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1.
J Dairy Sci ; 105(2): 1387-1401, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34955269

RESUMO

Antibiotic dry cow therapy (aDCT) at the end of lactation is an effective mastitis control measure. Selective dry cow therapy means that only infected or presumed-infected cows are treated, instead of aDCT being used as a treatment for all cows. Because antibiotic resistance poses a global threat, livestock production is under increasing pressure to reduce antibiotic use. Changes in management should not, however, impair animal welfare or cause significant economic losses. Our objective was to compare milk yield and somatic cell count (SCC) between aDCT-treated and untreated cows in herds that used selective aDCT, taking into account risk factors for reduced yield and high SCC. The information source was 2015 to 2017 Dairy Herd Improvement data, with 4,720 multiparous cows from 172 Finnish dairy farms. The response variables were test-day milk yield (kg/d) and naturally log-transformed composite SCC (×1,000 cells/mL) during the first 154 d in milk (DIM). The statistical tool was a linear mixed-effects model with 2-level random intercepts, cows nested within herds, and a first-order autoregressive [AR(1)] correlation structure. The overall proportion of aDCT-treated cows was 25% (1,176/4,720). Due to the interaction effect, SCC on the last test day prior to dry-off affected postcalving milk yield differently in aDCT-treated cows than in untreated cows. A higher SCC prior to dry-off correlated with a greater daily yield difference after calving between cows treated and untreated. The majority of cows had SCC < 200,000 cells/mL before dry-off, and as SCC before dry-off decreased, difference in yield between aDCT-treated and untreated cows decreased. Postcalving SCC was lower for aDCT-treated cows compared with untreated cows. To illustrate, for cows with an SCC of 200,000 cells/mL before dry-off, compared with untreated cows, aDCT-treated cows produced 0.97 kg/d more milk and, at 45 DIM, had an SCC that was 20,000 cells/mL lower. Higher late-lactation SCC and lactational mastitis treatments were associated with higher postcalving SCC. A dry period lasting more than 30 d was associated with higher yields but not with SCC. Our findings indicate that a missed aDCT treatment for a high-SCC cow has a negative effect on subsequent lactation milk yield and SCC, which emphasizes the importance of accurate selection of cows to be treated.


Assuntos
Mastite Bovina , Leite , Animais , Bovinos , Contagem de Células/veterinária , Indústria de Laticínios , Feminino , Lactação , Glândulas Mamárias Animais , Gravidez , Estudos Retrospectivos
2.
Int J Syst Evol Microbiol ; 62(Pt 9): 2169-2173, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22058322

RESUMO

A significant number of Enterococcus strains from pristine waters of two brooks in Finland formed a distinct cluster on the basis of whole-cell protein fingerprinting by one-dimensional SDS-PAGE. The strains shared the following characteristics. Cells were ovoid, Gram-positive-staining and non-spore-forming, appearing singly or in pairs or chains. They were facultatively anaerobic and catalase-negative. Growth in broth containing 6.5 % NaCl or at 45 °C was weak or absent. Production of D antigen was variable. The strains tolerated 60 °C for 30 min, 40 % bile and tellurite, hydrolysed aesculin strongly and gelatin weakly, produced no acid from hippurate and did not reduce it, grew weakly at 10 °C, showed a strong reaction for the Voges-Proskauer test and produced acid from methyl α-d-glucoside, mannitol, sorbitol and sucrose, with weak or no production of acid from methyl α-d-mannoside, l-arabinose, gluconate and l-xylose. Several of the strains were selected for identification on the basis of sequencing of almost the whole 16S rRNA gene and partial atpA and pheS genes and of (GTG)(5)-PCR fingerprints. Partial atpA and pheS gene sequencing was also performed for those type strains of Enterococcus species without available sequences in the database. The pristine brook isolates formed a novel species, for which the name Enterococcus rivorum sp. nov. (type strain S299(T) = HAMBI 3055(T) = LMG 25899(T) = CCM 7986(T)) is proposed. On the basis of 16S rRNA gene sequence similarity, E. rivorum sp. nov. is related to the Enterococcus faecalis genogoup. It is distinguished from described Enterococcus species on the basis of 16S rRNA, atpA and pheS gene sequences and whole-cell protein and (GTG)(5)-PCR fingerprints. It is most closely related to E. faecalis, but DNA-DNA hybridization confirms it to represent a novel species.


