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L F Meisner

Publications and source records attributed to L F Meisner.

At least 55 records · Page 3Linked to original sources
PubMed1988

Cytogenetic instability with balanced chromosome changes in an SV40 transformed human uroepithelial cell line.

Cytogenetic analysis at the 15th, 34th, 50th, and 56th passages of an SV40 immortalized human uroepithelial cell line (SV-HUC-1) showed continuous chromosome change and marker formation. Throughout these passages the transformed cells maintained their epithelial morphology, were SV40 T antigen positive, did not shed infectious SV40 virus, and were repeatedly found to be nontumorigenic when innoculated into athymic nude mice. Each of the passages studied was characterized by extensive karyotypic changes due to formation, rearrangement, and disappearance of different markers. A marker involving chromosome 1 was stable at three of the passages studied, whereas markers involving the X chromosome changed at each passage studied. Because of the incorporation of several chromosomes or chromosome arms into markers, the karyotype was genetically balanced in the first passage studied, with no net loss or gain of chromosomal material despite a modal number of 44. In subsequent passages, despite continued instability and generation of new markers, there was a slight but additive loss of genomic balance which increased with time in culture. Since continued karyotypic rearrangements did not lead to tumorigenic conversion, it is probable that genetic instability coupled with selection for the most balanced genome may be important for the immortalization of this cell line.

Cell Line, Transformed↗
PubMed1988

Marker chromosome stability associated with neoplastic transformation of human uroepithelial cells.

Chromosome studies were performed on three independently derived tumor cell lines established from carcinomas induced in nude mice after innoculation of SV40 immortalized human uroepithelial cells that had been treated with methylcholanthrene. Tumor 1 was an undifferentiated carcinoma, while tumors 7 and 9 were both squamous carcinomas. After six to eight passages in vitro the tumor cells were each reinoculated into other nude mice to yield secondary tumors (1.1 and 7.1). Chromosome studies on both primary and secondary tumors demonstrated the same distinctive chromosome markers. Tumors 1 and 1.1 shared the same histopathology in addition to the same modal chromosome number and identical chromosomal duplications and deficiencies; the same was true of tumors 7 and 7.1. Tumor 9, which did not yield a secondary tumor, nevertheless showed the same chromosome pattern in different passages. The stability of the characteristic marker chromosomes in the three tumor cell lines distinguishes these malignant lines from the nonmalignant SV40 transformed parent line from which the three tumors derived because the parent line was characterized by extreme marker instability. This suggests that the stable marker chromosomes that characterize the tumor cell lines may be critical for their tumorigenicity, and that evolution of an adaptive neoplastic genome may select for cytogenetic stability as long as there are no new selective pressures.

Animals↗
PubMed1988

Neoplastic transformation of SV40-immortalized human urinary tract epithelial cells by in vitro exposure to 3-methylcholanthrene.

Normal human urinary tract epithelial cells (HUC) were neoplastically transformed in vitro using a step-wise strategy. First, a partially transformed non-virus-producing cell line was obtained after infection of HUC with simian virus 40 (SV40). This cell line (SV-HUC-1) was demonstrated to be clonal in origin, as 100% of cells contained at least five of seven marker chromosomes. Marker chromosomes were formed by balanced translocations resulting in a 'pseudodiploid' cell line. SV-HUC-1 showed altered growth properties in vitro (e.g. anchorage independent growth) but failed to form tumors in athymic nude mice, even after 3 years in culture (80 passages). In the studies reported here, SV-HUC-1 at early passages (P15-P19) were exposed to 3-methylcholanthrene (MCA) in three separate experiments. After a six-week post-treatment period of cell culture, cells were inoculated s.c. into athymic nude mice. In all experiments, MCA-treated SV-HUC-1 formed carcinomas in mice usually with a latent period of 5-8 weeks. These carcinomas showed heterogeneity with respect to histopathologies and growth properties in the mice and karyotypes. All the tumors retained SV-HUC-1 chromosome markers, but each independent transformant was aneuploid and contained unique new marker chromosomes. Chromosomes usually altered in tumor cells included numbers 3, 5, 6, 9, 11 and 13. Mutations in the ras family of cellular proto-oncogenes resulting in altered mobility of the p21 protein product were not detected in six cell lines established from independently derived tumors. It is not yet known whether other cellular proto-oncogenes are activated in these tumorigenic transformants. Neither control SV-HUC-1 (which were not exposed to MCA), nor early passage HUC exposed to MCA formed tumors when inoculated into mice. Thus, the tumorigenic transformation of HUC resulted from the combined actions of SV40 and MCA.

Animals↗
PubMed1987

Cell culture of human colon adenomas and carcinomas.

