RESUMEN
Macamides, amides of fatty acids first isolated from maca (Lepidium meyenii) are potentially responsible for the reduction of ischemic injury in the stroke animal model followed by maca extract administration. This deduction comes from its ability to inhibit the fatty acid amide hydrolase activity, an enzyme related to the endocannabinoid anandamide hydrolysis. However, no study about the effects of isolated macamides on in-vivo models has been published yet. Our objective was to evaluate the effect of a 10-day 30 mg/kg i.p. MCH1 administration, the macamide with the higher FAAH inhibition capability, on the neurological recovery and brain infarction area of Sprague-Dawley rats exposed to the transient middle cerebral artery occlusion (MCAO) model. Our results showed that the group receiving MCH1 for 10 days did not improve Garcia's neurological score compared to receiving the vehicle only. Likewise, the MCH1 group did not improve their sensorimotor dysfunction as indicated by the latency to detect and remove the tape from the contralateral forepaw in the adhesive removal test, and a similar number of errors with the contralateral forepaw in the foot fault test compared to the vehicle group at the 10th day. Evaluation of the spatial memory and learning using the Barnes test showed longer latency to reach the escape box in the Vehicle and MCH1 groups compared to the control group (no MCAO) only in the retrieval test, while no effect of MCAO procedure or MCH1 administration was observed in the reversal learning test. Despite the lack of behavioral effect of MCH1, analysis of the infarcted areas in the brain using the 2, 3, 5-Triphenyltetrazolium chloride (TTC) staining method in the seven consecutive coronal sections revealed that the infarcted area in the first (bregma + 4.2 mm) and fifth (bregma -3.8 mm) coronal sections of the MCAO + MCH1 group remained similar to the Control group. These results provide evidence that MCH1 can limit damage from ischemic stroke, although it is not reflected in neurological or sensorimotor behavior and spatial learning and memory.
Asunto(s)
Infarto de la Arteria Cerebral Media , Corteza Motora , Accidente Cerebrovascular , Animales , Ratas , Modelos Animales de Enfermedad , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Corteza Motora/efectos de los fármacos , Ratas Sprague-Dawley , Aprendizaje Espacial/efectos de los fármacos , Amidohidrolasas/antagonistas & inhibidoresRESUMEN
BACKGROUND: Hyperhidrosis affects up to 3% of the population and negatively affects patients' quality of life. Craniofacial hyperhidrosis is a common complaint which has been successfully treated with botulinum toxin B (Btx B) since 2004 at our hidrosis clinics. OBJECTIVE: To evaluate the safety and clinical effect of Btx B in craniofacial hyperhidrosis. METHODS: The dermatology life quality index (DLQI) was monitored before and after treatment in 38 patients with craniofacial hyperhidrosis. Sweating before and after treatment was monitored by measuring trans epidermal water loss and by collecting gravimetric data. Global Assessment of Therapy in a 5-grade scale was captured. RESULTS: DLQI scores were significantly improved at follow-up 2-4 weeks posttreatment and sweating was significantly reduced. DLQI scores before treatment were 13 ± 1 (mean ± SD) and posttreatment 5 ± 1 which was highly statistically significant (P < 0.001). Sweating before treatment monitored with trans epidermal water loss was 52 ± 31 g/m(2) /h which decreased to 18 ± 7 g/m(2) /h (P < 0.001) posttreatment. Gravimetric data yielded a sweat rate of 0.07 ± 0.08 mg/min at baseline, which consequently dropped to 0.02 ± 0.05 mg/min (P < 0.05) posttreatment. Regarding the Global Assessment of Therapy 87% of the patients were satisfied (score 4-5) with the treatment result. In a 2-year follow-up, 74% returned for further treatments after a median time of 5 months. Side-effects were mild and most commonly reported was stiffness of the forehead and the eyebrows. CONCLUSIONS: In this prospective, uncontrolled study Btx B seems to be both a safe and effective treatment in craniofacial hyperhidrosis improving quality of life and reducing extreme sweating.
