The atomic structure of the threefold surface of the icosahedral Ag-In-Yb quasicrystal

We report a study of the atomic structure of the threefold icosahedral (i-)Ag-In-Yb quasicrystal surface using scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). The LEED confirms that the surface exhibits quasicrystalline long-range order with the threefold symmetry expected from the bulk. The STM reveals large atomically flat terraces separated by steps of different heights. A comparison of atomically resolved STM images for the terraces and the step-height distribution with the bulk structure of isostructural i-Cd-Yb shows that the terraces are formed at bulk planes intersecting the centers of the rhombic triacontahedral clusters that make up the bulk structure of the system. However, the stability of particular terraces may be influenced by the density of atoms in the interstices (glue atoms that bind the clusters) in the terraces and also by the chemical environment in the underlying atomic plane. The surface exhibits screw dislocations, which is explained in terms of a continuous atomic density along the threefold axis.

Expression of parafibromin in major renal cell tumors

Parafibromin, encoded by HRPT2 gene, is a recently identified tumor suppressor. Complete and partial loss of its expression have been observed in hyperparathyroidism-jaw tumor (HPT-JT), parathyroid carcinoma, breast carcinoma, lung carcinoma, gastric and colorectal carcinoma. However, little has been known about its expression in renal tumors. In order to study the expression of parafibromin in a series of the 4 major renal cell tumors - clear cell renal cell carcinoma (ccRCC), papillary renal cell carcinoma (pRCC), chromophobe renal cell carcinoma (chRCC) and oncocytoma, one hundred thirty nine renal tumors including 61 ccRCCs, 37 pRCCs, 22 chRCCs and 19 oncocytomas were retrieved and used for the construction of renal tissue microarrays (TMAs). The expression of parafibromin was detected by immunohistochemical method on the constructed TMAs. Positive parafibromin stains are seen in 4 out of 61 ccRCCs (7%), 7 out of 37 pRCCs (19%), 12 out of 23 chRCCs (52%) and all 19 oncocytomas (100%). Parafibromin expression varies significantly (P<8.8×10⁻¹⁶) among the four major renal cell tumors and were correlated closely with tumor types. No correlation of parafibromin expression with tumor staging in ccRCCs, pRCCs and chRCCs, and Fuhrman nuclear grading in ccRCCs and pRCCs was seen. In summary, parafibromin expression was strongly correlated with tumor types, which may suggest that it plays a role in the tumorigenesis in renal cell tumors.

Influence of proline-rich inositol polyphosphate 5-phosphatase, on early development of fertilized mouse eggs, via inhibition of phosphorylation of Akt

OBJECTIVES

Proline-rich inositol polyphosphate 5-phosphatase (PIPP) is one of the signal-modifying enzymes that play pivotal regulatory roles in PI3K signalling pathway. The aim of this study was to determine the role of PIPP in early development of fertilized mouse eggs, via inhibition of Akt activity and subsequent downstream signalling events.

MATERIALS AND METHODS

The mRNA transcript levels of endogenous PIPP and Akt1, Akt2, Akt3 were detected in G(1) , S, G(2) and M phases of fertilized mouse eggs by RT-PCR. Levels of exogenous PIPP, phosphorylated Akt at Ser473, dephosphorylated cdc2 at Tyr15 and levels of CCNB1, were detected respectively by immunoblotting. Changes in Akt localization were observed by fluoroimmunoassay; meanwhile, changes in activity of Akt and its downstream MPF were detected. Percentages of cells undergoing division were determined by counting, using a dissecting microscope.

RESULTS

PIPP and Akt1 transcripts were detectable in G(1), S, G(2) and M phases of fertilized mouse eggs, but Akt2 and Akt3 were not. We also observed that overexpression of PIPP in fertilized eggs decreased expression of phosphorylated Akt at Ser473 and altered membrane localization of phosphorylated Akt at Ser473 specifically. Furthermore, overexpression of PIPP resulted in decreases in mitosis-phase promoting factor activity, level of dephosphorylated cdc2 at Tyr15 and cleavage rate of fertilized mouse eggs.

CONCLUSIONS

Our data suggest, for the first time, that PIPP may affect development of fertilized mouse eggs by inhibition of level of phosphorylated Akt at Ser473 and subsequent inhibition of downstream signal cascades.

Paracrine signals from mesenchymal cell populations govern the expansion and differentiation of human hepatic stem cells to adult liver fates

The differentiation of embryonic or determined stem cell populations into adult liver fates under known conditions yields cells with some adult-specific genes but not others, aberrant regulation of one or more genes, and variations in the results from experiment to experiment. We tested the hypothesis that sets of signals produced by freshly isolated, lineage-dependent mesenchymal cell populations would yield greater efficiency and reproducibility in driving the differentiation of human hepatic stem cells (hHpSCs) into adult liver fates. The subpopulations of liver-derived mesenchymal cells, purified by immunoselection technologies, included (1) angioblasts, (2) mature endothelia, (3) hepatic stellate cell precursors, (4) mature stellate cells (pericytes), and (5) myofibroblasts. Freshly immunoselected cells of each of these subpopulations were established in primary cultures under wholly defined (serum-free) conditions that we developed for short-term cultures and were used as feeders with hHpSCs. Feeders of angioblasts yielded self-replication, stellate cell precursors caused lineage restriction to hepatoblasts, mature endothelia produced differentiation into hepatocytes, and mature stellate cells and/or myofibroblasts resulted in differentiation into cholangiocytes. Paracrine signals produced by the different feeders were identified by biochemical, immunohistochemical, and quantitative reverse-transcription polymerase chain reaction analyses, and then those signals were used to replace the feeders in monolayer and three-dimensional cultures to elicit the desired biological responses from hHpSCs. The defined paracrine signals were proved to be able to yield reproducible responses from hHpSCs and to permit differentiation into fully mature and functional parenchymal cells.

CONCLUSION

Paracrine signals from defined mesenchymal cell populations are important for the regulation of stem cell populations into specific adult fates; this finding is important for basic and clinical research as well as industrial investigations.

