Attenuation of telomerase activity by hammerhead ribozyme targeting human telomerase RNA induces growth retardation and apoptosis in human breast tumor cells

Ribozyme possesses specific endoribonuclease activity and catalyzes the hydrolysis of specific phosphodiester bonds, which results in the cleavage of target RNA sequences. Here, we evaluated the ability of hammerhead ribozymes targeting human telomerase RNA (hTR) to inhibit the catalytic activity of telomerase and the proliferation of cancer cells. Hammerhead ribozymes were designed against 7 NUX sequences located in open loops of the hTR secondary structure. We verified the ribozyme specificity by in vitro cleavage assay by using a synthetic RNA substrate. Subsequently, we introduced ribozyme expression vector into human breast tumor MCF-7 cells and assessed the biologic effects of ribozyme. Hammerhead ribozyme R1 targeting the template region of hTR efficiently cleaved hTR in vitro, and stable transfectants of this ribozyme induced the degradation of target hTR RNA and attenuated telomerase activity in MCF-7 cells. Moreover, the ribozyme R1 transfectant displayed a significant telomere shortening and a lower proliferation rate than parental cells. Clones with reduced proliferation capacity showed enlarged senescence-like shapes or highly differentiated dendritic morphologies of apoptosis. In conclusion, the inhibition of telomerase activity by hammerhead ribozyme targeting the template region of the hTR presents a promising strategy for inhibiting the growth of human breast cancer cells.

Genetic diversity analyses of 10 indigenous Chinese pig populations based on 20 microsatellites

To study the genetic diversity of Chinese indigenous pig breeds, a total of 403 pigs from 10 local populations and 1 exotic Duroc breed were genotyped for 20 microsatellite markers. Heterozygosity and Wright's F-statistics (F(IS), F(ST), and F(IT)) were calculated to determine the genetic variation in those populations. The observed heterozygosities were in the range of 0.31 (Duroc) to 0.66 (Shengxian). The F(IS) value was in a range of -0.07 to 0.48. The mean F(ST) showed that approximately 78% of the genetic variation was within-population and 22% was across the populations. The 10 Chinese local breeds were classified into two major groups according to the phylogenetic tree, which was based on standard genetic distance. Four pig populations, Jianli, Ganxi Two Ends Black, Shaziling, and Dongshan were grouped into one branch. Before the study, these four populations were all classified as Central China Two Ends Black according to coat color, shape of the head, and shape of the ear. The Jinhua pig, which also has the two-ends-black coat color, was also grouped to the same branch but was not traditionally classified into this type. The five populations were located in various provinces in central China. The other five populations, Nanyang Black, Hainan Spotted, Huainan Black, Jiaxing Black, and Shengxian Spotted (black body, white feet), were grouped into another branch. The two groups of pig breeds had the same F(ST) value (0.14) when calculated separately. This value was similar to that of Iberian pigs (0.13) but smaller than that of the European pigs (0.27) as reported by other researchers. Our study showed that large genetic differentiation exists in Chinese pig breeds. The grouping of the five two-ends-black populations into one branch of the phylogenetic tree may indicate that the number of conservation farms can be decreased for this type of pig.

Fabrication of high quality cDNA microarray using a small amount of cDNA

DNA microarray technology has become an essential part of biological research. It enables the genome-scale analysis of gene expression in various types of model systems. Manufacturing high quality cDNA microarrays of microdeposition type depends on some key factors including a printing device, spotting pins, glass slides, spotting solution, and humidity during spotting. UsingEthe Microgrid II TAS model printing device, this study defined the optimal conditions for producing high density, high quality cDNA microarrays with the least amount of cDNA product. It was observed that aminosilane-modified slides were superior to other types of surface modified-slides. A humidity of 30+/-3% in a closed environment and the overnight drying of the spotted slides gave the best conditions for arraying. In addition, the cDNA dissolved in 30% DMSO gave the optimal conditions for spotting compared to the 1X ArrayIt, 3X SSC and 50% DMSO. Lastly, cDNA in the concentration range of 100-300 ng/ micro l was determined to be best for arraying and post-processing. Currently, the printing system in this study yields reproducible 9000 spots with a spot size 150 mm diameter, and a 200 nm spot spacing.

The pattern of gene copy number changes in bilateral breast cancer surveyed by cDNA microarray-based comparative genomic hybridization

The nature of genetic alterations in bilateral breast cancer (BBC) associated with the distinctive development of a second primary tumor or a metastatic lesion is not clearly established. In this study, patterns of promoter methylation and gene copy number changes were assessed for their utility in the distinction of two types of BBC (synchronous and metachronous). Seven cases of synchronous and five cases of metachronous breast cancer tissues were used in X chromosome inactivation assay to assess the methylation pattern of human androgen receptor gene. X chromosome inactivation assay alone did not provide enough information to distinguish the genetic origins of synchronous and metachronous BBC. When four pairs of paraffin-embedded BBC tissues were used in cDNA array-based CGH with placenta DNA as a reference, higher DNA copy number changes were observed from metachronous pairs (9.0%) than from synchronous pairs (3.1%). From the two cases of metachronous pairs tested, 44 genes were found to be commonly modulated in gene copy numbers in a cancer detected later.

Prenatal sonographic diagnosis of isolated agnathia: a case report

Agnathia is a rare malformation characterized by the absence of the mandible, microstomia, aplasia or hypoplasia of the tongue, and low-set or medially fused ears. It occurs alone or in combination with a variety of malformations such as holoprosencephaly. All previous cases of the prenatal diagnosis of agnathia have been accompanied with fatal anomalies. We report here the first case of isolated agnathia, which was diagnosed by prenatal sonography at 32 weeks of gestation. In this case, prenatal sonographic examination showed the severe defect of the chin, small opening of the mouth and severe polyhydramnios. There was no sonographic evidence of holoprosencephaly or anomalies in other organ systems. The diagnosis was confirmed postnatally.

Genome-scale analysis of resveratrol-induced gene expression profile in human ovarian cancer cells using a cDNA microarray

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a natural compound found in large quantities, most notably in grapes and red wine, which has been shown to have anti-inflammatory, chemopreventive and anti-angiogenic effects. We examined whether resveratrol has any effect on growth and gene expression in the human ovarian cancer PA-1 cells. We show that resveratrol inhibits cell growth and induces apoptosis in PA-1 human ovarian cancer cells. We also investigated the effect of resveratrol on changes of global gene expression during resveratrol-induced growth inhibition and apoptosis in PA-1 cells using a human cDNA microarray with 7,448 sequence-verified clones. Out of the 7,448 genes screened, 118 genes were founded to be affected in their expression levels by more than 2-fold after 24-h treatment with 50 micro M resveratrol. Resveratrol treatment of PA-1 cells at the final concentration of 50 micro M for 6, 12, 24 and 48 h and gene expression patterns were analyzed by microarray. Clustering of the genes modulated more than 2-fold at three of the above times points divided the genes into 2 groups. Within these groups, there were specific subgroups of genes whose expressions were substantially changed at the specified time points. One of the most highly up-regulated genes found in this study was NAD(P)H quinone oxidoreductase 1(NQO-1), which has recently been shown to be involved in p53 regulation. Although the precise roles of genes whose expression levels were found to fluctuate after resveratrol treatment remain to be elucidated, we hope that the new view of gene expression in human ovarian cancer cells following resveratrol exposure, as offered by this study, provides clues for the mechanism of resveratrol action.

Association of the CD14 gene -159C polymorphism with progression of IgA nephropathy

The risk factors associated with the progression of IgA nephropathy (IgAN), the most common form of glomerulonephritis, are unclear. It has been suggested that CD14 signalling in response to various microbes affects the natural history of chronic inflammatory conditions. It has been hypothesised that variants in the promoter region of the CD14 gene might alter the expression of CD14, and this in turn could influence the progressive nature of IgAN. PCR-RFLP was used to determine the polymorphism at the -159 site (T to C). The distribution of the CD14/-159 polymorphism was no different in patients with IgAN (n=216) compared to 171 healthy controls. After follow up for 86 months, it was found that an excess of the C genotype occurred in patients with progressive disease (p=0.03) and the risk of disease progression increased as the number of C alleles increased (p for trend = 0.002). The hazard ratio for progression in the patients with the CC genotype was 3.2 (p=0.025) compared with the patients possessing the TT genotype. After LPS stimulation, sCD14 was released more abundantly from the PBMCs of the TT subjects than from that of the CC subjects (p=0.006), even though mCD14 expression level was no different. In addition, the TT subjects released less IL-6 than the CC subjects after stimulation (p=0.0003). These results suggest that the CD14/-159 polymorphism is an important marker for the progression of IgAN and may modulate the level of the inflammatory responses.

