Specific and redundant functions of Gli2 and Gli3 zinc finger genes in skeletal patterning and development

The correct patterning of vertebrate skeletal elements is controlled by inductive interactions. Two vertebrate hedgehog proteins, Sonic hedgehog and Indian hedgehog, have been implicated in skeletal development. During somite differentiation and limb development, Sonic hedgehog functions as an inductive signal from the notochord, floor plate and zone of polarizing activity. Later in skeletogenesis, Indian hedgehog functions as a regulator of chondrogenesis during endochondral ossification. The vertebrate Gli zinc finger proteins are putative transcription factors that respond to Hedgehog signaling. In Drosophila, the Gli homolog cubitus interruptus is required for the activation of hedgehog targets and also functions as a repressor of hedgehog expression. We show here that Gli2 mutant mice exhibit severe skeletal abnormalities including cleft palate, tooth defects, absence of vertebral body and intervertebral discs, and shortened limbs and sternum. Interestingly, Gli2 and Gli3 (C.-c. Hui and A. L. Joyner (1993). Nature Genet. 3, 241–246) mutant mice exhibit different subsets of skeletal defects indicating that they implement specific functions in the development of the neural crest, somite and lateral plate mesoderm derivatives. Although Gli2 and Gli3 are not functionally equivalent, double mutant analysis indicates that, in addition to their specific roles, they also serve redundant functions during skeletal development. The role of Gli2 and Gli3 in Hedgehog signaling during skeletal development is discussed.

Plant viral synergism: the potyviral genome encodes a broad-range pathogenicity enhancer that transactivates replication of heterologous viruses

Synergistic viral diseases of higher plants are caused by the interaction of two independent viruses in the same host and are characterized by dramatic increases in symptoms and in accumulation of one of the coinfecting viruses. In potato virus X (PVX)/potyviral synergism, increased pathogenicity and accumulation of PVX are mediated by the expression of potyviral 5' proximal sequences encoding P1, the helper component proteinase (HC-Pro), and a fraction of P3. Here, we report that the same potyviral sequence (termed P1/HC-Pro) enhances the pathogenicity and accumulation of two other heterologous viruses: cucumber mosaic virus and tobacco mosaic virus. In the case of PVX-potyviral synergism, we show that the expression of the HC-Pro gene product, but not the RNA sequence itself, is sufficient to induce the increase in PVX pathogenicity and that both P1 and P3 coding sequences are dispensable for this aspect of the synergistic interaction. In protoplasts, expression of the potyviral P1/HC-Pro region prolongs the accumulation of PVX (-) strand RNA and transactivates expression of a reporter gene from a PVX subgenomic promoter. Unlike the synergistic enhancement of PVX pathogenicity, which requires only expression of HC-Pro, the enhancement of PVX (-) strand RNA accumulation in protoplasts is significantly greater when the entire P1/HC-Pro sequence is expressed. These results indicate that the potyviral P1/HC-Pro region affects a step in disease development that is common to a broad range of virus infections and suggest a mechanism involving transactivation of viral replication.

Mutations in the region encoding the central domain of helper component-proteinase (HC-Pro) eliminate potato virus X/potyviral synergism

Coinfection of tobacco plants with potato virus X (PVX) and any of several members of the potyvirus group causes a synergistic disease characterized by a dramatic increase in symptom severity correlated with a 3- to 10-fold increase in the accumulation of PVX in the first systemically infected leaves. We have recently shown that PVX/potyviral synergistic disease is mediated by expression of potyviral 5'-proximal sequences encoding P1, helper component-proteinase (HC-Pro), and a fraction of P3 (termed P1/HC-Pro sequence). Here we report the effect of mutations in this potyviral sequence on the induction of synergistic disease. Three transgenic tobacco lines expressing the tobacco etch potyvirus (TEV) P1/HC-Pro sequence with mutations within the P1 coding region were not impaired in their ability to mediate synergism when infected with PVX. In contrast, two of three transgenic lines with mutations in the HC-Pro coding region were unable to induce the synergistic increases in either symptom severity or PVX accumulation. Loss of synergistic function was associated with mutations within the region encoding the central domain of HC-Pro, while the ability to induce synergism was retained in a transgenic line expressing HC-Pro with an alteration in the amino-terminal "zinc-finger domain." In coinoculation experiments, a TEV mutant lacking the sequence encoding the zinc-linger domain of HC-Pro induced a typical synergistic response in interaction with PVX. The results indicate that the zinc-finger domain comprising the first 66 amino acid residues of HC-Pro is dispensable for induction of synergistic disease and transactivation of PVX multiplication, while regions within the central domain of HC-Pro are essential for both of these responses.

