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1.
Support Care Cancer ; 31(6): 341, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37195367

RESUMO

OBJECTIVE: To compare the complication rates, nutritional status, and physical state between esophageal cancer (EC) patients managed by nasogastric tube (NGT) feeding versus those managed by oral nutritional supplementation (ONS) during chemoradiotherapy. METHODS: EC patients undergoing chemoradiotherapy managed by nonintravenous nutritional support in our institute were retrospectively recruited and divided into an NGT group and an ONS group based on the nutritional support method. The main outcomes, including complications, nutritional status, and physical state, were compared between groups. RESULTS: The baseline characteristics of EC patients were comparable. There were no significant differences in the incidence of treatment interruption (13.04% vs. 14.71%, P = 0.82), death (2.17% vs. 0.00%, P = 0.84), or esophageal fistula (2.17% vs. 1.47%, P = 1.00) between the NGT group and ONS group. Body weight loss and decrease in albumin level were significantly lower in the NGT group than in the ONS group (both P < 0.05). EC patients in the NGT group had significantly lower Nutritional Risk Screening 2002 (NRS2002) and Patient-Generated Subjective Global Assessment (PG-SGA) scores and significantly higher Karnofsky Performance Status (KPS) scores than patients in the ONS group (all P < 0.05). The rates of grade > 2 esophagitis (10.00% vs. 27.59%, P = 0.03) and grade > 2 bone marrow suppression (10.00% vs. 32.76%, P = 0.01) were significantly lower in the NGT group than in the ONS group. There were no significant differences in the incidence of infection and upper gastrointestinal disorders or therapeutic efficacy between groups (all P > 0.05). CONCLUSIONS: EN through NGT feeding leads to significantly better nutritional status and physical state in EC patients during chemoradiotherapy than EN via ONS. NGT may also prevent myelosuppression and esophagitis..


Assuntos
Neoplasias Esofágicas , Estado Nutricional , Humanos , Estudos Retrospectivos , Nutrição Enteral/métodos , Intubação Gastrointestinal/efeitos adversos , Intubação Gastrointestinal/métodos , Neoplasias Esofágicas/terapia , Quimiorradioterapia/efeitos adversos
2.
Wiad Lek ; 74(6): 1457-1462, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34159937

RESUMO

OBJECTIVE: The aim: Is to determine informatively significant indicators of the physical state of the first-year students of higher education institutions. PATIENTS AND METHODS: Materials and methods: The study was conducted at Prydniprovska State Academy of Civil Engineering and Architecture in 2019-2020. The study involved 100 first-year female students of the main department between the ages of 17 and 18. The state of health of female students, their motivational needs, and the level of their physical development, physical fitness, and functional state were studied. RESULTS: Results: The study summarized knowledge and experience on the problem of selecting means for assessing the physical state of students, analyzed the motivational needs and health of female students, as well as identified informative indicators of the physical state of the female students by factor analysis. CONCLUSION: Conclusions: The study indicates the need for an obligatory survey on the health of the first-year female students at the beginning of the academic year; the inclusion of the elements of modern fitness programs in the curriculum of the Physical Education discipline and the organization of sectional classes in accordance with the results of the survey if possible in order to increase students' motivation to attend classes and differentiate training in classes aimed at improving the physical state of female students.


Assuntos
Instituições Acadêmicas , Universidades , Adolescente , Feminino , Humanos , Motivação , Educação Física e Treinamento , Estudantes
3.
J Nutr ; 150(9): 2295-2304, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32556204

