Decreases in Plasma Aβ1-40 Levels with Aging in Non-Demented Elderly with ApoE-ε4 Allele

This report examines plasma amyloid proteins A40 and A42 and apolipoprotein E (apoE) levels and their relationships with age in non-demented older adults with (N = 32) or without the apoE-4 allele (N = 94). A levels did not differ between the groups whereas the 4 allele was associated with a significant reduction in plasma apoE. In subjects with the 4 allele, increasing age was associated with significant reduction in plasma A40. Subjects without the 4 allele showed a significant positive correlation between A40 and A42 levels. There was also a significant correlation between plasma A40 and apoE levels in all subjects.     

Association of polymorphic markers of the lipid metabolism genes with diabetic polyneuropathy in type 1 diabetes mellitus

A possible association of the polymorphic markers 2/3/4 of the apolipoprotein E gene (APOE) and I /D of the apolipoprotein B gene (APOB) with diabetic polyneuropathy (DPN) was analyzed in patients with type 1 diabetes mellitus (T1DM) with (N=86) or without (N=94) clinical signs of DPN. The two groups did not differ significantly in allele and genotype frequencies of the 2/3/4 polymorphic marker of the APOE gene. Analysis of the allele and genotype frequency distributions of the I/D polymorphic marker of the APOB gene showed that risk of DPN is higher in carriers of allele I or genotype I/I (OR=1.66 and 2.01, respectively) and lower in carriers of allele D (OR=0.60). The results implicate the APOB gene, which codes for one of the major components of the lipid metabolism system, in DPN development in patients with T1DM.__________Translated from Molekulyarnaya Biologiya, Vol. 39, No. 2, 2005, pp. 230–234.Original Russian Text Copyright © 2005 by Voronko, Yakunina, Strokov, Lavrova, Nosikov.     

Effect of cell turgor on hydraulic conductivity and elastic modulus of Elodea leaf cells

Water relation parameters of leaf cells of the aquatic plant Elodea densa have been measured using the pressure probe. For cells in both the upper and lower epidermis it was found that the elastic modulus () and the hydraulic conductivity (Lp) were dependent on cell turgor (P). Lp was (7.8±5.5)·10^-7 cm s^-1 bar^-1 (mean±SD; n=22 cells) for P>4 bar in cells of the upper epidermis and was increasing by a factor of up to three for P0 bar. No polarity of water movement or concentration dependence of Lp was observed. For cells of the lower epidermis the Lp-values were similar and the hydraulic conductivity also showed a similar dependence on turgor. No wall ingrowth or wall labyrinths (as in transfer cells) could be found in the cells of the lower epidermis. The elastic modulus () of cells of the upper epidermis could be measured over the whole pressure range (P=0–7 bar) by changing the osmotic pressure of the medium. increased linearly with increasing turgor and ranged between 10 and 150 bar. For cells of the lower epidermis the dependence of on P was similar, although the pressure dependence could not be measured on single cells. The Lp-values are compared with literature data obtained for Elodea by a nuclear magnetic resonance (NMR)-technique. The dependence of Lp on P is discussed in terms of pressure dependent structural changes of the cell membranes and interactions between solute and water transport.Abbreviations P cell turgor pressure - Lp hydraulic conductivity - volumetric elastic modulus - T _1/2 half-time of water exchange of individual cell     

Polymorphism of the Apolipoprotein E Gene and Risk of Myocardial Infarction

The apolipoprotein E (ApoE) gene polymorphism resulting from nucleotide substitutions in exon 4 was analyzed in Russian and Tatar patients with myocardial infarction (MI) from Bashkortostan. Alleles 2, 3, and 4 were identified by PCR. The genotype frequency distribution proved to be age-dependent in healthy Russians, genotype 2/3 increasing in frequency in subjects over 45. Russians who suffered MI under 45 had lower frequencies of genotype E3/3 (50.00% vs. 75.47% in controls of the same age, = 0.013, OR = 0.33) and allele 3 (72.12% vs. 85.85%, = 0.020, OR = 0.43) and a higher frequency of allele 4 (22.12% vs. 10.38%, = 0.030, OR = 2.45). Russians who suffered MI complicated by cardiogenic shock (CS) had a significantly higher frequency of genotype 3/4 and lower frequencies of genotype 3/3 and allele 3 as compared with MI patients without CS. In Tatars, genotype 4/4 occurred at a frequency of 14.29% in patients who suffered MI under 45, and was not detected in healthy subjects of the same age ( = 0.024, OR = 17.85). Thus, the ApoE polymorphism was associated with higher risk of MI in Russians and Tatars under 45.     