5' proximal potyviral sequences mediate potato virus X/potyviral synergistic disease in transgenic tobacco

The interaction of potato virus X (PVX) and potato virus Y (PVY) in tobacco causes a synergistic disease characterized by a dramatic increase in symptom severity, a change in the regulation of PVX RNA replication, and an increase in accumulation of PVX. In this study we demonstrate that PVX also interacts synergistically with three other members of the potyvirus group of plant viruses, tobacco vein mottling virus (TVMV), tobacco etch virus (TEV), and pepper mottle virus. These synergisms resemble the classic PVX/PVY synergism with respect to both the increase in host response and the change in PVX replication. To determine if the induction of PVX/potyviral synergism requires potyviral genome replication per se or if the response is mediated by expression of one or more potyviral genes, we used tobacco plants stably transformed with various subsets of the TVMV genome. PVX infections of transgenic plants expressing the 5'-proximal region of the TVMV genome, including the protease-1, helper component protease, and protein-3 genes, result in symptoms resembling those of PVX/potyviral synergism. A similar synergistic-like response occurs when transgenic tobacco plants expressing the analogous but smaller region from the 5'-proximal region of the TEV genome were infected with PVX. Replication of PVX RNA is altered in transgenic plants expressing 5'-proximal sequences of either TVMV or TEV, and in a manner similar to that observed in double infections. These results indicate that replication of the potyviral genome is not required for PVX/potyviral synergism and that the response is mediated by expression of potyviral sequences which have been localized to the 5'-proximal third of the genomic RNAs of both TVMV and TEV.

Tandem repeat of C/EBP binding sites mediates PPARgamma2 gene transcription in glucocorticoid-induced adipocyte differentiation

Bone marrow stromal stem cells differentiate into many different types of cells including osteoblasts and adipocytes. Long-term glucocorticoid treatment decreases osteoblastic activity but increases adipocytes. We investigated the mechanism of glucocorticoid-induced PPARgamma2 transcription. Treatment of human bone marrow stromal cells with dexamethasone induced the differentiation of these cells into adipocytes as measured by oil-red O staining, and Northern blot analysis showed that dexamethasone strongly induced PPARgamma2 mRNA expression in cells cultured in adipocyte induction medium. Moreover, the mRNA of C/EBPdelta, an adipocyte-promoting transcription factor, was also induced by dexamethasone in the presence of induction medium. Gel mobility shift assays using purified GST-C/EBPdelta fusion protein showed that C/EBPdelta specifically binds to a 40-base pair DNA element from PPARgamma2 promoter, which was found to contain a tandem repeat of C/EBP binding sites. Transfection studies in mouse mesenchymal C3H10T1/2 cells showed that it is the tandem repeat of the C/EBP binding site in PPARgamma2 promoter region that regulates dexamethasone-mediated PPARgamma2 gene activation. We conclude that glucocorticoid-induced adipogenesis from bone marrow stromal cells is mediated through a reaction cascade in which dexamethasone transcriptionally activates C/EBPdelta; C/EBPdelta then binds to PPARgamma2 promoter and transactivates PPARgamma2 gene expression. This activated master regulator, in turn, initiates the adipocyte differentiation.

