Human EMR2, a novel EGF-TM7 molecule on chromosome 19p13.1, is closely related to CD97

The epidermal growth factor (EGF)-TM7 proteins [EMR1, (EGF-like molecule containing mucin-like hormone receptor 1) F4/80, and CD97] constitute a recently defined class B GPCR subfamily and are predominantly expressed on leukocytes. These molecules possess N-terminal EGF-like domains coupled to a seven-span transmembrane (7TM) moiety via a mucin-like spacer domain. Genomic mapping analysis has suggested a possible EGF-TM7 gene family on the human chromosome 19p13 region. In this study, a new member of the EGF-TM7 family, EMR2, which shares strikingly similar molecular characteristics with CD97, is described. In addition to mapping closely to CD97 on human chromosome 19p13.1, EMR2 contains a total of five tandem EGF-like domains and expresses similar protein isoforms consisting of various numbers of EGF-like domains as a result of alternative RNA splicing. Furthermore, EMR2 and CD97 exhibit highly homologous EGF-like domains and share identical gene organization, indicating that both genes are the products of a recent gene duplication event. The homologous EGF-like domains enable the identification of both EMR2 and CD97 by monoclonal antibodies (mAbs) raised against the first EGF-like domain of CD97, whereas mAbs directed against the extracellular spacer domain of CD97 are able to differentiate these two proteins. Both EMR2 and CD97 are highly expressed in immune tissues; however, unlike CD97, which is ubiquitously expressed in most cell types, EMR2 expression is restricted to monocytes/Mφ and granulocytes. EMR2 fails to interact with CD55, the cellular ligand for CD97, suggesting the possibility of a different cellular ligand(s). EMR2 may therefore have a unique function in cells of monocyte/Mφ and granulocyte lineages.

Ethnic and geographic variations in the prevalence of hepatitis A, B and C among aboriginal villages in Hualien, Taiwan

BACKGROUND

Taiwan is endemic for viral hepatitis infections. A field survey was performed in the isolated aborigines in Hualien, eastern Taiwan, to investigate the geographic and ethnic variations in hepatitis epidemiology.

MATERIALS AND METHODS

From 1996 to 1998, blood was drawn from 1,748 subjects from two southern Ami and two northern Atayal villages for serum markers of hepatitis A, B and C.

RESULTS

Hepatitis A infection approached 100% in all groups. Hepatitis B infection and carrier rates were higher in the Atayal than in the Ami (92.3% vs. 49.1% and 20.8% vs. 5.3%; p<0.01). Hepatitis C infection rates were higher in three villages (27.5%, 20.1% and 25.4% vs. 3.6%; p<0.01). Hepatitis C infection increased with age (p<0.01) while hepatitis B infection did not.

CONCLUSION

Hepatitis A infected most aborigines before the age of 15 years. Hepatitis B seldom infected people after the age of 15 years, while hepatitis C continued to infect people who were older. Geographic factors are important for hepatitis C infection, whereas for hepatitis B infection, in addition ethnicity is also important.

Theory of diluted magnetic semiconductor ferromagnetism

We present a theory of carrier-induced ferromagnetism in diluted magnetic semiconductors ( III1-xMnxV) which allows for arbitrary itinerant-carrier spin polarization and dynamic correlations. Both ingredients are essential in identifying the system's elementary excitations and describing their properties. We find a branch of collective modes, in addition to the spin waves and Stoner continuum which occur in metallic ferromagnets, and predict that the low-temperature spin stiffness is independent of the strength of the exchange coupling between magnetic ions and itinerant carriers. We discuss the temperature dependence of the magnetization and the heat capacity.

LNB-TM7, a group of seven-transmembrane proteins related to family-B G-protein-coupled receptors

A number of unusual seven-transmembrane molecules have recently been characterized that have significant amino acid sequence similarity within the membrane-spanning hydrophobic regions and intervening loops to members of G-protein-coupled receptor family B. However, in contrast to the family-B G-protein-coupled receptors, these molecules have unusually large N-terminal extracellular domains that contain a number of well- characterized protein modules. The range of cell types expressing these complex molecules and their potential roles in cell adhesion and signalling have become a major focus of research in a number of biological systems.

