Hidden proteome of synaptic vesicles in the mammalian brain.

Current proteomic studies clarified canonical synaptic proteins that are common to many types of synapses. However, proteins of diversified functions in a subset of synapses are largely hidden because of their low abundance or structural similarities to abundant proteins. To overcome this limitation, we have developed an "ultra-definition" (UD) subcellular proteomic workflow. Using purified synaptic vesicle (SV) fraction from rat brain, we identified 1,466 proteins, three times more than reported previously. This refined proteome includes all canonical SV proteins, as well as numerous proteins of low abundance, many of which were hitherto undetected. Comparison of UD quantifications between SV and synaptosomal fractions has enabled us to distinguish SV-resident proteins from potential SV-visitor proteins. We found 134 SV residents, of which 86 are present in an average copy number per SV of less than one, including vesicular transporters of nonubiquitous neurotransmitters in the brain. We provide a fully annotated resource of all categorized SV-resident and potential SV-visitor proteins, which can be utilized to drive novel functional studies, as we characterized here Aak1 as a regulator of synaptic transmission. Moreover, proteins in the SV fraction are associated with more than 200 distinct brain diseases. Remarkably, a majority of these proteins was found in the low-abundance proteome range, highlighting its pathological significance. Our deep SV proteome will provide a fundamental resource for a variety of future investigations on the function of synapses in health and disease.

Sequestration and efflux largely account for cadmium and copper resistance in the deep-sea Nitratiruptor sp. SB155-2 (phylum Campylobacterota).

In deep-sea hydrothermal vent environments, metal-enriched fluids and sediments abound, making these habitats ideal to study metal resistance in prokaryotes. In this investigation, we employed transcriptomics and shotgun proteomics with scanning transmission electron microscopy and energy-dispersive x-ray spectroscopy (STEM-EDX) to better understand mechanisms of tolerance for cadmium (Cd) and copper (Cu) at stress-inducing concentrations in Nitratiruptor sp. SB155-2 (phylum Campylobacterota). Transcriptomic profiles were remarkably different in the presence of these two metals, displaying 385 (19%) and 629 (31%) differentially transcribed genes (DTG) in the presence of Cd(II) and Cu(II), respectively, while only 7% of differentially transcribed (DT) genes were shared, with genes for non-specific metal transporters and genes involved in oxidative stress-response predominating. Transcriptomic and proteomic analyses confirmed that metal-specific DT pathways under Cu(II) stress, including those involving sulfur, cysteine, and methionine, are likely required for high-affinity efflux systems, while flagella formation and chemotaxis were over-represented under Cd(II) stress. Consistent with these differences, STEM-EDX analysis revealed that polyphosphate-like granules (pPLG), the formation of CdS particles, and the periplasmic space are crucial for Cd(II) sequestration. Overall, this study provides new insights regarding metal-specific adaptations of Campylobacterota to deep-sea hydrothermal vent environments.

In situ investigation of oxidation across a heterogeneous nanoparticle-support interface during metal support interactions.

Interactions between oxide supports and noble metal nanoparticles (NPs) is an area of intense research interest across all fields of catalysis. Oxygen spillover, metal support interactions (MSIs) and charge transfer are among many mechanisms observed and proposed as to how NP-support interfaces assist and enhance catalysis. This work studies the migration of oxygen across the Pd NP-CuO nanowire (NW) interface and beyond. X-ray photoelectron spectroscopy (XPS) and Kelvin probe force microscopy (KPFM) found an interaction between the Pd NP and CuO NW support, via the formation of PdO at the Pd-CuO interface. It was found, through in situ irradiation at high vacuum transmission electron microscopy (TEM), that oxygen enters the Pd NP lattice from the Pd-CuO interface via amorphization of the NP. Varying the amount of irradiation highlighted the different rates of amorphization of NPs, with full amorphization of a NP leading to the formation of an epitaxially driven PdO across the NPs. Interestingly, in situ heating in XPS observed a reduction to metallic Pd, found to be similarly amorphous during TEM investigation. On comparison with Pd supported on a non-reducible substrate - in which oxidation was found to proceed from the outer surface in, rather than the support interface (resulting in a PdO shell) - it is theorized that the oxidation and reduction of Pd on CuO forms a PdO NP surface full of Pd-PdO sites allowing for synergistic effects, of great use in the oxidation and hydrogenation of organic species.