Regulation of meiotic chromatin loop size by chromosomal position

At meiotic prophase, chromatin loops around a proteinaceous core, with the sizes of these loops varying between species. Comparison of the morphology of sequence-related inserts at different sites in transgenic mice demonstrates that loop size also varies with chromosomal geography. Similarly, chromatin loop lengths differ dramatically for interstitially and terminally located hamster telomeric sequences. Sequences, telomeric or otherwise, located at chromosome termini, closely associate with the meiotic proteinaceous core, forming shorter loops than identical interstitial sequences. Thus, we present evidence that different chromatin packaging mechanisms exist for interstitial versus terminal chromosomal regions, which act separately from those operating at the level of the DNA sequence. Chromosomal position plays the dominant role in chromatin packaging.

Cytotoxicity of PM(2.5) and PM(2.5--10) ambient air pollutants assessed by the MTT and the Comet assays

Ambient air particulate matters are classified into two distinct modes in size distribution, namely the coarse and fine particles. Correlation between high particulate concentration and adverse effects on human populations has long been recognized, however, the toxicology of these adverse effects has not been clarified. In the current report, the cytotoxic effects of the solvent-extractable organic compounds (SEOC) from fine particles smaller than 2.5 microm (PM(2.5)) and from coarse particles between 2.5-10 microm (PM(2.5-10)) were studied. Nine 24h consecutive monthly samples were tested to determine the correlation between cytotoxicity and total SEOC in two size fractions of particulate air pollution. Cytotoxicity of SEOC was measured by two micro-scale mammalian cells-based bioassays: the MTT cell proliferation assay, and the Comet assay for the detection of DNA damage. A well-defined mammalian cell line - Rat 6 rodent fibroblast was employed in the study. The SEOC extracts of air particulate matters were sub divided into two equal parts. One part was dissolved in DMSO, the other in KOH/hexane and then conjugated with bovine serum albumin to produce a lipid-soluble fraction for testing. The DMSO fraction would contain mainly the polycyclic aromatic hydrocarbons (PAH), alkanes and alkanols, while the lipid-soluble fraction would be enriched with fatty acids. The results from MTT assay showed that cytotoxicity of the PM(2.5) was much more severe than the PM(2.5-10), suggesting that toxic SEOC were confined to the fine particles. By and large, the DMSO solubles were much more toxic than the lipid solubles. The degree of cytotoxicity of the DMSO soluble samples is positively correlated to the amount of particulates present in the ambient air. For the PM(2.5), the winter samples were significantly more toxic than the summer samples in terms of cell killing, which seemed to be a direct reflection of the total loading of organic matter in the samples. Results from Comet assays showed that SEOC samples of PM(2.5) derived from winter months induced DNA damage at dosages resulting in no obvious cell killing in the MTT assay. Thus, long-term exposure to non-killing dosage of air pollutants may lead to the accumulation of DNA lesions, which may be one of the mechanisms responsible for the chronic adverse health effects of particulate air pollution.

Identification of genes from a 500-kb region at 7q11.23 that is commonly deleted in Williams syndrome patients

Williams syndrome (WS) is a multisystem developmental disorder caused by the deletion of contiguous genes at 7q11.23. Hemizygosity of the elastin (ELN) gene can account for the vascular and connective tissue abnormalities observed in WS patients, but the genes that contribute to features such as infantile hypercalcemia, dysmorphic facies, and mental retardation remain to be identified. In addition, the size of the genomic interval commonly deleted in WS patients has not been established. In this study we report the characterization of a 500-kb region that was determined to be deleted in our collection of WS patients. A detailed physical map consisting of cosmid, P1 artificial chromosomes, and yeast artificial chromosomes was constructed and used for gene isolation experiments. Using the techniques of direct cDNA selection and genomic DNA sequencing, three known genes (ELN, LIMK1, and RFC2), a novel gene (WSCR1) with homology to RNA-binding proteins, a gene with homology to restin, and four other putative transcription units were identified. LIMK1 is a protein kinase with two repeats of the LIM/double zinc finger motif, and it is highly expressed in brain. RFC2 is the 40-kDa ATP-binding subunit of replication factor C, which is known to play a role in the elongation of DNA catalyzed by DNA polymerase delta and epsilon. LIMK1 and WSCR1 may be particularly relevant when explaining cognitive defects observed in WS patients.

