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PubMed1996

New biodegradable oligoesters for pharmaceutical application.

Tartaric acid, malic acid, and glyceric acid were copolycondensed with glycolic acid at various molar ratios in feed to quickly synthesize biodegradable oligoesters. They were likely to have a moderately cross-linked structure with relatively low molecular weights and hydrophilic groups on the chains. In addition to macroscopic gels which were insoluble in any solvents, we could obtain the oligoesters which were insoluble in water but soluble in N,N-dimethylformamide. The degradation rate of the oligoesters was higher than that of lactic acid (LA) oligomers having molecular weights of a few thousands. On the contrary, their glass transition and flow temperatures were much higher than those of LA oligomers, indicating that their handling during the preparation of drug delivery dosage forms was much improved. The formulation of microspheres containing drugs from the oligoesters revealed that they were useful as biodegradable matrices having high degradation rates.

Antineoplastic Agents↗

PubMed2004

Interaction of lumican with aggrecan in the aging human sclera.

PURPOSE: Lumican is a keratan sulfate proteoglycan originally identified in cornea, but present in a variety of connective tissues where it presumably regulates collagen fibril formation and organization. The present study was designed to describe the chemical nature of lumican core protein in the aging human sclera. METHODS: Western blot analyses, immunohistochemistry, and immunoaffinity chromatography were used to detect and purify the lumican core protein from tissue extracts from human donors 6 to 89 years of age. Treatment of lumican with chondroitinase ABC, keratanase-I and -II, and/or endo-beta-galactosidase was used to determine the degree of glycosylation of the lumican core protein. RESULTS: Lumican was present in the human sclera as a 70- to 80-kDa core protein with short unsulfated lactosaminoglycan side chains. In addition, on Western blots, a larger >200-kDa species was apparent that was immunologically related to lumican. This high-molecular-weight material increased in scleral extracts with increasing age. The complex was most abundant in unreduced samples, and approximately two thirds of the 70- to 80-kDa lumican core protein was released from the complex on reduction of the scleral extract. Further characterization of the >200-kDa lumican-immunopurified complex indicated that aggrecan (the cartilage proteoglycan) was covalently associated with lumican. CONCLUSIONS: Reducible and nonreducible lumican-aggrecan interactions occur in the scleral extracellular matrix and result in the formation of high-molecular-weight complexes that increase with age. These results represent the first report demonstrating lumican-aggrecan interactions and suggest they may play a role in age-related scleral extracellular matrix changes.

Adolescent↗

PubMed1971

A hereditary immunoglobulin A abnormality: absence of light-heavy-chain assembly. Study of immunoglobulin synthesis in tonsillar cells.

A new immunoglobulin A abnormality, absence of assembly of alpha-chain and light-chain, was found in an adult female suffering from recurrent upper respiratory infection and tonsillitis since childhood, but otherwise healthy. The IgA abnormality was manifest in her serum by the presence of free alpha-chains, in her saliva by the presence of alpha-chains bound to secretory piece, and in her urine by the presence of free alpha-chains and free light-chains. The serum IgG and IgM were found to be complete, containing both heavy-chains and light-chains. Evidence for this immunoglobulin A abnormality was also found in the proposita's mother and elder son, demonstrating it to be a hereditary disorder. Studies performed with patient's tonsillar cells in short-term culture, using amino acids-(14)C, revealed synthesis and secretion of both free alpha-chains and free light-chains, in addition to synthesis and secretion of normally assembled IgG and IgM.

Adult↗

PubMed1973

Degradation of human fibrinogen by plasms alpha2-macroglobulin-enzyme complexes.

