RESUMO
PURPOSE: To determine the effects of rubber-cup polishing with different prophylaxis polishing pastes (PPP) on the color stability and surface properties of enamel and dental restorations. METHODS: Direct (DC) and indirect composite (IC) samples were produced in disc-shaped plexiglass molds (10 x 2 mm). Computer-aided design and computer-aided manufacturing (CAD-CAM) composite blocks (CC) were sliced at a 2 mm thickness and the vestibular enamel surfaces (ES) of human incisors were included. A total of 96 samples were prepared and randomly divided into three subgroups (n= 8). The color, surface gloss and roughness measurements were performed before and after rubber-cup polishing at 2000 rpm for 12 seconds. Analysis of variance was used for statistical evaluation. RESULTS: No significant difference was observed between the surface roughness change values after polishing with all three PPPs in DC, IC, and ES. However, in the CC group, Cleanic paste caused the highest roughness values and gloss reduction. The highest color change has occurred in the ES, and the least was observed in IC and CC groups. The type of PPP has a significant effect on the color stability and surface properties of enamel and dental restorations as well as the restorative material type. CLINICAL SIGNIFICANCE: Prophylaxis polishing pastes may have detrimental effects on the surface properties of restorative materials in relation to the type of abrasive they contained and the roughness value.
Assuntos
Resinas Compostas , Polimento Dentário , Humanos , Borracha/farmacologia , Materiais Dentários , Propriedades de Superfície , Esmalte Dentário , Teste de MateriaisRESUMO
This study aimed to prepare colchicine (CO), 4-hydroxyacetophenone (HA), and protocatechuic acid (CA) contained in transdermal rubber plasters into a more releasable and acrylate pressure-sensitive adhesive (PSA) to optimize traditional Touguling rubber plasters (TOU) with enhanced transdermal permeability by using deep eutectic solvents (DES) technology. We compared the difference in the release behavior of CO between rubber plaster and PSA, determined the composition of the patch through pharmacodynamic experiments, explored the transdermal behavior of the three components, optimized the patch formula factors, and improved the penetration of CO through the skin. We also focused on elucidating the interactions among the three components of DES and the intricate relationship between DES and the skin. The melting point of DES was determined using DSC, while FTIR, 13C NMR, and ATR-FTIR were used to explore the intricate molecular mechanisms underlying the formation of DES, as well as its enhancement of skin permeability. The results of this investigation confirmed the successful formation of DES, marked by a discernible melting point at 27.33°C. The optimized patch, formulated with a molar ratio of 1:1:1 for CO, HA, and CA, significantly enhanced skin permeability, with the measured skin permeation quantities being 32.26 ± 2.98 µg/cm2, 117.67 ± 7.73 µg/cm2, and 56.79 ± 1.30 µg/cm2 respectively. Remarkably, the optimized patch also demonstrated similar analgesic and anti-inflammatory effects compared to commercial diclofenac diethylamide patches in different pharmacodynamics studies. The formation of DES altered drug compatibility with skin lipids and increased retention, driven by the interaction among the three component molecules through hydrogen bonding, effectively shielding the skin-binding sites and enhancing component permeation. In summary, the study demonstrated that optimized DES patches can concurrently enhance the penetration of CO, HA, and CA, thereby providing a promising approach for the development of DES in transdermal drug delivery systems. The findings also shed light on the molecular mechanisms underlying the transdermal behavior of DES and offer insights for developing more effective traditional Chinese medicine transdermal drug delivery systems.
