Individual Subclasses Research Articles

Changes in Antigen-specific IgG1 Fc N-glycosylation Upon Influenza and Tetanus Vaccination

Antibody effector functions have been shown to be influenced by the structure of the Fc N-glycans. Here we studied the changes in plasma or serum IgG Fc N-glycosylation upon vaccination of 10 Caucasian adults and 10 African children. Serum/plasma IgG was purified by affinity chromatography prior to and at two time points after vaccination. Fc N-glycosylation profiles of individual IgG subclasses were determined for both total IgG and affinity-purified anti-vaccine IgG using a recently developed fast nanoliquid chromatography-electrospray ionization MS (LC-ESI-MS) method. While vaccination had no effect on the glycosylation of total IgG, anti-vaccine IgG showed increased levels of galactosylation and sialylation upon active immunization. Interestingly, the number of sialic acids per galactose increased during the vaccination time course, suggesting a distinct regulation of galactosylation and sialylation. In addition we observed a decrease in the level of IgG1 bisecting N-acetylglucosamine whereas no significant changes were observed for the level of fucosylation. Our data indicate that dependent on the vaccination time point the infectious agent will encounter IgGs with different glycosylation profiles, which are expected to influence the antibody effector functions relevant in immunity.

Eph receptor function is modulated by heterooligomerization of A and B type Eph receptors

Eph receptors interact with ephrin ligands on adjacent cells to facilitate tissue patterning during normal and oncogenic development, in which unscheduled expression and somatic mutations contribute to tumor progression. EphA and B subtypes preferentially bind A- and B-type ephrins, respectively, resulting in receptor complexes that propagate via homotypic Eph-Eph interactions. We now show that EphA and B receptors cocluster, such that specific ligation of one receptor promotes recruitment and cross-activation of the other. Remarkably, coexpression of a kinase-inactive mutant EphA3 with wild-type EphB2 can cause either cross-activation or cross-inhibition, depending on relative expression. Our findings indicate that cellular responses to ephrin contact are determined by the EphA/EphB receptor profile on a given cell rather than the individual Eph subclass. Importantly, they imply that in tumor cells coexpressing different Ephs, functional mutations in one subtype may cause phenotypes that are a result of altered signaling from heterotypic rather from homotypic Eph clusters.

A systematic analysis ofDrosophilaTUDOR domain-containing proteins identifies Vreteno and the Tdrd12 family as essential primary piRNA pathway factors

PIWI proteins and their bound PIWI-interacting RNAs (piRNAs) form the core of a gonad-specific small RNA silencing pathway that protects the animal genome against the deleterious activity of transposable elements. Recent studies linked the piRNA pathway to TUDOR biology as TUDOR domains of various proteins bind symmetrically methylated Arginine residues in PIWI proteins. We systematically analysed the Drosophila TUDOR protein family and identified four previously not characterized TUDOR domain-containing proteins (CG4771, CG14303, CG11133 and CG31755) as essential piRNA pathway factors. We characterized CG4771 (Vreteno) in detail and demonstrate a critical role for this protein in primary piRNA biogenesis. Vreteno physically and/or genetically interacts with the primary pathway components Piwi, Armitage, Yb and Zucchini. Vreteno also interacts with the Tdrd12 orthologues CG11133 (Brother of Yb) and CG31755 (Sister of Yb), which are essential for the primary piRNA pathway in the germline and probably replace the function of the related but soma-specific factor Yb.

LC/MS analysis of stratum corneum lipids: ceramide profiling and discovery

Ceramides (CERs) in the upper layer of the skin, the stratum corneum (SC), play a key role in the skin barrier function. In human SC, the literature currently reports 11 CER subclasses that have been identified. In this paper, a novel quick and robust LC/MS method is presented that allows the separation and analysis of all known human SC CER subclasses using only limited sample preparation. Besides all 11 known and identified subclasses, a 3D multi-mass chromatogram shows the presence of other lipid subclasses. Using LC/MS/MS with an ion trap (IT) system, a Fourier transform-ion cyclotron resonance system, and a triple quadrupole system, we were able to identify one of these lipid subclasses as a new CER subclass: the ester-linked ω-hydroxy fatty acid with a dihydrosphingosine base (CER [EOdS]). Besides the identification of a new CER subclass, this paper also describes the applicability and robustness of the developed LC/MS method by analyzing three (biological) SC samples: SC from human dermatomed skin, human SC obtained by tape stripping, and SC from full-thickness skin explants. All three biological samples showed all known CER subclasses and slight differences were observed in CER profile.

