Sex-specific association of urate and levodopa-induced dyskinesia in Parkinson's disease

BACKGROUND AND PURPOSE

As a major antioxidant, uric acid (UA) is known to be associated with the clinical progression of Parkinson's disease (PD). This study investigated whether baseline UA levels are associated with the risk for levodopa-induced dyskinesia (LID) in PD in a sex-dependent manner.

METHODS

In all, 152 patients with de novo PD (78 males and 74 females) who were followed up for >2 years were enrolled. The effect of baseline serum UA levels on LID-free survival was assessed by Cox regression, separately for sex, whilst being adjusted for potential confounding factors. The optimal UA level cut-off value to determine the high-risk group for LID was set using Contal and O'Quigley's method.

RESULTS

Levodopa-induced dyskinesia developed in 23 (29.5%) male patients and 30 (40.5%) female patients. Cox regression showed a significant interaction between UA level and sex. Higher UA levels were associated with a higher risk for LID in male PD patients (hazard ratio 1.380; 95% confidence interval 1.038-1.835; P = 0.027), although this relationship was not observed in female PD patients. The optimal UA level cut-off for LID in male PD was 7.2 mg/dl, and the high UA group had a 5.7-fold higher risk of developing LID than the low UA group.

CONCLUSIONS

Contrary to a presumptive beneficial role of UA, the present study demonstrated that higher UA levels are associated with increased risk of LID occurrence in male patients with PD, suggesting a sex-dependent role of UA in LID.

Cognitive anosognosia is associated with frontal dysfunction and lower depression in Parkinson's disease

BACKGROUND AND PURPOSE

Anosognosia refers to a deficit of self-awareness or impaired insight for cognitive and behavioral problems. Cognitive anosognosia was explored in de novo patients with Parkinson's disease (PD) and its relationship to cognitive function and neuropsychiatric symptoms was investigated.

METHODS

The cross-sectional study enrolled 340 drug-naïve patients with PD. According to the presence of mild cognitive impairment (MCI) and subjective cognitive complaint, patients were classified as patients with cognitive anosognosia (PD-CA, n = 74), with normal cognitive recognition (PD-NR, n = 184) or with cognitive underestimation (PD-CU, n = 82). After controlling for covariates, cognitive performance and neuropsychiatric symptoms were compared between the PD groups.

RESULTS

Cognitive anosognosia was found in 21.8% of patients with de novo PD. The PD-CA group showed poorer performance in all cognitive domains except for attention. Amongst PD patients with MCI, those with cognitive anosognosia showed lower composite z-scores in the Stroop color reading test than those without. The Beck Depression Inventory score in the PD-NR group was lower than that in the PD-CU group and higher than that in the PD-CA group. The Cognitive Complaints Interview score mediated the association between cognitive anosognosia and Beck Depression Inventory score.

CONCLUSIONS

Cognitive anosognosia in PD was associated with greater frontal dysfunction and lower depression. Since cognitive anosognosia has a harmful impact on PD patients and their caregivers due to overestimation of their abilities in everyday life, early identification of cognitive anosognosia in PD is important in management and prognosis.

Effects of Alzheimer's disease and Lewy body disease on subcortical atrophy

BACKGROUND AND PURPOSE

Subcortical structures are affected by neurodegeneration in Alzheimer's disease (AD) and Lewy body disease (LBD). Although the co-occurrence of AD and LBD pathologies and their possible interaction have been reported, the effect of AD and LBD on subcortical structures remains unknown. The effects of AD and LBD on subcortical atrophy and their relationship with cognitive dysfunction were investigated.

METHODS

The cross-sectional study recruited 42 patients with pure AD related cognitive impairment (ADCI), 30 patients with pure LBD related cognitive impairment (LBCI), 58 patients with mixed ADCI and LBCI, and 29 normal subjects. A general linear model was used to compare subcortical volume and shape amongst the groups, to investigate the independent and interaction effects of ADCI and LBCI on subcortical shape and volume, and to analyze the relationship between subcortical volume and cognitive dysfunction in each group.

RESULTS

Alzheimer's disease related cognitive impairment and LBCI were independently associated with subcortical atrophies in the hippocampus and amygdala and in the hippocampus and putamen respectively, but their interaction effect was not significant. Compared to the control group, the pure LBCI group exhibited additional local atrophies in the amygdala, caudate and thalamus. Subcortical atrophies correlated differently with cognitive dysfunction according to the underlying causes of cognitive dysfunction.

CONCLUSIONS

The patterns of subcortical atrophies and their correlation with cognitive dysfunction differ according to the underlying AD, LBD or concomitant AD and LBD.

Clinical relevance of amnestic versus non-amnestic mild cognitive impairment subtyping in Parkinson's disease

BACKGROUND AND PURPOSE

To clarify whether subtyping of amnestic and non-amnestic mild cognitive impairment (MCI) is clinically relevant in Parkinson's disease (PD) by analyzing patterns of neuroimaging and longitudinal cognitive changes.

METHODS

We performed comparative analyses of cortical thickness, hippocampal volume, white matter integrity and resting-state functional connectivity between the patients with de-novo PD with amnestic MCI (PD-aMCI) (n = 50) and non-amnestic MCI (PD-naMCI) (n = 50) subtypes. Additionally, we assessed the longitudinal rate of cognitive decline in each cognitive domain over time and the rate of dementia conversion in patients with de-novo PD-aMCI (n = 125) and PD-naMCI (n = 61).

RESULTS

The demographic data showed that scores in memory domains were lower in the PD-aMCI group compared with the PD-naMCI group. There were no significant differences in cortical thickness, hippocampal volume and white matter integrity between the two groups, although the PD-aMCI group exhibited more cortical thinning and hippocampal atrophy relative to the control group. The PD-aMCI group exhibited increased functional connectivity in the left posterior parietal region with the salience network relative to the PD-naMCI group. The longitudinal cognitive assessment demonstrated that patients with PD-aMCI exhibited a more rapid cognitive decline in frontal/executive function than those with PD-naMCI (P = 0.022). In addition, the PD-aMCI group had a higher risk of dementia conversion than the PD-naMCI group.

CONCLUSIONS

This study suggests that the designation of PD-MCI subtypes based on memory function would highlight the heterogeneity of functional correlates as well as the longitudinal cognitive prognosis.

