Diesel exhaust particles exacerbate allergic rhinitis in mice by disrupting the nasal epithelial barrier.

BACKGROUND: Diesel exhaust particles (DEP), traffic-related air pollutants, are considered environmental factors that affect allergic diseases adversely. However, the exact effect of DEP on allergic rhinitis (AR) is unclear. OBJECTIVE: We thought to investigate the effect of DEP on seasonal AR using a mouse model. METHODS: Ragweed-pollen-sensitized mice were nasally challenged with ragweed pollen in the presence or absence of DEP. The frequency of sneezing was evaluated immediately after each nasal challenge. The expression of a tight junction (TJ) protein, zonula occludens-1 (ZO-1), was examined by immunohistochemistry in AR mice. RPMI 2650 cells were used for in vitro examination of paracellular permeability. RESULTS: Mice challenged with ragweed pollen plus DEP showed increased frequency of sneezing compared with mice challenged with pollen alone. Interestingly, intranasal DEP pretreatment before ragweed pollen challenge increased ragweed-pollen-induced sneezing to levels comparable with the co-administration group. In vitro examination revealed that DEP reduced ZO-1 expression in RPMI 2650 cells. In addition, intranasal administration of DEP, but not ragweed pollen, disrupted nasal mucosal TJs in vivo. The effect of a single DEP treatment on ragweed-induced sneezing and ZO-1 expression persisted for at least 4 days and was inversely correlated. Finally, an antioxidant substance, N-acetyl-L-cysteine, inhibited DEP-mediated TJ disruption and exacerbation of sneezing in AR. CONCLUSIONS AND CLINICAL RELEVANCE: DEP disrupts TJs by a reactive oxygen species-mediated pathway, leading to the increased permeability of nasal epithelial cells. This may result in the promotion of allergen delivery into subepithelial tissues contributing to the exacerbation of immediate allergic responses.

Facilitation of bone resorption activities in synovial lavage fluid patients with mandibular condyle fractures.

The aim of this study was to investigate the bone resorption effect of the mediators delivered in joint cavity of patients with mandibular condyle fractures by detecting osteoclast markers using cellular biochemistry methods, and by analysing bone resorption activities via inducing osteoclast differentiation of the infiltrated cells from arthrocentesis. Sixteen joints in 10 patients with mandibular condyle fractures were evaluated. The control group consisted of synovial fluid (SF) samples from seven joints of four volunteers who had no clinical signs or symptoms involving the temporomandibular joint (TMJ) or disc displacement. We collected SF cells from all patients during therapeutic arthrocentesis. The infiltrating cells from TMJ SF were cultured, differentiated into tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like cells and examined bone resorption activities. We also investigated factors related to osteoclast induction of SF, using ELISA procedures. Osteoclast-like cells were induced from the SF cells obtained from all patients with condylar fractures. These multinucleated giant cells were positive for TRAP and actin, and had the ability to absorb dentin slices. The levels of macrophage colony-stimulating factor (M-CSF), prostaglandin E2 (PGE2), soluble form of receptor activator of nuclear factor kappa-B ligand (sRANKL) and osteoprotegerin (OPG), in SF samples from the patients, were significantly higher than in the controls. These findings indicate that bone resorption activities in SF from patients with mandibular condyle fractures were upregulated and may participate in the pathogenesis and wound healing.

Plant homeodomain finger protein 11 promotes class switch recombination to IgE in murine activated B cells.

BACKGROUND: Polymorphisms of the Plant homeodomain finger protein 11 (PHF11) are strongly associated with high serum IgE levels and clinical severity of atopic patients. However, the precise mechanism has not been fully elucidated. We investigated the role of Phf11 in class switch recombination (CSR) to IgE by activated B cells. METHODS: We generated Phf11 transgenic (Lckd-Phf11-Tg) mice that express the exogenous murine Phf11 in lymphocytes under the control of distal Lck promoter. We examined IL-4-induced CSR to IgE in activated Lckd-Phf11-Tg B cells in vitro. We analyzed production of ovalbumin (OVA)-specific IgE and nose-scratching symptoms in Lckd-Phf11-Tg mice using an OVA-induced allergic rhinitis model. RESULTS: The exogenous Phf11 promoted CSR to IgG1 and IgE in activated B cells with an increase in germ line transcript (GLT) γ1 and GLT ε expression. The exogenous Phf11 augmented transcriptional activity of the GLT γ1 and GLT ε promoters through permissive histone modifications and binding of NF-κB and STAT6. Furthermore, the exogenous Phf11 bound to the GLT ε promoter with increased binding of NF-κB. Silencing of the endogenous Phf11 reduced the frequency of CSR to IgE and GLT ε expression, but not to IgG1 or GLT γ1 expression, in activated B cells. In an allergic rhinitis model, Lckd-Phf11-Tg mice showed a significant increase in the production of OVA-specific IgE and the frequency of nose scratching. CONCLUSION: Phf11 accelerates CSR to IgE in activated B cells by increasing the transcriptional activity of GLT ε promoter and contributes to the exacerbation of allergic responses. These findings provide a novel therapeutic target for allergic diseases.