Assuntos
Solventes Eutéticos Profundos , Absorção Cutânea , Colchicina/metabolismo , Colchicina/farmacologia , Borracha/metabolismo , Borracha/farmacologia , Administração Cutânea , Pele/metabolismo , Adesivo TransdérmicoRESUMO
The list of EPA-approved disinfectants for coronavirus features many products for use on hard, non-porous materials. There are significantly fewer products registered for use on porous materials. Further, many common, high-touch surfaces fall in between non-porous materials such as glass and porous materials such as soft fabrics. The objective of this study was to assess the efficacy of selected commercially available disinfectant products against coronaviruses on common, high-touch surfaces. Four disinfectants (Clorox Total 360, Bleach solution, Vital Oxide, and Peroxide Multi-Surface Cleaner) were evaluated against Murine Hepatitis Virus A59 (MHV) as a surrogate coronavirus for SARS-CoV-2. MHV in cell culture medium was inoculated onto four materials: stainless steel, latex-painted drywall tape, Styrene Butadiene rubber (rubber), and bus seat fabric. Immediately (T0) or 2-hr (T2) post-inoculation, disinfectants were applied by trigger-pull or electrostatic sprayer and either held for recommended contact times (Spray only) or immediately wiped (Spray and Wipe). Recovered infectious MHV was quantified by median tissue culture infectious dose assay. Bleach solution, Clorox Total 360, and Vital Oxide were all effective (>3-log10 reduction or complete kill of infectious virus) with both the Spray Only and Spray and Wipe methods on stainless steel, rubber, and painted drywall tape when used at recommended contact times at both T0 and T2 hr. Multi-Surface Cleaner unexpectedly showed limited efficacy against MHV on stainless steel within the recommended contact time; however, it showed increased (2.3 times greater efficacy) when used in the Spray and Wipe method compared to Spray Only. The only products to achieve a 3-log10 reduction on fabric were Vital Oxide and Clorox Total 360; however, the efficacy of Vital Oxide against MHV on fabric was reduced to below 3-log10 when applied by an electrostatic sprayer compared to a trigger-pull sprayer. This study highlights the importance of considering the material, product, and application method when developing a disinfection strategy for coronaviruses on high-touch surfaces.
Assuntos
COVID-19 , Desinfetantes , Vírus da Hepatite Murina , Animais , Desinfetantes/farmacologia , Desinfecção/métodos , Camundongos , Borracha/farmacologia , SARS-CoV-2 , Hipoclorito de Sódio/farmacologia , Aço Inoxidável/farmacologiaRESUMO
Much fundamental research has already been performed to understand the mechanism of microbial rubber degradation. Due to the increasing amount of rubber waste, biotechnical methods to degrade that particular waste are strongly needed. The present study evaluates whether a microbial or an enzymatic process is more suitable for efficient biodegradation, due to less sensitivity towards rubber additives. Therefore we investigated the impact of 15 different frequently used rubber additives on cells of the potent rubber degrader Gordonia polyisoprenivorans VH2 and the enzyme Lcp1VH2. For this, cells were grown on poly(cis-1,4-isoprene) in presence of these rubber additives. Furthermore, the effect of those additives on the enzymatic cleavage of poly(cis-1,4-isoprene) by Lcp1VH2 was determined by in vitro studies. It was observed that additives, used to accelerate the vulcanization process, like N-cyclohexyl-2-benzothiazolesulfenamide and zinc-bis(N,N-dibenzyl-dithiocarbamate), are diminishing the growth of the microorganism depending on their concentration-higher toxicity with increasing concentration. In contrast, sulfur prevents cell growth, but does not affect Lcp1VH2. Stearic acid and paraffin wax were found to be consumed by G. polyisoprenivorans VH2. Plasticizers mainly prevent growth, but do not interfere with the enzyme activity. This study identified antioxidants as the most interfering group of additives for microbial and enzymatic rubber degradation. It was found that the in vitro degradation by Lcp1VH2 is much more resistant and less sensitive towards the investigated rubber additives, when compared to the in vivo approach. Therefore, an enzymatic process might be a promising method to enhance rubber degradation.