Response to sunitinib in Chinese KIT-mutated metastatic mucosal melanoma

e20017

Background: To investigate the possible relationship between sunitinib response and KIT mutation as well as KIT expression. Methods: We find that a 75-year male patient with KIT-mutated metastatic mucosal (primary: nasal, metastasis: left adrenal gland, lungs and right eye) melanoma has a very good response to sunitinib 37.5mg/d consecutively. We apply IHC sp assay to detect S100, HMB-45, CD117, VEGFR, PDGFR and EGFR in the melanoma sample of this patient. DNA is also extracted from paraffin-embedded melanoma sample of this patient and PCR is carried out to amplify several exons of C-KIT (exon11,13,17,18),B-RAF(exon11, 15) and N- RAS(exon1, 2). PCR products are sent to be directly sequenced. Clinical response, PFS and OS of the patient are evaluated. Results: Strong expression of S100, HMB45, CD117, VEFGR and PDGFR is detected by IHC in the tissue sample of the patient. Furthermore, direct sequencing after PCR reveals that V559A substitution is detected in exon 11 of KIT, with mutation of T into C at 1776, leading to substitution of Valine by Alanine at 559. No mutation was detected in exon 9, 13, 17, 18 of KIT, B-RAF15, 11 or N-RAS1, 2. The patient received sunitinib 37.5mg/d from July 2008 consecutively and evaluated PR (Recist: tumors shrink 70%) lasting for 5 months with Grade II myelosuppression and stomatitis. Now the patient is still alive and received sunitinib. Conclusions: Our case report suggests that response of melanoma patients to sunitinib might be correlated to KIT mutation and expression, and large-scale clinical trial in patients with KIT mutation and over-expression might be useful to shed light on treatment of melanoma patients with individual targeted therapy.

No significant financial relationships to disclose.

Endostatin combined with chemotherapy as first-line therapy for stage IV melanoma patients: A phase II clinical study

e20003

Background: To observe the efficacy and safety of rh-endostatin injection (Endostar) combined with chemotherapy as first line therapy for stage IV melanoma patients. Methods: From March 2007-March 2008, 20 metastatic melanoma patients were enrolled. Endostar (15 mg d1–14) combined with dacarbazine (250 mg/m2 d1–5) or temozolomide (300 mg d 1–5) and fotemustine (100 mg/m2 d6) were given every 28days. Response, toxicity and progression free survival(PFS) were analyzed. Results: Among 20 evaluable cases, with mean cycle 2.7±0.80, four achieved partial response, six stable disease, with response rate 20.0% (4/20) and clinical benefit rate 50.0% (10/20). The median PFS reached 4.5 months (95% CI: 3.85–6.9 months), overall survival 8.5 months (95% CI: 5.62–8.54 months), with 6 months PFS rate 35% (7/20), and 6 months survival rate 65% (13/20). The Grade 3/4 toxicity was mainly myelosuppression, 40% (8/20). One patient ceased the treatment because of sinus bradycardia. Conclusions: Endostar combined with chemotherapy show its efficacy on melanoma patients and may prolong PFS.

No significant financial relationships to disclose.

Durable response of the triple combination of temozolomide, sorafenib, and bevacizumab as second-line therapy for patients with stage IV acral melanoma

e20010

Background: Temozolomide (TMZ) is an oral formulation of dacarbazine with improved central nervous system penetration. Sorafenib inhibits Raf kinase and vascular endothelial growth factor (VEGF) receptor. Bevacizumab is a monoclonal antibody targeted against VEGF. TMZ plus sorafenib has shown efficacy in advanced melanoma. The triple combination, chemotherapy plus the complementary inhibition of VEGF signaling, was hypothesized to have synergistic effects on acral metastatic melanoma. Methods: Eligible are refractory (previous one systemic regimen failed) acral advanced melanoma, measurable disease (RECIST). Treatment includes TMZ 200 mg/m2/d (days 1–5), bevacizumab 5 mg/Kg (days 1, 14) and sorafenib 400 mg/bid (days 1–28), repeated every 28days. VEGFR, PDGFR, EGFR and CD117 of tumor tissue were detected by Immunohistochemistry (IHC) assay and the DNA was abstracted and amplified by PCR assay and then sequenced to detect the mutation of C-KIT (exon11,13,17,18),B- RAF(exon11, 15) and N-RAS(exon1, 2). Progression free survival (PFS), overall survival (OS), response and toxicity were assessed. Correlation was analyzed between gene mutations, IHC results and clinical response. Results: 50 patients were planned to recruit. Till December of 2008, 11 patients all in M1c stage have been enrolled and evaluated. One patient has achieved complete response (CR) which has been lasting 5 cycles. One patient has achieved partial response (PR) with a 69% tumor reduction which has been lasting 3 cycles. One patient achieved PR with a 41% tumor reduction which has been lasting 6 cycles. 6 pts got stable disease (all tumor reduction, range: 4–21%) lasting > 2 cycles (range: 3–4 cycles); and 2 PD after 1 cycle. The toxicity was moderate. It's too early to assess survival. It seemed no correlation between positive IHC results and response. It could not be decided if there is correlation between gene mutation/IHC results and response/survival. Conclusions: The triple combination (TMZ, sorafenib, and bevacizumab) regimen preliminary achieved durable clinical response especially the patients with CR or PR. The regimen is safe and well tolerated. More data will be presented in ASCO.

No significant financial relationships to disclose.

