Ca(2+) removal mechanisms in freshly isolated rabbit aortic endothelial cells

Calcium removal from the cytoplasm was investigated in freshly isolated aortic endothelial cells by monitoring changes in intracellular calcium ([Ca(2+)](i)) using ratiometric fura-2 fluorimetry. Blockade of the Na(+)/Ca(2+) exchanger (NCX) by replacement of external sodium with equi-molar N-methyl-D-glutamine (0Na PSS) decreased the removal rate by 52%. Blockade of the sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA) by cyclopiazonic acid (CPA) decreased the removal rate by 50%. Simultaneous application of CPA and 0Na PSS did not reduce the removal rate any further (53%). The lack of additivity of these two procedures, suggests that SERCA and the NCX function in series to lower [Ca(2+)](i). In addition, in the absence of extracellular Ca(2+), removal of external Na(+) markedly reduced the rate of loss of Ca(2+) from the ER further supporting the hypothesis that NCX is functionally linked to ER calcium release channels, and thus, plays an important role in ER calcium unloading. To investigate the mechanism for the coupling of NCX and SERCA, the same protocols as described above were repeated after treating the cells with cytochalasin D, which disrupts the cytoskeleton. This treatment uncoupled the NCX from SERCA, as evidenced by the resulting additive inhibitory effects of application of CPA and removal of extracellular Na(+) on the rate of Ca(2+) removal from the cytoplasm. These data suggest that in endothelial cells NCX and SERCA function in series to remove about half of the free Ca(2+) from the cytosol, while PMCA contributes to the other half of the Ca(2+) removal process.

Quantitative analysis of beta-adrenergic receptor subtypes in pig tissues

The density and distribution of beta1- and beta2-adrenergic receptors (betaAR) in porcine adipocytes, skeletal muscle, heart, lung, and liver were investigated using competitive displacement of ligand binding with subtype-selective ligands. Three experimental approaches were used to estimate the distribution of betaAR subtypes in adipocytes. Two approaches involved simultaneous linear regression analysis of multiple competitive displacement curves with the beta1AR-selective antagonist CGP 20712A and the beta2AR-selective ligand BRL 37344. For the third approach, radioligand saturation assays were perfomed using a concentration of CGP 20712A that completely blocked the beta1AR. All three approaches indicated the presence of multiple betaAR subtypes in porcine adipocytes and gave similar estimates for the proportion of these subtypes. Saturation assays in the presence of the beta1AR blocker CGP 20712A were conducted to determine the distribution of the betaAR subtypes in skeletal muscle, heart, lung, and liver. The proportions of the beta1AR and beta2AR were 81:19, 59:41, 72:28, 58:42, and 50:50 for adipose, skeletal muscle, heart, lung, and liver, respectively. These estimates based on receptor protein were consistent with published estimates of mRNA abundance in pig tissues but differ from estimates for other species. The predominance of beta1AR in adipocytes and skeletal muscle may contribute to the reduced efficacy of select betaAR agonists in pigs compared to other species because most of the ligands evaluated in growth studies are purported to be beta2AR selective. The density of the betaAR varied among tissues in the following order: heart = lung > adipocytes > skeletal muscle or = liver.

Effect of agricultural management on nematode communities in a mediterranean agroecosystem

The effects of agricultural management on the soil nematode community were investigated in a field study at depths of 0 to 10 cm and 10 to 20 cm during a peanut (Arachis hypogaea) growing season in Israel. Nineteen nematode families and 23 genera were observed. Rhabditidae, Cephalobus, Eucephalobus, Aphelenchus, Aphelenchoides, Tetylenchus, Tylenchus, Dorylaimus, and Discolaimus were the dominant family and genera. Ecological measures of soil nematode community structure, diversity, and maturity indices were assessed and compared between the managed (by fertilization, irrigation, and pesticide application) and unmanaged fields. The total number of nematodes at a 10-cm depth during peanut-sowing, mid-season, and harvest periods was higher in the treated (managed) plot than in the control (unmanaged) plot. Bacterivores and fungivores were the most abundant trophic groups in both plots and both depths. The relative abundance of each group averaged 60.8 to 67.3% and 11.5 to 19.6% of the nematode community, respectively. Plant parasites and omnivores-predators at the 0 to 10-cm depth were much less abundant than any other two groups in our experimental plots. During the growing season, except the harvest period, populations of plant parasites and omnivores-predators at the 10 to 20-cm depth were lower in the treated plot than in the control plot. Maturity index (MI), plant-parasite index (PPI), and ratio of fungivores and bacterivores to plant parasites (WI) were found to be more sensitive indicators than other ecological indices for assessing the response of nematode communities to agricultural management in an Israeli agroecosystem.