Assuntos
Enzimas/metabolismo , Bactéria Gordonia/metabolismo , Hemiterpenos/metabolismo , Látex/metabolismo , Borracha/farmacologia , Antioxidantes/farmacologia , Biodegradação Ambiental/efeitos dos fármacos , Reagentes de Ligações Cruzadas/química , Bactéria Gordonia/efeitos dos fármacos , Bactéria Gordonia/crescimento & desenvolvimento , Plastificantes/farmacologia , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
BACKGROUND: Allergic contact dermatitis (ACD) is the most common occupational disease. Although murine contact hypersensitivity provides a framework for understanding ACD, it carries important differences from its human counterpart. Unlike the contact hypersensitivity model, which is induced by potent sensitizers (ie, dinitrofluorobenzene), human ACD is induced by weak-to-moderate sensitizers (ie, nickel), which cannot induce reactions in mice. Distinct hapten-specific immune-polarizing responses to potent inducers were suggested in mice, with unclear relevance to human ACD. OBJECTIVE: We explored the possibility of distinct T-cell polarization responses in skin to common clinically relevant ACD allergens. METHODS: Gene-expression and cellular studies were performed on common allergens (ie, nickel, fragrance, and rubber) compared with petrolatum-occluded skin, using RT-PCR, gene arrays, and immunohistochemistry. RESULTS: Despite similar clinical reactions in all allergen groups, distinct immune polarizations characterized different allergens. Although the common ACD transcriptome consisted of 149 differentially expressed genes across all allergens versus petrolatum, a much larger gene set was uniquely altered by individual allergens. Nickel demonstrated the highest immune activation, with potent inductions of innate immunity, TH1/TH17 and a TH22 component. Fragrance, and to a lesser extent rubber, demonstrated a strong TH2 bias, some TH22 polarization, and smaller TH1/TH17 contributions. CONCLUSIONS: Our study offers new insights into the pathogenesis of ACD, expanding the understanding of T-cell activation and associated cytokines in allergen-reactive tissues. It is the first study that defines the common transcriptome of clinically relevant sensitizers in human skin and identifies unique pathways preferentially activated by different allergens, suggesting that ACD cannot be considered a single entity.
Assuntos
Alérgenos/farmacologia , Dermatite Alérgica de Contato/genética , Pele/efeitos dos fármacos , Transcriptoma/imunologia , Adulto , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Citocinas/genética , Citocinas/imunologia , Dermatite Alérgica de Contato/imunologia , Dermatite Alérgica de Contato/patologia , Feminino , Perfilação da Expressão Gênica , Haptenos/imunologia , Haptenos/farmacologia , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Níquel/imunologia , Níquel/farmacologia , Testes do Emplastro , Perfumes/farmacologia , Vaselina/farmacologia , Borracha/farmacologia , Pele/imunologia , Pele/patologia , Especificidade da Espécie , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologia , Equilíbrio Th1-Th2/efeitos dos fármacosRESUMO
In the medical field, attached bacteria can cause infections associated with catheters, incisions, burns, and medical implants especially in immunocompromised patients. The problem is exacerbated by the fact that attached bacteria are â¼1000 times more resistant to antibiotics than planktonic cells. The rapid spread of antibiotic resistance in these and other organisms has led to a significant need to find new methods for preventing bacterial attachment. The goal of this research was to evaluate the effectiveness of novel polymer coatings to prevent the attachment of three medically relevant bacteria. Tests were conducted with Pseudomonas aeruginosa, Staphylococcus epidermidis, and Staphylococcus aureus for oligomers derived from modifications of natural rubber (cis 1,4-polyisoprene). The different oligomers were: PP04, with no quaternary ammonium (QA); MV067, one QA; PP06, three QA groups. In almost all experiments, cell attachment was inhibited to various extents as long as the oligomers were used. PP06 was the most effective as it decreased the planktonic cell numbers by at least 50% for all bacteria. Differences between species sensitivity were also observed. P. aeruginosa was the most resistant bacteria tested, S. aureus, the most sensitive. Further experiments are required to understand the full extent and mode of the antimicrobial properties of these surfaces.
