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M Israel

Publications and source records attributed to M Israel.

At least 109 records · Page 6Linked to original sources
PubMed1983

Phase I trial of mitoxantrone by 24-hour continuous infusion.

Mitoxantrone (DAD) is a new agent which intercalates into DNA. Preclinical studies have demonstrated activity equal to or greater than that of doxorubicin in all tumor systems tested. In this phase I clinical trial, the schedule of drug administration consisted of a 24-hour continuous iv infusion repeated at 21-day intervals. Twenty-nine patients received a total of 66 courses over a dose range of 4-15 mg/m2. The dose-limiting toxic effect was leukopenia, with a wbc count nadir on Day 12 and resolution prior to Day 21. Other toxic effects were thrombocytopenia, mild phlebitis, and blue discoloration of veins. Objective tumor responses were seen in a patient with adenocarcinoma of the breast and in another patient with clear cell carcinoma of the vagina. An additional six patients with acute leukemia were treated at a dose of 12 mg/m2; a decrease in peripheral blast count was observed in four of these six patients. The toxicity of DAD by 24-hour iv infusion was similar to that previously reported for iv bolus administration. We recommend phase II evaluation of DAD at a dose of 12 mg/m2 by single iv injection at 21-day intervals. Patients with acute leukemia should be evaluated at higher dose levels.

Adolescent↗
PubMed1983

Relationship of adriamycin concentrations to the DNA lesions induced in hypoxic and euoxic L1210 cells.

Exponentially growing L1210 mouse leukemia cells were incubated with Adriamycin (ADR) under hypoxic (95% N2:5% CO2) or euoxic conditions (95% air:5% CO2) for 1 hr at 37 degrees at a drug concentration ranging from 2.8 X 10(-8) to 2.8 X 10(-4) M, i.e., from levels attained clinically by bolus delivery to the high levels used as an i.p. drug dwell or experimentally, in in vitro conditions. High-pressure liquid chromatography analyses showed diminishing efficiency in drug uptake by the cells as the dose was increased. There were no significant differences between hypoxic and euoxic cells in drug uptake and metabolism. The frequency of DNA protein-associated single-strand breaks and DNA-protein cross-links per 10(6) nucleotides, detected by the alkaline elution technique, increased with the dose in the range of 2.8 X 10(-8) to 2.8 X 10(-6) M in both euoxic and hypoxic cells and declined thereafter. However, the number of DNA lesions relative to a normalized drug level declined steadily, starting with the 2.8 X 10(-7) M concentration. Concentrations greater than 2.8 X 10(-6) M of ADR induced still another type of lesion, direct DNA strand breaks, only in euoxic cells. The results indicate that a common mechanism of interaction between drug and DNA is present in hypoxic and in euoxic cells at low ADR, while an O2-dependent mechanism becomes operational in euoxic cells at high ADR levels.

Animals↗
PubMed1983

Doxorubicin in pregnancy: possible transplacental passage.

Two pregnant women with lymphoproliferative disorders were treated with doxorubicin-containing regimens. Both patients delivered shortly after a dose of doxorubicin. One child was healthy and the other was stillborn. Measurements of anthracycline levels in placental, cord, and fetal tissues by high-performance liquid chromatography suggest that doxorubicin may be transported across the placenta.

Adult↗
PubMed1982

Isolation and characterization of polyoma virus mutants which grow in murine embryonal carcinoma and trophoblast cells.

Mouse trophoblast cell lines established from cultured midterm placenta and a cell line obtained from cultured blastocyst resemble trophectoderm cells. These cells are resistant to infection by wild-type polyoma virus. We have isolated six polyoma virus mutants capable of growing in trophoblast cell lines. Restriction enzyme analyses and marker rescue experiments revealed that the genetic changes necessary for the growth of these mutants ( PyTr mutants) in trophoblast cells were located in a regulatory region of the genome between the origin of viral DNA replication and the region encoding the viral structural proteins. PyTr mutants are, therefore, similar to PyEC mutants, described by others, which are able to grow in embryonal carcinoma cell lines such as F9 or PCC4. The nucleotide sequence of two independently obtained PyTr mutants has an identical 26-bp deletion from nucleotide 5131 to 5156. This deleted region is replaced by either the sequence GGGA or by viral DNA sequences that flank this deletion. PyECF9 mutants grow well in trophoblast and trophectoderm cells, but PyTr mutants do not grow in F9 or PCC4 cells.

Animals↗
PubMed1982

Adriamycin analogues. Preparation and antitumor evaluation of 7-O-(beta-D-glucosaminyl)daunomycinone and 7-O-(beta-D-glucosaminyl)adriamycinone and their N-trifluoroacetyl derivatives.

