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1.
Lab Med ; 55(1): 50-55, 2024 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-37226975

RESUMO

OBJECTIVE: The aim of this study was to assess the impact of hydroxocobalamin (OHCbl) infusion on arterial blood gas and oximetry values in patients with vasoplegic syndrome. METHODS: Blood samples collected from 95 patients receiving OHCbl infusion were assayed using the ABL90 FLEX Plus blood gas analyzer for the concentration of methemoglobin (MetHb), total hemoglobin (tHb), carboxyhemoglobin (COHb), arterial oxygen saturation (SaO2), arterial oxygen partial pressure (PaO2), and arterial carbon dioxide partial pressure (PaCO2). Interference of OHCbl on these variables was evaluated using the measured difference between the preinfusion and postinfusion samples. RESULTS: Blood MetHb (%) measured after the infusion of OHCbl (5g) were significantly higher than the baseline levels, with a median of 4.8 (IQR, 3.0-6.5) versus 1.0 (IQR, 1.0-1.2) (P < .001). Blood COHb (%) increased from a median of 1.3 (IQR, 1.0-1.8) to 1.7 (IQR, 1.3-2.2) (P < .001) following the OHCbl infusion. No differences were seen in median levels of tHb, PaO2, PaCO2, and SaO2 between pre- and post-OHCbl treatment. CONCLUSION: The presence of OHCbl in blood clearly interfered with the oximetry measurements of the hemoglobin component fractions by falsely increasing the levels of MetHb and COHb. Blood levels of MetHb and COHb cannot be reliably determined by the co-oximetry when OHCbl is known or suspected.


Assuntos
Hidroxocobalamina , Metemoglobina , Humanos , Metemoglobina/análise , Hidroxocobalamina/uso terapêutico , Hemoglobinas/análise , Oximetria , Carboxihemoglobina/análise , Oxigênio
2.
Biochim Biophys Acta Bioenerg ; 1864(4): 148996, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37437858

RESUMO

Using ultrafast spectroscopy and site-specific mutagenesis, we demonstrate the central role of a conserved tyrosine within the chromophore binding pocket in the forward (Pr â†’ Pfr) photoconversion of phytochromes. Taking GAF1 of the knotless phytochrome All2699g1 from Nostoc as representative member of phytochromes, it was found that the mutations have no influence on the early (<30 ps) dynamics associated with conformational changes of the chromophore in the excited state. Conversely, they drastically impact the extended protein-controlled excited state decay (>100 ps). Thus, the steric demand, position and H-bonding capabilities of the identified tyrosine control the chromophore photoisomerization while leaving the excited state chromophore dynamics unaffected. In effect, this residue operates as an isomerization-steric-gate that tunes the excited state lifetime and the photoreaction efficiency by modulating the available space of the chromophore and by stabilizing the primary intermediate Lumi-R. Understanding the role of such a conserved structural element sheds light on a key aspect of phytochrome functionality and provides a basis for rational design of optimized photoreceptors for biotechnological applications.


Assuntos
Fenômenos Bioquímicos , Fitocromo , Fitocromo/genética , Fitocromo/metabolismo , Tirosina , Ligação de Hidrogênio , Análise Espectral
3.
Chem Sci ; 14(23): 6295-6308, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37325146

RESUMO

A large number of novel phytochromes named cyanobacteriochromes (CBCRs) have been recently identified. CBCRs appear to be attractive for further in-depth studies as paradigms for phytochromes because of their related photochemistry, but simpler domain architecture. Elucidating the mechanisms of spectral tuning for the bilin chromophore down to the molecular/atomic level is a prerequisite to design fine-tuned photoswitches for optogenetics. Several explanations for the blue shift during photoproduct formation associated with the red/green CBCRs represented by Slr1393g3 have been developed. There are, however, only sparse mechanistic data concerning the factors controlling stepwise absorbance changes along the reaction pathways from the dark state to the photoproduct and vice versa in this subfamily. Conventional cryotrapping of photocycle intermediates of phytochromes has proven experimentally intractable for solid-state NMR spectroscopy within the probe. Here, we have developed a simple method to circumvent this hindrance by incorporating proteins into trehalose glasses which allows four photocycle intermediates of Slr1393g3 to be isolated for NMR use. In addition to identifying the chemical shifts and chemical shift anisotropy principal values of selective chromophore carbons in various photocycle states, we generated QM/MM models of the dark state and photoproduct as well as of the primary intermediate of the backward-reaction. We find the motion of all three methine bridges in both reaction directions but in different orders. These molecular events channel light excitation to drive distinguishable transformation processes. Our work also suggests that polaronic self-trapping of a conjugation defect by displacement of the counterion during the photocycle would play a role in tuning the spectral properties of both the dark state and photoproduct.

