Site-specific antibody of (Na(+) + K(+))-ATPase augments cardiac myocyte contraction without inactivating enzyme activity

(Na(+) + K(+))-ATPase regulates both excitability and contractility of the heart. Little is known about the molecular basis of the enzyme that underlies its cardiac regulatory functions. Here we demonstrate that the (833)KRQPRNPKTDKLVNE(847) region, which resides in the alpha-subunit of rat (Na(+) + K(+))-ATPase, directly participates in the regulation of cardiac contraction. A site-specific antibody (SSA95) against this peptide sequence markedly increased intracellular Ca(2+) transients and contraction (EC(50) = 11.4 nM) in intact rat heart cells without inactivating the (Na(+) + K(+))-ATPase. These novel findings establish the first link between a precise structural region of the (Na(+) + K(+))-ATPase and cardiac positive inotropy.

[The inhibitory effects of hepatocyte targeting pH-sensitive liposome mediated phosphorothioate antisense oligonucleotide on gene expression controlled by HCV 5'NCR]

Antisense oligodeoxynucleotide is a negative charged macromolecule and hence is difficult to penetrate cell membrane and liable to degradation. To increase the effective concentration of antisense drugs in the target cells, a hepatocyte-targeting liposome directed to asialoglycoprotein receptors exclusively expressing on the hepatocyte membrane was designed and prepared based on the receptor-mediated gene transfer. In order to accelerate endosomal exit of nucleic acid drugs, the liposomal formulation with pH-sensitive property was adopted. The hepatocyte-targeting and pH-sensitivity of liposome were analyzed by galactose-receptor competitive inhibition and hemolysis of chicken red blood cell. Antisense oligodeoxynucleotide, HCV363 against HCV 5'NCR, was delivered via prepared liposome to transgenic cell HepG2.9706 and evaluated for its inhibitory effect on luciferase expression controlled by HCV 5'NCR in HepG2.9706 using Luciferase Assay System The results showed that different concentrations (10, 20, 30 mmol/L) of galactose solutions reduce the delivery effects of liposome to some extend that were up to saturation when the concentrations of galactose solution exceed 20 mmol/L. Prepared liposomes mixed with chicken RBC are put into PBS buffers with different pH values(4.0-8.0), it was observed that the amount of heme is greatly released in acidic PBS (pH < 6) due to the fusion of liposome and RBC membranes. Liposome-mediated HCV363 has dose-dependent inhibitory activities on luciferase expression controlled by HCV 5'NCR in HepG2.9706 and the inhibitory rate is 86% at a concentration of 1.0 mumol/L. In conclusion, the liposome is proven to be a hepatocyte-targeting pH-sensitive delivery system that can increase the pharmaceutical effects of antisense drugs.

[Preparation optimization and properties of the aldehyde microscopic slides for oligonucleotide microarray fabrication]

The process for preparing the aldehyde slides was optimized and the properties of the aldehyde microscopic slides for immobilizing oligonucleotide were explored. The result shows that the concentration of aminosliane reagent plays an important role in the fluorescent background. Aldehyde slides with 2% aminosilane and 5% aldehyde treatment for 16 min and 30 min respectively immobilize oligonucleotide efficiently and have low fluorescence background. During oligonucleotide immobilization, terminal amino modification has no obvious specificity, but it can enhance the hybridization capacity of immobilized oligonucleotides. At low concentration (less than 10 mumol/L), hybridization signal has linear relationship with probe concentration, the hybridization signal reaches saturation when probe concentration is more than 20 mumol/L.

Induction of apoptosis by superoxide anion and the protective effects of selenium and Vitamin E

OBJECTIVE

The purpose of this study is to investigate the effect of superoxide anion on the apoptosis of cultured fibroblasts and the protective role of selenium and Vitamin E.

METHODS

Cultured fibroblasts (NIH3T3), with or without selenium or vitamin E in the medium, were treated by superoxide anion produced by xanthine/xanthine oxidase reaction system and changes in cell structure and DNA were observed microscopically and electrophoretically.

RESULTS

Apoptosis was observed when superoxide anion at a concentration of 5 nmol/L or 10 nmol/L had acted on the fibroblasts for 5-10 h. Selenium and Vitamin E in the medium inhibited the apoptosis significantly when their concentrations reached 1.15 mol/L and 2.3 mol/L respectively.

CONCLUSION

Selenium and vitamin E have protective effect against the apoptosis induced by superoxide anion. The effect of selenium is more remarkable than that of vitamin E.

Reduction of ultraviolet transmission through cotton T-shirt fabrics with low ultraviolet protection by various laundering methods and dyeing: clinical implications

BACKGROUND

The public has long been instructed to wear protective clothing against ultraviolet (UV) damage.

OBJECTIVE

Our purpose was to determine the UV protection factor (UPF) of two cotton fabrics used in the manufacture of summer T-shirts and to explore methods that could improve the UPF of these fabrics.

METHODS

Each of the two types of white cotton fabrics (cotton T-shirt and mercerized cotton print cloth) used in this study was divided into 4 treatment groups: (1) water-only (machine washed with water), (2) detergent-only (washed with detergent), (3) detergent-UV absorber (washed with detergent and a UV absorber), and (4) dyes (dyed fabrics). Ultraviolet transmission through the fabrics was measured with a spectrophotometer before and after laundry and dyeing treatments. Based on UV transmission through these fabrics, the UPF values were calculated.

RESULTS

Before any treatments, the mean UPFs were 4.94 for the T-shirt fabric and 3.13 for the print cloth. There was greater UVA (320-400 nm) than UVB (280-320 nm) transmission through these fabrics. After 5 washings with water alone and with detergent alone, UPF increased by 51% and 17%, respectively, for the cotton T-shirt fabric. Washing the T-shirt fabrics with detergent plus the UV-absorbing agent increased the UPF by 407% after 5 treatments. Dyeing the fabric blue or yellow increased the UPF by 544% and 212%, respectively. Similar changes in UPFs were observed for the print cloth fabric.

CONCLUSION

The two cotton fabrics used in this study offered limited protection against UV radiation as determined by spectrophotometric analysis. Laundering with detergent and water improves UPF slightly by causing fabric shrinkage. Dyeing fabrics or adding a UV-absorbing agent during laundering substantially reduces UV transmission and increases UPF. More UVA is transmitted through the fabrics than UVB.

Ultraviolet A and melanoma: a review

The incidence and mortality rates of melanoma have risen for many decades in the United States. Increased exposure to ultraviolet (UV) radiation is generally considered to be responsible. Sunburns, a measure of excess sun exposure, have been identified as a risk factor for the development of melanoma. Because sunburns are primarily due to UVB (280-320 nm) radiation, UVB has been implicated as a potential contributing factor to the pathogenesis of melanoma. The adverse role of UVA (320-400 nm) in this regard is less well studied, and currently there is a great deal of controversy regarding the relationship between UVA exposure and the development of melanoma. This article reviews evidence in the English-language literature that surrounds the controversy concerning a possible role for UVA in the origin of melanoma. Our search found that UVA causes DNA damage via photosensitized reactions that result in the production of oxygen radical species. UVA can induce mutations in various cultured cell lines. Furthermore, in two animal models, the hybrid Xiphophorus fish and the opossum (Mondelphis domestica), melanomas and melanoma precursors can be induced with UVA. UVA radiation has been reported to produce immunosuppression in laboratory animals and in humans. Some epidemiologic studies have reported an increase in melanomas in users of sunbeds and sunscreens and in patients exposed to psoralen and UVA (PUVA) therapy. There is basic scientific evidence of the harmful effects of UVA on DNA, cells and animals. Collectively, these data suggest a potential role for UVA in the pathogenesis of melanoma. To date evidence from epidemiologic studies and clinical observations are inconclusive but seem to be consistent with this hypothesis. Additional research on the possible role of UVA in the pathogenesis of melanoma is required.

beta-Adrenergic stimulation synchronizes intracellular Ca(2+) release during excitation-contraction coupling in cardiac myocytes

To elucidate microscopic mechanisms underlying the modulation of cardiac excitation-contraction (EC) coupling by beta-adrenergic receptor (beta-AR) stimulation, we examined local Ca(2+) release function, ie, Ca(2+) spikes at individual transverse tubule-sarcoplasmic reticulum (T-SR) junctions, using confocal microscopy and our recently developed technique for release flux measurement. beta-AR stimulation by norepinephrine plus an alpha(1)-adrenergic blocker, prazosin, increased the amplitude of SR Ca(2+) release flux (J(SR)), its running integral (integralJ(SR)), and L-type Ca(2+) channel current (I(Ca)), and it shifted their bell-shaped voltage dependence leftward by approximately 10 mV, with the relative effects ranking I(Ca)> J(SR)>integralJ(SR). Confocal imaging revealed that the bell-shaped voltage dependence of SR Ca(2+) release is attributable to a graded recruitment of T-SR junctions as well as to changes in Ca(2+) spike amplitudes. beta-AR stimulation increased the fractional T-SR junctions that fired Ca(2+) spikes and augmented Ca(2+) spike amplitudes, without altering the SR Ca(2+) load, suggesting that more release units were activated synchronously among and within T-SR junctions. Moreover, beta-AR stimulation decreased the latency and temporal dispersion of Ca(2+) spike occurrence at a given voltage, delivering most of the Ca(2+) at the onset of depolarization rather than spreading it out throughout depolarization. Because the synchrony of Ca(2+) spikes affects Ca(2+) delivery per unit of time to contractile myofilaments, and because the myofilaments display a steep Ca(2+) dependence, our data suggest that synchronization of SR Ca(2+) release represents a heretofore unappreciated mechanism of beta-AR modulation of cardiac inotropy.