In vitro action of sho-seiryu-to on allergen-exposed mononuclear cells.

Although Sho-seiryu-to (SST), used as a traditional herbal (Kampo) medicine mainly in China and Korea, is shown to have immunomodulating potential, such as an anti-allergic one, its underlying mechanism has not been completely clarified. To partially address the issue, we explored its effects on allergen-exposed mononuclear cells. Male balb/c mice were intraperitoneally administered ovalbumin (OVA: 20 μg) plus alum or vehicle twice (Day 0 and Day 14). At Day 21, mice were sacrificed and splenocytes (mononuclear cells) were isolated and cultured in the presence or absence of OVA with or without SST. Thereafter, helper T-related cytokines in the culture supernatants were evaluated by means of ELISA. Protein level of interferon-γ was lower than 5.0 pg/mL in the supernatants from OVA– non-exposed or -exposed mononuclear cells in the presence or absence of OVA stimulation. On the other hand, SST induced the cytokine from both types of mononuclear cells in the presence (P < 0.05) or absence of OVA stimulation as compared to corresponding control. By contrast, interleukin (IL)-4 level tended to be decreased by SST in OVA-non-exposed mononuclear cells as did IL-13 in both non-exposed and exposed mononuclear cells as compared to vehicle. In conclusion, immunoregulating efficacy by SST on allergy-prone subjects may include, at least in part, restoring helper T balance mainly through hyperproduction of IFN-γ against mononuclear cells such as lymphocytes.

Clinical comparison between arthrocentesis and conventional conservative treatment with maxillomandibular fixation for unilateral high condylar fractures.

This study aimed to compare the effects of arthrocentesis and conventional closed reduction for unilateral mandibular condyle fractures. A total of 30 patients with unilateral condylar fractures were evaluated. Patients with a high condylar fracture and magnetic resonance evidence of joint effusion (JE) were divided into two groups: those treated with intra-articular irrigation and betamethasone injection (group I) and those given conservative treatment and rigid maxillomandibular fixation (MMF) (group II). All patients were assessed for mandibular range of motion (ROM), protrusive movements, lateral excursion movements on the fractured and non-fractured sides, pain in the temporomandibular joint and malocclusion, both before and after treatment. There were no significant differences in regard to protrusion, lateral excursion movement and incidence of malocclusion at 12 months after treatment between the groups (P > 0.05). In group I, ROM and joint pain showed good improvement from the early stages of treatment, and those patients had better outcomes as compared to group II for those parameters at 1 and 3 months after injury. The present findings indicate that arthrocentesis may be more effective and provide faster healing than conventional closed reduction.

Suppression of aggregate formation and apoptosis by transglutaminase inhibitors in cells expressing truncated DRPLA protein with an expanded polyglutamine stretch.

To elucidate the molecular mechanisms whereby expanded polyglutamine stretches elicit a gain of toxic function, we expressed full-length and truncated DRPLA (dentatorubral-pallidoluysian atrophy) cDNAs with or without expanded CAG repeats in COS-7 cells. We found that truncated DRPLA proteins containing an expanded polyglutamine stretch form filamentous peri- and intranuclear aggregates and undergo apoptosis. The apoptotic cell death was partially suppressed by the transglutaminase inhibitors cystamine and monodansyl cadaverine (but not putrescine), suggesting involvement of a transglutaminase reaction and providing a potential basis for the development of therapeutic measures for CAG-repeat expansion diseases.