4.
J Magn Reson ; 353: 107497, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37295281

RESUMO

Hyperpolarization via the solid-state photochemically induced dynamic nuclear polarization (photo-CIDNP) effect can be detected in frozen solutions of electron transfer proteins generating a radical-pair upon illumination. The effect has been observed in various natural photosynthetic reaction centers and in light-oxygen-voltage (LOV) sensing domains incorporating a flavin mononucleotide (FMN) as chromophore. In LOV domains, where a highly conserved cysteine is mutated to a flavin to interrupt its natural photochemistry, a radical-pair is generated by electron transfer from a nearby tryptophan to the photoexcited triplet state of FMN. During the photocycle, both the LOV domain and the chromophore are photochemically degraded, e.g., by the formation of singlet oxygen. This limits the time for collection of hyperpolarized nuclear magnetic resonance (NMR) data. We show that embedding of the protein into a trehalose sugar glass matrix stabilizes the protein for 13C solid-state photo-CIDNP NMR experiments which can be conducted at room temperature in a powder sample. Additionally, this preparation allows for incorporation of high amounts of protein further boosting the intensity of the detected signals from FMN and tryptophan at natural abundance. Signal assignment is aided by quantum chemical calculations of absolute shieldings. The underlying mechanism for the surprising absorption-only signal pattern is not yet understood. Comparison to calculated isotropic hyperfine couplings imply that the enhancement is not due to the classical radical-pair mechanism (RPM). Analysis of the anisotropic hyperfine couplings associated with solid-state photo-CIDNP mechanisms also show no simple correlation, suggesting a more complex underlying mechanism.


Assuntos
Flavoproteínas , Açúcares , Temperatura , Triptofano , Espectroscopia de Ressonância Magnética
5.
Photochem Photobiol Sci ; 21(9): 1627-1636, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35687310

RESUMO

The ability of some knotless phytochromes to photoconvert without the PHY domain allows evaluation of the distinct effect of the PHY domain on their photodynamics. Here, we compare the ms dynamics of the single GAF domain (g1) and the GAF-PHY (g1g2) construct of the knotless phytochrome All2699 from cyanobacterium Nostoc punctiforme. While the spectral signatures and occurrence of the intermediates are mostly unchanged by the domain composition, the presence of the PHY domain slows down the early forward and reverse dynamics involving chromophore and protein binding pocket relaxation. We assign this effect to a more restricted binding pocket imprinted by the PHY domain. The photoproduct formation is also slowed down by the presence of the PHY domain but to a lesser extent than the early dynamics. This indicates a rate limiting step within the GAF and not the PHY domain. We further identify a pH dependence of the biphasic photoproduct formation hinting towards a pKa dependent tuning mechanism. Our findings add to the understanding of the role of the individual domains in the photocycle dynamics and provide a basis for engineering of phytochromes towards biotechnological applications.


Assuntos
Nostoc , Fitocromo , Proteínas de Bactérias/química , Nostoc/metabolismo , Fitocromo/química , Ligação Proteica
6.
Photochem Photobiol Sci ; 21(4): 447-469, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35394641

RESUMO

Cyanobacteriochromes (CBCRs) are phytochrome-related photosensory proteins that play an essential role in regulating phototaxis, chromatic acclimation, and cell aggregation in cyanobacteria. Here, we apply solid-state NMR spectroscopy to the red/green GAF2 domain of the CBCR AnPixJ assembled in vitro with a uniformly 13C- and 15N-labeled bilin chromophore, tracking changes in electronic structure, geometry, and structural heterogeneity of the chromophore as well as intimate contacts between the chromophore and protein residues in the photocycle. Our data confirm that the bilin ring D is strongly twisted with respect to the B-C plane in both dark and photoproduct states. We also identify a greater structural heterogeneity of the bilin chromophore in the photoproduct than in the dark state. In addition, the binding pocket is more hydrated in the photoproduct. Observation of interfacial 1H contacts of the photoproduct chromophore, together with quantum mechanics/molecular mechanics (QM/MM)-based structural models for this photoproduct, clearly suggests the presence of a biprotonated (cationic) imidazolium side-chain for a conserved histidine residue (322) at a distance of ~2.7 Å, generalizing the recent theoretical findings that explicitly link the structural heterogeneity of the dark-state chromophore to the protonation of this specific residue. Moreover, we examine pH effects on this in vitro assembled holoprotein, showing a substantially altered electronic structure and protonation of the photoproduct chromophore even with a small pH drop from 7.8 to 7.2. Our studies provide further information regarding the light- and pH-induced changes of the chromophore and the rearrangements of the hydrogen-bonding and electrostatic interaction network around it. Possible correlations between structural heterogeneity of the chromophore, protonation of the histidine residue nearby, and hydration of the pocket in both photostates are discussed.


