[Effects of protein kinase C activity on CD44 expression and subcellular distribution in human erythrocytes]

The study was aimed to investigate the effects of protein kinase C (PKC) on standard type CD44 expression and subcellular distribution in human erythrocytes. PKC activity was detected by the incorporation of [gamma-(32)P]-ATP into exogenous substrate, phosphorylation of CD44 was determined by autoradiograph, distribution of CD44 was observed by indirect immunofluorescence, and expression of CD44 was analyzed by flow cytometry. The results showed that PKC activity reached the maximal level at 30 minutes after treatment with phorbol-myristate-acetate (PMA), and the peak of CD44 phosphorylation and CD44 expression appeared at the same time, which all increased significantly as compared with control group (p < 0.001). PKC activation resulted in CD44 aggregation on membrane and colocalization of PKC and CD44. Calphostin C could inhibit the above reaction resulted from PKC activation. It is concluded that PKC activation can up-regulate CD44 expression by phosphorylation, and result in the coherent migration and colocalization of CD44 and PKC in human erythrocytes.

Intracellular oxidative stress and cadmium ions release induce cytotoxicity of unmodified cadmium sulfide quantum dots

OBJECTIVE

To fully understand the cytotoxicity of after-degradation QDs, we synthesized CdS QDs and investigated its toxicity mechanism.

METHODS

Biomimetic method was proposed to synthesize cadmium sulfide (CdS) QDs. Thereafter MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay was conducted to evaluate their cytotoxicity. To investigate the toxicity mechanism, we subsequently conducted intracellular reactive oxygen species (ROS) measurement with DCFH-DA, glutathione (GSH) measurement with DTNB, and cellular cadmium assay using atomic absorption spectrometer. Microsized CdS were simultaneously tested as a comparison.

RESULTS

MTT assay results indicated that CdS QDs are more toxic than microsized CdS especially at concentrations below 40 microg/ml. While microsized CdS did not trigger ROS elevation, CdS QDs increase ROS by 20-30% over control levels. However, they both deplete cellular GSH significantly at the medium concentration of 20 microg/ml. In the presence of NAC, cells are partially protected from CdS QDs, but not from microsized particles. Additionally, nearly 20% of cadmium was released from CdS nanoparticles within 24h, which also accounts for QDs' toxicity.

CONCLUSION

Intracellular ROS production, GSH depletion, and cadmium ions (Cd(2+)) release are possible mechanisms for CdS QDs' cytotoxicity. We also suggested that with QD concentration increasing, the principal toxicity mechanism changes from intracellular oxidative stress to Cd(2+) release.

Nanoparticles and 3D sponge-like porous networks of manganese oxides and their microwave absorption properties

Hydrohausmannite nanoparticles (approximately 10 nm) were prepared by the hydrothermal method at 100 degrees C for 72 h. Subsequent annealing was done in air at 400 degrees C and 800 degrees C for 10 h, Mn(3)O(4) nanoparticles (approximately 25 nm) and 3D Mn(2)O(3) porous networks were obtained, respectively. The products were characterized by XRD, TEM, SAED and FESEM. Time-dependent experiments were carried out to exhibit the formation process of the Mn(2)O(3) networks. Their microwave absorption properties were investigated by mixing the product and paraffin wax with 50 vol%. The Mn(3)O(4) nanoparticles possess excellent microwave absorbing properties with the minimum reflection loss of -27.1 dB at 3.1 GHz. In contrast, the Mn(2)O(3) networks show the weakest absorption of all samples. The absorption becomes weaker with the annealing time increasing at 800 degrees C. The attenuation of microwave can be attributed to dielectric loss and their absorption mechanism was discussed in detail.

