, and cell death; the effects of suppression of TRPV1 or TRPC1, known to be activated by oxidative cysteine modifications, were stronger than those of TRPM2 or TRPM7. Interestingly, TRPV1 and TRPC1 were labeled by the cysteine-selective modification reagent, 5,5′-dithiobis (2-nitrobenzoic acid)-2biotin (DTNB-2Bio), and this was attenuated by pretreatment with APAP, suggesting that APAP and/or its oxidized metabolites act directly on the modification target cysteine residues of TRPV1 and TRPC1 proteins. In human liver tissue, TRPV1, TRPC1, TRPM2, and TRPM7 channels transcripts were localized mainly to hepatocytes and Kupffer cells. Our findings strongly suggest that APAP-induced Ca²⁺ entry and subsequent hepatocellular death are regulated by multiple redox-activated cation channels, among which TRPV1 and TRPC1 play a prominent role.

Impaired function is a common feature of neuropathy-associated glycyl-tRNA synthetase mutations

Charcot-Marie-Tooth disease type 2D (CMT2D) is an autosomal-dominant axonal peripheral neuropathy characterized by impaired motor and sensory function in the distal extremities. Mutations in the glycyl-tRNA synthetase (GARS) gene cause CMT2D. GARS is a member of the ubiquitously expressed aminoacyl-tRNA synthetase (ARS) family and is responsible for charging tRNA with glycine. To date, 13 GARS mutations have been identified in patients with CMT disease. While functional studies have revealed loss-of-function characteristics, only four GARS mutations have been rigorously studied. Here, we report the functional evaluation of nine CMT-associated GARS mutations in tRNA charging, yeast complementation, and subcellular localization assays. Our results demonstrate that impaired function is a common characteristic of CMT-associated GARS mutations. Additionally, one mutation previously associated with CMT disease (p.Ser581Leu) does not demonstrate impaired function, was identified in the general population, and failed to segregate with disease in two newly identified families with CMT disease. Thus, we propose that this variant is not a disease-causing mutation. Together, our data indicate that impaired function is a key component of GARS-mediated CMT disease and emphasize the need for careful genetic and functional evaluation before implicating a variant in disease onset.

The temperature sensitivity of a mutation in the essential tRNA modification enzyme tRNA methyltransferase D (TrmD)

Conditional temperature-sensitive (ts) mutations are important reagents to study essential genes. Although it is commonly assumed that the ts phenotype of a specific mutation arises from thermal denaturation of the mutant enzyme, the possibility also exists that the mutation decreases the enzyme activity to a certain level at the permissive temperature and aggravates the negative effect further upon temperature upshifts. Resolving these possibilities is important for exploiting the ts mutation for studying the essential gene. The trmD gene is essential for growth in bacteria, encoding the enzyme for converting G37 to m(1)G37 on the 3' side of the tRNA anticodon. This conversion involves methyl transfer from S-adenosyl methionine and is critical to minimize tRNA frameshift errors on the ribosome. Using the ts-S88L mutation of Escherichia coli trmD as an example, we show that although the mutation confers thermal lability to the enzyme, the effect is relatively minor. In contrast, the mutation decreases the catalytic efficiency of the enzyme to 1% at the permissive temperature, and at the nonpermissive temperature, it renders further deterioration of activity to 0.1%. These changes are accompanied by losses of both the quantity and quality of tRNA methylation, leading to the potential of cellular pleiotropic effects. This work illustrates the principle that the ts phenotype of an essential gene mutation can be closely linked to the catalytic defect of the gene product and that such a mutation can provide a useful tool to study the mechanism of catalytic inactivation.

The catalytic domain of topological knot tRNA methyltransferase (TrmH) discriminates between substrate tRNA and nonsubstrate tRNA via an induced-fit process

A conserved guanosine at position 18 (G18) in the D-loop of tRNAs is often modified to 2'-O-methylguanosine (Gm). Formation of Gm18 in eubacterial tRNA is catalyzed by tRNA (Gm18) methyltransferase (TrmH). TrmH enzymes can be divided into two types based on their substrate tRNA specificity. Type I TrmH, including Thermus thermophilus TrmH, can modify all tRNA species, whereas type II TrmH, for example Escherichia coli TrmH, modifies only a subset of tRNA species. Our previous crystal study showed that T. thermophilus TrmH is a class IV S-adenosyl-l-methionine-dependent methyltransferase, which maintains a topological knot structure in the catalytic domain. Because TrmH enzymes have short stretches at the N and C termini instead of a clear RNA binding domain, these stretches are believed to be involved in tRNA recognition. In this study, we demonstrate by site-directed mutagenesis that both N- and C-terminal regions function in tRNA binding. However, in vitro and in vivo chimera protein studies, in which four chimeric proteins of type I and II TrmHs were used, demonstrated that the catalytic domain discriminates substrate tRNAs from nonsubstrate tRNAs. Thus, the N- and C-terminal regions do not function in the substrate tRNA discrimination process. Pre-steady state analysis of complex formation between mutant TrmH proteins and tRNA by stopped-flow fluorescence measurement revealed that the C-terminal region works in the initial binding process, in which nonsubstrate tRNA is not excluded, and that structural movement of the motif 2 region of the catalytic domain in an induced-fit process is involved in substrate tRNA discrimination.

