Sugar-lectin interactions investigated through affinity capillary electrophoresis

The affinity interactions of Concanavalin A (Con A) with various saccharide oligomers (dextrins, dextrans, and selected N-linked glycans from various glycoproteins) have been investigated through a capillary electrophoresis approach. Con A has shown a notable binding discrimination between the alpha-1,6-linked dextran and alpha-1,4-linked dextrin oligomers. Both the binding capacity and binding discrimination appear to decrease with an increase in sugar chainlength. While the core structure of N-linked glycans is deemed to be responsible for the overall binding of various glycans to Con A, the presence of mannose units at the non-reducing ends was found to be very beneficial to the affinity interaction with Con A. Finally, a connection between the glycan-lectin interaction and glycoprotein-lectin interaction has also been suggested.

[Clinicopathologic analysis of rhinoscleroma]

OBJECTIVE

To investigate the clinicopathologic characteristics and reason of tissue injury caused by klebsiella rhinoscleromatis(KR) infection.

METHODS

Twenty-four cases of rhinoscleromas in the nasal and pharyngeal region in this hospital from March 1983 to March 1998 were studied retrospectively. Warthin-Starry (W-S) stain was used in all cases and CD43, CD20, CD68, Lysozyme mark were observed in eleven specimens by ABC immunochemical method. Two cases were studied further with transmission electron microscopy.

RESULTS

A great number of KR were found in Mikulicz cells and were confirmed further in the phagosomes in cytoplasm of Mikulicz cells, where a small number of endoplasmic reticulums and lysozymes was squeezed to the side of cells. A few of T-lymphocytes was found within the granuloma.

CONCLUSION

Cellular immunity function of the patient with rhinoscleroma was depressed and the response to immunization of host which regards to KR was the major cause of tissue injury.

A novel zidovudine uptake system in microglia

In the central nervous system (CNS), brain macrophages and microglia are the primary targets of productive human immunodeficiency virus 1 (HIV-1) infection. Zidovudine (ZDV), a thymidine derivative, has been reported to reduce the progression of the disease and prolong survival in patients with acquired immunodeficiency syndrome (AIDS) and AIDS dementia complex. Although a restricted ZDV distribution has been observed in the CNS, its accumulation in brain parenchyma has not been examined. We have investigated the uptake properties of radiolabeled ZDV by a continuous rat microglia cell line (MLS-9) grown as a monolayer on an impermeable surface. Although the organic cations verapamil, mepiperphenidol, quinidine, cimetidine, and N(1)-methylnicotinamide moderately inhibited ZDV uptake, the organic cation probes tetraethylammonium and 1-methyl-4-phenylpyridinium were weak inhibitors. ZDV uptake was significantly increased when the proton gradient was outward (pH(i) 6.3 < pH(o) 7.4; pH(i) approximately 7.1 < pH 8.0), whereas uptake decreased with extracellular acidification (pH(i) approximately 7.1 > pH(o) 6.0) or in the presence of the Na(+)/H(+) ionophore monensin. ZDV uptake was increased under depolarized membrane conditions (i.e., 138 mM K(+) in external medium) and decreased under hyperpolarized conditions (i.e., 2 mM K(+) in external medium), implying a membrane potential dependence. These results suggest that although ZDV transport system in microglia has some specificity features of an organic cation transporter, it involves a carrier, distinct from other cloned organic cation transporters, that is novel in its sensitivity to pH and membrane potential. This system may play a significant role in the transport of other weak organic cation substrates and/or metabolites in brain parenchyma.