Epitaxial Growth of InN Films by Molecular-Beam Epitaxy Using Hydrazoic Acid (HN3) as an Efficient Nitrogen Source

Epitaxial InN films have been successfully grown on c-plane GaN template by gas-source molecular-beam epitaxy with hydrazoic acid (HN3) as an efficient nitrogen source. Results in residual-gas analyzer show that the HN3 is highly dissociated to produce nitrogen radicals and can be controlled in the amounts of active nitrogen species by tuning HN3 pressure. A flat and high-purity InN epifilm has been realized at the temperature near 550 degrees C, and a growth rate of 200 nm/hr is also achieved. Moreover, the epitaxial relationship of the InN(002) on the GaN(002) is reflected in the X-ray diffraction, and the full-width at half-maximum of the InN(002) peak as narrow as 0.05 degrees is related to a high-quality crystallinity. An infrared photoluminescence (PL) emission peak at 0.705 eV and the integrated intensity increasing linearly with excitation power suggest that the observed PL can be attributed to a free-to-bound recombination.

Voxel-based analysis of the evolution of magnetization transfer ratio to quantify remyelination and demyelination with histopathological validation in a multiple sclerosis lesion

We present a new method for advanced image processing to separately quantify significant decreases and increases in the magnetization transfer ratio (MTR) of individual voxels of MS lesions as markers of demyelination and remyelination. We used this method to analyze the evolution of MTR in individual voxels of an acute, Gadolinium (Gd)-enhancing lesion that was available for pathology. Over 6.5 months following enhancement, MTR was low and stable in the lesion center (81% of the initially Gd-enhancing lesion volume (GdLV)) and MTR increased at the lesion border with normal-appearing white matter (14%GdLV). The estimated error of these measurements was less than 1.8%GdLV based on scan/rescan analysis. Histopathological analysis confirmed a demyelinated lesion centre with diffuse presence of macrophages/microglia and marked loss of oligodendrocytes and a partially remyelinated lesion border with diffuse presence of macrophages/microglia and relatively more oligodendrocytes compared to the lesion centre. The correlation of imaging and histopathological findings support the validity and sensitivity of our method of voxel-based MTR image processing for monitoring demyelination and remyelination in vivo.

Multiple sclerosis conference synopsis and discussion: cellular therapy for treatment of autoimmune diseases (October 2005)

At a conference held in October 2005, participants presented studies on high dose immunosuppression with hematopoietic cell transplant (HCT) for multiple sclerosis (MS), including neuroimmunological and magnetic resonance imaging (MRI) mechanistic approaches, clinical registry reports, and ongoing or newly-designed protocols. A discussion panel considered questions on how to define success, timing of controlled clinical trials, difficulty in patient recruitment, and future direction of high dose therapy.

The relation of focal white matter signal abnormality and focal volume loss in multiple sclerosis

There were two aims to this study. First, to explore how the reduction in the volume of abnormal T2-signal intensity associated with white matter (WM) lesions in multiple sclerosis (MS) relates to tissue loss resulting from focal pathology inside lesions. Second, to demonstrate that this volume of abnormal T2-signal intensity underestimates the actual size of the region to which the direct effects of lesion activity extend. For these purposes, we used deformation field analysis to quantify the evolution of local atrophy associated with a chronic peri-ventricular lesion in a patient with secondary progressive MS. This subject had particular features that may not necessarily co-exist in a group of unselected patients, which enabled interesting observations to be made. We show, quantitatively, that the focal WM lesion was associated with adjacent regional WM volume loss, which was disproportionate to concurrent diffuse atrophy in the rest of the normal appearing brain tissue, and that the loss of volume associated with the lesion was partially reciprocated by local ventricular expansion. Our observations re-emphasise the complex relationship between the change in the volume of abnormal signal intensity on magnetic resonance images and the tissue volume change directly related to lesion pathology. Multiple Sclerosis 2007; 13: 809-813. http:// msj.sagepub.com

Comparing individual- and area-based socioeconomic measures for the surveillance of health disparities: A multilevel analysis of Massachusetts births, 1989-1991