Assuntos
Enterococcus/classificação , Filogenia , Rios/microbiologia , DNA Bacteriano/genética , Enterococcus/genética , Enterococcus/isolamento & purificação , Finlândia , Genes Bacterianos , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Microbiologia da Água
3.
J Water Health ; 9(4): 670-9, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22048427

RESUMO

Exposure to cyanobacterial water blooms has been associated with various kinds of adverse health effects. In addition to cyanobacteria and their toxins, the bacteria associated with cyanobacteria could also be the etiological agents. We isolated Aeromonas strains (n = 176) from water samples (n = 38) taken from sites where cyanobacteria were suspected to have caused human health symptoms, of which fever and gastrointestinal symptoms were the most common. The isolates were screened by PCR for six virulence gene types (12 genes). The majority (90%) of the strains contained at least one of the virulence genes. Most common amplification products were those of genes (act/aerA/hlyA) that encode cytotoxic enterotoxin and haemolytic products. The genes encoding cytotonic enterotoxins (ast and alt), phospholipase (lip/pla/lipH3/alp-1), elastase (ahyB) and flagellin subunits (flaA/flaB) were also present in 5-37% of the Aeromonas strains. Analysed toxins (cyanobacterial hepatotoxins and neurotoxins, and bacterial endotoxins) were not detectable or were present in only low concentrations in the majority of the samples. The results indicated that the toxins were unlikely to be the main cause of the reported adverse health effects, whereas more attention should be paid to bacteria associated with cyanobacteria as a source of health effects.


Assuntos
Aeromonas/genética , Toxinas Bacterianas/química , Endotoxinas/química , Toxinas Marinhas/química , Microcistinas/química , Microbiologia da Água , Água/química , Aeromonas/patogenicidade , Toxinas de Cianobactérias , Monitoramento Ambiental , Regulação Bacteriana da Expressão Gênica , Recreação , Virulência , Poluentes da Água
4.
Prev Vet Med ; 188: 105268, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33530013

RESUMO

Mastitis remains the most expensive disease of dairy cows, and antibiotic dry cow therapy (DCT) at dry-off is an important part of mastitis control. Regardless of the infection status, blanket DCT is administered to all quarters of all cows, which is controversial due to the worldwide problem of antimicrobial resistance. Even though selective DCT of only infected cows is a more sustainable approach, choosing animals for treatment is not always straightforward. Our aim was to evaluate whether the herd-level DCT approach is associated with early lactation udder health problems, taking into account the cow characteristics. The information source was 2015-2017 Dairy Herd Improvement data with 7461 multiparous cows from 241 Finnish dairy herds. Information on the herd-level DCT approach was obtained from farmers' questionnaire responses in 2017, and the three different approaches were selective DCT, blanket DCT, and no DCT. The statistical tool for the data analysis was a generalized linear mixed model with a random herd effect for binary outcomes and a linear mixed model with a random herd effect for a continuous outcome. The two binary outcomes were the odds of having high milk somatic cell count (SCC ≥ 200 000 cells/mL) on the first test-day within 5-45 days in milk (DIM) and the odds of mastitis treatment in early lactation up to 45 DIM. The third outcome was the mean milk lnSCC (× 1000 cells/mL) within 120 DIM. Selective DCT was the prevailing treatment practice in our data. Blanket DCT was associated with lower SCC after calving. Cows more likely to have high SCC after calving were older cows, cows with high average SCC during the previous lactation, and cows with high milk yield near dry-off. A mastitis treatment in the early lactation was more likely if, during the previous lactation, the cow had high average SCC, high peak milk production, or high milk yield near dry-off. Our findings indicate that DCT is still effective in mastitis control. Cows with high milk yield, especially near dry-off, and cows with persistently high SCC require attention when considering next lactation udder health.


