Regulation of ROP GTPase cycling between active and inactive states is essential for vegetative organogenesis in Marchantia polymorpha.

Rho/Rac of plant (ROP) GTPases are plant-specific proteins that function as molecular switches, activated by guanine nucleotide exchange factors (GEFs) and inactivated by GTPase-activating proteins (GAPs). The bryophyte Marchantia polymorpha contains single copies of ROP (MpROP), GEFs [ROPGEF and SPIKE (SPK)] and GAPs [ROPGAP and ROP ENHANCER (REN)]. MpROP regulates the development of various tissues and organs, such as rhizoids, gemmae and air chambers. The ROPGEF KARAPPO (MpKAR) is essential for gemma initiation, but the functions of other ROP regulatory factors are less understood. This study focused on two GAPs: MpROPGAP and MpREN. Mpren single mutants showed defects in thallus growth, rhizoid tip growth, gemma development, and air-chamber formation, whereas Mpropgap mutants showed no visible abnormalities. However, Mpropgap Mpren double mutants had more severe phenotypes than the Mpren single mutants, suggesting backup roles of MpROPGAP in processes involving MpREN. Overexpression of MpROPGAP and MpREN resulted in similar gametophyte defects, highlighting the importance of MpROP activation/inactivation cycling (or balancing). Thus, MpREN predominantly, and MpROPGAP as a backup, regulate gametophyte development, likely by controlling MpROP activation in M. polymorpha.

Mobile PEAR transcription factors integrate positional cues to prime cambial growth.

Apical growth in plants initiates upon seed germination, whereas radial growth is primed only during early ontogenesis in procambium cells and activated later by the vascular cambium1. Although it is not known how radial growth is organized and regulated in plants, this system resembles the developmental competence observed in some animal systems, in which pre-existing patterns of developmental potential are established early on2,3. Here we show that in Arabidopsis the initiation of radial growth occurs around early protophloem-sieve-element cell files of the root procambial tissue. In this domain, cytokinin signalling promotes the expression of a pair of mobile transcription factors-PHLOEM EARLY DOF 1 (PEAR1) and PHLOEM EARLY DOF 2 (PEAR2)-and their four homologues (DOF6, TMO6, OBP2 and HCA2), which we collectively name PEAR proteins. The PEAR proteins form a short-range concentration gradient that peaks at protophloem sieve elements, and activates gene expression that promotes radial growth. The expression and function of PEAR proteins are antagonized by the HD-ZIP III proteins, well-known polarity transcription factors4-the expression of which is concentrated in the more-internal domain of radially non-dividing procambial cells by the function of auxin, and mobile miR165 and miR166 microRNAs. The PEAR proteins locally promote transcription of their inhibitory HD-ZIP III genes, and thereby establish a negative-feedback loop that forms a robust boundary that demarks the zone of cell division. Taken together, our data establish that during root procambial development there exists a network in which a module that links PEAR and HD-ZIP III transcription factors integrates spatial information of the hormonal domains and miRNA gradients to provide adjacent zones of dividing and more-quiescent cells, which forms a foundation for further radial growth.

Multiple roles of brassinosteroid signaling in vascular development.

Brassinosteroids (BRs) are plant steroid hormones that control growth and stress responses. In the context of development, BRs play diverse roles in controlling cell differentiation and tissue patterning. The vascular system, which is essential for transporting water and nutrients throughout the plant body, initially establishes a tissue pattern during primary development and then dramatically increases the number of vascular cells during secondary development. This complex developmental process is properly regulated by a network consisting of various hormonal signalling pathways. Genetic studies have revealed that mutants defective in BR biosynthesis or the BR signalling cascade exhibit a multifaceted vascular development phenotype. Furthermore, BR crosstalk with other plant hormones, including peptide hormones, coordinately regulates vascular development. Recently, the involvement of BR in vascular development, especially in xylem differentiation, has also been suggested in plant species other than the model plant Arabidopsis thaliana. In this review, we briefly summarize the recent findings on the roles of BR in primary and secondary vascular development in Arabidopsis and other species.

