Self-assembly of two- and three-dimensional coordination networks with hexamethylenetetramine and different silver(I) salts

Interesting two-dimensional networks with square or hexagonal cavities, and three-dimensional networks with different channels, have been obtained by varying the counterions, the molar ratio of metal to hmt (hmt = hexamethylenetetramine) and the pH values of the initial solutions. Among the eleven products isolated and structurally characterized, two have a metal-to-hmt molar ratio of 2:1 and are the first examples of Ag-hmt square networks, namely [Ag2(mu4-hmt)(NO2)2] (1) and [Ag2(mu4-hmt)(SO4)(H2O)].4H2O (2), two have a metal-to-hmt molar ratio of 1:1 and are 2-D networks with hexagonal cavities, namely [Ag(micro3-hmt)(NO2)] (3) and [Ag2(micro3-hmt)2](S2O6).2H2O (4), and seven present the metal-to-hmt molar ratios of 3:1, 2:1, 3:2, or 4:3 and are 3-D networks of novel topologies and with different channels, namely [Ag2(mu4-hmt)(micro4-ox)] (5), [Ag3(micro4-hmt)2(H2O)2](SO4)(HSO4). 2H2O (6), [Ag2(mu4-hmt)(mu2-O2CMe)](MeCO2).4.5 H2O (7), [Ag2(mu4-hmt)(mu3-maleate)].5H2O (8), [Ag3(mu4-hmt)(mu2-O2CPh)3] (9), [Ag4(mu4-hmt)3(H2O)](SO4)(NO3)2.3H2O (10), and [Ag12(mu4-hmt)6(mu3-HPO4)(mu2-H2PO4)3(H2PO4)7(H2O)](H3PO4).10.5H2O (11).

Highly stereoselective alpha-O-glucosylation of heterocyclic ketene aminals

A new series of alpha-glucosides of heterocyclic ketene animals have been synthesized. The double bonds of the glucosides resulted in Z or E configuration by using CaH2 or a Lewis acid as catalyst, respectively. A special complex of mercuric cyanide with glucopyranosides was the result when Hg(CN)2 was used to catalyze the reaction.

[Determination of EDTA residue in canned food products by RP-HPLC]

The homogenized sample is diluted with water. After adding copper(II) chloride solution and 20 mg of ascorbic acid, dilute the sample to the volume with water. After thorough mixing and microfiltration over a 0.45 microns filter, the filtrate is ready for injection into the HPLC system and detected at 254 nm. The 125 mm x 4 mm i.d. chromatographic column is packed with Hypersil ODS 5 microns, eluted with a mobile phase of water-methanol (80:20, V/V) containing 20 mmol/L tetrabutyl ammonium bromide, 0.03 mol/L sodium acetate buffer (pH 4) at a flow rate of 0.8 mL/min. The injection volume is 20 microL. The response value was linear between 10 mg/L-400 mg/L. The recovery was 95.5%-98.9%. The RSD was 0.82%-1.32%.

Tetrasaccharide multi-esters and xanthone glycosides from the roots of Polygala wattersii

Ten new tetrasaccharide multi-esters, watteroses A-J (1-10), and two new xanthone glycosides, wattersiixanthones A (11) and B (12), were isolated from the roots of Polygala wattersii, together with 11 known compounds (10 oligosaccharide multi-esters and a xanthone glycoside). The structures of new compounds were elucidated on the basis of chemical and spectroscopic evidence.

Oligosaccharide esters from the roots of Polygala arillata

Two new sucrose esters, arillatoses A (1) and B (2), and four new trisaccharide esters, arillatoses C-F (3-6), were isolated from the roots of Polygala arillata, together with four known sucrose esters, glomeratose E (7) and sibiricoses A(1) (8), A(5) (9), and A(6) (10). The structures of the new compounds were elucidated on the basis of chemical and spectroscopic evidence.

Thrombin stimulates MMP-9 mRNA expression through AP-1 pathway in human mesangial cells

AIM

To investigate the thrombin mediated induction of gelatinase B (MMP-9) in mesangial cells (MC) and the underlying role of activator protein-1 (AP-1).

METHODS

Cultured human mesangial cells were exposed to thrombin in the presence or absence of hirudin, curcumin, and c-fos antisense or sense oligonucleotides. Northern hybridization was employed to assess MMP-9 mRNA expression, and electrophoretic mobility shift assay (EMSA) for AP-1 DNA binding activity.

