Synthesis of a novel Cu/DPA-MOF/OP/CS hydrogel with high capability in antimicrobial studies.

Today, with the indiscriminate use of antibiotics, we face the resistance of some bacterial strains against some antibiotics. Therefore, it is essential to report and synthesize new compounds with antimicrobial properties. A novel copper/dipicolinic acid-metal-organic framework cross-linked oxidized pectin and chitosan (Cu/DPA-MOF/OP/CS) hydrogel polymer was synthesized under environmental conditions with the controllable process, which uses biodegradable polymer compounds such as pectin and chitosan in its structure. The efficient physicochemical features of the synthesized Cu/DPA-MOF/OP/CS hydrogel using SEM, FT-IR, TGA, BET, XRD, and EDS/mapping were identified and confirmed. The newly synthesized Cu/DPA-MOF/OP/CS hydrogel showed activity against Gram-positive and Gram-negative bacterial strains and fungal species, and significant antibacterial and antifungal properties were observed. In antibacterial activity, the MIC against Gram-positive species was in the range of 16-128 mg/mL, the MIC against Gram-negative species was in the range of 64-256 mg/mL, and the MIC against fungal species was in the range of 128-512 mg/mL. In antimicrobial evaluations, in addition to the MIC test, the MBC test, the MFC test, and the IZD test were performed, and the results were reported. The results were compared with commercial antibiotics in the market. Development of novel nanostructures based on hydrogel polymers with distinctive functionality can affect the performance of these nanostructures in different areas.

Fabrication of HKUST-1/ZnO/SA nanocomposite for Doxycycline and Naproxen adsorption from contaminated water.

Doxycycline and Naproxen are among the most widely used drugs in the therapy of CoVID 19 disease found in surface water. Water scarcity in recent years has led to research to treat polluted water. One of the easy and low-cost methods for treatment is adsorption. The utilize of Metal-Organic Frameworks (MOFs) to evacuate pharmaceutical contaminants from water sources has been considered by researchers in the last decade. In this research, HKUST-1/ZnO/SA composite with high adsorption capacity, chemical and water stability, recovery, and reuse properties has been synthesized and investigated. By adding 10 wt% of ZnO and 50 wt% of sodium alginate to HKUST-1, at 25 °C and pH = 7, the specific surface area is reduced by 60%. The parameters of drugs concentration C0 =(5,80) mg/L, time=(15,240) min, and pH= (2,12) were investigated, and the results showed that the HKUST-1/ZnO/SA is stable in water for 14 days and it can be used in 10 cycles with 80% removal efficiency. The maximum Adsorption loading of doxycycline and Naproxen upon HKUST-1/ZnO/SA is 97.58 and 80.04 mg/g, respectively. Based on the correlation coefficient (R2), the pseudo-second-order and the Langmuir isotherm models were selected for drug adsorption. The proposed mechanism of drug uptake is by MOFs, hydrogen bonding, electrostatic bonding, and acid-base interaction.

Determinants and mitigating factors of the brain drain among Egyptian nurses: a mixed-methods study.

BACKGROUND: A brain drain is a migration of employees in their quest for an improved level of living conditions, better earnings, access to advanced technology and secure political conditions in diverse places worldwide. The brain drain of nurses is an ongoing phenomenon that impacts the quality and quantity of the nursing workforce and affects the quality of care. The nurses' brain drain is commonly known as a result of the interplay of many factors. So, identification of these factors and how to manage them is a timely topic in nursing research. AIMS: This study aims to investigate determinants of the nurses' brain drain and mitigating factors from nurses' perspectives in Egypt. METHODS: Mixed-methods research was conducted using a concurrent triangulation design. A sample of 325 nurses who were working at an Egyptian university hospital answered a brain drain questionnaire while the qualitative investigation was guided by a semi-structured interview with a purposive sample of 35 nurses to elicit exploratory perspectives on factors causing brain drain and mitigation strategies. Results were analysed using inferential statistics and thematic data analysis. RESULTS: Both push and pull factors can predict about 99.6% and 97.5% of the nurses' brain drain, respectively. Seven themes were derived from the qualitative content analysis, and six themes were categorised under 'push-pull' factors. In addition, the 'mitigating factors theme' was identified with five sub-factors as possible solutions. Economic and work environment reasons were reported as the most influential for nurses' brain drain. CONCLUSIONS: Policymakers could use the identified factors from quantitative and qualitative data for creating a system that would improve nurses' conditions and policies, and prevent nurses' migration. Nursing leaders have a significant role with non-remuneration strategies in retaining nurses through creating an empowering work environment. In addition, shared governance, a strong nursing syndicate role and professorial marketing would be essential mitigating factors for the nurses' brain drain.

