Exploring the Benefits of 3D-Printed Bolus in Cone Beam CT for Modified Radical Mastectomy Breast Cancer

PURPOSE/OBJECTIVE(S)

To improve the accuracy of superficial dose coverage for patients undergoing modified radical mastectomy (MRM), boluses are frequently applied to the skin surface of targeted region during radiotherapy. The irregular curvature of MRM breast cases results in discrepancies of dosimetry and poor contact. Additionally, the presence of an air gap causes unnecessary high-dose escalation and uncertainty in dose calculation, making the use of commercial flat bolus problematic. This study evaluated the effectiveness of 3D-printed bolus by comparing it to commercial bolus in setup variations and dosimetric compliance through daily cone-beam computed tomography (CBCT) scans.

MATERIALS/METHODS

Ten patients underwent MRM were divided into 2 groups. 5 patients treated with 0.5 cm commercial bolus as group A while the other 5 patients covered by 3D Bolus as group B. 3D bolus was made of polylactic acid filament (PLA) and contoured in advance with thickness of 0.5 cm on the surface of target. Positional errors were recorded through daily image guidance and compared with the images. Both groups had right-sided breast with neck lymph nodes involved and received 50 Gy in 25 fractions using 4 partial arcs of the volumetric modulated arc therapy (VMAT) technique. The CBCTs were recalculated through treatment planning system (TPS) to assess superficial dose coverage. A two-tailed student's t-test was applied.

RESULTS

Groups A and B pitch angles were -0.203 ± 0.837° and 0.334 ± 0.909° (p = 0.0003). Roll angle were 0.313 ± 0.728° and -0.633 ± 1.286° (p = 0.0000013). Yaw angle were -0.034 ± 0.872° and 0.018 ± 0.883° (p = 0.721). There was a trend of differences in the Z-axis and significant statistical differences in the pitch and roll angles due to aligning gel layers directly with group A's body surface, while 3D bolus rigidly adherence to group B's delineated curve. In the planned target volume (PTV), the CI and HI of group A were 0.9448±0.0208 and 1.2061±0.0448, respectively, while 0.9776±0.0144 and 1.1472±0.0206 (p<0.005) were for group B. As for the superficial region, which is defined from body surface to 0.5cm inside PTV, CI and HI of A were 0.8290±0.0599 and 1.4675±0.2434, while for B, they were 0.9753±0.0214 and 1.1330±0.0126, respectively (p<0.005).

CONCLUSION

The study analyzed the results through image comparison and investigated the CI and HI between two types of boluses. The 3D bolus reduces setup errors and improves dose coverage especially when superficial region is concerned. Better consistency of patient repositioning and dosimetry can be achieved and proved by daily assessment of CBCT scan. The customization of 3D bolus with integration of TPS and CT scans provides a solution to the inadequacies of commercial bolus. The results suggest that the use of 3D bolus is a promising development in radiation therapy for MRM breast cancer patients.

Predicting Treatment Response of Esophageal Cancer Treated by Concurrent Chemoradiotherapy Using Pre- and Posttreatment 18F-FDG PET Metabolic Characteristics

PURPOSE/OBJECTIVE(S)

This study hypothesizes that metabolic characteristics of esophageal tumors can be used to predict treatment response, which considers changes in the primary tumor and lymph nodes, for patients receiving neoadjuvant concurrent chemoradiotherapy (CCRT).

MATERIALS/METHODS

This study retrospectively included 60 esophageal cancer patients receiving CCRT followed by surgery. All patients received 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) examinations prior to CCRT and in the interval between CCRT and surgery. On the pre-treatment FDG PET/CT images, the maximum standardized uptake value (SUVMaxPre) within the primary tumor was identified. By computerized methods, the CT images of pre- and post-treatment FDG PET/CT were registered. Then, the coordinates of SUVMaxPre were transformed to the post-treatment FDG PET images and delineated a sphere with a diameter of 5 cm to indicate the tumor position. After excluding air, the sphere was partitioned into several metabolic volumes by the optimal dichotomy of high and low metabolic FDG uptakes. Finally, the volume with the shortest distance to the center was adopted and represented by the maximum standardized uptakes (SUVMaxPost). Two additional features, SUVDiff and SUVDiffR, were defined as SUVMaxPost - SUVMaxPre and (SUVMaxPost - SUVMaxPre) / SUVMaxPre. Besides, for defining treatment response, the patients with and without residual tumors were defined as ypT+ and ESOCR based on the histopathology results of surgery. The ESOCR was further classified into pCR to indicate the absence of lymph node metastasis and LNM for remaining. Finally, the area under the receiver operating characteristic curve analysis (AUC) was conducted to assess the features' ability to differentiate two treatment responses. Kruskal-Wallis test was used to evaluate the differences in features between treatment responses.

RESULTS

Of the 60 patients, 55 were men (92%), and the mean age was 58. The number of tumors at the esophagus's upper, middle, and lower third were 8, 18, and 34, respectively. Ninety-eight percent of the tumors were squamous cell carcinomas (59/60). The patient numbers of ypT+ and ESOCR were 43 and 17 of which contained 13 pCR and 4 LNM. The SUVDiff and SUVDiffR exhibited a significant ability to identify the ESOCR with AUC = .337 (p = .05) and AUC = .290 (p = .012), respectively. In addition, a statistically significant difference was found among the three groups of ypT+, pCR, and LNM on SUVMaxPre (H = 6.252 and p = .044), SUVDiff (H = 7.948 and p = .019), and SUVDiffR (H = 8.405 and p = .015). In the post-hoc tests corrected by the Bonferroni, the difference between ypT+ and LNM was significant on these features.

CONCLUSION

The metabolic characteristics extracted from pre- and post-treatment FDG PET/CT images could indicate treatment response and disease progression. Further studies are warranted.

AD-9308 ameliorates the impacts of 4-HNE on the progress of pulmonary arterial hypertension in aldehyde dehydrogenase 2*1*2 knock-in mice

 

Endothelial dysfunctions play a critical role on the development of pulmonary arterial hypertension (PAH). It has been reported that the one-year mortality rate is still up to 15% even with PAH-targeted therapy, implying that there may be untargeted pathways. 4-hydroxynenonal (4-HNE), an unsaturated aldehyde, is highly induced in the lungs of PAH animals and its serum levels were also reported to be higher in PAH patients. 4-HNE is metabolized by mitochondrial aldehyde dehydrogenase (ALDH2), which is dysfunctional in near 40% of East Asian people. Currently, the impacts of 4-HNE on endothelial dysfunctions in the development of PAH are unclear. In terms of translational medicine, we proposed that modulation of 4-HNE level may alleviate the progress of PAH patients with ALDH2 deficiency.

We found that 4-HNE alone was not sufficient to induce pulmonary artery endothelial cell (PAEC) functional changes, including proliferation, migration and tube formation, whereas their effects emerge from the depletion of ALDH2. We further mimicked human ALDH2 functional deficiency by using daidzin (DZN), an inhibitor which is able to block the substrate binding site of ALDH2. ALDH2 functional inhibition alone did not induce any PAEC functional change, while an add-on of 4-HNE impaired PAEC functions. In addition, 4-HNE significantly reduced eNOS activity with combined DZN treatment. Consistent with the mechanism of ALDH2 activity-mediated angiogensis, ALDH2 enhancers Alda-1 and AD-5591 completely reverse the anti-angiogenic effects of 4-HNE in the presence of DZN. To further confirm whether ALDH2 functional deficiency impact on PAH development in mammals, heterozygous ALDH2*1/*2 transgenic and wild-type mice were subjected to chronic hypoxia to induce PAH. ALDH2*1/*2 transgenic mice had similar right ventricular systolic pressure (RVSP) as wild-type mice. However, after exposure to chronic hypoxia, ALDH2*1/*2 transgenic mice indeed developed a significantly higher RVSP than that in wild-type mice. Furthermore, we demonstrated that 4-HNE expression was profoundly enhanced in ALDH2*1/*2 transgenic mice by chronic hypoxia-induced PAH with pulmonary artery smooth muscle cell hyperplasia. More importantly, we found that AD-9308, an enhancer of ALDH2 significantly decreased hypoxia-induced RVSP elevation in heterozygous ALDH2*1/*2 transgenic mice.

