Growth-regulatory activity of the growth arrest-specific gene, GAS1, in NIH3T3 fibroblasts

The method described detects and confirms presence of pentobarbital residues in dry, extruded feeds at concentrations of 5-20 ppb. Dried feed is ground to a uniform powder and shaken overnight in methanol. A portion of the methanolic extract is evaporated, and the residue is reconstituted in phosphate-buffered saline. The aqueous extract is cleaned with a solid-phase extraction cartridge designed to extract barbiturate residues from biological matrixes. Dimethyl sulfoxide, tetramethylammonium hydroxide, and iodomethane are added to derivatize pentobarbital, 1,3-Dimethyl-pentobarbital is then acidified with dilute hydrochloric acid and extracted with isooctane. The organic layer is transferred and evaporated under a stream of nitrogen. The residue is reconstituted in a small volume of ethyl acetate for analysis by gas chromatography/mass spectrometry. The limit of detection is approximately 0.7 ppb. The method was validated with pentobarbital-fortified feed samples containing high concentrations of meat and bone meal.     

Predisposition for breast cancer in carriers of constitutional translocation 11q;22q

A translocation between the long arms of chromosomes 11 and 22, t(11;22)(q23;q11), is the most frequent constitutional reciprocal translocation in man. This chromosome abnormality has not previously been reported to be associated with an increased risk for neoplasia. The observation of one patient with a constitutional translocation t(11q;22q) and breast cancer prompted us to study the relationship between these two conditions. The incidence of breast cancer was determined in carriers of t(11q;22q). The karyotypes were determined by QFQ-banding, and the breakpoints were then further characterized by fluorescent in situ hybridization. Eight families with a total of 22 balanced carriers were found. In five of these families there was one case of breast cancer each. In another family a case of an unknown malignancy was reported in one member. No other malignancies were found among these patients. The number of breast cancer cases was significantly higher than expected among the translocation carriers (P < .001). The chromosomal breakpoints showed the same localization with the markers used, in the seven families studied. The association of constitutional translocation t(11q;22q) and breast cancer identifies a subset of patients with a highly increased risk for breast cancer who would benefit from counseling and screening. It also suggests the involvement of genes on 11q and/or 22q, in the tumorigenesis of breast cancer.     

Definition and refinement of a region of loss of heterozygosity at 11q23.3-q24.3 in epithelial ovarian cancer associated with poor prognosis

Previous cytogenetic and loss of heterozygosity (LOH) data suggest that disruption of chromosome 11q23-qter occurs frequently in epithelial ovarian cancer and is associated with an adverse clinicopathological phenotype. Ten polymorphic microsatellite repeat loci were analyzed by PCR from the 11q22-q25 region between D11S35 and D11S968 in 40 ovarian tumors (including 31 epithelial ovarian cancers). Two distinct regions of loss were detected, suggesting possible sites for genes involved in epithelial ovarian neoplasia: a large centromeric region between D11S35 and D11S933 (11q22-q23.3) and a telomeric 8.5-Mb region lying between D11S934 and D11S1320 (11q23.3-24.3) not previously defined. LOH of the latter region but not the former one was significantly associated with poor survival, despite all tumors in this study having LOH somewhere on chromosome 11. This analysis provides a starting point for positional cloning.     

Double heterozygosity for mutations in the BRCA1 and BRCA2 genes in a breast cancer patient

BACKGROUND: Germline mutations in the tumor suppressor genes BRCA1 and BRCA2 confer substantial increased lifetime risk for breast cancer, and in the case of BRCA1, for ovarian carcinoma as well. These two genes alone account for the vast majority of hereditary breast cancer families. Numerous mutations have been described in each gene, the majority of which are small insertions or deletions resulting in expression of a truncated protein. MATERIALS AND METHODS: Several common mutations can be detected using a polymerase chain reaction-mediated, site-directed mutagenesis assay, which transforms the amplicon derived from either the wild-type or mutant allele by adding or removing a restriction endonuclease site. We screened 49 putative sporadic breast tumors using this methodology, targeting four BRCA1 mutations (185delAG, 5382insC, R1443X, and E1250X) and a single BRCA2 mutation (6174delT). RESULTS: Using the polymerase chain reaction-mediated, site-directed mutagenesis assay, we identified two mutations, namely, a 185delAG mutation (BRCA1) and a 6174delT mutation (BRCA2). Interestingly, these two mutations were found in the same sample. None of the remaining 48 breast tumors showed evidence of these mutations. Allele-specific oligonucleotide probes were then employed in conjunction with the Universal GeneComb Test Kit, which confirmed the presence of mutations. CONCLUSIONS: Our data suggest that the common germline BRCA1 and BRCA2 mutations are infrequently encountered in sporadic breast cancers. The one case with dual BRCA1 and BRCA2 mutations suggests that this tumor may be hereditary in origin, despite the lack of a positive family history. Double heterozygosity for mutations in BRCA1 and BRCA2 may have increasingly significant implications with regard to predisposition to breast cancer.     

