Smad3 Mediates Activin-Induced Transcription of Follicle-Stimulating Hormone β-Subunit Gene

Synthesis of FSH by the anterior pituitary is regulated by activin, a member of the TGFβ superfamily of ligands. Activin signals through a pathway that involves the activation of the transcriptional coregulators Smad2 and Smad3. Previous work from our laboratory demonstrated that Smad3, and not Smad2, is sufficient for stimulation of the rat FSHβ promoter in a pituitary-derived cell line LβT2. Here, we used RNA interference technology to independently decrease the expression of Smad proteins in LβT2 cells to further investigate Smad2 and Smad3 roles in activin-dependent regulation of the FSHβ promoter. Down-regulation of Smad2 protein by small interfering RNA duplexes affects only basal transcription of FSHβ, whereas decreased expression of Smad3 abrogates activin-mediated stimulation of FSHβ transcription. Although highly related, Smad2 and Smad3 differ in their Mad homolog (MH) 1 domains, where the Smad2 protein contains two additional stretches of amino acids that prevent this factor from binding to DNA. We investigated whether these structural features contribute to differential FSHβ transactivation by Smad2 and Smad3. A variety of Smad chimera constructs were generated and used in transient transfection studies to address this question. Only cotransfection of chimera constructs that contain the MH1 domain of Smad3 results in activin-mediated stimulation of the rat FSHβ promoter. Furthermore, the insertion of Smad2 loops into Smad3 protein renders it inactive, suggesting that DNA binding is necessary for Smad3-mediated stimulation of the rat FSHβ promoter. Taken together, these results indicate that the functional differences between Smad2 and Smad3 in their ability to transactivate the rat FSHβ promoter lie primarily within the MH1 domain and involve structural motifs that affect DNA binding

Failed pneumoperitoneum for laparoscopic surgery following autologous Deep Inferior Epigastric Perforator (DIEP) flap breast reconstruction: a case report.

Laparoscopic abdominal surgery may prove difficult in patients who have undergone previous abdominal procedures. No reports in the medical literature have presented an aborted laparoscopic procedure for failed pneumoperitoneum following autologous flap-based breast reconstruction.A 55-year-old woman presented with recurrent invasive lobular carcinoma of the right breast as well as a history of ductal carcinoma in situ of the left breast. The patient desired to proceed with bilateral skin- and nipple-sparing mastectomies with right axillary lymph node biopsy, followed by immediate bilateral autologous deep inferior epigastric perforator (DIEP) flap-based breast reconstruction. Preoperatively, a computerized tomography angiogram was obtained for reconstructive preparation, which revealed a left adrenal mass. Ensuing work-up diagnosed a pheochromocytoma. Given the concern for breast cancer progression, the patient elected to proceed first with breast cancer surgery and reconstruction prior to addressing the adrenal tumor. Subsequently, 3 months later the patient was brought to the operating room for a laparoscopic left adrenalectomy for the pheochromocytoma. With complete pharmacologic abdominal relaxation, the abdomen proved too tight to accommodate sufficient pneumoperitoneum and the laparoscopy was aborted. The patient was evaluated in the outpatient setting for assessment of abdominal wall compliance at regular intervals. Five months later, the patient was taken back to the operating room where pneumoperitoneum was established without difficulty and the laparoscopic left adrenalectomy was performed without complications.Pneumoperitoneum for laparoscopic surgery subsequent to autologous DIEP flap-based breast reconstruction may prove difficult as a result of loss of abdominal wall compliance. Prior to performing laparoscopy in such patients, surgeons should consider the details of the patient's previous reconstructive procedure and assess potential risk factors for difficulty with insufflation. Lastly, careful abdominal examination should be performed to indicate whether laparoscopy for elective procedures should be delayed until abdominal wall compliance normalizes

Failed pneumoperitoneum for laparoscopic surgery following autologous Deep Inferior Epigastric Perforator (DIEP) flap breast reconstruction: a case report.

Laparoscopic abdominal surgery may prove difficult in patients who have undergone previous abdominal procedures. No reports in the medical literature have presented an aborted laparoscopic procedure for failed pneumoperitoneum following autologous flap-based breast reconstruction.A 55-year-old woman presented with recurrent invasive lobular carcinoma of the right breast as well as a history of ductal carcinoma in situ of the left breast. The patient desired to proceed with bilateral skin- and nipple-sparing mastectomies with right axillary lymph node biopsy, followed by immediate bilateral autologous deep inferior epigastric perforator (DIEP) flap-based breast reconstruction. Preoperatively, a computerized tomography angiogram was obtained for reconstructive preparation, which revealed a left adrenal mass. Ensuing work-up diagnosed a pheochromocytoma. Given the concern for breast cancer progression, the patient elected to proceed first with breast cancer surgery and reconstruction prior to addressing the adrenal tumor. Subsequently, 3 months later the patient was brought to the operating room for a laparoscopic left adrenalectomy for the pheochromocytoma. With complete pharmacologic abdominal relaxation, the abdomen proved too tight to accommodate sufficient pneumoperitoneum and the laparoscopy was aborted. The patient was evaluated in the outpatient setting for assessment of abdominal wall compliance at regular intervals. Five months later, the patient was taken back to the operating room where pneumoperitoneum was established without difficulty and the laparoscopic left adrenalectomy was performed without complications.Pneumoperitoneum for laparoscopic surgery subsequent to autologous DIEP flap-based breast reconstruction may prove difficult as a result of loss of abdominal wall compliance. Prior to performing laparoscopy in such patients, surgeons should consider the details of the patient's previous reconstructive procedure and assess potential risk factors for difficulty with insufflation. Lastly, careful abdominal examination should be performed to indicate whether laparoscopy for elective procedures should be delayed until abdominal wall compliance normalizes