Identification of the spinocerebellar ataxia type 2 gene using a direct identification of repeat expansion and cloning technique, DIRECT.

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant, neurodegenerative disorder that affects the cerebellum and other areas of the central nervous system. We have devised a novel strategy, the direct identification of repeat expansion and cloning technique (DIRECT), which allows selective detection of expanded CAG repeats and cloning of the genes involved. By applying DIRECT, we identified an expanded CAG repeat of the gene for SCA2. CAG repeats of normal alleles range in size from 15 to 24 repeat units, while those of SCA2 chromosomes are expanded to 35 to 59 repeat units. The SCA2 cDNA is predicted to code for 1,313 amino acids-with the CAG repeats coding for a polyglutamine tract. DIRECT is a robust strategy for identification of pathologically expanded trinucleotide repeats and will dramatically accelerate the search for causative genes of neuropsychiatric diseases caused by trinucleotide repeat expansions.

Continuous partially hydrolyzed guar gum intake reduces cold-like symptoms: a randomized, placebo-controlled, double-blinded trial in healthy adults.

OBJECTIVE: Partially hydrolyzed guar gum (PHGG), a water-soluble dietary fiber produced by the controlled partial enzymatic hydrolysis of guar gum beans, has various physiological roles. PHGG is expected to influence the immune function and prevent infections. The objective of this study was to examine the effect of continuous ingestion of PHGG for 12 weeks on the development of cold-like symptoms. PATIENTS AND METHODS: A placebo-controlled, double blind, randomized, parallel-group comparative study was conducted. 96 healthy Japanese adults received 5.2 g PHGG or placebo daily for 12 weeks. Cold-like symptoms were assessed based on patient diary, and the levels of short-chain fatty acids (SCFAs) in stool and blood immune markers at baseline and at weeks 6 and 12. RESULTS: The cumulative number of "no symptoms" days for all symptoms was significantly larger in the PHGG than in the placebo group. The result of the analysis by severity of cold-like symptoms also showed significant differences, with the PHGG group having a lower severity of cold-like symptoms. Propionic acid at weeks 6 and 12 and n-butyric acid and total SCFAs at week 12 were significantly higher in the PHGG than in the placebo group. The Interferon-γ level was significantly lower at week 6 in the PHGG than in the placebo group. CONCLUSIONS: PHGG intake may affect immune function and suppress cold-like symptoms through the production of SCFAs in healthy adults.

Blister beetle dermatitis caused by cantharidin in South Sudan in Op TRENTON: a case series.

Cantharidin-producing blister beetles are found worldwide. The pathognomonic feature of their toxin is a blistering dermatitis that presents an environmental health hazard. Cutaneous exposure to cantharidin can produce blistering dermatitis, most commonly seen on exposed skin, in the Bentiu region of South Sudan. This should be treated with appropriate cleaning, debridement and regular dressing changes to cope with extensive initial exudate. The best dressing combinations found were initial treatment with povidone-iodine and hydrocolloid, followed by hydrocolloid only. Hydrocolloid dressings were found to be the most effective at staying in place with South Sudan's high humidity. Prevention strategies should include covering exposed skin, wearing wide-brimmed hats, neck scarves and enclosed footwear, and avoidance of working under white light. Medical personnel should engage with the chain of command to include appropriate force protection education within the arrivals brief.

In vitro self-renewal division of hematopoietic stem cells.

Little is known about how hematopoietic stem cells (HSCs) self-renew. We studied the regeneration of HSCs in culture. Effects of various cytokines on cell division of CD34(-/low) c-Kit(+)Sca-1(+) lineage marker-negative (CD34(-)KSL) bone marrow cells of the mouse were first evaluated in serum-free single cell culture. We then performed a competitive repopulation assay on divided cells to ask if such cell division involved self-renewal of HSCs. In the presence of stem cell factor (SCF), thrombopoietin (TPO) induced a first cell division of CD34(-)KSL cells more efficiently than did interleukin (IL)-3 or IL-6. Multilineage repopulating cells were detected in a significant proportion of cells derived from single cells in culture with TPO and SCF, although this culture condition led to a substantial decrease in HSC number. These regenerated repopulating cells could be further transplanted into secondary recipients. When paired daughter cells were separately studied, one of a pair gave rise to repopulating cells with self-renewal potential, suggesting asymmetric self-renewal division. This study provides evidence that one HSC regenerates at least one HSC in culture.