Transient apoptosis elicited by insulin in serum-starved glioma cells involves Fas/Fas-L and Bcl-2

The expression of fas gene in glioma cells varies with growth stage. When insulin-elicited transient apoptosis of glioma cells was in progress, the expression of fas gene increased at both transcriptional and translational levels. In contrast, the expression of fas-L gene in glioma cells remained constant. Apoptosis occurred in the cells having high level of surface Fas protein. When the expression of Fas-L in U-373MG cells was suppressed by ribozyme, the insulin-elicited transient apoptosis vanished. Overexpression of Bcl-2 in U-373MG cells did not alter significantly the cell cycle progression and the expression of fas gene. However, these cells were resistant to insulin-trigged death. Therefore, insulin-elicited apoptosis involved Fas-related death signal, and which could be prevented by the protective effect of Bcl-2.

Optical configuration and color-representation range of a variable-pitch dot matrix holographic printer

The optical system configuration and design of a dot matrix holographic printer that can create image grating pixels of variable size, arbitrary pitch, and discretionary angle on a photoresist plate are presented. With the capability to vary spot size, grating orientation, and grating pitch on the fly, this newly developed holographic printer can apply a prespecified color at each specific viewing angle. Diffractive images with various visual effects and the wide color range that are possible by use of this system are examined in detail.

Kinase activation of the non-receptor tyrosine kinase Etk/BMX alone is sufficient to transactivate STAT-mediated gene expression in salivary and lung epithelial cells

Etk/BMX is a non-receptor protein tyrosine kinase that requires a functional phosphatidylinositol 3-kinase via the pleckstrin homology domain to be activated by cytokine. In the present study, a conditionally active form of Etk was constructed by fusing the hormone-binding domain of estrogen receptor (ER) to an amino terminus truncated form of Etk, PHDelta1-68Etk, to generate DeltaEtk:ER. In stably transfected Pa-4DeltaEtk:ER cells, the activity of DeltaEtk:ER was stimulated within minutes by the treatment of DeltaEtk:ER stimulant, estradiol, and sustained for greater than 24 h. A robust induction in the phosphorylation of signal transducers and activators of transcription (STAT) proteins, including STAT1, STAT3, and STAT5, was accompanied with DeltaEtk:ER activation. Moreover, the conditionally activated Etk stimulated STAT1- and STAT5-dependent reporter activities by approximately 160- and approximately 15-fold, respectively, however, elicited only a modest STAT3-mediated reporter activation. Qualitatively comparable results were obtained in lung A549 cells, indicating that DeltaEtk:ER inducible system could function in an analogous fashion in different epithelial cells. Furthermore, we demonstrated that Etk activation alone augmented cyclin D1 promoter/enhancer activity via its STAT5 response element in both Pa-4DeltaEtk:ER and A549 cells. Altogether, these findings support the notion that the activation of Etk kinase is sufficient to transactivate STAT-mediated gene expression. Hence, our inducible DeltaEtk:ER system represents a novel approach to investigate the biochemical events following Etk activation and to evaluate the contribution by kinase activation of Etk alone or in conjunction with other signaling pathway(s) to the ultimate biological responses.

Prevalence of TT virus DNA in eastern Taiwan aborigines

We studied the prevalence of TT virus (TTV) DNA in the general population of the eastern Taiwan aborigine villages, about 11% (34 of 317). There is no association between the presence of HBsAg and TTV DNA or between the presence of HCV RNA and TTV DNA. Therefore, the infection of HBV or HCV and the presence of TTV DNA appear to be independent from each other. The association between the presence of TTV DNA and the elevated alanine aminotransferase (and/or aspartate aminotransferase) activity was also investigated. The presence of TTV DNA was not found to be correlated with abnormal liver function (P = 0.574) when age, gender, and the presence of HBsAg, HCV RNA, and HGV RNA were all considered in the assay. The sequence homology of TTV DNA fragments between different isolates from Taiwan and N22 (the clone obtained from the original prototype strain) from Japan ranged from 84 to 97%. The recombinant protein encoded by the TTV DNA fragment corresponding to the open reading frame of N22 was expressed in E. coli successfully. However, no serum response against the recombinant protein was detected.