HTLV-1 cell lines differ in constitutively activated signaling pathways that can be altered by cytokine exposure

Examination of signaling pathways used by HTLV-1-infected rabbit cell lines revealed differences between one, RH/K30, that mediates asymptomatic infection and another, RH/K34, that causes lethal experimental leukemia. Both lines are IL-2 independent; RH/K30 produces IL-4 while RH/K34 produces IL-10. Examination of the Jak/STAT (Janus kinase/signal transducer and activator of transcription) activation of the lines revealed constitutive phosphorylation of Jak1 in both STAT6 phosphorylation, not previously reported for HTLV-1 cells, was observed in RH/K30; STAT1 and STAT3 were phosphorylated in RH/K34. Treatment with cytokines altered the activation of the STAT proteins: IL-2 induced STAT5 phosphorylation in both lines. Supernatant from RH/K34 or IL-10 induced STAT3 phosphorylation in RH/K30 cells. Supernatant from RH/K30 or IL-4 induced STAT6 phosphorylation in RH/K34 cells, which could be reversed with a Jak kinase inhibitor--AG-490.

[Function of vascular endothelial growth factor in ovarian hyperstimulation syndrome]

OBJECTIVE

To evaluate the function of vascular endothelial growth factor (VEGF) and other clinical indexes to forcast ovarian hyperstimulation syndrome (OHSS).

METHOD

Collecting the serum and follicular fluid (FF) of 42 cases in the in vitro fertilization and embryo transfer (IVF-ET) cycles and then analysis the relationship of the clinical and detected indexes between the OHSS (10 cases) and the non-OHSS (32 cases).

RESULTS

The concentration of VEGF in FF, E2 on the day of human chorionic gonadotropin (hCG) injection, basal luteinizing hormone (LH) and the number of ovum retried much higher in the OHSS than in the non-OHSS.

CONCLUSIONS

The concentration of VEGF in FF of OHSS cases is higher than that of controls, supporting the role of VEGF as a mediator of OHSS. Therefore VEGF in FF is a forcast index of OHSS.

Optical properties of single-walled 4 A carbon nanotubes

Optical properties of a series of finite sized hydrogenated carbon nanotubes with the smallest diameter of 4 A are studied systematically. Their absorption spectra are calculated with the localized-density-matrix method. The semiempirical MNDO parametric method 3 (PM3) Hamiltonian is employed. The finite optical gaps are predicted for the infinite long single-walled carbon nanotubes. Strong anisotropy characteristics of the dynamic polarizabilities are found for these tubes. The calculated results are in good agreement with the recent experimental findings. Further the compositions of the dipole-induced excitations are examined by projecting the corresponding density matrices onto the Hartree-Fock molecular orbital representation. Unlike the larger diameter carbon nanotubes whose absorption spectra are insensitive to the tube chiralities, the absorption spectra of 4 A single-walled carbon nanotubes depend very much on their chiralities. The chirality of the single-walled 4 A carbon nanotubes synthesized in the channels of the porous zeolites is thus determined to be (5,0) by comparing the calculated and measured absorption spectra.

[The electric pulse caused pore in the skin observed by fluorescence microscopy]

The objective of this study was to enunciate the difference in skin morphological changes between iontophroresis and electroporation for transdermal drug delivery (TDD). Fluorescence microscope was employed to observe the skin structure of human and snake in passive diffusion (control); iontophoresis was performed using direct current(0.5 mA/cm2) and electroporation was performed using intensive 380 V, pulse rate 4 ppm, pulse duration 5.5 ms, pulse number 100 and electric capacity 22 microF. Fluorescein was FITC. The results showed that for human skin in the passive, these were a few highlight fluorescent blots with scale of 15-30 microns and rough edge, but the edge of the blots became smooth and the scale did not change in the iontophoresis; when the scale of the blots was extended to 80-90 microns, the edge was smooth. For the snakes shin, the highlight blots were not sighted in the passive and iontophoresis, but they were found to be 25-30 microns in the electroporation. These data demonstrate that electric pulse can cause pore in the skin, thus creating a new route for drug permeation through skin.

