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PubMed2002

Loading of collagen-heparan sulfate matrices with bFGF promotes angiogenesis and tissue generation in rats.

The loading of biocompatible matrices with growth factors offers the opportunity to induce specific cell behavior. The attachment of heparan sulfate (HS) to these matrices may promote the binding, modulation, and sustained release of signaling molecules. In this study, basic fibroblast growth factor (bFGF) was bound to crosslinked collagenous matrices with and without covalently attached HS. The tissue response to these matrices was evaluated after subcutaneous implantation in rats. Attachment of HS to collagen matrices increased the bFGF binding capacity threefold and resulted in a more gradual and sustained release of the growth factor in vitro. bFGF primarily was located at the matrix margins. In vivo, the presence of HS without bFGF resulted in a transient vascularization, predominantly at the matrix periphery. Angiogenesis was further enhanced by combining HS with bFGF. In contrast to collagen-HS and collagen/bFGF matrices, collagen-HS/bFGF matrices remained highly vascularized throughout the matrix during the 10-week implantation period. In addition, these latter matrices revealed an intense and prolonged tissue response and considerably promoted the generation of new tissue. Foreign body reactions were only observed sporadically at this time interval. It is concluded that bFGF loading of collagen-HS matrices has additional value for those tissue-engineering applications that require enhanced angiogenesis and generation of new tissue.

Animals↗
PubMed2006

Predictive value of the serum level of N-terminal pro-brain natriuretic peptide and high-sensitivity C-reactive protein in left ventricular remodeling after acute myocardial infarction.

This study was designed to measure the correlation between left ventricular (LV) remodeling 3 months after successful reperfusion therapy, and the levels of serum N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity C-reactive protein (hs-CRP) at 3 days after acute myocardial infarction (AMI), and to determine the predictive levels of NT-proBNP and hs-CRP for LV remodeling. A total of 106 patients with first AMI were included in this study. Each patient was examined by echocardiography (ECG) on the third day and third month after AMI, and LV remodeling was determined by the difference in the LEV end-diastolic volume (LVEDV) between the third day and the third month. Serum NT-proBNP and hs-CRP level were measured 3 days after AMI. Then the correlation between the 3-months change in LVEDV and the levels of serum NT-proBNP or hs-CRP was determined. In addition, sensitivity and specificity were calculated with a receiver operating characteristic (ROC) curve to identify correspondence with LV remodeling (defined as the change rate of LVEDV >20%). Our results showed that the correlation coefficients with the change of LVEDV were 0.706 for serum NT-pro BNP (P<0.001) and 0.596 for hs-CRP (P<0.05). With a cutoff value of 0.2, the area under the ROC curve (AUC) was 0.894 for NT-proBNP and 0.825 for hs-CRP. Although the AUC did not statistically differ between NT-proBNP and hs-CRP, NT-proBNP is more effective than serum hs-CRP as a marker to predict LV remodeling.

C-Reactive Protein↗
PubMed1989

Effects of heat and other inducers of the stress response on protein degradation in Chinese hamster and Drosophila cells.

Many recent studies have suggested that heat and other inducers of the heat shock (stress) response in eukaryotic cells might result in the generation of abnormal proteins which would result in the overloading of protein degradation systems and the stabilization of proteins involved in positively regulating heat shock (hs) gene expression. In this study we have examined the effects different heat treatments and other hs inducers have on protein degradation in Chinese hamster ovary (CHO) and Drosophila Kc and Schneider cells. We have found that intermediate temperatures which induced the hs response (42 degrees C in CHO and 34 degrees C in Kc cells) did increase protein degradation rates whereas, higher temperatures which also induced the hs response (45 degrees C in CHO and 37 degrees C in Kc cells) initially increased but then decreased protein degradation rates. While these results are consistent with a model in which the protein degradation system is being overloaded and/or components of it are being depleted, we have found several conditions which induce hs proteins which rule out this mechanism. Exposure of either cell type to amino acid analogs (5 mM canavanine or 5 mM S-aminoethyl cysteine) resulted in the rapid degradation of those proteins which had incorporated the analogs in both CHO and Drosophila cells. However, the addition of analogs had little or no effect on the degradation of preexisting proteins, indicating that the introduction of abnormal proteins probably didn't overload the protein degradation system(s). The addition of 100 microM cadmium sulfate or 100 microM sodium arsenite had little or no effect on protein degradation rates in CHO cells even though both were good inducers of the hs proteins. Thus, exposure to inducers of the hs response does not universally increase protein degradation rates nor does it stabilize preexisting proteins. Therefore, the degradation of abnormal proteins is probably not involved in inducing the hs genes.