Asunto(s)
Inhibidores de la Liberación de Acetilcolina/uso terapéutico , Toxinas Botulínicas Tipo A/uso terapéutico , Hiperhidrosis/tratamiento farmacológico , Adulto , Relación Dosis-Respuesta a Droga , Cara , Femenino , Estudios de Seguimiento , Humanos , Hiperhidrosis/fisiopatología , Inyecciones Intradérmicas , Masculino , Estudios Prospectivos , Cuero Cabelludo , Sudoración/efectos de los fármacos , Resultado del TratamientoRESUMEN
Patients with acute myelogenous leukemia or myelodysplastic syndrome may respond to farnesyl transferase inhibitors (FTIs) with partial or complete response rates noted in about 30% of such patients. FTIs prevent the attachment of a lipid farnesyl moiety to dependent proteins prior to their insertion into the plasma membrane and thereby prevent activity of these prenylation-dependent proteins, but their mechanism of tumor suppression remains unknown. Many patients receiving FTIs do experience myelosuppression. In this work, the in vitro effects of the FTI, R115777 on normal and leukemic hematopoiesis have been examined as have its effects on apoptosis induction and cell cycle profile in both leukemic blasts and normal CD34+ cells. R115777 was inhibitory to normal CD34+ cell proliferation and to leukemic blast cells, but did not affect long-term culture initiating cell frequency nor NOD-SCID reconstituting capacity. No induction of apoptosis or cell cycle changes were noted in AML blasts. These data suggest that myelosuppression with R115777 occurs largely at the intermediate to late progenitor stage of hematopoiesis and that cyclic use might avoid long-term marrow suppression.
Asunto(s)
Transferasas Alquil y Aril/antagonistas & inhibidores , Antineoplásicos/farmacología , Inhibidores Enzimáticos/farmacología , Hematopoyesis/efectos de los fármacos , Leucemia/tratamiento farmacológico , Quinolonas/farmacología , Animales , Antígenos CD34/metabolismo , Apoptosis/efectos de los fármacos , Caspasa 3 , Caspasas/metabolismo , Adhesión Celular/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Ensayo de Unidades Formadoras de Colonias , Farnesiltransferasa , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Poli(ADP-Ribosa) Polimerasas/metabolismo , Factores de Tiempo , Células Tumorales Cultivadas/efectos de los fármacos , Células Tumorales Cultivadas/trasplanteRESUMEN
AIMS: Interferon-gamma (IFN-gamma) has been shown to upregulate MHC class I and II expression, and to promote generation of specific antitumor immune responses. We hypothesized that intratumoral administration of an IFN-gamma gene transfer vector facilitates its enhanced local production and may activate effector cells locally. We conducted a phase I dose-escalation study of a replication-deficient adenovirus-interferon-gamma construct (TG1041) to determine safety and tolerability of intratumoral administration, in advanced or locally recurrent melanoma. METHODS: Patients were enrolled at four successive dose levels: 10(7) infectious units (iu) (n=3), 10(8) iu (n=3), 10(9) iu (n=3), and 10(10) iu (n=2) per injection per week for 3 weeks. TG1041 was injected in the same tumor nodule weekly in each patient. Safety, toxicity, local and distant tumor responses and biologic correlates were evaluated. RESULTS: A total of 11 patients were enrolled and received the planned three injections per cycle. One patient with stable disease received a second cycle of treatment. A maximum tolerated dose was not reached in this study. No grade 4 toxicities were observed. Two grade 3 toxicities, fever and deep venous thrombosis were observed in one patient. The most frequently reported toxicities were grade 1 pain and redness at the injected site (n=8), and grade 1 fatigue (n=5) patients. Clinical changes observed at the local injected tumor site included erythema (n=5), a minor decrease in size of the injected lesion (n=5) and significant central necrosis by histopathology (n=1). Systemic effects included stable disease in one patient. Correlative studies did not reveal evidence of immunologic activity. CONCLUSION: Weekly intratumoral administration of TG1041 appears to be safe and well tolerated in patients with advanced melanoma.