Intra-arterial hepatic bio-chemotherapy for the treatment of melanoma patients with liver metastasis: A phase II clinical study

e20014

Background: To investigate the efficacy and safety of hepatic intra-arterial infusion of cisplatin, fotemustine combined with systemic dacarbazine for the treatment of melanoma patients with liver metastasis. Methods: From 2005.7 to 2008.7, thirty-six melanoma patients with liver metastatic were enrolled. Systemic dacarbazine (250mg/m2 d1–5) and intra-arterial hepatic (i.a.h.) of cisplatin (75mg/m2 d6) and fotemustine (100mg/m2 d7) were given repeated for 4-weeks. Response, progress free survival(PFS), and toxicity were analyzed. Results: 27 of the 36 patients were evaluable, with mean cycle 2.16±1.19, one achieved CR, one PR and seven SD. The disease control rate was 33.3% (9/27) with a median PFS of 3.5 months (95% CI 3.45–7.02months), overall survival of 7.5 months (95 CI 6.87–11.06 months, following to 2008.8). The Grade 3/4 toxicity was mainly myelosuppression, with occurrence rates of 40.7% (10/27). Conclusions: Intra-arterial hepatic chemotherapy show its efficacy and may prolong PFS in melanoma patients with liver metastasis.

No significant financial relationships to disclose.

An assessment of the resolution limitation due to radiation-damage in x-ray diffraction microscopy

X-ray diffraction microscopy (XDM) is a new form of x-ray imaging that is being practiced at several third-generation synchrotron-radiation x-ray facilities. Nine years have elapsed since the technique was first introduced and it has made rapid progress in demonstrating high-resolution three-dimensional imaging and promises few-nm resolution with much larger samples than can be imaged in the transmission electron microscope. Both life- and materials-science applications of XDM are intended, and it is expected that the principal limitation to resolution will be radiation damage for life science and the coherent power of available x-ray sources for material science. In this paper we address the question of the role of radiation damage. We use a statistical analysis based on the so-called "dose fractionation theorem" of Hegerl and Hoppe to calculate the dose needed to make an image of a single life-science sample by XDM with a given resolution. We find that for simply-shaped objects the needed dose scales with the inverse fourth power of the resolution and present experimental evidence to support this finding. To determine the maximum tolerable dose we have assembled a number of data taken from the literature plus some measurements of our own which cover ranges of resolution that are not well covered otherwise. The conclusion of this study is that, based on the natural contrast between protein and water and "Rose-criterion" image quality, one should be able to image a frozen-hydrated biological sample using XDM at a resolution of about 10 nm.

Three-dimensional coherent x-ray diffraction imaging of a ceramic nanofoam: determination of structural deformation mechanisms

Ultralow density polymers, metals, and ceramic nanofoams are valued for their high strength-to-weight ratio, high surface area, and insulating properties ascribed to their structural geometry. We obtain the labrynthine internal structure of a tantalum oxide nanofoam by x-ray diffractive imaging. Finite-element analysis from the structure reveals mechanical properties consistent with bulk samples and with a diffusion-limited cluster aggregation model, while excess mass on the nodes discounts the dangling fragments hypothesis of percolation theory.

Facile synthesis of cyclopropene analogues of aluminum and an aluminum pinacolate, and the reactivity of LAl[eta(2)-C(2)(SiMe(3))(2)] toward unsaturated molecules (L=HC[(CMe)(NAr)](2), Ar=2,6-i-Pr(2)C(6)H(3))

Reduction of LAlI(2) (1) (L = HC[(CMe)(NAr)](2), Ar = 2,6-i-Pr(2)C(6)H(3)) with potassium in the presence of alkynes C(2)(SiMe(3))(2), C(2)Ph(2), and C(2)Ph(SiMe(3)) yielded the first neutral cyclopropene analogues of aluminum LAl[eta(2)-C(2)(SiMe(3))(2)] (3), LAl(eta(2)-C(2)Ph(2)) (4), and LAl[eta(2)-C(2)Ph(SiMe(3))] (5), respectively, whereas reduction of 1 in the presence of Ph(2)CO gave an aluminum pinacolate LAl[O(2)(CPh(2))(2)] (6), irrespective of the amount of Ph(2)CO employed. The unsaturated molecules CO(2), Ph(2)CO, and PhCN inserted into one of the Al-C bonds of 3 leading to ring enlargement to give novel aluminum five-membered heterocyclic systems LAl[OC(O)C(2)(SiMe(3))(2)] (7), LAl[OC(Ph)(2)C(2)(SiMe(3))(2)] (8), and LAl[NC(Ph)C(2)(SiMe(3))(2)] (9) in high yields. In contrast, 3 reacted with t-BuCN, 2,6-Trip(2)C(6)H(3)N(3) (Trip = 2,4,6-i-Pr(3)C(6)H(2)), and Ph(3)SiN(3) resulting in the displacement of the alkyne moiety to afford LAl[N(2)(Ct-Bu)(2)] (10) with an unprecedented aluminum-containing imidazole ring, and the first monomeric aluminum imides LAlNC(6)H(3)-2,6-Trip(2) (11) and LAlNSiPh(3) (12). All compounds have been characterized spectroscopically. The variable-temperature (1)H NMR studies of 3 and ESR measurements of 3 and 4 suggest that the Al-C-C three-membered-ring systems can be best described as metallacyclopropenes. The (27)Al NMR resonances of 2 and 3 are reported and compared. Molecular structures of compounds 3, 4, 6.OEt(2), 8.OEt(2), and 9 were determined by single-crystal X-ray structural analysis.

[The clinical effect of Tropisetron in the prevention of nausea and vomiting induced by anti-cancer drugs]

OBJECTIVE

To compare the efficacy and adverse effects of Tropisetron with Kytril in the prevention of nausea and vomiting induced by anti-cancer drugs.

METHODS

In a clinical randomized controlled cross-over trial, 34 patients (19 among them treated with regimens containing cisplatin) were randomized into A and B group. In group A, Tropisetron was given in the first cycle and Kytril in the second cycle, while in group B Kytril was given in the first and Tropisetron in the second cycle of the same chemotherapy.

RESULTS

In the Tropisetron treated group, the response rate was 97.1% with 4.5 episodes of vomiting on the first day of chemotherapy, while that in the Kytril treated patients was 94.1% with 3 episodes of vomiting. There was no statistical difference between the 2 groups. Control of delayed emesis and other adverse reactions were comparable in both arms and there was no notable difference between Tropisetron and Kytril.

CONCLUSION

Tropisetron is an effective anti-emetic drug to prevent nausea and vomiting caused by anti-tumor agents, and its adverse reactions are mild.

