Routine minimally invasive aortic valve procedures

BACKGROUND

Due to the lack of objective evidence supporting the advantages and early technical difficulties, minimally invasive aortic valve procedures were performed on a highly selective rather than routine basis.

METHODS

From September 1997 to February 1999, one surgeon routinely used upper or transverse minimally invasive sternotomy to perform 46 consecutive cases of aortic valve procedures (M), whereas two other surgeons performed 40 aortic valve procedures through a conventional sternotomy (C).

RESULTS

More time consuming and technically demanding surgeries were done in M. There was one death in each group. Aortic clamp time was longer in M (93+/-40 vs 59+/-24 min, P=0.001). There were no differences in operating time, pump time, intubation duration, bleeding and intensive care unit stay. The advantages of minimally invasive aortic valve operation included better postoperative ejection fraction (58+/-17 vs 51+/-10%, P=0.04), decreased pain score (3+/-2 vs 5+/-2, P=0.004), less transfusion (19 vs 55%, P=0.02), shorter duration of chest tube drainage, and cosmetically more acceptable surgical wound (6.8+/-2.2 vs 5.2+/-2.0, P=0.018). From our series, we could not find any negative effects of minimal access surgery.

CONCLUSIONS

Our study demonstrated that aortic valve surgeries could be performed routinely by the minimally invasive approach with a high degree of effectiveness and safety.

Discriminatory detection of extended-spectrum beta-lactamases by restriction fragment length dimorphism-polymerase chain reaction

Plasmid-mediated resistance mechanisms to beta-lactams, comprising mostly extended-spectrum beta-lactamase (ESBL) production, lead to resistance against even the most recently developed beta-lactams in enterobacteria, which is now a serious threat to antibiotic therapy. In this work, the diagnostic ability of the restriction fragment length dimorphism (RFLD)-polymerase chain reaction (PCR) method in clinical samples was evaluated. Nine newly designed primer pairs were used to differentiate the genes encoding TEM-1a, SHV-12, MOX-1, MIR-1 and Toho-1 beta-lactamases. The RFLD-PCR was carried out successfully and these genes were differentiated by the sizes of their PCR product. This discriminatory detection of the genes was also confirmed by digestion with unique restriction enzyme sites and sequencing of the PCR products. The fragment sizes of PCR products digested with the enzymes were identical to the sizes calculated from nucleotide sequences of five beta-lactamase genes deposited in EMBL, GenBank and/or DDBJ databases and the sequences were also identical. In conclusion, the method and newly designed primers applied in this work can differentiate the ESBLs rapidly and effectively.

Caspase 3-mediated cleavage of p21WAF1/CIP1 associated with the cyclin A-cyclin-dependent kinase 2 complex is a prerequisite for apoptosis in SK-HEP-1 cells

Apoptosis of SK-HEP-1 human hepatoma cells induced by treatment with ginsenoside Rh2 (G-Rh2) is associated with rapid and selective activation of cyclin A-associated cyclin-dependent kinase 2 (Cdk2). Here, we show that in apoptotic cells, the Cdk inhibitory protein p21(WAF1/CIP1), which is associated with the cyclin A-Cdk2 complex, undergoes selective proteolytic cleavage. In contrast, another Cdk inhibitory protein, p27(KIP1), which is associated with cyclin A-Cdk2 and cyclin E-Cdk2 complexes, remained unaltered during apoptosis. Ectopic overexpression of p21(WAF1/CIP1) suppressed apoptosis as well as cyclin A-Cdk2 activity induced by treatment of SK-HEP-1 cells with G-Rh2. The suppressive effects of p21(WAF1/CIP1) were much higher in the cells transfected with p21D112N, an expression vector that encodes a p21(WAF1/CIP1) mutant resistant to caspase 3 cleavage. Overexpression of cyclin A in SK-HEP-1 cells dramatically up-regulated cyclin A-Cdk2 activity and accordingly enhances apoptosis induced by treatment with G-Rh2. These up-regulating effects were blocked by coexpression of a dominant negative allele of cdk2. Furthermore, olomoucine, a specific inhibitor of Cdks, also blocked G-Rh2-induced apoptosis. These data suggest that the induction of apoptosis in human hepatoma cells treated with G-Rh2 occurs by a mechanism that involves the activation of cyclin A-Cdk2 by caspase 3-mediated cleavage of p21(WAF1/CIP1).

