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To evaluate the safety and efficacy of L-glutamine in reducing vaso-occlusive crisis (VOC) and improving cerebral arterial blood flow in children with sickle cell disease (SCD). This is an interventional randomized controlled trial that recruited sixty SCD patients, aged 9.2 ± 3.7 years, who had at least two VOCs during the last 12 months and on a stable dose of hydroxyurea. They were randomly assigned in a 1:1 ratio to receive glutamine (0.3 gm/kg/dose/12h) orally for 24 weeks or the standard of care (SOC). All patients had VOCs in the last year > 3, those on glutamine had a higher number of VOCs and hospitalization for VOC in the last year. There was a decreasing trend in the number, severity, and hospitalization of VOC and a significantly lower cumulative number of VOCs and hospitalizations in the glutamine group than in SOC (p = 0.008, p < 0.001 respectively). Time-averaged mean maximum velocity for the glutamine group had a marginal increase in both middle cerebral arteries, all values remained normal within a normal range, and in both internal carotid arteries, values increased from abnormally low to normal ranges at week 24. Glutamine reduced the number of VOCs and severity and may have a potentially favorable impact on the cerebral arterial flow velocities.
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Fever of unknown origin (FUO) is a serious challenge for physicians. The aim of the present study was to consider epidemiology and dynamics of FUO in countries with different economic development. The data of FUO patients hospitalized/followed between 1st July 2016 and 1st July 2021 were collected retrospectively and submitted from referral centers in 21 countries through ID-IRI clinical research platform. The countries were categorized into developing (low-income (LI) and lower middle-income (LMI) economies) and developed countries (upper middle-income (UMI) and high-income (HI) economies). This research included 788 patients. FUO diagnoses were as follows: infections (51.6%; n = 407), neoplasms (11.4%, n = 90), collagen vascular disorders (9.3%, n = 73), undiagnosed (20.1%, n = 158), miscellaneous diseases (7.7%, n = 60). The most common infections were tuberculosis (n = 45, 5.7%), brucellosis (n = 39, 4.9%), rickettsiosis (n = 23, 2.9%), HIV infection (n = 20, 2.5%), and typhoid fever (n = 13, 1.6%). Cardiovascular infections (n = 56, 7.1%) were the most common infectious syndromes. Only collagen vascular disorders were reported significantly more from developed countries (RR = 2.00, 95% CI: 1.19-3.38). FUO had similar characteristics in LI/LMI and UMI/HI countries including the portion of undiagnosed cases (OR, 95% CI; 0.87 (0.65-1.15)), death attributed to FUO (RR = 0.87, 95% CI: 0.65-1.15, p-value = 0.3355), and the mean duration until diagnosis (p = 0.9663). Various aspects of FUO cannot be determined by the economic development solely. Other development indices can be considered in future analyses. Physicians in different countries should be equally prepared for FUO patients.
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Doenças Transmissíveis , Febre de Causa Desconhecida , Infecções por HIV , Humanos , Febre de Causa Desconhecida/epidemiologia , Febre de Causa Desconhecida/etiologia , Febre de Causa Desconhecida/diagnóstico , Estudos Retrospectivos , Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/epidemiologia , ColágenoRESUMO
The prevalence of spontaneous coronary artery dissection (SCAD) has increased over the last decades in young adults presenting with acute coronary syndrome. Although the diagnostic tools, including intracoronary imaging, have permitted a more accurate diagnosis of SCAD, the prognosis and overall outcomes remain dismal. Furthermore, the disproportionate sex distribution affecting more women and the underdiagnosis in many parts of the world render this pathology a persistent clinical challenge, particularly since the management remains largely supportive with a limited and controversial role for percutaneous or surgical interventions. The purpose of this review is to summarize the available literature on SCAD and to provide insights into the gaps in knowledge and areas requiring further investigation.
