Modern management of acne.

Acne is a chronic inflammatory disease of the pilosebaceous unit resulting from androgen-induced increased sebum production; altered keratinisation; bacterial colonisation of hair follicles on the face, neck, chest and back by Propionibacterium acnes; and an inflammatory response in the skin. The exact way these processes interact and the order in which they occur in the pathogenesis of acne are still unclear. Scarring that occurs from acne, particularly severe acne, can persist a lifetime and have long lasting psychosocial effects. Depression, social isolation and suicidal ideation are frequent comorbidities in acne. Despite the plethora of topical and systemic treatments available for acne, there is a relative lack of quality evidence for its application. Of the systemic treatments available, oral isotretinoin remains the most effective well established treatment for acne that targets all the aetiological factors. Current guidelines for the treatment of acne are based largely on expert consensus and advocate a combination of topical agents in mild to moderate cases and reserve the use of systemic therapies for moderate to severe or refractory cases of acne. However, given the psychosocial impacts of acne, there is a strong argument for early, effective treatment with systemic therapy when topical and general measures have failed.

Atopic dermatitis: the new frontier.

Atopic dermatitis (AD) is the most common inflammatory skin condition in adults and children. AD is a chronic disease that has a considerable negative impact on the quality of life of patients and their families. Most cases of AD may be effectively treated with topical therapies that are directed at decreasing cutaneous inflammation and alleviating pruritus. These therapies include emollients, antihistamines, topical corticosteroids, topical calcineurin inhibitors and antimicrobial and antiseptic measures; more refractory cases may require additional oral immunosuppression (eg, cyclosporine, azathioprine, methotrexate and mycophenolate). Improved understanding of the immune pathogenesis of AD, including the role of T helper cells and the inflammatory pathways involved, has led to breakthrough translational clinical research and treatment. New targeted immunotherapies, such as inhibitors of interleukin (IL)-4, IL-13, IL-31, Janus associated kinase and phosphodiesterase, have had promising results from phase 2 and 3 trials for patients with moderate to severe AD.

Using Amplicon Sequencing To Characterize and Monitor Bacterial Diversity in Drinking Water Distribution Systems.

Drinking water assessments use a variety of microbial, physical, and chemical indicators to evaluate water treatment efficiency and product water quality. However, these indicators do not allow the complex biological communities, which can adversely impact the performance of drinking water distribution systems (DWDSs), to be characterized. Entire bacterial communities can be studied quickly and inexpensively using targeted metagenomic amplicon sequencing. Here, amplicon sequencing of the 16S rRNA gene region was performed alongside traditional water quality measures to assess the health, quality, and efficiency of two distinct, full-scale DWDSs: (i) a linear DWDS supplied with unfiltered water subjected to basic disinfection before distribution and (ii) a complex, branching DWDS treated by a four-stage water treatment plant (WTP) prior to disinfection and distribution. In both DWDSs bacterial communities differed significantly after disinfection, demonstrating the effectiveness of both treatment regimes. However, bacterial repopulation occurred further along in the DWDSs, and some end-user samples were more similar to the source water than to the postdisinfection water. Three sample locations appeared to be nitrified, displaying elevated nitrate levels and decreased ammonia levels, and nitrifying bacterial species, such as Nitrospira, were detected. Burkholderiales were abundant in samples containing large amounts of monochloramine, indicating resistance to disinfection. Genera known to contain pathogenic and fecal-associated species were also identified in several locations. From this study, we conclude that metagenomic amplicon sequencing is an informative method to support current compliance-based methods and can be used to reveal bacterial community interactions with the chemical and physical properties of DWDSs.

The skin microbiome: Associations between altered microbial communities and disease.

A single square centimetre of the human skin can contain up to one billion microorganisms. These diverse communities of bacteria, fungi, mites and viruses can provide protection against disease, but can also exacerbate skin lesions, promote disease and delay wound healing. This review addresses the current knowledge surrounding the healthy skin microbiome and examines how different alterations to the skin microbial communities can contribute to disease. Current methodologies are considered, changes in microbial diversity and colonisation by specific microorganisms are discussed in the context of atopic dermatitis, psoriasis, acne vulgaris and chronic wounds. The recent impact of modern Westernised lifestyles on the human skin microbiome is also examined, as well as the potential benefits and pitfalls of novel therapeutic strategies. Further analysis of the human skin microbiome, and its interactions with the host immune system and other commensal microorganisms, will undoubtedly elucidate molecular mechanisms for disease and reveal gateways for novel therapeutic treatment strategies.

