Sensitive distance-based paper-based quantification of mercury ions using carbon nanodots and heating-based preconcentration

This article reports the first fluorescent distance-based paper device coupled with an evaporating preconcentration system for determining trace mercury ions (Hg²⁺) in water. The fluorescent nitrogen-doped carbon dots (NCDs) were synthesized by a one-step microwave method using citric acid and ethylenediamine. The fluorescence turn-off of the NCDs in the presence of Hg²⁺ was visualized with a common black light, and the distance of the quenched fluorescence correlated to Hg²⁺ concentration. The optimal conditions for pH, NCD concentration, sample volume, and reaction time were investigated. Heating preconcentration was used to improve the detection limits of the fluorescent distance-based paper device by a factor of 100. Under the optimal conditions, the naked eye limit of detection (LOD) was 5 μg L⁻¹ Hg²⁺. This LOD is sufficient for monitoring drinking water where the maximum allowable mercury level is 6 μg L⁻¹ as established by the World Health Organization (WHO). The fluorescent distance-based paper device was successfully applied for Hg²⁺ quantification in water samples without interference from other cations. The proposed method provides several advantages over atomic absorption spectroscopy including ease of use, inexpensive material and fabrication, and portability. In addition, the devices are simple to fabricate and have a long shelf-life (>5 months).

This article reports the first fluorescent distance-based paper device coupled with an evaporating preconcentration system for determining trace mercury ions (Hg²⁺) in water.     

Bcl-x(L) prevents apoptosis of late-stage erythroblasts but does not mediate the antiapoptotic effect of erythropoietin

The long form of B-cell lymphoma-x (Bcl-x(L)), an outer mitochondrial membrane protein, has been proposed to mediate the antiapoptotic action of erythropoietin on erythroid progenitor cells and to be necessary for heme synthesis in erythroblasts. Mice with conditional knockout of Bcl-x(L) (conditional bcl-x(-/-) mice) develop severe anemia that has been attributed to hemolysis and is accompanied by splenomegaly. We characterized further the anemia of conditional bcl-x(-/-) mice and investigated the role of Bcl-x(L) in the action of erythropoietin and in heme synthesis. We analyzed peripheral blood cells and cultured splenic erythroblasts of conditional bcl-x(-/-) mice and littermates that were rendered anemic by bleeding. Although they had massive splenic erythroblastosis, conditional bcl-x(-/-) mice had decreased circulating reticulocytes compared to littermates even prior to bleeding the littermates. Compared to erythroblasts of bled littermates, bcl-x(-/-) erythroblasts cultured with erythropoietin underwent apoptosis during the later, hemoglobin-synthesizing stages of differentiation. The bcl-x(-/-) erythroblasts synthesized heme, but at reduced rates compared to bled littermate erythroblasts. When cultured without erythropoietin, bcl-x(-/-) erythroblasts underwent apoptosis at early stages of differentiation, prior to hemoglobin synthesis. Bcl-x(L) is not required for heme synthesis and does not mediate the antiapoptotic effects of erythropoietin, but it prevents ineffective erythropoiesis due to apoptosis in late-stage, hemoglobin-synthesizing erythroblasts.     

