Lentiviral protein delivery of meganucleases in human cells mediates gene targeting and alleviates toxicity.

Site-specific endonucleases can be engineered for custom recognition of any genetic locus and used for gene targeting. Yet, the prolonged expression and accumulation of these nucleases in cells lead to toxic effect. Here we describe an efficient and quantitative method for introducing nucleases into cells as proteins packaged within lentiviral vector particles. I-CreI-derived meganucleases, which can be engineered as single-chain proteins, were incorporated into lentiviral vector particles either without modification or as fusions with cyclophilin A. The small amount of nuclease delivered by the viral particles is sufficient to induce efficient targeted mutagenesis in human HEK293H and primary T cells. When a repair template sequence was packaged in the lentiviral vector, high levels of homologous gene targeting were obtained and toxicity was markedly reduced.

[Gonadal function in primary apparent male osteoporosis. 12 cases]. / Etude de la fonction gonadique au cours de l'ostéoporose masculine en apparence primitive. Douze cas.

The testicular endocrine function was studied in 12 patients aged from 33 to 76 years (mean: 56.3 +/- 11.5 years) presenting with an apparently primary vertebral osteoporosis and in 14 age-matched controls (mean: 52.6 +/- 12.8 years). The mean bone mineral content, measured in the vertebral column by biphoton absorptiometry, was lower in patients than in control (P +/- 0.01). Plasma levels of testosterone, oestradiol, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were the same in both groups. In two patients of each group, a rise of LH with normal testosteronaemia was suggestive of compensated Leydig's cell deficiency. There was no correlation between bone mineral content, plasma testosterone, LH, FSH level and the subjects' weight and height. However, a positive correlation was found between plasma oestradiol level and bone mineral contents in patients with osteoporosis (P +/- 0.01) ans in all subjects under study (P +/- 0.05). This study shows that primary osteoporosis is not due to testicular deficiency and suggests a possible action of oestradiol on male bone.

Chronic destructive oligoarthritis associated with Propionibacterium acnes in a female patient with acne vulgaris: septic-reactive arthritis?

Propionibacterium acnes is an anaerobic bacillus implicated in certain chronic arthritides. This report describes an HLA-B27+ 17-year-old woman with acne vulgaris who presented with rapidly destructive arthritis in the left shoulder as well as an evolving left subclavicular adenopathy. One year later, arthritis was detected in the left knee; the inflammatory synovial fluid was sterile. Growth of P acnes was observed in cultures of the shoulder synovium and lymph nodes, but polymerase chain reaction was negative for Borrelia, Chlamydia, and Ureaplasma DNA. Three months of treatment with amoxicillin and rifampicin led to clinical disappearance of the oligoarthritis, but arthritis recurred in the left knee after discontinuation of therapy. On biopsy, bacteria were undetectable in the knee synovium, but chronic arthritis was evident histologically. Antibiotics were reintroduced for 12 months and were again effective against the clinical symptoms. Although the asymmetry, histologic features, arthritis-acne association, and genetic predisposition of this chronic destructive oligoarthritis would seem to indicate a reactive arthropathy, the isolation of P acnes from 2 distinct specimens prompted us to propose calling this a case of septic-reactive arthritis, which is further supported by the absence of progression after antibiotic therapy and the persistence of the rheumatism. To our knowledge, this is the first demonstration of the efficacy of prolonged antibiotic therapy on the joint manifestations of chronic rheumatism associated with acne.