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At least 19 recordsLinked to original sources
PubMed1979

Lipid composition of aminopterin-resistant and sensitive strains of Streptococcus pneumoniae. Effect of aminopterin inhibition.

The polar lipids of Streptococcus pneumoniae wild type and aminopterin-resistant strains were analysed. The membrane contained only two acid phospholipids, phosphatidylglycerol and cardiolipin, and a large amount of two glycolipids, glucosyldiglyceride and galactosylglucosyldiglyceride. The unsaturated acyl chains ranged from 58 to 87% of total fatty acids, depending on the strain and on growth conditions. No relation could be established between aminopterin resistance and polar lipid or fatty acid compositions. However, in the presence of bacteriostatic concentrations of aminopterin, the wild type and the resistant mutant did not have the same behavior. The resistant strain maintained its fatty acid composition and a normal [32P]phosphate distribution among phospholipids while the wild type shifted to a higher content in unsaturated fatty acids and to a high relative cardiolipin labelling. Such a differencein [32P] distribution was not observed when bacteriostatic concentrations of chloramphenicol were used, or when growth was stopped after amino acid deprivation induced by high concentrations of isoleucine. The biochemical basis of the aminopterin resistant character of the amiA mutants are not yet well understood but the present study establishes that the mutation confers a certain insensitivity of the lipid metabolism to aminopterin.

Aminopterin↗
PubMed1987

An aminopterin-like syndrome without aminopterin (ASSAS).

In two patients that closely resembled the phenotype of the syndrome produced by aminopterin in early pregnancy, no evidence of maternal exposure could be elicited. These, plus two similar cases from the literature, suggest the existence of an "aminopterin-like syndrome sine aminopterin" (ASSA) syndrome. Characteristic traits are: ossification defects of the cranium, temporal recession of hairline with upswept frontal hair pattern, ocular hypertelorism, prominent nose root, low set posteriorly rotated ears, limited elbow movement, variable digital defects, simian creases, short stature, and mild to moderate psychomotor retardation. Autosomal recessive inheritance is a possibility.

Abnormalities, Multiple↗
PubMed1994

Aminopterin Syndrome Sine Aminopterin (ASSA) syndrome in two siblings: further delineation of the syndrome and review of the literature.

In this report we describe two sibs with an unusual and complex pattern of severe malformations resembling Aminopterin Syndrome Sine Aminopterin (ASSA) syndrome, the phenotypic features of which are similar to those of aminopterin embryopathy. Six nonfamilial cases of ASSAS have been published in the literature to date. Our family with two affected sibs of different sexes supports the previous suggestion of autosomal recessive inheritance. Consanguinity of parents was excluded in this family, just as in all of the previously reported cases. Similar cases from the literature are briefly reviewed.

Abnormalities, Drug-Induced↗
PubMed2000

Further case of aminopterin syndrome sine aminopterin in a Spanish child.

We report on a Spanish child with clinical manifestations suggestive of aminopterin syndrome sine aminopterin (ASSA), having unusual hair pattern, syndactyly of fingers and toes, low-set thumbs, high-arched palate, and mild developmental delay. However, he does not show other characteristic features of ASSA such as ossification defects of the cranium, microcephaly, hypertelorism, cryptorchidism, or growth retardation. Differences from and similarities with Juberg-Hayward syndrome are discussed. Because few patients have been reported so far it is difficult to distinguish between these two conditions, and it may be that they are variants of the same nosological entity. Consanguinity of parents in this family supports autosomal recessive inheritance of ASSA.

Abnormalities, Multiple↗
PubMed1990

Aminopterin-like syndrome sine aminopterin associated with translocation involving chromosomes 5 and 10.

We studied a baby born with physical features suggestive of the aminopterin syndrome, but without exposure of the mother to aminopterin during pregnancy. G-banded chromosomes from peripheral blood lymphocytes had a normal 46,XX pattern. However, in 50 skin fibroblasts there was a normal female karyotype in 5 cells and 45 cells showed an apparently balanced reciprocal translocation involving the long arm of chromosome 5 (band q35) and the long arm of chromosome 10 (band q22). The relation of this mosaicism to the abnormal phenotype is unclear.

Abnormalities, Multiple↗
PubMed1994

Fetus with features of Crane-Heise syndrome and aminopterin syndrome sine aminopterin (ASSAS).

A male fetus with multiple congenital abnormalities is reported. The parents of the fetus are consanguineous. There were unusual facial features, digital anomalies, cleft palate, a malformed tongue that prevented swallowing, absent clavicles and genital hypoplasia. The fetus had features suggestive of both Crane-Heise syndrome and aminopterin syndrome sine aminopterin (ASSAS), and may represent part of a spectrum of abnormalities including these conditions.

