Post-processed data and graphical tools for a CONUS-wide eddy flux evapotranspiration dataset.

Large sample datasets of in situ evapotranspiration (ET) measurements with well documented data provenance and quality assurance are critical for water management and many fields of earth science research. We present a post-processed ET oriented dataset at daily and monthly timesteps, from 161 stations, including 148 eddy covariance flux towers, that were chosen based on their data quality from nearly 350 stations across the contiguous United States. In addition to ET, the data includes energy and heat fluxes, meteorological measurements, and reference ET downloaded from gridMET for each flux station. Data processing techniques were conducted in a reproducible manner using open-source software. Most data initially came from the public AmeriFlux network, however, several different networks (e.g., the USDA-Agricultural Research Service) and university partners provided data that was not yet public. Initial half-hourly energy balance data were gap-filled and aggregated to daily frequency, and turbulent fluxes were corrected for energy balance closure error using the FLUXNET2015/ONEFlux energy balance ratio approach. Metadata, diagnostics of energy balance, and interactive graphs of time series data are included for each station. Although the dataset was developed primarily to benchmark satellite-based remote sensing ET models of the OpenET initiative, there are many other potential uses, such as validation for a range of regional hydrologic and atmospheric models.

A Pilot Study on the Effect of Peer Support on Quality of Life of Adolescents with Autism Spectrum Disorder and Gender Dysphoria.

Gender dysphoria (GD) and Autism Spectrum Disorder (ASD) co-occur relatively often, but there is no evidence-based treatment for this specific group. Therefore, we examined the effects of a group intervention for adolescents with ASD and GD in a pilot study with a pre-post-test design. The adolescents completed questionnaires on quality of life, self-esteem, gender dysphoric feelings, and social responsiveness. Results show that participating in this peer support group seems to increase aspects of quality of life, i.e., increased parent-reported psychological well-being and decreased psychological complaints. Even though more research is needed, these results indicate that peer support is an invaluable part of treatment for adolescents with ASD and GD.

Genotoxic and mutagenic potential of camphorquinone in L5178/TK+/- mouse lymphoma cells.

OBJECTIVES: Camphorquinone (CQ) is the most important photoinitiator used in dental composite resins. Sparse data indicate a mutagenic potential of CQ. Therefore, it was aim of this study to evaluate the cytotoxicity, genotoxicity, and mutagenicity of CQ in L5178Y TK+/- mouse lymphoma cells. METHODS: L5178Y/TK+/- cells were exposed to different concentrations of non-irradiated CQ (0.25-2.5mM). Cytotoxicity was evaluated by propidium iodide assay, determination of suspension growth rate, relative total growth and the mitotic index. Intracellular levels of reactive oxygen/nitrogen species (ROS/RNS) were quantified by 2',7'-dichlorofluoresceine diacetate (DCFH-DA). Early induction of DNA strand breaks and oxidative DNA base lesions was assessed using the 8-hydroxyguanine DNA-glycosylase 1 (hOGG1)-modified alkaline comet assay, whereas mutagenicity of CQ was determined in the mouse lymphoma TK assay (MLA), according to OECD Guideline No. 490. RESULTS: CQ (0.5-2.5mM) induced concentration- and time-dependent inhibition of cell growth associated with increased ROS/RNS production, amounting to 2342%±1108% of controls after 90min at 2.5mM. Additionally, CQ concentration-dependently caused direct DNA-damage, i.e. formation of DNA strand breaks and 8-hydroxy-2'-deoxyguanosine. Whereas the MLA indicated lack of mutagenicity of CQ after a 4h of treatment, CQ concentration-dependently increased total mutant frequency (MF) after 24h (about 2-fold at 2.5mM). But, based on the global evaluation factor concept, increase in MF did not reach biologically relevance. SIGNIFICANCE: CQ induced concentration-dependent, cytotoxic and genotoxic effects in L5178Y/TK+/- cells, most likely due to oxidative stress, but without mediating obvious biological relevant mutagenicity.

Minor salivary glands of the lips: a novel, easily accessible source of potential stem/progenitor cells.