Taken together, our data demonstrate that 4-HNE and ALDH2 functional deficiency potentially contribute to PAH development and worsening, and that ALDH2 enhancers may be promising as a PAH adjunct therapy, particularly for patients with ALDH2 nonfunctional alleles.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Technology, Taiwan

The dynamic properties of intermediate filaments during organelle transport

Intermediate filament (IF) dynamics during organelle transport and their role in organelle movement were studied using Xenopus laevis melanophores. In these cells, pigment granules (melanosomes) move along microtubules and microfilaments, toward and away from the cell periphery in response to alpha-melanocyte stimulating hormone (alpha-MSH) and melatonin, respectively. In this study we show that melanophores possess a complex network of vimentin IFs which interact with melanosomes. IFs form an intricate, honeycomb-like network that form cages surrounding individual and small clusters of melanosomes, both when they are aggregated and dispersed. Purified melanosome preparations contain a substantial amount of vimentin, suggesting that melanosomes bind to IFs. Analyses of individual melanosome movements in cells with disrupted IF networks show increased movement of granules in both anterograde and retrograde directions, further supporting the notion of a melanosome-IF interaction. Live imaging reveals that IFs, in turn, become highly flexible as melanosomes disperse in response to alpha-MSH. During the height of dispersion there is a marked increase in the rate of fluorescence recovery after photobleaching of GFP-vimentin IFs and an increase in vimentin solubility. These results reveal a dynamic interaction between membrane bound pigment granules and IFs and suggest a role for IFs as modulators of granule movement.

Structural changes in intermediate filament networks alter the activity of insulin-degrading enzyme

The intermediate filament (IF) protein nestin coassembles with vimentin and promotes the disassembly of these copolymers when vimentin is hyperphosphorylated during mitosis. The aim of this study is to determine the function of these nonfilamentous particles by identifying their interacting partners. In this study, we report that these disassembled vimentin/nestin complexes interact with insulin degrading enzyme (IDE). Both vimentin and nestin interact with IDE in vitro, but vimentin binds IDE with a higher affinity than nestin. Although the interaction between vimentin and IDE is enhanced by vimentin phosphorylation at Ser-55, the interaction between nestin and IDE is phosphorylation independent. Further analyses show that phosphorylated vimentin plays the dominant role in targeting IDE to the vimentin/nestin particles in vivo, while the requirement for nestin is related to its ability to promote vimentin IF disassembly. The binding of IDE to either nestin or phosphorylated vimentin regulates IDE activity differently, depending on the substrate. The insulin degradation activity of IDE is suppressed approximately 50% by either nestin or phosphorylated vimentin, while the cleavage of bradykinin-mimetic peptide by IDE is increased 2- to 3-fold. Taken together, our data demonstrate that the nestin-mediated disassembly of vimentin IFs generates a structure capable of sequestering and modulating the activity of IDE.

Dynamic contrast-enhanced and T2-weighted magnetic resonance imaging study of the correlation between tumour angiogenesis and growth kinetics

Accumulating evidence indicates that tumour growth is angiogenesis-dependent. Non-invasive assessment of the relationship between tumour growth and associated angiogenesis is essential for diagnosis and for therapeutic interventions. We utilized a combination of high-resolution T2-weighted and dynamic contrast-enhanced magnetic resonance imaging to investigate the dynamics of angiogenesis during tumour growth in a mouse tumour model expressing Epstein-Barr virus-encoded latent membrane protein 1 isolated from a nasopharyngeal carcinoma in Taiwan. Serial imaging acquisitions were performed starting on the third day after subcutaneous implantation of tumours, through day 28. We observed a progressive increase in tumour volume until day 14, followed by rapid and exponential growth. The volume transfer constant, K(trans), also increased significantly on day 14, and then gradually decreased, suggesting that the angiogenic switching occurs prior to significant tumour growth. At the initial stage, the K(trans) values were significantly higher in the tumour peripheral region than in the tumour core, but, during tumour growth, the K(trans) values in the region between the tumour periphery and core gradually increased, becoming larger than those of the periphery. These results demonstrate that the ability to perform repeated measurements assessing the correlation between tumour growth kinetics and tumour angiogenesis makes it possible to determine the critical time of angiogenic switching prior to rapid tumour growth, as well as suggesting the timing of therapy.

Arsenite-induced cytotoxicity in dorsal root ganglion explants

Peripheral neuropathy is common in people chronically overexposed to arsenic. We studied sodium arsenite (arsenite)-induced cytotoxicity in dorsal root ganglion (DRG) explants. Incubation with arsenite concentration- and time-dependently increased the expression of stress proteins, heat shock protein 70, and heme oxygenase-1 in DRG explants. Furthermore, apoptosis was involved in the arsenite-induced cytotoxicity in the treated DRG. Elevation in cytosolic cytochrome c levels and reduction in procaspase 3 levels suggested an involvement of the mitochondrial pathway in arsenite-induced apoptosis in this preparation. At the same time, increases in the activating transcription factor-4 and C/EBP homologous protein and reduction in procaspase 12 levels indicated activation of the endoplasmic reticulum (ER) pathway in the arsenite-induced cytotoxicity in DRG explants. Salubrinal (30 microM), an ER inhibitor, was found to attenuate arsenite-induced DNA fragmentation and reduction in procaspase 12 in DRG explants. Cytotoxic effects by arsenite, sodium arsenate (arsenate), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were compared, and the potency was as follows: arsenite >>> arsenate>MMA and DMA. Recombinant adenovirus vectors encoding glial-cell-derived neurotrophic factor (AdGDNF) genes allowed a stable delivery of GDNF genes to the infected cells in DRG explants. Applied in this manner, AdGDNF was found to inhibit arsenite-induced DNA fragmentation in DRG explants. Moreover, AdGDNF attenuated the arsenite-induced reduction in procaspases 3 and 12 levels. Taken together, our study demonstrates that arsenite is capable of inducing cytotoxicity in DRG explants. Both ER and mitochondria pathways are involved in the arsenite-induced apoptosis in DRG explants. Glial-cell-derived neurotrophic factor appears to be protective against arsenite-induced peripheral neuropathy.

The motility and dynamic properties of intermediate filaments and their constituent proteins

Intermediate filament (IF) proteins exist in multiple structural forms within cells including mature IF, short filaments or 'squiggles', and non-filamentous precursors called particles. These forms are interconvertible and their relative abundance is IF type, cell type- and cell cycle stage-dependent. These structures are often associated with molecular motors, such as kinesin and dynein, and are therefore capable of translocating through the cytoplasm along microtubules. The assembly of mature IF from their precursor particles is also coupled to translation. These dynamic properties of IF provide mechanisms for regulating their reorganization and assembly in response to the functional requirements of cells. The recent findings that IF and their precursors are frequently associated with signaling molecules have revealed new functions for IF beyond their more traditional roles as mechanical integrators of cells and tissues.

Tracking melanosomes inside a cell to study molecular motors and their interaction

Cells known as melanophores contain melanosomes, which are membrane organelles filled with melanin, a dark, nonfluorescent pigment. Melanophores aggregate or disperse their melanosomes when the host needs to change its color in response to the environment (e.g., camouflage or social interactions). Melanosome transport in cultured Xenopus melanophores is mediated by myosin V, heterotrimeric kinesin-2, and cytoplasmic dynein. Here, we describe a technique for tracking individual motors of each type, both individually and in their interaction, with high spatial (approximately 2 nm) and temporal (approximately 1 msec) localization accuracy. This method enabled us to observe (i) stepwise movement of kinesin-2 with an average step size of 8 nm; (ii) smoother melanosome transport (with fewer pauses), in the absence of intermediate filaments (IFs); and (iii) motors of actin filaments and microtubules working on the same cargo nearly simultaneously, indicating that a diffusive step is not needed between the two systems of transport. In concert with our previous report, our results also show that dynein-driven retrograde movement occurs in 8-nm steps. Furthermore, previous studies have shown that melanosomes carried by myosin V move 35 nm in a stepwise fashion in which the step rise-times can be as long as 80 msec. We observed 35-nm myosin V steps in melanophores containing no IFs. We find that myosin V steps occur faster in the absence of IFs, indicating that the IF network physically hinders organelle transport.

A nestin scaffold links Cdk5/p35 signaling to oxidant-induced cell death

The intermediate filament protein, nestin, has been implicated as an organizer of survival-determining signaling molecules. When nestin expression was related to the sensitivity of neural progenitor cells to oxidant-induced apoptosis, nestin displayed a distinct cytoprotective effect. Oxidative stress in neuronal precursor cells led to downregulation of nestin with subsequent activation of cyclin-dependent kinase 5 (Cdk5), a crucial kinase in the nervous system. Nestin downregulation was a prerequisite for the Cdk5-dependent apoptosis, as overexpression of nestin efficiently inhibited induction of apoptosis, whereas depletion of nestin by RNA interference had a sensitizing effect. When the underlying link between nestin and Cdk5 was analyzed, we observed that nestin serves as a scaffold for Cdk5, with binding restricted to a specific region following the alpha-helical domain of nestin, and that the presence and organization of nestin regulated the sequestration and activity of Cdk5, as well as the ubiquitylation and turnover of its regulator, p35. Our data imply that nestin is a survival determinant whose action is based upon a novel mode of Cdk5 regulation, affecting the targeting, activity, and turnover of the Cdk5/p35 signaling complex.

Intermediate filament proteins participate in signal transduction

How timely transport of chemical signals between the distal end of long axonal processes and the cell bodies of neurons occurs is an interesting and unresolved issue. Recently, Perlson et al. presented evidence that cleavage products of newly synthesized vimentin, an intermediate filament (IF) protein, interact with mitogen-activated protein (MAP) kinases at sites of axon injury. These IF fragments appear to be required for the transport of these kinases to the cell body along microtubule tracks. The truncated vimentin is instrumental in signal propagation as it provides a scaffold that brings together activated MAP kinases (such as Erk 1 and Erk2), as well as importin beta and cytoplasmic dynein. The authors propose that this all-in-one transport complex has the extraordinary ability to travel towards the cell body and enter the nucleus where the kinases activate and influence gene expression so that a neuron can generate a timely response to injury.

Keratin 8 phosphorylation by protein kinase C delta regulates shear stress-mediated disassembly of keratin intermediate filaments in alveolar epithelial cells

Phosphorylation of keratin intermediate filaments (IF) is known to affect their assembly state and organization; however, little is known about the mechanisms regulating keratin phosphorylation. In this study, we demonstrate that shear stress, but not stretch, causes disassembly of keratin IF in lung alveolar epithelial cells (AEC) and that this disassembly is regulated by protein kinase C delta-mediated phosphorylation of keratin 8 (K8) Ser-73. Specifically, in AEC subjected to shear stress, keratin IF are disassembled, as reflected by their increased solubility. In contrast, AEC subjected to stretch showed no changes in the state of assembly of IF. Pretreatment with the protein kinase C (PKC) inhibitor, bisindolymaleimide, prevents the increase in solubility of either K8 or its assembly partner K18 in shear-stressed AEC. Phosphoserine-specific antibodies demonstrate that K8 Ser-73 is phosphorylated in a time-dependent manner in shear-stressed AEC. Furthermore, we showed that shear stress activates PKC delta and that the PKC delta peptide antagonist, delta V1-1, significantly attenuates the shear stress-induced increase in keratin phosphorylation and solubility. These data suggested that shear stress mediates the phosphorylation of serine residues in K8, leading to the disassembly of IF in alveolar epithelial cells. Importantly, these data provided clues regarding a molecular link between mechanically induced signal transduction and alterations in cytoskeletal IF.

Organ-specific toxicokinetics and dose-response of arsenic in tilapia Oreochromis mossambicus

We appraised organ-specific toxicokinetics and dose responses of arsenic burdens in tilapia Oreochromis mossambicus. We kinetically linked an Area-under-the-curve (AUC)-based acute toxicity model and a pharmacodynamic model to derive dose-response relationships between equilibrium organ-specific arsenic concentrations and mortality effects. The AUC-based acute toxicity model was also used to derive organ-specific internal effect concentration (IEC)-time-response relationships, which can also be applied to predict a time-mortality profile. We conducted a 7-day exposure experiment to obtain toxicokinetic parameters, whereas the AUC-based acute toxicity model was verified with LC50(t) data obtained from a 7-day acute toxicity bioassay. Our results demonstrated that 96-hour LC50 and incipient LC50 for tilapia exposed to arsenic are 28.68 (95% confidence interval to 24.92 to 32.44) and 25.55 mg L(-1), respectively. Dose-response relationships followed the Hill equation, which could be expressed as organ-specific bioconcentration factors and incipient LC50. Organ-specific dose-response relationships showed that muscle, gill, and liver have a relatively steep sigmoid dose-response profile in that IEC50 were 26.6, 62.5, and 78.5 microg g(-1) dry wt (dw), respectively. Organ-specific arsenic internal lethal burdens were the highest in the gill and the lowest in the muscle in waterborne-exposed tilapia. The IEC and target-organ concentrations derived in this study can be used in site-specific risk assessment.

Methicillin-resistant Staphylococcus aureus bacteraemia in neonatal intensive care units: an analysis of 90 episodes

AIM

To delineate the clinical features of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in infants hospitalized at the neonatal intensive care unit.

METHODS

Episodes of MRSA bacteraemia in Chang Gung Children's Hospital neonatal intensive care unit from 1997 to 1999 were reviewed for incidence, predisposing factors, clinical presentations, treatment and outcome.

RESULTS

Ninety episodes of MRSA bacteraemia were identified. The overall rate of MRSA bacteraemia was 1.05 per 1000 patient days during the 3-y period. Most of the patients were premature infants (76%), with prior operation or invasive procedures (39%), had an indwelling intravascular catheter (79%) and exposure to antibiotic therapy (96%). A localized cutaneous infection was found in 53.3% of the episodes. The most common clinical diagnoses were catheter-related infections (54.4%), skin and soft tissue infections (21.1%), bacteraemia without a focus (20%) and pneumonia (16.7%). Metastatic infection occurred in 18% of these infants. Among the patients treated with vancomycin for < or = 14 d, 88.7% did not develop any complications, and 11.3% developed a recurrence.

CONCLUSIONS

MRSA is an established pathogen in our NICU. MRSA bacteraemia in the neonates predominantly presented as catheter-related infections, and metastatic infections were not infrequently seen. In uncomplicated MRSA bacteraemia, treatment with vancomycin for < or = 14 d seems to be adequate.

Specific in vivo phosphorylation sites determine the assembly dynamics of vimentin intermediate filaments

Intermediate filaments (IFs) continuously exchange between a small, depolymerized fraction of IF protein and fully polymerized IFs. To elucidate the possible role of phosphorylation in regulating this equilibrium, we disrupted the exchange of phosphate groups by specific inhibition of dephosphorylation and by specific phosphorylation and site-directed mutagenesis of two of the major in vivo phosphorylation sites determined in this study. Inhibition of type-1 (PP1) and type-2A (PP2A) protein phosphatases in BHK-21 fibroblasts with calyculin-A, induced rapid vimentin phosphorylation in concert with disassembly of the IF polymers into soluble tetrameric vimentin oligomers. This oligomeric composition corresponded to the oligopeptides released by cAMP-dependent kinase (PKA) following in vitro phosphorylation. Characterization of the 32P-labeled vimentin phosphopeptides, demonstrated Ser-4, Ser-6, Ser-7, Ser-8, Ser-9, Ser-38, Ser-41, Ser-71, Ser-72, Ser-418, Ser-429, Thr-456, and Ser-457 as significant in vivo phosphorylation sites. A number of the interphase-specific high turnover sites were shown to be in vitro phosphorylation sites for PKA and protein kinase C (PKC). The effect of presence or absence of phosphate groups on individual subunits was followed in vivo by microinjecting PKA-phosphorylated (primarily S38 and S72) and mutant vimentin (S38:A, S72:A), respectively. The PKA-phosphorylated vimentin showed a clearly decelerated filament formation in vivo, whereas obstruction of phosphorylation at these sites by site-directed mutagenesis had no significant effect on the incorporation rates of subunits into assembled polymers. Taken together, our results suggest that elevated phosphorylation regulates IF assembly in vivo by changing the equilibrium constant of subunit exchange towards a higher off-rate.

Specific in vivo phosphorylation sites determine the assembly dynamics of vimentin intermediate filaments

Intermediate filaments (IFs) continuously exchange between a small, depolymerized fraction of IF protein and fully polymerized IFs. To elucidate the possible role of phosphorylation in regulating this equilibrium, we disrupted the exchange of phosphate groups by specific inhibition of dephosphorylation and by specific phosphorylation and site-directed mutagenesis of two of the major in vivo phosphorylation sites determined in this study. Inhibition of type-1 (PP1) and type-2A (PP2A) protein phosphatases in BHK-21 fibroblasts with calyculin-A, induced rapid vimentin phosphorylation in concert with disassembly of the IF polymers into soluble tetrameric vimentin oligomers. This oligomeric composition corresponded to the oligopeptides released by cAMP-dependent kinase (PKA) following in vitro phosphorylation. Characterization of the (32)P-labeled vimentin phosphopeptides, demonstrated Ser-4, Ser-6, Ser-7, Ser-8, Ser-9, Ser-38, Ser-41, Ser-71, Ser-72, Ser-418, Ser-429, Thr-456, and Ser-457 as significant in vivo phosphorylation sites. A number of the interphase-specific high turnover sites were shown to be in vitro phosphorylation sites for PKA and protein kinase C (PKC). The effect of presence or absence of phosphate groups on individual subunits was followed in vivo by microinjecting PKA-phosphorylated (primarily S38 and S72) and mutant vimentin (S38:A, S72:A), respectively. The PKA-phosphorylated vimentin showed a clearly decelerated filament formation in vivo, whereas obstruction of phosphorylation at these sites by site-directed mutagenesis had no significant effect on the incorporation rates of subunits into assembled polymers. Taken together, our results suggest that elevated phosphorylation regulates IF assembly in vivo by changing the equilibrium constant of subunit exchange towards a higher off-rate.

Mechanical hemolysis in a hemodialysis patient with carotid-jugular arteriovenous fistula

Renal anemia is mainly caused by inadequate synthesis of erythropoietin from diseased kidneys. At the present time, recombinant human erythropoietin (rHuEPO) is used to correct anemia successfully in most patients with end-stage renal diseases. Nevertheless, poor response to rHuEPO still exists in some hemodialysis patients and its mechanism in some cases remains obscure. Herein, we describe a rare case of rHuEPO hyporesponsiveness due to mechanical hemolysis induced by a traumatic carotid-jugular arteriovenous fistula (AVF) in the presence of subclinical aluminum intoxication. Following surgical resection of the traumatic AVF and 8 months of desferrioxamine treatment, the responsiveness to rHuEPO was restored and the rHuEPO dose requirements reduced.

A review of environmental and economic regulations for promoting industrial waste recycling in Taiwan

The objective of this paper is to present a compilation of recent Taiwan government laws/regulations to promote industrial waste recycling. The description is thus centered on legislation/regulations concerning general industrial wastes recycling in the policies of environmental protection, economic incentives and engineering technologies (3E) that have become effective since 2001. The regulatory system, including Waste Disposal Act, Resource Recycling/Reuse Act, Environmental Basis Law, and Statute for Upgrading Industries, not only gives financial incentives, but also provides technical assistance and information transfer on promoting industrial waste recycling. In order to further utilize the recyclable resources and upgrade the environmental technology, Taiwan's Environmental Protection Administration (EPA), in cooperation with the Ministry of Economic Affairs (MOEA), has jointly ventured some promotion programs, which highlight an Industrial Waste Exchange Information Center and Environmental Technology Park Development Program, also described in the paper.

Nestin promotes the phosphorylation-dependent disassembly of vimentin intermediate filaments during mitosis

The expression of the intermediate filament (IF) protein nestin is closely associated with rapidly proliferating progenitor cells during neurogenesis and myogenesis, but little is known about its function. In this study, we examine the effects of nestin expression on the assembly state of vimentin IFs in nestin-free cells. Nestin is introduced by transient transfection and is positively correlated with the disassembly of vimentin IFs into nonfilamentous aggregates or particles in mitotic but not interphase cells. This nestin-mediated disassembly of IFs is dependent on the phosphorylation of vimentin by the maturation/M-phase-promoting factor at ser-55 in the amino-terminal head domain. In addition, the disassembly of vimentin IFs during mitosis appears to be a unique feature of nestin-expressing cell types. Furthermore, when the expression of nestin is downregulated by the nestin-specific small interfering RNA in nestin-expressing cells, vimentin IFs remain assembled throughout all stages of mitosis. Previous studies suggest that nonfilamentous vimentin particles are IF precursors and can be transported rapidly between different cytoplasmic compartments along microtubule tracks. On the basis of these observations, we speculate that nestin may play a role in the trafficking and distribution of IF proteins and potentially other cellular factors to daughter cells during progenitor cell division.

Measurement of serum vitamin E isomers in fullterm and preterm infants

BACKGROUND

This study was conducted with the following aims: (1) to construct a methodology by high-performance liquid chromatography (HPLC) to measure vitamin E levels in our neonatal units; (2) to establish a reference range of serum vitamin E levels in fullterm neonates and their mothers; and (3) to compare these to levels in the preterm group.

METHODS

During a 6-month period from September 1996 to February 1997, cord blood of 34 uneventful fullterm neonates (gestational age 38-42 weeks, birth weight 2840-3530 g) and venous blood of their healthy mothers were collected. Venous blood of 35 preterm neonates (gestational age 28-34 weeks, birth weight 940-1980 g) was collected at the same time. Serum vitamin E levels were measured by HPLC. The serum vitamin E/total lipids ratio was also examined.

RESULTS

Serum levels of alpha-tocopherol in 34 fullterm neonates and their mothers were 0.212+/-0.127 and 1.160+/-0.513 mg/dl, and of gamma-tocopherol were 0.029+/-0.019 and 0.214+/-0.122 mg/dl, respectively. All fullterm neonates except 2 had serum levels less than 0.5 mg/dl. There was a positive relationship between serum E levels and total lipids. In addition, the correlation between neonatal vitamin E/total lipids ratios and maternal vitamin E/total lipids ratio was statistically significant. The serum level of alpha-tocopherol in 35 preterm infants was 0.170+/-0.090 mg/dl and that of gamma-tocopherol was 0.020+/-0.015 mg/dl; both levels were much lower than those of their fullterm counterparts. But the vitamin E/total lipids ratios did not significantly differ.

CONCLUSIONS

We conclude that (1) measurement of serum vitamin E levels by the HPLC method is practical, and is useful in evaluating deficiencies in preterm infants and possibly useful in monitoring the adequacy after supplementation in future study, and (2) preterm infants had a much lower level of serum tocopherol, but no difference was seen in vitamin E/total lipids ratio.

