The Role of Galectin-3: From Oligodendroglial Differentiation and Myelination to Demyelination and Remyelination Processes in a Cuprizone-Induced Demyelination Model.

The aim of this work was to combine our previously published results with our new data to show how galectin-3 (Gal-3) controls myelin integrity and function, promotes oligodendroglial cell differentiation, and regulates microglial responses to limit cuprizone- (CPZ)-induced demyelination and foster remyelination. In this study, 8-week-old Gal-3-deficient (Lgals3 -/-) and wild type (WT) mice were fed a diet containing 0.2 % CPZ w/w for 6 weeks, after which CPZ was withdrawn in order to allow remyelination. Our results show that remyelination was less efficient in Lgals3 -/- than in WT mice. Electron microscopic images from remyelinated sections in Lgals3 -/- mice revealed collapsed axons with a defective myelin wrap, while remyelinated WT mice had normal axons without relevant myelin wrap disruption. MMP-3 expression increased during remyelination in WT but not in Lgals3 -/- mice. The number of CD45+, TNFα+ and TREM-2b+ cells decreased only in WT mice only, with no alterations in Lgals3 -/- mice during demyelination and remyelination. Therefore, Gal-3 influences remyelination by mechanisms involving the tuning of microglial cells, modulation of MMP activity, and changes in myelin architecture.

Effect of interferon-ß1b on CXCR4-dependent chemotaxis in T cells from multiple sclerosis patients.

Multiple sclerosis (MS) is an inflammatory, demyelinating and neurodegenerative disease triggered by infiltration of activated T cells into the central nervous system. Interferon (IFN)-ß is an established, safe and effective treatment for patients with relapsing-remitting MS (RRMS). The cytokine can inhibit leucocyte infiltration into the central nervous system; however, little is known about the precise molecular mechanisms. Previously, in vitro application of IFN-ß1b was shown to reduce CXCL12/CXCR4-mediated monocyte migration. Here, we analysed the effects of IFN-ß1b on CXCR4-dependent T cell function. In vitro exposure to IFN-ß1b (1000 U/ml) for 20 h reduced CXCR4-dependent chemotaxis of primary human T cells from healthy individuals and patients with RRMS. Investigating the IFN-ß1b/CXCR4 signalling pathways, we found no difference in phosphorylation of ZAP70, ERK1/2 and AKT despite an early induction of the negative regulator of G-protein signalling, RGS1 by IFN-ß1b. However, CXCR4 surface expression was reduced. Quantitative real time-PCR revealed a similar reduction in CXCR4-mRNA, and the requirement of several hours' exposure to IFN-ß1b supports a transcriptional regulation. Interestingly, T cells from MS patients showed a lower CXCR4 expression than T cells from healthy controls, which was not reduced further in patients under IFN-ß1b therapy. Furthermore, we observed no change in CXCL12-dependent chemotaxis in RRMS patients. Our results demonstrate clearly that IFN-ß1b can impair the functional response to CXCR4 by down-regulating its expression, but also points to the complex in vivo effects of IFN-ß1b therapy.

T cell participation in autoreactivity to NC16a epitopes in bullous pemphigoid.

Bullous pemphigoid is a blistering skin disease characterized by autoantibodies against the NC16a domain of bullous pemphigoid 180. This study was performed to characterize and map the fine specificity of T cell responses to NC16a. Peripheral blood mononuclear cells (PBMC) from a total of 28 bullous pemphigoid patients and 14 matched controls were tested for proliferative and cytokine responses to recombinant NC16a and a complete panel of 21 overlapping peptides spanning this region of BP180. Proliferative responses to NC16A and the peptide panel in the patients with active disease were similar in frequency and magnitude to those in healthy donors, and included late responses typical of naive cells in approximately 60% of each group. Interleukin (IL)-4 responses were slightly stronger for six peptides, and significantly stronger for Nc16a, in patients than in controls. Factor analysis identified factors that separate responses to the peptide panel discretely into IL-4, T helper type 2 (Th2) pattern, interferon (IFN)-γ, Th1 pattern and IL-10 or transforming growth factor [TGF-ß, regulatory T cell (Treg )] pattern. Factors segregating IL-10 versus IFN-γ were predicted by active blistering or remission, and TGF-ß or IL-10 versus IFN-γ by age. Finally, we confirmed a significant up-regulation of IgE responses to BP180 in the patients with pemphigoid. This shows the complexity of T cell phenotype and fine autoreactive specificity in responses to NC16A, in patients and in normal controls. Important disease-associated factors determine the balance of cytokine responses. Of these, specific IL-4 and IgE responses show the strongest associations with pemphigoid, pointing to an important contribution by Th2 cytokines to pathogenesis.