RESULTS

The levels of MMP-9 mRNA in the cell treated with different doses of thrombin (500, 1500, and 4500 u/L, respectively) were 1.1, 3.3, and 4.8 times higher than that in the control, respectively. There was also an increase in AP-1 binding activity (3.5, 5.9, and 7.1 fold than that of the control) in accordance with MMP-9 mRNA levels in the presence of thrombin. Hirudin, curcumin, and c-fos antisense oligonucleotides could block thrombin-induced expression of MMP-9 mRNA as well as AP-1 binding activity.

CONCLUSION

Thrombin is a potent stimulator of MMP-9 gene expression in human mesangial cells, and the underlying intracellular events are mediated, at least partly, by AP-1 pathway.

[Surgical treatment for the recurrent patients after palatopharyngoplasty]

OBJECTIVE

To study the surgical treatment for the recurrent patients after palatopharyngoplasty (PPP).

METHOD

Five patients which were confirmed recurrence by sleep survey and examinations were reported.

RESULT

The pharyngeal cavity was narrower obviously ten months after ppp than before ppp. The anteroposterior and transverse distances were (4.06 +/- 2.94) mm and (11.40 +/- 4.16) mm respectively. After dilatation, the distances were (11.90 +/- 3.25) mm and (21.00 +/- 4.18) mm separately, and were increased significantly than before (P < 0.01). Two patients were cured and three cases marked, and all patients were not recurrent post-operation with no complications.

CONCLUSION

The recurrence was mainly concerned with the unsuitable manipulation in PPP. Selecting the cooperation and proper surgical treatment, the better effect was also obtained for the recurrent patients.

[Expressions and their clinical significance of bcl-2 and nm23 in epithelial ovarian carcinoma]

The expressions of bcl-2 and nm23 protein in epithelial ovarian carcinoma were analyzed by immunohistochemical method. The results were that 1. the positive expression of bcl-2 protein was 60% (27/45) in epithelial carcinoma; the positive expression of bcl-2 protein in Grade I was 31.25% (5/16), in Grade II 57.14% (8/14), in Grade III 93.33% (14/15) and there were significant differences among them (P < 0.05); 2. the positive expression of nm23 protein was 40% (18/45) in epithelial carcinoma; the positive expression of bcl-2 protein in Stage I/II was 57.1% (12/21), in Stage III/IV 25% (6/24), and there was significant difference between them (P < 0.05). We conclude that the expressions of bcl-2 and nm23 protein are associated with tumor differentiation and clinical stage respectively. Analyzing the expressions of bcl-2 and nm23 are beneficial to the prognosis of the ovarian tumor patients.

[Effect of thrombin on cell proliferation and plasminogen activator inhibitor type (PAI-1) expression in human embryonic glomerular mesangial cells]

OBJECTIVE

To explore the effect of thrombin on cell proliferation and plasminogen-activator inhibitor Type 1(PAI-1) expression in human embryonic glomerular mesangial cells.

METHODS

Methyl-tetragolium (MTT) incorporation, fibrin plate assay and Northern blotting hybridization were used to examine the mesangial cells proliferation, protein activity and mRNA expression of PAI-1 in cultured human embryonic mesangial cells induced by thrombin, respectively.

RESULTS

Thrombin enhanced glomerular mesangial cell proliferation, PAI-1 protein activity and mRNA expression in a dose-dependent manner, which could be blocked by hirudin, a specific inhibitor of thrombin.

CONCLUSION

Thrombin could enhance mesangial cell proliferation, and up-regulate protein activity and mRNA expression of PAI-1 in cultured human embryonic glomerular mesangial cells. It may play an important role in the pathogenesis of glomerulosclerosis induced by thrombin.

Bis(dicyclohexylammonium) adipate monohydrate

In the asymmetric unit of the title compound, 2C(12)H(24)N(+).C(6)H(8)O(4)(2-).H(2)O, the carboxylate ion lies about an inversion center, the water molecule is on a twofold axis and the sec-ammonium cation is in a general position. Cations link the oxygen ends of two adjacent carboxylate anions to form an eight-membered ring [N.O 2.683 (3) and 2.711 (3) A]. The ion pair propagates as a linear chain and adjacent chains are linked through the water molecules [O.O 2.966 (3) A] into layers.

[Expression of citrate transporter mRNA in the kidneys of rats with metabolic acidosis]

The purpose of the present study was to examine whether metabolic acidosis affects the expression of rat renal Na(+)/citrate cotransporter. Female Wistar rats were pair-fed with normal rat chow and drinking water (control) or water with 0.28 mol/L NH4Cl (metabolic acidosis). The mRNA of two renal Na(+)/citrate cotransporters, which were respectively expressed on apical and basolateral membrane, were measured by Northern blot with two probes, SDCT1 and SDCT2. Animals were sacrificed on day 1,3 and 7. On the 1st day, the blood plasma HCO(-)3 of acidosis group decreased significantly (P<0.01), but the mRNA abundance did not change. On the 3rd day in the acidosis group, the blood plasma HCO(-)3 increased slightly more than that on the 1st day, but was still significantly lower than that of the control group (P<0.01). Both the probes detected some increase in mRNA of brush border and basolateral Na(+)/citrate cotransporter. On the 7th day, the blood plasma HCO(-)3 of the acidosis group continuously increased and there was no significant difference between the two groups. The abundance of brush border and basolateral Na(+)/citrate cotransporter mRNA increased, but there was no difference between those of the 3rd day and the 7th day. It is concluded that metabolic acidosis can induce increase of Na(+)/citrate cotransporter mRNA, which may be responsible for hypocitraturia.

Mechanisms of attachment and internalization of Cryptosporidium parvum to biliary and intestinal epithelial cells

BACKGROUND & AIMS

Although infection of the intestinal and biliary tracts by Cryptosporidium parvum is a major problem in patients with the acquired immunodeficiency syndrome, the specific microbial and host molecules involved in C. parvum infection are unknown. We tested the hypothesis that lectin-carbohydrate interactions and cytoskeleton reorganization are involved in the infection of biliary and intestinal epithelia by C. parvum.

METHODS

In vitro models of cryptosporidial infection using human biliary and intestinal epithelial cell lines were used to assay C. parvum attachment and invasion.

RESULTS

Exposure of C. parvum sporozoites to the sugar, galactose-N-acetylgalactosamine (Gal/GalNAc), and to bovine mucin reduced C. parvum attachment to biliary and intestinal epithelia up to 70%. Preincubation of cell monolayers with either lectins specific to Gal/GalNAc, or glycosidases that specifically release Gal/GalNAc oligosaccharides from glycoproteins, decreased attachment up to 80%. Cytochalasin B and cytochalasin D, but not nocodazole, decreased invasion of cells by C. parvum up to 70% without affecting attachment. During cell invasion (but not attachment), confocal microscopy showed recruitment of actin (but not tubulin) in biliary and intestinal epithelia directly adjacent to C. parvum.

CONCLUSIONS

Gal/GalNAc epitopes of glycoproteins on the epithelial apical membrane and Gal/GalNAc-specific sporozoite surface lectins are involved in the mechanism(s) of C. parvum attachment to intestinal and biliary epithelial cells, and actin remodeling in host cells is required for C. parvum invasion.

[Operations for laryngeal carcinoma with reservation of laryngeal function]

OBJECTIVE

To study the long term results and functional recovery of partial laryngectomy in the treatment of glottic and supraglottic types of laryngeal carcinoma.

METHOD

A series of 70 cases operated on between July 1978 and August 1998 were analysed, of whom 60 were glottic, 10 were supraglottic type laryngeal carcinoma. Among them, 22 cases underwent vocal cord resection, 22 vertical hemilaryngectomy, 17 Majer-Piquet's operation, 7 horizontal hemilaryngectomy, 2 Arslan's operation.

RESULT

1, 3, 5-year survival rates were 98.53%, 87.04% and 78.26% respectively. Decannulation rate was 100%. All patients could finally take food by mouth without inspiration, and could speak as soon as decannulated. Complication and recurrence rates were 15.71% and 13.04% separately.

CONCLUSION

Partial laryngectomy is an effective operation on laryngeal carcinoma with reservation of laryngeal function. It not only can totally excise neoplasm and prolong life, but also can better reserve laryngeal function and improve the quality of patient's life.

Synthesis, Characterization and Crystal Structures of Monomeric and Imidazolate-Bridged Polymeric Copper(II) Complexes of 5-Methyl-1,5,9-triazanonane

Two complexes [Cu(mtan)(H2O)(ClO4)](ClO4) (Im = imidazolate) (1) and [Cu(mtan)(Im)]n (ClO4)2n (mtan = 5-methyl-1,5,9-triazanonane) (2) have been prepared and characterized. Single-crystal X-ray analysis reveals that (1) crystallizes in the orthorhombic space group Pbcm, with a 8.906(5), b 12.255(6), c 14.821(4) Å and V 1618(1) Å3, and complex (2) crystallizes in the orthorhombic space group Pca21, with a 11.125(7), b 9.149(6), c 15.180(7) Å and 1545(1) Å3. The copper(II) atom in complex (1) is in a distorted square-pyramidal geometry, being coordinated by three nitrogen atoms from an mtan ligand and one oxygen atom from an aqua ligand at the basal plane and one perchlorate oxygen atom at the apical position. The structure of complex (2) features polymeric cationic chains composed of [Cu(mtan)(Im)]+ repeating units and discrete perchlorate anions. The Cu(1) atom in each unit has a severely distorted trigonal-bipyramidal geometry, being coordinated by three nitrogen atoms from one mtan ligand and two nitrogen atoms from two Im groups. The structural units are linked by -Im groups to give one-dimensional chains. The variable-temperature magnetic measurement on the powder sample of (2) reveals intrachain, medium antiferromagnetic interaction with g = 2.240 and J = –36.45 cm–1 through the -Im bridges.

[Clinical analysis of vocal cord leukoplakia in 32 cases]

OBJECTIVE

To investigate the types and curative effects of the leukoplakia of the vocal cord.

METHOD

From 1990 to 1996, 32 patients (38 sides) with leukoplakia of vocal cord were operated in our hospital, postoperative follow-up ranged from 2 to 7 years.

RESULT

There were eighteen cases of simple leukoplakia and fourteen cases of leukoplakia with mild, moderate and severe atypical hyperplasia in this study. None of simple leukoplakia had malignant change. But there were 33%, 75% and 75% of cases had malignant change in the leukoplakia with mild, moderate and severe atypical hyperplasia respectively. To surgical methods, there was no significant difference, in the rate of malignant change either by the microlaryngoscopy or thyrotomy.

CONCLUSION

Simple leukoplakia can be cured. More attention should be paid to the leukoplakia with any types of atypical hyperplasia during clinical management. The postoperative results were not depend on the surgical methods.

Effects of ICAM-1 antisense oligonucleotide on the tubulointerstitium in mice with unilateral ureteral obstruction

Effects of ICAM-1 antisense oligonucleotide on the renal tubulointerstitium in mice with unilateral ureteral obstruction.

BACKGROUND

To extend our previous study of the therapy of the renal lesions of unilateral ureteral obstruction (UUO) in mice by an inhibitor of intercellular adhesion molecule-1 (ICAM-1), we investigated the blocking effects of ICAM-1 antisense oligonucleotides (ASONs) on the ICAM-1 expression in mouse kidney.

METHODS

First, ICAM-1 ASON was transducted into mouse renal tubular epithelial cells to investigate the effects of ICAM-1 ASON in vitro. Second, fluorescein isothiocyanate (FITC)-labeled ICAM-1 ASON was injected intravenously to determine the distribution of the ASON in vivo. Third, the expression of ICAM-1 in kidney and the changes of renal morphology were observed to investigate the therapeutic effects of ICAM-1 ASON on the UUO mice in vivo.

RESULTS

The expressions of ICAM-1 in the epithelial cells induced by interleukin-1beta were inhibited by ICAM-1 ASON at the dosages of 100 and 200 nmol/L. Twenty-four hours after an introvenous injection with FITC-labeled ICAM-1 ASON, the highest level of fluorescein was detected within the proximal tubules in mouse kidney. Results of immunohistology and Northern blot showed that the ICAM-1 expression was markedly reduced in the obstructed kidney after treatment with ICAM-1 ASON. The ASON also alleviated the infiltration of inflammatory cells and accumulation of the extracellular matrix in the tubulointerstitium of UUO mice without apparent side effects.

CONCLUSION

Our data demonstrate that ICAM-1 ASON is taken up primarily by the proximal tubular cells of mouse kidney. ICAM-1 ASON can selectively inhibit the ICAM-1 expression of the renal tubular cells both in vitro and in vivo.

Cryptosporidium parvum induces apoptosis in biliary epithelia by a Fas/Fas ligand-dependent mechanism

Although the clinical features of sclerosing cholangitis from opportunistic infections of the biliary tree in patients with acquired immunodeficiency syndrome (AIDS) are well known, the mechanisms by which associated pathogens, such as Cryptosporidium parvum, cause disease are obscure. Using an in vitro model of biliary cryptosporidiosis, we observed that C. parvum induces apoptosis in cultured human biliary epithelia. Both caspase protease inhibitors and neutralizing antibodies to either Fas receptor (Fas) and Fas ligand (FasL) inhibited this process; neutralizing antibodies to other apoptotic cytokines [interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and transforming growth factor-beta (TGF-beta)] had no effect. C. parvum stimulated FasL membrane surface translocation, increased both FasL and Fas protein expression in infected biliary epithelia, and induced a marked increase of soluble FasL (but not IL-1beta, TNF-alpha, and TGF-beta) in supernatants from infected cells. When a coculture model is used in which infected and uninfected cell populations were physically separated by a semipermeable membrane, both uninfected biliary epithelia and uninfected Fas-sensitive Jurkat cells (but not a Fas-resistant Jurkat cell line) underwent apoptosis when cocultured with infected biliary epithelia. Moreover, both a neutralizing antibody to FasL and a metalloprotease inhibitor blocked the apoptosis in uninfected cocultured cells. Activation of caspase activity was also observed in uninfected cocultured biliary epithelia. The data suggest that C. parvum induces apoptosis in biliary epithelia by a Fas/FasL-dependent mechanism involving both autocrine and paracrine pathways. These observations may be relevant to both the pathogenesis and therapy of the cholangitis seen in AIDS patients with biliary cryptosporidiosis.