Effect of ventilation mode on gas exchange during partial liquid ventilation at different perfluorocarbon doses in surfactant-depleted lung

Although gas ventilation is an integral part of partial liquid ventilation (PLV), the role of ventilation mode during PLV is not established, especially at a varying perfluorocarbon dose. In 10 surfactant-depleted rabbits, PLV was performed at a low dose (10 ml/kg) and at a functional residual capacity (FRC) dose (30 ml/kg) of perfluorodecalin in pressure-control (PC) and volume-control (VC) modes in balanced sequence. In these four PLV trials, PC mode was adjusted to be identical to VC mode with regard to tidal volume and inspiratory-to-expiratory ratio. PaO2 during PLV in PC mode was higher than in VC mode at the Low dose (159 plus minus 93 mm Hg, 115 plus minus 75 mm Hg, respectively: p = 0.005) and at the FRC dose (228 +/- 114 mm Hg, 164 +/- 104 mm Hg, respectively: p = 0.002). PaCO2 during PLV in PC mode was lower than in VC mode at the Low dose (59 +/- 18 mm Hg, 72 +/- 20 mm Hg, respectively: p = 0.005), whereas PaCO2 at the FRC dose was not different between modes. Curves of inspiratory flow appeared least deformed with PLV in PC mode at the Low dose, whereas they were saw-tooth deformed with PLV in VC mode at both doses. Actual time for inspiratory gas flow during PLV was shorter in PC mode compared with VC mode at both doses. In conclusion, in surfactant-depleted rabbit, gas exchange during PLV was better with PC mode compared with VC mode, especially at a low perfluorocarbon dose. Given the same tidal volume, PC appeared to insufflate the perfluorocarbon-filled lung better than VC at both low and FRC doses of perfluorocarbon.

Highly efficient and catalytic conversion of aldoximes to nitriles

Catalytic dehydration of aldoximes can be performed highly efficiently with a catalyst system of [RuCl(2)(p-cymene)](2)/molecular sieves under essentially neutral and mild conditions, and various types of cyano compounds are produced in good to excellent yields. [reaction: see text]

Comparison and evaluation of copper complex-containing siloxane polymers as stationary phases for capillary gas chromatography

Two metallomesogenic polymers. P-C11CuC18 and P-C11CuC12 consisting of flexible aliphatic side chains with copper carboxylate complexes have been synthesized on the basis of addition reactions with polysiloxane. The applicability of the prepared columns to the analysis of phthalate esters that are of environmental concern was assessed. For preparation of the capillary column with its wall coated with the metallomesogenic polymer, both static and dynamic methods were employed. Factors affecting the retention and the sample selectivity on both columns were examined. A better separation of phthalates was achieved with P-C11CuC18 than P-C11CuC12. The former phase showed a higher solute-solvent interaction than the latter. With static coating, the wall-coated P-C11CuC18 capillary column (15 m x 250 microm I.D.) showed that the baseline separation of all 14 phthalates could be achieved within 38 min with high reproducibility. The calibration graphs for phthalate ester determination were linear over the range of 10-625 microg ml(-1). The mass detection limits were lower than the ng range based on three times the standard deviation of seven measurements of the lowest peak that could be detected.

Close correlation of p53 mutation to microvascular invasion in hepatocellular carcinoma

Mutation of p53 is a poor prognostic indicator of hepatocellular carcinoma (HCC). Although poor histologic differentiation of HCC has been associated with p53 mutations, the exact reasons for unfavorable clinical outcomes in patients with HCC remain to be clarified. In this study, we evaluate the association between p53 mutation and histopathologic features of HCCs, as well as tumor recurrences and survival. We examined 20 HCCs and surrounding liver tissues from patients who underwent surgical resection, and we performed direct sequencing of p53 gene. p53 mutations were found in 9 of 20 HCCs; none were found in the surrounding liver tissue. p53 mutations were frequent in large, multinodular, and poorly differentiated HCCs. Five of 9 with p53 mutation (in contrast, none of 11 with wild-type mutation) showed microvascular invasions. Hepatocellular carcinoma recurred in 6 of 9 with p53 mutation, in contrast to only 2 of 11 with wild-type mutation. The 1-year survival rate with p53 mutation was significantly lower than that with wild-type. In conclusion, it is suggested that p53 mutations tend to be commonly associated with microvascular invasions, which may result in micrometastasis, followed by frequent recurrences.

Vascular effects of estrogen in type II diabetic postmenopausal women

OBJECTIVES

We assessed the effects of estrogen on vascular dilatory and other homeostatic functions potentially affected by nitric oxide (NO)-potentiating properties in type II diabetic postmenopausal women.

BACKGROUND

There is a higher cardiovascular risk in diabetic women than in nondiabetic women. This would suggest that women with diabetes do not have the cardioprotection associated with estrogen.

METHODS

We administered placebo or conjugated equine estrogen, 0.625 mg/day for 8 weeks, to 20 type II diabetic postmenopausal women in a randomized, double-blinded, placebo-controlled, cross-over design.

RESULTS

Compared with placebo, estrogen tended to lower low-density lipoprotein (LDL) cholesterol levels by 15 +/- 23% (p = 0.007) and increase high-density lipoprotein (HDL) cholesterol levels by 8 +/- 16% (p = 0.034). Thus, the ratio of LDL to HDL cholesterol levels significantly decreased with estrogen, by 20 +/- 24%, as compared with placebo (p = 0.001). Compared with placebo, estrogen tended to increase triglyceride levels by 16 +/- 48% and lower glycosylated hemoglobin levels by 3 +/- 13% (p = 0.295 and p = 0.199, respectively). However, estrogen did not significantly improve the percent flow-mediated dilatory response to hyperemia (17 +/- 75% vs. placebo; p = 0.501). The statistical power to accept our observation was 81.5%. Compared with placebo, estrogen did not significantly change E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, monocyte chemoattractant protein-1 or matrix metalloproteinase-9 levels. Compared with placebo, estrogen tended to decrease tissue factor antigen and increase tissue factor activity levels by 7 +/- 46% and 5 +/- 34%, respectively (p = 0.321 and p = 0.117, respectively) and lower plasminogen activator inhibitor-1 levels by 16 +/- 31% (p = 0.043).

CONCLUSIONS

The effects of estrogen on endothelial, vascular dilatory and other homeostatic functions were less apparent in type II diabetic postmenopausal women, despite the beneficial effects of estrogen on lipoprotein levels.

Gasless laparoscopy-assisted colorectal surgery

BACKGROUND

Laparoscopy has gained wide acceptance as a treatment modality in a variety of colonic and rectal disorders. Currently, most laparoscopic procedures are performed using a carbon dioxide (CO2) pneumoperitoneum, which can lead to cardiopulmonary loading and subsequent complications. The object of this study was to assess the feasibility of gasless laparoscopy-assisted colorectal surgery (GLACS) as an alternative method.

METHODS

Patients with benign colonic lesions were enrolled in the study. The operative field was exposed with a subcutaneous wire lifting system. A small incision, ~5 cm in length, was made early in the operation. The surgeon operated through the trocar ports and this incision using both laparoscopic and conventional instruments. The cardiopulmonary responses of the patients were monitored continuously during the operation.

RESULTS

Fifteen consecutive patients underwent GLACS. In two patients (13.3%), conversion to open surgery was necessary. The exposure and ease of the procedure were acceptable. However, when the patients were stratified into hemicolectomy and sigmoidectomy groups, GLACS scored more favorably in the sigmoidectomy group. There were no operative deaths. One minor complication developed postoperatively. All of the patients recovered uneventfully, with return of bowel function in 2.8 +/- 0.1 days. The mean postoperative hospital stay was 6.4 +/- 0.4 days. The cardiac and pulmonary status of the patients remained stable during the operation.

CONCLUSION

Gasless laparoscopy-assisted colorectal surgery is technically feasible; thus, it provides an alternative means for the performance of minimal-access surgery.

Epilepsy in Chinese culture

This article reviewed the meaning and development of epilepsy in Chinese culture. The theories of Yin and Yang and the five elements, fundamentals of traditional Chinese medicine, were introduced, which form the context of understanding of the etiology, classification, and treatment of epilepsy in traditional Chinese medicine.