[Syntheses, reactions and spectroscopic properties of cluster compounds containing ME4 (M = Mo, W; E = S, Se) units]

The synthetic reactions and spectroscopic studied of molybdenum (tungsten) -copper (silver, iron) -sulphur (selenium) cluster compounds, which can be prepared by the stepwise or unit construction reactions through the successive addition ML (L = Cl, Br, Sr, R2 etc) across six edges or four faces of ME4 (M = Mo, W; E = S, Se) tetrahedra, are described. A series of Mo (W)-Cu-S cluster compounds, (Et4N)2 [MCu2E4 (S2CNR2)2], (Et4N)2 [MCu2E3O (S2CNR2)2], [MCu2E4 (dppe)2] (dppe = bis (diphenylphosphine) ethane), (Et4N)2 [MCu3E4 (S2CNR2)4] (M = Mo, E = Se, R = Et (1a), R2 = C4H8 (1b), R = PhCH2 (lc)), (Et4N)2 [MCu4E4 (S2CNR2)4] (M = Mo, E = Se, R = Me (2)) (Et4N)2 [M2Cu4S8 (S2CNEt2)2], (Et4N)2 [M2Cu4S6O2- (S2CNC4H8)2], [Mo2Cu4S8 (dppm)2], [Mo2Cu4S6O2 (dppm)2], (dppm = bis (diphenylphosphine) -methane), (Et4N)4 (ME4Cu10L12) (M = Mo, E = Se, L = PhCH2S (3)), MoFe3Se4 (mu-R2NCS2)2 (R2NCS2)4 have been prepared and characterized by UV, IR and X-ray diffraction analyses.

[An etiological and pathologic study of Rhinoscleroma]

OBJECTIVE

To investigate the clinicopathologic characteristics and mechanism of tissue injury caused by Klebsiella rhinoscleromatis (KR) infection.

METHODS

Thirty-three cases of rhinoscleromas in the nasal and pharyngeal region seen in this hospital from Jan. 1980 to Mar. 2000 were studied retrospectively. Warthin-Starry (W-S) stain was used to study all cases. Five cases were studied further with transmission electron microscope.

RESULTS

W-S stain revealed a great number of KR in Mikulicz cells within the granuloma. Electron microscopy demonstrated a number of phagosomes in the cytoplasm of Mikulicz cells where many KR were found. A small number of other organelles such as endoplasmic reticulums and lysozymes were squeezed to the side of cells. There were many granular substances on the surface of intracellular bacteria, which were not found on the extracellular KR.

CONCLUSION

KR is a facultative intracellular bacteria that is able to resist the digestion of macrophages and to proliferate in them. Formation of granulomas and fibrosis in KR infiltrated regions is the major cause of tissue injury.

Distinct FTDP-17 missense mutations in tau produce tau aggregates and other pathological phenotypes in transfected CHO cells

Multiple tau gene mutations are pathogenic for hereditary frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), with filamentous tau aggregates as the major lesions in the CNS of these patients. Recent studies have shown that bacterially expressed recombinant tau proteins with FTDP-17 missense mutations cause functional impairments, i.e., a reduced ability of mutant tau to bind to or promote the assembly of microtubules. To investigate the biological consequences of FTDP-17 tau mutants and assess their ability to form filamentous aggregates, we engineered Chinese hamster ovary cell lines to stably express tau harboring one or several different FTDP-17 mutations and showed that different tau mutants produced distinct pathological phenotypes. For example, delta K, but not several other single tau mutants (e.g., V337 M, P301L, R406W), developed insoluble amorphous and fibrillar aggregates, whereas a triple tau mutant (VPR) containing V337M, P301L, and R406W substitutions also formed similar aggregates. Furthermore, the aggregates increased in size over time in culture. Significantly, the formation of aggregated delta K and VPR tau protein correlated with reduced affinity of these mutants to bind microtubules. Reduced phosphorylation and altered proteolysis was also observed in R406W and delta K tau mutants. Thus, distinct pathological phenotypes, including the formation of insoluble filamentous tau aggregates, result from the expression of different FTDP-17 tau mutants in transfected Chinese hamster ovary cells and implies that these missense mutations cause diverse neurodegenerative FTDP-17 syndromes by multiple mechanisms.