Association of Relative Dysglycemia With Hospital Mortality in Critically Ill Patients: A Retrospective Study.

OBJECTIVES: Relative dysglycemia has been proposed as a clinical entity among critically ill patients in the ICU, but is not well studied. This study aimed to clarify associations of relative hyperglycemia and hypoglycemia during the first 24 hours after ICU admission with in-hospital mortality and the respective thresholds. DESIGN: A single-center retrospective study. SETTING: An urban tertiary hospital ICU. PATIENTS: Adult critically ill patients admitted urgently between January 2016 and March 2022. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Maximum and minimum glycemic ratio (GR) was defined as maximum and minimum blood glucose values during the first 24 hours after ICU admission divided by hemoglobin A1c-derived average glucose, respectively. Of 1700 patients included, in-hospital mortality was 16.9%. Nonsurvivors had a higher maximum GR, with no significant difference in minimum GR. Maximum GR during the first 24 hours after ICU admission showed a J-shaped association with in-hospital mortality, and a mortality trough at a maximum GR of approximately 1.12; threshold for increased adjusted odds ratio for mortality was 1.25. Minimum GR during the first 24 hours after ICU admission showed a U-shaped relationship with in-hospital mortality and a mortality trough at a minimum GR of approximately 0.81 with a lower threshold for increased adjusted odds ratio for mortality at 0.69. CONCLUSIONS: Mortality significantly increased when GR during the first 24 hours after ICU admission deviated from between 0.69 and 1.25. Further evaluation will necessarily validate the superiority of personalized glycemic management over conventional management.

Gene co-expression network analysis identifies BEH3 as a stabilizer of secondary vascular development in Arabidopsis.

In plants, vascular stem cells located in the cambium continuously undergo self-renewal and differentiation during secondary growth. Recent advancements in cell sorting techniques have enabled access to the transcriptional regulatory framework of cambial cells. However, mechanisms underlying the robust control of vascular stem cells remain unclear. Here, we identified a new cambium-related regulatory module through co-expression network analysis using multiple transcriptome datasets obtained from an ectopic vascular cell transdifferentiation system using Arabidopsis cotyledons, Vascular cell Induction culture System Using Arabidopsis Leaves (VISUAL). The cambium gene list included a gene encoding the transcription factor BES1/BZR1 Homolog 3 (BEH3), whose homolog BES1 negatively affects vascular stem cell maintenance. Interestingly, null beh3 mutant alleles showed a large variation in their vascular size, indicating that BEH3 functions as a stabilizer of vascular stem cells. Genetic analysis revealed that BEH3 and BES1 perform opposite functions in the regulation of vascular stem cells and the differentiation of vascular cells in the context of the VISUAL system. At the biochemical level, BEH3 showed weak transcriptional repressor activity and functioned antagonistically to other BES/BZR members by competing for binding to the brassinosteroid response element. Furthermore, mathematical modeling suggested that the competitive relationship between BES/BZR homologs leads to the robust regulation of vascular stem cells.

Current Balloon Devices for Ablation of Atrial Fibrillation.

Balloon-based catheter ablation is a valuable option for the treatment of atrial fibrillation (AF) because contiguous lesions can be created to achieve pulmonary vein isolation (PVI), and the method is less dependent than traditional ablation methods on the operator's skill and experience. Cryoballoon ablation is used universally worldwide, with its efficacy and safety being comparable to the efficacy and safety of standard radiofrequency ablation, and the procedure can be completed in a relatively short time. Hot balloon ablation was developed in Japan. The balloon maintains its compliance even during the energy delivery, and a large areal ablation lesion is created. Furthermore, the hot balloon system is the only system for which oesophageal cooling is a standard feature. Laser balloon ablation, which is performed under direct endoscopic vision, has proven to be effective and safe for achieving a PVI. The laser balloon system provides an improved field of view and automated circumferential ablation for a rapid and effective PVI. The authors have reviewed the currently available balloon systems as used for AF ablation, i.e., PVI, and have provided detailed insight and perspectives on the currently available cryoballoon and hot balloon technologies, plus laser balloon technology.

