Merkel cell carcinoma - a population-based epidemiological study in Finland with a clinical series of 181 cases

BackgroundMerkel cell carcinoma (MCC) is a rare malignancy of the skin, and its incidence is reported to be rising. The purpose of this study was to calculate its incidence and survival ratios, and to describe the clinical characteristics of Merkel cell carcinoma patients in Finland.MethodsWe calculated the incidence of MCC based on data from the Finnish Cancer Registry. In addition, patient files from hospitals and primary health care centres were reviewed for detailed data on the treatment and disease recurrence of 181 patients diagnosed with MCC in Finland during 1983–2004, and relative survival ratios were calculated for them.ResultsThe incidence (per 100,000) of MCC in Finland in 1989–2008 was 0.11 for men and 0.12 for women, adjusted for age to the world standard population. The mean age at diagnosis was 76 years (range 27–100), and 69% of the patients were women. The most common site of the primary tumour was the head and neck (53%). No extra benefit was gained from a wide surgical margin (⩾2 cm) compared to a margin of 0.1–0.19 cm, but an intralesional excision was more often associated with local recurrence. None of the patients with Stage I–II disease who had received postoperative radiotherapy to the tumour bed had a local recurrence. The 5-year relative survival ratio amongst men was 36% (95% confidence interval 20–54%), and amongst women 69% (56 to −82%).ConclusionsMCC is a rare disease in Finland, with incidence rates similar to those in the other Nordic countries. Our results support the view that complete excision with clear margins and post operative radiotherapy decrease local recurrences.     

RB1 gene in Merkel cell carcinoma: hypermethylation in all tumors and concurrent heterozygous deletions in the polyomavirus‐negative subgroup

Sequestration of the tumor suppressor retinoblastoma protein (RB) by the Merkel cell polyomavirus (MCV) is a crucial step in the pathogenesis of Merkel cell carcinoma (MCC). RB expression is frequently lost, particularly in MCV‐negative MCC tumors, through yet unknown mechanisms. We compared the genomic copy number changes of 13 MCV‐positive and 13 ‐negative MCC tumors by array comparative genomic hybridization. The analysis revealed increased genomic instability, amplification of 1p34.3–1p34.2, and losses of 11p in the absence of MCV infection. Deletions of the RB1 locus were also detected at high rates in MCV‐negative tumors. None of the tumors with heterozygous RB1 losses expressed RB in immunohistochemistry. RB1 promoter hypermethylation was studied with a methylation‐specific multiplex ligation‐dependent probe amplification technique. The RB1 promoter was methylated in all tumor specimens at CpG islands located close to the ATG start codon, albeit at low levels. The pattern of hypermethylation was similar in all MCC samples, despite RB expression, survival or MCV status. In conclusion, the frequent heterozygous losses of the RB1 locus could partly explain the decreased RB expression in MCV‐negative MCC tumors, although the effects of RB1 mutations, coinciding promoter hypermethylation and, for example, miRNA regulation, cannot be excluded.     

Potentially probiotic bacteria induce efficient maturation but differential cytokine production in human monocyte-derived dendritic cells

AIM： To analyze the ability of nine different potentially probiotic bacteria to induce maturation and cytokine production in human monocyte-derived dendritic cells （moDCs）.
METHODS： Cytokine production and maturation of moDCs in response to bacterial stimulation was analyzed with enzyme-linked immunosorbent assay （ELISA） and flow cytometric analysis （FACS）, respectively. The kinetics of mRNA expression of cytokine genes was determined by Northern blotting. The involvement of different signaling pathways in cytokine gene expression was studied using specific pharmacological signaling inhibitors.
RESULTS： All studied bacteria induced the maturation of moDCs in a dose-dependent manner. More detailed analysis with S. thermophilus THS, B. breve Bb99, and L. lactis subsp, cremoris ARH74 indicated that these bacteria induced the expression of moDC maturation markers HLA class Ⅱ and CD86 as efficiently as pathogenic bacteria. However, these bacteria differed in their ability to induce moDC cytokine gene expression. S. thermophilus induced the expression of pro-inflammatory （TNF-α, IL-12, IL-6, and CCL20） and Thl type （IL-12 and IFN-γ） cytokines, while B. breve and L. lactis were also potent inducers of antiinflammatory IL-10. Mitogen-activated protein kinase （MAPK） p38, phosphatidylinositol 3 （PI3） kinase, and nuclear factor-kappa B （NF-κB） signaling pathways were shown to be involved in bacteria-induced cytokine production. CONCLUSION： Our results indicate that potentially probiotic bacteria are able to induce moDC maturation, but their ability to induce cytokine gene expression varies significantly from one bacterial strain to another,     

Probiotic Leuconostoc mesenteroides ssp. cremoris and Streptococcus thermophilus induce IL-12 and IFN-γ production