Late postictal residual perfusion abnormality in epileptogenic zone found on 6-hour postictal SPECT

BACKGROUND

Temporal evolution of regional hyperperfusion in the late postictal stage in epilepsy has not been clearly defined.

OBJECTIVE

To establish the late temporal evolution of the perfusion in epileptogenic zones using 6-hour postictal SPECT.

METHODS

Ictal 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) SPECT was performed in 10 patients with intractable epilepsy (4 temporal lobe epilepsy, 6 neocortical epilepsy) followed by delayed acquisition and another 6-hour postictal SPECT after reinjection of 99mTc-HMPAO. The delayed acquired SPECT was subtracted from the reinjection SPECT to yield the 6-hour postictal SPECT. Interictal SPECT was acquired on another day. Late postictal perfusion was examined visually, and asymmetric indexes were compared with each other on ictal, 6-hour postictal, and interictal SPECT.

RESULTS

Ictal SPECT images of delayed acquisition were visually and quantitatively similar to those of early acquisition. In 7 of 10 patients, 6-hour postictal SPECT showed hyperperfusion. In one patient, the 6-hour postictal SPECT image showed less perfusion than the interictal SPECT image in the epileptogenic zone.

CONCLUSIONS

Late postictal hyperperfusion was found in more than half of the patients. Postictal perfusion abnormalities did not come back to the interictal phase 6 hours after ictus and these were identified on ictal/postictal 99mTc- HMPAO SPECT.

A new strategy to predict the neoplastic polyps of the gallbladder based on a scoring system using EUS

BACKGROUND

A new method to predict neoplastic polyps of the gallbladder using a scoring system based on five endoscopic ultrasonography (EUS) variables is presented.

METHODS

EUS data from patients with gallbladder polyps who were to undergo cholecystectomy were used for the construction of an EUS scoring system in polyps between 5 and 15 mm in diameter (reference group). The EUS scoring system developed from those patients was applied to other patients (validation group).

RESULTS

In the reference group, size was the most significant predictor of neoplastic polyp. All polyps 5 mm or less in diameter were non-neoplastic and 94% of polyps of greater than 15 mm were neoplastic in the reference group. For polyps between 5 and 15 mm in diameter, the area under the receiver-operating characteristic curves (ROC) plots for the endoscopic scoring system was significantly greater than that under the ROC plots for polyp size alone (p < 0.01). In the validation group, the risk of neoplastic polyp was significantly higher for polyps with a score of 6 or greater compared with those with a score of less than 6 (p < 0.01).

CONCLUSIONS

Our data show that a score based on five EUS variables identifies those patients at risk of neoplasia when polyps are between 5 and 15 mm in diameter. (Gastrointest Endosc 2000;52:372-9).

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.

Multiplex in-cell reverse transcription-polymerase chain reaction for the simultaneous detection of p210 and p190 BCR-ABL mRNAs in chronic myeloid leukemia and Philadelphia-positive acute lymphoblastic leukemia cell lines

We designed a novel multiplex in-cell reverse transcription-polymerase chain reaction method for the simultaneous detection and differentiation of p190 and p210 BCR-ABL mRNAs within single cells from the human chronic myeloid leukemia and Philadelphia positive acute lymphoblastic leukemia. Human K562 chronic myeloid leukemia and SUP B-15 Ph+ acute lymphoblastic leukemia cell lines were used as positive controls for p210 and p190 BCR-ABL mRNAs, respectively. HL60 cell line was used as a negative control. After the leukemia cells were fixed and permeabilized, without extracting nucleic acids, the mRNAs were reverse transcribed to cDNAs, and the cDNAs were amplified by multiplex polymerase chain reaction with fluorescent primers specific for p190 and p210 BCR-ABL mRNAs. After transfer onto glass slides by cytospin, the amplified cells were detected by fluorescence microscopy. Fluorescence microscopy after propidium iodide or 4',6-diamidino-2-phenylindone counterstaining showed that the positive K562 cells exhibited a yellow-green fluorescent cytoplasm around a red nucleus, and that the positive SUP B-15 cells exhibited an orange cytoplasm around a blue nucleus. Only the red or blue nucleus was visible in respective negative HL60 cells. The specificity of amplification was confirmed by the absence of a signal when control experiments were performed either with RNase digestion of mRNA or without reverse transcriptase/Taq polymerase. We conclude that the multiplex in-cell reverse transcription-polymerase chain reaction method is capable of simultaneously detecting and differentiating the p210 and p190 BCR-ABL mRNAs of chronic myeloid leukemia and Philadelphia-positive acute lymphoblastic leukemia cells, and that it may be useful in quantitatively monitoring the minimal residual disease during therapy.