Synthesis of a tetrahomodioxacalix[4]arene tetraamide and the crystal structure of its lead ion complex

The 1,4-alternate tetrahomodioxacalix[4]arene tetraamide 4 with four p-phenyl groups on its upper rim was synthesized. In two-phase metal picrate extraction, 4 exhibited Pb2+ selectivity with formation of a 1:1 complex in chloroform. In the solid-state structure of the 4*Pb(Pic)2 complex, Pb2+ is bound by the carbonyl oxygens of two adjacent amide groups and an aryl-alkyl ether oxygen atom of one of these amide-containing substituents. The crystal structure and 1H NMR spectrum of the 4*Pb2+ complex reveals pi-metal ion complexation of one aromatic ring in the ligand with Pb2+.

Differential expression of various cytokine and chemokine genes between proliferative and non-proliferative glomerulonephritides

BACKGROUND

Intraglomerular cellular proliferation is one of the major determinants for dividing various glomerulonephritis (GN) into two groups, such as proliferative versus non-proliferative. Cytokines and chemokines are involved in the pathogenetic pathways and would affect the functional and histologic sequelae. We hypothesized that the morphological difference might be based on the differential intrarenal expression of various cytokines and chemokines. We quantified the intrarenal gene expression of various cytokines and chemokines, and correlated it with clinical parameters.

METHODS

Total RNA was extracted from 54 proliferative GN (PGN) core biopsy specimens and 42 non-proliferative GN (NPGN) specimens. Using the internal competitors, RT-PCR was instituted to quantify mRNAs.

RESULTS

The magnitude of the gene expressions of IL-2, IFN-gamma, and IFN-gamma/IL-10 ratio were significantly higher in PGN than in NPGN. RANTES and IL-8 had more abundant gene messages in PGN. It was shown that Th1 cytokine was upregulated if GN was mediated by immune complexes regardless of cellular proliferation. But chemokines had the elevated levels of expression in PGN among immune complex-mediated GN. Up-regulation of the IFN-gamma/IL-10 ratio and TNF-alpha was associated with poor renal function at the time of biopsy. Renal tissues from the patients with a non-nephrotic range of proteinuria showed abundant messages for proinflammatory cytokines and chemokines.

CONCLUSION

Th1, proinflammatory cytokines, and chemokines were more abundant in proliferative GN, and correlated with unfavorable clinical parameters. We propose that the clinical manifestations and diverse histologic features of human GN are associated with differential expressions of specific cytokines and chemokines.

Specific association of transcripts of tbzF and tbz17, tobacco genes encoding basic region leucine zipper-type transcriptional activators, with guard cells of senescing leaves and/or flowers

Induction by low temperature is a common feature of the lip19 subfamily members of the basic region leucine zipper gene family in plants. Here, we characterize two tobacco (Nicotiana tabacum) genes, tbzF and tbz17, belonging to the lip19 subfamily, whose gene products, TBZF and TBZ17, show 73% identity and are located in nuclei. They preferentially bind to DNA fragments spanning A-box/G-box and C-box/G-box hybrid motifs and show transactivation activity in cobombarded tobacco BY-2 cells, indicating they function as transcriptional activators. Transcripts of tbzF were detected at a high level in senescing leaves and flowers. In contrast, tbz17 transcripts could be shown to accumulate in aged leaves but not in flowers. In situ hybridization analysis revealed transcripts of tbzF and tbz17 to be predominantly located in guard cells and vascular tissues of senescing leaves. These results suggest that TBZF and TBZ17 are both involved in controlling gene transcription related to functions of guard cells in senescing leaves and that TBZF bifunctionally acts in floral development.

Evidence that Gal11 protein is a target of the Gal4 activation domain in the mediator

The mediator is an approximately 20 protein complex that is essential for the transcription of most genes in yeast. It is contacted by a number of gene-specific activators, but the details of these interactions are not well understood in most cases. Here, evidence is presented that the mediator component Gal11 represents at least one target of the Gal4 activation domain (AD). Deletion of Gal11 is shown to decrease the affinity of the Gal4 AD for the mediator, and direct binding of an N-terminal domain of Gal11 with the Gal4 AD is demonstrated. Quantitative studies, however, indicate that the K(D) of the 1:1 Gal4 AD--Gal11 complex is modest. Combined with in vivo data showing that Delta gal11 cells exhibit reduced, but still significant, Gal4-mediated gene expression, these results suggest that the dimeric activator might also contact another protein in the mediator in addition to Gal11.

Adenomatous polyposis coli gene mutation and decreased wild-type p53 protein expression in oral submucous fibrosis: a preliminary investigation

OBJECTIVE

The purpose of this study was to identify the adenomatous polyposis coli (APC) tumor suppressor gene mutation and level of wild-type p53 protein expression in patients with oral submucous fibrosis (OSF).

STUDY DESIGN

Cells from OSF and control subjects were cultured in Dulbecco modified Eagle medium with 10% fetal bovine serum at 37 degrees C. Genomic DNA was extracted from cultured cells and used as a template for polymerase chain reaction amplification of the APC tumor suppressor gene. The presence of wild-type p53 protein in cell lysates of cultured cells was analyzed by Western blot. Data were analyzed by the sign test for nonparametric samples and by analysis of variance.

RESULTS

The results showed that the APC gene of explant cultured cells from OSF patients (8/8) had a CGA-to-GGA transition mutation at codon 498 that resulted in an Arg-to-Gly missense mutation (P <.01). All (8/8) normal HGF cultures revealed expression of the wild-type APC protein. Cells cultured from 7 of 8 OSF patients were also found to have a single nucleotide deletion at nucleotide 1494 that resulted in creating a stop codon (TGA) at codon 504 (P <.01). This created a premature signal for the endpoint of translation and thus resulted in the generation of a truncated protein product that encodes a polypeptide of 503 amino acid residue. It was found that wild- type p53 protein in human gingival fibroblast cell cultures was significantly higher than in OSF cells (P <.01).

CONCLUSION

Alterations of the APC and wild-type p53 tumor suppressor genes in OSF may imply a risk for progression to oral cancer.

Association between insulin-like growth factor-2 and metastases after transcatheter arterial chemoembolization in patients with hepatocellular carcinoma: a prospective study

BACKGROUND

Hypoxia up-regulates insulin-like growth factor-2 (IGF-2) and thus stimulates the growth of hepatocellular carcinoma (HCC) cells. In the current study, the authors prospectively evaluated changes in plasma IGF-2 levels in HCC patients after transcatheter arterial chemoembolization (TACE), which usually results in hypoxic insult to liver tissue. The authors also examined the association between changes in plasma IGF-2 levels after TACE and HCC progression, especially in relation to metastasis.

METHODS

Plasma IGF-2 levels were measured before and 4 weeks after TACE in 46 patients with HCC. Three months after TACE, the patients were evaluated for the occurrence of metastatic HCC.

RESULTS

In 13 of the 46 patients, post-TACE plasma IGF-2 levels decreased by > 20% (Group 1) compared with their basal levels; in 18 patients, the IGF-2 levels changed within 20% (Group 2) and in 15 patients the IGF-2 levels increased by > 20% (Group 3). Plasma IGF-2 levels had a tendency to increase in patients with large-sized tumors, high serum alpha-fetoprotein (AFP) levels, and the heterogeneous uptake of iodized oil. Metastatic foci were found in 9 patients in Group 3 (60%), in contrast to only 3 patients in Group 2 (17%) and in none of the patients in Group 1 (P = 0.001). On multivariate analysis, higher Child-Pugh scores and increased plasma IGF-2 levels (Group 3) were found to be independent risk factors for metastasis.

CONCLUSIONS

Increased plasma IGF-2 levels after TACE, which are common in patients with large-sized tumors and high serum AFP levels, appear to be associated with the occurrence of metastatic HCC after TACE.