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Anomalias dos Vasos Coronários , Doenças Vasculares , Adulto Jovem , Humanos , Feminino , Vasos Coronários , Angiografia Coronária , Doenças Vasculares/diagnóstico por imagem , Doenças Vasculares/terapia , Prognóstico , Anomalias dos Vasos Coronários/diagnóstico por imagem , Anomalias dos Vasos Coronários/epidemiologiaRESUMO
INTRODUCTION: The prevalence and impact of pulmonary embolism (PE) in patients with lead-related infective endocarditis undergoing transvenous lead extraction (TLE) are unknown. METHODS: Twenty-five consecutive patients with vegetations ≥10 mm at transoesophageal echocardiography were prospectively studied. Contrast-enhanced chest computed tomography (CT) was performed before (pre-TLE) and after (post-TLE) the lead extraction procedure. RESULTS: Pre-TLE CT identified 18 patients (72%) with subclinical PE. The size of vegetations in patients with PE did not differ significantly from those without (median 20.0 mm [interquartile range: 13.0-30.0] vs. 14.0 mm [6.0-18.0], p = 0.116). Complete TLE success was achieved in all patients with 3 (2-3) leads extracted per procedure. There were no postprocedure complications related to the presence of PE and no differences in terms of fluoroscopy time and need for advanced tools. In the group of positive pre-TLE CT, post-TLE scan confirmed the presence of silent PE in 14 patients (78%). There were no patients with new PE formation. Large vegetations (≥20 mm) tended to increase the risk of post-TLE subclinical PE (odds ratio 5.99 [95% confidence interval (CI): 0.93-38.6], p = 0.059). During a median 19.4 months follow-up, no re-infection of the implanted system was reported. Survival rates in patients with and without post-TLE PE were similar (hazard ratio: 1.11 [95% CI: 0.18-6.67], p = 0.909). CONCLUSION: Subclinical PE detected by CT was common in patients undergoing TLE with lead-related infective endocarditis and vegetations but was not associated with the complexity of the procedure or adverse outcomes. TLE procedure seems safe and feasible even in patients with large vegetations.
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Desfibriladores Implantáveis , Endocardite Bacteriana , Endocardite , Marca-Passo Artificial , Infecções Relacionadas à Prótese , Embolia Pulmonar , Desfibriladores Implantáveis/efeitos adversos , Remoção de Dispositivo/métodos , Endocardite/diagnóstico por imagem , Endocardite/epidemiologia , Endocardite Bacteriana/diagnóstico por imagem , Endocardite Bacteriana/epidemiologia , Humanos , Marca-Passo Artificial/efeitos adversos , Prevalência , Infecções Relacionadas à Prótese/diagnóstico por imagem , Infecções Relacionadas à Prótese/epidemiologia , Infecções Relacionadas à Prótese/etiologia , Embolia Pulmonar/diagnóstico por imagem , Embolia Pulmonar/epidemiologia , Embolia Pulmonar/terapia , Estudos RetrospectivosRESUMO
BACKGROUND: Transvenous lead extraction is the standard therapy for cardiac device-related infection. In some patients, however, a hybrid surgical and transvenous approach may be necessary. METHODS AND RESULTS: We present three cases who underwent transvenous lead extraction for an infected CRT-D system. In all cases the CS lead could not be retrieved transvenously due to extensive fibrosis. The lead was successfully extracted through left minithoracotomy in two patients and midline sternotomy in one patient. CONCLUSION: In cases where the coronary sinus lead shows severe fibrosis, a transvenous approach can be used to free the proximal part of the lead, while the distal adhesions can be removed surgically through a limited thoracic incision.
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Seio Coronário , Desfibriladores Implantáveis , Seio Coronário/cirurgia , Remoção de Dispositivo , Fibrose , Humanos , Toracotomia , Resultado do TratamentoRESUMO
Superior vena cava (SVC) syndrome is a rare disease induced by thrombosis and consequent occlusion of SVC, negatively affecting morbidity and mortality. The incidence of SVC syndrome from central venous catheters and pacemaker or defibrillator leads is increasing. Optimal treatment of pacemaker or defibrillator-related SVC syndrome is not well defined. Lead extraction causes mechanical trauma to the vessel wall. In addition, subsequent device implantation on the contralateral side can be an added factor for venous occlusion. The use of leadless pacemakers could be an interesting option to reduce the risk of SVC restenosis after lead extraction. We report a clinical case of PM leads-related SVC syndrome referred to our centers and treated with transvenous lead extraction, leadless pacemaker implantation and subsequent percutaneous angioplasty and stenting of the SVC and left innominate vein.
