Regulation of hormone-induced cyclic AMP response to parathyroid hormone and prostaglandin E2 in cells cultured from human giant cell tumors of bone.

Cells dispersed from human giant cell tumors of bone and grown in monolayer culture increase intracellular cyclic AMP (cAMP) when incubated with parathyroid hormone (PTH) or prostaglandin E2 (PGE2). When cells are continuously exposed to PTH, cAMP levels increase acutely but then decrease rapidly to pretreatment values despite continued presence of hormone or addition of new hormone. Preincubation of cells with PTH for periods as short as 10 min results in a decrease in the capacity of cells to increase cAMP content when re-exposed to maximal stimulatory concentrations of PTH. The decrease in the magnitude of the PTH-induced cAMP response observed in cells pretreated with this hormone is dependent on the concentration of PTH present during the preincubation. The loss of cAMP response in cells pretreated with either PGE2 or PTH is hormone specific in that cells made refractory by pretreatment with one hormone still increase cAMP content when exposed to the other. Although the cells are not releasing measurable amounts of prostaglandins into the medium, pretreatment with indomethacin results in an increase in the magnitude of the cAMP response to PGE2. The PTH-induced cAMP response is not affected by indomethacin pretreatment. The loss of PTH responsiveness produced by hormone preincubation is consistent with the phenomenon of "down-regulation" observed with ligand-receptor interactions in a variety of tissues.     

The Danish National Register of assisted reproductive technology: content and research potentials

European Journal of Epidemiology - The Danish National Register of assisted reproductive technology (ART) was initially established in 1994. The register comprises complete information on all ART...     

Breaking the speed of the sound of loneliness: Sexual partner change and the fear of intimacy

Following a thematic analysis of responses, a qualitative study of sexuality and alcohol use was undertaken in three bars/clubs in Oslo. Interviews with two persons (one male, one female) with high rates of sexual partner change were selected for detailed interpretative and contextual analysis, the aim being to examine the underlying motives for this mode of action. The principal motivations underpinning the man's behaviour linked to sex drive, impulsivity, and opportunity. He expressed cynicism, distance, loneliness and an element of narcissism. The woman's sexual activity on the other hand was motivated by intoxication, chance, the desire to offer care, arousal, and love. The data suggest that much more than sexual pleasure is being sought in the kinds of encounters described. A basic motive underpinning this behaviour appears to be a fear of intimacy mixed with the search for a sense of self-worth.     

Functional capacity vs side effects: treatment attributes to consider when individualising treatment for patients with rheumatoid arthritis

Clinical Rheumatology - Individualisation of rheumatoid arthritis (RA) treatment needs to take account of individual patients’ preferences to increase patient-centeredness in treatment...     

Response to hormones of cells cultured from human giant cell tumors of bone.

Giant cell tumors of bone obtained from 7 patients were dispersed with clostridial collagenase and trypsin and adherent cells were maintained in culture. Early cultures contained both mononucleated and multinucleated cells presumably derived from the stromal and giant cells of the original tumor. The original multinucleated cells did not survive for greater than 7-10 days whereas the mononucleated cells persisted and could be passaged by trypsinization. In 5 of 7 early cultures exposed to parathyroid hormone (PTH) there was a rise in cAMP within 5-10 min in both cells and medium which averaged approximately 12-fold. None of the cells responded to calcitonin and a variable rise in cAMP was seen after incubation with prostaglandin E2. In cells cultured from 3 tumors the PTH response disappeared with passage of the cells, but in the remaining 2, PTH response persisted through multiple passages. The presence as well as the magnitude of the PTH-induced cAMP response in these cells is consistent with a skeletal origin.