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Importance: Evidence-based weight management treatments (WMTs) are underused; strategies are needed to increase WMT use and patients' weight loss. Objective: To evaluate the association of a primary care-based weight navigation program (WNP) with WMT use and weight loss. Design, Setting, and Participants: This cohort study comprised a retrospective evaluation of a quality improvement program conducted from October 1, 2020, to September 30, 2021. Data analysis was performed from August 2, 2022, to March 7, 2024. Adults with obesity and 1 or more weight-related condition from intervention and control sites in a large academic health system in the Midwestern US were propensity matched on sociodemographic and clinical factors. Exposure: WNP, in which American Board of Obesity Medicine-certified primary care physicians offered weight-focused visits and guided patients' selection of preference-sensitive WMTs. Main Outcomes and Measures: Primary outcomes were feasibility measures, including rates of referral to and engagement in the WNP. Secondary outcomes were mean weight loss, percentage of patients achieving 5% or more and 10% or more weight loss, referral to WMTs, and number of antiobesity medication prescriptions at 12 months. Results: Of 264 patients, 181 (68.6%) were female and mean (SD) age was 49.5 (13.0) years; there were no significant differences in demographic characteristics between WNP patients (n = 132) and matched controls (n = 132). Of 1159 WNP-eligible patients, 219 (18.9%) were referred to the WNP and 132 (11.4%) completed a visit. In a difference-in-differences analysis, WNP patients lost 4.9 kg more than matched controls (95% CI, 2.11-7.76; P < .001), had 4.4% greater weight loss (95% CI, 2.2%-6.4%; P < .001), and were more likely to achieve 5% or more weight loss (odds ratio [OR], 2.90; 95% CI, 1.54-5.58); average marginal effects, 21.2%; 95% CI, 8.8%-33.6%) and 10% or more weight loss (OR, 7.19; 95% CI, 2.55-25.9; average marginal effects, 17.4%; 95% CI, 8.7%-26.2%). Patients in the WNP group were referred at higher rates to WMTs, including bariatric surgery (18.9% vs 9.1%; P = .02), a low-calorie meal replacement program (16.7% vs 3.8%; P < .001), and a Mediterranean-style diet and activity program (10.6% vs 1.5%; P = .002). There were no between-group differences in antiobesity medication prescribing. Conclusions and Relevance: The findings of this cohort study suggest that WNP is feasible and associated with greater WMT use and weight loss than matched controls. The WNP warrants evaluation in a large-scale trial.
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Obesidad , Atención Primaria de Salud , Pérdida de Peso , Programas de Reducción de Peso , Humanos , Femenino , Masculino , Atención Primaria de Salud/estadística & datos numéricos , Estudios Retrospectivos , Persona de Mediana Edad , Adulto , Obesidad/terapia , Programas de Reducción de Peso/métodos , Programas de Reducción de Peso/estadística & datos numéricos , Navegación de Pacientes , Mejoramiento de la Calidad , Estudios de CohortesRESUMEN
Excessive consumption of antibiotics is considered one of the top public health threats, this necessitates the development of new compounds that can hamper the spread of infections. A facile green technology for the biosynthesis of Zinc oxide nanoparticles (ZnO NPs) using the methanol extract of Spirulina platensis as a reducing and stabilizing agent has been developed. A bunch of spectroscopic and microscopic investigations confirmed the biogenic generation of nano-scaled ZnO with a mean size of 19.103 ± 5.66 nm. The prepared ZnO NPs were scrutinized for their antibacterial and antibiofilm potentiality, the inhibition zone diameters ranged from 12.57 ± 0.006 mm to 17.33 ± 0.006 mm (at 20 µg/mL) for a variety of Gram-positive and Gram-negative pathogens, also significant eradication of the biofilms formed by Staphylococcus aureus and Klebsiella pneumoniae by 96.7% and 94.8% respectively was detected. The free radical scavenging test showed a promising antioxidant capacity of the biogenic ZnO NPs (IC50=78.35 µg/mL). Furthermore, the anti-inflammatory role detected using the HRBCs-MSM technique revealed an efficient stabilization of red blood cells in a concentration-dependent manner. In addition, the biogenic ZnO NPs have significant anticoagulant and antitumor activities as well as minimal cytotoxicity against Vero cells. Thus, this study offered green ZnO NPs that can act as a secure substitute for synthetic antimicrobials and could be applied in numerous biomedical applications.