Simultaneous detection of ATP and GTP by covalently linked fluorescent ribonucleopeptide sensors

A noncovalent RNA complex embedding an aptamer function and a fluorophore-labeled peptide affords a fluorescent ribonucleopeptide (RNP) framework for constructing fluorescent sensors. By taking an advantage of the noncovalent properties of the RNP complex, the ligand-binding and fluorescence characteristics of the fluorescent RNP can be independently tuned by taking advantage of the nature of the RNA and peptide subunits, respectively. Fluorescent sensors tailored for given measurement conditions, such as a detection wavelength and a detection concentration range for a ligand of interest can be easily identified by screening of fluorescent RNP libraries. The noncovalent configuration of a RNP becomes a disadvantage when the sensor is to be utilized at very low concentrations or when multiple sensors are applied to the same solution. Here, we report a strategy to convert a fluorescent RNP sensor in the noncovalent configuration into a covalently linked stable fluorescent RNP sensor. This covalently linked fluorescent RNP sensor enabled ligand detection at a low sensor concentration, even in cell extracts. Furthermore, application of both ATP and GTP sensors enabled simultaneous detection of ATP and GTP by monitoring each wavelength corresponding to the respective sensor. Importantly, when a fluorescein-modified ATP sensor and a pyrene-modified GTP sensor were co-incubated in the same solution, the ATP sensor responded at 535 nm only to changes in the concentration of ATP, whereas the GTP sensor detected GTP at 390 nm without any effect on the ATP sensor. Finally, simultaneous monitoring by these sensors enabled real-time measurement of adenosine deaminase enzyme reactions.

Recognition of guanosine by dissimilar tRNA methyltransferases

Guanosines are important for biological activities through their specific functional groups that are recognized for RNA or protein interactions. One example is recognition of N(1) of G37 in tRNA by S-adenosyl-methionine (AdoMet)-dependent tRNA methyltransferases to synthesize m(1)G37-tRNA, which is essential for translational fidelity in all biological domains. Synthesis of m(1)G37-tRNA is catalyzed by TrmD in bacteria and by Trm5 in eukarya and archaea, using unrelated and dissimilar structural folds. This raises the question of how dissimilar proteins recognize the same guanosine. Here we probe the mechanism of discrimination among functional groups of guanosine by TrmD and Trm5. Guanosine analogs were systematically introduced into tRNA through a combination of chemical and enzymatic synthesis. Single turnover kinetic assays and thermodynamic analysis of the effect of each analog on m(1)G37-tRNA synthesis reveal that TrmD and Trm5 discriminate functional groups differently. While both recognize N(1) and O(6) of G37, TrmD places a much stronger emphasis on these functional groups than Trm5. While the exocyclic 2-amino group of G37 is important for TrmD, it is dispensable for Trm5. In addition, while an adjacent G36 is obligatory for TrmD, it is nonessential for Trm5. These results depict a more rigid requirement of guanosine functional groups for TrmD than for Trm5. However, the sensitivity of both enzymes to analog substitutions, together with an experimental revelation of their low cellular concentrations relative to tRNA substrates, suggests a model in which these enzymes rapidly screen tRNA by direct recognition of G37 in order to monitor the global state of m(1)G37-tRNA.

A recurrent loss-of-function alanyl-tRNA synthetase (AARS) mutation in patients with Charcot-Marie-Tooth disease type 2N (CMT2N)

