With the aim to individuate alleles that may reflect a higher susceptibility to the disease, in the present study we analyzed the HLA allele frequency distribution in a group of 99 Italian patients ...affected by a severe or extremely severe form of COVID‐19. After the application of Bonferroni's correction for multiple tests, a significant association was found for HLA‐DRB1*15:01, ‐DQB1*06:02 and ‐B*27:07, after comparing the results to a reference group of 1017 Italian individuals, previously typed in our laboratory. The increased frequencies observed may contribute to identify potential markers of susceptibility to the disease, although controversial results on the role of single HLA alleles in COVID‐19 patients have been recently reported.
A common variant in the promoter of the human stromelysin gene, causing reduced enzyme expression, has been associated with the progression of coronary atherosclerosis. On the other hand, increased ...stromelysin activity may promote plaque rupture. The present study was undertaken to investigate the relationship between the genetic variation in the human stromelysin gene promoter and common carotid geometry. Forty-two healthy male subjects without major coronary heart disease risk factors were investigated. The polymorphism in the stromelysin gene promoter was studied through polymerase chain reaction amplification with the use of mutagenic primers. Age, blood pressure, lipids, glucose, viscosity, and body mass index were similar in homozygotes for the 5A allele (5A/5A), heterozygotes (5A/6A), and homozygotes for the 6A allele (6A/6A). Serum matrix metalloproteinase-3 levels did not differ significantly among genotypes. Common carotid diameters and intima-media thickness, measured by noninvasive ultrasonography, were significantly larger in 6A/6A subjects (for respective 6A/6A, 5A/6A, and 5A/5A subjects, diameter at the R wave was 0.63±0.09, 0.55±0.06, and 0.53±0.04 cm mean±SD, P <0.005 by ANOVA; intima-media thickness was 765±116, 670±116, and 630±92 μm mean±SD, P <0.05 by ANOVA). Wall shear stress, calculated as blood velocity×blood viscosity/internal diameter, was significantly lower in 6A/6A subjects (for respective 6A/6A, 5A/6A, and 5A/5A subjects, mean wall shear stress was 10.4±2.9, 13.5±3.5, and 12.6±1.9 dyne/cm mean±SD, P <0.05 by ANOVA).The results demonstrate that the gene polymorphism in the promoter region of stromelysin is associated with structural and functional characteristics of the common carotid artery in healthy male subjects without major risk factors for atherosclerosis. Individuals with the 6A/6A genotype (associated with lower enzyme activity) show a triad of events, namely, increased wall thickness, enlarged arterial lumen, and local reduction of wall shear stress, which might predispose them to atherosclerotic plaque localization.
Hypertension and type 2 diabetes mellitus (T2DM) cause endothelial dysfunction probably through increased oxidant stress. Paraoxonase (PON1) is an high-density lipoprotein (HDL)-linked anti-oxidant ...enzyme whose capacity is influenced by a genetic polymorphism at codon 192. In the present study we have investigated the role of PON1 polymorphism on endothelial function in subjects with T2DM with or without hypertension. Three groups of male subjects were enrolled: 65 healthy control subjects without T2DM or hypertension (CON), 51 with only T2DM (DM), and 67 with both hypertension and T2DM (HYP+DM). The PON1 Gln192Arg polymorphism was determined by polymerase chain reaction (PCR) amplification and restriction analysis. Endothelial function was evaluated as flow-mediated vasodilatation (FMD) of the brachial artery after forearm ischemia. Data were analyzed according to the presence or absence of the Arg allele. Subjects with T2DM had markedly impaired FMD, compared with those of the CON group. In the CON and HYP+DM groups no difference was observed in FMD between subjects homozygous for the Gln allele and those carrying the Arg allele. In the DM group FMD was lower among those carrying the Arg allele compared with Gln/Gln homozygotes (2.1+/-2.4% vs. 6.2+/-5.2%, p=0.002). In conclusion, the present findings demonstrated that FMD was less impaired in normotensive diabetic subjects homozygous for the Gln allele, consistent with the notion that this isoform has a more effective antioxidant action that serves to protect circulating low-density lipoprotein (LDL). Hypertension seems to abolish the protective effect of the Gln isoform. These findings, however, warrant further investigation to clarify their clinical import.