Abnormalities, Multiple↗
PubMed1965

Hematological studies in the inbred offsprings obtained from Wistar strain albino rats treated with 4-amino-pteroylglutamic acid (Aminopterin), as viewed from heredity. 3. Alkaline phosphatase activity of peripheral neutrophils, bone marrow activity and life span of the erythrocytes in the inbred offsprings obtained from Wistar strain albino rats treated with successive oral administration of Aminopterin.

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Alkaline Phosphatase↗
PubMed1985

Enhanced polyglutamylation of aminopterin relative to methotrexate in the Ehrlich ascites tumor cell in vitro.

The polyglutamylation of aminopterin and methotrexate (N10-methylaminopterin) was compared in the Ehrlich ascites tumor in vitro. Three poly-gamma-glutamyl conjugates of methotrexate and aminopterin were detected, although at an equal (1 microM) extracellular drug concentration, the net accumulation of aminopterin polyglutamates exceeded that for the methotrexate polyglutamyl derivatives by a factor of 9. When compensation was made for transport differences between these compounds by adjusting the extracellular drug concentrations to achieve equivalent intracellular monoglutamyl substrate levels, the polyglutamylation of aminopterin was still 2.8-fold greater than that for methotrexate, suggesting that aminopterin is a better substrate for the folylpolyglutamate synthetase as well as the transport carrier. An additional metabolite of aminopterin was detected within seconds following drug exposure. This derivative did not bind tightly to dihydrofolate reductase, yet it was rapidly converted to a polyglutamate. The formation of both aminopterin polyglutamates and these novel derivatives was enhanced by increases in the free intracellular level of aminopterin. Aminopterin polyglutamates were bound tightly to dihydrofolate reductase and were retained intracellularly relative to unaltered aminopterin when Ehrlich cells containing these forms were suspended in drug-free medium. These findings support a role for the polyglutamylation of aminopterin as a critical element in drug action and as a factor in addition to membrane transport in the disparate antifolate potencies of aminopterin and methotrexate.

Aminopterin↗
PubMed1983

Effect of "aminopterin" on epithelial tissues.

The folic acid antagonist, 4-aminopteroyl glutamic acid ("aminopterin"), is a potent inhibitor of growth and of connective tissue proliferation. The present study indicates that the suppressive effects of "aminopterin" on epithelial structures are more striking than on connective tissue, as revealed by observation of interference with wound healing and epithelization, atrophy and ulceration of mucosa, alopecia, and prompt suppressive effects in such dermatologic disorders as psoriasis and chronic indurative dermatoses. "Aminopterin" was administered orally in daily doses of 1.5 to 2.0 mg. to thirteen patients with psoriasis (of whom six had associated arthritis) and to five patients with chronic indurative dermatoses. The latter included one patient with chronic atopic eczematoid dermatitis with associated asthma, one with chronic eczematoid seborrheic dermatitis, one with chronic discoid lupus erythematosus involving the face, and two with scleroderma. In all patients there were remissions in cutaneous lesions, which appeared most commonly between the 5th and 10th day of "aminopterin" therapy. Treatment was interrupted in most patients after an initial course of 14 to 28 mg. because of the regular occurrence of shallow ulceration of the buccal mucosa and frequent development of abdominal cramps. Remissions persisted for periods ranging from two weeks to several months, after which lesions returned which responded to further courses of "aminopterin." The therapeutic response was more complete in the seven patients with psoriatic arthritis than in in six subjects with uncomplicated psoriasis. In four patients with psoriatic arthritis in whom the responses to "aminopterin" and cortisone were compared, arthritic manifestations were considerably more relieved by cortisone, but improvement in psoriasis was consistently more complete and more sustained with "aminopterin." No evidence of a summative effect of cortisone and "aminopterin" on psoriasis was observed when the two were employed concomitantly, although amelioration of arthritic symptoms was more complete than when cortisone was given alone. Topical application of "aminopterin" in a 1% ointment was found to be ineffective. "Aminopterin" is a toxic drug, and its administration must be carefully supervised. The citrovorum factor has proved useful in overcoming "aminopterin" toxicity but interferes with its therapeutic effects. It is suggested that "aminopterin" may prove useful in other dermatologic disorders and in cutaneous manifestations of some systemic diseases which, in certain instances, have been temporarily benefited by cortisone.

Adult↗
PubMed1984

New folate analogs of the 10-deaza-aminopterin series. Basis for structural design and biochemical and pharmacologic properties.