OBJECTIVES: Cells with stem/progenitor properties have been detected in major salivary glands, but no data are available on their presence within minor salivary glands (MSGs). This study aimed to isolate and characterize potential stem/progenitor cells from human MSGs. MATERIALS AND METHODS: MSGs of the lower lip were surgically obtained during biopsy for Sjogren's syndrome investigation that finally proved to be histologically normal. The established MSG cultures were assessed for morphology, proliferation, colony-forming-unit efficiency, multipotentiality, and immunophenotypic characteristics. RESULTS: A mixed population of fibroblast-like and a few flat-shaped epithelial-like cells was obtained. These cells were capable for osteogenic, adipogenic, and neurogenic differentiation. Evidence for strong stem cell potency was observed by the detection of early stem cell markers, like Nanog, Oct-3/4, and SSEA-3. These cells also expressed characteristic mesenchymal stem cell markers, including CD90-Thy1, CD105, CD49f, CD81, nestin, CD146, and Stro-1, but were negative for CD117/C-KIT, CD45, and CD271/NFG. In addition, positivity for keratins 7/8 in part of the population was indicative of an epithelial phenotype, whereas these cells were negative for aquaporin-1 expressed in acinar/myoepithelial cells during development. CONCLUSIONS: Based on these data, a cell population with stem/progenitor characteristics was primarily isolated from labial MSGs. The morphologic and immunophenotypic features indicated that this population is mixed with mesenchymal (mainly) and epithelial characteristics. CLINICAL RELEVANCE: Due to their large number and superficial distribution in labial mucosa, MSGs may be proposed as a potential easily accessible source of adult stem/progenitor cells for regenerative therapies of glandular organs with parenchymal pathology.

Comparative characterization of STRO-1(neg)/CD146(pos) and STRO-1(pos)/CD146(pos) apical papilla stem cells enriched with flow cytometry.

OBJECTIVE: Stem Cells residing in the Apical Papilla (SCAP) of human permanent teeth represent a promising cell source for dental tissue regeneration. Therefore, the functional and molecular properties of specific subpopulations existing within heterogeneous cultures should be further investigated to give insight whether their selection could be beneficial for targeted therapeutic applications. DESIGN: In this study we extensively characterized SCAP cultures established from 10 healthy subjects, as well as their STRO-1(pos/)CD146(pos) and STRO-1(neg/)CD146(pos) subpopulations isolated with fluorescence-activated cell sorting. SCAP were analyzed for embryonic (Nanog, Oct3/4, SSEA-3, TRA-1-60), mesenchymal (STRO-1, CD146/MUC18, CD105/endoglin, CD24, CD90/Thy-1, CD81-TAPA, CD34, CD49f/a6-integrin), neural (CD271/NGFR, nestin) and hematopoietic (CD117/c-kit, CD45) stem cell (SC) markers using flow cytometry. Multipotentiality was evaluated with culture specific staining (Alizarin-Red-S, Oil- Red-O) and RT-PCR analysis for osteo/odontogenic (DSPP, BSP, ALP, osteocalcin, osteonectin, BMP-2, Runx2), adipogenic (lipoprotein-lipase-LPL) and neurogenic (Neurofilament/NFL-L, nestin, ß-tubulin-III, NCAM) markers. RESULTS: Our results showed that the STRO-1(pos)/CD146(pos) subpopulation demonstrated higher CFU efficiency and much higher expression of several embryonic and mesenchymal SC markers compared to the non-sorted SCAP. They also showed enhanced odontogenic differentiation potential, as evidenced by higher mineralization capacity and expression of osteo/odontogenic markers. By contrast, absence of STRO-1 in the STRO-1(neg)/CD146(pos) subpopulation yielded the opposite results and was associated with significant downgrading of the above-mentioned properties. CONCLUSIONS: These results suggest that STRO-1(pos)/CD146(pos) SCAP cells represent a very promising adult MSCs source with enhanced multipotent SC properties that could be easily isolated with simple flow cytometric methods to be used for tissue engineering applications.

Comparative analysis of in vitro osteo/odontogenic differentiation potential of human dental pulp stem cells (DPSCs) and stem cells from the apical papilla (SCAP).