Charcot-Marie-Tooth (CMT) disease comprises a heterogeneous group of peripheral neuropathies characterized by muscle weakness and wasting, and impaired sensation in the extremities. Four genes encoding an aminoacyl-tRNA synthetase (ARS) have been implicated in CMT disease. ARSs are ubiquitously expressed, essential enzymes that ligate amino acids to cognate tRNA molecules. Recently, a p.Arg329His variant in the alanyl-tRNA synthetase (AARS) gene was found to segregate with dominant axonal CMT type 2N (CMT2N) in two French families; however, the functional consequence of this mutation has not been determined. To investigate the role of AARS in CMT, we performed a mutation screen of the AARS gene in patients with peripheral neuropathy. Our results showed that p.Arg329His AARS also segregated with CMT disease in a large Australian family. Aminoacylation and yeast viability assays showed that p.Arg329His AARS severely reduces enzyme activity. Genotyping analysis indicated that this mutation arose on three distinct haplotypes, and the results of bisulfite sequencing suggested that methylation-mediated deamination of a CpG dinucleotide gives rise to the recurrent p.Arg329His AARS mutation. Together, our data suggest that impaired tRNA charging plays a role in the molecular pathology of CMT2N, and that patients with CMT should be directly tested for the p.Arg329His AARS mutation.

Allosteric communication in cysteinyl tRNA synthetase: a network of direct and indirect readout

Protein structure networks are constructed for the identification of long-range signaling pathways in cysteinyl tRNA synthetase (CysRS). Molecular dynamics simulation trajectory of CysRS-ligand complexes were used to determine conformational ensembles in order to gain insight into the allosteric signaling paths. Communication paths between the anticodon binding region and the aminoacylation region have been identified. Extensive interaction between the helix bundle domain and the anticodon binding domain, resulting in structural rigidity in the presence of tRNA, has been detected. Based on the predicted model, six residues along the communication paths have been examined by mutations (single and double) and shown to mediate a coordinated coupling between anticodon recognition and activation of amino acid at the active site. This study on CysRS clearly shows that specific key residues, which are involved in communication between distal sites in allosteric proteins but may be elusive in direct structure analysis, can be identified from dynamics of protein structure networks.

Compound heterozygosity for loss-of-function lysyl-tRNA synthetase mutations in a patient with peripheral neuropathy

Charcot-Marie-Tooth (CMT) disease comprises a genetically and clinically heterogeneous group of peripheral nerve disorders characterized by impaired distal motor and sensory function. Mutations in three genes encoding aminoacyl-tRNA synthetases (ARSs) have been implicated in CMT disease primarily associated with an axonal pathology. ARSs are ubiquitously expressed, essential enzymes responsible for charging tRNA molecules with their cognate amino acids. To further explore the role of ARSs in CMT disease, we performed a large-scale mutation screen of the 37 human ARS genes in a cohort of 355 patients with a phenotype consistent with CMT. Here we describe three variants (p.Leu133His, p.Tyr173SerfsX7, and p.Ile302Met) in the lysyl-tRNA synthetase (KARS) gene in two patients from this cohort. Functional analyses revealed that two of these mutations (p.Leu133His and p.Tyr173SerfsX7) severely affect enzyme activity. Interestingly, both functional variants were found in a single patient with CMT disease and additional neurological and non-neurological sequelae. Based on these data, KARS becomes the fourth ARS gene associated with CMT disease, indicating that this family of enzymes is specifically critical for axon function.

Effects of high-K+, Na+-deficient solution on contractility of the smooth muscles of the bovine trachea

A high-K+, Na+-deficient (I-154 K+) solution induced contraction followed by gradual relaxation of the smooth muscles of the bovine trachea, while hyperosmotic addition of 65 mM KCl induced a large sustained contraction. Exposure of the muscle to the I-154 K+ solution induced an increase in the ratio of cellular water content and a sustained increase in oxidized flavoprotein fluorescence or reduced pyridine nucleotide fluorescence. The I-154 K+ solution also induced a sustained increase in [Ca2+]i level. Decreases in developed tension and increases in cellular water content were both prevented by the addition of sucrose or NaCl but not pyruvate. Substitution of KI for KCl in the I-154 K+ solution produced a greater inhibition of contraction, while substitution with K-propionate produced no inhibition of contraction. Moreover, decreases in developed tension and increases in cellular water content were both prevented by addition of 100 microM 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS), but not 10 microM bumetanide or 1 mM acetazolamide. In conclusion, I-154 K+ solution induced-relaxation in the bovine trachea may be due to swelling of smooth muscle cells and the mechanism of swelling is probably involved in DIDS-sensitive anion movement.

