Dermatological conditions during TNF-α-blocking therapy in patients with rheumatoid arthritis: a prospective study

Various dermatological conditions have been reported during tumor necrosis factor (TNF)-α-blocking therapy, but until now no prospective studies have been focused on this aspect. The present study was set up to investigate the number and nature of clinically important dermatological conditions during TNF-α-blocking therapy in patients with rheumatoid arthritis (RA). RA patients starting on TNF-α-blocking therapy were prospectively followed up. The numbers and natures of dermatological events giving rise to a dermatological consultation were recorded. The patients with a dermatological event were compared with a group of prospectively followed up RA control patients, naive to TNF-α-blocking therapy and matched for follow-up period. 289 RA patients started TNF-α-blocking therapy. 128 dermatological events were recorded in 72 patients (25%) during 911 patient-years of follow-up. TNF-α-blocking therapy was stopped in 19 (26%) of these 72 patients because of the dermatological event. More of the RA patients given TNF-α-blocking therapy (25%) than of the anti-TNF-α-naive patients (13%) visited a dermatologist during follow-up (P < 0.0005). Events were recorded more often during active treatment (0.16 events per patient-year) than during the period of withdrawal of TNF-α-blocking therapy (0.09 events per patient-year, P < 0.0005). The events recorded most frequently were skin infections (n = 33), eczema (n = 20), and drug-related eruptions (n = 15). Other events with a possible relation to TNF-α-blocking therapy included vasculitis, psoriasis, drug-induced systemic lupus erythematosus, dermatomyositis, and a lymphomatoid-papulosis-like eruption. This study is the first large prospective study focusing on dermatological conditions during TNF-α-blocking therapy. It shows that dermatological conditions are a significant and clinically important problem in RA patients receiving TNF-α-blocking therapy.     

A "Fille du Roy" introduced the T14484C Leber hereditary optic neuropathy mutation in French Canadians

The predominance of the T14484C mutation in French Canadians with Leber hereditary optic neuropathy is due to a founder effect. By use of genealogical reconstructions of maternal lineages, a woman married in Quebec City in 1669 is identified as the shared female ancestor for 11 of 13 affected individuals, who were previously not known to be related. These individuals carry identical mitochondrial haplogroups. The current geographic distribution of French Canadian cases overlaps with that of the founder's female descendants in 1800. This is the first example of genealogical reconstruction to identify the introduction of a mitochondrial mutation by a woman in a founder population.     

On the nature and origin of DNA strand breaks in elongating spermatids

Transient DNA strand breaks are generated in the whole population of elongating spermatids and are perfectly coincident with histone H4 hyperacetylation at chromatin-remodeling steps. Given the limited DNA repair capacity of elongating spermatids, chromatin remodeling may present a threat to genetic integrity of the male gamete. The nature of the DNA strand breakage, the enzymes involved, and the role of H4 hyperacetylation in the process must be determined to further investigate the potential mutagenic consequences of this important transition. We used the metachromatic dye acridine orange in combination with fluorescence-activated cell sorting to achieve separation of spermatids according to their condensation state. Using single-cell electrophoresis (comet assay), in both alkaline and neutral conditions, we demonstrated that double-stranded breaks account for most of the DNA fragmentation observed in purified elongating spermatids. DNA strand breaks were generated in round spermatids as a result of de novo histone hyperacetylation induced by trichostatin A, whereas an increase in endogenous DNA strand breaks was observed in elongating spermatids. Using a short-term culture of testicular cells, we demonstrated that DNA strand breaks in spermatids were abolished on incubation with two functionally different topoisomerase II inhibitors. Hence, topoisomerase II appears as the unique enzyme responsible for the transient double-stranded breaks in elongating spermatids but depends on histone hyperacetylation for its activity.     

Cel6B of Thermobifidus fusca and a Cel5-CBM6 of Ruminococcus albus containing a cellulose binding site show synergistic effect on hydrolysis of native plant cellulose

We have established an improved large deletion method in Escherichia coli genome using a combination of two different recombination systems, lambda Red and Cre/loxP. The loxP site could be rapidly and efficiently integrated in the genome by lambda Red and large deletions of both 117- and 165-kbp regions could be generated in 100% efficiency by Cre/loxP. Comparative genomic hybridization microarray experiments of deletion strains indicated that deletions were generated only in expected regions of the genome. These results have demonstrated that the method is useful for genome engineering in E. coli.     