Corrosion and hydrogen evolution rate control for X-65 carbon steel based on chitosan polymeric ionic liquids: experimental and quantum chemical studies.

The corrosion performance of carbon steel was tested in four polymeric ionic liquids (PILs) that differed only in the fatty acid linked to the chitosan (CS) amine group. The measurements were implemented involved the hydrogen evolution rate (HER), gravimetric measurements, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and quantum chemical estimations. The morphology and the elements arranged on the metal were considered by a scanning electron microscopy (SEM) system attached to an energy dispersive X-ray (EDX) system. The addition of polymeric ionic liquids hindered the rate of hydrogen generation. The order of the inhibitors efficiency was CSPTA-lauric > CSPTA-myristic > CSPTA-palmitic > CSPTA-stearic. The polarization method proved that the percentage inhibition efficiency increases with increasing the inhibitors concentration in 1 M HCl, representing a drop in the corrosion rate of carbon steel. On the other hand, the percentage inhibition decreased with the increase in temperature. Quantum chemical calculations revealed that the tested ionic liquids could react with the iron surface via electron transfer from the metal atom to ionic liquid molecule.

Immune tolerance elicited via unique ocular and oral routes.

Immune tolerance can be induced by numerous methods. This review article aims to draw lines of similarity and contrast between two unique models of immune tolerance, namely Anterior Chamber Associated Immune Deviation (ACAID) and Nickel-induced oral tolerance. ACAID is an immune tolerance model that leads to the generation of CD4(+) T regulatory cells and CD8(+) T regulatory cells in the periphery after the injection of an antigen into the anterior chamber of the eye. Nickel-induced oral tolerance is another immune tolerance model that is induced by the contact allergen Nickel and leads to the generation of Nickel-specific CD4(+) CD25(+) T regulatory cells after oral exposure. The goal of comparing different models of immune tolerance is to identify which mechanisms are universal and which mechanisms are model-specific. The knowledge of such mechanisms would allow scientists and clinicians to better intervene in different immune deregulation scenarios.

Combined aspirin and cilostazol treatment is associated with reduced platelet aggregation and prevention of exercise-induced platelet activation.

BACKGROUND: Cilostazol has proven efficacy in increasing walking distance in claudicants, but it has not been demonstrated to be more effective than placebo in secondary cardiovascular prevention. The direct effect of exercise on platelet function remains less well defined. We have investigated the effect of combination treatment with aspirin and cilostazol on platelet activity in claudicants subjected to repeated treadmill exercise. METHODS: Nineteen claudicants completed a double-blind, randomised, controlled, cross-over trial. Each subject received a 2-week course of aspirin (75mg) and placebo and aspirin and cilostazol (100mg twice daily). Following each 2-week treatment period, patients participated in a standardised treadmill test (3.2kmh(-1), 10 degrees incline) walking to maximal claudication distance. The exercise was repeated thrice in total, and blood was sampled before and after exercise. Platelet activation was measured using free platelet counting aggregation, flow cytometry for surface markers of platelet activation and soluble P-selectin assay. RESULTS: Compared to aspirin and placebo, combination treatment with aspirin and cilostazol was associated with reduced arachidonic-acid-induced platelet aggregation (p<0.01, Wilcoxon signed-rank test). Aspirin and placebo treatment were associated with elevated P-selectin expression, platelet-monocyte aggregation and reduced CD42b expression (p<0.05, Wilcoxon signed-rank test) post-exercise. No difference was seen in spontaneous platelet aggregation whilst soluble P-selectin was reduced post-exercise with combination treatment with aspirin and cilostazol (p<0.05, Wilcoxon signed-rank test). CONCLUSIONS: Combination treatment with aspirin and cilostazol results in suppression of platelet activation and reduces the effect of exercise on platelets. The benefit seen may be a result of cilostazol enhancing the inhibitory effect of aspirin on the cyclo-oxygenase pathway.

Increased platelet-monocyte aggregation in male claudicants with the Pl(A1/A2) polymorphism of Gp IIb/IIIa.