Helper-dependent adenoviral vectors deleted of all viral coding sequences have shown an excellent gene expression profile in a variety of animal models, as well as a reduced toxicity after systemic ...delivery. What is still unclear is whether long-term expression and therapeutic dosages of these vectors can be obtained also in the presence of a preexisting immunity to adenovirus, a condition found in a high proportion of the adult human population. In this study we performed intramuscular delivery of helper-dependent vectors carrying mouse erythropoietin as a marker transgene. We found that low doses of helper-dependent adenoviral vectors can direct long-lasting gene expression in the muscles of fully immunocompetent mice. The best performance-i.e., 100% of treated animals showing sustained expression after 4 months-was achieved with the latest generation helper-dependent backbones, which replicate and package at high efficiency during vector propagation. Moreover, efficient and prolonged transgene expression after intramuscular injection was observed with limited vector load also in animals previously immunized against the same adenovirus serotype. These data suggest that human gene therapy by intramuscular delivery of helper-dependent adenoviral vectors is feasible.
Background
To examine levels of serum homocysteine (Hcy), vitamin B12 and folic acid in patients with pseudoexfoliation glaucoma (PEXG), primary open-angle glaucoma (POAG), and healthy control ...subjects.
Methods
This study included 36 patients with PEXG, 40 with POAG, and 40 age-matched healthy subjects. Fasting plasma Hcy concentrations and levels of serum vitamin B12 and folic acid were measured using competitive chemiluminescent enzyme immunoassay; values exceeding 14 μm/l were considered elevated.
Results
Mean plasma Hcy was significantly higher in PEXG (16.55 ± 7.23 μm/l) compared with POAG (13.91 ± 3.61 μm/l) and controls (13.12 ± 5.13 μm/l) (
p
= 0.03 and
p
= 0.0007 respectively).
There were no statistical differences in serum vitamin B12 and folic acid levels among PEXG, POAG and control subjects (
p
> 0.05). A moderate, although statistically significant, relationship between Hcy and folic acid levels was found in the PEXG group (R
2
= 0.23,
p
= 0.003). Hcy levels were found not to be related with folic acid or vitamin B12 in either POAG or control subjects.
Conclusions
In this study, plasma Hcy is significantly higher in PEXG group than the POAG and control groups. Hyper-Hcy might play a role in the pathogenesis of PEXG. Hyper-Hcy may be an independent factor stressing vasculopathy in addition to pseudoexfoliation, so might be a modifiable risk factor for PEXG.
Human serum paraoxonase-1 (PON1) is thought to play a role in the favorable vascular effects of high-density lipoproteins, mainly through a reduction in low-density lipoprotein oxidation. Endothelial ...dysfunction, characterized by an impaired capacity of the arteries to dilate in response to a number of stimuli, represents the earliest stage of atherosclerosis. We performed the present study in 37 patients with peripheral arterial disease, with the aim of investigating the influence of PON1 Q192R polymorphism and activity on peripheral endothelial function, evaluated as brachial-artery flow-mediated vasodilation (FMV). Patients with the R allele (QR or RR genotype,
n
=
19) had significantly higher PON1 activity 408
U/mL (309–456) versus 180
U/mL (141–243),
p
<
0.001 and greater brachial FMV (5.7
±
3.9% versus 3.0
±
2.8%,
p
<
0.001) than those with Q allele (QQ genotype,
n
=
18). In the whole population, PON1 activity showed a direct relation to brachial FMV (
r
=
0.46,
p
=
0.004). In a multivariate linear regression analysis, the only independent predictors of brachial FMV were PON1 activity (
β
=
0.40,
p
=
0.008), brachial-artery diameter (
β
=
−0.39,
p
=
0.01) and male sex (
β
=
−0.27,
p
=
0.04).
