A multi-prong global study provides insights to gut microbiota and mucosal immunity in dusp6-deficiency conferred obesity-resistance

Obesity is now a plague in developed countries and more than one third of U.S. adults are obese. Gut microbiota plays profound roles in host energy harvest, metabolism and inflammatory response associated with the development of obesity. Dusp6-deficient mice have been shown to be resistant to diet-induced-obesity (DIO) but the mechanism is still unclear. Using a gnotobiotic mouse model, we found that the transplantation of fecal/gut microbiota derived from dusp6-deficient mice can significantly increase energy expenditure and reduce weight-gain of the recipient mice. By analyzing fecal 16s rRNA genes, dusp6-deficient mice have different composition of gut microbiota when compared with wild-type mice. We also demonstrated that dusp6-deficient mice were resistant to DIO-mediated dysbiosis of gut microbiota. Upon further analysis of the intestinal transcriptome, we found that dusp6 deficiency is an important regulator of several metabolic pathways and genes related to intestinal barrier. Moreover, our analyses have shown that dusp6-deficient mice could alleviate DIO-induced inflammation.. This study demonstrates that dusp6 deficiency is a strong genetic factor that dominates diet effect on shaping gut microbiota and it remodels mucosal immunity to retain HFD-resistant homeostasis of gut microbiota. Our findings shed lights on obesity and obesity-derived metabolic disease treatment with novel therapeutic candidates/strategies such as DUSP6 pharmacological inhibitors and the development of microbiota-based therapeutics.

Interventions to improve patient understanding of cancer clinical trial participation: a systematic review

Patient misunderstanding of cancer clinical trial participation is identified as a critical issue and researchers have developed and tested a variety of interventions to improve patient understanding. This systematic review identified nine papers published between 2000 and 2013, to evaluate the effects of interventions to improve patient understanding of cancer clinical trial participation. Types of interventions included audio-visual information, revised written information and a communication training workshop. Interventions were conducted alone or in combination with other forms of information provision. The nine papers, all with methodological limitations, reported mixed effects on a small range of outcomes regarding improved patient understanding of cancer clinical trial participation. The methodological limitations included: (1) the intervention development process was poorly described; (2) only a small element of the communication process was addressed; (3) studies lacked evidence regarding what information is essential and critical to enable informed consent; (4) studies lacked reliable and valid outcome measures to show that patients are sufficiently informed to provide consent; and (5) the intervention development process lacked a theoretical framework. Future research needs to consider these factors when developing interventions to improve communication and patient understanding during the informed consent process.

Norepinephrine and corticosterone in the medial prefrontal cortex and hippocampus predict PTSD-like symptoms in mice

This study measured changes in brain extracellular norepinephrine (NE) and free corticosterone (CORT) levels in a mouse model of post-traumatic stress disorder and related them to hyperarousal and fear memory retention. To this end, microdialysis in the medial prefrontal cortex (mPFC) and the hippocampus (HPC) of male C57BL/6NCrl mice was performed during an acoustic startle response (ASR) and following an electric foot shock (FS), as well as during an ASR and recall of contextual fear (CF) 1 day later. Changes in ASR-stimulated NE levels in the mPFC corresponded to ASR 34 days after FS. Changes in basal and ASR-stimulated extracellular NE levels in the HPC, in contrast, were related to expression of early (day 2) and late (day 34) CF after FS. The increase in extracellular NE levels correlated in a U-shape manner with arousal levels and CF, thus suggesting a non-direct relationship. Stress of different modalities/strength (ASR, FS and CF) caused a similar relative increase in free CORT levels both in the mPFC and the HPC. One day after FS, ASR-induced increases in the CORT content in the mPFC tended to correlate with the FS-potentiated ASR in a U-shape manner. Taken together, these data show that the intracerebral increase in free CORT was likely related to an immediate response to stress, whereas NE neurotransmission in the forebrain predicted arousal and CF 1 month after trauma.

Impaired thrombin generation in Reelin-deficient mice: a potential role of plasma Reelin in hemostasis

BACKGROUND

Reelin is a large extracellular glycoprotein that is present in the peripheral blood. That Reelin interacts with the coagulation components and elicits a functional role in hemostasis has not yet been elucidated.

OBJECTIVES

The hemostatic activity of Reelin is investigated and defined in this study.

METHODS

The interplay of Reelin with coagulation components was elucidated by far-Western and liposome/platelet binding assays. In vivo and ex vivo hemostasis-related analyses of Reelin-deficient mice and plasma were also performed.

RESULTS

Reelin interacted with the liposomes containing phosphatidylserine (PS) or phosphatidylcholine. Instead of interacting with known Reelin receptors (ApoE receptor 2, very low density lipoprotein receptor and integrin β1), Reelin interacted with PS of the activated platelets. The interaction between Reelin and the coagulation factors of thrombin and FXa was also demonstrated with the Kd of 11.7 and 21.2 nm, respectively. Reelin-deficient mice displayed a prolonged bleeding time and an increase in rebleeding rate. Despite the fact that Reelin deficiency had no significant effect on the clotting time of prothrombin and activated partial thromboplastin time, the fibrin clot formation was abnormal and the fibrin clot structure was relatively loosened with reduced clot strength. Abnormal fibrinogen expression did not account for the hemostatic defects associated with Reelin deficiency. Instead, thrombin generation was impaired concomitant with an altered prothrombin cleavage pattern.

CONCLUSIONS

By interacting with platelet phospholipids and the coagulation factors, thrombin and FXa, Reelin plays a selective role in coagulation activation, leading to thrombin generation and formation of a normal fibrin clot.

The complex interplay among bacterial motility and virulence factors in different Escherichia coli infections

Motility mediated by the flagella of Escherichia coli is important for the bacteria to move toward host cells. Here, we present the relationship among bacterial motility, virulence factors, antimicrobial susceptibility, and types of infection. A total of 231 clinical E. coli isolates from different infections were collected and analyzed. Higher-motility strains (motility diameter ≥6.6 mm) were more common in spontaneous bacterial peritonitis (SBP) (SBP 59 %, colonization 32 %, urinary tract infection 16 %, urosepsis 34 %, and biliary tract infection 29 %; p < 0.0001). Compared with the higher-motility group, there was a higher prevalence of afa and ompT genes (p = 0.0160 and p = 0.0497, respectively) in E. coli strains with lower motility. E. coli isolates with higher and lower motility were in different phylogenetic groups (p = 0.018), with a lower prevalence of A and B1 subgroups in higher-motility strains. Also, the patterns of virulence factors and antibiotic susceptibility of E. coli isolates derived from various infections were significantly different. This study demonstrates that the prevalence of higher-motility strains was greater in E. coli isolates from SBP compared to other types of infection. Various types of E. coli infection were associated with differences in bacterial motility, virulence factors, and antibiotic susceptibility. More bacterial virulence factors may be necessary for the development of extraintestinal infections caused by E. coli isolates with lower motility.

Clinical and microbiological characteristics of Klebsiella pneumoniae from community-acquired recurrent urinary tract infections

Understanding the pathogenesis of recurrent urinary tract infection (RUTI) and whether it is attributable to reinfection with a new strain or relapse with the primary infecting strain is of considerable importance. Because previous studies regarding community-acquired Klebsiella pneumoniae RUTI are inconclusive, we undertook this study to evaluate the characteristics of the host and the bacterial agent K. pneumoniae in RUTI. A prospective study was designed, using consecutive patients diagnosed with community-acquired K. pneumoniae-related UTI from January 2007 to December 2009. Of the total 468 consecutive episodes, we found 7 patients with RUTI. All the patients with RUTI were elderly (median, 74 years), with diabetes (100 %, 7 out of 7). Clinical K. pneumoniae isolates derived from the same patients with RUTI revealed identical genomic fingerprints, indicating that K. pneumoniae UTI relapsed despite appropriate antibiotic therapy. The antimicrobial resistance, growth curve and biofilm formation of the recurrent isolates did not change. K. pneumoniae strains causing RUTI had more adhesion and invasiveness than the colonization strains (p < 0.01). When we compared the recurrent strains with the community-acquired UTI strains, the prevalence of diabetes mellitus was significant (100 % vs 53.7 %, p = 0.03) in the RUTI group. Our data suggest that K. pneumoniae strains might be able to persist within the urinary tract despite appropriate antibiotic treatment, and the greater adhesion and invasiveness in the recurrent strains may play an important role in recurrent infections.