Impairment of antigen-presenting cell function in mice lacking expression of OX40 ligand.

OX40 expressed on activated T cells is known to be an important costimulatory molecule on T cell activation in vitro. However, the in vivo functional significance of the interaction between OX40 and its ligand, OX40L, is still unclear. To investigate the role of OX40L during in vivo immune responses, we generated OX40L-deficient mice and a blocking anti-OX40L monoclonal antibody, MGP34. OX40L expression was demonstrated on splenic B cells after CD40 and anti-immunoglobulin (Ig)M stimulation, while only CD40 ligation was capable of inducing OX40L on dendritic cells. OX40L-deficient and MGP34-treated mice engendered apparent suppression of the recall reaction of T cells primed with both protein antigens and alloantigens and a significant reduction in keyhole limpet hemocyanin-specific IgG production. The impaired T cell priming was also accompanied by a concomitant reduction of both T helper type 1 (Th1) and Th2 cytokines. Furthermore, antigen-presenting cells (APCs) derived from the mutant mice revealed an impaired intrinsic APC function, demonstrating the importance of OX40L in both the priming and effector phases of T cell activation. Collectively, these results provide convincing evidence that OX40L, expressed on APCs, plays a critical role in antigen-specific T cell responses in vivo.

Size effects of polystyrene nanoparticles on atopic dermatitislike skin lesions in NC/NGA mice.

Nano-sized particles are diffusing in the environment with the development of nanotechnology. Polystyrene (PS) nanoparticles are modified industrial products and pharmaceutical agents, however, adverse effects of PS nanoparticles remain to be elucidated. In the present study, we investigated the effects of PS nanoparticles with different sizes on the atopic dermatitis (AD)-like skin lesions in NC/Nga mice assumed to show the skin barrier defect/dysfunction in the presence or absence of mite allergen. Male NC/Nga mice were injected intradermally with three different-sized PS nanoparticles (25, 50, or 100 nm) and/or mite allergen into their right ears. We evaluated clinical scores, ear thickening, histological findings and the local protein expression of inflammatory molecules in the ear and Ig production in serum. PS nanoparticles aggravated AD-like skin lesions related to mite allergen, which was paralleled by the local protein levels of interleukin-4, CCL2/monocyte chemotactic protein-1, CCL3/macrophage inflammatory protein-1 alpha, and CCL4/macrophage inflammatory protein-1 beta. In contrast, PS nanoparticles decreased interferon-gamma expression. Furthermore, exposure to PS nanoparticles induced ear swelling and CC-chemokine expression in the absence of allergen. These effects were greater with the smaller PS nanoparticles than with the larger ones regarding overall trend. These results suggest that exposure to PS nanoparticles under skin barrier defect/dysfunction can exacerbate AD-like skin lesions related to mite allergen in a size-dependent manner. The enhancing effects may be accounted for by T helper 2-biased immune responses. Furthermore, PS nanoparticles can evoke skin inflammation via the overexpression of CC-chemokines even in the absence of allergen in atopic subjects.

Dietary supplementation with fructooligosaccharides attenuates airway inflammation related to house dust mite allergen in mice.

Fructooligosaccharides (FOS) are prebiotic supplements that can enhance immunological responses in the host to activate mucosal immunity, probably through regulation of gastrointestinal microflora. An area that has not been investigated, however, is the therapeutic potential of prebiotics on allergic airway diseases. The purpose of this study is to evaluate the effects of dietary supplementation with FOS on a murine model of allergic airway inflammation induced by the house dust mite allergen Dermatophagoides farinae (Der f). Male C3H/HeN mice were intratracheally administered with Der f and were fed a diet containing 0% or 2.5% FOS ad libitum. Supplementation with FOS alleviated mite allergen-related airway inflammation characterized by eosinophilic inflammation and goblet cell hyperplasia, which was evidenced by cytological and histological examinations. In addition, the FOS-supplemented diet reduced the serum allergen-specific IgG1 level as compared with a control diet in the presence of the mite allergen. Moreover, FOS tended to suppress the expression of IL-5 and eotaxin in the lungs, which is enhanced by mite allergen. These results suggest that dietary supplementation with FOS can prevent/improve allergic airway inflammation induced by the mite allergen. This effect can be at least partially associated with the inhibition of allergen-specific Ig production and probably with that of IL-5 and eotaxin expression.

