Keratins are naturally derived proteins that can be fabricated into several biomaterials morphologies including films, sponges and hydrogels. As a physical matrix, keratin biomaterials have several ...advantages of both natural and synthetic materials that are useful in tissue engineering and controlled released applications. Like other naturally derived protein biomaterials, such as collagen, keratin possess amino acid sequences, similar to the ones found on extracellular matrix (ECM), that may interact with integrins showing their ability to support cellular attachment, proliferation and migration. The ability of developing biomaterials that mimic ECM has the potential to control several biological processes and this is the case for keratin which has been used in a variety of biomedical applications due to its biocompatibility and biodegradability. This review describes the progress to date towards the use of keratin in the field of wound healing, tissue engineering and drug delivery applications, with highlight to reports of particular relevance to the development of the underlying biomaterials science in this area.
Cancer cells depend on altered metabolism and nutrient uptake to generate and keep the malignant phenotype. The hexosamine biosynthetic pathway is a branch of glucose metabolism that produces ...UDP-GlcNAc and its derivatives, UDP-GalNAc and CMP-Neu5Ac and donor substrates used in the production of glycoproteins and glycolipids. Growing evidence demonstrates that alteration of the pool of activated substrates might lead to different glycosylation and cell signaling. It is already well established that aberrant glycosylation can modulate tumor growth and malignant transformation in different cancer types. Therefore, biosynthetic machinery involved in the assembly of aberrant glycans are becoming prominent targets for anti-tumor drugs. This review describes three classes of glycosylation, O-GlcNAcylation, N-linked, and mucin type O-linked glycosylation, involved in tumor progression, their biosynthesis and highlights the available inhibitors as potential anti-tumor drugs.
SARS-CoV-2 in Pregnancy-The First Wave de Vasconcelos Gaspar, Andreia; Santos Silva, Isabel
Medicina (Kaunas, Lithuania),
03/2021, Letnik:
57, Številka:
3
Journal Article
Recenzirano
Odprti dostop
COVID-19, a disease caused by SARS-CoV-2, is a public health emergency. Data on the effect of the virus on pregnancy are limited.
We carried out a retrospective descriptive study, in order to ...evaluate the obstetric results on pregnant women in which SARS-CoV-2 was detected through RT-PCR of the nasopharyngeal swab, at admission to the maternity hospital.
From 16 March to 31 July 2020, 12 SARS-CoV-2 positive pregnant women have been hospitalized. Eleven were hospitalized for initiation or induction of labor, corresponding to 0.64% of deliveries in the maternity hospital. One pregnant woman was hospitalized for threatened abortion, culminating in a stillbirth at 20 weeks of gestation. Regarding the severity of the disease, nine women were asymptomatic and three had mild illness (two had associated cough and one headache). Three had relevant environmental exposure and a history of contact with infected persons. None had severe or critical illness due to SARS-CoV-2. There were no maternal deaths. The following gestational complications were observed: one stillbirth, one preterm labor, one preterm prelabor rupture of membranes, and one fetal growth restriction. Four deliveries were eutocic, two vacuum-assisted deliveries and five were cesarean sections. The indications for cesarean section were obstetric.
SARS-CoV-2 infection was found in a minority of hospitalized pregnant women in this sample. Most are asymptomatic or have mild illness, from gestational complications to highlight stillbirth and preterm birth. There were no cases of vertical transmission by coronavirus.
Background: Intrauterine devices are effective long-lasting contraceptive methods with a high rate of satisfaction among users. This study aimed at determining women’s perception of intrauterine ...contraception, before and after its placement, and assessing the impact of contraceptive counseling on that perception. Methods: Descriptive prospective study, carried out through a questionnaire, regarding women who underwent a Family Planning (FP) consultation in a Tertiary Hospital Center, from September 1, 2020 to August 31, 2021. Results: 108 women were included in this study. Contraceptive methods used prior to the consultation were mainly hormonal (62%) and barrier (30%). The main reason for choosing the intrauterine device was the advice given by the physician or other health professional (87%). The greatest concern of women regarding this method was the placement process (27%), especially with regard to pain associated with the procedure (50%). 79% of women considered that they were fully clarified prior to device placement. After placement, mean pain intensity was 3.94 (SD = 2.273; Visual Analogue Scale), and it was found to be lower than women’s perception prior to placement. 73% thought the process was simpler than expected and 88% would advise the method to other women. All users reported having been informed about possible complications or adverse effects associated with this contraceptive method. Conclusions: Results indicate that the choice of long-acting contraception is mainly associated with correct medical advice. Most of the women were clear after family planning consultation, which made the intrauterine device placement easier and less painful than expected.