Structural modification of the N10 position of 4-amino folates affects mediated membrane transport in mammalian cells but has little or no effect on target enzyme (dihydrofolate reductase) inhibition. Some of these modifications have been associated with differential effects on transport in various cell types in a manner which favored greater accumulation and persistence of drug in responsive tumor cells than in normal proliferative tissue. With the aid of identifying new structures with greater potential for differential mediated accumulation, we have studied three new 10-alkyl analogs of 10-deaza-aminopterin. Two of these analogs showed therapeutic efficacy substantially greater than 10-deaza-aminopterin, an analog with antitumor properties superior to methotrexate. These analogs, the 10-methyl, 10-ethyl, and 10,10-dimethyl derivatives, were equivalent to the parent compound, 10-deaza-aminopterin, and aminopterin, and slightly more potent than methotrexate, as inhibitors of L1210 cell dihydrofolate reductase. The three new analogs, 10-deaza-aminopterin, and aminopterin exhibited similar transport properties in L1210, Ehrlich, and S180 cells. Efflux and influx Vmax were similar to those of methotrexate, but influx Km was 4- to 14-fold lower than for methotrexate. That is, substitution at N10, but not at C10, reduced influx potential in these tumor cells. These differences in transport properties among this group of analogs which determine net accumulation were reflected in the individual values for growth-inhibitory potency. In contrast to that seen in tumor cells, alkylation at both N10 and C10 reduced influx potential (increased Km) in isolated intestinal epithelial cells from mouse small intestine. Influx was in the order aminopterin greater than 10-deaza-aminopterin with further reduction in each series showing a magnitude in proportion to the size of the 10 substituent. Otherwise, influx Vmax and efflux were similar for the group. Accumulation of polyglutamates in small intestine was greater following aminopterin administration than following administration of other analogs (10-ethyl, 10-deaza-aminopterin less than methotrexate less than 10-deaza-aminopterin). Polyglutamate accumulation for all the analogs was greater in tumor cells, but accumulation of each varied between the two tumors (L1210 and S180) examined. Differences among the analogs were not as great in L1210 as in S180 cells, and their metabolism was not in the same relative order.(ABSTRACT TRUNCATED AT 400 WORDS)

Aminopterin↗
PubMed2001

Requirement of de novo protein synthesis for aminopterin-induced apoptosis in a mouse myeloma cell line.

Cells synthesize nucleotides through de novo and salvage pathways that require the activities of dihydrofolate reductase (DHFR) and hypoxanthine-guanine phosphoribosyltransfease (HGPRT), respectively. Aminopterin, an inhibitor of dihydrofolate reductase, has been demonstrated to allow HGPRT(-) cells to be negatively selected. However, the pathway by which aminopterin leads to cell death remains to be clarified. In this study, we characterized features of cellular responses induced by aminopterin treatment in P3-X63-Ag8.653, a mouse HGPRT(-) myeloma cell line. Upon treatment with aminopterin, the cells readily underwent an apoptotic process, as assessed by DNA fragmentation assay and electron microscopic analysis. Aminopterin-induced apoptosis was drastically reduced by addition of actinomycin D and cycloheximide, indicating that active RNA and protein synthesis is required for the apoptotic effect of aminopterin. Interestingly, the induction of c-myc gene expression preceded the activity of DNA fragmentation in aminopterin-treated cells. Taken together, these results suggest that cells deficient in the salvage pathway of purine biosynthesis are susceptible to aminopterin-induced apoptosis that requires de novo synthesis of proapoptotic factors, including Myc oncoprotein.

Aminopterin↗
PubMed1991

Multidrug resistance phenotype associated with selection of an aminopterin resistant dog kidney cell line.

A determination of the mechanisms of drug resistance in tumour cells is important for developing strategies to combat such resistance in persons receiving chemotherapy. This report describes a combined cellular, biochemical, and molecular analysis of a dog kidney cell line selected for resistance to increasing levels of the hydrophilic antifolate, aminopterin. Three distinct drug resistance phenotypes were observed in cells exhibiting high levels of aminopterin resistance. Two of these phenotypes were decreased aminopterin accumulation and increased levels of dihydrofolate reductase specific activity. The third drug resistance phenotype was noted initially as cross resistance to a variety of hydrophobic drugs indicating multidrug resistance. Biochemical assays demonstrated reduced accumulation of the hydrophobic fluorescent drug daunorubicin and of 3H-colchicine in the aminopterin resistant cells. These results were then correlated with increased levels of the multidrug resistance (mdr) gene product, P-glycoprotein, and mdr mRNA levels in the aminopterin resistant cells. However, experiments designed to prove a role for expression of the mdr gene in providing a degree of aminopterin resistance were unsuccessful. It is concluded that aminopterin selection in these dog kidney cells resulted in expression of at least three distinct drug resistance phenotypes and that one of these phenotypes, multidrug resistance, represented a secondary response to the aminopterin selection.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Phase-selective AC adsorptive stripping voltammetric assay for aminopterin and 10-Edam in human serum.