Dual effects of atmospheric pressure plasma jet on skin wound healing of mice

Cold plasma has become an attractive tool for promoting wound healing and treating skin diseases. This article presents an atmospheric pressure plasma jet (APPJ) generated in argon gas through dielectric barrier discharge, which was applied to superficial skin wounds in BALB/c mice. The mice (n = 50) were assigned randomly into five groups (named A, B, C, D, E) with 10 animals in each group. Natural wound healing was compared with stimulated wound healing treated daily with APPJ for different time spans (10, 20, 30, 40, and 50 seconds) on 14 consecutive days. APPJ emission spectra, morphological changes in animal wounds, and tissue histological parameters were analyzed. Statistical results revealed that wound size changed over the duration of the experimental period and there was a significant interaction between experimental day and group. Differences between group C and other groups at day 7 were statistically significant (p < 0.05). All groups had nearly achieved closure of the untreated control wounds at day 14. The wounds treated with APPJ for 10, 20, 30, and 40 seconds showed significantly enhanced daily improvement compared with the control and almost complete closure at day 12, 10, 7, and 13, respectively. The optimal results of epidermal cell regeneration, granulation tissue hyperplasia, and collagen deposition in histological aspect were observed at day 7. However, the wounds treated for 50 seconds were less well healed at day 14 than those of the control. It was concluded that appropriate doses of cold plasma could inactivate bacteria around the wound, activate fibroblast proliferation in wound tissue, and eventually promote wound healing. Whereas, over doses of plasma suppressed wound healing due to causing cell death by apoptosis or necrosis. Both positive and negative effects may be related to the existence of reactive oxygen and nitrogen species (ROS and RNS) in APPJ.

Low temperature plasma promoting fibroblast proliferation by activating the NF-κB pathway and increasing cyclinD1 expression

The potential applications of low temperature plasma (LTP) in wound healing have aroused the concern of many researchers. In this study, an argon atmospheric pressure plasma jet was applied to generate LTP for treatment of murine fibroblast cell (L929) cultured in vitro to investigate the effect of NF-κB pathway on fibroblast proliferation. The results showed that, compared with the control, L929 cells treated with plasma for less than 20 s had significant increases of proliferation; the productions of intracellular ROS, O₂⁻ and NO increased with prolongation of LTP treatment time; NF-κB pathway was activated by LTP in a proper dose range, and the expression of cyclinD1 in LTP-treated cells increased with the same trend as cell proliferation. After RNA interference to block p65 expression, with the same treatment time, RNAi-treated cells proliferated more slowly and expressed less cyclinD1 than normal cells. Furthermore, pretreatment with N-acetyl-L-cysteine (NAC) markedly prevented the plasma-induced changes in cells. In conclusion, the proliferation of L929 cells induced by LTP was closely related to NF-κB signaling pathway, which might be activated by appropriate level of intracellular ROS. These novel findings can provide some theoretical reference of LTP inducing cell proliferation and promoting wound healing.