Assuntos
Fotorreceptores Microbianos , Fitocromo , Proteínas de Bactérias/química , Pigmentos Biliares/química , Pigmentos Biliares/metabolismo , Histidina , Concentração de Íons de Hidrogênio , Luz , Fotorreceptores Microbianos/química , Fitocromo/metabolismo
7.
J Pharm Pract ; 35(6): 1000-1006, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33960219

RESUMO

BACKGROUND: Emerging data suggest that coagulopathy, cytokine storm, and acute respiratory distress syndrome are associated with the 2019 coronavirus disease (COVID-19). The prevalence of hypercoagulable state in these patients is unknown, but appears to be higher compared to those with other critically ill patients. Elevated D-dimer, large blood vessels clots, deep vein thrombosis, pulmonary embolism and disseminated intravascular coagulation have been reported in patients diagnosed with COVID-19 either on admission or during hospitalization and may be predictors of poor outcomes. METHODS: We performed a comprehensive literature review using the search terms of COVID-19; severe acute respiratory syndrome coronavirus-2, coagulopathy, thrombosis and anticoagulation in PubMed, Ovid, google scholar, Medline and EMBASE databases from December 2019 to May 30, 2020. RESULTS: A total of 64 relevant studies were reviewed; of which, 4 studies met the inclusion criteria and were included for analysis. The majority of the studies were retrospective involving 525 critically ill COVID-19 patients. The most commonly studied anticoagulant administered was low molecular weight heparins. Anticoagulation dosing varied throughout the studies and may be classified as standard venous thromboembolism prophylaxis, intermediate dosing, or full dose anticoagulation. The most studied objective was improvement in coagulopathy. Significant reduction in D-dimer, improvement in coagulopathy markers such as Interlukin-6, fibrinogen degradation product level, as well as lymphocyte count were reported. CONCLUSION: Despite the limited quality of studies analyzed, prophylaxis and higher intensity dosed anticoagulation is associated with improved pulmonary oxygenation, decreased coagulopathy markers and decreased mortality in COVID-19 patients.


Assuntos
Transtornos da Coagulação Sanguínea , Tratamento Farmacológico da COVID-19 , Trombose , Humanos , SARS-CoV-2 , Estado Terminal , Estudos Retrospectivos , Anticoagulantes/uso terapêutico , Transtornos da Coagulação Sanguínea/tratamento farmacológico , Trombose/prevenção & controle
8.
J Immunol ; 207(1): 133-152, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34183371

RESUMO

Autosomal recessive (AR) STAT1 deficiency is a severe inborn error of immunity disrupting cellular responses to type I, II, and III IFNs, and IL-27, and conferring a predisposition to both viral and mycobacterial infections. We report the genetic, immunological, and clinical features of an international cohort of 32 patients from 20 kindreds: 24 patients with complete deficiency, and 8 patients with partial deficiency. Twenty-four patients suffered from mycobacterial disease (bacillus Calmette-Guérin = 13, environmental mycobacteria = 10, or both in 1 patient). Fifty-four severe viral episodes occurred in sixteen patients, mainly caused by Herpesviridae viruses. Attenuated live measles, mumps, and rubella and/or varicella zoster virus vaccines triggered severe reactions in the five patients with complete deficiency who were vaccinated. Seven patients developed features of hemophagocytic syndrome. Twenty-one patients died, and death was almost twice as likely in patients with complete STAT1 deficiency than in those with partial STAT1 deficiency. All but one of the eight survivors with AR complete deficiency underwent hematopoietic stem cell transplantation. Overall survival after hematopoietic stem cell transplantation was 64%. A diagnosis of AR STAT1 deficiency should be considered in children with mycobacterial and/or viral infectious diseases. It is important to distinguish between complete and partial forms of AR STAT1 deficiency, as their clinical outcome and management differ significantly.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Linfo-Histiocitose Hemofagocítica , Infecções por Mycobacterium , Mycobacterium bovis , Humanos , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo
9.
J Phys Chem B ; 125(5): 1331-1342, 2021 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-33523656