Robust Packing of a Self-Assembling Iridium Complex via Endocytic Trafficking for Long-Term Lysosome Tracking.

Live cell imaging of lysosome positioning and motility is critical to studying lysosome status and function for pharmacological interventions. To create a super stable lysosomal probe for long-term live cell imaging, we have designed and synthesized an aromatic-peptide-conjugated cyclometalated iridium(III) complex that emits light via π-π stacking oriented self-assembly in water at extremely low concentration. Through endocytic trafficking, self-assemblies are transformed from nanoparticles into sturdily packed networks that are stabilized in lysosomal acidic environment. Upon short time/low dose treatment of the iridium complex at passage 0, live cell lysosomal tracking is applicable beyond the 14th passage of cells with high labelling rate and a mild decline in luminescence intensity. The illuminated lysosomes are trackable using super-resolution imaging to study their response to cellular processes.

Functionalized mesoporous silica nanoparticles for innovative boron-neutron capture therapy of resistant cancers.

Treatment resistance, relapse and metastasis remain critical issues in some challenging cancers, such as chondrosarcomas. Boron-neutron capture therapy (BNCT) is a targeted radiation therapy modality that relies on the ability of boron atoms to capture low energy neutrons, yielding high linear energy transfer alpha particles. We have developed an innovative boron-delivery system for BNCT, composed of multifunctional fluorescent mesoporous silica nanoparticles (B-MSNs), grafted with an activatable cell penetrating peptide (ACPP) for improved penetration in tumors and with gadolinium for magnetic resonance imaging (MRI) in vivo. Chondrosarcoma cells were exposed in vitro to an epithermal neutron beam after B-MSNs administration. BNCT beam exposure successfully induced DNA damage and cell death, including in radio-resistant ALDH+ cancer stem cells (CSCs), suggesting that BNCT using this system might be a suitable treatment modality for chondrosarcoma or other hard-to-treat cancers.

Self-Assembly-Directed Cancer Cell Membrane Insertion of Synthetic Analogues for Permeability Alteration.

Inspired by the metamorphosis of pore-forming toxins from soluble inactive monomers to cytolytic transmembrane assemblies, we developed self-assembly-directed membrane insertion of synthetic analogues for permeability alteration. An expanded π-conjugation-based molecular precursor with an extremely high rigidity and a long hydrophobic length that is comparable to the hydrophobic width of plasma membrane was synthesized for membrane-inserted self-assembly. Guided by the cancer biomarker expression in vitro, the soluble precursors transform into hydrophobic monomers  forming assemblies inserted into the fluid phase of the membrane exclusively. Membrane insertion of rigid synthetic analogues destroys the selective permeability of the plasma membrane gradually. It eventually leads to cancer cell death, including drug resistant cancer cells.

Regulating Higher-Order Organization through the Synergy of Two Self-Sorted Assemblies.

The extracellular matrix (ECM) is the natural fibrous scaffold that regulates cell behavior in a hierarchical manner. By mimicking the dynamic and reciprocal interactions between ECM and cells, higher-order molecular self-assembly (SA), mediated through the dynamic growth of scaffold-like nanostructures assembled by different molecular components, was developed. Designed and synthesized were two self-sorted coumarin-based gelators, a peptide molecule and a benzoate molecule, which self-assemble into nanofibers and nanobelts, respectively, with different dynamic profiles. Upon the dynamic growth of the fibrous scaffold assembled from peptide gelators, nanobelts assembled from benzoate gelators transform into a layer-by-layer nanosheet, reaching ninefold increase in height. By using light and an enzyme, the spatial-temporal growth of the scaffold can be modified, leading to in situ height regulation of the higher-order architecture.