A-6G variant of the angiotensinogen gene and essential hypertension in Han, Tibetan, and Yi populations

To investigate the relationship between the A-6G variant in the promoter of the angiotensinogen gene and essential hypertension in Han, Tibetan, and Yi populations. All patients with essential hypertension were selected by WHO criteria. And the polymorphism of the A-6G variant was determined by PCR/RFLP. The data were analyzed by t test and chi2 test. There was no significant difference in the genotype or allele frequencies between normotensives and hypertensives in the Han, Tibetan, and Yi populations, respectively. However, when the subjects were divided into male and female subgroups, the genotype distributions among hypertensives and normotensives of the Tibetan female group were as follows: AA, 37% vs. 48%; AG, 52% vs. 48%; GG, 11% vs. 4%, respectively and the frequency of the G allele was significantly higher in hypertensives than in normotensives in the Tibetan female group (0.37 vs. 0.28, chi2=4.25, p<0.05). In addition, we observed that there was a significant difference between the Han and Tibetan normotensive groups in the distributions of the allele and genotype frequencies of the A-6G variant. The frequency of the G allele was 0.29 and 0.17 in the Tibetan normotensive and Han groups, respectively (p<0.001). The G allele of the A-6G variant was associated with hypertension in the Tibetan females, but not in the Yi or Han females. And we confirmed that there was a significant difference in the prevalence of the allele frequencies of the A-6G variant between the Han and Tibetan normotensive groups.

[Effect of injectio Salvia Miltiorrhiza on gentamicin ototoxicity-induced activity of nitric oxide synthase in cochlear stria vascularis of guinea pig]

AIM

to investigate the change of nitric oxide synthase (NOS) activity in cochlear stria vascularis (SV) of guinea pig after gentamicin (GM) and Salvia Miltiorrhiza (SM) injection, and to explore the protective role of injectio SM on GM ototoxicity.

METHODS

NADPH-diaphorase histochemistry staining and image quantitative analysis technique, combined with auditory brainstem response (ABR) measurement.

RESULTS

SM + GM significantly reduced NOS activity in cochlear SV and ABR threshold as compared with CM along (P < 0.01); and ABR threshold shift was in high correlation with NOS activity (rControl = -0.9464; rGM = -0.9117; rSM + GM = -0.8958; P < 0.01).

CONCLUSION

SM can reduce NOS activity in cochlear SV so as to alleviate GM ototoxicity, thus ameliorate hearing function.

[FTIR studies on two compounds containing cyanide]

Two compounds containing cyanide [Ni(1,10-phen)2O2MoS2(CuCN)]n and [ZnCu4 (CN)6(dmf)4]n have been synthesized. The FTIR spectra and the crystal structure of those clusters have also been deal with. The stretching frequency of cyanide is alterable with the different coordinated environments.

[Analyses on the association of CA-repeat polymorphism and A1166-->C variant in the 3'-flanking region of AT(1)R gene with essential hypertension in Tibetans]

OBJECTIVE

To investigate whether CA-repeat polymorphism and A1166 --> C variant in the 3n-flanking region of AT(1)R gene are in association with the genetic susceptibily to essential hypertension (EH) in Tibetans.

METHODS

A case-control study was carried out. Sibpair analysis and family linkage analysis were conducted. The CA-repeat polymorphism of AT &(1) R gene was identified by polymerase chain reaction(PCR) with fluorescence labeled dCTP as substrate and by semi-automatic sequence technology. The A1166 -->C variant was detected by PCR-RFLP.

RESULTS

Association of AT&(1)R gene locus with EH was confirmed through the case-control study in well-characterized group of 113 Tibetan EH patients and 131 normotensives(chi(2)=26.44, P<0.001). A closer examination of this gene locus found 11 alleles from Tibetan population; allele A7 (138 bp) was more frequent in both the patients and the controls. Allele A8(140 bp) was in strong positive association with genetic susceptibility to EH in Tibetans. Frequency of allele A8 was 20.5% in EH and 7.3% in normotensives. The difference of allele frequencies between the groups was significant (chi(2)=9.64, P=0.002, OR=3.46, 95% CI 1.44-8.51). Affected sibpair analysis showed chi(2)=3.85, P=0.025; family linkage analysis gave Lod score of 0.80. No association between A1166 --> C variant in AT(1)R gene and EH in Tibetans was observed (P>0.05).

CONCLUSION

The result suggests that CA-repeat polymorphism of AT(1)R gene be in association with EH in Tibetans, which implicates that AT(1)R gene may be in linkage disequilibrium with the causative genes of EH.

Syntheses and structures of the arylaluminum chalcogenides (ArAlE)2 (Ar = 2-(NEt2CH2)-6-MeC6H3, E = Se; Ar = 2,6-(NEt2CH2)2C6H3, E = Se, Te)

Two intramolecular stabilized arylaluminum dihydrides, (2-(NEt2CH2)-6-MeC6H3)AlH2 (1) and (2,6-(NEt2CH2)2C6H3)AlH2 (2), were prepared by reducing the corresponding dichlorides with an excess of LiAlH4 in diethyl ether. Reactions of 1 and 2 with elemental selenium afforded the dimeric arylaluminum selenides [(2-(NEt2CH2)-6-MeC6H3)AlSe]2 (3) and [(2,6-(NEt2CH2)2C6H3)AlSe]2 (4). Reaction of 2 with metallic tellurium gave the dimeric arylaluminum telluride [(2,6-(NEt2CH2)2C6H3)AlTe]2 (5). The possible reaction pathway is discussed, and molecular structures determined by single-crystal X-ray analyses are presented for 3 and 5.

Association analysis of variants in the core promoter region of angiotensinogen gene with essential hypertension in Tibetan population

OBJECTIVE

To detect the variants in the core promoter region of angiotensinogen(AGT) gene, and to analyse the relationship between the AGT gene polymorphisms and essential hypertension in Tibetan population.