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Nanopartículas del Metal , Nanopartículas , Spirulina , Óxido de Zinc , Animales , Chlorocebus aethiops , Óxido de Zinc/farmacología , Óxido de Zinc/química , Células Vero , Nanopartículas/química , Antibacterianos/farmacología , Antibacterianos/química , Biopelículas , Nanopartículas del Metal/química , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/farmacología , Extractos Vegetales/químicaRESUMEN
Obesity is the most common chronic condition in the United States (US), yet primary care physicians face barriers in providing obesity treatment. This study examines the prevalence of American Board of Obesity Medicine (ABOM) certified obesity specialists on the faculty of US Family Medicine residency training programmes, the preparedness of graduating resident physicians to treat obesity, and residency training programme director preferences for supporting faculty development to improve residency education in obesity management. This cross-sectional on-line survey of programme directors addressed the number of ABOM-certified faculty, perceived graduate preparedness to treat obesity, and priorities to improve faculty expertise and obesity curriculum. Of 672 eligible programme directors, 298 (44%) responded to our survey. Most programmes (76%) had no ABOM-certified faculty. The proportion of programme directors assessing their graduates as prepared to care for patients with obesity has significantly decreased in the last 5 years (2018: 74%, 2022: 58%, p = .016). Residents in programmes with ABOM-certified faculty member were more likely to be assessed as very prepared to provide medical care (18% vs. 7.8% p = .047). A majority (54%) of programme directors identified limited faculty training and expertise as the biggest faculty and resident-level barrier to quality obesity care. This study demonstrates an important trend towards increasing ABOM-certification among Family Medicine residency programme faculty and an urgent need to prioritise faculty development to improve faculty expertise and resident training to address the obesity epidemic.
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Docentes Médicos , Medicina Familiar y Comunitaria , Internado y Residencia , Obesidad , Humanos , Estados Unidos , Obesidad/terapia , Obesidad/epidemiología , Medicina Familiar y Comunitaria/educación , Estudios Transversales , Encuestas y Cuestionarios , Educación de Postgrado en Medicina , Curriculum , Masculino , FemeninoRESUMEN
Microbial fuel cell (MFC) is a bio-electrical energy generator that uses respiring microbes to transform organic matter present in sludge into electrical energy. The primary goal of this work was to introduce a new approach to the green electricity generation technology. In this context a total of 6 bacterial isolates were recovered from sludge samples collected from El-Sheikh Zayed water purification plant, Egypt, and screened for their electrogenic potential. The most promising isolates were identified according to 16S rRNA sequencing as Escherichia coli and Enterobacter cloacae, promising results were achieved on using them in consortium at optimized values of pH (7.5), temperature (30°C) and substrate (glucose/pyruvate 1%). Low level red laser (λ = 632.8nm, 8mW) was utilized to promote the electrogenic efficiency of the bacterial consortium, maximum growth was attained at 210 sec exposure interval. In an application of adding standard inoculum (107 cfu/mL) of the photo-stimulated bacterial consortium to sludge based MFC a significant increase in the output potential difference values were recorded, the electricity generation was maintained by regular supply of external substrate. These results demonstrate the future development of the dual role of MFCs in renewable energy production and sludge recycling.