Fabry - Perot interference in a nanotube electron waveguide

The behaviour of traditional electronic devices can be understood in terms of the classical diffusive motion of electrons. As the size of a device becomes comparable to the electron coherence length, however, quantum interference between electron waves becomes increasingly important, leading to dramatic changes in device properties. This classical-to-quantum transition in device behaviour suggests the possibility for nanometer-sized electronic elements that make use of quantum coherence. Molecular electronic devices are promising candidates for realizing such device elements because the electronic motion in molecules is inherently quantum mechanical and it can be modified by well defined chemistry. Here we describe an example of a coherent molecular electronic device whose behaviour is explicitly dependent on quantum interference between propagating electron waves-a Fabry-Perot electron resonator based on individual single-walled carbon nanotubes with near-perfect ohmic contacts to electrodes. In these devices, the nanotubes act as coherent electron waveguides, with the resonant cavity formed between the two nanotube-electrode interfaces. We use a theoretical model based on the multichannel Landauer-Büttiker formalism to analyse the device characteristics and find that coupling between the two propagating modes of the nanotubes caused by electron scattering at the nanotube-electrode interfaces is important.

[The effect of IFN-alpha 2b-thymus peptides combined therapy in chronic hepatitis B]

OBJECTIVE

To determine the effects of IFN-alpha 2b associated with thymus peptides in treatment of chronic hepatitis B.

METHODS

A total of 52 individuals with chronic hepatitis B received IFN-alpha 2b(5 x 10(6) IU/ml qod) for 6 months and thymus peptides(20 mg qod) for 3 months. 50 patients received SMMC or other medicine such as WuWeizi, CuiPenCao served as control. There were no differences between two groups in sex, age, duration and seriousness of the disease.

RESULTS

The primary outcome measure for efficacy was the percentage of HBV DNA/HBeAg negativity after 6 months therapy. Rate of HBV DNA negativity was 75% and that of HBeAg was 73.1%, the inhibitory activity of IFN-alpha 2b against HBV was significantly higher than that of the control. Except transient fever, leukopenia and thrombocytopenia appearing at the beginning of the therapy, no serious adverse events were observed.

CONCLUSION

Potent inhibitory activity against HBV of IFN-alpha 2b is suggested and much works need to be done to improve the long-term effect of the therapy.

Cost of genetic counseling and testing for BRCA1 and BRCA2 breast cancer susceptibility mutations

Counseling and predictive testing are now available for the recently isolated BRCA1 and BRCA2 breast cancer susceptibility genes. We examined the societal costs of providing this counseling and testing to women at risk of having a breast cancer susceptibility mutation. Genetic counselors in a research program prospectively monitored the time necessary to provide counseling and results disclosure. A time-motion study was used to determine time spent on phone calls, preparation, and documentation for counseling. Study participants were surveyed to determine travel time and need for dependent care during counseling. The test cost was calculated using the charge for full BRCA1/2 gene sequencing (Myriad Genetics, Inc.) multiplied by a Medicare-based cost-to-charge ratio. Counselors spent an average of 4.2 h providing genetic counseling for women at risk of having a susceptibility mutation. Genetic counseling without testing cost on average $213, whereas counseling, testing, and disclosure of results totaled $2057. A brief physician-based counseling instead of genetic counselor-based counseling would produce only small reductions in total costs. Providing counseling and testing to the study population averaged $8034 per mutation found. The cost of testing and counseling exceeded $2000. The counseling portion of the cost comprised only 16% of the total cost, with the remainder representing costs associated with testing; thus, alternatives to full genetic counseling that shorten counseling time are unlikely to have a large impact on the overall cost of counseling and testing. The cost of detecting a mutation within a population of women is highly dependent on the prevalence of the mutation in the population.

