Mutations in Cytosine-5 tRNA Methyltransferases Impact Mobile Element Expression and Genome Stability at Specific DNA Repeats

The maintenance of eukaryotic genome stability is ensured by the interplay of transcriptional as well as post-transcriptional mechanisms that control recombination of repeat regions and the expression and mobility of transposable elements. We report here that mutations in two (cytosine-5) RNA methyltransferases, Dnmt2 and NSun2, impact the accumulation of mobile element-derived sequences and DNA repeat integrity in Drosophila. Loss of Dnmt2 function caused moderate effects under standard conditions, while heat shock exacerbated these effects. In contrast, NSun2 function affected mobile element expression and genome integrity in a heat shock-independent fashion. Reduced tRNA stability in both RCMT mutants indicated that tRNA-dependent processes affected mobile element expression and DNA repeat stability. Importantly, further experiments indicated that complex formation with RNA could also contribute to the impact of RCMT function on gene expression control. These results thus uncover a link between tRNA modification enzymes, the expression of repeat DNA, and genomic integrity.

Increased expression of exon 2 deleted MEFV transcript in familial Mediterranean fever patients

A defect in MEFV gene expression regulation has been implicated in familial Mediterranean fever (FMF) etiopathophysiology. Here we show significantly higher expression level in second exon lacking MEFV transcript in FMF patients compared with healthy controls (P=0.026). Our results also point out a possible role of exon 2 deleted MEFV transcript in FMF pathogenesis.

Cancer-related false knowledge in relatives of cancer patients and the general public

PURPOSE

Although there are many myths about cancer in Turkey, there is no study evaluating Turkish public's knowledge about cancer. The goals of our research were to: 1) measure the extent of knowledge of cancer among the Turkish public; 2) determine the differences in extent of cancer-related knowledge between participants who have relatives with cancer and those who do not; and 3) determine the sources of knowledge possessed.

METHODS

Data were obtained from a total of 415 participants (244 female, 171 male), all of them sitting at the Marmara University Faculty of Medicine Hospital (MUFMH) outpatient clinic waiting area for non-cancer-related reasons. Each participant completed a 3-part questionnaire. Appropriate statistical tests were used for comparison.

RESULTS

The mean age was 41 years. Of 415 participants, 65.3% stated that they had one or more cancer patient in their immediate family; 70.1% of the participants had a high-school education or greater. The questionnaire showed that, depending on the question, anywhere from 1.7% to 88.5% of the general public possesses some false information; furthermore, the difference in accuracy between relatives of cancer patients and non-relatives was marginal. Only 3 specific questions, related to the following ideas, rendered answers that were statistically significantly different between these 2 groups: breast cancer is only seen in females (p <0.005), cell phones cause cancer (p <0.001), and cancer is always very painful (p <0.001).

CONCLUSION

The proportion of false knowledge about cancer was unacceptably high in our cohort. Broader efforts should be made to inform the Turkish public about cancer.

Genotoxic effects of 1064-nm Nd:YAG and 532-nm KTP lasers on fibroblast cell cultures

BACKGROUND

Several different laser types are used in cutaneous surgery. The neodymium:yttrium-aluminium-garnet (Nd:YAG) and frequency-doubled Nd:YAG (KTP, potassium titanyl phosphate) lasers are widely used in dermatology.

OBJECTIVES

To investigate the possible genotoxic effects on fibroblasts of irradiation with a 1064-nm Nd:YAG laser and a 532-nm KTP laser.

METHODS

Fibroblast cell cultures were exposed to each of the lasers, using 10-mm spot size at 60 ms pulse duration with 10, 20, 40 J/cm(2) and 3, 6, 12 J/cm(2) fluences, respectively. Fibroblasts in passages 1-6 were used. During laser irradiation, 96-well microplate cultures were kept on a cooling block and transported on ice and in the dark, and processed immediately for single-cell gel electrophoresis (SCGE) assay (also known as a comet assay).

RESULTS

DNA damage was determined by computerized assessment of comet assay. There was increasing damage with increasing numbers of passages. For the Nd:YAG laser, the greatest damage occurred on passages 5 and 6, whereas the greatest damage appeared at passages 3 and 4 for KTP and returned to baseline at passages 5 and 6. Damage also increased with each dose increment for both wavelengths. At the highest dose for both wavelengths (Nd:YAG 40 J/cm(2) and KTP 12 J/cm(2)), damage was higher with the Nd:YAG laser.