Is the proton radius a player in the redefinition of the International System of Units?

It is now recognized that the International System of Units (SI units) will be redefined in terms of fundamental constants, even if the date when this will occur is still under debate. Actually, the best estimate of fundamental constant values is given by a least-squares adjustment, carried out under the auspices of the Committee on Data for Science and Technology (CODATA) Task Group on Fundamental Constants. This adjustment provides a significant measure of the correctness and overall consistency of the basic theories and experimental methods of physics using the values of the constants obtained from widely differing experiments. The physical theories that underlie this adjustment are assumed to be valid, such as quantum electrodynamics (QED). Testing QED, one of the most precise theories is the aim of many accurate experiments. The calculations and the corresponding experiments can be carried out either on a boundless system, such as the electron magnetic moment anomaly, or on a bound system, such as atomic hydrogen. The value of fundamental constants can be deduced from the comparison of theory and experiment. For example, using QED calculations, the value of the fine structure constant given by the CODATA is mainly inferred from the measurement of the electron magnetic moment anomaly carried out by Gabrielse's group. (Hanneke et al. 2008 Phys. Rev. Lett. 100, 120801) The value of the Rydberg constant is known from two-photon spectroscopy of hydrogen combined with accurate theoretical quantities. The Rydberg constant, determined by the comparison of theory and experiment using atomic hydrogen, is known with a relative uncertainty of 6.6×10(-12). It is one of the most accurate fundamental constants to date. A careful analysis shows that knowledge of the electrical size of the proton is nowadays a limitation in this comparison. The aim of muonic hydrogen spectroscopy was to obtain an accurate value of the proton charge radius. However, the value deduced from this experiment contradicts other less accurate determinations. This problem is known as the proton radius puzzle. This new determination of the proton radius may affect the value of the Rydberg constant . This constant is related to many fundamental constants; in particular, links the two possible ways proposed for the redefinition of the kilogram, the Avogadro constant N(A) and the Planck constant h. However, the current relative uncertainty on the experimental determinations of N(A) or h is three orders of magnitude larger than the 'possible' shift of the Rydberg constant, which may be shown by the new value of the size of the proton radius determined from muonic hydrogen. The proton radius puzzle will not interfere in the redefinition of the kilogram. After a short introduction to the properties of the proton, we will describe the muonic hydrogen experiment. There is intense theoretical activity as a result of our observation. A brief summary of possible theoretical explanations at the date of writing of the paper will be given. The contribution of the proton radius puzzle to the redefinition of SI-based units will then be examined.

A cross-ethnic comparison on incidence of suicide

BACKGROUND

Suicide rates vary widely across nations and ethnic groups. This study aims to explore potential factors contributing to inter-ethnic differences in suicide rates.

METHOD

Study subjects came from a case-control psychological autopsy study conducted in Taiwan, including 116 consecutive suicides from two aboriginal groups and Taiwanese Han; 113 of them each matched with two living controls. Gender-, age- and method-specific suicide rates, population attributable fraction (PAF) of suicide for five major risk factors, help-seeking before suicide and emergency medical aid after suicide were compared between the three ethnic groups.

RESULTS

One aboriginal group (the Atayal) had significantly higher adjusted rate ratios (RR) of suicide than the other aboriginal group (the Ami) [RR 0.20, 95% confidence intervals (CI) 0.12-0.34] and the Han (RR 0.26, 95% CI 0.16-0.40). Such differences can be explained by higher PAFs of suicide for three major risk factors (substance dependence, PAF 47.6%, 95% CI 25.5-64.2; emotionally unstable personality disorder, PAF 52.7%, 95% CI 32.8-69.0; family history of suicidal behaviour, PAF 43.5%, 95% CI 23.2-60.2) in this group than in the other two groups. This higher suicide rate was substantially reduced from 68.2/100 000 per year to 9.1/100 000 per year, comparable with the other two groups, after stepwise removal of the effects of these three risk factors. Suicide rates by self-poisoning were also significantly higher in this group than in the other two groups.

CONCLUSIONS

Higher rates of specific risk factors and use of highly lethal pesticides for suicide contributed to the higher suicide rate in one ethnic group in Taiwan. These findings have implications for developing ethnicity-relevant suicide prevention strategies.

Generation of a novel factor IX with augmented clotting activities in vitro and in vivo

BACKGROUND

Hemophilia B is an X-linked inherited disorder caused by the lack of functional factor IX (FIX). Currently, treatment of hemophilia B is performed by intravenous infusion of plasma-derived or recombinant FIX.

OBJECTIVE

In an effort to reduce factor usage and cost, we investigated the potential use of FIX variants with enhanced specific clotting activity.

METHODS

Seven recombinant FIX variants using alanine replacement were generated and assayed for their activity in vitro and in vivo.

RESULTS

One variant containing three substitutions (V86A/E277A/R338A, FIX-Triple) exhibited 13-fold higher specific clotting activity and a 10-fold increased affinity for human FVIIIa compared with FIX-wild-type (FIX-WT) and was thus investigated systematically in vivo. Liver-specific FIX-Triple gene expression following hydrodynamic plasmid delivery revealed a 3.5-fold higher specific clotting activity compared with FIX-WT. Human FIX-Triple and FIX-WT knock-in mice were generated and it was confirmed that FIX-Triple has 7-fold higher specific clotting activity than FIX-WT under normal physiological conditions. Protein infusion of FIX-Triple into hemophilia B mice resulted in greater improvement of hemostasis than that achieved with FIX-WT. Moreover, tail-vein administration of a serotype 8 recombinant Adeno-associated vector (AAV8) expressing either FIX-WT or FIX-Triple in hemophilia B mice demonstrated a 7-fold higher specific clotting activity of FIX-Triple than FIX-WT.

CONCLUSIONS

Our results indicate that the FIX-Triple variant exhibits significantly enhanced clotting activity relative to FIX-WT due to tighter binding to FVIIIa, as demonstrated both in vitro and in vivo. Therefore, FIX-Triple is a good candidate for further evaluation in protein replacement therapy as well as gene-based therapeutic strategies.

Maize VP1 complements Arabidopsis abi3 and confers a novel ABA/auxin interaction in roots

The maize Vp1 gene and abi3 gene of Arabidopsis are believed to be orthologs based on similarities of the mutant phenotypes and amino acid sequence conservation. Here we show that expression of VP1 driven by the 35S promoter can partially complement abi3-6, a deletion mutant allele of abi3. The visible phenotype of seed produced from VP1 expression in the abi3 mutant background is nearly indistinguishable from wild type. VP1 fully restores abscisic acid (ABA) sensitivity of abi3 during seed germination and suppresses the early flowering phenotype of abi3. The temporal regulation of C1-beta-glucuronidase (GUS) and chlorophyll a/b binding protein (cab3)-GUS reporter genes in developing seeds of 35S-VP1 lines were similar to wild type. On the other hand, two qualitative differences are observed between the 35S-VP1 line and wild type. The levels of CRC and C1-GUS expression are markedly lower in the seeds of 35S-VP1 lines than in wild type suggesting incomplete complementation of gene activation functions. Similar to ectopic expression of ABI3 (Parcy et al., 1994), ectopic expression of VP1 in vegetative tissue enhances ABA inhibition of root growth. In addition, 35S-VP1 confers strong ABA inducible expression of the normally seed-specific cruciferin C (CRC) gene in leaves. In contrast, ectopic ABA induction of C1-GUS is restricted to a localized region of the root elongation zone. The ABA-dependent C1-GUS expression expanded to a broader area in the root tissues treated with exogenous application of auxin. Interestingly, auxin-induced lateral root formation is completely suppressed by ABA in 35S-VP1 plants but not in wild type. These results indicate VP1 mediates a novel interaction between ABA and auxin signaling that results in developmental arrest and altered patterns of gene expression.

Efficient evolutionary algorithm for the thin-film synthesis of inhomogeneous optical coatings

We propose an efficient evolutionary approach for the thin-film synthesis of inhomogeneous optical coatings. The proposed approach consists of global and local strategies by integration of decreasing-based mutations and self-adaptive mutations by means of family competition and adaptive rules. Numerical results indicate that the proposed approach performs robustly and is competitive with other approaches. Our approach, although somewhat slower, is flexible and can easily be adopted to other application domains. Our approach is also able to generate homogeneous solutions with two materials available.