Assuntos
Bovinos/fisiologia , Indústria de Laticínios , Lactação , Mastite Bovina/fisiopatologia , Animais , Contagem de Células/veterinária , Feminino , Finlândia/epidemiologia , Glândulas Mamárias Animais/fisiologia , Glândulas Mamárias Animais/fisiopatologia , Estudos Retrospectivos , Fatores de Risco
5.
Prev Vet Med ; 180: 105028, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32474334

RESUMO

Antibiotic dry cow therapy (DCT) is an important part of most mastitis control programs. Updating DCT recommendations is an ongoing topic due to the global problem of antimicrobial resistance. Finland, along with other Nordic countries, has implemented selective DCT for decades. Our study analyzed Dairy Herd Improvement (DHI) information from 241 Finnish farmers who participated in a survey about their drying-off practices. The aim was to evaluate herd-level associations between milk somatic cell count (SCC), milk production, and various antimicrobial DCT approaches both cross-sectionally in 2016 and longitudinally in 2012-2016. The three DCT approaches in the study were selective, blanket, and no DCT use. An additional aim was to evaluate whether dynamic changes occurred in herd-average SCC and annual milk production over five years, and whether these potential changes differed between different DCT approaches. The method for the longitudinal analyses was growth modeling with random coefficient models. Differences in SCC and milk production between farms with different DCT approaches were minor. Regardless of the farm's DCT approach, annual milk production increased over the years, while average SCC was reasonably constant. The variability in SCC and milk production across all DCT groups was low between years, and most of the variability was between farms. Compared to other milking systems, farms with automatic milking system (AMS) had higher SCC, and in 2016 higher milk production. The results of this study suggest that it is possible to maintain low herd-average SCC and good milk production when using selective DCT and following the guidelines for prudent antimicrobial use. Average SCC and milk production varied across the herds, suggesting that advice on DCT practices should be herd-specific. The methodology of growth modeling using random coefficient models was applicable in analyzing longitudinal data, in which the time frame was relatively short and the number of herds was limited.


Assuntos
Anti-Infecciosos/administração & dosagem , Bovinos/fisiologia , Contagem de Células/veterinária , Indústria de Laticínios/métodos , Lactação , Leite/metabolismo , Animais , Bovinos/crescimento & desenvolvimento , Feminino , Finlândia , Estudos Retrospectivos
6.
Eur J Pharm Biopharm ; 148: 1-9, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31917332

RESUMO

Metastatic tumors are the main cause of cancer-related death, as the invading cancer cells disrupt normal functions of distant organs and are nearly impossible to eradicate by traditional cancer therapeutics. This is of special concern when the cancer has created multiple metastases and extensive surgery would be too dangerous to execute. Therefore, combination chemotherapy is often the selected treatment form. However, drug cocktails often have severe adverse effects on healthy cells, whereby the development of targeted drug delivery could minimize side-effects of drugs and increase the efficacy of the combination therapy. In this study, we utilized the folate antagonist methotrexate (MTX) as targeting ligand conjugated onto mesoporous silica nanoparticles (MSNs) for selective eradication of folate receptor-expressing invasive thyroid cancer cells. The MSNs was subsequently loaded with the drug fingolimod (FTY720), which has previously been shown to efficiently inhibit proliferation and invasion of aggressive thyroid cancer cells. To assess the efficiency of our carrier system, comprehensive in vitro methods were employed; including flow cytometry, confocal microscopy, viability assays, invasion assay, and label-free imaging techniques. The in vitro results show that MTX-conjugated and FTY720-loaded MSNs potently attenuated both the proliferation and invasion of the cancerous thyroid cells while keeping the off-target effects in normal thyroid cells reasonably low. For a more physiologically relevant in vivo approach we utilized the chick chorioallantoic membrane (CAM) assay, showing decreased invasive behavior of the thyroid derived xenografts and an increased necrotic phenotype compared to tumors that received the free drug cocktail. Thus, the developed multidrug-loaded MSNs effectively induced apoptosis and immobilization of invasive thyroid cancer cells, and could potentially be used as a carrier system for targeted drug delivery for the treatment of diverse forms of aggressive cancers that expresses folate receptors.