Characterization of mouse homolog of brain acyl-CoA hydrolase: molecular cloning and neuronal localization

Acyl-CoA hydrolase could provide a mechanism via its potency to modulate cellular concentrations of acyl-CoAs for the regulation of various cellular events including fatty acid metabolism and gene expression. However, only limited evidence of this is available. To better understand the physiological role of this enzyme, we characterized a mouse brain acyl-CoA hydrolase, mBACH. The cloned cDNA for mBACH encoded a 338-amino-acid polypeptide with >95% identity to the human and rat homologs, indicating that the BACH gene is highly conserved among species. This was supported by the similarity in genomic organization of the BACH gene between humans and mice. Bacterially expressed mBACH was highly active against long-chain acyl-CoAs with a relatively broad specificity for chain length. While palmitoyl-CoA hydrolase activity was widely distributed in mouse tissues, it was marked in the brain, consistent with mBACH being almost exclusively distributed in this tissue, where >80% of the enzyme activity was explained by mBACH present in the cytosol. Immunohistochemistry demonstrated a neuronal localization of mBACH in both the central and peripheral nervous systems. In neurons, mBACH was distributed throughout the cell body and neurites. Although four isoforms except mBACH itself, that may be generated by the alternative use of exons of a single mBACH gene, were cloned, their mRNA levels in the brain were estimated to be negligible. However, a 50-kDa polypeptide besides the major one of 43-kDa seemed to be translated from the mBACH mRNA with differential in-frame ATG triplets used as the initiation codon. These findings will contribute to the functional analysis of the BACH gene using mice including genetic studies.

Autologous peripheral stem-cell transplantation after intensive chemotherapy in a case of CD30 (Ki-1)-positive anaplastic large-cell lymphoma

Simultaneous treatment with peripheral blood stem-cell (PBSC) transplantation and intensive chemotherapy was evaluated in a case of non-Hodgkin's lymphoma (NHL) with poor prognosis. A 59-year-old male diagnosed with a high-grade, anaplastic large-cell (Ki-1) NHL, involving fractures in the left hip, underwent computed tomography and gallium scintigram surveillance. The patient received chemotherapy with epirubicin hydrochloride, cyclophosphamide, vincristine and prednisolone, and the fractured hip bone was repaired following the first course of chemotherapy. After the second and third courses of chemotherapy, PBSCs were harvested and cryopreserved. The patient then received a further course of chemotherapy and PBSC transplantation was conducted using infused cells consisting of 9.63 x 10(6)/kg CD34 cells and 2.24 x 10(5)/kg granulocyte macrophage colony-forming units. Recovery of platelet and white blood cell counts occurred 10 and 8 days, respectively, after PBSC infusion and the patient remains well.

Purpura due to aspirin-induced platelet dysfunction aggravated by drinking alcohol

We report a rare case of prominent purpura induced by aspirin and enhanced by alcohol. A 44-year-old woman presented with a history of generalized purpura. She drank alcohol once or twice a week and regularly took an analgesic preparation, containing aspirin and acetaminophen, for alleviation of headaches. When purpura was evident the patient's liver function was within normal limits and her coagulation time was normal but her bleeding time was prolonged. Red blood cell, white blood cell and platelet counts were normal but a poor response to platelet agonists demonstrated platelet dysfunction. After stopping the analgesic and abstaining from alcohol for 5 days, platelet aggregation, in response to the agonists, returned to normal and purpura disappeared. When the patient took further doses of the analgesic preparation for 3 days for headache relief, but did not drink alcohol, platelet aggregation was again abnormal but purpura was only slight.

A therapeutic strategy for isolated plasmacytoma of bone

Two cases of solitary plasmacytoma of bone (SPB) were diagnosed. The first case was a 41-year-old woman, complaining of fatigue from her lumbar region to her legs. The second case was a 56-year-old man complaining of poor gait and severe lumbago with numbness in the toes of both feet. Magnetic resonance imaging showed the osteolytic lesion in the 12th thoracic bone in the first patient and around the 2nd, 3rd and 4th lumbar bones in the second patient. In both patients serum analysis revealed the monoclonal component of immunoglobulin G (IgG) protein with kappa-light chain, and considering this and other findings SPB was diagnosed. Both patients were first treated with irradiation around the involved bone and then with a course of chemotherapy. In the first patient the tumour region of the bone was surgically removed and replaced with a ceramic spacer. The symptoms of both patients were ameliorated, and the patients remained in good condition for around 3 years without conversion to multiple myeloma. In view of the overall effectiveness of treatments for SPB, our therapeutic strategy deserves careful evaluation.

Treatment of acute myeloblastic leukaemia in a patient with Bombay blood type: a case report

A 62-year-old female was admitted to our hospital with suspected acute leukaemia and after investigation we diagnosed acute myeloblastic leukaemia (AML-M1). The patient's blood type was found to be the very rare Bombay type and surveillance of her relatives showed the same blood type in her male cousin on her mother's side. Alongside chemotherapy the patient received 4000 ml of frozen Bombay-type red cells, 1400 ml of concentrated red cells in manitol adenine phosphate solutions and 360 units of type O concentrated platelets without marked effects. The anti-H antibody was initially at 128 dilution but for unknown reasons increased to 2048 dilution after remission of AML-M1. About 3 months after hospitalization the patient died of Cryptococcus neoformans pneumonia despite strict precautions against infection. Although AML-M1 is a common adult leukaemia and is chemosensitive to anti-leukaemic drugs, neither AML-M1 in a patient with Bombay-type red cells nor its treatment with chemotherapy and transfusion with type Oh frozen red cells have previously been reported.