The effect of decreasing renal function on lipoprotein profiles

Progressive chronic kidney disease (CKD) is accompanied by dyslipidemia that is characterized by increased concentrations of intact and partially metabolized ApoB and ApoC-III-containing triglyceride-rich lipoproteins in very low-density lipoprotein, intermediate density lipoprotein (IDL) and low-density lipoprotein. The purpose of the present study was to characterize the distribution of individual discrete lipoprotein subclasses in relation to the glomerular filtration rate (GFR) in nondiabetic CKD subjects. Fifty-one subjects (33 patients with CKD and 18 asymptomatic subjects) with GFR ranging from 12 to 120 mL/min were studied. Individual ApoA- and ApoB-containing lipoprotein subclasses (Lp) were determined in plasma by sequential immunoaffinity chromatography and subsequent determination of apolipoprotein composition by electroimmunoassays. GFR was measured as plasma clearance of iohexol or (51)Cr-ethylenediaminetetraacetic acid. There were no changes in concentrations of ApoA-containing lipoproteins with decreasing GFR. The levels of ApoB-containing lipoproteins increased significantly with decreasing GFR. There was a moderate increase of cholesterol-rich LpB and a 3-fold increase of ApoB- and ApoC-III-containing lipoproteins in subjects in the two lowest quintiles of GFR. This was accompanied by a significant increase of plasma ApoC-III. Reduced renal function is associated with a complex alteration of the lipoprotein profile that is predominantly characterized by increased concentrations of triglyceride-rich lipoprotein subclasses containing both ApoB and ApoC-III.

FcγRIV deletion reveals its central role for IgG2a and IgG2b activity in vivo

Cellular Fcγ receptors are essential for IgG-dependent effector functions in vivo. There is convincing evidence that selective activating Fcγ receptors are responsible for the activity of individual IgG subclasses. Thus, IgG1 activity is absent in FcγRIII-deficient mice, and several studies suggest that the activity of the most potent IgG subclasses, IgG2a and IgG2b, might be dependent on either individual or a combination of activating FcγRs. To study the role of individual activating FcγRs for IgG subclass activity, we generated an FcγRIV-deficient mouse and showed that a variety of IgG2a- and IgG2b-dependent effector functions are impaired in the absence of this activating Fc receptor in models of autoimmunity and antibody-dependent cellular cytotoxicity.

High-density lipoprotein heterogeneity and function in reverse cholesterol transport

HDL is a cardioprotective lipoprotein, at least in part, because of its ability to mediate reverse cholesterol transport (RCT). It is becoming increasingly clear that the antiatherogenic effects of HDL are not only dependent on its concentration in circulating blood but also on its biological 'quality'. This review summarizes our current understanding of how the biological activities of individual subclasses of HDL particles contribute to overall HDL performance in RCT. Recent work indicates that apolipoprotein A-I-containing nascent HDL particles are heterogeneous and that such particles exert different effects on the RCT pathway. RCT from macrophages has been examined in detail in mice and the roles of plasma factors (lecithin-cholesterol acyltransferase, cholesterol ester transfer protein, phospholipid transfer protein) and cell factors (ATP-binding cassette transporter A1, ATP-binding cassette transporter G1, scavenger receptor class B type 1) have been evaluated. Manipulation of such factors has consistent effects on RCT and atherosclerosis, but the level of plasma HDL does not reliably predict the degree of RCT. Furthermore, HDL cholesterol or apolipoprotein A-I levels do not necessarily correlate with the magnitude of cholesterol efflux from macrophages; more understanding of the contributions of specific HDL subspecies is required. The antiatherogenic quality of HDL is defined by the functionality of HDL subspecies. In the case of RCT, the rate of cholesterol movement through the pathway is critical and the contributions of particular types of HDL particles to this process are becoming better defined.

