Proton exchange between titratable amino acid residues and the surrounding solution gives rise to exciting electric processes in proteins. We present a proton titration scheme for studying acid-base equilibria in Metropolis Monte Carlo simulations where salt is treated at the Debye-Hückel level. The method, rooted in the Kirkwood model of impenetrable spheres, is applied on the three milk proteins α-lactalbumin, β-lactoglobulin, and lactoferrin, for which we investigate the net-charge, molecular dipole moment, and charge capacitance. Over a wide range of pH and salt conditions, excellent agreement is found with more elaborate simulations where salt is explicitly included. The implicit salt scheme is orders of magnitude faster than the explicit analog and allows for transparent interpretation of physical mechanisms. It is shown how the method can be expanded to multiscale modeling of aqueous salt solutions of many biomolecules with nonstatic charge distributions. Important examples are protein-protein aggregation, protein-polyelectrolyte complexation, and protein-membrane association.
The main advantage of the intrahepatic Glissonian procedure over other techniques is the possibility of gaining a rapid and precise access to the left Glissonian sheaths facilitating left hemihepatectomy, bisegmentectomy 2-3, and individual resections of segments 2, 3, and 4. The authors believe that the intrahepatic Glissonian technique facilitates laparoscopic liver resection and may increase the development of segment-based laparoscopic liver resection.
Hal itosis is an embarrassing symptom with a significant social impact. Halitosis affects millions of people worldwide and many resources are spent annually in products to improve halitus, unsuccessfully. The study of halitosis in a scientific basis is justified once halitosis causes social restriction, decreases life quality and may be an indication of serious diseases. Aim: To elaborate a protocol for halitosis assessment in order to minimize costs, avoid unnecessary tests and provide a guideline for diagnosis. METHODS: The protocol was created based on the literature and on the authors' personal experiences, adopting an evidence-based anamnesis. Results: There are many causes of halitosis and most of them are related to the oral cavity; others are related to otolaryngologic and respiratory diseases. Gastrointestinal diseases, liver/renal impairment and other metabolic syndromes are less frequent, but also important causes of halitosis. Conclusion: There are important costs involved in halitosis assessment and treatment, including medical appointments, specialist assessment, and complementary tests. Such costs would be minimized by adopting a protocol of evidence-based anamnesis and a flowchart for a rational clinical investigation.
A simple, easy, and safe procedure aiming to improve liver regeneration could be of great clinical benefit in critical situations such as major hepatectomy, trauma, or hemorrhage. Low-power laser irradiation (LPLI) has come into a wide range of use in clinical practice by inducing regeneration in healthy and injured tissues. However, the effect of LPLI on the process of liver regeneration, especially those related to the molecular mechanisms, is not fully understood. Thus, the aim of the present study was to investigate the main molecular mechanisms involved in liver regeneration of partially hepatectomized rats exposed to LPLI. We used Wistar male rats, which had their remaining liver irradiated or not with LPLI (wavelength of 632.8 nm and fluence of 65 mW/cm(2)) for 15 min after a 70% hepatectomy. We subsequently investigated hepatocyte growth factor (HGF), Met, Akt, and Erk 1/2 signaling pathways through protein expression and phosphorylation analyses along with cell proliferation (proliferating cell nuclear antigen (PCNA) and Ki-67) using immunoblotting and histological studies. Our results show that LPLI can improve liver regeneration as shown by increased HGF protein expression and the phosphorylation levels of Met, Akt, and Erk 1/2 accompanied by higher levels of the PCNA and Ki-67 protein in the remnant livers. In summary, our results suggest that LPLI may play a clinical role as a simple, fast, and easy-to-perform strategy in order to enhance the liver regenerative capacity of a small liver remnant after hepatectomy.
No predictor of NASH was found. Surgeons' evaluation could not identify NASH individuals. Routine liver biopsy during bariatric operations is mandatory to differentiate NASH and nonalcoholic fatty liver disease.