Interaction of Apolipoprotein E ε 4 With Other Genetic and Non-Genetic Risk Factors in Late Onset Alzheimer Disease: Problems Facing the Investigator

The Apolipoprotein E4 allele (Apo-4) is the major susceptibility gene for late onset Alzheimer Disease (AD) but epidemiological data suggest that the effect of this allele is modified in different individuals by genetic or environmental factors. Age and head injury are major non-genetic factors modifying the Apo-4 risk. There is conflicting data as to whether alleles of other chaperon proteins (such as alpha-1-antichymotrypsin (ACT)) or Apo-4 receptors (such as the VDRL receptor) modify the Apo-4 risk for AD. We analyze problems posed by genetic association studies including those of multiple comparisons and selection of controls, the latter problem exacerbated by the wide variations in Apolipoprotein E allele frequencies observed in different groups and localities.     

Time delays in single species growth models

Summary A general model is considered for the growth of a single species population which describes the per unit growth rate as a general functional of past population sizes. Solutions near equilibrium are studied as functions of = 1/b, the reciprocal of the inherent per unit growth rate b of the population in the absense of any density constraints. Roughly speaking, it is shown that for large the equilibrium is asymptotically stable and that for small the solutions show divergent oscillations around the equilibrium. In the latter case a first order approximation is obtained by means of singular perturbation methods. The results are illustrated by means of a numerically integrated delay-logistic model.     

ε-caprolactam,a new powerful inducer for the formation of Rhodococcus rhodochrous J1 nitrilase

We found that -caprolactam is a new powerful inducer for the formation of Rhodococcus rhodochrous J1 nitrilase. When Rhodococcus rhodochrous J1 cells were cultivated at 28°C for 120 h in a nutrient medium supplemented with 0.5% (w/v) -caprolactam, an enormous amount of nitrilase was formed in the cells which corresponded to approximately 30% of all soluble protein. The level of -caprolactam in the culture broth barely decreased in the course of cultivation. -Butyrolactam and -valerolactam also caused effective induction. The induction of nitrilase formation by -caprolactam was also observed in some other Rhodococcus strains.     

Gender- and age-specific contributions of additional DNA sequence variation in the 5′ regulatory region of the <Emphasis Type="Italic">APOE</Emphasis> gene to prediction of measures of lipid metabolism

In the present study of 9,000 individuals representative of the general population, we have considered whether the addition of common single nucleotide polymorphisms (SNPs) in the promoter region of Apolipoprotein E (APOE) improve the statistical explanation of variation in lipid traits and test the hypothesis that the estimated genotype effects are independent of factors indexed by gender and age. To address these questions, we have asked, for each gender and for each 20-year age strata (young: 20–39 years; middle-aged: 40–59 years; old: 60–79 years; very old: 80–100 years), how much trait variation is associated with the traditional 2, 3, and 4 allelic variations defined by the g.2059TC and g.2197CT SNPs in the fourth exon of the APOE gene, and how much additional trait variation is associated with genotypes defined by combining the g.2059TC and g.2197CT SNPs with one, two, or three promoter SNPs. Our study demonstrates that the pleiotropic effects of genotype variation defined by the traditional 2, 3, and 4 alleles on five plasma measures of lipid metabolism manifest differently in women and men and change significantly during the life cycle for high-density lipoprotein cholesterol in women. Multi-site genotypes defined by adding SNPs located in the 5 promoter region to the traditional g.2059TC and g.2197CT SNPs doubled the estimate of genetic variance of high-density lipoprotein and apolipoprotein Al in middle-aged females.     