Comparison of hand-assisted laparoscopic nephroureterectomy with open surgery for upper urinary tract tumor

Herein we report on our initial experience in performing nephroureterectomy by hand-assisted laparoscopic surgery, and compare the results with those performed by traditional open methods. From December 2000 to September 2001, 10 patients with upper urinary tract tumors underwent hand-assisted laparoscopic nephroureterectomy. Except for one patient who required elective conversion to open surgery due to renal vein injury, this cohort of 9 patients was compared to a group of 35 patients who had received traditional open nephroureterectomy over the last 2 years. Demographic, intraoperative and postoperative data were compared retrospectively. These two groups were similar in age, body mass index, operation time and time to postoperative oral intake. However, the hand-assisted laparoscopy group was found to have significantly less blood loss, less need for parenteral narcotic and a shorter length of time needed for postoperative hospitalization than the open group. Thus, in this report we have demonstrated hand-assisted laparoscopic nephroureterectomy to be a safe and efficacious treatment of malignant urinary collecting tumors. We believe the benefits of this minimally invasive surgery make it a viable alternative technique for management of upper urinary tract tumor.

Hereditary hemorrhagic telangiectasia: demonstration of portosystemic venous shunts using power Doppler sonography and sonographically guided percutaneous transhepatic portovenography

Hereditary hemorrhagic telangiectasia is a rare autosomal dominant inherited disease associated with vascular abnormalities, which may occur in any organ. Cases of hereditary hemorrhagic telangiectasia accompanied by intrahepatic portosystemic venous shunts, however, have rarely been described. We report a case of hereditary hemorrhagic telangiectasia in which intrahepatic portosystemic shunts were detected using power Doppler sonography and portovenography with percutaneous transhepatic contrast agent injection. On gray-scale sonography, the common hepatic artery was dilated, and dilated tubular structures mimicking dilated biliary tracts were found. Power Doppler sonography demonstrated the continuity of tortuous vascular channels connecting a branch of the right portal vein to a branch of the right hepatic vein. The dilated vascular channels and tributaries of the right hepatic vein showed a monophasic waveform pattern on spectral analysis. Portovenography showed a tangle of vascular structures connecting with a branch of the right hepatic vein.

HLA-DRB1 antigens in Taiwanese patients with juvenile-onset systemic lupus erythematosus

OBJECTIVE

This study was done to investigate the frequency of HLA-DRB1 antigens in juvenile-onset systemic lupus erythematosus (SLE) in the Taiwanese population.

PATIENTS AND METHODS

Thirty-four Taiwanese patients with juvenile onset SLE and 200 unrelated healthy controls were studied. HLA-DRB1 typing was performed with polymerase chain reaction (PCR) and the sequence-specific oligonucleotide probe (SSO) typing method.

RESULT

Among the 14 investigated DRB1 alleles, the frequency of HLA-DRB1*1602 was higher in juvenile onset SLE patients than the controls (15.15% vs 4.50%, odds ratio 3.66, 95% confidence interval 1.15-11.68, Pc = 0.04). Although there were differences in the frequencies of DRB1*0301, DRB1*0803, and DRB1*1501 between patients and controls, the associations were statistically insignificant.

CONCLUSION

The frequency of HLA-DRB1*1602 was significantly higher in patients with juvenile onset SLE than in healthy controls. This finding differs from those in the previous studies in Caucasian and Japanese adult onset SLE patients.

Stepwise logistic regression analysis of tumor contour features for breast ultrasound diagnosis

To assist the ultrasound (US) differential diagnosis of solid breast tumors by using stepwise logistic regression (SLR) analysis of tumor contour features, we retrospectively reviewed 111 medical records of digitized US images of breast pathologies. They were pathologically proved benign breast tumors from 40 patients (i.e., 40 fibroadenomas) and malignant breast tumors from 71 patients (i.e., 71 infiltrative ductal carcinomas). Radiologists, before analysis by the computer-aided diagnosis (CAD) system, segmented the tumors manually. The contour features were calculated by measuring the radial length of tumor boundaries. The features selection process was accomplished using a stepwise analysis procedure. Then, an SLR model with contour features was used to classify tumors as benign or malignant. In this experiment, cases were sampled with "leave-one-out" test methods to evaluate the SLR performance using a receiver operating characteristic (ROC) curve. The accuracy of our SLR model with contour features for classifying malignancies was 91.0% (101 of 111 tumors), the sensitivity was 97.2% (69 of 71), the specificity was 80.0% (32 of 40), the positive predictive value was 89.6% (69 of 77), and the negative predictive value was 94.1% (32 of 34). The CAD system using SLR can differentiate solid breast nodules with relatively high accuracy and its high negative predictive value could potentially help inexperienced operators to avoid misdiagnoses. Because the SLR model is trainable, it could be optimized if a larger set of tumor images were supplied.

Auditory brainstem evoked potentials in healthy full-term and pre-term infants

BACKGROUND

Auditory brainstem evoked potentials (ABEP) are used to evaluate the integrity of auditory pathways. Since there are difficulties in the performance and still no reference ranges for pre-term infants in Taiwan, the purpose of this study was to evaluate the characteristics of ABEP in full-term and pre-term infants.

METHODS

Forty full-term and 52 pre-term infants were enrolled between January and December 1997. ABEP study was performed at 3-7 days after birth, 3, 6 and 12 months of age in the full-term group while the pre-term infants were assessed at 34-36 weeks of gestational age, at term age, and at 3, 6, 12 months of corrected age. Acoustic stimulation of mixed frequency rarefaction clicks was presented to each ear through earphones. The clicks were presented at an intensity of 70-90 dB (hearing level) and a gradual decrement of intensity to 20-40 dB to determine the threshold. Electrical activity was picked up by surface electrodes. Latency of peaks I, III, V, inter-peak latency I-III, III-V, I-V and the threshold were assessed.

RESULTS

In the full-term group, the peak and inter-peak latencies decreased with age. In the pre-term group, the responses of 70 dB stimulus intensity were 53.8%, 58%, 82.8%, 88.9%, 100% in the sequence and the threshold of response decreased with age.

CONCLUSION

There are maturational changes after birth in both full-term and pre-term infants. We conclude that ABEP study is a sensitive, non-invasive tool for the evaluation of auditory pathway in infants.

Sonographic appearance of lipoma of the inferior vena cava

Lipomas of the major central veins are rare, and their sonographic features have rarely been reported. We report a case in which a lipoma of the inferior vena cava (IVC) was incidentally identified during liver sonography in a 68-year-old man. Sonography of the upper abdomen revealed coarsening of the liver echotexture, with a relatively small liver and atrophy of the right hepatic lobe. A 2-cm hypoechoic hepatic nodule was visualized in segment IV. Sonography also showed a 2.2- x 1.8-cm, highly echogenic, homogeneous nodule in the hepatic segment of the IVC at its junction with the right atrium. The lumen of the IVC was partially occluded. The CT and MRI appearances of the IVC lesion were consistent with a lipoma, which was not treated because there was no clinical evidence of obstruction. Histopathologic analysis following a sonographically guided biopsy of the liver nodule revealed hepatocellular carcinoma, which was treated by percutaneous ethanol injection.

Fluconazole therapy in neonatal candidemia

We reviewed 62 episodes (from 59 infants) of neonatal candidemia that occurred between January 1994 and June 1999. Except 5 term babies, all infants were premature (median gestational age [GA], 30 weeks) and birth weight was less than 2,500 g (median, 1,300 g). Most infants had reported risk factors and other neonatal problems. The age at onset of candidemia ranged from 15 to 173 days with a median of 34 days. In addition to catheter removal, all but one infants received antifungal agents and candidemia was eradicated subsequently in 46 episodes (75%). Eighteen infants with 19 episodes ever received fluconazole therapy. Fluconazole was administered as the first line agent in 6 episodes and successfully cleared candidemia in 5 episodes. Fluconazole was used as an alternative agent in an additional 13 episodes after amphotericin B (am B) +/- flucytosine were given for a period without a satisfactory result and eradication of candidemia was achieved in 8 episodes subsequently. All 18 infants tolerated fluconazole well and no withdrawal was required on account of its adverse effect. In contrast, am B alone was administered as the first line agent in 55 episodes and successfully cleared candidemia in 32 episodes (58%). This retrospective analysis suggests that fluconazole appears to be safe in neonates and can be used as an alternative agent in treating neonatal candidemia. A large-scaled prospective study may be needed.