CONCLUSIONS

Different patterns of cellular damage were seen for different cell-culture passages, treatment doses, and laser wavelengths. These dose ranges are generally used for the treatment of vascular and pigmented lesions and for rejuvenation purposes. As replicative ageing or cell senescence is one of the critical factors determining the extent of cell damage induced by laser therapy, these results may have important implications for clinical practice.

A case of Ferguson–Smith type multiple keratoacanthomas associated with keratoacanthoma centrifugum marginatum: response to oral acitretin

Keratoacanthoma centrifugum marginatum (KCM) is a rare entity, usually classified as solitary keratoacanthoma (KA). The Ferguson-Smith type is the most common form of multiple KAs. Because development of multiple KAs and KCM in a single patient has rarely been reported, this association presents a therapeutic challenge. We report a 46-year-old man with Ferguson-Smith multiple KAs and KCM, who was successfully treated with acitretin.

Lack of association between leptin G2548A gene polymorphism and Behçet's disease

BACKGROUND

Behçet's disease is a chronic, multisystem, inflammatory disease characterized by the predominance of T-helper 1 cytokines. The disease is also characterized by infiltration of lymphocytes and neutrophils into the affected tissues. Because cytokines are involved in the regulation of lymphocyte and phagocyte functions, they may play an important role in the pathogenesis of Behçet's disease. Leptin, a member of the gp 130 family of cytokines, induces a strong T-helper 1 response and is regarded as a proinflammatory inducer. Recent studies have shown that serum leptin concentration was increased in patients with Behçet's disease and correlated with disease activity.

OBJECTIVES

We aimed to investigate the role of G2548A polymorphism of leptin gene in patients with Behçet's disease and compare the results with healthy controls.

PATIENTS AND METHODS

A total of 93 subjects with Behçet's disease and 125 healthy controls were included in this study. Analyses of G-2548A polymorphism of the LEP gene were performed using the PCR-restriction fragment length polymorphism technique. The genotypes (GG, GA, and AA of leptin G2548A) and alleles (G and A of leptin 2548) were scored and the frequency was estimated. The frequencies of the alleles and genotypes in patients and controls were compared. We analysed the correlation between leptin gene polymorphism and the clinical features of BD.

RESULTS

Both genotype and allele frequencies were not significantly different between controls and Behçet's disease patients [OR=0.67, 95% CI (0.35-1.29), P=0.197 and OR=0.77, 95% CI (0.52-1.15), P=0.184]. We did not find any significant relationship between leptin gene polymorphism and the clinical features of BD (P>0.05).

CONCLUSION

In the present case-control study, we found no evidence of an association between the G-2548A variant of the leptin gene and BD among Turks. Further studies are needed to investigate serum leptin level to explain the mechanisms behind the lack of association between leptin G2548A gene polymorphism and BD.

Stevens-Johnson syndrome in two patients treated with cranial irradiation and phenytoin

Stevens-Johnson syndrome (SJS) is a severe cutaneous eruption that most often appears as an adverse reaction to medication. In this report, we present two patients diagnosed with SJS, which developed in patients with brain tumour, after receiving cranial irradiation and phenytoin. Concomitant application of these two therapies may play an important role in the occurrence of the disease.

Combination of narrow band UVB and topical calcipotriol for the treatment of vitiligo

BACKGROUND

Narrow band ultraviolet B (NB-UVB) phototherapy has been used successfully for the treatment of vitiligo. Recently, topical calcipotriol has also been claimed to be effective, either as monotherapy or as a part of combination therapies.

OBJECTIVE

The aim of the present study was to compare the clinical efficacy of NB-UVB and NB-UVB plus topical calcipotriol in the treatment of vitiligo.

METHODS

NB-UVB treatment was given to 24 patients with generalized vitiligo three times weekly. Topical calcipotriol cream was only applied to the lesions located on the right side of the body. Treatment was continued for 6 months. Treatment efficacy was evaluated by determining the average response rates of the lesions at 3-month intervals.