Assuntos
Cloridrato de Fingolimode/administração & dosagem , Metotrexato/administração & dosagem , Nanopartículas , Neoplasias da Glândula Tireoide/tratamento farmacológico , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Embrião de Galinha , Membrana Corioalantoide/patologia , Sistemas de Liberação de Medicamentos , Cloridrato de Fingolimode/farmacologia , Receptores de Folato com Âncoras de GPI/metabolismo , Humanos , Metotrexato/farmacologia , Invasividade Neoplásica/prevenção & controle , Dióxido de Silício/química , Neoplasias da Glândula Tireoide/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
7.
J Microbiol Methods ; 60(2): 195-205, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15590094

RESUMO

Fluorogenic artificial substrates facilitate sensitive enzyme activity measurements for a variety of processes in soil and other environmental samples. It is possible to use in situ pH for measurements on condition that the substrates are chemically stable. We studied the stability of 12 different methyl umbellipherone (MUF) and amino methyl coumarine (AMC) derivatives used as substrates for arylsulphatase, alpha-glucosidase, beta-glucosidase, beta-xylosidase, cellobiosidase, chitinase, phosphomonoesterase (PME), phoshodiesterase (PDE), esterase, lipase and alanine- and leucine aminopeptidases (AP) over the pH range from 4.0 to 8.0 in modified universal buffer (MUB). Stability of the substrates for lipase (4-MUF-heptanoate) and esterase (4-MUF-acetate) measurements was poor, especially at the higher pH values. Chitinase substrate, 4-MUF-N-acetyl-beta-D-glucosamide, was unstable at high pH values whereas the substrate for PME activity measurement (4-MUF-phosphate) disintegrated at low pH. The other substrates and MUF and AMC standard solutions were stable over the pH range studied. The optima between pH 4 and 8 of the 11 different enzyme activities were measured in three forest and two agricultural soil samples and in one activated sludge sample. In soil, for alanine and leucine AP the pH optima were usually 7.5 or higher, for arylsulphatase, beta-glucosidase, beta-xylosidase, esterase and PDE between 4 and 5.5, and for cellobiosidase between 4 and 5. alpha-Glucosidase had an optimum below 5.5 but also exhibited high activity at pH 7. Soil-dependent variation in pH optima were observed for chitinase, esterase, PDE and PME. Enzyme activities were also measured in 0.5 M acetate buffer at pH 5.5. This buffer yielded the highest activities in all soil samples for arylsulphatase, PDE and PME.


Assuntos
Cumarínicos/metabolismo , Enzimas/metabolismo , Solo/análise , Umbeliferonas/metabolismo , Cumarínicos/química , Enzimas/química , Finlândia , Concentração de Íons de Hidrogênio , Umbeliferonas/química
8.
Syst Appl Microbiol ; 38(3): 161-8, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25852023

RESUMO

Three groups of Aeromonas strains isolated from Finland lakes experiencing cyanobacterial blooms could not be assigned to any known species of this genus on the basis of 16S rRNA and rpoD gene sequences. The Multilocus Phylogenetic Analysis (MLPA) of the concatenated sequence of seven genes (gyrB, rpoD, recA, dnaJ, gyrA, dnaX and atpD; 4093bp) showed that the three groups of strains did not cluster with any known Aeromonas spp. and formed three independent lineages. This was confirmed by performing the analysis with their closest relatives using 15 genes (the latter 7 and cpn60, dnaK, gltA, mdh, radA, rpoB, tsf, zipA; 8751bp). Furthermore, ANI results between the genomes of the type strains of the three potential new species and those of their close relatives were all <96% which is the previously proposed cutoff value for differentiating species within this genus. The in silico DDH values of the three type strains of the new species also showed a similarity<70% with the most closely related species indicating they belong to different taxa. The three groups of strains could be differentiated from each other and from other known Aeromonas species on the basis of several phenotypic characters. This polyphasic study revealed that the 3 groups of strains represent 3 novel Aeromonas species for which the names Aeromonas aquatica sp. nov. (type strain AE235T=CECT 8025T=LMG 26712T), Aeromonas finlandiensis sp. nov. (type strain 4287DT=CECT 8028T=LMG 26709T) and Aeromonas lacus sp. nov. (type strain AE122T=CECT 8024T=LMG 26710T) are proposed.


