Microscale Biosignatures and Abiotic Mineral Authigenesis in Little Hot Creek, California.

Hot spring environments can create physical and chemical gradients favorable for unique microbial life. They can also include authigenic mineral precipitates that may preserve signs of biological activity on Earth and possibly other planets. The abiogenic or biogenic origins of such precipitates can be difficult to discern, therefore a better understanding of mineral formation processes is critical for the accurate interpretation of biosignatures from hot springs. Little Hot Creek (LHC) is a hot spring complex located in the Long Valley Caldera, California, that contains mineral precipitates composed of a carbonate base (largely submerged) topped by amorphous silica (largely emergent). The precipitates occur in close association with microbial mats and biofilms. Geological, geochemical, and microbiological data are consistent with mineral formation via degassing and evaporation rather than direct microbial involvement. However, the microfabric of the silica portion is stromatolitic in nature (i.e., wavy and finely laminated), suggesting that abiogenic mineralization has the potential to preserve textural biosignatures. Although geochemical and petrographic evidence suggests the calcite base was precipitated via abiogenic processes, endolithic microbial communities modified the structure of the calcite crystals, producing a textural biosignature. Our results reveal that even when mineral precipitation is largely abiogenic, the potential to preserve biosignatures in hot spring settings is high. The features found in the LHC structures may provide insight into the biogenicity of ancient Earth and extraterrestrial rocks.

Comparative value of tumour grade, hormonal receptors, Ki-67, HER-2 and topoisomerase II alpha status as predictive markers in breast cancer patients treated with neoadjuvant anthracycline-based chemotherapy.

The aim of this study was to evaluate the predictive value of five different biological factors in breast cancer patients treated with neoadjuvant anthracycline-based chemotherapy: (1) tumour grade scored according to the Elston-Ellis classification, (2) hormonal receptor (HR) status; (3) tumour cell proliferation evaluated by Ki-67 staining, (4) HER-2 and topoisomerase II alpha (TopoIIalpha) expression evaluated by immunohistochemistry (IHC), (5) HER-2 and TopoIIalpha amplification evaluated by real-time polymerase chain reaction (PCR). 119 patients with operable breast cancer were treated with six cycles of FEC (100 5-fluorouracil (5-FU) 500 mg/m2, Epirubicin 100 mg/m2, Cyclophosphamide 500 mg/m2). Tumour response was assessed clinically and by computed tomography (CT) scan, then by pathological assessment. The clinical overall response (OR) was 80%, with 19% of complete responders (CR). The radiological OR was 71%, with 16% of CR. A pathological CR was demonstrated in 13% of the patients according to the Sataloff classification. In the multivariate analysis, the absence of HR expression and Ki-67 > or = 20% were predictive for a clinical CR. A high tumour grade was predictive for a pathological CR. Overexpression or amplification of HER2 or Topollcalpha were not predictive of response.

Chemotherapy response of breast cancer depends on HER-2 status and anthracycline dose intensity in the neoadjuvant setting.

We evaluated the predictive value of a tumor's HER-2 status for chemotherapy response in the neoadjuvant setting and the effect of anthracycline dose intensity on this predictive value. HER-2 status was evaluated by immunochemistry on microbiopsy before neoadjuvant chemotherapy (monoclonal antibody CB-11; Novocastra) in 39 patients (group A) treated with FEC50 (500 mg/m(2) 5-fluorouracil, 50 mg/m(2) epirubicin, and 500 mg/m(2) cyclophosphamide) and 40 patients (group B) treated with FEC100 (500 mg/m(2) 5-fluorouracil, 100 mg/m(2) epirubicin, and 500 mg/m(2) cyclophosphamide). All tumors were stage II or noninflammatory stage III adenocarcinoma. Overall response rate (OR) was evaluated through ultrasound and mammographic measurements. Pathological complete response was evaluated by tumor excision and axillary node resection after six cycles of chemotherapy. Patient and tumor characteristics (age, tumor size, clinical nodal status, SBR grade, hormonal receptor status, and HER-2 expression) were similar in the two groups. In univariate analyses, anthracycline dose was the only factor predictive of response (OR = 61.5% with FEC50; OR = 82.5% with FEC100; P = 0.038). When anthracycline dose was correlated with HER-2 status, an OR of 73.9% was demonstrated in HER-2- tumors (tumors without HER-2 overexpression), and an OR of 12.5% was demonstrated in HER-2+ tumors (tumors with HER-2 with overexpression) in group A. In group B, an OR of 69.5% was demonstrated in HER-2- tumors, and an OR of 100% was demonstrated in HER-2+ tumors. There was no difference in OR for HER-2- tumors treated with FEC50 or FEC100 (P = 0.74). On the other hand, erbB-2+ tumors treated with FEC100 had a significantly better OR than HER-2+ tumors treated with FEC50 (P = 0.0003). In a multivariate analysis, the most powerful predictive factor of OR was a conditional variable associating anthracycline dose with HER-2 status. Low-dose anthracycline and HER-2+ predicted a poor OR, low- or high-dose anthracycline and HER-2- predicted an intermediate OR, and high-dose anthracycline and HER-2+ predicted a high OR. Our results merit additional studies, given the possibility for choosing anthracycline dose according to a tumor's HER-2 status.

[Germ-line mutations of the BRCA1 gene in northeastern France]. / Mutations germinales du gène BRCA1 dans le Nord-Est de la France.

Thirty-seven breast/ovarian or breast-only cancer families selected on a regional basis have been analyzed for mutations at BRCA1. By combining direct sequence analysis and protein truncation test, mutations were detected in 14 families (38%). We found seven different mutations, two of which have not been described before. Mutations at BRCA1 were present in 60% of breast/ovarian and 32% of breast-only cancer families. Mutations were frequent in families with at least one breast cancer case before age 40 (44%) and/or one bilateral breast cancer case (54%). Two mutations, namely 3600del11 and G1710X, are frequent in the population native from northeastern France. Oriented BRCA1 analysis should facilitate carrier detection in breast and/or ovarian cancer families stemming from this French area.

Idarubicin and high dose cytarabine: a new salvage treatment for refractory or relapsing non-Hodgkin's lymphoma.

Twenty three patients with relapsing (n = 11) or refractory (n = 12) non-Hodgkin's lymphoma (NHL) to one or two prior anthracycline based combination chemotherapy regimens were treated as second or third line regimen with 3 induction cycles of Idarubicin (IDA) (7 mg/m2/d i.v. d1-d3) and high dose cytarabine (HD Ara-C) (1 g/m2/12 h i.v. d1-d3), each cycle was repeated every 3 weeks. Responding patients received a maintenance therapy with monthly cycles of IDA: 15 mg/m2 d1-d3, Etoposide 100 mg/m2 d1-d3, both by oral route. Twenty two patients are evaluable and we observed 13 CR and 1 PR with an overall response rate of 61% (14/23: 95% Cl = 38.5% 80.3%). The median time to progression was 32 months (6.5 - 63 + m.). The response rate to IDA-HD Ara C was not different for patients with (n = 14) or without (n = 9) objective response to the last prior therapy. The main toxicity was hematological: all patients experienced grade 4 neutropenia and 22 patients had grade 4 thrombopenia, but there were no toxic deaths. IDA and HD-Ara-C combination is highly effective in refractory or relapsed. NHL. As hematological toxicity was the limiting factor for further escalation of dose-intensity, further studies might include hematopoietic growth factors support in the therapeutic scheme.