RESUMO

BACKGROUND: The influence of triacylglycerol (TAG) physical properties on satiety remains poorly understood. OBJECTIVES: The objective was to investigate if and how TAG digestion and absorption, modulated only by differences in TAG crystallinity, would differentially affect short-term satiety in healthy men. METHODS: We tempered 500 mL 10% palm stearin oil-in-water emulsions such that the lipid droplets were either undercooled liquid (LE) or partially crystalline solid (SE). Fifteen healthy men (mean ± SD age: 27.5 ± 5.7 y; BMI: 24.1 ± 2.5 kg/m2; fasting TAG: 0.9 ± 0.3 mmol/L) consumed each beverage at two 6-h study visits separated by ≥6 d after an overnight fast, along with 1500 mg acetaminophen suspended in water. The participants characterized the emulsion sensory properties, completed satiety visual analog scale ratings, and had serial blood samples collected for 6-h analysis of plasma peptide YY (PYY), glucagon-like peptide-1 (GLP-1), ghrelin, leptin, glucose-dependent insulinotropic polypeptide (GIP), insulin, and acetaminophen (for assessing gastric emptying). Repeated-measures ANOVAs and 2-tailed paired t tests were used to analyze the changes from baseline and incremental area under the curve (iAUC) values, respectively. RESULTS: With consumption of LE compared with SE, there was a 358% higher fullness (P = 0.015) and a 103% lower average appetite (P = 0.041) score, along with higher iAUC values for PYY (P = 0.011) and GLP-1 (P = 0.028) (103% and 66% higher, respectively), but not for ghrelin (P = 0.39), based on change from baseline values. Acetaminophen response trended toward significance (P = 0.08) and was 15% higher with LE. SE was rated as 44% thicker (P = 0.034) and 24% creamier (P = 0.05) than LE. CONCLUSIONS: The suppression of TAG digestion by the presence of partially crystalline lipid droplets blunted the appetite-suppressing effects of an oil-in-water emulsion.This trial was registered at clinicaltrials.gov as NCT03990246.


Assuntos
Emulsões , Refeições , Resposta de Saciedade/efeitos dos fármacos , Triglicerídeos/química , Triglicerídeos/farmacologia , Acetaminofen/sangue , Acetaminofen/farmacocinética , Adulto , Analgésicos não Narcóticos/sangue , Analgésicos não Narcóticos/farmacocinética , Área Sob a Curva , Estudos Cross-Over , Humanos , Masculino , Triglicerídeos/administração & dosagem , Adulto Jovem
4.
J Basic Microbiol ; 60(8): 679-690, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32378234

RESUMO

Bacillus sp. SFC 500-1E, a bacterial strain isolated from tannery sediments, is able to remove Cr(VI) and simultaneously tolerate high concentrations of phenol. In this study, we used high-resolution microscopies, fluorescence polarization techniques, and several biochemical approaches to improve our understanding about the adaptive mechanisms of this strain to survive in the presence of Cr(VI) and phenol, both individually and simultaneously. Among adaptive strategies developed by Bacillus sp. SFC 500-1E, an increase in bacterial size, such as length, width, and height, and ultrastructural alterations, such as electron-dense precipitates, the presence of exopolymers, and cell lysis, are noteworthy. The exopolymers observed were consistent with the extensive biofilm formation and exopolysaccharides and extracellular protein quantification. At the cell membrane level, a rapid rigidity was induced in Cr(VI) + phenol treatment. This effect was counteracted after 16 h by changes at the level of phospholipids, mainly in the composition of fatty acids (FAs); in particular, an increase in the unsaturated fatty acid/saturated fatty acid ratio was detected. This study shows evidence of some adaptive responses displayed by Bacillus sp. SFC 500-1E, which allows it to survive in stressful conditions.


Assuntos
Bacillus/citologia , Bacillus/efeitos dos fármacos , Cromo/farmacologia , Fenol/farmacologia , Bacillus/metabolismo , Biodegradação Ambiental , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Membrana Celular/ultraestrutura , Cromo/metabolismo , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Ácidos Graxos/química , Fosfolipídeos/química , Estresse Fisiológico
5.
Wiad Lek ; 73(9 cz. 2): 2044-2048, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33148857

RESUMO

OBJECTIVE: The aim: Of the study is to characterize the internal acts of the United Nations on the regulation of the right to health of its staff. PATIENTS AND METHODS: Materials and methods: Achieving the purpose of the study is ensured due to the analysis of internal acts of the United Nations, doctrinal sources on the issue selected. The methodological basis is a number of special and general methods. CONCLUSION: Conclusions: The right to health guaranteed by the International Bill of Human Rights is comprehensive and closely linked to labour human rights. International civil servants of the UN system are not exempt. Thus, within the United Nations, a number of acts have been developed, the provisions of which set out recommendations aimed at reducing possible cases of infection of workers, maintaining their mental health while on quarantine, informing staff about their actions in case of illness, testing workers, etc. However, these acts need to be improved.


