5FU continuous infusion in heavily pretreated advanced breast cancer patients.

BACKGROUND: Despite advances in the first- and secondline treatment of advanced breast cancer, optimal therapy thereafter remains controversial. Treatment of heavily pretreated patients is not standardized, often of low efficacy, and limited by comorbidity. In these patients, an effective treatment with low toxicity is needed. PATIENTS AND METHODS: We retrospectively analyzed all metastatic breast cancer patients treated with 5-fluorouracil as continuous infusion (CI-5FU) with daily doses of 150-300 mg/m(2). RESULTS: 43 patients were treated with CI-5FU until disease progression. The median number of metastatic sites was 3. Most patients were heavily pretreated with a median of 3 palliative chemotherapies (range 1-11). 42 patients were evaluable for objective response; among them 5 (12%) showed a partial response (PR) and 6 (15%) showed stable disease (SD) lasting at least 6 months, leading to a clinical benefit (CB) rate (complete response + PR + SD ≥ 6 months) of 27%. The median time to progression of patients with CB was 10 months (range 3-22). Overall survival of all patients from the start of CI-5FU was 8 months (range 1-75) and from the time of first metastases 42 months (range 9-281). Toxicity was low even in patients with hepatic insufficiency. CONCLUSION: CI-5FU showed a positive efficacy/toxicity ratio. Taking into account the high number of previous treatments, it results in a remarkable CB rate of 27%.

Primary tumor excision in stage IV breast cancer at diagnosis without influence on survival: a retrospective analysis and review of the literature.

BACKGROUND: Patients with synchronous metastastic breast cancer and intact primary tumor traditionally undergo systemic treatment. Surgical intervention at the primary site is typically reserved for palliation and often replaceable by radiation. Nevertheless, local surgery in metastatic breast cancer has become an issue of great controversy since retrospective studies published during the recent years suggested a slight benefit from an operative procedure. We evaluated the effect of surgery on long-term survival and progression-free survival in synchronous stage IV breast cancer. METHODS: We retrospectively reviewed the records of all breast cancer patients treated at our institution between 1986 and 2007. Information recorded for each patient included age, tumor characteristics, metastasis characteristics, therapy, progression-free survival, and overall survival. Survival data were compared between surgical and nonsurgical patients. RESULTS: 61 patients with synchronous metastastic breast cancer and intact primary tumor were analyzed. 26 patients (43%) received no primary site surgery and 35 (57%) patients had surgery. Overall survival and progression-free survival determined via the Kaplan-Meier method showed no significant difference between the surgery and the non-surgery group. CONCLUSION: In patients with metastatic breast cancer, the operation of the primary tumor did not influence overall survival or progression-free survival.

Association between intestinal tight junction permeability and whole-body electrical resistance in healthy individuals: a hypothesis.

OBJECTIVE: Intestinal permeability describes non-carrier-mediated modes of transport through the intestinal epithelium. Wrist-ankle bioimpedance analysis (BIA) is a standard method to determine body composition based on the measurements of whole-body electrical resistance and reactance values. The present report deals with the coincidentally observed associations between permeability results and electrical raw values of BIA and their subsequent reproduction in a larger group of individuals. METHODS: Tetrapolar wrist-ankle BIA was performed on day 1 in the initial sample (12 women, 36 +/- 11 y of age) and the validation sample (36 healthy subjects, 26 women and 10 men, 35 +/- 14 y of age). Intestinal permeability tests (lactulose and mannitol) were implemented within 1 wk thereafter. Wrist-ankle electrical resistance plus electrical resistance between current-conducting electrodes and voltage-sensing electrodes (Rtotal) was measured at 5 kHz and 100 kHz. RESULTS: Permeability and bioimpedance raw values were normal, indicating normal tight junction permeability and normal hydration. Lactulose correlated to R(50total) in the initial sample (rho = 0.639, P = 0.025) and in the validation sample (rho = 0.673, P < 0.001). Weaker associations to R(50total) were observed with mannitol (rho = 0.381, P = 0.008) and lactulose/mannitol (rho = 0.369, P = 0.010) in the total group of individuals. Regression analyses demonstrated that R(50total) alone accounted for 41.3% of the variance in lactulose permeability. CONCLUSION: The nature of the observed positive association between intestinal tight junction permeability and whole-body electrical resistance is unclear. We hypothesize that regulation involving submolecular mechanisms based on the principles of quantum physics might have caused the observed association. Such coherent mechanisms might possibly play a role in basal physiologic regulation in humans.

The blue-light receptor YtvA acts in the environmental stress signaling pathway of Bacillus subtilis.

The general stress response of the bacterium Bacillus subtilis is regulated by a partner-switching mechanism in which serine and threonine phosphorylation controls protein interactions in the stress-signaling pathway. The environmental branch of this pathway contains a family of five paralogous proteins that function as negative regulators. Here we present genetic evidence that a sixth paralog, YtvA, acts as a positive regulator in the same environmental signaling branch. We also present biochemical evidence that YtvA and at least three of the negative regulators can be isolated from cell extracts in a large environmental signaling complex. YtvA differs from these associated negative regulators by its flavin mononucleotide (FMN)-containing light-oxygen-voltage domain. Others have shown that this domain has the photochemistry expected for a blue-light sensor, with the covalent linkage of the FMN chromophore to cysteine 62 composing a critical part of the photocycle. Consistent with the view that light intensity modifies the output of the environmental signaling pathway, we found that cysteine 62 is required for YtvA to exert its positive regulatory role in the absence of other stress. Transcriptional analysis of the ytvA structural gene indicated that it provides the entry point for at least one additional environmental input, mediated by the Spx global regulator of disulfide stress. These results support a model in which the large signaling complex serves to integrate multiple environmental signals in order to modulate the general stress response.