Hepatocellular carcinoma associated with focal nodular hyperplasia. Report of a case with clonal analysis

We describe a hepatocellular carcinoma partially surrounded by focal nodular hyperplasia in a 65-year-old female patient. In order to clarify the relationship of the hepatocellular carcinoma and the adjacent focal nodular hyperplasia, clonal analysis was conducted. The clonal analysis was based on the methylation pattern of the polymorphic X-chromosome-linked androgen receptor gene (HUMARA). The allelic bands from the amplification of the focal nodular hyperplasia and of the hepatocellular carcinoma showed a significant reduction in the intensity of one of the two alleles as compared with two alleles of equal intensity in the buff coat after HhaI digestion, which indicated that these two parts were monoclonal. However, the inactivated allele in the focal nodular hyperplasia and that in the hepatocellular carcinoma were not identical. Therefore, the focal nodular hyperplasia and hepatocellular carcinoma probably derived from the clonal expansion of two different clones.

Sonographic features of xanthogranulomatous pyelonephritis

PURPOSE

The purpose of this study was to describe the various sonographic features of xanthogranulomatous pyelonephritis (XGP).

METHODS

We retrospectively reviewed the CT, sonographic, and medical records of patients diagnosed with XGP from January 1981 to December 1998. Twenty-seven patients for whom XGP was histopathologically confirmed were included in the study. There were 12 men and 15 women, with an age range of 21-86 years (mean, 57 years). All patients had undergone sonography of the kidneys. The renal size, shape, and outline were recorded. The presence of perinephric fluid accumulation, of obstructive uropathy, or of internal echoes in the dilated collecting system and the echotexture of the renal parenchyma were documented.

RESULTS

We categorized the XGP into 4 groups on the basis of the sonographic features: (1) diffuse hydronephrotic, 12 patients (44%); (2) diffuse parenchymal, 9 patients (33%); (3) diffuse contracted, 4 patients (15%); and (4) segmental or focal, 2 patients (7%). A localized perinephric fluid collection was present in 4 patients (15%). The preoperative sonographic diagnoses were pyonephrosis (n = 14, 52%), renal pelvic tumor with possible associated infection (n = 5, 19%), renal parenchymal mass (n = 2, 7%), hydronephrosis (n = 2, 7%), and chronic pyelonephritis with renal atrophy (n = 4, 15%). XGP was considered a possible diagnosis in only 11 patients (41%).

CONCLUSIONS

XGP has no specific sonographic features but is suggested by parenchymal thinning and hydronephrosis, sonographic signs of chronic obstructive uropathy caused by stones; echoes in the dilated collecting system; and a perinephric fluid collection. CT, needle biopsy, or both are recommended to further evaluate and confirm sonographically suspected XGP.

The role of high-resolution ultrasonography in management of calcific tendonitis of the rotator cuff

This article predicts the possibility of resorption of the calcific plaques in the shoulder using high-resolution ultrasonography (HRUS) and color Doppler ultrasound (CDUS), and evaluates the therapeutic effect of US-guided fine-needle multiple punctures of the calcific plaque. A total of 100 patients with calcific tendenosis were divided into 3 groups: In group 1, patients having chronic shoulder pain received conservative treatment; in group 2, patients having acute exacerbation of shoulder pain also received conservative treatment; and group 3 patients received US-guided fine-needle multiple punctures or aspiration. In CDUS, all images were classified as grade 0 (no color flow signals), grade 1 (weak spotty color flow signal), grade 2 (few rod-like color flow signals), grade 3 (many rod-like or linear color flow signals). In the follow-up study, marked improvement of patients' clinical condition with more than 50% size reduction of calcific plaque was defined as an effective treatment. There was no significant difference between group 1 and group 3 (p = 0.558) in CDUS, but there was a significant difference between group 1 and group 2 (p = 0.000), and group 2 and group 3 (p = 0.000) on the basis of classification of grade < 1 and grade > or = 1. There was also significant difference in the follow-up result of effective management between group 1 and group 3 (p = 0.000), and group 1 and group 2 (p = 0.000). In conclusion, HRUS with CDUS proved to be a good modality in evaluating the possibility of resorption of shoulder calcification and, if CDUS > or = grade 1 in calcific tendonitis, we highly recommend conservative treatment with regular follow-up. On the other hand, if CDUS < grade 1, fine-needle repeated puncture could be considered as an effective alternative treatment.

Hand-assisted laparoscopic radical nephrectomy of renal cell carcinoma--a case report

A 62-year-old female patient with chronic medical history of DM and hypertension was admitted due to traffic accident. She was asymptomatic until 5 days before admission. She was referred to our medical center with an abdominal CT revealing left renal tumor. The diameter of the renal mass was 50 mm. On ultrasonographic examination, a heterogenous lesion over the left kidney was noted. Renal scanning showed a cold nodule in the left kidney. Hand-assisted laparoscopic transperitoneal radical nephrectomy was performed smoothly. The kidney was removed from the hand port in the supraumbilical skin incision with a volume of 14 x 7 x 6 cm3 and weight of 570 gm. The operation time was 5 hours, blood loss was 200 cc, and no significant change of blood pressure was noted during the surgery. The patient's postoperative course was uneventful. The pathological report of this mass was renal cell carcinoma.

Mitotic reorganization of the intermediate filament protein nestin involves phosphorylation by cdc2 kinase

The intermediate filament protein nestin is expressed during early stages of development in the central nervous system and in muscle tissues. Nestin expression is associated with morphologically dynamic cells, such as dividing and migrating cells. However, little is known about regulation of nestin during these cellular processes. We have characterized the phosphorylation-based regulation of nestin during different stages of the cell cycle in a neuronal progenitor cell line, ST15A. Confocal microscopy of nestin organization and (32)P in vivo labeling studies show that the mitotic reorganization of nestin is accompanied by elevated phosphorylation of nestin. The phosphorylation-induced alterations in nestin organization during mitosis in ST15A cells are associated with partial disassembly of nestin filaments. Comparative in vitro and in vivo phosphorylation studies identified cdc2 as the primary mitotic kinase and Thr(316) as a cdc2-specific phosphorylation site on nestin. We generated a phosphospecific nestin antibody recognizing the phosphorylated form of this site. By using this antibody we observed that nestin shows constitutive phosphorylation at Thr(316), which is increased during mitosis. This study shows that nestin is reorganized during mitosis and that cdc2-mediated phosphorylation is an important regulator of nestin organization and dynamics during mitosis.

Bladder wall calcification after intravesical chemotherapy with mitomycin C--a case report

Bladder wall calcification has relatively few etiologies. We present such a case and review the literature to discuss it and the method for management. This case suffered from bladder wall calcification about 3 years after intravesical chemotherapy of mitomycin C. It was found accidentally during the transurethral resection of recurrent bladder tumor. The pathology confirmed the recurrence of transitional cell carcinoma combined with marked calcification. A repeat cystoscopy was done 3 months later. Massive calcified deposits in bladder wall especially in lesion of previous transurethral resection were still noted. Randomized biopsy showed dystrophic calcification without evidence of malignancy. We suggest that biopsy and/or resection (if possible) is a reasonable approach to eliminate the possibility of invasive bladder cancer.

Study of plasma endothelin-1 concentrations in Taiwanese neonates with respiratory distress

BACKGROUND

Endothelin-1 (ET-1) is a novel and potent endothelium-derived vasoconstriction peptide present in human plasma. In this study, plasma ET-1 concentrations were determined and their physiological significance was evaluated in Taiwanese neonates with respiratory distress.

METHODS

Sixty newborn infants consisting of 22 with respiratory distress syndrome (RDS), 13 with transient tachypnea of newborn (TTNB), 4 with meconium aspiration syndrome, 10 healthy preterm and 11 healthy full-term infants were included for plasma ET-1 determination. Plasma ET-1 levels were measured by enzyme immunoassay at the of age of 1 day. For those who were diagnosed with RDS, plasma ET-1 concentrations were scheduled for evaluation at the ages of 1, 2, 3, 7, 14, 28, and 35 days as long as oxygen was being used.

