Development of flow cytometry and its application in plant research / 生物工程学报

Flow cytometry is a multi-parameter, rapid and efficient method for qualitative analysis and quantitative determination of various fluorescently labeled particles in liquid flow. Flow cytometry has been applied in multiple disciplines such as immunology, virology, molecular biology, cancer biology and infectious disease monitoring. However, the application of flow cytometry in plant research is hampered due to the special composition and structure of plant tissues and cells, such as cell walls and secondary metabolites. In this paper, the development, composition and classification of flow cytometry were introduced. Subsequently, the application, research progress and application limitations of flow cytometry in plant field were discussed. At last, the development trend of flow cytometry in plant research was prospected, which provides new perspectives for broadening the potential application scope of plant flow cytometry.

A unique formulation of sodium bicarbonate buffered pantoprazole powder for oral suspension: perspectives from an active controlled cross-over bioequivalence study

Background:The aim was determining bioequivalence between pantoprazole buffered powder for oral suspension and pantoprazole enteric coated tablets under fasting conditions in healthy volunteers.Methods:In randomized cross-over study, participants were administered a single oral dose of pantoprazole powder as suspension 40 mg (sodium bicarbonate as buffer) or one enteric coated tablet of pantoprazole 40 mg, with240�ml of water as per the randomization schedule in each study period. Blood samples were collected at pre-dose and at 0.33, 0.67, 1, 1.33, 1.67, 2, 2.33, 2.67, 3, 3.33, 3.67, 4, 4.5, 5, 5.5, 6, 7, 8, 9, 10, 12, 14, 16and 24hours post-dose. Plasmaconcentration of pantoprazole was determined with LC-MS and various pharmacokinetic parameters like Cmax, AUC0-t, AUC0-inf were compared between test and reference groups.Results:Amongst 41 subjects, Cmax(3752.4�84.6 vs. 3521.7�99.5 ng/ml)was achieved higher in less Tmaxtime (1 (0.28) vs. 2.3 (0.83) hrs)with test drug as compared to reference drug. The ratios of geometric least square mean and its 90% confidence interval on log transformed Cmax, AUC0-t and AUC0-inffor pantoprazole fall within the acceptance criteria of 80% to 125%. No adverse events were observed.Conclusions:Pantoprazole powder for oral suspension 40 mg (sodium bicarbonate as buffer) was well tolerated and bioequivalent with pantoprazole enteric coated tablets IP 40 mg in terms of rate and extent of absorption under fasting conditions. At same time, the shift in AUC to the left with reduction in Tmaxwith the new formulation is suggestive of faster rate of absorption.

Novel biopharmaceutical development investigations towards drug and formulation performance optimization

For a drug to excerpt pharmacological action after oral intake, it first needs to be released from the formulation, get into solution (dissolve), be absorbed, and reach the systemic circulation. Since only solubilized drugs can be absorbed, and thus have therapeutic effect, the understanding of the dissolution and drug release processes of a drug product is of primary importance. Such understanding allows a robust formulation development with an ideal in vivo performance. In order to meet set standards, the performance assessment of oral drug products, such as dissolution testing, often applies conditions that are not reflective of the in vivo environment. The use of non-physiologically relevant dissolution method during the drug product development phase can be misleading and give poor mechanistic understanding of the in vivo dissolution process. Hence, we hypothesized that applying physiologically relevant conditions to the dissolution test would result in more accurate in vivo predictability for a robust and precise development process. Since the buffering system in the intestinal lumen operates at low molarity values, phosphate buffer at low buffer capacity was used as a first approach to an in vivo relevant parameter. Furthermore, a biphasic system was used, that is, the low buffer capacity medium was paired with an organic layer (n-octanol) to mimic the concurrent drug absorption that happens with the in vivo dissolution. Both poorly and highly soluble drugs in immediate release formulations (ibuprofen and metronidazole, respectively) were tested in this set-up to assess the dissolution in the aqueous medium and the partitioning to the organic phase. Additionally, enteric coated formulations were tested in bicarbonate buffer at the in vivo reported molarities values to assess the impact of buffer species on drug dissolution. The evaluated parameters were the buffer system (bicarbonate buffer vs. phosphate buffer), buffer capacity and medium pH. In all approaches, dissolution was also carried out in compendial buffer for comparison purposes. Our results demonstrate that the USP-recommended dissolution method greatly lacked discriminatory power, whereas low buffer capacity media discriminated between manufacturing methods. The use of an absorptive phase in the biphasic dissolution test assisted in controlling the medium pH due to the drug removal from the aqueous medium. Hence, the applied noncompendial methods were more discriminative to drug formulation differences and manufacturing methods than conventional dissolution conditions. In this study, it was demonstrated how biphasic dissolution and a low buffer capacity can be used to assess drug product performance differences. This can be a valuable approach during the early stages of drug product development for investigating drug release with improved physiological relevance. Similarly, all the enteric coated formulations displayed a fast release in phosphate buffer and complied with the compendial performance specifications. On the other hand, they all had a much slower drug release in bicarbonate buffer and failed the USP acceptance criteria. Also, the nature of the drug (acid vs base) impacted the dissolution behavior in bicarbonate buffer. This study indicates that compendial dissolution test for enteric coated tablets lacks physiological relevance and it needs to be reevaluated. Thus, an in vivo relevant performance method for EC products is needed. Overall, the findings of this thesis comprehensively demonstrates that meaningful differences in performance and accordance to clinical reports were only obtained when physiological relevant conditions were applied. Hence, our results indicate that the central hypothesis was answered positively

