Dimers of polar chromophores in solution: role of excitonic interactions in one- and two-photon absorption properties.

The possibility to exploit a bottom-up approach to design and synthesize multichromophoric structures from a single molecular unit is strategic for the targeted synthesis of molecular compounds with well defined linear and nonlinear absorption properties. In this view, it is important to be able to predict the properties of multichromophoric units, based on the knowledge of the properties of the individual chromophores and their mutual arrangement. To this end, we present a combined experimental and theoretical study on 4-(para-di-n-butylaminostyryl)-pyridine, a push-pull molecule, and its dimer, 4,4'-bis(para-di-n-butylaminostyryl)-2,2'-bipyridine, formed by connecting the two pyridine groups into a bipyridine structure. One photon absorption and fluorescence spectra are measured in solvents of different polarity, and two-photon absorption spectra are recorded in dichloromethane. Experimental results are compared with results of TDDFT (Time-Dependent Density Functional Theory) and CIS (Configuration Interaction with Single excitation) methods implemented in the Gaussian03 program suite. An essential-state analysis of optical spectra is used to rationalize the observed behavior.

Glycosylated podophyllotoxin congeners: loss of microtubule inhibition and permission of invasion in vitro.

Podophyllotoxin (PPT) and its glycosylated congeners, 4'-demethylepipodophyllotoxin 9-[4,6-O-(R)-ethylidene-beta-D-glucopyranoside] (VP-16-213) and 4'-demethylepipodophyllotoxin 9-[4,6-O-(R)-thenylidene-beta-D-glucopyranoside] (VM-26), were studied for their effects on the following activities of MO4 mouse fibrosarcoma cells in vitro: growth as an aggregate in culture on a gyrotory shaker, directional migration from an aggregate explanted on glass, organization of the cytoplasmic microtubule complex as inferred from immunostaining with an antiserum against tubulin, and invasion into fragments of 9-day-old embryonic chick cardiac muscle. At concentrations that inhibited growth (greater than or equal to 0.03 microgram/ml), PPT arrested directional migration, abolished the cytoplasmic microtubule complex, and interfered with invasion. VM-26 (0.1-1.0 microgram/ml) and VP-16-213 (1-30 micrograms/ml) interfered with growth but permitted directional migration, organization of the cytoplasmic microtubule complex, and invasion. These observations imply that microtubule inhibitors are anti-invasive because they interfere with the assembly of the cytoplasmic microtubule complex and not because they inhibit growth.

Antiinvasive activity of estramustine on malignant MO4 mouse cells and on DU-145 human prostate carcinoma cells in vitro.

Estramustine (EM) is a conjugate of estradiol and nor-nitrogen mustard (nor-HN2), which is effective in the treatment of prostate cancer. We have compared the effect of EM with that of the known microtubule inhibitor vinblastine (VLB) on the following functions of malignant MO4 mouse cells and of DU-145 human prostate cancer cells in vitro: directional migration, invasion; and the organization and the assembly/disassembly equilibrium of microtubule complexes. The circular area covered by cells migrating from an aggregate explanted on a solid substrate was taken as an index of directional migration. Invasion was studied through confrontation of MO4 or DU-145 cells with fragments of embryonic chick heart in organ culture. Microtubules were investigated immunocytochemically and through immunodetection on protein blots. VLB and EM inhibited directional migration and invasion of MO4 and DU-145 cells in a dose-dependent manner; equimolar combinations of estradiol plus nor-nitrogen mustard did not mimic these effects. At anti-invasive concentrations VLB led to partial disassembly of microtubule complexes, whereas EM resulted in an abnormal pattern of microtubule complexes without alteration of the overall assembly/disassembly equilibrium. Combined treatment with VLB and EM resulted in an enhanced VLB effect, namely complete disassembly. In all tests DU-145 cells were more sensitive to both VLB and EM than were MO4 cells, and the effects were less reversible. The present experiments showed that EM shares an anti-invasive activity with other microtubule inhibitors.

Effects of tubulozole on the microtubule system of cells in culture and in vivo.