The absence of individual-level socioeconomic information in most US health surveillance data necessitates using area-based socioeconomic measures (ABSMs) to monitor health inequalities. Using the 1989-1991 birth weight data from Massachusetts, the authors compared estimates of health disparities detected with census tract- and block group-level ABSMs pertaining to poverty and education, as well as parental education, both independently and together. In separate models, adjusted for infant's sex, mother's age, and parents' race/ethnicity, worst-off categories of census tract ABSMs and parental education had a comparable birth weight deficit of approximately 70 g. Similar results were observed for low birth weight (<2,500 g), with worst-off categories of census tract ABSMs and parental education having an odds ratio of approximately 1.37 (p < 0.001). In mutually adjusted models for birth weight and low birth weight, census tract ABSMs still detected an effect estimate nearly 50% of that detected by parental education. Additionally, census tract ABSMs detected socioeconomic gradients in birth weight among births to mothers aged less than 25 years, an age group in which educational attainment is unlikely to be completed. These results suggest that aptly chosen ABSMs can be used to monitor socioeconomic inequalities in health. The risk, if any, in the absence of individual-level socioeconomic information is a conservative estimate of socioeconomic inequalities in health.

Comparing individual- and area-based socioeconomic measures for the surveillance of health disparities: A multilevel analysis of Massachusetts births, 1989-1991

The absence of individual-level socioeconomic information in most US health surveillance data necessitates using area-based socioeconomic measures (ABSMs) to monitor health inequalities. Using the 1989-1991 birth weight data from Massachusetts, the authors compared estimates of health disparities detected with census tract- and block group-level ABSMs pertaining to poverty and education, as well as parental education, both independently and together. In separate models, adjusted for infant's sex, mother's age, and parents' race/ethnicity, worst-off categories of census tract ABSMs and parental education had a comparable birth weight deficit of approximately 70 g. Similar results were observed for low birth weight (<2,500 g), with worst-off categories of census tract ABSMs and parental education having an odds ratio of approximately 1.37 (p < 0.001). In mutually adjusted models for birth weight and low birth weight, census tract ABSMs still detected an effect estimate nearly 50% of that detected by parental education. Additionally, census tract ABSMs detected socioeconomic gradients in birth weight among births to mothers aged less than 25 years, an age group in which educational attainment is unlikely to be completed. These results suggest that aptly chosen ABSMs can be used to monitor socioeconomic inequalities in health. The risk, if any, in the absence of individual-level socioeconomic information is a conservative estimate of socioeconomic inequalities in health.

Brain atrophy after immunoablation and stem cell transplantation in multiple sclerosis

The authors measured brain atrophy in nine patients undergoing immunoablation and autologous hematopoietic stem cell transplantation for multiple sclerosis. From baseline to 1 month after treatment, atrophy was 10 times faster than before treatment. A patient with non-CNS lymphoma showed comparable acute brain atrophy after analogous therapy. These observations suggest that brain atrophy after immunoablation may not be due entirely to the resolution of edema but may be related to chemotoxicity.

Lead inhibited N-methyl-D-aspartate receptor-independent long-term potentiation involved ryanodine-sensitive calcium stores in rat hippocampal area CA1

Lead exposure is known to be associated with cognitive dysfunction in children. Impairment of the induction of long-term potentiation (LTP) has been reported in area CA1 of rat hippocampus following lead exposure in vivo and in vitro. The present study was carried out to investigate whether the alterations of N-methyl-d-aspartate (NMDA) receptor-independent LTP following lead exposure involve internal calcium stores in hippocampus CA1 synapses. Monosynaptic field excitatory postsynaptic potentials in hippocampal slice area CA1 were recorded using the whole-cell patch-clamp upon acute lead treatment, and these studies were coupled with calcium imaging experiments to observe internal calcium changes in cultured hippocampal neurons. Inhibiting calcium release by ryanodine significantly reduced NMDA receptor-independent LTP, and depletion of internal calcium stores with thapsigargin blocked this form of LTP. Caffeine, an agonist of ryanodine receptors, enhanced this form of LTP. However, caffeine-enhanced NMDA receptor-independent LTP was depressed after bath application of lead. Moreover, lead further decreased ryanodine- and thapsigargin-reduced NMDA receptor-independent LTP. Calcium imaging also confirmed that lead had an effect on internal calcium release and uptake. Taken together, these results demonstrated that lead inhibited NMDA receptor-independent LTP by action on calcium release and uptake by ryanodine-sensitive stores in rat hippocampal area CA1.