The title compounds were prepared by Koenigs-Knorr condensation of 3,4,6-tri-O-acetyl-2-deoxy-2-[(trifluoroacetyl)amino]-alpha-D-glucopyranosyl bromide with daunomycinone or a side-chain protected adraimycinone, followed by selective hydrolysis of blocking groups. Despite poor complexation with DNA and weak growth-inhibitory properties in vitro, the glucosaminyl analogues of the antitumor antibiotics daunorubicin and adriamycin, at their optimal (highest nontoxic) doses, exhibited antileukemic activity equivalent to that of adriamycin against a usually drug-refractory mouse leukemia model system (L1210) in vivo. These findings, together with other data from these laboratories, continue to support the hypothesis that the mechanism of action of adriamycin and related agents cannot be due exclusively to DNA binding, as has earlier been believed.

Animals↗
PubMed1982

Adriamycin analogues. Novel anomeric ribofuranoside analogues of daunorubicin.

The synthesis, cell growth-inhibitory activity, in vivo antileukemic activity, and extent of DNA binding of the alpha- and beta-anomeric 7-O-(3-amino-3,5-dideoxy-D-ribofuranosyl)daunomycinones and their trifluoroacetamides are described. These compounds are unique in that they are the first reported furanoside analogues of the antitumor antibiotics daunorubicin and adriamycin. Continuing analysis of structure-activity relationships amongst natural and semisynthetic anthracyclines fails to reveal a predictable relationship between in vivo antitumor activity and the in vitro properties of DNA complexation and cell growth inhibition.

Animals↗
PubMed1982

Adriamycin analogues. Preparation and biological evaluation of some N-perfluoroacyl analogues of daunorubicin, adriamycin, and N-(trifluoroacetyl)adriamycin 14-valerate and their 9,10-anhydro derivatives.

The experimental and clinical antitumor activity, as well as the low toxicity, of N-(trifluoroacetyl)adriamycin 14-valerate (AD 32), a non-DNA binding anthracycline analogue, has led us to prepare and evaluate several N-perfluoroacyl analogues of daunorubicin, adriamycin, and N-(trifluoroacetyl)adriamycin 14-valerate. Target compounds were prepared by reaction of the appropriate perfluoroacyl anhydride with daunorubicin in chloroform-ether, with adriamycin in cold pyridine, and with adriamycin 14-valerate in ethyl acetate. In connection with this work, it was found that reaction of perfluoroacyl anhydrides with N-acylated or N-unsubstituted anthracyclines in pyridine at room temperature afforded with ease and in good yield the corresponding 9,10-anhydro-N-acylated derivatives. A number of products showed good to highly significant antitumor activity in vivo against the murine P388 leukemia system. However, the lack of in vivo antitumor activity of the pentafluoropropionyl and heptafluorobutyryl analogues of N-(trifluoroacetyl)adriamycin 14-valerate is noteworthy. The results continue to show that non-DNA binding anthracycline analogues can exhibit in vivo antitumor activity. Loss of the anthracycline 9-carbinol function by dehydration leads to reduction of biological activity as compared to the parent compound.

Animals↗
PubMed1982

Adriamycin analogues. Preparation of 9,10-anhydrodaunorubicin, 9,10-anhydroadriamycin, and some related compounds.

The title compounds, as well as 9,10-anhydro-N-(trifluoroacetyl)adriamycin 14-valerate (9,10-anhydro-AD 32), were prepared starting from daunorubicin, adriamycin, and N-(trifluoroacetyl)adriamycin 14-valerate (AD 32), respectively. In addition, 9-deoxydaunorubicin and 9-deoxy-AD 32 were obtained by catalytic hydrogenation of the appropriate olefin. All of the products were significantly less active than the parent drugs in inhibiting the growth of CCRF-CEM (human lymphoblastic leukemic) cells in culture. The results suggest the importance of the tertiary alcohol function, as found in the parent compounds at the anthracycline 9 position, in contributing to the expression of biological activity of these agents.

Animals↗
PubMed1982

In vitro inhibition of Pseudomonas aeruginosa elastase by metal-chelating peptide derivatives.

Pseudomonas aeruginosa elastase is a zinc metalloendopeptidase, probably responsible for the tissue destruction observed during infections with this organism. The elastase of a virulent Pseudomonas aeruginosa strain (Habs serotype 1) was isolated and found to have a molecular weight of 35,000; it readily degraded elastin and cartilage proteoglycans. A series of amino acid and peptide derivatives containing the metal-chelating moieties hydroxamate, phosphoryl, or thiol were synthesized and tested as potential inhibitors of the enzyme. Inhibition constants (K(i)s) for the compounds were determined with the chromophoric substrate furylacryloyl-glycyl-l-leucyl-l-alanine. The hydroxamic acid derivatives of benzyloxycarbonyl-glycine, benzyloxycarbonyl-l-leucine and benzyloxycarbonyl-l-phenylalanine had inhibition constants in the range of 11 to 28 muM. The 2-mercaptoacetyl derivatives of l-leucyl-d-phenylalanine and l-leucyl-l-phenylalanine had K(i) values of 34 and 1.5 muM, respectively, demonstrating the stereospecificity of the inhibition. The most potent inhibitors tested were 2- mercaptoacetyl-l-phenylalanyl-l-leucine and phosphoryl-l-leucyl-l-phenylala-nine (K(i) = 0.2 muM). Similar compounds lacking the metal-chelating moiety were about 3 orders of magnitude poorer inhibitors. When the inhibition of the enzyme activity towards azocasein, elastin, or cartilage was examined, inhibitor concentrations approximately 50-fold higher than the respective K(i)s were required to obtain 60 to 90% inhibition. Virtually complete inhibition was achieved with these substrates at inhibitor concentrations 500-fold higher than the respective K(i)s (0.1 to 14 mM). Although, 2-mercaptoacetyl-l-phenylalanyl-l-leucine and phosphoryl-l-leucyl-l-phenylalanine exhibited the same affinity to the enzyme, the latter was inferior in inhibiting cartilage proteoglycan degradation. 2-Mercaptoacetyl-l-phenylalanyl-l-leucine represents a class of potent elastase inhibitors that might prove useful in the management of P. aeruginosa infections.