METHODS

This is a case-control study consisting of 103 essential hypertensive subjects and 82 normotensive controls matched by age and sex. The variants in the AGT gene core promoter region were screened by polymerase chain reaction/single strand conformation polymorphism(PCR/SSCP) and further identified by automated sequencing. The A(-6)G polymorphism was determined in DNA extracted from leucocytes by polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP).

RESULTS

(1) There were two different electrophoresis band patterns in PCR/SSCP analysis. PCR product direct sequencing showed that the two band patterns represented the AA, AC genotypes in the (-20) site of AGT gene respectively. The distribution of A(-20)C genotype was almost identical in essential hypertensive and normotensive groups (P>0.8). The A allele frequency was very high in both groups (control: 0.9175, hypertensive: 0.9124). (2)Distribution of genotype in the (-6) site of AGT gene was much different between the patient group and control group (P<0.005). The frequency of G allele was statistically higher in the patient group than in controls (0.374 vs 0.220, P<0.025).

CONCLUSION

Both Tibetan hypertensives and normotensives have higher frequency of A allele in AGT gene (-20) site. The higher frequency of G allele in the AGT gene (-6) site in Tibetan hypertension patients suggests that this allele may be the genetic susceptibility factor in the proceeding of essential hypertension in the Tibetan population.

[Tachycardia ameliorated by electroacupuncture in morphine withdrawal rats]

OBJECTIVE

To establish morphine withdrawal tachycardia model of rat and to observe the effect of electroacupuncture (EA) with different frequency on its heart rate.

METHODS

Morphine dependence was induced in Wistar rats by injection of morphine for 8 days successively, and EA 1 mA in strength was given after withdrawal of morphine with different frequencies of 2 Hz, 15 Hz and 100 Hz, the heart rate and blood pressure were recorded in the awaked rats.

RESULTS

Morphine abstinent rats showed a 24% increase of heart rate as compared with that of the normal control group, but no significant change was observed in blood pressure. The 100 Hz and 15 Hz EA produced a 13.4% and 13.1% decrease of heart rate respectively, whereas 2 Hz EA produced insignificant change.

CONCLUSION

The reducing effect of percutaneous electric stimulation on tachycardia in heroin addicts revealed clinically can be replicated in the rat model.

An optimal condition of bronchial cell proliferation stimulated by insulin-like growth factor-I

BACKGROUND

It is known that growth hormones such as insulin-like growth factor-I (IGF-I) and several kinds of cytokines are involved in the regeneration process of injured epithelial cells in chronic respiratory inflammatory diseases such as bronchial asthma. Repetitive degeneration/regeneration processes of the airway epithelial layer is supposed to be responsible for the remodeling and irreversible organic changes of the airway in bronchial asthma. The purpose of this study is to establish a simple and reliable in vitro method for studying airway epithelial cell growth and proliferation using IGF-I.

METHOD

By altering the number of cultured epithelial cells (strain NCI-H(292)), culture duration before stimulation with IGF-I, concentration of IGF-I, and duration of IGF-I stimulation, the optimum conditions for epithelial cell growth was determined. The epithelial cell growth was evaluated using [methyl-(3)H]thymidine uptake.

RESULT

Among various culture conditions, the epithelial cells cultured at 1 x 10(3) cells/well for 24 h followed by 24 h of stimulation by 10(-8) M of IGF-I showed the highest growth.

CONCLUSION

The method for the evaluation of epithelial cell growth established in this study requires a small number of cells and has no complicated procedure. This simple model enables us to investigate the effect of various substances on bronchial epithelial cell growth in the presence of IGF-I.

[Effect of 2/100 Hz transcutaneous electrical nerve stimulation on sexual dysfunction and serum sex hormone of heroin addicts]

OBJECTIVE

To evaluate the effect of 2/100 Hz electrical stimulation produced by Han's acupoint nerve stimulator (HANS) in treating heroin induced sex dysfunction.

METHODS

Thirty-three heroin addicts were randomly divided into 2 groups to receive either buprenorphine (BPN group, n = 16) or HANS plus small dose of BPN (HANS group, n = 17) for 14 days. The doses of BPN were tailored according to individual requirement that could totally abolish withdrawal syndrome. The frequency of HANS was 2 Hz and 100 Hz shifting automatically, each lasting for 3 seconds. The stimulation was applied to 8 acupoints, the Hegu and Laogong of one upper limb, Neiguan and Waiguan of another limb, Sanyinjiao and Xingjian of both lower limbs, for 30 min. The therapy was carried out 3-4 times per day in the initial two weeks of treatment, and reduced to 1-2 times per day in the following 2 weeks.

RESULTS

(1) The urine analysis for morphine in both groups turned to negative 14 days after treatment. (2) After 2 weeks of treatment, the composite score (Visual Analog Scale, VAS) of sexual function in HANS group showed a 102% increase (P < 0.01) compared with before treatment and was 107% of that in the BPN group (P < 0.01). (3) After 4 weeks treatment the serum concentration of luteinizing hormone (LH) and testosterone (T) in the HANS group showed a 137% and 118% increase respectively compared with those before treatment (P < 0.05), and the level of LH was 79.6% of that in the BPN group (P < 0.05).

CONCLUSION

The 2/100 Hz transcutaneous electrical stimulation produced by Han's acupoint nerve stimulator could improve the recovery of sexual function and raise the serum concentration of LH and T in heroin addicts.

Functional characterization of a potassium-selective prokaryotic glutamate receptor

Ion channels are molecular pores that facilitate the passage of ions across cell membranes and participate in a range of biological processes, from excitatory signal transmission in the mammalian nervous system to the modulation of swimming behaviour in the protozoan Paramecium. Two particularly important families of ion channels are ionotropic glutamate receptors (GluRs) and potassium channels. GluRs are permeable to Na+, K+ and Ca2+, are gated by glutamate, and have previously been found only in eukaryotes. In contrast, potassium channels are selective for K+, are gated by a range of stimuli, and are found in both prokaryotes and eukaryotes. Here we report the discovery and functional characterization of GluR0 from Synechocystis PCC 6803, which is the first GluR found in a prokaryote. GluR0 binds glutamate, forms potassium-selective channels and is related in amino-acid sequence to both eukaryotic GluRs and potassium channels. On the basis of amino-acid sequence and functional relationships between GluR0 and eukaryotic GluRs, we propose that a prokaryotic GluR was the precursor to eukaryotic GluRs. GluR0 provides evidence for the missing link between potassium channels and GluRs, and we suggest that their ion channels have a similar architecture, that GluRs are tetramers and that the gating mechanisms of GluRs and potassium channels have some essential features in common.