AIM： To investigate the capacity of potentially probiotic strains from six bacterial genera to induce cytokine production alone or in combinations in order to identify potential enhancing or synergistic effects in order to select probiotic bacteria for in vivo purposes.
METHODS： Cytokine production in human peripheral blood mononuclear cells （PBMC） in response to stimulation with eleven different potentially probiotic bacterial strains from Streptococcus, Lactobacillus, Bifidobacterium, Lactococcus, L euconostoc a n d Propionibacterium genera was analysed. Production and mRNA expression of TNF-α, IL-12, IFN-y and IL-10 were determined by ELISA and Northern blotting, respectively.
RESULTS： All tested bacteria induced TNF-α production. The best inducers of Thl type cytokines IL-12 and IFN-y were Streptococcus and Leuconostoc strains. All BiHdobacterium and Propionibacterium strains induced higher IL-IO production than other studied bacteria. Stimulation of PBMC with any bacterial combinations did not result in enhanced cytokine production suggesting that different bacteria whether gram-positive or gram- negative compete with each other during host cell interactions.
CONCLUSION： The probiotic S. thermophilus and Leuconostoc strains are more potent inducers of Thl type cytokines IL-12 and IFN-γ than the probiotic Lactobacillus strains. Bacterial combinations did not result in enhanced cytokine production.     

Milk containing probiotic Lactobacillus rhamnosus GG and respiratory illness in children: a randomized, double-blind, placebo-controlled trial

Background/Objectives:To determine whether long-term daily consumption of milk containing probiotic Lactobacillus rhamnosus GG (GG) decreases respiratory illness in children.Subjects/Methods:A randomized, double-blind, placebo-controlled trial was conducted with 523 children aged 2-6 years attending day care centers in Finland. Subjects received either normal milk or the same milk with GG on three daily meals for 28 weeks. Daily recording of childrens' symptoms was done by parents. Primary outcome data from 501 subjects were available for analysis, and data from 128 subjects were analyzed as completed cases in terms of recovery of GG in fecal samples.Results:Number of days with at least one respiratory symptom in all subjects was 5.03/month (95% confidence interval (CI): 4.92-5.15) in the GG group and 5.17/month (95% CI: 5.05-5.29) in the placebo group incidence rate ratio (IRR) 0.97; 95% CI: 0.94-1.00; P=0.098). In the completed cases, the figures were 4.71 days/month (95% CI: 4.52-4.90) in the GG group and 5.67 days/month (95% CI: 5.40-5.94) in the placebo group (IRR 0.83; 95% CI: 0.78-0.88; P<0.001).Conclusions:Consumption of GG reduced the occurence of respiratory illness in children attending day care centers in the completed cases subgroup, but not in the total population. Thus, future clinical trials are warranted to clarify the association between fecal recovery of a probiotic and the symptom prevalence.     

Sentinel node biopsy in local anaesthesia in patients with head and neck Merkel cell carcinoma

The purpose of this study was to evaluate the applicability of sentinel lymph node (SLN) biopsy in patients with head and neck Merkel cell carcinoma (MCC). A prospective study for nine stage I MCC head and neck patients was conducted between 2001 and 2005. Patients underwent SLN biopsy in conjunction with radical tumour excision. Nine consecutive head and neck MCC patients were included, of whom five were women. All the patients were at stage I. In one patient, no SLNs could be localised on lymphoscintigraphy or perioperatively; eight patients underwent removal of one eight SLNs. None of the patients had any complications directly related to the SLNB. Those patients who demonstrated metastatic disease in the SLNs had waiting periods of 25 and 54 days, respectively. Only the free microvascular free flap reconstructions were done under general anaesthesia, the other reconstructions and the removal of the SLNs were done under local anaesthesia. Aggressive nature and the head and neck location of most MCCs is challenging for the surgeon. Patients are usually elderly with comorbities, which sets limits for anaesthesia. In our opinion, it is not mandatory to perform SLN biopsy under general anaesthesia.     

The effect of dimethyl sulfoxide (DMSO) on dentin bonding and nanoleakage of etch-and-rinse adhesives

Objective

The objective was to examine the effect of a solvent dimethyl sulfoxide (DMSO) on resin–dentin bond durability, as well as potential functional mechanisms behind the effect.

Methods

Microtensile bond strength (μTBS) was evaluated in extracted human teeth in two separate experiments. Dentin specimens were acid-etched and assigned to pre-treatment with 0.5 mM (0.004%) DMSO as additional primer for 30 s and to controls with water pre-treatment. Two-step etch-and-rinse adhesive (Scotchbond 1XT, 3M ESPE) was applied and resin composite build-ups were created. Specimens were immediately tested for μTBS or stored in artificial saliva for 6 and 12 months prior to testing. Additional immediate and 6-month specimens were examined for interfacial nanoleakage analysis under SEM. Matrix metalloproteinase (MMP) inhibition by DMSO was examined with gelatin zymography. Demineralized dentin disks were incubated in 100% DMSO to observe the optical clearing effect.

Results

The use of 0.5 mM DMSO had no effect on immediate bond strength or nanoleakage. In controls, μTBS decreased significantly after storage, but increased significantly in DMSO-treated group. The control group had significantly lower μTBS than DMSO-group after 6 and 12 months. DMSO also eliminated the increase in nanoleakage seen in controls. 5% and higher DMSO concentrations significantly inhibited the gelatinases. DMSO induced optical clearing effect demonstrating collagen dissociation.

Significance

DMSO as a solvent may be useful in improving the preservation of long-term dentin–adhesive bond strength. The effect may relate to dentinal enzyme inhibition or improved wetting of collagen by adhesives. The collagen dissociation required much higher DMSO concentrations than the 0.5 mM DMSO used for bonding.