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1.
Placenta ; 129: 30-35, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36198245

RESUMO

INTRODUCTION: Selective serotonin reuptake inhibitors (SSRIs) are commonly used medication for the treatment of depression during pregnancy. Their use may affect various biological molecules such as enzymes which regulate placental hormonal production and xenobiotic metabolism. Our aim was to investigate the effect of maternal SSRI use on activities of three placental enzymes. METHODS: We analyzed activities of xenobiotic metabolism enzymes cytochrome P450 1A1 (CYP1A1), aromatase (CYP19A1), and glutathione-S-transferase (GST) from placental microsomal and cytosolic subcellular fractions. Term placentas were collected from 47 SSRI users and 49 control women participating Kuopio Birth cohort (KuBiCo) during the years 2013-2015. Among SSRI users, escitalopram was the most widely used SSRI medication. RESULTS: The mean enzyme activities of all studied enzymes were lower in SSRI users compared to controls. A statistically significant difference was observed in the enzyme activities of CYP19A1 (p = 0.001) and CYP1A1 (p = 0.002) between the study groups after adjusting for use of additional medication, gestational diabetes, sex of the newborn and gestational weeks at delivery. SSRI use had no significant effect on placental GST enzyme activity. DISCUSSION: Our results indicate that SSRI medication alters placental enzyme activities. This may lead disturbances in maternal steroid hormone balance as well as in xenobiotic metabolism and may provide risk for both developing fetus and pregnant women.


Assuntos
Citocromo P-450 CYP1A1 , Placenta , Recém-Nascido , Feminino , Gravidez , Humanos , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1A1/farmacologia , Placenta/metabolismo , Aromatase/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Xenobióticos/metabolismo , Xenobióticos/farmacologia
2.
Phytopathology ; 108(8): 925-934, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29600888

RESUMO

'Candidatus Liberibacter solanacearum' (CLso) haplotype C is associated with disease in carrots and transmitted by the carrot psyllid Trioza apicalis. To identify possible other sources and vectors of this pathogen in Finland, samples were taken of wild plants within and near the carrot fields, the psyllids feeding on these plants, parsnips growing next to carrots, and carrot seeds. For analyzing the genotype of the CLso-positive samples, a multilocus sequence typing (MLST) scheme was developed. CLso haplotype C was detected in 11% of the T. anthrisci samples, in 35% of the Anthriscus sylvestris plants with discoloration, and in parsnips showing leaf discoloration. MLST revealed that the CLso in T. anthrisci and most A. sylvestris plants represent different strains than the bacteria found in T. apicalis and the cultivated plants. CLso haplotype D was detected in 2 of the 34 carrot seed lots tested, but was not detected in the plants grown from these seeds. Phylogenetic analysis by unweighted-pair group method with arithmetic means clustering suggested that haplotype D is more closely related to haplotype A than to C. A novel, sixth haplotype of CLso, most closely related to A and D, was found in the psyllid T. urticae and stinging nettle (Urtica dioica, Urticaceae), and named haplotype U.


Assuntos
Bactérias/classificação , Bactérias/genética , Variação Genética , Hemípteros/microbiologia , Urtica dioica/microbiologia , Animais , Haplótipos , Insetos Vetores , Tipagem de Sequências Multilocus , Filogenia , Doenças das Plantas/microbiologia
3.
J Microsc ; 270(1): 98-109, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29071713

RESUMO

We set out to study connected porosity of crystalline rock using X-ray microtomography and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) with caesium chloride as a contrast agent. Caesium is an important radionuclide regarding the final deposition of nuclear waste and also forms dense phases that can be readily distinguished by X-ray microtomography and SEM-EDS. Six samples from two sites, Olkiluoto (Finland) and Grimsel (Switzerland), where transport properties of crystalline rock are being studied in situ, were investigated using X-ray microtomography and SEM-EDS. The samples were imaged with X-ray microtomography, immersed in a saturated caesium chloride (CsCl) solution for 141, 249 and 365 days and imaged again with X-ray microtomography. CsCl inside the samples was successfully detected with X-ray microtomography and it had completely penetrated all six samples. SEM-EDS elemental mapping was used to study the location of caesium in the samples in detail with quantitative mineral information. Precipitated CsCl was found in the connected pore space in Olkiluoto veined gneiss and in lesser amounts in Grimsel granodiorite. Only a very small amount of precipitated CsCl was observed in the Grimsel granodiorite samples. In Olkiluoto veined gneiss caesium was found in pinitised areas of cordierite grains. In the pinitised areas caesium was found in notable excess compared to chloride, possibly due to the combination of small pore size and negatively charged surfaces. In addition, elevated concentrations of caesium were found in kaolinite and sphalerite phases. The findings concerning the location of CsCl were congruent with X-ray microtomography.