Light and electron microscopic investigations on mammalian cells in vitro and in vivo showed that tubulozole-C (R 46 846), the cis-isomer of tubulozole, a new synthetic anticancer drug, interfered with the structure and function of microtubules in both interphase and mitotic cells. The activity of this compound in experimental tumor systems can thus be explained partly by a direct antimitotic effect and partly by the disintegration of the normal subcellular organization of the nondividing cells. At concentrations which affect the microtubule system, tubulozole-C arrested directional migration of transformed cells and malignant invasion in a three-dimensional organ culture system. Investigations in vivo show that malignant L1210 leukemia cells are more susceptible to the antimicrotubular effect of tubulozole-C than are the normal leukocytes of the host. The trans-isomer of tubulozole (tubulozole-T, R 48 265), which has no antitumor activity in vivo, did not affect the microtubule system of cells in vitro or their capacity for directional migration or for malignant invasion.

Invasiveness and metastatic capability of rat fibroblast-like cells before and after transfection with immortalizing and transforming genes.

Invasion in vitro and in vivo and spontaneous metastasis was investigated in cell lines before and after introduction of immortalizing (polyoma large-T and activated myc) genes and of transforming (polyoma middle-T and activated ras) genes in Fischer rat cells. Invasion in vitro was tested by confrontation of rat cells with embryonic chick heart fragments in organ culture. Invasion in vivo and metastasis was evaluated in nude mice and in syngeneic rats after injection of cells i.p. or s.c. in the flank and after implantation of cell aggregates s.c. in the tail. Rat cells were also analyzed for the presence of myc oncogenes, and for the expression of ras oncogenes. Cells from primary or low passage rat embryo (REF) cells were not invasive in vitro and did not produce tumors in vivo. Cell lines (LTRAT1, LTaRAT1) derived from REF cultures after transfection with plasmids encoding polyoma large-T antigens, behaved like REF cells. Cell lines (REFpEJgpt4, REFpEJmycN7) established from REF cultures after transfection with either a plasmid encoding an activated human ras protein or with the latter plasmid plus one containing an activated myc gene, were invasive in vitro and in vivo and produced invasive and metastatic tumors in syngeneic rats. Cell lines (FR3T3) established in an apparently spontaneous way were invasive in vitro and produced invasive tumors in vivo without metastasis. Derivatives of FR3T3 (FRLT1, MTT4, MMC1, and PyT21) transfected with plasmids encoding one or more of the polyoma antigens, differed from FR3T3 cells by a shorter latency period of tumor formation (less than 1 versus 1 to 3 weeks). Like FR3T3 tumors, FRLT1, MTT4, MMC1, and PyT21 tumors were invasive but not metastatic. Other spontaneously established lines (Rat1) were invasive and metastatic. Cells (Rat1pEJ6.6) derived from Rat1 cultures after transfection with a plasmid encoding an activated ras protein, showed shorter tumor latency periods (less than 1 versus 7 weeks). A thymidine kinase deficient Rat1 derivative (Rat2) was not invasive in vitro but produced invasive and metastatic tumors in vivo with long (9 to 21 weeks) latency periods. Rat2pT24B4 cells derived by us from Rat2 cells after transfection with a plasmid containing a mutated human ras gene (pT24), were invasive in vitro and in vivo as were cells derived from Rat2 tumors. We conclude from our experiments that invasiveness and metastatic capability are often acquired by established REF-derived cell lines in an apparently spontaneous way.(ABSTRACT TRUNCATED AT 400 WORDS)

Thermal transformations and stability of organometallic materials with electrical and optical properties: the case of polycrystalline cis-[Ir(CO)2Cl(C5H5N)].

In this paper the solid-state transformations under heating of cis-[Ir(CO)2Cl(C5H5N)] are discussed. The complexity of the transformations was revealed by integrating infrared spectroscopy, conventional and bidimensional X-ray diffraction, thermal analysis, and hot stage optical microscopy. During heating anisotropic expansion of the lattice along the Ir-Ir stacking takes place. Then cis-[Ir(CO)2Cl(C5H5N)] undergoes an irreversible solid-solid phase transition to a lattice of higher symmetry followed by a reversible transition into the amorphous phase. Under proper cooling a partial recrystallization takes place. Experiments in the presence of oxygen must be carried out in short time periods to avoid oxidation from Ir(I) to Ir(III).

Effect of dipyridamole on invasion of five types of malignant cells in organ culture.