Assuntos
Aeromonas/classificação , Aeromonas/isolamento & purificação , Lagos/microbiologia , Análise por Conglomerados , DNA Ribossômico/química , DNA Ribossômico/genética , RNA Polimerases Dirigidas por DNA , Finlândia , Genes Bacterianos/genética , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Filogenia , RNA Ribossômico 16S/genética
9.
J Med Chem ; 42(24): 5053-8, 1999 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-10585214

RESUMO

Novel tetra-, tri-, and P,P'-dipivaloyloxymethyl esters of clodronic acid were synthesized, and their properties as possible prodrugs of clodronate were evaluated in vitro. All pivaloyloxymethyl esters were significantly more lipophilic (log P(app) ranged from -2.1 to 7. 4) than clodronate (log P(app) < or = -5.4), which suggests that it may be possible to change the intestinal absorption mechanism of clodronate from a paracellular to a transcellular pathway by a prodrug approach. Pivaloyloxymethyl esters degraded rapidly in 10% rabbit liver homogenate, and half-lives of tri- and P,P'-diesters were 1.1 and 14 min, respectively. The intermediate degradation products were further degraded, and clodronic acid was released in quantitative amounts. In human serum, the stability of pivaloyloxymethyl esters was comparable to their stability in phosphate buffer (pH 7.4), which suggests that their degradation in human serum is mostly due to the chemical hydrolysis. Benzoyloxypropyl esters of clodronic acid were also synthesized, but they did not release clodronic acid due to the enzymatic and chemical stability of the formed 3-hydroxypropyl phosphonate esters and are, therefore, not prodrugs.


Assuntos
Ácido Clodrônico/química , Difosfonatos/síntese química , Pró-Fármacos/síntese química , Animais , Benzoatos/química , Benzoatos/metabolismo , Disponibilidade Biológica , Sangue/metabolismo , Carboxilesterase , Hidrolases de Éster Carboxílico/metabolismo , Fenômenos Químicos , Físico-Química , Ácido Clodrônico/metabolismo , Ácido Clodrônico/farmacocinética , Difosfonatos/metabolismo , Estabilidade de Medicamentos , Meia-Vida , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Absorção Intestinal , Fígado/metabolismo , Fosfodiesterase I , Diester Fosfórico Hidrolases/metabolismo , Pró-Fármacos/metabolismo , Coelhos , Soluções , Relação Estrutura-Atividade
10.
J Med Chem ; 42(8): 1473-6, 1999 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-10212134

RESUMO

P,P'-Diacetyl, P,P'-dibutyroyl, P,P'-dipivaloyl, and P,P'-dibenzoyl (dichloromethylene)bisphosphonic acid dianhydride disodium salts (2a-d) were synthesized and evaluated as novel bioreversible prodrugs of clodronate. The anhydrides were prepared by reacting anhydrous tetrasodium clodronate with a large excess of the corresponding acid anhydride. The dianhydrides 2a-d alone were more lipophilic than the parent clodronate, as determined by drug partitioning between 1-octanol and phosphate buffer at pH 7.4. They also were stable toward chemical hydrolysis in aqueous solutions (pH 7.4 and 2.0). The half-lives for chemical degradation in a buffer solution at 37 degrees C varied from 0.7 to 286 h and from 15 to 790 h at pH 2.0 and 7.4, respectively. The dianhydrides 2a,b,d underwent complete enzymatic hydrolysis to clodronate in 80% serum at 37 degrees C after 1 min, although 2c had a half-life of 3.3 h. The aqueous solubility of clodronate decreased considerably in the presence of Ca2+ ions. This is most probably due to formation of poorly water-soluble chelates, which may also hinder the oral absorption of clodronate. However, Ca2+ ions did not have an effect on the aqueous solubility of clodronic acid dianhydrides, and therefore, these prodrugs may improve oral absorption of the parent drug. In conclusion, these novel dianhydride derivatives may be potentially useful prodrugs of clodronate which, due to their lipophilicity and lack of Ca2+ chelating, increase its bioavailability after oral administration.