The CAG regimen (low-dose cytarabine, aclarubicin hydrochloride and granulocyte colony-stimulating factor) for the treatment of elderly acute myelomonocytic leukaemia: a case study

Elderly patients with acute myelomonocytic leukaemia (AMMoL) frequently have a poor quality of life after induction of remission using high-intensity treatment; we seek a more appropriate regimen for such patients. An 86-year-old man was hospitalized with a diagnosis of AMMoL (FAB classification M4), of abnormal karyotype, and complications of diabetes mellitus and complete right bundle branch block. He was treated with CAG therapy (cytarabine 10 mg/m2 subcutaneously every 12 h for 14 consecutive days; aclarubicin hydrochloride 10 mg/m2 per day, bolus intravenously for 4 consecutive days; granulocyte colony-stimulating factor 100 microg/day, subcutaneous injection for 14 consecutive days) every 3 months. White blood cell counts were at their lowest (around 600 - 800/microl) 12 days after the end of therapy, but returned to about 2000 - 2300/microl 30 days after stopping therapy. No symptoms of drug-related toxicity, except slight nausea, were found. Complete remission with a good quality of life was induced and lasted over 2 years suggesting that CAG therapy might prove effective in elderly patients with AMMoL.

Isolated factor VII deficiency diagnosed after a life-threatening brain haemorrhage

A 65-year-old man was admitted to another hospital with a life-threatening brain haemorrhage, and laboratory examinations on admission revealed prolonged prothrombin time with normal activated partial thromboplastin time. To establish the cause of his abnormal coagulation, he was referred to our clinic. Neither the patient nor his family had any previous history of bleeding symptoms. His liver function was within normal limits but coagulation tests showed increased plasma activities of factors II, VIII, IX, X, with reduced activities of factors V and VII. The activity of factor VII was less than 2% but no inhibitor of factor VII was detected in the plasma. We concluded that the patient had a rare congenital isolated factor VII deficiency although he had not shown earlier bleeding problems, presumably because of compensation for the factor VII deficiency by enhanced activities of components of the extrinsic coagulation pathway, factors II, VIII, IX and X.

Congenital dislocation of the knee reduced spontaneously or with minimal treatment

Six cases of congenital dislocation of the knee (CDK) reduced spontaneously or with minimal treatment were investigated. Reduction was achieved from 4 days to 3 months after birth. Clinical results were good, although in four cases, hyperextension < or = 20 degrees persisted. In view of the perinatal complications and associated anomalies, CDK reduced with no or minimal treatment is supposed to be a category of congenital postural deformity. We believe that it is advisable to wait 1 month for spontaneous reduction of CDK in cases not associated with clubfoot, arthrogryposis multiplex congenita, and Larsen's syndrome.

[Exposure to blood during midwifery operations--a questionnaire study]

A self-administered questionnaire was mailed to all midwives working in Nara Prefecture to investigate blood exposure events at delivery and to consider protective measures for the exposure. Out of the 203 midwives 193 responded to the questionnaire. The median number of deliveries in which the midwives had assisted within the past one year was 35 after excluding those who had not assisted in deliveries at all. The incidence of needle-stick injuries was estimated to be 86.2 per 100 persons within the past one year. The occurrence in the subgroup who had worked as midwife for less than 5 years was 2-3 times higher than that in those who worked for more than 5 years. Over 90% of the midwives had experiences of direct blood contact events to the skin while assisting in their 10 most recent deliveries. Blood contact events occurred in the finger-hand-arm area in 85% of the midwives, on the legs in 62%, in the face in 20% and in the eyes in 1%. Around 20% of the midwives had unintentionally sucked amniotic fluid when using a tracheal catheter on a newborn. The most common occasion where direct blood contact events occurred was while bathing an infant for removing blood and amniotic fluid. The midwives wore a disposal gown more often when assisting in labors of parturient women infected with blood-born infectious diseases than without the diseases, and similarly for wearing gloves when measuring blood loss and for usage of a mechanical device for sucking amniotic fluid in the tracheae of an infant. Based on the results obtained in this questionnaire study and our previous study about blood contact events observed in a delivery room, protective measures for midwives against exposure to blood at delivery are required and some ideas are presented.