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1.
Mol Genet Metab ; 137(1-2): 18-25, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35868242

RESUMO

OBJECTIVES: Pathogenic biallelic variants in PCK1 coding for the cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) cause PEPCK-C deficiency, a rare disorder of gluconeogenesis presenting with hypoglycemia, lactic acidosis, and hepatopathy. To date, there has been no systematic analysis of its phenotypic, biochemical, and genetic spectrum. METHODS: All currently published individuals and a novel patient with genetically confirmed PEPCK-C deficiency were included. Clinical, biochemical, and genetic findings were analyzed. Protein and in-silico prediction score modeling was applied to analyze potential variant effects. RESULTS: Thirty-two individuals from 25 families were found, including one previously unreported patient. The typical biochemical pattern was hypoglycemia triggered by catabolic situations, elevated urinary concentrations of tricarboxylic acid cycle metabolites, mildly elevated alanine and aspartate aminotransferase and elevated lactate concentrations in serum. Plasma glutamine concentrations were elevated in some patients and may be a suitable marker for newborn screening. With adequate treatment, biochemical abnormalities usually normalized following a hypoglycemic episode. Symptom onset usually occurred in infancy with a broad range from neonatal age to adulthood. Regardless of the genotype, different phenotypes with a broad clinical spectrum were found. To date, eight genotypes with nine different PCK1 variants were identified, of which alleles with the recurrent variant c.925G > A; p.(Gly309Arg) are predominant and appear to be endemic in the Finnish population. Protein modeling suggests altered manganese- and substrate-binding as superordinate pathomechanisms. CONCLUSIONS: Environmental factors appear to be the main determinant for the phenotype in patients with biallelic variants in PCK1. Based on the biochemical pattern, PEPCK-C deficiency is a recognizable cause of childhood hypoglycemia. It is a treatable disease and early diagnosis is important to prevent metabolic derailment and morbidity. Newborn screening can identify at least a sub-cohort of affected individuals through elevated glutamine concentrations in dry blood.


Assuntos
Glutamina , Hipoglicemia , Humanos , Glutamina/genética , Manganês , Fosfoenolpiruvato , Fosfoenolpiruvato Carboxiquinase (GTP)/genética , Hipoglicemia/genética , Genótipo , Fenótipo , Hipoglicemiantes , Lactatos , Aspartato Aminotransferases/genética , Alanina
2.
Phys Rev Lett ; 126(16): 162501, 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33961478

RESUMO

We report the first measurement of the average of the electron-proton and positron-proton elastic scattering cross sections. This lepton charge-averaged cross section is insensitive to the leading effects of hard two-photon exchange, giving more robust access to the proton's electromagnetic form factors. The cross section was extracted from data taken by the OLYMPUS experiment at DESY, in which alternating stored electron and positron beams were scattered from a windowless gaseous hydrogen target. Elastic scattering events were identified from the coincident detection of the scattered lepton and recoil proton in a large-acceptance toroidal spectrometer. The luminosity was determined from the rates of Møller, Bhabha, and elastic scattering in forward electromagnetic calorimeters. The data provide some selectivity between existing form factor global fits and will provide valuable constraints to future fits.

3.
Int J Pharm ; 571: 118759, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31622744

RESUMO

The sensation of dry mouth also referred to as xerostomia is becoming increasingly common worldwide. Current treatment strategies include topical agents, sialagogues and saliva substitutes. The latter have been reported to be ineffective as special physicochemical features of natural saliva have so far been ignored (e.g., buffer capacity, osmolality, etc.). The aim of this study was to comprehensively investigate the most relevant physicochemical properties of three products frequently used in the clinics and compare them to unstimulated whole saliva (UWS). Sialin-Sigma®, Glandomed® and Xylitol CVS HealthTM Dry Mouth Spray were characterized regarding their pH, osmolality, electrical conductivity, buffer capacity, rheological behaviour, microstructure, surface tension and wettability and compared to UWS. The influence of residual saliva was examined under consideration of the conditions of xerostomia to assess whether the quantity given in the instruction for use is appropriate. All three products showed significant differences to UWS regarding the values received. Only Xylitol CVS HealthTM Dry Mouth Spray showed a comparable wettability. It could be further determined that the recommended doses were too low. These data can not only be used for an improved understanding of saliva, but also for the development of a replacement fluid to successfully alleviate xerostomia.