Staged reimplantation of total knee arthroplasty after Candida infection

Prosthetic joint infection with Candida is uncommon. Only 28 cases have been reported in the English literature. Successful reimplantation after eradication of Candida infection has been reported in 3 hip joints and only 1 knee. We present the case of a 68-year-old woman with chronic Candida parapsilosis infection of a prosthetic knee joint. Removal of the prosthesis, thorough débridement, and antifungal therapy treated the infection successfully. Antifungal therapy included 6 weeks of parenteral administration of fluconazole followed by 4 weeks of oral fluconazole. The involved knee joint was reimplanted 3 months after initial treatment. The prosthetic joint was pain free and functioned satisfactorily during the ensuing 4 years. No recurrence of infection was noted. The principle in treating Candida prosthetic infection generally has been the same as that of bacterial prosthetic infection. In chronic cases, removal of implants, thorough débridement, and effective antifungal therapy are mandatory for the eradication of infection. Reimplantation of the prosthesis can be performed successfully in a staged surgical procedure with the interval between the 2 stages shortened to 3 months.

Decreased serum IgE level, decreased IFN-gamma and IL-5 but increased IL-10 production, and suppressed cyclooxygenase 2 mRNA expression in patients with perennial allergic rhinitis after treatment with a new mixed formula of Chinese herbs

A new mixed formula of Chinese herbs containing Shin-yi-san + Xiao-qing-long-tang + Xiang-sha-liu-jun-zi-tang by the weight of 9 + 3 + 3 g/day was prescribed for the treatment of patients with perennial allergic rhinitis for 3 months (the composition of each herb is shown in the tables of the article). We classified the patients into high (H-IgE) and low IgE (L-IgE) groups according to the titer of serum total IgE (> 200 KIU/l in H-IgE vs. < 200 KIU/l in L-IgE) and the presence of house dust mite-specific IgE. The nasal symptomatic score in the high IgE group was significantly improved from 7.19 +/- 0.18 before treatment to 2.67 +/- 0.37 after treatment. In addition, the serum total and house dust mite-specific IgE level were also decreased after treatment. For elucidating the working mechanism of the mixed formula, the Th1 (IFN-gamma) and Th2 (IL-4, IL-5, IL-10 and IL-13) cytokine production by phytohemagglutinin (PHA)-stimulated mononuclear cells (2 x 10(6) cells/ml) and cyclooxygenase type 2 (COX-2) mRNA expression in LPS or IL-13-stimulated PMN were compared before and after 3 months of treatment. We found that the mixed formula treatment significantly enhanced IL-10 but decreased IFN-gamma and IL-5 production by PHA-stimulated mononuclear cells. The IL-5 production was also decreased by PHA-stimulated lymphocyte. In addition, the COX-2 mRNA expression in stimulated PMN was significantly suppressed after treatment. These results suggest that the new mixed formula treatment is beneficial to the patients with perennial allergic rhinitis via modulating the function of lymphocytes and neutrophils.

Comparison of blood counts in venous, fingertip and arterial blood and their measurement variation

We compared routine blood pictures in venous, fingertip and arterial blood and their measurement variation. A pair of venous and fingertip blood samples were simultaneously collected from 24 volunteers, and another pair of venous and arterial samples from another 12 volunteers. The volunteers were healthy adults, aged 20-22 years, with males and females in equal numbers. Three aliquots of blood were taken from each person for three measurements of blood counts, including haemoglobin concentration and haematocrit, using an automatic haematology analyser. Compared to arterial blood, there was a significant increase of erythrocyte count (2.7%) and haematocrit (3.1%) in the venous blood. The total and large leucocyte counts were significantly higher (9.2% and 12.6%, respectively) in the fingertip blood than in the venous blood. There were a decreasing number of leucocytes in the fingertip blood with repeated sampling. The intermeasurement variation for total leucocyte or haemoglobin measurement was significantly larger as measured with the fingertip blood or arterial blood than with the venous blood. The intermeasurement coefficients of variation of haemoglobin (1.3%) and small leucocyte ratio or platelet (approximately 4.0%) measurements with venous and arterial blood were the smallest and largest, respectively. Volume of arterial plasma was diminished by 2-3% after microcirculation. Elevation of total leucocyte count in the fingertip blood was mainly due to the increase of granulocytes. Measurement with venous blood was of better precision than with fingertip or arterial blood.

Sodium nitroprusside induces apoptosis of H9C2 cardiac muscle cells in a c-Jun N-terminal kinase-dependent manner

Sodium nitroprusside (SNP) induces apoptosis in H9C2 cardiac muscle cells. Treatment with an exogenous NO donor SNP (2 mM) to H9C2 cells resulted in apoptotic morphological changes; a bright blue-fluorescent condensed nuclei and chromatin fragmentation by fluorescence microscope of Hoechst 33258-staining. The activity of caspase-3 like protease was increased during SNP-induced cell death. However, the activity of caspase-1 like protease was not affected by SNP. Pretreatment with Z-VAD-FMK (a pan-caspase inhibitor) or Ac-DEVD-CHO (a specific caspase-3 inhibitor) abrogated the SNP-induced cell death. SNP markedly activated three MAP kinases (JNK/SAPK, ERK and p38 MAP kinase) in the cardiac muscle cells. In this study, selective inhibition of the ERK or p38 MAPK pathway (by PD98059 or SB203580, respectively) had no effect on the extent of SNP-induced apoptosis in cardiac muscle cells. In contrast, inhibition of the JNK pathway by transfection of a dominant negative mutant of JNK markedly reduced the extent of SNP-induced cell death. Taken together, we suggest that JNK/SAPK will be related to SNP-induced apoptosis of H9C2 cardiac muscle cells.

PCDD and PCDF exposures in workers and controls living near an industrial waste incinerator

This study measured the levels of 17 congeners of PCDDs/PCDFs in serum to compare the levels between potentially exposed workers at an industrial waste incinerator and any residents with no known exposures. The 1,2,3,6,7,8- and 1,2,3,7,8,9-HxCDD were detected in serum of workers but in controls. Likewise, 1,2,3,7,8-PeCDF, 1,2,3,6,7,8- and 1,2,3,7,8,9-HxCDF were detected only in serum of workers. The international toxic equivalent (TEQ) levels of PCDDs/PCDFs in sera of workers are much higher than in controls. Among PCDDs, the proportion of total concentration and TEQ level is dominated predominantly by 1,2,3,6,7,8- and 1,2,3,7,8,9-HxCDD. We need extensive studies to estimate human exposure and are continuing this investigation.

Ischemic bile duct injury as a serious complication after transarterial chemoembolization in patients with hepatocellular carcinoma

BACKGROUND

Bile duct injuries after transarterial chemoembolization (TACE) have been reported; however, the exact pathogenic mechanisms and clinical implications of the injuries remain to be clarified.

STUDY

A total of 950 consecutive patients with hepatocellular carcinoma (HCC) were studied. Among them, 807 were treated with TACE and the remaining 143 were treated with transarterial chemoinfusion (TACI) of cisplatin.

RESULTS

None of 143 patients with HCC treated with TACI were found to have any radiographic evidence of biliary injury. In contrast, of the 807 patients treated with TACE, 17 (2%) developed biliary complications. Of all complications, 12 (71%) were subcapsular bilomas; 3 (17%), focal strictures of the common hepatic duct or common bile duct; and 2 (12%), diffuse mild dilatation of the intrahepatic bile ducts. Interestingly, 2 of the 12 bilomas were found in the lobe that was not embolized with gelatin sponge particles. The median numbers of TACE tended to be greater in the patients with focal stricture than in those with bilomas (6.0 vs. 2.5; p = 0.08). All 3 patients with focal strictures and 4 of the 12 patients with bilomas had associated serious bacterial infections at presentation.

CONCLUSIONS

Bilomas seem to be caused by iodized oil rather than gelatin sponge particles; focal strictures of large bile ducts seem to be caused by gelatin sponge particles. We suggest that adjustments in the amounts of iodized oil or gelatin sponge particles and in the sites of embolization may reduce ischemic biliary injuries after TACE.

Levels of PCDDs and PCDFs in two kinds of fast foods in Korea

We initiated an attempt to gather preliminary Korean fast food data on the concentrations, whole weight and international toxic equivalent (TEQ), in two kinds of fast foods, hamburger and fried chicken. The levels of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) in hamburgers are detected to be lower than in fried chickens. Total TEQ level of PCDDs in fried chicken is 47.45 times higher than in hamburger. In case of PCDFs, it is 48.61 times. Even though these are compared to the only one brand and three samples each, we think that these high levels of PCDDs/PCDFs in fried chicken are very important data because of the potentially increasing daily intake. If we continue to survey for PCDDs/PCDFs in fast foods more even, especially fried chicken, these data will be useful to calculate the estimated daily intake of TEQ levels of PCDDs/PCDFs in Korea.