Sex and Ethnic Disparities in High-Density Lipoprotein Subclasses∗

Synopsis: Several epidemiological studies have shown race and sex differences in conventional lipoprotein parameters. Descriptive studies on these differences in novel lipid subfractions, high-density lipoprotein (HDL) subclasses in particular, are very scant. Previous studies were performed only on biracial groups and in high-risk populations. Purpose: To determine the variances of the HDL subfractions in an ethnically diverse healthy adult population and to ascertain their impact on cardiovascular outcomes. Methods: Multi-Ethnic study of Atherosclerosis (MESA) is a population based study (n = 6814) of white (38%), black (28%), Chinese (22%), and Hispanic (12%) subjects, aged 45–84 years, with no self-reported cardiovascular disease. This is a post-hoc analysis of the NHLBI limited access dataset of MESA subjects who had data on lipid subclasses available (n = 6697). Individual lipoprotein subclasses were measured on frozen plasma specimens (−70 °C) using nuclear magnetic resonance spectroscopy. The end points analyzed were all-cause mortality, all CVD events and composite cardiovascular events. Chinese were arbitrarily selected as a reference cohort (lowest cardiovascular event rate). Multivariate analysis of variance was used to adjust for age, body mass index, hypertension, diabetes, any lipid-lowering medication and smoking. Results: Men had a greater incidence of cardiovascular events compared with women. Similarly, white subjects had more events compared with the other ethnic groups. The distribution of outcomes and the HDL subclasses across the various groups is detailed in the figure. Women had increased levels of HDL cholesterol and total HDL particles as well as significantly higher levels of large and medium HDL particles compared to men. Chinese subjects had greater levels of small HDL among all the racial groups. HDL size was greater among African-American subjects, and they had greater levels of large HDL compared with the other groups. Overall, interpretation of the HDL subclass distribution pattern reveals that the concentration of small HDL particles was inversely related to the number of cardiovascular outcomes across all the different ethnic groups. Conclusions: There were clear sex and race differences in HDL subclasses in this multiethnic cohort. These differences might provide a different atherogenic profile that is not apparent in a standard lipid panel. The current analysis might suggest a potential protective effect of small HDL on cardiovascular events.

Functional linkage as a direction for studies in oxidative stress: α-adrenergic receptorsThis review is one of a selection of papers published in a Special Issue on Oxidative Stress in Health and Disease.

The alpha-adrenergic receptors (adrenoceptors) are activated by the endogenous agonists epinephrine and norepinephrine. They are G protein-coupled receptors that may be broadly classified into alpha1 (subclasses alpha1A, alpha1B, alpha1D) and alpha2 (subclasses alpha2A, alpha2B, alpha2C). The alpha1-adrenoceptors act by binding to G(alpha)q subunits of the G proteins, causing activation of phospholipase C (PLC). PLC converts phosphatidylinositol 4,5-bisphosphate into inositol trisphosphate (IP3) and diacylglycerol (DAG), which have downstream effects on cytosolic Ca2+ concentration. The alpha2-adrenoceptors bind to G(alpha)i thus inhibiting adenylyl cyclase and decreasing cAMP levels. DAG alters protein kinase C activity and cAMP activates protein kinase A. The downstream pathways of the two receptors may also interact. Activation of alpha1- and alpha2-adrenoceptors in vascular smooth muscle results in vasoconstriction. However, the densities of individual receptor subclasses vary between vessel beds or between vessels of various sizes within the same bed. In vasculature, the densities of adrenoceptor subclasses differ between conduit arteries and arterioles. These differences, along with differences in coupling mechanisms, allow for fine regulation of arterial blood flow. This diversity is enhanced by interactions resulting from homo- and heterodimer formation of the receptors, metabolic pathways, and kinases. Reactive oxygen species generated in pathologies may alter alpha1- and alpha2-adrenoceptor cascades, change vascular contractility, or cause remodeling of blood vessels. This review emphasizes the need for understanding the functional linkage between alpha-adrenoceptor subtypes, coupling, cross talk, and oxidative stress in cardiovascular pathologies.