Modulation of cell growth by the hepatitis C virus nonstructural protein NS5A

Hepatitis C virus nonstructural protein, NS5A, is a phosphoprotein produced from the processing of the viral polyprotein precursor. NS5A associates with several cellular proteins in mammalian cells, and the biological consequences of this interaction are currently unknown. To this end, five stable NS5A-expressing murine and human cell lines were established. Tetracycline-regulated NIH3T3 cells and rat liver epithelial cells as well as the constitutive, NS5A-expressing, human Chang liver, HeLa, and NIH3T3 cells all exhibited cell growth retardation compared with the control cells. Cell cycle analysis by flow cytometry indicated that the NS5A-expressing human epitheloid tumor cells had a reduced S phase and an increase in the G(2)/M phase, which could be explained by a p53-dependent induction of p21(Waf1/Cip1) protein and mRNA levels. NS5A interacts with Cdk1 in vivo and in vitro, and a significant portion of the p21(Waf1/Cip1) was found to be in a complex with Cdk2 in the NS5A-expressing human hepatic cell line. Cdk1 and cyclin B1 proteins were also reduced in human Chang liver cells consistent with the increase in G(2)/M phase. Our results suggest that the NS5A protein causes growth inhibition and cell cycle perturbations by targeting the Cdk1/2-cyclin complexes.

Optical coating designs using the family competition evolutionary algorithm

A robust evolutionary approach, called the Family Competition Evolutionary Algorithm (FCEA), is described for the synthesis of optical thin-film designs. Based on family competition and adaptive rules, the proposed approach consists of global and local strategies by integrating decreasing mutations and self-adaptive mutations. The method is applied to three different optical coating designs with complex spectral quantities. Numerical results indicate that the proposed approach performs very robustly and is very competitive with other approaches.

Electrokinetic flow in a planar slit covered by an ion-penetrable charged membrane

The electrokinetic flow of an electrolyte solution in a planar slit covered by an ion-penetrable charged membrane layer is analyzed theoretically. An approximate analytical expression for the spatial variation in the electrical potential is derived, and the electroosmotic velocity, the total electric current, and the streaming potential of the system under consideration are evaluated. The effects of epsilon' (relative permittivity of liquid phase/relative permittivity of membrane layer), eta' (viscosity of liquid phase/viscosity of membrane layer) and the valence of anions (coions) on the volumetric flow rate and total current are examined. We show that the effect of the valence of cations (counterions) on the volumetric flow rate is less significant than that of epsilon' and that of eta'. However, the effect of epsilon' on the total current is less significant than that of the valence of cations and that of eta'. The variation of total current as a function of ionic strength is found to have a local minimum, regardless of whether a pressure gradient is applied or not. The absolute streaming potential has a local maximum as the concentration of fixed charge varies, which was not found in previous studies.

A genetic algorithm with adaptive mutations and family competition for training neural networks

In this paper, we present a new evolutionary technique to train three general neural networks. Based on family competition principles and adaptive rules, the proposed approach integrates decreasing-based mutations and self-adaptive mutations to collaborate with each other. Different mutations act as global and local strategies respectively to balance the trade-off between solution quality and convergence speed. Our algorithm is then applied to three different task domains: Boolean functions, regular language recognition, and artificial ant problems. Experimental results indicate that the proposed algorithm is very competitive with comparable evolutionary algorithms. We also discuss the search power of our proposed approach.

A family competition evolutionary algorithm for automated docking of flexible ligands to proteins

In this paper, we study an evolutionary algorithm for flexible ligand docking. Based on family competition and adaptive rules, the proposed approach consists of global and local strategies by integrating decreasing mutations and self-adaptive mutations. To demonstrate the robustness of the proposed approach, we apply it to the problems of the first international contests on evolutionary optimization. Following the description of function optimization, our approach is applied to a dihydrofolate reductase enzyme with the anti-cancer drug methotrexate and with two analogs of the antibacterial drug trimethoprim. Our numerical results indicate that the proposed approach is robust. The docked lowest energy structures have rms derivations ranging from 0.72 A to 1.98 A with respect to the corresponding crystal structure.

Tin-protoporphyrin potentiates arsenite-induced DNA strand breaks, chromatid breaks and kinetochore-negative micronuclei in human fibroblasts

Numerous reports have shown that oxidative stress is involved in arsenite-induced genetic damage. Arsenite is also a potent inducer of heme oxygenase (HO)-1. To understand whether HO-1 could function as a cellular antioxidant and protect cells from arsenite injury, the effects of tin-protoporphyrin (SnPP), a competitive inhibitor of HO-1, on arsenite-induced genetic damage were examined in human skin fibroblasts (HFW). In the present study, we found that SnPP at 100 microM significantly potentiated arsenite-induced cytotoxicity, DNA strand breaks (assayed by alkaline single cell gel electrophoresis(SCGE)), and chromatid breaks. Although arsenite alone mainly induced kinetochore-plus micronuclei (K(+)-MN), SnPP only synergistically enhanced kinetochore-negative micronuclei (K(-)-MN). The increase in K(-)-MN by SnPP cotreatment was consistent with the increase in DNA strand breaks and chromatid breaks caused by SnPP. However, at higher arsenite doses, K(+)-MN was significantly reduced by SnPP. Pretreatment of HFW cells with hemin, an inducer of HO-1, significantly attenuated the cytotoxicity of arsenite. Therefore, the present results suggest that HO-1 induction by arsenite plays certain roles in protecting cells from arsenite-induced injury.

Prevention of acute and delayed cisplatin-induced nausea and vomiting with intravenous ondansetron plus intravenous dexamethasone

BACKGROUND

We conducted a prospective study to evaluate the anti-emetic effect of cisplatin-induced nausea and vomiting with intravenous (i.v.) ondansetron plus i.v. dexamethasone.

METHODS

One hundred forty-six chemotherapy (CT)-naive patients were enrolled in the study. They were scheduled to receive cisplatin 50 to 100 mg/m2 (mean, 53 mg/m2) on day 1 followed immediately by continuous infusion of 5-fluorouracil with or without other CT agents on the subsequent days. Three 8 mg doses of ondansetron i.v. were given at 4-hour intervals plus 20 mg dexamethasone i.v. infusions from the start of CT, followed by 5 mg dexamethasone i.v. every 12 hours, and the administration of dexamethasone was discontinued after the completion of CT.

RESULTS

The rates of complete protection from acute and delayed vomiting/nausea obtained in these patients were 97.3%/93.2% and 71.2%/60.3%, respectively. The rates of complete protection from both acute and delayed nausea were 70.5% and 58.9%, respectively. By comparison, the total control rate of vomiting was less in female patients than in male patients (p = 0.017), and the total control rate of nausea was lower in the age group less than 50 years (p = 0.045). The time from the start of CT to the onset of nausea appeared to be earlier than that for vomiting (log-rank test, p = 0.045). Adverse events tended to be minor, with constipation and hiccups as the most common.

CONCLUSION

These results indicate that i.v. ondansetron plus i.v. dexamethasone is a feasible anti-emetic therapy in an inpatient setting. I.v. ondansetron plus i.v. dexamethasone is highly effective in preventing acute cisplatin-induced nausea and vomiting.

Recombinant polyclonal antibody libraries

We describe a technology for generating recombinant polyclonal antibody libraries (PCALs) that enables the creation and perpetuation of standardized mixtures of polyclonal whole antibodies specific for a multiantigen (or polyantigen). Therefore, this technology combines the advantages of targeting multiple antigenic determinants -- high avidity, low likelihood of antigen 'escape variants', and efficient mediation of effector functions, with the advantages of using monoclonal antibodies -- unlimited supply of standardized reagents and the availability of the genetic material for desired manipulations. The technology for generating recombinant polyclonal antibody libraries begins with the creation of phage display Fab (antibody) libraries. This is followed by selection of sublibraries with desired antigen specificities, and mass transfer of the variable region gene pairs of the selected sublibraries to a mammalian expression vector for generation of libraries of polyclonal whole antibodies. We review here our experiments for selection of phage display antibody libraries against microbes and tumor cells, as well as the recent literature on the selection of phage display antibody libraries to multiantigen targets.