Summary Large-scale mapping of antigens and epitopes is pivotal for developing immunotherapies but challenging, especially for eukaryotic pathogens, owing to their large genomes. Here, we developed an integrated platform for genome phage display (gPhage) to show that unbiased libraries of the eukaryotic parasite Trypanosoma cruzi enable the identification of thousands of antigens recognized by serum samples from patients with Chagas disease. Because most of these antigens are hypothetical proteins, gPhage provides evidence of their expression during infection. We built and validated a comprehensive map of Chagas disease antibody response to show how linear and putative conformation epitopes, many rich in repetitive elements, allow the parasite to evade a buildup of neutralizing antibodies directed against protein domains that mediate infection pathogenesis. Thus, the gPhage platform is a reproducible and effective tool for rapid simultaneous identification of epitopes and antigens, not only in Chagas disease but perhaps also in globally emerging/reemerging acute pathogens.
Purpose: Liver ischemia-reperfusion injury is a phenomenon presents in events like liver resections and transplantation. The restoration of blood flow may leads to local and systemic injury. Several techniques have been developed in order to avoid or ameliorate ischemia-reperfusion injury in clinical situations. The application of a sttuter reperfusion after the ischemic event (postconditioning) could alters the hydrodynamics and stimulates endogenous mechanisms that attenuate the reperfusion injury. The present study was designed to evaluate the potential protective effect of postconditioning in a model of ischemia-reperfusion in rats. Methods: Hepatic anterior pedicle of median and left anterolateral segments were exposed and clamped for 1 hour. Two hours later, clamp was released in two different ways: Control Group (n=7): clamp was release straightforward; Postconditioning Group (n=7): clamp was released intermittently. Lipid peroxidation (malondialdehyde) and expression of the glutathione-s-transferase--3 gene were studied. Results: Lipid peroxidation was significantly decreased in ischemic and non-ischemic liver by postconditioning. GST-3 gene was overexpressed in postconditioned group, but not significantly. Conclusion: Postconditioning induced hepatoprotection by reducing lipid peroxidation in the ischemic and non-ischemic liver. Key words: Liver. Ischemia. Reperfusion. Lipid Peroxidation. Rats. RESUMOObjetivo: A lesão de isquemia-reperfusão hepática é um fenômeno presente em eventos tais como ressecções hepáticas e transplante de fígado. A restauração do fluxo sangüíneo após a isquemia gera lesões locais e sistêmicas. Várias técnicas foram desenvolvidas com o objetivo de evitar ou diminuir a lesão de isquemia-reperfusão hepática em situações clínicas. A utilização da reperfusão intermitente após o evento isquêmico (pós-condicionamento) pode alterar a hidrodinâmica e estimular mecanismos endógenos que atenuam o dano da reperfusão. O presente estudo foi realizado para avaliar o potencial efeito protetor do pós-condicionamento em um modelo de isquemia-reperfusão em ratos. Métodos: O pedículo dos lobos mediano e ântero-lateral foi isolado e clampeado por 1 hora. Após 2 horas, o pedículo foi liberado de duas maneiras diferentes: Grupo Controle (n=7): clampe liberado de uma só vez; Grupo Pós-condicionamento (n=7): clampe liberado de maneira intermitente. Malondialdeído (MDA) e expressão do gene GST-3 foram estudadas nos grupos. Resultados: A peroxidação lipídica foi significativamente diminuída no fígado isquêmico e no fígado não isquêmico pelo pós-condicionamento. A expressão do gene GST-3 aumentou, porém não significativamente, no grupo pós-condicionamento. Conclusão: O pós-condicionamento induziu hepatoproteção pela redução da peroxidação lipídica nos fígados isquêmico e não isquêmico. Descritores: Fígado. Isquemia. Reperfusão. Peroxidação de Lipídeos. Ratos.
As a result of the SARS-CoV-2 pandemic numerous scientific groups have generated antibodies against a single target: the CoV-2 spike antigen. This has provided an unprecedented opportunity to compare the efficacy of different methods and the specificities and qualities of the antibodies generated by those methods. Generally, the most potent neutralizing antibodies have been generated from convalescent patients and immunized animals, with non-immune phage libraries usually yielding significantly less potent antibodies. Here, we show that it is possible to generate ultra-potent (IC50 < 2 ng/ml) human neutralizing antibodies directly from a unique semisynthetic naïve antibody library format with affinities, developability properties and neutralization activities comparable to the best from hyperimmune sources. This demonstrates that appropriately designed and constructed naïve antibody libraries can effectively compete with immunization to directly provide therapeutic antibodies against a viral pathogen, without the need for immune sources or downstream optimization.
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