Tissue factor dependent pathway and the diagnosis of pre-eclampsia.

Pre-eclampsia (P-EC) is a major contributor to perinatal and maternal morbidity and mortality worldwide. Its etiology and pathogenesis remains poorly understood, and differential diagnosis is problematic. During a normal pregnancy, coagulation activation is essential for physiological placental hemostasis, but women with P-EC tend to be more hypercoagulable than normal pregnant women. A common proposed mechanism for P-EC is utero-placental thrombosis. Indeed, multiple placental microthrombi are frequently observed in women with P-EC, and these may compromise placental perfusion and fetal development. This suggests that predisposing factors to thrombosis could contribute to the development of P-EC. Thus studying circulating hemostatic proteins may help elucidate some of the pathogenesis of P-EC and may provide a rational basis for its differential diagnosis and effective treatment. Preliminary studies by our group on third-trimester women suggest that raised circulating factor VII (FVII) is a selective marker for P-EC when women with P-EC were compared with healthy nonpregnant or normal pregnant women groups. Plasma FVII levels have shown good sensitivity and specificity for P-EC of 90% and 80%, respectively. However, significant comparable changes in the other tissue factor (TF)-dependent pathway factors (activated FVII), TF, and tissue factor pathway inhibitor were not observed. Thus we propose the use of plasma FVII as a potential marker of P-EC.

Platelet function in pre-eclampsia.

Pronounced hemostatic changes occur during pregnancy, and the balance shifts markedly in favor of hypercoagulability. Although primarily a result of a marked rise in the levels of several procoagulants and a fall in some natural anticoagulants, platelet activation also contributes to this prothrombotic tendency. Several studies have confirmed the accentuation of platelet activation in pre-eclampsia (P-EC), which remains an important obstetric complication affecting ~2 to 4% of pregnancies. Although there is still a long way to go, significant inroads have been made in the understanding of this enigmatic condition. Whereas the pathogenesis of P-EC is protean and involves a complex interplay of placental and maternal tissues, platelet activation is likely to contribute to several clinical features. Several techniques have been used to assess platelet activation in P-EC. Detection of aberrations of platelet function and activation appear to have predictive value for its diagnosis. The findings also lend support to the use of antiplatelet agents as prophylaxis in those women with a high risk of developing the condition.

Multidrug resistance in a urothelial cancer cell line after 1-hour mitomycin C exposure.

PURPOSE: A factor pertinent to the design of cancer chemotherapy is multidrug resistance. Research in this area conventionally involves in vitro models using resistant cell lines generated by continuous low dose drug exposure for many months, unlike the exposure experienced by residual superficial bladder cancer cells during chemotherapy adjuvant to resection. Recently we noted a measure of multidrug resistance induced by 3 short exposures to mitomycin C during 10 weeks. We currently report detectable functional resistance after a single 1-hour insult. MATERIALS AND METHODS: RT112 bladder cancer cells (Catalog No. ACC 418, Deutsche Sammlung von Mikroorganismen und Zellkulturen, Braunschweig, Germany) were exposed to a range of mitomycin C concentrations for 1 hour. Cells regrew in 3 of 24 cultures at 15.6, 3.91 and 0.98 mg/ml exposure. These cells were subjected to 3 functional tests of cross resistance to epirubicin, including MTT cytotoxicity assay, quantitative accumulation by flow cytometry and nuclear uptake or exclusion by live cell fluorescence microscopy. RESULTS: MTT assay and flow cytometry revealed clear indications of resistance. Intracellular distribution, in which nuclear exclusion indicates resistance, was distinctively resistant in 1 subline and another 2 were equivocal. CONCLUSIONS: Results indicate that some multidrug resistance potential exists even in a cloned cell line that is capable of surviving 1 short drug exposure and expanding after that insult. The exposures used are consistent with those probably experienced by many superficial transitional cell carcinoma cells during an intravesical chemotherapy application. The result gives added weight to considering multidrug resistance induction in dose scheduling or drug combinations for topical chemotherapy.

Detection and quantification of thrombomodulin in human semen.