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Marca-Passo Artificial , Síndrome da Veia Cava Superior , Trombose , Humanos , Marca-Passo Artificial/efeitos adversos , Stents/efeitos adversos , Síndrome da Veia Cava Superior/cirurgia , Síndrome da Veia Cava Superior/terapia , Trombose/complicações , Veia Cava SuperiorRESUMO
OBJECTIVE: To study the combined effect of modified genioglossus advancement (MGGA) and radiofrequency tongue base reduction (RFTBR) a long with anterolateral advancement (ALA) pharyngolplasty on OSA patients with retrolingual airway collapse. STUDY DESIGN: Prospective clinical study. SETTING: Zagazig and Benha Universities Medical Hospitals. PATIENTS AND METHODS: Twenty-one patients (21)with multilevel OSA underwent modified genioglossus advancement with radiofrequency tongue base reduction and anterolateral advancement pharyngolplasty. All patients were assessed before and 6 months after surgery by history talking, clinical examination, Epworth Sleepiness Scale evaluation fiberoptic examination during muller's maneuver, drug induced sleep endoscopy (DISE), panoramic X-ray, Cephalometry and polysomnography. RESULTS: Postoperative mean ± SD Epworth Sleepiness Scale (ESS) significantly decreased from 18.86 ± 2.03to 8.19 ± 1.86 (P-value was <0.001 95% (CI) 9.80 to 11.53).postoperative mean ± SD AHI decreased from 53.39 ± 14.10 to 26.66 ± 5.44 (P-value was <0.001 95% CI 22.37 to 32.81), postoperative mean ± SD LOS increased from 68.33 ± 9.12 to 86.0 ± 4.96 (P-value was <0.001 95% (CI) 15.24 to21.33).Based on cephalometric analysis postoperative mean ± SD PAS at mid retrolingual point in mm increased from 6.43 ± 1.25 to 11.98 ± 1.69 (P-value was <0.001 95% (CI) 4.78 to 6.32), also postoperative mean ± SD Distance between H-MP in mm decreased from 23.38 ± 1.14 to 15.17 ± 0.97 (P-value was 0.001 95% (CI) 7.66 to 8.76).The postoperative mean ± SD distance from hyoid to menton (H-me) in mm decreased from 39.47 ± 2.37to24.83 ± 2.43(P-value was 0.001 95% (CI) 7.31 to 8.41), the mean ± SD distance of genioglossus muscle advancement in mm was 14.45 ± 1.12.With a success rate defined as AHI < 20 and/or 50% reduction in AHI of the pre- operative value, the surgical success was 81%. CONCLUSION: MGGA with RFTBR along with anterolateral advancement pharyngoplasty in a single session is well tolerated and safe surgery in the treatment of multilevel OSA patients. It is effective in reducing respiratory parameters and subjective symptoms of OSA.
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Apneia Obstrutiva do Sono , Cefalometria , Humanos , Polissonografia , Estudos Prospectivos , Apneia Obstrutiva do Sono/cirurgia , Língua/cirurgia , Resultado do TratamentoRESUMO
This paper provides a thorough investigation of the effect of a top low-permeability (TLK) layer on transient saltwater intrusion dynamics prompted by water table fluctuations and sea level rise. Laboratory experiments were conducted on a 2D-sandbox and numerical simulations were performed using the SEAWAT code. Four cases were investigated, including a homogeneous case and three cases, where the top layer thickness (Wtop) was equal to 0.2H, 0.33H and 0.5H, respectively, where H was the aquifer thickness. The experimental and numerical results show that the toe length decreases linearly with increasing the thickness of the TLK layer. The results also suggest that lowering the permeability of the upper part of the aquifer causes faster saltwater removal process. The sensitivity analysis shows that decreasing the top layer permeability causes further reduction of the intrusion length. Nonetheless, the results evidence that this method yields relatively little reduction of the saline water intrusion length if the upper layer thickness is inferior or equal to a fifth of the total aquifer thickness, regardless of the permeability value of the top layer. The field-scale modelling results demonstrate that the performance of the TLK layer weakens noticeably as the hydraulic gradient decreases. The results show that the TLK layer achieved a maximum saltwater wedge reduction of 31% in the case where Wtop = 0.75H, which means that lowering the permeability of three fourths of the aquifer thickness only induced a toe length reduction by nearly a third of its original length. In addition to providing a quantitative analysis of SWI dynamics in bi-layered coastal aquifers, this study questions the performance and practicality of the artificial reduction of the upper aquifer permeability as a countermeasure for seawater intrusion control.