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Electricidad , Aguas del Alcantarillado , ARN Ribosómico 16S/genética , Enterobacter cloacae , Escherichia coli , Ácido PirúvicoRESUMEN
Repurposing natural compounds as inhibitory targets to combat bacterial virulence is an important potential strategy to overcome resistance to traditional antibiotics, in the present study, the antibacterial activity of micro-curcumin and nano-sized curcumin was investigated against four predominant bacterial pathogens, namely, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis. Curcumin bactericidal susceptibility could be summarized as the order, P. aeruginosa > B. subtilis > S. aureus > E. coli. Molecular docking analysis was conducted to confirm the impact of curcumin on the most vital and positively identified quorum-sensing pathway signaling proteins SecA-SecY, LsrR, PqsR (MvfR), AgrA which act as key players in the bacterial communication systems. The in silico physicochemical properties revealed that curcumin as a nutraceutical can be classified as a drug-like compound. An in vivo infected wound model was employed in four groups of albino rats. Topical application of nano-curcumin lotion showed a marked reduction in wound area (98.8%) as well as nearly 100% reduction in total bacterial viable count compared to the control group, on the fifteenth day post-treatment post-injury. The obtained data suggested that curcumin nanoparticles exhibited superior antibacterial activity and may possess clinical utility as a novel topical antimicrobial and wound healing agent.
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Curcumina , Staphylococcus aureus , Ratas , Animales , Curcumina/farmacología , Curcumina/química , Simulación del Acoplamiento Molecular , Escherichia coli , Antibacterianos/farmacología , Antibacterianos/química , Bacterias , Pseudomonas aeruginosaRESUMEN
OBJECTIVE: Acute pain is the most common type of pain. The aim of the present work was carried out to study the antinociceptive effect and pharmacological mechanisms of thiocyanoacetamide (Thm) in rats exposed to thermal pain stimulus. MATERIALS AND METHODS: The anti-nociceptive effect of the newly synthesized compound, Thm was studied in comparison to that of paracetamol (Para), dexamethasone (Dex), and morphine (Morph) at different doses using a hot plate test at a constant temperature of 48.0 ± 0.5°C. During this test, the latency time (LT) was measured when rats express pain behavior. Then, the pharmacological mechanisms were determined using receptor-antagonist drugs. RESULTS: Firstly, the obtained result showed pain modulation of the pretreated rats with Thm at 10 mg/kg dose proved by the delay of latency time during the thermal test. This significant antinociceptive activity of the thiocyanoacetamide was more effective than that of paracetamol or dexamethasone and less than that of morphine. Second, the pretreatment with acebutolol or risperidone antagonist drugs of, respectively, adrenergic and serotonin receptors demonstrated the elimination of pain modulation with Thm 10 mg/kg dose proved by a short latency time of rat's response in hot plate test. In this case, the pharmacological mechanism of Thm was characterized by the involvement of adrenergic and serotoninergic systems. CONCLUSIONS: It may be concluded that Thm constitutes a promising antinociceptive drug including beta-adrenergic and serotoninergic targets. The present study warrants further investigation to determine the side effects of this compound.
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Acetaminofén , Dolor Agudo , Ratas , Animales , Morfina/farmacología , Analgésicos/farmacología , Analgésicos/uso terapéutico , Adrenérgicos , Dexametasona , Relación Dosis-Respuesta a Droga , CalorRESUMEN
BACKGROUND: Primary care patients with obesity seldom receive effective weight management treatment in primary care settings. This study aims to understand PCPs' perspectives on obesity treatment barriers and opportunities to overcome them. STUDY DESIGN: This is an explanatory sequential mixed methods study in which survey data was collected and used to inform subsequent qualitative interviews. SETTINGS AND PARTICIPANTS: PCPs who provide care to adult patients in an academic medical center in the Midwestern US. METHODOLOGY: PCPs (n = 350) were invited by email to participate in an online survey. PCPs were subsequently invited to participate in semi-structured interviews to further explore survey domains. ANALYTIC APPROACH: Survey data were analyzed using descriptive statistics. Interviews were analyzed using directed content analysis. RESULTS: Among 107 survey respondents, less than 10% (n = 8) used evidence-based guidelines to inform obesity treatment decisions. PCPs' identified opportunities to improve obesity treatment including (1) education on local obesity treatment resources (n = 78, 73%), evidence-based dietary counseling strategies (n = 67, 63%), and effective self-help resources (n = 75, 70%) and (2) enhanced team-based care with support from clinic staff (n = 53, 46%), peers trained in obesity medicine (n = 47, 44%), and dietitians (n = 58, 54%). PCPs also desired increased reimbursement for obesity treatment. While 40% (n = 39) of survey respondents expressed interest in obesity medicine training and certification through the American Board of Obesity Medicine, qualitative interviewees felt that pursuing training would require dedicated time (i.e., reduced clinical effort) and financial support. CONCLUSIONS: Opportunities to improve obesity treatment in primary care settings include educational initiatives, use of team-based care models, and policy changes to incentivize obesity treatment. Primary care clinics or health systems should be encouraged to identify PCPs with specific interests in obesity medicine and support their training and certification through ABOM by reimbursing training costs and reducing clinical effort to allow for study and board examination.
