Complete sequencing of TP53 predicts poor response to systemic therapy of advanced breast cancer

TP53 has been implicated in regulation of the cell cycle, DNA repair, and apoptosis. We studied, in primary breast tumors through direct cDNA sequencing of exons 2-11, whether TP53 gene mutations can predict response in patients with advanced disease to either first-line tamoxifen therapy (202 patients, of whom 55% responded) or up-front (poly)chemotherapy (41 patients, of whom 46% responded). TP53 mutations were detected in 90 of 243 (37%) tumors, and one-fourth of these mutations resulted in a premature termination of the protein. The mutations were observed in 32% (65 of 202) of the primary tumors of tamoxifen-treated patients and in 61% (25 of 41) of the primary tumors of the chemotherapy patients. TP53 mutation was significantly associated with a poor response to tamoxifen [31% versus 66%; odds ratio (OR), 0.22; 95% confidence interval (CI), 0.12-0.42; P < 0.0001]. Patients with TP53 gene mutations in codons that directly contact DNA or with mutations in the zinc-binding domain loop L3 showed the lowest response to tamoxifen (18% and 15% response rates, respectively). TP53 mutations were related, although not significantly, to a poor response to up-front chemotherapy (36% versus 63%; OR, 0.34; 95% CI, 0.09-1.24). In multivariate analysis for response including the classical parameters age and menopausal status, disease-free interval, dominant site of relapse, and levels of estrogen receptor and progesterone receptor, TP53 mutation was a significant predictor of poor response in the tamoxifen-treated group (OR, 0.29; 95% CI, 0.13-0.63; P = 0.0014). TP53-mutated and estrogen receptor-negative (<10 fmol/mg protein) tumors appeared to be the most resistant phenotype. Interestingly, the response of patients with TP53 mutations to chemotherapy after tamoxifen was not worse than that of patients without these mutations (50% versus 42%; OR, 1.35, nonsignificant). The median progression-free survival after systemic treatment was shorter for patients with a TP53 mutation than for patients with wild-type TP53 (6.6 and 0.6 months less for tamoxifen and up-front chemotherapy, respectively). In conclusion, TP53 gene mutation of the primary tumor is helpful in predicting the response of patients with metastatic breast disease to tamoxifen therapy. The type of mutation and its biological function should be considered in the analyses of the predictive value of TP53.     

Phycocyanin: laser activation, cytotoxic effects, and uptake in human atherosclerotic plaque

Phycocyanin is a phycobiliprotein with peak absorption at 620 nm. The laser activation, cytotoxic effects, and uptake into atherosclerotic plaque of phycocyanin was studied. Optimal activation was produced by argon dye laser at 0.5 W and a total energy dose of 300 J/cm2 at 620 nm and 650 nm, irradiated through blood with a hematocrit of 8%. Activation was evidenced by reduction of optical density by 0.3 units at 340 nm caused by oxidation of the reduced nicotinamide adenine dinucleotide phosphate (NADPH) in a buffered reaction solution containing 0.1 mg/ml of phycocyanin. Cytotoxicity was evaluated by measuring viability of mouse myeloma cells in culture after incubation with phycocyanin (0.25 mg/ml) and irradiated by 300 J/cm2 at 514 nm. After 72 hours post-treatment the cells showed 15% viability compared to 69% and 71% for control cells exposed to laser only or phycocyanin only, respectively. Atherosclerotic artery segments obtained within 5 hours postmortem were perfused with 0.1 mg/ml phycocyanin in oxygenated Krebs Ringer solution at 30 mm Hg for 5 minutes followed by washout with phycocyanin-free Krebs for 10 minutes. Artery sections examined histologically by light and fluorescence microscopy showed specific fluorescence localization within the plaque particularly at the elastic laminae and to a larger extent at the internal elastic lamina but not in the medial muscle layer. In conclusion, phycocyanin is a cytotoxic photosensitizer that exhibits specific binding to plaque and is activated at a wavelength minimally absorbed by blood. These properties suggest potential therapeutic use for plaque localization and regression.     

Research in medical sciences in Israel, 1994-97, an overview of institutions, investigators, and funding.

