Biomedical subjects

N I Goldstein

Publications and source records attributed to N I Goldstein.

45 records · Page 3Linked to original sources

PubMed1978

Selecting somatic cell hybrids with hat media and nystatin methyl ester.

The structurally modified polyene antibiotic nystatin methyl ester (NME) has been utilized as a half-selection agent for isolating interspecific mouse--Syrian hamster hybrids. By using HAT media supplmented with NME we have isolated hybrid clones from polyethylene glycol-fused cultures of biochemically defective mouse (A9 or B82) and genetically normal Syrian hamster (KHK/C13) cells. Unfused parental cells were killed in HAT-NME media as a result of their genetic defect, absence of hypoxanthine guanine-phosphoribosyl transferase-HGPRT-(A9) or thymidine kinase--TK-(B82), or innate sensitivity to NME (BHK/C13). In contrast, hybrid cells proliferated and clones were isolated after 3 weeks growth in HAT-NME media, indicating the genetic complementation had occurred and polyene resistance was expressed as a dominant phenotypic property in the hybrids. The presently described technique is efficient in eliminating unfused parental cells and should prove useful in isolating other types of hybrids formed between genetically defective and normal parental cells.

Cell Separation↗

PubMed1977

Effect of polyene macrolide antibiotics on invertebrate tissue culture cells.

The effect of amphotericin B (AB) and amphotericin B methyl ester (AME) on viability and DNA synthesis in three insect cell lines, Trichoplusia ni (Tn) Carpocapsa pomonella 169 (Cp) and Aedes aegypti (Aa), has been evaluated. In all cases AME was less toxic than AB and inhibited DNA synthesis to a lesser degree than AB. However, the three cell lines differed in their response to the two polyene macrolide antibiotic preparations. Tn and Aa cell responded in a similar manner when exposed to either AME or AB, whereas Cp cells were more sensitive to both antibiotics than Tn or Aa cells.

Aedes↗

PubMed1976

The effect of fetal bovine serum on polyene macrolide antibiotic cytotoxicity and antifungal activity.

The relationships between fetal bovine serum (FBS) concentration and polyene macrolide antibiotic cytotoxicity to animal cells and to fungi were evaluated. The toxicity of amphotericin B (AB) and its derivative, amphotericin B methyl ester (AME), toward KB cells was found to be directly related to fetal bovine serum concentration. At higher FBS levels, increased concentrations of AB and AME were required to reduce 72-hr KB viable cell numbers of 50% of control values. Similarly, polyene macrolide antibiotic levels required to inhibit the growth of Saccharomyces cerevisiae to 50% of controls, and for obtaining minimum fungicidal concentrations (MFC), were greater when higher levels of FBS were used. In addition, AME was less toxic than AB toward KB cells grown in media containing 2, 5, 10, 15 or 20% FBS, whereas the antifungal activities of AB and AME were similar. AME was also capable of eliminating Candida albicans, Saccharomyces cerevisiae, Aspergillus niger or Fusarium moniliforme from KB cultures at antibiotic levels which exhibited less cell toxicity than did the concentrations of AB required for a similar response. These findings indicate that AME may be a potentially useful antifungal antibiotic for tissue culture systems.

Amphotericin B↗

PubMed1976

Reduced toxicity of amphotericin B methyl ester (AME) vs. amphotericin B and fungizone in tissue culture.

The comparative toxicities of amphotericin B methyl ester (AME), the parent antibiotic amphotericin B (AB), and the deoxycholate solubilized complex of AB, Fungizone (FZ), toward five cell lines has been determined as measured by early membrane damage (51Cr release), 24 hr survival, 72 hr viability, and growth rate. Cells used were of turtle (TH-1), marsupial (PT K2), human MA 160), rabbit (RK-13) and hamster (BHK-21) origin. AME: (a) caused less membrane damage at 1 hr than AB or FZ; (b) was less toxic than AB or FZ as indicated by 24 hr cell survival and 72 hr cell viability; and (c) was required in higher levels than AB or FZ to reduce the growth rate of all five cell lines. Spectrophotometric analysis of residual polyene levels indicated that AME had good stability in tissue culture medium. Previous studies have indicated that AME has the same in vitro antifungal activity as the parent antibiotic AB (1, 2). These findings suggest that AME may prove to be superior to AB and FZ for use as an antifungal agent in tissue culture systems.

Amphotericin B↗

PubMed1976

In vitro anti-mycoplasmal activity of amphotericin B methyl ester.

The polyene macrolide antibiotic amphotericin B (AB) and its chemically modified derivative amphotericin B methyl ester (AME) were tested for in vitro activity against Acholeplasma laidlawii, Spiroplasma citri and Mycoplasma gallisepticum. Both polyene macrolide preparations demonstrated anti-mycoplasmal activity. However, AME was mycoplasmacidal toward all three strains of mycoplasma at levels which previous studies have indicated would be permissible for most cell culture systems, whereas the levels of AB required for similar activity would be physiologically intolerable for tissue culture cells. In addition, AME was 100 fold more active than AB toward A. laidlawii, 10 fold more active than AB toward S. citri and demonstrated equivalent activity as AB toward M gallisepticum. The in vitro anti-mycoplasmal activity of AME and AB was directly correlated with polyene macrolide antibiotic levels and the number of treated mycoplasma.