RESULTS

On the first day of life, there was no significant difference in plasma ET-1 concentrations between healthy preterm and term infants (3.92 +/- 0.88 vs. 3.56 +/- 1.98 pg/mL, p = 0.606). However, plasma ET-1 concentrations of infants with RDS were significantly higher than those with TTNB (6.46 +/- 0.58 vs. 3.77 +/- 1.29 pg/mL, p < 0.001). In RDS infants, plasma ET-1 concentrations showed no significant difference between those who developed bronchopulmonary dysplasia (BPD, N = 4) and those who recovered (non-BPD, n = 18) (7.84 +/- 1.85 vs. 5.81 +/- 2.76 pg/mL, p = 0.242).

CONCLUSION

Plasma ET-1 concentrations were similar in preterm and term infants. ET-1 concentrations were higher in infants with RDS than in infants with TTNB, which suggests that plasma ET-1 levels can be useful in the differential diagnosis. However, the plasma ET-1 concentrations can not be a predictor for BPD.

Sonographic features of breast abscesses with emphasis on "hypoechoic rim" sign

BACKGROUND

There are only limited reports on the ultrasound (US) features of breast abscess. The purpose of this paper is to review the US features of breast abscess with emphasis on "hypoechoic rim" sign which is more commonly seen in chronic abscess.

METHODS

In a period of 10 years, 20,998 patients were referred for breast US examinations. Medical records identified 204 patients in whom breast abscess was diagnosed. All patients were examined using high-resolution real-time US scanners. The initial ultrasound reports and hard copy images were all carefully reviewed. The grading of the echogenicity of the abscess was classified from grade 0 to grade 5. The contours of the lesions were described as smooth, macrolobulated, microlobulated, irregular, zigzag, spiculate or indistinct. The wall thickness was measured to document the presence of "hypoechoic rim" which denoted a wall thickness greater than 2 mm. The associated findings and other acoustic phenomena related to the lesion were recorded.

RESULTS

One hundred and thirty-six patients (136/204) having specific aspiration and/or biopsy/histopathological results were included in the study. All of the 136 patients showed abnormal US findings (100%). Most lesions showed grade 1 or grade 2 echogenicity (117, 86%). The contour of the abscess was usually smooth (42, 31%), macrolobulated (42, 31%), or irregular (22, 16%). A hypoechoic rim was noticed in 18 lesions (13%). Focal skin thickening was chiefly noticed in 91% of superficial abscesses (39/43) and 17% of intramammary abscesses (14/84). Diffuse skin thickening was exclusively evident in the breasts coexisting with mastitis. Hypoechoic interstitial streaks were not a common finding (7%), occurring in acute abscesses. The other findings included surrounding hypoechoic amorphous tissue (26%), posterior wall enhancement (71%), distal enhancement (60%) and lateral shadows (57%).

CONCLUSIONS

US plays an important role in confirmation of the clinical diagnosis of breast abscess and aids significantly in the management of inflammatory breast diseases. Presence of the hypoechoic rim surrounding a fluid space or a central area of low-level echoes (i.e., grade 1 to grade 3) is indicative of a chronic abscess.

Adrenal cyst--a case report

Adrenal cysts are rare and mostly silent clinically. Herein we report a case of adrenal cyst. A 55-year-old female was incidentally found to have a left suprarenal cystic lesion with a calcified wall by abdominal sonography during a work-up for her epigastralgia and left flank pain. Then, computed tomography (CT) revealed a left adrenal cystic mass with wall calcification, magnetic resonance imaging (MRI) showed left retroperitoneal cystic mass with fluid content, and angiography demonstrated an avascular lesion. Surgical exploration was performed via a flank incision and a calcified cystic adrenal mass was excised. The pathologic diagnosis was adrenal pseudocyst with calcified wall. We discuss the diagnosis and management of adrenal cyst and briefly review the literature.

Effect of hypocapnia in the first three days of life on the subsequent development of periventricular leukomalacia in premature infants

Several etiologies for causing periventricular leukomalacia (PVL) in preterm infants have been investigated worldwidely. The aim of this study is to investigate whether hypocapnia plays a role in the pathogenesis of the subsequent development of PVL. From Jan. 1997 to June 1998, 91 premature infants (mean gestational age 28.8 +/- 2.5 weeks and birth body weight 1169 +/- 385 g) born in Chung Gung Children's Hospital requiring mechanical ventilation in the first 72 hrs were enrolled in our study. Serial neuorosonogram were followed on day 1, 3, 7 and then at least every 2 to 3 weeks until discharge. These infants were divided into two groups defined as the PVL group and non-PVL group. Variables comprising perinatal data were analyzed and compared between these two groups to screen out possible risk factors related to the development of PVL. There was no difference noted. As for the effect of PaCO2, we found the infants with PVL to have mean lower PaCO2 during the first 72 hours of life. (P = 0.004). Logistic regression model revealed that the incidence for PVL increased significantly when mean PaCO2 is lowered to less than 25 mmHg. Hypocapnia during the first three days of life seems to be an important etiological factor associated with the development of periventricular leukomalacia. Therefore, the ventilatory strategy in the care of the premature neonates should not only provide adequate ventilation but also careful avoidance of hypocapnia.

New horizons in cytoskeletal dynamics: transport of intermediate filaments along microtubule tracks

Until recently, the dynamic properties of intermediate filaments (IF) were attributed primarily to the exchange of subunits between a disassembled pool and polymerized 10nm filaments. During interphase, this subunit exchange process was thought to produce local modifications in IF structure. During cell division, shifts in the equilibrium between subunits and polymers were thought to lead to either the global or regional disassembly of IF networks, thereby facilitating their distribution into daughter cells. Recently, novel structural forms of IF that undergo rapid and directed transport in several cell types were revealed. Time-lapse observations of motile IF structures in different cell systems have also revealed novel insights into the mechanisms underlying the transport of cytoskeletal components throughout the cytoplasm and the molecular basis of the 'crosstalk' between different cytoskeletal systems.

Cystitis glandularis mimics bladder cancer--three case reports and literature review

Cystitis glandularis is an uncommon proliferative disorder of the mucus-producing glands within the mucosa and submucosa of urinary bladder epithelium. We report three cases with gross hematuria on first presentation. Both sonography and computer tomography revealing bladder tumor and transurethral resection was performed in all three cases. Cystitis glandularis was confirmed by pathology. Short-term follow-up of sonography and cystoscopy showed good results.

New halogenated [11C]WAY analogues, [11C]6FPWAY and [11C]6BPWAY--radiosynthesis and assessment as radioligands for the study of brain 5-HT1A receptors in living monkey

[Carbonyl-(11)C]WAY-100635 ([(11)C]WAY) is an established radioligand for the study of brain serotonin(1A) (5-HT(1A)) receptors in living animals and humans with positron emission tomography (PET). There is a recognised need to develop halogenated ligands for 5-HT(1A) receptors, either for labelling with longer-lived fluorine-18 for more widespread application with PET or with iodine-123 for application with single photon emission tomography (SPET). Here we used autoradiography and PET to assess two new halogenated analogues of WAY, namely 6BPWAY and 6FPWAY [N-(2-(1-(4-(2-methoxyphenyl)-piperazinyl)ethyl))-N-(2-(6-bromo-/fluoro-pyridinyl))cyclohexanecarboxamide] as prospective radioligands, initially using carbon-11 as the radiolabel. Labelling of 6BPWAY and 6FPWAY with carbon-11 was accomplished by acylation of the corresponding secondary amine precursors with [carbonyl-(11)C]cyclohexanecarbonyl chloride. After incubation of human brain crysections with [(11)C]6BPWAY or [(11)C]6FPWAY, the highest accumulation of radioactivity was observed in cortical areas and the hippocampal formation. Both radioligands had high nonspecific binding. There was a rapid accumulation of radioactivity in the monkey brain after intravenous injection of [(11)C]6BPWAY and [(11)C]6FPWAY. High accumulation of radioactivity was observed in the frontal and temporal cortex and the raphe nuclei, areas known to contain a high density of 5-HT(1A) receptors. The ratios of radioactivity in receptor-rich temporal cortex to that in receptor-poor cerebellum at peak equilibrium were 1.9 (at 10 min) and 3.0 at (at 20 min) for [(11)C]6BPWAY and [(11)C]6FPWAY, respectively. In pretreatment experiments with high doses of unlabelled WAY, the level of radioactivity in the frontal and temporal cortex and the raphe nuclei was reduced to the same level as in the cerebellum. Radioactive metabolites of [(11)C]6FPWAY appeared at a rate similar to those for [(11)C]WAY, with 17% of the radioactivity in plasma represented by unchanged radioligand after 40 min. Radioactive metabolites of [(11)C]6BPWAY appeared much more slowly. At 40 min after injection 45% of the radioactivity in plasma still represented unchanged radioligand. The results indicate that 6-pyridinyl radiohalogented analogues of WAY are new leads to radioligands for PET or SPET.