Assuntos
Anidridos/síntese química , Ácido Clodrônico/química , Pró-Fármacos/síntese química , Anidridos/sangue , Anidridos/química , Anidridos/farmacologia , Humanos , Hidrólise , Cinética , Pró-Fármacos/química
11.
J Microbiol Methods ; 45(3): 155-65, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11348673

RESUMO

Application of DNA fingerprinting methods enables the detection of diverse members of soil bacterial consortia, even including those bacteria not yet cultivated. However, extraction and purification of DNA from soil samples without bias is difficult. We compared five different DNA isolation methods and three purification methods for rhizosphere soil samples. Purified DNA extracts were amplified in PCR using universal bacterial primers and the PCR products were analysed with denaturing gradient gel electrophoresis (DGGE) for the visualisation of DNA bands representing dominant bacterial species. Both the isolation and purification methods affected the apparent bacterial community structure of the samples.


Assuntos
Bactérias/genética , DNA Bacteriano/isolamento & purificação , Microbiologia do Solo , Eletroforese/métodos , Reação em Cadeia da Polimerase/métodos
12.
Eur J Pharm Biopharm ; 57(2): 343-6, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15018994

RESUMO

Lipophilic conjugates of idebenone (IDE) with short-chain alkylamino acids were previously synthesized and evaluated in vitro for their antioxidant properties. In this study, their susceptibility to chemical and enzymatic hydrolysis was evaluated. Results indicated that these derivatives release the parent drug quantitatively via enzymatic hydrolysis by serum and liver esterases, with a cleavage rate related to the length of the alkyl side chain. Consequently, the present lipoamino acid conjugates of IDE are prodrugs and their in vivo effects are mediated through the parent compound released in the body.


Assuntos
Benzoquinonas/química , Benzoquinonas/metabolismo , Aminoácidos/química , Aminoácidos/metabolismo , Animais , Bovinos , Avaliação Pré-Clínica de Medicamentos/métodos , Estabilidade de Medicamentos , Estabilidade Enzimática/fisiologia , Metabolismo dos Lipídeos , Lipídeos/química , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Ubiquinona/análogos & derivados
13.
Int J Food Microbiol ; 23(1): 71-8, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7811573

RESUMO

Growth of known species of Enterococcus, Lactococcus and Streptococcus and Aerococcus viridans in selective and nonselective liquid media routinely used to enumerate faecal streptococci was measured optically at different temperatures. Growth of environmental isolates was measured in some of these media. Growth of the reference strains on Bile esculin azide agar at elevated incubation temperatures was tested. The results revealed only minor differences between media but strong influence of incubation temperature. Some media tended to yield higher cell densities than others. For many species the inoculum size affected maximum turbidity. To combine selective media with selective incubation temperatures seems to be necessary to achieve satisfactory reliability in traditional liquid enumeration methods for faecal streptococci. Because of the diversity of this group, optimal selectivity and recovery can hardly be achieved simultaneously.