Assuntos
Saliva Artificial/química , Saliva/química , Xerostomia/terapia , Administração Oral , Adulto , Aerossóis , Soluções Tampão , Linhagem Celular , Relação Dose-Resposta a Droga , Rotulagem de Medicamentos , Células Epiteliais , Feminino , Voluntários Saudáveis , Humanos , Masculino , Mucosa Bucal/citologia , Saliva Artificial/administração & dosagem , Xilitol/administração & dosagem , Xilitol/química
4.
Environ Epigenet ; 4(2): dvy011, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29992049

RESUMO

Epigenetic modifications, of which DNA methylation is the most stable, are a mechanism conveying environmental information to subsequent generations via parental germ lines. The paternal contribution to adaptive processes in the offspring might be crucial, but has been widely neglected in comparison to the maternal one. To address the paternal impact on the offspring's adaptability to changes in diet composition, we investigated if low protein diet (LPD) in F0 males caused epigenetic alterations in their subsequently sired sons. We therefore fed F0 male Wild guinea pigs with a diet lowered in protein content (LPD) and investigated DNA methylation in sons sired before and after their father's LPD treatment in both, liver and testis tissues. Our results point to a 'heritable epigenetic response' of the sons to the fathers' dietary change. Because we detected methylation changes also in the testis tissue, they are likely to be transmitted to the F2 generation. Gene-network analyses of differentially methylated genes in liver identified main metabolic pathways indicating a metabolic reprogramming ('metabolic shift'). Epigenetic mechanisms, allowing an immediate and inherited adaptation may thus be important for the survival of species in the context of a persistently changing environment, such as climate change.

5.
Gene Ther ; 24(5): 298-307, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28346436

RESUMO

Correction of patient-specific induced pluripotent stem cells (iPSC) upon gene delivery through retroviral vectors offers new treatment perspectives for monogenetic diseases. Gene-modified iPSC clones can be screened for safe integration sites and differentiated into transplantable cells of interest. However, the current bottleneck is epigenetic vector silencing. In order to identify the most suitable retroviral expression system in iPSC, we systematically compared vectors from different retroviral genera, different promoters and their combination with ubiquitous chromatin opening elements (UCOE), and several envelope pseudotypes. Lentiviral vectors (LV) pseudotyped with vesicular stomatitis virus glycoprotein were superior to gammaretroviral and alpharetroviral vectors and other envelopes tested. The elongation factor 1α short (EFS) promoter mediated the most robust expression, whereas expression levels were lower from the potent but more silencing-prone spleen focus forming virus (SFFV) promoter. Both full-length (A2UCOE) and minimal (CBX3) UCOE juxtaposed to two physiological and one viral promoter reduced transgene silencing with equal efficiency. However, a promoter-specific decline in expression levels was not entirely prevented. Upon differentiation of transgene-positive iPSC into endothelial cells, A2UCOE.EFS and CBX3.EFS vectors maintained highest transgene expression in a larger fraction of cells as compared with all other constructs tested here. The function of UCOE diminished, but did not fully counteract, vector silencing and possibilities for improvements remain. Nevertheless, the CBX3.EFS in a LV background exhibited the most promising promoter and vector configuration for both high titer production and long-term genetic modification of human iPSC and their progeny.


Assuntos
Vetores Genéticos/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Regiões Promotoras Genéticas , Retroviridae/genética , Transgenes , Células Cultivadas , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Inativação Gênica , Células HeLa , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Fator 1 de Elongação de Peptídeos/genética , Transfecção/métodos , Transfecção/normas
6.
Phys Rev Lett ; 118(9): 092501, 2017 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-28306315

RESUMO

The OLYMPUS Collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, R_{2γ}, a direct measure of the contribution of hard two-photon exchange to the elastic cross section. In the OLYMPUS measurement, 2.01 GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range of ≈20° to 80°. The relative luminosity between the two beam species was monitored using tracking telescopes of interleaved gas electron multiplier and multiwire proportional chamber detectors at 12°, as well as symmetric Møller or Bhabha calorimeters at 1.29°. A total integrated luminosity of 4.5 fb^{-1} was collected. In the extraction of R_{2γ}, radiative effects were taken into account using a Monte Carlo generator to simulate the convolutions of internal bremsstrahlung with experiment-specific conditions such as detector acceptance and reconstruction efficiency. The resulting values of R_{2γ}, presented here for a wide range of virtual photon polarization 0.456<ε<0.978, are smaller than some hadronic two-photon exchange calculations predict, but are in reasonable agreement with a subtracted dispersion model and a phenomenological fit to the form factor data.

