Oxidative Stress Status in the Transition of Hypertrophy to Heart Failure

In response to a variety of stressful conditions such as pressure overload, volume overload, myocardial infarction and different types of cardiomyopathies, the heart undergoes an adaptation process during which it grows in size, a phenomenon referred to as hypertrophy. During this compensatory phase, the heart is better able to meet the increased work demand. However, if left untreated for a prolonged period, it can advance into the decompensated hypertrophic or the failing stage. It is now clear that transition of heart hypertrophy to the failure stage involves a number of abnormalities which include ionic imbalances, impairment in energy production and utilization, altered calcium metabolism and defects in the contractile proteins. More recently, alterations in free radicals and antioxidant reserve have been identified in the hypertrophy as well as failing stages. Discussion in this review is focussed on the role of oxidative stress in both compensated and decompensated stages, in various animal models of heart failure. Some clinical data on oxidative stress in heart failure patients is also reviewed. It is suggested that an increase in oxidative stress may play a role in the pathogenesis of heart failure.     

幽门螺杆菌cagⅡ对胃上皮细胞IL-8基因转录的影响及机制

目的探讨HpcagⅡ对胃上皮细胞IL-8基因转录的影响及信号传导机制。方法构建 cagⅡ基因位点缺失Hp突变株及带有IL-8报告基因的人胃癌细胞系L5F11,用液体闪烁计数仪测定荧光素酶(IL8转录)活性,用ELISA法测定IL8蛋白浓度。结果所有Hp突变株诱导荧光素酶活性与IL8蛋白浓度较亲代菌株26695均降低[(0．13±0．01)×cpm比(0．59±0．05)×(P<0．01);(0．73±0．13)ng／ml比(2．22±0．65)ng／ml,(P<0．05)]。PTK抑制剂herbimycinA不仅抑制Hp诱导的荧光素酶活性[(0．71±0．18)×cpm比(1．51±0．23)×cpm,(P<0．05)],而且抑制IL-8蛋白表达[(0．83±0．41)ng／ml比(3．22±0．59)ng／ml,(P<0．05)],但herbimycinA对TNFα诱导的荧光素酶活性及IL8蛋白表达均无影响(P均>0．05);PKA抑制剂H7抑制TNFα诱导的荧光素酶活性[(0．74±0．16)×cpm比(2．62±0．26)×cpm,(P<0．001)]及IL8蛋白表达[(1．45±0．38)ng／ml比(4．12±0．43)ng／ml,(P<0．01)],而对Hp诱导的荧光素酶活性无影响(P>0．05)。结论HpcagⅡ中的多基因能够调节胃上皮细胞IL-8基因转录,且这一作用主要经蛋白酪氨酸激酶途径。     

Concrete by Preplaced Aggregate Method Using Silica Fume and Polypropylene Fibres

Preplaced aggregate concrete (PAC) is prepared in two steps, with the coarse aggregate being initially laid down in the formwork, after which a specialised grout is injected into it. To enhance the properties of concrete and to reduce the emission of CO₂ produced during the production of cement, supplementary cementitious materials (SCMs) are used to partially substitute ordinary Portland cement (OPC). In this study, 100 mm × 200 mm (diameter x height) PAC cylinders were cast with 10 per cent of cement being substituted with silica fume; along with that, 1.5% dosage of Macro polypropylene fibres were also introduced into the coarse aggregate matrix. Compressive strength test, splitting tensile strength test, mass loss at 250 °C, and compressive strength at 250 °C were performed on the samples. PAC samples with 10% of cement replaced with Silica Fume (SPAC) were used as control samples. The primary objective of this study was to observe the effect of the addition of Polypropylene fibres to PAC having Silica fume as SCM (FRPAC). The aforementioned tests showed that FRPAC had a lower compressive strength than that of the control mix (SPAC). FRPAC had greater tensile strength than that of NPAC and SPAC. Mass loss at 250 °C was greater in SPAC compared to FRPAC. The compressive strength loss at 250 °C was significantly greater in FRPAC compared to SPAC. FRPAC exhibited a greater strain for the applied stress, and their stress-strain curve showed that FRPAC was more ductile than SPAC.     