Vectors for Genetically-Encoded Tags for Electron Microscopy Contrast in Drosophila.

BACKGROUND: One of the most notable recent advances in electron microscopy (EM) was the development of genetically-encoded EM tags, including the fluorescent flavoprotein Mini-SOG (Mini-Singlet Oxygen Generator). Mini-SOG generates good EM contrast, thus providing a viable alternative to technically-demanding methods such as immuno-electron microcopy (immuno-EM). Based on the Mini-SOG technology, in this paper, we describe the construction, validation and optimization of a series of vectors which allow expression of Mini-SOG in the Drosophila melanogaster genetic model system. FINDINGS: We constructed a Mini-SOG tag that has been codon-optimized for expression in Drosophila (DMS tag) using PCR-mediated gene assembly. The photo-oxidation reaction triggered by DMS was then tested using these vectors in Drosophila cell lines. DMS tag did not affect the subcellular localization of the proteins we tested. More importantly, we demonstrated the utility of the DMS tag for EM in Drosophila by showing that it can produce robust photo-oxidation reactions in the presence of blue light and the substrate DAB; the resultant electron micrographs contain electron-dense regions corresponding to the protein of interest. The vectors we generated allow protein tagging at both termini, for constitutive and inducible protein expression, as well as the generation of transgenic lines by P-element transformation. CONCLUSIONS: We demonstrated the feasibility of Mini-SOG tagging in Drosophila. The constructed vectors will no doubt be a useful molecular tool for genetic tagging to facilitate high-resolution localization of proteins in Drosophila by electron microscopy.

Usefulness of Surgical Apgar Score on Predicting Survival After Surgery for Gastric Cancer.

BACKGROUND: Complete surgical resection is essential for a cure for most gastric cancer. Recently it was reported that surgical Apgar score (SAS) can predict postoperative complication and that postoperative complication is associated with poor long-term survival. The aim of this study is to assess whether SAS can predict overall survival (OS) after surgery for gastric cancer. METHODS: We retrospectively compared clinicopathological characteristics and survival between high and low SAS score groups in patients who underwent gastrectomy for gastric cancer. RESULTS: Low-scored SAS group (group L) was significantly more common among ASA-PS 2, open approach, total gastrectomy, D2 lymph node dissection, postoperative complication grade 2-4, deep tumor invasion, lymph node metastases, and advanced pathological TNM stage than high-scored SAS group (group H). The 5-year OS of group H and group L were 81.6 and 55.9 %, respectively (p < .001); OS of group L tended to be poorer than that of group H in stage III patients (p = .060) and in stage IV patients (p < .001). In multivariate analysis, pathological stage and SAS were identified as independent predictors for OS. CONCLUSIONS: SAS is useful for predicting survival after surgery for gastric cancer.

Randomly selected suppressor mutations in genes for NADH : quinone oxidoreductase-1, which rescue motility of a Salmonella ubiquinone-biosynthesis mutant strain.