This study demonstrates that human plasma alpha(2)-macroglobulin preparations possess an enzymic activity that degrades fibrinogen, resulting in the formation of products whose structure resembles that of circulating fibrinogen catabolites. The sequence of degradation is similar to that observed in plasmin-catalyzed digests, in that Aalpha-chain fragmentation precedes that of Bbeta-chain. The addition of plasminogen activators to plasma induced an increase in the N-alpha-tosyl-l-arginine methyl ester HCl esterase and fibrinogenolytic activity associated with alpha(2)-macroglobulin purified from this plasma, indicating that the enzymic activity of the complex was preserved and could be increased in the presence of other plasma enzyme inhibitors. Immunochemical studies demonstrated that an alpha(2)-macroglobulin-plasmin complex had formed in urokinase-treated plasma. This alpha(2)-macroglobulin preparation manifested an esterolytic profile like that of a complex prepared from plasmin and purified alpha(2)-macroglobulin. After complex formation with alpha(2)-macroglobulin in plasma, plasmin retained less than 0.1% of its fibrinogenolytic activity. That plasmin expressed its activity while bound to alpha(2)-macroglobulin was suggested by immunoprecipitation of this activity with alpha(2)-macroglobulin antibody and by the demonstration that pancreatic trypsin inhibitor did not effectively inhibit its fibrinogenolytic or esterolytic activity. These results raise the possibility that, in addition to its activity as a major plasma proteolytic enzyme inhibitor, alpha(2)-macroglobulin may modulate enzyme-substrate interactions, such as those resulting in the formation of circulating fibrinogen catabolites, by providing a mechanism for the preservation and protection of a portion of the enzymic activity in the presence of other circulating inhibitors.

Acetates↗

PubMed1994

Angiotensin II induces delayed mitogenesis and cellular proliferation in rat aortic smooth muscle cells. Correlation with the expression of specific endogenous growth factors and reversal by suramin.

By means of a rat aortic smooth muscle (RASM) cell culture model, the effects of angiotensin II (AII) on early proto-oncogene gene expression, DNA synthesis, and cell proliferation were measured and compared to known mitogens. In 24-h [3H]-thymidine incorporation assays, AII was found to be a weak mitogen when compared to potent mitogens such as fetal bovine serum and platelet-derived growth factor (PDGF). In contrast, when assays were carried out for 48 h, AII induced a significant dose-dependent stimulation of DNA synthesis, which more than doubled at 3 nM AII, and was maximal (five- to eightfold above control) at 100 nM AII. Treatment of cells with the AII type 1 receptor antagonist losartan inhibited the mitogenic effects of AII. AII also stimulated smooth muscle cell proliferation, as indicated by an absolute increase in cell number after AII stimulation of RASM cells for 5 d. AII stimulation of RASM cell growth correlated with the increased expression of specific endogenous growth factors, including transforming growth factor beta 1 (TGF-beta 1) and PDGF A-chain. However, addition of either PDGF- or TGF-beta 1-neutralizing antibodies failed to significantly reduce the delayed mitogenic effects induced by AII. In contrast, we found that AII-stimulated mitogenesis could be inhibited in a dose-dependent manner by the growth factor inhibitor drug suramin. Taken together, our results indicate that enhanced endogenous growth factor expression may represent the direct mechanism by which AII promotes smooth muscle cell growth in some vascular hyperproliferative diseases.

3T3 Cells↗

PubMed2001

Plasmacytoma with aberrant expression of myeloid markers, T-cell markers, and cytokeratin.

Plasmacytomas are localized neoplastic proliferations of monoclonal plasma cells. When multifocal, the process is referred to as multiple myeloma. These lesions exhibit a pattern of antigen expression and cytomorphology that usually leads to a ready diagnosis. However, potentially troublesome variations in immunophenotype occur. We describe a case of a plasmacytoma from a patient who presented with sudden onset of pain and a lytic lesion of the left proximal humerus. Hematoxylin and eosin-stained sections showed a lymphoproliferative lesion composed of large lymphoid cells, some with plasmacytoid and immunoblastic features. The lesion also showed significant mitotic activity. Immunohistochemical staining was positive for CD45 (LCA), CD56 (N-CAM), CD43 (MT1), and cytokeratin CAM5.2. There was also clonal staining for lambda light chains. In addition, flow cytometric analysis showed positivity for myeloid markers such as CD13, CD33, CD38, and CD138. Significant negative markers include CD20 (L26), CD45RO (UCHL-1), and CD79alpha. The unusual phenotypic features of this plasmacytoma illustrate potential diagnostic pitfalls. It is important to fully study such lesions to correctly classify them, because this has significant impact on prognosis and management.

Antigens, Differentiation, T-Lymphocyte↗

PubMed1992

Production and characterization of two monoclonal antibodies directed against the integrin beta 1 chain.

The production and characterization of two new monoclonal antibodies (MAbs), designated MAR4 and MAR5, raised against the partially purified alpha 5 beta 1 integrin, are described. The reactivity of these 2 MAbs on tumor cell lines indicated that they reacted on all the cells expressing the beta 1 subunit independently of the alpha 5 expression. Both MAbs were found to immunoprecipitate on 3 cell lines, a protein of 120 KD corresponding to the molecular weight be the beta 1 chain, in addition to proteins of other MW corresponding to the alpha subunits differentially expressed by these cells. The cross-competition experiments showed that MAR4 and MAR5 recognize the same epitope. These 2 MAbs seem to be useful reagents for the characterization of the VLA expression in tumor cells.

Animals↗

PubMed2005

Cooperating pre-T-cell receptor and TCF-1-dependent signals ensure thymocyte survival.

Intrathymic T-cell maturation critically depends on the selective expansion of thymocytes expressing a functionally rearranged T-cell receptor (TCR) beta chain. In addition, TCR-independent signals also contribute to normal T-cell development. It is unclear whether and how signals from the 2 types of pathways are integrated. Here, we show that T-cell factor-1 (TCF-1), a nuclear effector of the canonical wingless/int (wnt)/catenin signaling pathway, ensures the survival of proliferating, pre-TCR(+) thymocytes. The survival of pre-TCR(+) thymocytes requires the presence of the N-terminal catenin-binding domain in TCF-1. This domain can bind the transcriptional coactivator beta-catenin and may also bind gamma-catenin (plakoglobin). However, in the absence of gamma-catenin, T-cell development is normal, supporting a role for beta-catenin. Signaling competent beta-catenin is present prior to and thus arises independently from pre-TCR signaling and does not substantially increase on pre-TCR signaling. In contrast, pre-TCR signaling significantly induces TCF-1 expression. This coincides with the activation of a wnt/catenin/TCF reporter transgene in vivo. Collectively, these data suggest that efficient TCF-dependent transcription requires that pre-TCR signaling induces TCF-1 expression, whereas wnt signals may provide the coactivator such as beta-catenin. The 2 pathways thus have to cooperate to ensure thymocyte survival at the pre-TCR stage.

Animals↗

PubMed2006

Endothelial Lu/BCAM glycoproteins are novel ligands for red blood cell alpha4beta1 integrin: role in adhesion of sickle red blood cells to endothelial cells.

The Lutheran (Lu) blood group and basal cell adhesion molecule (BCAM) antigens are both carried by 2 glycoprotein isoforms of the immunoglobulin superfamily representing receptors for the laminin alpha(5) chain. In addition to red blood cells, Lu/BCAM proteins are highly expressed in endothelial cells. Abnormal adhesion of red blood cells to the endothelium could potentially contribute to the vaso-occlusive episodes in sickle cell disease. Considering the presence of integrin consensus-binding sites in Lu/BCAM proteins, we investigated their potential interaction with integrin alpha(4)beta(1), the unique integrin expressed on immature circulating sickle red cells. Using cell adhesion assays under static and flow conditions, we demonstrated that integrin alpha(4)beta(1) expressed on transfected cells bound to chimeric Lu-Fc protein. We showed that epinephrine-stimulated sickle cells, but not control red cells, adhered to Lu-Fc via integrin alpha(4)beta(1) under flow conditions. Antibody-mediated activation of integrin alpha(4)beta(1) induced adhesion of sickle red cells to primary human umbilical vein endothelial cells; this adhesion was inhibited by soluble Lu-Fc and vascular cell adhesion molecule-1 (VCAM-1)-Fc proteins. This novel interaction between integrin alpha(4)beta(1) in sickle red cells and endothelial Lu/BCAM proteins could participate in sickle cell adhesion to endothelium and potentially play a role in vaso-occlusive episodes.