Vascular effects of synthetic or natural progestagen combined with conjugated equine estrogen in healthy postmenopausal women

BACKGROUND

Synthetic, not natural, progestagen may negate the favorable effects of estrogen. Nonetheless, observational studies report no differences in risk for clinical cardiovascular events between users of unopposed estrogen and users of estrogen combined with synthetic progestin.

METHODS AND RESULTS

In a double-blind study, we randomly assigned 20 healthy postmenopausal women to micronized progesterone (MP) 200 mg or medroxyprogesterone acetate (MPA) 10 mg for 10 days with conjugated equine estrogen (CEE) 0.625 mg for 25 days and the remaining 5 days off cyclically during 2 months, followed by crossover to the alternate therapy. CEE+MP and CEE+MPA significantly improved the percent flow-mediated dilator response to hyperemia relative to baseline measurements (P=0.004 by ANOVA) by a similar degree (P=0.863). Both therapies significantly decreased E-selectin, intercellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule (VCAM)-1 levels from baseline values (P<0.001, P=0.048, and P=0.016 by ANOVA, respectively) by a similar degree (P=0.977 for ICAM-1 and P=0.541 for VCAM-1, respectively). CEE+MPA decreased E-selectin levels more than CEE+MP did (P=0.040). Both therapies significantly decreased monocyte chemoattractant protein-1 levels from baseline values (P<0.005 by ANOVA) by a similar degree (P=0.194). Both therapies significantly decreased tissue factor antigen and increased tissue factor activity levels from baseline values (P=0.003 and P<0.001 by ANOVA, respectively) by a similar degree (P=0.652 for antigen and P=0.173 for activity). Both therapies significantly lowered plasma plasminogen activator inhibitor-1 levels from baseline values (P<0.001 by ANOVA) by a similar degree (P=0.533).

CONCLUSIONS

CEE+MP and CEE+MPA provide similar improvement in endothelium-dependent vasodilator responsiveness and effects on markers of inflammation, hemostasis, and fibrinolysis inhibition in healthy postmenopausal women.

Hepatitis C virus core protein promotes cell proliferation through the upregulation of cyclin E expression levels

AIMS/BACKGROUND

The hepatitis C virus (HCV) core protein is known to play an important role in hepatocarcinogenesis. Recent studies have suggested that the increased proliferation rate of hepatocytes is a major risk factor for the development of hepatocellular carcinoma. In this study, we investigated whether the HCV core protein promotes the cell growth rate through the modulation of cyclin E expression levels.

METHODS/RESULTS

HCV core stable transfectant Rat-1 cell lines showed a markedly increased proliferation rate compared to mock cells. Cyclin E expression and its associated kinase activities were remarkably increased in HCV core stable transfectants. Cyclin E mRNA levels were also upregulated in these cell lines.

CONCLUSIONS

Our data suggest that the HCV core protein promotes cell proliferation through upregulation of the cyclin E expression levels, implying this property of HCV core protein plays an important role in hepatocarcinogenesis.

Estrogens decrease reperfusion-associated cortical ischemic damage: an MRI analysis in a transient focal ischemia model

BACKGROUND AND PURPOSE

Early identification of irreversible cerebral ischemia is critical in defining strategies that influence neuronal survival after stroke. We used MRI to investigate the effects of 17beta-estradiol (E2) on the temporal evolution of focal ischemia.

METHODS

Female rats were ovariectomized and divided into 1 of 2 groups: ovariectomy alone (OVX; n=4) or ovariectomy with estrogen replacement (OVX+E2; n=3). Both groups were then subjected to 1-hour middle cerebral artery occlusion (MCAO), with the use of a standardized endovascular monofilament model, followed by reperfusion. Sequential diffusion-weighted (DWI) and T2-weighted (T2WI) MRI were obtained during and after the MCAO. In separate groups of animals (n=5 for OVX and OVX+E2), cerebral blood flow (CBF) was measured by laser-Doppler methods before, during, and after occlusion.

RESULTS

DWI detected similar lesion characteristics during MCAO in both groups. In the OVX group, lesion size did not change during reperfusion, but the signal intensity ratio increased early and stabilized during the latter stages. In contrast, DWI lesion size decreased during reperfusion in OVX+E2 rats by 50% to 60% (P<0.05), a size reduction almost exclusively limited to cortical regions. During MCAO, the signal intensity ratio in OVX+E2 rats was reduced compared with OVX rats. Reperfusion further attenuated the signal intensity ratio in cortical but not subcortical regions (P<0.05 versus OVX). T2WI revealed no lesions in either group during MCAO, but it detected lesion sizes similar to that of DWI during reperfusion. Furthermore, similar patterns and magnitudes of estrogen treatment-related decrease in lesion size were noted after reperfusion. T2WI demonstrated less intense signal intensity ratio changes in both groups compared with DWI. There were no differences in CBF between groups either during occlusion, early reperfusion, or 1 day after reperfusion.

CONCLUSIONS

This study strongly suggests that estrogens selectively protect cortical tissue from ischemic damage during MCAO and that this protection is exerted during both the occlusion and reperfusion phases of ischemia and does not involve an estrogen-related change in CBF.

Temporal recruitment of the mSin3A-histone deacetylase corepressor complex to the ETS domain transcription factor Elk-1

The transcriptional status of eukaryotic genes is determined by a balance between activation and repression mechanisms. The nuclear hormone receptors represent classical examples of transcription factors that can regulate this balance by recruiting corepressor and coactivator complexes in a ligand-dependent manner. Here, we demonstrate that the equilibrium between activation and repression via a single transcription factor, Elk-1, is altered following activation of the Erk mitogen-activated protein kinase cascade. In addition to its C-terminal transcriptional activation domain, Elk-1 contains an N-terminal transcriptional repression domain that can recruit the mSin3A-histone deacetylase 1 corepressor complex. Recruitment of this corepressor is enhanced in response to activation of the Erk pathway in vivo, and this recruitment correlates kinetically with the shutoff of one of its target promoters, c-fos. Elk-1 therefore undergoes temporal activator-repressor switching and contributes to both the activation and repression of target genes following growth factor stimulation.

Carcinoembryonic antigen in monitoring of response to systemic chemotherapy in patients with metastatic colorectal cancer

The response to chemotherapy of solid tumors is generally assessed by measuring tumors visualized by imaging. However, the response assessment based on imaging is not always feasible because patients often have disease not measurable by imaging, such as diffuse peritoneal dissemination. We evaluated the correlation between the change on imaging and change in CEA levels for assessing chemotherapeutic response of patients with metastatic colorectal cancer. Between July 1993 and August 1999 we retrospectively examined 136 patients with metastatic colorectal carcinoma, all of whom had measurable lesions. Forty patients received oral tegafur-uracil (300 mg/m2/day) plus folinic acid (60 mg/day) for 4 weeks, repeated every 5 weeks, as the firstline treatment. Another 96 patients received either a weekly intravenous bolus injection of 5-fluorouracil (400 mg/m2) plus folinic acid (20 mg/m2), or an intravenous bolus injection of 5-fluorouracil (425 mg/m2) plus folinic acid (20 mg/m2) for 5 consecutive days every month. Responders, based on CEA assessment, were defined as those with a greater than 50% drop in CEA level for more than 4 weeks. The pretreatment CEA levels were elevated beyond the normal cutoff value in 110 (81%) patients. A response rate of 18.4% (95% CI, 11.9-24.9%), including 8 complete remissions and 17 partial remissions, was achieved according to imaging studies. The response rate assessed by CEA was 25% (34/136). Sixteen responders (47%) based on CEA had no remission on imaging. The sensitivity of change in CEA levels in the prediction of true responders and progressive diseases on imaging were 72% and 81%, respectively. In terms of the positive predictive value, change in CEA levels in the prediction of true responders and progressive disease on imaging were 53% and 85%, respectively. Patients with remarkable falls on CEA levels survived significantly longer than nonresponders (P < 0.001, log-rank test). At follow-up of 48 months the median survival for responders and nonresponders assessed by CEA was 28 months and 13 months, respectively. These data suggest that measurement of CEA levels might be helpful in monitoring chemotherapeutic response when imaging study is unsuitable for assessing the response in clinical practice. Furthermore, measurement of CEA levels may be helpful in determining the prognosis of patients with metastatic colorectal cancer receiving chemotherapy.