Abstract The beneficial effect of treatment with bone marrow mononuclear cells (BMMCs) was evaluated in different therapeutic windows in a rat model of focal ischemia induced by thermocoagulation of ...the blood vessels in the left motor, somestesic, and sensorimotor cortices. We also compared the therapeutic benefits between BMMCs and bone marrow-derived mesenchymal stem cells (MSCs). BMMCs and MSCs were obtained from donor rats and injected into the jugular vein after ischemia. BMMCs-treated animals received approximately 3 × 107 cells at post-ischemic days (PIDs) 1, 7, 14, or 30. MSCs-treated animals received approximately 3 × 106 cells at PIDs 1 and 30. Control animals received only the vehicle. The animals were then evaluated for functional sensorimotor recovery weekly with behavioral tests (cylinder test and adhesive test). Significant recovery of sensorimotor function was only observed in the cylinder test in animals treated with BMMCs at PIDs 1 and 7. Similar effects were also observed in the animals treated with MSCs 1 day after ischemia, but not in animals treated with MSCs 30 days after ischemia. Significant decrease in glial scarring did not seem to be a mechanism of action of BMMCs, since treatment with BMMCs did not change the level of expression of GFAP, indicating no significant change in the astrocytic scar in the periphery of the ischemic lesion. These results suggest that BMMCs might be an efficient treatment protocol for stroke only in the acute/subacute phase of the disease, and its efficiency in inducing functional recovery is similar to that of MSCs.
CD43 (leukosialin) is a large sialoglycoprotein abundantly expressed on the surface of most cells from the hematopoietic lineage. CD43 is directly involved in the contact between cells participating ...in a series of events such as signaling, adherence and host parasite interactions. In this study we examined the role of CD43 in the immune response against Trypanosoma cruzi, the protozoan parasite that causes Chagas' disease, a potential life-threatening illness endemic in 21 Latin American countries according to the WHO. The acute stage of infection is marked by intense parasitemia and cardiac tissue parasitism, resulting in the recruitment of inflammatory cells and acute damage to the heart tissue. We show here that CD43
mice were more resistant to infection due to increased cytotoxicity of antigen specific CD8+ T cells and reduced inflammatory infiltration in the cardiac tissue, both contributing to lower cardiomyocyte damage. In addition, we demonstrate that the induction of acute myocarditis involves the engagement of CD43 cytoplasmic tripeptide sequence KRR to ezrin-radixin-moiesin cytoskeletal proteins. Together, our results show the participation of CD43 in different events involved in the pathogenesis of T. cruzi infection, contributing to a better overall understanding of the mechanisms underlying the pathogenesis of acute chagasic cardiomyopathy.
Wool and silk were dissolved and used for the preparation of blended films. Two systems are proposed: (1) blend films of silk fibroin and keratin aqueous solutions and (2) silk fibroin and keratin ...dissolved in formic acid. The FTIR spectra of pure films cast from aqueous solutions indicated that the keratin secondary structure mainly consists of α-helix and random coil conformations. The IR spectrum of pure SF is characteristic of films with prevalently amorphous structure (random coil conformation). Pure keratin film cast from formic acid shows an increase in the amount of β-sheet and disordered keratin structures. The FTIR pattern of SF dissolved in formic acid is characteristic of films with prevalently β-sheet conformations with β-sheet crystallites embedded in an amorphous matrix. The thermal behavior of the blends confirmed the FTIR results. DSC curve of pure SF is typical of amorphous SF and the curve of pure keratin show the characteristic melting peak of α-helices for the aqueous system. These patterns are no longer observed in the films cast from formic acid due to the ability of formic acid to induce crystallization of SF and to increase the amount of β-sheet structures on keratin. The nonlinear trend of the different parameters obtained from FTIR analysis and DSC curves of both SF/keratin systems indicate that when proteins are mixed they do not follow additives rules but are able to establish intermolecular interactions. Degradable polymeric biomaterials are preferred candidates for medical applications. It was investigated the degradation behavior of both SF/keratin systems by in vitro enzymatic incubation with trypsin. The SF/keratin films cast from water underwent a slower biological degradation than the films cast from formic acid. The weight loss obtained is a function of the amount of keratin in the blend. This study encourages the further investigation of the type of matrices presented here to be applied whether in scaffolds for tissue engineering or as controlled release drug delivery vehicles.