Success rates of formocresol pulpotomy and indirect pulp therapy in the treatment of deep dentinal caries in primary teeth

PURPOSE: This study was performed to retrospectively evaluate treatment of deep caries in primary molars with formocresol pulpotomy (FP) and indirect pulp therapy (IPT). METHODS: 133 primary molars with deep caries approaching the pulp were treated with FP (N = 78) or IPT (N = 55) and followed 2-7 years. All IPTs received immediate stainless steel crowns (SSCs); 61 FPs got an immediate SSC, 13 an intermediate restorative material (IRM), and 4 amalgam. Thirteen IPTs and 25 FPs had pre-operative pain compatible with a diagnosis of reversible pulpitis. Treatment notes and radiographs were independently assessed. RESULTS: Overall IPT success was 93% (51/55) versus 74% (58/78) for FP. Molars with pain compatible with a diagnosis of reversible pulpitis were successfully treated by IPT 85% (11/13) versus 76% (19/25) for FP. FP-treated molars exhibited earlier exfoliation 38% (30/78), while all IPT molars exhibited normal exfoliation. FPs receiving immediate SSCs had 50/61 (82%) succeed; FPs restored with an IRM temporary succeeded 5/13 (39%), amalgam 3/4 (75%). CONCLUSIONS: IPT success was significantly higher than FP (P = 0.01) in the treatment of deep caries. Both IPT and FP were successful in treating teeth with pain compatible with the diagnosis of reversible pulpitis. FP significantly hastened the exfoliation of pulpotomized primary molars (P = 0.001). IPT in primary teeth can be successfully used in a one step procedure. SSCs placed immediately after FP significantly increased FP success vs. FP followed by IRM temporary (P = 0.01).     

Self-reported differences between oral health attitudes of pre-clinical and clinical students at a dental teaching institute in Saudi Arabia

ObjectiveTo compare the attitudes of preclinical and clinical dental students toward their own oral health using the Hiroshima University-Dental Behavioral Inventory (HU-DBI).MethodsThe English-language version of the 20-item HU-DBI was distributed to all preclinical and clinical students at the College of Dentistry, University of Dammam, Kingdom of Saudi Arabia. Dichotomized (agree/disagree) responses to 12 HU-DBI items were used in this study, with a maximum possible score of 12. Responses to the remaining eight statements reflected general oral health attitudes and were excluded from the analysis. Data were analyzed statistically.ResultsThe overall response rate was 72.2% (preclinical, 72.5%; clinical, 72%). The mean HU-DBI score was significantly higher among clinical than among preclinical dental students (7 vs. 5.8; P < 0.05). Higher proportions of preclinical than clinical students did not worry about visiting the dentist but postponed dental visits until they experienced toothache. Furthermore, more preclinical than clinical students reported that their gums bled upon brushing, used a child-sized toothbrush, had observed white, sticky deposits on their teeth, and used strong strokes for toothbrushing. More clinical than preclinical students reported that they did not feel that the condition of their teeth was worsening despite brushing, worried about the color of their teeth, brushed each of their teeth carefully, and checked their teeth in the mirror after brushing.ConclusionsDental health awareness programs should be implemented and information about positive oral health attitudes should be provided to the students at an initial stage of dental training.     