Effect of eotaxin on the generationof reactive oxygen species from eosinophil cell line, YY-1

BACKGROUND

The CC chemokine eotaxin is a selective chemoattractant for eosinophils. Eosinophils have been considered to be the major effector cells in allergic inflammation, since not only eosinophil-specific granule proteins but also reactive oxygen species (ROS) from eosinophils may cause the damage to the cells or tissue of the mucosal epithelium. In this study, we examined the effect of eotaxin on ROS from an eosinophil cell line, YY-1.

METHODS

ROS in luminol-dependent reaction were examined. Calcium ionophore A23187 were added to the mixture of YY-1 cells with luminol, and then ROS were determined.

RESULTS

Eotaxin primed the production of ROS from YY-1 cells. ROS from untreated YY-1 cells evoked with calcium ionophore A23187 in luminol-dependent chemiluminescence gave a maximal value of 1,928 +/- 223 intensity counts (IC; mean +/- SE, n = 4) and an integral value of 17.04 +/- 1. 51 IC (x10(-4)), while eosinophils that were treated with eotaxin gave a maximal value of 2,264 +/- 86 IC (10 nM), 2,691 +/- 124 IC (100 nM) and an integral value of 21.22 +/- 0.67 IC (x10(-4); 10 nM), 26.20 +/- 1.41 IC (x10(-4); 100 nM).

CONCLUSION

Eotaxin might play important roles in the pathogenesis of allergic inflammation through eosinophil activation by priming of eosinophil oxidative metabolism as well as involvement in selective eosinophil chemotaxis.

Whole-blood flow-cytometric analysis of induction of adhesion molecules expression on eosinophils stimulated by phorbol-12-myristate-13-acetate/ionomycin

BACKGROUND

Activation of eosinophils is closely associated with the pathology of allergic inflammatory disease, especially bronchial asthma. We recently investigated the activation of eosinophils by applying whole blood to a flow cytometer. We measured here beta1 and beta2 integrin on eosinophils stimulated by phorbol-12-myristate-13-acetate (PMA)/ionomycin to evaluate eosinophil activation in vitro using whole blood.

METHODS

Heparinized whole blood was diluted with the same volume of RPMI 1640, then cells were incubated in the presence or absence of PMA and ionomycin for 45 min at 37 degrees C. After hemolyzation with lysing solution, flow-cytometric findings for CR3, LFA1-alpha, LFA1-beta and VLA-4 expression on eosinophils were examined.

RESULTS

Mean fluorescent intensity (MFI) of CR3 and LFA1-beta stimulated by PMA and ionomycin was significantly higher than that of the unstimulated control. MFI of LFA1-alpha showed no significant difference from the unstimulated control. On the other hand, MFI of VLA-4 tended to decrease.

CONCLUSIONS

Our method to distinguish eosinophils from various cell groups in whole blood is simple and time-saving, similar to conditions in vivo and may allow intensive investigation of eosinophils in clinical laboratories as well as in research laboratories. We are currently investigating the influence of different kinds of stimulations, regulation factors or agents on eosinophils using this method.

CCR3 mRNA expression in bronchial epithelial cells and various cells in allergic inflammation

BACKGROUND

RANTES and eotaxin are important chemokines involved in the activation and migration of eosinophils and are considered to play a major role in allergic inflammation.

METHODS

In this study, we used RT-PCR to investigate the kinds of cells that express mRNA for CCR3, a common receptor of these chemokines, and eotaxin, a ligand for CCR3.

RESULTS

CCR3 mRNA was expressed in eosinophils, peripheral mononuclear cells, an eosinophilic cell line (EoL-1), a bronchial epithelial cell line (NCI-H(292)), human endothelial cells and nasal washings from patients with allergic rhinitis.

CONCLUSION

These results suggest that the CCR3-eotaxin system plays an important role in generating inflammation, since these substances are expressed not only in cells implicated in activation or migration of eosinophils but also in various other cells involved in allergic inflammation.

Heteromeric kainate receptors formed by the coassembly of GluR5, GluR6, and GluR7

In the CNS kainate subtype glutamate receptors (GluRs) are likely to be heteromeric assemblies containing multiple gene products. However, although recombinant kainate receptors from the GluR5-GluR7 gene family have been studied extensively in their homomeric forms, there have been no tests to determine whether these subunits can coassemble with each other. We used the GluR5 selective agonists (RS)-2-amino-3-(3-hydroxy-5-tertbutylisoxazol-4-yl)propanoic acid (ATPA) and (S)-5-iodowillardiine (I-will) to test for the coassembly of GluR5 with GluR6 and GluR7 by measuring changes in rectification that occur for heteromeric receptors containing both edited and unedited Q/R site subunits. Birectifying ATPA and I-will responses resulting from polyamine block for homomeric GluR5(Q) became outwardly rectifying when GluR6(R) was coexpressed with GluR5(Q), although GluR6 was not activated by ATPA or I-will, indicating the formation of heteromeric receptors. Similar approaches showed the coassembly of GluR7 with GluR6 and GluR5. Heteromeric kainate receptors containing both GluR5 and GluR6 subunits exhibited novel functional properties, including reduced desensitization and faster recovery from desensitization than those recorded for homomeric GluR5. Coexpression of GluR6 with GluR5 also enhanced the magnitude of responses to GluR5 selective agonists. In contrast, the coassembly of GluR7 with GluR6 markedly decreased the amplitude of agonist responses. Our results indicate that, similar to AMPA receptors, the kainate receptor subunits GluR5-GluR7 exhibit promiscuous coassembly. The formation of heteromeric kainate receptors may help to explain why the functional properties of native kainate receptors differ from those that have been reported for recombinant kainate receptors.

