Analysis of 4-nitroquinoline-1-oxide induced mutations at the hprt locus in mammalian cells: possible involvement of preferential DNA repair

Mutation spectra induced by 4-nitroquinoline 1-oxide (4NQO)at the hprt locus for both normal (AA8) and 4NQO-sensitive (UV5)Chinese hamster ovary cells were determined to investigate theeffect of DNA repair on the nature of induced mutations. TheUV5 cell line is three times more sensitive to 4NQO than theAA8 parental cell line. In UV5 cells, the dGuo-N2-AQO adduct,which is considered to be the most toxic and mutagenic adductin Escherichia coli, is poorly repaired. The molecular natureof 30hprt mutants isolated from AA8 and 20 isolated from UV5cells was determined by sequence analysis of in vitro amplifiedhprtcDNA. Both similarities and differences emerged. In bothcell lines we found that (i) 4NQO is basically a base substitutionmutagen acting almost exclusively at G residues and (ii) G transversionsare prevalent over G transitions in both cell lines, independentlyfrom the ability to repair dGuo-N2-AQO. A high proportion (13/25)of splice mutations was observed in AA8 cells, statisticallydifferent (P < 0.04, Fisher‘s exact test) from theincidence of splice mutants in UV5 cells (4/20). In AA8 mutants,all but two of the point mutations were due to lesions localizedon the non-transcribed strand, suggesting preferential repairof the transcribed strand. Compared with AA8, the proportionof mutants due to lesions present on the transcribed strandwas higher in UV5 cells, as expected if a preferential repairmechanism was impaired in the sensitive cell line. Our dataare consistent with the molecular defect in DNA repair recentlycharacterized in UV5. ³To whom correspondence should be addressed     

Comparison of scintigraphy with indium-111 leukocyte scan and ultrasonography in assessment of x-ray-demonstrated lesions of crohn's disease

The aim of this study was to compare the results obtained with an indium-111 scan with those obtained with less expensive and harmless ultrasonography to evaluate the location and inflammatory activity of Crohn's disease. Thirty-one patients previously studied with x-ray underwent abdominal¹¹¹In scans and ultrasonography (US). Sensitivity and specificity of US in detecting lesions seen with¹¹¹In scan were 77% and 92.8%, respectively. Sensitivity and specificity of¹¹¹In scan in detecting x-ray-defined lesions were 69.2% and 92.7%; the figures for US were 73% and 93.3%, respectively. Considering the evaluation of disease activity, ultrasonographic bowel wall thickness was significantly related to scintigraphic intensity of emission (r=0.75 P<0.01). Our experience suggests that US provided information about the location and inflammatory activity of lesions similar to that obtained from¹¹¹In scan.     

Rifabutin as salvage therapy for Helicobacter pylori eradication: Cornerstones and novelties

When several Helicobacter pylori eradication treatments fail, guidelines recommend a cultured guided approach; however, culture is not widely available. Therefore, a rifabutin based regimen could be the best solution. Rifabutin indeed shows a low rate of antibiotic resistance. Rifabutin is generally used in combination with amoxicillin in a triple therapy, with eradication rates about 80% in third-line regimens. The ideal duration of this therapy should range between 10 and 12 d. Combinations with antibiotics other than amoxicillin have demonstrated even better results, such as vonoprazan, which is a type of novel acid suppressor drug. Finally, a new formulation of triple therapy in a single capsule is under investigation, which is a field that deserves further investigation. Some notes of caution about rifabutin should be mentioned. This drug is used to treat tuberculosis or atypical mycobacteria; therefore, before starting a rifabutin-based eradication regimen, Mycobacterium tuberculosis infection should be thoroughly tested, since its use could promote the development of antibiotic resistance, thus affecting its effectiveness against Koch’s bacillus. Additionally, some serious side effects must be evaluated before starting any rifabutin-based therapy. Adverse effects include fever, nausea, vomiting and bone marrow suppression. For this reason, full blood count surveillance is required.     

The possible utility of steroids in the prevention of relapses of Crohn's disease in remission. A preliminary study

In Crohn's disease, prednisone is believed to be ineffective for relapse prevention. Because all patients with Crohn's Disease Activity Index lower than 150 and with some altered lab tests (erythrocyte sedimentation rate, C-reactive protein, alpha-1-acid glycoprotein, alpha-1-acid antitrypsin, and white blood cell count) had a clinical relapse in 18 months of follow-up, we tried to ascertain whether methylprednisolone could reduce the risk of clinical relapse in such patients. Eighteen patients were included in a controlled study against placebo. Nine patients were treated with methylprednisolone at a dosage of 0.25 mg/kg daily for a period of 6 months; treatment was discontinued if disease relapsed or if lab tests were normalized. During the steroid treatment, 1 of 9 patients showed a clinical relapse; in 7, the normalization of lab tests was obtained; in 5 of these 7 patients a relapse occurred within 1 month after the suspension of the treatment; in 1 patient, lab tests remained altered. In those 9 patients on placebo, relapses occurred in 7. We conclude that methylprednisolone was effective in the prevention of relapses for patients in clinical remission but with altered lab tests.     