OBJECTIVE: The aim of this study was to compare the in vitro osteo/odontogenic differentiation potential of mesenchymal stem cells (MSCs) derived from the dental pulp (dental pulp stem cells - DPSCs) or the apical papilla (stem cells from the apical papilla - SCAP) of permanent developing teeth. DESIGN: DPSCs and SCAP cultures were established from impacted third molars of young healthy donors at the stage of root development. Cultures were analysed for stem cell markers, including STRO-1, CD146, CD34 and CD45 using flow cytometry. Cells were then induced for osteo/odontogenic differentiation by media containing dexamethasone, KH(2)PO(4) and ß-glycerophosphate. Cultures were analysed for morphology, growth characteristics, mineralization potential (Alizarin Red method) and differentiation markers (dentine sialophosphoprotein-DSPP, bone sialoprotein-BSP, osteocalcin-OCN, alkaline phosphatase-ALP), using immunocytochemistry and reverse transcriptase-polymerase chain reaction. RESULTS: All DPSCs and SCAP cultures were positive for STRO-1, CD146 and CD34, in percentages varying according to cell type and donor, but negative for CD45. Both types of MSCs displayed an active potential for cellular migration, organization and mineralization, producing 3D mineralized structures. These structures progressively expressed differentiation markers, including DSPP, BSP, OCN, ALP, having the characteristics of osteodentin. SCAP, however, showed a significantly higher proliferation rate and mineralization potential, which might be of significance for their use in bone/dental tissue engineering. CONCLUSIONS: This study provides evidence that different types of dental MSCs can be used in tissue engineering/regeneration protocols as an approachable stem cell source for osteo/odontogenic differentiation and biomineralization that could be further applied for stem cell-based clinical therapies.

The dual function of nitrite under stomach conditions is modulated by reducing compounds.

Salivary nitrite plays a role in the lipid peroxidation process of muscle tissue in simulated gastric fluid. The objectives of our study were to elucidate the fate of nitrite in the presence of reducing compounds and to evaluate its effect on lipid peroxidation during digestion. Nitrite at pH 3 (possibly NO(2.), not NO.) can oxidize beta-carotene, but the addition of reducing compounds, ascorbic acid or polyphenols, alters its effect. Ascorbic acid alone promoted the formation of NO. from nitrite only up to pH 3, but the addition of iron ions facilitated the formation of NO. up to pH 5.5. NO prevented membranal lipid peroxidation under stomach conditions. Nitrite, only in the presence of reducing compounds, achieved the same goal but at much higher concentrations. Addition of polyphenols to nitrite synergistically improved its antioxidant effect. Therefore, to promote NO. production and to achieve better control of the lipid peroxidation process in the stomach, a nitrite-rich meal should be consumed simultaneously with food rich in polyphenols.

Orthodontic force decreases the eruption rate of rat incisors.

The aim of this study was to determine whether a force applied in an antero-posterior direction would adequately reduce incisor eruption. This is needed to achieve a constant direction of force which is one of the demands for a good model for studying orthodontic tooth movement. Twenty male Wistar rats aged 11-12 weeks were divided into two equal groups: in the appliance group, a superelastic closed coil spring (25 cN) was placed between the upper left first molar and the incisors. The control group consisted of animals without an appliance. In both groups, cuts were created on the labial surfaces of the upper and lower incisors. The distance from the gingival reference point to the midpoint of the cut was measured for 10 days at 2 day intervals. Upper incisor inclination was determined as the distance from the most mesial point of the upper left first molar to the incisal edge of the ipsilateral incisor on days 0 and 10. Statistical analysis was carried out using two-way analysis of variance and a Bonferroni post- test to estimate reliability. The eruption rates of the maxillary incisors in the appliance group were significantly decreased when compared with the control group during the whole experiment. In the appliance group, the eruption rates of the mandibular incisors were decreased more than those of the maxillary incisors (P<0.01). There was no difference in incisor inclination between the appliance and control groups on day 10 (P=0.81). The applied force of 25 cN in an antero-posterior direction diminished incisor eruption to a level which enabled a constant direction of orthodontic force for 10 days.

Highly Uniform Epitaxial ZnO Nanorod Arrays for Nanopiezotronics.

Highly uniform and c-axis-aligned ZnO nanorod arrays were fabricated in predefined patterns by a low temperature homoepitaxial aqueous chemical method. The nucleation seed patterns were realized in polymer and in metal thin films, resulting in, all-ZnO and bottom-contacted structures, respectively. Both of them show excellent geometrical uniformity: the cross-sectional uniformity according to the scanning electron micrographs across the array is lower than 2%. The diameter of the hexagonal prism-shaped nanorods can be set in the range of 90-170 nm while their typical length achievable is 0.5-2.3 mum. The effect of the surface polarity was also examined, however, no significant difference was found between the arrays grown on Zn-terminated and on O-terminated face of the ZnO single crystal. The transmission electron microscopy observation revealed the single crystalline nature of the nanorods. The current-voltage characteristics taken on an individual nanorod contacted by a Au-coated atomic force microscope tip reflected Schottky-type behavior. The geometrical uniformity, the designable pattern, and the electrical properties make the presented nanorod arrays ideal candidates to be used in ZnO-based DC nanogenerator and in next-generation integrated piezoelectric nano-electromechanical systems (NEMS).