Myocardial regeneration by activation of multipotent cardiac stem cells in ischemic heart failure

In this study, we tested whether the human heart possesses a cardiac stem cell (CSC) pool that promotes regeneration after infarction. For this purpose, CSC growth and senescence were measured in 20 hearts with acute infarcts, 20 hearts with end-stage postinfarction cardiomyopathy, and 12 control hearts. CSC number increased markedly in acute and, to a lesser extent, in chronic infarcts. CSC growth correlated with the increase in telomerase-competent dividing CSCs from 1.5% in controls to 28% in acute infarcts and 14% in chronic infarcts. The CSC mitotic index increased 29-fold in acute and 14-fold in chronic infarcts. CSCs committed to the myocyte, smooth muscle, and endothelial cell lineages increased approximately 85-fold in acute infarcts and approximately 25-fold in chronic infarcts. However, p16(INK4a)-p53-positive senescent CSCs also increased and were 10%, 18%, and 40% in controls, acute infarcts, and chronic infarcts, respectively. Old CSCs had short telomeres and apoptosis involved 0.3%, 3.8%, and 9.6% of CSCs in controls, acute infarcts, and chronic infarcts, respectively. These variables reduced the number of functionally competent CSCs from approximately 26,000/cm3 of viable myocardium in acute to approximately 7,000/cm3 in chronic infarcts, respectively. In seven acute infarcts, foci of spontaneous myocardial regeneration that did not involve cell fusion were identified. In conclusion, the human heart possesses a CSC compartment, and CSC activation occurs in response to ischemic injury. The loss of functionally competent CSCs in chronic ischemic cardiomyopathy may underlie the progressive functional deterioration and the onset of terminal failure.     

Dihydropyrimidinones: efficient one-pot green synthesis using Montmorillonite-KSF and evaluation of their cytotoxic activity

A simple, efficient, cost-effective, recyclable and green approach has been developed for the synthesis of new dihydropyrimidinone analogs via the Biginelli reaction. The methodology involves a multicomponent reaction catalyzed by “HPA-Montmorillonite-KSF” as a reusable and heterogeneous catalyst. This method gives an efficient and much improved modification of the original Biginelli reaction, in terms of yield and short reaction times under solvent free conditions. All the derivatives were subjected to cytotoxicity screening against a panel of four different human cancer cell lines viz. colon (Colo-205), prostate (PC-3), leukemia (THP-1) and lung (A549) to check their effect on percentage growth. MTT [3-(4,5-dimethylthiazol-yl)-diphenyl tetrazoliumbromide] cytotoxicity assay was employed to check IC₅₀ values. Of the synthesized analogs, 16a showed the best activity with IC₅₀ of 7.1 ± 0.8, 13.1 ± 1.4, 13.8 ± 0.9 and 14.7 ± 1.1 μM against lung (A549), leukemia (THP-1), prostate (PC-3) and colon (Colo-205) cancer lines, respectively. The 16a analog was further checked for its effect on cancer cell properties through clonogenic (colony formation) and scratch motility (wound healing) assays and thereby was found that it reduced both the colony formation and migratory properties of the lung cancer cell line (A549). Further, molecular docking studies were performed with 16a to show its binding mode.

The general method for the preparation of DHPM analogs; cytotoxic activity and binding mode of the most active derivative against PI3Kγ and CDK2 targets.     

Effect of the Source-to-Substrate Distance on Structural,Optoelectronic, and Thermoelectric Properties of Zinc Sulfide Thin Films

Zinc sulfide (ZnS) thin films with variable structural, optical, electrical, and thermoelectric properties were obtained by changing the source-to-substrate (SSD) distance in the physical-vapor-thermal-coating (PVTC) system. The films crystallized into a zinc-blende cubic structure with (111) preferred orientation. The films had a wide 3.54 eV optical band gap. High-quality homogenous thin films were obtained at 60 mm SSD. The sheet resistance and resistivity of the films decreased from 10¹¹ to 10¹⁰ Ω/Sq. and from 10⁶ to 10⁵ Ω-cm, when SSD was increased from 20 mm to 60 mm, respectively. The phase and band gap were also verified by first principles that were in agreement with the experimental results. Thermoelectric characteristics were studied by using the semi-classical Boltzmann transport theory. The high quality, wide band gap, and reduced electrical resistance make ZnS a suitable candidate for the window layer in solar cells.