Hydro-nanofibrous mesh deep cell penetration: a strategy based on peeling of electrospun coaxial nanofibers

A two-step strategy for coaxial electrospinning and postelectrospinning is an effective method for fabricating superfine nanofibers composed of highly swellable hydrogels. Alginate and poly(ε-caprolactone) [PCL] were coelectrospun via fibrous meshes with a coaxial nozzle; alginate at the core was subsequently cross-linked in calcium chloride solution. The PCL sheath was removed from the meshes by repeated organic-phase washing. The peeling process was monitored by scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry, and the complete removal of the PCL outer layers was confirmed by the thinning of the fiber volume. The obtained alginate hydronanofiber showed extreme water-swellability and mass erosion depending on the degree of cross-linking. We also measured the nanoscale and macroscale mechanical properties of a single nanofiber and of the whole mesh by atomic force microscopy and rheometry. Quantitative analysis of nanomechanical properties indicated that the hydronanofiber with higher cross-linking density had higher stiffness and Derjaguin-Müller-Toporov modulus. Cells laid on the mesh and the vertical infiltration distance were visualized and quantified by confocal laser scanning microscopy. Cells on the mesh with higher cross-linking density infiltrated deeply to the bottom of the mesh. Thus, hydrogel-like nanofibrous meshes are versatile matrices allowing for deep infiltration of cells throughout the mesh via manipulation of the mechanical properties of the nanofiber.

Bone marrow-derived clonal mesenchymal stem cells inhibit ovalbumin-induced atopic dermatitis

Mesenchymal stem cells (MSCs) possess immunomodulatory activities, including suppression of T- and B-cell activation. However, their effects on atopic dermatitis (AD) have not yet been studied. Using an ovalbumin-induced AD mouse model, we investigated whether MSCs can be used as therapeutics in AD. We isolated both allogeneic and syngeneic clonal MSCs (cMSCs) from mouse bone marrow according to the subfractionation culturing method. Our cMSCs suppressed both T- and B-cell activation. T-cell proliferation and cytokine production, including interferon (IFN)-γ and interleukin (IL)-4, were suppressed by inhibition of transcription factors, such as T-bet, GATA-3, and c-Maf. Those transcription factors were nitric oxide dependent. Immunoglobulin E (IgE) suppression occurred through downregulation of AID and BLIMP-1, important regulators for isotype class switch and B-cell differentiation. The cMSCs were injected intravenously into ovalbumin-induced AD mouse model, and the therapeutic effects were analyzed. Injection of both allogeneic and syngeneic cMSCs in an AD mouse model inhibited cell infiltration in skin lesions and decreased the serum level of IgE. IL-4 expression was also suppressed by cMSCs in both the lymph node and skin. The cMSCs migrated to skin lesions and draining lymph nodes. Taken together, these data demonstrated that cMSCs, which suppressed T- and B-cell functions, can be used for the treatment of AD in mice.

Prognostic indicators of gastric carcinoma confined to the muscularis propria

AIMS

Gastric carcinoma confined to the muscularis propria (MPGC) is considered an intermediate-stage carcinoma. A method of discriminating between more favourable and less favourable prognostic groups of this entity is critically needed in dealing with this heterogeneous disease. The aim of this study was to examine the correlation between survival of patients with MPGC and its various clinicopathological parameters.

METHODS AND RESULTS

Various clinicopathological parameters were studied in 171 tissue samples including: macroscopic appearance, size, age, sex, stage, invasion depth, Lauren and Ming classifications, extent, lymphatic emboli and nodal metastasis. Tumours macroscopically resembling early gastric cancers, younger patient age, absence of lymphatic tumour emboli and lower stage were significantly associated with better prognosis of MPGC by univariate analysis. Tumours macroscopically resembling early gastric cancers, younger patient age and Lauren's diffuse type were significantly associated with a better prognosis of MPGC by multivariate analysis.

CONCLUSIONS

These indicators are practical parameters for predicting patient prognosis in clinical practice. The description of these parameters should be carefully noted in the final report and pathologists should evaluate the macroscopic appearance of MPGC.

Quantitative Analysis of Interleukin-6 Expression in Porcine Spleen Cells and Alveolar Macrophages using Real-Time PCR

Interleukin-6 (IL-6), a multifocal cytokine produced by lymphoid and non-lymphoid cells, regulates immune responses, acute-phase reactions against bacterial infections, and haematopoiesis. After cloning and sequencing of porcine IL-6, the expression pattern of porcine IL-6 mRNA was evaluated through real-time RT-PCR using porcine immune cells (spleen cells and alveolar macrophages) following stimulation with LPS. The sequence has been reported to GenBank with Accession no. AF 518322. The nucleotide sequence was different at the 89th and 205th positions in comparison with M80258, but only at the 205th with M86722. Comparison of porcine IL-6, Accession no. AF 518322, with IL-6 of human, canine, ovine, and mouse showed homologies of 78%, 81%, 82% and 73% in nucleotide sequence and 42%, 69%, 61% and 42% in amino acids. Expression of IL-6 mRNA was induced by stimulation with LPS. IL-6 mRNA expression in alveolar macrophages peaked at 2 h and decreased sharply to control levels at 4 h, whereas it peaked at 14 h and decreased at 24 h in spleen cells after stimulation with LPS (1 microg/ml). These results suggest that IL-6 mRNA expression in porcine immune cells is cell-type specific and the results of this study could be used as the basis for research on the porcine immune system.

Comparative analysis on the 5'-untranslated region of bovine viral diarrhea virus isolated in Korea

Samples of 249 bovine abortuses, one intestine, and four diarrheal stools from 254 cows were collected, and bovine viral diarrhea virus (BVDV) was detected by reverse transcription-polymerase chain reaction (RT-PCR). Subsequently, virus isolation was preformed with PCR-positive samples, and then PCR product of 5^′-untranslated region (UTR) of BVDV isolate was sequenced and analyzed. Among the samples collected, 20 (from 17 bovine abortuses, one intestine, and two diarrheal stools) were positive for BVDV RT-PCR; four BVDVs (from two bovine abortuses, one intestine, and one diarrheal stool) were isolated. When the four isolates were biotyped in cell culture, one BVDV isolate from a bovine abortus was cytopathic and the others were non-cytopathic. In addition, three isolates were genotyped as BVDV-1 and one isolate from a diarrheal stool as BVDV-2. In phylogenetic analysis, it suggested that the BVDV-2 isolate in Korea is closer to the North American strains than Asian strains. This is the first report on the identification and isolation of BVDV-2 in Korea.

Stable transformation of rice (Oryza sativa L.) via microprojectile bombardment of highly regenerative, green tissues derived from mature seed

A highly efficient and reproducible transformation system for rice ( Oryza sativa L. cv. Taipei 309) was developed using microprojectile bombardment of highly regenerative, green tissues. These tissues were induced from mature seeds on NB-based medium containing 2,4-dichlorophenoxyacetic acid (2,4-D), 6-benzylaminopurine (BAP) and high concentrations of cupric sulfate under dim light conditions; germinating shoots and roots were completely removed. Highly regenerative, green tissues were proliferated on the same medium and used as transformation targets. From 431 explants bombarded with transgenes [i.e. a hygromycin phosphotransferase ( hpt) gene plus one of a wheat thioredoxin h ( wtrxh), a barley NADP-thioredoxin reductase ( bntr), a maize Mutator transposable element ( mudrB) or beta-glucuronidase ( uidA; gus) gene], 28 independent transgenic events were obtained after an 8- to 12-week selection period, giving a 6.5% transformation frequency. Of the 28 independent events, 17 (61%) were regenerable. Co-transformation of the second introduced transgene was detected in 81% of the transgenic lines tested. Stable integration and expression of the foreign genes in T(0) plants and T(1) progeny were confirmed by DNA hybridization, western blot analyses and germination tests.