7.
Hum Exp Toxicol ; 34(11): 1139-47, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25673179

RESUMO

Anabolic androgenic steroids lead to cardiac complications and have been shown to exhibit proapoptotic effects in cardiac cells; however, the mechanism involved in those effects is unclear. The aim of this study was to assess whether apoptosis and the activation of caspase-3 (Casp-3) induced by testosterone in high concentrations involves increments in tumor necrosis factor-α (TNF-α) concentrations and angiotensin-converting enzyme (ACE) activity in cardiomyocytes (H9c2) cell cultures. Cardiomyocytes were treated with testosterone (5 × 10(-6) mol/L), doxorubicin (9.2 × 10(-6) mol/L), testosterone + etanercept (Eta; 6.67 × 10(-5) mol/L), testosterone + losartan (Los; 10(-7) mol/L), and testosterone + AC-DEVD-CHO (10(-5) mol/L; Casp-3 inhibitor). Apoptosis was determined by flow cytometry and by the proteolytic activity of Casp-3. We demonstrated that incubation of H9c2 cells for 48 h with testosterone causes the apoptotic death of 60-70% of the cells and co-treatments with Eta, Los, or AC-DEVD-CHO reduced this effect. Testosterone also induces apoptosis (concentration dependent) and increases the proteolytic activity of Casp-3, which were reduced by co-treatments. TNF-α and ACE activities were elevated by testosterone treatment, while co-treatment with Los and Eta reduced these effects. We concluded that an interaction between testosterone, angiotensin II, and TNF-α induced apoptosis and Casp-3 activity in cultured cardiomyocytes, which contributed to the reduced viability of these cells induced by testosterone in toxic concentrations.


Assuntos
Miócitos Cardíacos/efeitos dos fármacos , Peptidil Dipeptidase A/metabolismo , Testosterona/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Linhagem Celular , Miócitos Cardíacos/metabolismo , Ratos , Sistema Renina-Angiotensina/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
8.
Klin Padiatr ; 227(1): 41-4, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25565197

RESUMO

Here we report on a case of primary cryptococcal skin infection in an immunocompetent 8-year-old boy. The infection first manifested itself as a subcutaneous abscess around the proximal joint of his right thumb after a minor injury from contact with a thorny shrub. After surgical incision and drainage was performed, Cryptococcus neoformans var. neoformans was the only pathogen cultured from the lesion. An agglutination test for the capsular antigen in serum displayed negative results and the immunological work-up revealed no underlying immunodeficiency. A "watch and wait" strategy - one without systemic antifungal treatment - was adopted and this resulted in uneventful healing. In summary, primary cryptococcal skin infections in immunocompetent hosts may be managed successfully by surgical treatment in combination with careful clinical follow-up. This approach may help avoid unnecessary antimicrobial treatments.


Assuntos
Abscesso/terapia , Antifúngicos/administração & dosagem , Criptococose/terapia , Cryptococcus neoformans , Dermatomicoses/terapia , Drenagem , Imunocompetência , Polegar , Abscesso/diagnóstico , Criança , Terapia Combinada , Criptococose/diagnóstico , Dermatomicoses/diagnóstico , Seguimentos , Humanos , Masculino , Polegar/lesões
9.
Rev. bras. plantas med ; 17(3): 392-397, Jul-Sep/2015. tab, graf
Artigo em Português | LILACS | ID: lil-752554