Assuntos
Direito à Saúde , Nações Unidas , Direitos Humanos , Humanos
6.
AAPS PharmSciTech ; 20(2): 62, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-30627934

RESUMO

In this study, a method employing THz Raman imaging to characterize the solid state of acetaminophen within a solid dispersion prepared by hot melt extrusion was reported. The peak at 89 cm-1 originating from the crystalline lattice vibrations provides unambiguous discrimination between crystalline and amorphous N-acetyl-para-aminophenol (APAP; acetaminophen) contents in the hot melt extrusion (HME) extrudates. Extrudates from four different HME processes (two different temperatures and two levels of screw speeds) were analyzed and compared. The results show that both high process temperature and high screw speed favor the formation of amorphous APAP solid dispersions. Finally, the high spatial resolution (~ 1 µm) Raman images of the extrudates prepared at 170°C and 200 rpm show a near-complete amorphous APAP dispersion in an HPMC matrix, confirming an efficient HME process. The study demonstrates that THz Raman imaging is ideally suited for the identification of different solid physical states of the APIs in a polymer matrix, and provides direct visualization of their distribution in HME extrudates.


Assuntos
Acetaminofen/química , Temperatura Alta , Derivados da Hipromelose/química , Análise Espectral Raman/métodos , Imagem Terahertz/métodos , Acetaminofen/análise , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Derivados da Hipromelose/análise , Solubilidade
7.
Microbiology (Reading) ; 163(5): 669-677, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28535844

RESUMO

Alkanes are widespread pollutants found in soil, freshwater and marine environments. Marinobacter hydrocarbonoclasticus (Mh) strain SP17 is a marine bacterium able to use many hydrophobic organic compounds, including alkanes, through the production of biofilms that allow their poor solubility to be overcome. This study pointed out that temperature is an environmental factor that strongly affects the biofilm formation and morphology of Mh on the model alkanes, hexadecane and paraffin. We showed that Mh biofilm formation and accumulation of intracytoplasmic inclusions are higher on solid alkanes (hexadecane at 10 °C and paraffin at 10 °C and 30 °C) than on liquid alkane (hexadecane at 30 °C) or soluble substrate (lactate at both temperatures). We also found that Mh produces more extracellular polymeric substances at 30 °C than at 10 °C on alkanes and none on lactate. We observed that bacterial length is significantly higher at 10 °C than at 30 °C on lactate and hexadecane. On paraffin, at 30 °C, the cell morphology is markedly altered by large rounded or irregularly shaped cytoplasmic inclusions. Altogether, the results showed that Mh is able to adapt and use alkanes as a carbon source, even at low temperature.

8.
Adv Gerontol ; 29(2): 337-341, 2016.
Artigo em Russo | MEDLINE | ID: mdl-28514555

RESUMO

Assessment of the physical status of older women conducted anthropometry and bioimpendance analysis. Body type determined by the gender dimorphism index of J. Tanner (1951). It was found that in the studied sample representative of gynecomorphic and mesomorphic body types were determined in a high percentage of cases: 46,15 and 49,11 %. Women andromorphic body type were found less frequently - 4,74 %. Women with gynecomorphic body type were smaller mass and transverse dimensions of the body, unlike representatives with andromorphic and gynecomorphic body types. The absolute content of fat and lean body mass tended to increase from gynecomorphic body types representatives to andromorphic. The results of anthropometric measurements, bioimpedance analysis and determined by the gender dimorphism index of J. Tanner provide results about adaptive possibilities the human body and can serve as markers (predictors) of somatic diseases.


Assuntos
Envelhecimento/fisiologia , Antropometria/métodos , