The human microbiome in immunobullous disorders and lichen planus.

For several decades, there has been a significant growth in the incidence of autoimmune diseases. Studies indicate that genetic factors may not be the only trigger for disease development and that dysbiosis of the microbiome may be another mechanism involved in the pathogenesis of autoimmune diseases. The role of the microbiome in the development of common skin disorders such as psoriasis, atopic dermatitis, acne and rosacea is increasingly well understood. However, few studies have focused on lichen planus and the rare acquired immunobullous diseases, both mucocutaneous groups of disorders linked to skin, oral and gut microbiomes. This review provides an insight into the current understanding of how the microbiome may contribute to the development of autoimmunity and to the maintenance and exacerbation of acquired immunobullous and lichenoid diseases. These mechanisms may have implications for future preventive and therapeutic approaches.

A pilot study of the gingival response when smokers switch from smoking to vaping.

Introduction Tobacco smoking is one of the most important risk factors for periodontitis as it alters the host response to plaque. Although the prevalence of tobacco smoking has declined in recent years, the use of electronic-cigarettes (vaping) has increased. The effect of vaping on the gingiva is unknown and an evidence-base needs to be established before providing dental advice about the use of these products.Objective To compare the gingival health of a group of established smokers before and after substituting vaping for smoking tobacco.Design Pilot.Setting Guy's Dental Hospital (England) from April-December 2015.Materials and methods Twenty established smokers (all staff members at Guy's Hospital) with mild periodontal disease replaced their regular smoking habits with the use of e-cigarettes for two weeks.Main outcome measure The primary outcome measure of gingival inflammation was bleeding on probing. Levels of selected pro-inflammatory cytokines in GCF, saliva and serum samples were also determined.Results and conclusions There was a statistically significant increase in gingival inflammation when tobacco smokers switched from smoking to vaping for two weeks. However, this result must be interpreted with extreme caution since this is only a pilot study. Nonetheless, this study should provide a stepping stone to encourage further investigation of the effects of vaping on periodontal health.

The gut and oral microbiome in HIV disease: a workshop report.

Recent years have seen a massive expansion in our understanding of how we interact with our microbial colonists. The development of new, rapid sequencing techniques such as pyrosequencing and other next-generation sequencing systems have enabled us to begin to characterise the constituents of our diverse microbial communities, revealing the astonishing genetic richness that is our microbiome. Despite this, our ignorance of how these communities change over the course of an HIV infection is profound. Whilst some steps have been made to characterise the HIV microbiome at selected sites, these reports are still limited and much remains to be done. It has become apparent, however, that host-microbiota interactions are perturbed during HIV infections, with microbial translocation of potential pathogens linked to a variety of different HIV complications, including more rapid progression of disease. The use of probiotics and prebiotics has been investigated as treatments to alleviate symptoms for a variety of conditions, and is now being proposed for the treatment of symptoms associated with HIV. However, this is a new area of investigations and many questions remain unanswered. What we know about both of these topics is a drop in the ocean compared with what we need to know. In this article, we report on a workshop where these two major under-investigated research areas were presented, and future directions explored and discussed.

Innate immunity in HIV-1 infection: epithelial and non-specific host factors of mucosal immunity- a workshop report.

The interplay between HIV-1 and epithelial cells represents a critical aspect in mucosal HIV-1 transmission. Epithelial cells lining the oral cavity cover subepithelial tissues, which contain virus-susceptible host cells including CD4(+) T lymphocytes, monocytes/macrophages, and dendritic cells. Oral epithelia are among the sites of first exposure to both cell-free and cell-associated virus HIV-1 through breast-feeding and oral-genital contact. However, oral mucosa is considered to be naturally resistant to HIV-1 transmission. Oral epithelial cells have been shown to play a crucial role in innate host defense. Nevertheless, it is not clear to what degree these local innate immune factors contribute to HIV-1 resistance of the oral mucosa. This review paper addressed the following issues that were discussed at the 7th World Workshop on Oral Health and Disease in AIDS held in Hyderabad, India, during November 6-9, 2014: (i) What is the fate of HIV-1 after interactions with oral epithelial cells?; (ii) What are the keratinocyte and other anti-HIV effector oral factors, and how do they contribute to mucosal protection?; (iii) How can HIV-1 interactions with oral epithelium affect activation and populations of local immune cells?; (iv) How can HIV-1 interactions alter functions of oral epithelial cells?

Epithelial discrimination of commensal and pathogenic Candida albicans.