Cytotoxicity and arecoline mechanisms in human gingival fibroblasts in vitro

Betel nut chewing, like cigarette smoking, is a popular oral habit which impinges on the daily lives of a population of approximately 200 million. People who chew betel nuts have a higher prevalence of periodontal diseases than those who do not. Many of the undesirable effects of betel nuts have been attributed to arecoline, a major component of the particular alkaloid in betel nuts. In this in vitro study, we have focused on the effects of arecoline and the role it could play in periodontal breakdown via its direct effects on human gingival fibroblasts. Human gingival fibroblasts were derived from three healthy individuals undergoing crown-lengthening procedures. We found that arecoline is cytotoxic to human gingival fibroblasts at a concentration higher than 50 micrograms/ml by depleting intracellular thiols and inhibiting mitochondrial activity (P < 0.05). In addition, the cells displayed a marked arrest at G2/M phase in a dose-dependent manner. Repeated and long-term exposure to arecoline could impair the gingival fibroblast functions. As they are cytotoxic, the use of betel nut products in conjunction with periodontal therapy may interfere with optimal healing and/or lead to further periodontal breakdown.

Effect on human attention of exposure to the electromagnetic field emitted by mobile phones

This study examined the effect of exposure to the electromagnetic field emitted by mobile phones on human attention. Three measures of attention were administered to 72 teenagers, 37 of whom were mobile phone users. The results showed that the mobile phone users performed better on one of the three measures of attention than did the non-mobile phone users. The results suggest that exposure to the electromagnetic field emitted by mobile phones may have a mild facilitating effect on attention functions, which is consistent with previous observations that exposure to the electromagnetic field has a facilitating effect on cognitive processing. The possibility that mobile phone users may be naturally better at multiple tasking tasks was discussed.

Neuroprotective effects of phenolic A ring oestrogens

We have formulated the 'phenolic A ring hypothesis' for the neuroprotective effects of oestrogens based upon several observations: (i) structure-activity relationships show that a phenolic A ring and at least two additional rings are required for neuroprotection while oestrogenicity requirements are more stringent; (ii) neuroprotection with phenolic A ring compounds occurs in cells that lack oestrogen receptors and are not antagonized by anti-oestrogens; (iii) phenolic A ring compounds rapidly activate a variety of signal transduction pathways that are known to be involved in cell homeostasis; and (iv) in vivo, treatment with oestrogens results in a neuronal type-independent neuronal protection from ischaemic insult. Potential mechanisms of actions that may be involved in the neuroprotective effects of phenolic A ring compounds are: (i) oestrogen redox cycling that potently inhibits oxidative stress; (ii) interactions with signal transduction pathways including the transcription factor cAMP response element binding protein; and (iii) induction of anti-apoptotic proteins. These signalling pathways may individually or collectively contribute to the plethora of neuronal cell types that are protected from a variety of insults by oestrogen-like compounds.

A Korean family with a dominantly inherited beta-thalassemia due to Hb Durham-N.C./Brescia

We describe the molecular and the hematological characteristics of a Korean family with a dominantly inherited beta-thalassemia. Carriers were characterized by moderate anemia, hypochromia, microcytosis, elevated Hb A2 and Hb F levels, and splenomegaly. DNA analysis revealed a CTG (Leu) to CCG (Pro) substitution at codon 114 of the beta-globin gene, that leads to a highly unstable hemoglobin variant, Hb Durham-N.C./Brescia, and this was linked to the beta haplotype V, [+----+-], and framework 2. RNA analysis showed that the proband had comparable levels of mutant and normal beta-mRNA. Translation of the mutant mRNA would give rise to non-functional hyperunstable beta-globin chains, and their degradation would, by placing an additional burden on the proteolytic process of the red blood cell precursors, result in a more severe phenotype.

17-beta estradiol can reduce secondary ischemic damage and mortality of subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a unique disorder commonly occurring when an aneurysm ruptures, leading to bleeding and clot formation, with a higher incidence in females. To evaluate the influence of 17-beta estradiol (E2) in the outcome of subarachnoid hemorrhage, SAH was induced by endovascular puncture of the intracranial segment of internal carotid artery in 15 intact females (INT), 19 ovariectomized females (OVX), and 13 ovariectomized female rats with E2 replacement (OVX + E2). Cerebral blood flow was recorded before and after SAH. All animals were decapitated immediately after death or 24 hours after SAH for clot area analysis. Brains were sliced and stained with 2,3,5-triphenyltetrazolium chloride (TTC) for secondary ischemic lesion analysis. The cortical cerebral blood flow (CBF), which was measured by a laser-Doppler flowmeter, decreased to 29.6%+/-17.7%, 22.8%+/-8.3%, and 43.5%+/-22.9% on the ipsilateral side (P = 0.01), and decreased to 63.4%+/-14.1%, 57.4%+/-11.0%, and 66.6%+/-17.9% on the contralateral side (P = 0.26) in INT, OVX, and OVX + E2, respectively. The subcortical CBF, which were measured by the H2 clearance method, were 7.77+/-12.03, 7.80+/-8.65, and 20.58+/-8.96 mL 100 g(-1) min(-1) on the ipsilateral side (P < 0.01), and 21.53+/-2.94, 25.13+/-3.01, and 25.30+/-3.23 mL 100 g(-1) min(-1) on the contralateral side in INT, OVX, and OVX + E2, respectively. The mortality was 53.3%, 68.4%, and 15.4% in INT, OVX, and OVX + E2, respectively (P = 0.01), whereas no significant difference in clot area was noted among the groups. The secondary ischemic lesion volume was 9.3%+/-8.4%, 24.3%+/-16.3%. and 7.0%+/-6.4% in INT, OVX, and OVX + E2, respectively (P < 0.01). This study demonstrated that E2 can reduce the mortality and secondary ischemic damage in a SAH model without affecting the clot volume.

Selective targeting of MAPKs to the ETS domain transcription factor SAP-1

MAPK pathways play important roles in regulating the key cellular processes of proliferation, differentiation, and apoptosis. There are multiple MAPK pathways, which are subject to different regulatory cues. It is important that these pathways maintain specificity in signaling to elicit the activation of a specific program of gene expression. MAPK-docking domains in several transcription factors have been shown to play important roles in determining the specificity and efficiency of their phosphorylation by MAPKs. Here we investigate the mechanisms by which MAPKs are targeted to the ETS domain transcription factor SAP-1. We demonstrate that SAP-1 contains two different domains that are required for its efficient phosphorylation in vitro and activation in vivo by ERK2 and a subset of p38 MAPKs. The D-domain is closely related to other MAPK-docking domains, but exhibits a novel specificity and serves to promote selective targeting of ERK2, p38alpha, and p38beta(2) to SAP-1. A second important region, the FXF motif, also plays an important role in directing MAPKs to phosphorylate SAP-1. The FXF motif promotes targeting by ERK2 and, to a lesser extent, p38alpha, but not p38beta(2). Our data therefore demonstrate that a modular system of motifs is responsible for directing specific MAPK subtypes to SAP-1, but also point to important distinctions in the mechanism of action of the D-domain and FXF motif.

Hepatitis C virus core protein inhibits interleukin 12 and nitric oxide production from activated macrophages

A characteristic feature of hepatitis C virus (HCV) infection is a high frequency of persistence and the progression to chronic liver diseases. Recent data suggest that prevalent T helper (Th) 2 immunity as well as weak HCV-specific T-cell response is associated with viral persistence. Here, we showed that the production of interleukin 12 (IL-12) and nitric oxide (NO) that is critical for the induction of Th1 and innate immunity, but not that of tumor necrosis factor alpha (TNF-alpha), was significantly suppressed in both HCV core-expressing macrophage cell lines and mouse peritoneal macrophages treated with recombinant core protein. In addition, IL-12 p40 promoter activity was repressed by the presence of HCV core in macrophages stimulated with lipopolysaccharride (LPS) following IFN-gamma treatment, indicating that IL-12 production may be downregulated at the transcriptional level. We also found that proliferation of T cells and IFN-gamma production in mixed lymphocyte reactions (MLR) with core-expressing cells were inhibited. Taken together, our results suggest that HCV core protein could play roles in suppressing the induction of Th1 immunity through inhibition of IL-12 and NO production.