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Borracha/química , Borracha/farmacologia , Staphylococcus/efeitos dos fármacos , Hemiterpenos/química , Hemiterpenos/farmacologia , Humanos , Látex/química , Látex/farmacologia , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa/fisiologia , Infecções Estafilocócicas/prevenção & controle , Staphylococcus/fisiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/fisiologiaRESUMO
ABSTRACT: Salmonella can be isolated from animal food, ingredients, and animal food manufacturing surfaces. There are limited data regarding the sanitation of animal food manufacturing surfaces. This experiment evaluated the effects of nine chemical treatments on reduction of Salmonella Typhimurium contamination on various manufacturing surfaces. This experiment was a 9 × 5 factorial with nine chemical treatments and five surfaces. The nine chemical treatments included one with no inoculation or sanitation treatment (negative control). In the other eight treatments, inoculation with Salmonella Typhimurium was followed by either no sanitation treatment (positive control) or treatment with ground corn; liquid commercial formaldehyde; liquid food-grade sanitizer; liquid medium chain fatty acid blend of caprylic, caproic, and capric acids (MCFA); dry commercial calcium propionate; dry commercial acidulant; and dry commercial benzoic acid. The five surfaces included stainless steel, plastic, polypropylene tote bag, rubber belt, and rubber tire. Plastic had higher levels of Salmonella in the positive control than did the polypropylene tote bag; other surfaces had intermediate levels (P < 0.05). Surfaces treated with formaldehyde had no detectable Salmonella after treatment, and surfaces treated with MCFA had at least a 4-log reduction compared to the control (P < 0.05). The dry acidulant was the most effective dry sanitizer tested, but it had no impact on Salmonella concentration on rubber tires (P < 0.05). Whereas liquid sanitizers were the most effective in this experiment, they have limitations for use in dry bulk systems. In summary, formaldehyde, food-grade sanitizer, and MCFA were the most effective chemical treatments to reduce Salmonella surface contamination. Surface type can also influence Salmonella mitigation strategies; specifically, stainless steel and plastic can be more challenging to sanitize within animal food facilities.
Assuntos
Salmonella typhimurium , Aço Inoxidável , Animais , Formaldeído/farmacologia , Polipropilenos/farmacologia , Borracha/farmacologiaRESUMO
The objective was to determine effects of old and new rubber matting in a slatted, indoor cattle feeding facility on cattle growth performance, locomotion, and carcass characteristics. In experiment 1, fall-born Angus × Simmental steers (N = 207; body weight = 222 ± 38 kg) were blocked by weight and assigned to 32 pens. Pens were randomly assigned to 1 of 4 treatments: no matting/concrete (CONC1), 12-yr-old Animat Pebble matting (OLD1), new Animat Maxgrip matting (MG), and new Animat Pebble matting (PEB1). Steers were fed a common diet for 209 d with a minimum stocking density of 3.40 m2 per animal. Final body weight (BW) and average daily gain (ADG) were affected (P = 0.02 and P < 0.01, respectively) by treatment with steers on PEB1 finishing heaviest with the greatest growth, MG and CONC1 intermediate, and OLD1 finishing at the lightest final BW with the least growth. Flooring treatment did not affect overall dry matter intake (DMI; P = 0.16) or gain to feed ratio (G:F; P = 0.94). Flooring treatment did not affect (P ≥ 0.19) any carcass traits. Locomotion scores (LS) were affected (P < 0.01) by flooring treatment with CONC1 having the worst mobility while OLD1, MG, and PEB1 were similar (P ≥ 0.24). Locomotion score had a day effect (P < 0.01) where cattle gait and mobility worsened as days on feed increased. In experiment 2, fall-born Angus × Simmental steers (N = 189; BW = 352 ± 43 kg) were blocked by weight and assigned to 21 pens. Pens were randomly assigned to 1 of 3 treatments: no matting/concrete (CONC2), 15-yr-old Animat Pebble matting (OLD2), and new Animat Pebble matting (PEB2). Steers were fed a common diet for 152 d with a stocking density of 2.65 m2 per steer. After 152 d on feed, flooring treatment did not affect (P ≥ 0.30) BW, ADG, or DMI nor did treatment affect (P ≥ 0.17) carcass traits. However, steers housed on OLD2 or PEB2 had improved locomotion scores (P = 0.02) compared with steers housed on CONC2. Locomotion score had a day effect (P < 0.01) as cattle gait and mobility worsened with greater number of days on feed, regardless of treatment. Overall, results suggest that new rubber matting increased ADG and HCW during a 209-d trial when cattle were stocked at 3.4 m2 in small pens and that rubber matting regardless of age improved cattle locomotion scores in slatted indoor feeding facilities.
