Carcinoid syndrome symposium on treatment modalities for gastrointestinal carcinoid tumours: symposium summary.

OBJECTIVE: To develop a collaborative approach for the treatment of gastrointestinal carcinoid tumours and carcinoid syndrome. PARTICIPANTS: Leaders in the medical, endocrine, radiologic and surgical treatment of carcinoid disease were selected to present papers at the Carcinoid Syndrome Symposium on Treatment Modalities for Gastrointestinal Carcinoid Tumours and participate in the workshop that followed. EVIDENCE: A multidisciplinary symposium with experts in the field of carcinoid syndrome was organized at the University of Calgary. Data presented, participation of the attendees and a review of the literature were used in the workshop to develop a collaborative approach to the management of carcinoid tumours. BENEFITS: Carcinoid tumours are rare and few centres have large experiences in their treatment. Before the development of this collaboration, patients with carcinoid tumours received a unidisciplinary approach depending on referral patterns. The development of a multidisciplinary neuroendocrine clinic helped to unify the approach to these patients, yet a consensus on the treatment of carcinoid tumours was lacking. The expertise at the symposium allowed for consensus and the development of treatment algorithms, including biochemical screening, radiographic localization and surgical intervention, for gastrointestinal carcinoid tumours. The role of medical and hormonal therapy after cytoreducion is presented. RECOMMENDATION: Patients with carcinoid tumours require a multidisciplinary approach to their care.

Persistent/recurrent hyperparathyroidism: a comparison of sestamibi scintigraphy, MRI, and ultrasonography.

For patients with persistent or recurrent hyperparathyroidism, parathyroid imaging is indicated to confirm the presence of abnormal parathyroid gland(s) and identify their location. These imaging techniques are being modified constantly and newer methods have been developed. Sestamibi scintigraphy, MRI and sonography were compared in 23 patients with persistent or recurrent hyperparathyroidism. Preoperative 99m-Technetium Sestamibi (MIBI), MRI and ultrasonographic (US) studies of 23 patients with 25 histopathologically confirmed abnormal parathyroid glands were compared, using independent prospective interpretations. All patients had been operated upon previously for hyperparthytroidism. Accuracy of various combinations of MRI, MIBI, and US also were calculated. The results are shown for all abnormal glands (n =25); sensitivities and accuracies were 88 and 84% for MRI, 80 and 80% for MIBI, and 58 and 44% for US. For only parathyroid adenomas (n = 18), sensitivities and accuracies were 89 and 89% for MRI, 94 and 94% for MIBI, and 58 and 39% for US. Finally, for parathyroid hyperplasia (n = 7 glands in five patients), sensitivities and accuracies were 83 and 71% for MRI, 43 and 43% for MIBI, and 57 and 57% for US. Either MIBI or MRI results were significantly better for detecting abnormal parathyroid glands than US (P < 0.01), but MRI and MIBI were not statistically different. Combining MRI and MIBI produced a combined accuracy of 92%, whereas combining either of these tests with US did not improve on the accuracy of either test alone. In conclusion, for patients with persistent or recurrent hyperparathyroidism, MRI and MIBI are equally accurate for detecting abnormal parathyroid glands, and the combination of both tests may be more accurate than either test alone.

Pseudodelta sign on computed tomography: an indication of bilateral interhemispheric hemorrhage.

The "pseudodelta sign" is introduced as an indicator of interhemispheric hemorrhage. This sign, appearing in computed tomography (CT) scans, consists of hyperattenuated extra-axial blood surrounding blood flowing in the superior sagittal sinus, which shows lower attenuation. To determine the prevalence of interhemispheric hemorrhage and the pseudodelta sign in patients with post-traumatic extra-axial hemorrhage, the authors reviewed the charts and CT scans of 198 such patients. The patients had been admitted to a tertiary-care hospital between Jan. 1, 1986, and Dec. 1, 1990. Interhemispheric hemorrhage was visible in 18 cases; the pseudodelta sign was seen in 14 of these. In 8 of the 14 cases the interhemispheric hemorrhage consisted of bilateral subdural hematoma, and in 3 it consisted of unilateral subdural hematoma. In the remaining three cases the appearance of the interhemispheric blood was nonspecific, and the hemorrhage may have been subdural or subarachnoid. The pseudodelta sign may be a good indicator of interhemispheric hemorrhage in either the subdural or subarachnoid space.

Hydroxyapatite orbital implants. Scanning with technetium-99m MDP.

Porous hydroxyapatite spheres are an ideal prosthetic device for orbital implantation because they are incorporated into soft tissues. Once vascularized, an eye prosthesis can be coupled to the sphere by a peg placed within a central motility hole. This hole should not be drilled while the sphere is avascular because of the risk of infection. Radionuclide scanning with Tc-99m methylene diphosphonate has been used to assess implant vascular ingrowth because radiophosphonate deposition within the sphere parallels vascularization. Using this technique, the authors examined the hydroxyapatite implants of 15 patients 6 months following insertion. Results showed that complete vascularization is best defined by planar imaging rather than SPECT. While the relative intensity of implant activity may be an important feature, uniformity of activity is probably more significant.

The nonhistone chromosomal protein, H2A-specific protease, is selectively associated with nucleosomes containing histone H1.

We have determined the distribution of the nucleosomal bound nonhistone chromosomal protein, H2A-specific protease, in calf thymus and liver chromatin. The protease was unevenly distributed in chromatin with domains containing histone H1 being selectively complexed with the enzyme. Moreover, the protease had a preference for the less compact chromatin domains enriched in the H1 subtypes H1a and -c. We have demonstrated that ubiquitinated H2A is a substrate of the H2A-specific protease and that the enzyme is a serine protease which can be inactivated with protease inhibitors only after it is released from the nucleosome. Possible functions of the protease in modulating chromatin structure are discussed.