Amplification of CFTR exon 9 sequences to multiple locations in the human genome

Cloning and characterization of the cystic fibrosis transmembrane conductance regulator (CFTR) gene led to the identification and isolation of cDNA and genomic sequences that cross-hybridized to the first nucleotide binding fold of CFTR. DNA sequence analysis of these clones showed that the cross-hybridizing sequences corresponded to CFTR exon 9 and its flanking introns, juxtapositioned with two segments of LINE1 sequences. The CFTR sequence appeared to have been transcribed from the opposite direction of the gene, reversely transcribed, and co-integrated with the L1 sequences into a chromosome location distinct from that of the CFTR locus. Based on hybridization intensity and complexity of the restriction fragments, it was estimated that there were at least 10 copies of the "amplified" CFTR exon 9 sequences in the human genome. Furthermore, when DNA segments adjacent to the insertion site were used in genomic DNA blot hybridization analysis, multiple copies were also detected. The overall similarity between these CFTR exon 9-related sequences suggested that they were derived from a single retrotransposition event and subsequent sequence amplification. The amplification unit appeared to be greater than 30 kb. Physical mapping studies including in situ hybridization to human metaphase chromosomes showed that multiple copies of these amplified sequences (with and without the CFTR exon 9 insertion) were dispersed throughout the genome. These findings provide insight into the structure and evolution of the human genome.

Low-temperature Plasma Promotes Fibroblast Proliferation in Wound Healing by ROS-activated NF-κB Signaling Pathway

Low-temperature plasma (LTP) has shown great promise in wound healing, although the underlying mechanism remains poorly understood. In the present study, an argon atmospheric pressure plasma jet was employed to treat L929 murine fibroblasts cultured in vitro and skin wounds in BALB/c mice. The in vitro analysis revealed that treatment of fibroblasts with LTP for 15 s resulted in a significant increase in cell proliferation, secretion of epidermal growth factor (EGF) and transforming growth factor-βi (TGF-βi), production of intracellular reactive oxygen species (ROS), and the percentage of cells in S phase, protein expression of phosphorylated p65 (P-p65) and cyclinD1, but a noted decrease in the protein expression of inhibitor kappa B (IκB). The in vitro experiments demonstrated that 30-s LTP treatment enhanced the number of fibroblasts and the ability of collagen synthesis, while 50-s treatment led to the opposite outcomes. These results suggested that LTP treatment promotes the fibroblast proliferation in wound healing by inducing the generation of ROS, upregulating the expression of P-p65, downregulating the expression of IκB, and activating the NF-κB signaling pathway and consequently altering cell cycle progression (increased DNA synthesis in S phage).

Refined localization of the asparagine synthetase gene (ASNS) to chromosome 7, region q21.3, and characterization of the somatic cell hybrid line 4AF/106/KO15

We have mapped the asparagine synthetase gene (ASNS) to 7q21.3 by fluorescence in situ hybridization. While this study refined the localization of the gene, it also revealed a rearrangement in a somatic cell hybrid line which was used in previous ASNS mapping. Using additional probes from other regions of human chromosome 7, we showed that this cell line (4AF/106/KO15) contained a rearranged chromosome 7 in which a segment of the long arm was apparently duplicated and inserted into the short arm. Caution should be used therefore when interpreting data obtained from this cell line for gene mapping studies.

Genes encoding general initiation factors for RNA polymerase II transcription are dispersed in the human genome

General transcription factors are required for accurate initiation of transcription by RNA polymerase II. Human cDNAs encoding subunits of these factors have been cloned and sequenced. Using fluorescence in situ hybridization (FISH), we show here that the genes encoding the TATA-box binding protein (TBP), TFIIB, TFIIE alpha, TFIIE beta, RAP30, RAP74 and the 62 kDa subunit, of TFIIH are located at the human chromosomal bands 6q26-27, 1p21-22, 3q21-24, 8p12, 13q14, 19p13.3 and 11p14-15.1, respectively. This dispersed localization of a group of functionally related gene provides insights into the molecular mechanism of human genome evolution and their possible involvement in human diseases.