The clinical usefulness of ictal SPECT in temporal lobe epilepsy: the lateralization of seizure focus and correlation with EEG

PURPOSE

To analyze the relationship between ictal electroencephalography (EEG) and ictal single-photon emission computed tomography (SPECT) and to evaluate the diagnostic usefulness of ictal SPECT as an independent presurgical evaluation technique.

METHODS

Sixty-eight patients with temporal lobe epilepsy who underwent temporal lobectomy with good surgical outcome were included in this study. Ictal SPECT was performed during video-EEG monitoring. The ictal EEG was analyzed in 5-second intervals from the initiation of the ictal rhythm. Lateralized EEG dominance was determined by the amplitude, frequency, or regional patterns of ictal rhythm for each 5-second interval. The total ictal EEG was divided into three periods: preinjection (maximum, 30 seconds), the initial part of the postinjection period (30 seconds), and the latter part of the postinjection period (30 to 60 seconds). The results of ictal SPECT were compared with the lateralized EEG dominance of each period and at seizure onset.

RESULTS

Fifty-four of 68 ictal EEGs correctly lateralized seizure focus ipsilateral to the side of surgery. Ictal SPECT correctly lateralized the epileptogenic temporal lobe in 61 of 68 patients (mean injection time, 29.8 seconds from onset). Multivariate analysis indicated that only the EEG dominance of the preejection period correlated significantly with the concordant hyperperfusion of ictal SPECT. Correct lateralization of ictal SPECT occurred in 10 of 14 patients with nonlateralized ictal EEG.

CONCLUSIONS

Preinjection neuronal activity seems to be important for the accurate interpretation of the hyperperfused patterns of ictal SPECT. Ictal SPECT is an independent and confirmatory presurgical evaluation technique.

Acculturation and health in Korean Americans

Despite increasing research on the relationships between acculturation and health, it is unclear whether (1) ethnic group variation occurs in acculturation-health relationships, (2) acculturation components vary differently in relationship to health, (3) biculturalism has beneficial effects on health and (4) multidimensional health relationships occur with acculturation. This study examined the Korean American ethnic group, considering how acculturation was related with five dimensions of health: smoking, physical activity, fat intake, body weight, and reported health. Pretested questionnaires were mailed to a national sample with Korean American surnames, and 55% of the deliverable sample responded, producing 356 usable questionnaires. Acculturation was measured using a two-culture matrix model and Gordon's theoretical work, and showed three distinct groups (acculturated, bicultural and traditional) and four components (American structural, American cultural, Korean structural and Korean cultural). Bicultural men were least likely to smoke, while acculturated and bicultural women were more likely to smoke than traditional women. Korean structural and cultural components were related to men's smoking. Higher acculturation was related to light physical activity, but not to vigorous physical activity. Fat intake did not differ by acculturation status. Higher acculturation was associated with higher body weight and better self-reported health only in men. Higher American cultural component scores were associated with better self-reported health in men. Among Korean Americans, acculturation components varied in their relationships with health, beneficial effects of being bicultural on health were not found, and acculturation-health relationships were multidimensional. Overall, ethnic group variation in health occurred, with Korean Americans similar to some ethnic groups but different than others. Future health research and practice can benefit by acknowledging the complexity of acculturation and its multidimensional effects on health.

The lateralizing and surgical prognostic value of a single 2-hour EEG in mesial TLE

We investigated 109 patients who received anterior temporal lobectomy for intractable mTLE by post-operative follow-up for at least 11/2 years. We reviewed pre-operative 2-hour interictal EEGs, counted interictal epileptiform discharges (IEDs), and compared the lateralization of IEDs with the side of surgery and surgical outcome. Twenty of 22 patients who had no spikes and 44 of 51 who had unitemporal spikes became seizure free after surgical resection. The correct lateralization of the epileptogenic side was possible in 90. 9% of the patients with unitemporal IEDs. In 12 seizure-free patients of 15 patients with less than 70% predominance of IED in one temporal lobe, the positive predictive value of the lateralization was 41.7%. In 16 seizure-free patients of 21 with more than 70% preponderance of IED in one lobe, the positive predictive value was 81.3%. Surgical outcome of patients with unitemporal and bitemporal IEDs were not significantly different. Interictal scalp EEG can be used as a lateralizing tool in mTLE when the temporal IEDs appear with more than 70% preponderance in one side. Although the presence of bitemporal IEDs often causes confusion in terms of the correct lateralization, it does not affect the surgical outcome.

