Malignant papillary neoplasms of the intrahepatic bile ducts: CT and histopathologic features

OBJECTIVE. We describe the CT and pathologic features of malignant papillary neoplasms of the intrahepatic bile ducts in 15 patients. CONCLUSION. CT is a useful technique for revealing intraductal lesions, although the findings are nonspecific and variable. When intraductal masses or nodules are seen with localized dilatation of the intrahepatic bile ducts on CT scans, malignant papillary neoplasms of the intrahepatic bile ducts should be included in the differential diagnosis.     

The impact of social capital on depression among older Chinese and Korean immigrants: similarities and differences

Objectives: The objective of this study is to examine similarities and differences in terms of the influence of social capital on depression among older Chinese and Korean immigrants.

Methods: The study used data collected from both 172 Chinese and 210 Korean immigrants living in Los Angeles County. The variables included depression Geriatric Depression Scale-Short Form, (GDS-SF), social capital (five indices of norms, trust, partnership in community, information sharing, and political participation), and demographics.

Results: The study found that partnership in community was significantly associated with a lower level of depression for both the groups. On the other hand, political participation was only associated with a lower level of depression for older Chinese immigrants. Also, norms and information sharing were only associated with a lower level of depression for older Korean immigrants.

Conclusion: There was an evidence for the correlation between social capital and depression in older Chinese and Korean immigrant population. It suggests the needs to develop social programs and service in order to build more social capital for older immigrants.     

Usefulness of Known Computed Tomography and Clinical Criteria for Diagnosing Strangulation in Small-Bowel Obstruction: Analysis of True and False Interpretation Groups in Computed Tomography

Computed tomography (CT) criteria have proven useful, but not sufficient, for diagnosis of bowel strangulation. The purpose of the present study was to evaluate the useof clinical criteria in the interpretation of CT scans as a means of improving the diagnostic accuracy of CT, especially in patients whose CT scans are equivocal for distinguishing simple obstruction from strangulated obstruction. We analyzed the CT scans of 136 patients with simple (n = 70) or strangulated (n = 66) small-bowel obstruction. Three radiologists interpreted the CT scans independently for the presence of intestinal strangulation. According to their interpretation, 136 patients were divided into two groups, i.e., a false and a true interpretation group. The diagnostic value of known CT and four clinical criteria (tenderness, tachycardia, fever, and leukocytosis) were compared in the two groups. The diagnostic accuracy of CT criteria for distinguishing simple obstructions from strangulated small-bowel obstructions ranged between 73% and 80%. Of the 136 patients, 31 belonged to the false group and 105 to the true group. The CT criteria that were highly specific in both groups included severe mesenteric haziness, serrated beak, and poor bowel wall enhancement. Among the clinical criteria, both tachycardia and leukocytosis were highly specific in both groups. The number of positive clinical criteria was helpful in making a diagnosis; none or one clinical criterion indicated a simple obstruction, whereas three or four criteria indicated a strangulated obstruction; when this result was applied retrospectively to the false group, the CT diagnostic accuracy improved in 19 of the 31 patients. The use of clinical criteria when CT findings are equivocal, may overcome the inherent limitations of CT for diagnosing strangulated small-bowel obstruction.     

Metabolically stable bradykinin B2 receptor agonists enhance transvascular drug delivery into malignant brain tumors by increasing drug half-life

Background  

The intravenous co-infusion of labradimil, a metabolically stable bradykinin B2 receptor agonist, has been shown to temporarily enhance the transvascular delivery of small chemotherapy drugs, such as carboplatin, across the blood-brain tumor barrier. It has been thought that the primary mechanism by which labradimil does so is by acting selectively on tumor microvasculature to increase the local transvascular flow rate across the blood-brain tumor barrier. This mechanism of action does not explain why, in the clinical setting, carboplatin dosing based on patient renal function over-estimates the carboplatin dose required for target carboplatin exposure. In this study we investigated the systemic actions of labradimil, as well as other bradykinin B2 receptor agonists with a range of metabolic stabilities, in context of the local actions of the respective B2 receptor agonists on the blood-brain tumor barrier of rodent malignant gliomas.     

Characteristics of the sequence effect in Parkinson's disease

The sequence effect (SE) in Parkinson's disease (PD) is progressive slowing of sequential movements. It is a feature of bradykinesia, but is separate from a general slowness without deterioration over time. It is commonly seen in PD, but its physiology is unclear. We measured general slowness and the SE separately with a computer‐based, modified Purdue pegboard in 11 patients with advanced PD. We conducted a placebo‐controlled, four‐way crossover study to learn whether levodopa and repetitive transcranial magnetic stimulation (rTMS) could improve general slowness or the SE. We also examined the correlation between the SE and clinical fatigue. Levodopa alone and rTMS alone improved general slowness, but rTMS showed no additive effect on levodopa. Levodopa alone, rTMS alone, and their combination did not alleviate the SE. There was no correlation between the SE and fatigue. This study suggests that dopaminergic dysfunction and abnormal motor cortex excitability are not the relevant mechanisms for the SE. Additionally, the SE is not a component of clinical fatigue. Further work is needed to establish the physiology and clinical relevance of the SE. © 2010 Movement Disorder Society.     

Dopamine transporter immunoreactivity in monkey cerebral cortex: regional, laminar, and ultrastructural localization

Dopamine (DA) influences a number of cognitive and motor functions that are mediated by the primate cerebral cortex, and the DA membrane transporter (DAT) is known to be a critical regulator of DA neurotransmission in subcortical structures in rodents. To gain insight into the possible functional role of cortical DAT, we compared the regional, laminar, and ultrastructural distribution of DAT immunoreactivity to that of tyrosine hydroxylase (TH), the rate-limiting enzyme in DA synthesis, in the cerebral cortex of macaque monkeys. DAT-immunoreactive (DAT-IR) axons were present throughout the cortical mantle, with substantial differences in density and laminar distribution across cytoarchitectonic areas. In particular, high densities of DAT-IR axons were present in certain regions (e.g., posterior parietal cortex, dentate gyrus) not previously thought to receive a substantial DA input. The laminar distribution of DAT-IR axons ranged from a restricted localization of labeled axons to layer 1 in lightly innervated regions to the presence of axons in all six cortical layers, with a particularly dense plexus in deep layer 3, in highly innervated regions. These regional and laminar patterns paralleled those of TH-IR axons, but several differences in fiber morphology and ultrastructural localization of DAT were observed. For example, in contrast to TH, DAT immunoreactivity in the cortex was localized predominantly to small-diameter profiles, whereas, in the dorsolateral caudate nucleus, DAT and TH immunoreactivities were present in both large-diameter and small-diameter profiles, which may represent varicose and intervaricose axon segments, respectively. Overall, the distribution of DAT-IR axons confirms and extends the results of previous reports, using other markers of DA axons, that the DA innervation of the primate cerebral cortex is global but specialized on both a regional basis and a laminar basis. In particular, these observations reveal an anatomical substrate for a direct and potent influence of DA over neuronal activity in posterior parietal cortex and in certain regions of the temporal lobe. However, due to its predominant distribution to small-diameter profiles, immunoreactivity for DAT may not be an appropriate ultrastructural marker for larger DA varicosities in the primate cortex. Moreover, this distribution of DAT suggests that cortical DA fibers may permit greater neurotransmitter diffusion than subcortical DA axons.