Placental Mammals Acquired Functional Sequences in NRK for Regulating the CK2-PTEN-AKT Pathway and Placental Cell Proliferation.

The molecular evolution processes underlying the acquisition of the placenta in eutherian ancestors are not fully understood. Mouse NCK-interacting kinase (NIK)-related kinase (NRK) is expressed highly in the placenta and plays a role in preventing placental hyperplasia. Here, we show the molecular evolution of NRK, which confers its function for inhibiting placental cell proliferation. Comparative genome analysis identified NRK orthologs across vertebrates, which share the kinase and citron homology (CNH) domains. Evolutionary analysis revealed that NRK underwent extensive amino acid substitutions in the ancestor of placental mammals and has been since conserved. Biochemical analysis of mouse NRK revealed that the CNH domain binds to phospholipids, and a region in NRK binds to and inhibits casein kinase-2 (CK2), which we named the CK2-inhibitory region (CIR). Cell culture experiments suggest the following: 1) Mouse NRK is localized at the plasma membrane via the CNH domain, where the CIR inhibits CK2. 2) This mitigates CK2-dependent phosphorylation and inhibition of PTEN and 3) leads to the inhibition of AKT signaling and cell proliferation. Nrk deficiency increased phosphorylation levels of PTEN and AKT in mouse placenta, supporting our hypothesis. Unlike mouse NRK, chicken NRK did not bind to phospholipids and CK2, decrease phosphorylation of AKT, or inhibit cell proliferation. Both the CNH domain and CIR have evolved under purifying selection in placental mammals. Taken together, our study suggests that placental mammals acquired the phospholipid-binding CNH domain and CIR in NRK for regulating the CK2-PTEN-AKT pathway and placental cell proliferation.

Dosing Optimization of Ampicillin-Sulbactam Based on Cystatin C in Elderly Patients with Pneumonia.

Ampicillin-sulbactam is a first-line therapy for pneumonia and is mainly excreted by the kidney. It is important to optimize the dose and dosing interval of ampicillin-sulbactam because in patients with decreased renal function and low skeletal muscle mass, such as the elderly, excess drug may burden renal function. In this study, we evaluated indices of renal function and optimized the dose and dosing interval of ampicillin-sulbactam based on pharmacokinetics (PK) and pharmacodynamics theory in elderly patients. The serum concentrations of ampicillin and sulbactam were measured by HPLC, and PK parameters were calculated. Correlations between the clearance of ampicillin or sulbactam and renal function were evaluated, and dosing optimization was calculated based on PK parameters. The PK parameters of ampicillin were CL = 6.5 ± 4.0 L/h, Vd = 19.3 ± 0.2 L, Ke = 0.4 ± 0.2, and t1/2 = 2.7 ± 1.6 h. The most correlated renal function index was estimated glomerular filtration rate (eGFRcys-c) calculated by serum cystatin-c (r = 0.7374, correlation formula; CL of ampicillin = 0.1937 × eGFRcys-c-0.6726). Based on this formula, we calculated the clearance of ampicillin and developed dosing regimens for the elderly. Serum cystatin-c concentration is an ideal index to optimize ampicillin-sulbactam antimicrobial therapy in elderly patients with pneumonia.

Fused-Nonacyclic Multi-Resonance Delayed Fluorescence Emitter Based on Ladder-Thiaborin Exhibiting Narrowband Sky-Blue Emission with Accelerated Reverse Intersystem Crossing.

Developing organic luminophores with unique capability of strong narrowband emission is both crucial and challenging for the further advancement of organic light-emitting diodes (OLEDs). Herein, a nanographitic fused-nonacyclic π-system (BSBS-N1), which was strategically embedded with multiple boron, nitrogen, and sulfur atoms, was developed as a new multi-resonance thermally activated delayed fluorescence (MR-TADF) emitter. Narrowband sky-blue emission with a peak at 478 nm, full width at half maximum of 24 nm, and photoluminescence quantum yield of 89 % was obtained with BSBS-N1. Additionally, the spin-orbit coupling was enhanced by incorporating two sulfur atoms, thereby facilitating the spin-flipping process between the excited triplet and singlet states. OLEDs based on BSBS-N1 as a sky-blue MR-TADF emitter achieved a high maximum external electroluminescence quantum efficiency of 21.0 %, with improved efficiency roll-off.

