Personality profiles of patients with dissociative trance disorder in Singapore

This report studies the personality of individuals who suffer from dissociative trance disorder and examines whether the personality profiles could predict the individual's frequency of trance states. A total of 58 cases were given the Eysenck Personality Questionnaire (EPQ) and their personal information harvested from the case notes and through subsequent interviews. The subjects were also reassessed 1 year later to obtain their frequency of trance states. For both sexes, there were lower extraversion scores and higher psychoticism, neuroticism, and lie scores in the sample compared to the Singapore norms. Of the 47 subjects traced, total episodes of trances that occurred over the 1-year period was positively correlated with neuroticism and negatively with extraversion scores. The high lie scores in individuals with dissociative trance disorder could be a reflection of their concern of how others perceive them. The motivation could be that of restoration of self-esteem or "face." The profiles in the EPQ could be used to predict the individual's frequency of trance states. Subjects with personality traits like nervousness, excitability, and emotional instability were more likely to have a higher frequency of trance states.     

Elevated platelet vesicular monoamine transporter density in untreated patients diagnosed with major depression

The intraneuronal uptake of monoamines into brain synaptic vesicles is mediated by the vesicular monoamine transporter (VMAT2). This transporter plays a major role in monoamine storage and quantal release. Recently we demonstrated a high degree of similarity between the pharmacodynamic characteristics of platelet and brain VMAT2. In the present study we measured the VMAT2 density, using [3H]dihydrotetrabenazine ([3H]TBZOH) as a ligand, in platelets of untreated patients diagnosed with major depressive disorder (MDD) (n=10; three with recurrent depression and seven with first episode depression) compared to sex- and age-matched healthy control subjects (n=23). A significant elevation in the VMAT2 density (B(max)) was observed in the platelets of untreated MDD patients (+24%) compared to healthy control subjects. No significant change was found in the affinity constant (K(d)). The increased platelet VMAT2 density may reflect depression-related enhancement of the capacity to accumulate monoamines in the vesicles in the presence of lower monoamine turnover.     

Vitamin D Analogs

Patients with chronic renal failure frequently develop secondary hyperparathyroidism, primarily as a result of phosphate retention and low serum 1,25(OH)2D3. Replacement therapy with calcitriol or its synthetic precursor alfacalcidol [1alpha(OH)D3] often produces hypercalcemia, especially when combined with calcium-based phosphate binders. In addition, the natural vitamin D compounds can exacerbate the hyperphosphatemia in patients with chronic renal failure. This combined increase in calcium and phosphate has been correlated with vascular calcification leading to coronary artery disease, the most common cause of mortality in renal patients. Several vitamin D analogs have now been developed that retain the direct suppressive action of calcitriol on the parathyroid glands but have less calcemic activity, thereby offering a safer and more effective means of controlling secondary hyperparathyroidism. Maxacalcitol [22-oxa-1,25(OH)2D3] and falecalcitriol [1,25(OH)2-26,27-F6-D3] are currently available in Japan, and paricalcitol [19-nor-1,25(OH)2D2] and doxercalciferol [1alpha(OH)D2] are available in the US. The mechanisms by which these analogs exert their selective actions on the parathyroid glands are under investigation. The low calcemic activity of maxacalcitol has been attributed to its rapid clearance from the circulation. This prevents sustained effects on intestinal calcium absorption and bone resorption, but still allows a prolonged suppression of parathyroid hormone gene expression. The selectivity of the other analogs is achieved by distinct mechanisms. Understanding how these compounds exert their selective actions on the parathyroid glands will aid in the design of safer, more effective analogs.     

Cytochrome c oxidase deficiency due to a novel SCO2 mutation mimics Werdnig-Hoffmann disease

