The Relationship between Psychological Safety and Management Team Effectiveness: The Mediating Role of Behavioral Integration.

This study explores whether there is an indirect effect of psychological safety on team effectiveness in management teams, operating through the mediating variable of behavioral integration. Whilst there exists a fair amount of research on the relationship between psychological safety and team effectiveness, few have looked at potential mechanisms that can explain this association in management teams. We propose behavioral integration to be a potential mediator.

Cognitive impairment associated with carcinoid syndrome.

Objectives: To evaluate the cognitive performance of patients with carcinoid syndrome (CS) compared with population norms and cancer patients with non-neuroendocrine (non-NET) liver metastases.

Background: The release of serotonin into the systemic circulation from metastatic small bowel neuroendocrine tumors (SB NET) causes CS. Many patients with CS followed in a multidisciplinary NET clinic seemed to exhibit a unique cognitive impairment.

Role of imaging in the preoperative staging of small bowel neuroendocrine tumors.

Background: Imaging studies are important in the preoperative staging of patients with small bowel neuroendocrine tumors (NET) and when selecting patients for cytoreduction procedures for metastatic disease. The purpose of this study was to assess the accuracy of preoperative imaging compared with operative findings in the staging of small bowel NET.

Study Design: Sixty-four patients with small bowel NET undergoing laparotomy and who had preoperative imaging with combinations of CT, MR, and radionuclide scintigraphy were reviewed.

Impairment of cognitive function reported by patients suffering from carcinoid syndrome.

Background: Carcinoid syndrome (CS) is characterized by symptoms of diarrhea, flushing, bronchospasm, and valvular heart disease. It has been our impression that patients with CS also exhibit features of cognitive impairment. The purpose of this pilot study was to evaluate if symptoms of cognitive impairment were reported by patients with CS.

The palliative benefit of aggressive surgical intervention for both hepatic and mesenteric metastases from neuroendocrine tumors.

Background: Metastatic neuroendocrine tumors (NETs) can present with complications of gastrointestinal tract obstruction or ischemia and carcinoid syndrome (CS). The purpose of this study was to assess whether aggressive surgical intervention of metastatic NETs provides effective palliation from these symptoms.

Methods: Sixty-six patients with metastatic gastrointestinal tract NETs that presented with either CS and/or obstructive symptoms were retrospectively reviewed.

Differential expression of the five somatostatin receptor subtypes in human benign and malignant insulinomas - predominance of receptor subtype 4.

Insulinomas constitute a subgroup of pancreatic endocrine tumors showing B cell differentiation and clinical symptoms related to inappropriate insulin secretion (WHO). Many endocrine tumors express somatostatin receptors (sstrs), which can be visualized by octreotide scintigraphy; however, about half of all insulinomas are reported to be negative. Previous immunohistochemical investigations with antibodies to sstr subtypes 1, 2, 3, and 5 have revealed differences in expression between various neuroendocrine tumors.

Prognostic indicators for carcinoid neuroendocrine tumors of the gastrointestinal tract.

Factors that determine the clinical course and outcome of patients with gastrointestinal (GI) carcinoid tumors are complex and multifaceted. These include the site of origin within the GI tract, the size of the primary tumor, and the anatomical extent of disease, whether localized, regional, or metastatic to distant sites. The new World Health Organization (WHO) histological classification of endocrine tumors, including carcinoids, represents a significant advance in terms of providing a consistent framework for histopathological interpretation that should facilitate multicenter research on treatment outcomes.

The palliative role of 131I-MIBG and 111In-octreotide therapy in patients with metastatic progressive neuroendocrine neoplasms.

Background: Radiolabeled octreotide and metaiodobenzylguanidine (MIBG) have demonstrated limited antitumor effect on neuroendocrine neoplasms (NENs). The purpose of this study was to assess the palliative benefit of radionuclide therapy (RNT) in NENs.

Methods: Since April 2001, RNT for progressive, nonsurgically resectable NENs was utilized.

131I-meta-iodobenzylguanidine in the management of metastatic midgut carcinoid tumors.

The management of metastatic neuroendocrine tumors incorporates multimodal therapy with surgery, biotherapy, and chemotherapy. Tumor-targeted therapies using radiolabeled octreotide and metaiodobenzylguanidine (mIBG) represent a novel treatment approach. The aim of this study was to evaluate the effectiveness of 131I-mIBG in the treatment of metastatic midgut carcinoid tumors.

Bone mineral density in well-differentiated thyroid cancer patients treated with suppressive thyroxine: a systematic overview of the literature.

Background: The effects of subclinical hyperthyroidism on bone mineral density (BMD) induced by suppressive thyroxine therapy in patients with well-differentiated thyroid cancer (WDTC) remains unclear. An overview of the current literature was undertaken to evaluate studies to date.

Methods: A systematic medline search yielded a total of 11 studies appropriate for review which included premenopausal women, postmenopausal women, and men on suppressive thyroxine post thyroidectomy for WDTC.

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.

Guidelines for the diagnosis and treatment of acromegaly: a Canadian perspective.

Acromegaly is a chronic, debilitating condition caused by excessive secretion of growth hormone (GH). In the majority of cases the condition results from benign pituitary adenomas or, rarely, from ectopic production of GH-releasing hormone. Regardless of the cause, excess GH results in physical disfigurement associated with arthropathy, diabetes, hypertension, cardiac dysfunction, obstructive sleep apnea and colonic neoplasia.

Advances toward the implantable artificial pancreas for treatment of diabetes.