Para que um medicamento exerça a ação farmacológica após a ingestão oral, ele primeiro precisa ser liberado da formulação, dissolver, ser absorvido e atingir a circulação sistêmica. Uma vez que apenas medicamentos solubilizados podem ser absorvidos e, assim, ter efeito terapêutico, a compreensão dos processos de dissolução e liberação de um medicamento é de extrema importância. Tal compreensão permite o desenvolvimento de uma formulação robusta com o desempenho in vivo ideal. Para atender aos padrões regulatórios previamente estabelecidos, a avaliação da performance de formulações orais, como por exemplo, o teste de dissolução, frequentemente aplica condições que não refletem o ambiente fisiológico. O uso de métodos de dissolução não fisiologicamente relevante durante a fase de desenvolvimento do medicamento pode gerar resultados equivocados sem uma compreensão mecanistica do processo de dissolução in vivo. Portanto, a hipótese desse trabalho é que a aplicação de condições fisiologicamente relevantes no teste de dissolução resultaria em uma predição mais precisa da dissolução in vivo para um processo de desenvolvimento robusto e preciso. Uma vez que o sistema tampão no lúmen intestinal possui baixa molaridade, o tampão fosfato com baixa capacidade tamponante foi usado como uma primeira abordagem como um meio de dissolução fisiologicamente relevante. Além disso, foi utilizado um sistema bifásico, ou seja, o meio de baixa capacidade tamponante combinado a uma fase orgânica (n-octanol) para imitar a absorção in vivo. Formulações de liberação imediata contendo fármacos de baixa e de alta solubilidade (ibuprofeno e metronidazol, respectivamente) foram testadas no sistema bifásico para avaliar a dissolução no meio aquoso e a partição para a fase orgânica. Ademais, formulações com revestimento entérico foram testadas em tampão bicarbonato nos valores de molaridades fisiológicos para avaliar o impacto da espécie tamponante na dissolução do fármaco. Os parâmetros avaliados foram o sistema tampão (tampão bicarbonato vs. tampão fosfato), capacidade tamponante e pH médio. Em todas as abordagens, a dissolução também foi realizada em tampão farmacopeico para fins de comparação. Nossos resultados demonstraram que o método de dissolução farmacopeico não foi discriminativo, enquanto o meio com menor capacidade tamponante diferenciou entre as formulações obtidas via granulação úmida ou compressão direta. Ademais, a utilização da fase orgânica no teste de dissolução bifásica auxiliou no controle do pH do meio aquoso. Portanto, os métodos não compendiais aplicados foram mais discriminativos do que as condições de dissolução convencionais. Neste estudo, foi demonstrado como a dissolução bifásica e uma baixa capacidade tamponante podem ser usadas para avaliar as diferenças na performance de formulações. Esta pode ser uma abordagem valiosa durante os estágios iniciais do desenvolvimento de medicamentos para investigar a liberação destes sob condições fisiologicamente relevantes. Da mesma forma, todas as formulações com revestimento entérico exibiram uma liberação rápida em tampão de fosfato e atenderam às especificações farmacopeicas. Entretanto, a liberação do fármaco foi muito mais lenta em tampão de bicarbonato e consequentemente não cumpriram com as especificações farmacopeicas. Além disso, a natureza do fármaco (ácido vs. base) impactou o comportamento de dissolução no tampão de bicarbonato. Este estudo indica que o teste de dissolução convencional para comprimidos de liberação retardada não possui relevância fisiológica e precisa ser reavaliado. Portanto, os resultados desta tese demonstram de forma abrangente que diferenças significativas na performance condizentes com relatórios clínicos foram obtidas apenas quando as condições fisiológicas relevantes foram aplicadas. Esses resultados indicam que a hipótese central foi respondida positivamente

Indicadores de estabilidad aeróbica en ensilajes de la mezcla Tithonia diversifolia/Pennisetum purpureum enriquecidos con lactobacillus / Indicators of aerobic stability in silages of the mixture Tithonia diversifolia/Pennisetum purpureum enriched with lactobacillus

RESUMEN En épocas de escasez, los ganaderos recurren a conservar el alimento mediante procesos de fermentación anaeróbica, conocidos como ensilajes. Una vez que el silo es abierto, el sustrato resulta aeróbicamente estable, cuando, al momento de la apertura, conserva su integridad nutricional. Esto es el resultado de un ambiente ácido que restringe los efectos deletéreos de la acción de microrganismos patógenos, expresado en indicadores de estabilidad a la exposición aeróbica. Uno de los problemas empíricos que enfrenta el productor es resolver la pregunta de cómo evitar el deterioro del ensilaje, una vez es abierto, por lo cual, esta investigación apunta a la resistencia en el periodo de exposición aeróbica (PEA) de un ensilaje de Pennisetum purpureum (PP), con diferentes niveles de sustitución de Tithonia diversifolia (TD). El estudio, se adelantó en el Centro Internacional de Agricultura Tropical en Colombia. Con un ensilaje de 90 días de fermentación, se realizó una prueba de estabilidad aeróbica de siete días, usando ensilajes de un kilogramo, a diferentes proporciones (%) de TD/PP: 100/0, 67/33, 33/67 y 0/100, enriquecidos con dos aditivos basados en Lactobacillus. Se midió el cambio de la materia seca, temperatura y el pH, encontrándose una estabilidad a la exposición aeróbica. El papel de TD es notable, una vez que el ensilado entra en el PEA, debido a la capacidad tampón que amortigua el cambio de pH, una vez que se abre el silo, generando mayor estabilidad aeróbica.

