Extra-articular pigmented villonodular synovitis of the temporomandibular joint: case report and review of the literature

Pigmented villonodular synovitis (PVNS) is a benign proliferative disorder of the synovial tissue, that usually affects the knee, ankle and other major joints. Involvement of the temporomandibular joint is, however, very rare. We describe a new case of recurrent PVNS arising from the temporomandibular joint that was classified as diffuse extra-articular type and was successfully treated surgically. The etiology and clinical features of PVNS are discussed and the previously reported cases in the literature are reviewed.

Lysozyme microencapsulation within biodegradable PLGA microspheres: urea effect on protein release and stability

Lysozyme was encapsulated within biodegradable poly(D, L-lactide-co-glycolide) microspheres by a double emulsion solvent evaporation method for studying its release mechanism associated with protein stability problems. When urea, a protein unfolding agent, was added into the incubation medium lysozyme release rate from the microspheres increased with the increase in urea concentration. The enhanced lysozyme release was attributed to the suppression of protein aggregation, to the facilitated diffusion of unfolded lysozyme by an efficient reptile motion of unfolded protein molecules through porous channels in microspheres, and to the largely decreased extent of nonspecific protein adsorption onto the enlarged surface area of degrading polymer microspheres in the presence of urea. Encapsulating lysozyme in an unfolded form within PLGA microspheres was attempted by using urea as an excipient. This new urea-based formulation exhibited a more sustained lysozyme release profile than the control formulation, and released lysozyme from the microspheres showed a much less amount of lysozyme dimer population while maintaining a correct conformation after refolding in the incubation medium. This study provides new insights for the formulation of protein encapsulated PLGA microspheres.

Inhibition of tumor necrosis factor-alpha-induced apoptosis by Asparagus cochinchinensis in Hep G2 cells

A human hepatoma cell line, Hep G2 cells, is a reliable system for the study of alcohol-induced hepatotoxicity. In this study, we investigated the effect of an aqueous extract of Asparagus cochinchinensis(MERRIL) (Liliaceae) roots (ACAE) on ethanol (EtOH)-induced cytotoxicity in Hep G2 cells. ACAE (1-100 microg/ml) dose-dependently inhibited the EtOH-induced tumor necrosis factor-alpha (TNF-alpha) secretion. ACAE (1-100 microg/ml) also inhibited the EtOH and TNF-alpha-induced cytotoxicity. Furthermore, we found that ACAE inhibited the TNF-alpha-induced apoptosis of Hep G2 cells. These results suggest that ACAE may prevent the EtOH-induced cytotoxicity through inhibition of the apoptosis of Hep G2 cells.

Leukemic cell line, KG-1 has a functional loss of hOGG1 enzyme due to a point mutation and 8-hydroxydeoxyguanosine can kill KG-1

We tested the cytotoxic action of 8-hydroxyguanine (8ohG) by observing the viability of several leukemic cell lines (KG-1, U937, Jurkat and K 562) in the presence of 8-hydroxydeoxyguanosine (8ohdG), a nucleoside of 8ohG. It was found that 8ohdG showed cytotoxic action only to KG-1 and that only KG-1 showed a homozygous arginine 209 to glutamine mutation in the hOGG1 gene with an almost negligible hOGG1 enzyme activity. Possibly, the selective cytotoxicity in 8ohdG to KG-1 may be due to its low capacity to cope with an increase in the 8ohG level in DNA resulting from the incorporation of 8ohdG present in the culture media. The mutational impairment of hOGG1 in KG-1 is the first report in leukemic cell lines. Using KG-1 with impaired hOGG1, we demonstrated cytotoxicity of 8ohdG probably due to its incorporation into cellular DNA. This new property of KG-1 may allow it to serve as an useful tool for studies of OGG1, oxidative DNA damage and the cytotoxic action of 8ohG. Oncogene (2000) 19, 4476 - 4479.

Efficacy of MRI in complicated congenital heart disease with visceral heterotaxy syndrome

PURPOSE

The authors' goal was to assess the diagnostic accuracy and clinical effect of MRI compared with echocardiography and catheterization in the evaluation of cardiac defects with situs ambiguous.

METHOD

Twenty-two patients with visceral heterotaxy syndrome were included.

RESULTS

Because situs determined by the relation between the pulmonary artery and bronchi showed most predominantly a tendency toward lateralization, this was regarded as the standard reference of situs determination. For the purpose of this study, patients were classified as having right isomerism (n = 13) or left isomerism groups (n = 9). MRI has several advantages compared with echocardiography or cardiac angiography for examining patients with situs ambiguous. (1) The bronchial, pulmonary arterial, and splenic situs can be readily determined, and discrepancies (n = 2) can be assessed easily. (2) Venoatrial connections are adequately imaged. In particular, all types of total and partial anomalous pulmonary venous return are delineated, regardless of whether restrictions of pulmonary blood flow or pulmonary venous obstructions are involved (n = 4). The courses of vertical veins were easily identified, and the prearterial position was revealed in only one of seven right isomerisms with total anomalous pulmonary venous return. The drain pattern of the hepatic vein can be visualized using three-dimensional spatial information and is useful for total cavopulmonary connection design. (3) Associated complicated cardiac anomalies, particularly the size or peripheral stenosis of the pulmonary arteries, may be evaluated, and this information is useful for palliative shunt operations.

CONCLUSION

Because of its wide field of view and imaging, which is not restricted by associated anomalies, a thorough understanding of the cardiovascular anatomy of the situs ambiguous can be achieved using MRI, which is of considerable value in the surgical correction of this complicated anomaly. MRI can obviate or facilitate catheterization in these critically ill patients.

Transcriptional autoregulation of the bone related CBFA1/RUNX2 gene

The runt related transcription factor CBFA1 (AML3/PEBP2alphaA/RUNX2) regulates expression of several bone- and cartilage-related genes and is required for bone formation in vivo. The gene regulatory mechanisms that control activation and repression of CBFA1 gene transcription during osteoblast differentiation and skeletal development are essential for proper execution of the osteogenic program. We have therefore defined functional contributions of 5' regulatory sequences conserved in rat, mouse and human CBFA1 genes to transcription. Deletion analysis reveals that 0.6 kB of the bone-related rat or mouse CBFA1 promoter (P1, MASNS protein isoform) is sufficient to confer transcriptional activation, and that there are multiple promoter domains which positively and negatively regulate transcription. Progressive deletion of promoter segments between nt -351 and -92 causes a striking 30- to 100-fold combined decrease in promoter activity. Additionally, 5' UTR sequences repress reporter gene transcription 2- to 3-fold. Our data demonstrate that CBFA1 is a principal DNA binding protein interacting with the 5' region of the CBFA1 gene in osseous cells, that there are at least three CBFA1 recognition motifs in the rat CBFA1 promoter, and that there are three tandemly repeated CBFA1 sites within the 5' UTR. We find that forced expression of CBFA1 protein downregulates CBFA1 promoter activity and that a single CBFA1 site is sufficient for transcriptional autosuppression. Thus, our data indicate that the CBFA1 gene is autoregulated in part by negative feedback on its own promoter to stringently control CBFA1 gene expression and function during bone formation.

