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.