Asunto(s)
Adenoviridae/genética , Terapia Genética , Interferón gamma/genética , Melanoma/terapia , Adulto , Anciano , Femenino , Terapia Genética/efectos adversos , Vectores Genéticos/administración & dosificación , Humanos , Inyecciones Intralesiones , Interleucina-6/sangre , Interleucina-6/metabolismo , Masculino , Melanoma/diagnóstico , Melanoma/inmunología , Persona de Mediana Edad , Microglobulina beta-2/metabolismoRESUMEN
Ultrastructural studies of marrow and examination of the in vivo processes of stem cell homing and mobilization show that multipotential hematopoietic progenitors are able to traverse endothelial cells. The regulation of this process by various classes of chemokines was studied in this report, using an in vitro model of transendothelial migration. Human umbilical vein endothelial cells (HUVECs) or bone marrow-derived endothelial cells (BMECs) were grown to confluence on 3-microm microporous membrane inserts and placed in 24-well culture plates. CD34(+) cells isolated from normal volunteer donor marrow by immunoadsorption or magnetic bead selection techniques were added to the inserts and various individual chemokines were added to the lower chamber of the culture plates in serum-free conditions. After 24 h, the percentage of transmigrated cells was determined. A mean of 8.5% of unfractionated marrow CD34(+) populations migrated, and all chemokines tested, with the exception of macrophage inflammatory protein-1alpha (MIP-1alpha), had some positive effect on this migration. The greatest effects were seen with stroma-derived factor-1alpha (SDF-1alpha) and stroma-derived factor-1beta (SDF-1beta), with lesser effects noted for other chemokines and cytokines. When the CD34(+) population was subselected for expression of CD38, a greater fraction of the CD38(-) cells migrated as compared to the CD38(+) fraction. CD34(+) cells isolated from mobilized peripheral blood and cord blood also migrated in response to chemokines. Chemokines of the CC, CXC, and CX(3)C classes as well as other hematopoietic cytokines may modulate the process of stem cell transmigration of endothelial cells. Further understanding of this process may help elucidate the mechanism of stem cell mobilization and homing.
Asunto(s)
Antígenos CD34/análisis , Quimiocinas/farmacología , Células Madre Hematopoyéticas/efectos de los fármacos , Anticuerpos/farmacología , Calcio/metabolismo , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Quimiocinas CC/farmacología , Quimiocinas CX3C/farmacología , Quimiocinas CXC/farmacología , Relación Dosis-Respuesta a Droga , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/inmunología , Humanos , Interleucina-8/farmacología , Receptores CXCR4/inmunologíaRESUMEN
Burkitt's lymphoma cell lines have been important in vitro models for studying the pathogenesis of Burkitt's lymphoma (BL) and for exploring new treatment strategies. A new EBV(-) Burkitt's lymphoma cell line (GA-10) was established from a patient with a clinically aggressive, chemorefractory BL and characterized. Although functional p-glycoprotein could not be demonstrated by dye-efflux assays, both p53 genes were mutated in the GA-10 cells, perhaps contributing to the resistant phenotype of the original neoplasm. Two properties of BL cells which may be useful targets for novel cytotoxic therapeutics are their surface expression of CD77, the receptor for Shiga toxin (Stx), and their high rate of proliferation. Expression of CD77 on the GA-10 cells was heterogeneous in that certain subclones expressed high levels of CD77 and correspondingly exhibited strong growth inhibition by Stx while others showed low levels of CD77 expression and weak Stx-induced growth inhibition. Flavopiridol, a potent inhibitor of cell cycle progression through G1 and G2, induced cytotoxicity of the GA-10 cells with an LC(50) of approximately 40 nM vs 70 nM for HL-60 cells (P < 0.05). The concentrations of flavopiridol at which only 10% of the cells were viable (LC(10)) were approximately 280 nM for the GA-10 cells and 520 nM for the HL-60 cells (P < 0.05). Dose-related induction of apoptosis in response to flavopiridol was demonstrated in the GA-10 cells by morphology, TUNEL assay, and activation of caspase-3. Flavopiridol was also cytotoxic to seven other BL cell lines tested. These data suggest that flavopiridol may have therapeutic value in the treatment of Burkitt's lymphoma.
Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Linfoma de Burkitt/genética , Linfoma de Burkitt/patología , Caspasas/metabolismo , Flavonoides/farmacología , Genes p53/genética , Piperidinas/farmacología , Células Tumorales Cultivadas/citología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Adulto , Linfoma de Burkitt/metabolismo , Caspasa 3 , Caspasas/efectos de los fármacos , División Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Activación Enzimática/efectos de los fármacos , Humanos , Masculino , Mutación , Toxina Shiga/farmacología , Trihexosilceramidas/metabolismoRESUMEN
ABSTRACT Macrophage inflammatory protein-1alpha (MIP-1alpha) is a C-C chemokine which has antiproliferative effects on early hematopoietic progenitors and stimulatory effects on later progenitors. It also possesses chemotactic and activating properties for monocytes, macrophages, and T-cells. CD34+ progenitors isolated utilizing an avidin-biotin immunoadsorption column produced significant amounts of MIP-1alpha from 24 h onward when cultured in medium with 10% fetal calf serum (>200 pg/ml). Such production persisted through 96 h of culture and was greater when such progenitors were cocultured with a preformed marrow stromal layer (4000 pg/ml at 24 h). The production of MIP-1alpha declined over time of coculture with stromal layers, and stromal layers themselves produced minimal MIP-1alpha as detected by ELISA: <100 pg/ml. In contrast, CD34+ cells isolated by flow cytometry or by magnetic bead adsorption produced minimal MIP-1alpha (0-30 pg/ml). MIP-1alpha production also increased when cells isolated by these two methods were cocultured with stromal layers. The difference in MIP-1alpha production could not be accounted for by differences in purity of the CD34+ population between isolation methods nor on the basis of monocytic or lymphocytic contamination as assessed by the presence of CD14 or CD3 positive cells. CD34+ cells isolated by immune adsorption had increased expression of endothelial and mesenchymal associated antigens, however, suggesting that this subpopulation might account for the MIP-1alpha production observed. Freshly isolated CD34+ cells expressed MIP-1alpha message as assessed by RT-PCR and by in situ hybridization. Coculture of CD34+ cells isolated by any means with stromal cells increased transforming growth factor-beta (TGF-beta) production, in this case by the stromal layer itself. Both MIP-1alpha and TGF-beta have been found to influence cell cycle status and proliferation status of early hematopoietic progenitors, and both have potential effects on accessory cell function. These studies indicate that progenitor-stromal cell interactions may influence local cytokine output, thus potentially influencing progenitor cycling status and accessory cell activation. The method of isolation of CD34+ progenitors may influence secretion of certain cytokines and chemokines.
Asunto(s)
Antígenos CD34/metabolismo , Proteínas Inflamatorias de Macrófagos/biosíntesis , Células Madre/metabolismo , Células del Estroma/metabolismo , Factor de Crecimiento Transformador beta/biosíntesis , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/metabolismo , Calcio/metabolismo , Comunicación Celular , Separación Celular/métodos , Células Cultivadas , Quimiocina CCL3 , Quimiocina CCL4 , Técnicas de Cocultivo , Regulación de la Expresión Génica , Humanos , Leucemia/patología , Proteínas Inflamatorias de Macrófagos/farmacología , ARN/genética , ARN/metabolismo , Células Madre/citología , Células Madre/efectos de los fármacos , Células del Estroma/citología , Factor de Crecimiento Transformador beta/genética , Células Tumorales CultivadasRESUMEN
The successful eradication of cancer cells in the setting of minimal residual disease may require targeting of metastatic tumor deposits that evade the immune system. We combined the targeting flexibility and specificity of mAbs with the immune effector function of the chemokine RANTES to target established tumor deposits. We describe the construction of an Ab fusion molecule with variable domains directed against the tumor-associated Ag HER2/neu, linked to sequences encoding the chemokine RANTES (RANTES.her2.IgG3). RANTES is a potent chemoattractant of T cells, NK cells, monocytes, and dendritic cells, and expression of RANTES has been shown to enhance immune responses against tumors in murine models. RANTES.her2.IgG3 fusion protein bound specifically to HER2/neu Ag expressed on EL4 cells and on SKBR3 breast cancer cells as assayed by flow cytometry. RANTES.her2.IgG3 could elicit actin polymerization of THP-1 cells and transendothelial migration of primary T lymphocytes. RANTES.her2.IgG3 prebound to SKBR3 cells also facilitated migration of T cells. RANTES.her2.IgG3 bound specifically to the CCR5 chemokine receptor, as demonstrated by flow cytometry, and inhibited HIV-1 infection via the CCR5 coreceptor. RANTES.her2.IgG3, alone or in combination with other chemokine or cytokine fusion Abs, may be a suitable reagent for recruitment and activation of an expanded repertoire of effector cells to tumor deposits.