All mucosal surfaces are lined by epithelial cells and are colonised by opportunistic microbes. In health, these opportunistic microbes remain commensal and are tolerated by the immune system. However, when the correct environmental conditions arise, these microbes can become pathogenic and need to be controlled or cleared by the immune system to prevent disease. The mechanisms that enable epithelial cells to initiate the 'danger' signals activated specifically by pathogenic microbes are critical to mucosal defence and homeostasis but are not well understood. Deciphering these mechanisms will provide essential understanding to how mucosal tissues maintain health and activate immunity, as well as how pathogens promote disease. This review focuses on the interaction of the human fungal pathogen Candida albicans with epithelial cells and the epithelial mechanisms that enable mucosal tissues to discriminate between the commensal and pathogenic state of this medically important fungus.

Oral epithelial cells and their interactions with HIV-1.

As the AIDS pandemic has continued, our understanding of the events that occur during the entry and infection of conventional, susceptible cells has increased dramatically, leading to the development of control therapies for HIV-infected individuals. However, an ongoing hole in our understanding is how HIV crosses the mucosal barriers to gain access to permissive cells, despite how important this information would be in developing successful vaccines and other preventative measures such as topical anti-HIV microbicides. In particular, our knowledge of the role that epithelial cells of the mucosal surfaces play in infection - both during early phases and throughout the life of an infected individual, is currently hazy at best. However, several studies in recent years suggest that HIV can bind to and traverse these mucosal epithelial cells, providing a reservoir of infection that can subsequently infect underlying permissive cells. Despite this interaction with epithelial cells, evidence suggests HIV-1 does not productively infect these cells, although they are capable of transferring surface-bound and transcytosed virus to other, permissive cells. Further, there appear to be key differences between adult and infant epithelial cells in the degree to which HIV can transcytose and infect the epithelium. Thus, it is clear that, whilst not primary targets for infection and virus replication, epithelial cells play an important role in the infection cycle and improving our understanding of their interactions with HIV could potentially provide key insights necessary to develop effective preventative therapies.

Epithelial cell innate response to Candida albicans.

With the advent of treatments and diseases such as AIDS resulting in increasing numbers of patients with suppressed immune systems, fungal diseases are an escalating problem. Candida albicans is the most common of these fungal pathogens, causing infections in many of these patients. It is therefore important to understand how immunity to this fungus is regulated and how it might be manipulated. Although work has been done to identify the receptors, fungal moieties, and responses involved in anti-Candida immunity, most studies have investigated interactions with myeloid or lymphoid cells. Given that the first site of contact of C. albicans with its host is the mucosal epithelial surface, recent studies have begun to focus on interactions of C. albicans with this site. The results are startling yet in retrospect obvious, indicating that epithelial cells play an important role in these interactions, initiating responses and even providing a level of protection. These findings have obvious implications, not just for fungal pathogens, but also for identifying how host organisms can distinguish between commensal and pathogenic microbes. This review highlights some of these recent findings and discusses their importance in the wider context of infection and immunity.

Relative efficiency of two warming devices during laparoscopic cholecystectomy.

Intraoperative hypothermia is a known consequence of general anaesthesia. Forced air warming devices are commonly used to prevent hypothermia in anaesthesia, but there are limited data on the use of radiant warming devices. Previous trials comparing the efficacy of forced air and radiant warming devices have reported discordant results. The current study evaluated the efficacy of these devices during elective laparoscopic cholecystectomy, where surgery was expected to last > 60 minutes. Twenty-nine patients were randomised to either a forced air warming device (Warm-touch; group 1, n = 15) or a radiant warming device applied to the face (Sun-touch; group 2, n = 14). All fluids were given via a standardised fluid warmer set at 41 degrees C. Oesophageal temperature was measured every 15 minutes until the end of the procedure. Between-group, over-time temperatures and interaction were analysed using a linear mixed model. Statistical significance was ascribed at P < or = 0.05. The median (range) time of surgery was 90 (60 to 180) minutes. Mean (SD) oesophageal temperatures in the Warm-touch and Sun-touch groups were at 15 minutes 36.2 (0.30) degrees C and 36.2 (0.57) degrees C, and at 90 minutes 36.2 (0.44) degrees C and 35.9 (0.29) degrees C respectively. There was no statistically significant temperature difference between groups (P = 0.69) or over time (P = 0.61), and no interaction between time and treatment group (P = 0.97). Postoperative headache was recorded in four Sun-touch and no Warm-touch patients (P = 0.04). No difference in the efficacy of the Sun-touch warming device compared with the Warm-touch was demonstrated. Operational-mode side-effects may limit the use of the Sun-touch device.