2-Chlorodeoxyadenosine (cladribine) induces apoptosis in human monocyte-derived dendritic cells.

2-Chlorodeoxyadenosine (cladribine, CdA) is an immunosuppressive drug that is licensed to treat hairy cell leukaemia, and has been shown recently to have beneficial effects in patients with multiple sclerosis (MS). The therapeutic effects of CdA have been suggested to be mediated partly through its potent toxicity towards lymphocytes. However, the effects of CdA on other immune cells are poorly understood. In the present study, we investigated the effects of CdA on the induction of apoptosis in human monocytes, monocyte-derived immature (ImDC) and mature (mDC) dendritic cells. Treatment of monocytes with CdA strongly induced apoptosis after 24 h, while apoptosis induction in DC was evident after 72 h. Furthermore, CdA treatment strongly induced caspase-3 and caspase-9 in monocytes, whereas activation of caspases was undetected in DC. The mitochondrial membrane potential in DC was reduced significantly after CdA treatment. DNA hypodiploid assessment showed fragmented nuclei in DC after CdA treatment together with activation of p53 protein. These results revealed that CdA induces caspase-independent apoptosis in DC and suggest cell type specific effects of CdA. This mechanism may contribute to the effect of CdA in autoimmune diseases.

Immunohistochemical localization, purification, and characterization of human urinary bladder glutathione S-transferases.

This study describes immunohistochemical localization, purification and characterization of glutathione S-transferase (GST) of human urinary bladder. Even though all the three major classes of isoenzymes (alpha, mu, and pi) were expressed in human bladder, more than 90% of total GST activity was accounted for by a pi class anionic form. Human bladder alpha, mu, and pi class GSTs were immunologically related to respective isoenzymes of other human tissues. GST pi was present in all 13 samples analyzed, whereas GST alpha and mu were detected in nine and eleven samples, respectively. GST alpha of human bladder appeared to be unique, because unlike this class of GSTs of other human tissues, bladder enzyme had lower affinity for GSH linked to epoxy-activated Sepharose 6B affinity resin. Immunohistochemical staining indicated localization of GST alpha in epithelial surface cells, underlying submucosa and smooth muscle, whereas mu and pi class isoenzymes were predominantly distributed in epithelial surface cells. These results suggest that human bladder GSTs may play an important role in providing protection against xenobiotics because epithelium is considered a target for several carcinogens and all the three classes of isoenzymes are expressed in these cells.

Effect of diallyl sulfide, a naturally occurring anti-carcinogen, on glutathione-dependent detoxification enzymes of female CD-1 mouse tissues.

The present studies were undertaken to elucidate the mechanism(s) of the anti-neoplastic effect of diallyl sulfide (allyl sulfide, DAS), a naturally occurring organosulfide abundant in vegetables of the Allium genus, against benzo[a]pyrene (B[a]P)-induced carcinogenesis in the mouse. DAS treatment caused a significant increase in glutathione S-transferase (GST) activity, an enzyme system responsible for detoxification of a variety of electrophilic xenobiotics including several harmful B[a]P metabolites, of mouse stomach in a dose-dependent manner. This activity in the stomach of mice treated with 25, 50 and 75 mumol DAS was higher by 1.13-, 1.20- and 1.58-fold, respectively, when compared to the control. Purification and quantitation of GST from equal amounts (1.2 g) of control and 50 mumol DAS-treated mice stomach tissues demonstrated that elevation in activity occurred as a result of increased de novo synthesis of the enzyme protein. DAS treatment also resulted in increased pulmonary GST activity, but not in a dose-dependent fashion. On the other hand, treatment of mice with DAS did not alter hepatic GST activity. Interestingly, a small but statistically significant (P less than or equal to 0.05) reduction in kidney GST activity was observed in mice treated with 50 or 75 mumol DAS, as compared to the control. The effect of DAS treatment was also assessed on glutathione (GSH) peroxidase activity, another GSH-dependent detoxification enzyme, in mouse tissues. Treatment of animals with 25, 50 and 75 mumol DAS increased stomach GSH peroxidase activity by 1.64-, 1.93- and 2.52-fold, respectively, over the control. This enzyme activity in the lungs of mice treated with 25, 50 and 75 mumol DAS was higher by 1.44-, 1.54- and 1.21-fold, respectively, when compared to the control. On the other hand, GSH peroxidase activity in liver and kidney was unchanged by DAS treatment. These results suggest that DAS and perhaps other naturally occurring organosulfur compounds may exert an anti-neoplastic effect by modulating GSH-dependent detoxification enzymes.