Extraction of corn germ oil with supercritical CO2 and cosolvents.

The aim of this work was to investigate corn germ oil extraction using supercritical CO2 and cosolvents addition (hexane, acetone and ethanol). The effects of temperature (45-85 °C) and pressure (15-25 MPa) on the extract yield were evaluated for the tests conducted only with supercritical CO2. The addition of cosolvents to supercritical CO2 was also examined at 25 MPa and 60 °C. The conventional Soxhlet extraction with different organic solvents was also performed for comparison purposes. The results of extraction with supercritical fluid showed that the yields increased with pressure at each temperature, but decreased with temperature increase. Mathematical modeling was applied to describe extraction curves, with very good fits. The addition of cosolvents led to higher yield, with a maximum yield of 13.81% using ethanol. The analysis of fatty acids profile did not present significant differences among the evaluated methods. On the other hand, the antioxidant activity of the extracts obtained by supercritical CO2 extraction was higher than the ones verified for the extracts collected after conventional Soxhlet extraction. Therefore, the use of supercritical CO2 extraction could be an interesting way to preserve antioxidant properties of this oil in order to use it for pharmaceutical purposes.

Pharmacokinetics of Prophylactic Ampicillin-Sulbactam and Dosing Optimization in Patients Undergoing Cardiovascular Surgery with Cardiopulmonary Bypass.

UNLABELLED: Antibiotic concentrations must be maintained at an adequate level throughout cardiovascular surgery to prevent surgical site infection. This study aimed to determine the most appropriate timing for intraoperative repeated dosing of ampicillin-sulbactam, a commonly used antibiotic prophylaxis regimen, to maintain adequate concentrations throughout the course of cardiovascular surgery with cardiopulmonary bypass (CPB). The total plasma concentrations of ampicillin were monitored in 8 patients after ampicillin (1 g)-sulbactam (0.5 g) administration via initial intravenous infusion and subsequent CPB priming. Pharmacokinetic parameters were estimated and used to predict the free plasma concentrations of ampicillin. The mean values for the volume of distribution, elimination rate constant, elimination half-life, and total clearance of ampicillin were 15.8±4.1 L, 0.505±0.186 h(-1), 1.52±0.47 h, and 7.72±2.72 L/h, respectively. When ampicillin (1 g)-sulbactam (0.5 g) was intravenously administered every 3, 4, 6, and 12 h after the start of CPB, the predicted free trough plasma concentrations of ampicillin were 15.20, 8.25, 2.74, and 0.13 µg/mL, respectively. Therefore, an every-6-h regimen was needed to maintain the free ampicillin concentration at more than 2 µg/mL during cardiovascular surgery with CPB. We suggest that the dose and dosing interval for ampicillin-sulbactam should be adjusted to optimize the efficacy and safety of treatment, according to the minimum inhibitory concentrations for methicillin-sensitive Staphylococcus aureus isolates at each institution. REGISTRATION NUMBER: UMIN000007356.

Population pharmacokinetic-pharmacodynamic target attainment analysis of sulbactam in patients with impaired renal function: dosing considerations for Acinetobacter baumannii infections.

UNLABELLED: This study aimed to perform a pharmacokinetic (PK)-pharmacodynamic (PD) target attainment analysis of sulbactam against Acinetobacter baumannii in patients with impaired renal function. The PK data (188 plasma samples and 27 urine samples) were modeled simultaneously. The mean population parameters were CLr (l/h) = 0.0792 × CLcr (ml/min), CLnr (l/h) = 2.35, Vc (l) = 12.2, Q (l/h) = 4.68 and Vp (l) = 4.44, where CLr and CLnr are the renal and non-renal clearances, Vc and Vp are the distribution volumes of the central and peripheral compartments and Q is intercompartmental clearance. The creatinine clearance (CLcr) was the most significant covariate. The determined MIC of sulbactam against A. baumannii clinical isolates (n = 27) was 0.75-6.0 µg/ml with MIC50 and MIC90 of 1 and 4 µg/ml, respectively. For sulbactam regimens, a Monte Carlo simulation estimated the probabilities of attaining the bactericidal target (60% of the time above the MIC) and determined the PK-PD breakpoints (the highest MICs at which the probabilities were 90% or more). In a patient with a CLcr of 15 ml/min, a regimen of 1 g twice daily achieved a 90% or more probability against the A. baumannii isolate population; however, 2 g four times daily was needed for a 90% or more probability in a patient with a CLcr of 90 ml/min. The results of the PK-PD target attainment analysis are useful when choosing the sulbactam regimen based on the CLcr of the patient and the susceptibility of A. baumannii. REGISTRATION NUMBER: UMIN000007356.