Molecular characterization of a variant Ph1 translocation t(9;22;11) (q34;q11;q13) in chronic myelogenous leukemia (CML) reveals the translocation of the 3'-part of BCR gene to the chromosome band 11q13

We performed cloning and sequence analysis of translocation junctions at 11q- and 22q- (Ph1) chromosomes and the corresponding germline DNAs of a variant Ph1-positive CML with t(9;22;11)(q34;q11;q13). Southern blot analysis using probes for different regions of bcr mapped the translocation break near the 5'-side of bcr exon 4. Cloning, Southern blot analysis and restriction map analysis of both bcr fragments showed that the part of bcr 3'- to the translocation break moved to 11q13. Sequence analysis of the translocation junction on the Ph1 chromosome showed that the translocation break occurred 63 bp upstream of exon 4. Compared to the germline sequence, bcr sequence from the translocated partners showed deletion of seven basepairs at the site of translocation. A probe derived from the 5'-region of the clone isolated from the 11q- chromosome identified clonal rearrangements in the leukemic DNA. Restriction map and sequence analysis showed that this clone consisted of the 3'-half of the glutathione S-transferase Pi (GST-Pi) gene and the 3'-part of bcr. We identified two point mutations in the GST-Pi allele involved in translocation. Northern blot analysis showed that the GST-Pi gene was expressed in the leukemic cells at blast crisis but not at chronic phase; however, no fusion mRNA between GST-Pi and bcr was identified. We did not find any sequence homology between 11q13 DNA and 22q11 DNA around the translocation breakpoints; however, sequences homologous to ALU repeats were identified close to the sites of translocation breaks at 22q11 and 11q13. This study supports our hypothesis that variant Ph1 translocations may occur as primary cytogenetic changes similar to the classical Ph1 translocations.     

Germline mutations of the BRCA1 and BRCA2 genes in a breast and ovarian cancer patient

Nitric oxide (NO) has been implicated as a modulator of the vascular effects of angiotensin II (ANG II) in the kidney. We used a NO-sensitive microelectrode to study the effect of ANG II on NO release, and to determine the effect of selective inhibition of the ANG II subtype I receptor (AT1) with losartan (LOS) and candesartan (CAN). NO release from isolated and perfused renal resistance arteries was measured with a porphyrin-electroplated, carbon fiber. The vessels were microdissected from isolated perfused rat kidneys and perfused at constant flow and pressure in vitro. The NO-electrode was placed inside the glass collection cannula to measure vessel effluent NO concentration. ANG II stimulated NO release in a dose-dependent fashion: 0.1 nM, 10 nM and 1000 nM ANG II increased NO-oxidation current by 85+/-18 pA (n = 11), 148+/-22 pA (n = 11), and 193+/-29 pA (n = 11), respectively. These currents correspond to changes in effluent NO concentration of 3.4+/-0.5 nM, 6.1+/-1.1 nM, and 8.2+/-1.3 nM, respectively. Neither LOS (1 muM) nor CAN (1 nM) significantly affected basal NO production, but both AT1-receptor blockers markedly blunted NO release in response to ANG II (10 nM): 77+/-6% inhibition with LOS (n = 8) and 63+/-9% with CAN (n = 8). These results are the first to demonstrate that ANG II stimulates NO release in isolated renal resistance arteries, and that ANG II-induced NO release is blunted by simultaneous AT1-receptor blockade. Our findings suggest that endothelium-dependent modulation of ANG II-induced vasoconstriction in renal resistance arteries is mediated, at least in part, by AT1-receptor-dependent NO release.     

A review on family history of breast cancer: screening and counseling proposals for women with familial (non-hereditary) breast cancer

In a neural model of olfactory bulb processing, we demonstrate the putative role of the modulation of two types of inhibition, inspired by electrophysiological data on the effect of acetylcholine and noradrenaline on olfactory bulb synaptic transmission. Feedback regulation of modulation based on bulbar activity serves to 'normalize' the activity of output neurons in response to different levels of input activities. This mechanism also decreases the overlap between pairs of output patterns (Mitral cell activities), enhancing the discrimination between overlapping olfactory input patterns. The effect of the modulation at the two levels of interneurons is complementary: while an increase in periglomerular inhibition decreases the number of responding output neurons, a decrease in granule cell inhibition increases the firing frequencies of these neurons.     

Y(C_(16)H_(16)N_2O_2)(NO_3)_3(CH_3SOCH_3)的合成和晶体结构

合成了硝酸钇（Ⅲ）与双希夫碱Ｎ，Ｎ′－二亚水杨基乙二胺、二甲基亚砜的配合物〔Ｙ（Ｃ６Ｈ４ＯＨＣＨＮＣ２Ｈ４ＮＣＨＣ６Ｈ４ＯＨ）（ＮＯ３）３（ＣＨ３ＳＯＣＨ３）〕。ｘ—射线单晶结构分析表明该晶体属单斜晶系、空间群为Ｐ２１／ｎ，ａ＝０．９６３１（２）ｎｍ，ｂ＝１．６４１４（５）ｎｍ，ｃ＝１．６２０９（３）ｎｍ，β＝１０２．９８（２）°，Ｚ＝４，Ｄｘ＝１．６５３Ｍｇ·ｍ－３。Ｙ（Ⅲ）配位数为９，配位几何为畸变的单帽四方反棱柱，所有的配位原子均为氧原子，分别来自三个硝酸根，一个二甲基亚砜和二个双希夫碱，中心离子被双希夫碱桥联，组成一维无限长链。     