Projections of the oval nucleus of the hyperstriatum ventrale in the budgerigar: relationships with the auditory system

The afferent and efferent projections of a vocal control nucleus, the oval nucleus of the hyperstriatum ventrale (HVo), were mapped out in a parrot, the budgerigar (Melopsittacus undulatus) to determine the relationships of this nucleus to the auditory system. In budgerigars, HVo is connected to both the anterior forebrain pathway as well as to nuclei forming the descending projection system to the brainstem (Durand et al. [1997] J. Comp. Neurol. 377:179-206). Previous studies (Brauth et al. [1997] Proc. N. Y. Acad. Sci. 807:368-385; Durand and Brauth [1998] Neurosci Abstr 24:78.9) indicate that HVo lesions disrupt vocal performance and that HVo neurons show long latency electrophysiologic auditory responses. HVo has also been shown to receive input from neurons in the immediately adjacent HV (Durand et al. [1997] J. Comp. Neurol. 377:179-206). Thus, the focus of the present study was to elucidate relationships between HVo, its immediately adjacent surround and telencephalic auditory nuclei. The results show that, although the lateral and medial portions of HVo are interconnected with one another, inputs to these areas and their surrounds are distinctively different. The most substantial auditory system inputs are derived from the frontal lateral neostriatum (NFl) and supracentral nucleus of the lateral neostriatum (NLs); these project primarily to the lateral HVo and lateral HVo surround. The medial HVo and surround receive only sparse or modest input from auditory nuclei, including the caudomedial neostriatum (NCM), neostriatum intermedium pars lateralis (NIL), Fields L1 and L3, and the neostriatum intermedium pars ventrolateralis (NIVL). Other sources of input to the HVo surround include the hyperstriatum accessorium (HA), the supralaminar area of the frontal neostriatum (NAs), the ventral anterior archistriatum (AAv), the medial archistriatum (Am) and the medial HV. Neurons in the HV immediately medial to HVo project to a shell region around the entire nucleus. Both the ventral paleostriatum (VP) and ventral part of the central nucleus of the lateral neostriatum (NLc) project to HVo but not to the surround. Previously described projections (Durand et al., 1997) from HVo to the NAom, NLc, and the magnicellular nucleus of the lobus parolfactorius (LPOm) were confirmed.

[Analysis of eleven isolated transfusion transmitted virus genotype]

OBJECTIVE

To analyze transfusion transmitted virus (TTV) genotype in hepatitis patients and healthy people.

METHODS

DNA fragment of TTV was amplified by polymerase chain reaction with nested primers in eight patients with liver disease and three healthy persons. The nested PCR products were cloned and sequenced.

RESULTS

A TTV DNA sequence of 222 bp (primer sequence excluded) was compared among the 11 subjects. The similarity between N22 and WH1, WH2, WH3, GZ1, GZ2, GZ3, SD2, SD3 was 97.0%, 97.0%, 98.0%, 98.0%, 95.0%, 95.0%, 94.6% and 95.5%, respectively. The similarity between TXO11 and GZ4, SD1, XJ1 was 98.0%, 98.0% and 95.0%, respectively.

CONCLUSION

According to Okamoto's method, the eleven TTV clones are classified into two subtypes: genotype 1a and 1b.

Profile of ligand binding to the porcine beta2-adrenergic receptor

Chinese hamster ovary cells expressing the porcine beta2-adrenergic receptor (betaAR) were used to determine the binding kinetics of agonists and antagonists by competitive displacement of the radioligand [125I]iodocyanopindolol. Several purported agonists, including isoproterenol, epinephrine, norepinephine, dobutamine, salbutamol, and terbutaline, exhibited dual-affinity displacement curves, which is characteristic of agonist binding to betaAR. In each case, the addition of guanosine triphosphate (GTP) eliminated the high-affinity state and resulted in a one-site displacement curve. All of the antagonists modeled to only one site in the presence or absence of GTP. Several ligands, including ones used to promote animal growth (clenbuterol, L-644,969, and ractopamine) and the beta3AR-selective agonist BRL 37344 modeled to only one site, suggesting that these ligands would not be full agonists at the porcine beta2AR (pbeta2AR). Most of the tested ligands exhibited binding affinities that were similar to published values for the beta2AR from other species. However, several exceptions were observed. The BRL 37344 ligand bound the pbeta2AR with a 10-fold higher affinity than the human beta2AR, and the Kd of this was similar to Kd values reported for the human and rat beta3AR. The Kd of the pbeta2AR for ICI 118,551 was 50-fold higher than that for the beta2AR from rats and humans. For both BRL 37344 and ICI 118,551 the subtype-selective character of these ligands was different in the pig compared with the human and rat. These data demonstrate the value of using species-specific betaAR for selection of agonists and antagonists. Further, these data support the growing evidence that few ligands are full agonists for pbetaAR and that binding data may be useful for identifying ligands with full agonist potential.