Conformation of the diphtheria toxin T domain in membranes: a site-directed spin-labeling study of the TH8 helix and TL5 loop

The isolated T domain of diphtheria toxin was mutated by cysteine-scanning mutagenesis at 28 consecutive sites (residues 328-355) that comprise the TH8 helix and the TL5 interhelical loop in the native toxin. After derivatizing the mutant proteins with a sulfhydryl-selective nitroxide reagent, we examined the mobility of each nitroxide and its accessibility to polar and nonpolar paramagnetic reagents, before and after insertion into phospholipid bilayers. The data obtained with the proteins in solution at pH 8 are generally consistent with predictions from the crystal structure of the toxin. Upon membrane binding at pH 4.6, a major structural reorganization of the domain was seen, which dramatically reduced the accessibility of most residues in this region to the polar reagent nickel(II)-ethylenediaminediacetate complex (NiEDDA). Many of these residues also showed reduced accessibility to the nonpolar reagent O(2). Periodic accessibility of the nitroxide side chains along the sequence to these reagents shows that TH8 remains largely helical in the membrane-bound state, with one surface associated with protein and the other facing the hydrophobic interior of the bilayer. In addition, the TL5 loop also appears to become alpha-helical in the membrane, with one surface in contact with protein and the other in contact with the bilayer interior. These findings provide a structural framework for understanding how the T domain forms a transmembrane channel and mediates translocation of diphtheria toxin's enzymic moiety across a membrane.

Discrimination between sialic acid-containing receptors and pseudoreceptors regulates polyomavirus spread in the mouse

Variations in the polyomavirus major capsid protein VP1 underlie important biological differences between highly pathogenic large-plaque and relatively nonpathogenic small-plaque strains. These polymorphisms constitute major determinants of virus spread in mice and also dictate previously recognized strain differences in sialyloligosaccharide binding. X-ray crystallographic studies have shown that these determinants affect binding to the sialic acids. Here we report results of further experiments designed to test the importance of specific contacts between VP1 and the carbohydrate moieties of the receptor. With minor exceptions, substitutions at positions predicted from crystallography to be important in binding the terminal alpha-2,3-linked sialic acid or the penultimate sugar (galactose) destroyed the ability of the virus to replicate in cell culture. Substitutions that prevented binding to a branched disialyloligosaccharide were found to result in viruses that were both viable in culture and tumorigenic in the mouse. Conversely, substitutions that allowed recognition and binding of the branched carbohydrate chain inhibited spread in the mouse, though the viruses remained viable in culture. Mice of five different inbred strains, all highly susceptible to large-plaque virus, showed resistance to the spread of polyomavirus strains bearing the VP1 type which binds the branched-chain receptor. We suggest that glycoproteins bearing the appropriate O-linked branched sialyloligosaccharide chains are effective pseudoreceptors in the host and that they block the spread of potentially tumorigenic or virulent virus strains.

Carbon nanotube actuators

Electromechanical actuators based on sheets of single-walled carbon nanotubes were shown to generate higher stresses than natural muscle and higher strains than high-modulus ferroelectrics. Like natural muscles, the macroscopic actuators are assemblies of billions of individual nanoscale actuators. The actuation mechanism (quantum chemical-based expansion due to electrochemical double-layer charging) does not require ion intercalation, which limits the life and rate of faradaic conducting polymer actuators. Unlike conventional ferroelectric actuators, low operating voltages of a few volts generate large actuator strains. Predictions based on measurements suggest that actuators using optimized nanotube sheets may eventually provide substantially higher work densities per cycle than any previously known technology.

[The measurement of QT dispersion using wavelet transformation]

This paper addressed the application of wavelet to the measurement of QT dispersion and presented a new method using multi-thresholds to determinate the end point of T-wave. The results geined by computer and human were compared. We also suggested that QT dispersion be defined as the SD of 12 QT intervals.

Carbon structures with three-dimensional periodicity at optical wavelengths

Porous carbons that are three-dimensionally periodic on the scale of optical wavelengths were made by a synthesis route resembling the geological formation of natural opal. Porous silica opal crystals were sintered to form an intersphere interface through which the silica was removed after infiltration with carbon or a carbon precursor. The resulting porous carbons had different structures depending on synthesis conditions. Both diamond and glassy carbon inverse opals resulted from volume filling. Graphite inverse opals, comprising 40-angstrom-thick layers of graphite sheets tiled on spherical surfaces, were produced by surface templating. The carbon inverse opals provide examples of both dielectric and metallic optical photonic crystals. They strongly diffract light and may provide a route toward photonic band-gap materials.

The role of hydrophobic interactions in binding of polyamines to non NMDA receptor ion channels

Block of kainate subtype glutamate receptor channels by internal polyamines was analysed using outside out patches from HEK 293 cells transiently transfected with GluR6(Q). Tetramines with different numbers and spacing of methylene groups between NH2 groups produced biphasic rectification well fit by the Woodhull model for a weakly permeable ion channel blocker. Such analysis revealed an increase in binding energy of 611 cal M(-1) for each methylene group added over the range 6-12 (CH2), suggesting that a major component of block by polyamines involves hydrophobic binding. Isomers with the same number of CH2 groups but different spacing between NH2 groups showed similar affinity. Due to differences in pKa values for protonation of NH2 groups, the average charge on the tetramines studied would be expected to vary from 3.98 to 2.22 at physiological pH; despite this, the voltage dependence of block was similar for all tetramines tested, with a mean value for ztheta of 1.82, similar to values for polyamines with five or six NH2 groups. In contrast, for 1,3-propane diamine (DA3 ztheta 0.83), and the N-propyl- (ztheta 1.42) and N,N'-diethyl- (ztheta 1.37) analogues of DA3, there was an increase in the voltage dependence of block on addition of hydrophobic groups.