Differences in the Impact of Intensive Rehabilitation on Hereditary Ataxias and the Cerebellar Subtype of Multiple System Atrophy.

Multiple system atrophy-cerebellar type (MSA-C) exhibits faster disease progression than does hereditary spinocerebellar degeneration (hSCD). In this study, we aimed to investigate the differences in the treatment effects and sustainability of intensive rehabilitation between patients with hSCD and those with MSA-C. Forty-nine patients (hSCD = 30, MSA-C = 19) underwent a 2- or 4-week intensive rehabilitation program. Balance function was evaluated using the scale for the assessment and rating of ataxia (SARA) and the balance evaluation systems test (BESTest) at pre-intervention, post-intervention, and 6-month follow-up. Notably, both groups demonstrated beneficial effects from the rehabilitation intervention. However, differences were observed in the magnitude and duration of these effects. In the hSCD group, the SARA scores at follow-up remained similar to those at baseline, indicating sustained benefits. However, the MSA-C group showed some deterioration in SARA scores compared with baseline scores but maintained improvements on the BESTest, demonstrating partial sustainability. Differences, mainly in sustainability, were observed between the hSCD and MSA-C groups. This may be due to varying rates of symptom progression. The findings of this study are significant when considering the frequency of follow-ups based on disease type.

A small peptide modulates stomatal control via abscisic acid in long-distance signalling.

Mammalian peptide hormones propagate extracellular stimuli from sensing tissues to appropriate targets to achieve optimal growth maintenance 1 . In land plants, root-to-shoot signalling is important to prevent water loss by transpiration and to adapt to water-deficient conditions 2, 3 . The phytohormone abscisic acid has a role in the regulation of stomatal movement to prevent water loss 4 . However, no mobile signalling molecules have yet been identified that can trigger abscisic acid accumulation in leaves. Here we show that the CLAVATA3/EMBRYO-SURROUNDING REGION-RELATED 25 (CLE25) peptide transmits water-deficiency signals through vascular tissues in Arabidopsis, and affects abscisic acid biosynthesis and stomatal control of transpiration in association with BARELY ANY MERISTEM (BAM) receptors in leaves. The CLE25 gene is expressed in vascular tissues and enhanced in roots in response to dehydration stress. The root-derived CLE25 peptide moves from the roots to the leaves, where it induces stomatal closure by modulating abscisic acid accumulation and thereby enhances resistance to dehydration stress. BAM receptors are required for the CLE25 peptide-induced dehydration stress response in leaves, and the CLE25-BAM module therefore probably functions as one of the signalling molecules for long-distance signalling in the dehydration response.

Structural Validity of the Mini-Balance Evaluation Systems Test in Individuals With Spinocerebellar Ataxia: A Rasch Analysis Study.

OBJECTIVE: To examine the structural validity of the Mini-Balance Evaluation Systems Test (Mini-BESTest) in individuals with spinocerebellar ataxia (SCA). DESIGN: Methodological research on data gathered in a cross-sectional study. A Rasch analysis was conducted (partial credit model). SETTING: Inpatients in a hospital rehabilitation setting. PARTICIPANTS: A pooled sample of patients with SCA (N=65 [total 110 data]; 23 women, 42 men; mean±SD age 63.1±9.9y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We evaluated the Mini-BESTest's category structure, unidimensionality, and measurement accuracy (0: unable to perform or requiring help to 2: normal performance). RESULTS: The Mini-BESTest rating scale fulfilled the category functioning criteria. The analysis of the standardized Rasch residuals showed the scale's unidimensionality, but there were 7 item pairs indicating local dependence. All of the items fit the underlying scale construct (dynamic balance), with the exception of item #1, "Sit to stand," which was an underfit. The Mini-BESTest demonstrated adequate reliability (person separation reliability=.87) and separated the patients into 5 strata. The item-difficulty measures ranged from -4.49 to 2.02 logits, and the person ability-item difficulty matching was very good (the mean of person ability=-.07 logits and the mean of item difficulty=.00). No floor or ceiling effects were detected. The keyform identified items with small (#11, "Walk with head turns, horizontal") and large (#3, "Stand on 1 leg") item thresholds. CONCLUSIONS: The Mini-BESTest has a unidimensional balance assessment scale with good category structure and reliability even for individuals with SCA. However, it also has some inherent shortcomings such as fit statistics, local item dependencies, and item thresholds. The results obtained when the Mini-BESTest is administered to patients with cerebellar ataxia should, thus, be interpreted cautiously.