Apolipoprotein E phenotypes and hyperlipidemia

Summary Apolipoprotein E phenotypes were determined in 361 patients with hyperlipidemia and in controls. The E2 isoform was significantly more frequent in the group of hyperlipidemics (P<0.0005). This was not due to a higher frequency of E-2/2 homozygotes with type III hyperlipoproteinemia, but rather to a significantly higher frequency of E2 heterozygotes (P<0.0005). Subgrouping of hyperlipidemics into patients with a) hypertriglyceridemia, b) hypercholesterolemia and c) mixed hyperlipidemia revealed i) that isoform E2 was significantly more frequent in patients with hypertriglyceridemia (0.001>P>0.005), ii) that isoform E4 was significantly more frequent in patients with hypercholesterolemia (0.01>P>0.005) and iii) that isoforms E2 (P>0.005) and E4 (0.05>P>0.025) were both more frequent in patients with mixed hyperlipidemia. Roughly 20% of patients with mixed hyperlipidemia had one of the rare phenotypes E-4/4,-4/2 or-2/2. We conclude that alleles 2 and 4 both contribute to the susceptibility for, and/or phenotypic expression of hyperlipidemia. Whereas the gene 2 seems to exert its influence on plasma lipoproteins by an abnormal gene product (E2) that has reduced binding activity to lipoprotein receptors, the mechanism underlying the association of the 4 gene with hyperlipidemia is presently unclear.     

Protein kinase C expression and subcellular distribution in chronic myocardial ischemia: Comparison of two different canine models

We studied protein kinase C (PKC) isozyme expression and activity distribution in two models of chronically ischemic canine myocardium: (1) single vessel obstruction (SVO), produced by tight stenosis of LAD followed by preconditioning and acute ischemia (40 min); (2) three vessel obstruction (3VO), produced by LAD-stenosis and gradual occlusion of right coronary artery and left circumflex. In both models after 8 weeks of chronic ischemia the dogs were either sacrificed or had PTCA of the LAD with a follow up of another 4 weeks. Control dogs were sham operated. PKC activity was measured in subcellular fractions of tissue samples from anterior and posterior regions in the presence of histone and -[³²P]-ATP. PKC isozymes were detected by Western blotting. All regions perfused by the obstructed coronaries were dysfunctional at 8 weeks when compared to baseline, with improvement of anterior wall function after PTCA of LAD. PKC activity was elevated in the membrane fraction of SVO, but unchanged in the 3VO model. PKCs , , and prevailed in cytosol fraction of the controls (cytosol/membrane ratios were ± 3.34, 1.38 and 4.56 for , and , respectively), consistent with PKC activity distribution, while was not detected. There was no significant difference between the groups concerning the relative membrane amount of the isozymes. PKCs and were decreased in the cytosol fraction of both models at 8 weeks (for anterior region, by 56 and 57% in SVO and by 49 and 46% in 3VO, respectively) without there being any differences between anterior and posterior regions, and were low also in the PTCA group. PKC distribution however varied between the two models. The amount of PKC isozyme was downregulated by 45% after 8 weeks of chronic ischemia and returned towards the control values after PTCA in the anterior region of SVO, while it did not change in anterior wall after 8 weeks in 3VO but was significantly decreased (by 47%) in posterior region after PTCA. In conclusion, our results suggest modified PKC signalling in chronically ischemic canine myocardium.     

Genetic Association between the Apolipoprotein E (APOE) Gene and Different Forms of Alzheimer's Disease

Allele 4of the apolipoprotein E (APOE) gene is associated with higher risk for family or sporadic Alzheimer's disease (AD) in many, though not all, ethnic groups. The APOEallele and genotype frequency distributions were evaluated in 207 AD patients without vascular disorders, 62 AD patients with vascular disorders (combined AD), and 206 control individuals (ethnic Russians from the Russian population). The frequency of allele 4in patients with early-onset and late-onset AD was three times higher than in controls (P< 0.000001). The increase in the frequency of 4in mixed dementia cases over controls was somewhat less but still significant (P= 0.0019). Relative risk of AD in carriers of allele 4was five times higher than in carriers of alleles 2and 3(P< 0.000001). Allele 2showed evidence of a protective effect in the early-onset AD group (P= 0.015). These results suggest that APOEallele 4is a universal factor of early-onset, late-onset, and combined AD in ethnic Russians from Russia.     