Phylogenetic analysis of a retroposon family as represented on the human X chromosome

SINE-R elements constitute a class of retroposons derived from the long terminal repeat (LTR) of the human endogenous retrovirus HERV-K family that are present in hominoid primates and active in the human genome. In an investigation of the X chromosome, we identified twenty-five SINE-R elements with between 89.6 and 97.7% homology with the SINE-R.C2 element that is human specific, originally identified in the gene for the C2 component of complement. SINE-R.C2 and a sequence HS307 that we previously identified in a region of Xq21.3 that has a recently created homology with a 4 Mb block in Yp11.2 are amongst the group of elements that have diverged furthest from the parent HERV-K10 sequence. The sequence on the X chromosome resemble those that we previously described on chromosomes 7 and 17 and the Y chromosome, with a similar range of variation. Phylogenetic analysis from the retroposon family including those of African great apes using the neighbor-joining method suggests that the SINE-R retroposon family have evolved independently during primate evolution. Further investigation of SINE-R elements on the sex chromosomes, particularly in recently created regions of X-Y homology, may cast light on the timing of the retroposition process and its possible relevance to recent evolutionary change.

Magnetic resonance imaging of unroofed coronary sinus: three cases

Unroofed coronary sinus is a rare cardiac anomaly in which communication occurs between the coronary sinus and the left atrium due to the partial or complete absence of the roof of the coronary sinus. It is usually associated with other cardiovascular anomalies, especially persistent left superior vena cava. It is often not discovered during cardiac catheterization without clinical suspicion. We report three cases of unroofed coronary sinus which were incidentally detected by magnetic resonance imaging.

Vasoconstrictive eicosanoid responses to extracorporeal circulation with or without an oxygenator in fetal lambs

INTRODUCTION

This study measured levels of vasoconstrictive eicosanoids during ovine fetal cardiac bypass and compared the measurements between two groups: (1) a group in which the placenta functioned as the only source of oxygen supply during the bypass (the placenta group), and (2) a group in which an artificial oxygenator, instead of the placenta, was included in the bypass circuit (the oxygenator group).

MATERIALS AND METHODS

A total of 16 fetal lambs were randomly assigned into either the oxygenator group or the placenta group. Following anesthesia, the fetal cardiac bypass procedure was performed. The placenta group used a centrifugal pump as the pumping device without an oxygenator during the bypass. The bypass circuit in the oxygenator group consisted of a roller pump and a membrane oxygenator. The fetal cardiac bypass procedure was performed for 30 minutes at normothermia in both groups. For the measurements of thromboxane B2(TXB2) and prostaglandin E2 (PGE2), blood samples were taken before the bypass, at 5 minutes, 15 minutes, and 30 minutes after the start of cardiac bypass, and at 15 minutes after weaning from the bypass. TXB2 and PGE2 levels were determined by radioimmunoassay with PGE2(125I) and TXB2(125I) assay systems. Hemodynamic observations and arterial blood gas analyses were done every 10 minutes.

RESULTS

The mean arterial pressure and heart rate ranged from 69.8 to 82.6 mmHg and 169 to 182/min during the bypass in the oxygenator group, and from 14.4 to 44.7 mmHg and 64.3 to 75/min in the placenta group. Arterial blood gas analysis showed severe hypercapnia and hypoxemia with acidosis during and after the bypass in the placenta group. Bypass flow rates were maintained at 140.3-164.0 ml/kg/min in the oxygenator group, while flow rates were suboptimal (74.3-97.0 ml/kg/min) in the placenta group. There were no statistically significant differences in PGE2 concentrations before, during, or after bypass, although the placenta group displayed a tendency to higher measurements during bypass, compared to the oxygenator group. The placenta group also showed higher TXB2 measurements than the oxygenator group during the bypass (p = 0.0457).

CONCLUSIONS

We have demonstrated increase measurements of PGE2 and TXB2 in the placenta group when compared with the oxygenator group in an ovine fetal cardiac bypass model, although the PGE2 difference failed to reach statistical significance.

Groucho/TLE/R-esp proteins associate with the nuclear matrix and repress RUNX (CBF(alpha)/AML/PEBP2(alpha)) dependent activation of tissue-specific gene transcription

The Runt related transcription factors RUNX (AML/CBF(alpha)/PEBP2(alpha)) are key regulators of hematopoiesis and osteogenesis. Using co-transfection experiments with four natural promoters, including those of the osteocalcin (OC), multi drug resistance (MDR), Rous Sarcoma Virus long terminal repeat (LTR), and bone sialoprotein (BSP) genes, we show that each of these promoters responds differently to the forced expression of RUNX proteins. However, the three RUNX subtypes (i.e. AML1, AML2, and AML3) regulate each promoter in a similar manner. Although the OC promoter is activated in a C terminus dependent manner, the MDR, LTR and BSP promoters are repressed by three distinct mechanisms, either independent of or involving the AML C terminus, or requiring only the conserved C-terminal pentapeptide VWRPY. Using yeast two hybrid assays we find that the C terminus of AML1 interacts with a Groucho/TLE/R-esp repressor protein. Co-expression assays reveal that TLE proteins repress AML dependent activation of OC gene transcription. Western and northern blot analyses suggest that TLE expression is regulated reciprocally with the levels of OC gene expression during osteoblast differentiation. Digital immunofluorescence microscopy results show that TLE1 and TLE2 are both associated with the nuclear matrix, and that a significant subset of each colocalizes with AML transcription factors. This co-localization of TLE and AML proteins is lost upon removing the C terminus of AML family members. Our findings indicate that suppression of AML-dependent gene activation by TLE proteins involves functional interactions with the C terminus of AML at the nuclear matrix in situ. Our data are consistent with the concept that the C termini of AML proteins support activation or repression of cell-type specific genes depending on the regulatory organization of the target promoter and subnuclear localization.

Asymmetric synthesis of 1,2-amino alcohols using (S)-indoline chiral auxiliary

Chiral hydrazones 1 reacted with aryl- or alkyl-lithiums at -78 degrees C in a short reaction time, within 10 min, to afford arylated or alkylated chiral hydrazines 3 with extremely high diastereoselectivity (up to >99% de) and high chemical yields. The hydrazines are readily converted to chiral amino alcohols 4.

Na(+)-dependent transporters mediate HCO(3)(-) salvage across the luminal membrane of the main pancreatic duct

To study the roles of Na(+)-dependent H(+) transporters, we characterized H(+) efflux mechanisms in the pancreatic duct in wild-type, NHE2(-/-), and NHE3(-/-) mice. The pancreatic duct expresses NHE1 in the basolateral membrane, and NHE2 and NHE3 in the luminal membrane, but does not contain NHE4 or NHE5. Basolateral Na(+)-dependent H(+) efflux in the microperfused duct was inhibited by 1.5 microM of the amiloride analogue HOE 694, consistent with expression of NHE1, whereas the luminal activity required 50 microM HOE 694 for effective inhibition, suggesting that the efflux might be mediated by NHE2. However, disruption of NHE2 had no effect on luminal transport, while disruption of the NHE3 gene reduced luminal Na(+)-dependent H(+) efflux by approximately 45%. Notably, the remaining luminal Na(+)-dependent H(+) efflux in ducts from NHE3(-/-) mice was inhibited by 50 microM HOE 694. Hence, approximately 55% of luminal H(+) efflux (or HCO(3)(-) influx) in the pancreatic duct is mediated by a novel, HOE 694-sensitive, Na(+)-dependent mechanism. H(+) transport by NHE3 and the novel transporter is inhibited by cAMP, albeit to different extents. We propose that multiple Na(+)-dependent mechanisms in the luminal membrane of the pancreatic duct absorb Na(+) and HCO(3)(-) to produce a pancreatic juice that is poor in HCO(3)(-) and rich in Cl(-) during basal secretion. Inhibition of the transporters during stimulated secretion aids in producing the HCO(3)(-)-rich pancreatic juice.

Microsatellite instability and mutations of E2F-4 in hepatocellular carcinoma from Korea

It has been suggested that genetic changes in cancers are related to genomic instability. To evaluate a possible correlation between growth-regulatory genes and genomic instability in HCC, we investigated microsatellite instability and mutations of TGF-beta type II receptor (TGF-beta RII) and E2F-4 genes in each pair of tumor and surrounding nontumor liver tissues, collected from 19 patients with HCC. By the identification of mutations in six different genetic loci (D1S170, D2S123, D4S395, D13S126, D13S260, and D16S402), one or more alterations in microsatellite markers were identified in 13/19 (68%) hepatocellular carcinoma specimens. When two repeated sequences of TGF-beta RII gene, poly(A)(10) tract in exon 8 and poly(GT)(3) tract in exon 9, were analyzed by polymerase chain reaction-single strand conformational polymorphism, none of the 19 hepatocellular carcinoma specimens showed mutations. When amplicons of poly(AGC)(13) tract of E2F-4 were analyzed by cloning and automated sequencing, 5/19 (36%) hepatocellular carcinomas showed deletion mutation in one or two AGC repeats and such mutations were identified only among cases with microsatellite instability. These results suggest that both microsatellite instability and mutations of E2F-4 occur commonly in hepatocellular carcinoma and play an important role in hepatocarcinogenesis.

Improved detection of individual nodal involvement in squamous cell carcinoma of the esophagus by FDG PET

Because both the number and location of metastatic lymph nodes and the N stage influence survival in esophageal cancer, accurate noninvasive evaluation of individual lymph node groups for the presence of metastasis is essential for therapeutic planning. Therefore, we investigated the accuracy of FDG PET for evaluating individual lymph groups in esophageal cancer patients and compared the results with those of CT and endoscopic sonography (ES).

METHODS

Sixty-one consecutive patients with histologically proven primary esophageal carcinoma were studied prospectively with FDG PET. Thirteen patients who were treated nonsurgically were excluded from data analysis. The remaining 48 patients underwent esophagectomy and lymph node dissection. All 48 patients underwent CT scanning, including the lower neck, thorax, and upper abdomen, with intravenous administration of contrast medium. ES was performed in 45 of the patients but was incomplete in 12 patients because of esophageal stenosis. The accuracies of FDG PET, CT, and ES were compared with histologic findings.

RESULTS

During surgery, a total of 382 lymph node groups were dissected in 48 patients, of which 100 node groups in 32 patients were malignant on histologic examination. For assessing metastasis to individual groups, FDG PET showed 57% sensitivity, 97% specificity, and 86% accuracy, whereas CT showed 18% sensitivity (P < 0.0001), 99% specificity (P = 0.033), and 78% accuracy (P = 0.003). For N staging, FDG PET was correct in 83% (40/48) of the patients, whereas CT and ES were correct in 60% (29/48; P = 0.006) and 58% (26/45; P = 0.003), respectively.

CONCLUSION

FDG PET is more accurate than is CT or ES for evaluating metastasis to individual lymph node groups and for N staging in esophageal cancer and thus may be helpful in determining the therapeutic plan.

Novel amiloride-sensitive sodium-dependent proton secretion in the mouse proximal convoluted tubule

The proximal convoluted tubule (PCT) reabsorbs most of the filtered bicarbonate. Proton secretion is believed to be mediated predominantly by an apical membrane Na(+)/H(+) exchanger (NHE). Several NHE isoforms have been cloned, but only NHE3 and NHE2 are known to be present on the apical membrane of the PCT. Here we examined apical membrane PCT sodium-dependent proton secretion of wild-type (NHE3(+/+)/NHE2(+/+)), NHE3(-/-), NHE2(-/-), and double-knockout NHE3(-/-)/NHE2(-/-) mice to determine their relative contribution to luminal proton secretion. NHE2(-/-) and wild-type mice had comparable rates of sodium-dependent proton secretion. Sodium-dependent proton secretion in NHE3(-/-) mice was approximately 50% that of wild-type mice. The residual sodium-dependent proton secretion was inhibited by 100 microM 5-(N-ethyl-N-isopropyl) amiloride (EIPA). Luminal sodium-dependent proton secretion was the same in NHE3(-/-)/NHE2(-/-) as in NHE3(-/-) mice. These data point to a previously unrecognized Na(+)-dependent EIPA-sensitive proton secretory mechanism in the proximal tubule that may play an important role in acid-base homeostasis.

High-level expression of canine parvovirus VP2 using Bombyx mori nucleopolyhedrovirus vector

For the potential use as recombinant vaccine, canine parvovirus (CPV) major capsid protein VP2 was expressed using Bombyx mori nucleopolyhedrovirus (BmNPV) vector. CPV VP2 gene was introduced into polyhedrin-based BmNPV transfer vector pBmKSK3, and recombinant virus BmK1-Parvo was prepared. When anti-CPV.VP2 monoclonal antibody was employed in immunofluorescence staining, an intense signal was observed within BmK1-Parvo-infected Bm5 cells but not within uninfected cells or cells infected with a wild-type BmNPV-K1. In hemagglutination assay, the expression level of VP2 were 3.2 x 10(3) HA units/ml from infected Bm5 cells, 2.1x 10(5) HA units/larvae from infected larval fat body, and 1.6x 10(6) HA units/ml from infected larval hemolymph. These results suggested that BmNPV vector system using B. mori larva as host could be applied to efficient mass-production of recombinant vaccines.

Focal cortical dysplasia: comparison of MRI and FDG-PET

PURPOSE

The purpose of this work was to compare the use of MRI and [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) in the diagnosis of focal cortical dysplasia (FCD).

METHOD

Nineteen patients with surgically proven FCD were analyzed retrospectively. MRI was performed in all patients, and FDG-PET was performed in 17 patients. We compared the MR and FDG-PET findings of FCD according to the histologic findings that were classified into three grades.

RESULTS

Four cases were classified as Grade I, 4 cases as Grade II, and 11 cases as Grade III FCD. The lesions were detected on MRI in 9 (82%) of the 11 patients with Grade III FCD and in only 1 (13%) of the 8 patients with Grade I and II FCD. Cortical hypometabolism of the lesion was revealed on FDG-PET in 6 (86%) of the 7 patients with Grade I and II FCD and in 9 (90%) of the 10 patients with Grade III FCD. The extent of the cortical abnormality was larger on FDG-PET than on MRI in 11 (65%) of the 17 patients.

CONCLUSION

FDG-PET is more useful in delineating the cortical abnormality in patients with mild degrees of FCD. The extent of the lesion was larger or similar on FDG-PET compared with that of the MRI.

A case of Goodpasture's syndrome with massive pulmonary hemorrhage

We present a typical case of Goodpasture's syndrome with massive pulmonary hemorrhage and acute deterioration of renal function. A 20-year-old male was admitted due to severe azotemia (blood urea nitrogen 214.7 mg/dL, serum creatinine 30.2 mg/dL) and was treated with emergency hemodialysis. On the 4th hospital day, a sudden onset of pulmonary hemorrhage developed. The circulating level of anti-glomerular basement membrane antibody was then elevated highly, and the kidney biopsy showed crescentic glomerulonephritis and linear deposition of IgG along the glomerular capillary. The patient was treated with intravenous high dose-steroid, oral cyclophosphamide and plasma exchanges. The pulmonary hemorrhage improved with the therapy, however, his renal function did not improve. He is currently on a regular schedule of hemodialysis.

High-level expression of a foreign gene by a recombinant baculovirus with an expanded host range

The usefulness of host range expanded viruses as an expressionvector system was investigated by following the expression ofthe E. coli lacZ gene. The host range expanded recombinantviruses were obtained from Sf-21 or BmN-4 cells coinfected withAutographa californica and Bombyx mori nuclearpolyhedrosis viruses. Among the host range expanded viruses,RecB-8 and RecS-B6 have similar enzyme digestion profiles butdifferent infection characteristics in cells. Therefore, tostudy the foreign gene expression efficiency of these twoviruses, we constructed recombinant viruses RecB8-LacZ andRecSB6-LacZ containing the lacZ gene instead of the polyhedringene. Also, the host range expanded recombinant AcNPV, Bac-BH,containing lacZ gene in the polyhedrin gene locus was constructedby substitution of the 0.6 kb region within the helicase gene ofBacPAK6 with that of BmNPV. beta-Galactosidase expressionefficiency by these viruses were determined and compared in Sf-21and BmN-4 cells. The result showed that Bac-BH has highexpression efficiency only in Sf-21 cells, whereas RecB8-LacZhas high expression efficiency both in Sf-21 and BmN-4 cells.Also, in BmN-4 cells, beta-galactosidase expressionefficiency of RecB8-LacZ was higher than that of recombinantBmNPV (BmK1-LacZ containing lacZ gene in polyhedrin gene locus).In addition, the expression efficiency was not correlated withvirus titer.

Pulmonary venous flow from fetal to neonatal period

There are few reports about the effect of fetal or transitional circulation on the pulmonary venous flow. The purposes of this study were to investigate flow patterns of the pulmonary vein serially from fetal to neonatal period and to determine the relationship between pulmonary venous flow and other parameters from aortic and mitral valve. Pulmonary venous flow velocity was analyzed in 21 normal term human fetuses. Postnatal follow-up studies were performed at 1, 6, 24 h, 3 days, 1 week and 1 month. In each time point, pulsed Doppler echocardiography was used to interrogate right upper pulmonary vein, mitral and aortic valve. The measured parameters of pulmonary vein were heart rate, velocity time integral (VTI), and velocities at systolic peak (S), at diastolic peak (D), at nadir between S and D (O), and at nadir between D and the next S (X). E/A ratio and VTI were measured for mitral valve and peak systolic velocity and VTI for aortic valve. Pulmonary venous flow in fetus was phasic and continuous with low velocity. One hour after birth, without a change of flow pattern, all velocities increased dramatically. These high velocities showed a significant decrease during 24 h after birth. Three days after birth, the velocity decreased slightly and flow pattern changed from continuous to interrupted pattern with or without atrial reversal. No Doppler parameters from aortic or mitral valve showed any correlation with parameters from pulmonary vein. In conclusion, the flow pattern of the pulmonary vein in fetus may result from low pulmonary flow and decreased capacitance of the pulmonary venous system. Sudden increase in the pulmonary flow after birth is likely to be responsible for the highest velocities recorded immediately after birth. Left to right shunt through the ductus arteriosus may also contribute to the flow pattern observed in the first several days, as do changes in reservoir function of the pulmonary vein.

Mutations of hepatitis C virus 1b NS5A 2209-2248 amino acid sequence is not a predictive factor for response to interferon-alpha therapy and development of hepatocellular carcinoma

Genetic changes between codons 2209 and 2248 of NS5A of genotype 1b hepatitis C virus (HCV-1b) have been reported to be associated with the sensitivity to interferon-alpha (IFN-alpha). The present study was performed to analyze such relationship in Korean patients with chronic hepatitis C and HCV-1b (n=19), including 12 chronic hepatitis C patients treated with IFN-alpha, 3 chronic hepatitis C patients without treatment as controls, and 4 patients with hepatocellular carcinoma (HCC). Two serum samples, before and after the treatment, were analyzed for the mutations by reverse transcription-polymerase chain reaction, cloning and sequencing. The mutations were identified in 32% (6/19), including five intermediate type (1-3 mutations) and one mutant type (4 or more). In 12 patients treated with IFN-alpha, the number of amino acid substitutions in NS5A2209-2248 was not associated with outcome of the treatment. Two HCV isolates with NS5A2209-2248 mutations from HCC patients were intermediate type. These results do not support that the NS5A2209-2248 determines interferon sensitivity of HCV-1b and that the mutations is associated with development of HCC.

Crystal structure of the nuclear matrix targeting signal of the transcription factor acute myelogenous leukemia-1/polyoma enhancer-binding protein 2alphaB/core binding factor alpha2

Transcription factors of the acute myelogenous leukemia (AML)/polyoma enhancer-binding protein (PEBP2alpha)/core-binding factor alpha (CBFA) class are key transactivators of tissue-specific genes of the hematopoietic and bone lineages. AML-1/PEBP2alphaB/CBFA2 proteins participating in transcription are associated with the nuclear matrix. This association is solely dependent on a highly conserved C-terminal protein segment, designated the nuclear matrix targeting signal (NMTS). The NMTS of AML-1 is physically distinct from the nuclear localization signal, operates autonomously, and supports transactivation. Our data indicate that the related AML-3 and AML-2 proteins are also targeted to the nuclear matrix in situ by analogous C-terminal domains. Here we report the first crystal structure of an NMTS in an AML-1 segment fused to glutathione S-transferase. The model of the NMTS consists of two loops connected by a flexible U-shaped peptide chain.

TGF-beta-induced cell-cycle arrest through the p21(WAF1/CIP1)-G1 cyclin/Cdks-p130 pathway in gastric-carcinoma cells

Transforming growth factor-beta1 (TGF-beta) inhibits cell-cycle progression of many types of cells by arresting them in G(1)/S phase through inhibition of the active cyclin-Cdk complexes that lead to inhibition of Rb phosphorylation. In gastric-cancer cells, SNU16, TGF-beta treatment induced enhanced expression of p21(WAF1/CIP1) (p21), which inhibited the kinase activity of cyclin-D- and cyclin-E-associated Cdks and blocked p130 phosphorylation. TGF-beta also enhanced the stability of p130, suggesting that hypophosphorylation of p130 and increased stability of p130 contribute to p130-mediated G(1) arrest in gastric-cancer cells. Our results demonstrate that p21 and p130 are major downstream targets of TGF-beta in gastric-cancer cells and that a p21-G(1) cyclin/Cdks-p130/E2F pathway mediates growth inhibition by TGF-beta in these cells.

Secondary cardiac tumor in children

We describe our clinical experience of eight cases of secondary cardiac tumor. The pathology of the tumors were lymphoma (three), Wilms' tumor (two), malignant teratoma (one), neuroblastoma (one), and pleuropulmonary blastoma (one). Metastatic sites were the right atrium in Wilms' tumor and neuroblastoma, the left atrium in pleuropulmonary blastoma and malignant teratoma, and multiple sites in lymphoma. Primary masses in the mediastinum extended directly to the heart (three lymphoma, malignant teratoma, pleuropulmonary blastoma). Wilms' tumor and neuroblastoma showed cardiac metastases through the inferior vena cava. Many cases revealed vague abnormal cardiovascular findings (symptoms in six; physical signs in five). In five cases surgery was performed to relieve the possible obstruction to flow and to identify the pathology (lymphoma in three, Wilms' tumor in one, and malignant teratoma in one). Chemotherapy prior to operation resulted in the disappearance of the intracardiac masses in each case of Wilms' tumor and pleuropulmonary blastoma. All three patients with lymphoma died immediately after operation. Four died of multiple metastases or Pneumocystis pneumonia several months after operation. This study indicates that suspicion of a secondary cardiac tumor is crucial to early diagnosis. Because of the poor postoperative outcome, surgery for secondary cardiac tumors should be done cautiously only in cases with definite hemodynamic decompensation.

Development of a novel expression vector system using Spodoptera exigua nucleopolyhedrovirus

To develop a novel Spodoptera exigua nucleopolyhedrovirus (SeNPV) expression vector system, we examined characteristics of the SeNPV polyhedrin expression in S. exigua cells (Se301). While the extracellular virus titer of SeNPV was 100-fold lower than that of Autographa californica nucleopolyhedrovirus (AcNPV), the levels of polyhedral inclusion body (PIB) formation and polyhedrin expression were higher in SeNPV. To investigate foreign gene expression under the control of the polyhedrin promoter, polyhedrin-based transfer vector pSeKSK2 was constructed, and then recombinant virus SeK1-LacZ was constructed by inserting E. coli lacZ gene as a reporter gene into a genomic DNA of SeNPV using this transfer vector. The beta-Galactosidase activity of SeK1-LacZ in Se301 was about 1.3 times higher than that of BacPAK6. Thus, the SeNPV expression vector system constructed in this study would be very useful in the expression of foreign proteins, specifically for the enhancement of the pesticidal properties of SeNPV by inserting pesticidal genes.

Thermolabile 8-hydroxyguanine DNA glycosylase with low activity in senescence-accelerated mice due to a single-base mutation

8-hydroxyguanine (8-oxoguanine; oh8Gua) DNA glycosylase (OGG1) repairs oh8Gua, a highly mutagenic oxidative DNA damage. In the present study, we compared two strains of senescence-accelerated mouse (SAM) expressing senescence-prone phenotypes, SAMP1 and SAMP8, with one strain of SAM expressing senescence-resistant phenotype, SAMR1. We found three distinct characteristics of OGG1 in SAMPs: (i) low activity (10-40% of the SAMRI enzyme in all organs and ages observed), (ii) thermolability, and (iii) mutation from Arg (CGG) in SAMR1 to Trp (TGG) at codon 304. There was no difference in the levels of mRNA and protein. As expected, oh8Gua level in tissues was higher in the SAMPs. In contrast, O6-methylguanine-DNA methyltransferase, which repairs alkylated DNA, showed no difference in its activity. The impairment of oh8Gua repair activity caused by the 304 mutation in OGG1 may be one of the factors contributing to the high somatic mutation rate and the accelerated senescence observed in these strains.

Noise level of drilling instruments during mastoidectomy

Exposure to intense noise has been identified as a potential risk in the development of hearing impairment. Social concern about excessive noise is increasing and this also extends to the operating room. A noise level study was performed in the operating room during mastoidectomy with a sound level meter and it was analyzed by a sound-analyzing program. The drilling instruments used included the Stryker, Midas, M.P.S. and Med-Next. The operator was exposed to sound levels from 69 to 83 dBA. The loudest drilling instrument was the Midas and it produced an average sound level of 83 dBA to the operator. The mean exposure time was 41 minutes during mastoidectomy. This is below the occupational noise-level regulations in Korea. However, considering that individual susceptibility to noise varies and that the otologic surgeon is repeatedly exposed to prolonged drilling noise, ear protection is recommended for the operators of high-speed drilling instruments.

Pulmonary hypertension in a child with juvenile-type autosomal recessive polycystic kidney disease

An 11 year-old girl, whose condition was diagnosed as juvenile-type autosomal recessive polycystic kidney disease (ARPKD) at five years of age, presented with chest pain and dyspnea that had developed suddenly two months previously. Two-dimensional echocardiography, Doppler study and cardiac catheterization confirmed pulmonary hypertension. The underlying mechanism of the diagnosis was not defined. Two and a half months after the onset of symptoms, the patient died of pulmonary hypertensive crisis. Careful regular checks of cardiopulmonary status using two-dimensional echocardiography and Doppler should be considered for the early detection of pulmonary hypertension even in an asymptomatic patient with juvenile-type ARPKD.

Identification of cDNAs for Sox-4, an HMG-Box protein, and a novel human homolog of yeast splicing factor SSF-1 differentially regulated during apoptosis induced by prostaglandin A2/delta12-PGJ2 in Hep3B cells

We have examined specific genes whose expression is altered during apoptosis induced by prostaglandin (PG)A2 and Delta12-PGJ2 in human hepatocellular carcinoma Hep3B cells. Using mRNA differential display, we have identified two genes: one is specifically up-regulated and encodes for human Sox-4 (Sry-HMG box gene) and the other is significantly down-regulated and is the human homolog of yeast Ssf-1, a novel splicing factor. Northern blot analysis confirmed their differential expressions. Interestingly, Sox-4 was highly expressed in subcutaneous tumors grown in nude mice as a xenograft from Hep3B cells. These results suggest that the expression of Sox-4 may be related to the apoptosis pathway leading to cell death as well as to tumorigenesis, and that Ssf-1 gene may serve as a negative regulator of PGA2/Delta12-PGJ2-mediated Hep3B cell apoptosis.

Adenovirus-mediated p53 tumor suppressor gene therapy against subcutaneous HuH7 hepatoma cell line nodule of nude mice

Mutations of the tumor-suppressor gene p53 have been found in 30-50% cases of hepatocellular carcinoma (HCC). In this study, E1-negative adenoviral vector encoding wild-type p53 under the control of the human cytomegalovirus promoter (AdCMV-p53w) was constructed to evaluate its therapeutic efficacy against tumor nodules developing after injection of HuH7 cell lines in ten nude mice. When each nodule had reached 10 mm in perpendicular diameter, 1.5 x 10(8) pfu of AdCMV-p53w per session was injected intratumorally as follows: In group I (n=3), five sessions were injected every other day. In group II (n=3), only one session. Group III (n=4) as negative controls. The mice were sacrificed at 28 days post AdCMV-p53w injection. Tumor growth was significantly suppressed and delayed in group I and II compared to group III as compared by tumor volume at the end of observation. These results suggest that AdCMV-p53w may not only be effective in treating HCCs expressing mutant p53, but also useful as a local injectable gene therapy.