The primary mobile electron-carrier in the aerobic respiratory chain of Salmonella is ubiquinone. Demethylmenaquinone and menaquinone are alternative electron-carriers involved in anaerobic respiration. Ubiquinone biosynthesis was disrupted in strains bearing deletions of the ubiA or ubiE genes. In soft tryptone agar both mutant strains swam poorly. However, the ubiA deletion mutant strain produced suppressor mutant strains with somewhat rescued motility and growth. Six independent suppressor mutants were purified and comparative genome sequence analysis revealed that they each bore a single new missense mutation, which localized to genes for subunits of NADH : quinone oxidoreductase-1. Four mutants bore an identical nuoG(Q297K) mutation, one mutant bore a nuoM(A254S) mutation and one mutant bore a nuoN(A444E) mutation. The NuoG subunit is part of the hydrophilic domain of NADH : quinone oxidoreductase-1 and the NuoM and NuoN subunits are part of the hydrophobic membrane-embedded domain. Respiration was rescued and the suppressed mutant strains grew better in Luria-Bertani broth medium and could use l-malate as a sole carbon source. The quinone pool of the cytoplasmic membrane was characterized by reversed-phase HPLC. Wild-type cells made ubiquinone and menaquinone. Strains with a ubiA deletion mutation made demethylmenaquinone and menaquinone and the ubiE deletion mutant strain made demethylmenaquinone and 2-octaprenyl-6-methoxy-1,4-benzoquinone; the total quinone pool was reduced. Immunoblotting found increased NADH : quinone oxidoreductase-1 levels for ubiquinone-biosynthesis mutant strains and enzyme assays measured electron transfer from NADH to demethylmenaquinone or menaquinone. Under certain growth conditions the suppressor mutations improved electron flow activity of NADH : quinone oxidoreductase-1 for cells bearing a ubiA deletion mutation.

Distributions and ranges of values of blood and urinary biomarker of inflammation and oxidative stress in the workers engaged in office machine manufactures: evaluation of reference values.

BACKGROUND: Interleukins, interferons and oxidative DNA products are important biomarkers assessing the inflammations and tissue damages caused by toxic materials in the body. We tried to evaluate distributions, reference values and age related changes of blood levels of inflammatory cytokines, C-reactive protein (CRP), IgE and urine levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) among workers in a cohort study evaluating the health influences of toner particles. METHODS: A total of 1366 male workers under age 50 years (age 19-49 years; 718 exposed and 648 not exposed to toner particles) in a cross sectional study of 1614 (categorized as 809 exposed and 805 not exposed, age 19-59 years) workers in a photocopier company has been followed prospectively as the cohort. Blood levels of interleukin (IL)-4, IL-6, IL-8, interferon-γ (IFN-γ), CRP, IgE and urine 8-OHdG were measured annually for 5 years. RESULTS: Reference values of the biomarkers are; CRP: 0.01-0.63×10(-2) g/L, IgE: 6-1480 IU/mL, IL-4: 2.6-76.1 pg/mL, IL-6: 0.4-4.9 pg/mL and 8-OHdG: 1.5-8.2 ng/mgCr. We could not evaluate reference values for IL-8 and IFN- γ because most of the values were below the sensitivity limits (2.0 pg/mL and 0.1 IU/mL, respectively). There were no differences of the biomarker levels between the toner exposed and the control workers. We observed a statistically significant age related decrease of serum IL-4 levels. CONCLUSIONS: This is the first report assessing the distributions and reference values of inflammatory biomarker levels in a large scaled cohort. We observed age related changes of some of the biomarkers. We could not detect any differences of the studied biomarker values between the toner exposed and the control workers.

The effect of intraoperative use of high-dose remifentanil on postoperative insulin resistance and muscle protein catabolism: a randomized controlled study.

OBJECTIVE: We investigated the effect of the intraoperative use of a high dose remifentanil on insulin resistance and muscle protein catabolism. DESIGN: Randomized controlled study. PATIENTS AND INTERVENTION: Thirty-seven patients undergoing elective gastrectomy were randomly assigned to 2 groups that received remifentanil at infusion rates of 0.1 µg·kg(-1)·min(-1) (Group L) and 0.5 µg·kg(-1)·min(-1) (Group H). MAIN OUTCOME MEASURES: Primary efficacy parameters were changes in homeostasis model assessment as an index of insulin resistance (HOMA-IR) and 3-methylhistidine/creatinine (3-MH/Cr). HOMA-IR was used to evaluate insulin resistance, and 3-MH/Cr was used to evaluate the progress of muscle protein catabolism. Intraoperative stress hormones, insulin, and blood glucose were assessed as secondary endpoints. RESULTS: Eighteen patients in Group L and 19 in Group H were examined. HOMA-IR values varied within normal limits in both groups during surgery, exceeding normal limits at 12 h after surgery and being significantly elevated in Group L. There were no significant differences in the 3-MH/Cr values between the 2 groups at any time point. The stress hormones (adrenocorticotropic hormone, cortisol, and adrenaline) were significantly elevated in Group L at 60 min after the start of surgery and at the initiation of skin closure. There were no significant differences in insulin values, but blood glucose was significantly elevated in Group L at 60 min after the start of surgery and at the start of skin closure. CONCLUSION: Use of high-dose remifentanil as intraoperative analgesia during elective gastrectomy reduced postoperative insulin resistance, although it did not reduce postoperative muscle protein catabolism.