BACKGROUND: Mutations in the SCO2 gene have been associated with fatal cardioencephalomyopathy. OBJECTIVE: To report a novel SCO2 mutation with prominent spinal cord involvement mimicking spinal muscular atrophy (Werdnig-Hoffmann disease). PATIENT AND METHODS: An infant girl presented at birth with generalized weakness, hypotonia, and lactic acidosis. At 1 month of age she developed hypertrophic cardiomyopathy and died of heart failure 1 month later. Neuroradiological studies were unremarkable. Muscle biopsy specimens showed groups of atrophic and hypertrophic fibers, but mutation screening of the SMN gene was negative. Histochemical and biochemical studies of respiratory chain complexes were performed, and the whole coding region of the SCO2 gene was sequenced. RESULTS: Findings from muscle histochemistry studies showed virtually undetectable cytochrome c oxidase activity, but normal succinate dehydrogenase reaction. Biochemical analysis in muscle confirmed a severe isolated cytochrome c oxidase deficiency. Pathologic findings of the brain were unremarkable, but the ventral horns of the spinal cord showed moderate-to-severe loss of motor neurons and astrocytosis. Sequencing of the SCO2 gene showed the common E140K mutation, and a novel 10 base-pair duplication of nucleotides 1302 to 1311, which disrupts the reading frame of the messenger RNA and gives rise to a truncated protein. CONCLUSION: The SCO2 mutations should be considered in the differential diagnosis of children with spinal muscular atrophy without mutations in the SMN gene.     

Framing effects and risky decisions in starlings

Animals are predominantly risk prone toward reward delays and risk averse toward reward amounts. Humans in turn tend to be risk-seeking for losses and risk averse for gains. To explain the human results, Prospect Theory postulates a convex utility for losses and concave utility for gains. In contrast, Scalar Utility Theory (SUT) explains the animal data by postulating that the cognitive representation of outcomes follows Weber's Law, namely that the spread of the distribution of expected outcomes is proportional to its mean. SUT also would explain human results if utility (even if it is linear on expected outcome) followed Weber's Law. We present an experiment that simulates losses and gains in a bird, the European Starling, to test the implication of SUT that risk proneness/aversion should extend to any aversive/desirable dimension other than time and amount of reward. Losses and gains were simulated by offering choices of fixed vs. variable outcomes with lower or higher outcomes than what the birds expected. The subjects were significantly more risk prone for losses than for gains but, against expectations, they were not significantly risk averse toward gains. The results are thus, in part, consistent with Prospect Theory and SUT and show that risk attitude in humans and birds may obey a common fundamental principle.     

Directional selection is the primary cause of phenotypic diversification

Selection is widely accepted as the principal force shaping phenotypic variation within populations. Its importance in speciation and macroevolution has been questioned, however, because phenotypic differences between species or higher taxa sometimes appear to be nonadaptive. Here, we use the quantitative trait locus (QTL) sign test to evaluate the importance of directional selection in phenotypic divergence. If a trait has a history of directional selection, QTL effects should be mostly in the same direction; otherwise QTLs with antagonistic effects should be common. Analysis of QTL effects for 572 traits from 86 studies revealed significantly fewer antagonistic QTLs than expected under neutrality, a result that validates Darwin's claim that phenotypic diversification is caused mainly by selection. Moreover, interspecific trait differences were more strongly or consistently selected than intraspecific differences, strengthening a growing consensus among students of speciation that directional selection is the primary cause of speciation. Contrary to studies of selection in contemporary populations, life history traits appear to be selected more strongly than morphological traits, but traits related to the timing of development are weakly selected relative to most other traits.     

FDG-PET improves the staging and selection of patients with recurrent colorectal cancer

Whole-body fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has proved effective in the diagnosis and staging of recurrent colorectal cancer. In this study, we analysed how PET affects the management of patients with recurrent colorectal cancer by permitting more accurate selection of candidates for curative resection. The data of 79 patients with known or suspected recurrent colorectal cancer were analysed. Conventional imaging modalities (CIM) and PET results were compared with regard to their accuracy in determining the extent and the resectability of tumour recurrence. Recurrence was demonstrated in 68 of the 79 patients. The data indicate that PET was superior to CIM for detection of recurrence at all sites except the liver. Based on the CIM+PET staging, surgery with curative intent was proposed in 39 patients and was indeed achieved in 31 of them (80%). PET was more accurate than CIM alone in predicting the resectability or non-resectability of the recurrence (82% vs 68%, P=0.02). It is concluded that whole-body FDG-PET is highly sensitive for both the diagnosis and the staging of patients with recurrent colorectal cancer. Its use in conjunction with conventional imaging procedures results in a more accurate selection of patients for surgical treatment with curative intent.     