Asunto(s)
Antígenos de Neoplasias/genética , Quimiocina CCL5/inmunología , Quimiocinas/fisiología , Epítopos/genética , Inmunoglobulina G/genética , Proteínas Recombinantes de Fusión/química , Secuencia de Aminoácidos , Antígenos de Neoplasias/fisiología , Secuencia de Bases , Células Cultivadas , Quimiocina CCL5/metabolismo , Quimiocinas/genética , Quimiotaxis , Endotelio Vascular/inmunología , Endotelio Vascular/fisiología , Epítopos/fisiología , Humanos , Inmunoglobulina G/biosíntesis , Inmunoglobulina G/metabolismo , Datos de Secuencia Molecular , Unión Proteica/genética , Unión Proteica/inmunología , Ingeniería de Proteínas , Receptor ErbB-2/genética , Receptores CCR5/metabolismo , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Recombinantes de Fusión/farmacología , Linfocitos T/inmunología , Venas UmbilicalesRESUMEN
Stimulation of CD34(+)-enriched marrow or light density marrow with various growth factor combinations can generate granulocyte progenitors and mature neutrophils in vitro. In this work, we have examined the influence of irradiated marrow stromal layers on growth factor-induced myeloid and early multipotential progenitor expansion from enriched marrow CD34+ progenitors. We have also explored whether the addition of early-acting growth factors known to enhance myelopoiesis in long-term culture, such as fibroblast growth factor (b-FGF), insulin growth factor (IGF-1), c-kit ligand or stem cell factor (SCF), and flk-2flt-3 ligand (FL), can lengthen survival of CD34+ progenitors in these cultures. Stromal cell coculture resulted in greater numbers of total cells and CFU-GM at day 7 and day 14, but with the addition of multiple growth factors, these effects of stromal cell coculture were diminished. At day 14, generally < 1% of the expanded cells over stromal coculture conditions were CD34+, with up to 90% demonstrating CD15 positivity. Culture of CD34+ cells in the presence of early-acting growth factors did not cause significant expansion of CD34+ cells over a 14-day life span, even in the presence of marrow stromal cells. These data suggest that although stromal cell coculture for a period up to 14 days can enhance expansion of total cell numbers and CFU-GMs, stromal cell presence does not lead to expansion of CD34+ cells in these cultures and may diminish the number of clonogenic cells present when growth factors with differentiating capacity are present. Mature neutrophils harvested from such cultures are capable of chemotaxis, actin polymerization, and migration, suggesting a replete functional status.
Asunto(s)
Antígenos CD34 , Células Madre Hematopoyéticas/fisiología , Neutrófilos/fisiología , Células del Estroma/fisiología , Actinas , Quimiotaxis , Técnicas de Cocultivo , Sustancias de Crecimiento/farmacología , Células Madre Hematopoyéticas/efectos de los fármacos , Humanos , Neutrófilos/efectos de los fármacos , FagocitosisRESUMEN
The specific capsular polysaccharide of Streptococcus pneumoniae type 9N (American type 9) contains D-glucose, D-glucuronic acid, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-2-deoxy-D-mannose in the molar ratio of 2:1:1:1. Accumulated data from spectroscopic (13C and 1H nuclear magnetic resonance) and methylation analyses of the native and specifically degraded polysaccharide indicated that it was linear and composed of the following pentasaccharide repeating unit; -4)-alpha-D-GlcpA-(1 leads to 3)-alpha-D-Glcp-(1 leads to 3)-beta-D-ManpNAc-(1 leads to 4)-alpha-D-Glcp-(1 leads to 4)-beta-D -GlcpNAc(1 leads to. Structural regions in the type 9N polysaccharide common to those of types 9A, 9L, and 9V have been identified which account for the cross-reactivity of this groups of polysaccharides.
Asunto(s)
Compuestos de Cromo , Polisacáridos Bacterianos , Streptococcus pneumoniae/análisis , Secuencia de Aminoácidos , Amino Azúcares/análisis , Fenómenos Químicos , Química , Cromo , Espectroscopía de Resonancia Magnética , Metilación , Oxidación-ReducciónRESUMEN
The acidic polysaccharide (K6) antigen from Escherichia coli LP 1092 contains D-ribose and 3-deoxy-D-manno-octulosonic acid in the molar ratio of 2:1, respectively. Spectroscopic data (13C- and 1H-n.m.r.), methylation analyses, and periodate oxidation indicate that the polysaccharide is composed of the foregoing components essentially in the following trisaccharide sequence: leads to 2)-beta-D-Ribf-(1 leads to 2)-beta-D-Ribf-(1 leads to 7)-alpha-D-KDO-(2 leads to. The polysaccharide also contains O-acetyl substituents (approximately 0.2-0.3 mol per KDO residue).