Anemia, Sickle Cell↗

PubMed2005

The mitochondrial respiratory complex I is a target for 15-deoxy-delta12,14-prostaglandin J2 action.

The prostaglandin J2 derivative 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) is a very active compound with important effects on inflammation, apoptosis, and cell growth processes. To exert this broad range of effects, 15d-PGJ2 binds and alters the activity of diverse proteins, which consequently are postulated to be mediators of its action. Among them are the transcription factors peroxisome proliferator-activated receptor gamma and nuclear factor kappaB, which are thought to play an essential role in the antitumorigenic and anti-inflammatory actions of 15d-PGJ2. Here, we show that 15d-PGJ2, at micromolar concentrations, efficiently blocks state 3 oxygen consumption in intact nonsynaptic mitochondria isolated from rat cerebral cortex. This effect is attributable to the inhibition by this prostaglandin of the activity of the enzyme NADH-ubiquinone reductase (complex I) of the mitochondrial respiratory chain. In addition to this, 15d-PGJ2 dramatically increases the rate of reactive oxygen species generation by complex I. The inhibition by 15d-PGJ2 of complex I activity was abolished by dithiothreitol, which raises the possibility that adduct formation with a critical component of complex I accounts for the inhibitory effect of this prostaglandin. These results clearly identified mitochondrial complex I as a new target for 15d-PGJ2 actions.

Animals↗

PubMed1994

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE): clinical, biochemical, and genetic features of an autosomal recessive mitochondrial disorder.

We studied the clinical, biochemical, and genetic features of eight patients with the autosomal recessive mitochondrial syndrome mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). MNGIE is clinically characterized by ophthalmoparesis, peripheral neuropathy, leukoencephalopathy, gastrointestinal symptoms (recurrent nausea, vomiting, or diarrhea) with intestinal dysmotility, and histologically abnormal mitochondria in muscle. Brain MRI scans were consistent with leukodystrophy in seven patients examined. Nerve conduction and EMG studies were compatible with a sensorimotor neuropathy; quantitative EMG of two patients suggested a myogenic process. Muscle mitochondrial enzyme analysis revealed a partial defect of cytochrome c oxidase activity in five patients; three had additional respiratory chain enzyme defects. Two patients had isolated complex I defects, and one had normal respiratory chain function. Southern blot analysis revealed multiple deletions of mitochondrial DNA in four of eight patients.

Adolescent↗

PubMed2004

A study on the interaction between p60 c-Src receptor tyrosine kinase and arylcarboxylic and arylacetic acid derivatives based on docking modes and in vitro activity.

The fundamental role that receptor tyrosine kinases play in cancer and other proliferative diseases has provided the impetus for an extensive effort on the part of both academic and pharmaceutical laboratories to develop highly specific inhibitors. In this study, inhibitory activity of previously synthesized arylacetic and arylcarboxylic acid derivatives were examined against substrate of tyrosine kinase. It can be assumed that the activity of compounds becomes higher when the -CH(2) linkage exist between aromatic ring and the amide group of the side chain. In addition, when the R(1) and R(2) substitutents are methyl group in both series, the higher activity observed. The data obtained from docking study (DOCK4.0) indicated that compounds 2, 4, 7, 8, 11 render satisfactory interaction with the active site of enzyme, Lys295 of p60(c-Src) tyrosine kinase. Comparison of this interaction and the evaluation of biological data showed that compound 4 is the most active among the entire derivatives.