IL-17 drives psoriatic inflammation via distinct,target cell-specific mechanisms

Psoriasis is a chronic inflammatory skin disease characterized by abnormal keratinocyte proliferation and differentiation and by an influx of inflammatory cells. The mechanisms underlying psoriasis in humans and in mouse models are poorly understood, although evidence strongly points to crucial contributions of IL-17 cytokines, which signal via the obligatory adaptor CIKS/Act1. Here we identify critical roles of CIKS/Act1-mediated signaling in imiquimod-induced psoriatic inflammation, a mouse model that shares features with the human disease. We found that IL-17 cytokines/CIKS-mediated signaling into keratinocytes is essential for neutrophilic microabscess formation and contributes to hyperproliferation and markedly attenuated differentiation of keratinocytes, at least in part via direct effects. In contrast, IL-17 cytokines/CIKS-mediated signaling into nonkeratinocytes, particularly into dermal fibroblasts, promotes cellular infiltration and, importantly, leads to enhanced the accumulation of IL-17–producing γδT cells in skin, comprising a positive feed-forward mechanism. Thus, CIKS-mediated signaling is central in the development of both dermal and epidermal hallmarks of psoriasis, inducing distinct pathologies via target cell-specific effects. CIKS-mediated signaling represents a potential therapeutic target in psoriasis.Psoriasis is a common chronic inflammatory skin disease affecting up to 2–3% of the population worldwide. This disease has an incompletely defined etiology and is characterized by dysregulated proliferation and differentiation of keratinocytes, dermal angiogenesis, and immune cell infiltration. Currently there is no cure, but efficacious treatments to control symptoms exist. The development of psoriasis involves an intricate interplay of genetic and environmental factors. Multiple susceptibility gene loci have been identified, including genes encoding proteins involved in keratinocyte differentiation and function as well as proteins involved in inflammatory responses. Psoriasis is associated with serious comorbidities, such as metabolic syndrome and cardiovascular disease, likely reflecting a systemic inflammatory component of the disease (comprehensively reviewed in ref. 1).The choreography underpinning the development of pathology in psoriasis is incompletely understood and may differ among individuals and among the various mouse models of this disease. Nevertheless, a number of inflammatory cytokines, including IFN-γ, IL-1 (α,β), IL-36 (α,β,γ), IL-22, and, especially, TNF-α and the IL-23/IL-17 axis, have been implicated in psoriatic inflammation in mouse models and/or humans (2, 3). IL-17–producing cells are found in lesions from psoriatic patients and may be key factors driving pathology (4–6). Importantly, recent clinical trials have shown therapies targeting IL-12/IL-23 (p40), IL-23 (p19), and IL-17 or its receptor (IL-17RA) to be highly efficacious (7–9). Furthermore, comprehensive genomewide association studies have identified Il12b and Il23a, which encode the IL-23 subunits, and Traf3ip2, which encodes CIKS [connection to IκB kinase and stress-activated protein kinase, also known as “Act1” (NF-κB activator 1)], the obligate adaptor for IL-17 receptor signaling, as strong susceptibility loci for psoriasis (1, 10, 11).IL-17 (IL-17A) is the signature cytokine of Th17 cells and usually is coproduced together with the closely related IL-17F, with which it can form heterodimers. Increased expression of these cytokines has been linked not only to psoriasis but also to other inflammatory diseases (reviewed in ref. 12). In addition to Th17 cells and CD8⁺ cells secreting IL-17 (Tc17 cells), innate lymphoid γδT cells, invariant natural killer T (iNKT) cells, and innate lymphoid cells-3 (ILC3) also produce IL-17 cytokines (13). Indeed dermal γδT cells appear to be the main producers of IL-17 in several mouse models of psoriasis (5). IL-17–producing dermal γδT cells also are present in humans, and their numbers are increased in psoriatic lesions (5, 14).IL-17C is an additional member of the IL-17 cytokine family that has been implicated in psoriasis (15–17). IL-17C seems to overlap functionally with IL-17A but is primarily produced by epithelial cells, including keratinocytes (18). Among the three IL-17 cytokines associated with psoriasis—A, C, and F—IL-17A appears to be the most potent. All three are members of an extended family (IL-17A–F) that signals via cognate heteromeric receptors composed of members of the IL-17 receptor family (RA–RE), with the IL-17RA chain likely common to all receptors (19). The IL-17 receptor family members encode a SEFIR-like (similar expression to fibroblast growth factor genes and IL-17 receptors) domain in their cytoplasmic tails, which also is present within the adaptor protein CIKS (20, 21). Upon ligand engagement, CIKS is recruited to IL-17 cytokine receptors via heterotypic SEFIR domain association (22, 23). Consistent with a pathogenic role for IL-17 cytokines in various diseases, CIKS is critical for the development of collagen-induced arthritis, lupus, and asthma in mouse models (24–26).The importance of IL-17 cytokines in psoriatic inflammation has been addressed in several mouse models, although questions remain. Psoriasis-like inflammation induced upon intradermal injections of IL-23 in mice was reported to be largely dependent on the presence of IL-17RA; however other studies have highlighted the critical contributions of IL-22 (27–29). Topical application of the TLR7/8 ligand imiquimod (IMQ) induces skin inflammation in mice that mimics various aspects of human psoriasis (5, 30). This potent immune activator also is used for the treatment of warts and superficial basal cell carcinomas but can induce psoriasis-like skin flares as a side effect in susceptible patients (31). IMQ-induced psoriatic inflammation was reported to be critically dependent on IL-23 as well as on the presence of IL-17RA (30), although whether IL-17RA signaling is absolutely required in this model has been questioned recently (32).Here we describe previously undescribed mechanisms by which CIKS-mediated signaling contributes to specific psoriatic pathologies in the IMQ model. We demonstrate that CIKS-mediated signaling downstream of IL-17 cytokines critically disrupts the regulation of keratinocyte proliferation and differentiation and is essential for the formation of neutrophilic microabscesses. Notably, these effects are completely dependent on CIKS signaling within keratinocytes. We also demonstrate that CIKS contributes to the recruitment of inflammatory cells, especially to the IMQ-induced increase in IL-17–expressing cells, but, in contrast to the epidermal pathologies, these latter effects depend on CIKS signaling in nonkeratinocytes, specifically in dermal fibroblasts. These findings reveal cellular targets and mechanisms by which CIKS-mediated signaling effects specific psoriatic pathologies, and they identify CIKS as a potential therapeutic target in psoriasis.     