RESUMO

RESUMO No Brasil, a família Malvaceae está representada por aproximadamente 200 espécies e algumas foram descritas como gastroproteroras. Pavonia alnifolia A.St.-Hil. (Malvaceae) foi selecionada após uma abordagem quimiossistemática, considerando-se sua potencial capacidade em prevenir lesões gástricas. Assim, a atividade gastroprotetora do extrato etanólico de caules de P. alnifolia foi avaliada utilizando o modelo de indução aguda da lesão gástrica por etanol acidificado em camundongos. Além disso, foram quantificados o teor de flavonóides, pelo método de cloreto de alumínio, e de polifenóis, pelo método Folin-Ciocalteu, uma vez que a relação desses componentes com a proteção gástrica foi evidenciada. Os ensaios apontaram redução acentuada das lesões gástricas em camundongos tratados com o extrato da planta em todas as doses ensaiadas (10, 100 e 300 mg/kg). Esse efeito pode estar relacionado com a presença de polifenóis, cujo teor encontrado foi 74,3 ± 7,5 µg equivalente de pirogalol/mg do material vegetal examinado e 82,7 ± 7,1 µg equivalente de pirogalol /mg da amostra no extrato preparado por percolação e teor de flavonoides totais, que por sua vez apresentou um resultado de 17,1 ± 1,4 µg/mg de extrato. O extrato apresentou proteção da mucosa gástrica e este efeito pode estar relacionado à presença dos polifenóis e flavonóides encontrados


ABSTRACT Gastro protective activity of the Pavonia alnifolia A.St.-Hil. extract. In Brazil, the Malvaceae family is represented by at about 200 species. Some of those species are known as gastro protective ones. The Pavonia alnifolia A.St.-Hil (Malvaceae) was selected after a chemosystematic approach. The gastro preventive activity of the ethanol extract of stems Pavonia alnifolia was evaluated through the use of the Ethanol:chlroridric acid model on mice. The quantification of the total flavonoids (aluminum chloride method) and total polyphenols (Folin-Ciocalteu method) was also performed since the relation of those components with gastric protection has been previously highlighted. The tests showed a significant reduction of the ulcer formation in the mice treated with the plant extract (10, 100 and 300 mg/kg). This effect may be related to the presence of polyphenols whose content was found to be 74.3 ± 7.5 µg/mg of vegetal material and 82.7 ± 7.1 µg/mg of crude extract and flavonoids, which in turn showed a content of 17.1 ± 1.4 µg/mg dry extract


Assuntos
Extratos Vegetais/análise , Malvaceae/classificação , Flavonoides/análise , Polifenóis/análise
10.
Acta Chir Orthop Traumatol Cech ; 79(1): 59-64, 2012.
Artigo em Tcheco | MEDLINE | ID: mdl-22405551

RESUMO

PURPOSE OF THE STUDY: The aim of the study was to evaluate the group of patients treated for varus arthritic knee by the method of high tibial osteotomy from the lateral approach and to assess its role in the present-day orthopaedic surgery which also offers other options such as distraction osteotomy from the medial approach, autologous chondrocyte transplantation or alloplasty. MATERIAL AND METHODS: The study included 101 patients, 41 women and 60 men, undergoing lateral valgus high tibial osteotomy at our department between 2003 and 2007. The age of patients at the time of surgery ranged from 34 to 61 years, with an average of 54 years. The follow-up period was in the range of 2 to 7 years, with an average of 5.2 years. Moderate varus gonarthrosis was the most frequent indication for osteotomy. Each procedure was preceded by arthroscopy with treatment of the pathologies found; these most frequently included a torn medial meniscus, synovitis or medial compartment chondropathy. The outcomes were evaluated using a system of clinical and radiographic assessment (A) and the Lysholm score (B) before and after surgery. RESULTS: The A system evaluation showed excellent, good and poor results in 42, 47 and 12 patients, respectively. The average Lysholm score was 51 points before surgery and 73 points at the final follow-up examination; the average improvement was by 22 points. The average mechanical axis was 2 degrees of varus before and 6 degrees of valgus after surgery. The minimal correction of the axis was 4 degrees and the maximal correction was 18 degrees. The average change of the axis was 8 degrees. Complications were recorded in 21% of the patients. None of the patients had delayed healing, pseudoarthrosis, fracture of the tibial plateau or peroneal nerve palsy. DISCUSSION: Long-term excellent and good outcomes were found more often in the patients with a greater resulting valgus angle. After surgery the average anatomical axis was 7.4 degrees of valgus for good and excellent results, and 4.3 degrees of valgus for poor results. This is in agreement with the common recommendation that osteotomy should produce mild overcorrection. The 95% osteotomy survival rate in this study is in accordance with the results reported by Coventry et al. and Sprenger et al. With strict adherence to the indication criteria, we did not find any clear relationship between the severity of knee injury before surgery and the subjective evaluation of post-operative clinical outcome. The patient's body mass index (BMI) had no effect on the outcome, but the majority of our patients had a BMI below 30 (average, 28.2). The range of motion after surgery was not significantly limited. Both the occurrence of complications and alignment maintenance are comparable with the results of distraction osteotomy. CONCLUSIONS: The mid-term results of valgus osteotomy performed by the technique described by Coventry et al. testify to the lasting success of this method. Satisfaction with its outcome can be expected in about 90% of the patients in a 5-year post-operative period. To achieve this, it is necessary to strictly observe the indication criteria, operative technique and thorough arthroscopic treatment of the joint. Also, the necessity of slight over-correction to 8 degrees of valgus is emphasised.