Typical dermoscopic patterns of benign melanocytic nevi

Dermoscopy often is an effective diagnostic tool for differentiating benign and malignant pigmented skin lesions. The observed dermoscopic structures and patterns of lesions provide valuable sources of information that are not accessible by routine clinical examination. Recognition and interpretation of these dermoscopic structures and patterns require training and experience. Mentioned here are some fundamental guidelines for differentiating malignant and benign lesions. Some of the classic patterns associated with a list of benign melanocytic nevi also have been illustrated. Additional research is needed to identify other patterns of these benign lesions. More importantly, analysis of the prevalence of various patterns associated with the various benign lesions will be helpful to clinicians having the responsibility of making in vivo diagnoses of benign compared with malignant melanocytic neoplasms.

Interaction of Cd and citric acid, EDTA in red soil

Adsorption and desorption process of cadmium in red soil (Ferrisols) as well as the influence by media's pH were investigated in detail with and without citric acid and EDTA. Experimental results clearly showed that Cd adsorption in red soil was affected significantly by the coexisted organic chemicals. In the presence of citric acid and EDTA, Cd adsorption in red soil increased with pH in acid media but decreased in high pH one. Further studies placed stress on the adsorbed Cd in red soil which was found to be existed mainly as exchangeable one at pH < 5.5, and desorption rate by 0.10 mol/L NaNO3 gave a peak-shaped curve due to the difference of specifically and nonspecifically adsorbed Cd with pH's change.

Ca2+ signalling between single L-type Ca2+ channels and ryanodine receptors in heart cells

Ca2+-induced Ca2+ release is a general mechanism that most cells use to amplify Ca2+ signals. In heart cells, this mechanism is operated between voltage-gated L-type Ca2+ channels (LCCs) in the plasma membrane and Ca2+ release channels, commonly known as ryanodine receptors, in the sarcoplasmic reticulum. The Ca2+ influx through LCCs traverses a cleft of roughly 12 nm formed by the cell surface and the sarcoplasmic reticulum membrane, and activates adjacent ryanodine receptors to release Ca2+ in the form of Ca2+ sparks. Here we determine the kinetics, fidelity and stoichiometry of coupling between LCCs and ryanodine receptors. We show that the local Ca2+ signal produced by a single opening of an LCC, named a 'Ca2+ sparklet', can trigger about 4-6 ryanodine receptors to generate a Ca2+ spark. The coupling between LCCs and ryanodine receptors is stochastic, as judged by the exponential distribution of the coupling latency. The fraction of sparklets that successfully triggers a spark is less than unity and declines in a use-dependent manner. This optical analysis of single-channel communication affords a powerful means for elucidating Ca2+-signalling mechanisms at the molecular level.

[Construction of a deep coverage rice BAC library and identification of clones associated with disease-resistant genes]

A BAC library for IRBB56, an accession pyramiding Xa4, xa5 and xa13 three bacterial blight resistance genes, was constructed. The library contains 55,296 clones with an average insert size of 132 kb. Based on a haploid genome size of 450 Mb, the coverage of the library was about 14 genome equivalents that make it one of the most comprehensive BAC libraries available in rice and provide 99.99% possibility to isolate any interested rice genes or sequences in the library. To determine the representation of organelle DNA homologues in the library, the library was screened with three different chloroplast genes and four mitochondrial genes, respectively. Results from this screening showed that less than 1% of clones in the library contain organelle genomic DNA homologues. Then, DNA markers on three different chromosomes linked to Xa4, xa5, and xa13, and a PCR fragment of rice UROD gene, were used to screen the library resulting in a range of 11-106 hits that will promote the isolation of these genes. The deep coverage and the large insert size of the library will facilitate physical mapping, isolation, and cloning of rice genes.