OBJECTIVES: To investigate the relationship between the Pl(A1/A2) polymorphism and platelet activation and aggregation in patients with Peripheral Arterial Disease (PAD). DESIGN: A prospective single-centre cohort study. METHODS: 45 patients with PAD on aspirin 75mg were recruited and phenotyped/genotyped for the Gp IIb/IIIa Pl(A1/A2) polymorphism. Platelet-Monocyte Aggregation (PMAs) was evaluated using flow-cytometry. RESULTS: The formation of PMAs in the Pl(A2) group was higher but not statistically significant (p=0.17). However, when males were analysed separately, the formation of PMAs was significantly higher in the Pl(A2) group (p=0.0192). No difference was seen in the females. CONCLUSIONS: In this study we show that the Pl(A1/A2) polymorphism primarily affects the aggregation of platelets to monocytes in males. The effect is not observed in females and understanding the mechanism behind this may help elucidate the way the polymorphism alters platelet function in the presence of aspirin.

Platelet monocyte aggregates and monocyte chemoattractant protein-1 are not inhibited by aspirin in critical limb ischaemia.

OBJECTIVES: Platelet monocyte aggregates (PMA) and monocyte chemoattractant protein-1 (MCP-1) play a significant role in atherosclerotic disease but the effect of aspirin and their role in peripheral arterial disease (PAD) requires further investigation. We have compared p-selectin, PMA and MCP-1 in patients with PAD treated with aspirin (75 mgs daily), with age matched controls not treated with aspirin. MATERIALS AND METHODS: Using flow cytometry and ELISA, P-selectin, PMA and MCP-1 were compared in 3 populations; healthy controls (n=12), intermittent claudication (n=19) and critical limb ischaemia (CLI), (n=10). RESULTS: P-selectin was significantly higher in CLI patients (3.48% positive) compared to the claudicants (1. 36% positive) and the controls (1.76% positive). PMA levels were significantly higher for CLI population (44.5% positive) compared to the claudicants (20.48% positive) and the controls (28.33% positive). MCP-1 levels expression was significantly higher for the CLI patients (175.4 pg/mL) compared to the claudicants (76.1 pg/mL) and the controls (117.0 pg/mL). CONCLUSION: Despite aspirin treatment CLI patients have higher platelet activation and MCP-1 expression than controls and claudicants. With increasing severity of disease aspirin is unable to suppress markers of platelet activation and pro-atherosclerotic chemokine expression which may represent another form of aspirin resistance.

Outcomes of intra-arterial thrombolysis for acute limb ischemia.

Intra-arterial thrombolysis is an alternative treatment to surgery for acute limb ischemia. We report our own experiences by retrospectively assessing initial and long-term outcomes using this strategy. Patients (n = 48; 50 events) underwent thrombolysis according to our protocol (64.6% male, median age 68.5 years). Using thrombolysis as an initial treatment strategy, overall limb survival on index admission was 84%. Of this group who had successful limb salvage, 76% was attributable to thrombolysis alone, and 24% had limb salvage attributable to subsequent surgery after failed thrombolysis or anticoagulation. Significant complications occurred in 8% of cases, and no deaths were attributed to thrombolysis. Patients alive at 6 and 24 months after index admission who had limb salvage attributable to thrombolysis alone had limb survival rates of 89% and 82%, respectively. The majority of these patients had not required subsequent secondary procedures to maintain limb survival. Thrombolysis is an acceptable and less invasive treatment of acute limb ischemia, with many patients not needing subsequent surgery.

Treadmill exercise in claudicants on aspirin results in improved antioxidant status but only minimal platelet activation.

The consequence of exercise on platelets remains controversial and adverse effects may result from repeated ischaemia reperfusion injury. We investigated platelet activation (platelet P-selectin (PS), and activated glycoprotein (Gp) IIb/IIIa), platelet-monocyte aggregates (PMA) and total plasma antioxidant status (TPAS) in claudicants after exercise. Twenty claudicants, taking 75 mg of aspirin daily, were subjected to repeated treadmill testing (3 km/h, 10% inclination). Blood was sampled before and after exercise. Activated GpIIb/IIIa, PS and PMA were quantified with flow cytometry. TPAS was quantified using a decolourisation assay. Percent positive cells for PS (pre-exercise 3.76% vs. 40 min post-exercise 4.10%; P < 0.05) and platelet-monocyte aggregates (pre-exercise: 25.31% vs. 40 min post-exercise 26.99%; P < 0.05) were significantly higher after exercise. Relative median fluorescence (RMF) for activated GpIIb/IIIa was significantly higher 40 min after exercise (pre-exercise: 3.04 vs. 40 min post-exercise: 4.01; P < 0.05). TPAS was significantly higher post-exercise (pre-exercise: 1.31 mmol/l vs. 1 min post-exercise: 1.40 mmol/l and 40 min post-exercise: 1.38 mmol/l; P < 0.01). Following moderate exercise, 'aspirin treated claudicants' show marginal platelet activation, PMA formation and a favourable improvement in antioxidant status. Further studies are required to assess the effect of additional antiplatelet agents and the significance of platelet-monocyte interactions. The possibility that aspirin contributes to the TPAS changes following exercise needs to be investigated.