Preoperative management of surgical patients by "shortened fasting time": a study on the amount of total body water by multi-frequency impedance method.

AIM: Preoperative fasting is an established procedure to be practiced for patients before surgery, but optimal preoperative fasting time still remains controversial. The aim of this study was to investigate the effect of "shortened preoperative fasting time" on the change in the amount of total body water (TBW) in elective surgical patients. TBW was measured by multi-frequency impedance method. METHODS: The patients, who were scheduled to undergo surgery for stomach cancer, were divided into two groups of 15 patients each. Before surgery, patients in the control group were managed with conventional preoperative fasting time, while patients in the "enhanced recovery after surgery (ERAS)" group were managed with "shortened preoperative fasting time" and "reduced laxative medication." TBW was measured on the day before surgery and the day of surgery before entering the operating room. Defecation times and anesthesia-related vomiting and aspiration were monitored. RESULTS: TBW values on the day of surgery showed changes in both groups as compared with those on the day before surgery, but the rate of change was smaller in the ERAS group than in the control group (2.4±6.8% [12 patients] vs. -10.6±4.6% [14 patients], p<0.001). Defecation times were less in the ERAS group. Vomiting and aspiration were not observed in either group. CONCLUSION: The results suggest that preoperative management with "shorted preoperative fasting time" and "reduced administration of laxatives" is effective in the maintenance of TBW in elective surgical patients.

Effect of heparin-binding EGF-like growth factor and amphiregulin on the MAP kinase-induced production of vascular endothelial growth factor by human granulosa cells.

The function of granulosa cells is regulated by various hormones and growth factors. Our aim is to clarify the regulation of vascular endothelial growth factor (VEGF) production induced by heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin (AR) in a human granulosa cell line, KGN. KGN cells were cultured and incubated for 24 h with HB-EGF and AR. The levels of VEGF in the culture media were measured by an enzyme-linked immunosorbent assay. The activation of MAP kinase in KGN cells was detected by Western blot analysis. VEGF production was significantly increased by HB-EGF or AR alone in a dose-dependent manner, whereas it was decreased by AG1478 or U0126. The MAP kinase activity was increased by treatment with HB-EGF or AR. The results suggested that VEGF is induced by HB-EGF and AR through mechanisms involving MAP kinase. The increase in VEGF may contribute to neovascularization, which in turn would promote various ovulation phenomena as well as follicular growth.

Oral rehydration therapy for preoperative fluid and electrolyte management.

AIM: Preoperative fluid and electrolyte management is usually performed by intravenous therapy. We investigated the safety and effectiveness of oral rehydration therapy (ORT) for preoperative fluid and electrolyte management of surgical patients. METHODS: The study consisted of two studies, designed as a prospective observational study. In a pilot study, 20 surgical patients consumed 1000 mL of an oral rehydration solution (ORS) until 2 h before induction of general anesthesia. Parameters such as serum electrolyte concentrations, fractional excretion of sodium (FENa) as an index of renal blood flow, volume of esophageal-pharyngeal fluid and gastric fluid (EPGF), and patient satisfaction with ORT were assessed. In a follow-up study to assess the safety of ORT, 1078 surgical patients, who consumed ORS until 2 h before induction of general anesthesia, were assessed. RESULTS: In the pilot study, water, electrolytes, and carbohydrate were effectively and safely supplied by ORT. The FENa value was increased at 2 h following ORT. The volume of EPGF collected following the induction of anesthesia was 5.3±5.6 mL. In the follow-up study, a small amount of vomiting occurred in one patient, and no aspiration occurred in the patients. CONCLUSION: These results suggest that ORT is a safe and effective therapy for the preoperative fluid and electrolyte management of selected surgical patients.