[The construction and evaluation of antisense RNA expression vector targeting at HCV 5'NCR]

Antisense RNA is an important field of antisense technique. In order to explore a novel approach for the treatment of hepatitis C virus (HCV) infection and prove the availability of transgenic cellular model HepG2. 9706, an antisense RNA was designed targeting at the highly conserved 5'NCR and translation initiation site of HCV RNA at nt positions 13-397. It was inserted into the downstream of SV40 promotor sequence of pGL3 control vector in which luciferase gene is deleted. The antisense RNA expression vector (pHCV-asR) was constructed and identified by PCR, endonucleases reaction and DNA sequencing. Its expression in transfected HepG2 cells was tested by RT-PCR. To evaluate the inhibitory activities of pHCV-asR, HepG2. 9706 cells were transfected using this construct via Lipofectin method. Luciferase activity in cell lysates was measured for quantitative determining antiviral effects within the cells. The results showed that the inserted sequence of the pHCV-asR is the same as the designed sequence and can express in HepG2 cells. It was also found that pHCV-asR in HepG2. 9706 has a dose-dependent inhibitory effects on luciferase expression controlled by HCV 5'NCR with a inhibitory rate of 57%.

[Application of autotransfusion hemodilution in laryngectomy]

OBJECTIVE

To study the application and clinical significance of autotransfusion hemodilution in laryngectomy.

METHOD

Autotransfusion hemodilution was adopted in 30 patients with III or IV stage laryngeal carcinoma during operation as the experimental group, and the blood transfusion only was adopted in the patients with excessively blood loss. The other 30 patients with the same stages of disease and the same kinds of operation were performed as the control group, without autotransfusion hemodilution and the blood transfusion was adopted if necessary.

RESULT

Blood transfusion was necessary to be performed only in 8 patients of the experimental group, on the contrary, it was necessary in 19 of 30 patients of the control group (P < 0.01). There were no complications during the operations, and the postoperative complications were no significance (P > 0.05) between two groups.

CONCLUSION

The application of autotransfusion hemodilution may be of help to a plenty of patients with laryngeal carcinoma in advanced stage to keep off the blood transfusion during laryngectomy.

[Advances in the study on effect of traditional Chinese medicine on gene expression]

OBJECTIVE

To review the progresses in the study on the effect of traditional Chinese medicine (TCM) on gene expression.

METHOD

Consulting more than 20 domestic relevant documents of recent years and summarizing several representative kinds of TCM.

RESULT AND CONCLUSION

The curative effect of TCM has something to do with its bioactive composition that promotes the regulation of gene expression; and the continued study on this mechanism of regulation may contribute to the modernization of TCM theory.

Culture and adenoviral infection of adult mouse cardiac myocytes: methods for cellular genetic physiology

Rapid development of transgenic and gene-targeted mice and acute genetic manipulation via gene transfer vector systems have provided powerful tools for cardiovascular research. To facilitate the phenotyping of genetically engineered murine models at the cellular and subcellular levels and to implement acute gene transfer techniques in single mouse cardiomyocytes, we have modified and improved current enzymatic methods to isolate a high yield of high-quality adult mouse myocytes (5.3 +/- 0.5 x 10(5) cells/left ventricle, 83.8 +/- 2.5% rod shaped). We have also developed a technique to culture these isolated myocytes while maintaining their morphological integrity for 2-3 days. The high percentage of viable myocytes after 1 day in culture (72.5 +/- 2.3%) permitted both physiological and biochemical characterization. The major functional aspects of these cells, including excitation-contraction coupling and receptor-mediated signaling, remained intact, but the contraction kinetics were significantly slowed. Furthermore, gene delivery via recombinant adenoviral infection was highly efficient and reproducible. In adult beta(1)/beta(2)-adrenergic receptor (AR) double-knockout mouse myocytes, adenovirus-directed expression of either beta(1)- or beta(2)-AR, which occurred in 100% of cells, rescued the functional response to beta-AR agonist stimulation. These techniques will permit novel experimental settings for cellular genetic physiology.

[Determination of inositol by reversed-phase high performance liquid chromatography]

A new method for determination of inositol by reversed-phase high performance liquid chromatography was studied. The method used a Shim-Pack CLC-C18 column, acetonitrile-water (10:90, V/V) as the mobile phase at a flow rate of 1.0 mL/min with detection wavelength at 196 nm. The RSD of the results was 0.8%. It is simple, rapid, accurate, and useful for quantitative determination of inositol product.