High incidence of translocations t(11;14)(q13;q32) and t(4;14)(p16;q32) in patients with plasma cell malignancies

Abnormalities involving the 14q32 region are recurrent chromosomal changes in plasma cell malignancies. Recent preliminary molecular analyses found IGH rearrangements in almost 100% of human myeloma cell lines and in 75% of patients. However, no systematic study analyzing the nature of the partner chromosomal regions have been reported thus far. To define the exact incidence of illegitimate IGH rearrangements and the respective incidence of partner genes cloned to date, we analyzed 141 patients with either multiple myeloma (MM, n = 127) or primary plasma cell leukemia (PCL, n = 14) using fluorescence in situ hybridization. The overall incidence of illegitimate recombinations was 57% (80 of 141 patients). Analysis of this incidence according to Durie and Salmon stage, patients' status, i.e., MM versus primary PCL and diagnosis versus relapse, immunoglobulin type and subtype, and beta2-microglobulin value, did not show any correlation. To analyze the nature of the partner chromosomal region, we selected probes specific for the following genes: FGFR3 (4p16), MYC (8q24), CCND1 (11q13), MAF (16q23), and BCL2 (18q21). These probes, combined with differentially labeled 14q32 probes, were used for dual-color fluorescence in situ hybridization on interphase plasma cells. Among the 80 patients with illegitimate IGH rearrangement, we identified 23 IGH-CCND1 fusion cases [i.e., t(11;14)], 17 IGH-FGFR3 fusion cases [i.e., t(4;14)], 3 IGH-MYC fusion cases [i.e., t(8;14)], and only one IGH-MAF fusion case. No IGH-BCL2 fusion case was detected. In 37 of 80 patients, none of these partner genes was involved. Analysis of cases with specific translocations according to their bioclinical features at diagnosis did not show any correlation. This study demonstrated that CCND1 and FGFR3 genes are involved together in about 50% of MM and primary PCL patients with illegitimate IGH rearrangements.     

Cytochrome b in human complex II (succinate-ubiquinone oxidoreductase): cDNA cloning of the components in liver mitochondria and chromosome assignment of the genes for the large (SDHC) and small (SDHD) subunits to 1q21 and 11q23

Complex II (succinate-ubiquinone oxidoreductase) is an important enzyme complex in both the tricarboxylic acid cycle and the aerobic respiratory chains of mitochondria in eukaryotic cells and prokaryotic organisms. In this study, the amino acid sequences of the large (cybL) and small (cybS) subunits of cytochrome b in human liver complex II were deduced from cDNAs isolated by homology probing with mixed primers for the polymerase chain reaction. The mature cybL and cybS contain 140 and 103 amino acids, respectively, and show little similarity to the amino acid sequences of the subunits from other species in contrast to the highly conserved features of the flavoprotein (Fp) subunit and iron-sulfur protein (Ip) subunit. From hydrophobicity analysis, both cybL and cybS appear to have three transmembrane segments, indicating their role as membrane-anchors for the enzyme complex. Histidine residues, which are possible heme axial ligands in cytochrome b of complex II, were found in the second transmembrane segment of each subunit. The genes for cybL (SDHC) and cybS (SDHD) were mapped to chromosome 1q21 and 11q23, respectively by fluorescent in situ hybridization (FISH).     

Can mammography screening explain the race difference in stage at diagnosis of breast cancer?

BACKGROUND: A race difference in the stage at diagnosis of breast cancer is well established: African American women are less likely than white women to be diagnosed at a localized stage. The purpose of this study was to determine the extent to which the observed race (black/white) difference in stage at diagnosis of breast cancer could be accounted for by race differences in the mammography screening history. METHODS: This was a population-based, retrospective study of 145 African American and 177 white women with newly diagnosed breast cancer in Connecticut, between January, 1987 and March, 1989. Cases were ascertained through active surveillance of 22 Connecticut hospitals. RESULTS: Black women were diagnosed more commonly with later stage cancer (TNM stage > or = II) (age-adjusted odds ratio [OR] = 2.01, 95% confidence interval [CI] 1.24-3.24) than were white women. Blacks were also more likely than whites to report that they had not received a mammogram in the 3 years before development of symptoms or diagnosis (OR = 2.05, 95% CI 1.26-3.35); this association was not altered substantially with adjustment for socioeconomic status. In race-specific analyses, mammography was protective against later stage diagnosis in white women, but not in black women. With adjustment for mammography screening, the OR for the race-stage association was reduced only minimally, and race remained a significant predictor of stage at diagnosis. CONCLUSIONS: In these population-based data, history of mammography screening was not an important explanatory variable in the race-stage association. Specifically, history of mammographic screening accounted for less than 10% of the observed black/white difference in stage at diagnosis of breast cancer.