Peripheral nerve injury and repair

Peripheral nerve injuries are common, and there is no easily available formula for successful treatment. Incomplete injuries are most frequent. Seddon classified nerve injuries into three categories: neurapraxia, axonotmesis, and neurotmesis. After complete axonal transection, the neuron undergoes a number of degenerative processes, followed by attempts at regeneration. A distal growth cone seeks out connections with the degenerated distal fiber. The current surgical standard is epineurial repair with nylon suture. To span gaps that primary repair cannot bridge without excessive tension, nerve-cable interfascicular auto-grafts are employed. Unfortunately, results of nerve repair to date have been no better than fair, with only 50% of patients regaining useful function. There is much ongoing research regarding pharmacologic agents, immune system modulators, enhancing factors, and entubulation chambers. Clinically applicable developments from these investigations will continue to improve the results of treatment of nerve injuries.

Detection of Helicobacter pylori DNA in human biliary tree and its association with hepatolithiasis

Recently, several authors have reported that Helicobacter pylori DNA has been found in human bile. The aim of this study is to investigate the presence of H. pylori in the biliary tree of Koreans, including the bile, biliary epithelium, and gallstones. This study analyzed intrahepatic bile, bile duct tissue, and gallstones from 43 patients with hepatobiliary disease (PTCS group), gallbladder bile and tissue from 23 patients with gallbladder disease (CCT group), and eight patients without hepatobiliary disease (control group). H. pylori was examined by PCR with two different primers. PCR was positive in 4/43 (9.3%) by 26 kDa protein antigen primer and in 5/43 (11.6%) by urease A gene primer in bile from the PTCS group. However, in intrahepatic duct tissue, PCR was positive in only one case. PCR of gallbladder bile, tissue, and intrahepatic duct stones was negative. Upon intrahepatic bile analysis, the pH was significantly lower in PCR-positive than in negative cases (P < 0.05). In conclusion, H. pylori DNA may be present in the bile when there are certain environmental changes, such as lowered pH; however, H. pylori does not colonize the bile duct epithelium. We could find no pathogenetic role for H. pylori in the formation of hepatolithiasis.

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.

Detection of Helicobacter pylori DNA in human biliary tree and its association with hepatolithiasis

Recently, several authors have reported that Helicobacter pylori DNA has been found in human bile. The aim of this study is to investigate the presence of H. pylori in the biliary tree of Koreans, including the bile, biliary epithelium, and gallstones. This study analyzed intrahepatic bile, bile duct tissue, and gallstones from 43 patients with hepatobiliary disease (PTCS group), gallbladder bile and tissue from 23 patients with gallbladder disease (CCT group), and eight patients without hepatobiliary disease (control group). H. pylori was examined by PCR with two different primers. PCR was positive in 4/43 (9.3%) by 26 kDa protein antigen primer and in 5/43 (11.6%) by urease A gene primer in bile from the PTCS group. However, in intrahepatic duct tissue, PCR was positive in only one case. PCR of gallbladder bile, tissue, and intrahepatic duct stones was negative. Upon intrahepatic bile analysis, the pH was significantly lower in PCR-positive than in negative cases (P < 0.05). In conclusion, H. pylori DNA may be present in the bile when there are certain environmental changes, such as lowered pH; however, H. pylori does not colonize the bile duct epithelium. We could find no pathogenetic role for H. pylori in the formation of hepatolithiasis.

Epithelial cell-specific laminin 5 is required for survival of early thymocytes

The gene LamC2 encoding the gamma2 chain of laminin 5, an epithelial cell-specific extracellular matrix protein, was identified in a PCR-based subtracted cDNA library from mouse thymic stromal cells. The mRNA existed in two alternative forms (5.1 and 2.4 kb). The full-length message was highly expressed in SCID thymus and in a nurse cell line, but not in other thymic epithelial cell lines, while the short form was more widely expressed. In situ hybridization and immunohistochemical staining revealed laminin 5 expression mostly in the subcapsular region of the adult thymus. Addition to fetal thymic organ cultures of a cell adhesion-blocking mAb to the alpha3 chain of laminin 5 interrupted T cell development. There was a 40% reduction in the total yield of thymocytes, and the most profound decrease (75-90%) was seen in the CD25+CD44+ and CD25+CD44-subsets of the CD4-CD8- double negative fraction. Most of the surviving double negative thymocytes expressed Sca-1, and there were significant increases in the number of cells with CD69 expression and in the fraction of annexin V-stained cells. None of these changes were observed with a nonblocking anti-laminin alpha3 chain mAb. These results suggest that the interaction between double negative thymoctyes and laminin 5 made by subcapsular epithelial cells is required for the survival and differentiation of mouse thymocytes.

