H2-D2 exchange reaction with MgCl2-supported Ziegler catalyst by stopped-flow method

The effect of hydrogen on the chain transfer reaction in the initial stage of propene polymerization with MgCl₂-supported Ziegler catalyst was studied through H₂-D₂ exchange reaction using the stopped-flow method. When the exchange reaction was carried out with various catalyst components at room temperature for 5 min, HD was produced only in case of using the catalyst with Al(C₂H₅)₃. In case of the stopped-flow method (reaction time ca. 0.1 s), the catalyst without pre-treatment with Al(C₂H₅)₃ showed no activity for the H₂-D₂ exchange reaction (no HD produced), while the catalyst with pre-treatment had exchange activity. As the chain transfer activity of H₂ in propene polymerization shows the same tendency, it is evident that chain transfer with H₂ occurs via atomic hydrogen generated on the pre-treated catalyst.     

Clinical concerns with inhaled β2-agonists

Inhaled β₂-agonists, when used regulary, cause subtle but significant worsening of asthma control. Overuse of inhaled β₂-agonists is associated with increased risk of death from asthma in a dose-response fashion. β₂-Agonists enhance airway responses to allergens, including induced airway hyperresponsiveness and induced airway inflammation. This is a plausible explanation for β₂-agonist-worsened asthma control. These direct effects of inhaled β₂-agonists, including increased airway response to allergen, tolerance, etc., may partially explain the association of overuse with asthma death. However, it is probable that the major reason for the association of β₂-agonists overuse and asthma mortality is an indirect effect. Inhaled β₂-agonists are effective relievers and preventers of bronchoconstriction and asthma symptoms but fail to treat the underlying pathogenesis, namely the airway inflammation. Thus, overuse may mask the true asthma severity and result in both an underappreciation and undertreatment of the disease. This would provide a rational explanation for the relationship of inhaled β₂-agonist use and mortality and also would fit the dose-response pattern. Inhaled β₂-agonists should be used exclusively as needed for relief of symptoms and their requirement should be infrequent the need for excessive doses of β₂-agonists provides a useful marker of asthma (lack of) control.     

HPC2/ELAC2 gene variants associated with incident prostate cancer

The HPC2/ELAC2 gene on chromosome 17p11 was identified as a candidate gene for hereditary prostate cancer (HPC) susceptibility. Two HPC2 gene missense variants, Ser217Leu (Leu217) and Ala541Thr (Thr541) have been associated with incident prostate cancer cases in some studies, but not in others. We tested for possible associations between the two HPC2 gene variants and prostate cancer risk in incident prostate cancer cases (199) and healthy male controls (525) from the Calgary region. The Thr541 variant showed linkage disequilibrium with the Leu217 variant. The number of Leu217 homozygotes in the case and control groups (8.6versus 8.5%) was not statistically different. Leu217 carrier status was associated with prostate cancer risk (cases 61.8% versus controls 50.3%) (OR 1.6, 95% CI 1.15–2.23). Additional analysis found that this association was not due to the co-existence of Thr541 variant (OR1.59, P=0.009). Logistic regression found that the relationship between the log odds of being a Thr541carrier and age depends on case/control status. Thr541 carriers had an increased risk for late-onset prostate cancer (P=0.028). Prostate intraepithelial neoplasia (PIN) was more common in the Leu217 allele carriers compared to non-carriers (42.3 versus 26.7%) (OR 2.05, 95% CI 1.10–3.83), and in the Thr541 carriers compared to non-carriers (50.0 versus 34.6%) (OR 1.89, 95% CI 0.75–4.78). In summary, the HPC2 gene variants Leu217 and Thr541 were associated with an increased risk for prostate cancer and for PIN in males undergoing radical prostatectomies in the Calgary region.     