Control of cisplatin-induced emesis with intravenous ondansetron plus intravenous dexamethasone: a crossover study of triple 8-mg dose of ondansetron

Two hundred seventy-five patients were enrolled in one of two arms in a crossover fashion. Arm A: three 8-mg doses of ondansetron intravenous (IV) were given at 4-hour intervals plus dexamethasone 20 mg IV from the start of chemotherapy followed by dexamethasone 5 mg IV every 12 hours. Arm B: as in arm A but with three 8-mg doses of ondansetron IV were given at 24-hour intervals substituted for ondansetron IV given at 4-hour intervals. There were 237 patients in arm A and 223 patients in arm B. Complete protection from acute and delayed vomiting/nausea obtained in arm A was 94.5%/90.3% and 71.3%/57.8%, respectively; protection obtained in arm B was 92.7%/91.0% and 71.7%/60.5%, respectively. No differences were observed in control of acute emesis after the addition of dexamethasone to ondansetron, given as either a triple 8-mg dose at 4-hour intervals or a single 8-mg dose. The triple dose of ondansetron given at 24-hour intervals was also not more effective than ondansetron given at 4-hour intervals in preventing delayed emesis when dexamethasone was added. However, the former improved control of delayed nausea on day 2. Adverse events tended to be minor, with constipation and hiccup the most common.

Tuberculosis presenting with pelvic mass, peritoneal lesions, and elevation of serum CA125 mimicking malignant tumor: a case report

Tuberculosis is a curable infective disease which can mimic a malignant tumor. We report on a young woman who presented with abdominal fullness, body weight loss, and microcytic anemia. A pelvic mass and peritoneal lesions were found. The serum CA125 level was high. The initial gynecologic echo and abdominal CT scan revealed bilateral ovarian mass with peritoneal lesions, and malignancy was highly suspected. Diagnostic laparoscopy was performed, and peritoneal tuberculosis was pathologically proven. Combination anti-tuberculosis therapy was prescribed for one year. She was followed up in the outpatient clinic regularly with symptom improvement, body weigh gain, and improvement of anemia. We suggest that in cases of a pelvic mass and peritoneal lesions, with elevation of the serum CA125 level, tuberculosis should always be kept on the list of differential diagnoses. A tissue diagnosis should always be obtained before treatment, regardless of initial image study and laboratory findings.

Transactivation of the human cdc2 promoter by adenovirus E1A. E1A induces the expression and assembly of a heteromeric complex consisting of the CCAAT box binding factor, CBF/NF-Y, and a 110-kDa DNA-binding protein

Cyclin-dependent kinases (CDKs) play an important role in the eukaryotic cell cycle progression. Cdc2 (CDK1) is expressed in late G(1)/S phase and required for G(2) to M phase transition in higher eukaryotes. The oncoproteins, SV40 large T antigen and adenovirus E1A, induce a 110-kDa protein which specifically recognizes the two inverted CCAAT motifs of the cdc2 promoter in cycling cells and plays an essential role in transactivation of the human cdc2 promoter. Since these CCAAT motifs also conform to the consensus binding sites for the ubiquitous heterotrimeric transcription factor, CBF/NF-Y, the role of CBF/NF-Y in the transactivation of the cdc2 promoter was examined in this study. Our results indicate that CBF/NF-Y and the 110-kDa protein interact with the CCAAT box motif to form a heteromeric complex. However, mutagenesis of the pentanucleotide CCAAT motif or in the presence of urea greater than 2.5 M, no heteromeric complex was formed. In contrast, the 110-kDa protein could still bind the mutant CCAAT motif or with the wild type motif in the presence of 2.5 M urea. Furthermore, E1A.12S induced the gene expression of all three subunits of CBF/NF-Y. Coexpression of E1A and a dominant negative mutant NF-YA subunit significantly reduced the E1A-mediated transactivation of the cdc2 promoter in a dose-dependent manner. These results support the conclusion that E1A protein mediates optimal transactivation of the human cdc2 promoter by inducing the expression and assembly of a heteromeric complex consisting of the 110-kDa protein and the CBF/NF-Y which interacts with the two CCAAT motifs of the cdc2 promoter.

Inhibition of secretion by 1,3-Cyclohexanebis(methylamine), a dibasic compound that interferes with coatomer function

We noted previously that certain aminoglycoside antibiotics inhibit the binding of coatomer to Golgi membranes in vitro. The inhibition is mediated in part by two primary amino groups present at the 1 and 3 positions of the 2-deoxystreptamine moiety of the antibiotics. These two amines appear to mimic the epsilon-amino groups present in the two lysine residues of the KKXX motif that is known to bind coatomer. Here we report the effects of 1, 3-cyclohexanebis(methylamine) (CBM) on secretion in vivo, a compound chosen for study because it contains primary amino groups that resemble those in 2-deoxystreptamine and it should penetrate lipid bilayers more readily than antibiotics. CBM inhibited coatomer binding to Golgi membranes in vitro and in vivo and inhibited secretion by intact cells. Despite depressed binding of coatomer in vivo, the Golgi complex retained its characteristic perinuclear location in the presence of CBM and did not fuse with the endoplasmic reticulum (ER). Transport from the ER to the Golgi was also not blocked by CBM. These data suggest that a full complement of coat protein I (COPI) on membranes is not critical for maintenance of Golgi integrity or for traffic from the ER to the Golgi but is necessary for transport through the Golgi to the plasma membrane.

Transactivation of the human cdc2 promoter by adenovirus E1A in cycling cells is mediated by induction of a 110-kDa CCAAT-box-binding factor

Cyclin-dependent protein kinases (Cdks) are key regulatory proteins of the eukaryotic cell cycle. Cdc2 is expressed in late G1/S phase and functions in the G2 to M phase transition. Adenovirus E1A proteins are known to induce the expression of p34cdc2 and DNA synthesis in normal quiescent cells. In this study, mutational analysis of the human cdc2 promoter revealed that transactivation of the promoter by the E1A proteins in cycling cells is mediated through the two CCAAT box binding motifs. A 110-kDa protein (CBF/cdc2) was identified in nuclear extracts from monkey kidney (CV-1) cells stably expressing E1A as well as from adenovirus-transformed human 293 cells. Further, we show that this EIA-inducible CBF/cdc2 is related to the CBF which was shown to activate the heat shock protein 70 promoter. Analyses of the functional domain(s) of E1A required for the induction of the CBF and transactivation of the cdc2 promoter in these conditions revealed that E1A mutants which were defective in binding the pRB family of proteins or the cellular p300 protein were still active in assays measuring the induction of the CBF and transactivation of the cdc2 promoter, albeit with reduced efficiencies. But the E1A mutant which lost both functional domains was inactive in these assays. These results suggest that E1A has redundant functional domains for the induction of the 110-kDa CBF and activation of human cdc2 gene expression.

Potassium currents in freshly dissociated uterine myocytes from nonpregnant and late-pregnant rats

In freshly dissociated uterine myocytes, the outward current is carried by K+ through channels highly selective for K+. Typically, nonpregnant myocytes have rather noisy K+ currents; half of them also have a fast-inactivating transient outward current (ITO). In contrast, the current records are not noisy in late pregnant myocytes, and ITO densities are low. The whole-cell IK of nonpregnant myocytes respond strongly to changes in [Ca2+]o or changes in [Ca2+]i caused by photolysis of caged Ca2+ compounds, nitr 5 or DM-nitrophene, but that of late-pregnant myocytes respond weakly or not at all. The Ca2+ insensitivity of the latter is present before any exposure to dissociating enzymes. By holding at -80, -40, or 0 mV and digital subtractions, the whole-cell IK of each type of myocyte can be separated into one noninactivating and two inactivating components with half-inactivation at approximately -61 and -22 mV. The noninactivating components, which consist mainly of iberiotoxin-susceptible large-conductance Ca2+-activated K+ currents, are half-activated at 39 mV in nonpregnant myocytes, but at 63 mV in late-pregnant myocytes. In detached membrane patches from the latter, identified 139 pS, Ca2+-sensitive K+ channels also have a half-open probability at 68 mV, and are less sensitive to Ca2+ than similar channels in taenia coli myocytes. Ca2+-activated K+ currents, susceptible to tetraethylammonium, charybdotoxin, and iberiotoxin contribute 30-35% of the total IK in nonpregnant myocytes, but <20% in late-pregnant myocytes. Dendrotoxin-susceptible, small-conductance delayed rectifier currents are not seen in nonpregnant myocytes, but contribute approximately 20% of total IK in late-pregnant myocytes. Thus, in late-pregnancy, myometrial excitability is increased by changes in K+ currents that include a suppression of the ITO, a redistribution of IK expression from large-conductance Ca2+-activated channels to smaller-conductance delayed rectifier channels, a lowered Ca2+ sensitivity, and a positive shift of the activation of some large-conductance Ca2+-activated channels.