RESUMO

Cyanobacteriochromes (CBCRs) are photoreceptors of the phytochrome superfamily showing remarkable variability in the wavelengths of the first electronic transition-sometimes denoted as Q band-compared to canonical phytochromes. Both classes carry the same cofactor, a bilin, but the molecular basis for the wide variation of their absorption properties is still a matter of debate. The interaction between the cofactor and the surrounding protein moiety has been proposed as a possible tuning factor. Here, we address the impact of hydrogen-bonding interaction between the covalently bound tetrapyrrole cofactor (phycocyanobilin, PCB) and a conserved tyrosine residue (Y302) in the second GAF (cGMP-specific phosphodiesterase, adenylyl cyclases, and FhlA) domain of the red-/green-switching CBCR AnPixJ (AnPixJg2). In the wild type, AnPixJg2 shows absorption maxima of 648 and 543 nm for the dark-adapted (Pr) and photoproduct (Pg) states, respectively. The Y302F mutation leads to the occurrence of an additional absorption band at 687 nm, which is assigned to a new spectroscopically identified sub-state called PIII. Similar spectral changes result upon mutating the Y302F-homologue in another representative red-/green-switching CBCR, Slr1393g3. Molecular dynamics simulations on the dark-adapted state suggest that the removal of the hydrogen bond leads to an additional PCB sub-state differing in its A- and D-ring geometries. The origin of the Q band satellite in the dark-adapted state is discussed.


Assuntos
Cianobactérias , Fotorreceptores Microbianos , Fitocromo , Proteínas de Bactérias/genética , Pigmentos Biliares , Ligação de Hidrogênio , Fotorreceptores Microbianos/genética , Fitocromo/genética , Propionatos , Tirosina
10.
BMC Vet Res ; 17(1): 41, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33478485

RESUMO

BACKGROUND: Despite clinical importance and frequent occurrence of sinus disease, little is known about the size of paranasal sinuses and their communication in ponies and small horses. To examine the shape and volume of the paranasal sinuses and evaluate the sinonasal communication, three-dimensional (3D) reconstructions of computed tomography (CT) datasets of 12 healthy adult Shetland ponies were performed and analysed. Linear measurements of head length and width were taken. Using semi-automatic segmentation, 3D-models of all sinus compartments were created. Volumetric measurement of the seven sinus compartments were conducted and statistical analysis was performed. Sinus volumes were compared between the left and right sinuses and the relation to age and head size was evaluated. RESULTS: Structure and shape of the paranasal sinus system in Shetland ponies was similar to that of large horses. All seven sinus compartments on each side of the head were identified (rostral maxillary sinus, ventral conchal sinus, caudal maxillary sinus, dorsal conchal sinus, middle conchal sinus, frontal sinus, sphenopalatine sinus). The existence of a bilateral cranial and a caudal system formed by a maxillary septum was visible in all 12 individuals. The volumetric sizes of the left and right sinuses did not differ significantly (p > 0.05). A positive correlation between the size of the paranasal sinuses and the head length was shown. A relation between sinus volumes and age could not be proved in adult ponies aged > six years. Communication between single sinus compartments was identified. Furthermore, communication with the nasal cavity over the nasomaxillary aperture (Apertura nasomaxillaris) and a common sinonasal channel (Canalis sinunasalis communis) as well as its splitting up into a rostral and a caudolateral channel could be seen. Examination of the sinonasal communication was challenging and only a descriptive evaluation was possible. CONCLUSIONS: Our findings concerning the size, shape and volumetric dimensions of Shetland pony CT images could help improve CT interpretation of abnormal clinical cases as well as aiding clinicians to develop and select appropriate instruments for medical inspection and treatments.