ABSTRACT In times of scarcity, farmers resort to preserving food through anaerobic fermentation processes, known as silage. Once the silo is opened, the substrate is aerobically stable if it retains its nutritional integrity when opening. This is the result of an acidic environment that restricts the deleterious effects of the action of pathogenic microorganisms, expressed as indicators of stability to aerobic exposure. One of the empirical problems faced by the producer is to solve the question of how to avoid deterioration of the silage once it is opened, for which this research points to the resistance in the period of aerobic exposure (PEA) of a silage of Pennisetum purpureum (PP) with different levels of substitution of Tithonia diversifolia (TD). The study was conducted at the International Center for Tropical Agriculture in Colombia. With a 90-day fermentation silage, a seven-day aerobic stability test was carried out, using a kilogram silage at different proportions (%) of TD/PP: 100/0, 67/33, 33/67 and 0/100 enriched with two Lactobacillus-based additives. The change in dry matter, temperature and pH was measured, finding stability to aerobic exposure. The role of TD is remarkable once the silage enters the PEA due to the buffer capacity that buffers the change in pH once the silo is opened, generating greater aerobic stability.

Ambiente alimentar em São Leopoldo, Rio Grande do Sul, Brasil: associação com variáveis sociodemográficas da vizinhança / Food environment in São Leopoldo, Rio Grande do Sul, Brazil: the association with neighborhood sociodemographic variables

Resumo O objetivo deste estudo é descrever o ambiente alimentar de um município de médio porte do Sul do Brasil e relacionar a disponibilidade de diferentes tipos de comércios de alimentos com características socioeconômicas e demográficas do entorno. Trata-se de estudo ecológico em 45 buffers, de 400m, em São Leopoldo, Rio Grande do Sul. O buffer foi calculado a partir do centróide das residências das mulheres participantes de um projeto de pesquisa maior. Todas as ruas foram percorridas para a identificação dos estabelecimentos de alimentos, que tiveram suas coordenadas geográficas registradas, bem como foram avaliados, através do questionário NEMS (Nutrition Environment Measures Survey in Stores), sobre disponibilidade, preço e qualidade de 108 itens. Os comércios foram classificados em supermercados, mercearias, fruteiras e lojas de conveniência. Os supermercados e as mercearias estavam em maior número nos buffers de menor renda e mercearias mais presentes naqueles de maior tercil populacional. Observa-se relação direta entre escores do NEMS e tercil de renda para supermercados, mercearias e fruteiras e indireta para os mesmos comércios e tercil populacional. A disponibilidade de alimentos saudáveis se mostrou mais elevada em áreas de maior renda e menor número de habitantes, o que sinaliza a necessidade de melhor distribuição dos comércios e variedades de alimentos.

Abstract The scope of this study is to describe the food environment of a medium-sized municipality in southern Brazil and compare the availability of different types of food outlets in neighborhood socioeconomic and demographic environments. An ecological study was carried out in 45 buffers of 400m in São Leopoldo county, RS. The buffer was calculated from the center point of the residences of women participating in a larger research project. All streets were surveyed to identify food stores and record their geographical coordinates, as well as apply the NEMS questionnaire on the availability, price and quality of 108 items. The commercial outlets were classified as supermarkets, grocery stores, fruit stores and convenience stores. Supermarkets and grocery stores were present in higher quantity in lower income buffers and grocery stores were more prevalent in those with higher population tertiles. Another result was a direct relationship between NEMS and tertile income scores for supermarkets, grocery stores and fruit stores, and an indirect relationship for the same stores and population tertile. The availability of healthy food was higher in areas with higher income and lower numbers of inhabitants, indicating the need for better distribution of food stores and availability of varieties of food in the municipality.

