http://dx.doi.org/10.1016/j.surg.2009.03.01

Two growth inhibitors were identified in culture medium conditioned by a human keratinocyte cell line, HaCat. TGF-beta was detected in media conditioned by growing or confluent HaCat cells, as well as in media conditioned at physiological (1 mM) or low (0.03 mM) Ca2+ concentrations. However, a considerable part of transforming growth factor beta (TGF-beta) in media conditioned at a physiological Ca2+ concentration was in active form, whereas most TGF-beta in media conditioned at a low Ca2+ concentration was latent. The other growth-inhibitory activity, which was detected only in media conditioned by confluent cells at a physiological Ca2+ concentration, was purified to homogeneity by a four-step procedure. The N-terminal amino acid sequence of the 33-kDa protein was identical with that of insulin-like growth factor binding protein-6 (IGFBP-6). Purified IGFBP-6 inhibited the growth of HaCat and Balb/MK keratinocyte cell lines, as well as Mv1Lu cells. The growth activity was also demonstrated by human recombinant IGFBP-6. In summary, HaCat cells secrete at least two possible autocrine growth inhibitors: TGF-beta which is secreted constitutively, but activated in a Ca(2+)-dependent manner, and IGFBP-6 which is secreted in a cell density- and Ca(2+)-dependent manner.

No abstract

Objective: As it is now known that primary aldosteronism (PA) is more prevalent than was previously recognized, and is a potentially curable cause of hypertension and related cardiovascular diseases, the search for a safe and effective means of its diagnosis has reemerged as a topic of interest. Adrenal venous sampling is the gold standard for diagnosis of PA, but the technique is challenging and the small right adrenal vein can be particularly difficult to cannulate. Our objective was to evaluate the usefulness of computed tomography during angiography (angio-CT) in increasing the success of adrenal venous sampling and to identify factors associated with cannulation failure. Design: Retrospective review. Methods: A total of 140 consecutive patients with suspected PA except Cushing's syndrome treated at a single hospital from June 2008 to May 2013 were included. Catheter misplacement and correct cannulation rates before angio-CT and success rate of sampling after angio-CT were calculated. Univariate analysis for factors related to incorrect cannulation included gender, age, height, weight, BMI, and adrenal nodules. Successful sampling was biochemically defined according to cortisol concentrations in the venous blood samples. Results: Angio-CT detected misplaced catheters in 13 patients (9.3%). The calculated correct cannulation rate of adrenal vein sampling increased from 86.4% before angio-CT to 95.7% after CT (P!0.001, McNemar's test). Univariate analysis showed a tendency for a higher rate of failure of right adrenal venous sampling in taller patients (PZ0.052, Mann-Whitney's U test). Conclusion: Angio-CT improved success of adrenal venous sampling.

A mutant gelsolin, [His321]gelsolin, was isolated from R1, a flat revertant of human activated c-Ha-ras oncogene-transformed NIH/3T3 cells (EJ-NIH/3T3) produced by ethylmethanesulfonate treatment. [His321]Gelsolin has a histidine instead of a proline residue at position 321 and suppresses the tumorigenicity of EJ-NIH/3T3 cells when it is constitutively expressed [Müllauer, L., Fujita, H., Ishizaki, A. & Kuzumaki, N. (1993) Oncogene 8, 2531-2536]. To investigate the biochemical consequences of the amino acid substitution of His321, we expressed the [His321]gelsolin and wild-type gelsolin in Escherichia coli, purified them, and analyzed their effects on actin, polyphosphoinositol lipids and phospholipase C. [His321]Gelsolin has decreased actin-filament-severing activity and increased nucleating activity compared with wild-type gelsolin in vitro. Furthermore, compared to wild-type gelsolin both nucleation and severing by [His321]gelsolin are inhibited more strongly by the phosphoinositol lipids phosphatidylinositol 4-phosphate (PtdInsP) and phosphatidylinositol 4,5-bisphosphate (PtdInsP2). In addition, [His321]gelsolin inhibits PtdInsP2 hydrolysis by phospholipase C gamma 1 more strongly than wild-type gelsolin in vitro because of its higher binding capacity for phosphoinositol lipid. Gelsolin has six homologous amino acid repeats called S1-S6. Our results suggest that the segment S3 which contains the mutation is functionally relevant for regulation of gelsolin's activities even though the relevant actin-binding domains are in segments 1, 2, and 4-6, and that the region around the residue 321 may contain a phosphoinositol-lipid-binding site. Altered functions of [His321]gelsolin might be important for the loss of tumorigenicity of the ras-transformed cells.