Assuntos
Cavalos/anatomia & histologia , Seios Paranasais/anatomia & histologia , Fatores Etários , Animais , Feminino , Cabeça/anatomia & histologia , Masculino , Cavidade Nasal/anatomia & histologia , Seios Paranasais/diagnóstico por imagem , Tomografia Computadorizada por Raios X/veterinária
11.
Anat Histol Embryol ; 50(3): 431-438, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33331012

RESUMO

Equine paranasal sinuses are susceptible to inflammation. Insufficient drainage through the nasal passages and meatus may lead to the accumulation of inspissated purulent discharge. Particularly in ponies, these anatomical structures are suspected to be relatively small. To date, there are no reports considering the morphology of nasal conchal bullae in small horse breeds such as Shetland ponies. The aim of the present study was to evaluate the size of the conchal bullae and the medial nasal conchae of Shetland ponies and their relation to the skull dimension using computed tomography. Reconstructed images of healthy adult heads of Shetland ponies were used. Linear skull measurements as well as two cranial indices of the head dimensions were taken. Length, width and height of the dorsal and ventral conchal bullae and the medial nasal conchae were measured in relation to the skull and compared with the data of skulls of large breed horses. The anatomical proportions of pony heads were characterized by a smaller cranial index and a greater nasal index than those of large breed horses. Shetland ponies showed a longer cranial length compared with the nasal length. Heads are consistently smaller, and the relationship of the bullae to the head length was also smaller than those measured in large breed horses. A negative correlation between the head and bullae size was found. In conclusion, this study suggests that Shetland ponies have distinguishing proportions of the head. These findings are relevant for clinical examination and surgical treatment of equine sinus disease in those breeds.


Assuntos
Doenças dos Cavalos , Seios Paranasais , Animais , Vesícula/veterinária , Doenças dos Cavalos/diagnóstico por imagem , Cavalos , Cavidade Nasal/diagnóstico por imagem , Seios Paranasais/diagnóstico por imagem , Conchas Nasais/diagnóstico por imagem
12.
Crit Care Explor ; 2(12): e0287, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33381763

RESUMO

OBJECTIVES: Coagulopathy of coronavirus disease 2019 is largely described as hypercoagulability, yet both thrombotic and hemorrhagic complications occur. Although therapeutic and prophylactic anticoagulant interventions have been recommended, empiric use of antifactor medications (heparin/enoxaparin) may result in hemorrhagic complications, including death. Furthermore, traditional (antifactor) anticoagulation does not address the impact of overactive platelets in coronavirus disease 2019. The primary aim was to evaluate if algorithm-guided thromboelastography with platelet mapping could better characterize an individual's coronavirus disease 2019-relatedcoagulopathic state and, secondarily, improve outcomes. DESIGN SETTING AND PATIENTS: Coronavirus disease 2019 patients (n = 100), receiving thromboelastography with platelet mapping assay upon admission to an 800-bed tertiary-care hospital, were followed prospectively by a hospital-based thromboelastography team. Treating clinicians were provided with the option of using a pre-established algorithm for anticoagulation, including follow-up thromboelastography with platelet mapping assays. Two groups evolved: 1) patients managed by thromboelastography with platelet mapping algorithm (algorithm-guided-thromboelastography); 2) those treated without thromboelastography with platelet mapping protocols (non-algorithm-guided). Outcomes included thrombotic/hemorrhagic complications, pulmonary failure, need for mechanical ventilation, acute kidney injury, dialysis requirement, and nonsurvival. INTERVENTIONS: Standard-of-care therapy with or without algorithm-guided-thromboelastography support. MEASUREMENTS AND MAIN RESULTS: Although d-dimer, C-reactive protein, and ferritin were elevated significantly in critically ill (nonsurvivors, acute kidney injury, pulmonary failure), they did not distinguish between coagulopathic and noncoagulopathic patients. Platelet hyperactivity (maximum amplitude-arachidonic acid/adenosine diphosphate > 50 min), with or without thrombocytosis, was associated with thrombotic/ischemic complications, whereas severe thrombocytopenia (platelet count < 100,000/µL) was uniformly fatal. Hemorrhagic complications were observed with decreased factor activity (reaction time > 8 min). Non-algorithm-guided patients had increased risk for subsequent mechanical ventilation (relative risk = 10.9; p < 0.0001), acute kidney injury (relative risk = 2.3; p = 0.0017), dialysis (relative risk = 7.8; p < 0.0001), and death (relative risk = 7.7; p < 0.0001), with 17 of 28 non-algorithm-guided patients (60.7%) dying versus four algorithm-guided-thromboelastography patients (5.6%) (p < 0.0001). Thromboelastography with platelet mapping-guided antiplatelet treatment decreased mortality 82% (p = 0.0002), whereas non-algorithm-guided (compared with algorithm-guided-thromboelastography) use of antifactor therapy (heparin/enoxaparin) resulted in 10.3-fold increased mortality risk (p = 0.0001). CONCLUSIONS: Thromboelastography with platelet mapping better characterizes the spectrum of coronavirus disease 2019 coagulation-related abnormalities and may guide more tailored, patient-specific therapies in those infected with coronavirus disease 2019.