The presence of fibrin degradation products, thrombin-like enzyme, prothrombin fragments, thrombin-activatable fibrinolysis inhibitor, plasmin and other active components of blood coagulation and fibrinolysis in seminal plasma has been reported. In the present study we investigate the presence of thrombomodulin in human semen. Using an Imubind thrombomodulin enzyme-linked immunosorbent assay (American Diagnostica Inc., Stamford, Connecticut, USA), seminal thrombomodulin levels were measured in 47 semen specimens obtained from subfertile individuals, normally fertile individuals, semen donors as well as vasectomized individuals, and in a further group defined by normality in several parameters derived from the World Health Organization fertility criteria. Conventional semen parameters were analysed in all semen samples. Thrombomodulin is quantifiable in human semen at a concentration lower than that normally found in citrated blood plasma samples. Slightly higher levels were seen for fertile stratifications compared with infertile individuals but without significant difference, given the numbers accrued. A vasectomized group showed the lowest value. In conclusion, our results establish the presence of thrombomodulin in human semen and suggest its production both upstream and downstream from the level of a vasectomy lesion.

Hemoglobinopathies in the Sudan.

In a prospective study, we evaluated hematological parameters in freshly obtained venous blood samples from 632 Sudanese patients attending the outpatient department at Khartoum Teaching Hospital, Khartoum, Sudan, in the period between March and July 2005. The patients were surveyed for full blood count (FBC) and hemoglobin (Hb) electrophoresis using a cellulose acetate method. Hb S [beta6(A3)Glu-->Val] was the most common abnormal Hb, which was not unexpected because the subjects live in the center of a malaria-affected area. The study showed low hematological parameters due to various causes including poor nutrition as well as infections and hemolytic processes.

Distribution of mast cell subtypes in interstitial cystitis: implications for novel diagnostic and therapeutic strategies?

AIMS: To identify the presence and geographical distribution of mast cell (MC) subtypes: MCT (tryptase positive-chymase negative) and MCTC (tryptase positive-chymase positive) in bladder tissue. METHODS: Bladder tissue was obtained from patients with painful bladder syndrome/interstitial cystitis (n=14) and normal histology from University Hospital Southampton tissue bank. Sequential tissue slices were immunohistochemically stained for MC subtypes using anti-MC tryptase (for MCT and MCTC) and anti-MC chymase (for MCTC). Stained sections were photographed, and positively stained MCs were quantified using ImageJ. Data were analysed using descriptive statistics and individual paired t-tests. RESULTS: There was a significant difference in the density of MCs between each layer of the disease bladder, with the greatest accumulation within the detrusor (p<0.001). There was a significant increase in MCTC subtype in the lamina (p=0.009) in painful bladder syndrome/interstitial cystitis. CONCLUSIONS: Our results suggest that mastocytosis is present within all layers of disease bladder, especially the muscle layer. The varying increase in MC subtypes in the lamina and mucosa may explain the variability in painful bladder syndrome/interstitial cystitis symptoms. A high influx of MCTC in the mucosa of individuals who also had ulceration noted within their diagnostic notes may be of the Hunner's ulcer subclassification. These findings suggest a relationship between the pathogenesis of MC subtypes and the clinical presentation of painful bladder syndrome/interstitial cystitis. A cohort study would further elucidate the diagnostic and/or therapeutic potential of MCs in patients with painful bladder syndrome/interstitial cystitis.

Tissue factor expression by a human kidney proximal tubular cell line in vitro: a model relevant to urinary tissue factor secretion in disease?

AIM: To study baseline and stimulated tissue factor (TF) production from a normal, albeit immortalised, human kidney proximal tubular cell line (HKC-5), in order to establish a model for investigating the role of inflammatory mediators in the increased urinary TF (uTF) seen in inflammatory and neoplastic disease. METHODS: TF procoagulant activity, expression and secretion in HKC-5 cells were investigated using TF activity and antigen assays, fluorescence confocal microscopy and immunocytochemistry. TF expression in the HKC-5 cells was also studied using reverse transcription (RT)-PCR and its synthesis was suppressed using antisense oligodeoxynucleotide (ODN), directed against human TF mRNA. Cells were stimulated, after serum deprivation, with bacterial lipopolysaccharide (LPS), an agonist known to enhance TF expression in monocytes. They were also subject to serum starvation. RESULTS: Analysis by RT-PCR showed TF production by stimulated and actively metabolising HKC-5 cells. Antisense ODN treatment resulted in approximately 50% suppression of TF synthesis compared to a mismatch ODN. The amount of TF produced by the HKC-5 cells was time dependent and coincides with a decrease in the intracellular TF levels. LPS up-regulated TF production in HKC-5 cells. Reducing fetal calf serum concentrations in the culture medium decreased TF production and secretion. CONCLUSION: Stimulated TF synthesis and secretion in vitro by HKC-5 cells is consistent with the hypothesis that uTF is produced by tubular cells influenced by mediators of disease states and provides a model for further mechanistic investigations.