[Study on improvement of liver cirrhosis and liver function in hepatolenticular degeneration patients treated with integrated Traditional and Western medicine]

OBJECTIVE

To observe the effects of sodium dimercaptosulphonate (DMPS) plus Gandou tablet, DMPS and calcium disodium ethylene diaminotetraacetate (EDTA) on improving liver cirrhosis and liver function of hepatolenticular degeneration (HLD) patients.

METHODS

One hundred and forty-six HLD patients were divided into A, B, C three groups, and treated with DMPS plus Gandou tablet, DMPS and EDTA respectively, the therapeutic course was 8 weeks for three groups. The ultrasonography of liver, electrophoresis of serum protein and excretion of urinary copper were observed.

RESULTS

The ultrasonography of liver was improved in all groups, the rate of improvement of group A was 54.0%, B was 44.0% and C was 39.1%. The amounts of serum albumin in A and B groups increased (P < 0.01, P < 0.05), and gamma-globulin decreased in all groups (P < 0.05). The excretion of urinary copper increased obviously in all groups (P < 0.01), and A, B groups increased more than that of C group (P < 0.05).

CONCLUSIONS

The de-copper therapy could improve liver cirrhosis and liver function. The effect of DMPS plus Gandou tablet was better than that of DMPS and EDTA.

Dissociations between psychobiologic reactivity and emotional expression in children

Although there are general assumptions that physiological and behavioral indices of emotion are interrelated, empirical research has revealed inconsistent findings with regard to their degree of association, particularly in children. Two studies were conducted to examine the relations between cardiovascular reactivity and emotional behavior. In the first study, 3- to 6-year-olds completed challenging tasks during which measures of their physiological responses and facial expressions were obtained. With age, children's heart rate decreased, vagal tone increased, and facial expressions became slightly more exaggerated. However, children's physiologic reactions were unrelated to their concurrent facial expression when all children were considered, when only boys were considered, and when children extreme in their physiologic reactions were considered. Only among girls was physiologic reactivity moderately associated with concurrent negative expressiveness. In the second study, 4- and 5-year-olds' physiologic reactivity was examined as a predictor of later overt emotional reaction to venipuncture episodes. Children's overt emotional reactions were consistent across repeated venipunctures, and girls were more visibly distressed than boys. As in the first study, physiologic reactivity was generally unrelated to children's behavioral responses. Findings have implications for assumptions about the degree of coupling between biological and behavioral emotional systems in childhood.

Simultaneous intrastriatal and intranigral dopaminergic grafts in the parkinsonian rat model: role of the intranigral graft

The current transplantation strategy in experimental and clinical Parkinson's disease (PD) has been to place nigral dopaminergic grafts not in their ontogenic site (substantia nigra) but in their target area (striatum). Although intrastriatal dopaminergic grafts are capable of reinnervating the striatum, they fail to reinnervate the nigra, which may be an important factor limiting the efficacy of fetal tissue transplantation in parkinsonian patients. We have previously shown that simultaneous intrastriatal and intranigral dopaminergic grafts (double grafts) may provide a more complete restoration of the nigrostriatal circuitry (Mendez et al. [1996] J Neurosci 16:7216-7227; Mendez and Hong [1997] Brain Res 778:194-205). In the present study, we investigated the contribution of the intranigral graft to functional recovery in double-grafted hemiparkinsonian rats. Twenty Wistar rats with unilateral 6-hydroxydopamine (6-OHDA) lesions of the nigrostriatal pathway were divided into two groups and received either double grafts (n = 10) or intrastriatal grafts alone (n = 10). Following transplantation, both intrastriatally and double-grafted animals had a significant decrease in rotational behavior. However, only animals with double grafts exhibited a significant increase in contralateral adjusting step performance. The intranigral graft was subsequently lesioned by a second 6-OHDA injection. Following the second lesion, animals with double grafts exhibited a significant reversal of rotational behavior and a 51% reduction in contralateral adjusting step performance. The reversal in functional recovery correlated with a significant loss of intranigral grafted neurons. These results suggest that the intranigral graft has an important role in the functional recovery of double-grafted animals. Restoration of dopaminergic innervation to both the nigra and the striatum may be crucial for optimizing graft efficacy and may be a superior strategy in neural transplantation for PD.