These finding support the importance of PON1 activity as a modulating factor of the endothelial function.
To set-up a method for a direct evaluation in human serum of paraoxonase enzymatic activities, establishing a possible correlation with Q192R genotype polymorphism.
101 different human serum samples ...were genotyped for paraoxonase Q192R polymorphism by PCR restriction analysis, and evaluated spectrophotometrically with regard to paraoxon and 2-coumaranone hydrolytic activities. Both activities of paraoxonase were assayed, quantified through normalization by arylesterase activity, and compared with the data concerning Q/R genetic polymorphism.
The mean normalized paraoxonase activity was found to be significantly higher in RR than in QQ human sera (3.99
±
0.6
versus 1.32
±
0.44;
P
<
0.0001); instead, the 2-coumaranone hydrolysis showed an opposite trend (0.10
±
0.02
versus 0.23
±
0.04, in RR and QQ sera respectively;
P
<
0.0001).
These methods were successfully applied to the whole serum, suggesting a possible use of this approach for a clinically relevant phenotypic characterization.
Mild hyperhomocysteinemia is considered an important risk factor for vascular disease. A common polymorphism (677C
→
T) in the methylenetetrahydrofolate reductase (MTHFR) gene is associated with a ...decreased enzyme activity and consequent higher circulating levels of homocysteine. We hypothesized that the serum levels of homocysteine and/or the MTHFR polymorphism could influence the risk for coronary artery disease (CAD) in patients with heterozygous familial hypercholesterolemia (FH), who are genetically prone to atherosclerosis.
We determined the MTHFR genotype and fasting total serum homocysteine level in 249 adult patients (103 males and 146 females) with heterozygous FH. MTHFR polymorphism was a major determinant of serum homocysteine in adult FH of both sexes.
The logistic regression analysis showed that in FH patients a high level of homocysteine (>12
μmol/l, corresponding to the upper quartile of serum distribution) was the most significant predictor of CAD (
n
=
99) in all the groups considered (all CAD, previous myocardial infarction, myocardial infarction plus angiographically confirmed CAD). The adjusted odds ratio (OR (95% CI)) for the homocysteine-associated risk of CAD (upper quartile versus lower quartiles) was 3.27 (1.60–6.62) in males and females considered together, 5.67 (1.50–21.3) in males and 2.78 (1.17–6.62) in females. LDL cholesterol (upper quartile versus lower quartiles) and hypertension were the other variables independently associated with CAD. In both sexes MTHFR polymorphism was not an independent predictor of CAD.
Plasma concentration of serum homocysteine, but not MTHFR genotype, is associated with an increased risk of CAD in male and female patients with heterozygous FH.
Hydroxy-methyl-glutaryl CoA (HMG-CoA) reductase inhibitors, known also as “statins”: atorvastatin, cerivastatin, fluvastatin, lovastatin, pravastatin and simvastatin, are powerful hypolipidemic ...agents which often enable physicians to attain target values, as established by the NCEP guidelines, especially when a marked and consistent reduction in LDL cholesterol is necessary. With the exception of cerivastatin which was recently withdrawn from worldwide sale because of the worrying incidence of fatal cases of rhabdomyolysis possibly due to high dosages and concomitant use of other drugs such as gemfibrozil or cyclosporin, statins are safe in the long term, as demonstrated by their widespread use in the past 15 years and recently by large-scale clinical trials like the Heart Protection Study. Amongst the currently available statins atorvastatin, extended release fluvastatin and simvastatin have a major effect in lowering LDL cholesterol. Nevertheless, some physicochemical and especially pharmacokinetic differences between the various strains of statins might influence the choice of a particular one as treatment option for an individual patient and might explain some differences that have been described when effects other than the specific hypocholesterolemic one are concerned. These include a possible different action on circulating HDL cholesterol and may be on other systems of biological and physiopathological relevance in the determinism of atherosclerosis and its complications.
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