Biomedical subjects

R D Ferguson

Publications and source records attributed to R D Ferguson.

21 records · Page 2Linked to original sources

PubMed1990

Vascular lesions involving the cranial base: combined surgical and interventional radiologic approach.

Advantages and possible complications of combined surgical and interventional radiologic approach to vascular lesions involving the cranial base are presented in three case examples. The methodology and technology of endovascular embolization and occlusion techniques, selection of embolic materials, functional testing to prevent neurologic injury and surgical implications of these treatment modalities are discussed. Emphasis is placed on individualization of each combined approach relative to the aforementioned factors.

Catheterization↗

PubMed1990

Preoperative superselective arteriolar embolization: a new approach to enhance resectability of spinal tumors.

The extent of surgical resection of spinal tumors is frequently limited by blood loss and technical difficulty associated with the vascularity of the tumors. We report here the use of superselective percutaneous arterial embolization to reduce the rate of blood loss at the time of surgical resection and enhance resectability. The types of tumors treated were metastatic renal carcinoma, metastatic thyroid carcinoma, metastatic melanoma, and giant cell tumor of the sacrum. Two of the patients required repeated embolization and surgery for recurrent symptoms. The estimated blood loss in seven of nine procedures performed on the six patients ranged from 300 to 800 ml, after which no transfusion was required. In two procedures, extensive resection of very large tumors resulted in larger losses of blood, and postoperative transfusion was necessary. No significant complications of embolization or surgery occurred. A key factor in our embolization technique is the use of microfibrillar collagen, which allows occlusion of tumor vessels as small as 20 microns and may prevent reconstitution of the embolized vessels by collateral flow. We conclude that preoperative arterial embolization enhances the resectability of a variety of spinal tumors by reducing intraoperative blood loss. This may provide an additional benefit by reducing the risk related to postoperative transfusion. By permitting a more aggressive surgical approach, the use of preoperative embolization also has the potential to improve outcome in patients with spinal tumors.

Adult↗

PubMedDate not supplied

A topographical model of mu-opioid and brain somatostatin receptor selective ligands. NMR and molecular dynamics studies.

We have refined the 1H NMR-based conformations of the mu-opioid receptor selective peptides related to somatostatin of general formula Xxx-Yyy1-Cys-Zzz-D-Trp-Lys(Orn)5-Thr-Pen-Thr8- NH2, where Xxx, Yyy, Zzz are 0, D-Phe and Tyr for 1; 0, D-Tic and Tyr for 2; Gly, D-Tic and Tyr for 3; and 0, D-Phe and Tic for 4, respectively, (Kazmierski et al., J. Am. Chem. 113, 2275-2283), using a molecular-dynamics approach. We present evidence that the NMR data are compatible with beta II'-, gamma- and gamma'-turns for the central tetrapeptide Tyr-D-Trp-Lys/Orn-Thr. Based on detailed structural and topographical considerations, we suggest that the mu-opioid receptor selectivity of 2 is due to a particular spatial arrangement of aromatic side chains of D-Tic1 and Tyr3 (7.5 A), and that the opioid receptor recognition domain is located in the N-terminal part of the peptide while the somatostatin receptor recognition domain is determined by the central, turn forming part of this class of cyclic peptides. A model for a mu-opioid selective ligand has emerged from these studies that shows excellent structural similarities to rigid opioid alkaloids.

Amino Acid Sequence↗