The cerebrovascular response to traditional acupuncture after stroke

Acupuncture is useful in treating the nausea and vomiting related to chemotherapy, adult postoperative surgery pain and postoperative dental pain. We obtained single-photon emission computed tomography (SPECT) brain perfusion images of six patients with middle cerebral artery occlusion obtained before and after acupuncture and compared the changes in regional cerebral blood flow (rCBF) to those in normal control. Images were obtained before and after acupuncture at six traditional acupoints (LI 4, 10, 11, 15 and 16 and TE5) in the affected arm. The baseline image was subtracted from the postacupuncture image, to produce a subtraction image displaying only voxels with values >2 SD from the mean and those voxels were coregistered to the baseline SPECT or T2-weighted MRI. Similar images were obtained before and after acupuncture of eight normal volunteers. Statistical parametric mapping with a threshold of P =0.001 and a corrected P of 0.05 was performed for group comparison between postacupuncture and baseline SPECT. Focally increased CBF was seen in all patients especially in the hypoperfused zone surrounding the ischaemic lesion, the ipsilateral or contralateral sensorimotor area, or both. Normal subjects showed increased rCBF mainly in the parahippocampal gyrus, premotor area, frontal and temporal areas bilaterally and ipsilateral globus pallidus. Acupuncture stimulation after stroke patients appears to activate perilesional or use-dependent reorganised sites and might be a way of looking at brain reorganisation.

Endocarditis associated with Escherichia coli in a sea lion (Zalophus californianus)

Endocarditis associated with Escherichia coli was diagnosed in a 2-year-old male California sea lion (Zalophus californianus). The diagnosis was based on light microscopic examination and bacterial isolation from the valvular lesion. This is the first case of bacterial endocarditis reported in a sea lion.

Encephalomyelitis associated with akabane virus infection in adult cows

Between August and September 2000, five 2-7-year-old cows in Korea exhibited neurologic signs and were diagnosed as infected with Akabane virus based on the results of histopathology, immunohistochemistry, serology, and reverse transcription polymerase chain reaction (RT-PCR) analysis. Immunohistochemistry and RT-PCR were equally effective and sensitive for diagnosing Akabane virus infection during the early stage of infection. Typical lymphohistiocytic inflammation characterized by perivascular mononuclear cell infiltration, gliosis, neuronophagia, and neuronal loss was noted in the brain and the ventral horn gray matter of the spinal cord. The lesions in the brain were most prominent in the pons and medulla oblongata. Akabane virus antigen was detected in the brain and spinal cord, mainly in degenerating neurons and glial cells. RT-PCR analysis revealed a target band of expected size in four cows. This is the first report on an outbreak of natural Akabane virus infection in adult cattle.

Morganelliasis pneumonia in a captive jaguar

Suppurative bronchopneumonia was discovered in a 6-yr-old male jaguar (Panthera onca onca) that died after a 1 wk history of anorexia, depression, and respiratory difficulty. Morganella morganii was isolated as a pure culture from the lung, spleen, and heart blood. This is the first record of M. morganii induced pneumonia in a jaguar.

Gallbladder lymphangioma: MR findings

Intraabdominal lymphangiomas are rare lesions that can be difficult to diagnose. We report ultrasonographic (US), computed tomographic (CT), magnetic resonance (MR) imaging, and pathologic findings in a patient with cavernous lymphangioma originating in the gallbladder. US and CT showed a multiseptated cystic mass in the gallbladder fossa. T2-weighted MR images and MR cholangiopancreatography depicted the lumen of the gallbladder and thin septations of the cystic mass, which originated in the gallbladder. Endoscopic retrograde cholangiopancreatography showed no apparent communication between the cyst and the gallbladder. Histologic findings obtained during the operation were consistent with cavernous lymphangioma. Its characteristic histology was observed in the subserosal layer of the gallbladder. This case is a rare instance of cavernous lymphangioma originating in the gallbladder preoperatively diagnosed by MR and MR cholangiopancreatography.

Pleckstrin homology domain interacts with Rkp1/Cpc2, a RACK1 homolog, to modulate Pck2-mediated signaling process in Schizosaccharomyces pombe

Rkp1/Cpc2, a fission yeast RACK1 homolog, interacts with Pck2, a PKC homolog, and is involved in the regulation of pck2-mediated signaling process. The N-terminal region of split pleckstrin homology domain (nPH) in human PLC-gamma1 bound to Rkp1/Cpc2 concomitantly with Pck2. nPH inhibited kinase activity of GST-Pck2 purified from Schizosaccharomyces pombe in vitro. The lethality induced by pck2(+) overexpression was suppressed by coexpression of either rkp1(+) or nPH domain. This result suggests that Rkp1/Cpc2 interacts with PH domain-containing protein and regulates the Pck2-mediated signaling process in S. pombe.

Antiplatelet activity of green tea catechins is mediated by inhibition of cytoplasmic calcium increase

We have previously reported that green tea catechins (GTC) display a potent antithrombotic activity, which might be due to antiplatelet rather than anticoagulation effects. In the current study, we investigated the antiplatelet mechanism of GTC. We tested the effects of GTC on the aggregation of human platelets and on the binding of fluorescein isothiocyanate-conjugated fibrinogen to human platelet glycoprotein (GP) IIb/IIIa. GTC inhibited the collagen-, thrombin-, adenosine diphosphate (ADP)-, and calcium ionophore A23187-induced aggregation of washed human platelets, with 50% inhibitory concentration values of 0.64, 0.52, 0.63, and 0.45 mg/ml, respectively. GTC significantly inhibited fibrinogen binding to human platelet surface GPIIb/IIIa complex but failed to inhibit binding to purified GPIIb/IIIa complex. These results indicate that the antiplatelet activity of GTC may be due to inhibition of an intracellular pathway preceding GPIIb/IIIa complex exposure. We also investigated the effects of GTC on intracellular calcium levels, which are critical in determining the activation status of platelets and on induction of platelet aggregation by thapsigargin, which is a selective inhibitor of the Ca(2+)-ATPase pump. Pretreatment of human platelets with GTC significantly inhibited the rise in intracellular Ca(2+) concentration induced by thrombin treatment, and GTC significantly inhibited the thapsigargin-induced platelet aggregation. We also examined the effect of GTC on the second messenger, inositol 1,4,5-triphosphate (IP(3)). GTC significantly inhibited the phosphoinositide breakdown induced by thrombin. Taken together, these observations suggest that the antiplatelet activity of GTC is be mediated by inhibition of cytoplasmic calcium increase, which leads to the inhibition of fibrinogen-GPIIb/IIIa binding via the activation of Ca(2+)-ATPase and inhibition of IP(3) formation.