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Nutricionistas , Médicos de Atención Primaria , Neumonía por Pneumocystis , Adulto , Humanos , Atención Primaria de Salud/métodos , Obesidad/terapia , Encuestas y Cuestionarios , Atención Integral de Salud , Actitud del Personal de Salud , Médicos de Atención Primaria/psicologíaRESUMEN
Inflammatory pain is part of the body's defense mechanism and plays an important role in the healing process. Although some drugs are efficient and intensively used for their potent anti-inflammatory properties, they present problematic side effects. The aim of this study was to evaluate the anti-nociceptive effect of the thiocyanoacetamide (Thm) compared to paracetamol (Para), dexamethasone (Dex) and morphine (Morph) and to study inflammatory mediators on models of acute inflammatory pain in rats using the formalin injection test in the hind paw of rats as chemical stimulus. The obtained results showed significant modulation of pain by Thm pretreatment with a maximum at an effective dose (10 mg/kg) proved by the absence of licking and biting of the affected paw during the early and late phases of inflammation. This effect was comparable to Dex at 10 mg/kg, Para at 400 mg/kg and less than Morph at 5 mg/kg pretreatment doses. The study of anti-inflammatory targets showed that Thm pretreatment maintained plasma serotonin release at normal level compared to the negative control group (T-) and corrected the decrease in the plasma level of prostaglandins after inflammatory induction with no variation in the level of histamine in different groups. The evaluation of inflammation mediators demonstrated that the pretreatment with Thm induced the decrease in the amount of both IL-1 Beta and TNF alpha in plasma and the increase in their amount in the tissue of the injection site. The Thm has been promoted as an anti-nociceptive drug that induces modulation of inflammatory mediators.
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Analgésicos , Mediadores de Inflamación , Ratas , Animales , Analgésicos/uso terapéutico , Dolor/tratamiento farmacológico , Dolor/inducido químicamente , Antiinflamatorios/uso terapéutico , Acetaminofén/efectos adversosRESUMEN
This study was conducted to evaluate the impact of human activities on the ecological health and food chain at the shores of four Nile Islands in Great Cairo including El-Qeratten, El-Waraq, El-Zamalek, and El-Manial. Water quality, bacteria, phytoplankton, benthic algae, zooplankton, macrobenthic invertebrates, and bony fishes were examined at each island shore over two seasons including the lowest and the highest flow (February and July 2020, respectively). The obtained results showed that the average values of most of the chemicals in Nile Island's water were within the Egyptian water quality limits. Discriminant analysis of physicochemical factors revealed a similarity between El-Waraq and El-Qerateen and between El-Manial and El-Zamalek. El-Qeratten was the most polluted island. It has the highest total and fecal coliform bacteria count (3.155 and 3.050 Log MPN/100 mL, respectively). El-Zamalek shores have the highest phytoplankton (33,582 cells × 104 L-1) and zooplankton count (310,891 organisms × m-3) and phyto-biochemical values. Biochemical analysis of phytoplankton demonstrated the richness of the bulk by protein (> 85% of biomass), indicating that phytoplankton has a high nutritional value. Elevated zooplankton count was recorded at El-Zamalek, which coincided with the peak of phytoplankton abundance. Mollusca were the dominant macrobenthic invertebrates on most of the island's shores. Bony fishes were represented by 27 species and two crustaceans. The levels of the metals in fish samples were compared with the food safety guideline endorsed by the World Health Organization and Food and Agriculture Organization (WHO/FAO) to evaluate the toxicity level.