Assuntos
Meios de Cultura/química , Enterococcus/crescimento & desenvolvimento , Lactococcus/crescimento & desenvolvimento , Streptococcus/crescimento & desenvolvimento , Ágar , Contagem de Colônia Microbiana , Especificidade da Espécie , Temperatura , Microbiologia da Água
14.
Eur J Pharm Sci ; 11(2): 173-80, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10915965

RESUMO

The synthesis and preliminary evaluation of novel alkyl and acyloxymethyl esters of etidronic acid as etidronate prodrugs is reported. Tetramethyl ester of etidronic acid was found be isomerized at pH 7.4 and P-C-P bridge was rearranged to P-C-O-P. This unwanted process was prevented via acylation of the bridging carbon's alcohol group. Acylation showed to be stable if one or more phosphonic OH- groups were substituted. However, when none of the phosphonic OH- groups were substituted, the acylation was chemically hydrolysed and the parent drug was released. This finding was successfully applied in the design of tetrapivaloyloxymethyl ester of acetylated etidronic acid which released etidronic acid via enzymatic (first step) and chemical (second step) hydrolysis in liver homogenate. However, the corresponding tri-substituted pivaloyloxymethyl ester having adequate water-solubility and lipophilicity (logP(app) 0.6 at pH 7.4), is probably the most potential prodrug candidate reported to enhance the oral bioavailability of etidronate.


Assuntos
Ácido Etidrônico/síntese química , Pró-Fármacos/síntese química , Animais , Difosfonatos/sangue , Difosfonatos/síntese química , Difosfonatos/farmacocinética , Ácido Etidrônico/sangue , Ácido Etidrônico/farmacocinética , Humanos , Fígado/metabolismo , Pró-Fármacos/farmacocinética , Coelhos
15.
Int J Pharm ; 213(1-2): 135-42, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11165101

RESUMO

Clodronate, like other bisphosphonates, is poorly absorbed from the gastrointestinal tract, mainly due to its high hydrophilicity and ability to form complexes with divalent cations in the gastrointestinal tract. One strategy for improving oral absorption of these types of molecules is to develop more lipophilic derivatives. The importance of lipophilicity and calcium chelation in the absorption of clodronate was evaluated by studying the penetration of clodronate and its mono-, di-, and triphenyl esters through human intestinal Caco-2 cells. The transport rates of [(14)C]-clodronate and its mono-, di-, and triphenyl esters were quantified by calculating their apparent permeability coefficients (P(app)) both in normal (1.3 mM) calcium concentration and in 'minimum-calcium model'. The transport rate of 1 mM clodronate was very low (0.25 x 10(-7) cm/s), while the removal of calcium from the apical side increased this transport rate 6-fold. The transport rate of clodronate was increased with increasing dose. Mono- and diphenyl esters did not significantly enhance the transport of clodronate. Triphenyl ester, however, increased the transport rate 17-fold compared with parent clodronate. Removal of calcium did not affect the transport rates of di- or triphenyl esters, which indicated that the esterification of hydroxyl groups of clodronate decreased calcium complex formation. These results indicate that clodronate is transported paracellularly through Caco-2 cells and that calcium decreases strongly its absorption. They further suggest that at least three phosphate hydroxyl groups need to be substituted until the permeation route is changed from paracellular to transcellular.


Assuntos
Analgésicos não Narcóticos/farmacocinética , Cálcio/farmacologia , Ácido Clodrônico/análogos & derivados , Ácido Clodrônico/farmacocinética , Analgésicos não Narcóticos/química , Transporte Biológico Ativo/efeitos dos fármacos , Células CACO-2 , Fenômenos Químicos , Físico-Química , Ácido Clodrônico/química , Humanos , Absorção Intestinal , Lipídeos/química , Peso Molecular , Sais de Tetrazólio , Tiazóis
16.
Water Sci Technol ; 50(1): 155-8, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15318502