Stress analysis of the distal locking screws for femoral interlocking nailing

In femoral locked nailing, the distal locking screws are vulnerable to mechanical failure. Biomechanical studies have shown that the stress on these screws is substantially affected by the fit of the nail in the medullary canal. In this study, a "closed form" mathematical model based on elastic beam-column theory was developed to investigate how the nail-cortical contact, which was simulated by a linear elastic foundation, affected the stress on the distal locking screws. Providing data for the model was a construct of a fractured femur with an intramedullary locked nail loaded by an eccentric vertical load. The stress on the locking screw was analyzed as a function of the distance from the fracture to the locking screw in the distal fragment under two situations: with and without nail-cortical contact in the distal fragment. With nail-cortical contact, the screw stress decreased as the length of nail-cortical contact and the distance between the distal locking screw and the fracture site increased, but this stress contrarily increased when the nail reached the femoral region at which the screw length increased. The screw stress was much higher without nail-cortical contact than with contact and continued to increase as the nail was inserted further. The mathematical model developed here can be a convenient means of rapid stress evaluation and parametric analysis for locked femoral nailing. It may be used to improve the design of interlocking nails and surgical technique.

The nonfeminizing enantiomer of 17beta-estradiol exerts protective effects in neuronal cultures and a rat model of cerebral ischemia

Estrogens are potent neuroprotective compounds in a variety of animal and cell culture models, and data indicate that estrogen receptor (ER)-mediated gene transcription is not required for some of these effects. To further address the requirement for an ER in estrogen enhancement of neuronal survival, we assessed the enantiomer of 17beta-estradiol (ENT-E(2)), which has identical chemical properties but interacts only weakly with known ERs, for neuroprotective efficacy. ENT-E(2) was both as potent and efficacious as 17beta-estradiol in attenuating oxidative stress-induced death in HT-22 cells, a murine hippocampal cell line. Further, ENT-E(2) completely attenuated H(2)O(2) toxicity in human SK-N-SH neuroblastoma cells at a 10 nM concentration. In a rodent model of focal ischemia, 17beta-estradiol (100 microgram/kg) or ENT-E(2) (100 microgram/kg), injected 2 h before middle cerebral artery occlusion, resulted in a 60 and 61% reduction in lesion volume, respectively. ENT-E(2), at the doses effective in this study, did not stimulate uterine growth or vaginal opening in juvenile female rats when administered daily for 3 days. These data indicate that the neuroprotective effects of estrogens, both in vitro and in vivo, can be disassociated from the peripheral estrogenic actions.

Definition of the anterior choroidal artery territory in rats using intraluminal occluding technique

This manuscript delineates the territory of the anterior choroidal artery (AChA) in rats, as defined by the induction of an AChA infarction. By advancing a 0.24-mm surgical suture up the internal carotid artery (ICA) to a point 0.5-2 mm proximal to the middle cerebral artery (MCA) origin, the AChA could be occluded and a reliable AChA distribution infarction was produced in 62% (23/37) of animals. The infarct volume, as defined by TTC staining, was 55+/-7 mm(3). Maps of the infarction, generated by measuring the entire area of overlapping coronal slices, demonstrated that the internal capsule was always damaged. Other areas that might be affected included the hippocampus, thalamus, amygdaloid complex, piriform cortex, dorsal caudatoputamen, and lateral ventricular wall. Positioning the coated suture proximal to the AChA produced a much smaller infarct involving the medial and lateral hypothalamus, preoptic region, optic chiasm, and marginal region of the internal capsule near to the lateral hypothalamus exempt from AChA territory damage. A causative relationship between AChA occlusion and a deep cerebral infarct centered on the internal capsule was further established by: (1) identifying the AChA on the non-ischemic side with colored silicone perfusion, and subsequent similar delineation on the ischemic side, and (2) delineating infarction in the silicone perfused AChA region using hematoxylin and eosin staining and the TUNEL method. The AChA usually originated from the ICA (91% of cases), 1.75+/-0.12 mm proximal to the MCA bifurcation. Approximately 27% of the AChAs had periamygdaloid branch(es) on its initial segment.

Expression of transforming growth factor beta-1 in chronic hepatitis and hepatocellular carcinoma associated with hepatitis C virus infection

BACKGROUND

Transforming growth factor beta-1 (TGF beta 1) has been suggested to play a role in the development, growth or progression of hepatocellular carcinoma (HCC). Genotype and serum titer of HCV also affect the occurrence of HCC in chronic hepatitis C. In this study, we were to evaluate the effects of genotype or serum titer of HCV on the expression of TGF beta 1. We also intended to examine the correlation between the up-regulation of TGF beta 1 and the association with HCC in patients with chronic hepatitis C.

METHODS

We studied 19 patients with chronic hepatitis C and 18 with HCC associated with HCV infection. HCV genotype was determined by line probe reverse hybridization assay and the amount of HCV-RNA was quantitated by branched DNA signal amplification assay. Serum TGF beta 1 level was measured by enzyme linked immunosorbent assay.

RESULTS

HCV genotypes of patients with HCC were similar to those without it. Serum HCV-RNA titer was higher in genotype 1b than in non-1b (p < 0.05). Serum TGF beta 1 levels were higher in HCC than in chronic hepatitis (p < 0.05). However, there was no significant difference in the serum TGF beta 1 level between genotype 1b and non-1b. Also, it was not correlated with the serum HCV-RNA titer or alanine aminotransferase levels.

CONCLUSION

TGF beta 1 seems to be overexpressed in HCC compared to that of chronic hepatitis C: it was not affected by serum ALT levels, genotype or serum HCV titer. It is suggested that TGF beta 1 may be associated with the malignant transformation of hepatocyte or the progression of HCV-associated HCC.

Randomized trial comparing weekly bolus 5-fluorouracil plus leucovorin versus monthly 5-day 5-fluorouracil plus leucovorin in metastatic colorectal cancer

BACKGROUND/AIMS

The purpose of this study was to compare the efficacy and toxicity profiles of weekly intravenous (i.v.) bolus injection of 5-fluorouracil plus low-dose leucovorin with the Mayo Clinics' monthly 5-day schedule of 5-fluorouracil and leucovorin in the treatment of metastatic colorectal cancer.

METHODOLOGY

A total of 96 patients with previously untreated metastatic colorectal cancer were randomized to receive either a weekly i.v. bolus injection of 5-fluorouracil 400 mg/m2 plus leucovorin 20 mg/m2 (weekly arm), or i.v. bolus injection of 5-fluorouracil 425 mg/m2 plus leucovorin 20 mg/m2 for 5 consecutive days every 4 or 5 weeks (monthly arm). Therapy was continued until disease progression or unacceptable toxicity appeared. In the presence of disease progression, the study regimen was stopped and second-line treatment was instituted after the patient was discontinued from this study.

RESULTS

There was no significant difference of response rates between both regimens. The response rate were 14.3% in the weekly arm (2 CR and 5 PR, 95% CI: 2.6-25.2%) and 10.6% in the monthly arm (1 CR and 4 PR; 95% CI: 6.5-32.3%), respectively (P = 0.8957). The survival times were also similar between the two (P = 0.4207, log-rank test). The median survival were 15.8 months in the monthly arm and 18.4 months in the weekly arm. Hematologic toxicity was minimal in both arms. However, the monthly arm produced a higher toxicity in severe (grade 3-4) diarrhea (14.9% vs. 2%; P = 0.029) and stomatitis (8.5% vs. 0; P = 0.054).

CONCLUSIONS

Weekly bolus injection of 5-fluorouracil and low-dose leucovorin achieved a similar response rate and survival as compared with the Mayo Clinics' monthly 5-day schedule, but severe toxicity was less commonly seen using the weekly regimen. As current chemotherapeutic treatment for metastatic colorectal cancer is largely palliative rather than curative, the weekly bolus regimen may be a more favorable approach in managing metastatic colorectal cancer.

Phase II study of oral tegafur-uracil and folinic acid as first-line therapy for metastatic colorectal cancer: Taiwan experience

BACKGROUND

Tegafur-uracil has become an important regimen in the treatment of metastatic colorectal cancer. Tegafur is a prodrug that is converted to 5-fluorouracil (5-FU) and has been reported to be less toxic and to have a higher therapeutic index. The additional advantage of tegafur is oral administration, an important consideration to improve the quality of life in these patients. Tegafur in combination with uracil is thought to have greater anti-tumor activity due to the inhibitory effect of uracil on the degradation of 5-FU by hepatic dihydropyrimidine dehydrogenase. Tegafur with folinic acid has been reported with modest efficacy and acceptable toxicity. The purpose of this study was to evaluate the effectiveness and toxicity profile of oral tegafur-uracil plus folinic acid in Chinese patients with metastatic colorectal cancer.