The relationship between high density lipoprotein subclass profile and plasma lipids concentrations

HDL particles posses multiple antiatherogenic activities and the identification and differentiation of individual HDL subclasses may be useful in documentation and understanding of metabolic changes of different HDL subclasses. The major plasma lipids exist and are transported in the form of lipoprotein complexes. Hence, alterations in plasma lipids levels can interfere with the composition, content, and distribution of plasma lipoprotein subclasses that affect atherosclerosis risk. The research review major discussed the relationship between plasma lipids levels and HDL subclasses distribution. The general shift toward smaller size of HDL particle size in HTG, HCL and MHL subjects, and the changes were more prominent with the elevation of TG and TC levels which imply that HDL maturation might be abnormal and RCT pathway might be weaken, and these changes were more seriously in MHL subjects. Plasma contents of small sized HDL particles significantly higher, whereas those of large sized HDL particles were significantly lower with elevation of TG/HDL-C and TC/HDL-C ratios. Increased in the TC/HDL-C ratio alone did not influence the distributions of HDL subclasses significantly when the TG/HDL-C ratio was low (TG/HDL-C ≤ 2.5). Hence, the TG/HDL-C ratio might be more sensitive to reflect the alteration of HDL subclass distribution than the TC/HDL-C ratio. In LDL-C/HDL-C ≤ 2.3 group, the pattern of distribution in HDL subclass was in agreement with the normolipidemic subjects. Moreover, considering the relative ease of measuring TC/HDL-C, TG/HDL-C and LDL-C/HDL-C ratios, as opposed to measuring HDL subclasses, these 3 ratios together may be a good indicator of HDL subclass distribution. The protective effect of increased apoA-I levels against the reduction of HDL2b caused by elevated TG concentration. On one hand, plasma HDL-C and apoA-I appear to play a coordinated role in the assembly of HDL particles and the determination of their contents among the total subjects. On the other hand, the apoA-I level might be a more powerful factor than HDL-C to influence the distribution of HDL subclasses in hyperlipidemic subjects. At the same time, from point of HDL subclasses distribution, the plasma lipids, apos concentrations and apos ratios should be considered while assessing the CHD risk. Abnormality of HDL subclasses distribution may result in accelerated atherosclerosis, therapeutic normalization of attenuated antiatherogenic HDL function in terms of both particle number and distribution of HDL particles is the target of innovative pharmacological approaches to large-sized HDL particles rising, including enhanced apoA-I levels.

Lipid, fatty acid and tocol distribution of coriander fruit's different parts

High amounts of neutral lipids (NL) were found (95.65% of total lipids) in whole fruit oil, while glycolipids (GLs) occurred at high levels in pericarp oil (73.21% of total lipids). Triacylglycerol was found to be the principal lipid fraction of NL which formed 93% in seed and whole fruit. However, monoacylglycerol constituted the major fraction of NL in pericarp (34.5%). At least two GLs and five phospholipids (PL) were identified. The GL composition of the pericarp is characterized by monogalactosylacylglycerol as the major fraction with a percentage of 53.39% of total lipids. The major individual PL subclasses were phosphatidylcholine followed by phosphatidylethanolamine in seed and whole fruit. However, the PL were not detected in pericarp oil. The principal fatty acids identified in most lipid classes were petroselinic acid (C18:1 n − 12), linoleic acid (C18:2 n − 6), palmitic (C16:0) and oleic acid (C18:1 n − 9). The total tocopherol and tocotrienol (tocol) contents were 27.78 mg/100 g oil in whole fruit, 26.42 mg/100 g oil in seed and 5.36 mg/100 g oil in pericarp. Fruit and seed oils were characterized by a high amount of γ-tocotrienol with 19.56 mg/100 g oil. However, α-tocopherol (1.82 mg/100 g oil) was found to be the tocol marker in pericarp oils. The results are important as an indication of the potentially economical utility of Coriandrum sativum L. seed oil as a new source of PL.

Antihypertensive Agents and Risk of Parkinson’s Disease, Essential Tremor and Dementia: A Population-Based Prospective Study (NEDICES)

Background: Recent interest in antihypertensive agents, especially calcium channel blockers, has been sparked by the notion that these medications may be neuroprotective. A modest literature, with mixed results, has examined whether these medications might lower the odds or risk of Parkinson’s disease (PD) or dementia. There are no data for essential tremor (ET). Objective: To examine the association between antihypertensive use (defined broadly and by individual subclasses) and ET, PD and dementia. For each disorder, we used cross-sectional data (association with prevalent disease) and prospective data (association with incident disease). Methods: Prospective population-based study in Spain enrolling 5,278 participants at baseline. Results: Use of antihypertensive medications (aside from β-blockers) was similar in prevalent ET cases and controls. Baseline use of antihypertensive agents was not associated with reduced risk of incident ET. Antihypertensive medication use was not associated with prevalent or incident PD. Calcium channel blocker use was marginally reduced in prevalent dementia cases (OR_adjusted = 0.63, p = 0.06) but was not associated with reduced risk of incident dementia (RR_adjusted = 1.02, p = 0.95). Conclusions: We did not find evidence of a protective effect of antihypertensive medications in these three neurodegenerative disorders.