Linezolid dosage in pediatric patients based on pharmacokinetics and pharmacodynamics.

Linezolid pharmacokinetic profile in pediatric patients has not been fully characterized, and the dose needed to achieve a pharmacokinetic-pharmacodynamic (PK-PD) target has yet to be established because its efficacy is associated with the area under the plasma drug concentration-time curve (AUC24)/minimum inhibitory concentration (MIC) ratio. The present study aimed to define the pharmacokinetic parameters of intravenous linezolid in pediatric patients and assess the rationale for the approved dosage recommendations. Linezolid was safe, tolerated well, and clinically effective for treating Gram-positive bacteria in five pediatric patients (3-11 years). The mean values for the volume of distribution and total clearance (CL) in a one-compartment model were estimated to be 0.646 ± 0.239 l/kg and 0.171 ± 0.068 l/h/kg, respectively (mean ± S.D.). Based on this analysis, the AUC24 and trough drug concentration in plasma (C(min)) for linezolid doses were predicted to be 175.4 µg h/ml and 3.4 µg/ml for 30 mg/kg/day, 204.7 µg h/ml and 4.3 µg/ml for 35 mg/kg/day, and 263.2 µg h/ml and 6.2 µg/ml for 45 mg/kg/day, respectively. Taking into account that AUC24 should be ≥ 200 µg h/ml for MIC of 2.0 µg/ml (to achieve an AUC24/MIC ratio of ≥ 100) and C(min) should be approximately 7 µg/ml (to avoid thrombocytopenia), we consider the approved dosage of 30 mg/kg/day to be fundamentally rational, but can be underdosed against bacteria with MIC of 2.0 µg/ml; therefore, a dose of 35-45 mg/kg/day is more appropriate to ensure the efficacy and safety of linezolid in pediatric patients.

Functional Divergence in Solute Permeability between Ray-Finned Fish-Specific Paralogs of aqp10.

Aquaporin (Aqp) 10 is a member of the aquaglyceroporin subfamily of water channels, and human Aqp10 is permeable to solutes such as glycerol, urea, and boric acid. Tetrapods have a single aqp10 gene, whereas ray-finned fishes have paralogs of this gene through tandem duplication, whole-genome duplication, and subsequent deletion. A previous study on Aqps in the Japanese pufferfish Takifugu rubripes showed that one pufferfish paralog, Aqp10.2b, was permeable to water and glycerol, but not to urea and boric acid. To understand the functional differences of Aqp10s between humans and pufferfish from an evolutionary perspective, we analyzed Aqp10s from an amphibian (Xenopus laevis) and a lobe-finned fish (Protopterus annectens) and Aqp10.1 and Aqp10.2 from several ray-finned fishes (Polypterus senegalus, Lepisosteus oculatus, Danio rerio, and Clupea pallasii). The expression of tetrapod and lobe-finned fish Aqp10s and Aqp10.1-derived Aqps in ray-finned fishes in Xenopus oocytes increased the membrane permeabilities to water, glycerol, urea, and boric acid. In contrast, Aqp10.2-derived Aqps in ray-finned fishes increased water and glycerol permeabilities, whereas those of urea and boric acid were much weaker than those of Aqp10.1-derived Aqps. These results indicate that water, glycerol, urea, and boric acid permeabilities are plesiomorphic activities of Aqp10s and that the ray-finned fish-specific Aqp10.2 paralogs have secondarily reduced or lost urea and boric acid permeability.

Development of initial loading procedure for teicoplanin in critically ill patients with severe infections.