Modeling the growth curve for Spirulina (Arthrospira) maxima, a versatile microalga for producing uniformly labelled compounds with stable isotopes

The paper presents a five-phase model to describe batch culture of Spirulina maxima under limitations of light and nutrients nitrogen andsulfur. The general equation for the exponential, linear, decelerating andstationary phases of the growth curve took into account that (i) the specificgrowth rate was proportional to the local light intensity in thephotobioreactor; (ii) light attenuation was due to cell's absorption andreflection and observed the Lambert-Beer's law with a total absorptioncoefficient (_T) that was the sum of absorption coefficient(_a) and reflection coefficient (_r); (iii) thecomposition of the alga and its absorption _a changed withtime and (iv) the specific growth rate was influenced by nutrients ofnitrogen and sulfur in the culture medium according to a Monod's law.Two successive equations describing the death phase were proposed basedon the hypothesis that the death rate accelerated with the %PSC until itreached its maximum. From that point the %PSC decreased and the deathrate reduced. Our model fitted very well the cultures grown in the photobioreactor developed in our laboratory.     

Substitutions of the Conserved Thr42 Increased the Roles of the ε-Subunit of Maize CF1 as CF1 Inhibitor and Proton Gate

The conserved residue Thr42 of -subunit of the chloroplast ATP synthase of maize (Zea mays L.) was substituted with Cys, Arg, and Ile, respectively, through site-directed mutagenesis. The over-expressed and refolded -proteins were purified by chromatography on DEAE-cellulose and FPLC on mono-Q column, which were as biologically active (inhibiting Ca²⁺-ATPase activity and blocking proton gate) as the native subunit isolated from chloroplasts. The T42C and T42R showed higher inhibitory activities on the soluble CF₁(–) Ca²⁺-ATPase than the WT. The T42I inhibited the Ca²⁺-ATPase activity of soluble CF₁ and restored photophosphorylation activity of membrane-bound CF₁ deficient in the most efficiently. Far-ultraviolet CD spectra showed that the portions of -helix and -sheet structures of the three mutants were somewhat different from WT. Thus the conserved residue Thr42 may be important for maintaining the structure and function of the -subunit and the basic functions of the -subunit as far as an inhibitor of Ca²⁺-ATPase and the proton gate are related.     

Red fluorescence spectra as a new means of determining the rate of damage to photosynthesis apparatus in plants caused by stress

A new method is presented for determining the rate of damage to photosynthesis apparatus efficiency caused by stress using the red fluorescence spectra of plant leaves. A direct connection was found between the position of the red fluorescence maximum _max and the photosynthesis apparatus efficiency . The method was tested on several examples and good results were obtained.     

The association of the human ε-globin gene with the nuclear matrix: a reconsideration

The association of the human -globin gene with the nuclear matrix was studied in erythroid and non-erythroid cell lines. Using a high salt method to prepare histone depleted nuclei we studied the association of variety of fragments covering a 7.8 kb region which contains the human -globin gene. We furthermore studied the association of a set of DNA fragments covering the 13 kb human G/A-globin gene domain, the 16 kb /-globin gene domain and the 10 kb -globin gene domain with the nuclear matrix of K562 and Raji cells. The results show that all fragments studied are easily released from the nuclear matrix, indicating no specific association.Summarizing our results we could say that a region starting 5.7 kb 5 to the human -globin gene and ending 4 kb 3 to the human -globin gene seems to contain no attachment sites with the nuclear matrix of both erythroid and non-erythroid cells.     

IgE heavy chain constant region genes in atopic dermatitis and senile erythroderma patients

By Southern hybridization using a genomic DNA fragment carrying a human IgE heavy chain constant region gene (C ) as a probe, we analyzed the organization of human C genes and their flanking regions in 23 atopic dermatitis and 6 senile erythroderma patients with elevated serum IgE levels, and 6 atopic dermatitis patients with normal IgE levels. On Barn HI, Hind III, and Eco RI digestions, we detected three hybridizable fragments containing three human C genes, C 1, C 2, and C 3, respectively, in all leukocyte DNAs. These fragments were almost identical in size among patients and healthy donors. Pst I digestion generated a genetic polymorphism. We, however, could find no correlation between this polymorphism and the disorders. It was concluded that among the patients and healthy donors, there was no marked difference in the organization of the functional C gene and its flanking region containing a class switch region. Our conclusion cannot rule out the presence of genetic abnormalities of this region in some atopic dermatitis patients which are not resolvable by our method. In the course of this study, we found a novel C -like gene in placenta DNA which differs from the three C genes commonly present in normal human DNA.     