Phospholipid composition of postmortem schizophrenic brain by 31P NMR spectroscopy

Cell membrane abnormalities due to changes in phospholipid (PL) composition and metabolism have been implicated in schizophrenia pathogenesis. That work has generally assessed membrane phospholipids from nonneural tissues such as erythrocytes and platelets. High-resolution (31)P NMR spectroscopy was used to characterize PLs of gray matter in postmortem brain for 20 schizophrenics, 20 controls, and 7 patients with other mental illnesses (psychiatric controls). Tissues from frontal, temporal, and occipital cortices were extracted with hexane-isopropanol, and (31)P NMR spectra were obtained in an organic-solvent system to resolve the major PL classes (based on headgroups) and subclasses (based on linkage at the sn - 1 position). Surprisingly, repeated-measures multivariate analysis of variance revealed no overall differences among the groups. There were no significant differences (P < .05) among the three groups for any individual PL subclass, including lysophospholipids. The sum of all phosphatidylethanolamine headgroups was significantly lower for schizophrenics than for controls or psychiatric controls in the frontal cortex. The present results are minimally correlated with previous results for aqueous PL metabolites on these same samples. The metabolite changes measured by in vivo (31)P MRS in schizophrenia do not appear to reflect PL concentration changes. The present results offer very little support for the phospholipid hypothesis of schizophrenia.

In vivo enzymatic modulation of IgG glycosylation inhibits autoimmune disease in an IgG subclass-dependent manner

IgG antibodies are potent inducers of proinflammatory responses. During autoimmune diseases such as arthritis and systemic lupus erythematosus, IgG autoantibodies are responsible for the chronic inflammation and destruction of healthy tissues by cross-linking Fc receptors on innate immune effector cells. The sugar moiety attached to the asparagine-297 residue in the constant domain of the antibody is critical for the overall structure and function of the molecule. Removal of this sugar domain leads to the loss of the proinflammatory activity, suggesting that in vivo modulation of antibody glycosylation might be a strategy to interfere with autoimmune processes. In this work, we investigated whether removal of the majority of the IgG-associated sugar domain by endoglycosidase S (EndoS) from Streptococcus pyogenes is able to interfere with autoimmune inflammation. We demonstrate that EndoS injection efficiently removes the IgG-associated sugar domain in vivo and interferes with autoantibody-mediated proinflammatory processes in a variety of autoimmune models. Importantly, however, we observed a differential impact of EndoS-mediated sugar side chain hydrolysis on IgG activity depending on the individual IgG subclass.

Describing the geographic spread of dengue disease by traveling waves

Dengue is a human disease transmitted by the mosquito Aedes aegypti. For this reason geographical regions infested by this mosquito species are under the risk of dengue outbreaks. In this work, we propose a mathematical model to study the spatial dissemination of dengue using a system of partial differential reaction–diffusion equations. With respect to the human and mosquito populations, we take into account their respective subclasses of infected and uninfected individuals. The dynamics of the mosquito population considers only two subpopulations: the winged form (mature female mosquitoes), and an aquatic population (comprising eggs, larvae and pupae). We disregard the long-distance movement by transportation facilities, for which reason the diffusion is considered restricted only to the winged form. The human population is considered homogeneously distributed in space, in order to describe localized dengue dissemination during a short period of epidemics. The cross-infection is modeled by the law of mass action. A threshold value as a function of the model’s parameters is obtained, which determines the rate of dengue dissemination and the risk of dengue outbreaks. Assuming that an area was previously colonized by the mosquitoes, the rate of disease dissemination is determined as a function of the model’s parameters. This rate of dissemination of dengue disease is determined by applying the traveling wave solutions to the corresponding system of partial differential equations.