[Effect of different prescriptions for tonifying kidney on RNA transcription activity in isolated nuclei and protein synthesis activity in free-cell extracts of the different organs of presenile mice]

OBJECTIVE

To study the anti-aging mechanism of Zuoguiyin (a prescription for tonifying Kindney Yin) and Yishenbao (a prescription for tonifying Kidney Yang) in presenile mice.

METHODS

Using male, 14 months old presenile mice as a model of Kidney-Asthenia, the effects of Zuoguiyin and Yishenhao on RNA transcription activity in isolated nuclei and protein synthesis activity in free-cell extracts of the liver, brain, kidney and testes of the presenile mice were observed.

RESULTS

RNA transcription activity in isolated nuclei and protein synthesis activity in free-cell extracts of the four organs of the presenile mice group were distinctly lower than those of young mice group (3 months old). After above-mentioned two prescriptions were given to the presenile mice for two months, RNA transcription activity in isolated nuclei and protein synthesis activity in free-cell extracts of the four organs of the two treated groups were obviously higher than those of control group (P < 0.05 or P < 0.01), but there was no difference between two treated groups.

CONCLUSIONS

Both Zuoguiyin and Yishenbao could promote RNA transcription activity in isolated nuclei and protein synthesis activity in free-cell extracts of Kidney-Asthenia and presenile mice.

Choice of reference axis in ocular wave-front aberration measurement

The geometrical center of the pupil has often been used as the reference axis in ocular wave-front aberration measurement. However, the geometrical center of the pupil may shift when the pupil size changes under different conditions. In particular, for subjective methods, defining the center of the pupil precisely during the actual measurement is not always practical. Furthermore, the geometrical center of the pupil may not define the chief ray of the ocular optics because of the Stiles-Crawford apodization effect, which has a peak location that often deviates from the geometrical center of the pupil. We present the coefficient transformation table of the Taylor polynomial up to the sixth order with respect to reference axis shift. We illustrate the effect of wave-front aberration change with reference axis shift with experimental data. This type of wave-front aberration change could be a true measurement error if there is an error in defining the reference axis. We also propose using the coaxially sighted corneal reflex as a better reference axis in aberration measurement.

A new ion chamber with a movable photodiode monitor for absolute intensity measurements of soft X-rays

A new ion-chamber system with a movable monitor detector for the measurement of soft X-ray absolute intensity is introduced. The calibration results are also given.

Effects of radiation on wound healing

The pathological changes of radiation on wound healing in rats were observed by macroscopic, microscopic, and electronmicroscopic examination and detection of collagen types. We found that the wound healing process was obviously delayed by irradiation. First, the early phase inflammatory response was severely inhibited. In particular, the number of infiltrating macrophages and neutrophils was decreased, blood vessels were injured, and hemorrhage was evident. Second, the formation and maturation of granulation tissue were slowed down, fibroblasts were injured, and transcription of types and collagen mRNAs and synthesis and secretion of collagen were reduced. Finally, the reepithelialization process was delayed and the healing time was prolonged.

Materials with negative compressibilities in one or more dimensions

Rare crystal phases that expand in one or more dimensions when hydrostatically compressed are identified and shown to have negative Poisson's ratios. Some of these crystals (i) decrease volume and expand in two dimensions when stretched in a particular direction and (ii) increase surface area when hydrostatically compressed. Possible mechanisms for achieving such negative linear and area compressibilities are described for single crystals and composites, and sensor applications are proposed. Materials with these properties may be used to fabricate porous solids that either expand in all directions when hydrostatically compressed with a penetrating fluid or behave as if they are incompressible.

Probing the structure of the diphtheria toxin channel. Reactivity in planar lipid bilayer membranes of cysteine-substituted mutant channels with methanethiosulfonate derivatives

Previous work has established that the 61 amino acid stretch from residue 322 to 382 in the T-domain of diphtheria toxin forms channels indistinguishable in ion-conducting properties from those formed by the entire T-domain. In the crystal structure of the toxin's water-soluble form, the bulk of this stretch is an alpha-helical hairpin, designated TH8-9. The present study was directed at determining which residues in TH8-9 line the ion-conducting pathway of the channel; i.e., its lumen or entrances. To this end, we singly mutated 49 of TH8-9's 51 residues (328-376) to cysteines, formed channels with the mutant T-domain proteins in planar lipid bilayers, and then determined whether they reacted with small, charged, lipid-insoluble, sulfhydryl-specific methanethiosulfonate (MTS) derivatives added to the bathing solutions. The indication of a reaction, and that the residue lined the ion-conducting pathway, was a sudden change in single-channel conductance and/or flickering behavior. The results of this study were surprising in two respects. First, of the 49 cysteine-substituted residues in TH8-9 tested, 23 reacted with MTS derivatives in a most unusual pattern consisting of two segments: one extending from 329 to 341 (11 of 13 reacted), and the other from 347 to 359 (12 of 13 reacted); none of the residues outside of these two segments appeared to react. Second, in every cysteine mutant channel manifesting an MTS effect, only one transition in single-channel conductance (or flickering behavior) occurred, not the several expected for a multimeric channel. Our results are not consistent with an alpha-helical or beta-strand model for the channel, but instead suggest an open, flexible structure. Moreover, contrary to common sense, they indicate that the channel is not multimeric but is formed from only one TH8-9 unit of the T-domain.

Organization of diphtheria toxin T domain in bilayers: a site-directed spin labeling study

The diphtheria toxin transmembrane (T) domain was spin-labeled at consecutive residues in a helical segment, TH9. After binding of the T domain to membranes at low pH, the nitroxide side chains generated by spin labeling were measured with respect to their frequency of collision with polar and nonpolar reagents. The data showed that the helical structure of TH9 in solution is conserved, with one face exposed to water and the other to the hydrophobic interior of the bilayer. Measurement of the depth of the nitroxide side chains from the membrane surfaces revealed an incremental change of about 5 angstroms per turn, which is consistent with a transmembrane orientation of an alpha helix. These results indicate that the helix forms the lining of a transmembrane water-filled channel.