Combination therapy with WEE1 inhibition and trifluridine/tipiracil against esophageal squamous cell carcinoma.

Despite advanced therapeutics, esophageal squamous cell carcinoma (ESCC) remains one of the deadliest cancers. Here, we propose a novel therapeutic strategy based on synthetic lethality combining trifluridine/tipiracil and MK1775 (WEE1 inhibitor) as a treatment for ESCC. This study demonstrates that trifluridine induces single-strand DNA damage in ESCC cells, as evidenced by phosphorylated replication protein 32. The DNA damage response includes cyclin-dependent kinase 1 (CDK1) (Tyr15) phosphorylation as CDK1 inhibition and a decrease of the proportion of phospho-histone H3 (p-hH3)-positive cells, indicating cell cycle arrest at the G2 phase before mitosis entry. The WEE1 inhibitor remarkedly suppressed CDK1 phosphorylation (Try15) and reactivated CDK1, and also increased the proportion of p-hH3-positive cells, which indicates an increase of the number of cells into mitosis. Trifluridine combined with a WEE1 inhibitor increased trifluridine-mediated DNA damage, namely DNA double-strand breaks, as shown by increased γ-H2AX expression. Moreover, the combination treatment with trifluridine/tipiracil and a WEE1 inhibitor significantly suppressed tumor growth of ESCC-derived xenograft models. Hence, our novel combination treatment with trifluridine/tipiracil and a WEE1 inhibitor is considered a candidate treatment strategy for ESCC.

Molecular Mechanisms Underlying the Establishment and Maintenance of Vascular Stem Cells in Arabidopsis thaliana.

The vascular system plays pivotal roles in transporting water and nutrients throughout the plant body. Primary vasculature is established as a continuous strand, which subsequently initiates secondary growth through cell division. Key factors regulating primary and secondary vascular developments have been identified in numerous studies, and the regulatory networks including these factors have been elucidated through omics-based approaches. However, the vascular system is composed of a variety of cells such as xylem and phloem cells, which are commonly generated from vascular stem cells. In addition, the vasculature is located deep inside the plant body, which makes it difficult to investigate the vascular development while distinguishing between vascular stem cells and developing xylem and phloem cells. Recent technical advances in the tissue-clearing method, RNA-seq analysis and tissue culture system overcome these problems by enabling the cell-type-specific analysis during vascular development, especially with a special focus on stem cells. In this review, we summarize the recent findings on the establishment and maintenance of vascular stem cells.

Sucrose Signaling Contributes to the Maintenance of Vascular Cambium by Inhibiting Cell Differentiation.

Plants produce sugars by photosynthesis and use them for growth and development. Sugars are transported from source-to-sink organs via the phloem in the vasculature. It is well known that vascular development is precisely controlled by plant hormones and peptide hormones. However, the role of sugars in the regulation of vascular development is poorly understood. In this study, we examined the effects of sugars on vascular cell differentiation using a vascular cell induction system named 'Vascular Cell Induction Culture System Using Arabidopsis Leaves' (VISUAL). We found that sucrose has the strongest inhibitory effect on xylem differentiation, among several types of sugars. Transcriptome analysis revealed that sucrose suppresses xylem and phloem differentiation in cambial cells. Physiological and genetic analyses suggested that sucrose might function through the BRI1-EMS-SUPPRESSOR1 transcription factor, which is the central regulator of vascular cell differentiation. Conditional overexpression of cytosolic invertase led to a decrease in the number of cambium layers due to an imbalance between cell division and differentiation. Taken together, our results suggest that sucrose potentially acts as a signal that integrates environmental conditions with the developmental program.