4.
J Colloid Interface Sci ; 512: 536-547, 2018 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-29100158

RESUMO

HYPOTHESIS: Amphiphilic character of surfactants drives them at the interface of dispersed systems, such as emulsions. Hemicellulose-rich wood extracts contain assemblies (lignin-carbohydrate complexes, LCC) with natural amphiphilicity, which is expected to depend on their chemical composition resulting from the isolation method. Lignin-derived phenolic residues associated with hemicelluloses are hypothesized to contribute to emulsions' interfacial properties and stability. EXPERIMENTS: We investigated the role of phenolic residues in spruce hemicellulose extracts in the stabilization of oil-in-water emulsions by physical and chemical approach. Distribution and changes occurring in the phenolic residues at the droplet interface and in the continuous phase were studied during an accelerated storage test. Meanwhile, the physical stability and lipid oxidation in emulsions were monitored. FINDINGS: Naturally associated lignin residues in GGM act as vehicles for anchoring these hemicelluloses into the oil droplet interface and further enable superior stabilization of emulsions. By adjusting the isolation method of GGM regarding their phenolic profile, their functionalities, especially interfacial behavior, can be altered. Retaining the native interactions of GGM and phenolic residues is suggested for efficient physical stabilization and extended protection against lipid oxidation. The results can be widely applied as guidelines in tailoring natural or synthetic amphiphilic compounds for interfacial stabilization.


Assuntos
Emulsões , Mananas/química , Óleos/química , Fenóis/química , Picea/química , Tensoativos/química , Água/química , Lignina/química , Oxirredução
5.
Curr Med Res Opin ; 34(4): 683-688, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29043849

RESUMO

OBJECTIVE: Patient-controlled oral analgesia has gained popularity in postoperative pain management. Anesthesia and surgery delay gastrointestinal tract function and this may therefore decrease bioavailability of drugs taken by mouth. To hasten absorption, an orodispersible ibuprofen tablet has been developed. In this study, we evaluated the pharmacokinetics and feasibility of orodispersible ibuprofen tablets in spine surgery patients. METHODS: The study design was a prospective clinical trial where each patient served as her/his own control. Fifteen patients aged 19-75 years were given two orodispersible ibuprofen 200 mg tablets the day before surgery and two more tablets immediately after surgery. Blood samples for ibuprofen concentrations were taken at intervals for 6 hours following pre- and postsurgical administration of ibuprofen. RESULTS: The mean preoperative area under time-concentration curve for ibuprofen (AUC0-360) was 4806 (SD 1104) min·mg/L, and after surgery it was 2141 (583) min·mg/L (mean difference 2664, 95% CI for difference 2003 to 3325, p < .001). The mean of the maximum preoperative plasma concentration of ibuprofen was three times higher, 26.7 (7.7) mg/L, than the postoperative value of 8.6 (2.1) mg/L (mean diff. 18.1, 95% CI 13.9 to 22.4, p < .001). Times to maximum concentration were similar pre- and postoperatively at 155 (58) minutes and 169 (113) minutes (p = .67). No serious or unexpected adverse events were recorded. CONCLUSIONS: While orodispersible ibuprofen tablets were feasible, ibuprofen absorption decreased immediately after surgery compared to the day before surgery. Thus, further studies are needed to establish the adequate initial postoperative dose.


Assuntos
Ibuprofeno/farmacocinética , Dor Pós-Operatória/tratamento farmacológico , Administração Oral , Adulto , Idoso , Disponibilidade Biológica , Feminino , Humanos , Ibuprofeno/administração & dosagem , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos Prospectivos , Comprimidos , Adulto Jovem
6.
J Clin Pharm Ther ; 38(2): 104-8, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23442020