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Água Subterrânea , Água do Mar , Monitoramento Ambiental , PermeabilidadeRESUMO
Subsurface physical barriers are amongst the most effective methods to mitigate seawater intrusion in coastal aquifers. The main objective of this study was to examine the impact of cutoff walls on saltwater upconing using laboratory and numerical modelling experiments. Physical experiments were first completed to reproduce the saltwater upconing process in a laboratory-scale coastal aquifer model incorporating an impermeable cutoff wall. Numerical modelling was used for validation purposes and to perform additional simulations to explore the protective effect of cutoff walls against saltwater upconing. The results suggest that the cutoff wall did not substantially delay the saltwater upconing mechanism in the investigated configurations. Laboratory and numerical observations showed the existence of some residual saline water, which remained on the upper part of the aquifer on the seaward side of the wall following the retreat of the saltwater. The protective effect of cutoff walls was noticeably sensitive to the design parameters. Specifically, cutoff walls installed close to the pumping well enabled the implementation of higher pumping rates, therefore a more optimal use of the freshwater, especially for deeper wells. The results highlighted that the penetration depth of the cutoff walls may not necessarily need to exceed the depth of the pumping well to ensure effectiveness, which is of great importance from construction and economic perspectives.
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Água Subterrânea , Monitoramento Ambiental , Água Doce , Laboratórios , Água do Mar , Poços de ÁguaRESUMO
Huperzine A (HupA) is an anti-Alzheimer's therapeutic and a dietary supplement for memory boosting that is extracted mainly from Huperziacae plants. Endophytes represent the upcoming refuge to protect the plant resource from distinction but their HupA yield is still far from commercialization. In this context, UV and gamma radiation mutagenesis of the newly isolated HupA-producing Alternaria brassicae AGF041 would be applied in this study for improving the endophytic HupA yield. Compared to non-irradiated cultures, UV (30-40 min, exposure) and γ (0·5 KGy, dose) irradiated cultures, each separately, showed a significant higher HupA yield (17·2 and 30·3%, respectively). While, application of a statistically optimized compound irradiation (0·70 KGy of γ treatment and 42·49 min of UV exposure, sequentially) via Response Surface Methodology (RSM) resulted in 53·1% production increase. Moreover, a stable selected mutant strain CM003 underwent batch cultivation using a 6·6 l bioreactor for the first time and was successful for scaling up the HupA production to 261·6 µg l-1 . Findings of this research are demonstrated to be valuable as the employed batch fermentation represents a successful starting step towards the promising endophytic HupA production at an industrial scale.
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Alcaloides/metabolismo , Alternaria/genética , Alternaria/metabolismo , Reatores Biológicos/microbiologia , Inibidores da Colinesterase/metabolismo , Huperzia/metabolismo , Sesquiterpenos/metabolismo , Cromatografia Líquida de Alta Pressão , Endófitos/isolamento & purificação , Endófitos/metabolismo , Fermentação , Raios gama , Huperzia/microbiologia , Fármacos Neuroprotetores/metabolismo , Raios UltravioletaRESUMO
BACKGROUND: Many medications (including most antihypertensives) and physiological factors affect the aldosterone/renin ratio (ARR) when screening for primary aldosteronism (PA). We sought to validate a novel equilibrium angiotensin II (eqAngII) assay and compare correlations between the aldosterone/angiotensin II ratio (AA2R) and the current ARR under conditions affecting the renin-angiotensin system. METHODS: Among 78 patients recruited, PA was excluded in 22 and confirmed in 56 by fludrocortisone suppression testing (FST). Peripheral levels of eqAngII, plasma renin activity (PRA) and direct renin concentration (DRC) were measured. RESULTS: EqAngII showed good consistency with DRC and PRA independent of PA diagnosis, posture, and fludrocortisone administration. EqAngII showed close (P < 0.01) correlations with DRC (r = 0.691) and PRA (r = 0.754) during FST. DRC and PRA were below their assays' functional sensitivity in 43.9% and 15.1%, respectively, of the total 312 samples compared with only 7.4% for eqAngII (P < 0.01). Bland-Altman analysis revealed an overestimation of PRA and DRC compared with eqAngII in a subset of samples with low renin levels. The AA2R showed not only consistent changes with the ARR but also close (P < 0.01) correlations with the ARR, whether renin was measured by DRC (r = 0.878) or PRA (r = 0.880). CONCLUSIONS: Dynamic changes of eqAngII and the AA2R show good consistency and close correlations with renin and the ARR. The eqAngII assay shows better sensitivity than DRC and PRA assays, especially at low concentrations. Whether the AA2R can reduce the impact of some factors that influence the diagnostic power of the ARR warrants further study.