Copolymerization of styrene with acrylonitrile initiated by 2-methyl-2-undecanethiol

The copolymerization of styrene (St) with acrylonitrile (AN) initiated with 2-methyl-2-undecanethiol (RSH) was investigated. Kinetic studies revealed that the initial rate of the copolymerization, which does not occur spontaneously in the absence of RSH, obeys the following expression: R_p ∝? [RSH]^x, where x is 0,5 when [RSH] ranges from 3,4.10^?4 to 3,4.10^?3 mol/l and 0 when [RSH] is larger than 3,4.10^?3 mol/l. The initial copolymerization rate, R_p, increases with increasing percentage of AN in the monomer feed. From the slope of ln R_p vs. 1/T, the apparent activation energy, E_app, was calculated to be 17 kJ/mol in the temperature range of 30°C to 50°C. RSH is the only initiating species, and it also plays a role as chain-transfer agent. The value of M _w/M _n, which varies from 1,5 to 2,0, is typical of a free-radical poymerization. The reactivity ratios were calculated to be r_St = 0,42 ± 0,04 and r_AN = 0,02 ± 0,03. It seems to be unnecessary to introduce a penultimate effect for explaining the experimental data.     

Using CHADS2, R2CHADS2, CHA2DS2-VASc score for mortality prediction in patients with abnormal low and high ankle-brachial index

Abnormal low and high ankle brachial index (ABI) is regarded as peripheral artery disease (PAD) which has extremely high morbidity and mortality. How to identify high-risk PAD patients with increased mortality is very important to improve the outcome. CHADS₂, R₂CHADS₂, and CHA₂DS₂-VASc score are clinically useful scores to evaluate the annual risk of stroke in patients with atrial fibrillation. However, there was no literature discussing the usefulness of these scores for cardiovascular (CV) and all-cause mortality prediction in the patients with abnormal ABI. This longitudinal study enrolled 195 patients with abnormal low (< 0.9) and high ABI (> 1.3). CHADS₂, R₂CHADS₂, and CHA₂DS₂-VASc score were calculated for each patient. CV and all-cause mortality data were collected for outcome prediction. The median follow-up to mortality was 90 months. After multivariate analysis, CHADS₂, R₂CHADS₂, and CHA₂DS₂-VASc score were significant predictors of CV and all-cause mortality (all P < 0.001). CHA₂DS₂-VASc score had a better additive predictive value than CHADS₂ and R₂CHADS₂ score for CV mortality prediction. R₂CHADS₂ and CHA₂DS₂-VASc score had better additive predictive values than CHADS₂ score for all-cause mortality prediction. In conclusion, our study is the first study to investigate the usefulness of CHADS₂, R₂CHADS₂, and CHA₂DS₂-VASc score for mortality prediction in patients with abnormal ABI. Our study showed all three scores are significant predictors for CV and all-cause mortality although there are some differences between the scores. Therefore, using the three scoring systems may help physicians to identify the high-risk PAD patients with increased mortality.     

Fibrinogen-like protein 2 expression correlates with microthrombosis in rats with type 2 diabetic nephropathy

Fibrinogen-like protein 2 (fgl2),a novel prothrombinase,is involved in microthrombosis.We examined fgl2 expression in the glomerular and tubulointerstitial capillaries and its correlation with microthromsis in rats with streptozocin-induced type 2 diabetic nephropathy.Our RT-PCR and immunoblotting analysis showed that fgl2 mRNA and protein levels were increased in microvascular endothelial cells of the glomeruli and renal interstitia at week 19 and became significantly elevated with the development of diabetic nephropathy (P < 0.01).Fgl2 was not or only weakly expressed in the renal tissues of normal rats.Furthermore,a direct significant correlation (r=0.543,P < 0.01) was found between fgl2 expression and microthrombotic capillaries in the renal tissues.Enzyme linked immunosorbent assays (ELISA) additionally showed that circulating TNF-α levels in rats with type 2 diabetes were significantly elevated and closely correlated with fgl2 expression (r=0.871,P < 0.01).Our results suggest that fgl2 may activate renal microthrombosis,thus contributing to glomerular hypertension and renal ischemia.     