Effect of Using Methylphenidate on Salivary Flow Rate and Salivary Buffering Capacity in Children with Attention-deficit/Hyperactivity Disorder

ABSTRACT Objective: Most drugs used to treat attention-deficit/hyperactivity disorder treatment can affect saliva secretion. Methylphenidate is the most commonly prescribed drug for the treatment of attention-deficit/hyperactivity disorder and was approved for use in children over the age of 6 years. However, limited information is available on the use and long-term adverse effects of methylphenidate in preschool children (< 6 years). We explored the effects of methylphenidate on salivary flow rate and salivary buffering capacity during treatment for attention-deficit/hyperactivity disorder. Methods: Children who were diagnosed with attention-deficit/hyperactivity disorder by expert psychiatrists, under medical treatment, and those who had no other systemic diseases were included. Stimulated saliva samples were collected before prescription of methylphenidate and after 15 days, 30 days and 3 months of regular drug intake. The samples were analysed for Streptococcus mutans, as well as salivary buffering capacity and salivary flow rate. Twenty children (age range, 6-15 years) with attention-deficit/hyperactivity disorder were included. Results: The mean salivary buffering capacity value at month 3 was significantly lower than that at baseline and at day 15. Regarding the distribution according to salivary flow rate, statistically significant differences were found between baseline and the first month and between baseline and month 3 These results indicate that methylphenidate consumption in children with attention-deficit/hyperactivity disorder leads to reduced salivary buffering capacity and salivary flow rate after 3 months of follow-up. Conclusion: Parents should be informed about necessary preventive dental treatments to minimize the negative oral and dental effects of long-term drug use in children.

Mammals of Cajuru State Forest and surroundings: a neglected but important Protected Area for the Cerrado conservation in the São Paulo state, Brazil / Mamíferos da Floresta Estadual de Cajuru e arredores: uma Área Protegida negligenciada mas importante para a conservação do Cerrado no estado de São Paulo, Brasil

Abstract: The Cerrado has been severely impacted by anthropogenic disturbances, with a tiny proportion of its original extent remaining in its southern portions. In the state of São Paulo, only 7% of this vegetation remains and relatively little is known about the biodiversity of these fragments. To fill this knowledge gap, we inventoried medium and large-sized terrestrial mammals of a neglected region, including a sustainable use protected area, Cajuru State Forest (CSF), adjacent native vegetation remnants protected by the Native Vegetation Protection Law and owned by a paper and cellulose company (Dois Córregos Farm; DCF), and their surroundings. We recorded 20 native mammal species, five of which are endangered with extinction, including the giant anteater, puma, and maned wolf. We found no significant differences in species richness between CSF and DCF but we found higher estimated species richness for the surrounding areas. Besides encompassing a larger and more heterogeneous area, the surrounding area still has a relatively high proportion (>30%) of native vegetation, providing habitat and resources for many species. The estimated mammal species richness for the entire study area was similar to that found in the largest protected area of the Cerrado in São Paulo State, the Jataí Ecological Station and its surroundings. We conclude that our study area still harbors a relatively rich community of large mammals and is important for the conservation of endangered species. This finding is particularly timing since the current State administration is considering to transfer the economic exploitation of CSF to the private sector. We therefore endorse an existing proposal to uplist this protected area, which still lacks a management plan, to a more restricted management category. Besides actions regarding this governmental PA, we argue that it is also important to involve the private sector in a conservation plan for the region.

Resumo: O Cerrado tem sido severamente impactado por distúrbios antrópicos e, especialmente na sua porção sul, poucos são os fragmentos remanescentes desse bioma. No estado de São Paulo, resta aproximadamente 7% da cobertura original de Cerrado e relativamente pouco se sabe sobre a biodiversidade desses remanescentes. Para preencher essa lacuna, inventariamos mamíferos terrestres de médio e grande porte de uma região pouco estudada que inclui uma Unidade de Conservação (UC) de uso sustentável (Floresta Estadual de Cajuru; CSF), áreas de vegetação nativa protegidos pela Lei de Proteção da Vegetação Nativa e pertencentes a uma empresa de papel e celulose (Fazenda Dois Córregos; DCF), e seus entornos. Registramos 20 espécies de mamíferos nativos, cinco dos quais ameaçados de extinção, incluindo o tamanduá-bandeira, a onça parda e o lobo-guará. Não encontramos diferenças significativas na riqueza de espécies entre CSF e DCF, mas encontramos maior riqueza estimada de espécies para o entorno. Além de abranger uma área maior e mais heterogênea, essa área ainda apresenta uma proporção relativamente grande (> 30%) de vegetação nativa, fornecendo habitat e recursos para muitas espécies. A estimativa da riqueza de espécies para toda a nossa área de estudo foi semelhante à encontrada na maior UC de Cerrado no Estado de São Paulo, a Estação Ecológica de Jataí e entorno. Concluímos que a área de estudo abriga uma comunidade rica de grandes mamíferos, sendo importante para a conservação de várias espécies ameaçadas de extinção. Essa descoberta é particularmente oportuna, uma vez que o governo estadual está considerando transferir a exploração econômica da CSF para o setor privado. Endossamos, desta forma, uma proposta existente para elevar esta UC, que ainda carece de um plano de manejo, para uma categoria de manejo mais restritiva. Além disso, argumentamos que também é importante envolver a iniciativa privada em um plano de conservação para a região.