Deregulation of cdc2 gene expression correlates with overexpression of a 110 kDa CCAAT box binding factor in transformed cells

Eukaryotic cell cycle progression is regulated by an orderly and sequential activation of several cyclin-dependent kinases, which phosphorylate key substrates during this process. p34cdc2, the catalytic subunit of cdc2 kinase, is expressed at the late G1/S boundary and is required for the G2-->M phase transition. Transactivation of the human cdc2 promoter by the DNA tumor virus-encoded oncogenic protein SV40 large T antigen is mediated by induction of a novel 110 kDa CCAAT box binding factor (CBF/cdc2). To investigate whether induction of CBF/cdc2 is an intrinsic property of the viral oncoprotein or is a common event during transformation of normal cells, expression of CBF/cdc2 was analyzed in many human tumor cell lines and in rodent cells spontaneously transformed or stably expressing various oncogenes. Our results showed that CBF/cdc2 was overexpressed in all transformed cells examined, including human 293, MCF-7, HeLa and HepG2 cells. Moreover, expression of CBF/cdc2 was elevated in spontaneously transformed rat liver epithelial cells (C4T), but not detectable in the non-tumorigenic parental (RLE) cells. The elevated levels of CBF/cdc2 expression in C4T cells correlated well with increased cdc2 mRNA and p34cdc2 levels. CBF/cdc2 was also overexpressed in a rat liver epithelial cell line (WB) stably transfected with various oncogenes, v-myc, v-Ha-ras and mutated rat neu and v-src. Using an electrophoretic mobility shift assay, specific binding of CBF/cdc2 to the CCAAT box motifs of the human cdc2, cycA and cdc25C promoters was detected, suggesting that transcription of these cell cycle regulatory genes are coordinately activated by CBF/cdc2.

Surface characterization and biological properties study of silicone rubber membrane grafted with phospholipid as biomaterial via plasma induced graft copolymerization

Poly(2-methacryloyloxyethyl phosphorylcholine) (pMPC) was grafted onto the surface of a silicon rubber (SR) membrane (pMPC-SR) by plasma induced grafted copolymerization (PIP). Argon plasma was used to activate the SR surfaces. Determination was also made of the influences of grafted copolymerization reaction time, reaction temperature, and monomer concentration on polymerization yield. The surface properties of SR were characterized by ATR-FTIR, ESCA, and SEM. In those analyses the ATR-FTIR spectra indicated that the pMPC grafted onto the SR surface at 1720 and 3300 cm(-1). The elemental composition and different carbon bindings on the surface of the SR were examined by ESCA. An increasing P1s/C1s value g was obtained in the grafted polymerization yield with a concentration of 0.05-0.5M of MPC in the isolated ethanol solution. The surface morphologies of pMPC-SR differed more than those of control and Ar plasma treated surfaces. The difference could have been caused by the homogeneous graft polymerization of pMPC onto the SR membrane. In the biological analyses, protein adsorption on pMPC-SR surfaces was reduced. The reduced level increased with an increase in the pMPC grafted amount. The epithelial cell attachment and growth onto these samples were suppressed. The blood compatibility for a series of pMPC-SR surfaces was examined by platelet adhesion. Blood platelet morphologies in contact with the high ratio of pMPC-SR surfaces were maintained, meaning that in this case the release reaction for platelets never occurred. Consequently, the high amount of pMPC-SR surface had excellent blood compatibility, further suggesting that prevention of adhesion, activation of platelets, and adsorption of blood protein could be achieved.

Cloning of the American cockroach Cr-PII allergens: evidence for the existence of cross-reactive allergens between species

BACKGROUND

Previously, we have identified the 28 and 32 kd proteins as additional important allergens from the American cockroach (Periplaneta americana) Cr-PII allergenic fraction.

OBJECTIVE

The aim of this study was the cloning of P. americana Cr-PII allergens.

METHODS

A lambdagt22A cDNA library constructed from P. americana mRNA was packaged into Escherichia coli Y1090 (r-), and clones recognized by murine anti-Cr-PII monoclonal antibodies and human IgE antibodies were isolated, sequenced, and subcloned into pET 21 and expressed in E. coli BL21(DE3).

RESULTS

Six Cr-PII-positive clones recognized by human IgE antibodies were isolated. Two clones, C6 and C17, were sequenced, and we found encoding proteins of 228 and 274 amino acids with no cysteine or any potential N-glycosylation site, with predicted masses of 25.8 and 31.14 kd, respectively. Both molecules contain internal repeated sequences with a 94% identity between them. C6 and C17 showed 59% and 77.3% skin reactivities, respectively, on 22 cockroach-sensitive atopic patients. Both clones were found to have 28.9% to 31.8% identities to ANG12 protein, a precursor of the African malaria mosquito (Anopheles gambiae) and 82.7% to 85.1% identity to a nucleotide sequence of the German cockroach (Blattella germanica) Bla g Bd90K allergen. The anti-C6 and anti-C17 antibodies were able to recognize Cr-PII, recombinant proteins, five commercial American extracts, and two German cockroach extracts. Moreover, the binding of anti-C6 and anti-C17 antibodies to recombinant protein can be inhibited by B. germanica crude extract. Furthermore, Northern blot analyses have shown that B. germanica mRNAs could be detected by both cDNA probes.

CONCLUSION

Our findings provide the first evidence of antigenic cross-reactivity between P. americana and B. germanica allergens on molecular levels. The results will be a great aid in facilitating the epitope mapping and improving diagnostic and therapeutic reagents for both cockroach species.

Four-wave mixing between a soliton and noise in a system with large amplifier spacing

Depletion of soliton energy by four-wave mixing between a soliton and amplifier noise in a system with 100-km amplifier spacing is studied. Dispersion exponentially decreasing fiber is used as transmission fiber. Improvement of the system by the use of a sliding-frequency filter to reduce noise power and the depletion of soliton energy is shown. The system can be further improved by compensation for depleted soliton energy.

Sodium and calcium inward currents in freshly dissociated smooth myocytes of rat uterus

Freshly dissociated myocytes from nonpregnant, pregnant, and postpartum rat uteri have been studied with the tight-seal patch-clamp method. The inward current contains both INa and ICa that are vastly different from those in tissue-cultured material. INa is abolished by Na+-free medium and by 1 microM tetrodotoxin. It first appears at approximately -40 mV, reaches maximum at 0 mV, and reverses at 84 mV. It activates with a voltage-dependent tau of 0.2 ms at 20 mV, and inactivates as a single exponential with a tau of 0. 4 ms. Na+ conductance is half activated at -21.5 mV, and half inactivated at -59 mV. INa reactivates with a tau of 20 ms. ICa is abolished by Ca2+-free medium, Co2+ (5 mM), or nisoldipine (2 microM), and enhanced in 30 mM Ca2+, Ba2+, or BAY-K 8644. It first appears at approximately -30 mV and reaches maximum at +10 mV. It activates with a voltage-dependent tau of 1.5 ms at 20 mV, and inactivates in two exponential phases, with tau's of 33 and 133 ms. Ca2+ conductance is half activated at -7.4 mV, and half inactivated at -34 mV. ICa reactivates with tau's of 27 and 374 ms. INa and ICa are seen in myocytes from nonpregnant estrus uteri and throughout pregnancy, exhibiting complex changes. The ratio of densities of peak INa/ICa changes from 0.5 in the nonpregnant state to 1.6 at term. The enhanced role of INa, with faster kinetics, allows more frequent repetitive spike discharges to facilitate simultaneous excitation of the parturient uterus. In postpartum, both currents decrease markedly, with INa vanishing from most myocytes. Estrogen-enhanced genomic influences may account for the emergence of INa, and increased densities of INa and ICa as pregnancy progresses. Other influences may regulate varied channel expression at different stages of pregnancy.