Acetates↗

PubMed1996

Development of bioactive functions in hydrangeae dulcis folium. V. On the antiallergic and antimicrobial principles of hydrangeae dulcis folium. (2). Thunberginols C, D, and E, thunberginol G 3'-O-glucoside, (-)-hydrangenol 4'-o-glucoside, and (+)-hydrangenol 4'-O-glucoside.

Following the characterization of thunberginols A, B, and F, six bioactive principles, thunberginols C, D, and E, thunberginol G 3'-O-glucoside, (-)-hydrangenol 4'-O-glucoside, and (+)-hydrangenol 4'-O-glucoside, were isolated from Hydrangeae Dulcis Folium, the processed leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO, together with four kaempferol and quercetin oligoglycosides. Their chemical structures have been determined on the basis of chemical and physicochemical evidence. Thunberginols C, D, E, and G and (-)-hydrangenol 4'-O-glucoside showed antiallergic activity in the in vitro bioassay using the Schultz-Dale reaction. These components also exhibited inhibitory activities on the histamine release from rat mast cells and on the histamine-induced contraction in isolated guinea pig tracheal chain. In addition, thunberginols C, D, E, and G showed antimicrobial activities against oral bacteria.

Animals↗

PubMed2003

Further studies on the structure of polysaccharides from the lichen Flavoparmelia caperata (L.) Hale.

A water-soluble polysaccharide called PC-2 was previously isolated from Flavoparmelia caperata (L.) Hale and assigned to alpha(1-3)(1-4)glucan. However, PC-2 separated into three components, PC-2A, PC-2B, and PC-2C (a single peak in HPLC, respectively) on further purification. Methylation analysis and (1)H- and (13)C-NMR spectroscopic studies suggested that PC-2A is composed of repeating units of [alpha-D-Glc1-3](3), : [alpha-D-Glc1-4](2), while PC-2B and PC-2C are partly branched galactoglucomannans consisting of (1-3)- and (1-4)-linked alpha-D-glucopyranosyl units as the main chain. In addition we confirmed that the polysaccharide fraction PB-2 from the lichen of the same genus, Flavoparmelia baltimorensis (Gyelink & Foriss) Hale, is identical to PC-2 based on the chemical and spectroscopic data.

Lichens↗

PubMed1996

Expression of the chitinase III gene of Aeromonas sp. no. 10S-24 in Escherichia coli.

The chitinase III gene of Aeromonas sp. No. 10S-24 was expressed in Escherichia coli. Production of chitinase III by E. coli was 3-fold higher than that of chitinases in the culture supernatant of Aeromonas sp. The enzyme from E. coli was purified and characterized. The molecular weight of the chitinase III from E. coli was estimated by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) to be 55,000. This agreed with the calculated molecular weight of the mature chitinase III (54,111). However, it was different from that of the enzyme from Aeromonas sp. It showed that the chitinase III from Aeromonas sp. had an additional sugar chain, causing the higher molecular weight. Chitinase III from E. coli had almost the same enzymatic properties as chitinase III from Aeromonas sp., but the specific activity of the chitinase III from E. coli is slightly higher than that of the native chitinase III. Both enzymes hydrolyzed chitosan (80% deacetylated) well.

Aeromonas↗

PubMed2006

Photooxidative degradation and conformational changes in syndiotactic polypropylene/clay nanocomposites.