EST analysis of mouse retina and RPE/choroid cDNA libraries.

PURPOSE: cDNA libraries from the mouse retina have recently been reported, but no well characterized library from the retinal pigment epithelium (RPE) or choroid of the mouse has yet appeared in the literature. To complement these libraries and to provide the first mouse RPE/choroid library, we used freshly dissected tissue from adult C57BL/6J mice to construct new retina and RPE/choroid libraries. METHODS: Eyes from 100 six to eight week old C57BL/6J mice were dissected in groups of 10. The whole retina and RPE/choroid were isolated individually and then homogenized before RNA isolation. Over 5000 clones each were sequenced from the unamplified and un-normalized retina and RPE/choroid libraries. All sequences were analyzed using GRIST (GRouping and Identification of Sequence Tags), a bioinformatics program for gene identification and clustering. RESULTS: The RPE/choroid library contained 3145 clusters with 76% of the clusters representing single clones. Nearly 87% of the clusters corresponded to named genes in GenBank, and 8% of the RPE clusters remain unidentified. The retina library contained 3190 clusters of which 78% represented only one clone. Approximately 85% of the clusters matched sequences in GenBank, and 9% of the clusters remain unidentified. The clones most abundant in each library were all well-known sequences and both libraries contained a number of tissue specific or tissue-enhanced genes. CONCLUSIONS: These new libraries should provide a valuable resource for gene discovery and cDNAs for expression analysis and functional studies.

Age-related changes in the transcriptional profile of mouse RPE/choroid.

To evaluate the age-related changes in gene expression occurring in the complex of retinal pigmented epithelium, Bruch's membrane, and choroid (RPE/choroid), we examined the gene expression profiles of young adult (2 mo) and old (24 mo) male C57BL/6 mice. cDNA probe sets from individual animals were synthesized using total RNA isolated from the RPE/choroid of each animal. Probes were amplified using the Clontech SMART system, radioactively labeled, and hybridized to two different Clontech Atlas mouse cDNA arrays. From each age group, three independent triplicates were hybridized to the arrays. Statistical analyses were performed using the Significance Analysis of Microarrays program (SAM version 1.13; Stanford University). Selected array results were confirmed by semi-quantitative RT-PCR analysis. Of 2,340 genes represented on the arrays, approximately 60% were expressed in young and/or old mouse RPE/choroid. A moderate fraction (12%) of all expressed genes exhibited a statistically significant change in expression with age. Of these 150 genes, all but two, HMG14 and carboxypeptidase E, were upregulated with age. Many of these upregulated genes can be grouped into several broad functional categories: immune response, proteases and protease inhibitors, stress response, and neovascularization. RT-PCR results from six of six genes examined confirmed the differential change in expression with age of these genes. Our study provides likely candidate genes to further study their role in the development of age-related macular degeneration and other aging diseases affecting the RPE/choroid.

Acute hyperoxia-induced transcriptional response in the mouse RPE/choroid.

Oxidative stress has been studied in the retinal pigmented epithelium (RPE) in vitro but not in vivo. Our purpose, therefore, was to develop an in vivo model of acute oxidative stress in the C57BL/6J mouse. Mice were exposed to > or = 98% oxygen for 0, 2, or 6 h, and amplified total RNA from the RPE/choroid was applied to microarrays examining about 2200 unique genes. Statistical analysis determined that 642 genes, out of a total of 1349 expressed, were significantly downregulated at only 2 h, only 6 h, or both 2 and 6 h, and a single gene, ubiquitin, was upregulated. These genes are involved in all aspects of cellular functions, and there are no major differences among the three groups. The effect of hyperoxia on the RPE/choroid in vivo appears to be very similar to oxidative stress studies performed with an RPE cell line in vitro. All 11 genes identified as being regulated by all three oxidants in our previous study, and were expressed by mouse, were also differentially regulated by hyperoxia. At least for the initial response to an oxidative challenge, the in vitro ARPE-19 cell line is a reasonable model for in vivo studies.

Microarray analysis of H2O2-, HNE-, or tBH-treated ARPE-19 cells.

Oxidative stress plays a key role in aging diseases of the posterior pole of the eye such as age-related macular degeneration. The oxidative stress response of in vitro RPE cells has been studied for a small number of genes. However, a comprehensive transcriptional response has yet to be elucidated. The purpose of this study was to determine if the transcription of a common set of genes is altered by exposure of ARPE-19 cells to three major generators of oxidative stress, hydrogen peroxide (H2O2), 4-hydroxynonenal (HNE), and tert-butylhydroperoxide (tBH). As expected, a common response was observed that included 35 genes differentially regulated by all three treatments. Of these, only one gene was upregulated, and only by one oxidant, while all other responses were downregulation. The majority of these genes fell into five functional categories: apoptosis, cell cycle regulation, cell-cell communication, signal transduction, and transcriptional regulation. Additionally, a large number of genes were differentially regulated by one oxidant only, including the majority of the conventional oxidative stress response genes present on the Clontech Human 1.2 microarray. This study raises questions regarding the generality of results that involve the use of a single oxidant and a single cell culture condition.