Assuntos
Osteoartrite do Joelho/cirurgia , Osteotomia/métodos , Tíbia/cirurgia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/complicações
11.
Exp Brain Res ; 203(3): 629-35, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20449728

RESUMO

The brain can be considered a dynamical system which is able to oscillate at multiple frequencies. To study the brain's preferred oscillation frequencies, the resonance frequencies in the frequency response of the system can be assessed by stimulating the brain at various stimulation frequencies. Furthermore, the event-related potential (ERP) can be considered as the brain's impulse response. For linear dynamical systems, the frequency response should be equivalent to the frequency transform of the impulse response. The present study test whether this fundamental relation is also true for the frequency transform of the ERP and the frequency response of the brain. Results show that the spectral characteristics of both impulse and frequency response in the gamma frequency range are significantly correlated. Thus, we speculate that the resonance frequencies determine the frequency spectrum of the impulse response. This, in turn, implies that both measures are determined by the same, individually specific, neuronal generator mechanisms.


Assuntos
Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Estimulação Acústica , Eletroencefalografia , Potenciais Evocados , Feminino , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
12.
Z Orthop Unfall ; 147(4): 427-32, 2009.
Artigo em Alemão | MEDLINE | ID: mdl-19693738

RESUMO

AIM: Amputation injuries in children occur in motor vehicle, farming and, importantly, lawn mower accidents. Treatment of lawn mower related injuries is complicated by gross wound contamination, avascular tissue, soft tissue defects and exposed bone. Many treatment options exist and often an adequate prosthetic supply is needed for rehabilitation. We report on an 8-year old boy who got under a ride-on lawn mower and sustained a subtotal amputation of his right foot. After initial surgery an amputation was subsequently necessary. For this, it had to be taken into account that the traumatic loss of the talus, calcaneus and parts of the cuboid bone would result in a length shortening of the right leg and so far not injured metatarsal and tarsal bones had to be sacrificed. Thus, we aimed to develop a new operation technique to optimize stump length as well as preserve tarsal bones and the possibility of limb growth. METHOD: In order to achieve this, we performed a new stump forming operation in which we integrated uninjured tarsal and metatarsal bones. First a Lisfranc's amputation was performed and a metatarsal bone was kept aside. The talus, calcaneus as well as the cuboid bone were either completely or almost completely destroyed and were removed. The remaining cuneiform bones were transfixed by a notched metatarsal bone, thus achieving a tarsal arthrodesis, and the cartilages of the proximal joint surfaces were removed. The cartilage of the cranial and caudal navicular as well as the distal tibial joint surface was also removed and an arthrodesis between the distal tibia and the navicular bone was achieved by crossed Kirschner wires. Finally the cuneiform bones were placed inferior to the navicular bone. Further stump coverage was managed by skin and muscle flaps as well as split skin graft. RESULT: Our patient was discharged on day 34. A fluent gait without crutches as well as sports activities were possible again as early as 6 1/2 months after the injury. CONCLUSION: Using our stump forming technique we hope to prevent some complications of amputation injuries. Because of the intact epiphysis a bone overgrowth is hopefully prevented and growth potential is preserved and by inclusion of tarsal and metatarsal bones in the stump formation a length discrepancy is minimized.