Comparison of treatment outcomes for imipramine for female genuine stress incontinence

OBJECTIVE

To assess the efficacy of imipramine as a treatment of genuine stress incontinence and to explore the possible determining factors for treatment success and failure.

DESIGN

A prospective study.

SETTING

University department of obstetrics and gynaecology.

PARTICIPANTS

Forty women with genuine stress incontinence were enrolled.

METHODS

Each woman was treated with 25 mg imipramine three times a day for three months.

MAIN OUTCOME MEASURES

Each woman had a 20-minute pad test and urodynamic study including uroflowmetry, both filling and voiding cystometry, and stress urethral pressure profile before and after treatment.

RESULTS

After treatment, 35% (n = 14) were cured, 25% (n = 10) improved by > or = 50% and in the remaining 40% (n = 16) treatment failed. The efficacy of successful treatment was 60% (95% CI 44.8-75.2). The median age and parity, as well as menopausal status, showed no statistical differences between the two groups. The pre-treatment data including pad weight, functional urethral length, maximal urethral pressure, bladder compliance at urgency, bladder capacity, and average and maximal flow rates showed no statistical differences between the two groups except urethral closure pressure (P = 0.001). Besides, the functional urethral length and urethral closure pressure were significantly improved in the treatment success group. After medication, the median functional urethral length was 3 cm (intraquantile range [IQR] 2.3-3) in the treatment success group vs 2.3 cm (IQR 2-3) in the treatment failure group (P = 0.028). The urethral closure pressure was 77 cmH2O (IQR 61-105) for the treatment success group vs 40 cmH2O (IQR 34-53) in the treatment failure group (P < 0.0001).

CONCLUSIONS

The efficacy of imipramine for genuine stress incontinence was 60% (95% CI 44.8-75.2). The pre-treatment high urethral closure pressure may serve as a predictor for treatment success.

The gene expression of the amiloride-sensitive epithelial sodium channel alpha-subunit is regulated by antagonistic effects between glucocorticoid hormone and ras pathways in salivary epithelial cells

The functional expression of the amiloride-sensitive epithelial sodium channel (ENaC) in select epithelia is critical for maintaining electrolyte and fluid homeostasis. Although ENaC activity is strictly dependent upon its alpha-subunit expression, little is known about the molecular mechanisms by which cells modulate alpha-ENaC gene expression. Previously, we have shown that salivary alpha-ENaC expression is transcriptionally repressed by the activation of Raf/extracellular signal-regulated protein kinase pathway. Here, this work further investigates the molecular mechanism(s) by which alpha-ENaC expression is regulated in salivary epithelial Pa-4 cells. A region located between -1.5 and -1.0 kilobase pairs of the alpha-ENaC 5'-flanking region is demonstrated to be indispensable for the maximal and Ras-repressible reporter expression. Deletional analyses using heterologous promoter constructs reveal that a DNA sequence between -1355 and -1269 base pairs functions as an enhancer conferring the high level of expression on reporter constructs, and this induction effect is inhibited by Ras pathway activation. Mutational analyses indicate that full induction and Ras-mediated repression require a glucocorticoid response element (GRE) located between -1323 and -1309 base pairs. The identified alpha-ENaC GRE encompassing sequence (-1334/-1306) is sufficient to confer glucocorticoid receptor/dexamethasone-dependent and Ras-repressible expression on both heterologous and homologous promoters. This report demon- strates for the first time that the cross-talk between glucocorticoid receptor and Ras/extracellular signal-regulated protein kinase signaling pathways results in an antagonistic effect at the transcriptional level to modulate alpha-ENaC expression through the identified GRE. In summary, this study presents a mechanism by which alpha-ENaC expression is regulated in salivary epithelial cells.