Surveillance versus nonsurveillance for femoro-popliteal bypass grafts.

This is a study of 97 patients who underwent 106 femoropopliteal bypass grafts (9 bilateral bypasses) for short-distance claudication and critical ischemia. Patients were divided into 2 groups. The first group (n=64) was followed up by use of duplex scans. The second group (n=42) was followed up in clinic without duplex surveillance. Twenty-three patients from the surveillance group developed stenoses of the grafts. Of these, 14 underwent successful angioplasty. A total of 43 grafts became blocked. Graft occlusion was significantly more common in the nonsurveillance group (n=29) as compared to the surveillance group (n=14) after both 1 and 3 years of observation (p=0.001). Patients with critical ischemia showed a higher rate of graft occlusion than the claudicants (p=0.0075). Sixteen patients in the nonsurveillance group underwent above/below-knee amputation compared to 1 in the surveillance group. There was no significant difference in the mortality rate in the 2 groups. Graft surveillance helped to improve patency of grafts by identifying the correctable lesions.

Synthesis of novel 2-[2-(substituted amino)phenethyl]-1 H-benzimidazoles; 3,4-dihydro and 1,2,3,4,-tetrahydropyrimido[1,6-a]-benzimidazoles as potential antiulcer agents.

In an effort to establish new antiulcer agents a series of 2-(2-substituted amino)-1 H-benzimidazoles 8, 9, 14; 1,3-disubstituted-3,4-dihydropyrimido[1,6-a]benzimidazoles 4, 7, 11, 12; 3-substituted-3,4-dihydropyrimido[1,6-a]benzimidazol-1 (2H)-thiones (or (2H)-ones) 10, 17 and 3-substituted-1,2,3,4-tetrahydropyrimido[1,6-a]benzimidazoles 15 were synthesized. Representative members were selected to evaluate their gastric antisecretory activity using an in vivo pylorus ligated rat method. Omeprazole was used as reference. The results indicated that the test compounds exhibit gastric antisecretory activity. The percent inhibition+/-SEM at the indicated dose level was demonstrated as omeprazole (59%+/-0.16 at 3 mg/kg) > 15a (53%+/-1.39 at 3 mg/kg) > 7a (51%+/-1.04 at 1 mg/kg) > 10a (50%+/-1.36 at 3 mg/kg).

Outcome of "kissing stents" for aortoiliac atherosclerotic disease, including the effect on the non-diseased contralateral iliac limb.

PURPOSE: To assess outcomes following "kissing stents" for aortoiliac atherosclerotic disease, particularly in the non-diseased/non-symptomatic limb. METHODS: Twenty-four patients underwent kissing stenting over 36 months. There were 36 symptomatic and 12 non-symptomatic/non-diseased limbs. Patients were prospectively followed with 3-monthly clinical assessment as well as duplex ultrasound. RESULTS: At 23.5 months follow-up (range 3-36 months), 75% of patients had improvement in symptoms, 20% no change and 5% had deterioration. Sixty-one percent of limbs maintained an increase in ankle-brachial pressure index of >0.1. There were 15 reinterventions in nine patients, including three in non-symptomatic/non-diseased limbs. Primary patency at 6, 12 and 24 months was 94%, 81% and 58%, respectively. Primary assisted and secondary patency rates were 96%, 84% and 84% respectively for diseased limbs, and 92% and 100% for non-symptomatic/non-diseased limbs. Although reinterventions were required, there were no long-term occlusions in the non-diseased/non-symptomatic limb. CONCLUSION: Kissing stents offer an invaluable alternative to surgery. There were no long-term occlusions following kissing stents in a previously non-symptomatic/non-diseased limb.

Duplex follow-up of aorto-iliac stents.