LRRK2 variant associated with Alzheimer's disease

Overlapping neurodegenerative pathologies (including Alzheimer's disease, AD) have been described in Parkinson's disease (PD) patients with leucine-rich repeat kinase-2 (LRRK2) mutations. We analyzed a LRRK2 PD (R1628P) risk variant in a group of 885 subjects comprising of AD and controls. The frequency of the R1628P allele was higher in AD compared to controls (3.5% vs. 1.6%, OR 2.3, 95 CI 1.2-4.4, p = 0.018). In vitro, the mean percentage of apoptosis and cell death observed for the R1628P transfected human cell lines was higher compared to wild type 21.8 ± 1.9, vs. 17.1 ± 1.3, p < 0.05, 30.2 ± 2.2 vs. 25.7 ± 1.3, p < 0.05). The LRRK2 R1628P variant increases the risk of AD in our population and our in vitro findings suggest that it is a functional variant and predisposes to apoptosis.     

Current issues with β2-adrenoceptor agonists

The discovery that dessicated adrenal glands had beneficial effects in asthma arose in 1900 following a vogue for studying organotherapy at the end of the 19th century. The adrenal hormone adrenaline was found to have sympathomimetic properties and was isolated and synthesized in 1901. The first nonselective β-agonist, isoproterenol, was isolated in 1940, followed by the development of selective β₂-agonists in the 1960s and the introduction of the long-acting β₂-agonists in the 1990s. The introduction of β₂-selectivity reduced adverse effects, as did developments in inhaler technology that allowed subjects to inhale much smaller doses of drug selectively to the airways. The β₂-agonists are some of the more important drugs to have been developed in the 20th century. Excessive doses can cause problems, and attempts to maximize the benefit from β₂-agonists and to reduce adverse effects has led to considerable epidemiological, clinical, and mechanistic research over the last 50 yr.     

Ring-opening-closing alternating copolymerization of 2-methyl-2-oxazoline with N-methyldiacrylamide

This paper describes a new ring-opening-closing alternating copolymerization (ROCAC) of 2-methyl-2-oxazoline (five-membered cyclic imino ether, 1 ) with N-methyldiacrylamide ( 2 ). The reaction of a 1 : 1 monomer feed ratio proceeded without any added catalyst to give an alternating copolymer 3 having two structural units formed by ring-opening and ring-closing (cyclization). The structure of copolymer 3 was determined by ¹H, ¹³C NMR, and IR spectroscopies. The extent of cyclization was at most 65%. The copolymerization was reasonably explained by a mechanism of propagation via zwitterion intermediates.     

Phenotypic variability in monozygotic twins with neurofibromatosis 2

Mutations in the neurofibromatosis 2 (NF2) tumor suppressor gene on chromosome 22q12 cause a clinically variable autosomal dominant syndrome characterized by bilateral vestibular schwannomas (VSs), other nervous system tumors, and early onset lenticular cataracts. We studied three pairs of monozygotic (MZ) twins with NF2, all with bilateral VSs, to separate genetic from nongenetic causes of clinical variability. The evaluation included gadolinium-enhanced high-resolution magnetic resonance imaging of the head and spine, neuro-ophthalmic examination with slit lamp, physical examination, and zygosity testing with microsatellite markers. Each MZ pair was concordant for general phenotypic subtype (mild or severe) and often for the affected organ systems. However, the MZ pairs were discordant for some features of disease presentation or progression. For example, all three pairs were discordant for presence or type of associated cranial tumors. We hypothesize that phenotypic differences between NF2 MZ twins are at least partly due to stochastic processes, such as the loss of the second NF2 allele or alleles of other genes. © 1996 Wiley-Liss, Inc.     

Polymerization of olefins with the TiCl4/SiO2 catalyst system modified with MgCl2

MgCl₂/TiCl₄/SiO₂ catalysts were prepared by treating TiCl₄/SiO₂ with MgCl₂ · 2THF (THF: tetrahydrofuran) at different Mg/Ti ratios. The catalysts were analysed by X-ray, electron spin resonance (ESR), atomic absorption spectrometry to determine the crystal structure, oxidation state of titanium and also contents of Ti, Al and Mg. Homo- and copolymerizations of ethylene and propene were conducted with them using Al(i-C₄H₉)₃ as a cocatalyst. The results of polymerization were correlated with the analytical data of the catalyst.     

