Mammalian SNM1 is required for genome stability

The protein encoded by SNM1 in Saccharomyces cerevisiae has been shown to act specifically in DNA interstrand crosslinks (ICL) repair. There are five mammalian homologs of SNM1, including Artemis, which is involved in V(D)J recombination. Cells from mice constructed with a disruption in the Snm1 gene are sensitive to the DNA interstrand crosslinker, mitomycin (MMC), as indicated by increased radial formation following exposure. The mice reproduce normally and have normal life spans. However, a partial perinatal lethality, not seen in either homozygous mutant alone, can be noted when the Snm1 disruption is combined with a Fancd2 disruption. To explore the role of hSNM1 and its homologs in ICL repair in human cells, we used siRNA depletion in human fibroblasts, with cell survival and chromosome radials as the end points for sensitivity following treatment with MMC. Depletion of hSNM1 increases sensitivity to ICLs as detected by both end points, while depletion of Artemis does not. Thus hSNM1 is active in maintenance of genome stability following ICL formation. To evaluate the epistatic relationship between hSNM1 and other ICL repair pathways, we depleted hSNM1 in Fanconi anemia (FA) cells, which are inherently sensitive to ICLs. Depletion of hSNM1 in an FA cell line produces additive sensitivity for MMC. Further, mono-ubiquitination of FANCD2, an endpoint of the FA pathway, is not disturbed by depletion of hSNM1 in normal cells. Thus, hSNM1 appears to represent a second pathway for genome stability, distinct from the FA pathway.

Positional cloning of a novel Fanconi anemia gene, FANCD2

Fanconi anemia (FA) is a genetic disease with birth defects, bone marrow failure, and cancer susceptibility. To date, genes for five of the seven known complementation groups have been cloned. Complementation group D is heterogeneous, consisting of two distinct genes, FANCD1 and FANCD2. Here we report the positional cloning of FANCD2. The gene consists of 44 exons, encodes a novel 1451 amino acid nuclear protein, and has two protein isoforms. Similar to other FA proteins, the FANCD2 protein has no known functional domains, but unlike other known FA genes, FANCD2 is highly conserved in A. thaliana, C. elegans, and Drosophila. Retroviral transduction of the cloned FANCD2 cDNA into FA-D2 cells resulted in functional complementation of MMC sensitivity.

[Recurrent polychondritis (von Meyenburg-Altherr-Uehlinger syndrome]

Relapsing polychondritis is a rare systemic disease. Main symptoms are recurrent inflammations of the cartilage tissues, the eyes, and the cardiovascular system. Etiology and pathogenesis are obscure, there are hints for an immunologic disorder.

PATIENT

Our patient has suffered from the disease since the age of 12 years. The patient has experienced recurrent keratitis with spontaneous ulcerations for 15 years.

[Ptosis operations with silicone suspension at the eyebrow]

In severe ptosis with minimal or absent levator muscle function the lid can be connected with the frontalis muscle by means of silicone material. In our 18 patients (21 ptotic lids) the silastic rods arranged as a double sling to Crawford gave better results than the thinner silastic tube single slings.

[Ptosis surgery: shortening the levator aponeurosis of Müller's muscle and the tarsus using an anterior approach]

In cases of moderate congenital ptosis, better lid elevation can be achieved by resection of the levator muscle through a skin incision, combined with tarsectomy and shortening of the superior tarsal muscle. The function of the levator muscle can thus be fully exploited.

Novel cyclopentenoid cyanohydrin rhamnoglucosides from flacourtiaceae1

Two novel cyclopentenoid cyanohydrin glycosides, (1 S,4 R)-and (1 R,4 S)-1-[6- O-(alpha- L-rhamnopyranosyl)-beta- D-glucopyranosyloxy]-4-hydroxy-2-cyclopentene-1-carbonitrile, were isolated from seeds of the Indian medicinal plant HYDNOCARPUS PENTANDRA (F. Ham.) Oken (Flacourtiaceae) and characterized by optical rotations as well as (1)H-and (13)C-NMR spectra. The structural assignment is founded on these data and on degradation with alpha- L-rhamnosidase to the corresponding beta- D-glucopyranosides, epivolkenin and taraktophyllin, also present in the seeds in small amounts. Earlier reports of cyclopentenoid rhamnoglucosides from Passifloraceae are rejected.

Chlamydia trachomatis isolation in patients with endometritis after cesarean section

Cervical specimens for Chlamydia were collected from 110 patients with endometritis after cesarean section and from 52 intrapartum patients without clinical infection. The C. trachomatis isolation rate was not statistically different between these groups.

Can whole blood be used instead of separated low density cells for examination of the mitogen response?

The response of whole blood and separated low density cells to 3 mitogenic lectins [Phytohaemagglutinin (PHA), Pokeweed mitogen (PWM) and Concanavalin (Con-A)] was tested in 133 normal individual of all ages, including cord blood. The results obtained with the two methods correlated poorly (r = 0.16 for PHA; 0.47 for PWM and 0.42 for Con-A). Thus, the two methods measure different things and results are not comparable.