Cardiac phantom measurement validating the methodology for a cardiac multi-centre trial with positron emission tomography

In an ongoing international multi-centre trial, positron emission tomography (PET) is being used to evaluate the effect of a new P-selectin antagonist on the infarct size in patients with acute myocardial infarction, treated with thrombolysis. Although it is possible to correct for site-dependent factors, it is desirable to reduce these factors to a minimum. Therefore, acquisition and reconstruction protocols have been defined that can be closely followed by all participating centres. The resulting reconstructed images are transferred to the core centre for central processing with semi-automatic software. This paper reports on the multi-centre phantom experiment that was carried out to assess the inter-centre reproducibility of defect size determination with this protocol. Also, the spatial resolution of the short axis slices was examined. In addition, the analysis procedure was applied to normal PET studies to evaluate the specificity of perfusion defect detection. The transmural cold defect in the phantom occupied 14.8% of the left ventricular area. The automated analysis was applied to the phantom measurements from the 14 participating PET cameras. It yielded an accurate estimate of 15.1% with a standard deviation of 0.6%, indicating excellent reproducibility. The spatial resolution in the short axis slices was similar for all PET systems: 9.6+/-0.8 mm. The same procedure produced a defect size of zero in the studies of normal volunteers. This study indicates that cardiac studies from multiple PET systems can be pooled for statistical analysis.     

Is bariatric surgery safe in academic centers?

Contemporary outcomes of bariatric surgery are not well defined. Our aim was to document the outcomes of bariatric surgery on the basis of surgeon caseload and affiliation. We analyzed prospectively collected Florida-wide hospital discharge data. Forty-four surgeons undertook bariatric surgery in 933 patients during 1999. The ten surgeons who averaged more than two operations/month undertook 764 operations; 162 (17%) were done by academic surgeons. Complications [14% vs 7% (P = 0.008, chi-square)], length of stay (5 +/- 0.7 vs 4 +/- 0.1 days), and hospital charges (in thousands) ($31 +/- 4.0 vs $24 +/- 0.4) were greater in academic than in community-based centers (P < 0.05, Wilcoxon rank-sum). However, 36 per cent of patients operated upon by academic surgeons had a high Severity Index compared with only 16 per cent of patients operated upon by community-based surgeons (P < 0.001, chi-square). In high-risk patients complications (40% vs 46%), length of stay (7 +/- 1.0 vs 6 +/- 0.4 days), and hospital charges (in thousands) ($42 +/- 6 vs $35 +/- 2) were similar between academic and community-based surgeons. We conclude that outcomes of bariatric surgery in high-risk patients are similar among academic and community-based surgeons. Academic surgeons undertake bariatric surgery in high-risk patients more frequently than community-based surgeons, which underlies their increased complication rate. These prospectively collected data reflect surgical outcomes more accurately than clinical series and will impact our practice of bariatric surgery.     

Combined endovascular and surgical treatment of head and neck paragangliomas--a team approach

BACKGROUND: Paragangliomas are highly vascular tumors of neural crest origin that involve the walls of blood vessels or specific nerves within the head and neck. They may be multicentric, and they are rarely malignant. Surgery is the preferred treatment, and these tumors frequently extend to the skull base. There has been controversy concerning the role of preoperative angiography and embolization of these tumors and the benefits that these procedures offer in the evaluation and management of paragangliomas. METHODS: Forty-seven patients with 53 paragangliomas were treated from the period of 1990-2000. Initial evaluation usually included CT and/or MRI. All patients underwent bilateral carotid angiography, embolization of the tumor nidus, and cerebral angiography to define the patency of the circle of Willis. Carotid occlusion studies were performed with the patient under neuroleptic anesthesia when indicated. The tumors were excised within 48 hours of embolization. RESULTS: Carotid body tumors represented the most common paraganglioma, accounting for 28 tumors (53%). All patients underwent angiography and embolization with six patients (13%), demonstrating complications (three of these patients had embolized tumor involving the affected nerves). Cerebral angiography was performed in 28 patients, and 5 of these patients underwent and tolerated carotid occlusion studies. The range of mean blood loss according to tumor type was 450 to 517 mL. Postoperative cranial nerve dysfunction depended on the tumor type resected. Carotid body tumor surgery frequently required sympathetic chain resection (21%), with jugular and vagal paraganglioma removal frequently resulting in lower cranial nerve resection. These patients required various modes of postoperative rehabilitation, especially vocal cord medialization and swallowing therapy. CONCLUSIONS: The combined endovascular and surgical treatment of paragangliomas is acceptably safe and effective for treating these highly vascular neoplasms. Adequate resection may often require sacrifice of one or more cranial nerves, and appropriate rehabilitation is important in the treatment regimen.