Multidrug-resistant Salmonella typhimurium and Salmonella enteritidis identified by multiplex PCR from animals

Antibiotic resistance in Salmonella enteritidis and S. typhimurium, one of most frequent etiologic pathogens of food-borne bacterial gastroenteritidis in humans, is a serious health problem worldwide. Fifteen and 22 each of S. enteritidis and S. typhimurium were isolated from animals from 1983 to 1999 in Korea and tested for their antibiotic resistance patterns and phage types. S. enteritides isolates were highly resistant to sulfonamides (86.7%) and four of them (26.6%) showed multiple antibiotic resistance. The most frequent phage type (PT) of S. enteritids was PT1 (33.3%) even though none of them had multiple antibiotic resistance. S. typhimurium isolates were highly resistant to streptomycin, sulfonamides, and tetracycline, 100%, 95.5%, and 86.4% respectively. The incidence of multiple antibiotic resistance of S. typhimurium isolates was extremely high (100%) comparing to S. enteritidis isolates (26.7%). Two of the five ACSSuT type S. typhimurium isolates, resistant to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline, were phage type DT104. All S. typhimurium isolates were sensitive to florfenicol. For the rapid detection of multiple antibiotic resistant S. enteritidis and S. typhimurium isolates, particularly ACSSuT type S. typhimurium DT104, antibiotic resistance genes, cmlA/tetR, PSE-1, and TEM, and Salmonella spp. Specific gene, SipB/C, were amplified using four pairs of primers in hot-started multiplex polymerase chain reaction. Two Korean isolates of S. typhimurium DT104 showed TEM amplicons instead of PSE-1 for the ampicillin resistance. The multiplex PCR used in this study was useful in rapid detection of ACSSuT type S. typhimurium and identification of b-lactamase gene distribution among Salmonella isolates.

Mitochondrial cytochrome b gene sequence diversity in the Korean hare, Lepus coreanus Thomas (Mammalia, Lagomorpha)

Partial sequences of the mitochondrial cytochrome b gene of the Korean hare (Lepus coreanus) were analyzed to determine the degree of genetic diversity. Nine haplotypes were observed, and the maximum Tamura-Nei nucleotide distance among them was 2.8%, indicating that genetic diversity of L. coreanus is moderate. In order to clarify the Korean hare's taxonomic status and relationship with the Manchurian hare (L. mandshuricus) and the Chinese hare (L. sinensis), these nine haplotypes of the Korean hare were compared with 13 haplotypes from five other species of eastern Asian Lepus including L. mandshuricus and L. sinensis. The Korean hare was distinct in its cytochrome b gene, and it is confirmed that L. coreanus is a valid species, as noted by Jones and Johnson (1965, Univ. Kansas Publ. (Mus. Nat. Hist.) 16:357). Further analyses of mtDNA cytochrome b gene with additional specimens of L. coreanus from North Korea and other species of Lepus from eastern Asia are needed to clarify the taxonomic status of the divergent mtDNA clades of L. mandshuricus and L. sinensis.

Evaluation of the petrifilm plate method for the enumeration of aerobic microorganisms and coliforms in retailed meat samples

This study was designed to compare the effectiveness and applicability of the Petrifilm plate method with the Association of Official Analytical Chemists' (AOAC) standard aerobic count method and violet red bile agar method for meat products. The comparison was carried out using 303 meat samples collected from various retailers: 110 pork samples, 87 chicken samples, and 107 beef samples. In the comparison of the correlation coefficient (R) between the conventional method and the Petrifilm plate method by a linear regression analysis, the correlation coefficient in total microorganisms was 0.99, 0.95, and 0.94 in pork, beef, and chicken samples, respectively. The correlation coefficient in coliform count was 0.83, 0.96, and 0.81 in pork, beef, and chicken samples, respectively. Based on the high correlation in the total microorganism count, it might be possible to replace the conventional methods with the Petrifilm plate method. For coliform counts, the Petrifilm plate method also showed a generally high correlation coefficient, except for pork samples, which are more subject to contamination. The Petrifilm plate method was simpler and less time-consuming in sample preparation and, in procedures, faster than the conventional method. These results suggested that the 3M Petrifilm plate method could replace the conventional methods in the analysis of microorganism contamination measurement in meat products.

Modulatory effects of ionized alkali mineral complex (IAMC) on mRNA expression of porcine cytokines

It has been recognized that ionized alkali mineral complex (IAMC)-fed farm animals demonstrate higher weight gains but less incidence of diseases than the unfed ones. However, how these beneficial effects in the IAMC-fed animals are induced has not yet been elucidated clearly. In this study, porcine peripheral blood mononuclear cells (PBMC) were cultured for 4, 24, and 48 hr in the presence of IAMC, and the effects of IAMC on mRNA expression of porcine cytokines were evaluated via a reverse transcription-polymerase chain reaction (RT-PCR). Expression levels of IL-4, IL-6, and IL-10 in IAMC-treated cells were usually higher than those in the untreated ones. However, IAMC-treated cells demonstrated a reduced expression of IL-2. In addition, expression of IFN-gamma was generally reduced in the cells treated with IAMC. The expression of IL-12 p35 and IL-12 p40 was not detectable in both the untreated and the IAMC-treated cells. Therefore, these results indicate that IAMC has immunomodulatory effects in vitro on the expression of porcine Th1-and Th2-type cytokines.

Isolation of a novel gene from Schizosaccharomyces pombe: stm1+ encoding a seven-transmembrane loop protein that may couple with the heterotrimeric Galpha 2 protein, Gpa2

A putative seven transmembrane protein gene, stm1(+), which is required for proper recognition of nitrogen starvation signals, was isolated as a multicopy suppressor of a ras1 synthetic lethal mutant in Schizosaccharomyces pombe. Under nitrogen-deficient conditions, transcription of the stm1 gene was induced; deletion of stm1 was associated with early entry into G(1) arrest. Under nutritionally sufficient conditions, overexpression of Stm1 inhibited vegetative cell growth, resulted in decreased intracellular cAMP levels, increased the expression of the meiosis-specific genes ste11, mei2, and mam2, and facilitated sexual development in homothallic cells. However inhibition of vegetative cell growth and reduction of cAMP levels were not observed in a deletion mutant of the heterotrimeric G protein Galpha2 gene, gpa2, that is responsible for regulating intracellular cAMP levels, a key factor in determining the sexual development in S. pombe. Stm1 protein was shown to interact with Gpa2 through its C-terminal transmembrane domains 5-7. Mutation at Lys(199) in the C-terminal domain (stm1(K199A)) abolished the Stm1 overexpression effect on lowering cAMP levels. Induction of ste11, a meiosis-specific gene transcription factor, by Stm1 overexpression was enhanced in gpa2-deleted cells but was absent in a deletion mutant of sty1, a key protein kinase that links mitotic control with environmental signals and induces stress-responsive genes. Moreover, deletion of both stm1 and ras1 caused delayed entry into G(1) arrest in S. pombe when the cells were grown in a nitrogen-deficient medium. Thus we consider that the stm1 gene can function through Gpa2-dependent and/or -independent pathways and may play a role in providing the prerequisite state for entering the pheromone-dependent differentiation cycle in which heterotrimeric Galpha1 protein, Gpa1, and Ras1 play major roles. Stm1 could function as a sentinel molecule sensing the nutritional state of the cells, stopping the proliferative cell cycle, and preparing the cell to enter meiosis under nutritionally deficient conditions.