13.
Eur J Med Chem ; 182: 111588, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31421630

RESUMO

Intrinsically disordered proteins are an emerging class of proteins without a folded structure and currently disorder-based drug targeting remains a challenge. p53 is the principal regulator of cell division and growth whereas MDM2 consists its main negative regulator. The MDM2-p53 recognition is a dynamic and multistage process that amongst other, employs the dissociation of a transient α-helical N-terminal ''lid'' segment of MDM2 from the proximity of the p53-complementary interface. Several small molecule inhibitors have been reported to inhibit the formation of the p53-MDM2 complex with the vast majority mimicking the p53 residues Phe19, Trp23 and Leu26. Recently, we have described the transit from the 3-point to 4-point pharmacophore model stabilizing this intrinsically disordered N-terminus by increasing the binding affinity by a factor of 3. Therefore, we performed a thorough SAR analysis, including chiral separation of key compound which was evaluated by FP and 2D NMR. Finally, p53-specific anti-cancer activity towards p53-wild-type cancer cells was observed for several representative compounds.


Assuntos
Antineoplásicos/farmacologia , Proteínas Intrinsicamente Desordenadas/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Proteína Supressora de Tumor p53/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Benzilaminas/síntese química , Benzilaminas/química , Benzilaminas/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cianetos/síntese química , Cianetos/química , Cianetos/farmacologia , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Formiatos/síntese química , Formiatos/química , Formiatos/farmacologia , Humanos , Indóis/síntese química , Indóis/química , Indóis/farmacologia , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Estrutura Molecular , Proteínas Proto-Oncogênicas c-mdm2/química , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Relação Estrutura-Atividade , Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/metabolismo
14.
Pediatr Rheumatol Online J ; 17(1): 37, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286990

RESUMO

BACKGROUND: Deficiency of interleukin-36 receptor antagonist (DITRA) is a life threatening monogenic autoinflammatory disease caused by loss of function mutations in the IL36RN gene. Affected patients develop recurrent episodes of generalized pustular psoriasis (GPP) with systemic inflammation and fever. We here review and analyze the literature on pediatric DITRA patients who have been treated by biologicals targeting inflammatory cytokines. METHOD: A database research was performed to identify all relevant articles on pediatric DITRA patients treated with biologicals. According to defined response criteria therapeutic efficacy was analyzed. RESULTS: Our literature research revealed 12 pediatric patients with DITRA who have received treatment with biologicals and we add a further not yet reported patient. Out of these 13 patients 10 were homozygous including 6 with the p.Leu27Pro, 3 with the p.Arg10 Argfs* and 1 with the p.Thr123Met mutation. 3 patients were compound heterozygous. In total 28 flares were treated with biological agents- targeting IL-1, IL-17, IL-12/23 and TNF-α. Complete response was achieved in 16 flares (57%), a partial reponse was seen in 2 flares (7%), and no response was observed in 10 flares (36%). Response rates were heterogeneous among the different agents. While complete/partial/no response with inhibition of TNF-alpha could be achieved in 7 (58%)/1 (8%)/4 (33%), the inhibition of IL-17 and of IL-12/23 led in each 4 flares to a 100% complete response. IL-1 inhibition led to complete/partial response in each 1 (13%) and was not effective in 6 (76%) flares. Of note, the novel patient was successfully treated with weekly dosed adalimumab. CONCLUSIONS: DITRA is a rare disease that has to be considered in GPP with systemic inflammation and fever. It can be effectively treated with specific biological inhibition of TNF-alpha, IL-12/23 and IL- 17, while anti-IL-1 treatment seems less effective. Weekly dosed adalimumab appears to be a treatment option for pediatric patients. Further reports and studies of biological treated pediatric DITRA patients are warranted for evaluation of optimal treatment.