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Admixtures of levobupivacaine, fentanyl and epinephrine are increasingly used in epidural pain management. Neither the compatibility nor the stability of levobupivacaine with fentanyl and epinephrine is known and therefore we examined the chemical, physical and microbiological stability of levobupivacaine-fentanyl-epinephrine and levobupivacaine-fentanyl admixtures prepared in the hospital pharmacy. METHODS: Fentanyl and epinephrine were added into commercial levobupivacaine infusion bags. The components were analysed by HPLC and assays were performed up to 60 days of storage of the bags both protected and exposed to light at room temperature and stored in the refrigerator. In addition, sterility, bacterial endotoxins, organoleptic properties, pH and mass of the admixture were determined. RESULTS AND DISCUSSION: Levobupivacaine, fentanyl and epinephrine concentrations remained within the ± 10% specification limit during 60 days storage in the refrigerator in tightly closed secondary packing material and protected from light and for at least 40 days at room temperature. The degradation of epinephrine exceeded 10% within 60 hours when exposed to light. The solutions were microbiologically and physically stable. WHAT IS NEW AND CONCLUSION: Epidural analgesic admixtures of levobupivacaine and fentanyl with or without epinephrine have to be stored in a tightly closed secondary package protected from light. The extended stability, up to 60 days, in a refrigerator enables the centralized preparation in the hospital pharmacy.


Assuntos
Analgésicos/química , Bupivacaína/análogos & derivados , Epinefrina/química , Fentanila/química , Analgesia Epidural/métodos , Bupivacaína/química , Cromatografia Líquida de Alta Pressão , Embalagem de Medicamentos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Levobupivacaína
7.
Allergy ; 66(11): 1457-68, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21884529

RESUMO

BACKGROUND: In persistent chronic rhinosinusitis (CRS), conventional treatment is often insufficient. Long-term, low-dose administration of macrolides has been suggested as a treatment option. The MACS (Macrolides in chronic rhinosinusitis) study is a randomized placebo-controlled trial evaluating the efficacy of azithromycin (AZM) in CRS. METHODS: We describe a group of patients with recalcitrant CRS with and without nasal polyps unresponsive to optimal medical and (in 92% also) surgical treatment. Patients were treated with AZM or placebo. AZM was given for 3 days at 500 mg during the first week, followed by 500 mg per week for the next 11 weeks. Patients were monitored until 3 months post-therapy. The assessments included Sino-Nasal Outcome Test-22 (SNOT-22), a Patient Response Rating Scale, Visual Analogue Scale (VAS), Short Form-36 (SF-36), rigid nasal endoscopy, peak nasal inspiratory flow (PNIF), Sniffin' Sticks smell tests and endoscopically guided middle meatus cultures. RESULTS: Sixty patients with a median age of 49 years were included. Fifty per cent had asthma and 58% had undergone revision sinus surgery. In the SNOT-22, Patient Response Rating Scale, VAS scores and SF-36, no significant difference between the AZM and the placebo groups was demonstrated. Nasal endoscopic findings, PNIF results, smell tests and microbiology showed no relevant significant differences between the groups either. CONCLUSION: At the investigated dose of AZM over 3 months, no significant benefit was found over placebo. Possible reasons could be disease severity in the investigated group, under-dosage of AZM and under-powering of the study. Therefore, more research is urgently required.


Assuntos
Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Rinite/tratamento farmacológico , Sinusite/tratamento farmacológico , Adulto , Idoso , Antibacterianos/administração & dosagem , Azitromicina/administração & dosagem , Doença Crônica , Método Duplo-Cego , Esquema de Medicação , Endoscopia , Feminino , Humanos , Macrolídeos/administração & dosagem , Macrolídeos/uso terapêutico , Masculino , Pessoa de Meia-Idade , Rinite/cirurgia , Sinusite/cirurgia , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
8.
Rhinology ; 49(3): 356-63, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21858269

RESUMO

Chronic rhinosinusitis without and with nasal polyps (CRSwNP and CRSsNP), and antrochoanal polyps are different phenotypes with different pathomechanisms. Indoleamine 2,3-dioxygenase (IDO) is an enzyme expressed in many cells involved in the catabolism of the essential amino acid tryptophan to kynurenine. IDO might have a role in allergic airway inflammation. The aim was to evaluate if IDO expression is associated with CRSsNP, CRSwNP, or ACP. One hundred fifty specimens from the nasal cavity and sinus mucosa were immunohistochemically stained with mAb anti-IDO. The expression of epithelial and leukocyte IDO was associated with CRSwNP and ACP. The presence of ASA intolerance, asthma, atopy, smoking and use of medication did not significantly change the results. The different expression of IDO could putatively indicate the differences in the pathomechanisms of CRSsNP, CRSwNP and ACP. Further studies on the role of IDO in upper airways pathologies are required.


