Expression of cystic fibrosis transmembrane conductance regulator corrects defective chloride channel regulation in cystic fibrosis airway epithelial cells.

The cystic fibrosis transmembrane conductance regulator (CFTR) was expressed in cultured cystic fibrosis airway epithelial cells and Cl- channel activation assessed in single cells using a fluorescence microscopic assay and the patch-clamp technique. Expression of CFTR, but not of a mutant form of CFTR (delta F508), corrected the Cl- channel defect. Correction of the phenotypic defect demonstrates a causal relationship between mutations in the CFTR gene and defective Cl- transport which is the hallmark of the disease.     

Expression and characterization of the cystic fibrosis transmembrane conductance regulator.

Cystic fibrosis (CF) is a common lethal genetic disease that manifests itself in airway and other epithelial cells as defective chloride ion absorption and secretion, resulting at least in part from a defect in a cyclic AMP-regulated, outwardly-rectifying Cl- channel in the apical surface. The gene responsible for CF has been identified and predicted to encode a membrane protein termed the CF transmembrane conductance regulator (CFTR). Identification of a cryptic bacterial promoter within the CFTR coding sequence led us to construct a complementary DNA in a low-copy-number plasmid, thereby avoiding the deleterious effects of CFTR expression on Escherischia coli. We have used this cDNA to express CFTR in vitro and in vivo. Here we demonstrate that CFTR is a membrane-associated glycoprotein that can be phosporylated in vitro by cAMP-dependent protein kinase. Polyclonal and monoclonal antibodies directed against distinct domains of the protein immunoprecipitated recombinant CFTR as well as the endogenous CFTR in nonrecombinant T84 cells. Partial proteolysis fingerprinting showed that the recombinant and non-recombinant proteins are indistinguishable. These data, which establish several characteristics of the protein responsible for CF, will now enable CFTR function to be studied and will provide a basis for diagnosis and therapy.     

Sex chromatin as a marker in some rabbit cells

Zusammenfassung In frisch isolierten Kaninchenfibroblasten-und Leukocyten kann kein Geschlechtsdimorphismus festgestellt werden. Nach einigen Tagen Zellkultivierung findet man in 84–93% (durchschnittlich 91,5%) der weiblichen Fibroblasten den Geschlechtschromatinkörper. Nur 0–2% (durchschnittlich 0,5%) der männlichen Fibroblasten weisen ein dem Geschlechtschromatinkörper ähnliches Gebilde auf. In Leukocytenkulturen sind die entsprechenden Zahlen 82–90% (durchschnittlich 89%) für weibliche, 0–1% (durchschnittlich 0,3%) für männliche Zellen. Diese Daten lassen den Geschlechtschromatinkörper als brauchbaren Zellmarkierer beim Kaninchen erscheinen.     

Germline mutations in the ribonuclease L gene in families showing linkage with HPC1.

Although prostate cancer is the most common non-cutaneous malignancy diagnosed in men in the United States, little is known about inherited factors that influence its genetic predisposition. Here we report that germline mutations in the gene encoding 2'-5'-oligoadenylate(2-5A)-dependent RNase L (RNASEL) segregate in prostate cancer families that show linkage to the HPC1 (hereditary prostate cancer 1) region at 1q24-25 (ref. 9). We identified RNASEL by a positional cloning/candidate gene method, and show that a nonsense mutation and a mutation in an initiation codon of RNASEL segregate independently in two HPC1-linked families. Inactive RNASEL alleles are present at a low frequency in the general population. RNASEL regulates cell proliferation and apoptosis through the interferon-regulated 2-5A pathway and has been suggested to be a candidate tumor suppressor gene. We found that microdissected tumors with a germline mutation showed loss of heterozygosity and loss of RNase L protein, and that RNASEL activity was reduced in lymphoblasts from heterozyogous individuals compared with family members who were homozygous with respect to the wildtype allele. Thus, germline mutations in RNASEL may be of diagnostic value, and the 2-5A pathway might provide opportunities for developing therapies for those with prostate cancer.     

内蒙古草地挥发性有机物的预研究

内蒙古草原挥发性有机物的研究在大气化学、大气环境领域具有重要的作用。2001年夏季,利用便携式光离子化检测器以及采样仪器对于内蒙古草原的一些优势草种进行了测量,得到了对内蒙古草原挥发性有机物的初步认识。     

Zur « Lipoidlöslichkeit » von Arzneimitteln

Summary The solubility of phenazon, 4-aminophenazon and aminophenazon in heptan, neatsfoot oil, lard, lecithin and chloroform was determined. The results demonstrate that the solubility in chloroform or heptan cannot be taken as a measure of the fat-solubility, and that the solubility of phenazon in lipids has to be taken into consideration in determining the so-called antipyrinspace as a measure of total body water.     

Steroidal peptides

Zusammenfassung Es wird die Möglichkeit erwogen, dass Steroide mit geeignet gebauten Peptidseitenketten am Aufbau oder Transport von Hormonen beteiligt sein könnten. Über die erstmalige Darstellung von Steroidpeptiden wird berichtet. Als Beispiele werden die Synthesen der beiden geschützten Steroidpeptide III und IV beschrieben.

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Part XXIV of a series entitledSteroids and Related Natural Products. For the preceding contribution see:J. P. Kutney, W. Cretney, G. R. Pettit, andJ. C. Knight, Tetrahedron, in press.

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A preliminary report of this study was presented (April 9, 1964) at the Third International Symposium on the Chemistry of Natural Products, Kyoto (Japan).

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This investigation was supported by National Science Foundation Research Grant GB-249.