Roles of outward potassium currents in the action potentials of guinea pig ureteral myocytes

Outward currents of freshly dissociated ureteral myocytes consist mainly of Ca(2+)-activated K+ current (IKCa) and a transient outward current (ITO). No delayed rectifier current was apparent. IKCa is small and nondecaying and fluctuates actively and irregularly. Blocking IKCa decreased resting membrane conductance and prolonged action potential plateaus, showing its roles in maintaining the resting potential and in repolarizing action potentials. It is also responsible for the membrane potential fluctuations on action potential plateaus. Neither 8-(diethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride nor caffeine reduced the fluctuations in the outward current or in the action potentials, indicating that internal Ca2+ storage contributes little to the fluctuations. ITO has fast activation and inactivation kinetics with inactivation time constants of approximately 15 and 150 ms, respectively. Its highly negative voltage-availability relationship (V0.5 = -70.5 mV) suggests a low availability (< 5%) at normal resting potentials. It has only trivial effects on action potentials.

Constitutive expression of mature transforming growth factor beta1 in the liver accelerates hepatocarcinogenesis in transgenic mice

Transforming growth factor beta-1 (TGF-beta1) is a potent inhibitor of hepatocyte growth both in vivo and in vitro. In this study, we analyzed the effects of TGF-beta1 on both naturally occurring and diethylnitrosamine-induced hepatocarcinogenesis using single transgenic TGF-beta1 and double transgenic c-myc/TGF-beta1 mice in which the expression of both transgenes was targeted to the liver. Hepatocellular tumors developed spontaneously in 59% (10 of 17) of the TGF-beta1 mice by 16-18 months of age. Coexpression of TGF-beta1 and c-myc transgenes in the liver accelerated hepatic tumor growth in both the presence and absence of carcinogenic treatment. Moreover, diethylnitrosamine-initiated tumors in the c-myc/TGF-beta1 mice showed a high rate of malignant conversion associated with a reduced expression or lack of TGF-beta receptor type II. The results suggest that overexpression of TGF-beta1 may contribute to liver carcinogenesis and that loss of TGF-beta receptor type II transduced inhibitory growth signals and up-regulation of c-myc are critical steps in liver tumor progression.

The conserved B3 domain of VIVIPAROUS1 has a cooperative DNA binding activity

The biochemical activities that underlie the genetically defined activator and repressor functions of the VIVIPAROUS1 (VP1) protein have resisted in vitro analysis. Here, we show that a glutathione S-transferase (GST) fusion protein, including only the highly conserved B3 domain of VP1, has a highly cooperative, sequence-specific DNA binding activity. GST fusion proteins that include larger regions of the VP1 protein have very low activity, indicating that removal of the flanking protein sequences is necessary to elicit DNA binding in vitro. DNA competition and DNase I footprinting analyses show that B3 binds specifically to the Sph element involved in VP1 activation of the C1 gene, whereas binding to the G-box-type VP1-responsive element is of low affinity and is nonspecific. Footprint analysis of the C1 promoter revealed that sequences flanking the core TCCATGCAT motif of Sph also contribute to the recognition of the Sph element in its native context. The salient features of the in vitro GST-B3 DNA interaction are in good agreement with the protein and DNA sequence requirements defined by the functional analyses of VP1 and VP1-responsive elements in maize cells.

Growth requirements and neoplastic transformation of two types of normal human breast epithelial cells derived from reduction mammoplasty

A chemically defined culture medium was developed to support the growth of two distinctly different types of normal human breast epithelial cells (HBEC) derived from reduction mammoplasty. Type I cells expressed luminal epithelial cell markers and were deficient in gap junctional intercellular communication (GJIC), whereas Type II cells expressed basal epithelial cell markers and were efficient in GJIC. In this study, we examined and compared the growth factor and hormone requirements of these two types of cells and a series of cell lines that were obtained by sequential transfection with SV40 DNA (extended lifespan, nontumorigenic), treatment with 5-bromodeoxyuridine (BrdU)/black light (immortal and weakly tumorigenic), and infection of a virus carrying the neu oncogene (highly tumorigenic). Growth of Type I cells was inhibited by withdrawing epidermal growth factor (EGF), hydrocortisone (HC), or insulin (INS) from the culture media, but was enhanced by fetal bovine serum (FBS) supplementation. Growth of Type II cells was inhibited by withdrawal of EGF, HC, or INS from the media, and was inhibited by FBS supplementation. Withdrawal of human transferrin (HT) or 17 beta-estradiol (E2) from the media did not alter the growth of Type I or Type II cells. SV40 transfected Type I cell lines still required EGF, HC, or INS for optimal growth. However, the highly tumorigenic cell line did not show a growth dependence on EGF, HC, or INS but did appear to require HT and 3,3',5-triiodo-D.L. thyronine (T3) for optimal growth. In addition, FBS stimulated the growth of these cell lines. Thus, this study shows that Type I HBEC are distinctly different from Type II HBEC in growth response to FBS and that neoplastically transformed Type I cells could become growth factor and hormone independent.

Roles of Ca2+ and Na+ in the inward current and action potentials of guinea pig ureteral myocytes

Physiological roles of Ca2+ vs. Na+ in membrane currents and action potentials of ureteral myocytes were investigated on freshly dissociated guinea pig ureteral myocytes with the patch-clamp method. The myocytes are spindle shaped, with cell volume of 2,473 microm3, surface area of 2,014 microm2, capacitance of 48.2 pF, resting potential of -47.9 mV, and membrane conductance of 840 pS. The membrane current consists of a slow inward Ca2+ current (ICa) conducted by L-type Ca2+ channels and an actively fluctuating Ca2+-activated K+ current [IK(Ca)] conducted by Ca2+-activated maxi-K+ channels. ICa dominates the membrane current by being long lasting and more active at less depolarized potentials than IK(Ca) and by regulating IK(Ca). Ca2+-free media, Co2+, and nifedipine reduce or block ICa, whereas high extracellular Ca2+ concentration and BAY K 8644 enhance it. Action potential amplitudes and plateaus are regulated correspondingly. Related changes are also seen in IK(Ca) In contrast, no fast inward current attributable to Na+ was found. Replacing extracellular Na+ with tris(hydroxymethyl)aminomethane had no apparent effects on the inward or outward current or on the action potentials.

Properties of inward calcium current in guinea pig ureteral myocytes

Ureteral myocytes of guinea pigs have L-type Ca2+ channels (I(Ca)). In 3 mM Ca2+, maximum I(Ca) was 3.38 microA/cm2. Voltage at which conductance is 50% of maximum (V0.5) of I(Ca) was -1.0 mV in 3 mM Ca2+ and +22 mV in 30 mM Ca2+, with slope factors of 8 mV. V0.5 of steady-state inactivation of I(Ca) was -16.2 and +1.1 mV in 3 and 30 mM Ca2+, respectively, with similar slope factors of about -6 mV. A window current reaching 20-25% of the maximum I(Ca) was active between -20 and 0 mV. I(Ca) inactivated very slowly, with time constants of 217.6 and 2,455.9 ms with no voltage dependency. When Ba2+ was used as the charge carrier, the amplitude and inactivation kinetics of the Ba2+ current were similar to those for I(Ca). These results indicate that the ureteral myocyte has little Ca2+-mediated Ca2+ channel inactivation, a feature significantly associated with the slow I(Ca) inactivation. The slow inactivation and the window current are essential for the sustained membrane depolarization during the plateau of ureteral action potentials.

Scheduling nursing personnel on a microcomputer

Suggests that with the shortage of nursing personnel, hospital administrators have to pay more attention to the needs of nurses to retain and recruit them. Also asserts that improving nurses' schedules is one of the most economic ways for the hospital administration to create a better working environment for nurses. Develops an algorithm for scheduling nursing personnel. Contrary to the current hospital approach, which schedules nurses on a person-by-person basis, the proposed algorithm constructs schedules on a day-by-day basis. The algorithm has inherent flexibility in handling a variety of possible constraints and goals, similar to other non-cyclical approaches. But, unlike most other non-cyclical approaches, it can also generate a quality schedule in a short time on a microcomputer. The algorithm was coded in C language and run on a microcomputer. The developed software is currently implemented at a leading hospital in Taiwan. The response to the initial implementation is quite promising.