Surveillance of Major Canine Pathogens in Feral Dogs and Big Cats at the Domestic-Wildlife Interface in Panna Tiger Reserve, India

The present study was conducted at Panna Tiger Reserve of Madhya Pradesh for sero-surveillance for canine parvovirus (CPV), canine distemper virus (CDV) and canine adenovirus (CAV) infections in feral dogs. Biological samples were also collected from the wild carnivore species which were immobilized or died during the study period. Serum samples were subjected for detection of IgG antibodies against CPV, CDV and CAV infections. Additionally biological samples of wild carnivores were subjected to molecular diagnosis of CPV and CDV genes. Seroprevalence for CPV, CDV and CAV infections was observed as 3.5%, 4.4% and 0.89%, respectively, whereas for mixed infections of CPV+CDV, CPV+CAV, CDV+CAV and CPV+CDV+CAV, it was observed as 48.2%, 1.7%, 4.4% and 36.6%, respectively. Sex wise, age wise and distance wise seroprevalence was non-significant in the present study. Seroprevalence for CPV, CDV and CAV infections in cats was observed as 50%, 100 % and 0%, whereas in wild carnivores, it was observed as 100%, 90% and 0% respectively. PCR based diagnosis in the wild carnivore also revealed CDV positive cases. Serological and genomic evidence of pathogens in dogs-cats of buffer villages and wild carnivores of Panna tiger reserve indicated that the viruses may pose a high risk of spillover to wild carnivores. Study also indicated that dog population is immuned to major infectious diseases but can be a threat to the compromised wild carnivore species including tigers

Ammonium chloride lysis method versusnon-lysis method for isolation of human adipose-derived stem cells / 中国组织工程研究

BACKGROUND: A general standard has not been established for the extraction and purification of adipose-derived stem cells (ADSCs). An erythrocyte lysis step for stromal vascular fraction is the commonly used method in the procedure for ADSCs isolation. However, there is a lack of evidence on whether this step will have adverse effects on human ADSCs (hADSCs). OBJECTIVE: To test the efficiency of two hADSCs isolation methods, which are erythrocyte-lysis method based on ammonium chloride and non-lysis method. Moreover, the biological characteristics of the hADSCs isolated by the two methods were also compared. METHODS: After collagenase digestion of lipoaspirate, erythrocyte lysis buffer was used to purify stromal vascular fraction in erythrocyte-lysis method, while in non-lysis method the buffer was not used. A Muse™ cell analyzer was used to assess living cell counting and proportion of stromal vascular fraction in both methods. Then hADSCs were cultured to the second passage for next testing. Cell morphology was observed under light microscope. Cell phenotype was detected by flow cytometry. Cell counting kit-8 was used to evaluate cell proliferation. Oil red O staining and alizarin staining were used to evaluate adipogenic and osteogenic ability of hADSCs after adipogenic and osteogenic induction. This study was approved by the Ethics Committee of the Plastic Surgery Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, and informed consents were signed by all participants. RESULTS AND CONCLUSION: (1) Compared with the erythrocyte lysis group, hADSCs obtained in the non-lysis group contained a larger number and a larger percentage of non-erythrocyte living cells. (2) The two groups of hADSCs were spindle-shaped and arranged as a fish shape. (3) The cell phenotypes of both groups met the phenotypic requirements for human mesenchymal stem cells. (4) The cell proliferation in the non-lysis group was faster than that in the erythrocyte lysis group, while there was no difference in the adipogenic and osteogenic abilities between the two groups. In conclusion, the use of erythrocyte lysis buffer reduces the isolation efficiency of hADSCs and inhibits cell proliferation. The non-lysis isolation method does not affect phenotypes, adipogenic and osteogenic ability of hADSCs. Therefore, it is not recommended to implement erythrocyte lysis during the isolation of hADSCs.

Development of stability indicating method for the simultaneous estimation of alogliptin and pioglitazone in bulk and tablet dosage form by reversed-phase ultra-performance liquid chromatography method

The objective of the work is to develop and validate a new reverse phased ultra-performance chromatography method and its stability studies for the simultaneous estimation of alogliptin and pioglitazone in bulk and tablet dosage form. The column of the method was BEH C18 (2.1× 50 mm, 1.7 µ) used as a stationary phase and the mobile phase was 45:55 v/v of phosphate buffer (pH 3) and methanol, respectively. The injection volume was 2 µl and flow rate was maintained at 0.3 ml/minute. The wavelength was 280 nm and the runtime was 3 minutes. The retention time of alogliptin was 0.4 minutes and pioglitazone was 0.529 minutes. The Linearity of the alogliptin was 6.25–37.5 µg/ml and pioglitazone was 15–90 µg/ml. The newly developed method could be used for the routine analysis of pure drug and its formulations in accordance with the ICH Q2 (R1) guidelines.

Capacidad buffer de la saliva y su relación con la prevalencia de caries, con la ingesta de diferentes bebidas comerciales / Buffer capacity of saliva and its relation to the prevalence of caries, with the intake of different commercial drinks

Resumen En la actualidad tanto el consumo de jugos, como de bebidas gaseosas, es muy común en la dieta diaria de la población infantil, estas ofrecen diferentes sabores, además de un alto contenido de azúcar. En este estudio se hizo un análisis de la capacidad buffer de la saliva ante la ingesta de diferentes tipos de bebidas consideradas saludables y no saludables. Se utilizaron dos tipos de instrumentos, un examen clínico aplicado a 62 estudiantes para determinar la prevalencia de caries según ICDAS y un segundo instrumento que consta de una tabla aplicada a los mismos 62 estudiantes con la finalidad de analizar la capacidad buffer de la saliva mediante la toma del pH a intervalos de 15, 35 y 45 minutos después de ingerir las bebidas. Como conclusión se obtuvo que para las bebidas consideradas no saludables el pH tardó más en neutralizarse, mientras que la bebida saludable logró su neutralización más rápido, con una baja prevalencia de caries.