Transdermal iontophoretic delivery of enoxacin from various liposome-encapsulated formulations

The major purpose of this work was to study the effect of various liposome formulations on the iontophoretic transport of enoxacin through excised rat skin. The electrochemical stability of these liposomes was also evaluated. The encapsulation percentage of enoxacin was significantly enhanced after 6 h incubation in an electric field; whereas the fusion of liposomes was inhibited by application of electric current. The results of iontophoretic drug transport showed that the permeability of enoxacin released from liposomes was higher compared with that of free drug. The iontophoretic permeability of enoxacin released from liposomes increased with a decrease in the fatty acid chain length of the phospholipid, which may be due to the different phase transition temperatures of the phospholipids. Incorporation of charged phospholipid resulted in an alteration of the transdermal behavior of enoxacin: the iontophoretic permeation as well as the amount of enoxacin partitioned in skin was greatly reduced after incorporation of stearylamine in liposomes, which can be attributed to the competitive ion effect. The enoxacin released from stratum corneum-based liposomes showed the highest amount of enoxacin partitioned into skin depot. The results of employing cathodal iontophoresis on negative charged liposomes suggested that the liposomal vesicles or phospholipids may carry enoxacin into deeper skin strata via the follicular route.

Once daily isepamicin treatment in complicated urinary tract infections

Isepamicin is a new aminoglycoside, derived from gentamicin B, which is more stable than other aminoglycosides against inactivating enzymes, and is less nephrotoxic. We evaluated the efficacy and safety of a once daily isepamicin in the treatment of complicated urinary tract infections (UTIs), as compared with amikacin. During the period May, 1997, to January, 1998, a total of 52 patients with similar demographic and baseline characteristics were enrolled into a prospective, randomized, open-label, single-center trial at the Veterans General Hospital-Kaohsiung. Eleven patients were excluded for protocol violation. The remaining 41 patients were included in the efficacy analysis. Study subjects included 16 men and 25 women, with a mean age of 57.9 (range 18-95) years. Clinical improvement was noted in 100% of patients in both the isepamicin and amikacin group. No statistically significant difference was observed between the 2 groups in regard to the rapidity of defervescence, relief of dysuria and urinary frequency, and clearance of bacteriuria and pyuria. Bacteriological cure rates were 89.4% for the isepamicin group and 100% for the amikacin group. Fifteen of 25 subjects who received isepamicin and 16 of 27 subjects who received amikacin had an adverse effect, all of which were considered to be mild except for one in the amikacin group, who had an adverse event of moderate severity (vomiting). Seven (3 isepamicin and 4 amikacin) adverse events were considered probably or possibly related to the study drug, which included eosinophilia (2 isepamicin), liver function impairment (1 isepamicin, 2 amikacin), renal function impairment (1 amikacin) and flushed face (1 amikacin). However, none of the patients had a life-threatening or severe adverse event that required discontinuation of the drug. These results show that once daily administration of isepamicin is as effective and safe as amikacin in treatment of complicated UTIs.

Early detection of unilateral occlusion of duplicated uterus with ipsilateral renal anomaly in young girls: two case reports with three-dimensional sonography

Early detection of unilateral occlusion of duplicated uterus with ipsilateral renal anomaly is very rare and difficult. We present two cases using three-dimensional (3D) sonography as a noninvasive, comprehensive and effective method in the early detection of this syndrome in the young girls. The two young, unmarried girls had irregular abdominal discomfort and pain during the recent few years. Series traditional study showed pelvic lesions, but failed to recognized the definite cause. With 3D sonography, we demonstrated the rare congenital anatomic relationships and gave the optimal management. The girls recovered soon and had uneventful OPD follow-up. Application of 3D sonography in the suspected young girls avoids unnecessary examinations and invasive interventions, decreases the morbidity and improves their quality of life.

Chitosan hydrogel as a base for transdermal delivery of berberine and its evaluation in rat skin

Berberine is the main ingredient of Coptis spp. This study selected berberine as a model drug to design a transdermal delivery system for the treatment of cutaneous leishmaniasis. Berberine was incorporated into chitosan hydrogel to prepare ointments. The physicochemical properties of the ointments and the release profile of berberine were investigated. The results indicated that the viscosity of chitosan hydrogel increased with an increasing amount of lactic acid or EDTA. The effect of EDTA on the viscosity was greater than that of lactic acid. By differential scanning calorimetry (DSC) measurement, no interaction was found to occur between chitosan and the soluble berberine. The release rate of berberine was inversely proportional to ointment viscosity. In in vitro skin perfusion studies, only trace amounts of berberine permeated through the rat skin due to its low oil-water partition coefficient. Surfactants were used as penetration enhancers to increase the percutaneous absorption of berberine. Among the enhancers, benzalkonium chloride was found to be the most efficient. Additionally, Tween 80 could increase the loading amount of berberine in the skin.