[Soil biota and its role in soil ecology]

Soil organisms alter soil physical, chemical and biological properties in different ways. The composition and structure of biotic communities at one hierarchical level can influence the spatial heterogeneity of resource at other hierarchical levels, and the latter is supported by a number of biologically relevant spheres-functional domains in soil. In this paper, the role of soil biota in soil ecosystem processes was assessed, and the relationship between soil biodiversity and ecosystem function was presented. Soil ecosystem responses to global change were also discussed.

Resonant electron scattering by defects in single-walled carbon nanotubes

We report the characterization of defects in individual metallic single-walled carbon nanotubes by transport measurements and scanned gate microscopy. A sizable fraction of metallic nanotubes grown by chemical vapor deposition exhibits strongly gate voltage-dependent resistance at room temperature. Scanned gate measurements reveal that this behavior originates from resonant electron scattering by defects in the nanotube as the Fermi level is varied by the gate voltage. The reflection coefficient at the peak of a scattering resonance was determined to be about 0.5 at room temperature. An intratube quantum dot device formed by two defects is demonstrated by low-temperature transport measurements.

Expression of the porcine beta2-adrenergic receptor in Chinese hamster ovary cells

The gene for the porcine beta2-adrenergic receptor (pbeta2AR) was transfected into Chinese hamster ovary (CHO) cells for expression. Fourteen stable cell lines were obtained and exhibited receptor densities ranging from 12 to 2,371 fmol/mg membrane protein. The receptor density was not correlated with estimates of gene copy number obtained by Southern hybridization. The pbeta2AR in CHO cells exhibited saturable binding of [125I]CYP (Kd = 14.5 pM) and stereospecificity for (-)- and (+)-isoproterenol. The relative affinities for (-)-isoproterenol (ISO), (-)-epinephrine (EPI), and (-)-norepinephrine (NEPI) were ISO > EPI > NEPI, which are characteristic of beta2AR. The affinity values for these ligands were similar to those in other species. Binding of ISO, EPI, and NE revealed two affinity states of the betaAR; the high-affinity state was eliminated by adding Gpp(NH)p, a nonhydrolyzable GTP analogue. Binding of the antagonist propranolol modeled to only one affinity state, and Gpp(NH)p did not affect binding. Multiple affinity states are characteristic of agonist-induced coupling of betaAR with G-proteins, and the data suggest that the cloned pbetaAR is functionally competent. Data confirm that the pbeta2AR is the pig version of beta2AR. Stable CHO cell lines will be useful for characterization of pbeta2AR and screening and designing potential drugs that may be used to enhance pig production.

Experimental infection of nonenveloped DNA virus (TTV) in rhesus monkey

Virus fragments homologous to TTV were detected previously from an enterically transmitted outbreak of non-A-E hepatitis [Luo et al., 1999]. To test the susceptibility of the Rhesus monkey to this virus and to establish its transmission routes, 6 Rhesus monkeys were inoculated, 3 orally and another 3 intravenously. The inoculum was prepared by extracting and filtering feces collected from a patient during the incubation period identified in the described outbreak. A second group of 3 monkeys was used for the passage study. The feces and blood samples were collected for detection of the virus by polymerase chain reaction (PCR). Four animals were subjected to liver biopsies and bile aspiration by open surgery for in situ virus detection. Viremia occurred in 4-7 days after intravenous and 7-10 days after oral inoculation. The virus was excreted in feces a few days after oral infection and simultaneously with viremia after intravenous inoculation. The virus was also detected in bile during the viremic phase. There was a prolonged carrier state with persistent viremia and virus excretion in feces for more than 6 months. Serum transaminase levels were not raised during the infection. The virus was present in both the cytoplasm and nuclei of hepatocytes, but no significant pathology was found. Therefore, the Rhesus monkey is susceptible to TT virus infection, but the virus seems nonpathogenic. Infection of the liver may be established either by oral or parenteral inoculation. The virus may be released from liver into the blood or via bile into feces, so it may be transmitted by both blood and fecal routes.