Electrophoretic studies of polygalacturonate oligomers and their interactions with metal ions

Polygalacturonic acid, a linear homopolysaccharide, was investigated by capillary electrophoresis (CE) using linear polyacrylamide-coated capillaries and laser-induced fluorescence (LIF) detection. A successful separation of its fluorescently labeled oligomers was achieved through sieving in polyacrylamide entangled matrices. The reaction conditions for the derivatization of polygalacturonic acid were optimized. In studying the interactions between polygalacturonic acid and various metal ions, the end-label, free-solution electrophoretic (ELFSE) technique, developed earlier in our laboratory (Sudor, J., Novotny, M. V., Anal. Chem. 1995, 67, 4205-4209) was found preferable to the sieving method. ELFSE is fast and convenient in that no polymer solutions are needed for the separation. The investigation showed that for the moderately large oligomers, the strongest binding occurred with calcium and cadmium ions, while the smallest interaction was observed with magnesium ions.

Endothelin 1 transcription is controlled by nuclear factor-kappaB in AGE-stimulated cultured endothelial cells

Incubation of bovine aortic endothelial cells (BAECs) with erythrocytes from patients with type 2 diabetes induced an increase in endothelin 1 (ET-1) production. The effect of erythrocytes on ET-1 synthesis was dependent on glycemic control. ET-1 levels after incubation with erythrocytes derived from patients with HbA(1c) levels <6% were just half the levels observed after incubation with erythrocytes from patients with HbA(1c) levels >8%. Nepsilon-(carboxymethyl)lysine (CML)-containing protein isolated from patients' erythrocytes induced ET-1, and CML-containing protein-dependent ET-1 induction was blocked by the recombinant decoy peptide soluble receptor for advanced glycation end products (AGEs), which comprises the NH2-terminal Ig domain of the receptor for AGEs. In vitro-generated AGEs induced ET-1 mRNA transcription (nuclear run-on assay and Northern blot) in a time- and dose-dependent manner. Transient transfection of BAECs with a chimeric construct containing the 5' promoter region of the ET-1 gene linked to a reporter gene confirmed that AGE induced ET-1 promoter activity. Electrophoretic mobility shift assay confirmed AGE-inducible binding of members of the nuclear factor-kappab (NF-kappaB) family to a potential binding site at -2,090 bp. Binding was functionally significant because overexpression of the cytoplasmic inhibitor of NF-kappaB or deletion of the NF-kappaB binding site reduced ET-1 induction, whereas overexpression of NF-kappaB p65 induced ET-1 even in the absence of AGEs. Thus, ET-1 transcription is controlled by the AGE-inducible redox-sensitive transcription factor NF-kappaB.

The molecular basis of phosphatidylcholine preference of human group-V phospholipase A2

Human group-V phospholipase A(2) (hVPLA(2)) is a secretory phospholipase A(2) (PLA(2)) that is involved in eicosanoid formation in such inflammatory cells as macrophages and mast cells. We showed that hVPLA(2) can bind phosphatidylcholine membranes and hydrolyse phosphatidylcholine molecules much more efficiently than human group-IIa PLA(2), which accounts for its high activity on the outer plasma membrane of mammalian cells. To understand the molecular basis of the high phosphatidylcholine specificity of hVPLA(2), we mutated several residues (Gly-53, Glu-56 and Glu-57) that might be involved in interaction with an active-site-bound phospholipid molecule. Phospholipid head-group specificities of mutants determined using polymerized mixed-liposome substrates indicate that a small glycine residue in position 53 is important for accommodating a bulky choline head group. Also, results indicated that two anionic residues, Glu-56 and Glu-57, favourably interact with cationic head groups of phosphatidylcholine and phosphatidylethanolamine. Together, these steric and electrostatic properties of the active site of hVPLA(2) allow for effective binding and hydrolysis of a bulky cationic choline head group of phosphatidylcholine, which is unique among mammalian secretory PLA(2)s.