Cystic fibrosis transmembrane conductance regulator regulates luminal Cl-/HCO3- exchange in mouse submandibular and pancreatic ducts

We have demonstrated previously the regulation of Cl-/HCO3- exchange activity by the cystic fibrosis transmembrane conductance regulator (CFTR) in model systems of cells stably or transiently transfected with CFTR (Lee, M. G., Wigley, W. C., Zeng, W., Noel, L. E., Marino, C. R., Thomas, P. J., and Muallem, S. (1999) J. Biol. Chem. 274, 3414-3421). In the present work we examine the significance of this regulation in cells naturally expressing CFTR. These include the human colonic T84 cell line and the mouse submandibular gland and pancreatic ducts, tissues that express high levels of CFTR in the luminal membrane. As in heterologous expression systems, stimulation of T84 cells with forskolin increased the Cl-/HCO3- exchange activity independently of CFTR Cl- channel activity. Freshly isolated submandibular gland ducts from wild type mice showed variable Cl-/HCO3- exchange activity. Measurement of [Cl-]i revealed that this was largely the result of variable steady-state [Cl-]i. Membrane depolarization with 5 mM Ba2+ or 100 mM K+ increased and stabilized [Cl-]i. Under depolarized conditions wild type and DeltaF/DeltaF mice had comparable basal Cl-/HCO3- exchange activity. Notably, stimulation with forskolin increased Cl-/HCO3- exchange activity in submandibular gland ducts from wild type but not DeltaF/DeltaF mice. Microperfusion of the main pancreatic duct showed Cl-/HCO3- exchange activity in both the basolateral and luminal membranes. Stimulation of ducts from wild type animals with forskolin had no effect on basolateral but markedly stimulated luminal Cl-/HCO3- exchange activity. By contrast, forskolin had no effect on either basolateral or luminal Cl-/HCO3- exchange activity of ducts from DeltaF/DeltaF animals. We conclude that CFTR regulates luminal Cl-/HCO3- exchange activity in CFTR-expressing cells, and we discuss the possible physiological significance of these findings regarding cystic fibrosis.

Transient upregulation of CBFA1 in response to bone morphogenetic protein-2 and transforming growth factor beta1 in C2C12 myogenic cells coincides with suppression of the myogenic phenotype but is not sufficient for osteoblast differentiation

The bone morphogenetic protein (BMP)-2 is a potent osteoinductive signal, inducing bone formation in vivo and osteoblast differentiation from non-osseous cells in vitro. The runt domain-related protein Cbfa1/PEBP2alphaA/AML-3 is a critical component of bone formation in vivo and transcriptional regulator of osteoblast differentiation. To investigate the relationship between the extracellular BMP-2 signal, Cbfa1, and osteogenesis, we examined expression of Cbfa1 and osteoblastic genes during the BMP-2 induced osteogenic transdifferentiation of the myoblastic cell line C2C12. BMP-2 treatment completely blocked myotube formation and transiently induced expression of Cbfa1 and the bone-related homeodomain protein Msx-2 concomitant with loss of the myoblast phenotype. While induction of collagen type I and alkaline phosphatase (AP) expression coincided with Cbfa1 expression, Cbfa1 mRNA was strikingly downregulated at the onset of expression of osteopontin (OPN) and osteocalcin (OCN) genes, reflecting the mature osteoblast phenotype. TGF-beta1 treatment effectively suppressed myogenesis and induced Cbfa1 expression but was insufficient to support osteoblast differentiation reflected by the absence of ALP, OPN, and OCN. We addressed whether induction of Cbfa1 in response to BMP-2 results in the transcriptional activation of the OC promoter which contains three enhancer Cbfa1 elements. Transfection studies show BMP-2 suppresses OC promoter activity in C2C12, but not in osteoblastic ROS 17/2.8 cells. Maximal suppression of OC promoter activity in response to BMP-2 requires sequences in the proximal promoter (up to nt -365) and may occur independent of the three Cbfa sites. Taken together, our results demonstrate a dissociation of Cbfa1 expression from development of the osteoblast phenotype. Our findings suggest that Cbfal may function transiently to divert a committed myoblast to a potentially osteogenic cell. However, other factors induced by BMP-2 appear to be necessary for complete expression of the osteoblast phenotype.

Monitoring antibody titers to recombinant Core-NS3 fusion polypeptide is useful for evaluating hepatitis C virus infection and responses to interferon-alpha therapy

To evaluate the clinical feasibility of the antibody titer against a chimeric polypeptide (named Core 518), in which a domain of Core and NS3 of hepatitis C virus (HCV) was fused, ELISA was performed in a total of 76 serum samples. Each serum was serially diluted using two-fold dilution method with distilled water into 10 concentrations. They were all positive for second generation anti-HCV assay (HCV EIA II; Abbott Laboratories). Genotyping RT-PCR, quantitative competitive RT-PCR, and RIBA (Lucky Confirm; LG Biotech) were also assayed. Anti-Core 518 antibody was detected in x 12800 or higher dilutions of sera from 35 of 43 chronic hepatitis C (81.4%) and nine of 16 hepatocellular carcinoma sera (56.3%), one of four cirrhosis (25%), 0 of four acute hepatitis C, and one of nine healthy isolated anti-HCV-positive subjects (p=0.0000). The anti-Core 518 antibody titers were well correlated with the presence of HCV RNA in serum (p=0.002). The anti-Core 518 antibody titers decreased significantly in nine of ten responders to IFN-alpha treatment. Monitoring anti-Core 518 titers may be helpful not only for differentiating the status of HCV infection among patients with various type C viral liver diseases, but also for predicting responses to IFN-alpha treatment.

TT virus infection among blood donors and patients with non-B, non-C liver diseases in Korea

BACKGROUND/AIMS

A novel virus, designated the TT virus (TTV), was isolated from the serum of a patient with posttransfusion hepatitis of unknown etiology, in Japan. Subsequently, TTV was suggested to be a causative agent in a proportion of cases with cryptogenic hepatitis in Japan. This study aimed to elucidate the significance of TTV infection in cases with cryptogenic liver disease in Korea, a neighbor of Japan.

METHODS

The prevalence of TTV infection was studied in 120 patients with liver diseases, including 85 patients diagnosed as having non-B, non-C liver diseases. As controls, 220 blood donors were also examined. TTV DNA was detected by polymerase chain reaction, and the sequence was analyzed by phylogenetic analysis.

RESULTS

Fourteen (14.0%) of 100 accepted blood donors, 23 (19.2%) of 120 rejected blood donors, and 15 (17.6%) of 85 patients with non-B, non-C liver diseases were positive for TTV DNA. The prevalences of TTV infection among these groups were not significantly different. Phylogenetic analysis suggested the existence of four major genotypes of TTV The proportions of each genotype among patients with non-B, non-C liver diseases were not different from those among accepted blood donors.

CONCLUSIONS

TTV exists in Korea, but the prevalence among patients with non-B, non-C liver diseases was almost the same as that among blood donors. TTV may not be the main causative agent of cryptogenic liver disease in Korea. The relationship between non-B, non-C liver diseases and TTV genotype remains unclear, although TTV can be classified into four genotypes.

Maintenance of myoglobin concentration in human skeletal muscle after heavy resistance training

The aim of this study was to determine the effects of 8 weeks of resistance training (RT) on the myoglobin concentration ([Mb]) in human skeletal muscle, and to compare the change in the [Mb] in two different RT protocols. The two types of protocol used were interval RT (IRT) of moderate to low intensity with a high number of repetitions and a short recovery time, and repetition RT (RRT) of high intensity with a low number of repetitions and a long recovery time. A group of 11 healthy male adults voluntarily participated in this study and were divided into IRT (n = 6) and RRT (n = 5) groups. Both training protocols were carried out twice a week for 8 weeks. At the completion of the training period, the one-repetition maximal force values and isometric force were increased significantly in all the subjects, by about 38.8% and 26.0%, respectively (P < 0.01). The muscle fibre composition was unchanged by the 8 weeks of training. The muscle fibre cross-sectional areas were increased significantly by both types of training in all fibre types (I, IIa and IIb, mean + 16.1 %, P < 0.05). The [Mb] showed no significant changes at the completion of the training [IRT from 4.63 (SD 0.63) to 4.48 (SD 0.72), RRT from 4.47 (SD 0.75) to 4.24 (SD 0.80) mg x g(-1) wet tissue] despite a significant decrease in citrate synthase activity [IRT from 5.27 (SD 1.45) to 4.49 (SD 1.48), RRT from 5.33 (SD 2.09) to 4.85 (SD 1.87) micromol x min(-1) x g(-1) wet tissue; P < 0.05] observed after both protocols. These results suggested that myoglobin and mitochondria enzymes were regulated by different mechanisms in response to either type of RT. Moreover, the maintained [Mb] in hypertrophied muscle should preserve oxygen transport from capillaries to mitochondria even when diffusion distance is increased.