Amino Acids↗
PubMed2006

Bone-specific heparan sulfates induce osteoblast growth arrest and downregulation of retinoblastoma protein.

The heparan sulfate (HSs) sugars of the extracellular matrix (ECM) play a key role during both development and wound repair in regulating the flow of growth and adhesive factors across their cell surface receptors. The aim of this study was to assess the structural and functional differences of HS chains extracted from the conditioned media (soluble), cell surface, and ECM of primary human osteoblast cultures, and to analyze their effects on osteoblast cell growth. HS chains from these compartments were characterized through a combination of enzymatic degradation, anion exchange chromatography, and molecular sieving. Although the chains were all approximately the same size, they varied systematically in their sulfate content, suggesting differences in their protein-binding domains. When added to pre-confluent hFOB1.19 osteoblast cultures, HS doses exceeding 500 ng/ml inhibited proliferation, without affecting viability, irrespective of their origin. Furthermore, HS doses of 500 ng/ml also downregulated retinoblastoma, Cyclin A and CDK1 protein expression, indicating that high doses of osteoblast HS negatively regulate cell cycle, resulting in growth arrest; when high doses of HS were withdrawn after a prolonged period, linear cell growth was reestablished. Thus, despite differences in sulfation, HS from either the soluble, cell surface, or matrix compartments of primary human osteoblast cultures are functionally similar with respect to their effects on growth. Binding assays revealed that the HS chains bound TGFbeta1, a known inhibitor of osteoprogenitor growth, at higher affinity than a suite of other bone-related, heparin-binding growth factors. Overcoming such sugar-mediated inhibition may prove important for wound repair.

Adult↗
PubMed2006

Differential experiences during the holocaust and suicidal ideation in older adults in treatment for depression.

Data were used on 275 Jewish individuals aged 50 and older in outpatient treatment for depression in this retrospective cross-sectional study. Holocaust survivors who were in work camps, in ghettos, or in hiding (HS-WGH) and holocaust survivors who were in concentration camps (HS-CC) were more likely to suffer posttraumatic stress disorder compared to other survivors (HS-OT) and controls. The HS-WGH and HS-CC groups had at least a threefold greater odds of suicidal ideation compared to controls. Suicidal ideation rates did not differ significantly between HS-OT group and controls. Among survivors, HS-WGH had a threefold greater odds of suicidal ideation compared to HS-OT. The results are applicable to survivors of similar atrocities and show that differing types and severities of traumatic experiences have important implications for treatment planning.

Aged↗
PubMed2004

Nuclear and cytoskeletal alterations of in vitro matured porcine oocytes under hyperthermia.

The effects of heat shock (HS) on the nucleus and cytoskeleton of in vitro matured pig oocytes were examined in this study. Porcine cumulus-oocyte complexes (COCs) were aspirated from 3 to 6 mm diameter follicles and subjected to standard in vitro maturation (IVM) procedures for 42 hr. In Experiment 1, IVM-derived oocytes were then randomly allocated to different HS treatments at 41.5 degrees C for 0 (control, C0h, n = 101), 1 (HS1h, n = 113), 2 (HS2h, n = 104), and 4 hr (HS4h, n = 111), respectively. An additional control group of oocytes was cultured for 4 hr without HS (C4h, n = 93). Immunocytochemical staining was performed using anti-tubulins and FITC-conjugated mouse IgG for microtubule (MT) labeling. The chromatin and microfilaments (MFs) were stained using Hoechst 33342 and rhodamine-phalloidin, respectively. In the severe HS (4 hr), the chromosomes of the MII oocytes became an aggregated chromatin structure and separated into groups. The spindle MTs were completely depolymerized or formed MT arrays. The relative fluorescence intensity (RFI) or amount of the MF structures including transzona processes (TZPs), vitelline ring (VR), and pericytoplasmic MF, were changed in various degrees. The reversibility of these alterations in the chromatin and the cytoskeleton depended on the duration of the HS. In general, abnormalities in the chromosomes, spindle MTs and the percentages of oocytes with pericytoplasmic MTs increased with length of HS treatment. The size of the spindle and the RFI of MFs in the HS oocytes were also altered. The significant changes in the nucleus and the cytoskeleton in porcine oocytes after HS may be associated with reduced development under hyperthermia and, perhaps, with the low pregnancy rates in domestic species during hot seasons.

