The intermediate role of 18-hydroxycorticosteroids in aldosterone biosynthesis

Zusammenfassung Durch ihre Eigenschaft, bestimmte Stufen bei der Bildung radioaktiv markierten Aldosterons aus¹⁴C-Progesteron bzw.³H-11-Desoxycorticosteron zu hemmen, erwiesen sich 11-Desoxycorticosteron, Corticosteron und 18-Hydroxycorticosteron als wesentliche Zwischenstufen der Aldosteronbiosynthese. 18-Hydroxy-11-desoxycorticosteron hingegen scheint an der Bildung von Aldosteron nicht beteiligt zu sein.     

Human dystrophin expression in mdx mice after intramuscular injection of DNA constructs

Duchenne's muscular dystrophy (DMD), which affects one in 3,500 males, causes progressive myopathy of skeletal and cardiac muscles and premature death. One approach to treatment would be to introduce the normal dystrophin gene into diseased muscle cells. When pure plasmid DNA is injected into rodent skeletal or cardiac muscle, the cells express reporter genes. We now show that a 12-kilobase full-length human dystrophin complementary DNA gene and a 6.3-kilobase Becker-like gene can be expressed in cultured cells and in vivo. When the human dystrophin expression plasmids are injected intramuscularly into dystrophin-deficient mdx mice, the human dystrophin proteins are present in the cytoplasm and sarcolemma of approximately 1% of the myofibres. Myofibres expressing human dystrophin contain an increased proportion of peripheral nuclei. The results indicate that transfer of the dystrophin gene into the myofibres of DMD patients could be beneficial, but a larger number of genetically modified myofibres will be necessary for clinical efficacy.     

Delineation of a 50 kilobase DNA segment containing the recombination site in a sporadic case of Huntington's disease.

No detectable rearrangements involving chromosome 4p16.3 have been observed in patients with Huntington's disease (HD). New mutations for HD could involve structural alterations which might aid the localization of the defective gene. We have reinvestigated a well documented sporadic case of HD. DNA haplotyping with markers between D4S10 and the telomeric locus D4S141 reveals a recombination event in one chromosome of the sporadic HD patient. The site of recombination maps within a 50 kilobase (kb) region, about 700 kb from the 4p telomere. Based on the extremely low HD mutation rate and significantly decreased recombination in the distal region of 4p, we hypothesize a direct link between the site of the recombination and HD in this patient.     

ACTH-Stimulierung der Corticosteroidbiosynthese durch Freisetzung «gebundener» 21-Desoxypregnene

Summary Impairment of 21-hydroxylation was observed when 4-C¹⁴-cholesterol was transformed into 4-C¹⁴-corticosteroids in slices of bovine adrenal cortex, whereas corticosteroid synthesis from 4-C¹⁴-progesterone proceeded freely. ACTH stimulated corticosteroid formation from 4-C¹⁴-cholesterol but not from 4-C¹⁴-progesterone. It is therefore suggested that ACTH facilitates the «release» of 21-desoxypregnenes, which are present in a «bound» form after synthesis from cholesterol in intact adrenocortical tissue, and which are unavailable for the following reactions without conditioning by ACTH.