RESULTS

The average response rates of patients receiving combination of NB-UVB plus calcipotriol and NB-UVB alone were 51 +/- 19.6% and 39 +/- 18.9%, respectively. The median cumulative UVB dose and number of UVB exposures for initial repigmentation were 6345 mj/cm(2) (range; 2930-30980) and 18 (range; 12-67) for the combination therapy, and 8867.5 mj/cm(2) (range; 2500-30980) and 24 (range; 15-67) for the narrow band UVB therapy, respectively.

CONCLUSIONS

These findings indicate that concurrent topical calcipotriol potentates the efficacy of NB-UVB in the treatment of vitiligo. This combination not only provides earlier pigmentation with lower total UVB dosage and less adverse UVB effects, but also reduces the duration and cost of treatment as well.

Methotrexate and ciclosporin combination for the treatment of severe psoriasis

BACKGROUND

Psoriasis is a chronic skin disease that often requires long-term therapy to control the symptoms. Combination therapies for severe psoriasis have advantages for disease control and are thought to reduce long-term side-effects.

OBJECTIVE

To assess the efficacy and side-effects of methotrexate plus ciclosporin used in combination for the treatment of severe psoriasis.

METHODS

In this prospective study, 20 patients were treated with the combination of methotrexate and ciclosporin. Methotrexate was given intramuscularly as a single weekly dose of 10 mg and ciclosporin at a dose of 3.5 mg/kg/day in two equally divided doses. Clinical response was assessed according to clinical outcome and the Psoriasis Area and Severity Index which were evaluated at the beginning of therapy (PASI1), after cessation of one agent (PASI2), and at the end of therapy (PASI3).

RESULTS

All the patients had previously received one or more systemic treatment. There were 10 women and 10 men (mean age 44 years). The median (minimum to maximum) duration of methotrexate and ciclosporin treatments were 12.5 (4-55) and 14.0 (4-80) weeks, respectively. Median duration of combination therapy was 9.5 weeks (range 4-50). The median of previously used and end-of-study cumulative doses of methotrexate were 181.8 mg (range 0-785) and 330.8 mg (range 50-845), respectively. The median PASI scores were decreased by 77.4% (range 51.2-90.2) and 75.9% (range 10.1-100) at PASI2 and PASI3, respectively.

CONCLUSION

Patients with severe psoriasis had clinically significant improvement after the initiation of combination therapy. Healing rate was decreased upon cessation of one of the medications. Short-term side-effects were minor, transient and manageable. Long-term follow-up of patients treated with this combination is needed.

Neutrophilic dermatosis of the dorsal hands in a farmer

Neutrophilic dermatosis of the dorsal hands is a recently described disorder, which is similar to Sweet's syndrome. It is characterized by erythematous plaques, pustules and haemorrhagic bullae located solely on the dorsal surface of the hands. We describe a 57-year-old man with neutrophilic dermatosis of the dorsal hands that occurred following exposure to a chemical fertilizer. There are few cases reported in the literature regarding neutrophilic dermatosis and the aetiology remains unclear. For the present case, we propose that neutrophilic dermatosis of the dorsal hands might have been induced by the chemical fertilizer.

The role of ascorbic acid on collagen structure and levels of serum interleukin-6 and tumour necrosis factor-alpha in experimental lathyrism