Cloning, expression, and chromosomal localization to 11p12-13 of a human LIM/HOMEOBOX gene, hLim-1

We have identified a putative transcription factor, designated hLim-1, from human fetal brain using degenerate polymerase chain reaction (PCR) and cDNA library screening. The deduced open reading frame, derived from sequencing a 3.0-kb hLim-1 cDNA, encodes a protein of 384 amino acids with two cysteine-rich LIM domains and one homeobox (HOX) DNA-binding domain. The nucleotide sequence of hLim-1 cDNA is 87% identical to mouse Lim-1 and the predicted amino acid sequence is greater than 97% conserved. Expression patterns of hLim-1 were evaluated by Northern analysis and reverse transcription (RT)-PCR coupled with Southern blotting. HLim-1 expression was observed in human brain, thymus, and tonsillar tissue. Expression of hLim-1 was also observed in 58% of acute myelogenous leukemia (AML) cell lines and in four of five primary samples from patients with chronic myeloid leukemia (CML) in myeloid blast transformation. The gene encoding hLim-1 was mapped using fluorescence in situ hybridization (FISH) to human chromosome 11p12-13. The expression pattern and structural characteristics of the hLim-1 gene suggest that it encodes a transcriptional regulatory protein involved in the control of differentiation and development of neural and lymphoid cells. Its expression in CML in blast crisis suggests that it may be involved with progression in this disease; a prospective study is required to confirm this.

Refined mapping of the GM2 activator protein (GM2A) locus to 5q31.3-q33.1, distal to the spinal muscular atrophy locus

The GM2 activator locus (GM2A) had previously been considered as a candidate gene for some forms of spinal muscular atrophy (SMA; mapped to 5q11.2-q13.3). It was eliminated as a possible candidate because PCR-based mapping failed to localize the gene to chromosome 5, as was previously reported using an ELISA-based methodology. However, we demonstrated that the PCR primers used preferentially amplified a processed pseudogene (GM2AP) that we mapped to chromosome 3 and that GM2A was located on chromosome 5. In this report, we reconsider the candidacy of GM2A by refining its localization on chromosome 5 using fluorescence in situ hybridization. We localize GM2A to 5q31.3-q33.1; thus, it is not a candidate gene for SMA.

Direct detection of expanded trinucleotide repeats using PCR and DNA hybridization techniques

Recently, unstable trinucleotide repeats have been shown to be the etiologic factor in seven neuropsychiatric diseases, and they may play a similar role in other genetic disorders which exhibit genetic anticipation. We have tested one polymerase chain reaction (PCR)-based and two hybridization-based methods for direct detection of unstable DNA expansion in genomic DNA. This technique employs a single primer (asymmetric) PCR using total genomic DNA as a template to efficiently screen for the presence of large trinucleotide repeat expansions. High-stringency Southern blot hybridization with a PCR-generated trinucleotide repeat probe allowed detection of the DNA fragment containing the expansion. Analysis of myotonic dystrophy patients containing different degrees of (CTG)n expansion demonstrated the identification of the site of trinucleotide instability in some affected individuals without any prior information regarding genetic map location. The same probe was used for fluorescent in situ hybridization and several regions of (CTG)n/(CAG)n repeats in the human genome were detected, including the myotonic dystrophy locus on chromosome 19q. Although limited at present to large trinucleotide repeat expansions, these strategies can be applied to directly clone genes involved in disorders caused by large expansions of unstable DNA.

Torasemide reduces dilated cardiomyopathy, complication of arrhythmia, and progression to heart failure

The aim of this study was to analyze the incidence and types of arrhythmia and their relationship with the severity and prognosis of chronic heart failure (CHF) in patients with dilated cardiomyopathy (DCM), and to investigate the therapeutic effect of torasemide versus furosemide on CHF and incidence of arrhythmia. DCM patients with NYHA cardiac function II-IV were continuously monitored using a 24-h dynamic electrocardiogram (Holter), and arrhythmia incidence was analyzed by computer automatic analysis combined with manual assessment. In total, 125 participants were evenly divided into two groups: torasemide group which received 10 mg oral torasemide once daily) and regular anti-heart failure treatment (N=65), and furosemide group which received torasemide (20 mg once daily orally) and regular antiheart failure treatment (N=60). Another 60 normal healthy persons served as the normal control group. Incidence and severity of arrhythmia increased when degree of CHF was elevated. Size of left atrium was related to atrial fibrillation and size of left ventricle was related to malignant arrhythmia. At 3 months after treatment, cardiac function in both groups improved and incidence and severity of arrhythmia in both groups were reduced. However, left ventricular ejection fraction (LVEF) was higher in the torasemide group than in the furosemide group, while incidence of arrhythmia was lower in the torasemide group. Arrhythmias frequently occurred in patients with DCM and HF. Type of cardiac arrhythmia is closely related to ventricular enlargement and cardiac function grade. Torasemide is better for improving cardiac function to reduce arrhythmia and CHF compared to furosemide.