Plasma-induced grafted polymerization of acrylic acid and subsequent grafting of collagen onto polymer film as biomaterials

Polyacrylic acid (pAA) was introduced onto Ar-plasma treatment silicone rubber (SR) membrane surfaces by plasma-induced grafted polymerization. Collagen (type III) was also linked with the carboxylic group of pAA grafted onto the SR surface via a carbodiimine agent to obtain a secondary structure of SR. The SR surface properties were characterized by ATR-FTIR, ESCA, contact angle, and SEM. The biocompatibility of the SR surface was evaluated by a culture of cornea epithelial (CE) cells. Subsequently, 75-450 micrograms cm-2 of pAA were obtained on the SR surfaces under different reactive conditions; 3-12 micrograms cm-2 of collagen were linked on modified surfaces of SR. Moreover, ATR-FTIR and ESCA were utilized to confirm the proceedings of these reactions. The hydrophility of the modified SR was measured by a contact angle meter. The values of contact angle for SR grafted with pAA were approximately 45-50 degrees; a 50-55 degrees contact angle on pAA-g-SR to be further linked with collagen was subsequently obtained. Moreover, the influence of surface properties toward migration, growth and attachment of CE cells on the modified surfaces was also examined. Here, untreated SR was used as a control. Experimental results indicated that the number of CE cells attached onto the controlled SR was negligible. The attachment of cells onto pAA-grafted surfaces was clearly observed and peusopoda occurred; however, cell growth was depressed. This depression may have been caused by the acid environment of the pAA-grafted membrane. Nevertheless, both cell attachment and growth onto collagen-linked surfaces were significant. In addition, the morphology of the cells attached onto this surface was considered normal for primary cells. Collagen introduced on the SR surface was not denatured, i.e the natural properties of collagen were maintained. The results obtained in this study will hopefully lead to the successful development of modified SR for clinical applications.

Localization and interaction of the cis-acting elements for abscisic acid, VIVIPAROUS1, and light activation of the C1 gene of maize

The C1 regulatory gene of the maize anthocyanin pathway is regulated by a combination of developmental and environmental signals that include the Viviparous1 (Vp1) gene, abscisic acid (ABA), and light. Using protoplast electroporation and particle bombardment assays, we have defined c/s-acting elements that are necessary and sufficient for the activation of C1 by ABA, VP1, and light, respectively. The sequence from positions -142 to -132 (CGTCCATGCAT) is essential for VP1 activation, whereas a larger overlapping element from -147 to -132 (CGTGTCGTCCATGCAT) is necessary and sufficient for activation by ABA. A separate light (blue and red)-responsive c/s element is located between positions -116 and -59. Light interacts synergistically with the ABA and VP1 responses in transient expression assays, suggesting that combinatorial interaction between modules plays a role in integrating these signals in the developing seed.

Reduced growth capacity of hepatocytes from c-myc and c-myc/TGF-alpha transgenic mice in primary culture

We have previously shown that coexpression of c-myc and TGF-alpha in the liver results in accelerated replicative senescence and promotes tumor development in young adult transgenic mice. Here we describe the characteristics of hepatocyte proliferation in primary cultures established from 10-week-old control, c-myc and c-myc/TGF-alpha transgenic mice. A variety of cellular and functional changes occurred in the transgenic livers at this age including enhanced polypoidization and impairment of hepatic functions. Control mouse hepatocytes demonstrated a high level of DNA synthesis in serum-free medium with a maximum at day three in culture at which time 70% of the cells were in S phase. In contrast, DNA synthesis peaked one day later and was reduced by 50% in the cultured c-myc and c-myc/TGF-alpha hepatocytes. Also, higher frequency of apoptosis was observed in the transgenic hepatocytes. However, in hepatocytes isolated from c-myc/TGF-alpha mice, which show early appearance of preneoplastic lesions in vivo, the DNA synthesis continued for 6 days in culture in contrast to a sharp decrease in the labeling index of control and c-myc hepatocytes after 3-4 days in culture. The results suggest that proliferative features of the transgenic hepatocytes in vitro reflect the general properties of these cells in vivo and thus may provide a model for studies on senescence and transformation of hepatocytes.

11-Oxo-tetrodotoxin and a specifically labelled 3H-tetrodotoxin

Tetrodotoxin was oxidized to a hydrated aldehyde, 11-oxo-tetrodotoxin, which shares the specificity of tetrodotoxin for the Na+ channel of the isolated voltage-clamped frog skeletal muscle fiber, but is four to five times more potent. It binds to the solubilized Na+ channel of eel electroplax with a similarly higher potency, because of an equilibrium dissociation constant about 0.25, and a dissociation rate constant 2.4 times slower than those for tetrodotoxin. 11-Oxo-tetrodotoxin can be reduced to regenerate a tetrodotoxin, which is chemically and biologically indistinguishable from the original tetrodotoxin. By reducing with tritiated sodium borohydride, a 3H marker can be inserted regiospecifically to yield 11-[3H]-tetrodotoxin. Because it has a defined specific activity of > 2.5 Ci/mmole, and a 3H marker which does not exchange with solvent proton, 11-[3H]-tetrodotoxin is an ideal tracer for tetrodotoxin. It may enable studies of problems which require higher signals and/or better stability of the marker than those obtainable from currently available tracer Na(+)-channel ligands.

Artificial cornea: surface modification of silicone rubber membrane by graft polymerization of pHEMA via glow discharge

A method for producing various surfaces of silicone rubber membrane (SR) was developed in this study by grafting various amounts of poly(2-hydroxy ethyl methacrylate) (pHEMA) onto SR by plasma-induced grafted polymerization (PIP) as a homobifunctional membrane. The elemental composition and different carbon bindings on the surface of SR were examined by electron spectroscopy for chemical analysis with the amount of O1s/C1s being approximately 0.7 at 1 min, 60 W, 200 mTorr of Ar-plasma treatment. The peroxide group introduced on SR was measured via 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the amount of 6.85 x 10(-8) mol cm-2 reached optimum value at 1 min of Ar-plasma treatment. After Ar-plasma treated SR, the peroxide group (33D peak) was introduced on the surface of SR by negative spectra of secondary ion mass spectroscopy analysis, whereas ester groups (72D peak) were observed for pHEMA-grafted SR. For the in vitro test, the influence of various surfaces of SR on attachment and growth of rabbit corneal epithelial cells (CEC) was studied by cell culture assay. These results indicated that 56-150 micrograms cm-2 of pHEMA grafted onto SR were suitable values for attachment and growth of CEC. On the contrary, the large grafted amounts (500-1650 micrograms cm-2) of pHEMA on SR were insufficient for attachment and growth of CEC. For the in vivo test, the migration of CEC from host cornea to implant was investigated by slit lamp microscopy. The experimental results indicated that SRs grafted with pHEMA were completely covered with CEC 3 weeks after implantation of the membranes into the host cornea. These results provide a valuable reference for developing an artificial cornea.

Two types of normal human breast epithelial cells derived from reduction mammoplasty: phenotypic characterization and response to SV40 transfection

A culture method to grow two morphologically distinguishable normal human breast epithelial cell types derived from reduction mammoplasty has been developed. Type I cells were characterized by a more variable cell shape, smooth cell colony boundaries, the expression of epithelial membrane antigen (EMA) and keratin 18 and the non-expression of keratin 14 and alpha 6 integrin. In addition, the Type I cells were growth stimulated by fetal bovine serum (FBS) and were deficient in gap junctional intercellular communication (GJIC). In contrast, Type II cells were characterized by a uniform cell shape, expression of keratin 14 and alpha 6 integrin and the non-expression of EMA and keratin 18. In addition, Type II cells were growth inhibited by FBS and were proficient in GJIC. Type I cells can be induced by cholera toxin to change their morphology to a Type II cell morphology. Hence, Type I cells antigenically resemble luminal epithelial cells, while the Type II cells more closely resemble basal epithelial cells. Type I and Type II cells were transfected with SV40 DNA. Clones with extended lifespans were obtained from both Type I and Type II cells by SV40 transfection. Some (2/9) of the SV40-transfected Type I cell clones became immortal (> 100 cumulative population doubling level), whereas none (0/8) of the SV40-transfected Type II cell clones became immortal. The SV-40-transfected Type I and Type II cell-derived extended life clones and immortal cell lines phenotypically resembled their parental cells with respect to EMA, keratin 14 and keratin 18 expression and GJIC. Each (9/9) of the SV40 transfected Type I cell clones grew in soft agar; none (0/8) of the SV40-transfected Type II cell clones were capable of growing in soft agar. These results provide evidence that normal human breast epithelial cells, derived from reduction mammoplasty, can be separated into two morphologically and antigenically different cell types and that these two different cell types significantly differ in their response to an oncogenic (SV40) stimulus.