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Angiotensina II/sangue , Hiperaldosteronismo/diagnóstico , Espectrometria de Massas em Tandem/métodos , Adolescente , Adulto , Idoso , Aldosterona/sangue , Cromatografia Líquida de Alta Pressão , Feminino , Fludrocortisona/química , Humanos , Imunoensaio , Masculino , Pessoa de Meia-Idade , Radioimunoensaio , Renina/sangue , Adulto JovemRESUMO
Data are relatively scarce on gastro-intestinal tuberculosis (GITB). Most studies are old and from single centers, or did not include immunosuppressed patients. Thus, we aimed to determine the clinical, radiological, and laboratory profiles of GITB. We included adults with proven GITB treated between 2000 and 2018. Patients were enrolled from 21 referral centers in 8 countries (Belgium, Egypt, France, Italy, Kazakhstan, Saudi Arabia, UK, and Turkey). One hundred four patients were included. Terminal ileum (n = 46, 44.2%), small intestines except terminal ileum (n = 36, 34.6%), colon (n = 29, 27.8%), stomach (n = 6, 5.7%), and perianal (one patient) were the sites of GITB. One-third of all patients were immunosuppressed. Sixteen patients had diabetes, 8 had chronic renal failure, 5 were HIV positive, 4 had liver cirrhosis, and 3 had malignancies. Intestinal biopsy samples were cultured in 75 cases (78.1%) and TB was isolated in 65 patients (86.6%). PCR were performed to 37 (35.6%) biopsy samples and of these, 35 (94.6%) were positive. Ascites samples were cultured in 19 patients and M. tuberculosis was isolated in 11 (57.9%). Upper gastrointestinal endoscopy was performed to 40 patients (38.5%) and colonoscopy in 74 (71.1%). Surgical interventions were frequently the source of diagnostic samples (25 laparoscopy/20 laparotomy, n = 45, 43.3%). Patients were treated with standard and second-line anti-TB medications. Ultimately, 4 (3.8%) patients died and 2 (1.9%) cases relapsed. There was a high incidence of underlying immunosuppression in GITB patients. A high degree of clinical suspicion is necessary to initiate appropriate and timely diagnostic procedures; many patients are first diagnosed at surgery.
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Mycobacterium tuberculosis , Tuberculose Gastrointestinal/diagnóstico , Tuberculose Gastrointestinal/microbiologia , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Biópsia , Comorbidade , Gerenciamento Clínico , Suscetibilidade a Doenças , Feminino , Humanos , Masculino , Técnicas de Diagnóstico Molecular , Imagem Multimodal , Estudos Retrospectivos , Avaliação de Sintomas , Resultado do Tratamento , Tuberculose Gastrointestinal/terapiaRESUMO
Taxol, a phyto-extracted diterpenoid, is the most commercially needed drug in cancer chemotherapy. In spite of the microbial production of taxol being successful and prospective, the reported yields are still not sufficient for large-scale production. Thus, the discovery of new taxol-producing microbial strains and production enhancement methodologies such as process optimization, strain improvement, and immobilization technique are the main objectives. In this paper, a taxol-producing start strain Epicoccum nigrum TXB502 (initial yield 61.35 µg L-1) was isolated from Taxus baccata and identified by morphological and molecular tools. The optimum cultivation and nutritional conditions were assessed by testing one parameter at a time approach that resulted in 88.59% significant production increase. In addition, a stable mutant with improved productivity (40.07% yield increase in comparison with the parent strain) was successfully developed after gamma irradiation mutagenesis of the start strain. The taxol titer was further improved via testing different immobilization carriers for both spores and mycelia of this mutant. Over taxol production was achieved using alginate-immobilized mycelia with the feasibility of conducting six successive production cycles in a semi-continuous form. The final total concentration reached 8187.77 µg taxol 6 L-1 which represents approximately 22-fold increase, as compared to the initial titer of the start strain. These findings can pave the way for the prospective industrial manufacturing of taxol, as the achieved taxol production in this study is the highest reported by academic laboratories for microbial cultures. KEY POINTS: ⢠Discovery of a new taxol-producing endophytic fungus E. nigrum TXB502 strain. ⢠Taxol yield was successfully improved via bioprocess optimization and strain mutagenesis. ⢠Alginate-immobilized mycelia were efficient for a semi-continuous production of taxol. ⢠The final total concentration of taxol showed approximately 22-fold increase as compared to the initial titer.