Urinary Interleukin-2 Inhibition in Patients with Cystitis

An inhibitor of interleukin-2 activity (IL-2-IN) is present in the urine of most patients during the acute phase of untreated bacterial cystitis (UTI). We measured urinary IL-2-IN activity in 30 adults with uncomplicated UTIs and followed the patients for an additional 6 months. Urinary IL-2-IN activity ranged between 0 and 1.97 units/mg urine creatinine (U/mg u.c.). Relatively low levels of IL-2-IN (< 0.5 U/mg u.c.) correlated with a prior history of recurrent UTIs (p < 0.01), and also were predictive of a subsequent UTI during the 6 month follow-up, regardless of the prior medical history (p < 0.01). Measurement of urinary IL-2-IN during the untreated phase of a UTI may prove helpful for directing antibiotic prophylaxis against subsequent UTIs.     

Silencing of SARS-CoV-2 with modified siRNA-peptide dendrimer formulation

Background

First vaccines for prevention of Coronavirus disease 2019 (COVID-19) are becoming available but there is a huge and unmet need for specific forms of treatment. In this study we aimed to evaluate the anti-SARS-CoV-2 effect of siRNA both in vitro and in vivo.

Methods

To identify the most effective molecule out of a panel of 15 in silico designed siRNAs, an in vitro screening system based on vectors expressing SARS-CoV-2 genes fused with the firefly luciferase reporter gene and SARS-CoV-2-infected cells was used. The most potent siRNA, siR-7, was modified by Locked nucleic acids (LNAs) to obtain siR-7-EM with increased stability and was formulated with the peptide dendrimer KK-46 for enhancing cellular uptake to allow topical application by inhalation of the final formulation – siR-7-EM/KK-46. Using the Syrian Hamster model for SARS-CoV-2 infection the antiviral capacity of siR-7-EM/KK-46 complex was evaluated.

Results

We identified the siRNA, siR-7, targeting SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) as the most efficient siRNA inhibiting viral replication in vitro. Moreover, we showed that LNA-modification and complexation with the designed peptide dendrimer enhanced the antiviral capacity of siR-7 in vitro. We demonstrated significant reduction of virus titer and lung inflammation in animals exposed to inhalation of siR-7-EM/KK-46 in vivo.

Conclusions

Thus, we developed a therapeutic strategy for COVID-19 based on inhalation of a modified siRNA-peptide dendrimer formulation. The developed medication is intended for inhalation treatment of COVID-19 patients.

     

Association of eotaxin-2 gene polymorphisms with plasma eotaxin-2 concentration

Chemokine (C–C motif) ligand 24 (CCL24, eotaxin-2) is a CC chemokine that recruits and activates cells bearing the CC chemokine receptor 3, which play a major role in asthma. Previously, we observed a significant association between a single nucleotide polymorphism (SNP) in eotaxin-2 (CCL24+1272A G) and a lower risk of asthma. Consequently, this study has followed up on those genetic effects by evaluating the association between the SNP and plasma eotaxin-2 concentration in 172 asthmatics and 135 normal controls. Asthmatics had significantly higher plasma eotaxin-2 levels than did normal controls (P=0.02). The SNP (CCL24+1272A G) and two haplotypes (ht2 and ht6) were strongly associated with plasma eotaxin-2 levels in asthmatics (CCL24+1272A G: P=0.006, ht2: P=0.006, and ht6: P=0.002). The CCL24+1272A G allele and the ht2 and ht6 haplotypes showed a gene–dose effect on the plasma eotaxin-2 levels in asthmatics (P=0.005–0.032). In conclusion, the susceptibility of patients with asthma to high eotaxin-2 production may be due to genetic effects of the CCL24+1272A G polymorphism, ht2 and ht6 haplotypes.     