Dipyridamole (DPD) has been shown to inhibit the motility of cells in culture. We have tested the effect of DPD on the invasion in confronting organ culture of the following malignant cell lines: mouse MO4 cells; rat NBT II bladder tumor cells; human SA4 glioblastoma cells; mouse LLC H61 lung carcinoma cells; and mouse F87 C1.6T2 melanoma x lymphocyte hybrid cells. At concentrations of 20 micrograms/ml or higher, DPD inhibited the invasion of all cell types into embryonic chick heart. In serum-free culture medium the anti-invasive concentration of DPD was about ten times lower. Anti-invasive concentrations of DPD also inhibited proliferation of the malignant cells. Both inhibition of invasion and of proliferation were reversible.

In vitro invasiveness of human bladder cancer from cell lines and biopsy specimens.

Aggregates prepared from cell lines established from a human transitional cell carcinoma of the urothelium (Hu 456) or from apparently normal urothelium before (Hu 609) and after phenotypic transformation (Hu 609T) were confronted with fragments of embryonic chick cardiac muscle in organ culture. In this assay a correlation was found between in vitro invasiveness of animal cell lines and their capacity to produce invasive tumours in syngeneic animals. The invasiveness of cells from established human urothelial lines was compared to the invasiveness of cells from established human urothelial lines was compared to the invasiveness of cells from fresh biopsy specimens of a normal urothelium, a non-invasive papilloma, and a metastasizing transitional cell carcinoma. Cells from all established lines (Hu 609, Hu 609T and HU 456) and from the biopsy specimens of the transitional cell carcinoma occupied and eventually replaced the cardiac muscle by contrast with cells from the normal urothelium or from the non-invasive papilloma. We concluded that the organ culture assay for invasiveness might be used to define malignancy of human bladder cell lines and to follow the various steps during the acquisition of invasiveness in vitro.

Tumorigenicity, invasiveness and metastatic capability of FR3T3 rat cells before and after transfection with bovine papilloma virus type 1 DNA.

Fischer rat FR3T3 cells were tested for tumorigenicity, invasive and metastatic capabilities before and after transfection, either with the entire bovine papilloma virus type 1 (BPV-1) genome or with a plasmid (pV69) containing a 69 per cent Bam H1-Hind III fragment of the BPV-1 genome as well as bacterial sequences. Cell lines were grouped as parental, pV69-transfectants, BPV-1 transfectants, in vitro derivatives, and in vivo derivatives. The tumorigenic, invasive and metastatic capabilities of these cell lines were examined in vivo through s.c., and i.p. injections of cell suspensions and through s.c. implantations of cellular aggregates into syngeneic rats. Invasiveness was tested in vitro through confrontations with embryonic chick heart fragments in organ culture. All cell lines including parental lines, were found to be invasive in vitro and tumorigenic in vivo; all tumors were invasive. It is, therefore, not possible to draw conclusions about the role of BPV-1 gene sequences in the acquisition of the invasive phenotype. Transfection with BPV-1 genes conveyed the metastatic phenotype upon parental FR3T3 cells, which were themselves found to be non-metastatic. With regards to this, no differences were found between BPV-1 transfectants compared with pV69 transfectants. Untransfected cells became metastatic also through passage in vivo as an s.c. tumor. The expression of the metastatic phenotype was not noticeably correlated with alterations of growth characteristics of the cell lines. We concluded that the implication of BPV-1 gene sequences in conveying the metastatic phenotype upon FR3T3, if any, was indirect, presumably through alterations of the host cell genome. Our experiments illustrate the need for long-term observations with parental cell lines before drawing conclusions about the role of oncogenes in the acquisition of the malignant phenotype.

Effect of inhibitors of glycosylation and carbohydrate processing on invasion of malignant mouse MO4 cells in organ culture.

Inhibitors of glycosylation and carbohydrate processing were used to investigate the role of carbohydrates exposed at the cell surface in invasion. Malignant mouse MO4 cells were confronted with embryonic chick heart in organ culture, an assay shown to be relevant for a number of aspects of invasion in vivo. Tunicamycin (1.0 microgram/ml), 2-deoxy-D-glucose (100 mM), beta-OH-norvaline (1.0 mM), and Monensin (0.1 microgram/ml) reversibly inhibited the invasion of MO4 cells. At these concentrations the drugs also inhibited the growth of MO4 cells. 1-Deoxynojirimycin (10mM), swainsonine (0.4 microgram/ml), and Marcellomycin (0.1 microgram/ml) permitted invasion. Marcellomycin also reversibly inhibited the growth of MO4 cells. These results show that drugs known to interfere with the glycosylation or processing of carbohydrate chains of glycoproteins in different ways have different effects on the invasion of MO4 cells in vitro.