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Antineoplásicos/metabolismo , Ascomicetos/genética , Ascomicetos/metabolismo , Raios gama , Mutagênese , Paclitaxel/biossíntese , Ascomicetos/efeitos da radiação , Meios de Cultura/química , Fermentação , Microbiologia Industrial/métodos , Micélio/metabolismo , Taxus/microbiologiaRESUMO
Selenium nanoparticles (SeNPs) were successfully synthesized using the culture extract of Monascus purpureus ATCC16436 grown on sugarcane bagasse under solid-state fermentation. The rapid synthesis of SeNPs was completed after 30 min as confirmed by UV-Vis spectroscopy. Functional groups present in the synthesized SeNPs samples were confirmed by Fourier transform infrared spectroscopy. The synthesized SeNPs showed a single-phase crystalline structure. Transmission electron microscope revealed the spherical shape and the mean particle size was 46.58 nm. Dynamic light scattering analysis showed that the synthesized SeNPs were monodispersed and the recorded polydispersity index value was 0.205. Zeta potential value of - 24.01 mV indicated the high stability of SeNPs. Besides, the biological activities of antioxidant, anticancer and antimicrobial as well as the photocatalytic activities were also studied. SeNPs showed promising antioxidant activity with 50% inhibitory concentration of 85.92 µg mL-1. Based on the MTT assay, SeNPs inhibited the proliferation of normal human melanocytes, human breast and liver cancer cell lines with 50% inhibitory concentrations of 45.21, 61.86 and 200.15 µg mL-1, respectively. SeNPs showed broad spectrum of antimicrobial potential against the tested human and plant pathogens. SeNPs showed efficient degradation of methylene blue dye. Moreover, the effect of gamma irradiation on the production enhancement of SeNPs was also adopted. Exposure of the fungal spores to gamma rays at 1000 Gy increased the yield of SeNPs to approximately fivefold. Hence, this study suggests a new and alternate approach with the excellent biotechnological potentiality for the production of SeNPs.
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Anti-Infecciosos , Raios gama , Nanopartículas Metálicas/química , Monascus/química , Selênio/química , Esporos Fúngicos/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Azul de Metileno/químicaRESUMO
Taxol is the most profitable drug ever developed in cancer chemotherapy; however, the market demand for the drug greatly exceeds the supply that can be sustained from its natural sources. In this study, Aspergillus fumigatus TXD105-GM6 and Alternaria tenuissima TER995-GM3 were immobilized in calcium alginate beads and used for the production of taxol in shake flask cultures. In an effort to increase the taxol magnitude, immobilization conditions were optimized by response surface methodology program (RSM). The optimum levels of alginate concentration, calcium chloride concentration, and mycelium fresh weight were 5%, 4%, and 15% (w/v), respectively. Under these conditions, taxol production by the respective fungal strains was intensified to 901.94 µg L-1 and 529.01 µg L-1. Moreover, the immobilized mycelia of both strains were successfully used in the repeated production of taxol for six different fermentation cycles. The total taxol concentration obtained in all cycles reached 4540.14 µg L-1 by TXD105-GM6 and 2450.27 µg L-1 by TER995-GM3 strain, which represents 7.85- and 6.31-fold increase, as compared to their initial titers. This is the first report on the production of taxol in semi-continuous fermentation. To our knowledge, the taxol productivity achieved in this study is the highest reported by academic laboratories for microbial cultures which indicates the future possibility to reduce the cost of taxol production.