Lathyrism is characterized by defective collagen synthesis due to inhibition of lysyl oxidase, an enzyme essential for interfibrillar cross-linking. The lathyritic agent beta-aminoproprionitrile (beta-APN) is considered an appropriate agent for studying connective tissue metabolism. We investigated the effects of ascorbic acid on collagen structure and serum cytokine levels in experimentally induced lathyrism. Forty Wistar rats weighing 200-300 g were used in the study: three test groups of 10 rats each (groups 2, 3 and 4) and 10 rats used as a control group (group 1). Experimental lathyrism was induced with daily subcutaneous injections of beta-APN in the test groups for 40 days. On the 40th day, skin biopsies were taken from the control group (group 1) and group 2, to evaluate the effect of beta-APN on dermal collagen. After the 40th day, 10 rats received ascorbic acid 100 mg/kg intraperitoneally daily for 15 days (group 3) and 10 rats (group 4) received no medication and served as a control for group 3. On the 55th day, skin biopsies were taken from groups 3 and 4. Serum concentrations of interleukin-6 and tumour necrosis factor-alpha were assessed in each group by enzyme-linked immunosorbent assay. Ultrastructural examination of the skin biopsies in group 1 revealed normal-appearing epidermal and dermal structures. Group 2 showed disorganization of the epidermis and collagen structure, and vacuolization of the endoplasmic reticulum in fibroblasts. In group 3, ultrastructural examination revealed significant improvement in the structure of dermal collagen after administration of ascorbic acid, whereas the changes in group 4 were unremarkable. Ascorbic acid administration significantly decreased the concentrations of serum cytokines in group 3 compared with group 2 (P < 0.001). Ascorbic acid administration significantly improved dermal collagen structure and serum cytokine levels in experimental lathyrism.

Overexpression of bcl-2 in lymphocytes of psoriatic skin

Bcl-2 overexpression in lymphocytes play an important part in immunological and inflammatory diseases. In the present study, we investigated the bcl-2 expression in dermal lymphocytes of psoriatic skin biopsy samples. From the archives of the Department of Pathology, Ondokuz Mayis University Medical School (Samsun, Turkey), tissue sections belonging to 28 psoriasis cases and 10 chronic non-specific inflammatory skin disease cases were immunohistochemically stained by bcl-2. Positive staining was semiquantitatively graded from 1+ to 4+. Of the 28 psoriasis cases 20 were found to express bcl-2. Our data suggest that bcl-2-mediated inflammation plays a part in the pathogenesis and recurrent character of psoriasis.

Expression of bcl-2 protein in active skin lesions of Behçet's disease

BACKGROUND

Expression of bcl-2 protein has been shown to play an important role in the pathogenesis of some inflammatory as well as neoplastic disorders. In this study we have investigated the presence of bcl-2 protein in active skin lesions of Behçet's disease and compared these results with normal skin samples of Behçet's disease (BD) patients and BD unrelated leukocytoclastic vasculitis.

METHODS

Active skin lesions of 23 Behçet's disease patients, normal skin samples of seven Behçet's disease patients, and archival biopsy specimens of 23 cutaneous leukocytoclastic vasculitis were investigated for the presence of bcl-2 protein by immunohistochemical methods. Results of staining were assessed semiquantitatively. Chi-square tests were used for statistical analysis.

RESULTS

Expression of bcl-2 protein were demonstrated in 16 of 23 (69.5%) and 8 of 23 (34.7%) patients with Behçet's disease and leukocytoclastic vasculitis, respectively. There were statistically significant difference between two groups (x2 = 4.27, P < 0.05). None of the normal skin samples of Behçet's disease patients showed bcl-2 expression.

CONCLUSION

Expression of bcl-2 protein may play a particular role in the development of skin lesions in Behçet's disease by causing prolonged survival of infiltrating lymphocytes.

Bcl-2 expression in skin pathergy reaction of Behçet's disease

BACKGROUND

Bcl-2 expression in leukocytes plays an important role in autoimmune and inflammatory disease.

OBJECTIVE

In the present study, we investigated the Bcl-2 expression in the skin pathergy reaction (SPR) of Behçet's disease (BD).

METHODS

The skin pathergy test (SPT) was performed on 23 patients with BD and 7 healthy controls. After 48 h, SPT specimens were taken by punch biopsy. Control samples were also obtained from the normal skin of 7 patients with BD and 11 patients with BD-unrelated leukocytoclastic vasculitis. Biopsy specimens were evaluated by routine histopathological examination and immunohistochemical Bcl-2 staining.

RESULTS

The SPT was clinically positive in 9 of 23 patients and histopathologically positive in 13 but never in the healthy controls. The majority of leukocytes in 12 of 13 histopathologically positive specimens were stained with Bcl-2. Only 3 BD-unrelated leukocytoclastic vasculitis samples showed Bcl-2 positivity. No Bcl-2 staining was found in healthy controls and normal skin samples of patients with BD.

CONCLUSION

Our data may suggest a role of Bcl-2-mediated inflammation in the pathogenesis of the SPR in BD.