Methicillin-resistant Staphylococcus aureus (MRSA) is now endemic in many hospitals. Infection with MRSA is more frequent in the intensive care unit (ICU) than in general wards. Therefore, appropriate treatments for MRSA infections will lead to good outcomes in the ICU. Teicoplanin is an anti-MRSA agent. Recently, it was recommended at a new target trough concentration of 15-30 µg/mL. However, the initial loading procedure for teicoplanin to allow it to reach the target concentration promptly remains uncertain. Therefore, this study aimed to determine the appropriate initial loading procedure for teicoplanin in critically ill patients with severe infections. We performed a retrospective study in patients given teicoplanin in the ICU in order to determine the initial loading procedure to promptly reach the target trough concentration. We then evaluated the trough concentration on the third day after commencement of teicoplanin therapy. The mean loading dose and trough concentration were 11.5±1.0 mg/kg and 18.9±5.9 µg/mL, respectively. A correlation (r=0.45, p=0.046) was shown between teicoplanin loading dose and trough concentration. The correlation equation was trough concentration=2.563·loading dose -10.672. In the cases of 11.0 and 15.0 mg/kg for the loading dose, respectively, trough concentrations were 17.5 and 27.8 µg/mL. We suggested that an initial loading dose of 11-15 mg/kg every 12 h for 3 doses should be administered to promptly achieve the target trough concentration of 15-30 µg/mL on the third day after commencement of teicoplanin therapy in the ICU.

Boric acid transport activity of marine teleost aquaporins expressed in Xenopus oocytes.

Marine teleosts ingest large amounts of seawater containing various ions, including 0.4 mM boric acid, which can accumulate at toxic levels in the body. However, the molecular mechanisms by which marine teleosts absorb and excrete boric acid are not well understood. Aquaporins (Aqps) are homologous to the nodulin-like intrinsic protein (NIP) family of plant boric acid channels. To investigate the potential roles of Aqps on boric acid transport across the plasma membrane in marine teleosts, we analyzed the function of Aqps of Japanese pufferfish (Takifugu rubripes) expressed in Xenopus laevis oocytes. Takifugu genome database contains 16 genes encoding the aquaporin family members (aqp0a, aqp0b, aqp1aa, aqp1ab, aqp3a, aqp4a, aqp7, aqp8bb, aqp9a, aqp9b, aqp10aa, aqp10bb, aqp11a, aqp11b, aqp12, and aqp14). When T. rubripes Aqps (TrAqps) were expressed in X. laevis oocytes, a swelling assay showed that boric acid permeability was significantly increased in oocytes expressing TrAqp3a, 7, 8bb, 9a, and 9b. The influx of boric acid into these oocytes was also confirmed by elemental quantification. Electrophysiological analysis using a pH microelectrode showed that these TrAqps increase B(OH)3 permeability. These results indicate that TrAqp3a, 7, 8bb, 9a, and 9b act as boric acid transport systems, likely as channels, in marine teleosts.

Pharmacokinetics of ampicillin-sulbactam and the renal function-based optimization of dosing regimens for prophylaxis in patients undergoing cardiovascular surgery.

UNLABELLED: Surgical site infections are a major cause of postoperative morbidity and mortality in cardiovascular surgery. Proper antibiotic prophylaxis can reduce the rate of such infections, but the concentration of antibiotic must be maintained at an adequate level throughout the operation. This study aimed to use renal function to determine the most appropriate timing for intraoperative repeated dosing of ampicillin-sulbactam, a commonly used prophylactic antibiotic, to maintain adequate concentrations throughout the course of surgery. The mean volume of distribution, elimination rate constant, elimination half-life, and total clearance of ampicillin were 13.2 l, 0.652 h⁻¹, 1.32 h, and 8.45 l/h, respectively. A statistically significant (P < 0.0001) correlation (r = 0.771) was observed between the total clearance of ampicillin and creatinine clearance of the patients. Plasma concentrations of ampicillin were simulated with the pharmacokinetic parameters obtained. We developed a nomogram for adjusting the dosing interval according to renal function and predicted ampicillin trough concentrations. We revealed the best dosage and dosing interval for cardiovascular surgery by analyzing the perioperative pharmacokinetics of ampicillin-sulbactam administered prophylactically. We suggest that the dosage and dosing interval for ampicillin-sulbactam should be adjusted to optimize treatment efficacy and safety, on the basis of the MIC90 of methicillin-sensitive Staphylococcus aureus (MSSA) in each institution. TRIAL REGISTRATION: UMIN000007356.