The effects of TBC3214, a selective endothelin ETA receptor antagonist, on orthodontic tooth movement in rats.

Many chemical messengers are involved in the process of alveolar bone and periodontal ligament remodelling during orthodontic tooth movement. Among them is probably endothelin-1 (ET-1). Its role in this process has been partly explained using tezosentan, which affects endothelin A (ET(A)) and endothelin B (ET(B)) receptors. Tezosentan enhances orthodontic tooth movement. The aim of this study was to determine the possible effects of a highly selective ET(A) antagonist on orthodontic tooth movement in rats. Thirty male Wistar rats, 11-12 weeks of age, divided into three equal groups. In group I, a closed-coil spring was used and they were treated daily with 15 mg/kg body weight of TBC3214, a highly selective ET(A) antagonist. A closed-coil spring was also used in group II and the animals were treated daily with a placebo. Group III were treated daily with a placebo. The coil spring delivered a force of 25 cN and was attached between the upper left first molar and upper left incisor. The distance between the teeth was measured with a digital calliper (accuracy +/- 0.01 mm) on days 0, 7, 14, 21, 24, 32, 37, and 40. The differences in the distance between the teeth were calculated to determine the amount of tooth movement. Statistical analysis was performed using two-way analysis of variance, Bonferroni's correction, and paired t-tests. The distance between the upper left first molar and the upper left incisor decreased in groups I and II. In group I, tooth movement was significantly less on days 32 and 37 (P < 0.01) and on day 40 (P < 0.001) compared with group II. In group III, the distance between the teeth increased during the study (P < 0.001). In animals treated daily with TBC3214, tooth movement was significantly less compared with the animals treated with a placebo. It is concluded that ET-1, which is the predominant form of endothelin isopeptides, is involved in orthodontic tooth movement in rats, probably by enhancing bone resorption via ET(A) receptors.

Measurement of the asymmetry in the decay Omega+-->LamdaKappa+-->rhopi+Kappa+.

The asymmetry in the rho angular distribution in the sequential decay Omega+-->LamdaKappa+-->rhopi+Kappa+. has been measured to be alphaOmegaalphaLamda=[+1.16+/-0.18(stat)+/-0.17(syst)]x10(-2) using 1.89x10(6) unpolarized Omega+ decays recorded by the HyperCP (E871) experiment at Fermilab. Using the known value of alphaLamda, and assuming that alphaLamda=-alphaLamda, alphaOmega=[-1.81+/-0.28(stat)+/-0.26(syst)]x10(-2). A comparison between this measurement of alphaOmegaalphaLamda and recent measurements of alphaOmegaalphaLamda made by HyperCP shows no evidence of a violation of CP symmetry.

Nitrogen loads through baseflow, stormflow, and underflow to Rehoboth Bay, Delaware.

A detailed study of water and nitrogen (N) discharge from a small, representative subwatershed of Rehoboth Bay, Delaware, was conducted to determine total N loads to the bay. The concentrations of ammonium (NH4(+)), nitrate + nitrite (NO3(-) + NO2(-)), and dissolved and particulate organic N were determined in baseflow and storm waters discharging from Bundicks Branch from October 1998 to April 2002. A novel hydrographic separation model that accounts for significant decreases in baseflow during storm events was developed to estimate N loads during unsampled storms. Nitrogen loads based on gauged flows alone (7100-19,100 kg/yr) significantly underestimated those based on land use-land cover (LULC) and estimated N export factors from different classes of LULC (32,000-40,600 kg/yr). However, when ungauged underflow and associated N loads were included in the total loads (25,500-33,800 kg/yr), there was much better agreement with LULC export models. This suggests that in permeable coastal plain sediments, underflow contributes significantly to N fluxes to estuarine receiving waters, particularly in drier years. Based on the similarity in LULC, N loads from the Bundicks Branch subwatershed were used to estimate upland loads to the entire Rehoboth Bay Watershed (259,000-316,000 kg/yr). These N loads from the watershed were much greater than those from direct atmospheric deposition (49,000-64,500 kg/yr) and from a local wastewater treatment plant (9700-13,700 kg/yr). While the watershed was the principal source of N at all times during the year, the relative contributions from the watershed, wastewater, and direct atmospheric deposition varied predictably with season.