Random amplification of polymorphic DNA typing of Listeria monocytogenes isolated from meat

To investigate the epidemiological characteristics of Listeria monocytogenes isolated from imported or domestic meats, L. monocytogenes was isolated and identified through biochemical and serological tests, and epidemiological analysis of the isolates was carried out through the random amplification of polymorphic DNA (RAPD) method. Fifty-four isolates were identified as L. monocytogenes through biochemical tests, of which 36 (67%) were confirmed as serotype 1, and 18 (33%) were serotype 4, through the microagglutination test. In the molecular epidemiological analysis using RAPD method, the isolates could be classified into 10, 6 and 6 types using three random primers, PB1, PB4, and HLWL74, respectively. Forty composite profiles were identified by a combination of the three primers. RAPD analysis demonstrated the relationships between the isolates from beef from Korea and the USA, pork from Korea and Denmark. These results suggested that RAPD could be a useful typing tool for the epidemiological study of L. monocytogenes and other bacteria.

Application of nucleotide sequence of RNA polymerase beta-subunit gene (rpoB) to molecular differentiation of serovars of Salmonella enterica subsp. enterica

To establish a molecular differentiation method for Salmonella enterica subsp. enterica, a hyper-variable region of RNA polymerase beta-subunit (rpoB) of S. enterica subsp. enterica (I), serotype Typhimurium, and Escherichia coli were investigated through comparison of nucleotide sequence of the region. The hyper-variable region was identified at 612-937 of the gene. After PCR amplification of the region in the 17 serotypes and two biotypes of serotype Gallinarum of S. enterica subsp. enterica (I), the nucleotide sequences of the region were determined and compared. All serotypes were distantly related to E. coli with 82.8-84.7% identities in nucleotide sequence while showing 96.6-100% identities with each other. According to the phylogenetic analysis based on the sequenced region with the neighbor-joining method, relatedness of biotype Gallinarum to serotype Enteritidis and biotype Pullorum was determined. Biotype Gallinarum was more closely related to serotype Enteritidis than biotype Pullorum. These results suggested that the 612-937 variable region of rpoB might be useful for molecular evolutionary analysis of serotypes of S. enterica subsp. enterica (I).

Recurrent pyogenic cholangitis: comparison between MR cholangiography and direct cholangiography

PURPOSE

To compare the accuracy of magnetic resonance (MR) cholangiography with that of direct cholangiography for the evaluation of recurrent pyogenic cholangitis.

MATERIALS AND METHODS

Twenty-four patients with recurrent pyogenic cholangitis underwent MR cholangiography before surgery, and 18 of these 24 also underwent direct cholangiography. Two reviewers evaluated MR cholangiograms and direct cholangiograms and focused on identifying intrahepatic ductal dilatation, stricture, and calculi, as well as coexistent parenchymal abnormalities, on the basis of the classification of the internal lobes and segments of the liver. These observations were compared with surgical findings.

RESULTS

According to examination results in the surgical specimens, 24 patients had 46 segmental abnormalities. MR cholangiography depicted all 46 (100%) segments with ductal dilatation, 22 (96%) of 23 segments with focal ductal stricture, and 43 (98%) of 44 segments with ductal calculi. Eighteen patients who underwent direct cholangiography had 32 segmental abnormalities according to examination results in the surgical specimens. Direct cholangiography depicted 15 (47%) of 32 segments with ductal dilatation, eight (44%) of 18 segments with focal ductal stricture, and 14 (45%) of 31 segments with ductal calculi.

CONCLUSION

MR cholangiography is superior to direct cholangiography for accurate topographic evaluation of recurrent pyogenic cholangitis because it is able to depict all of the biliary tree, despite obstruction or stenosis.

Sphingolipid metabolic changes during chiral C2-ceramides induced apoptosis in human leukemia cells

N-acetylsphingosine (C2-ceramide) is a synthetic water-soluble ceramide mimicking the activity of natural ceramides. By fixing chiral conformation on carbon numbers 2 and 3 in the ceramide structure, four chiral C2-ceramides naming d-erythro-, l-erythro-, d-threo- and l-threo C2-ceramide were synthesized. We have investigated the chiral effects of these C2-ceramides on the sphingolipid metabolism, particularly on both the sphingolipid biosynthetic pathway and on the degradation pathway. In both HL-60 and U937 cells, the chiral C2-ceramide (10 microM) showed sphingosine accumulation monitored fluoromatrically by a high performance liquid chromatographic separation of the sphingoid bases. Most importantly, in HL-60 cells, l-erythro C2-ceramide induced a 50 fold increase in sphingosine as compared to the control, while l-threo C2-ceramide exhibited a minimal 7-fold increase. In contrast, sphinganine, another sphingoid base, showed less accumulation by any chiral C2-ceramide tested under the same conditions. These results suggested that chiral C2-ceramide primarily acts on the sphingolipid degradation pathway rather than on the sphingolipid biosynthetic route. The strong G0/G1 phase arrest in the cell cycle by treatment of l-erythro C2-ceramide indicates that the blockade of the sphingolipid degradation pathway might be concomitantly involved in the dysfunction of the cell cycle. On the other hand, the fact that all chiral C2-ceramides tested failed to inhibit the activity of sphingosine kinase acting on the removal of sphingosine by producing sphingosine-l-phosphate demonstrates that chiral C2- ceramides may increase sphingosine by activating various ceramidases by which natural ceramides are divided into sphingosine and free fatty acids. However, the precise steps involved in this interaction are still unknown.