Effectiveness of Open Fenestration for Autosomal Dominant Polycystic Liver Disease.

Autosomal dominant polycystic liver disease (ADPLD) is a rare disease with variable clinical presentations, characterized by cystic enlargement of the liver. The diagnosis is made based on family history, patient's age, and liver phenotype and is confirmed by imaging tests. The treatment aims to reduce symptoms caused by the increased liver volume and can be performed by aspiration with sclerotherapy, fenestration, and liver resection. Although ADPLD is a rare disease, it is an important differential diagnosis of cystic diseases such as polycystic kidney disease; therefore, the aim of this article was to present the diagnostic and therapeutic approach of a case of ADPLD and conducting a literature review. This is the case of a 32-year-old male patient, who was hospitalized due to abdominal pain, hepatomegaly, lack of appetite, and weight loss. Imaging propaedeutics showed a significant increase in the liver volume due to hepatic cysts. After a multidisciplinary evaluation, given the clinical changes and the location of the hepatic cysts, fenestration was performed by laparotomy. The postoperative period was uneventful. The treatment was efficient in promoting symptomatic relief and improving the quality of life in this patient. Case reports on this disease are quite limited in the currently available literature, and there are gaps in knowledge with regard to the diagnosis and management of ADPLD. The importance of this article is that it will highlight the limitations in treatment options and allow physicians to make a more informed decision when diagnosing and treating a patient with ADPLD in the future.

Boric acid transport activity of human aquaporins expressed in Xenopus oocytes.

Boric acid is a vital micronutrient that is toxic at high concentrations in animals. However, the mechanisms underlying boric acid transport in animal cells remain unclear. To identify the plasma membrane boric acid channels in animals, we analyzed the function of human aquaporins (AQPs), which are homologous to the nodulin-like intrinsic protein family of plant boric acid channels. When human AQPs were expressed in Xenopus laevis oocytes, the results of the swelling assay showed that boric acid permeability significantly increased in oocytes expressing AQP3, 7, 8, 9, and 10, but not in those expressing AQP1, 2, 4, and 5. The boric acid influxes of these oocytes were also confirmed by elemental quantification. Electrophysiological analysis using a pH microelectrode showed that these AQPs transported boric acid (B(OH)3 ) but not borate ions (B(OH)4- ). These results indicate that AQP3, 7, 8, 9, and 10 act as boric acid transport systems, likely as channels in humans.

Polycystic Liver Disease: Pathophysiology, Diagnosis and Treatment.

Polycystic liver disease (PLD) is a clinical condition characterized by the presence of more than 10 cysts in the liver. It is a rare disease Of genetic etiology that presents as an isolated disease or assoc\iated with polycystic kidney disease. Ductal plate malformation, ciliary dysfunction, and changes in cell signaling are the main factors involved in its pathogenesis. Most patients with PLD are asymptomatic, but in 2-5% of cases the disease has disabling symptoms and a significant reduction in quality of life. The diagnosis is based on family history of hepatic and/or renal polycystic disease, clinical manifestations, patient age, and polycystic liver phenotype shown on imaging examinations. PLD treatment has evolved considerably in the last decades. Somatostatin analogues hold promise in controlling disease progression, but liver transplantation remains a unique curative treatment modality.

Concentration-Dependent Activity of Pazufloxacin against Pseudomonas aeruginosa: An In Vivo Pharmacokinetic/Pharmacodynamic Study.

