Distinguishing characteristics of a new neuroblastoma cell line

The characteristics of a new neuroblastoma cell line (MC-NB-1) established from the bone marrow of a 2-year-old male are described. Morphologically, the cells appear as flattened and epithelial-like or as small and spherical. Electron microscopy demonstrated microtubules and dense core secretory granules. The doubling time was approximately 35 hr. Isoenzyme patterns and catecholamine secretion indicated a human line of neuronal origin. The soft agar tumor colony forming system demonstrated drug resistance in vitro comparable to in vivo nonresponsiveness. The stemline karyotype of MC-NB-1 is 44,Y,del(1) (p22:), -4, -7, +del(7)(q22:), -16, +t(7;16)(16pter leads to 16q24::7q22 leads to 7q32), -17. Additionally, double-minute bodies were observed. However, no evidence of homogeneous staining regions (HSRs) were detected.     

Antenatal diagnosis of severe beta thalassemia during the first trimester of pregnancy

Prenatal diagnosis of hemoglobinopathies may be obtained during the first trimester of pregnancy by a combination of chorion biopsy and DNA mapping. This study illustrates 2 DNA approaches which are available for identification of abnormal globin genes. These include restriction fragment length polymorphisms (RFLPs) and direct gene mapping.     

Clonal chromosome abnormalities in human breast carcinomas I. Twenty-eight cases with primary disease

Cytogenetic analysis was performed on a selected series of short-term cultures of primary breast carcinomas from 28 patients. All patients had histopathologically confirmed malignancies, with the majority (25/28 cases) demonstrating infiltrating ductal carcinoma. All 28 cases evidenced clonal chromosome abnormalities, with 10/28 displaying only numeric aberrations, whereas 18/28 displayed clonal structural alterations. In near-diploid tumors the most common numeric changes were — 17 and — 19. However, trisomy 7 was the only numeric change in two near-diploid tumors. Structural chromosome alterations were primarily isochromosomes, apparent terminal deletions, and unbalanced non-reciprocal translocations. Chromosomes 1 (10/18–56%) and 6 (8/18–44%) were most frequently altered in this series. Breakpoints of clonal structural abnormalities were shown to cluster to several chromosome segments, including 1p22-q11, 3p11, 6p11–13, 7p11-q11, 8p11-q11, and 19q13. Analysis of the gain or loss of specific chromosome segments revealed that the most consistent tendency was over-representation of 1q, 3q, and 6p. © 1993 Wiley-Liss, Inc.     

Atypical brainstem representation of onset and formant structure of speech sounds in children with language-based learning problems

This study investigated how the human auditory brainstem represents constituent elements of speech sounds differently in children with language-based learning problems (LP, n = 9) compared to normal children (NL, n = 11), especially under stress of rapid stimulation. Children were chosen for this study based on performance on measures of reading and spelling and measures of syllable discrimination. In response to the onset of the speech sound /da/, wave V-V(n) of the auditory brainstem response (ABR) had a significantly shallower slope in LP children, suggesting longer duration and/or smaller amplitude. The amplitude of the frequency following response (FFR) was diminished in LP subjects over the 229-686 Hz range, which corresponds to the first formant of the/da/ stimulus, while activity at 114 Hz, representing the fundamental frequency of /da/, was no different between groups. Normal indicators of auditory peripheral integrity suggest a central, neural origin of these differences. These data suggest that poor representation of crucial components of speech sounds could contribute to difficulties with higher-level language processes.     

Recurrent chromosome changes in 62 primary gastric carcinomas detected by comparative genomic hybridization

Comparative genomic hybridization (CGH) has been applied to detect recurrent chromosome alterations in 62 primary gastric carcinomas. Several nonrandom chromosomal changes, including gains of 8q (31 cases, 50%), 20q (29 cases, 47%) with a minimum gain region at 20q11. 2-q12, 13q (21 cases, 34%) with a minimum gain region at 13q22, and 3q (19 cases, 31%) were commonly observed. The regions most frequently lost included: 19p (23 cases, 37%), 17p (21 cases, 33%), and 1p (14 cases, 23%). High copy number gain (DNA sequence amplification) was detected in 6 cases. Amplification of 8q23-q24.2 and 20q11.2-q12 were observed in 3 cases. Gain of 20q and loss of 19p were confirmed by fluorescence in situ hybridization using corresponding bacterial artificial chromosomes (BAC) clones from those regions. The gain and loss of chromosomal regions identified in this study provide candidate regions involved in gastric tumorigenesis.     

Cellular localization of Saint Louis encephalitis virus replication.

Replication of Saint Louis encephalitis (SLE) virus was inhibited when PS cells were treated with actinomycin D, daunomycin or cordycepin during the first 9 hr after infection. Autoradiography of SLE virus-infected pulse labelled cells demonstrated that viral RNA synthesis is localized within the nuclear area. Nuclei purified from cells after 12 hr of infection contained heterogeneous 20 S to 26 S viral RNA but no SLE virus genome sized 43 S RNA. Later during infection, nuclei isolated from infected cells contained large amounts of 43 S and 20 S to 26 S RNAs. The 43 S viral RNA present in cells late in infection could not be removed with 1% Tween 80: Nonidet P 40. Purified nuclei isolated from cells early in infection supported the synthesis of 43 S virion RNA in the absence of cytoplasmic factors. The cytoplasmic membrane fraction prepared from cells early in infection contained heterogeneous 10 S to 26 S RNA species; later during infection these membranes contained viral 43 S, 26 S to 30 S and 4 S RNA. These results suggest that the nucleus is an important site of early viral synthesis.     

Microdissection and microcloning of chromosomal alterations in human breast cancer

Summary The recognition of recurring sites of chromosome changes in malignancies has greatly facilitated the identification of genes implicated in the pathogenesis of human cancers. Based especially upon recent studies [1–4], it appears increasingly likely that a subset of recurring chromosome alterations will be recognized in human breast cancer. Currently recognized chromosome changes characterizing breast carcinoma include the recognition of cytologic features of gene amplification (e.g. double minutes [dmins] and homogeneously staining regions [HSRs]) [5–8]. As these and other chromosome regions are implicated in recurring abnormalities in breast cancer, it will become increasingly important to have band-or region-specific genomic libraries and probes in order to facilitate high resolution physical mapping and ultimately to clone breast cancer related genes [9]. Toward this end an important recent development in physical mapping has been the establishment of chromosome microdissection as a rapid and reproducible approach to rapidly isolate and characterize chromosome region-specific DNA, greatly facilitating the initial steps in positional cloning of disease-related genes [10–13]. In this brief report, we will highlight the application of chromosome microdissection to the generation of region-specific probes for both fluorescent in situ hybridization (FISH) and the generation of genomic microclone libraries. Additionally, efforts using this methodology to generate a microclone library encompassing the early onset breast/ovarian cancer (BRCA1) gene will be presented.Presented by Jeffrey M. Trent at the 16th Annual San Antonio Breast Cancer Symposium, San Antonio TX, USA, November 4, 1993; Minisymposium on Molecular Genetics in Breast Cancer.