Monocytes and plasma tissue factor levels in normal individuals and patients with deep venous thrombosis of the lower limbs: potential diagnostic tools?

INTRODUCTION: Tissue factor (TF) is the main physiological initiator of blood coagulation; it is membrane-bound on monocytes (mTF) and free in plasma (pTF). Abnormal expression of TF by monocytes has been implicated in various diseases. We therefore quantified monocytes expressing TF and pTF levels in patients with lower-limb deep venous thrombosis (DVT). MATERIALS AND METHODS: DVT was confirmed by Duplex Scan. Blood mTF levels under resting condition (baseline), after incubation without (unstimulated) and with (stimulated) lipopolysaccharide (LPS), and total mTF levels were determined by flow cytometry using two analytical methods (Histogram and Quadrant-Statistics). Plasma TF levels were measured using an enzyme-linked immunoabsorbent assay (ELISA). Results were compared with age-matched controls. RESULTS: Histogram analysis in patients with DVT showed significantly elevated mTF levels for baseline, unstimulated and total mTF over controls. For Quadrant-Statistics, DVT patients also showed significantly raised baseline, unstimulated, stimulated and total mTF. Similarly, pTF levels were significantly raised in subjects with DVT compared to controls. Baseline mTF levels correlated with pTF levels by Histogram and Quadrant-Statistics analysis. Using the relative operating characteristic (ROC) curve, baseline mTF and pTF assays displayed sensitivity and specificity in detecting DVT. Quadrant-Statistics baseline mTF and pTF gave the best discrimination. CONCLUSIONS: The TF assays used in this study showed acceptable sensitivity and specificity and are cost-effective and practical. Therefore, they should be considered in patients with, or at risk of, DVT.

Thrombin activatable fibrinolysis inhibitor (TAFI): a role in pre-eclampsia?

Pre-eclampsia (P-Ec) is a complex multisystem disorder of unknown aetiology reported to occur in about 6% to 8% of all pregnancies throughout the world. This disease is associated with fibrin deposition and occlusive lesions in placental vessels. Pro-thrombin activatable fibrinolysis inhibitor (pro-TAFI) is a relatively recently described glycoprotein that can be converted into its active form (TAFIa) by thrombin, thrombin-thrombomodulin and plasmin. TAFIa potentially inhibits fibrinolysis by removing C-terminal lysine and arginine residues from fibrin. These residues are required for adsorption of tissue-type plasminogen activator (t-PA) and plasminogen to fibrin. Therefore, TAFIa decreases plasmin formation and protects the fibrin clot against lysis. An increased of pro-TAFI/TAFIa levels has been reported in some clinical conditions associated with thrombotic tendency, as type II diabetes mellitus, deep vein thrombosis and symptomatic artery disease. Few studies have investigated pro-TAFI/TAFIa in normal or complicated pregnancy but contrasting results were reported. Understanding the role of pro-TAFI/TAFIa in the pathogenesis of P-Ec can hold great promise for improving P-Ec management. In this context, a large-scale study evaluating plasma TAFI antigen and activity, its synthesis and metabolism in pre-eclamptic women is required. Recently new selective TAFIa inhibitors have been developed. The design of a new therapy to treat and/or prevent P-Ec, based on successful use of TAFIa inhibitors, may have significant clinical ramifications.

Seminal thrombin-activatable fibrinolysis inhibitor: a regulator of liquefaction.

Several active components of the haemostatic system have been identified in human semen. Here we investigated the presence of thrombin-activatable fibrinolysis inhibitor (TAFI) in seminal plasma. Using an enzyme-linked immunosorbent assay, TAFI levels were measured in 36 semen specimens obtained from subfertile, normally fertile, fertile sperm donor and vasectomized individuals. TAFI was detectable in human semen. Its levels were highest in vasectomized individuals compared with the other groups, including a pooled normal semen parameter stratification group (by World Health Organization criteria). This elevation in the vasectomy group was found to be statistically significant in comparison with the normally fertile (P < 0.01) and the pooled normal semen parameter groups (P < 0.05). Seminal TAFI levels showed a significant positive correlation with total sperm count and sperm density. In contrast, a negative association was observed with semen volume, days of sexual abstinence and liquefaction time. The highly motile sperm group showed low TAFI levels. Our results establish the presence of TAFI in seminal plasma with a probable role in the protection of the seminal clot against lysis. It also suggests a downstream (post-testicular) source for its production. This reinforces the involvement of the conventional haemostatic system in the coagulation and liquefaction properties of human semen.