Many feedlots in the Midwest have constructed slatted indoor cattle feeding facilities to improve winter pen conditions and decrease land requirements. Finishing cattle in indoor feeding facilities can increase cattle growth and carcass value, but greater prevalence of cattle lameness is a concern. Rubber matting is commonly used in these facilities, but it is a consumable product with a variable lifespan. This study evaluated the effects of old and new rubber matting in a slatted, indoor cattle feeding facility on cattle growth performance, locomotion, and carcass characteristics in two experiments. In experiment 1, steers in pens with new Animat Pebble matting had increased growth compared with steers in pens with no matting and 12-yr-old Animal Pebble matting. Furthermore, steers in pens with no matting had the poorest locomotion scores. In experiment 2, flooring treatments did not affect cattle growth or carcass traits, but steers in pens with old or new rubber matting had more desirable locomotion scores than cattle in pens with no matting. Therefore, new rubber matting can improve cattle growth in small pens with slatted floors when cattle were stocked at 3.4 m2 per steer (experiment 1) and that rubber matting regardless of age improved cattle locomotion.
Assuntos
Ração Animal , Borracha , Ração Animal/análise , Animais , Composição Corporal , Bovinos , Dieta/veterinária , Locomoção , Borracha/farmacologia , Aumento de PesoRESUMO
Millions of people are burned worldwide every year and 265,000 of the cases are fatal. The development of burn treatment cannot consist only of the administration of a single drug. Due to the infection risk, antibiotics are used in conjunction with gels and damp bandages. In this work, an inexpensive curative based on silver sulfadiazine (SS) and natural rubber latex (NRL) was developed to treat burn wounds. It was produced by the casting method. The infrared spectrum presented no interaction between drug and biopolymer. At the same time, electronic micrographs showed that the SS crystals are inserted on the polymeric dressing surface. Mechanical properties after the drug incorporation were considered suitable for dermal application. About 32.4% of loaded SS was released in 192 h by the dressings that also inhibited the growth of Candida albicans and Candida parapsilosis at 75.0 and 37.5 µg·mL-1, respectively. The curative proved to be biocompatible when applied to fibroblast cells, in addition to enhancing cellular proliferation and, in the hemocompatibility test, no hemolytic effects were observed. The good results in mechanical, antifungal and biological assays, combined with the average bandage cost of $0.10, represent an exciting alternative for treating burn wounds.
Assuntos
Bandagens , Queimaduras/tratamento farmacológico , Queimaduras/microbiologia , Candida/fisiologia , Borracha/farmacologia , Sulfadiazina de Prata/uso terapêutico , Animais , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Cinética , Camundongos , Testes de Sensibilidade Microbiana , Células NIH 3T3 , Ovinos , Sulfadiazina de Prata/química , Sulfadiazina de Prata/farmacologia , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
To fabricate antibacterial activity and simultaneous strengthened and toughened carboxylated nitrile butadiene rubber (XNBR) composites, starch was oxidized by H2O2 to achieve oxidized starch (OST) with different carboxyl content, meanwhile, ZnO were utilized to promote the in-situ interfacial reaction for improving compatibility of starch and XNBR. The formation of ionic cross-link networks and "Zinc-carboxylate polymers" in the XNBR/OST/ZnO composites were confirmed by FT-IR, XRD, XPS, SEM-EDS and TEM. Interestingly, because of the carboxyl groups of OSTs which provided a low pH surroundings to inhibit the growth of bacteria, XNBR/OST/ZnO composites achieved a significant antibacterial activity. Noteworthy, the sulfur-free XNBR composites achieved 3.04 and 1.99 times increase for tensile strength and elongation at break compared with neat XNBR. The mechanism of simultaneous strengthened and toughened for composites had been proposed. These new sustainable, green and facile fabricated XNBR/OST/ZnO could be utilized as the medical protective appliance to against the bacteria.