μ-Terephthalato-bis[bis(1,10-phenanthroline)copper(I)] diperchlorate

The title compound, [Cu(2)(C(8)H(4)O(4))(C(12)H(8)N(2))(4)](ClO(4))(2), was prepared from the hydrothermal reaction of CuCl(2), 1,4-dicyanobenzene, 1,10-phenanthroline and water at 443 K. The compound is a dimer in which the cation lies about an inversion center. The terephthalate moiety acts as a bridging ligand and the phenanthrolines as terminal ligands. The unique Cu atom is coordinated by two O and four N atoms in a distorted octahedral geometry, with Cu-O distances of 1.955 (2) and 2.815 (2) A, and Cu-N distances of 2.008 (2) to 2.216 (2) A.

Bis(N,N-diethyl-1,1-diselenocarbamato-Se)selenium, [(Se2CNEt2)2Se]

The polyseleno title compound, bis(N,N-diethylselenocarbamoyl) triselenide, [(Se(2)CNEt(2))(2)Se] or C(10)H(20)N(2)Se(5), is obtained from the disproportion of sodium N,N-diethyl-1,1-diselenocarbamate. An Se atom connects two N,N-diethyl-1,1-diselenocarbamate groups with Se-Se distances in the range 2.4500 (11)-2.8601 (12) A

Affinity capillary electrophoretic studies of complexation between dextrin oligomers and polyiodides

Capillary electrophoresis (CE) has been applied to the study of complexation between dextrins and polyiodides. A baseline separation of fluorescently labeled dextrin oligomers has provided a unique platform for the observation of a contribution of single oligomers to the complexation process that could previously be measured only in bulk. The complex formation was easily recognized through comparison of peak migration times and peak shapes in the presence and absence of polyiodides. The degree of polymerization (DP) number was found crucial in the binding process, but the I2/I- ratio in a solution also appeared to determine the nature of complexation. The effects of buffer pH and ionic strength upon complexation were also briefly investigated. Diodearray spectra in the visible wavelength range confirmed the differential complexation of unlabeled maltodextrins with different DP values after a CE iodine affinity separation. 13C-nuclear magnetic resonance (NMR) spectral data on differently sized dextrin fractions were found to be in good agreement with the results from CE measurements.

Enhancement of survival of stored dopaminergic cells and promotion of graft survival by exposure of human fetal nigral tissue to glial cell line--derived neurotrophic factor in patients with Parkinson's disease. Report of two cases and technical considerations

The authors have studied the ability of glial cell line-derived neurotrophic factor (GDNF) to promote survival of human fetal dopaminergic tissue after a storage period of 6 days and subsequent implantation into the human putamen. The results indicate that GDNF promotes survival of stored dopaminergic cells. Cells stored without GDNF had a 30.1% decrease in survival time compared with those exposed to GDNF. Two patients with Parkinson's disease received bilateral putaminal implants of fetal dopaminergic cells exposed to GDNF for 6 days and showed enhancement of graft survival as assessed by positron emission tomography scanning. A mean increase of 107% in putaminal fluorodopa uptake from baseline values was observed 12 months postgrafting.