Defect-assisted electronic metal-support interactions: tuning the interplay between Ru nanoparticles and CuO supports for pH-neutral oxygen evolution.

Electronic metal-support interactions (EMSIs) comprise an area of intense study, the manipulation of which is of paramount importance in the improvement of heterogeneous metal nanoparticle (NP) supported catalysts. EMSI is the transfer of charge from the support to NP, enabling more effective adsorption and interaction of reactants during catalysis. Ru NPs on CuO supports show different levels of EMSI (via charge transfer) depending on their crystal structure, with multiple twinned NPs showing greater potential for EMSI. We use magnetron-assisted gas phase aggregation for the synthesis of batches of Ru NPs with different populations of single crystal and multiple twinned nanoparticles, which were deposited on CuO nanowires (NWs). The surface charging of the Ru-CuO catalysts was investigated by Kelvin probe force microscopy (KPFM) and X-ray photoelectron spectroscopy (XPS). By doubling the population of multiple twinned NPs, the surface potential of the Ru-CuO catalysts increases roughly 4 times, coinciding with a similar increase in the amount of Ru4+. Therefore, tuning the amount of EMSI in a catalyst is possible through changing the population of multiple twinned Ru NPs in the catalyst. Increasing the amount of multiple twin NPs resulted in improved activity in the oxygen evolution reaction (a roughly 2.5 times decrease in the overpotentials when the population of multiple twinned NPs is increased) and better catalyst stability. This improvement is attributed to the fact that the multiple twin NPs maintained a metallic character under oxidation conditions (unlike single crystal NPs) due to the EMSI between the NP and support.

Mechanoresponsive Alignment of Molecular Self-Assembled Negatively Charged Nanofibrils.

Inspired by the mechanoresponsive orientation of actin filaments in cell, we introduce a design paradigm of synthetic molecular self-assembling fibrils that respond to external mechanical force by transforming from a macroscopically disorder state to a highly ordered uniaxial aligned state. The incorporation of aromatic-containing amino acids and negatively charged amino acids lead to self-assembly motifs that transform into uniform nanofibrils in acidic solution. Adjusting the pH level of aqueous solution introduces optimal negative charge to the surface of self-assembling nanofibrils inducing long-range electrostatic repulsion forming a nematic phase. Upon external mechanical force, nanofibrils align in the force direction. Via evaporation casting in capillary confinement, the solvated synthetic self-assembling nanofibrils transform into scalable lamellar domains. Adjusting capillary geometry and drying procedure offers further parameters for tuning the mesoscale alignment of nanofibrils generating a variety of interference colors. The design paradigm of mechanoresponsive alignment of self-assembled nanofibrils as an addition of nanofabrication techniques is potentially employable for realizing biomimetic optical structures.

Utilizing ballistic nanoparticle impact to reconfigure the metal support interaction in Pt-TiN electrocatalysts.

Tuning the metal support interaction (MSI) in heterogeneous catalysts is of utmost importance for various applications in different catalysis reactions. Pt-TiN systems are strong contenders for commercial catalysts, although the charge screening of Pt and non-involvement of N reduces their effective MSI and limits it to the Pt-Ti interface. Here, the bias driven landing of gas phase synthesized Pt nanoparticles (NPs) is used to change the nature of the MSI and enhance the charge transfer phenomenon. Bias driven landing of the Pt NPs translates their impact energies to the TiN surface, resulting in a weakening of the Ti-N bonds. This facilitates a new interaction between the Pt and N atoms, resulting in an electronic equilibration in the N-Pt-Ti triumvirate, nullifying the charge screening of Pt. This change in the nature of the MSI enables long range charge transfer throughout the catalyst surface and an increase in the electrocatalytic hydrogen evolution reaction (HER) activity of the Pt-TiN system.