RESUMO

Artificial recharge of groundwater offers a semi-natural means to produce raw water for drinking-water plants. Surface water works are increasingly being replaced by artificial groundwater works in Finland. Two municipalities, one serving 30,000 and the other 170,000 inhabitants, have considered filtering river water through eskers for the production of potable water. In this study the removal of bacteriophages during infiltration of river water was estimated, for the evaluation of treatment adequacy in a field study. A 5-m-deep column of sand was constructed and used to mimic the percolating phase in infiltration. An artificial esker was constructed on the riverbank by isolating a 2-m-wide, 2-m-deep and 18-m-long bed of coarse sand with plastic. The sand bed represented the saturated zone. River water was pumped at a rate of 40 L/h to the sand column. The river water was spiked with F+ specific RNA phage MS2 by adding phage suspension during one week at an average concentration of 4.3 x 10(9) PFU/mL. Samples for phage assays were taken during one month, from four sampling sites, on the basis of detention time as estimated by a tracer experiment with sodium chloride. The median count of MS2 for percolated water was 2.4 x 10(5) PFU/mL, representing a 96.7% reduction. During the passage of 6 m in the saturated zone, a further reduction of 98.5% occurred. During the passage from 6 m to 12 m the additional reduction was 99.97%. The overall reduction was between 6 and 7 log10 units. The removal of MS2 phages was rather efficient, although the esker material was coarse, mainly sandy, gravel.


Assuntos
Fagos RNA/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Filtração , Finlândia , Rios , Solo
17.
J Microbiol Methods ; 81(1): 48-55, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20138194

RESUMO

Storage of samples is often an unavoidable step in environmental data collection, since available analytical capacity seldom permits immediate processing of large sample sets needed for representative data. In microbiological soil studies, sample pretreatments may have a strong influence on measurement results, and thus careful consideration is required in the selection of storage conditions. The aim of this study was to investigate the suitability of prolonged (up to 16 weeks) frozen or air-dried storage for divergent soil materials. The samples selected to this study were mineral soil (clay loam) from an agricultural field, humus from a pine forest and compost from a municipal sewage sludge composting field. The measured microbiological parameters included functional profiling with ten different hydrolysing enzyme activities determined by artificial fluorogenic substrates, and structural profiling with bacterial 16S rDNA community fingerprints by amplicon length heterogeneity analysis (LH-PCR). Storage of samples affected the observed fluorescence intensity of the enzyme assay's fluorophor standards dissolved in soil suspension. The impact was highly dependent on the soil matrix and storage method, making it important to use separate standardisation for each combination of matrix type, storage method and time. Freezing proved to be a better storage method than air-drying for all the matrices and enzyme activities studied. The effect of freezing on the enzyme activities was small (<20%) in clay loam and forest humus and moderate (generally 20-30%) in compost. The most dramatic decreases (>50%) in activity were observed in compost after air-drying. The bacterial LH-PCR community fingerprints were unaffected by frozen storage in all matrices. The effect of storage treatments was tested using a new statistical method based on showing similarity rather than difference of results.


Assuntos
Bactérias/genética , Proteínas de Bactérias/genética , Enzimas/genética , Metagenômica/métodos , Microbiologia do Solo , Manejo de Espécimes/métodos , Bactérias/classificação , Proteínas de Bactérias/isolamento & purificação , Dessecação , Enzimas/isolamento & purificação , Congelamento
20.
Water Res ; 43(20): 5075-86, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19783028

RESUMO

Bacteria colonizing BAC filters used in drinking water purification from lake water were characterized by morphology, physiological tests, whole cell protein profiles and PLFA (phospholipid fatty acid) composition, and identified by partial 16S rRNA gene sequencing. Epifluorescence revealed prothecate bacteria to dominate in BAC. The majority of the isolates belonged to order Burkholderiales of beta-Proteobacteria, a few to Comamonadaceae but the majority to an undescribed family and the related sequences belonged mainly to uncultured bacteria. Among the less common alpha-Proteobacteria the genus Sphingomonas and the genera Afipia, Bosea or Bradyrhizobium of the Bradyrhizobiaceae family were detected. The majority of cultured bacteria persisting in the BAC biofilter were Burkholderiales, which according to ecological information are efficient in the mineralisation of dissolved organic matter in BAC. The biotechnical potential of the previously uncultured dominant bacteria warrants to be further studied.


Assuntos
Betaproteobacteria/isolamento & purificação , Carvão Vegetal , Filtração/métodos , Alphaproteobacteria/isolamento & purificação , Betaproteobacteria/citologia , Betaproteobacteria/genética , Biodegradação Ambiental , Biodiversidade , Filogenia , RNA Ribossômico 16S/genética
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