Animals↗
PubMed2004

Clinical value of obtaining sputum and cough swab samples following inhaled hypertonic saline in children with cystic fibrosis.

Prompt detection and treatment of lower respiratory tract infection are essential in the management of patients with cystic fibrosis (CF), who often have signs or symptoms of respiratory infection without any pathogens being isolated from sputum or cough swab specimens. The aims of this study were to assess the efficacy and clinical value of obtaining sputum and oropharyngeal cough swab samples following induction with hypertonic saline (HS) in this group of patients. Forty-three outpatients with CF, mean age 7.2 years (range, 1.8-12.9 years), were recruited over a 2-year period. Nebulized salbutamol was administered, followed by 6% HS. Sputum was preferentially obtained before and after HS induction if possible. If the patient was not able to expectorate, oropharyngeal cough swabs were taken instead. Four patients were able to expectorate sputum before and 19 after HS induction. The procedure was tolerated in 41 of 43 patients. Pathogens were isolated from 13 patients' HS-induced samples, but not from their corresponding preinduced specimens, and 4 patients' preinduced specimens cultured organisms which were not identified from their HS-induced samples. Significant changes were made in the management of 13 (30.2%) patients directly resulting from the positive culture of pathogens only from HS-induced samples. Cultures from oropharyngeal cough swab or expectorated sputum specimens following inhalation of HS provide additional microbiological information which is of clinical value and may lead to changes in patient management.

Administration, Inhalation↗
PubMed1996

Heparin causes the accumulation of heparan sulfate in cultures of arterial smooth muscle cells.

Heparin infusion in an experimental animal model of arterial injury causes a significant increase in the proteoglycan (PG) component of the extracellular matrix in the injured arteries (Snow, A. D., Bolender, R. P., Wight, T. N., and Clowes, A. W. (1990) Am. J. Pathol. 137, 313-330). The mechanisms responsible for this heparin-induced increase in arterial PGs are not understood. To address this question, we have examined the effect of heparin on PG synthesis and accumulation by aortic smooth muscle cells in culture. Heparin causes a dose-dependent increase in the accumulation of PGs while the greatest percentage change among the different types of PGs is a doubling of the amount of heparan sulfate (HS) accumulated in the cell layer. There is also a selective enrichment of HS in the trypsin-resistant component of the cell layer indicating a specific modification in intracellular PGs. This change is due to the accumulation of large HS glycosaminoglycans (GAGs) which elute at K(av) approximately 0.3 on Sepharose CL-6B (Mr approximately 50,000) under dissociative conditions and which are absent from the controls. These GAGs are located inside the cell as is indicated by their retention after heparitinase or trypsin treatment of the cell layer. Furthermore, the increased accumulation of labeled HS in steady-state heparin-treated cells above controls does not appear for several hours after the addition of [35S]sulfate, indicating that HS accumulation is due to decreased degradation of the HS and not new synthesis. This possibility is further supported by the fact that degradation of the intracellular large HS in trypsinized cells is delayed for 2 h by incubation with heparin. These results suggest that heparin may reduce the intracellular degradation of HS through competitive inhibition of endogenous heparitinase.

Animals↗
PubMed1998

Induction of systemic lupus erythematosus-like disease in mice by immunization with heparan sulfate.