Assuntos
Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Pólipos Nasais/epidemiologia , Rinite/epidemiologia , Rinite/metabolismo , Sinusite/epidemiologia , Sinusite/metabolismo , Adulto , Idoso , Doença Crônica , Comorbidade , Eosinófilos/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pólipos Nasais/fisiopatologia , Rinite/fisiopatologia , Sinusite/fisiopatologia , Adulto Jovem
9.
J Appl Microbiol ; 106(1): 199-212, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19054229

RESUMO

AIMS: To test interactions between pathogenic strains of Streptomyces turgidiscabies, S. scabies and S. aureofaciens. To study biological control of S. turgidiscabies and S. scabies using the nonpathogenic Streptomyces strain (346) isolated from a scab lesion and a commercially available biocontrol agent (S. griseoviridis strain K61; 'Mycostop'). METHODS AND RESULTS: Pathogenic strains of S. turgidiscabies and S. aureofaciens inhibited growth of S. scabies in vitro, whereas strain 346 and S. griseoviridis inhibited the pathogenic strains and were subsequently tested for control of scab in the greenhouse and field. Strains 346 and K61 suppressed development of common scab disease caused by S. turgidiscabies in the greenhouse. Strain 346 reduced incidence of S. turgidiscabies in scab lesions on potato tubers in the field. CONCLUSIONS: Streptomyces turgidiscabies shows antagonism against S. scabies that occurs in the same scab lesions and shares the ecological niche in the field. Biocontrol of S. turgidiscabies is possible with nonpathogenic Streptomyces strains but interactions may be complicated. SIGNIFICANCE AND IMPACT OF THE STUDY: Streptomyces turgidiscabies may have potential to displace S. scabies under the Scandinavian potato growing conditions. Biological control of the severe potato scab pathogen, S. turgidiscabies, is demonstrated for the first time. The results can be applied to enhance control of common scab.


Assuntos
Antibiose , Controle Biológico de Vetores , Doenças das Plantas/microbiologia , Raízes de Plantas/microbiologia , Solanum tuberosum/microbiologia , Streptomyces/patogenicidade , Concentração de Íons de Hidrogênio , Reação em Cadeia da Polimerase , Streptomyces/crescimento & desenvolvimento , Streptomyces/isolamento & purificação
10.
Diabetologia ; 52(4): 664-74, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19089403

RESUMO

AIMS/HYPOTHESIS: Cannabinoid type 1 receptor (CB1R) antagonists such as rimonabant (Rim) represent a novel approach to treat obesity and related metabolic disorders. Recent data suggest that endocannabinoids are also produced by human adipocytes. Here we studied the potential involvement of endocannabinoids in the negative crosstalk between fat and muscle. METHODS: The protein level of CB1R in human skeletal muscle cells (SkM) during differentiation was analysed using western blotting. SkM were treated with adipocyte-conditioned medium (CM) or anandamide (AEA) in combination with the CB1R antagonists Rim or AM251, and insulin-stimulated Akt phosphorylation and glucose uptake were determined. Furthermore, signalling pathways of CB1R were investigated. RESULTS: We revealed an increase of CB1R protein in SkM during differentiation. Twenty-four hour incubation of SkM with CM or AEA impaired insulin-stimulated Akt(Ser473) phosphorylation by 60% and up to 40%, respectively. Pretreatment of cells with Rim or AM251 reduced the effect of CM by about one-half, while the effect of AEA could be prevented completely. The reduction of insulin-stimulated glucose uptake by CM was completely prevented by Rim. Short-time incubation with AEA activated extracellular regulated kinase 1/2 and p38 mitogen-activated protein kinase, and impaired insulin-stimulated Akt(Ser473) phosphorylation, but had no effect on Akt(Thr308) and glycogen synthase kinase 3alpha/beta phosphorylation. In addition, enhanced IRS-1 (Ser307) phosphorylation was observed. CONCLUSIONS/INTERPRETATION: Our results show that the CB1R system may play a role in the development of insulin resistance in human SkM. The results obtained with CM support the notion that adipocytes may secrete factors which are able to activate the CB1R. Furthermore, we identified two stress kinases in the signalling pathway of AEA and enhanced IRS-1(Ser307) phosphorylation, potentially underlying the development of insulin resistance.