O objetivo deste estudo foi estimar a prevalência de hipertensão em adultos residentes nas comunidades ribeirinhas do rio Madeira, previamente à operação da Usina Hidrelétrica Santo Antônio. Estudo ...transversal da prevalência de hipertensão arterial realizado com 841 adultos. Informações sobre condições sociodemográficas, morbidade referida, hábitos de vida, consumo de peixe e dados antropométricos foram avaliados. O método de regressão logística foi utilizado para estimar a odds ratio e seus respectivos intervalos de confiança. Entre os ribeirinhos, 26% (IC95%: 23%29%) dos adultos apresentaram hipertensão: 29% entre os homens (IC95%: 24%-33%) e 23% entre as mulheres (IC95%: 19%-27%). Nos homens, os fatores associados à hipertensão foram idade, IMC, glicemia e local de residência. Entre as mulheres, os fatores preditivos foram idade, triglicerídeos e glicemia. Os resultados deste estudo podem contribuir com a formulação de estratégias de monitoramento para prevenção de eventos cardiovasculares por parte dos órgãos de saúde estadual e municipal.
Lippia origanoides is a honey shrub which has showed hypotensive potential assessed by in vivo studies. The aim of this work is the development of a pharmaceutical formulation composed by an ...optimized extract obtained from aerial parts of L. origanoides. The quantification of the naringenin marker in the dry extract and tablets developed was performed, as well as the assessment of the oral acute toxicity in rats. The hydroalcoholic extract of L. origanoides was spray-dried with the addition of colloidal silicon dioxide (Lo-HAE/CSD), and then applied in the preparation of eight different lots of tablets. The influence of the diluent (cellulose or babassu mesocarp), the presence of binder, and the percentage of lubricant, as well as organoleptic and physicochemical characteristics were screened. For the quantification of the marker content both in Lo-HAE/CSD and in the tablets, an analytical curve of the naringenin standard was fitted, and the samples were then analyzed in UFLC. The toxicological assessment was performed in female Wistar rats according to the Acute Toxic Class Method from OECD. The developed tablets produced meet acceptable macroscopic characteristics, and the presence of babassu as diluent provided improved physicochemical properties. The best content of Lo-HAE/CSD in the tablet (100.27%) was identified for the lot containing babassu, composed by 1.0% magnesium stearate, without PVP binder in its formulation. Moreover, Lo-HAE/CSD showed no signs of toxicity. Therefore, the babassu mesocarp powder is a promising pharmaceutical excipient for the development of herbal tablets containing the Lippia origanoides extract.
Silk fibroin (SF) and elastin (EL) scaffolds were successfully produced for the first time for the treatment of burn wounds. The self-assembly properties of SF, together with the excellent chemical ...and mechanical stability and biocompatibility, were combined with elastin protein to produce scaffolds with the ability to mimic the extracellular matrix (ECM). Porous scaffolds were obtained by lyophilization and were further crosslinked with genipin (GE). Genipin crosslinking induces the conformational transition from random coil to β-sheet of SF chains, yielding scaffolds with smaller pore size and reduced swelling ratios, degradation and release rates. All results indicated that the composition of the scaffolds had a significant effect on their physical properties, and that can easily be tuned to obtain scaffolds suitable for biological applications. Wound healing was assessed through the use of human full-thickness skin equivalents (EpidermFT). Standardized burn wounds were induced by a cautery and the best re-epithelialization and the fastest wound closure was obtained in wounds treated with 50SF scaffolds; these contain the highest amount of elastin after 6days of healing in comparison with other dressings and controls. The cytocompatibility demonstrated with human skin fibroblasts together with the healing improvement make these SF/EL scaffolds suitable for wound dressing applications.
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