Experimental systemic lupus erythematosus (SLE)-like disease was induced in BALB/c mice by immunization with heparan sulfate, the major glycosaminoglycan of glomerular basement membrane. Following booster injections with heparan sulfate (HS), high levels of anti-HS, anti-dsDNA, and anti-cardiolipin antibodies were detected in the sera of the immunized mice. An enzyme-linked immunospot (ELISPOT) assay indicted that IgG anti-HS and anti-dsDNA antibody-secreting cells were present in the kidneys and most likely contributed to antibody localization. Antibodies eluted from the kidneys of immunized mice were found to react strongly with HS and dsDNA when tested in vitro. The HS-immunized mice developed moderate to severe levels of proteinuria. Histologic examination of kidneys from HS-immunized mice revealed deposition of immunoglobulin in the kidneys. Our results describe the induction of SLE-like disease in normal mice following immunization with HS. This experimental model may be useful for understanding the immunologic basis for autoimmunity to HS.

Animals↗
PubMed1993

Accumulation of heparan sulfate in the culture of human melanoma cells with different metastatic ability.

Glycosaminoglycans were metabolically labeled in subconfluent cultures of highly metastatic 7Gp122 and poorly metastatic IC8 variants and of the low metastatic parental M4Be human melanoma cell line. Proteoglycans were separated by DEAE Trisacryl chromatography from the culture medium, from the heparin extract of the cell layer and from the heparin-extracted cell residue lyzed with detergents. Glycosaminoglycans were released from the proteoglycans by reductive alkaline hydrolysis and heparan sulfate (HS) was detected by deaminative cleavage with nitrous acid. Expressed on cell protein basis, the labeled HS content in the medium and in the cell layer decreased with increasing metastatic ability. The extraction of HS with heparin from the 7Gp122 cells indicated that this variant was enriched in (polypeptide bound) HS non inserted into the plasma membrane, compared with the low metastatic IC8 and M4Be cells. The HS fraction in heparin extract and in the heparin-extracted cell residue exhibited molecular mass heterogeneity on gel permeation chromatography and it contained HS fragments. Scission with nitrous acid followed by molecular sieve chromatography of the degradation products indicated that the tetra- and disaccharide repeats separated by the N-sulfated glucosamine residue were present in about equal amounts and constituted 60% of the HS chains in the IC8 and M4Be cells. HS from 7Gp122, IC8 and M4Be cells did not bind antithrombin III with high affinity but it was capable of binding bFGF in in vitro assay.

Antithrombin III↗
PubMed1983

The role of canal-neck interaction for the perception of horizontal trunk and head rotation.

The present report considers the conscious perception of passive horizontal rotations of the trunk, the head, or both, by human observers. It examines in particular how this perception depends on the interaction of canal and neck afferents. Three sets of sinusoidal stimulations (0.2 Hz) were applied to subjects (Ss): Rotations of (1) whole body (pure labyrinthine stimuli, lambda), of (2) only the trunk with the head stationary in space (pure neck stimuli, nu), and of (3) both head and trunk, each with an amplitude and a direction of its own, giving rise to various in-phase and counter phase combinations of lambda and nu.--The Ss were to estimate the magnitude of their turning sensations (psi). In doing so, they were to concentrate either on the rotation of their trunk in space (TS) or of their head in space (HS), or of the head relative to the trunk (HT). The TS and HS turning sensations induced by pure lambda-stimuli were essentially the same as to magnitude and direction. Pure nu-stimulation also led to TS and HS turning sensations. However, the former had the direction of the trunk-to-head (T delta S) deflection, the latter that of the head-to-trunk deflection. The nu-induced HS turning sensation represented an illusion, since the head remained stationary in space. When the lambda- and nu-stimuli were combined, the interaction could be described by a linear summation of their effects. The estimates of TS turning followed the equation psi HS approximately lambda-nu, thus well reflecting the actual TS rotation. The estimates of HS could be described by psi HS approximately lambda+k nu; the term k nu represents the "nu-illusion" contaminating the HS turning sensation. The estimates of HT turning were roughly proportional to nu alone and, therefore, close to the actual HT rotation. We conclude that humans may derive a rather faithful information about trunk rotation from the combined activation of canal and neck afferents, but that the sensation of passive head rotation is contaminated by an (illusionary) contribution from neck afferents. These additive and subtractive modes of interaction have parallels in postural reflexes as well as in neuronal responses that are known from cat.