Recent research on development of the implantable artificial pancreas for treatment of diabetes is reviewed, based on a Medline literature search that focused on glucose sensors, insulin pumps, and pump control systems. To achieve a closed feedback loop, a clinically applicable implantable artificial pancreas requires miniaturization and coordination of three components: an insulin pump, a blood glucose monitor, and a control system. Recent clinical studies have demonstrated that implantable insulin pumps are feasible for satisfactory control of diabetes for over a year, with the major complication being obstruction of the infusion catheter.

The diagnosis and management of acromegaly: a Canadian consensus report.

Objective: To reach a Canadian consensus on the diagnosis and management of acromegaly.

Diagnosis: documenting autonomous growth-hormone hypersecretion and imaging of the pituitary.

Treatment: surgical resection, adjunctive therapy with bromocriptine or octreotide and radiation therapy.

Vasoactive intestinal peptide in cirrhotic rats: hemodynamic effects and mesenteric arterial receptor characteristics.

Vasoactive intestinal peptide (VIP) blood levels in cirrhosis are elevated, but its hemodynamic and receptor characteristics remain unclarified. We aimed to quantify VIP receptor characteristics in mesenteric arteries, plasma VIP concentration by radioimmunoassay (RIA), and the hemodynamic effects of VIP infusion in bile duct-ligated (BDL) cirrhotic and sham-operated control rats. Mesenteric arterial membranes were prepared by ultracentrifugation, and receptor characteristics were studied using 125I-labeled VIP as a radioligand.

Structure-activity relationships for relaxation of smooth muscle by VIP.

Utilizing VIP and five VIP analogues, concentration-response curves for relaxation of rat mesenteric artery and rat gastric longitudinal muscle were determined for comparison with our previously published radioligand binding data on rat smooth muscle and other tissues. The biological potency of the VIP analogues in the present study compared more closely with their potency for VIP receptor binding in smooth muscle tissue (arteries) vs. other tissues (pituitary, brain, liver).

Comparative study of vascular relaxation and receptor binding by PACAP and VIP.

The pharmacological properties of the pituitary adenylate cyclase activating peptides (PACAPs) and vasoactive intestinal peptide (VIP) were compared using: (i) relaxation of vascular and gastric smooth muscle in vitro, and (ii) radioligand binding to membrane preparations of a variety of tissues. Vasoactive intestinal peptide and PACAP-27 were similarly potent in relaxing rat mesenteric arteries, porcine coronary arteries, and rat gastric smooth muscle, whereas PACAP-38 was either more or less potent than the other two peptides depending on the tissue model. Cross-desensitization to relaxation and radioligand binding studies of porcine coronary arteries suggested that VIP and the PACAPs interact with a common receptor in this tissue.

Somatostatin-induced contraction mediated by endothelial TXA2 production in canine cerebral arteries.

Whether somatostatin causes endothelium-dependent contraction (EDC) in isolated canine basilar arteries was examined. Somatostatin (10(-8)-10(-6) M) caused transient contractions in a dose-dependent manner. These contractions were abolished by removal of the endothelium, while the contractile response to neuropeptide Y occurred even after removal of the endothelium.

Cerebral vascular effects of peptide histidine methionine in canine and bovine species.

Peptide histidine methionine (PHM) is a neuropeptide with structural homology to vasoactive intestinal peptide (VIP), itself a putative vasodilatory neurotransmitter. Intra-arterial administration of PHM caused a transient, dose-dependent increase in canine vertebral artery blood flow in vivo. PHM was less potent in this effect than VIP.

Selective effect of castration on the anterior pituitary VIP receptor of male rats.

We investigated the effect of surgical castration of male rats on the binding of [Tyr(125I)10]VIP to receptors on the anterior pituitary gland, superior mesenteric artery, brain, liver, and prostate gland. In anterior pituitary membranes the maximum number of VIP binding sites was increased whereas binding affinity was decreased 24 hours following castration. In particular, the high affinity equilibrium dissociation constant (KD) increased from 0.

PHI preferentially binds to VIP receptors in normal rat tissues.

Vasoactive intestinal peptide (VIP) and peptide histidine isoleucine (PHI) are homologous neuropeptides with parallel biological actions. These similarities raise the question whether VIP and PHI have common or distinct mechanisms of action, including receptors. The present study attempted to distinguish specific binding sites for VIP and PHI in normal rat tissues using the homologous radioligands [Tyr(125I)10]VIP and [Tyr(125I)10]rat PHI.

Developmental and lactational changes in the rat anterior pituitary VIP receptor.

The regulation of female rat anterior pituitary vasoactive intestinal peptide (VIP) receptors was examined during postnatal development and lactation. VIP receptor binding to anterior pituitary membranes from 1- to 60-week-old rats and lactating rats was examined using HPLC purified [Tyr(125I)10]VIP. Nonlinear regression of competitive binding studies indicated the presence of 2 VIP binding sites in 3-week and older animals, whereas only 1 site was identified in 1- and 2-week-old rats.

Relaxation of isolated bovine coronary arteries by vasoactive intestinal peptide.

The relaxant action of vasoactive intestinal peptide (VIP) was investigated using helical strips of four major branches of bovine coronary arteries. The concentration of VIP causing 50 percent of maximal relaxation ranged from 23 to 90 nM. Preincubation of arterial strips with VIP shifted the concentration-response curves for contractions elicited by potassium chloride or prostaglandin F2 alpha to the right.

Selectivity for binding of peptide analogs to vascular receptors for vasoactive intestinal peptide.

The structure-activity relationships for vasoactive intestinal peptide (VIP) receptor binding were studied using N-terminally modified VIP analogs. VIP fragments, and VIP receptor antagonists. Tissue sources included bovine coronary artery, rat mesenteric artery, rat pituitary, rat brain synaptosomes, and rat liver.