Effects of three resin monomers on the cellular glutathione concentration of cultured human gingival fibroblasts.

OBJECTIVES: Oral and systemic cells are permanently exposed to various types of xenobiotics, such as dental restorative materials, which may subsequently cause adverse effects. Objective of the present investigation was to analyze the effects of three important resin monomers on the glutathione metabolism of human gingival fibroblasts after an incubation period of 4h. METHODS: Cells were exposed to various concentrations of 2-hydroxyethyl methacrylate (HEMA; 0.1-10 mM), triethylene-glycol dimethacrylate (TEGDMA; 0.05-2.5 mM), and urethane dimethacrylate (UDMA; 0.005-0.25 mM). Subsequently, cellular glutathione (GSH) concentrations were determined after a treatment period of 4h using the monobromobimane assay. Data were statistically evaluated using Tukey ANOVA with p<0.05. RESULTS: GSH depletion was dependent on the type of the resin monomer: UDMA>TEGDMA>HEMA. The concentrations for a 50%-reduction of cellular GSH varied between 0.1 mM (0.05 mM) (UDMA), 0.33 mM (0.09 mM) (TEGDMA), and 1.6 mM (0.8 mM) (HEMA). Simultaneously, no decrease of cell numbers was found at any tested concentration. SIGNIFICANCE: These data indicate that the investigated resins may cause cell damage due to depletion of intracellular GSH level even at low concentrations within a short period of time. The decrease of GSH is an early reaction, which is triggered prior to other cytotoxic alterations.

ROS formation and glutathione levels in human oral fibroblasts exposed to TEGDMA and camphorquinone.

Glutathione (GSH) is important for the self-protection of cells against oxidative stress and toxic xenobiotics, whereas reactive oxygen species (ROS) at elevated concentrations may cause detrimental alterations of cell membranes, DNA, and other cellular structures. The present investigation addressed the effects of triethylene-glycoldimethacrylate (TEGDMA) and camphorquinone (CQ) on glutathione metabolism and the formation of ROS in oral cells. Primary human pulp fibroblasts were exposed to various concentrations of TEGDMA and CQ (0.1-5 mM). Subsequently, GSH concentration and ROS formation were analyzed with the use of the monobromobimane assay (GSH) and 2',7'-dichlorofluorescein diacetate (DCFH-DA) (ROS). The endogenous ROS hydrogen peroxide (H2O2) was used as a positive control (0.02-2 mM). TEGDMA significantly decreased GSH at concentrations between 0.5 and 5 mM (p<0.05), but did not elevate ROS levels. Contrary, CQ increased ROS formation at concentrations>or=1 mM, but had only a moderate effect on GSH at the highest test concentration. Hydrogen peroxide increased ROS and simultaneously decreased GSH at concentrations of >or=0.2 mM. These data show that the investigated substances may cause cell damage due to various mechanisms, GSH decrease and/or ROS increase. As a consequence, TEGDMA and CQ released into an aqueous environment from resinous materials might interact, thus generating significant cytotoxic effects even at low concentrations.

Search for the lepton-number-violating decay Xi(-)-->pmu(-)mu(-).

A sensitive search for the lepton-number-violating decay Xi(-)-->pmu(-)mu(-) has been performed using a sample of approximately 10(9) Xi(-) hyperons produced in 800 GeV/c p-Cu collisions. We obtain B(Xi(-)-->pmu(-)mu(-))<4.0x10(-8) at 90% confidence, improving on the best previous limit by 4 orders of magnitude.

Search for DeltaS = 2 nonleptonic hyperon decays.

A sensitive search for the rare decays Omega(-)--> Lambdapi(-) and Xi(0)--> ppi(-) has been performed using data from the 1997 run of the HyperCP (Fermilab E871) experiment. Limits on other such processes do not exclude the possibility of observable rates for |DeltaS| = 2 nonleptonic hyperon decays, provided the decays occur through parity-odd operators. We obtain the branching-fraction limits B(Omega(-)-->Lambdapi(-)) < 2.9 x 10(-6) and B(Xi(0)--> ppi(-)) < 8.2 x 10(-6), both at 90% confidence level.

Evidence for the decay sigma+ --> pmu+ mu-.