Adolescent↗
PubMed1986

Induction of a heat shock puff by hypoxia in polytene foot pad chromosomes of Sarcophaga bullata.

The single large heat-responsive puff (hs puff) in polytene foot pad cells of fly pupae (Sarcophaga bullata) is shown to be inducible by oxygen deprivation but not, as in other systems, by reoxygenation following an hypoxic treatment. The ambient oxygen concentration must drop below 2% for the hs puff to be maximally induced but the puff is fully inducible and transcriptionally active even in the complete absence of oxygen. Lack of oxygen is also compatible with continued transport of puff materials (formation and dissipation of puff droplets at the hs locus). Hypoxia-induced hs puffs persist indefinitely (greater than 2 days) at maximal or intermediate size and only regress completely after oxygen is resupplied. The induction of the hs puff during hypoxia is highly specific and does not seem to involve activation of any other chromosomal loci, yet the reaction is not confined to the giant foot pad cells or to specific developmental stages. Azide poisoning of cultured foot pads simulates the in vivo effects of hypoxia. The induction of the hs puff by azide, heat, or other means is inhibited by sulfhydryl reagents (iodoacetamide, arsenite) and fluoride, but not by an inhibitor of substrate-linked phosphorylation (arsenate). Instead, arsenate, like other uncouplers (2,4-dinitrophenol) is an inducer of the hs locus. The hs puff can be fully induced by hypoxia at any temperature between 2 degrees and 45 degrees C. The rate of puff expansion is strictly temperature dependent and the temperature characteristics of this process are remarkably similar to those of a promoter RNA polymerase association.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Cholesterol-dependent changes of glycosaminoglycan pattern in human aorta.

Glycosaminoglycans are regular constituents of the arterial wall and essential for its structure and function. The arteriosclerosis-dependent changes of glycosaminoglycans were investigated, the degree of arteriosclerosis was monitored by the cholesterol content of the tissue. Histological characterization was achieved by electron microscopy. Total glycosaminoglycans were isolated from 33 delipidated segments of human aorta thoracica after exhaustive proteolytic digestion, and fractionated into the individual glycosaminoglycans by a multistep purification procedure. Chondroitin sulfate (CS), dermatan sulfate (DS), heparan sulfate (HS), and hyaluronate (HA) were identified and quantified by chemical and enzymatic analysis. The concentration of total and individual glycosaminoglycans, expressed as mg/g delipidated dry weight of tissue, decreased significantly with increasing cholesterol content of tissue (p = 0.0005-0.005). The extent of decrease differed between the individual glycosaminoglycans as indicated by a shift in the CS/DS:HA:HS ratio from 47:32:21 in low cholesterol aortic segments to 59:29:12 in cholesterol-rich specimens. Determination of the relative molecular masses (Mr) revealed 58 kDa for CS/DS and 92 kDa for HS with a (statistically not significant) increase of the molecular mass of CS/DS and a decrease of HS with increasing cholesterol content. The copolymeric CS/DS glycosaminoglycans were disintegrated enzymatically into CS and DS containing fragments. A significantly higher relative DS content (p = 0.01) was found in cholesterol-rich arterial tissue (32.5%) as compared with low cholesterol tissue samples (28.8%). Cell culture experiments revealed that human arterial HS is able to inhibit the proliferation of cultured human arterial smooth muscle cells. The HS concentration required for a 30% inhibition of smooth muscle cell proliferation was in the same order as the tissue concentration of HS. This confirms the function of HS as an endogenous inhibitor of cell division and its impact for the development of atherosclerosis.

Aorta, Thoracic↗
PubMed1986

Plasma levels of arginine vasotocin, prolactin, aldosterone and corticosterone during prolonged dehydration in the domestic fowl: effect of dietary NaCl.