Immunostimulatory effects of anionic alkali mineral complex solution Barodon in porcine lymphocytes

The anionic alkali mineral complex solution, Barodon (Barodon-S.F. Corp., Korea), was evaluated for its effectiveness as a nonspecific immunostimulator in pigs. The effects of Barodon were determined by analysis of feed efficiency, growth rate, and phenotype of leukocyte subpopulations using monoclonal antibodies specific to porcine leukocyte differentiation antigens and flow cytometry (FC). The study was focused to investigate the change in proportion of the CD4+CD8+ double positive T lymphocyte subpopulation (dpp) which exists uniquely in pigs. In addition, the mitogen-stimulated lymphoproliferative response, tissue distribution in lymphoid organs and the adjuvant effect of Barodon on hog cholera vaccine efficiency were determined. The study has revealed the average daily gain rates and feed conversion rates were significantly (p<0.05) improved in either group of pigs fed with 0.05% Barodon-spray feed (Tx-1) or pigs fed with 3% Barodon-fermented feed (Tx-2) in comparison with group of pigs fed with feed containing no Barodon (control). The proportion of cells expressing CD4+ antigen in Barodon-treated group increased from 3 weeks posttreatment and was significantly higher (p<0.05) than that of control at 8 weeks posttreatment. Particularly, the significantly higher proportion was maintained from 8 weeks through 13 weeks posttreatment in Tx-1 group (p<0.05). The proportion of cells expressing CD8+ antigen was significantly higher at 3 weeks posttreatment in Tx-2 (p<0.01). Proportion of MHC class II-expressing cells was significantly higher in Tx-1 and Tx-2 group at 11 weeks and 8 weeks posttreatment (p<0.05), respectively. In addition, the proportion of Non T/Non B (N) cells was also significantly higher in Tx-2 at 3 weeks posttreatment (p<0.01) and maintained to 13 weeks posttreatment (p<0.1). Between Barodon-treated groups, the proportion of MHC class II-expressing cells was observed to be larger in Tx-2 than Tx-1 from 3 weeks to 8 weeks posttreatment (p<0.05). However, there were no significant difference in the proportions of CD2+ cells, B cells, monocytes and granulocytes between Barodon-treated and control group during the experiment. Dual-color FC analysis, study has revealed an increased proportion of dpp present in lymphocytes obtained from peripheral blood (PB) and mesenteric lymph node (MLN) of Barodon-treated group at 8 and 11 weeks posttreatment. The proportion of dpp in PB was 27.5% and 32.1% in Tx-1 and Tx-2, respectively, but only 2.2% in control group at 8 weeks posttreatment. In MLN, the proportion was 45.1% and 52.1% in Tx-1 and Tx-2, respectively, otherwise 16.5% in control group at 8 weeks posttreatment. The mitogen-stimulated activity was significantly higher in Tx-1 than in the control group at 11 weeks posttreatment when cells were stimulated with Con A and PHA, respectively (p<0.01). Also, Con A-, PHA and PWM-stimulated activity was significantly higher in Tx-2 than in the control group at the same time (p<0.05). The tissue distribution of CD4+, CD8+ and CD4+CD8+ dpp in MLN and spleen was significantly larger in Tx-1 and Tx-2 than in the control group (p<0.01). Also, a larger proportion of dpp was observed in Tx-2 than Tx-1 in spleen between Barodon-treated groups (p<0.01). In conclusion, the study has demonstrated that Barodon had an immunostimulatory effect on pigs through proliferation and activation of porcine immune cells, specially CD4+CD8+ dpp lymphocytes.

Detection of canine distemper virus (CDV) through one step RT-PCR combined with nested PCR

A one step reverse transcription PCR (RT-PCR) combined nested PCR was set up to increase efficiency in the diagnosis of canine distemper virus (CDV) infection after developement of nested PCR. Two PCR primer sets were designed based on the sequence of nucleocapsid gene of CDV Onderstepoort strain. One-step RT-PCR with the outer primer pair was revealed to detect 10(2) PFU/ml. The sensitivity was increased hundredfold using the one-step RT-PCR combined with the nested PCR. Specificity of the PCR was also confirmed using other related canine virus and peripheral blood mononuclear cells (PBMC) and body secretes of healthy dogs. Of the 51 blood samples from dogs clinically suspected of CD, 45 samples were revealed as positive by one-step RT-PCR combined with nested PCR. However, only 15 samples were identified as positive with a single one step RT-PCR. Therefore approximately 60% increase in the efficiency of the diagnosis was observed by the combined method. These results suggested that one step RT-PCR combined with nested PCR could be a sensitive, specific, and practical method for diagnosis of CDV infection.

Differential effects of fumonisin B1 on cell death in cultured cells: the significance of the elevated sphinganine

Fumonisins are specific inhibitors of ceramide synthase in sphingolipid metabolism. An alteration in sphingolipid metabolism as a result of fumonisin exposure is related to cell death (Yoo et al., 1992). The objective of this study was to investigate whether elevated free sphinganine levels are related to the sensitivity of cultured cells to fumonisin exposure. Fumonisin B1 elevated the intracellular free sphinganine concentraions in both LLC-PK1 and Chinese hamster ovary (CHO) cells. However, CHO cells are resistant to fumonisin cytotoxicity at 50 microM, while LLC-PK1 cells are sensitive at concentrations greater than 35 microM. The intracellular concentration of free sphinganine in LLC-PK, cells treated at 50 microM fumonisin B1 for 72 h was approximately 1450 pmol/mg protein relative to the 37 pmol observed in the control culture. Under the same conditions, the population of apoptotic cells in the 50 M fumonisin B1-treated culture was approximately 37% of the total compared to 12% in the control. The caspase III-like activity after 72 h in the 50 microM fumonisin B1-exposed culture increased to approximately 50 pmol/mg protein/hr compared to 6 pmol/mg protein/hr in the control. L-cycloserine, a serine palmitoyltransferase inhibitor, reduced the fumonisin B1-stimulated caspase III-like activity down to the control level. Under the same culture conditions, the intracellular concentration of free sphinganine after L-cycloserine plus fumonisin B1 treatment was 140 pmol/mg protein compared to 1450 pmol/mg protein in fumonisin B1 alone. The intracellular concentration of free sphinganine in CHO cells treated with 50 microM fumonisin B1 for 72 h was approximately 460 pmol/mg protein, indicating that the mass amount of elevated free sphinganine in the CHO cells was about 32% of that in LLC-PK1 cells. Adding exogenous sphinganine to the CHO cells along with 50 microM fumonisin B1 treatment for 72 h caused both necrosis and apoptosis. In conclusion, the elevated endogenous sphinganine acts as a contributing factor to the fumonisin-induced cell death.

Rkp1/Cpc2, a fission yeast RACK1 homolog, is involved in actin cytoskeleton organization through protein kinase C, Pck2, signaling

The Rkp1/Cpc2, a fission yeast RACK1 homolog, interacted with Pck2, one of the known PKC homologs, in vivo and in vitro. The rkp1-deletion mutants (Deltarkp1) are elongated and the pck2-deletion mutant (Deltapck2) showed abnormal morphology. The double-deletion mutant (Deltarkp1Deltapck2) showed more aberrant cell shapes and was sensitive to high salt concentration. Both Deltarkp1 and Deltapck2 cells were sensitive to latrunculin B (Lat B) which inhibits actin polymerization. The cells expressing the human RACK1 homolog complemented the latrunculin B sensitivity of Deltarkp1 indicating that human RACK1 is a functional homolog of Rkp1/Cpc2. We propose that Rkp1/Cpc2 may function as a receptor for Pck2 in the regulation of actin cytoskeleton organization during cell wall synthesis and morphogenesis of Schizosaccharomyces pombe.