Abstract Nowadays the consumption of juices, and soft drinks, is very common in the children's diet, they offer different flavours and a high content of sugar. In this study, an analysis of the buffer capacity of the saliva was made in view of the intake of different types of beverages considered healthy and unhealthy. Two types of instruments were used, a clinical test applied to 62 students to determine the prevalence of caries according to ICDAS and a second instrument that consists of a chart applied to the same 62 students with the purpose of analyzing the buffer capacity by taking the pH on intervals of 15, 35 and 45 minutes after drinking the beverages. As a conclusion, it was obtained that for the drinks considered unhealthy, the pH took longer to neutralize, while the healthy drink achieved its neutralization faster, with a low prevalence of caries.

Salivary flow rate, pH and buffering capacity in patients undergoing fixed orthodontic treatment – A prospective study

Background: Human saliva has got many important functions like lubrication of the oral tissues, making oral functions like speech, mastication and deglutition possible and also protecting teeth and oral mucosal surfaces in different ways. Dental Caries is one of the common complications in patients undergoing orthodontic treatment. Subjects with impaired saliva flow rate often show high caries incidence. A low flow rate combined with a low or moderate buffer effect clearly indicates poor salivary resistance against microbial attack. Aim: To investigate the changes in stimulated and unstimulated salivary flow rate, pH and buffer capacity in patients undergoing therapy with fixed orthodontic appliances. Materials and Methods: Salivary flow rate, pH and buffering capacity of 20 patients who underwent fixed orthodontic treatment at Department of Orthodontics, Ragas Dental College and Hospital, Chennai were examined using GC saliva check buffer kit. The procedure was carried out during the initiation of orthodontic treatment and subsequently, one month and six months after the placement of appliance. Results: Results showed there was a significant increase in the salivary flow rate one month and six months after placement of fixed appliance while pH and buffering capacity showed no significant changes. Conclusion: Salivary flow rate increases significantly during fixed orthodontic treatment. Salivary pH and buffering capacity showed no significant changes suggesting that they are not sole factors for demineralization in orthodontic patients.

Effect of PEG400 Concentration in Receiving Solution on Drug Transdermal Test in Vitro / 中国实验方剂学杂志

Objective: To investigate the effect of varying concentrations of polyethylene glycol(PEG)400 in receiving solution on in vitro transdermal test of drugs. Method: 5-Fluorouracil(5-FU) was selected as a model drug,by preparing different concentrations of PEG400-phosphate buffer solution(PBS) as the receiving solution,the receiving chamber did not add drug,the excised rat skins were treated with various additives for 12 h,then replaced by PBS and added the saturated model drug into the donor compartment to determine the transdermal parameters of the drug.Meanwhile,scanning electron microscopy(SEM) was employed to monitor the effect of PEG400 with different concentration on the stratum corneum of rat skin. Result: The 10%,15% and 40% PEG400-PBS groups had no significant effect on in vitro transdermal absorption parameters of the 5-FU.The steady transdermal rate and cumulative penetration rate of the drug in 20% and 30% PEG400-PBS groups were significantly higher than that in the PBS group(PPConclusion: In the rat skin transdermal test,the concentration of PEG400 in receiving solution should be controlled below 20%.

Factors affecting cell loss in flow cytometry of mouse immune cells / 西安交通大学学报(医学版)

Objective: To explore the factors affecting cell loss in multicolor flow cytometry of mouse immune cells. Methods: C57BL/6J mice were used in the experiment. Splenocytes were isolated and resuspended twice with buffers of different types, compositions and pH; then the number of viable cells was counted to observe which factors affected the amount of cell loss during staining. Results: During flow cytometric labeling of mouse immune cells, buffer types significantly affected the amount of cell loss. Washing with PBS buffer containing potassium ions caused obvious cell loss, while slight shift in buffer pH and whether or not FBS/BSA was added had no significant effect on cell loss. Moreover, centrifugation speed also significantly affected cell loss. Conclusion: The use of potassium-containing PBS buffer during flow cytometric staining of mouse immune cells resulted in significant cell loss. The potassium-free PBS buffer and moderate centrifugation speed should be recommended.

Effectiveness of casein phosphopeptide-amorphous calcium phosphate and xylitol chewing gums on salivary pH, buffer capacity, and Streptococcus mutans levels: An interventional study

The aim of the study is to compare the anticariogenic effectiveness of Casein phosphopeptide- Amorphous Calcium phosphate (CPP-ACP) and xylitol chewing gums based on salivary pH, buffer capacity, and Streptococcus mutans levels. Materials and Methods: A group of twenty individuals in the age group of 18–25 years were randomly divided into two Groups A and B. Test arm A received xylitol gums and test arm B received CPP-ACP gums and they were instructed to use the gums thrice daily for 2 weeks. Unstimulated salivary samples were collected before they began the use of the gums for baseline values, 24 h after beginning the usage of chewing gums and at the end of 14 days. The samples were analyzed for pH, buffer capacity, and S. mutans levels. Results: A statistically significant reduction of salivary S. mutans levels, improvement in salivary pH, and buffer capacity were displayed in both groups 24 h and 14 days after the intervention when compared with baseline. Group B showed more statistically significant improvement in pH than group A after 24 h (P = 0.028) and at the end of 2 weeks (P = 0.041). Conclusion: CPP-ACP has better ability than xylitol in improving the pH of saliva. Both CPP-ACP and xylitol gums individually have remarkable ability in bringing down S. mutans levels while simultaneously improving the pH and buffer of saliva.