Optimization of nimesulide-loaded solid lipid nanoparticles (SLN) by factorial design,release profile and cytotoxicity in human Colon adenocarcinoma cell line

The aim of this work is development of a nontoxic, long-term stable solid lipid nanoparticles (SLN) formulation for the loading of Nimesulide (NiM) by a 2² factorial design. The optimized formulation was composed of 10?wt% of glyceryl behenate and 2.5?wt% of poloxamer 188. Immediately after production, Z-Ave of NiM-SLN was 166.1?±?0.114?nm, with a polydispersity index (PI) of 0.171?±?0051 and zeta potential nearly neutral (?3.10?±?0.166?mV). A slight increase of Z-Ave was recorded for NiM-SLN stored at 25?°C for a period of 15?days, whereas at 4?°C particles kept size within similar range. Long-term stability was monitored using TurbiscanLab^®, showing a high stability of the nanoparticles with variations in the backscattering profiles below 10%. The release profile of NiM-SLN followed a sustained pattern with ca. 30% of drug released up to 24?h. Empty-SLN and NiM-SLN were nontoxic after exposing Caco-2 cells to the highest concentration (100?μg/mL) up to 48?hours (cell viability higher than 80%). NiM-SLN were lyophilized using different cryoprotectants, producing particles of 463.1?±?36.63?nm (PI 0.491?±?0.027) with 5% trehalose. Solid character of NiM-SLN was confirmed by DSC, recording a recrystallization index of 83% for NiM-SLN and of 74% for lyophilized SLN.     

Disruption of testicular steroidogenesis and epididymal function by inhaled benzo(a)pyrene

The objective of this study was to evaluate the effect of sub-acute exposure to inhaled benzo(a)pyrene (BaP) on testicular steroidogenesis and epididymal function in Fisher 344 rats. Animals were assigned randomly to two control groups and one experimental group for each exposure regimen. Treatment consisted of sub-acute exposure of rats via inhalation to 25, 75, and 100 microg BaP/m(3), 4 h daily for 10 days. Control animals were either exposed to carbon black (CB; sham) to control for inert BaP carrier or they remained unexposed (UNC). Blood samples were collected immediately after the cessation of exposures (time 0) and at 24, 48, and 72 h post-cessation of exposure, to assess the effect of bioavailable BaP on systemic testosterone and luteinizing hormone (LH) concentrations by radioimmunoassay (RIA). Progressive sperm motility of stored sperm (cauda epididymal sperm) was determined microscopically, while density of stored sperm was determined by hemocytometric counting. Progressive motility of stored sperm was reduced in rats exposed to 75 and 100 microg BaP/m(3) compared with their counterparts that were exposed to 25 microg BaP/m(3) or controls. Plasma testosterone concentrations declined as a result of exposure of rats to 75 microg BaP/m(3) from 0 to 48 h post-termination of exposure compared with controls (P<0.05; treatment x time interaction). This decrease was followed subsequently by a compensatory increase in the plasma concentrations of this steroid at 72 h post-cessation of exposures compared with previous time periods and controls (P<0.05). Increases in the mean plasma LH concentrations were observed in rats exposed to 75 microg BaP/m(3) compared with controls, throughout the time periods studied (P<0.05; treatment x time interaction). These data suggest that sub-acute exposure to inhaled BaP contributes to reduced testosterone concentrations and consequently impaired epididymal function of exposed animals.     

The experience of persons with allergic respiratory symptoms: practicing yoga as a self-healing modality

The purpose of this study was to describe the experience of persons with allergic respiratory symptoms who practice yoga as a self-healing modality. Fifteen participants were interviewed. Using the content analysis method, 5 themes emerged from the data: perceived positive effects, powerful and harmonious inner energy, mindfulness and self-awareness, understanding self and others, and promoting and achieving a state of balance and harmony. These findings foster the value of knowing the experience of persons who practice yoga as an intervention in holistic nursing.     