Preparation and optical properties of fullerene/ferrocene hybrid hexagonal nanosheets and large-scale production of fullerene hexagonal nanosheets.

The supramolecular nanoarchitectures, C(60)/ferrocene nanosheets, were prepared by a simple liquid-liquid interfacial precipitation method and fully characterized by means of SEM, STEM, HRTEM, XRD, Raman and UV-vis-NIR spectra. The highly crystallized C(60)/ferrocene hexagonal nanosheets had a size of ca. 9 microm and the formulation C(60)(ferrocene)(2). A strong charge-transfer (CT) band between ferrocene and C(60) was observed at 782 nm, indicating the presence of donor-acceptor interaction in the nanosheets. Upon heating the nanosheets to 150 degrees C, the CT band disappeared due to the sublimation of ferrocene from the C(60)/ferrocene hybrid, and C(60) nanosheets with an fcc crystal structure and the same shape and size as the C(60)/ferrocene nanosheets were obtained.

Preoperative fluid and electrolyte management with oral rehydration therapy.

PURPOSE: We hypothesized that oral rehydration therapy using an oral rehydration solution may be effective for preoperative fluid and electrolyte management in surgical patients before the induction of general anesthesia, and we investigated the safety and effectiveness of oral rehydration therapy as compared with intravenous therapy. METHODS: Fifty female patients who underwent breast surgery were randomly allocated to two groups. Before entry to the operation room and the induction of general anesthesia, 25 patients drank 1000 ml of an oral rehydration solution ("oral group") and 25 patients were infused with 1000 ml of an intravenous electrolyte solution ("intravenous group"). Parameters such as electrolyte concentrations in serum and urine, urine volume, vital signs, vomiting and aspiration, volumes of esophageal-pharyngeal fluid and gastric fluid (EPGF), and patient satisfaction with the therapy (as surveyed by a questionnaire) were assessed. RESULTS: After treatment, the serum sodium concentration and the hematocrit value, which both declined within the normal limits, were significantly higher in the oral group than in the intravenous group (sodium, 140.8 +/- 2.9 mEq x l(-1) in the oral group and 138.7 +/- 1.9 mEq x l(-1) in the intravenous group; P = 0.005; hematocrit, 39.03 +/- 4.16% in the oral group and 36.15 +/- 3.41% in the intravenous group; P = 0.01). No significant difference was observed in serum glucose values. Urine volume was significantly larger in the oral group (864.9 +/- 211.5 ml) than in the intravenous group (561.5 +/- 216.0 ml; P < 0.001). The fractional excretion of sodium (FENa), as an index of renal blood flow, was increased in both groups following treatment (0.8 +/- 0.5 in the oral group and 0.8 +/- 0.3 in the intravenous group). Patient satisfaction with the therapy favored the oral rehydration therapy, as judged by factors such as "feeling of hunger", "occurrence of dry mouth", and "less restriction in physical activity". The volume of EPGF collected following the induction of anesthesia was significantly smaller in the oral group than in the intravenous group (6.03 +/- 9.14 ml in the oral group and 21.76 +/- 30.56 ml in the intravenous group; P < 0.001). No adverse events or adverse reactions were observed in either group. CONCLUSION: The results suggest that the oral rehydration therapy with an oral rehydration solution before surgery is superior to the current preoperative intravenous therapy for the provision of water, electrolytes, and carbohydrates, and this therapy should be considered as an alternative to the intravenous therapy for preoperative fluid and electrolyte management in selected surgical patients in whom there is no reason to suspect delayed gastric emptying.