The bacterium Pseudomonas aeruginosa is known to be associated with nosocomial infections around the world. Pazufloxacin, a potent DNA gyrase inhibitor, is known to be an effective drug candidate. However, it has not been clarified whether the pharmacokinetic (PK)/pharmacodynamic (PD) of pazufloxacin was effective against P. aeruginosa. Herein, we demonstrated that the PK/PD index of pazufloxacin against P. aeruginosa infection is used to optimize the dosing regiments. We constructed an in vivo infection model by infecting P. aeruginosa into the thigh of a mouse to determine the PD, and we measured the serum concentration of pazufloxacin to construct the PK model using high-performance liquid chromatography. The therapeutic efficacy of pazufloxacin was correlated with the ratio of the area under the free concentration time curve at 24 h to the minimum inhibitory concentration (fAUC24/MIC), and the maximum free concentration to the MIC (fCmax/MIC). Each contribution rate (R2) was 0.72 and 0.65, respectively, whereas the time at which the free drug concentration remained above the MIC (R2 = 0.28). The target value of pazufloxacin fAUC24/MIC for stasis was 46.1, for 1 log10 it was 63.8, and for 2 log10 it was 100.8. Moreover, fCmax/MIC for stasis was 5.5, for 1 log10 it was 7.1, and for 2 log10 it was 10.8. We demonstrated that the in vivo concentration-dependent activity of pazufloxacin was effective against the P. aeruginosa infection, and successfully made the PK/PD model sufficiently bactericidal. The PK/PD model will be beneficial in preventing the spread of nosocomial infections.

Comparisons of plasma aldosterone and renin data between an automated chemiluminescent immunoanalyzer and conventional radioimmunoassays in the screening and diagnosis of primary aldosteronism.

Determining values of plasma renin activity (PRA) or plasma active renin concentration (ARC), plasma aldosterone concentration (PAC), and aldosterone-to-renin ratio (ARR) is essential to diagnose primary aldosteronism (PA), but it takes several days with conventional radioimmunoassays (RIAs). Chemiluminescent enzyme immunoassays for PAC and ARC using the Accuraseed® immunoanalyzer facilitated the determination, but relations between Accuraseed® immunoanalyzer-based and RIA-based values in samples of PA confirmatory tests and adrenal venous sampling remained to be elucidated. We addressed this issue in the present study. This is a prospective, cross-sectional study. ARC and PAC values were measured by the Accuraseed® immunoanalyzer in samples, in which PRA and PAC values had been measured by the PRA-FR® RIA and SPAC®-S Aldosterone kits, respectively. The relations between Accuraseed® immunoanalyzer-based and RIA-based values were investigated with regression analyses. The optimal cutoff of Accuraseed® immunoanalyzer-based ARR for PA screening was determined by the receiver operating characteristic analysis. After log-log transformations, linear relations with high coefficients of determination were observed between Accuraseed® immunoanalyzer-based and RIA-based data of renin and aldosterone. Following the PA guidelines of Japan Endocrine Society, Accuraseed® immunoanalyzer-based cutoffs were calculated from the regression equations: the basal PAC for PA screening >12 ng/dL, PAC for the saline infusion test >8.2 ng/dL, ARC for the furosemide-upright test <15 pg/mL, and ARR for the captopril challenge test >3.09 ng/dL per pg/mL. The optimal cutoff of Accuraseed® immunoanalyzer-based ARR for PA screening was >2.43 ng/dL over pg/mL not to overlook bilateral PA patients. The present study provided conversion formulas between Accuraseed® immunoanalyzer-based and RIA-based values of renin, aldosterone, and ARR, not only in basal samples but also in samples of PA confirmatory tests and adrenal venous sampling. Although validation studies are awaited, the present study will become priming water of harmonization of renin and aldosterone immunoassays.

Pulmonary Tuberculosis After Therapy with Anti-Tumor Necrosis Factor (TNF) for Crohn Disease: A Case Report.

BACKGROUND Adalimumab is a biological anti-tumor necrosis factor (TNF) agent which induces and maintains remission in patients with moderate-to-severe Crohn disease (CD). An adverse effect of its use is reactivation of latent infections, such as tuberculosis (TB). TB is caused by Mycobacterium tuberculosis and continues to be an important public health problem in some developing countries, such as Brazil. The present report describes the case of a patient with CD who developed pulmonary TB while receiving adalimumab therapy. CASE REPORT A 38-year-old penitentiary worker presented with colonic CD that was intolerant to azathioprine and was started on adalimumab. After 3 months, he experienced coughing, fever, and weight loss, and was diagnosed with pulmonary TB. A chest X-ray and tuberculin skin test performed before he started taking adalimumab were negative for latent TB. The patient was treated for 9 months to cure his infection. The use of adalimumab was suspended while the TB was investigated and he took mesalazine to achieve clinical and endoscopic remission of CD. CONCLUSIONS Adequate screening and chemoprophylaxis for latent TB are indicated in patients at high risk of infection. In patients with inflammatory bowel disease, after anti-TNF therapy is started, strict monitoring is required so that opportunistic infections can be detected early and morbidity and mortality reduced in this population.