METHODS

Between May 1998 and August 1999, 40 patients with metastatic colorectal carcinoma were enrolled in this study. All the patients had to have measurable lesions. The initial dose of tegafur-uracil was 300 mg/m2/day for 28 days, followed by a 7-day rest period. Folinic acid was administered orally at a dose of 60 mg/day concurrently with tegafur-uracil. For patients with neutrophil count <1500/microl or a platelet count <100,000/microl after treatment, the treatment was postponed for a maximum of 2 weeks. After that time, if the neutrophil count was 1000-1500/microl and the platelet count was 70,000-100,000 microl, the dose of tegafur-uracil was reduced by 50%, and if lower values resulted, the treatment was discontinued.

RESULTS

Forty patients received a total of 318 courses of treatment and a response rate of 32.5% (95% CI, 18-47%), including five complete remissions and eight partial remissions, was achieved. Toxicity was mild and generally tolerable. Gastrointestinal toxicities, including diarrhea, nausea and vomiting, were the major side effects. Seven incidences (17.5%) of grade 3-4 gastrointestinal toxicity were observed. Hematological toxicities were minimal with no evidence of severe (grade 3 or 4) leukopenia and thrombocytopenia. No episode of hepatic, renal, cardiac or neurological toxicity occurred. Two patients (5%) developed transient painful fissuring erythroderma over their palms and soles (the hand-foot syndrome).

CONCLUSIONS

The data from our study indicate that oral tegafur-uracil plus folinic acid is an active and tolerable first-line treatment for Chinese patients with metastatic colorectal cancer, with the additional advantage of being easily administered at home.

Factors predictive of survival in patients with node-positive colorectal cancer in Taiwan

BACKGROUND/AIMS

Preoperative CEA levels, depth of tumor penetration, and the number of positive lymph nodes were reported as independent factors prognostic of survival in colorectal cancer patients. This study was carried out in an effort to evaluate the prognostic significance of these three factors in patients with Dukes' C colorectal cancer in Taiwan.

METHODOLOGY

Between 1992 and 1994, a total of 112 patients with node-positive colorectal cancer were evaluated retrospectively at the Veteran General Hospital-Taipei. All patients underwent potentially curative surgery and received 5-fluorouracil based adjuvant chemotherapy. Reference to the Dukes' classification was according to the classical criteria described in 1932 for carcinoma of the rectum and adapted for use in colonic tumors. Data on the location of the tumor, depth of penetration, number of positive lymph nodes, degree of tumor differentiation, and preoperative CEA levels were analyzed to understand their association with survival. Blood samples for CEA measurement were taken a few days before operation. A multivariate analysis using the Cox's proportional hazards regression model was then performed to determine the most important independent predictors of survival among all the possible variables.

RESULTS

Using univariate analysis the number of positive lymph nodes (P < 0.001), penetration of the bowel wall (P < 0.001), and preoperative CEA levels (P < 0.001) were found as significant prognostic factors, while the degree of tumor differentiation, location of the tumor, age and sex were not significant. Using multivariate Cox analysis the number of positive lymph nodes, penetration of the bowel wall, and preoperative CEA levels were still found as independent prognostic factors in node-positive colorectal cancer patients.

CONCLUSIONS

Data obtained from our study indicates that preoperative CEA levels, depth of tumor penetration, and the number of positive lymph nodes were independent prognostic factors in Dukes' C colorectal cancer patients. They could serve as appropriate modifications of the initial Dukes scheme in node-positive diseases.

DOH1, a class 1 knox gene, is required for maintenance of the basic plant architecture and floral transition in orchid

We report here the isolation and identification of an orchid homeobox gene, DOH1, from Dendrobium Madame Thong-In. Analyses of its sequence and genomic organization suggest that DOH1 may be the only class 1 knox gene in the genome. DOH1 mRNA accumulates in meristem-rich tissues, and its expression is greatly downregulated during floral transition. In situ hybridization analysis demonstrates that DOH1 is also expressed in the incipient leaf primordia and is later detected in the same region of the inflorescence apex, as in DOMADS1. Overexpression of DOH1 in orchid plants completely suppresses shoot organization and development. Transgenic orchid plants expressing antisense mRNA for DOH1 show multiple shoot apical meristem (SAM) formations and early flowering. In addition, both the sense and antisense transformants exhibit defects in leaf development. These findings suggest that DOH1 plays a key role in maintaining the basic plant architecture of orchid through control of the formation and development of the SAM and shoot structure. Investigations of DOMADS1 expression in the SAM during floral transition reveal that the precocious flowering phenotype exhibited by DOH1 antisense transformants is coupled with the early onset of DOMADS1 expression. This fact, together with the reciprocal expression of DOH1 and DOMADS1 during floral transition, indicates that downregulation of DOH1 in the SAM is required for floral transition in orchid and that DOH1 is a possible upstream regulator of DOMADS1.

Biochemical characterization of the TATA-binding protein-Gal4 activation domain complex

It has been suggested that complexes between gene-specific activators and the TATA-binding protein (TBP) play an important role in the expression of many genes. However, few detailed studies of well defined activator-TBP complexes have been reported. An analysis of the biochemical properties of the complex formed by the acidic activation domain (AAD) of the yeast activator Gal4 and TBP is presented here. This is shown to be composed of two AAD and one TBP molecule. DNA binding experiments reveal that TATA-containing DNAs and the Gal4 AAD bind TBP competitively, suggesting that the AAD and TATA boxes recognize overlapping surfaces of TBP. The kinetics of the formation and dissociation of the AAD(2)-TBP complex is also probed. The impact of these findings on models for Gal4-mediated transcriptional activation is considered.

Intracortical osteosarcoma: report of a case

Intracortical osteosarcoma is the rarest anatomic variation of osteosarcoma. There have been only 12 cases reported in the English-language literature. We present a case of osteosarcoma in an 18-year-old Taiwanese man that originated within the cortex of the tibial diaphysis. The initial radiograph revealed a lytic mass confined to the cortex, mimicking a benign bone lesion. Histopathologic examination of the biopsy specimen showed an osteoblastic osteosarcoma mingled with some fibroblastic foci. He underwent en bloc resection, and a metallic prosthetic intercalary stem was used to replace the larger bone defect. Adjuvant chemotherapy was administered before and after the operation. He was free of disease during 40 months of follow-up. A review of all reported cases of intracortical osteosarcoma revealed that the initial method of treatment plays an important role in local recurrence and distant metastasis. Local excision and curettage leads to the worst results. The outcomes of more recently reported cases have improved because of early awareness of the possibility of malignancy and advances in chemotherapy. However, whether patients with intracortical osteosarcoma have a different prognosis from those with conventional osteosarcoma cannot be determined, because of the small number of intracortical osteosarcoma cases available for analysis.

Experimental model of hepatic fibrosis following repeated periportal necrosis induced by allylalcohol

BACKGROUND/AIMS

In most patients with chronic viral hepatitis the predominant lobular location of hepatic necrosis and fibrosis is the periportal zone. We established a new simple model of hepatic fibrosis in rats by repetitive periportal necrosis with allylalcohol.

METHODS

Of 40 male adult rats, 30 were injected with 0.62 mmol/kg of allylalcohol intraperitoneally twice a week, the remaining 10 with normal saline as controls. Ten rats were killed at each of 4, 8, and 16 weeks later. The extent of fibrosis was evaluated according to the portal-portal extent. Transforming growth factor (TGF) beta1 mRNA in liver tissues was detected by reverse transcriptase polymerase chain reaction, and its levels were determined by the endpoint titers of serial two-fold dilutions of cDNA.

RESULTS

After 4 weeks, periportal fibrosis was produced in only 6 out of 10 rats, and was mild in extent. However, after 8 weeks, 8 out of 9 survivors showed moderate to severe fibrosis, which corresponded to a score of 7 or more. The extent of fibrosis correlated significantly with the amount of collagen and TGFbeta1 mRNA expression in liver tissues. The collagen content and expression of TGFbeta1 mRNA were also upregulated significantly in liver tissues with a fibrosis score of 7 or more.

CONCLUSIONS

Hepatic fibrosis can be sufficiently induced by repetitive intraperitoneal injection of 0.62 mmol/kg of allylalcohol twice a week for 8 weeks. This simple model of hepatic fibrosis, in which TGFbeta1 is overexpressed at the transcriptional level, may be useful in the study of patients who have predominantly periportal necrosis and fibrosis.