Local magnetization transfer ratio signal inhomogeneity is related to subsequent change in MTR in lesions and normal-appearing white-matter of multiple sclerosis patients

Multiple sclerosis (MS) lesions show differing degrees of demyelination and remyelination. Changes in myelin content are associated with changes in magnetization transfer on MRI. Since acute inflammation and demyelination are spatially and temporally inhomogeneous, we hypothesized that local magnetic transfer ratio (MTR) heterogeneity might be predictive of subsequent changes in MTR. To test this hypothesis, we analyzed MTR images obtained in 14 subjects, at baseline and after 2 months follow-up. We segmented lesions and normal-appearing white-matter (NAWM), calculated MTR signal inhomogeneity maps at baseline and MTR lesion difference maps between baseline and follow-up. We found that regions with low MTR inhomogeneity at baseline experienced little further change in MTR on follow-up. The mean change in lesion MTR between baseline and follow-up was 0.10 +/- 3.70; in NAWM it was -0.09 +/- 2.02. We found that regions with high MTR inhomogeneity at baseline would change MTR on follow-up: (1) voxels with significantly high MTR in regions of high MTR inhomogeneity at baseline showed a mean decrease in MTR between baseline and follow-up of -2.51 +/- 4.68 in lesions and -1.41 +/- 3.00 in NAWM; (2) voxels with low MTR in regions of high MTR inhomogeneity at baseline showed a mean increase in MTR between baseline and follow-up of 2.61 +/- 6.07 in lesions. These changes in MTR were significantly different (P < 0.001). These results suggest that calculation of MTR signal inhomogeneity may provide a method for quantifying the potential for remyelination and demyelination, and thus could provide an important MRI biomarker for assessing the efficacy of therapies targeting remyelination.

CO(2) sensitivity of voltage gating and gating polarity of gapjunction channels--connexin40 and its COOH-terminus-truncated mutant

The CO(2) sensitivity of transjunctional voltage ( V(j)) gating was studied by dual voltage clamp in oocytes expressing mouse Cx40 or its COOH terminus (CT)-truncated mutant (Cx40-TR). V(j) sensitivity, determined by a standard V(j) protocol (20 mV V(j) steps, 120 mV maximal), decreased significantly with exposure to 30% CO(2). The Boltzmann values of control versus CO(2)-treated oocytes were: V(0) = 36.3 and 48.7 mV, n = 5.4 and 3.7, and G(j min) = 0.21 and 0.31, respectively. CO(2) also affected the kinetics of V(j)-dependent inactivation of junctional current ( I(j)); the time constants of two-term exponential I(j) decay, measured at V(j) = 60 mV, increased significantly with CO(2) application. Similar results were obtained with Cx40-TR, suggesting that CT does not play a role in this phenomenon. The sensitivity of Cx40 channels to 100% CO(2) was also unaffected by CT truncation. There is evidence that CO(2) decreases the V(j) sensitivity of Cx26, Cx50 and Cx37 as well, whereas it increases that of Cx45 and Cx32 channels. Since Cx40, Cx26, Cx50 and Cx37 gate at the positive side of V(j), whereas Cx45 and Cx32 gate at negative V(j), it is likely that V(j) behavior with respect to CO(2)-induced acidification varies depending on gating polarity, possibly involving the function of the postulated V(j) sensor (NH(2)-terminus).