Assuntos
Acidentes , Cotos de Amputação/cirurgia , Amputação Traumática/cirurgia , Traumatismos do Pé/cirurgia , Procedimentos de Cirurgia Plástica/instrumentação , Procedimentos de Cirurgia Plástica/métodos , Criança , Humanos , Masculino , Resultado do Tratamento
13.
Oncol Rep ; 16(3): 597-601, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16865261

RESUMO

Tumor hypoxia leads to adaptive responses in cancer cells, including an induction of vasculogenesis initiated by circulating endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs). The aim of the present study was to correlate the number of EPCs and CECs with the oxygenation of cervical cancer. Blood concentrations of EPCs were detected by FACS analysis with antibodies for CD34 and vascular endothelial growth factor receptor 2 (VEGFR2). CECs were evaluated by double staining for 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine-labeled acetylated low density lipoprotein (Di-LDL) and lectin in a cell culture assay. Ten patients with cervical cancer were compared with ten healthy volunteers. Intratumoral oxygen tension was assessed polarographically with the computerized Eppendorf histography system. Analysis of CEC numbers revealed no difference between patients and controls. However, patients had lower concentrations of CD34-positive hematopoietic stem cells (HSCs) but a significantly higher fraction of EPCs related to the number of HSCs (1.09% versus 0.53%). This fraction was significantly inversely correlated to the median oxygen tension (r = -0.74, p = 0.015). Our study shows for the first time a significant inverse correlation between the fraction of EPCs and intratumoral oxygen tension. We conclude that the fraction of EPCs should be further evaluated as a useful and convenient marker in the prediction of tumor tissue oxygenation.


Assuntos
Endotélio Vascular/metabolismo , Células Neoplásicas Circulantes/metabolismo , Oxigênio/metabolismo , Células-Tronco/metabolismo , Neoplasias do Colo do Útero/metabolismo , Feminino , Humanos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
15.
Chem Biol Interact ; 157-158: 363-5, 2005 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-16429486

RESUMO

Previous studies in rodents and nonhuman primates have demonstrated that pretreatment with cholinesterases can provide significant protection against behavioral and lethal effects of nerve agent intoxication. Human butyrylcholinesterase (HuBuChE) purified from plasma has been shown to protect against up to 5 x LD50s of nerve agents in guinea pigs and non-human primates, and is currently being explored as a bioscavenger pretreatment for human use. A recombinant form of HuBuChE has been expressed in the milk of transgenic goats as a product called Protexia. Protexia was supplied by Nexia Biotechnologies (Que., Canada) as a purified solution with a specific activity of 600 U/mg. Initial in vitro studies using radiolabeled 3H-soman or 3H-DFP (diisopropyl fluorophosphate) demonstrated that these inhibitors specifically bind to Protexia. When Protexia was mixed with soman, sarin, tabun or VX using varying molar ratios of enzyme to nerve agent (8:1, 4:1, 1:1 and 1:4, respectively), the data indicated that 50% inhibition of enzyme activity occurs around the 1:1 molar ratio for each of the nerve agents. Protexia was further characterized for its interaction with pyridostigmine bromide and six unique carbamate inhibitors of cholinesterase. IC50 and Ki values for Protexia were determined to be very similar to those of HuBuChE purified from human plasma. These data suggest that Protexia has biochemical properties very similar to those HuBuChE when compared in vitro. Together these data the continued development of the goat milk-derived recombinant HuBuChE Protexia as a potential bioscavenger of organophosphorus nerve agents.


Assuntos
Butirilcolinesterase/farmacologia , Neurônios/efeitos dos fármacos , Neurotoxinas/antagonistas & inibidores , Animais , Butirilcolinesterase/química , Carbamatos/antagonistas & inibidores , Cabras , Humanos , Neurônios/enzimologia , Neurônios/patologia , Neurotoxinas/farmacologia , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacologia
16.
Opt Express ; 12(6): 1150-6, 2004 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-19474933

RESUMO

A simple formalism to estimate modal power loss coefficients for an overmoded rectangular waveguide with rough surfaces is presented. The method is based on small index differences where the true radiation modes are approximated by free space modes. Loss coefficients are important in order to establish more accurate channel models for, e.g., optical backplane communication systems. The theory is validated by comparing the loss coefficients of a squeezed rectangular waveguide with the loss coefficients of a slab waveguide.