Assuntos
Butadienos/química , Nitrilas/química , Borracha/química , Amido/química , Antibacterianos/química , Antibacterianos/farmacologia , Nanocompostos/química , Oxirredução , Pseudomonas fluorescens/efeitos dos fármacos , Borracha/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Temperatura , Resistência à Tração , Zea mays/metabolismo , Óxido de Zinco/químicaRESUMO
BACKGROUND/PURPOSE (S): Nosocomial pathogens can develop biofilms on hospital surfaces and medical devices; however, few studies have focused on the evaluation of mono-and dual-species biofilms developed by nosocomial pathogens under different growth conditions. METHODS: This study investigated biofilm development by nosocomial pathogens (Acinetobacter baumannii, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) on biomaterials in different culture media and their components of the extracellular matrix biofilm. RESULTS: The mono-species biofilms showed cell densities from 7.50 to 9.27 Log10 CFU/cm2 on natural rubber latex type I (NLTI) and from 7.58 to 8.79 Log10 CFU/cm2 on stainless steel (SS). Dual-species biofilms consisted of S. aureus + P. aeruginosa (7.87-8.27 Log10 CFU/cm2 in TSBP and TSBME onto SS; p < 0.05), E. coli + P. aeruginosa (8.32-8.86 Log10 CFU/cm2 in TSBME onto SS and TSBP onto NLTI; p < 0.05), and S. aureus + E. coli (7.82 Log10 CFU/cm2 in TSBME onto SS; p < 0.05). Furthermore, biofilm detachment after proteinase K treatment was 5.54-32.81% compared to 7.95-24.15% after DNase I treatment in the mono-dual species biofilm matrix. Epifluorescence microscopy and scanning electron microscopy (SEM) enabled visualizing the bacteria and extracellular polymeric substances of biofilms on SS and NLTI. CONCLUSION: Nosocomial pathogens can develop biofilms on biomaterials. Mono-species biofilms of Gram-negative bacteria showed lower densities than dual-species biofilms in TSBME and TSBP. Additionally, dual-species biofilms showed a higher concentration of proteins and eDNA in the extracellular matrix.
Assuntos
Materiais Biocompatíveis/farmacologia , Biofilmes/efeitos dos fármacos , Infecção Hospitalar/microbiologia , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Aderência Bacteriana , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Técnicas de Cocultura , Contagem de Colônia Microbiana , Meios de Cultura/farmacologia , DNA Bacteriano/metabolismo , Matriz Extracelular de Substâncias Poliméricas/efeitos dos fármacos , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Matriz Extracelular de Substâncias Poliméricas/ultraestrutura , Humanos , Borracha/farmacologia , Aço Inoxidável/farmacologiaRESUMO
The incorporation of the prepared Ag-SiO2 core-shell particles in natural rubber matrix was investigated on antibacterial and mechanical properties of resulting composites. Significant antibacterial effect against S. aureus (Gram positive) and P. aeruginosa (Gram negative) was observed and achieved inhibition growth up to 85 and 90%, respectively, after 24 h depending on the amount of Ag-SiO2 core-shell. It was found that SiO2 acted as crosslinking agent and controlling the amount of silver release. UV-vis spectra and TEM, XRD showed Ag-SiO2 core-shell particles formation. SEM, FTIR, XRD and mechanical analysis showed uniform distribution of Ag-SiO2 core-shell into rubber matrix with enhanced tensile strength.