Cell lines were established from colon adenomas, including tubular and villous polyps, primary adenocarcinomas, and metastases arising in patients with colon adenocarcinomas. The protocol for cultivating these diverse tissues includes primary cultivation of tissue explants on a type I collagen gel followed by nonenzymatic subculture of the epithelial outgrowth. All early passages were accomplished using low subculture ratios. Cultured cells elaborate morphological structures which are similar to features present in the tissues from which they were cultivated. Specifically, all structural features of colon epithelial cells were identified, including junction formation, prominent microvilli, and mucin secretion, in several cell lines. Five cell lines cultured from colonic neoplasms at different stages of cancer progression were selected for detailed characterization. Cells grown from two tubular polyps had normal human karyotypes. Cells from a villous polyp and all adenocarcinomas were aneuploid with stable marker chromosomes. The established cell lines exhibit distinct phenotypes based on growth characteristics in vitro and in athymic mice; and it is suggested that these cell lines represent useful models for studying the evolution of colon cancer from a benign to an aggressive cell type.

Adenocarcinoma↗
PubMed1987

Apparent Prader-Willi phenotype in a woman with ring chromosome 9.

A 25-year-old mentally retarded woman was evaluated because of her socially inappropriate behavior. She had a phenotype so closely resembling that of the Prader-Willi syndrome that several experienced clinical geneticists immediately identified her as having that condition. Chromosome analysis showed a ring chromosome 9 but no apparent abnormality of chromosome 15.

Adult↗
PubMed1987

Newborn infant with del(9)(pter----q32:) and multiple congenital anomalies including arrhinencephaly, cardiac malformations, and rudimentary ears.

A deletion of the long arm of chromosome 9(pter----q32:) in a newborn infant at 38 weeks of gestation was associated with a syndrome of arrhinencephaly, rudimentary ears, hypoplastic lungs and ureters, redundant nuchal skin folds, and congenital heart defects. Other findings included a Sydney line, macrocephaly, talipes equinovarus, oligohydramnios, and amnion nodosum. Detailed pathologic observations and the chromosome abnormality are described.

Abnormalities, Multiple↗
PubMed1987

Updating the N syndrome: occurrence of lymphoid malignancy and possible association with an increased rate of chromosome breakage.

Further studies on a family with the N syndrome, a multiple congenital anomaly/mental retardation syndrome first described by Hess et al in 1974, showed increased chromosome breakage in the affected brothers and in their unaffected mother, all 3 of whom died of lymphoid malignancy. It is suggested that the N syndrome is the result of an X-linked recessive mutation that produces a characteristic MCA/MR syndrome and chromosome instability. We postulate that this chromosome instability in the lymphoid cells of hemizygotes and in approximately half of the lymphoid cells of the heterozygote predisposes to a specific form of lymphoid malignancy.

Abnormalities, Multiple↗
PubMed1987

Effect of interferon alpha, interferon beta, and interferon gamma on the in vitro growth of human renal adenocarcinoma cells.

Interferon-alpha, interferon-beta, and interferon-gamma differ in their antiproliferative effects for several cell lines. Interferons were thus assessed for their activity in inhibiting proliferation of three renal cell carcinoma cell lines. The malignant epithelial phenotype of each of these cell lines was confirmed by electron microscopy, histology, karyotype and tumorigenicity. When compared on an anti-viral unit basis, naturally produced interferon-beta was more effective than natural interferon-alpha for all cell lines and clones. Proliferation of each of the cell lines was inhibited by interferon-gamma. In all cases, removal of interferons from culture media resulted in resumption of the rate of cell growth after a variable delay of 6-10 days. If the antiproliferative effects of interferons predominate in mediating tumor regression, clinical response may depend upon the type of interferon to which the tumor is exposed.

Adenocarcinoma↗
PubMed1987

Mechanisms in cyclophosphamide induction of cytogenetic damage in human lymphocyte cultures.

Low-dose cyclophosphamide treatment of human lymphocyte cultures in concentrations ranging from 0.001 to 0.00001 microgram/ml produced a statistically significant dose response in chromosome breakage and cell death. However, a dose as high as 0.2 micrograms/ml did not produce significant damage in comparably treated whole blood cultures. These results suggest that lymphocytes in culture have the ability to metabolize the nonmutagenic cyclophosphamide parent compound to its more mutagenic metabolite, but that such conversion may be prevented by binding of cyclophosphamide to red blood cells.

Biotransformation↗
PubMed1984

Synergistic effect of TPA and T-cell mitogens in nonmammalian vertebrates.

The phorbol ester, 12-0-tetradecanoyl-phorbol-13-acetate (TPA) was used as a comitogen with the plant lectins phytohemagglutinin (PHA) and concanavalin A (ConA) in short-term cultures of whole blood from nonmammalian vertebrates. Stimulation with TPA in addition to standard mitogens resulted in a synergistic effect, consistently yielding more metaphases than cultures stimulated with either PHA, ConA, or TPA alone and is successful with blood samples as small as 0.1 ml. The increased mitotic index makes it possible to use different banding procedures for systematic studies. Also, because the amount of blood needed is so small, this procedure, unlike other published techniques, does not require the destruction of smaller animals to do chromosome studies.