Activity-guided isolation of triterpenoid acyl CoA cholesteryl acyl transferase (ACAT) inhibitors from Ilex kudincha

Activity-guided fractionation of a methanol extract of the leaves of Ilex kudincha led to the isolation of seven acyl CoA cholesteryl acyl transferase (ACAT) inhibitory triterpenes. Four of them were identified by spectroscopic methods as ulmoidol (4), 23-hydroxyursolic acid (5), 27-trans-p-coumaroyloxyursolic acid (6), and 27-cis-p-coumaroyloxyursolic acid (7), and three were new compounds named ilekudinols A-C (1-3). The structures of these new triterpenoids were elucidated as 2alpha, 3beta-dihydroxy-24-nor-urs-4(23),11-dien-28,13beta- olide (1), 2alpha, 3beta-dihydroxy-24-nor-urs-4(23),12-dien-28-oic acid (2), and 3beta, 24,28-trihydroxylupane (3). Compounds 1-7 showed potent inhibitory activity in the ACAT assay.

Sucrose esters and xanthone C-glycosides from the roots of Polygala sibirica

Six new sucrose esters, sibiricoses A(1)-A(6) (1-6), two new xanthone C-glycosides, sibiricaxanthones A (7) and B (8), and a new acetophenone glycoside, sibiricaphenone (9), were isolated from the roots of Polygala sibirica together with six known glycosides. The structures of new compounds were elucidated on the basis of chemical and spectroscopic evidence. The structure of the known xanthone glycoside, polygalaxanthone III (10), was revised.

Suppression of inducible cyclooxygenase 2 gene transcription by aspirin and sodium salicylate

The pharmacological action of salicylate cannot be explained by its inhibition of cyclooxygenase (COX) activity. In this report, the effects of aspirin and sodium salicylate on COX-2 expressions in human umbilical vein endothelial cells and foreskin fibroblasts were evaluated. Aspirin and sodium salicylate at therapeutic concentrations equipotently blocked COX-2 mRNA and protein levels induced by interleukin-1beta and phorbol 12-myristate 13-acetate. The suppressing effect was more pronounced in cultured cells deprived of fetal bovine serum for 24 h, suggesting that it may be cell cycle related. Salicylate inhibited nascent COX-2 transcript synthesis but had no effect on COX-2 mRNA stability. It inhibited COX-2 promoter activity in a concentration-dependent manner. In mice pretreated with aspirin (10 and 30 mg/kg), followed by challenge with lipopolysaccharide, COX-2 mRNA expression in peritoneal macrophages was markedly suppressed. These findings suggest that salicylate exerts its antiinflammatory action in part by suppressing COX-2 induction, thereby reducing the synthesis of proinflammatory prostaglandins.

Differential sensitivity of transcription factors to mustard-damaged DNA

Nitrogen mustard (bis(2-chloroethyl) methylamine, HN2) inhibited the binding of upstream factors Sp1 and AP2 to their consensus sequences. At concentrations where 50% of the consensus sequence DNA contained at least one lesion, HN2 inhibited formation of the Sp1 complex by 37% (40 microM HN2) and the AP2 complex by 40% (50 microM HN2). The binding of the TATA binding protein (TBP) to the TATA element was also inhibited by HN2, whereas sulphur mustard and the monofunctional sulphur mustard 2-chloroethyl ethyl sulphide (CEES) resulted in a disproportional extent of inhibition with respect to the level of alkylation. The level of alkylation of the TBP oligonucleotide varied significantly at 100 microM drug, with 80, 42 and 15% of HN2, sulphur mustard and CEES, respectively. However, this level of alkylation inhibited formation of the TBP-DNA complex by 70, 70 and 45%, respectively. This differential sensitivity of transcription factors to mustard-induced DNA damage therefore appears to reside dominantly in the stereochemical differences between the specific mustard lesions.