Transdermal iontophoretic delivery of diclofenac sodium from various polymer formulations: in vitro and in vivo studies

The objective of this study was to evaluate the in vitro and in vivo transdermal iontophoresis of various diclofenac sodium polymer formulations. The excised rat skin, human skin as well as cellulose membrane were used to examine the in vitro drug permeation whereas the microdialysis technique was used to monitor the drug concentration in vivo. Polymer solutions based on polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose (HPMC) binary system showed higher drug permeability than that of single polymer vehicle. The effect of formulations on drug permeation through cellulose membrane was quite different from those through rat skin and human skin, which can be explained by the different permeation pathways between them. It appeared to be a membrane-controlled mechanism but not the vehicle matrix-controlled mechanism for diclofenac hydrogels when using skin as the diffusion barrier. The recovery of diclofenac sodium in the in vivo microdialysis was approximately 80-90%, indicating this technique can be used in the intradermal drug monitoring. For all the polymer formulations tested, there was a good relationship between the in vitro and in vivo drug permeation. A synergistic effect on drug permeation was observed when transdermal iontophoresis combined with the pretreatment of cardamom oil as a permeation enhancer.

An adaptive fuzzy-neural-network controller for ultrasonic motor drive using the LLCC resonant technique

In this study an adaptive fuzzy-neural-network controller (AFNNC) is proposed to control a rotary traveling wave-type ultrasonic motor (USM) drive system. The USM is derived by a newly designed, high frequency, two-phase voltage source inverter using two inductances and two capacitances (LLCC) resonant technique. Then, because the dynamic characteristics of the USM are complicated and the motor parameters are time varying, an AFNNC is proposed to control the rotor position of the USM. In the proposed controller, the USM drive system is identified by a fuzzy-neural-network identifier (FNNI) to provide the sensitivity information of the drive system to an adaptive controller. The backpropagation algorithm is used to train the FNNI on line. Moreover, to guarantee the convergence of identification and tracking errors, analytical methods based on a discrete-type Lyapunov function are proposed to determine the varied learning rates of the FNNI and the optimal learning rate of the adaptive controller. In addition, the effectiveness of the adaptive fuzzy-neural-network (AFNN) controlled USM drive system is demonstrated by some experimental results.

Bcl-2 overexpression prevents apoptosis-induced Madin-Darby canine kidney simple epithelial cyst formation

BACKGROUND

Madin-Darby canine kidney (MDCK) cells develop into simple epithelial cell cysts when cultured in type I collagen gel. We found that MDCK cells initially grow into multilayer cell aggregates and subsequently develop central lumen that contain apoptotic cells. We hypothesized that apoptosis might be essential for the formation of MDCK cysts.

METHODS

Using MDCK cells cultured in collagen gel as the experimental model, we investigated how renal cells organize to form cysts. To delineate the role of apoptosis in the process of cyst formation, MDCK cells were transfected with the bcl-2 gene. Characterization of apoptosis was studied by morphological and biochemical methods.

RESULTS

Bcl-2 overexpression conferred resistance to apoptosis. Cultured in collagen gel, Bcl-2 transfectants rarely formed a simple epithelial cyst, but instead remained as a multilayer cell aggregate containing central or multiple lumens, or even developing into branching structures.

CONCLUSIONS

Because Bcl-2 overexpression averts cyst cavitation, these data clearly indicate that apoptosis is an essential initial event for renal cyst formation.