Assuntos
Tecido Adiposo/fisiologia , Resistência à Insulina/fisiologia , Músculo Esquelético/fisiologia , Receptor Cross-Talk/fisiologia , Receptor CB1 de Canabinoide/fisiologia , Adipócitos/efeitos dos fármacos , Adipócitos/fisiologia , Tecido Adiposo/efeitos dos fármacos , Ácidos Araquidônicos/farmacologia , Moduladores de Receptores de Canabinoides/farmacologia , Técnicas de Cultura de Células , Diferenciação Celular , Endocanabinoides , Humanos , Músculo Esquelético/citologia , Músculo Esquelético/efeitos dos fármacos , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Pirazóis/farmacologia , Receptor CB1 de Canabinoide/antagonistas & inibidores , Rimonabanto
11.
Phytopathology ; 98(11): 1190-8, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18943407

RESUMO

Rhizoctonia solani is an important soilborne and seedborne fungal pathogen of potato (Solanum tuberosum). The initial infection of sprouts prior to emergence causes lesions and may be lethal to the sprout or sprout tip, which results in initiation and compensatory growth of new sprouts. They emerge successfully and do not suffer significant damage. The mechanism behind this recovery phenomenon is not known. It was hypothesized that infection may induce pathogen defense in sprouts, which was investigated in the present study. Tubers were sprouted in cool and moist conditions in darkness to mimic conditions beneath soil. The basal portion of the sprout was isolated from the apical portion with a soft plastic collar and inoculated with highly virulent R. solani. Induction of defense-related responses was monitored in the apical portion using microarray and quantitative polymerase chain reaction techniques at 48 and 120 h postinoculation (hpi) and by challenge-inoculation with R. solani in two experiments. Differential expression of 122 and 779 genes, including many well-characterized defense-related genes, was detected at 48 and 120 hpi, respectively. The apical portion of the sprout also expressed resistance which inhibited secondary infection of the sprouts. The observed systemic induction of resistance in sprouts upon infection with virulent R. solani provides novel information about pathogen defense in potato before the plant emerges and becomes photosynthetically active. These results advance our understanding of the little studied subject of pathogen defense in subterranean parts of plants.


Assuntos
Luz , Doenças das Plantas/genética , Rhizoctonia/fisiologia , Solanum tuberosum/genética , Solanum tuberosum/microbiologia , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Interações Hospedeiro-Patógeno , Imunidade Inata/genética , Análise de Sequência com Séries de Oligonucleotídeos , Doenças das Plantas/microbiologia
12.
Cell Mol Life Sci ; 65(19): 2979-99, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18516495

RESUMO

Traditional medicine has been a fertile source for revealing novel lead molecules for modern drug discovery. In plants, terpenoids represent a chemical defense against environmental stress and provide a repair mechanism for wounds and injuries. Interestingly, effective ingredients in several plant-derived medicinal extracts are also terpenoid compounds of monoterpenoid, sesquiterpenoid, diterpenoid, triterpenoid and carotenoid groups. Inflammatory diseases and cancer are typical therapeutic indications of traditional medicines. Thus folk medicine supports the studies which have demonstrated that plant-derived terpenoid ingredients can suppress nuclear factor-kappaB (NF-kappaB) signaling, the major regulator in the pathogenesis of inflammatory diseases and cancer.We review the extensive literature on the different types of terpenoid molecules, totalling 43, which have been verified both inhibiting the NF-kappaB signaling and suppressing the process of inflammation and cancer. It seems that during evolution, plants have established a terpene-based host defense which also represents a cornucopia of effective therapeutic compounds for common human diseases.


Assuntos
Anti-Inflamatórios/metabolismo , Antineoplásicos/metabolismo , NF-kappa B/antagonistas & inibidores , Terpenos/metabolismo , Anti-Inflamatórios/química , Anti-Inflamatórios/uso terapêutico , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Humanos , Medicina Tradicional , Estrutura Molecular , NF-kappa B/metabolismo , Neoplasias/tratamento farmacológico , Plantas/química , Terpenos/química , Terpenos/uso terapêutico
13.
Arch Virol ; 152(10): 1941-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17564759

RESUMO

Viruses of the species Bean common mosaic virus (BCMV) and Bean common mosaic necrosis virus (BCMNV) were simultaneously detected by the different size of PCR amplicons in lima bean plants (Phaseolus lunatus) displaying deforming mosaic symptoms in Peru. Phylogenetic analysis of partial deduced CP amino acid sequences indicated that the Peruvian BCMV isolates belong to new strains. One isolate differed from the other Peruvian isolates, and also from the ten previously described BCMV strains recognized by responses on differential bean varieties. The sequence of the 3'-proximal part (2547 nucleotides) of the genome confirmed that this isolate also belongs to BCMV.