Is There a Genetic Basis for the Deposition of β-Amyloid After Fatal Head Injury?

1. Alzheimer's disease is a heterogeneous disorder that may be caused by genetic or environmental factors or by a combination of both. Abnormalities in chromosomes 1, 14, and 21 have all been implicated in the pathogenesis of the early-onset form of the disease, while the 4 allele of the apolipoprotein E gene (on chromosome 19) is now recognized as a risk factor for early- and late-onset sporadic and familial Alzheimer's disease.2. The best-established environmental trigger for the disease is a head injury, based on epidemiological and neuropathological evidence. Approximately 30% of patients who die after a single episode of severe head injury show intracerebral deposition of -amyloid protein (A), a protein that is thought to be central to the pathogenesis of Alzheimer's disease.3. Recent studies have revealed an over-representation of the apoE 4 allele in those head-injured patients displaying A pathology, thus providing the first evidence for a link between a genetic susceptibility (apoE 4) and an environmental trigger (head injury) in the development of Alzheimer-type pathology.     

Kinetic comparison of caiman ε-crystallin and authentic lactate dehydrogenases of vertebrates

Kinetic comparison of -crystallins isolated from the avian and reptilian species and the authentic lactate dehydrogenases (LDHs) was undertaken in order to clarify the identities of these structural lens proteins in relation to their enzymatic activity. Caiman -crystallin similar to the previously characterized duck -crystallin appeared to possess a genuine and stable LDH activity as detected by nitro blue tetrazolium staining on polyacrylamide gels and conventional kinetic assays. Kinetic parameters for pyruvate,l-lactate, NAD⁺, and three structural analogues of the coenzyme in this -crystallin catalyzed reaction were also determined and compared. Despite the structural similarities between -crystallins and chicken heart LDH, differences in charge and kinetic properties have been revealed by native isozyme electrophoresis and kinetic analysis as examined by initial velocity and substrate inhibition studies. It is found that the kinetic data analyzed for caiman -crystallin were more fitted with a compulsory ordered Bi-Bi sequential mechanism similar to those for the authentic LDHs and duck -crystallin. Caiman -crystallin has for the first time been established as a heart-type LDH based on the kinetic analysis and comparison with the authentic heart- and muscle-type LDHs from pig and chicken.     

Polymorphisms of the apolipoprotein and angiotensin converting enzyme genes in young North Karelian patients with coronary heart disease

The genes encoding apolipoproteins (apos) A-I, B, C-III and E as well as that encoding the angiotensin converting enyzme (ACE) have been proposed as candidate genes for coronary heart disease (CHD). We determined the common polymorphisms of the apo genes, previously found to influence serum lipid levels at the population level, and the insertion/deletion polymorphism of the ACE gene, recently reported to reflect the risk of myocardial infarction, in 82 very young (mean, 41 years) North Karelian Finns with symptomatic CHD and 50 controls of similar age. Patients with familial hypercholesterolemia had been excluded from this material. None of the polymorphisms examined, including the apo A-I promoter MspI, apo C-III SstI and apo B XbaI restriction fragment polymorphisms, a common variation of apo E (2, 3 and 4 alleles) and an ACE insertion/deletion (I/D) polymorphism, was significantly associated with the risk of premature CHD. Patients with CHD had a higher mean serum LDL cholesterol/HDL cholesterol ratio than controls (3.15±1.30 vs 2.72±0.98, P < 0.05), but no significant associations between the common apo gene polymorphisms and serum lipid levels were disclosed in either group. It is possible that other genetic loci than those proposed to be associated with accelerated atherosclerosis may be more important as risk factors of symptomatic CHD at the age of 40 years.