Clinical manifestations of Korean female gouty patients

In an endeavor to analyse the clinical characteristics of female gout, we reviewed 36 women with gout. Twenty-seven (75%) developed the first symptomatic episode of gout after the onset of the menopause. The mean age at onset of gout was 54.3 years (range 15-87 years). Twenty-two patients (61%) had hypertension, 17 (47%) had renal insufficiency, 13 (36%) used diuretics and 10 (28%) were taking cyclosporine for a renal allograft. Tophaceous gout occurred in 10 patients (27%) and polyarticular involvement was seen in 16 (44%) at initial presentation. Five of nine premenopausal patients were taking cyclosporine and four had renal insufficiency. A comparison with a control group of 72 randomly selected male patients with gout showed that the female patients were frequently receiving diuretics at the time of the attack and had significantly lower mean uric acid excretion, whereas significantly more male patients showed heavy alcohol consumption and precipitating events for an acute attack compared with the female patients. There were no significant differences between the sexes for onset age, hypertension, renal insufficiency, distribution of joint involvement, tophi and mean serum uric acid concentration. The female patients in this study had a lower mean age at onset of gout than in previous studies, which was attributed to the inclusion of renal transplantation patients. Transplantation gout patients receiving cyclosporine lower the mean age at onset of female gout and this is an emerging problem in female gout.

A zebrafish ftz-F1 (Fushi tarazu factor 1) homologue requires multiple subdomains in the D and E regions for its transcriptional activity

A zebrafish Ftz-F1 homologue, zFF1A (zebrafish Ff1a or Nr5a2, a member of nuclear receptor superfamily) and its C-terminally truncated variant (zFF1B) were previously identified. Due to lack of the identity box (I-box) and activation function 2 (AF-2) domain, zFF1B lacks transactivation function and fails to synergize with estrogen receptor (ER) in regulating promoters. It was speculated that the I-box might be involved in the zFF1A/ER interaction. In the present study, the function of the I-box was examined. In the absence of the I-box or with an altered heptad 9, the AF-2 of zFF1A was not functional, either in the presence or absence of ER. The GST pull-down assay showed that zFF1A and its mutants exerted similar physical contacts with ER-LBD, suggesting that the "dimerization" domain (I-box) is essential for the transcriptional activity of zFF1A. Moreover, nuclear receptor coactivator selectively activated zFF1 with the I-box but exerted no effect on zFF1B, indicating that the I-box is able to interact with the coactivators. By deletion study and analysis of the identified domains in GAL4-DNA binding domain, other regions of zFF1A critical for its AF were also delineated. Consistent with the mutation analysis, AF-2 was active only in the presence of the I-box. We also identified a novel AF domain (AF-3) located in the hinge region (amino acids 155-267), although the activity of AF-3 was inhibited by its flanking region. We suggest that the D and E regions of zFF1A possess both positive and negative transactivation functions, and interdomain "cross-talk" may confer the full transcriptional activity of the protein.

Comparison of human papillomavirus types 16, 18, and 6 capsid antibody responses following incident infection

The relationship between human papillomavirus (HPV) DNA in the genital mucosa and serum IgG to HPV-16, -18, and -6 was studied in a cohort of 588 college women. Among women with incident HPV infections, 59.5%, 54.1%, and 68.8% seroconverted for HPV-16, -18, or -6, respectively, within 18 months of detecting the corresponding HPV DNA. Transient HPV DNA was associated with a failure to seroconvert following incident HPV infection; however, some women with persistent HPV DNA never seroconverted. Antibody responses to each type were heterogeneous, but several type-specific differences were found: seroconversion for HPV-16 occurred most frequently between 6 and 12 months of DNA detection, but seroconversion for HPV-6 coincided with DNA detection. Additionally, antibody responses to HPV-16 and -18 were significantly more likely to persist during follow-up than were antibodies to HPV-6.