This is a summary of the second effort to characterize medical research activities in Israel (1994-97). The study relies on responses to a questionnaire sent to all participants in the first survey (1991-94) and to additional, including younger, investigators. There were 1450 direct responses this time versus 1088 the first time. The distribution of investigators is 60% hospital-based versus 40% in basic sciences. The average number of funding sources per investigator has decreased from 2.6 to 2.2; however the percentage of funded investigators has increased from 60% to 70%. The greatest concentration of funded investigators remains at the Hebrew University and Hadassah Medical Center, followed by Tel Aviv University and associated hospitals. The Chief Scientist's Office of the Ministry of Health funds more than 40% of funded investigators (more than double the next highest funding source, the US-Israel Binational Fund), followed in decreasing order by the National Academy of Sciences, Ministry of Science, German-Israeli Foundation for Scientific Research and Development (GIF), Israel Cancer Society, and NIH. The percentage of funded hospital-based investigators has increased from 59% to 62%; however, funding remains higher for basic science investigators. There has been an increase in the percentage of Ph.D.'s working in a hospital environment and an interesting anomaly is that the nonacademic-affiliated Ph.D. investigators in hospitals have been successful in receiving funding, so now a greater percentage of nonacademic hospital staff are funded than academic staff (69% versus 61%).     

Essential cryofibrinogenaemia,leukocytoclastic vasculitis and chronic purpura

Abstract. Cryofibrinogenaemia refers to the presence of cold-precipitable proteins in plasma but not in serum. It is usually associated with malignancy, tromboembolic diseases or various inflammatory processes; rarely it may be essential. The most common clinical presentations of cryofibrinogenaemia are cold-intolerance, purpura, skin necrosis and ulcers. We describe a middle-aged woman with essential cryofibrinogenaemia, leukocytoclastic vasculitis, and chronic purpura for over 25 years with several exacerbations. In patients with otherwise unexplained purpura or skin necrosis, determination of plasma cryofibrinogen should be considered.     

THE DISAPPEARANCE OF HCG AND RETURN OF PITUITARY FUNCTION AFTER ABORTION

Plasma concentrations of HCG/LH and FSH were monitored after a first trimester abortion in eighteen healthy female volunteers three times weekly until the onset of first menstruation. Plasma concentrations of the HCG were measured with a specific RIA for the beta subunit (beta-sub-HCG) from the samples of six of these subjects. The elimination of HCG during the first 12 days was studied from plasma concentrations measured by the radioimmunoassay of LH. The experimental data were well explained by a mathematical model consisting of three exponentially decreasing components. The half-lives of the two more slowly decreasing components were 27 and 168 h. The estimate of the complete disappearance of HCG was 37.7 days, when the specific (beta-sub-HCG) assay was used. Recovery of pituitary function occurred within 4--9 days after abortion, as judged by increased plasma FSH concentrations. In fourteen of eighteen subjects a midcycle LH peak was observed which occurred between 16 and 29 days after abortion. Plasma oestradiol concentrations increased 2--16 days after the rise in plasma FSH. Considerable amounts of HCG still circulated in the blood but the preovulatory peak of oestradiol never began before HCG/LH concentrations had decreased to below the range of the mid-cycle LH peak.     

H-2-dependent regulation of the high level of expression of ecotropic murine leukemia virus.

Adult B10.Y mice, which are congenic with C57BL/10ScSn ((B10) mice for the H-2 region, expressed a high titer of infectious ecotropic virus in the spleen. F1 hybrids between B10.Y and B10 mice were negative or had very low levels of virus expression. In (B10.Y x B10)F2 segregant mice, the high virus phenotype segregated with the H-2pa haplotype of B10.Y, whereas the virus-negative phenotype was associated with the H-2b haplotype of B10. Molecular hybridization experiments with a selected ecotropic AKR murine leukemia virus cyclic DNA probe indicated that both partner strains possessed ecotropic virus sequences and that the number of sequences present was the same in B10.Y mice as in B10 mice. This finding excluded the possibility that the H-2-related effect might be due to the presence of additional viral structural genes within or close to the H-2 region of B10.Y mice. The level of expression of this endogenous ecotropic virus was therefore affected by regulatory genes of the H-2 region.     

A case repot of Merkel cell carcinoma on chronic lymphocytic leukemia: differential diagnosis of coexisting lymphadenopathy and indications for early aggressive treatment

Background  

Chronic lymphocytic leukemia (CLL) is a monoclonal disorder, characterized by a progressive proliferation of functionally incompetent B lymphocytes. There is increased evidence of association between CLL and skin cancers, including the uncommon Merkel cell carcinoma (MCC).     

Computer-enhanced video microscopy: digitally processed microscope images can be produced in real time.

Digital processing techniques can be used to greatly enhance the available information in an optical image. Although this technology has been routinely used in many fields for a number of years, little application of digital image-processing techniques have been made toward analysis and enhancement of the types of images seen most often by the research biologist. We describe here a computer-based video microscope system that is capable of performing extensive manipulation and enhancement of microscope images in real time. The types of manipulations possible with these techniques greatly surpass the enhancement capabilities of photographic or video techniques alone. The speed and flexibility of this system enables experimental manipulation of the microscopic specimen based on its live processed image. These features greatly extend the power and versatility of the light microscope.