We report the first evidence for the decay Sigma(+)-->pmu(+)mu(-) from data taken by the HyperCP (E871) experiment at Fermilab. Based on three observed events, the branching ratio is B(Sigma(+)-->pmu(+)mu(-))=[8.6(+6.6)(-5.4)(stat)+/-5.5(syst)]x10(-8). The narrow range of dimuon masses may indicate that the decay proceeds via a neutral intermediate state, Sigma(+)-->pP(0),P0-->mu(+)mu(-) with a P0 mass of 214.3+/-0.5 MeV/c(2) and branching ratio B(Sigma(+)-->pP(0),P0-->mu(+)mu(-))=[3.1(+2.4)(-1.9)(stat)+/-1.5(syst)]x10(-8).

Search for CP violation in charged-Xi and Lambda hyperon decays.

We have compared the p and p angular distributions in 117 x 10(6) Xi- -->Lambdapi- -->ppi-pi- and 41 x 10(6) Xi+ -->Lambda pi+ -->p pi+pi+ decays using a subset of the data from the HyperCP experiment (E871) at Fermilab. We find no evidence of CP violation, with the direct-CP-violating parameter AXiLambda identical with (alphaXialphaLambda-alpha Xialpha Lambda)/(alphaXialphaLambda+alphaXialphaLambda)=[0.0+/-5.1(stat)+/-4.4(syst)] x 10(-4).

Clinical phase II study and pharmacological evaluation of rubitecan in non-pretreated patients with metastatic colorectal cancer-significant effect of food intake on the bioavailability of the oral camptothecin analogue.

A randomised, open label phase II study was performed in patients with advanced colorectal cancer to evaluate the safety, toxicity and antineoplastic activity of the topoisomerase I-inhibitor rubitecan. A cross-over design was chosen to determine the intrapatient variation of the bioavailability and pharmacokinetics of the anticancer agent depending on the timing of food intake in relation to the oral drug administration. Patients with previously untreated metastatic disease received two single oral doses of rubitecan 1.5 mg/m2 for assessment of the pharmacokinetics. They were randomised to have the first administration either after an overnight fasting period or immediately after a high calorie breakfast, and crossed over to the alternative schedule after a one-week washout period. After completion of the pharmacokinetic sampling, treatment continued with rubitecan given orally at a dose of 1.5 mg/m2/day, to be increased up to 2.0 mg/m2/day, under fasting conditions for 5 consecutive days per week until disease progression. 19 patients entered the trial after informed consent was obtained. A total number of 35 treatment cycles (median 2, range 1-4) were administered. All patients were evaluable for safety. The toxicity profile of rubitecan was generally mild to moderate, with sporadic cases of grade 4 toxicities (Common Toxicity Criteria (CTC) version 2.0) diarrhoea, leucopenia and neutropenia. None of 15 evaluable patients achieved an objective response. The majority had early disease progression. 14 patients were evaluable for pharmacokinetic analysis. The bioavailability of rubitecan was found to be strongly dependent on the timing of food intake with a fasted-to-fed ratio for C(max) of 1.98 (two-tailed P<0.001; ANOVA), T(max) 0.49 (P<0.001), AUC(0-8 h) 2.52 (P<0.001) and AUC(0-24 h) 1.64 (P=0.003). Rubitecan is well tolerated, but clinically inactive in colorectal cancer at the currently recommended dose and schedule. The bioavailability is strongly dependent on the timing of food intake in relation to the oral administration of the drug. The topoisomerase I-inhibitor should be administered under fasting conditions to achieve adequate drug exposure in future prospective trials in other tumour types.

Observation of the decay K- --> pi(-)mu(+)mu(-) and measurements of the branching ratios for K+/- --> pi(+/-)mu(+)mu(-).

Using data collected with the HyperCP (E871) spectrometer during the 1997 fixed-target run at Fermilab, we report the first observation of the decay K--->pi(-)mu(+)mu(-) and new measurements of the branching ratios for K+/--->pi(+/-)mu(+)mu(-). By combining the branching ratios for the decays K+-->pi(+)mu(+)mu(-) and K--->pi(-)mu(+)mu(-), we measure Gamma(K+/--->pi(+/-)mu(+)mu(-))/Gamma(K+/--->all) = (9.8+/-1.0+/-0.5)x10(-8). The CP asymmetry between the rates of the two decay modes is [Gamma(K+-->pi(+)mu(+)mu(-))-Gamma(K--->pi(-)mu(+)mu(-))]/[Gamma(K+-->pi(+)mu(+)mu(-))+Gamma(K--->pi(-)mu(+)mu(-))] = -0.02+/-0.11+/-0.04.