Three groups of White Plymouth Rock laying hens were adapted to three levels of dietary NaCl: low-NaCl food with tap water (LOW), high-NaCl food (1% NaCl w/w added) with tap water (HT), and high-NaCl food with 0.5% NaCl for drinking (HS). The birds were subjected to water deprivation (dehydration) for 18 days. Blood sampling was done at 2-4 day intervals. Plasma concentrations of arginine vasotocin (AVT), prolactin (PRL), aldosterone (ALDO) and corticosterone (CS) were determined by radioimmunoassay. Plasma osmolality, sodium, chloride, and potassium were also determined. In the normally hydrated hens fully adapted to the diets, there was a stepwise increase from LOW to HS in plasma osmolality (305, 315, 332 mOsm, for LOW, HT and HS, respectively), [Na+] (144, 153, 161 mM) and [Cl-] (109, 119, 127 mM) as well as in [AVT] (6, 14, 18 pg/ml) and [PRL] (16, 24, 34 ng/ml). Regressing [AVT] on osmolality gave a slope of 0.30 pg . ml-1/mOsm and a threshold of 273 mOsm. The slope of [PRL] on osmolality was 0.73 ng . ml-1/mOsm. The correlation coefficient of [AVT] and [PRL] was 0.67. LOW had high [ALDO] (165 pg/ml) which was suppressed to low levels in HT and HS (5-8 pg/ml), while [CS] was the same in all groups (0.9-1.1 ng/ml). Plasma [K+] was decreased in the high-NaCl groups (5.8 mM in LOW, 4.4 and 4.7 mM in HT and HS). Dehydration resulted within 2 days generally in a sharp (5-15%) increase in osmolality, [Na+] and [Cl-], which thereafter increased more slowly during the remaining 16 days in all groups, with the slowest increase in LOW. The levels of osmolality [Na+] and [Cl-] were 5% lower in LOW than in HT and HS, which showed the same levels during the dehydration period. Plasma [AVT] and [PRL] increased 2-4 fold within 2 days of dehydration; [AVT] reached a plateau at 29 pg/ml in all groups, but [PRL] continued to rise in all groups, fastest in LOW, reaching similar levels in all groups after 14-18 days of dehydration, about 85 ng/ml. The correlation coefficient of [AVT] and [PRL] was decreased by half (to 0.32) during dehydration. Plasma [ALDO] increased in all groups with dehydration, 1.7 fold in LOW and 3-6 fold in HT and HS, but the levels reached in HT and HS were only 15-30% of that seen in LOW.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenal Cortex Hormones↗
PubMed1989

The function of plant heat shock promoter elements in the regulated expression of chimaeric genes in transgenic tobacco.

A series of deletion mutants of a soybean heat shock (hs) gene promoter was generated and linked to the chloramphenicol acetyl transferase (CAT) coding sequence. These chimaeric promoter/reporter gene constructs were introduced into tobacco and thermoregulated expression of CAT activity was examined in leaf extracts. Three different types of gene fusions were tested using two different BIN19 vector constructions: (1) translational fusion between the N-terminus of the protein coding sequence of the heat shock gene Gmhsp17.3-B and CAT; (2) transcriptional fusions between the 5' nontranslated RNA regions of Gmhsp17.3-B and CAT; and (3) promoter fusions joining the hs promoter upstream sequences to the TATA box sequence of the delta CaMV 35S-CATter vector. Alternatively, multiple copies of a synthetic deoxyoligonucleotide with the soybean hs consensus element (HSE2) were used. Heat inducible CAT activities were detected except in plants containing a transcriptional fusion devoid of all but 18 nucleotides at the 5' terminus of the hs gene transcript. CAT activity was detectable in these plants only during the recovery at 25 degrees C after a hs (40 degrees C). Overlapping HSE-like promoter sequences seem to be necessary for the induction of heat inducible transcription of linked genes; synthetic HSE2 sequences have the capacity to reconstitute a hs promoter in combination with a TATA box sequence. Effective translation during hs seems to require sequences in the 5' non-translated leader of the hs protein mRNA; these sequences can be functionally replaced by the 5' leader sequence of the delta CaMV 35S promoter.

Amino Acid Sequence↗
PubMed2000

Characterization of aquatic humic substances and their metal complexes by immobilized metal-chelate affinity chromatography on iron(III)-loaded ion exchangers.