HBsAg clearance by Peg-interferon addition to a long-term nucleos(t)ide analogue therapy

The ideal endpoint of hepatitis B virus (HBV) antiviral therapy is HBsAg loss, a difficult goal to obtain, especially in HBeAg negative patients. Herein, we report the results obtained by the addition of peg-interferon α-2a to a long-lasting nucleos(t)ide analogue therapy in a HBeAg negative, genotype D patient with steadily HBV-DNA negative/HBsAg positive values. In 2002, our Caucasian 44-year-old male patient received lamivudine and, 4 years later, added adefovir because of a virological breakthrough. In 2011, considering his young age, liver stiffness (4.3 kPa) and HBsAg levels (3533 IU/mL), we added Peg-interferon α-2a for six months (3 in combination with nucleos(t)ide analogues followed by 3 mo of Peg-interferon α-2a monotherapy). A decrease of HBsAg levels was observed after 1 mo (1.21 log) of Peg-interferon and 3 mo (1.88 log) after the discontinuation of all drugs. Later, a complete clearance of HBsAg was obtained with steadily undetectable HBV-DNA serum levels (< 9 IU/mL). HBsAg clearance by the addition of a short course of Peg-interferon α-2a represents an important result with clinical and pharmaco-economic implications, considering that nucleos(t)ide analogues therapy in HBeAg negative chronic hepatitis B patients is considered a long-lasting/life-long treatment.     

Bosentan fosters microvascular de-remodelling in systemic sclerosis

Bosentan, a dual endothelin receptor antagonist, may reduce blood pressure by blocking the vasoconstrictor effect of endothelin-1. In systemic sclerosis (SSc) nailfold videocapillaroscopy (NVC); allows diagnostic and follow-up of microvascular damage. Distinct NVC patterns have been identified for the evaluation of severity of SSc microvascular damage. The objective of this study is to evaluate the modification of the microvasculature under Bosentan therapy in SSc patients with pulmonary arterial hypertension (PAH). Nine patients with PAH related to SSc in New York Heart Association classes III?CIV were treated with Bosentan 125?mg twice a day. NVC optical probe videocapillaroscopy equipped with 100× and 200× contact lenses and connected to image analyse software was performed before and after 12?months of Bosentan therapy to evaluate the modification of microvasculature. Nine PAH SSc patients treated with Iloprost were used as controls. Before Bosentan therapy, seven patients showed at NVC severe loss of capillaries with large avascular areas and vascular architectural disorganisation which are typically ??late?? SSc pattern. After 12?months of Bosentan, NVC pattern changed in seven patients from ??late?? into ??active?? SSc pattern. The disappearance of avascular areas and capillary haemorrhages was the most striking result. Two patients had an ??active?? SSc pattern, not modified by Bosentan treatment. These data show that Bosentan may improve NVC pattern in SSC and the presence of new capillaries suggests that it may favour angiogenesis. Bosentan may improve and stabilise the microvasculature in long-term treatment modulating the structural modifications detected by NVC.     

High rate of disease remission in moderate rheumatoid arthritis on etanercept therapy: data from GISEA, the Italian biologics register

The aim of this study was to evaluate the clinical outcomes of etanercept in rheumatoid arthritis (RA) patients with moderate or severe disease activity. We analyzed data from the Italian biologics register Gruppo Italiano Studio Early Arthritides (GISEA) to investigate the rate of disease remission and functional improvement, based on the 28-Joint Disease Activity Score (DAS28) and the (Health Assessment Questionnaire (HAQ) score in RA patients with moderate or severe disease activity beginning etanercept therapy. Disease was defined as severe (H-RA) with DAS28 ≥5.1 and moderate (M-RA) with DAS28 ≥3.2 to 5.1 at baseline. Patients were considered in remission if DAS28 was ≤2.6, and HAQ ≤0.5 defined normal function. We enrolled 953 RA patients, 320 with M-RA and 633 H-RA. Age and disease duration were similar in the two cohorts, but H-RA patients had significantly more comorbidities (p?<?0.01) and took significantly more disease-modifying antirheumatic drugs (p?<?0.001) than M-RA patients. After 1 year, the percentage of patients achieving disease remission and normal function (DAS28 ≤2.6 plus HAQ ≤0.5) was higher in M-RA (21.4 %) than in H-RA patients (14.8 %, p?=?0.007), regardless of the disease duration. Additionally, female gender (p?=?0.006) and H-RA class (p?=?0.002) negatively predicted disease remission at 1 year. However, the drug survival rate did not differ between the two subsets. This study confirms that etanercept was effective in the treatment of active RA, but best response, in terms of disease remission and normal function ability, was greater and easier to attain in M-RA patients. These findings may aid clinicians to choose the best strategy to treat RA.