Relating neocortical pathology to disability progression in multiple sclerosis using MRI

Cortical grey matter (cGM) develops a substantial burden of pathology in multiple sclerosis (MS). Previous cross-sectional studies have suggested a relationship between measures of cortical atrophy and disability. Our objective was to develop a method for automatically measuring the apparent cGM thickness as well as the integrity of the interface between cGM and subcortical white matter (GM/WM) both globally and regionally on T(1)-weighted MRI, and use this method in a longitudinal investigation of how these measures differed between patients with stable MS and patients with progressing disability. Measurements were made over the whole brain and for anatomically specified cortical regions, both cross-sectionally at baseline and longitudinally on two MRI scans performed on average 1 year apart. We found a higher average rate of apparent loss of cGM thickness across the whole brain in the group that progressed over the interscan interval compared to the group that remained stable (progressing = -3.13 +/- 2.88%/year, stable = 0.06 +/- 2.31%/year, P = 0.002). This difference was detected with regional measures in parietal and precentral cortex. In contrast, change in the GM/WM interface integrity did not show detectable regional differences, although the group of MS patients whose disability progressed showed a significant decrease in GM/WM interface integrity compared to the stable group (P = 0.003). Regional measures of apparent loss of cGM thickness enhance sensitivity to cortical pathological changes. A measure of integrity offers a new index of disease-associated cortical changes at the GM/WM interface. The results suggest that progression of disability in MS is associated with the progression of MRI-detectable cortical pathology.

Choosing area based socioeconomic measures to monitor social inequalities in low birth weight and childhood lead poisoning: The Public Health Disparities Geocoding Project (US)

STUDY OBJECTIVES

: To determine which area based socioeconomic measures can meaningfully be used, at which level of geography, to monitor socioeconomic inequalities in childhood health in the US.

DESIGN

Cross sectional analysis of birth certificate and childhood lead poisoning registry data, geocoded and linked to diverse area based socioeconomic measures that were generated at three geographical levels: census tract, block group, and ZIP code.

SETTING

Two US states: Massachusetts (1990 population=6,016,425) and Rhode Island (1990 population=1,003,464).

PARTICIPANTS

All births born to mothers ages 15 to 55 years old who were residents of either Massachusetts (1989-1991; n=267,311) or Rhode Island (1987-1993; n=96 138), and all children ages 1 to 5 years residing in Rhode Island who were screened for lead levels between 1994 and 1996 (n=62,514 children, restricted to first test during the study period).

MAIN RESULTS

Analyses of both the birth weight and lead data indicated that: (a) block group and tract socioeconomic measures performed similarly within and across both states, while ZIP code level measures tended to detect smaller effects; (b) measures pertaining to economic poverty detected stronger gradients than measures of education, occupation, and wealth; (c) results were similar for categories generated by quintiles and by a priori categorical cut off points; and (d) the area based socioeconomic measures yielded estimates of effect equal to or augmenting those detected, respectively, by individual level educational data for birth outcomes and by the area based housing measure recommended by the US government for monitoring childhood lead poisoning.

CONCLUSIONS

Census tract or block group area based socioeconomic measures of economic deprivation could be meaningfully used in conjunction with US public health surveillance systems to enable or enhance monitoring of social inequalities in health in the United States.