The analytical fractionation of aquatic humic substances (HS) by means of immobilized metal-chelate affinity chromatography (IMAC) on metal-loaded chelating ion exchangers is described. The cellulose HYPHAN, loaded with different trivalent ions, and the chelate exchanger Chelex 100, loaded to 90% of its capacity with Fe(III), were used. The cellulose HYPHAN, loaded with 2% Fe(III), resulted in HS distribution coefficients Kd of up to 10(3.7) mL/g at pH 4.0 continuously decreasing down to 10(1.5) at pH 12, which were appropriate for HS fractionation by a pH-depending chromatographic procedure. Similar distribution coefficients Kd were obtained for HS sorption onto Fe(III)-loaded Chelex 100. On the basis of Fe-loaded HYPHAN both, a low-pressure and high-pressure IMAC technique, were developed for the fractionation of dissolved HS applying a buffer-based pH gradient for their gradual elution between pH 4.0 and 12.0. By coupling the Chelex 100 column under high-pressure conditions with an inductively coupled plasma mass spectrometer an on-line characterization of HS metal species could be achieved. Using these fractionation procedures a number of reference HS were characterized. Accordingly, the HA (humic acids) and FA (fulvic acids) studied could be discriminated into up to 6 fractions by applying cellulose HYPHAN, significantly differing in their Cu(II) complexation capacity but hardly in their substructures assessed by conventional FTIR. In the case of using Chelex 100 exchanger resin two major UV active HS fractions were obtained, which significantly differ in their complexation properties for Cu(II) and Pb(II), respectively.

Chelating Agents↗
PubMed1999

Synaptophysin immunoreactivity in temporal lobe epilepsy-associated hippocampal sclerosis.

We have previously devised a semiquantitative grading system for hippocampal sclerosis (HS) in specimens resected for intractable temporal lobe epilepsy. The grades range from zero to four based on the amount and distribution of neuronal loss and gliosis. In the present study hippocampal sections from 25 patients who had temporal lobe epilepsy and had previously been assigned a grade were examined with synaptophysin immunohistochemistry, and the synaptic content in specific hippocampal fields was correlated with the results of the HS grading system. There was evidence of both significant synaptic loss and increased synaptic density in different fields of the hippocampus with increasing HS. A marked decrement of synaptic inmmunostaining was present in fields CA1 and CA4 that were highly correlated with HS grade. Sector CA4 seemed to respond in a more graded or continuous way to the pathological insults occurring in temporal lobe epilepsy than did CA1, which appeared to exhibit an all or nothing response. Also, while the width of the outer part of the molecular layer of the dentate (mid) gyrus decreased with increasing HS grade, the inner part of the mid became wider and showed an increased synaptic density so that the overall width of the mid was increased in the high-grade group. We conclude that quantitative measurement of synaptic loss in CAI and CA4 using synaptophysin immunohistochemistry is a sensitive method for detecting HS and correlates well with the empirically derived HS grading scale, with CA4 exhibiting a more graded response than CA1. In addition, a plasticity response in the inner part of the mld in patients with high-grade HS has been confirmed and quantitated.

Adult↗
PubMed1998

Activation of STAT proteins in the lung of rats following resuscitation from hemorrhagic shock.

Hemorrhagic shock (HS) initiates a series of inflammatory processes, including the production of proinflammatory cytokines at critical sites such as the lung. We have previously shown that granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6) mRNA are produced in the lungs of rats subjected to resuscitated HS and that both the ischemic and reperfusion phases of resuscitated HS were required. G-CSF and IL-6 activate STAT (signal transducers and activators of transcription) proteins which may sustain the inflammatory response that follows resuscitation in HS. We tested the hypothesis that STAT proteins are activated in the lungs of rats subjected to resuscitated HS and examined the factors contributing to their activation including duration of shock and duration of resuscitation. Sprague-Dawley rats were subjected to compensated (66.1 +/- 1.1 min) or decompensated (157.3 +/- 2.3 min) HS (mean arterial pressure 40 mmHg) followed by resuscitation and sacrifice at 4 or 8 h. The amount of activated Stat3 was increased 2.3- to 7-fold compared with sham control animals in all four experimental groups of resuscitated HS. Levels of Stat3 activation increased with increase in duration of shock but did not demonstrate differences at the 4 or 8 h time point of killing. These results indicate that resuscitated HS results in the activation of the intracellular signaling cascade that includes that activation of STAT proteins driven by cytokines such as G-CSF and IL-6.

Acute-Phase Proteins↗