[Fiber-optic bronchoscopic biopsy of bronchial smooth muscle. Efficacy of the technique in individuals with normal lung function and patients with COPD]. / Biopsia de músculo liso bronquial mediante fibrobroncoscopia. Eficacia de la técnica en individuos con función pulmonar normal y en pacientes con EPOC.

BACKGROUND AND OBJECTIVES: The epithelium and airway smooth muscles of patients with chronic obstructive pulmonary disease (COPD) or bronchial asthma undergo certain structural changes that are probably related to increased expression of inflammatory molecules and cell growth factors. Studying the relation between disease and changes in bronchial smooth muscle is difficult if investigation is restricted to samples from autopsies or thoracotomies. This study was designed to evaluate the probability of obtaining bronchial smooth muscle by endoscopic bronchial biopsy in patients with COPD and from individuals with normal lung function, the relation of disease to bronchial epithelial histology, and the potential usefulness of studying airway muscle remodeling events. METHODS: Forty-two patients undergoing diagnostic fiberoptic bronchoscopy were enrolled. Bronchial biopsies were taken systematically from the lobar and segmental dividing ridges. The epithelial structure was analyzed by conventional histology. The smooth muscle was identified by immunohistochemistry (anti-desmin antibody assay) and Western-blot analysis (anti-desmin, actin and myosin antibodies). RESULTS: Sixty-nine percent of the biopsies contained bronchial smooth muscle. The probability of obtaining smooth muscle was higher in segmental than in lobar biopsies (72 vs 30%, p < 0.05). This probability was unrelated to the presence of COPD or to signs of epithelial inflammation. The fragments allowed us to use electrophoresis to identify protein structures (myosin, actin, desmin) involved in muscle remodeling processes. CONCLUSIONS: Endoscopic biopsy of the bronchi allows us to obtain bronchial smooth muscle samples in a large percentage of patients, particularly when performed on segmental bronchi. The technique may be useful for future studies examining the processes of airway smooth muscle remodeling.

Contact activation in shock caused by invasive group A Streptococcus pyogenes.

OBJECTIVES: The aim of this study was to characterize abnormalities of coagulation in mice with experimental, invasive group A, streptococcal shock, in an attempt to explain the prolongation of the activated partial thromboplastin time identified in patients with streptococcal toxic shock syndrome. DESIGN: A longitudinal descriptive animal model study of coagulation times and single coagulation factors in mice infected with Streptococcus pyogenes. This was followed by an experimental study to determine whether streptococci or streptococcal products could activate the human contact system in vitro. SETTING: University infectious diseases and hemostasis molecular biology laboratories. SUBJECTS: CD1 outbred mice. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Coagulation times, single factor assays, and bradykinin assays were conducted on murine plasma at different times after streptococcal infection and compared with uninfected mice. In experiments in which streptococcal products were co-incubated with human plasma, we compared coagulation times, single factor assays, and activities against a range of chromogenic substrates with control plasma. In a murine model of streptococcal necrotizing fasciitis, the activated partial thromboplastin times were significantly prolonged in infected mice compared with controls, whereas prothrombin times were normal, suggesting an isolated abnormality of the intrinsic pathway. Bleeding was not seen. Prolongation of activated partial thromboplastin time was associated with reduced factor XII and prekallikrein, whereas levels of factors VIII, IX, XI, and high molecular weight kininogen were elevated. In vitro studies suggested that streptococcal supernatants can activate prekallikrein, in addition to causing plasminogen activation through the action of streptokinase. CONCLUSIONS: Prolongation of activated partial thromboplastin time in streptococcal toxic shock syndrome is associated with activation of the contact system, possibly contributing to the profound shock associated with streptococcal toxic shock syndrome.

An epithelial cell line that can stimulate alloproliferation of resting CD4+ T cells, but not after IFN-gamma stimulation.