Genetic Interaction between Arabidopsis SUR2/CYP83B1 and GNOM Indicates the Importance of Stabilizing Local Auxin Accumulation in Lateral Root Initiation.

Lateral root (LR) formation is an important developmental event for the establishment of the root system in most vascular plants. In Arabidopsis thaliana, the fewer roots (fwr) mutation in the GNOM gene, encoding a guanine nucleotide exchange factor of ADP ribosylation factor that regulates vesicle trafficking, severely inhibits LR formation. Local accumulation of auxin response for LR initiation is severely affected in fwr. To better understand how local accumulation of auxin response for LR initiation is regulated, we identified a mutation, fewer roots suppressor1 (fsp1), that partially restores LR formation in fwr. The gene responsible for fsp1 was identified as SUPERROOT2 (SUR2), encoding CYP83B1 that positions at the metabolic branch point in the biosynthesis of auxin/indole-3-acetic acid (IAA) and indole glucosinolate. The fsp1 mutation increases both endogenous IAA levels and the number of the sites where auxin response locally accumulates prior to LR formation in fwr. SUR2 is expressed in the pericycle of the differentiation zone and in the apical meristem in roots. Time-lapse imaging of the auxin response revealed that local accumulation of auxin response is more stable in fsp1. These results suggest that SUR2/CYP83B1 affects LR founder cell formation at the xylem pole pericycle cells where auxin accumulates. Analysis of the genetic interaction between SUR2 and GNOM indicates the importance of stabilization of local auxin accumulation sites for LR initiation.

Fasudil inhibits the expression of C/EBP homologous protein to protect against liver injury in acetaminophen-overdosed mice.

Acetaminophen (APAP) overdoses can cause severe liver injury. In this study, the protective effect of fasudil against APAP-induced liver injury was investigated. APAP (400 mg/kg) was administered to male C57BL/6J mice to induce liver injury, and fasudil (20 or 40 mg/kg) was injected 30 min before APAP administration. Fasudil markedly suppressed APAP-induced elevation in serum transaminase activity and hepatic necrosis and significantly reduced an increase in nitrotyrosine and DNA fragmentation. However, fasudil did not affect cytochrome P450 2E1 expression, N-acetyl-p-benzoquinone imine production or c-jun N-terminal kinase activation. In contrast, fasudil significantly inhibited an APAP-induced increase in expression of the transcription factor C/EBP homologous protein (CHOP) in the liver, accompanied by transcriptional suppression of ER stress-related molecules such as Ero1α, Atf4 and Grp78. These findings indicate that suppression of CHOP expression by fasudil exhibits a remarkable protective effect against APAP liver injury by regulating ER stress. We suggest that fasudil is a promising therapeutic candidate for treating APAP-induced liver injury.

Clinical and Angiographic Outcomes of Elective Paclitaxel-Coated Balloon Angioplasty in Comparison with Drug-Eluting Stents for De Novo Coronary Lesions in Large Vessels.

We retrospectively examined the feasibility of paclitaxel-coated balloon (PCB) angioplasty for de novo stenosis in large coronary vessels (LV; pre- or postprocedural reference vessel diameter ≥ 2.75 mm) in comparison with placement of drug-eluting stents (DESs).Consecutive de novo stenotic lesions in the LV electively and successfully treated with either PCB (n = 73) or DESs (n = 81) from January 2016 to December 2018 at our center were included. The primary endpoint was the incidence of target lesion failure (TLF), including cardiac death, nonfatal myocardial infarction, and target vessel revascularization. The impact of PCB on TLF was examined using Cox proportional hazards models by including 39 variables. The secondary endpoint, angiographic restenosis, defined as a follow-up percent diameter stenosis > 50, was examined in angiographic follow-up lesions after PCB angioplasty (n = 56) and DES placement (n = 53). This retrospective investigation was conducted in July 2022.The mean PCB size and length were 3.23 ± 0.42 and 18.4 ± 4.3 mm, respectively. The TLF frequency in the PCB group (6.8% during the mean observational interval of 1536 ± 538 days) was not significantly different from that in the DES group (14.6%, 1344 ± 606 days, P = 0.097). PCB was not a significant predictor of TLF in the univariate analysis (hazard ratio: 0.424; 95%CI: 0.15-1.21; P = 0.108). There was no angiographic restenosis after PCB angioplasty.The present observational single-center study showed that PCB for de novo stenosis in the LV had no significant adverse impact on TLF and had favorable angiographic outcomes.