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Cadena Alimentaria , Ríos , Animales , Egipto , Monitoreo del Ambiente , Islas , Ríos/químicaRESUMEN
<b>Background and Objective:</b> Astaxanthin (3,3'-dihydroxy-ß-ß-carotene-4,4'-dione) is a carotenoid, commonly found in marine environments has been reported to possess versatile biological properties including anti-inflammatory and antioxidant. In this study, the pancreatic protective effect of astaxanthin was investigated in D-Galactosamine-induced pancreas injury in rats. <b>Materials and Methods:</b> In this experimental study, MTT assay was used to determine cytotoxic effects of the Astaxanthin on pnc1 cells. A total of 30 adult albino rats divided into 5 groups, six rats in each. Group I was given an equal amount of distilled water, group II was received 400 mg kg<sup>1</sup> b.wt. D-galactosamine on 15th day, groups III-V were treated with astaxanthin (50 and 100 mg kg<sup>1</sup>) and/or silymarin (50 mg kg<sup>1</sup>) for 14 days + 400 mg kg<sup>1</sup> b.wt. D-galactosamine on the 15th day, respectively. <b>Results:</b> IC<sub>50 </sub>of Astaxanthin against the pnc1 cell line was 92.9 µg mL<sup>1</sup>. The daily oral administration of astaxanthin (50 and 100 mg kg<sup>1</sup>) as well as silymarin (50 mg kg<sup>1</sup>) for 14 days to rats treated with D-galactosamine resulted in a significant improvement in plasma AST, ALT, ALP as well as pancreatic TNF-α, IL-1ß, IL-10, NO and VEGF-C gene expression. On the other hand, inducible oral administration of astaxanthin increased the activity of pancreatic GSH, SOD, GPx, GR, CAT and the level of TBARs in D-galactosamine-treated pancreatic of rats. Furthermore, Astaxanthin almost normalized these effects in pancreatic tissue histoarchitecture and MRI examination. <b>Conclusion:</b> The obtained results showed that Astaxanthin protected experimental animals against D-galactosamine-induced pancreatic injury through activation of antioxidant enzymes and IL-10 and inhibition of VEGF-C activation.
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Antioxidantes , Galactosamina , Animales , Antioxidantes/farmacología , Galactosamina/toxicidad , Expresión Génica , Ratas , Factor C de Crecimiento Endotelial Vascular , XantófilasRESUMEN
BACKGROUND: Primary care providers (PCPs) are expected to help patients with obesity to lose weight through behavior change counseling and patient-centered use of available weight management resources. Yet, many PCPs face knowledge gaps and clinical time constraints that hinder their ability to successfully support patients' weight loss. Fortunately, a small and growing number of physicians are now certified in obesity medicine through the American Board of Obesity Medicine (ABOM) and can provide personalized and effective obesity treatment to individual patients. Little is known, however, about how to extend the expertise of ABOM-certified physicians to support PCPs and their many patients with obesity. AIM: To develop and pilot test an innovative care model - the Weight Navigation Program (WNP) - to integrate ABOM-certified physicians into primary care settings and to enhance the delivery of personalized, effective obesity care. METHODS: Quality improvement program with an embedded, 12-month, single-arm pilot study. Patients with obesity and ≥1 weight-related co-morbidity may be referred to the WNP by PCPs. All patients seen within the WNP during the first 12 months of clinical operations will be compared to a matched cohort of patients from another primary care site. We will recruit a subset of WNP patients (n = 30) to participate in a remote weight monitoring pilot program, which will include surveys at 0, 6, and 12 months, qualitative interviews at 0 and 6 months, and use of an electronic health record (EHR)-based text messaging program for remote weight monitoring. DISCUSSION: Obesity is a complex chronic condition that requires evidence-based, personalized, and longitudinal care. To deliver such care in general practice, the WNP leverages the expertise of ABOM-certified physicians, health system and community weight management resources, and EHR-based population health management tools. The WNP is an innovative model with the potential to be implemented, scaled, and sustained in diverse primary care settings.