Ethyl isopropylamiloride downregulates Na,K-ATPase gene expression which confers cytotoxicity in primary proximal tubule cell cultures

Our original attempt was to examine whether inhibition of Na/H exchange in proximal tubule would affect the expression of basolateral membrane protein Na,K-ATPase. Three amiloride analogues were tested within the range of 10(-6) M to 10(-4) M in primary cultures of proximal tubule cells. Only ethylisopropyl amiloride (EIPA) dose-dependently downregulated Na,K-ATPase activity in cultured proximal tubule cells. The time course study revealed that EIPA (10(-4) M) significantly decreased Na,K-ATPase alpha- and alpha-mRNA abundance within 4 hr and suppressed Na,K-ATPase alpha- and beta-mRNA levels by 76.3 +/- 4.5% and 85.5 +/- 5.8%, respectively, within 24 hr. The decrease in Na,K-ATPase mRNA was followed by a decrease in Na,K-ATPase activity by 22.5 +/- 10.8% and 48.8 +/- 5.9% within 12 and 24 hr, respectively, which could be reflected by a coordinate decrease in levels of both alpha- and mature beta-protein. The cell viability was not affected until 20 hr of EIPA treatment, when an increase in LDH release and cell detachment was observed. Because EIPA rapidly decreased intracellular pH (pHi) to 6.7 within 2 hr and raising pHi to 6.6 by metabolic acidosis could not elicit changes in Na,K-ATPase activity, EIPA-induced downregulation of Na,K-ATPase should not be mediated through H+. In view of the time course of EIPA effects on Na,K-ATPase subunit mRNA, protein, activity and cell toxicity, the cytotoxic effect is likely resulted from a decrease in Na,K-ATPase activity. Take together, we conclude that EIPA induces downregulation of Na,K-ATPase expression via both pre- and post-translational mechanisms, which confers cytotoxic effects on proximal tubule cells.

The amiloride-sensitive epithelial sodium channel alpha-subunit is transcriptionally down-regulated in rat parotid cells by the extracellular signal-regulated protein kinase pathway

Previous studies have shown that an inducible Raf-1 kinase protein, DeltaRaf-1:ER, activates the mitogen-activated protein kinase/extracellular signal-regulated protein kinase (ERK)-signaling pathway, which is required for the transformation of the rat salivary epithelial cell line, Pa-4. Differential display polymerase chain reaction was employed to search for mRNAs repressed by DeltaRaf-1:ER activation. Through this approach, the gene encoding the alpha-subunit of the amiloride-sensitive epithelial sodium channel (alpha-ENaC) was identified as a target of activated Raf-1 kinases. alpha-ENaC down-regulation could also be seen in cells treated with 12-O-tetradecanoyl-1-phorbol-13-acetate (TPA), indicating that the repression of steady-state alpha-ENaC mRNA level was dependent upon the activity of protein kinase C, the target of TPA, as well. Pretreatment of cells with a specific inhibitor of the ERK kinase pathway, PD 98059, markedly abolished the down-regulation of alpha-ENaC expression, consistent with the hypothesis that the ERK kinase-signaling pathway is involved in TPA-mediated repression. Moreover, through the use of transient transfection assays with alpha-ENaC-reporter and activated Raf expression construct(s), we provide the first evidence that activation of the ERK pathway down-regulates alpha-ENaC expression at the transcriptional level. Elucidating the molecular programming that modulates the expression of the alpha-subunit may provide new insights into the modulation of sodium reabsorption across epithelia.

Abnormal urodynamic findings after radical hysterectomy or pelvic irradiation for cervical cancer

OBJECTIVE

To assess urodynamic study results in patients with cervical cancer who had received radical hysterectomy or pelvic irradiation or radical hysterectomy with pelvic irradiation.

METHODS

Forty-two patients with stage IB cervical cancer after radical hysterectomy (group A), 11 patients at stage IB or IIA after pelvic irradiation (group B), 15 patients at stage IB or IIA after both radical hysterectomy and pelvic irradiation (group C) and 17 patients at stage IB before treatment (group D) as control were recruited for urodynamic examination. The evaluations for each case included a 20-min pad test, uroflowmetry, both filling and voiding cystometry, and stress urethral pressure profile. ANOVA method with Bonferroni test and Pearson chi2-test were utilized for statistical analysis.