Expression analysis and chromosomal assignment of the human SFRS5/SRp40 gene

Alternative splicing plays a major role in the regulation of gene expression. SFRS5/SRp40 is a member of the serine/arginine (SR) protein family of regulators of alternative pre-mRNA splicing. We cloned the human SFRS5 cDNA and observed two major SFRS5 transcripts, an approximately 1.8-kb short form and an approximately 3.3-kb long form, in both human and rat tissues. Both transcripts were detected in all human tissues examined, but there were notable tissue-specific differences in their relative abundance, the short form being most abundant in retina. Affinity-purified SFRS5 antisera recognized a single 40-kDa polypeptide in human and mouse retinal lysates. The abundant retinal expression of SFRS5 was not restricted to any specific cell type, since immunofluorescent labeling of human retinal sections identified the SFRS5 protein in nuclei of all three nuclear layers of the retina. The human SFRS5 gene was localized to human chromosome 14q24 by fluorescence in situ hybridization and PCR analysis of a human/hamster somatic cell hybrid panel.

Molecular requirements of endotoxin (ET) actions: changes in the immune adjuvant, TNF liberating and toxic properties of endotoxin during alkaline hydrolysis

The effect of alkaline pH and alkaline hydrolysis on the physico-chemical and biological properties of endotoxin (ET) isolated from Serratia marcescens ATCC 13477 by the Biovin procedure was studied. Major emphasis was put on the ion exchange column chromatography and immune adjuvant activity (ADA) of the alkali treated samples. To measure changes in some endotoxicity parameters, Limulus lysate clotting (LAL), chick embryo lethality, Shwartzman skin reactivity and in vitro TNF release were measured. The toxic properties of ET, with the unique exception of the Shwartzman skin reactivity, rapidly diminished during alkaline treatment. As immunogen CBre3, a recombinant HIV glycoprotein which spans the C terminus of gp 120 and the N terminus of gp 41, was used in CD-1 mice, alkali treated and immediately neutralized ET samples (zero time) were inactive as adjuvants, in some cases immunosuppression could be clearly seen. But if the alkaline hydrolysis was continued for 6 h, the ADA became higher than it had been for the starting ET sample. Further alkaline hydrolysis eliminated the ADA of the samples. Both NaOH and propylamine acted similarly on the ET preparation. Reaction kinetic studies of the NaOH detoxification indicated the cleavage of ester bound acyl groups with low binding energy. Chemical analyses of the samples revealed that changes occurred in the fatty acid composition, characterized by a loss of approximately half of the 3-OH myristic acid content.

Fluorescence in situ hybridization mapping of the cystic fibrosis transmembrane conductance regulator (CFTR) gene to 7q31.3

We have used the fluorescence in situ hybridization (FISH) technique to refine the localization of the cystic fibrosis transmembrane conductance regulator (CFTR) gene on human chromosome 7. The result shows that the gene is most likely located within band q31.3.

Localization of the human gene encoding the 13.3-kDa subunit of mitochondrial complex III (UQCRB) to 8q22 by in situ hybridization

We have localized the human gene encoding the 13.3-kDa subunit of mitochondrial complex III (UQCRB) to chromosome 8 using both radioactive in situ hybridization and fluorescence in situ hybridization. The additional peak obtained with the former method is attributed to the higher sensitivity of this technique, which results in hybridization of the probe to the less conserved pseudogene. We therefore conclude that the functional gene is most likely located at 8q22.