A fluorescent lipid analogue can be used to monitor secretory activity and for isolation of mammalian secretion mutants

The use of reporter proteins to study the regulation of secretion has often been complicated by posttranslational processing events that influence the secretion of certain proteins, but are not part of the cellular mechanisms that specifically regulate secretion. This has been a particular limitation for the isolation of mammalian secretion mutants, which has typically been a slow process. To provide a reporter of secretory activity independent of protein processing events, cells were labeled with the fluorescent lipid analogue C5-DMB-ceramide (ceramide coupled to the fluorophore boron dipyrromethene difluoride) and its secretion was followed by fluorescence microscopy and fluorescence-activated cell sorting. Brefeldin A, which severely inhibits secretion in Chinese hamster ovary cells, blocked secretion of C5-DMB-ceramide. At high temperature, export of C5-DMB-ceramide was inhibited in HRP-1 cells, which have a conditional defect in secretion. Using C5-DMB-ceramide as a reporter of secretory activity, several different pulse-chase protocols were designed that selected mutant Chinese hamster ovary cells that were resistant to the drug brefeldin A and others that were defective in the transport of glycoproteins to the cell surface. Mutant cells of either type were identified in a mutagenized population at a frequency of 10(-6). Thus, the fluorescent lipid C5-DMB-ceramide can be used as a specific marker of secretory activity, providing an efficient, general approach for isolating mammalian cells with defects in the secretory pathway.

Effects of lidocaine on rat myometrial sodium channels and implications for the management of preterm labor

OBJECTIVE

We examined the effects of lidocaine on ionic channels of single uterine myocytes and on the duration of pregnancy.

STUDY DESIGN

The electrophysiologic effects of lidocaine on the sodium, calcium, and potassium channels of freshly dissociated myocytes from rat uteri in late pregnancy were studied with the tight-seal patch-clamp method. Dose-response relations on the sodium and calcium currents and effects on the availability relation for sodium current were examined. Also studied were the effects of long-term administration of lidocaine on the duration of pregnancy.

RESULTS

Lidocaine blocks Na+ channels selectively, with an ED50 (concentration of lidocaine capable of blocking half of the Na+ current) of 0.11 mmol/L. It shifts the availability relations for sodium ion to more negative voltages. When administered from day 20 until delivery, lidocaine prolonged term by 7%.

CONCLUSION

Lidocaine can selectively block myometrial Na+ channels, thereby reducing excitability. It can prolong term in the pregnant rat. These observations suggest that lidocaine might be useful in the clinical management of preterm labor.

A method for linking VL and VH region genes that allows bulk transfer between vectors for use in generating polyclonal IgG libraries

Libraries of Ab fragments have been produced by others from light and heavy chain cDNAs derived from populations of B lymphocytes and expressed in bacteria. However, such libraries have not been transferred to eukaryotic expression vectors to generate polyclonal libraries of intact glycosylated Abs that can mediate effector functions. We present a method for transferring pairs of linked VL-VH region genes between circular prokaryotic and eukaryotic vectors. The key feature of the transfer is that the VL and VH region genes are linked head to head (<-->) in opposite transcriptional orientations. To illustrate this method, a pair of VL and VH region cDNAs derived from an existing hybridoma cell line were linked head to head by PCR, transferred as a unit between vectors, and expressed as an IgG Ab with Ag binding activity. Although we tested the transfer of a single VL-VH region gene pair, this system is expected to allow the bulk transfer of physically linked VL-VH region gene combinations between different circular vectors and the expression of the same library as either Ab fragments or intact Abs.

A method for linking VL and VH region genes that allows bulk transfer between vectors for use in generating polyclonal IgG libraries

Libraries of Ab fragments have been produced by others from light and heavy chain cDNAs derived from populations of B lymphocytes and expressed in bacteria. However, such libraries have not been transferred to eukaryotic expression vectors to generate polyclonal libraries of intact glycosylated Abs that can mediate effector functions. We present a method for transferring pairs of linked VL-VH region genes between circular prokaryotic and eukaryotic vectors. The key feature of the transfer is that the VL and VH region genes are linked head to head (&lt;--&gt;) in opposite transcriptional orientations. To illustrate this method, a pair of VL and VH region cDNAs derived from an existing hybridoma cell line were linked head to head by PCR, transferred as a unit between vectors, and expressed as an IgG Ab with Ag binding activity. Although we tested the transfer of a single VL-VH region gene pair, this system is expected to allow the bulk transfer of physically linked VL-VH region gene combinations between different circular vectors and the expression of the same library as either Ab fragments or intact Abs.

Release of TEA blockade of maxi-K+ channels by isoproterenol

The outward K+ current induced by step depolarization of freshly dispersed myocytes of guinea-pig taenia coli decreased about 80% upon treatment with 3 mM tetraethylammonium chloride (TEA). Isoproterenol (ISO, 2-5 microM) restored it to a large extent. This restoration did not occur in the presence of propranolol (2 microM). In single-channel recordings from cell-attached patches, the activity of maxi-K+ channel is dominant. When 3 mM TEA is incorporated in the pipette solution, the dominant channel-openings observed had much smaller unitary conductance. On the addition of ISO (2 microM) to the bath solution, but not to the pipette solution, K(+)-channel openings with unitary conductance similar to that without TEA treatment appeared. Cyclic AMP incorporated into the cytoplasm through the pipette was ineffective. These results indicate that ISO release TEA decrease of maxi-K+ channel conductance through some intracellular second messenger system other than adenylyl cyclase-protein kinase A system.

Enhancement of beta-adrenergic receptor activation of maxi-K+ channels by GM1 ganglioside

In freshly dispersed guinea-pig taenia coli myocytes, beta-adrenergic receptor agonist isoproterenol (ISO, 2-5 microM) increased the open probability (po) of the maxi-K+ channels through the G-protein, G. Subunit B of cholera toxin (0.1 nM) suppressed the ISO-induced increase of po of maxi-Ks+ channels but did not affect that induced by forskolin. Brief (20 min) treatment of the myocytes with GM1 ganglioside (GM1, 0.1-1.0 microM) enhanced the effectiveness of ISO-induced increase of po. This effect was blocked by 0.5% trypsin, which is known to prevent the incorporation of exogeneous GM1 into the membrane. The effect of GM1 was not shared by GM2 and GM3 gangliosides. These results suggest that the membrane-bound endogeneous GM1 may participate in the regulation of cellular response to beta-adrenergic agents.

Chimeric antibodies with anti-dextran-derived complementarity-determining regions and anti-p-azophenylarsonate-derived framework regions

The framework regions of antibodies fold into a conserved beta-sheet structure that acts as scaffolding for the antigen-contacting complementarity-determining regions (CDR). To test the structural equivalence of the frameworks between two antibodies with widely different combining sites, we created chimeric H and L chains by grafting the CDR of an alpha(1--&gt;6)dextran specific antibody onto the framework of a p-azophenylarsonate (Ars) specific antibody through oligonucleotide-directed mutagenesis of the anti-Ars variable region genes. Antibodies consisting of various chain combinations of the chimeric, anti-dextran, and anti-Ars derived H and L chains were generated in transfectomas and tested for binding to dextran and Ars. Of the newly created chimeric and/or hybrid antibodies, an antibody with the chimeric H chain and the anti-dextran L chain bound to dextran with the same association constant as the parental anti-dextran antibody, and like the anti-dextran antibody was shown by immunochemical mapping to have a site complementary to six glucose residues. None of the other new variable region combinations, including the all-chimeric combination, showed binding to either dextran or Ars. These results indicate that the H chain but not the L chain anti-dextran and anti-Ars frameworks are functionally equivalent. Attempts to confer dextran binding on the H and L chain chimeric antibody, by mutagenizing selected framework residues, were unsuccessful. This study demonstrates the important role of the frameworks in the precise alignment of the CDR for Ag binding.