Effect of thiopental, propofol, and etomidate on vincristine toxicity in PC12 cells

Neurotoxicity is the dose-limiting side-effect of vincristine in cancer therapy. Using the nerve growth factor (NGF)-dependent neurite outgrowth and cell proliferation of the PC12 pheochromocytoma cell line as an in vitro assay, the protective effect of different intravenous anesthetics was assessed. Vincristine (1 nmol/L) significantly decreased the percentage of neurite-forming cells from 68% +/- 9% to 27% +/- 7% within a 3-day incubation period. The longer neurites (> 2 x cell body) in particular proved to be extremely sensitive to vincristine (from 17% +/- 4% to 0% of total neurite-expressing cells). Flow cytometry results revealed an S-phase percentage of 15.85% +/- 3.25% after NGF induction, with vincristine reducing this percentage to 0.68% +/- 0.38%. Reversal of the inhibitory effect of vincristine was noted in the cells treated with thiopental or propofol but not etomidate. Bicuculline partially antagonized the protective effect of thiopental and propofol in both studies. We conclude that thiopental and propofol, but not etomidate, have a protective effect in vincristine-induced neurotoxicity. The protective effect produced by thiopental and propofol is probably secondary to activation of GABAA receptors.

Expression of apoptosis-regulating proteins p53, Bcl-2, and Bax in primary resected esophageal squamous cell carcinoma

Apoptosis plays a key role in the pathogenesis, aggressiveness, and therapy responsiveness of cancer. Proteins of the Bcl-2 family as well as p53 are important regulators of apoptosis. The present study retrospectively examines the expression of apoptosis-regulating proteins in primary resected esophageal squamous cell carcinoma (ESCC) and the correlation between the outcome of patients' treatment and the expression of the proteins. We used antibodies specific for the human p53, Bcl-2 and Bax proteins to examine the expression of these apoptosis-regulating proteins in 40 archival specimens of patients with primary resected esophageal squamous cell carcinoma. The overall expression of p53, Bcl-2, and Bax was 73%, 18%, and 100%, respectively. No significant correlations were found between the expression of p53, Bcl-2, and Bax. The expression of Bcl-2 had a negative influence on survival in this population of primary resected ESCC patients (p=0.03). But no differences in survival were observed in relation to the expression of p53 or Bax. In conclusion, Bcl-2 expression may provide additional and prognostic information for the clinical course of the disease and therefore to be developed as a prognostic indicator for primary resected esophageal squamous cell carcinoma.

Intra-abdominal actinomycosis with hepatic pseudotumor and xanthogranulomatous pyelonephritis in a 6-y-old boy

We report the case of a 6-y-old boy with actinomycosis, presenting as xanthogranulomatous pyelonephritis (XGP), hepatic pseudotumor and abdominal abscess. Symptoms included intermittent fever, abdominal pain and significant weight loss. Hepatic and renal tumor masses were suspected on sonography and computerized tomography. XGP and actinomycosis were proven by pathology. The patient recovered well with antibiotic alone.

Comparative genomic hybridization of esophageal squamous cell carcinoma: correlations between chromosomal aberrations and disease progression/prognosis

BACKGROUND

Esophageal carcinoma is a major cause of cancer-related deaths among males in Taiwan. However, to date, the genetic alterations that accompany this lethal disease are not understood.

METHODS

Chromosomal aberrations of 46 samples of esophageal squamous cell carcinoma (EC-SCC) were analyzed by comparative genomic hybridization (CGH), and their correlations with pathologic staging and prognosis were analyzed statistically.

RESULTS

In total, 321 gains and 252 losses were found in 46 tumor samples; thus, the average gains and losses per patient were 6.98 and 5.47, respectively. Frequent gain abnormalities were found on chromosome arms 1q, 2q, 3q, 5p, 7p, 7q, 8q, 11q, 12p, 12q, 14q, 17q, 20q, and Xq. Frequent deletions were found on chromosome arms 1p, 3p, 4p, 5q, 8p, 9p, 9q, 11q, 13q, 16p, 17p, 18q, 19p, and 19q. It was found that deletions of 4p and 13q12-q14 and gain of 5p were significantly correlated with pathologic staging. Losses of 8p22-pter and 9p also were found more frequently in patients with advanced disease. Gain of 8q24-qter was seen more frequently in patients with Grade 3 tumors. A univariate analysis found that pathologic staging; gains of 5p and 7q; and deletions of 4p, 9p, and 11q were significant prognostic factors. However, pathologic staging became the only significant factor in a multivariate analysis.