Spatial Regulation of nanos Is Required for Its Function in Dendrite Morphogenesis

Spatial control of mRNA translation can generate cellular asymmetries and functional specialization of polarized cells like neurons. A requirement for the translational repressor Nanos (Nos) in the Drosophila larval peripheral nervous system (PNS) implicates translational control in dendrite morphogenesis [1]. Nos was first identified by its requirement in the posterior of the early embryo for abdomen formation [2]. Nos synthesis is targeted to the posterior pole of the oocyte and early embryo through translational repression of unlocalized nos mRNA coupled with translational activation of nos mRNA localized at the posterior pole [3, 4]. Abolishment of nos localization prevents abdominal development, whereas translational derepression of unlocalized nos mRNA suppresses head/thorax development, emphasizing the importance of spatial regulation of nos mRNA [3, 5]. Loss and overexpression of Nos affect dendrite branching complexity in class IV dendritic arborization (da) neurons, suggesting that nos also might be regulated in these larval sensory neurons [1]. Here, we show that localization and translational control of nos mRNA are essential for da neuron morphogenesis. RNA-protein interactions that regulate nos translation in the oocyte and early embryo also regulate nos in the PNS. Live imaging of nos mRNA shows that the cis-acting signal responsible for posterior localization in the oocyte/embryo mediates localization to the processes of class IV da neurons but suggests a different transport mechanism. Targeting of nos mRNA to the processes of da neurons may reflect a local requirement for Nos protein in dendritic translational control.

Differences in discrimination of eye and mouth displacement in autism spectrum disorders

Individuals with Autism Spectrum Disorders (ASD) have been found to have impairments in some face recognition tasks [e.g., Boucher, J., & Lewis, V. (1992). Unfamiliar face recognition in relatively able autistic children. Journal of Child Psychology and Psychiatry, 33, 843–859.], and it has been suggested that this impairment occurs because these individuals do not spontaneously attend to the eyes [e.g., Pelphrey, K. A., Sasson, N. J., Reznick, J. S., Paul, G., Goldman, B. D., & Piven, J. (2002). Visual scanning of faces in autism. Journal of Autism and Developmental Disorders, 32, 249–261.], or attend selectively to the mouth [e.g., Langdell, T. (1978). Recognition of faces—approach to study of autism. Journal of Child Psychology and Psychiatry and Allied Disciplines, 19, 255–268; Joseph, R. M., & Tanaka J. (2003). Holistic and part-based face recognition in children with autism. Journal of Child Psychology and Psychiatry, 44, 529–542.]. Here, we test whether the eyes or the mouth are attended to preferentially by 16 males with ASD and 19 matched controls. Participants discriminated small spatial displacements of the eyes and the mouth. If the mouth region were attended to preferentially by individuals with ASD, we would expect ASD observers to be better at detecting subtle changes in mouth than eye displacements, relative to controls. Further, following Barton [Barton, J. J. S., Keenan, J. P., & Bass, T. (2001). Discrimination of spatial relations and features in faces: Effects of inversion and viewing duration. British Journal of Psychology, 92, 527–549.], we would expect to see differences in inversion effects as a function of feature manipulation between ASD and control groups. We found that individuals with ASD performed significantly differently than controls for the eye, but not the mouth, trials. However, we found no difference in inversion effects between the two groups of observers. Furthermore, we found evidence of distinct subclasses of individuals with ASD: those who performed normally, and those who were impaired. These results suggests that typical individuals are better able to make use of information in the eyes than some individuals with ASD, but that there is no clear autism “advantage” in the use of information in the mouth region.