It has previously been shown that IFN-gamma-induced up-regulation of HLA class II on the surface of epithelial cells is not sufficient to induce proliferation of allospecific CD4+ T cells in vitro. To further investigate this phenomenon, a human epithelial bladder carcinoma, T24, was induced to constitutively express HLA class II without IFN-gamma stimulation, by permanent transfection with the full-length class II transactivator (CIITA) gene. Proliferation of allospecific T cells to transfected and wild-type cells with and without prior activation with saturating levels of IFN-gamma for 4 days was examined. IFN-gamma-activated T24 did not induce any response from CD4+ T cells. However, T24.CIITA induced significant levels of alloproliferation, which could be abrogated by pretreatment of T24.CIITA with a mAb to LFA-3. Prestimulation of T24. CIITA with saturating levels of IFN-gamma for 4 days also prevented allospecific CD4+ T cell proliferation. These findings suggest that epithelial cells may be intrinsically able to process and present alloantigen and provide adequate costimulation. We propose that IFN-gamma has a secondary, as yet unidentified, effect that acts to negatively regulate this response, at least in some epithelial cells.

Small tidal volume ventilation using a zero deadspace tracheal tube.

The zero deadspace tracheal tube (ZEDS-TT) is a double-lumen endobronchial tube with a truncated bronchial limb. Functionally it is unrelated to the familiar endobronchial tube used in lung isolation surgery. It is placed in the same position as a regular tracheal tube and, by means of special connectors, one limb is used for inspiration and the other for expiration, thereby greatly reducing anatomical and apparatus deadspace. In this study, we have compared respiratory and ventilatory effects of reduction of tidal volume (VT) via a single-lumen tracheal tube and the ZEDS-TT during controlled ventilation with a Siemens Elema 900C Servo ventilator. Eleven consenting adult patients (ASA I and II) undergoing elective peripheral surgery were studied. Starting at a VT value of 10 ml kg-1, data were recorded for each tube type. VT was reduced by 2.5 ml kg-1 every 10 min and stabilized data recorded. Minute volume was kept constant by increasing ventilatory frequency at each reduction in VT. We found that the ZEDS-TT produced a significant reduction in PaCO2 and airway pressure for any VT used, while maintaining oxygenation.

Core temperature changes during open and laparoscopic colorectal surgery.

BACKGROUND: Perioperative hypothermia increases the morbidity of surgery. However, the true incidence of hypothermia during prolonged laparoscopic surgery is still unknown. To investigate this issue, we compared the temperature change between patients undergoing open and laparoscopic colorectal surgery. METHODS: Sixty consecutive patients who were undergoing laparoscopic (33) or open (27) colorectal surgery had a transesophageal temperature probe placed after induction of anesthesia. Core temperature values were measured at 15-min intervals. RESULTS: The groups were not statistically different with respect to age, sex, body surface area, or initial transesophageal temperature. The type of surgical access (open or laparoscopic) caused no difference in the incidence of hypothermia. The use of a forced-air warming device produced significantly less hypothermia during laparoscopic surgery. Men showed significantly less variability in temperature change than women. CONCLUSIONS: The incidence of hypothermia in open and laparoscopic colorectal surgery is similar. Forced-air warming devices are of value in prolonged laparoscopic surgery. A gender difference in the response to a hypothermic situation has not been previously reported. This finding warrants further investigation.

Anaesthetic breathing circuit obstruction due to blockage of tracheal tube connector by a foreign body--two cases.

Two cases are presented which illustrate the disastrous consequences possible when an anaesthetic breathing circuit is obstructed by a foreign body. Despite reports of previous similar cases, work practices and equipment manufacture or design continue to allow for such events to occur. The importance of both pre-anaesthetic testing of the entire circuit including attachments such as the tracheal tube connector and filters, and the removal of these parts should obstruction occur, is emphasised. Use of "clear" transparent breathing circuit components and opaque or brightly coloured packaging and caps which could potentially cause obstruction should decrease the incidence and facilitate the diagnosis of this problem.

A comparison of primary endothelial cells and endothelial cell lines for studies of immune interactions.