Effect of temperature on invasion of MO4 mouse fibrosarcoma cells in organ culture.

Invasion by MO4 mouse fibrosarcoma cells into fragments of embryonic chick heart or lung in organ culture was studied histologically and ultrastructurally at various temperatures between 12 and 40 degrees C. Invasion was absent for at least 7 days at or below temperatures of 29 degrees C. Invasion was invariably observed at or above 30.5 degrees C. Differences in invasion between 29 and 30.5 degrees C could not be ascribed to differences in growth, migration, or microtubule assembly/disassembly of MO4 cells. Neither could they be explained through differences in the attachment of MO4 cells to the heart fragments. Possible explanations for the absence of invasion at lower temperature are: altered resistance of the extracellular matrix in heart or lung fragments, and deficient expression of fucosylated glycoproteins at the surface of MO4 cells. A population of MO4 cells plated from the parent line and adapted to grow at 28 degrees C (MO(4)28 cell line) did not differ in invasiveness from the parent MO4 cells. We conclude that the temperature dependence of invasion in organ culture might indicate as yet unexplored aspects of the mechanisms of tumour invasion.

Effect of oncogene transfection or passage in vivo on malignant phenotypes of rat2 cells.

Rat2 cells are thymidine kinase-deficient derivatives from the immortalized rat embryo cell line Rat1. They show no phenotypic correlates of malignancy in vitro and produce tumors in syngeneic Fischer rats after long latency periods. We have investigated how transfection with oncogenes would alter the in vitro and in vivo behavior of Rat2 cells. Thus we have manipulated Rat2 cultures in various ways. The cell lines obtained were categorized as parental, in vitro subclones, untransfected in vivo derivatives, non-oncogene (neor and tk) transfectants, oncogene (mutated c-Ha-ras, polyoma middle-T, FBR v-gag-fos-fox) transfectants, and in vivo derivatives of transfectants. They were tested in vitro for morphotype, colony formation in soft agar, growth in organ culture, invasion in organ culture, and in vivo for latency period of tumor formation, tumor growth rate, invasiveness, and metastasis. Differences between the consequences of various manipulations were found in the number of malignancy-related phenotypic alterations. The following trend could be deduced from our data: induction of invasiveness in organ culture by all manipulations; morphotypic transformation and shortening of tumor-latency period by all oncogene transfections and by passage with tumor formation in vivo; growth in organ culture and increased tumor growth rate in vivo by transfection with ras-, or fos-oncogenes and by passage in vivo. Metastatic capability (present in parental Rat2 cell tumors) and colony formation in soft agar (absent in Rat2 cells) were not affected by the present manipulations. We concluded that differences between the oncogene-transfectants and the untransfected in vivo derivatives do not lie in the expression of malignancy-related phenotypes but in the time needed to acquire them.

[Mid-term clinical study of the effectiveness of and tolerability to simvastatin ++ in dyslipidemic patients]. / Studio clinico a medio termine sull'efficacia e tollerabilità della Simvastatina in pazienti dislipidemici.

The HGM-CoA reductase inhibitors, blaking up intracellular synthesis of cholesterol, support the receptorial captation of cholesterol with a reduction in plasma levels. The simvastatin efficacy was evaluated in 12 patients, mean age 59 +/- 10 years with a primary hypercholesterolemia. All the patients were on a pharmacologic wash out for at least 6 weeks and dietetic treatment (according to their weight and daily needs) for a week. Total cholesterol, HDL-cholesterol and triglycerides plasma levels were taken at time 0. Then a treatment with simvastatin 10 mg/die was begin for 4 weeks and than increased to 20 mg in patients with plasma cholesterol > 200 mg/100 ml at the end of fourth week. In some patients the dose was increased up to 40 mg for the elevated levels of plasma cholesterol at the end of the second month. All the parameters above were controlled monthly for three months. A control was performed at the end of sixth month of treatment. After 4 weeks treatment, simvastatin induced reduction in cholesterol plasma levels (p < 0.005), that continued during the whole time treatment (228 mg/dl at 24 week, p < 0.005 vs basal). The mean dosage of the simvastatin at fourth month was of 25 mg/die. During the treatment an increase of HDL plasma levels was noted, but this increment wasn't statistical significant (40 +/- 7 vs 45 +/- 9 mg/100 ml). No significant impairment of principal metabolic and laboratory parameters were observed during the treatment. These data indicate that simvastatin in small dose induce a reduction in cholesterol plasma levels with a significant increase in HDL without side effects.