CONCLUSIONS

CGH not only revealed novel chromosomal aberrations in EC-SCC, but also found possible genotypic changes associated with disease progression. Despite all of the possible associations of chromosomal aberrations with disease progression, the most important prognostic factor for patients with EC-SCC was pathologic staging.

Liver resection for hepatocellular carcinoma in patients with end-stage renal failure

BACKGROUND AND OBJECTIVES

Surgical resection remains the main option for curing hepatocellular carcinoma (HCC). However, liver resection in patients with end-stage renal disease (ESRD) is risky. The aim of this study is to clarify the role of liver resection for treating HCC in patients with ESRD.

METHODS

A retrospective review was carried out on 468 patients who underwent liver resection for HCC between 1989 and 1999. The clinicopathological characteristics and operative results of 12 patients who had ESRD (ESRD group) were compared with those of the other 456 patients who did not have ESRD (non-ESRD group). In the ESRD group, heparin-free hemodialysis using the periodic saline-rinse method was performed during the perioperative period.

RESULTS

The ESRD group had lower hemoglobin and a higher serum creatinine levels. Other patient background and tumor pathological characteristics were comparable between the two groups as well. The operative morbidity and mortality between the two groups were also similar. The 5-year disease-free survival rates for ESRD and non-ESRD groups were 35.0 and 34.2% (P = 0.31), respectively, while the 5-year actuarial survival rates were 67.8 and 53.3% (P = 0.54), respectively.

CONCLUSION

With improving techniques and knowledge of dialysis, liver resection for HCC is justified in selected patients with ESRD.

Effects of Fe(2+) on ion channels: Na(+) channel, delayed rectified and transient outward K(+) channels

The effects of Fe(2+) on the properties of three types of ion channels were studied in acutely dissociated rat hippocampal pyramidal neurons from area CA1 at postnatal ages of 7-14 days using the whole cell patch clamp technique. The results indicated that: (1) in the existence of Fe(2+), the activation voltage threshold of transient outward K(+) currents (I(A)) was decreased. The normalized current-voltage curves of activation were well fitted with a single Boltzmann function, and the V(1/2) was 2.44+/-1.14 mV (n=15) in control, whereas 1.79+/-1.53 (n=15), -2.96+/-0.92 (n=14), -5.11+/-1.31 (n=13), -9.05+/-1.64 mV (n=12) in 1, 10, 100 and 1000 microM Fe(2+), respectively. Differences between two groups were significant (P<0.05, n=12-15), except for that between the control and 1 microM (P>0.05, n=15). (2) Fe(2+) caused a left shift of the current-voltage curves of steady-state inactivation of I(A) in a concentration-dependent manner. The curves were well fitted with a single Boltzmann function with similar slope (P>0.05, n=10-13). The V(1/2) were -70.71+/-1.23 (n=13), -71.14+/-1.37 (n=13), -78.21+/-1.17 (n=11), -84.61+/-1.34 (n=12), and -89.68+/-2.59 mV (n=10) in control, 1, 10, 100 and 1000 microM Fe(2+), respectively. Fe(2+) also shifted the current-voltage curves of Na(+) channel steady-state inactivation to more negative depolarization potentials in parallel, with V(1/2), -67.37+/-1.33 mV (n=12) in control, and -67.52+/-1.28 mV (n=12), -68.24+/-1.61 mV (n=10), -71.58+/-1.45 mV (n=10), -76.65+/-1.76 mV (n=9) in 1, 10, 100 and 1000 microM Fe(2+) solutions, respectively. (3) In Fe(2+) solutions, the recovery from inactivation of I(A) was slowed. (4) With application of different concentrations of Fe(2+), the voltage threshold of activation of delayed rectified outward K(+) currents (I(K)) was decreased, while Fe(2+) showed a little inhibition at more positive depolarization. Briefly, the results demonstrated that Fe(2+) is a dose- and voltage-dependent, reversible modulator of I(A), I(K) and Na(+) channels. The results will be helpful to explain the mechanism of Fe(2+) physiological function and Fe(2+) intoxication in the central nervous system.