Effects of 6-O-α-maltosyl-ß cyclodextrin on lipid metabolism in Npc1-deficient Chinese hamster ovary cells.

Niemann-Pick disease Type C (NPC) is a lysosomal storage disorder caused by mutation of the NPC1/NPC2 genes, which ultimately results in the accumulation of unesterified cholesterol (UEC) in lysosomes, thereby inducing symptoms such as progressive neurodegeneration and hepatosplenomegaly. This study determines the effects of 6-O-α-maltosyl-ß cyclodextrin (Mal-ßCD) on lipid levels and synthesis in Npc1-deficient (Npc1-KO cells) and vehicle CHO cells. Compared to vehicle cells, Npc1-KO cells exhibited high level of UEC, and low levels of esterified cholesterols (ECs) and long-chain fatty acids (LCFAs). The difference in lipid levels between Npc1-KO and CHO cells was largely ameliorated by Mal-ßCD administration. Moreover, the effects of Mal-ßCD were reproduced in the lysosomes prepared from Npc1-KO cells. Stable isotope tracer analysis with extracellular addition of D4-deuterated palmitic acid (D4-PA) to Npc1-KO cells increased the synthesis of D4-deuterated LCFAs (D4-LCFAs) and D4-deuterated ECs (D4-ECs) in a Mal-ßCD-dependent manner. Simultaneous addition of D6-deuterated UEC (D6-UEC) and D4-PA promoted the Mal-ßCD-dependent synthesis of D6-/D4-ECs, consisting of D6-UEC and D4-PA, D4-deuterated stearic acid, or D4-deuterated myristic acid, in Npc1-KO cells. These results suggest that Mal-ßCD helps to maintain normal lipid metabolism by restoring balance among UEC, ECs, and LCFAs through acting on behalf of NPC1 in Npc1-KO cells and may therefore be useful in designing effective therapies for NPC.

A Propensity Score-Matched Comparison of Midterm Outcomes Between Drug-Coated Balloons and Drug-Eluting Stents for Patients with Acute Coronary Syndrome.

We conducted a single-center, retrospective, lesion-based study to examine the safety and efficacy of drug-coated balloons (DCBs) for de novo coronary stenosis in patients with acute coronary syndrome (ACS) by comparing them with those of drug-eluting stents (DESs).A total of 309 consecutive lesions in patients with ACS who were successfully treated by emergent procedures using either a DCB (n = 107) or a DES between January 2016 and December 2019 were included in the study. The primary endpoint was the incidence of target lesion failure (TLF), defined as cardiac death without mortality due to ACS, non-fatal myocardial infarction, and any target lesion revascularization, including acute occlusion, after DCB use and definite stent thrombosis after DES placement. A propensity score-matched analysis was used to adjust the 36 baseline variables. Retrospective investigations were conducted in January 2021.Baseline adjustment yielded 91 lesions in each group, with a mean balloon size of 3.02 ± 0.22 mm and a mean length of 20.9 ± 6.2 mm in the DCB group. The frequency of TLF in the DCB group (9.9% during the mean observational interval of 671 ± 508 days) was not significantly different from that in the DES group (13.2% during a period of 626 ± 543 days, P = 0.467). The cumulative TLF-free ratio in the DCB group was not significantly different from that in the DES group (P = 0.475, log-rank test).The present propensity score-matched comparison showed statistically equivalent midterm clinical outcomes after DCB use to those of DES placement for de novo lesions in patients with ACS treated by emergent procedures.

WIND transcription factors orchestrate wound-induced callus formation, vascular reconnection and defense response in Arabidopsis.