OBJECTIVES: to assess the feasibility of duplex follow up of aorto-iliac stents. MATERIAL AND METHODS: in addition to standard clinical and ankle/brachial pressure assessment, 75 patients undergoing aorto-iliac stenting for atherosclerotic disease were prospectively followed up with duplex ultrasound at 3 monthly interval up to 1 year and then annually. We attempted to directly visualise the stents wherever possible using standard 2D imaging, standard and power Doppler, as well as spectral Doppler. Patients had an angiogram at 12 months or sooner if a problem was identified on the duplex scan. RESULTS: mean follow up was 14 months (2-36). Complete visualisation of the pelvic arterial tree was achieved in 94% of scans. All patients had at least one satisfactory scan. Duplex detected 30 lesions in 23 patients. Twenty-seven lesions were confirmed at angiography. There were two false positives. Overall sensitivity, specificity and accuracy were 100%, 93% and 96% for patient undergoing angiography. CONCLUSION: duplex ultrasound follow up is feasible in the majority of patients.

Prenatal diagnosis of heterokaryotypic mosaic twins discordant for fetal sex.

The presence of a monozygotic twin gestation with discordant sex of the twins is a very rare constellation, which is referred to as heterokaryotypic monozygotic pregnancy. This constellation can develop either due to a chromosomal aberration after twinning or is - as in the following case - due to a mitotic error before twinning and an unequal distribution of mosaicism in both embryos. So far the diagnosis of heterokaryotypic monozygotic pregnancy has always been made postnatally, with only one exception (Gonsoulin et al., 1990). In this case we suspected the presence of monozygotic twins ultrasonically because of the chorionic and amniotic membrane characteristics. Surprisingly the sex of the fetuses was discrepant. As one of them had hydrops and a structural heart defect, we carried out an amniocentesis, which revealed mosaicism [45,X/46,X,i(Y)(p10)] of both fetuses. The female fetus with a predominant 45,X set of chromosomes and the typical intrauterine signs of the Ullrich-Turner syndrome (massive hygroma colli, hydrops fetalis and multiple cardiac defects) died during the 25th week of gestation due to cardiac decompensation. The other fetus appeared to be male with a predominance of a 46,X,i(Y)(p10) set of chromosomes and was born a few days after the intrauterine death of the hydropic fetus. In conclusion, our observation shows that ultrasonic evidence of discordant fetal sex in twins does not necessarily exclude monozygosity.

The mechanism of methyl mercury toxicity in isolated rat hepatocytes.

Mercury is the major component of dental amalgam restorative material, which typically has 50% pure elemental mercury. It is also used in some skin creams, and in the manufacturing of plastic, drugs and fungicides. The present study was designed to investigate the toxicity of methyl mercury (MeHg+) on isolated rat hepatocytes using several toxicity parameters. The hepatocytes were isolated by a collagenase perfusion technique and were incubated with different concentrations of MeHg+ (0.1-100 ppm) for 2 h. Through the incubation period the viability was determined by Trypan blue exclusion. Reduced glutathione (GSH) content and its enzymes, glutathione peroxidase (GSH-PX) and glutathione reductase (GSH-RX) were measured. Leakage of enzymes such as aspartate transaminase (AST), and alanine transaminase (ALT) were determined. The cell viability was reduced significantly after 1 h incubation when 0.1 and 1 ppm MeHg+ were applied. The decrease in the cell viability was dose- and time-dependent. A depletion of GSH content was observed with 100 ppm MeHg+ after 30 min of incubation. A significant decrease in GSH-RX was observed with 100 ppm during 15 and 30 min of incubation, while 10 ppm of MeHg+ significantly increased ALT leakage after 60 min. However, there was a significant increase in AST leakage with 100 ppm only. The present investigation indicates that the toxic effect of MeHg+ is most likely cytosolic enzyme related.

A study of the epidemiology of preterm labor.

A case-control study was designed in order to identify risk factors associated with preterm labor. All cases fulfilling the criteria of eligibility as preterm labor and attending the Ain Shams University Maternity Hospital during the period from January 1991 to June 1991 were included in the study. In the meanwhile, all women delivering after the 37th week of gestation during that period and in the same hospital and matched according to age (+/- 5 years) were included as the control group. Two hundred and thirty four cases and 216 controls were included in the study. An interview was performed to fill an epidemiologic and clinical questionnaire. Results showed that the lower the socioeconomic standard, the more the risk for preterm labor (p < 0.05), smoking whether active or passive is associated with preterm labor (p < 0.001), threatened or induced abortion, unwanted pregnancy, psychological trauma and surgical intervention during current pregnancy are associated with preterm labor (p < 0.001). History of preterm labor is associated with the present condition (p < 0.001). Anemia, hypertension, body weight less than 70 kgm are associated with preterm labor (p < 0.001).