Syndiotactic polypropylene nanocomposites based on layered silicates in various proportions were subjected to prolonged (246 h) ultraviolet (UV)-c irradiation. Fourier transform infrared (FT-IR) spectroscopy was used in order to investigate the molecular alterations of the polymeric matrix during the UV exposure relative to the concentration of nanoclay. It was found that a significant increase of the helical conformation upon the irradiation took place as a result of scissions of the polymeric chains. In addition, a simultaneous increase in the crystallinity was verified by X-ray diffraction (XRD) measurements. Furthermore, a variety of photooxidation products were detected, among them carboxylic acids, ketones, gamma-lactones, and esters. We report in this paper the impact of the clay on the degradation mechanism of syndiotactic polypropylene mostly by the production of additional free radicals. Therefore, the relative intensities of the produced photooxidative species are affected drastically as a function of the concentration of the layered silicate present. Finally, an interaction of the carbonyl groups formed in the polymer upon irradiation with the polar groups of the layered silicates was confirmed both from infrared and UV-visible spectroscopic studies.

Journal Article↗

PubMed1994

Transthoracic needle aspiration in the study of pulmonary infections in patients with HIV.

STUDY OBJECTIVE: To evaluate the safety and efficacy of transthoracic aspiration with an ultrathin needle in the microbiologic diagnosis of pulmonary infections in HIV-infected patients. DESIGN: Retrospective review of cases. SETTING: A 500-bed teaching hospital in Lleida, Spain. PATIENTS: Forty-five HIV-infected patients admitted between March 1989 and March 1993 with clinical and roentgenographic evidence of pulmonary infection and without contraindications for transthoracic needle aspiration (TNA). INTERVENTIONS: Forty-seven TNAs were performed in the emergency room (20) or during hospitalization (27). The TNA procedures were done without premedication and without fluoroscopic guidance. Specimens were processed using routine microbiologic and cytologic techniques; in addition, polymerase chain reaction (PCR) for Pneumocystis carinii was carried out since March 1992. Development of adverse effects was carefully evaluated. RESULTS: The TNA was effective in 29 (62 percent) out of 47 procedures. The diagnosis was obtained for 14 of 15 patients with P carinii pneumonia, 8 out of 14 patients with bacterial pneumonia, and 4 out of 12 patients with tuberculosis. Other pathogens recovered were Nocardia asteroides, Cryptococcus neoformans, Rhodococcus equi, and Mycobacterium avium. No false-positive results were obtained. Pneumothorax developed in eight (17 percent) procedures, but only one procedure resulted in a pleural drainage; the incidence of other adverse effects was low and clinically irrelevant. CONCLUSION: Our study suggests that TNA can be a useful technique in establishing the etiologic diagnosis of pulmonary infections in HIV-infected patients, with a good sensitivity, high specificity, and relatively low incidence of serious complications, with TNA appearing as a reliable alternative to more uncomfortable methods.

AIDS-Related Opportunistic Infections↗

PubMed2005

Determination of the orientation of T4 lysozyme vectorially bound to a planar-supported lipid bilayer using site-directed spin labeling.

Site-directed spin labeling is used to investigate the structure of adsorbed T4 lysozyme (T4L). A monolayer of T4L is prepared by tethering the protein selectively via a His-tag to the chelating headgroups (NTA Ni) of a planar quartz-supported lipid bilayer. This results in a vectorially oriented ensemble of proteins on the surface, which gives rise to angular-dependent electron paramagnetic resonance spectra. Similar measurements of spin-labeled lipid bilayers were used to characterize the structure and dynamics of the supports. Electron paramagnetic resonance line shape was analyzed using the stochastic Liouville equation approach developed by Freed and co-workers. The simulations reveal a conservation of the secondary and tertiary structure of T4L upon adsorption although slight conformational changes in the presence of the surface can be detected by probing tertiary contact sites. The orientation of the entire protein was deduced on the basis of an anisotropic motional model for the spin-labeled side chain. In addition, a polar order but azimuthal disorder of the molecules was assumed to fit the data. These results demonstrate the utility of site-directed spin labeling in combination with spectral simulation to study not only the secondary and tertiary structure of adsorbed proteins in monolayer coverage but also their orientation with respect to the surface.

Adsorption↗