Mixed and disseminated paracoccidioidomycosis after liver transplantation: Case report.

Paracoccidioidomycosis (PCM) is a systemic granulomatous fungal infection rarely associated with solid organ transplantation. We report the second case of PCM in an adult after liver transplantation. A 47-year-old woman who had undergone liver transplantation was hospitalized for flu-like symptoms and multiple erythematous ulcerated skin papules. There was lymphadenopathy, pulmonary compromise, and quickly progression to septic shock. PCM was confirmed by skin biopsy and serologic tests, and a satisfactory response to amphotericin B was achieved.

Pharmacokinetic/pharmacodynamic evaluation of teicoplanin against Staphylococcus aureus in a murine thigh infection model.

OBJECTIVES: Pharmacokinetic/pharmacodynamic (PK/PD) analysis using murine infection models is a well-established methodology for optimising antimicrobial therapy. Therefore, we investigated the PK/PD indices of teicoplanin againstStaphylococcus aureus using a murine thigh infection model. METHODS: Mice were rendered neutropenic by administration of a two-step dosing of cyclophosphamide. Then, isolates of methicillin-susceptibleS. aureus (MSSA) or methicillin-resistant S. aureus (MRSA) were inoculated into the thighs of neutropenic mice. PK/PD analyses were performed by non-linear least-squared regression using the MULTI program. RESULTS: Target values offCmax/MIC (r2 = 0.94) of teicoplanin for static effect and 1 log10 kill against MSSA were 4.44 and 15.44, respectively. Target values of fAUC24/MIC (r2 = 0.92) of teicoplanin for static effect and 1 log10 kill against MSSA were 30.4 and 70.56, respectively. Target values of fCmax/MIC (r2 = 0.91) of teicoplanin for static effect and 1 log10 kill against MRSA were 8.92 and 14.16, respectively. Target values of fAUC24/MIC (r2 = 0.92) of teicoplanin for static effect and 1 log10 kill against MRSA were 54.8 and 76.4, respectively. CONCLUSION: These results suggest thatfCmax/MIC and fAUC24/MIC are useful PK/PD indices of teicoplanin against MSSA and MRSA.

Light-inducible carotenoid production controlled by a MarR-type regulator in Corynebacterium glutamicum.

Carotenoid production in some non-phototropic bacteria occurs in a light-dependent manner to protect cells from photo-oxidants. Knowledge regarding the transcriptional regulator involved in the light-dependent production of carotenoids of non-phototrophic bacteria has been mainly confined to coenzyme B12-based photo-sensitive regulator CarH/LitR family proteins belonging to a MerR family transcriptional regulator. In this study, we found that bacteria belonging to Micrococcales and Corynebacteriales exhibit light-dependent carotenoid-like pigment production including an amino acid-producer Corynebacterium glutamicum AJ1511. CrtR is a putative MarR family transcriptional regulator located in the divergent region of a carotenoid biosynthesis gene cluster in the genome of those bacteria. A null mutant for crtR of C. glutamicum AJ1511 exhibited constitutive production of carotenoids independent of light. A complemented strain of the crtR mutant produced carotenoids in a light-dependent manner. Transcriptional analysis revealed that the expression of carotenoid biosynthesis genes is regulated in a light-dependent manner in the wild type, while the transcription was upregulated in the crtR mutant irrespective of light. In vitro experiments demonstrated that a recombinant CrtR protein binds to the specific sequences within the intergenic region of crtR and crtE, which corresponds to -58 to -7 for crtE, and +26 to -28 for crtR with respect to the transcriptional start site, and serves as a repressor for crtE transcription directed by RNA polymerase containing SigA. Taken together, the results indicate that CrtR light-dependently controls the expression of the carotenoid gene cluster in C. glutamicum and probably closely related Actinobacteria.