[Gabexate mesilate vs gabexate mesilate combined with octreotide in the prevention of postoperative complications of pancreatic surgery: preliminary results]. / Confronto fra gabesato mesilato da solo e in associazione con octreotide nella prevenzione delle complicanze postoperatorie in chirurgia pancreatica: risultati preliminari.

To date, gabexate mesilate, a synthetic protease inhibitor, has been used in the prophylaxis and treatment of acute pancreatitis, but has yet to be tested in preventing the postoperative complications of pancreatic surgery. For this purpose we planned a pilot study based on two treatment groups, each numbering 25 patients, submitted to high-risk pancreatic resection. In the first group, all patients received a continuous infusion of gabexate mesilate 1 g/day up to postoperative day 4; the second group of patients received the same treatment plus octreotide 0.1 mg every 8 hours for 5 days after surgery. All patients were followed until discharge with clinical and instrumental investigations to detect the onset of postoperative complications. The overall incidences of an uneventful course were 40% (10/25) and 32% (8/25), respectively. We found 12 complications closely related to pancreatic surgery in the former and 8 in the latter group. In the combined treatment group therefore we observe a 33% reduction in the incidence of related abdominal complications (12 vs 8). This favourable trend, however, needs to be confirmed in a larger multicentre trial.

Heparan sulfate at the surface of HeLa cells.

HeLa cells, labeled with Na235SO4, release into the culture medium 35SO4 bound to plasma membrane vesicles next to 35SO4-glycoproteins and free 35SO4. Plasma membrane vesicles, experimentally produced by treatment with formaldehyde, contain 35SO4 and their surface can be stained with high iron diamine. Scanning of chromatograms of the trypsinate from labeled cells demonstrates radioactivity on the spot of heparan sulfate. It is concluded that HeLa cells synthesize heparan sulfate, which is incorporated at the plasma membrane and released by shedding of small vesicles.

Tumor-selective cytotoxic effects of murine tumor necrosis factor (TNF) and interferon-gamma (IFN-gamma) in organ culture of B16 melanoma cells and heart tissue.

Organotypically cultured, confronting pairs of B16B16 cell clusters and fragments of embryonic chick or mouse heart, as used for the study of invasion in vitro, were treated with murine TNF plus IFN-gamma for 4 and 7 days. This treatment selectively killed the B16B16 cells and left the heart tissue intact as assayed by histology and by plating confronting pairs and spent medium on tissue culture substrate. Using this organ culture assay, which more closely mimics the situation in vivo, we confirmed the tumor-selective cytotoxic effects of combined treatment with TNF and IFN-gamma as observed in separate cultures of malignant and non-malignant cells on "artificial" substrate.

Recovery from growth inhibition in irradiated MO4 spheroids: suspension cultures versus explanted cultures.

Spheroids of MO4 mouse fibrosarcoma cells were irradiated with single doses of photons between 1 and 50 Gy. Growth of irradiated spheroids was followed in suspension culture and after explantation on glass. We found that MO4 spheroids recovered from higher doses of irradiation when they were explanted on glass than when they were kept in suspension culture. These results suggest that irradiated MO4 cell populations may become anchorage-dependent for growth.

Cytochemical localization of catalase in glyoxysomes isolated from maize scutella.

The localization of catalase in isolated maize scutellum glyoxysomes was investigated by means of the diaminobenzidine histochemical reaction. Only the membranes of the glyoxysomes become heavily stained after incubation with diaminobenzidine and H(2)O(2). If the glyoxysomes are lysed with Tricine buffer at pH 9, 70% of the catalase is solubilized, while the remaining 30% is tightly bound to an insoluble fraction formed mostly by glyoxysomal membranes. This suggests that catalase may be present also in the matrix of the glyoxysomes. The lack of staining of the matrix with diaminobenzidine is probably due to the high concentration of catalase in the membranes of the organelles.