Aminopterin was studied as a model compound for its analogues which maintain the pteridine ring in their structure. Its adsorptive behaviour on mercury was studied and the DC adsorptive stripping and phase-selective AC adsorptive stripping conditions were optimized. 10-Edam, an aminopterin analogue, was studied and shown to behave similarly to aminopterin. Phase-selective AC voltammetry provided the best signal and gave a detection limit of 4 x 10(-12) M aminopterin in aqueous solution employing an accumulation time of 10 min. The optimized method was applied to the analysis of both aminopterin and 10-Edam respectively in human serum. After extraction with a C18 reversed-phase cartridge the detection limit of the method was 1 x 10(-8) M aminopterin and the overall assay percentage recovery was 73.5% (n = 5) at a concentration of 5 x 10(-7) M aminopterin in serum. The analysis of 10-Edam at the same concentration in serum yielded the higher percentage recovery of 94.46% (n = 5) following the same procedure.

Adsorption↗
PubMed1984

New folate analogs of the 10-deaza-aminopterin series. Further evidence for markedly increased antitumor efficacy compared with methotrexate in ascitic and solid murine tumor models.

A group of folate analogs of the 10-deaza-aminopterin series, which were designed on the basis of the results of an intensive biochemical and pharmacokinetic program, have been examined in therapy experiments utilizing a group of murine tumor models. These new analogs were found to be markedly superior to methotrexate against four of five ascites tumors (L1210 leukemia, Sarcoma 180, Ehrlich carcinoma and Tapper carcinosarcoma) and against four of five solid tumors (S180, Tapper carcinosarcoma, E0771 mammary adenocarcinoma, Lewis lung carcinoma, and T241 sarcoma). Analogs alkylated (methyl or ethyl) at the 10 position of 10-deaza-aminopterin were found to be the most effective of the group. These analogs achieved log10 reduction in tumor burden several-fold greater in magnitude than methotrexate against L1210 and S180 ascites tumors and there were also long-term survivors. 10-Deaza-aminopterin itself gave a result intermediate between those obtained with the 10-alkyl derivatives and methotrexate. Against the solid forms of the Tapper tumor some partial regressions were obtained with methotrexate and 10-deaza-aminopterin, but a far greater number, extending over a longer period were obtained with the 10-ethyl derivative of 10-deaza-aminopterin. Against the E0771 tumor, 10-deaza-aminopterin was 2-fold and the ethyl derivative of 10-deaza-aminopterin was greater than 5-fold more effective than methotrexate in retarding tumor growth. Evidence for partial regressions and marked effects against metastatic disease were also obtained in the case of the 10-alkyl derivative. Similar results were also obtained with the T241 sarcoma. For Lewis lung carcinoma the relative potency was about the same but overall antitumor effects were more modest.

Aminopterin↗
PubMed1978

Antitumor properties of a new folate analog, 10-deaza-aminopterin, in mice.

A new folate analog, 10-deaza-aminopterin, was substantially more active than methotrexate, following sc administration in mice, against three of five ascites tumors and two of three solid tumors. For ascites tumors, maximum increases in lifespan (using 6--12 mg/kg q2d X 5) with 10-deaza-aminopterin versus methotrexate were + 171.2%/+ 149.8% against L1210 leukemia, +118.4%/+109.1% against P815 plasmacytoma, +64%/+20.9% against Ehrlich ascites carcinoma, +84.2%/+44.8% against Taper liver tumor, and greater than +159.6%/+64.0% against Sarcoma 180 with longterm survivors after 10-deaza-aminopterin. In a smaller number of experiments comparing LD10 dosages (given q2d X 5) of aminopterin, methotrexate, and 10-deaza-aminopterin, aminopterin was the least effective and 10-deaza-aminopterin was the most effective against the L1210 leukemia, Sarcoma 180, and Ehrlich ascites tumors. Following oral administration (3--6 mg/kg q2d X 5), a twofold greater increase in survival time was obtained against the L1210 leukemia with 10-deazaaminopterin (+122.8%) versus methotrexate (+57%). At a dosage of 6 mg/kg q1d X 5 against solid tumors, the relative tumor volumes (treated/control X 100%) were 12%/41% for Sarcoma 180, 16%/31% for Taper liver tumor, and 20%/30% for Ehrlich ascites carcinoma. Overall, the data suggest a broader spectrum of effective antitumor action in mice and a potential for the expanded clinical utility of this category of agent.

Aminopterin↗