Remyelination after cuprizone induced demyelination is accelerated in mice deficient in the polysialic acid synthesizing enzyme St8siaIV.

Polysialic acid (PSA) is a carbohydrate polymer added post-translationally on the neural cell adhesion molecule (NCAM) affecting its adhesion properties. It has been suggested that the presence of PSA in demyelinated lesions in multiple sclerosis could prevent axon-glia interactions inhibiting spontaneous remyelination. The enzyme St8siaIV is one of the two polysialyltransferases responsible for PSA synthesis, and it is predominantly active during adult life. Here we treated 8-10-weeks old St8siaIV deficient and wild-type mice for 5 weeks with cuprizone, which is a reliable model for de- and remyelination in the corpus callosum and cortex. Developmental myelination of the St8siaIV knock-out mice was not disturbed and adult mice showed normal myelin protein expression. Demyelination did not differ between transgenic and wild-type mice but early myelin protein re-expression and thus remyelination were accelerated in St8siaIV knock-out mice during the first week after withdrawal of the toxin. This was mainly due to enhanced oligodendrocyte precursor cells (OPC) differentiation and to a lesser extent to OPC recruitment. These data are proof of principle that PSA expression interferes at least to some extent with remyelination in vivo.

Extramammary Paget's disease--occupational exposure to used engine oil and a new skin grafting technique.

SUMMARY: Extramammary Paget's disease (EMPD) is a rare intraepithelial adenocarcinoma, affecting mainly 50-70-year-olds with a female preponderance of 3:1. Exposure to polyaromatic hydrocarbons (PAHs) is associated with a substantial risk of skin cancer. We report a case of 64-year-old male with longstanding occupational exposure to used engine oil presenting with EMPD of the left scrotum and groin.

Management of basal cell carcinoma by surveyed dermatologists in Scotland.

BACKGROUND: The British Association of Dermatologists (BAD) has produced guidelines for management of basal cell carcinoma (BCC) in the UK. OBJECTIVES: Our primary objectives were to assess the management of BCCs in Scotland and to compare it with BAD guidelines. Our secondary objectives were to audit waiting times and referral patterns. METHODS: In phase I of the audit, dermatologists in 14 centres across Scotland prospectively registered demographic and clinical data of all lesions suspected to be BCCs over a 6-week period between October and December 2000. In phase II, details of management of these lesions were evaluated by case note review. RESULTS: Of the 48 consultant dermatologists contacted, 42 took part in the survey. There were 524 clinically suspected BCCs seen in 470 patients; 164 lesions in 146 patients showed pathology other than BCC and were excluded from analysis, thus leaving 360 lesions available for analysis. There was wide variation in waiting times among Scottish dermatology centres. BCCs were equally distributed between the sexes, and lesions most commonly presented in those aged 71-80 years. A diagnostic biopsy was taken in 22% of lesions, and the rest were treated definitively after a clinical diagnosis of BCC, of which 90% were confirmed on histology. Nodulocystic lesions were the most common type of tumour, comprising 48% of lesions, and most BCCs were located on the head and neck region. Correlation of the histological type of BCC and treatment received showed that nodulocystic and morpheic BCCs were managed as recommended. There were more superficial BCCs treated with surgical excision than expected (22 of 34 lesions). Four of 21 recurrent tumours and 9 of 81 tumours on high-risk areas of the face were managed with curettage and cautery or cryotherapy, rather than surgical excision. Of the 297 excised tumours, 25 (9%) were incompletely excised. All the high-risk tumours and incompletely excised tumours were offered follow-up in the dermatology clinics. CONCLUSIONS: In general, BCCs are managed according to BAD guidelines in Scotland, but waiting times vary considerably.

A randomized trial of topical 5% 5-fluorouracil (Efudix cream) in the treatment of actinic keratoses comparing daily with weekly treatment.