Asunto(s)
Escherichia coli/inmunología , Polisacáridos Bacterianos/aislamiento & purificación , Azúcares Ácidos/análisis , Conformación de Carbohidratos , Secuencia de Carbohidratos , Espectroscopía de Resonancia MagnéticaRESUMEN
The native polysaccharide antigen isolated from type Ia group B Streptococcus by using pH-controlled growth conditions and extraction procedures contains D-galactose, D-glucose, 2-acetamido-2-deoxy-D-glucose, and sialic acid in the molar ratio of 2:1:1:1. The structure of the native type Ia antigen has been elucidated; it can be represented by the following repeating unit in which all the side-chain beta-D-galactopyranose units are masked by sialic acid residues: [Formula: see text] Removal of all the sialic acid groups yields the incomplete type Ia polysacharide antigen with exposed terminal beta-D-galactopyranose residues. Antisera to type Ia organisms produced in rabbits according to the Lancefield procedures contain antibodies specific for both the native and incomplete antigens. Although sialic acid is not itself a determinant in the formation of antibodies to the native polysaccharide, it is an essential part of a larger determinant. In order to maintain the high degree of immunologic specificity of the native antigen, this determinant must be at least a trisaccharide unit, because the native polysaccharide as isolated has terminal disaccharide units [alpha-D-NeuAcp-(2-->3)-beta-D-Galp] identical to those found in the human M and N blood group substances and fetuin. Formation of antibodies to the incomplete antigen is due to determinants terminating in beta-D-galactopyranose residues. These determinants are probably generated by the removal of the masking sialic acid residues from the cell-associated native polysaccharide by degradative processes that occur in organisms grown without pH control.
Asunto(s)
Antígenos Bacterianos , Polisacáridos Bacterianos/inmunología , Streptococcus agalactiae/inmunología , Conformación de Carbohidratos , Secuencia de Carbohidratos , Epítopos , Metilación , Ácidos Siálicos/inmunologíaAsunto(s)
Actinomyces/metabolismo , Polisacáridos Bacterianos , Streptococcus/metabolismo , Sacarosa/metabolismo , Animales , Cromatografía de Gases , Cricetinae , Fructosa/análisis , Glucosa/análisis , Humanos , Espectrometría de Masas , Metilación , Peso Molecular , Boca/microbiología , Polisacáridos Bacterianos/biosíntesis , Ratas , Streptococcus mutans/metabolismo , Streptococcus sanguis/metabolismoRESUMEN
A polysaccharide, isolated from rapeseed hulls by extraction with aqueous sodium hydroxide-sodium tetraborate, contained residues of L-arabinose, L-fucose, D-xylose, D-galactose, and D-glucose in the proportions of 2:8:25:13:52. Acetolysis furnished cellobiose, 6-O-alpha-D-xylopyranosyl-D-glucose, and 2-O-beta-D-galactopyranosyl D-xylose. The cleavage products from the methylated polysaccharide were examined by g.l.c. of the methyl glycosides and g.l.c.-mass spectrometry of the partially methylated, alditol acetates. The results show that the polysaccharide is a member of the xyloglucan group in which additional fucose and galactose residues terminate some of the side-chains. For comparative purposes, aspects of the structures of xyloglucans from nasturtium seeds and suspension-cultured sycamore cells have been re-examined.
Asunto(s)
Polisacáridos/análisis , Semillas/análisis , Fucosa/análisis , Galactósidos/análisis , Polisacáridos/aislamiento & purificaciónRESUMEN
Soluble enzymes in human dental plaque material were shown to synthetise a polysaccharide material when incubated with sucrose. The polysaccharide mixture was fractionated by gel chromatography and the major fraction (Mw congruent to 95,000) was characterised as a mixture of a alpha-(1 leads to 6)-linked glucan with branches linked alpha-(1 leads to 3) to the main chain and a beta-(2 leads to 6)-linked fructan with branches in the 1-position of the chain residues.