Activating protein-1, nuclear factor-kappaB, and serum response factor as novel target molecules of the cancer-amplified transcription coactivator ASC-2

ASC-2 was recently discovered as a cancer-amplified transcription coactivator molecule of nuclear receptors, which interacts with multifunctional transcription integrators steroid receptor coactivator-1 (SRC-1) and CREB-binding protein (CBP)/p300. Herein, we report the identification of three mitogenic transcription factors as novel target molecules of ASC-2. First, the C-terminal transactivation domain of serum response factor (SRF) was identified among a series of ASC-2-interacting proteins from the yeast two-hybrid screening. Second, ASC-2 specifically interacted with the activating protein-1 (AP-1) components c-Jun and c-Fos as well as the nuclear factor-kappaB (NFkappaB) components p50 and p65, as demonstrated by the glutathione S-transferase pull-down assays as well as the yeast two-hybrid tests. In cotransfection of mammalian cells, ASC-2 potentiated transactivations by SRF, AP-1, and NFkappaB in a dose-dependent manner, either alone or in conjunction with SRC-1 and p300. In addition, ASC-2 efficiently relieved the previously described transrepression between nuclear receptors and either AP-1 or NFkappaB. Overall, these results suggest that the nuclear receptor coactivator ASC-2 also mediates transactivations by SRF, AP-1, and NFkappaB, which may contribute to the putative, ASC-2-mediated tumorigenesis.

Environmental distribution and behavior of 3H and 14C around Wolsong Nuclear Power Plants

To estimate of the dispersion trend of 3H and 14C discharged from the Wolsung Nuclear Power Plants, the present level of 3H and 14C in environmental samples in the vicinity of the Wolsong site was studied. Tree-ring cellulose analyses were carried out for retrospective evaluation of 3H and 14C in the environment around the Wolsong Nuclear Power Plants. 3H released from the Wolsong Nuclear Power Plants has affected an area up to a 25-km radius from the site, while almost all 14C was deposited within a 2-km radius, reaching to a natural level over 2 km. Organically bound tritium concentrations in tree rings were strongly correlated with the gaseous tritium discharge rate, while delta14C (excess) in tree rings ranged from 204 per thousand to 460 per thousand, which did not significantly vary with year.

Telomerase activity in pure pancreatic juice for the diagnosis of pancreatic cancer may be complementary to K-ras mutation

BACKGROUND

The usefulness of K-ras mutation in pancreatic juice for the diagnosis of pancreatic cancer is questionable. Telomerase is positive in pancreatic cancer but rarely in benign pancreatic diseases. We conducted this study to determine the usefulness of K-ras mutation and telomerase activity in pancreatic juice for the diagnosis of pancreatic cancer.

METHODS

Pancreatic juice collected during endoscopic retrograde cholangiopancreatography was examined in 31 patients: 12 with pancreatic cancer, 11 with chronic pancreatitis, and 8 control patients. The K-ras gene was detected by using the restriction fragment length polymorphism method. Telomerase activity was detected by using the telomeric repeat amplification protocol.

RESULTS

K-ras mutation was positive in 75% (9 of 12) of pancreatic cancers and in 27% (3 of 11) of cases of chronic pancreatitis but in none of the control patients. Telomerase activity was detected in 92% (11 of 12) of pancreatic cancers and in 18% (2 of 11) of cases of chronic pancreatitis. The diagnostic value in pancreatic cancer was comparable between K-ras mutation and telomerase when evaluated separately. However, by combining these 2 methods, the specificity rose to 100%.

CONCLUSIONS

For the diagnosis of pancreatic cancer, telomerase activity in pancreatic juice may possibly be complementary to K-ras mutation because it may decrease the rate of false-positive diagnosis.

Fracture strength of all-ceramic crowns with varying core elastic moduli

The aim of this study was to investigate the fracture strength of aluminous porcelain jacket crowns on core structures with different elastic moduli. Forty standardized aluminous porcelain jacket crowns were fabricated and divided into four groups. Each crown was luted with zinc phosphate cement onto a master die with a known elastic modulus, and loaded until failure occurred. The fracture load was shown to increase with increasing elastic modulus of the core. Analysis of data by ANOVA revealed a significant difference (p < 0.05) between the four groups. The results suggested that core elastic modulus may have an influence on the fracture resistance of aluminous porcelain jacket crowns, and it may be appropriate to recommend the use of high modulus metals for core placement on teeth to be restored with all-ceramic crowns.