RESULTS

The mean ages in sequential groups A, B, C and D were 52.9 +/- 10.2, 62.5 +/- 13.5, 49.8 +/- 11.7 and 49.4 +/- 12.5 years (P = 0.02), respectively. The occurring frequency of either detrusor instability or low bladder compliance was 57%, 45%, 80% and 24%, respectively. Each group revealed decreased bladder capacity as 268.4 +/- 102.8, 164.1 +/- 62.9, 233.5 +/- 73.9 and 293.0 +/- 47.2 ml (P < 0.0001). However, the frequency of abdominal strain voiding was 100% in groups A, B and C as compared to 0% in group D (P < 0.01), and the frequency of abnormal residual urine (> 50 ml) was 41%, 27%, 40% and 24%. Although each case showed a poor pressure transmission ratio (< 100%), the frequency of positive pad test in each group was 81%, 46%, 100% and 18% (P < 0.001). The functional urethral length decreased in each group and was 2.6 +/- 0.8, 2.3 +/- 0.8, 2.5 +/- 0.8 and 2.9 +/- 0.6 cm, but there were no significant differences in maximal urethral pressure or urethral closure pressure among the four groups.

CONCLUSIONS

Our data show that abnormal urodynamic findings pre-exist in patients with cervical cancer before treatment especially in bladder storing function, and that these findings may worsen, or that new abnormal findings may happen after radical hysterectomy or pelvic irradiation, or both.

Collagen gel overlay induces apoptosis of polarized cells in cultures: disoriented cell death

In this study, we attempted to investigate the response of polarized cells to inappropriate interaction with the extracellular matrix. Cell lines of epithelial [Madin-Darby canine kidney (MDCK) and LLC-PK1], endothelial [bovine aortic endothelial cells (BAEC)], and mesenchymal (ESK-4 and NIH/3T3) origins were employed. With collagen gel overlay, MDCK cells underwent membrane remodeling and gradually developed lumen formation within 24 h. Apoptosis could also be observed following cell remodeling. The ratio of apoptosis was enhanced from 12.1 +/- 2.4% within 24 h to 58.4 +/- 9.8% at day 3, and finally the monolayer was disintegrated. Collagen gel overlay-induced apoptosis was not a result of physical stress, since agarose gel overlay did not induce any morphological alterations. All epithelial and endothelial cells examined developed apoptosis in response to collagen overlay. In contrast, collagen overlay did not affect growth of fibroblasts at all, although their growth under agarose gel was slightly hindered due to physical stress. Collagen overlay-induced apoptosis seems to be a unique phenomenon for polarized cells and thus is defined as "disoriented cell death." Furthermore, anti-alpha2-integrin antibody could abolish collagen overlay-induced morphological changes and apoptosis in MDCK cells, indicating that signals through alpha2-integrin on the apical membrane are required for disoriented cell death. Finally, Bcl-2 overexpression prolonged survival of MDCK cells in response to collagen overlay, but these cells eventually developed apoptosis due to downregulation of Bcl-2 protein. These findings indicate that inappropriate cell-matrix interaction results in apoptosis, which may account for cell death mechanisms during developmental processes or under pathological conditions.

Antibodies to E2 protein of hepatitis G virus in children: different responses according to age at infection

OBJECTIVES

To study viral persistence and antibody responses after hepatitis G virus (HGV) infection in children of various ages.

STUDY DESIGN

We performed an enzyme immunoassay for antibodies to E2 protein (anti-E2) of HGV and reverse-transcription polymerase chain reaction assay for HGV RNA on serum samples.

RESULTS

Of 28 infants born to HGV RNA-positive mothers, 17 were found to be positive for HGV RNA. None were positive for anti-E2. All 17 infected infants continued to have viremia except 1 who converted to HGV RNA-negative status at 24 months. Six infants had mild elevations of alanine aminotransferase levels (5 HGV-positive and 1 HGV-negative). An additional 14 HGV-infected children (aged 6 months to 14 years) with posttransfusion HGV infection were tested for anti-E2 3 months and 12 months after blood transfusion. None of the HGV RNA-positive serum samples were positive for anti-E2; however, 4 of the 8 children with resolving HGV infection were positive for anti-E2 1 year later.

CONCLUSIONS

Mother-to-infant transmission of HGV resulted in a high viral persistence rate and lack of immune responses to HGV. In contrast, anti-E2 appeared in children who recovered from posttransfusion HGV infection. Mode of transmission and age at infection may be important factors in determining persistent HGV infection and defective immune response to HGV.