Lipid abnormalities in succinate semialdehyde dehydrogenase ( Aldh5a1− /− ) deficient mouse brain provide additional evidence for myelin alterations

Earlier work from our laboratory provided evidence for myelin abnormalities (decreased quantities of proteins associated with myelin compaction, decreased sheath thickness) in cortex and hippocampus of Aldh5a1 − /− mice, which have a complete ablation of the succinate semialdehyde dehydrogenase protein [E.A. Donarum, D.A. Stephan, K. Larkin, E.J. Murphy, M. Gupta, H. Senephansiri, R.C. Switzer, P.L. Pearl, O.C. Snead, C. Jakobs, K.M. Gibson, Expression profiling reveals multiple myelin alterations in murine succinate semialdehyde dehydrogenase deficiency, J. Inher. Metab. Dis. 29 (2006) 143–156]. In the current report, we have extended these findings via comprehensive analysis of brain phospholipid fractions, including quantitation of fatty acids in individual phospholipid subclasses and estimation of hexose-ceramide in Aldh5a1 − /− brain. In comparison to wild-type littermates ( Aldh5a1 +/+ ), we detected a 20% reduction in the ethanolamine glycerophospholipid content of Aldh5a1 − /− mice, while other brain phospholipids (choline glycerophospholipid, phosphatidylserine and phosphatidylinositol) were within normal limits. Analysis of individual fatty acids in each of these fractions revealed consistent alterations in n-3 fatty acids, primarily increased 22:6n-3 levels (docosahexaenoic acid; DHA). In the phosphatidyl serine fraction there were marked increases in the proportions of polyunsaturated fatty acids with corresponding decreases of monounsaturated fatty acids. Interestingly, the levels of hexose-ceramide (glucosyl- and galactosylceramide, principal myelin cerebrosides) were decreased in Aldh5a1 − /− brain tissue (one-tailed t test, p = 0.0449). The current results suggest that lipid and myelin abnormalities in this animal may contribute to the pathophysiology.

Plasma Homocysteine Concentration in Patients With Poor or Good Coronary Collaterals

Elevated plasma homocysteine (Hcy) concentrations are associated with an increased risk of vascular disease. Hcy is known to inhibit endothelial cell proliferation in vitro. The purpose of the present study was to investigate the role of plasma Hcy concentrations on development of collateral circulation in single-vessel chronic total occlusion. Collateral status was determined by Rentrop's classification. Of 817 patients, 56 cases of pure single-vessel chronic total occlusion were studied. Plasma Hcy concentrations in patients with single-vessel total coronary occlusion were higher compared with controls (17.3 +/-12.6 micromol/L vs 10.9+/-4.9 micromol/L, p=0.015). There was no significant difference in plasma Hcy concentrations of the good and poor collateral groups (17.2+/-13.7 micromol/L vs 15.3+/-9.3 micromol/L, p=0.834). Plasma Hcy concentrations in individual Rentrop subclasses 0, 1, 2 and 3 were as follows: 15.9 +/-9.1, 16.3+/-12.4, 17.1+/-14.1 and 20.1+/-13.5 micromol/L (p=0.893). There was a positive linear correlation between Rentrop subclass and angina pectoris duration (r=0.41, p=0.003). Angina pectoris duration was the only independent variable affecting the development of coronary collaterals in the present study (odds ratio [confidence interval]: 1.85 [1.12-2.91], p=0.014). Patients with single-vessel chronic total occlusion had higher plasma Hcy concentrations than controls, but similar Hcy concentrations when compared according to the presence of poor or good coronary collaterals. There is a lack of association between plasma Hcy concentration and coronary collateral status in the current study.

Hypogalactosylation of Salivary and Gingival Fluid Immunoglobulin G in Patients With Advanced Periodontitis

Altered glycosylation of immunoglobulin G (IgG) has been found to affect certain immunological activities of IgG and to correlate with increased inflammation in various disease states. This work deals with the changes in distribution and galactosylation of IgG subclasses present in saliva and gingival crevicular fluid (GCF) of patients with initial and advanced periodontitis and of normal controls. IgG subclasses were quantified by dot-blot assay, and the degrees of expression of galactose in the total IgG and its individual subclasses were estimated by lectin immunoblot assay after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) separation of IgG and by capture enzyme-linked immunosorbent assay (ELISA), using biotinylated Ricinus communis (RCA-I) and Bandeiraea simplicifolia (BS-II) lectins. The distribution of IgG subclasses in both fluids was found to differ in periodontal patients compared to normal controls. In the periodontitis saliva and GCF, the IgG2 subclass dominated quantitatively, regardless of periodontal status. However, galactose was found to be expressed in IgG heavy chains in normal controls and patients with initial periodontitis but not, or at barely detectable levels, in advanced periodontitis. The results suggest that the shift toward hypogalactosylated glycoforms may occur during the process of inflammation of the gingiva.