Salivary characteristics in patients with familial alzheimer's disease due to e280a mutation / Características salivares en personas con enfermedad de alzheimer familiar por la mutación e280a

ABSTRACT Introduction: Alzheimer's disease is a neurodegenerative disorder characterized by the loss of cognitive functions. The prevalence of this disease worldwide is high, and therefore it is important to have a better understanding of the oral health needs and conditions of individuals with this disorder. The present study was carried out in a population with E280A mutation for Alzheimer's disease. The goal was to describe the salivary characteristics of persons with early familial Alzheimer's disease, in order to detect changes in the oral microbiome that can guide the dental management of these patients. Methods: transversal study in 37 participants living in the Metropolitan Area of the city of Medellín, aged 53 ± 6 years in average, in different stages of the disease: mild: 8, moderate: 7, and severe: 22, and evaluated by neuropsychological tests. Salivary samples were collected, evaluating saliva secretion rate and saliva buffer capacity, and conducting microbial analysis of the species most commonly found in the mouth. Results: 45.9% of participants showed a decreased rate of stimulated salivary secretion; salivary buffer capacity was decreased in 83.87% of participants, with average pH values of 3.449 ± 0.89 after the Ericsson test. Buffer capacity was altered in participants with decreased secretion rate and in those with no alteration in salivary secretion rate. High levels of microbial growth were observed, mainly for Streptococcus mutans and Candida albicans. Conclusions: This study suggests that other factors besides the pharmacological ones, like age and disease severity, may affect the salivary rate flow in patients with early familial Alzheimer's disease.

RESUMEN Introducción: la enfermedad de Alzheimer es una alteración neurodegenerativa caracterizada por la pérdida de funciones cognitivas. Existe una alta prevalencia de esta enfermedad a nivel mundial, por lo que resulta oportuno tener una mayor comprensión de las necesidades y condiciones de salud bucal de los sujetos con este desorden. El presente estudio se llevó a cabo en una población con mutación E280A para la enfermedad de Alzheimer. El objetivo consistió en describir las características salivares de las personas con enfermedad de Alzheimer familiar precoz, con el fin de detectar cambios en el microbioma bucal que puedan orientar el manejo odontológico de estos pacientes. Métodos: estudio transversal en 37 participantes que habitan el Área Metropolitana de la ciudad de Medellín, con una edad promedio de 53 ± 6 años, en diferentes estadios de la enfermedad: leve: 8, moderada: 7 y grave: 22, evaluados mediante pruebas neuropsicológicas. Se tomaron muestras salivares, se evaluó la tasa de secreción salivar y la capacidad buffer de la saliva y se efectuó un análisis microbiano de las principales especies presentes en boca. Resultados: el 45,9% de los participantes presentaron una tasa disminuida de secreción salivar estimulada; la capacidad buffer salivar estuvo disminuida en el 83,87% de los participantes, con valores promedios de pH luego de la prueba de Ericsson de 3,449 ± 0,89. La capacidad buffer se encontró alterada tanto en los participantes con tasa de secreción disminuida como en aquellos con tasa de secreción salivar no alterada. Se observó alto crecimiento microbiano, principalmente de Streptococcus mutans y Candida albicans. Conclusiones: este estudio sugiere que pueden existir otros factores, además de los farmacológicos, que afectan la tasa de flujo salivar en los pacientes con enfermedad de Alzheimer familiar precoz, como la edad y la severidad de la enfermedad.

ADSORCIÓN DE PLOMO (II) EN SOLUCIÓN ACUOSA CON TALLOS Y HOJAS DE Eichhornia crassipes / ADSORPTION OF LEAD (II) WITH STEMS AND LEAVES OF Eichhornia crassipes IN AQUEOUS SOLUTION

La presencia de metales pesados, como el plomo (Pb+2), en los cuerpos de agua genera alteraciones sobre la calidad ambiental y la salud pública, debido a su solubilidad y su capacidad de acumulación en la cadena trófica, problemática que se puede incrementar por la acumulación de Eichhornia crassipes, una maleza acuática con alta capacidad invasora, cuya presencia en los ecosistemas acuáticos favorece los procesos de eutrofización y crecimiento de microorganismos patógenos, vectores de enfermedades. Como alternativa para la eliminación de metales pesados y el aprovechamiento de tallos TEC y hojas HEC de E. crassipes, se evaluó la capacidad de adsorción y de eficiencia de remoción de Pb+2 en solución acuosa, de dicha biomasa. Inicialmente, se realizaron ensayos batch, para analizar la influencia de la dosis de adsorbente, tiempo de contacto y pH de la solución. Como método de disposición final, se analizó la calcinación, a temperaturas de 700 y 800°C. Los datos experimentales de equilibrio fueron correlacionados, utilizando los modelos de Langmuir y Freundlich. El modelo que mejor se ajustó fue el de Langmuir, con R² = 0,9816 TEC y R² = 0,9854 HEC, lográndose una máxima capacidad de adsorción de 172,41mg/g TEC y 131,58mg/g HEC, con 0,2g de biomasa/200mL, pH 5,5 y 3h de contacto. En todos los ensayos, se lograron remociones de Pb+2 superiores al 97%. Los ensayos de calcinación indican que, a temperaturas ≥800°C, es posible estabilizar la biomasa residual, impidiendo que los cationes metálicos removidos sean liberados de la matriz biológica, por efectos de soluciones lixiviantes de bajo pH.