Assuntos
Vírus do Mosaico/isolamento & purificação , Vírus do Mosaico/patogenicidade , Phaseolus/virologia , Potyvirus/isolamento & purificação , Sequência de Aminoácidos , Animais , Afídeos/virologia , Sequência de Bases , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , DNA Complementar/biossíntese , DNA Viral/análise , Escherichia coli/genética , Dados de Sequência Molecular , Vírus do Mosaico/genética , Técnicas de Amplificação de Ácido Nucleico , Peru , Filogenia , Doenças das Plantas/virologia , Folhas de Planta/virologia , Reação em Cadeia da Polimerase , Potyvirus/genética , RNA Viral/análise , RNA Viral/genética , RNA Viral/isolamento & purificação , Sementes/virologia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico
14.
Opt Lett ; 30(7): 756-8, 2005 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-15832929

RESUMO

We explore theoretically the possibility of generating broadband blue light by copropagating a short soliton pump pulse and a broader signal pulse in a microstructured fiber with a zero-dispersion wavelength located between the center wavelength of the pump and the signal pulses. We show that the unique properties of microstructured fibers should allow for broadening of the signal pulse's spectrum by as much as a factor of 50 through the conjugate action of cross-phase modulation and a soliton self-frequency shift. The physical mechanism that leads to this large spectral broadening is analyzed by use of an extended nonlinear Schrödinger equation.

15.
Opt Express ; 12(15): 3471-80, 2004 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-19483874

RESUMO

Enhancement of the bandwidth of supercontinuum generated in microstructured fibers with a tailored dispersion profile is demonstrated experimentally. The fibers are designed to have two zero-dispersion wavelengths separated by more than 700 nm, which results in an amplification of two dispersive waves at visible and infrared wavelengths. The underlying physics behind the broad continuum formation is discussed and analyzed in detail. The experimental observations are confirmed through numerical simulations.

16.
Opt Express ; 12(19): 4614-24, 2004 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-19484014

RESUMO

We investigate the effects of cross-phase modulation between the solitons and dispersive waves present in a supercontinuum generated in microstructured fibers by sub-30 fs pulses. Cross-phase modulation is shown to have a crucial importance as it extends the supercontinuum towards shorter wavelengths. The experimental observations are confirmed through numerical simulations.

17.
Opt Express ; 10(20): 1083-98, 2002 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-19451966

RESUMO

We report on the influence of the choice of the pump wavelength relative to the zero-dispersion wavelength for continuum generation in microstructured fibers. Different nonlinear mechanisms are observed depending on whether the pump is located in the normal or anomalous dispersion region. Raman scattering and the wavelength dependence of the group delay of the fiber are found to play an important role in the process. We give an experimental and numerical analysis of the observed phenomena and find a good agreement between the two.

18.
Genetics ; 159(1): 241-54, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11560901

RESUMO

Mutations in mtDNA-encoded components of the mitochondrial translational apparatus are associated with diverse pathological states in humans, notably sensorineural deafness. To develop animal models of such disorders, we have manipulated the nuclear gene for mitochondrial ribosomal protein S12 in Drosophila (technical knockout, tko). The prototypic mutant tko(25t) exhibits developmental delay, bang sensitivity, impaired male courtship, and defective response to sound. On the basis of a transgenic reversion test, these phenotypes are attributable to a single substitution (L85H) at a conserved residue of the tko protein. The mutant is hypersensitive to doxycyclin, an antibiotic that selectively inhibits mitochondrial protein synthesis, and mutant larvae have greatly diminished activities of mitochondrial redox enzymes and decreased levels of mitochondrial small-subunit rRNA. A second mutation in the tko gene, Q116K, which is predicted to impair the accuracy of mitochondrial translation, results in the completely different phenotype of recessive female sterility, based on three independent transgenic insertions. We infer that the tko(25t) mutant provides a model of mitochondrial hearing impairment resulting from a quantitative deficiency of mitochondrial translational capacity.