BACKGROUND: Topical 5-fluorouracil (5-FU) cream is widely used in the treatment of actinic keratoses (AKs) but the optimum treatment regimen that provides efficacy while minimizing side-effects remains unclear. OBJECTIVES: A randomized trial to compare the efficacy and side-effects of daily vs. weekly application of 5% 5-FU in the treatment of AKs of the scalp and face. PATIENTS/METHODS: Twenty patients were recruited and randomized to two groups. Group 1 (13 patients) applied 5% 5-FU twice daily for 3 weeks, group 2 (seven patients) applied 5% 5-FU twice daily for 1 day per week for 12 weeks. Patients were reviewed at weeks 3, 12, 24 and 52. At each review a lesion count and lesion map were completed and patients were asked to score efficacy and inflammation. RESULTS: At week 0 the median lesion count was the same in both groups, 17.5 lesions. At 12 weeks the median lesion count in group 1 had fallen to 0 where it remained for the duration of follow-up. In group 2 the median lesion count fell to 6 at 12 weeks, 5.5 at 24 weeks and was 3 at 52 weeks. The difference in the lesion count was significant at all time points after week 0: P < 0.05 at weeks 12 and 52, and P < 0.01 at week 24. The mean inflammation score was higher in patients clear of AKs at 12 weeks compared with those who had not cleared, 3.8 compared with 1.9. This difference was statistically significant (P < 0.05) suggesting that inflammation is necessary for efficacy. CONCLUSIONS: We conclude that daily application of 5% 5-FU cream is more effective than weekly application at clearing AKs from the scalp and face. Our results also suggest that inflammation is likely to be required to achieve a therapeutic effect.

Annual incidence and mortality of bullous pemphigoid in the Grampian Region of North-east Scotland.

BACKGROUND: Data on the annual incidence of bullous pemphigoid (BP) in the U.K. are scarce. OBJECTIVES: To estimate the annual incidence of BP in Grampian Region (North-east Scotland) and to assess the causes of mortality in this cohort of patients. METHODS: Details were obtained of all patients with a diagnosis of BP recorded in the database of the Pathology Department, Aberdeen Royal Infirmary between January 1991 and December 2001. Community Health Index population data were obtained from the Grampian Health Board and the annual incidence and age- and sex-specific incidence were calculated. Mortality data were obtained from the Patient Administration System and causes of death obtained from the Office of the Registrar for Births and Deaths for Scotland. RESULTS: Eighty-three patients met criteria for diagnosis of BP. The annual incidence of BP in Grampian region was estimated to be 14 cases per million per year. There was a clear and marked rise in the incidence in patients over the age of 80 years. Forty-eight per cent of patients with BP died within 2 years of diagnosis. The all-cause age-standardized mortality ratio was 576%. When compared with cause-specific mortality in the Grampian population over 60 years of age, respiratory disease accounted for a higher than expected number of deaths in our cohort of patients with BP (odds ratio 5.3, 95% confidence interval 3.0-9.4). CONCLUSIONS: North-east Scotland appears to have a relatively high incidence of BP when compared with incidence rates in continental Europe. The mortality rate in patients with BP is considerable, especially within the first 2 years of diagnosis.

Pyoderma gangrenosum complicating bilateral mammaplasty.

Pyoderma gangrenosum (PG) is an idiopathic necrotising cutaneous disorder. It is associated with systemic diseases like inflammatory bowel disease, monoclonal gammopathy, arthritides and haematological malignancy. PG occurring at sites of trauma, a phenomenon called pathergy, is well described. One of the manifestations of pathergy is PG occurring at sites of surgery. We describe a case of PG at sites of reduction mammaplasty and review the literature so far.

Squamous cell carcinoma in an area of necrobiosis lipoidica diabeticorum: a case report.

Ulceration in an area of necrobiosis lipoidica diabeticorum is a frequent complication but malignant transformation is rare. One such case is reported in a diabetic patient and the literature is reviewed.

Amplification dynamics of human-specific (HS) Alu family members.

We have investigated the distribution of several recently inserted Alu family members within representatives of diverse human groups. Human population studies using 65 unrelated human DNA samples, as well as a familial study to test inheritance, showed that individual Alu family members could be divided into three groups. The first group consisted of relatively older Alu family members which were monomorphic (homozygous) throughout the population tested (HS C3N1 and C4N6). The second group (HS C4N2, C4N5 and C4N8), apparently inserted into other repetitive regions of the genome, resulting in inconclusive results in the PCR test used. However, it is clear that these particular Alu insertions were present in a majority if not all of the loci tested. The third group was comprised of three dimorphic Alu family members (HS C2N4, C4N4 and TPA 25). Only a single Alu family member (TPA 25) displayed a high degree of dimorphism within the human population. This latter example also showed different allele frequencies in different human groups. The isolation and characterization of additional highly dimorphic Alu family members should provide a useful tool for human population genetics.