The presence of heavy metals such as lead (Pb+2) in water bodies causes alterations in environmental quality and public health due to their solubility and capacity of accumulation in the food chain. Problems that can be increased by the accumulation of Eichhornia crassipes an aquatic weed with high invasive capacity whose presence in the aquatic ecosystems favors the processes of eutrophication and growth of pathogenic microorganisms vectors of diseases. As an alternative for the removal of heavy metals and the use of TEC stems and HEC leaves of E. crassipes, the adsorption capacity and removal efficiency of Pb+2 in aqueous solution of this biomass were evaluated. Initially batch tests were performed to analyze the influence of the adsorbent dose, contact time and solution pH. As final disposal method, the calcination was analyzed at temperatures of 700 and 800°C. The equilibrium experimental data were correlated using the Langmuir and Freundlich models. The best fit model was the Langmuir model with R²=0.9816 TEC and R²=0.9854 HEC, achieving a maximum adsorption capacity of 172.41mg/g TEC and 131.58mg/g HEC with 0.2 g Of biomass/200mL, pH 5.5 and 3h of contact. Pb+2 removals above 97% were achieved in all tests. Calcination tests indicate that at temperatures ≥800°C it is possible to stabilize the residual biomass by preventing the removed metal cations from being released from the biological matrix by the effects of low pH leaching solutions.

Estudio de la solubilidad del nuevo sellador endodóntico MTA Endosealer Densell / Solubility of the new root canal sealer MTA Endosealer Densell

Objetivo: determinar la solubilidad del sellador MTA Endosealer Densell en una solución tisular buffer sintética. Materiales y métodos: se utilizó la modificación del Dr. Torabinejad de la especificación #30 de la ADA. Se prepararon 24 anillos de 1,5 mm de espesor por 20 mm de diámetro, utilizando el sellador endodóntico MTA Endosealer Densell. Se colocaron 12 muestras en frascos individuales con 50 ml de una solución tisular buffer. Los 12 discos restantes fueron colocados en frascos individuales con 50 ml de agua destilada. Resultados: el medio de inmersión actuó de forma estadísticamente significativa. Estos resultados opuestos manifiestan ciertos interrogantes y limitaciones a los presentes estudios y a las normativas utilizadas, por lo que es necesario buscar nuevas especificaciones que permitan evaluar en exigencia la calidad y la utilidad clínica de este tipo de materiales a base de agua.

DNA Extraction Method Optimization for Animal Medicines and Identification of Commercial Animal Medicines Using DNA Barcoding / 世界科学技术-中医药现代化

The DNA extraction method of animal medicine material is difficult and un-unified,which limits the application of molecular identification to identify animal medicines.In this study,based on the DNA extraction theory of SDS,we assessed the effects of three elements including different EDTA concentrations (0.025 mol·L-1,0.25 mol· L-1,and 0.5 mol· L-1) and whether containing NaCl and Triton X-100 in the lysis buffer on the quality of DNA extracted from different kinds of animal medicine.The optimized lysis buffer was used to extract DNA from 121 commercial animal medicines for original and species identification.The results showed that the lysis buffer of 1％ SDS,0.03 mol· L-1 Tris-HCl,0.25 mol· L-1 EDTA and 0.2 mol· L-1 NaCl had the optimum effect on DNA extraction.This lysis buffer can obtain DNA from animal medicine which is difficult to extract,such as Cicadae periostracum.The DNA extractions of 121 commercial animal medicines by optimized lysis buffer can satisfy the experimental requirements for molecular identification.All samples of commercial animal medicines can be accurately identified to the level of species.It was concluded that optimized lysis buffer can be used in the DNA extraction of different kinds of animal medicines except shells,secretions and processed products.This method provides technique support for the molecular identification of animal medicines.

Discussion on the Characteristics of Death Anxiety of the People in Mainland China / 中国医学伦理学

At present , the death anxiety of people in mainland China presents the main characteristics of col -lective avoidance , instantaneous outbreak , the vulnerability of death anxiety buffer system , and load social prob-lems of death anxiety .The taboo of death is linked to collective avoidance of death anxiety , and the avoidance to death causes the extrusion and deformation of most people ' s death anxiety .When people ' s death anxiety encoun-ters serious "death reminder", it will instantly break out .Due to the vulnerability of death anxiety buffer system and the impact of current social problems in mainland China , people ' s death anxiety presents a characteristic of brutal want on spread .