Tissue factor: a critical role in inflammation and cancer.

A series of coordinated enzymatic reactions takes place in the body whenever blood clots. The major physiological initiator of these reactions is a membrane-bound glycoprotein known as tissue factor (TF), which is normally separated from the bloodstream by the vascular endothelium. Bleeding, caused by injury or tissue damage, activates a complex enzyme cascade as TF becomes exposed to the bloodstream. In disease states, leukocytes or the vascular endothelium may abnormally express TF to cause intravascular coagulation. The blood-coagulation cascade is also relevant to diseases such as hemophilia, in which patients are deficient in blood proteins necessary for clotting, and is linked to vascular diseases such as heart attack and stroke, in which clotting can lead to the occlusion of blood vessels. Coagulation is also activated in inflammation and cancer. In this article, we discuss characteristics of TF and review its role in inflammation and cancer.

Diluted honey inhibits biofilm formation: potential application in urinary catheter management?

AIMS: Biofilms are ubiquitous and when mature have a complex structure of microcolonies in an extracellular polysaccharide and extracellular DNA matrix. Indwelling medical devices harbour biofilms which have been shown to cause infections and act as reservoirs for pathogens. Urinary catheters are often in place for considerable periods of time and are susceptible to both encrustation and biofilm formation. Strategies for minimising biofilm occurrence underpin an active research area in biomedicine. Manuka honey has, inter alia, well-established antibacterial properties. This study aims to assess the influence of honey on early biofilm formation in an established in vitro model. METHODS: An established model of early biofilm formation using static bacterial cultures in vinyl 96-well plates was used to grow Escherichia coli, strain ATC 25922 and Proteus mirabilis, strain 7002. Planktonic cells were removed and the residual biofilm was stained with crystal violet, which were subsequently eluted and quantified spectrophotometrically. Manuka honey (Unique Manuka Factor 15+) was added either with the bacteria or up to 72 hours after. RESULTS: Biofilms in this model was developed over 3 days, after which growth stalled. Mixed (1:1) cultures of E. coli and P. mirabilis grew slower than monocultures. In mixed cultures, honey gave a dose-dependent reduction in biofilm formation (between 3.3 and 16.7%w/v). At 72 hours, all concentrations inhibited maximally (p<0.001). Application of honey to cultures after 24 and 48 hours also reduced the adherent bacterial biomass (p<0.05-p<0.01). CONCLUSION: Manuka honey at dilutions as low as 3.3% w/v in some protocols and at 10% or above in all protocols tested significantly inhibits bacterial attachment to a vinyl substrate and reduces further early biofilm development. No augmentation of growth over untreated controls was observed in any experiment.

Tissue factor and tissue factor pathway inhibitor: a potential role in pregnancy and obstetric vascular complications?

Tissue factor (TF) is the principal cellular initiator of normal blood coagulation. As a result it is considered to be a major regulator of haemostasis and thrombogenesis. In vivo TF activity is regulated by specific circulating inhibitor known as "tissue factor pathway inhibitor (TFPI)". TF is also essential for other cellular processes including embryogenesis and angiogenesis as well as in implantation where it is particularly important in the first trimester. TF is highly expressed in syncytiotrophoblasts (STB) while TFPI is expressed in human umbilical vein endothelial cells (HUVEC). TFPI may be internalized via an endocytic pathway and recycled to the cell surface. The procoagulant tendency of STB may reflect a physiological need for immediate inhibition of hemorrhage in the placental intervillous spaces. Furthermore, the haemostatic balance involving STB and HUVEC may be critical for normal placental function and pregnancy outcome. Homozygous knockouts of both TF and TFPI are generally lethal in fetal mice; heterozygotes survive but with altered coagulation parameters. Despite their apparent association with placental microcirculation-thrombi-formation only few studies have addressed the role of TF and TFPI in the pathogenesis of gestational vascular complications. In this context, detailed studies could provide clinically relevant information.