Amphibians↗
PubMed1984

Comparison of prometaphase chromosome techniques with emphasis on the role of colcemid.

Six different techniques were evaluated to define better those technical factors that are most critical for obtaining prometaphase cells for banding analysis. Our results demonstrate: colcemid exposures of 30 min or less have no effect on increasing the yield of prometaphase cells, colcemid exposures of greater than 0.1 microgram/ml can be toxic, methotrexate depresses the mitotic index significantly and seems to increase the incidence of prometaphase cells only because it suppresses later forms; and (d) the optimum number of cytogenetically satisfactory prometaphase cells can be obtained with a 4-h exposure to a combination of low concentration actinomycin D (0.5 microgram/ml) and colcemid (0.1 microgram/ml). This technique inhibits chromosome condensation while permitting prometaphase cells to accumulate for 4 h.

Chromosome Aberrations↗
PubMed1984

Establishment and characterization of human colorectal cancer cell lines.

A protocol for establishment of human colorectal carcinoma cell lines from fresh surgically removed tissues is described. Twelve human colorectal carcinoma cell lines were established from 6 of 18 primary cancers and four of four metastases. Cell lines from concurrent primary tumors and metastases were established from two individual patients. Two primary cancers gave rise to multiple cell lines with differing biological characteristics. Factors contributing to our success appear to be differential selection on the basis of substrate adherence and the timing of passage. The protocol avoids the use of feeder layers or passage through athymic mice. The established cell lines exhibit a range of karyotypes, morphologies, and growth characteristics.

Biopsy↗
PubMed1983

'Expanded' Prader-Willi syndrome in a boy with an unusual 15q chromosome deletion.

A male infant showed features of the Prader-Willi syndrome (including profound hypotonia, cryptorchidism, and mildly dysmorphic facial appearance) but also had additional multiple malformations (congenital heart disease, unilateral renal malmigration, and bifid uvula). A deletion of the long arm of chromosome 15, larger than that usually demonstrated in children with Prader-Willi syndrome, was found. The cytogenetic findings suggest that the infant's hypotonia and cryptorchidism are explicable on the basis of the portion of the deletion usually associated with Prader-Willi syndrome (q11 to q12) but that his other features could be secondary to effects of the more distal region of the deleted segment (q13 to q15).

Chromosome Deletion↗
PubMed1982

Neonatal death in cousins with trisomy 10q and monosomy 4p due to a familial translocation.

Two cousins with trisomy for a part of the long arm of chromosome 10 and monosomy for the distal portion of the short arm of chromosome 4 are reported. These infants had severe, neonatally lethal multiple malformations. Certain of these malformations--including severe lower limb reductions, marked ophthalmologic anomalies and certain craniofacial features--are inconsistent with either a simple additive effect of the two component chromosomal anomalies, or chromosomal "epistasis" that would result in observing the phenotypic effect of only one of the chromosomal aberrations. Rather a synergistic effect of these two karyotypic anomalies has resulted in unique phenotypic features.

Abnormalities, Multiple↗
PubMed1981

The dup(3q) syndrome: report of eight cases and review of the literature.

Clinical and cytogenetic examinations were performed on eight unrelated infants with duplication of part of the long arm of chromosome 3. A review of published cases shows a clinical syndrome characterized by statomotoric retardation, shortened life span, and a multiple congenital anomalies (MCA) syndrome of abnormal head configuration, hypertrichosis, hypertelorism, ocular anomalies, anteverted nostrils, long philtrum, maxillary prognathia, down-turned corners of the mouth, highly arched or cleft plate, micrognathia, malformed auricles, short, webbed neck, clinodactyly, simian crease, talipes, and congenital heart disease. The dup(3q) syndrome is a clinically easily recognizable entity.

Abnormalities, Multiple↗
PubMed1979

Parachute mitral valve, coarctation of aorta, radius aplasia, and omphalocele in an infant with the trisomy 18 syndrome.

A premature infant with trisomy 18 had cardiac defects including parachute mitral valve, coarctation of the aorta, and a subcristal ventricular septal defect. The parachute mitral valve was funnel-shaped with a moderately-thick cone of fibrous tissue around the annulus and an eccentric orifice. Many forms of congenital cardiac defects have been described in the 18 trisomy syndrome. However, parachute mitral valve has not, to our knowledge, been part of the spectrum of cardiac defects in trisomy 18. Other anomalies were absent radii, omphalocele, and cleft palate and cleft lip; these have been observed previously in the 18 trisomy syndrome.

Abnormalities, Multiple↗