Wounding triggers de novo organogenesis, vascular reconnection and defense response but how wound stress evoke such a diverse array of physiological responses remains unknown. We previously identified AP2/ERF transcription factors, WOUND INDUCED DEDIFFERENTIATION1 (WIND1) and its homologs, WIND2, WIND3 and WIND4, as key regulators of wound-induced cellular reprogramming in Arabidopsis. To understand how WIND transcription factors promote downstream events, we performed time-course transcriptome analyses after WIND1 induction. We observed a significant overlap between WIND1-induced genes and genes implicated in cellular reprogramming, vascular formation and pathogen response. We demonstrated that WIND transcription factors induce several reprogramming genes to promote callus formation at wound sites. We, in addition, showed that WIND transcription factors promote tracheary element formation, vascular reconnection and resistance to Pseudomonas syringae pv. tomato DC3000. These results indicate that WIND transcription factors function as key regulators of wound-induced responses by promoting dynamic transcriptional alterations. This study provides deeper mechanistic insights into how plants control multiple physiological responses after wounding.

A homogeneous assay to determine high-density lipoprotein subclass cholesterol in serum.

Existing methods to measure high-density lipoprotein cholesterol (HDL-C) subclasses (HDL2-C and HDL3-C) are complex and require proficiency, and thus there is a need for a convenient, homogeneous assay to determine HDL-C subclasses in serum. Here, cholesterol reactivities in lipoprotein fractions [HDL2, HDL3, low-density lipoprotein (LDL), and very-low-density lipoprotein (VLDL)] toward polyethylene glycol (PEG)-modified enzymes were determined in the presence of varying concentrations of dextran sulfate and magnesium nitrate. Particle sizes formed in the lipoprotein fractions were measured by dynamic light scattering. We optimized the concentrations of dextran sulfate and magnesium nitrate before assay with PEG-modified enzymes to provide selectivity for HDL3-C. On addition of dextran sulfate and magnesium nitrate, the sizes of particles of HDL2, LDL, and VLDL increased, but the size of HDL3 fraction particles remained constant, allowing only HDL3-C to participate in coupled reactions with the PEG-modified enzymes. In serum from both healthy volunteers and patients with type 2 diabetes, a good correlation was observed between the proposed assay and ultracentrifugation in the determination of HDL-C subclasses. The assay proposed here enables convenient and accurate determination of HDL-C subclasses in serum on a general automatic analyzer and enables low-cost routine diagnosis without preprocessing.

Improved Formula for Predicting Hemodialyzability of Intravenous and Oral Drugs.

BACKGROUND: The rate of drug removal by hemodialysis needs to be considered when designing drug dosage regimens for patients on hemodialysis. We previously developed a simplified equation to predict the removal rates of intravenously administered drugs by hemodialysis. Here, we addressed shortcomings of this equation and developed a more accurate equation that can also predict the removal rates of orally administered drugs. METHODS: A total of 70 drugs with known pharmacokinetic and physical parameters and drug removal rates that were measured during hemodialysis in clinical cases were randomly assigned at a 4:1 ratio to a training data group or a test data group. A prediction equation was developed by performing stepwise multiple regression analyses using the training data (i.e., the removal rate by hemodialysis) as the objective variable and pharmacokinetic parameters as the explanatory variables. The equation was validated using the test data. RESULTS: Multiple regression analyses revealed that molecular weight (MW), protein binding rate, and fraction excreted unchanged in urine relative to the volume of distribution (Vd) were independently correlated with the drug clearance rate (adjusted coefficient of determination, 0.83; p = 2.2e-16). The following equation was obtained: drug removal rate by hemodialysis (%) = -17.32 × [log (MW)] - 0.39 × [protein binding rate (%)] + 0.06 × [fraction excreted unchanged in urine (%)/Vd (L/kg)] + 83.34. Validation of the equation using the test data showed a very high correlation between predicted and measured reduction rate (R = 0.93, p = 1.87e-6). Mean error was -3.34 (95% confidence interval: -10.03, 3.35), mean absolute error was 9.59, and root mean square error was 16.48. CONCLUSION: The modified equation derived in this study using pharmacokinetic and physical parameters as variables precisely predicted the removal rates of both intravenous and oral drugs by hemodialysis.