Ultraviolet-induced dna repair synthesis in lymphocytes from patients with actinic keratosis.

Actinic keratosis is an epidermal cancer in situ. Extensive exposure to sunlight is considered as a contributing factor to the etiology of this tumor. Ultraviolet (UV) light of solar radiation induces structural damage in DNA, which may give rise to mutations and transformed cells if the damage is not repaired.

Relationship between prostaglandin biosynthesis and the effect of insulin on hormone-stimulated lipolysis in rat adipose tissue.

Lipolysis in rat fat pads was studied by determination of free fatty acid and glycerol production in various experimental conditions (in the absence or presence of glucose, adrenalin and insulin). These results were compared to the accumulation of endogenous prostaglandins E2 and F2alpha during lipolysis. In the absence of glucose the prostaglandin production followed the adrenalin-induced fluctuations in released free fatty acids both in the presence or absence of insulin.

[Hormonal control of prostaglandins biosynthesis during lipolysis in rat adipose tissue (author's transl)].

Lipolysis in rat fat pads was studied by determination of free fatty acid and glycerol production in various experimental conditions (absence or presence of glucose, adrenaline and insulin). These results were compared to the accumulation of endogenous prostaglandins E2 and F2 alpha during lipolysis. In the absence of glucose the prostaglandin production followed the adrenaline-ininduced fluctuations in released free fatty acids both in the presence or absence of insulin.

DNA repair and frequency of x-ray and u.v.-light induced chromosome aberrations in leukocytes from patients with Down's syndrome.

DNA-repair and the frequency of chromosome aberration after u.v. and X-ray irradiation was studied on leukocytes from patients with Down's syndrome.

The location of repeated DNA sequences in the chromosomes of Chironomus tentans.

Polytene chromosomes of Chironomus tentans were hybridized in situ with in vivo labelled nuclear and chromosomal RNA. Nuclear RNA formed hybrids preferentially in five distinct regions considered to contain clustered, repeated DNA sequences. These are the two nucleolar organizer regions, Balbiani ring 1 and 2, and the 5 S RNA genes in region 2A of chromosome II, which together comprised almost 70% of the total number of grains over the complement.

Localization of 5 S RNA genes in Chirnomus tentans.

The genes for 5 S RNA in Chironomus tentans have been located to region 2A of chromosome II by cytological hybridization. RNA from individual chromosomes, nuclear sap and nucleoli of salivary gland cells hybridized with the identified 5 S RNA genes in region 2A of chromosome II. The results suggest a common origin of 5 S RNA in these different nuclear compartments.

Homology of Balbiani ring DNA in two closely related Chironomus species.

Cytogenetic analysis indicates that Balbiani Ring 2 (BR 2) in the two sibling species Chironomus tentans and Chironomus pallidivittatus arises from identifically banded segments in the salivary gland polytene chromosomes, although chromosomal rearrangements have occurred. In situ hybridization of BR 2 RNA to the polytene chromosomes of each individual species, as well as their F1 hybrids, reveals that the repetitious BR 2 DNA in the two species has, within the limits of the technique, retained identity of nucleotide sequences and degree of repetition. The DNA of the naturally expressed BR 1 and BR 3 in both species and that ot the galactose induced BR 6 in C.

Evidence for the placental origin of hyaluronidase in the maternal circulation.

The level of maternal serum hyaluronidase activity was shown to rise during pregnancy. Investigation of non-pregnant females did not demonstrate hormonal control of enzyme activity. The findings of a quantitative increase in serum hyaluronidase activity during pregnancy is presented in conjunction with previous evidence of a qualitative change in this enzyme as evidence for a placental origin of the increased activity demonstrated.

The chromosomal distribution of balbiani ring dna in chironomus tentans.

RNA from Balbiani ring 2 (BR 2) of Chironomus tentans salivary gland cells was hybridized to polytene chromosomes of rectum cells, in which the Balbiani ring is not expressed. The distribution of the RNA:DNA hybrids was studied by autoradiography, using ultrathin emulsion to increase the resolution. The grains were estimated to cover 3-5 polytene chromosome bands, which indicates that information expressed by transcription in BR 2 may be present in several adjoining chromomeres.

Treatment of psoriasis with oral psoralens and longwave ultraviolet light. Therapeutic results and cytogenetic hazards.

The purpose of the present investigation was to study the usefulness of oral treatment of psoriasis with psoralens and longwave ultraviolet light and the possible cytogenetic hazards of this therapy. 8-methoxypsoralen (8-MOP) in doses between 15 and 60 mg orally followed 2 hours later by UVA irradiation of one side of the body gave a healing of the irradiated side in 24 of 40 cases and an improvment in another 11 cases while only one case healed on the side of body that was not irradiated. The most common undesired side effect was pruritus on the irradiated side of the body.