Axonopathy and amyotrophy in mice transgenic for human four-repeat tau protein

Coding region and intronic mutations in the tau gene cause frontotemporal dementia and parkinsonism linked to chromosome 17. Some of these mutations lead to an overproduction of tau isoforms with four microtubule-binding repeats. Here we have expressed the longest four-repeat human brain tau isoform in transgenic mice under the control of the murine Thy1 promoter. Transgenic mice aged 3 weeks to 25 months overexpressed human tau protein in nerve cells of brain and spinal cord. Numerous abnormal, tau-immunoreactive nerve cell bodies and dendrites were seen. In addition, large numbers of pathologically enlarged axons containing neurofilament- and tau-immunoreactive spheroids were present, especially in spinal cord. Signs of Wallerian degeneration and neurogenic muscle atrophy were observed. When motor function was tested, transgenic mice showed signs of muscle weakness. Taken together, these findings demonstrate that overexpression of human four-repeat tau leads to a central and peripheral axonopathy that results in nerve cell dysfunction and amyotrophy.

Intrastriatal and intranigral grafting of hNT neurons in the 6-OHDA rat model of Parkinson's disease

The clinical findings on neural transplantation for Parkinson's disease (PD) reported thus far are promising but many issues must be addressed before neural transplantation can be considered a routine therapeutic option for PD. The future of neural transplantation for the treatment of neurological disorders may rest in the discovery of a suitable alternative cell type for fetal tissue. One such alternative may be neurons derived from a human teratocarcinoma (hNT). hNT neurons have been shown to survive and integrate within the host brain following transplantation and provide functional recovery in animal models of stroke and Huntington's disease. In this study, we describe the transplantation of hNT neurons in the substantia nigra (SN) and striatum of the rat model for PD. Twenty-seven rats were grafted with one of three hNT neuronal products; hNT neurons, hNT-DA neurons, or lithium chloride (LiCl) pretreated hNT-DA neurons. Robust hNT grafts could be seen with anti-neural cell adhesion molecule and anti-neuron-specific enolase immunostaining. Immunostaining for tyrosine hydroxylase (TH) expression revealed no TH-immunoreactive (THir) neurons in any animals with hNT neuronal grafts. THir cells were observed in 43% of animals with hNT-DA neuronal grafts and all animals with LiCl pretreated hNT-DA neuronal grafts (100%). The number of THir neurons in these animals was low and not sufficient to produce significant functional recovery. In summary, this study has demonstrated that hNT neurons survive transplantation and express TH in the striatum and SN. Although hNT neurons are promising as an alternative to fetal tissue and may have potential clinical applications in the future, further improvements in enhancing TH expression are needed.

Simultaneous intrastriatal and intranigral grafting (double grafts) in the rat model of Parkinson's disease

Experimental and clinical studies of neural transplantation in Parkinson's disease have focused on the placement of fetal dopaminergic grafts not in their ontogenic site (substantia nigra) but in the main nigral target area (striatum). The reason for this is the apparent inability of intranigral nigral grafts to extend axons for long distances reinnervating the ipsilateral striatum. This review presents previous work by our laboratory [I. Mendez, M. Hong, Reconstruction of the striato-nigro-striatal circuitry by simultaneous double dopaminergic grafts: a tracer study using fluorogold and horseradish peroxidase, Brain Res. 778 (1997) 194-205; I. Mendez, D. Sadi, M. Hong., Reconstruction of the nigrostriatal pathway by simultaneous intrastriatal and intranigral dopaminergic transplants, J. Neurosci. 16 (1996) 7216-7227] using a new transplantation strategy aimed at restoring dopaminergic innervation of the nigra and striatum by simultaneous dopaminergic transplants placed in the substantia nigra and ipsilateral striatum (double grafts) in the 6-hydroxydopamine lesioned adult rat brain. These double grafts achieve not only greater striatal reinnervation than the standard intrastriatal grafts but also produce a faster and more complete behavioural recovery six weeks after transplantation. Injection of the retrograde tracer fluorogold into the striatum and nigra resulted in fluorescent labeled cells within the intranigral graft and the intrastriatal graft and surrounding striatum, respectively suggesting that these double grafts promote at least partial reconstruction of the nigrostriatal dopaminergic pathway. This double graft strategy may have potential implications in clinical neural transplantation for Parkinson's disease.