Assuntos
Produtos Biológicos/uso terapêutico , Proteína Antagonista do Receptor de Interleucina 1/genética , Receptores de Interleucina/deficiência , Adolescente , Idade de Início , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Mutação com Perda de Função/genética , Masculino , Receptores de Interleucina/antagonistas & inibidores , Resultado do Tratamento
15.
GMS J Med Educ ; 34(3): Doc30, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28890921

RESUMO

Introduction: One of the most important extracurricular aspects of medical studies in Germany is a research thesis completed by most students. This research project often times conveys relevant competencies for the physician's role as scientist. Nevertheless, the choice of the right project remains a challenge. Reasons for this are among others, missing structures for a comprehensive overview of research groups and their respective projects. Description of the project: We developed the online platform Doktabörse as an online marketplace for doctoral research projects. The platform enables authorized researchers to create working groups and upload, deactivate and change research projects within their institute. For interested students, a front end with integrated search function displays these projects in a structured and well-arranged way. In parallel, the Doktabörse provides for a comprehensive overview of research at the medical faculty. We evaluated Researchers' and students' use of the platform. Results: 96,6% of students participating in the evaluation (n=400) were in favor of a centralized research platform at the medical faculty. The platform grew at a steady pace and included 120 research groups in June 2016. The students appreciated the structure and design of the Doktabörse. Two thirds of all uploaded projects matched successfully with doctoral students via the platform and over 94% of researchers stated that they did not need technical assistance with uploading projects and handling the platform. Discussion: The Doktabörse represents an innovative and well accepted platform for doctoral research projects. The platform is perceived positively by researchers and students alike. However, students criticized limited extent and timeliness of offered projects. In addition, the platform serves as databank of research at the medical faculty of the LMU Munich. The future potential of this platform is to provide for an integrated management solution of doctoral thesis projects, possibly beyond the medical field and faculty.


Assuntos
Dissertações Acadêmicas como Assunto , Pesquisa Biomédica , Bases de Dados como Assunto , Docentes de Medicina , Hospitais Universitários , Internet , Design de Software , Competência Clínica , Currículo , Alemanha , Humanos , Papel do Médico
16.
Acad Forensic Pathol ; 7(4): 632-639, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31240012

RESUMO

INTRODUCTION: The Summit County Medical Examiner's Office (SCMEO) observed 52 unexplained deaths during the month of July 2016 in which drug overdose was suspected. A fentanyl screening immunoassay performed on autopsy specimens was positive, but gas chromatograph/mass spectrometry (GC/MS) failed to confirm its presence. Carfentanil, a large wildlife tranquilizer, was later identified through reference lab testing as the cause of the sudden increase in overdoses. METHODS: Due to the large volume of cases which followed, a method for identifying carfentanil was developed utilizing in-house instrumentation. In addition, a retrospective analysis for all drug overdose cases was conducted through the SCMEO database from January 2009 through December 2016. RESULTS: Assessment of the data revealed a 277% increase in yearly overdose-related fatalities when comparing 2009 to 2016. Carfentanil was not identified in any other fatal drug overdoses in the area before the first appearance in Akron in July of 2016. There was an initial spike of 35 deaths in both July and August, which then decreased to 12 deaths in December. There was an almost equal distribution of carfentanil as a single agent and carfentanil mixed with multiple other illicit drugs. DISCUSSION: Current observations suggest carfentanil concentrations in overdose cases are decreasing; however, it may be present in combination with other drugs, especially other fentanyl analogs. The lower concentrations of carfentanil are much more difficult to detect in urine and peripheral blood, therefore making the testing of scene paraphernalia, central blood, and organ tissue more of a necessity.

18.
GMS Z Med Ausbild ; 32(3): Doc29, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26413167

RESUMO

INTRODUCTION: The importance of research, as promoted by the CanMEDS framework, is widely acknowledged. Many medical students in Germany work on a research project as part of their doctoral thesis whilst still going to medical school. However, a significant amount of projects are abandoned unfinished, which leads to substantial wastage of resources. One reason for this is an information deficit concerning undergraduate research projects. PROJECT DESCRIPTION: To counteract this, we introduced an annual event at LMU Munich called DoktaMed with more than 600 visitors each year. It combines medical convention and research fair including keynote lectures, workshops and poster sessions as well as an exhibition of research groups and institutes. DoktaMed is a peer-to-peer event organized by a team of 40 students. RESULTS: A needs analysis before its implementation underlined the information deficit as a possible cause for the high rate of abandoned projects. In the annual evaluation, visitors of DoktaMed rate the event with an average grade of 2.1 on a six-level Likert scale (n=558, SD=1.06, with "1=very good", "6=poor"). They stated to now feel better informed about the topic and regarded visiting DoktaMed as a worthwhile investment of time. DISCUSSION: Students are generally satisfied with the event and feel better informed after visiting DoktaMed. However, many students never visit DoktaMed for various reasons. A possible improvement would be to present a greater number of clinical studies in addition to the laboratory work that DoktaMed focuses on now. CONCLUSION: Evaluation after six years of DoktaMed is very promising. Visitors seem to be better informed. Nevertheless there is space for improvement in order to get more students and more faculty members involved. More studies are needed to assess long-term effects.