Post- and presynaptic GABA(B) receptor activation in neonatal rat rostral ventrolateral medulla neurons in vitro

Whole-cell patch recordings were made from immature (six- to 12-day-old) rat rostral ventrolateral medulla neurons in brainstem slices. GABA or the specific GABA(B) receptor agonist (-)baclofen (10-50 microM) by superfusion or by pressure ejection induced an outward current or a hyperpolarization, which persisted in a tetrodotoxin (0.3 microM)-containing Krebs' solution in nearly every cell tested. The GABA(B) receptor antagonists 2-hydroxy saclofen (50-200 microM) and CGP 35348 (50-200 microM) dose-dependently suppressed baclofen-currents. Baclofen-currents were suppressed by barium (1 mM) but not by tetraethylammonium (20 mM), low Ca2+ (0.24 mM) solution or in a solution containing the Ca2+ chelator BAPTA-AM (10 microM). The outward current had an estimated reversal potential of -98, -77 and -52 mV in 3.1, 7 and 15 mM [K+]o. Pre-incubation of slices with pertussis toxin (500 microg/ml for 5-7 h) or intracellular dialysis with GDP-beta-S (500 microM) markedly reduced baclofen-currents. Baclofen in low concentrations (1-3 microM) that caused slight or no change of holding currents and of inward or outward currents induced by exogenously applied glutamate or glycine/GABA, decreased excitatory and inhibitory postsynaptic currents by an average of 86.5 +/- 4.3% and 78.4 +/- 2.7%. The GABA(B) antagonist CGP 35348 (100 microM) increased the excitatory postsynaptic currents by an average of 64%, without causing a significant change in holding currents in 10/18 cells tested. Our results indicate the presence of post- and presynaptic GABA(B) receptors in the rostral ventrolateral medulla neurons. Activation of postsynaptic GABA(B) receptors induces an outward K+ current which is barium-sensitive, Ca2+-independent and may be coupled to a pertussis-sensitive G-protein. Activation of presynaptic GABA(B) receptors attenuates excitatory or inhibitory synaptic transmission. More importantly, the observation that CGP 35348 enhanced excitatory synaptic currents implies a removal of tonic activation of presynaptic GABA(B) receptors by endogenously released GABA (disinhibition), supporting the hypothesis that these receptors may have a physiological role in regulating the input and output ratio in a subset of rostral ventrolateral medulla neurons in vivo.

Hepatitis B surface antigenemia at birth: a long-term follow-up study

OBJECTIVE

To investigate the prevalence and outcome of hepatitis B surface antigenemia in newborns of hepatitis B e antigen (HBeAg)-positive hepatitis B surface antigen (HBsAg) carrier mothers under the current immunoprophylaxis program.

STUDY DESIGN

From 1984 to 1993, 665 high-risk newborns born to HBeAg-positive HBsAg carrier mothers were prospectively recruited. The newborns were tested for HBsAg soon after birth, before hepatitis B immune globulin administration. All newborns received hepatitis B immune globulin within 24 hours after birth plus subsequent hepatitis B vaccination. Those who were seropositive for HBsAg at birth were regularly followed up for their hepatitis B virus (HBV) markers, liver function profiles, and alpha-fetoprotein levels from 1984 to 1996.

RESULTS

Sixteen (2.4%) of the 665 subjects were found to be seropositive for HBsAg at birth, and all remained HBsAg-positive at 6 months of age. Twelve of the 16 received long-term follow-up care, and all were confirmed to have chronic HBV infection. Of the 12, 2 had HBeAg seroconversion, and 1 had alanine aminotransferase flares without HBeAg seroconversion. Delayed appearance of hepatitis B core antibody (anti-HBc) occurred in 2 without alanine aminotransferase elevation.

CONCLUSIONS

Current immunoprophylaxis strategy does not protect newborns with surface antigenemia, apparently acquired in utero, from becoming HBV carriers. Immunologic attempts to eliminate HBV may occur in carrier children infected in utero, despite their profound immune tolerance to HBV.