Follow-up results of transvenous occlusion of patent ductus arteriosus with the buttoned device

OBJECTIVES

The purpose of this presentation is to document results of buttoned device (BD) occlusion of patent ductus arteriosus (PDA) in a large number of patients with particular emphasis on long-term follow-up in an attempt to provide evidence for feasibility, safety and effectiveness of this method of PDA closure.

BACKGROUND

Immediate and short-term results of BD occlusion of PDA have been documented in a limited number of children.

METHODS

During a six-year period ending August 1996, transcatheter BD closure of PDA was attempted in 284 patients, ages 0.3 to 92 years (median 7) under a protocol approved by the local institutional review boards and FDA with an investigational device exemption in U.S. cases.

RESULTS

The PDAs measured 1 to 15 mm (median 4) at the narrowest diameter; 20 were larger than 8 mm and 10 larger than 10 mm. They were occluded with devices measuring from 15 to 35 mm delivered via 7F (N = 140) or 8F (N = 144) sheaths. Successful implantation of the device was accomplished in 278 (98%) of 284 patients. The Qp:Qs decreased from 1.8+/-0.6 (mean+/-SD) to 1.09+/-0.19 (p < 0.001). Effective occlusion defined as no (N = 167 [60%]) or trivial (N = 79 [28%]) residual shunt was achieved in 246 (88%) patients. All types of PDAs, irrespective of the shape (conical, tubular or short), size (small or large) or length (short or long) of the PDA and previously implanted Rashkind devices, could be occluded. Follow-up data, 1 to 60 months (median 24) after device implantation, were available in 234 (84%) patients. Seven (3%) patients required reintervention to treat residual shunt with (N = 2) or without (N = 5) hemolysis. Actuarial reintervention-free rates were 95% at 1 and 5 years. There was gradual reduction of actuarial residual shunts and were 40%, 28%, 21%, 14%, 11%, 10%, 6% and 0% respectively at 1 day, 1, 6, 12, 24, 36, 48 and 60 months after device implantation. Incorporation of folding plug over the button loop in 10 additional patients produced immediate and complete occlusion of PDA.

CONCLUSIONS

This large multiinstitutional experience confirms the feasibility, safety and effectiveness of buttoned device closure of PDAs. All types of PDAs irrespective of the shape, length and diameter can be effectively occluded. Incorporation of folding plug over the button loop produces complete PDA occlusion at the time of device implantation.

Changes in lymphatic function after complex physical therapy for lymphedema

Twenty-two extremities of 19 lymphedema patients (6 arms, 16 legs) were treated by 2 weeks of complex physical therapy (CPT) and self home maintenance therapy (bandage/wearing of elastic garment and exercise). In addition to the clinical response of volume reduction before and 3 months after CPT, we analyzed the functional changes of the peripheral lymphatic system by use of lymphoscintigraphy (LS). Before CPT, the main LS findings of lymphedema included dermal backflow (100%), absent or faintly visualized regional lymph nodes (95.5%), presence of collateral lymphatic vessels (68.2%), and no or barely visualized lymphatic vessels (27.3%). LS findings suggesting improved lymphatic function after CPT were a decrease in dermal backflow (72.7%), an increase in radioisotope uptake by lymphatic vessels (27.3%), and an increase in radioisotope uptake by lymph nodes (9.1%). 81.8% of limbs showed improved lymphoscintigraphic findings and no change in 9.1%. In the others (9.1%), LS findings appeared worse. There was, however, no correlation between LS "improvement" and the amount of limb volume reduction.

The Saccharomyces cerevisiae FAT1 gene encodes an acyl-CoA synthetase that is required for maintenance of very long chain fatty acid levels

The Saccharomyces cerevisiae FAT1 gene appears to encode an acyl-CoA synthetase that is involved in the regulation of very long chain (C20-C26) fatty acids. Fat1p, has homology to a rat peroxisomal very long chain fatty acyl-CoA synthetase. Very long chain acyl-CoA synthetase activity is reduced in strains containing a disrupted FAT1 gene and is increased when FAT1 is expressed in insect cells under control of a baculovirus promoter. Fat1p accounts for approximately 90% of the C24-specific acyl-CoA synthetase activity in glucose-grown cells and approximately 66% of the total activity in cells grown under peroxisomal induction conditions. Localization of functional Fat1p:green fluorescent protein gene fusions and subcellular fractionation of C24 acyl-CoA synthetase activities indicate that the majority of Fat1p is located in internal cellular locations. Disruption of the FAT1 gene results in the accumulation of very long chain fatty acids in the sphingolipid and phospholipid fractions. This includes a 10-fold increase in C24 acids and a 6-fold increase in C22 acids. These abnormal accumulations are further increased by perturbation of very long chain fatty acid synthesis. Overexpression of Elo2p, a component of the fatty acid elongation system, in fat1Delta cells causes C20-C26 levels to rise to approximately 20% of the total fatty acids. These data suggest that Fat1p is involved in the maintenance of cellular very long chain fatty acid levels, apparently by facilitating beta-oxidation of excess intermediate length (C20-C24) species. Although fat1Delta cells were reported to grow poorly in oleic acid-supplemented medium when fatty acid synthase activity is inactivated by cerulenin, fatty acid import is not significantly affected in cells containing disrupted alleles of FAT1 and FAS2 (a subunit of fatty acid synthase). These results suggest that the primary cause of the growth-defective phenotype is a failure to metabolize the incorporated fatty acid rather than a defect in fatty acid transport. Certain fatty acyl-CoA synthetase activities, however, do appear to be essential for bulk fatty acid transport in Saccharomyces. Simultaneous disruption of FAA1 and FAA4, which encode long chain (C14-C18) fatty acyl-CoA synthetases, effectively blocks the import of long chain saturated and unsaturated fatty acids.

Atypical pulmonary artery sling with diffuse-type pulmonary arteriovenous fistula

The case of a cyanotic infant with a rare combination of atypical pulmonary artery sling, imperforate anus, absence of the left kidney, interruption of the inferior vena cava, left side hemihypertrophy and diffuse-type pulmonary arteriovenous fistula is described. The clinical features were confusing, because of compounding abnormalities involving the respiratory tract and pulmonary circulation. The diagnostic approach to the etiology of cyanosis is discussed and the embryonic origin of pulmonary artery sling is reviewed.

Two cases of common bile duct stone after liver transplantation

Biliary complications after orthotopic liver transplants are a continuing cause of morbidity and mortality. Biliary stones and sludge are less well known complications of hepatic transplantation, although they have long been recognized. Recently we experienced two cases of biliary stones developed after liver transplantation. One 32-year-old male, who frequently admitted due to recurrent cholangitis, was treated with percutaneous transhepatic biliary drainage and choledochojejunostomy with cholecystectomy. The other 58-year-old male, who had stones in commone bile duct, was treated by endoscopic manipulation. They are in good condition without recurrent bile duct stones or its accompanying complications. Although stones and sludge are relatively infrequent after liver transplantation, surgical or interventional radiologic treatments are usually performed for treatment.