17.
J Appl Toxicol ; 23(3): 177-86, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12794939

RESUMO

Despite the contrasts in chemistry and toxicity, for blister and nerve chemical warfare agents there may be some analogous proteolytic and inflammatory mediators and pathological pathways that can be pharmacological targets for a single-drug multi-threat medical countermeasure. The dermal-epidermal separation caused by proteases and bullous diseases compared with that observed following exposure to the blister agent sulfur mustard (2,2'-dichlorodiethyl sulfide) has fostered the hypothesis that sulfur mustard vesication involves proteolysis and inflammation. In conjunction with the paramount toxicological event of cholinergic crisis that causes acute toxicity and precipitates neuronal degeneration, both anaphylactoid reactions and pathological proteolytic activity have been reported in nerve-agent-intoxicated animals. Two classes of drugs already have demonstrated multi-threat activity for both nerve and blister agents. Serine protease inhibitors can prolong the survival of animals intoxicated with the nerve agent soman and can also protect against vesication caused by the blister agent sulfur mustard. Poly (ADP-ribose) polymerase (PARP) inhibitors can reduce both soman-induced neuronal degeneration and sulfur-mustard-induced epidermal necrosis. Protease and PARP inhibitors, like many of the other countermeasures for blister and nerve agents, have potent primary or secondary anti-inflammatory pharmacology. Accordingly, we hypothesize that drugs with anti-inflammatory actions against either nerve or blister agent might also display multi-threat efficacy for the inflammatory pathogenesis of both classes of chemical warfare agent.


Assuntos
Substâncias para a Guerra Química/toxicidade , Gás de Mostarda/toxicidade , Soman/toxicidade , Animais , Anti-Inflamatórios/uso terapêutico , Inibidores da Colinesterase/toxicidade , Humanos , Peptídeo Hidrolases/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases , Poli(ADP-Ribose) Polimerases/uso terapêutico , Inibidores de Serina Proteinase/uso terapêutico
18.
J Endocrinol ; 176(1): 69-82, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12525251

RESUMO

Transforming growth factor beta1 (TGFbeta1) has been shown to exert strong inhibitory effects on adrenocortical cell steroidogenesis. However, the molecular targets of TGFbeta1 in adrenocortical cells appear to differ between species. Here, we report the first characterization of the regulatory effects of TGFbeta1 on the steroidogenic functions of the human adrenocortical tumor cell line NCI-H295R. After treatment with 2 ng/ml TGFbeta1 for 24 h, basal production of corticosterone, cortisol and androstenedione was dramatically decreased. When TGFbeta1 was added simultaneously with forskolin, the production of cortisol and 11-hydroxyandrostenedione was decreased by 85% whereas that of deoxycortisol was increased. When TGFbeta1 was added simultaneously with angiotensin II, aldosterone production was reduced by 80%. We observed that TGFbeta1 strongly inhibits forskolin-induced steroid 11beta-hydroxylase activity and CYP11B1 mRNA levels, as well as angiotensin II-induced aldosterone synthase activity and CYP11B2 mRNA levels. CYP11B1 and CYP11B2 gene products thus appear as the major steroidogenic enzymes down-regulated by TGFbeta1 in the human adrenocortical tumor cell line NCI-H295R.


Assuntos
Córtex Suprarrenal/metabolismo , Aldosterona/biossíntese , Androstenodiona/análogos & derivados , Citocromo P-450 CYP11B2/metabolismo , Hidrocortisona/biossíntese , Esteroide 11-beta-Hidroxilase/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Hormônio Adrenocorticotrópico/farmacologia , Análise de Variância , Androstenodiona/biossíntese , Angiotensina II/farmacologia , Colforsina/farmacologia , Corticosterona/biossíntese , Cortodoxona/metabolismo , Depressão Química , Humanos , RNA Mensageiro/análise , Esteroide 11-beta-Hidroxilase/genética , Células Tumorais Cultivadas
19.
J Appl Toxicol ; 21(4): 293-6, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11481662