Acholeplasma laidlawii↗

PubMed1975

Stimulatory effect of amphotericin B methyl ester on the grwoth of L-M and Vero cells.

The chemically modified polyene macrolide antibiotic, amphotericin B methyl ester (AME), exhibited a concentration-dependent growth stimulatory effect on established lines of mouse (L-M) and monkey (Vero) cells. Stimulation was indicated by increases in growth rate, and in the enhanced synthesis of DNA and RNA. In contrast, the parental antibiotic amphotericin B and the desoxycholate complex of amphotericin B, FungizoneR, did not elicit a similar proliferative response in L-M or Vero cells. AME was not growth-promoting toward low passage strains of mouse (PMK 6) and monkey cells (MGK 8).

Amphotericin B↗

PubMed1975

Toxicity of amphotericin B and its methyl ester toward normal and tumor cell lines.

The toxicity of amphotericin B, amphotericin B methyl ester (AME), and Fungizone toward three "normal" and three tumor-derived human and mouse cell lines was evaluated in monolayer culture. AME was less toxic than amphotericin B and Fungizone to all cell lines, but the sensitivity of the normal and tumor lines was different. The human (HEL-8 and WISH) and mouse (L-M) cells derived from normal tissue were more resistant to AME than the tumor-derived human (KB and HeLa) and mouse (RAG) cell as indicated by: (a) increased 24-hr survival, (b) increased 72-hr viability, and (c) growth rates at higher AME concentrations. In contrast, no pattern of differential sensitivity was observed with amphotericin B and Fungizone.

Amphotericin B↗

PubMedDate not supplied

Isolation and characterization of a human monoclonal antibody which reacts with breast and colorectal carcinoma.

A human monoclonal antibody with specificity for breast and colorectal carcinoma has been isolated after hybridoma formation between regional lymph node lymphocytes from a patient with breast carcinoma and a mouse x human heteromyeloma (SPAZ-4). The monoclonal, MAB 15.2.3, is an IgM, kappa, which binds to an epitope found on at least four glycoproteins with approximate molecular weights of 37, 39, 43 and 56 kilodaltons (kD). These antigens are expressed intracellularly and on the surface of breast and colorectal carcinoma cells and their level of expression is increased by treatment with recombinant human leukocyte (IFN-alpha A) or immune (IFN-gamma) interferon. Analysis of formalin-fixed tumor cell lines indicates specificity for carcinomas. Similarly, immunostaining of paraffin-embedded tissue indicates both cell membrane and intracytoplasmic reactivity with breast (8 of 12), colorectal (3 of 4) and prostate (1 of 3) carcinomas. By employing a series of enzymes which specifically cleave sugar residues on proteins, it was demonstrated that the binding of MAB 15.2.3 could be increased. These observations suggest that the epitope recognized by MAB 15.2.3. is protein in nature and expressed on a series of glycoproteins. Pretreatment of Colo 205 (human colorectal carcinoma) cells with MAB 15.2.3 prior to implantation into nude mice, results in a reduction in the size and weight of tumors. With appropriate genetic engineering, resulting in the conversion of this antibody to an IgG, MAB 15.2.3. could prove of value for the diagnosis and ultimately the therapy of human breast and colorectal carcinomas.

Antibodies, Monoclonal↗

PubMedDate not supplied

Apoptosis mediates the selective toxicity of caffeic acid phenethyl ester (CAPE) toward oncogene-transformed rat embryo fibroblast cells.

The active component of the folk medicine propolis, caffeic acid phenethyl ester (CAPE), displays selective toxicity toward cloned rat embryo fibroblast (CREF) cells transformed by a spectrum of diverse acting oncogenes. Identification of the mode of action of CAPE should provide useful information for possible applications of this compound for cancer therapy. The present study uses a series of oncogene transformed, oncogene-reverted and CAPE-resistant oncogene transformed CREF cells to investigate the mechanism underlying the increased sensitivity of transformed cells to CAPE. A direct relationship exists between the cytotoxic effects of CAPE and the induction of DNA fragmentation and apoptosis. DNA degradation into nucleosomal fragments and apoptotic shifts in DNA cell cycle profiles occur in CAPE-treated CREF cells transformed by wild-type 5 adenovirus (Ad5), a mutant Ad5 (H5hr1), the wild-type Ad5 E1A transforming gene, v-src, Ha-ras and the human papilloma virus type 18 transforming genes (HPV-18). In contrast, untransformed CREF cells, human fibroblast expression library-induced morphological revertants of Ad5- and v-src-transformed CREF cells, and Krev-1 expressing revertant Ha-ras-transformed CREF cells are resistant to CAPE-induced toxicity and apoptosis. Similarly, mutant Ad5-transformed CREF cells selected by step-wise growth in increasing concentrations of CAPE are resistant to growth inhibition and apoptosis induced by CAPE. These findings indicate that expression of the transformed phenotype by rodent cells evokes sensitivity to CAPE induced toxicity through apoptosis. The acquisition of CAPE sensitivity in rodent cells is independent of the mode of action of the oncogenic agent. CAPE may prove useful as an antiproliferative agent in cancer cells transformed by mechanistically diverse acting oncogenes.

Animals↗