Radionuclide cisternography in spontaneous intracranial hypotension with simultaneous leaks at the cervicothoracic and lumbar levels

This case report clearly illustrates defined simultaneous cerebrospinal fluid leaks at the cervicothoracic and upper lumbar areas. A 53-year-old woman without a remarkable medical history was hospitalized for sudden onset of severe headache. The headache lasted more than 1 week and standing or sitting positions exaggerated the symptoms, although it was relieved when the patient was recumbent. Radionuclide cisternography was performed using 150 MBq (4 mCi) Tc-99m DTPA. It revealed two cerebrospinal fluid leaks from the cervicothoracic junction bilaterally and the left side of the upper lumbar area. Epidural blood patching was tried at the lumbar level (L1-L2) and showed only a transient effect. A second trial of this method at the level of C7-T1 performed 2 days later resulted in immediate improvement of the symptoms without recurrence. The simultaneous cerebrospinal fluid leaks were detected successfully with radionuclide cisternography using Tc-99m DTPA, which provided a useful guideline for treatment despite the limitations of delayed scanning.

Protein-fatty acid complex for enhanced loading and stability within biodegradable nanoparticles

Lysozyme was hydrophobically modified with a fatty acid, sodium oleate, via an ion-pairing mechanism. Ionic binding between an anionic carboxylic group of sodium oleate and basic amino groups in lysozyme was primarily utilized to form lysozyme-oleate complex. The complex formation was pH dependent. The lysozyme-oleate complex dissolved in an organic solvent exhibited much higher conformational stability at elevated temperature compared with free lysozyme in the same solvent. The complex was formulated into biodegradable nanoparticles by a spontaneous emulsion and solvent diffusion method. The resultant formulation showed near 100% encapsulation efficiency of lysozyme within nanoparticles with < 100 nm in diameter with a narrow size distribution. Lysozyme could be loaded into the nanoparticles up to 18.6% (w/w) with concomitantly increased particle sizes. This study demonstrates a new formulation method of biodegradable nanoparticles with highly efficient encapsulation of proteins, which are potentially useful for oral protein delivery including mucosal vaccination.

Biodegradable polymeric micelles composed of doxorubicin conjugated PLGA-PEG block copolymer

Biodegradable polymeric micelles containing doxorubicin in the core region were prepared from a di-block copolymer composed of doxorubicin-conjugated poly(DL-lactic-co-glycolic acid) (PLGA) and polyethyleneglycol (PEG). The di-block copolymer of PLGA-PEG was first synthesized and the primary amino group of doxorubicin was then conjugated to the terminal hydroxyl group of PLGA, which had been pre-activated using p-nitrophenyl chloroformate. The resulting polymeric micelles in aqueous solution were characterized by measurement of size, drug loading, and critical micelle concentration. The micelles containing chemically-conjugated doxorubicin exhibited a more sustained release profile than PEG-PLGA micelles containing physically-entrapped doxorubicin. The cytotoxic activity of the micelles against HepG2 cells was greater than free doxorubicin, suggesting that the micelles containing conjugated doxorubicin were more effectively taken up cellularly, by an endocytosis mechanism rather than by passive diffusion. Confocal microscopic observation and flow cytometry analysis supported the enhanced cellular uptake of the micelles.

Effect of enrofloxacin-Na against pathogens related to the respiratory and alimentary diseases in suckling and weanling piglets

A field trial was conducted to evaluate effect of enrofloxacin-Na against pathogens related to the respiratory and alimentary diseases in eighty suckling piglets (6-7 days old) and eighty weanling piglets (5-6 weeks old). Respective twenty of the suckling and weanling piglets were assigned to each of 4 experimental groups; control (non-treated), clinical injection dose (CID), 2x clinical injection dose (2CID). and premix. A 0.05 ml (2.5 mg) of enrofloxacin-Na injection (5% solution, 1 ml) per kg body weight of piglets as CID was injected intramuscularly for 3 days and the clinical signs were observed for 9 days. The premix (150 ppm) of enrofloxacin-Na was administered with feed for 7 days ad libitum and the clinical signs were observed for 13 days. The enrofloxacin-Na-treated piglets showed a higher increase in body weight and a lower feed per gain than the control piglets. In addition, the treatment of enrofloxacin-Na, regardless of the route of administration, decreased the incidence rate of diarrhea in suckling piglets and respiratory symptoms in weanling piglets. The isolation index of E. coli and Cl. perfringens during the treatment periods was also lowered by the enrofloxacin-Na treatment in both suckling and weanling piglets. The antibiotics was also evaluated as safe locally and whole bodily as treated by injection or feeding. These results indicate that the newly developed antibiotics, enrofloxacin-Na, is very useful for the prevention and therapy of swine diseases in the pig industry.

Nontumorous hepatic arterial-portal venous shunts: MR imaging findings

PURPOSE

To determine the magnetic resonance (MR) imaging findings of small nontumorous hepatic arterial-portal venous (arterioportal) shunts in the liver.

MATERIALS AND METHODS

MR images in 25 patients with 38 small nontumorous arterioportal shunts verified with surgery or follow-up imaging were included in this study. The causes of arterioportal shunts were iatrogenic causes in 11 patients and/or cirrhotic changes in the remaining patients. Nonenhanced T1- and T2-weighted images and multiphase contrast material-enhanced dynamic images were retrospectively reviewed and compared with conventional hepatic arteriograms to determine the MR characteristics related to the focal hemodynamic changes.

RESULTS

On arterial-dominant-phase dynamic MR images, 29 (76%) of the 38 arteriographically suggested nontumorous arterioportal shunts displayed abnormal findings distinguished against the surrounding hepatic parenchyma, including wedge-shaped (n = 14), nodular (n = 9), or irregularly outlined (n = 6) areas of focal contrast enhancement. The signal intensity on nonenhanced T1- and T2-weighted images of the corresponding areas appeared unremarkable except for three wedge-shaped high-signal-intensity areas (three [8%] of 38) on T2-weighted images accompanied by prolonged contrast enhancement. Most (24 [83%] of 29) areas of abnormal signal intensity were located at the periphery of the liver parenchyma.

CONCLUSION

A small nontumorous arterioportal shunt should be considered one of the causes of focal parenchymal hyperperfusion abnormalities on contrast-enhanced dynamic MR images of the liver in the absence of abnormal signal intensity on static MR images.