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Manejo de la Obesidad , Humanos , Obesidad/psicología , Obesidad/terapia , Proyectos Piloto , Atención Primaria de Salud , Mejoramiento de la CalidadRESUMEN
Between 5% and 12% of children ages 2 to 5 years are diagnosed with a speech or language delay. Fifty percent of these children experience delays that persist into adolescence, and face educational and occupational challenges later in life. The causes of speech and language delay vary. Some children are born with physical or physiologic conditions that impede speech and language development, whereas others have cognitive or developmental conditions, such as autism spectrum disorder. Risk factors include male sex, prematurity, low birth weight, late birth order, larger family size, and maternal intimate partner (ie, domestic) violence. Although there is no required screening or universally recommended screening tool for speech or language delay, reliable milestone indicators and parent and physician questionnaires can help identify children in need of diagnostic evaluation. If further screening is warranted or if parental concern exists beyond the well-child visit, local resources are available for evaluation and intervention. These include agencies and school districts, as well as speech and language pathology subspecialists.
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Trastorno del Espectro Autista , Trastornos del Desarrollo del Lenguaje , Adolescente , Trastorno del Espectro Autista/diagnóstico , Trastorno del Espectro Autista/terapia , Niño , Preescolar , Discapacidades del Desarrollo/diagnóstico , Discapacidades del Desarrollo/terapia , Humanos , Trastornos del Desarrollo del Lenguaje/diagnóstico , Trastornos del Desarrollo del Lenguaje/terapia , Masculino , Instituciones Académicas , HablaRESUMEN
The plant-based-sea water culture medium is introduced to in vitro cultivation and in situ recovery of the microbiome of halophytes. The ice plant (Mesembryanthemum crystallinum) was used, in the form of juice and/or dehydrated plant powder packed in teabags, to supplement the natural sea water. The resulting culture medium enjoys the combinations of plant materials as rich source of nutrients and sea water exercising the required salt stress. As such without any supplements, the culture medium was sufficient and efficient to support very good in vitro growth of halotolerant bacteria. It was also capable to recover their in situ culturable populations in the phyllosphere, ecto-rhizosphere and endo-rhizosphere of halophytes prevailing in Lake Mariout, Egypt. When related to the total bacterial numbers measured for Suaeda pruinosa roots by quantitative-PCR, the proposed culture medium increased culturability (15.3-19.5%) compared to the conventional chemically-synthetic culture medium supplemented with (11.2%) or without (3.8%) NaCl. Based on 16S rRNA gene sequencing, representative isolates of halotolerant bacteria prevailed on such culture medium were closely related to Bacillus spp., Halomonas spp., and Kocuria spp. Seed germination tests on 25-50% sea water agar indicated positive interaction of such bacterial isolates with the germination and seedlings' growth of barley seeds.