Sonography of acute right side colonic diverticulitis

BACKGROUND

To describe the prevalence and sonographic findings and ultrasound diagnostic accuracy of the right side colonic diverticulitis in patients having right lower abdominal pain with indeterminate nature.

METHODS

A total of 934 patients with acute right lower abdominal pain of clinically indeterminate nature were referred for ultrasound examination (US). US studies were performed with 3.5 to 7.0 (or occasionally 10) MHz transducers using graded compression method. Twenty-three patients were finally diagnosed to have an uncomplicated acute diverticulitis of the right colon. The gray-scale sonographic images were reviewed. A retrospective study was undertaken to evaluate diagnostic contribution of US.

RESULTS

The prevalence of acute right side colonic diverticulitis was 2.5% in patients with clinically indeterminate acute right lower abdominal pain. Locations of the inflamed diverticula include cecum in 6 patients, proximal ascending colon in 15 patients, and distal ascending colon in only 2 patients. Sonography detected 21 inflamed diverticula with 1 false positive and 2 false negative results. The most typical sonographic feature of an inflamed diverticulum of right side colon was a rounded or oval-shaped hypoechoic or nearly anechoic structure (52%) protruding out from the segmentally thickened colonic wall. Some of them might contain strong echoes representing gas or feces (43%), or stone in the lumen (5%). Regional pericolic or peridiverticular fat thickening was noted in 57% of patients, and segmental colon wall thickening in 38%. US examination yielded a sensitivity of 91.3%, a specificity of 99.8%, an overall accuracy of 99.5%, a positive predictive value of 95.5%, and a negative predictive value of 99.7%. A positive sonogram made the likelihood of acute right side diverticulitis 456.5 times greater compared with the pretest clinical impression. US differentiated acute right side colonic diverticulitis from acute appendicitis with a 100% accuracy.

CONCLUSIONS

Ultrasound can be extremely useful in diagnosing acute right side colonic diverticulitis. Careful ultrasound evaluation of the right colon and the cecum may facilitate a correct diagnosis and help differentiate from acute appendicitis, and steer the surgeon to a more effective management.

Prophylaxis of intravenous immunoglobulin and acyclovir in perinatal varicella

Maternal chickenpox around the time of delivery can cause severe and even fatal illness in the newborn but an effectively preventive method has not yet been established. We proposed that a combination of intravenous immunoglobulin (IVIG) and acyclovir (ACV) intravenously could effectively prevent perinatal varicella. A group of 24 newborn infants whose mother had developed a varicella rash within 14 days before and after delivery were studied. Some 15 infants whose mothers' rash appeared within 7 days before and 5 days after delivery were categorised as an at-risk group and received IVIG prophylaxis (500 mg/kg) administered soon after birth or post-natal contact either alone or with intravenous acyclovir (5 mg/kg every 8 h) for a total of 5 days starting from 7 days after the onset of maternal rash. Of four infants receiving IVIG alone, two developed clinical varicella. None of ten infants receiving both IVIG and ACV contracted varicella. One infant receiving ACV alone had no varicella vesicles either. Of nine infants in the not at-risk group four had undetectable varicella-zoster virus antibody on admission and developed clinical varicella subsequently.

CONCLUSION

The combination of intravenous immunoglobulin given soon after birth and prophylactic acyclovir intravenously administered 7 days after the onset of maternal rash can effectively prevent perinatal varicella.

Adult Wilms' tumor associated with polycythemia--a case report

Both Wilms' tumor (nephroblastoma) in adults and polycythemia in Wilms' tumor are rare. Herein we report an extremely rare case of adult Wilms' tumor associated with polycythemia. A 41-year-old female was incidentally found to have right renal mass by abdominal sonography in a routine health examination. Laboratory examination revealed polycythemia (hemoglobin 20.2 g/dL). Although physical examination was unremarkable, CT scan revealed an homogeneous mass at the middle pole of right kidney, and chest x-ray revealed no metastatic lesions. Right radical nephrectomy was performed smoothly. Grossly, the tumor of 5 x 4.5 x 4.5 cm in size was well circumscribed, and had no vascular structure or collecting system involvement. Microscopic features were consistent with adult nephroblastoma. The post-operative course was uneventful. At follow-up, the patient was well, showed no evidence of recurrence and her hemoglobin level had returned to normal (hemoglobin 14.5 g/dl). We suggest that the relationship between polycythemia and Wilms' tumor should be carefully evaluated before surgical treatment.

Effect of amphetamine on extrastriatal D2 dopamine receptor binding in the primate brain: a PET study

[(11)C]raclopride binding to D2 dopamine receptors in the striatum is sensitive to drug-induced changes of endogenous dopamine concentration. We recently developed the new radioligand [(11)C]FLB 457, which is suitable for positron emission tomography (PET) studies of extrastriatal D2 dopamine receptors. The purpose of this PET study was to examine the effect of amphetamine on [(11)C]FLB 457 binding in extrastriatal regions. Each of three cynomolgus monkeys was examined at baseline conditions, 15 min and 3 h after I.V. injection of amphetamine (2 mg/kg). The effect of amphetamine was calculated from the ratio of specific [(11)C]FLB 457 binding to the binding in the cerebellum, a region which was used as reference for free and nonspecific binding in the brain. The changes of the ratio in the striatum, the thalamus, and the neocortex were between -1.2% and -15.5% at 15 min and -2.1% and -16.3% at 3 h, respectively, after amphetamine administration. The reductions of the binding ratios in the extrastriatal regions are similar to those reported for [(11)C]raclopride binding in the striatum. These data in a limited series of monkeys suggest that [(11)C]FLB 457 binding to D2 dopamine receptors in extrastriatal regions is sensitive to changes in the concentration of endogenous dopamine.

Polarized optical coherence imaging in turbid media by use of a Zeeman laser

A method that uses a Zeeman laser in conjunction with a Glan-Thompson analyzer to image an object in a turbid medium is proposed. A heterodyne signal is generated only when the scattering photons are partially polarized, and the spatial coherence is not seriously degraded after the signal propagates in the turbid medium. A system combining polarization discrimination with optical coherence detection to image the object in a scattering medium is successfully demonstrated. The medium is a solution of polystyrene microspheres measuring 1.072 mum in diameter suspended in distilled water contained in a 10-mm-thick quartz cuvette. The advantages of this optical system, including better selectivity of the weak partially polarized scattering photons and better imaging ability in higher-scattering media, are discussed.

Adrenal myelolipoma--report of two cases

Adrenal myelolipoma, which is composed of hematopoietic and adipose elements, is a rare benign tumor. Most adrenal myelolipomas are asymptomatic and are found incidentally. We report two cases of adrenal myelolipoma. One was a middle-aged woman with right flank pain. Tumor size increased 8 years later. The other patient was a 63-year-old man presenting with right flank soreness. The right adrenal tumor was found by abdominal sonography. Both of them received adrenalectomy to relieve symptoms and the pathologic results showed adrenal myelolipoma. The clinical, radiologic and pathologic characteristics of these two cases are discussed together with a review of the literature.