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Alginatos/química , Alternaria/metabolismo , Antineoplásicos/metabolismo , Aspergillus fumigatus/metabolismo , Células Imobilizadas/metabolismo , Paclitaxel/biossínteseRESUMO
RNA polymerase (RNAP) remains a relatively underexplored target with only rifampicin and fidaxomicin in clinical use. Hence, the concurrent rise in bacterial resistance rate urges the search for novel RNAP inhibitors with a novel mode of action. In this work, we investigated the impact of several systematic modifications including sidechain-to-sidechain macrocylization in the α-helical content and biological activity of a previously identified inhibitory sigma factor fragment. Ala-scan results, peptide truncation from both the N- and C-terminus and modifications inspired by other RNAP inhibitors revealed novel structure activity relationships but did not yield a superior sequence. Additionally, four insertion points for non-natural amino acids bearing side chains required for macrocylization were explored. Linear precursors showed improved stabilization of the α-helical content compared to the original sequence as demonstrated by circular dichroism (CD) spectroscopy. However, this increase in α-helicity did not translate into improved biological activity. Instead, complete abolishment of RNAP inhibitory activity occurred. We hypothesize three possible reasons for such a discrepancy and offer the basis for further optimization efforts for this peptidic RNAP inhibitor.
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Alanina/análise , RNA Polimerases Dirigidas por DNA/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Compostos Macrocíclicos/farmacologia , Peptídeos/farmacologia , Ciclização , RNA Polimerases Dirigidas por DNA/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Compostos Macrocíclicos/síntese química , Compostos Macrocíclicos/química , Micro-Ondas , Modelos Moleculares , Peptídeos/síntese química , Peptídeos/química , Estrutura Secundária de ProteínaRESUMO
Huperzine A (HupA) is a potent acetylcholinesterase (AChE) inhibitor of a great consideration as a prospective drug candidate for Alzheimer's disease treatment. Production of HupA by endophytes offers an alternative challenge to reduce the massive plant harvest needed to meet the increasing demand of HupA. In the current study, some endophytic fungal and actinobacterial isolates from the Chinese herb, Huperzia serrata, underwent liquid fermentation, alkaloid extraction, and screening for AChE inhibition and HupA production. Among these isolates, Alternaria brassicae AGF041 strain was the only positive strain for HupA production with the maximum AChE inhibition of 75.5%. Chromatographic analyses verified the identity of the produced HupA. The HupA production was efficiently maximized up to 42.89 µg/g of dry mycelia, after optimization of thirteen process parameters using multifactorial statistical approaches, Plackett-Burman and central composite designs. The statistical optimization resulted in a 40.8% increase in HupA production. This is the first report to isolate endophytic actinobacteria with anti-AChE activity from H. serrata, and to identify an endophytic fungus A. brassicae as a new promising start strain for a higher HupA yield.
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Alcaloides/biossíntese , Alternaria/metabolismo , Inibidores da Colinesterase/metabolismo , Fermentação , Huperzia/microbiologia , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Micélio , Estudos Prospectivos , SesquiterpenosRESUMO
UV and gamma irradiation mutagenesis was applied on Aspergillus fumigatus and Alternaria tenuissima in order to improve their producing ability of paclitaxel. Among the screened mutants, two stable strains (designated TXD105-GM6 and TER995-GM3) showed the maximum paclitaxel production. Paclitaxel titers of the two respective mutants were dramatically intensified to 1.22- and 1.24-fold, as compared by their respective parents. Immobilization using five different entrapment carriers of calcium alginate, agar-agar, Na-CMC, gelatin, and Arabic gum was successfully applied for production enhancement of paclitaxel by the two mutants. The immobilized cultures were superior to free-cell cultures and paclitaxel production by the immobilized mycelia was much higher than that of the immobilized spores using all the tried carriers. Moreover, calcium alginate gel beads were found the most conductive and proper entrapment carrier for maximum production of paclitaxel. The feasibility of the paclitaxel production by the immobilized mycelia as affected by incubation period, medium volume, and number of beads per flask was adopted. Under the favorable immobilization conditions, the paclitaxel titers were significantly intensified to 1.31- and 1.88-fold by the respective mutants, as compared by their free cultures. The obtained paclitaxel titers by the immobilized mycelia of the respective mutants (694.67 and 388.65 µg L-1) were found promising in terms of fungal production of paclitaxel. Hence, these findings indicate the future possibility to reduce the cost of producing paclitaxel and suggest application of the immobilization technique for the biotechnological production of paclitaxel at an industrial scale.