Assuntos
Dissertações Acadêmicas como Assunto , Pesquisa Biomédica/educação , Congressos como Assunto , Educação de Graduação em Medicina , Atitude do Pessoal de Saúde , Currículo , Alemanha , Humanos , Estudantes de Medicina
19.
ACS Chem Biol ; 9(3): 802-11, 2014 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-24405416

RESUMO

The inhibition of p53-MDM2 interaction is a promising new approach to non-genotoxic cancer treatment. A potential application for drugs blocking the p53-MDM2 interaction is acute myeloid leukemia (AML) due to the occurrence of wild type p53 (wt p53) in the majority of patients. Although there are very promising preclinical results of several p53-MDM2 antagonists in early development, none of the compounds have yet proven the utility as a next generation anticancer agent. Herein we report the design, synthesis and optimization of YH239-EE (ethyl ester of the free carboxylic acid compound YH239), a potent p53-MDM2 antagonizing and apoptosis-inducing agent characterized by a number of leukemia cell lines as well as patient-derived AML blast samples. The structural basis of the interaction between MDM2 (the p53 receptor) and YH239 is elucidated by a co-crystal structure. YH239-EE acts as a prodrug and is the most potent compound that induces apoptosis in AML cells and patient samples. The observed superior activity compared to reference compounds provides the preclinical basis for further investigation and progression of YH239-EE.


Assuntos
Antineoplásicos , Descoberta de Drogas , Indóis , Leucemia Mieloide Aguda/tratamento farmacológico , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Indóis/síntese química , Indóis/química , Indóis/farmacologia , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Modelos Moleculares , Estrutura Molecular , Ligação Proteica , Proteínas Proto-Oncogênicas c-mdm2/química , Relação Estrutura-Atividade
20.
Am J Med Genet A ; 164A(1): 251-8, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24352918

RESUMO

Rubinstein-Taybi syndrome (RTS) and Cornelia de Lange syndrome (CdLS) are genetically heterogeneous multiple anomalies syndromes, each having a distinctive facial gestalt. Two genes (CREBBP and EP300) are known to cause RTS, and five (NIPBL, SMC1A, SMC3, RAD21, and HDAC8) have been associated with CdLS. A diagnosis of RTS or CdLS is molecularly confirmed in only 65% of clinically identified cases, suggesting that additional causative genes exist for both conditions. In addition, although EP300 and CREBBP encode homologous proteins and perform similar functions, only eight EP300 positive RTS patients have been reported, suggesting that patients with EP300 mutations might be escaping clinical recognition. We report on a child with multiple congenital abnormalities and intellectual disability whose facial features and complex phenotype resemble CdLS. However, no mutations in CdLS-related genes were identified. Rather, a novel EP300 mutation was found on whole exome sequencing. Possible links between EP300 and genes causing CdLS are evident in the literature. Both EP300 and HDAC8 are involved in the regulation of TP53 transcriptional activity. In addition, p300 and other chromatin associated proteins, including NIPBL, SMCA1, and SMC3, have been found at enhancer regions in different cell types. It is therefore possible that EP300 and CdLS-related genes are involved in additional shared pathways, producing overlapping phenotypes. As whole exome sequencing becomes more widely utilized, the diverse phenotypes associated with EP300 mutations should be better understood. In the meantime, testing for EP300 mutations in those with features of CdLS may be warranted.


Assuntos
Síndrome de Cornélia de Lange/diagnóstico , Síndrome de Cornélia de Lange/genética , Proteína p300 Associada a E1A/genética , Exoma , Mutação da Fase de Leitura , Fenótipo , Autopsia , Diagnóstico Diferencial , Facies , Evolução Fatal , Heterozigoto , Humanos , Lactente , Masculino , Síndrome de Rubinstein-Taybi/diagnóstico , Síndrome de Rubinstein-Taybi/genética
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