Assuntos
DNA Mitocondrial/genética , Surdez/genética , Drosophila/genética , Mitocôndrias/metabolismo , Mutação , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/fisiologia , Animais , Animais Geneticamente Modificados , Antibacterianos/farmacologia , Northern Blotting , Southern Blotting , Núcleo Celular/genética , Clonagem Molecular , Cruzamentos Genéticos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Doxiciclina/farmacologia , Drosophila/fisiologia , Feminino , Humanos , Infertilidade Feminina/genética , Masculino , Modelos Genéticos , Oligonucleotídeos/metabolismo , Oxirredução , Fenótipo , Reação em Cadeia da Polimerase , Biossíntese de Proteínas , RNA Ribossômico/metabolismo , Análise de Sequência de DNA , Som , Fatores de Tempo , Transgenes
19.
Atherosclerosis ; 157(1): 57-64, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11427204

RESUMO

Polymorphisms of the angiotensin-converting enzyme (ACE) (insertion/deletion (I/D) in intron 16) and of the plasminogen activator inhibitor-1 (PAI-1) (promoter 4G/5G) genes have been linked with coronary heart disease (CHD) and/or myocardial infarction (MI). We studied the association of polymorphisms in these genes with CHD with linkage and association analyses in 118 families with premature and severe CHD and in 110 healthy controls. In linkage analysis there was no evidence for a linkage of the ACE or PAI-1 loci with CHD. However, in quantitative linkage analysis the ACE locus was linked with fasting glucose (P=0. 047) and fasting free fatty acid levels (P=0.029). In association analysis the ACE genotype frequencies of probands with CHD did not differ from those of healthy controls. Normoglycemic probands with MI and with the ACE polymorphism DD genotype had characteristics of the insulin resistance syndrome. They had higher levels of 1-h glucose (P=0.008) and 2-h free fatty acids (P=0.011) in an oral glucose tolerance test and higher levels of total (P=0.005) and very-low-density lipoprotein triglycerides (P=0.006) than probands with the ID or the II genotypes. The PAI-1 gene polymorphism was not associated with any of the variables of glucose or lipid metabolism. In conclusion, the ACE and PAI-1 gene polymorphisms are not linked with early-onset CHD. However, the ACE gene polymorphism is associated with features of the insulin resistance syndrome.


Assuntos
Doença das Coronárias/genética , Resistência à Insulina/genética , Peptidil Dipeptidase A/genética , Inibidor 1 de Ativador de Plasminogênio/genética , Idoso , Alelos , Doença das Coronárias/etiologia , Feminino , Finlândia , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Regiões Promotoras Genéticas
20.
Am J Hum Genet ; 68(6): 1475-84, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11349229

RESUMO

The sequence in the first hypervariable segment (HVS-I) of the control region has been used as a source of evolutionary information in most phylogenetic analyses of mtDNA. Population genetic inference would benefit from a better understanding of the variation in the mtDNA coding region, but, thus far, complete mtDNA sequences have been rare. We determined the nucleotide sequence in the coding region of mtDNA from 121 Finns, by conformation-sensitive gel electrophoresis and subsequent sequencing and by direct sequencing of the D loop. Furthermore, 71 sequences from our previous reports were included, so that the samples represented all the mtDNA haplogroups present in the Finnish population. We found a total of 297 variable sites in the coding region, which allowed the compilation of unambiguous phylogenetic networks. The D loop harbored 104 variable sites, and, in most cases, these could be localized within the coding-region networks, without discrepancies. Interestingly, many homoplasies were detected in the coding region. Nucleotide variation in the rRNA and tRNA genes was 6%, and that in the third nucleotide positions of structural genes amounted to 22% of that in the HVS-I. The complete networks enabled the relationships between the mtDNA haplogroups to be analyzed. Phylogenetic networks based on the entire coding-region sequence in mtDNA provide a rich source for further population genetic studies, and complete sequences make it easier to differentiate between disease-causing mutations and rare polymorphisms.


Assuntos
DNA Mitocondrial/genética , Mutação/genética , Filogenia , Códon/genética , Análise Mutacional de DNA , DNA Mitocondrial/química , Evolução Molecular , Finlândia , Genoma , Haplótipos/genética , Humanos , Dados de Sequência Molecular , Mutação de Sentido Incorreto/genética , Conformação de Ácido Nucleico , Polimorfismo Genético/genética , RNA Ribossômico/genética , RNA de Transferência/genética , Sequências Reguladoras de Ácido Nucleico/genética
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