Peroxisome proliferator-activated receptor-γ2 Pro12Ala polymorphism is associated with reduced risk for ischemic stroke with type 2 diabetes

Peroxisome proliferator-activated receptor (PPAR)-γ2 has important effects to insulin sensitivity, atherosclerosis, inflammation and endothelial cell function. Through these effects, PPAR-γ2 might be involved with the ischemic stroke in type 2 diabetes. To determine the role of PPAR-γ2 in genetic susceptibility to ischemic stroke in type 2 diabetes, we genotyped 302 ischemic stroke patients, 283 healthy controls and 141 type 2 diabetic patients without ischemic stroke (diabetes duration >10 years) for PPAR-γ2 Pro12Ala polymorphism by polymerase chain reaction-restriction fragment length polymorphism methods. PPAR-γ2 Pro/Ala genotype were lower in ischemic stroke patients than those observed in the control group (4.0% vs. 9.9%, OR = 0.38, P = 0.0046), and it were associated with the incidence of ischemic stroke in the multivariate analysis (OR = 0.43, P = 0.025). Genotypic analysis revealed that ischemic stroke patients with type 2 diabetes displayed a great lower prevalence of the Pro/Ala genotype (2.3%) than controls (9.9%) (OR = 0.21, P = 0.0047). And Pro/Ala genotype of type 2 diabetes patients with ischemic stroke were lower than type 2 diabetes patients without ischemic stroke (2.3% vs. 8.5%, OR = 0.25, P = 0.0321), however the significant association with ischemic stroke was not detected in the multivariate analysis (OR = 0.27, P = 0.051). These results suggest that the Pro/Ala genotype of PPAR-γ2 Pro12Ala polymorphism may be associated with reduced risk for ischemic stroke, and the possibility that it might have a protective effect for ischemic stroke with type 2 diabetes.     

Evaluating the association of common APOA2 variants with type 2 diabetes

Background  

APOA2 is a positional and biological candidate gene for type 2 diabetes at the chromosome 1q21-q24 susceptibility locus. The aim of this study was to examine if HapMap phase II tag SNPs in APOA2 are associated with type 2 diabetes and quantitative traits in French Caucasian subjects.     

The development of anti-interleukin-2 antibodies in patients treated with recombinant human interleukin-2 (IL-2)

Approximately 65% (11/17) of cancer patients participating in an ongoing Phase I clinical trial with recombinant interleukin-2 developed nonneutralizing serum IgG anti-interleukin-2 antibodies within 1 month of initiating therapy. These antibodies could be detected using any of several standard techniques including immunoblots and enzyme-linked immunosorbent assays. Western blot analysis and retention experiments with protein A-Sepharose indicate that the antibodies are specific for interleukin-2. The interleukin-2 mutein utilized in this clinical trial (des-ala-ser₁₂₅ r-IL-2) differs from the major species of the human T cell-derived lymphokine in that it lacks the N-terminal alanine of the native molecule, is not glycosylated, and possesses a serine-cysteine substitution at position 125. Another recombinant interleukin-2, identical to the mutein except that it retains the cysteine at position 125 (des-ala-cys₁₂₅ r-IL-2), strongly competes with the mutein in competitive enzyme-linked immunosorbent assays, suggesting that the amino acid substitution is not responsible for the recognition of the molecule by serum antibodies. Conversely, nonrecombinant T cell-derived interleukin-2 fails to compete in these assays and is not retained by protein A-Sepharose columns when mixed with high-titer antiserum. These results suggest that the anti-interleukin-2 serum antibodies generated in the course of treatment do not react with the nonrecombinant lymphokine but recognize epitopes peculiar to recombinant forms which are not dependent on the amino acid substitution at position 125. The failure of the antibodies to neutralize the biological activity of recombinant interleukin-2 (IL-2) in lymphocyte proliferation assays and to bind to the native lymphokine suggests that they may not affect IL-2-dependent cellular immune functionsin vivo.