Surgical correction for sinus venosus atrial septal defect with partial anomalous pulmonary venous connection in a dog.

A 5-year-old male toy poodle was referred for corrective surgery of an atrial septal defect. A sinus venosus-type atrial septal defect (ASD) with partial anomalous venous connection, suspected pulmonary hypertension, and pulmonary edema was confirmed by radiography, echocardiography, and cardiac computed tomography. Thoracic radiographs showed right heart enlargement. Echocardiography revealed right atrial and ventricular dilatation with mild flattening of the interventricular septum. Left-to-right shunt flow through the ASD was observed on color Doppler examination. Surgical correction of the sinus venosus ASD with a partial anomalous pulmonary venous connection was performed under cardiopulmonary bypass. A follow-up evaluation at 1 year after surgery showed resolution of the right-sided volume overload and no evidence of recurrence of ASD. Complications were not observed. Our findings indicate that surgical correction under cardiopulmonary bypass is a valid treatment option for an ASD with a partial anomalous pulmonary venous connection.

Occludin-deficient embryonic stem cells can differentiate into polarized epithelial cells bearing tight junctions.

Occludin is the only known integral membrane protein of tight junctions (TJs), and is now believed to be directly involved in the barrier and fence functions of TJs. Occludin-deficient embryonic stem (ES) cells were generated by targeted disruption of both alleles of the occludin gene. When these cells were subjected to suspension culture, they aggregated to form simple, and then cystic embryoid bodies (EBs) with the same time course as EB formation from wild-type ES cells. Immunofluorescence microscopy and ultrathin section electron microscopy revealed that polarized epithelial (visceral endoderm-like) cells were differentiated to delineate EBs not only from wild-type but also from occludin-deficient ES cells. Freeze fracture analyses indicated no significant differences in number or morphology of TJ strands between wild-type and occludin-deficient epithelial cells. Furthermore, zonula occludens (ZO)-1, a TJ-associated peripheral membrane protein, was still exclusively concentrated at TJ in occludin-deficient epithelial cells. In good agreement with these morphological observations, TJ in occludin-deficient epithelial cells functioned as a primary barrier to the diffusion of a low molecular mass tracer through the paracellular pathway. These findings indicate that there are as yet unidentified TJ integral membrane protein(s) which can form strand structures, recruit ZO-1, and function as a barrier without occludin.

Effect of nanoparticles on the male reproductive system of mice.

The effects of nanoparticles toward on the male reproductive system of mice were investigated. Three sizes (14, 56 and 95 nm) of carbon black nanoparticles were intratracheally administered (0.1 mg/mouse for 10 times every week) to ICR male mice to investigate their adverse effects on the reproductive function. The serum testosterone levels were elevated significantly in the 14- and 56-nm carbon nanoparticles-exposed groups. Histological examination showed partial vacuolation of the seminiferous tubules. In addition, the effects of particle number towards the male reproductive system were investigated. The particle number controlled 14-nm nanoparticles-exposed group (14 N group, which has approximately the same particle number per unit volume as the 56-nm nanoparticles) showed fewer effects than did the 56-nm nanoparticles-exposed groups. These results suggest that carbon nanoparticle-exposure has adverse effects on the mouse male reproductive function. Furthermore, the effects of nanoparticles on the male reproductive system depend on particle mass rather than particle number.

Rapid colorectal adenoma formation initiated by conditional targeting of the Apc gene.

Familial adenomatous polyposis coli (FAP) is a disease characterized by the development of multiple colorectal adenomas, and affected individuals carry germline mutations in the APC gene. With the use of a conditional gene targeting system, a mouse model of FAP was created that circumvents the embryonic lethality of Apc deficiency and directs Apc inactivation specifically to the colorectal epithelium. loxP sites were inserted into the introns around Apc exon 14, and the resultant mutant allele (Apc580S) was introduced into the mouse germline. Mice homozygous for Apc580S were normal; however, upon infection of the colorectal region with an adenovirus encoding the Cre recombinase, the mice developed adenomas within 4 weeks. The adenomas showed deletion of Apc exon 14, indicating that the loss of Apc function was caused by Cre-loxP-mediated recombination.