RESUMO

Soman-poisoned rats display cholinergic crisis, a systemic mast cell degranulation characteristic of anaphylactic reactions and an excitotoxin-like sequential seizure and neuronal degeneration. The protection of guinea pigs from soman lethality by prophylactic administration of the serine protease inhibitor suramin suggests a possible proteolytic component in soman poisoning. The present study tested the effect of N-tosyl-L-lysine chloromethyl ketone (TLCK), an inhibitor of trypsin-like serine proteases, on soman-induced toxic signs (convulsions, righting reflex) and survival time. Nine control guinea pigs receiving 2 x LD(50) (56 microg kg(-1), s.c.) of soman immediately followed by a therapeutic dose of atropine sulfate (17.4 mg kg(-1) i.m.) experienced severe convulsions, and 8/9 lost the righting reflex. Six of these nine animals expired within 65 min; the three remaining animals survived 24 h to termination of the experiment. When a second group of animals were given TLCK (12 mg kg(-1), i.p.) 30 min prior to a 2 x LD(50) soman challenge and atropine-sulfate therapy, 5/9 experienced convulsions and only 3/9 lost the righting reflex. All nine animals survived beyond 4 h, with six surviving to 24 h. Compared with soman controls, prophylaxis with TLCK significantly prevented the loss of righting reflex (P = 0.05) and enhanced 4-h survival (P = 0.005). Although, convulsions were reduced and 24-h survival was improved in TLCK-treated animals, these results were not statistically significant. The protection from soman toxicity by chemically distinct protease inhibitors such as suramin and TLCK suggests a role for pathological proteolytic pathways in soman intoxication.


Assuntos
Atropina/uso terapêutico , Inibidores da Colinesterase/intoxicação , Inibidores de Serina Proteinase/farmacologia , Soman/antagonistas & inibidores , Tosilina Clorometil Cetona/farmacologia , Animais , Atropina/administração & dosagem , Substâncias para a Guerra Química/intoxicação , Interações Medicamentosas , Cobaias , Injeções Intramusculares , Injeções Intraperitoneais , Injeções Subcutâneas , Dose Letal Mediana , Masculino , Reflexo/efeitos dos fármacos , Convulsões/induzido quimicamente , Convulsões/prevenção & controle , Soman/administração & dosagem , Soman/intoxicação , Soman/toxicidade , Fatores de Tempo , Tosilina Clorometil Cetona/administração & dosagem
20.
J Immunol ; 167(3): 1803-8, 2001 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-11466406

RESUMO

It has been reported recently that the bacterial respiratory pathogen Chlamydia pneumoniae is present in the cerebrospinal fluid of a subset of multiple sclerosis (MS) patients. However, it is not known whether this organism is a causative agent of MS, or merely an opportunistic pathogen that takes advantage of a disease process initiated by some other means. We report identification of a 20-mer peptide from a protein specific to C. pneumoniae which shares a 7-aa motif with a critical epitope of myelin basic protein, a major CNS Ag targeted by the autoimmune response in MS. This bacterial peptide induces a Th1 response accompanied by severe clinical and histological experimental autoimmune encephalomyelitis in Lewis rats, a condition closely reflective of many aspects of MS. Studies with peptide analogues suggest that different populations of encephalitogenic T cells are activated by the C. pneumoniae and myelin basic protein Ags. Mild experimental autoimmune encephalomyelitis was also observed when rats were immunized with sonicated C. pneumoniae in CFA.


Assuntos
Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/imunologia , Chlamydophila pneumoniae/imunologia , Encefalomielite Autoimune Experimental/imunologia , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Substituição de Aminoácidos/imunologia , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Células Cultivadas , Chlamydophila pneumoniae/genética , Encefalomielite Autoimune Experimental/microbiologia , Feminino , Regulação Bacteriana da Expressão Gênica , Cobaias , Injeções Subcutâneas , Dados de Sequência Molecular , Proteína Básica da Mielina/química , Proteína Básica da Mielina/imunologia , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Isoformas de Proteínas/administração & dosagem , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , Ratos , Ratos Endogâmicos Lew , Homologia de Sequência de Aminoácidos , Linfócitos T/imunologia , Linfócitos T/microbiologia , Células Tumorais Cultivadas/imunologia , Células Tumorais Cultivadas/microbiologia , Células Tumorais Cultivadas/transplante
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