The purpose of this study was to assess the suitability of using endothelial cell (EC) lines for studies of endothelial/immune interactions. The immortal human EC lines HMEC-1, ECV304 and EaHy926 were compared to human umbilical vein endothelial cells (HUVEC) for constitutive and induced expression of surface antigens known to be involved in interactions with T cells. These cell lines were also compared to HUVEC in transendothelial migration assays. Flow cytometry was used to measure cell surface expression of platelet/endothelial cell adhesion molecule-1 (PECAM-1), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, major histocompatibility complex (MHC) class I and MHC class II, CD40, CD95 (fas) and lymphocyte function associated antigen-3 (LFA-3) before and after treatment with the cytokines tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma). Polymerase chain reaction (PCR) was used to detect expression of the MHC class II transactivator. Significant differences were found in the ability to respond to cytokines between HUVEC and the cell lines, the greatest differences being induction of VCAM-1 and E-selectin in response to TNF-alpha and induction of MHC class II antigens in response to IFN-gamma. Thus unlike HUVEC, induction of VCAM-1 and E-selectin was not detectable on EaHy926 and ECV304 and barely detectable on HMEC-1. MHC class II antigens were not induced on ECV304 in response to IFN-gamma and nor was the class II transactivator (CIITA). Unlike HUVEC and the other cell lines, ECV304 were constitutively negative for PECAM-1. Constitutive and induced expression of MHC class I, ICAM-1, LFA/3, CD40 and fas were most conserved between the cell lines and showed little difference to HUVEC. The migration of peripheral blood mononuclear cells (PBMC) through all cell lines was significantly reduced compared to through HUVEC, suggesting that there is a functional difference between the cell lines with regard to interactions with lymphocytes. In conclusion this study has demonstrated significant differences in the ability of endothelial cell lines to respond to cytokines compared to primary HUVEC cultures. In particular ECV304 compares very poorly with HUVEC. Whether these differences are caused by immortalization procedures or reflect heterogeneity of EC arising from different vascular beds is discussed.

Rapid tracheal intubation with propofol, alfentanil and a standard dose of vecuronium.

We studied 60 ASA I patients with Mallampati grade 1 airways to compare emergency intubating conditions with either alfentanil 20 micrograms kg-1, propofol 2.5 mg kg-1 and vecuronium 0.1 mg kg-1, or with thiopentone 5 mg kg-1 and suxamethonium 1 mg kg-1. Ease of laryngoscopy, vocal cord status and cough response were graded. The trachea of all patients was intubated; 83% of patients in the alfentanil-propofol-vecuronium group and 86% in the thiopentone-suxamethonium group were considered to have satisfactory intubating conditions at 60 s. We conclude that the combination of alfentanil 20 micrograms kg-1, propofol 2.5 mg kg-1 and vecuronium 0.1 mg kg-1 provided adequate conditions for rapid tracheal intubation.

The role of nitric oxide in experimental murine sepsis due to pyrogenic exotoxin A-producing Streptococcus pyogenes.

Nitric oxide (NO) produced by inducible NO synthase (iNOS) mediates hypotension in endotoxemia. In this study, NO induction by a toxin-producing Streptococcus pyogenes isolate, H250, and by recombinant streptococcal pyrogenic exotoxin A (rSPEA) has been examined, both in vitro and in vivo. Streptococcal supernatants, but not rSPEA, induce production of nitrite by murine macrophages when both are coincubated with gamma interferon. Intraperitoneal injection of rSPEA did not cause significant production of NO. However, an elevated level of nitrate in serum was detected in a model of streptococcal fasciitis due to live H250. iNOS was localized to Kupffer cells, hepatocytes, and renal tubular cells by immunostaining. Administration of a NOS inhibitor, N(G)-monomethyl-L-arginine (L-NMMA), reduced peak concentrations of nitrate in serum but did not affect survival. NO is induced by H250, both in vitro and in vivo, mainly via SPEA-independent mechanisms. In this model, iNOS is expressed predominantly in the liver. Furthermore, in this model L-NMMA is not protective.

Lymphotoxin-alpha (TNF-beta) during sepsis.

T cell release of lymphotoxin-alpha (LT-alpha, or TNF-beta) is stimulated by pyrogenic exotoxins of Gram-positive bacteria and mitogens. In contrast to TNF-alpha, it is unknown whether LT-alpha plays any role in the pathogenesis of sepsis and, in particular, the pathogenesis of Gram-positive sepsis. Sera from patients with sepsis were examined for LT-alpha and compared with normal volunteers and pregnant women. LT-alpha was detected in 33% of sepsis sera (mean 608.4 pg/ml SE 306), 16% of normal sera (mean 167 pg/ml SE 87) and 23% of sera from pregnant women (mean 714 pg/ml SE 191). These differences were not significant and there were no differences within sepsis sera when grouped by the type of causative organism, or disease severity. LT-alpha detected by immunoassay in serum was not bioactive, in contrast to that produced in cell culture. Recombinant soluble TNF receptors (rSTNFR) neutralized the bioactivity of recombinant LT-alpha at rSTNFR concentrations which did not interfere with immunoreactivity and which are known to prevail in vivo. Hence, LT-alpha is unlikely to have a critical role in the pathogenesis of sepsis. Much of the potential bioactivity of this lymphokine may be abrogated by TNFR in serum.