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This study aimed to explore the analgesic, antioxidant, behavioral and toxicological effects of 3,5-diaminopyrazole and thiocyanoacetamide. Caffeine was used as reference drug whose effects are known after oral treatment with an efficient dose (10mg/kg/day) for 30days. The preliminary bioassays indicated that both compounds at this dose have strong antioxidant capacities and present highly analgesic effects. The behavioral study showed an activation of the rat memory by thiocyanoacetamide. This molecule caused a phobia state to open areas in the elevated plus maze and specifically agoraphobia in the open field with a lack in the development of the exploratory capacity. 3,5-Diaminopyrazole caused memory troubles in rats that forgot the pathway to the exit from the maze, and induced an anxiety state revealed by immobility in closed arms of the elevated plus maze. All these observations were compared to the treatment by the known analgesic, caffeine, which increased the state of vigilance of the rats and developed their exploratory capacity. The chronic treatment with the investigated compounds showed no sign of toxicity with the absence of effect on the body and organ weights, blood count, kidney and liver function and histology. 3,5-Diaminopyrazole and thiocyanoacetamide have potent antioxidant and analgesic activities that are higher than caffeine with a safety profile. The chronic treatment by thiocyanoacetamide activated the memory and caused an emotional state of agoraphobia, but 3,5-diaminopyrazole caused a memory impairment and an emotional state of anxiety. Thus, the present study warrants further investigations involving these novel molecules for a possible development of new strong analgesic and antioxidant drugs which have an effect on the memory capacity.
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Analgésicos/farmacología , Aprendizaje por Laberinto/efectos de los fármacos , Nitrilos/farmacología , Pirazoles/farmacología , Pruebas de Toxicidad Crónica/métodos , Analgésicos/síntesis química , Animales , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/métodos , Masculino , Aprendizaje por Laberinto/fisiología , Nitrilos/síntesis química , Pirazoles/síntesis química , Ratas , Ratas WistarRESUMEN
BACKGROUND: P. aeruginosa considered as a notoriously difficult organism to be controlled by antibiotics or disinfectants. The potential use of alternative means as an aid to avoid the wide use of antibiotics against bacteria pathogen has been recently arisen remarkably. OBJECTIVE: Effect of extremely low frequency positive electric pulse with different duty cycles on Pseudomonas aeruginosa (ATCC: 27853) growth by constructed and implemented exposure device was investigated in this study. METHODS: The exposure device was applied to give extremely low frequency in the range of 0.1 up to 20 Hz with the capability to control the duty cycle of each pulse with variation from 10% up to 100%. Growth curves of Pseudomonas aeruginosa were investigated before and after exposure to different frequencies (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 Hz) through measuring the optical density and cell count. Exposures to selected frequencies in the whole ranges of duty cycles were done. These studies were followed by DNA fragmentation, transmission electron microscope (TEM), antibiotic susceptibility tests, and dielectric measurements. RESULTS: Findings revealed inhibition effect by 48.56% and 47.4% together with change in the DNA structural properties for samples exposed to 0.5 Hz and 0.7 Hz respectively. Moreover the data indicated important role of duty cycle on the inhibition mechanism. CONCLUSION: It is concluded that there are two different mechanisms of interaction between positive electric pulse and microorganism occurred; 0.5 Hz caused rupture in cell wall while 0.7 Hz caused denaturation of the inner consistent of the cell.
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Electricidad , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/crecimiento & desarrollo , Antibacterianos/farmacología , Fragmentación del ADN/efectos de los fármacos , ADN Bacteriano/genética , Humanos , Infecciones por Pseudomonas/tratamiento farmacológico , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/genéticaRESUMEN
Among 42 plant species representing the flora of north Sinai, two possessed sand grain sheath encasing the roots. They are Panicum turgidum Forssk. and Stipagrostis scoparia (Trin.and Rupr.) deWinter. Rhizosheaths, compared to surrounding free sand, accommodated higher population density of microorganisms including associative diazotrophs. Isolates secured belonged to the species of Bacillus circulans, Paenib. macerans (Bacillus macerans), Enterobacter agglomerans, Agrobacterium radiobacter and Chryseomonas luteola (Pseudomonos luteola). The rhizosheath potentiality in re-vegetating sand dunes and arid lands, through nitrogen fixation, plant-water relationship and root continuity for nutrient uptake, are discussed.