Evaluation of expression patterns of feline CD28 and CTLA-4 in feline immunodeficiency virus (FIV)-infected and FIV antigen-induced PBMC

It is known that CD28, a positive costimulatory receptor, plays a very important role in inducing the optimal stimulation of T lymphocytes. CTLA-4 (CD152), however, acts as a negative regulator in T lymphocyte activation. The effect of an feline immunodeficiency virus (FIV) infection on the expression of feline CD28 and CTLA-4 was studied with FIV-infected and uninfected peripheral blood mononuclear cells (PBMC) using a competitive PCR assay. The nature of CD28 and CTLA-4 expression was also examined with fresh and antigen-stimulated PBMC. FIV infection induced a lower expression of CD28, but a higher expression of CTLA-4 in the infected PBMC than in the uninfected PBMC. Relatively high levels of CD28 expression were demonstrated in both the fresh and the antigen-stimulated PBMC. The expression level of CTLA-4 in the freshly isolated PBMC was rather low, however, FIV antigen stimulation induced a relatively high expression of CTLA-4 in feline PBMC.

Regulation of phospholipase D2 by H(2)O(2) in PC12 cells

Phospholipase D2 (PLD2) is expressed in brain and inhibited by synuclein, which is involved in Parkinson's and Alzheimer's diseases. However, the activation mechanism of PLD2 in neuronal cells has not been defined clearly. Hydrogen peroxide (H(2)O(2)) plays roles in the neurodegenerative diseases and also acts as a second messenger of various molecules such as nerve growth factor. To study regulation mechanisms of PLD2 by H(2)O(2) in neuronal cells, we have made stable PC12 cell lines expressing PLD2 (PLD2-PC12 cells). H(2)O(2) treatment stimulated PLD activity in PLD2-PC12 cells in a dose- and time-dependent manner. This activation was inhibited by the treatment with protein kinase C (PKC) inhibitors or by depletion of PKCalpha, -delta, and -epsilon. Phorbol ester markedly activated PLD2. Co-treatment with phorbol ester and H(2)O(2) did not show an additive effect. Chelation of extracellular calcium substantially blocked the H(2)O(2)-induced activation of PLD2. A calcium ionophore induced PLD2 activation in a PKC-dependent manner. Protein-tyrosine kinase inhibitors inhibited H(2)O(2)-induced PLD activation slightly. These data indicate that H(2)O(2) can activate PLD2 in PC12 cells and that this activation is largely dependent on PKC and Ca(2+) ions and minimally dependent on tyrosine phosphorylation.

Gene expression profile and identification of differentially expressed transcripts during human intrathymic T-cell development by cDNA sequencing analysis

The development of immature thymocytes to mature T-lymphocytes is a central process for establishing a functional immune system. The gene regulatory events involved in this process are of outstanding interest in understanding the generation of the T-cell repertoire as well as the differentiation of lineage-specific cells, such as CD4(+) helper T-cells or CD8(+) cytotoxic T-lymphocytes. While some essential genes involved in lineage decision and thymocyte differentiation have been already identified, the exact regulatory mechanisms and differential gene expressions are still unknown. The present study was performed to analyze the gene expression profile during T-cell development, in particular, during the differentiation of immature thymocytes into CD4(+) mature T-cells by analyses of expressed sequence tags (ESTs), and to elucidate novel human genes involved in this process. Based on distinct developmental stages, three PCR-based cDNA libraries from immature CD3(-),4(-),8(-) triple-negative, CD4(+),8(+) double-positive, and mature CD4(+),8(-) single-positive thymocytes were constructed. A total of 1477 randomly selected clones were analyzed by automated single-pass sequencing, and the assembly of ESTs resulted in 1027 different species of contig sequences. Among them, 392 contig sequences were matched to known genes, and several novel transcripts were discovered. The matched clones were classified into seven categories according to their functional aspects, and the gene expression profiles of the three thymocyte subsets were compared. The information obtained in current study will serve as a valuable resource for elucidating the molecular mechanism of intrathymic T-cell development.

Abdominal tuberculous lymphadenopathy: MR imaging findings

BACKGROUND

The purpose of this study was to evaluate the utility of magnetic resonance imaging (MRI) as a diagnostic tool in abdominal tuberculous lymphadenopathy.

METHODS

MRI studies of 11 patients with histologically proven abdominal tuberculous lymphadenopathy were reviewed with regard to anatomic distribution, size, shape, degree, and pattern of enhancement and relation of the lesions to adjacent structures.

RESULTS

The most common site of involvement was the periportal area (n = 6), followed by the peripancreatic (n = 5), mesenteric (n = 1), and paraaortic (n = 1) areas. Eight patients were readily diagnosed as having tuberculous lymphadenopathy on abdominal computed tomography. Three patients had a heterogeneously enhancing masslike lesion adjacent to the pancreas and were initially diagnosed as having cystic tumor of the pancreas. On MRI, 11 lesions showed T1 iso- or hypointensity and central T2 hyperintensity. Two lesions showed T1 iso- or hypointensity and central T2 hypointensity. The lesions with different T2 signal intensities showed different patterns of enhancement on contrast-enhanced dynamic studies. The relations between the enlarged lymph nodes and adjacent bile ducts or vascular structures were well depicted on MRI.

CONCLUSION

MRI was useful in differentiating enlarged lymph nodes abutting the pancreas initially diagnosed as cystic neoplasms on abdominal computed tomography.

Antithrombotic and antiplatelet activities of 2-chloro-3-[4-(ethylcarboxy)-phenyl]-amino-1,4-naphthoquinone (NQ12), a newly synthesized 1,4-naphthoquinone derivative

The possibility of NQ12 (2-chloro-3-[4-(ethylcarboxy)-phenyl]-amino-1,4-naphthoquinone) as a novel antithrombotic agent and its mode of action were investigated. The effects of NQ12 on platelet aggregation in human platelet-rich plasma in vitro, in rats ex vivo, and on murine pulmonary thrombosis in vivo, as well as the mode of antithrombotic action were examined. NQ12 potently inhibited ADP-, collagen-, epinephrine-, and calcium ionophore-induced human platelet aggregations in vitro concentration-dependently. NQ12 significantly inhibited rat platelet aggregation in an ex vivo study. NQ12 prevented murine pulmonary thrombosis in a dose-dependent manner. However, NQ12 did not affect coagulation parameters such as activated partial thromboplastin time, prothrombin time, and thrombin time. NQ12 inhibited fibrinogen binding to the platelet surface GPIIb/IIIa receptor, but failed to inhibit binding to the purified GPIIb/IIIa receptor. Thromboxane B(2) formation caused by thrombin or collagen was inhibited significantly by NQ12. The phosphoinositide breakdown induced by thrombin or collagen was inhibited concentration-dependently by NQ12. These results suggest that NQ12 may be a promising antithrombotic agent, and its antithrombotic activity may be due to antiplatelet aggregation activity, which may result from the inhibition of phosphoinositide breakdown and thromboxane A(2) formation.