Assuntos
Alternaria/metabolismo , Antineoplásicos/metabolismo , Aspergillus fumigatus/metabolismo , Paclitaxel/biossíntese , Alginatos/química , Alternaria/química , Alternaria/genética , Aspergillus fumigatus/química , Aspergillus fumigatus/genética , Células Imobilizadas/química , Células Imobilizadas/metabolismo , Fermentação , Microbiologia Industrial , Micélio/química , Micélio/genética , Micélio/metabolismoRESUMO
Widespread application of the plasma aldosterone/renin ratio (ARR) as a screening test has led to the recognition that primary aldosteronism (PA) is the most common specifically treatable and potentially curable form of hypertension, accounting for 5-10% of patients. Maximal detection requires accurate diagnostic approaches and awareness and control of factors that confound results, including most antihypertensives, posture, time of day, dietary salt, and plasma potassium. Recent studies have revealed potential for false positives in patients on beta-adrenoceptor blockers, and, when direct renin concentration (but not plasma renin activity) is used to measure renin, in women during the luteal phase of the menstrual cycle or receiving estrogen-containing contraceptives or hormonal replacement therapy. In addition to verapamil slow release, hydralazine and prazosin, moxonidine has minimal effects on the ARR and can be used to control hypertension during work-up. Fludrocortisone suppression testing, while probably the most reliable means of definitively confirming or excluding PA, is time consuming and expensive, requiring a five day inpatient stay. A novel approach, upright (seated) saline infusion suppression testing (SST), has shown excellent reliability with much greater sensitivity than conventional recumbent SST in a recent pilot study, and requires only a day visit. Accurate measurement of aldosterone is essential for each step of PA workup: introduction of new, highly reliable high-throughput mass spectrometric methods into clinical practice has represented a major advance. In response to concerns raised about accuracy of renin assays, new mass spectrometric methods for measuring angiotensin II are currently being assessed in the clinical setting.
Assuntos
Técnicas de Diagnóstico Endócrino/normas , Hiperaldosteronismo/diagnóstico , Hiperaldosteronismo/terapia , Programas de Rastreamento/normas , Melhoria de Qualidade , Aldosterona/sangue , Humanos , Programas de Rastreamento/métodos , Testes de Função Adreno-Hipofisária/normas , Renina/sangueRESUMO
Among 60 fungal endophytes isolated from twigs, bark, and mature leaves of different plant species, two fungal isolates named TXD105 and TER995 were capable of producing paclitaxel in amounts of up to 84.41 and 37.92 µg L-1, respectively. Based on macroscopic and microscopic characteristics, ITS1-5.8S-ITS2 rDNA sequence, and phylogenetic characteristic analysis, the two respective isolates were identified as Aspergillus fumigatus and Alternaria tenuissima. In the effort to increase paclitaxel magnitude by the two fungal strains, several fermentation conditions including selection of the proper fermentation medium, agitation rate, incubation temperature, fermentation period, medium pH, medium volume, and inoculum nature (size and age of inoculum) were tried. Fermentation process carried out in M1D medium (pH 6.0) and maintained at 120 rpm for 10 days and at 25 °C using 4% (v/v) inoculum of 5-day-old culture stimulated the highest paclitaxel production to attain 307.03 µg L-1 by the A. fumigatus strain. In the case of the A. tenuissima strain, fermentation conditions conducted in flask basal medium (pH 6.0) and maintained at 120 rpm for 14 days and at 25 °C using 8% (v/v) inoculum of 7-day-old culture were found the most favorable to attain the highest paclitaxel production of 124.32 µg L-1. Using the MTT-based assay, fungal paclitaxel significantly inhibited the proliferation of five different cancer cell lines with 50% inhibitory concentration values varied from 3.04 to 14.8 µg mL-1. Hence, these findings offer new and alternate sources with excellent biotechnological potential for paclitaxel production by fungal fermentation.