Anatomy of a founder effect: myotonic dystrophy in Northeastern Quebec

Founder effects are largely responsible for changes in frequency profiles of genetic variants in local populations or isolates. They are often recognized by elevated incidence of certain hereditary disorders as observed in regions of Charlevoix and Saguenay-Lac-Saint-Jean (SLSJ) in Northeastern Quebec. Dominantly transmitted myotonic dystrophy (DM1) is highly prevalent in SLSJ where its carrier rate reaches 1/550, compared with 1/5,000 to 1/50,000 elsewhere. To shed light on the origin of DM1 in this region, we have screened 50 nuclear DM1 families from SLSJ and studied the genetic variation in a 2.05 Mb (2.9 cM) segment spanning the site of the expansion mutation. The markers analyzed included 22 biallelic SNPs and two microsatellites. Among 50 independent DM1 chromosomes, we distinguished ten DM1-associated haplotypes and grouped them into three haplotype families, A, B and C, based on the relevant extent of allele sharing between them. To test whether the data were consistent with a single entry of the mutation into SLSJ, we evaluated the age of the founder effect from the proportion of recombinant haplotypes. Taking the prevalent haplotype A1_21 (58%) as ancestral to all the disease-associated haplotypes in this study, the estimated age of the founder effect was 19 generations, long predating the colonization of Nouvelle-France. In contrast, considering A1_21 as ancestral to the haplotype family A only, yielded the estimated founder age of nine generations, consistent with the settlement of Charlevoix at the turn of 17th century and subsequent colonization of SLSJ. We conclude that it was the carrier of haplotype A (present day carrier rate of 1/730) that was a driver of the founder effect, while minor haplotypes B and C, with corresponding carrier rates of 1/3,000 and 1/10,000, respectively, contribute DM1 to the incidence level known in other populations. Other studies confirm that this might be a general scenario in which a major driver mutation/haplotype issued from a founder effect is found accompanied by distinct minor mutations/haplotypes occurring at background population frequencies.Electronic Supplementary Material Supplementary material is available for this article at     

HIV infection among Quebec women giving birth to live infants.

This is the first anonymous unlinked seroprevalence study in Canada to use serum samples from newborns to determine the seroprevalence rate of human immunodeficiency virus (HIV) infection among childbearing women. Of the 68,808 samples tested 42 were confirmed as positive, for an overall crude seroprevalence rate of 6.1 per 10,000 live births (95% confidence interval [CI] 4.4 to 8.3), or 1 woman in 1638. Women who lived on Montreal island had an overall rate of 17.9 per 10,000 live births (95% CI 12.2 to 25.4), or 1 woman in 559. We observed a significant association between revenue index and seroprevalence; the rates were as high as 46.4 per 10,000 live births (95% CI 18.7 to 95.3), or 1 woman in 216, for Montreal island postal code areas with revenue indexes 20% or more below the provincial median. Extrapolation of the data suggested that 56 women with HIV infection gave birth to a live infant during 1989 in Quebec. Even though attempts to generalize the data from childbearing women to women of childbearing age have an inherent conservative bias, the results of our study suggest that 988 women (95% CI 713 to 1336) aged 15 to 44 years in Quebec had HIV infection in 1989. The actual number is likely substantially higher. The need for well-designed, creative interventions to prevent further HIV transmission to women is evident. Planning for the provision of medical and psychosocial services sensitive to specific needs of women who are already infected should start immediately.     

Variations de l'incidence des fractures de l'extrémité supérieure du fémur chez les personnes agées de la région de Québec.

To estimate the incidence of fracture of the proximal end of the femur in people aged 50 years or older living in the Quebec area in 1971, 1976 and 1981 we determined the number of admissions for such fractures to the 15 acute care hospitals in the region. From 1971 to 1981 the number of fractures increased by 71%; the increases for those aged 75 to 84 years and 85 years or over were 98% and 118% respectively. The variation is only partly explained by changes in sex and age distribution of the population; the incidence rates also increased. Among men aged 75 to 84 years the incidence rate per 1000 person-years rose from 2.63 in 1971 to 5.22 in 1981, an increase of 98%; the corresponding figures for men aged 85 years or more were 9.76 and 16.91, an increase of 73%. Among women aged 75 to 84 years the rate rose from 7.28 to 8.81, an increase of 21%; the corresponding figures for women aged 85 years or more were 20.40 and 24.27, an increase of 21% and 19% respectively.     

Factors affecting terrestrial movement in the amphibious mangrove rivulus (Kryptolebias marmoratus)

We hypothesised that the exploration tendency of the amphibious mangrove rivulus Kryptolebias marmoratus would be inhibited in the terrestrial environment because of constraints on terrestrial locomotion or orientation. Using a novel object test, we showed that the fish explored objects in the aquatic but not the terrestrial environment, supporting the existence of constraints on terrestrial exploration. In further tests of the effects of extrinsic factors on terrestrial movement between aquatic refuges, shallow water depth simulating desiccation risk and the presence of a conspecific simulating intraspecific competition increased emersion outside of refuges, while high water salinity had no effect. These extrinsic factors had little effect on terrestrial movement between different aquatic refuges, except possibly for the lowest water depth tested. A significant association observed between emersion activity and movement between aquatic refuges suggested that terrestrial movement in K. marmoratus might depend on the tendency of individuals to emerse.