Assuntos
Antibacterianos/farmacologia , Dióxido de Silício/farmacologia , Prata/farmacologia , Testes de Sensibilidade Microbiana/métodos , Nanopartículas/química , Pseudomonas aeruginosa/efeitos dos fármacos , Borracha/síntese química , Borracha/farmacologia , Staphylococcus aureus/efeitos dos fármacosRESUMO
Cadmium (Cd) is among the most widespread and toxic heavy metals becoming a severe threat to humans. A field study was conducted to examine the role of various zinc (Zn) fertilization treatments and cultivars on crop productivity and Zn and Cd concentrations in brown rice and rice straw. The Zn fertilization treatments included an unfertilized control, foliar applied Zn sulfate (ZnSO4) at panicle initiation stage, foliar applied ZnSO4 at milky stage, soil application of rubber ash, and soil-applied ZnSO4, while five rice cultivars were Swat-1, Shadab, Shua-92, Swat-2, and Sada Hayat. All the Zn fertilization treatments resulted in significantly higher number of panicles, number of spikelets per panicles, spikelet fertility, 1,000-grain weight, grain yield, brown rice and rice straw Zn concentrations, and significantly lower Cd concentrations. Soil application of rubber ash remained the best among all Zn fertilization treatments as it resulted in 73% higher grain yield and reduced Cd concentration by 51% as compared with control. Variations were also apparent among cultivars, and Shua-92 and Swat-2 performed better in terms of all studied attributes as compared with other cultivars. Conclusively, cultivar selection and Zn application are effective strategies to improve rice grain yield as well as quality. Rubber ash appeared a viable source of Zn having the ability to increase yield along with reducing Cd accumulation.
Assuntos
Cádmio/farmacocinética , Fertilizantes , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Borracha/farmacologia , Sulfato de Zinco/farmacologia , Biomassa , Humanos , Borracha/químicaRESUMO
Ti6A14V alloy has been mainly used as a biomaterial in the orthopaedic field. The present study describes the surface state of the Ti6A14V material and evaluates its in vitro haemocompatibility in terms of protein adsorption, platelet retention and haemolysis. The behaviour of the Ti6A14V alloy towards albumin and fibrinogen was compared to that of a reference medical-grade elastomer. The platelet retention test gave better results than those achieved with the elastomer. The haemolysis percentage of the alloy was almost zero. These results indicate that the Ti6A14V alloy is well tolerated by blood.
Assuntos
Materiais Biocompatíveis/farmacologia , Plaquetas/efeitos dos fármacos , Proteínas Sanguíneas/fisiologia , Titânio/química , Adsorção , Ligas , Proteínas Sanguíneas/efeitos dos fármacos , Fibrinogênio/efeitos dos fármacos , Fibrinogênio/fisiologia , Coração Auxiliar , Hemólise/efeitos dos fármacos , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Borracha/farmacologia , Albumina Sérica/efeitos dos fármacos , Albumina Sérica/fisiologia , Titânio/farmacologiaRESUMO
OBJECTIVE: To define both the limits of a mouse embryo bioassay for quality control in an assisted reproductive technology (ART) program and the areas where it can be effectively used. DESIGN: Embryos at the pronuclear and two-cell stage from three different strains of mice were used to assess the effectiveness of this assay for media quality control using five different media routinely used in ART. Pronuclear and two-cell embryos from CD-1 mice were used to test the ability of a mouse embryo bioassay to control for water quality, contaminants in the culture system, and fluctuations in the environmental conditions using a medium, culture system, and scoring technique that were optimized for this strain. RESULTS: The mouse embryo bioassay is not effective in differentiating media appropriate for supporting human embryo development since the development of mouse embryos in vitro is strain, stage, and media related. However, CD-1 embryos were shown to be sensitive to variations in water quality, pH, temperature, incubator conditions, and contaminants in the system when grown in a protein-free medium optimized for their development. Both total blastocyst number and the cell count in the blastocysts were affected. Pronuclear embryos were more sensitive to perturbations in the culture system than two-cell embryos. CONCLUSIONS: A mouse embryo bioassay can be effectively used as a means of quality control of water, chemicals, and contact materials and for technique standardization and training in an assisted reproduction program. All the conditions of the test should be defined, pronuclear embryos should be used, and the end point should be fully expanded blastocysts and/or cell numbers in these blastocysts where appropriate.