Cartilage↗
PubMed1982

STI usefulness during isometric exercise in labile hypertensive patients.

Measurement of the left ventricular systolic time intervals (STI) was considered a valid method in demonstrating the presence of a state of beta-drenergic hyperstimulation. The authors used this method during isometric exercise to differentiate between a group of 16 normal subjects (N) and 16 random labile hypertensives (LH), and between the N and 16 fixed hypertensives (FH). Exercise resulted in a general shortening (p less than 0.01) of the STI, an increase (p less than 0.01) in the systolic arterial pressure (SAP), and an increase (p less than 0.01) in the heart rate (HR) in all the groups studied. The study also demonstrated that the state of blood pressure (diagnosis) alone does not significantly influence the course of the exercise test, and that the interaction diagnosis-exercise gives quantitatively different results in the three groups, to the extent that it is possible to recognize a specific polygraphic pattern for the LH. In this group there is a greater shortening of the Q--S2 and the non-corrected LVET (p less than 0.01) than for the N. The behaviour for the FH falls between the other groups, but it is not possible to distinguish clearly between this group and its neighbour on either side. We conclude that the measurement of the STI during isometric exercise could be useful in determining a diagnostic pattern for subjects who show a lability in their blood pressure.

Adult↗
PubMed1982

Studies on presynaptic cholinergic mechanisms using analogues of choline and acetate.

Experiments in which analogues of choline and acetate were used in an attempt to elucidate presynaptic cholinergic mechanisms are described. The stimulation-induced accumulation of choline analogues in a sympathetic ganglion was used as an indicator of choline transport activation and the effects of various conditions on this phenomenon were tested. Acetylcholine synthesis and release, in the presence of choline, were then measured under similar conditions in order to explore the relationship between choline uptake and acetylcholine synthesis. Finally, the synthesis, storage and release of analogues of acetylcholine with altered acetyl moieties, propionylcholine and butyrylcholine, were studied using the Torpedo electric organ. Both of these analogues were incorporated into synaptic vesicles, but while butyrylcholine was as releasable as acetylcholine, propionylcholine was less releasable.

Acetates↗
PubMed1981

Distribution of radioactivity and anthracycline-fluorescence in tissues of mice one hour after [14C]-labeled AD 32 administration. Evidence for tissue aglycone formation.

Levels of radioactivity and total anthracycline fluorescence in tissues of A/JAX mice were compared 1 h after IV administration of unlabeled or [14C]-labeled AD 32 (50 mg/kg). Highest levels of both fluorescence and radioactivity were found in the small intestine (including contents) and liver, a result consistent with the known hepatobiliary excretion of AD 32 and metabolites. Significant accumulations of radioactivity and fluorescence were found in kidney, spleen, large intestine (including contents), lung, and heart. Lesser levels were found in muscle and fat. Little radioactivity and fluorescence were found in brain. Liquid chromatographic analysis of extracts of small intestine and liver homogenates showed N-trifluoroacetyladriamycin (AD 41) as the major fluorescent species, and also revealed N-trifluoroacetyladriamycinol (AD 92) and occasional low levels of AD 32. In addition, there was a major peak of nonfluorescent radioactive material and two fluorescent nonradioactive signals (unknowns 1 and 2), indicative of cleavage of the radiolabel from the chromophore.

Animals↗
PubMed1981

Comparative effects of adriamycin and N-trifluoroacetyladriamycin-14-valerate on cell kinetics, chromosomal damage, and macromolecular synthesis in vitro.

N-Trifluoroacetyladriamycin-14-valerate differs from Adriamycin in its rapid intracellular transport and lack of fluorescent binding to nuclei or chromosomes. Both of these anthracyclines cause inhibition in the incorporation of labeled precursors into nucleic acids, extensive chromosomal damage, and arrest of cell cycle traverse in G2. In human lymphoid cells, N-trifluoroacetyladriamycin-14-valerate, unlike Adriamycin, does not show cell cycle phase-specific or proliferation-related cytotoxic effects. In an L1210 soft-agar assay, both Adriamycin and N-trifluoroacetyladriamycin-14-valerate show no enhanced sensitivity of mid-S-phase cells to their cytotoxic action.

Animals↗