Alteration of pregnancy related hormones and fetal survival in F-344 rats exposed by inhalation to benzo(a)pyrene

The objective of this study was to evaluate the effect of subacute exposure to inhaled benzo(a)pyrene (BaP) on fetal survival and luteal maintenance using timed-pregnant Fisher 344 rats. Prior to assignment of pregnant rats to treatment and control groups, numbers of implantation sites were determined on gestation day (GD) 8 via midventral laparotomy. Subsequently, animals were assigned randomly to three treatment groups and two control groups. Treatment consisted of subacute exposure of rats via inhalation to BaP 25, 75, and 100 μg/m³, 4 h daily for 10 days (GD-11–20). Control animals were either sham exposed to carbon black (CB) to control for inert BaP carrier or remained unexposed (UNC). Blood samples were collected on days 15 and 17 of gestation via sinus orbital veini-puncture for plasma. Number of pups per litter was determined postpartum and fetal survival rate was expressed as a percentage of the corresponding implantation sites. Radioimmunoassays were used to determine plasma progesterone, estrogen, and prolactin (indirect measurement of decidual luteotropin) concentrations. Fetal survival among BaP-treated rats declined in a dose-dependent manner (25 μg/m³, 78.3% per litter; 75 μg/m³, 38.0% per litter; 100 μg/m³, 33.8% per litter; P<0.05) compared with CB (96.7% per litter) and UNC (98.9% per litter). Plasma progesterone, estrogen, and prolactin concentrations also declined as a result of subacute exposure of rats to BaP compared to controls. These data suggest that inhaled BaP compromised fetal survival and consequently luteotropic activity in the exposed animals.     

In vitro maturation of nascent reticulocytes to erythrocytes

Most studies of mammalian reticulocyte maturation have used blood reticulocytes.Nascent reticulocytes, as found in bone marrow, have not been available in developmentally synchronized populations. Nascent murine reticulocytes formed in vitro by enucleation of Friend virus-infected erythroblasts were purified and recultured for 110 hours. At 0 hours, all recultured cells were lobulated and contained dense, centralized reticulin. By 110 hours, about 20% to 25% of the cells became biconcave erythrocytes. Most ribosomes and cellular RNAs were degraded within 20 hours, and during that period, heme synthesis declined from a rate equal to that of late erythroblasts to less than 10% of that rate. Many mitochondria appeared normal until they showed outer membrane swelling, degradation, and apparent fusion with intracellular vacuoles at 40 hours of culture. During the period of mitochondrial loss, Bcl-X(L), an antiapoptotic protein that accumulates during erythroblast differentiation and maintains mitochondrial membrane integrity, demonstrated progressive decreases and changes consistent with deamidation. Nevertheless, the reticulocytes did not undergo apoptosis, because their apoptotic machinery was degraded. This experimental system that provides a developmentally synchronized population of nascent murine reticulocytes that mature into biconcave erythrocytes in vitro should be useful in further investigations of the cellular events involved in reticulocyte maturation.     

A prospective randomized study comparing retroperitoneal drainage with no drainage and no peritonization following radical hysterectomy and pelvic lymphadenectomy for invasive cervical cancer

OBJECTIVE: To evaluate the postoperative morbidity and lymphocyst formation in invasive cervical cancer patients undergoing radical hysterectomy and pelvic lymphadenectomy (RHPL) with no drainage and no peritonization compared with retroperitoneal drainage and peritonization. METHODS: Between July 1999 and May 2000, 100 patients with stage IA-IIA cervical cancer undergoing RHPL in Chiang Mai University Hospital were prospectively randomized to receive either no peritonization and no drainage (Group A = 48 cases) or retroperitoneal drainage and peritonization (Group B = 52 cases). Perioperative data and morbidity were recorded. Transabdominal and transvaginal sonography were performed at 4, 8 and 12 weeks postoperatively to detect lymphocyst formation. RESULTS: Both groups were similar regarding age, size and gross appearance of tumor, tumor histology and stage. There was no difference between groups in respect of operative time, need for blood transfusion, intraoperative complications, hospital stay, number of nodes removed, nodal metastases, and need for adjuvant radiation and chemotherapy. Asymptomatic lymphocysts were sonographically detected at 4, 8 and 12 weeks postoperatively in 3 (6.8%), 2 (4.6%), and 3 (7.7%) of 44, 43, and 39 patients, respectively in Group A, whereas none was found in Group B (P = 0.2). No significant difference was found in term of postoperative morbidity in the two groups. CONCLUSION: Routine retroperitoneal drainage and peritonization after RHPL for invasive cervical cancer can be safely omitted.