Assuntos
Bioensaio , Controle de Qualidade , Técnicas Reprodutivas , Animais , Bioensaio/métodos , Meios de Cultura , Endotoxinas/farmacologia , Feminino , Concentração de Íons de Hidrogênio , Incubadoras , Substâncias Macromoleculares , Camundongos , Camundongos Endogâmicos , Borracha/farmacologia , Temperatura , ÁguaRESUMO
Evaluation of biomaterials with the help of routine methods not always allow full and explicit stating of their toxicity. That is why we still seek new methods of evaluation of biocompatibility on the cellular level. Usage of changes in activity of interleukin after biomaterials implantation creates such a possibility. The aim of this work as use of changes in activity of cytokines IL-1 beta and cytokines IL-6 for evaluation of biocompatibility of chosen medical materials. The tests were made on mice to whom polyester and aramid fibres as well as discs of rubber drains were implanted into the peritoneal cavity. Evaluation of the changes of the level of interleukin-1 beta and interleukin-6 was made in the fluid from the peritoneal cavity 3, 7, 14 and 21 days after implantation. Introductory tests of changes in the level of IL-1 beta and IL-6 after implantation of biomaterials with different degree of biocompatibility allow to assume that testing their activity may be useful in evaluation of their toxic effect.
Assuntos
Líquido Ascítico/química , Materiais Biocompatíveis/farmacologia , Interleucina-1/análise , Interleucina-6/análise , Poliésteres/farmacologia , Polímeros/farmacologia , Borracha/farmacologia , Animais , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Peritônio/cirurgia , Próteses e ImplantesRESUMO
Rubber D-51A under examination, treated by thiuram, following long-time contact with drinking water (static conditions of the experiment) discharges thiuram into it, which significantly worsens the water quality. Drinking of this water by animals leads to functional disturbances in their organisms. Short-time contact of rubber D-51A with drinking water does not cause deterioration of its quality. Therefore rubber D-51A can be recommended to be used as pump gaskets.
Assuntos
Borracha/toxicidade , Abastecimento de Água , Animais , Relação Dose-Resposta a Droga , Drosophila , Interações Medicamentosas , Peixes , Ratos , Borracha/farmacologia , Engenharia Sanitária/instrumentação , Engenharia Sanitária/normas , Fatores de Tempo , Água/efeitos adversos , Água/farmacologia , Abastecimento de Água/normasRESUMO
The aim of the present study was to evaluate the efficacy of Elastoguard silver-releasing rubber in preventing Pseudomonas aeruginosa biofilm formation in water. Biofilm formation by P. aeruginosa under various conditions in an in vitro model system was compared for silver-releasing and conventional rubber. Under most conditions tested, the numbers of sessile cells attached to silver-releasing rubber were considerably lower with reference to conventional rubber, although the effect diminished with increasing volumes. The release of silver also resulted in a decrease in planktonic cells. By exposing both materials simultaneously to conditions for biofilm growth, it became obvious that the antibiofilm effect was due to a reduction in the number of planktonic cells, rather than to contact-dependent killing of sessile cells. The data demonstrate that the use of silver-releasing rubber reduces P. aeruginosa biofilm in water and reduces the number of planktonic cells present in the surrounding solution.
Assuntos
Biofilmes/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Borracha/farmacologia , Prata/farmacologia , Água/química , Aderência Bacteriana/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/crescimento & desenvolvimentoRESUMO
A new silicone material, Silastic MDX 4-4210, was tested by tissue culture and tissue implantation to compare host reaction with known toxic and nontoxic materials. It was not found to be toxic to a monolayer of HEL cells, and it evoked a minimal foreign body reaction when implanted in albino rats. Further clinical studies are indicated to evaluate host reaction of this silicone in long-term contact with human mucous membrane and skin tissue.