Enhanced transdermal delivery of tetracaine by electroporation

The effect of electroporation on the transport of tetracaine through skin in vitro was studied using side-by-side compartment diffusion cells method. After achieving steady state by passive diffusion, fluxes of tetracaine achieved with passive diffusion, electroporative pulse and iontophoresis were compared. Electroporation (square-wave pulse, voltage 130 V, pulse time 0.4 s, pulse frequency 40 pulses min(-1)) or iontophoresis (0.2.mA cm(-2), lasting for 4 h) increased the transport of tetracaine through skin. The flux of tetracaine at 0.25 h after electroporation (pulse number 400) was 54.6+/-6.0 microg.cm(-2).h(-1), that after iontophoresis was 17.4+/-5.8 microg.cm(-2).h(-1) and that after passive diffusion was 8.2+/-0.5 microg.cm(-2).h(-1). In addition, the fluxes of tetracaine increased with the increasing of pulse number. From these results, it is clear that electroporation is effective in enhancing transdermal delivery of tetracaine and its function is better than iontophoresis.

[Effects of bushen yizhi recipe on somatostatin-like immunopositive and somatostatin messenger ribonucleic acid expressed-positive neurons in Alzheimer's disease model rats]

OBJECTIVE

To observe the effect of Bushen Yizhi Recipe (BYD) on somatostatin-like (SS-like) immuno-reactivity and SS mRNA expressed-positive neurons in Alzheimer disease (AD) model rats induced by D-galactose intraperitoneal and ibotenic acid (IBO) intracerebral injection.

METHODS

Fifteen months Wistar rats were randomly divided into 4 groups: normal control; AD model control induced by D-galactose intraperitoneal injection and lesion of basal nucleus of Meynert with IBO; Huperzine A (Hup-A) treated group and BYD treated group fed with Hup-A or BYD respectively. The SS-like immunoreactivity and SS mRNA expressed-positive neurons in parietal lobe, hippocampal CA1 field and hilus of the dentate gyrus in the brains of rats, which were detected with immunohistochemistry and DIG-labelling cRNA-probe in situ hybridization.

RESULTS

Counts and integrations of optic density of SS-like immuno-reactivity and SS-mRNA expressed neurons in parietal lobe, hippocampal CA1 field and hilus of the dentate gyrus in BYD treated group increased compared with AD model rats.

CONCLUSION

BYD might protect the SS-ergic system against impairment of D-galactose and IBO in the brains of the AD model rats.

[The light polymerization of C60/C70 film in air]

The C60/C70 thin film was irradiated by 253.7 nm for 8 hour in air, and the IR spectrum show that the polymerization and oxidizing in C60/C70 thin film have taken place.

Experimental infection of nonenveloped DNA virus (TTV) in rhesus monkey

Virus fragments homologous to TTV were detected previously from an enterically transmitted outbreak of non-A-E hepatitis [Luo et al., 1999]. To test the susceptibility of the Rhesus monkey to this virus and to establish its transmission routes, 6 Rhesus monkeys were inoculated, 3 orally and another 3 intravenously. The inoculum was prepared by extracting and filtering feces collected from a patient during the incubation period identified in the described outbreak. A second group of 3 monkeys was used for the passage study. The feces and blood samples were collected for detection of the virus by polymerase chain reaction (PCR). Four animals were subjected to liver biopsies and bile aspiration by open surgery for in situ virus detection. Viremia occurred in 4-7 days after intravenous and 7-10 days after oral inoculation. The virus was excreted in feces a few days after oral infection and simultaneously with viremia after intravenous inoculation. The virus was also detected in bile during the viremic phase. There was a prolonged carrier state with persistent viremia and virus excretion in feces for more than 6 months. Serum transaminase levels were not raised during the infection. The virus was present in both the cytoplasm and nuclei of hepatocytes, but no significant pathology was found. Therefore, the Rhesus monkey is susceptible to TT virus infection, but the virus seems nonpathogenic. Infection of the liver may be established either by oral or parenteral inoculation. The virus may be released from liver into the blood or via bile into feces, so it may be transmitted by both blood and fecal routes.