Aging process is accompanied by increase of transglutaminase C

Crosslinking has been suggested as one of the mechanisms involved in the aging process. Among the various random or enzyme-mediated crosslinking reactions, transglutaminase (TGase)-catalyzed crosslinking activity has been proposed for its possible involvement in cell proliferation, differentiation, carcinogenesis, programmed death, and aging. Moreover, recent findings of TGase C as a putative signal transducer and cell cycle regulator has renewed interest in the study of TGase C in relation to aging phenomena. The ubiquitous presence of TGase C compared to the organ-specific localization of other types of TGases has attracted special attention as a cellular aging device. In the present investigation for in vitro studies, we have compared the pattern of TGase C in young and old human red blood cells, separated by density differentiation, and in early and late-passage or hydrogen peroxide-treated human primary fibroblasts. For in vivo study, we monitored the age-dependent changes of TGase C in the liver and brain tissues of 4, 12, 18, and 24-month-old Sprague-Dawley rats. We obtained evidence that both the activity and protein levels of TGase C were high in old RBC and late-passage or hydrogen peroxide-treated fibroblasts. Similar findings were seen in liver and brain tissue such as age-dependent increases in TGase activity and protein level in an organ-specific pattern. These data suggest that TGase C might play an active role in the cellular process with age.

Involvement of specific calmodulin isoforms in salicylic acid-independent activation of plant disease resistance responses

The Ca2+ signal is essential for the activation of plant defense responses, but downstream components of the signaling pathway are still poorly defined. Here we demonstrate that specific calmodulin (CaM) isoforms are activated by infection or pathogen-derived elicitors and participate in Ca2+-mediated induction of plant disease resistance responses. Soybean CaM (SCaM)-4 and SCaM-5 genes, which encode for divergent CaM isoforms, were induced within 30 min by a fungal elicitor or pathogen, whereas other SCaM genes encoding highly conserved CaM isoforms did not show such response. This pathogen-triggered induction of these genes specifically depended on the increase of intracellular Ca2+ level. Constitutive expression of SCaM-4 and SCaM-5 in transgenic tobacco plants triggered spontaneous induction of lesions and induces an array of systemic acquired resistance (SAR)-associated genes. Surprisingly, these transgenic plants have normal levels of endogenous salicylic acid (SA). Furthermore, coexpression of nahG gene did not block the induction of SAR-associated genes in these transgenic plants, indicating that SA is not involved in the SAR gene induction mediated by SCaM-4 or SCaM-5. The transgenic plants exhibit enhanced resistance to a wide spectrum of virulent and avirulent pathogens, including bacteria, fungi, and virus. These results suggest that specific CaM isoforms are components of a SA-independent signal transduction chain leading to disease resistance.

Natural course of supravalvar aortic stenosis and peripheral pulmonary arterial stenosis in Williams' syndrome

We investigated the catheterization and angiographic findings of 26 patients with Williams' syndrome to evaluate the natural course of supravalvar aortic stenosis and peripheral pulmonary arterial stenosis. The severity of the stenosis was correlated with age and body surface area in terms of the pulmonary arterial index, right ventricular systolic pressure, sinutubular ratio (ratio of measured to mean normal diameter of sinutubular junction), and systolic pressure gradient across the sinutubular junction. In patients with pulmonary arterial stenosis (n=20), right ventricular systolic pressure tended to decrease, and pulmonary arterial index increased, with increase in age and body surface area. Between the groups with and without pulmonary arterial stenosis, there was significant difference in age (mean 4.70 vs. 9.87, p=0.019), body surface area (0.62 vs. 1.16, p=0.002), pulmonary arterial index (152 vs. 317, p=0.002) and right ventricular systolic pressure (73.9 vs. 33.0, p=0.006). As all patients showed similar diameters at the sinutubular junction regardless of age and body size, sinutubular ratio decreased with increases in age and body surface area. The group with abnormal coronary arteries (n=7) had smaller sinutubular ratio (0.46 vs. 0.61, p=0.021) and higher pressure gradients between the left ventricle and the aorta (67.6 vs. 42.2, p=0.023) than did the group with normal coronary arteries. Stenosis of a coronary artery, or a branch of the aortic arch, was observed only in three patients with diffuse aortic stenosis. Our results suggest that, with time, peripheral pulmonary arterial stenosis tends to improve, and supravalvar aortic stenosis to progress. Failure of growth of the sinutubular junction might be responsible for the progression of the aortic lesion. Progression of the aortic lesion may be associated with involvement of the coronary arteries.

Non-linear cardiac dynamics and morning dip: an unsound circadian rhythm

The frequency of sudden cardiac death increases in the morning. The relationship between decreased complexity of heart rate dynamics and sudden cardiac death has been documented. An understanding of circadian variation in the complexity of cardiac dynamics may be important to predict and prevent sudden cardiac death. Dynamic 24-h electrocardiographic recordings were obtained from 30 healthy ambulant subjects aged 41-50 years, and the digitized data were partitioned into sections of 30 min duration. For each section, four indexes obtained from separate algorithms of non-linear dynamics of the RR interval--modified correlation dimension, Lyapunov exponent, approximate entropy, and fractal dimension--were calculated. Normalized low-(0.04-0.15 hertz) and high-frequency (> 0.15 hertz) components were also calculated. All four indexes of non-linear dynamics showed a remarkably similar circadian rhythm: a prominent morning dip preceded by a steep decline during the late night, a recovery during the evening and a peak around midnight. In the morning, the low-frequency component rose rapidly with concomitant reduction in the high-frequency component. The complexity of cardiac dynamics decreases significantly in the morning, and this may contribute to the ominously increased rate of cardiac death in the morning hours.

CDK4 down-regulation induced by paclitaxel is associated with G1 arrest in gastric cancer cells

Paclitaxel induces a cell cycle block at G2-M phase by preventing the depolymerization of microtubules and induces p53-independent apoptosis in many cancer cells. We observed that gastric cancer cells treated with paclitaxel have shown a cyclin-dependent kinase (CDK)4 down-regulation. This paclitaxel-induced CDK4 down-regulation resulted in a cell cycle arrest at G1-S phase. To confirm this observation, we prepared stable transfectants that overexpressed CDK4 and analyzed the cell cycle progression. Ectopic expression of CDK4 in SNU cells resulted in a release of paclitaxel-induced G1 arrest. The release of G1 arrest by enforced expression of CDK4 seems to make the cells more sensitive to paclitaxel-induced apoptosis. From this finding, we could then suggest that paclitaxel treatment induces both G1-S and G2-M blocks in the cell cycle progression of gastric cancer cells.

Percutaneous transluminal coronary angioplasty in a child with Kawasaki disease

A successful attempt at percutaneous transluminanl coronary angioplasty (PTCA) to relieve stenosis of the mid-portion of the left anterior descending artery was achieved in a 6-year 9-month old boy who had multiple coronary aneurysms and stenosis due to Kawasaki disease. Despite the progression of coronary stenosis he had been well except for the perfusion defect of the anterior wall of myocardium on 99mTc-MIBI SPECT with dipyridamole infusion until PTCA was carried out after 4-year 4-months of the onset of illness. The area of stenosis was 70% before PTCA and 20% after PTCA. No restenosis at the site of PTCA was observed on follow-up angiography at 26 months after PTCA. This successful attempt may indicate that this procedure should be considered early in subclinical stenosis to prevent ischemic cardiac damage.