Comparative genomic hybridization of esophageal squamous cell carcinoma: correlations between chromosomal aberrations and disease progression/prognosis

BACKGROUND

Esophageal carcinoma is a major cause of cancer-related deaths among males in Taiwan. However, to date, the genetic alterations that accompany this lethal disease are not understood.

METHODS

Chromosomal aberrations of 46 samples of esophageal squamous cell carcinoma (EC-SCC) were analyzed by comparative genomic hybridization (CGH), and their correlations with pathologic staging and prognosis were analyzed statistically.

RESULTS

In total, 321 gains and 252 losses were found in 46 tumor samples; thus, the average gains and losses per patient were 6.98 and 5.47, respectively. Frequent gain abnormalities were found on chromosome arms 1q, 2q, 3q, 5p, 7p, 7q, 8q, 11q, 12p, 12q, 14q, 17q, 20q, and Xq. Frequent deletions were found on chromosome arms 1p, 3p, 4p, 5q, 8p, 9p, 9q, 11q, 13q, 16p, 17p, 18q, 19p, and 19q. It was found that deletions of 4p and 13q12-q14 and gain of 5p were significantly correlated with pathologic staging. Losses of 8p22-pter and 9p also were found more frequently in patients with advanced disease. Gain of 8q24-qter was seen more frequently in patients with Grade 3 tumors. A univariate analysis found that pathologic staging; gains of 5p and 7q; and deletions of 4p, 9p, and 11q were significant prognostic factors. However, pathologic staging became the only significant factor in a multivariate analysis.

CONCLUSIONS

CGH not only revealed novel chromosomal aberrations in EC-SCC, but also found possible genotypic changes associated with disease progression. Despite all of the possible associations of chromosomal aberrations with disease progression, the most important prognostic factor for patients with EC-SCC was pathologic staging.

KAI1 metastasis suppressor gene is frequently down-regulated in cervical carcinoma

KAI1 is a metastasis suppressor gene located on human chromosome 11p11.2. It belongs to a structurally distinct family of cell surface glycoproteins. Decreased KAI1 expression has been observed in several common solid epithelial tumors, including prostatic, pancreatic, lung, hepatic, colorectal, ovarian, and esophageal cancers. A recent study also observed frequent loss of KAI1 expression in a number of squamous cell carcinomas of the cervix by immunohistochemical technique. To further confirm whether this gene is altered in this malignancy, we analyzed KAI1 expression in various stages of cervical carcinoma by a molecular method. Total cellular RNA was extracted from 84 primary invasive cervical carcinomas and 6 metastatic or recurrent lesions. cDNA was synthesized and was used for real-time quantitative polymerase chain reaction analysis. The level of KAI1 expression was obtained as the value of threshold cycle (Ct) and was quantitated with a comparative Ct method. In addition, paraffin blocks of the tumors were selected and prepared for immunohistochemical study with an anti-KAI1 polyclonal antibody, C-16. Both the real-time quantitative polymerase chain reaction method and immunohistochemical study revealed a frequent decrease in KAI1 expression in invasive cervical cancers and metastatic or recurrent lesions. However, the reduction in KAI1 was not related to progression of the disease. When tumor cell differentiation was analyzed, poorly differentiated tumors showed a greater decrease in KAI1 expression than well or moderately differentiated tumors (P < 0.001). Histologically, KAI1 loss was observed equally in both squamous cell carcinoma and adeno-/adenosquamous carcinoma. Since down-regulation of KAI1 occurs in both early and late stages of cervical cancer, we suggest that its involvement in the progression of this malignancy is an early event.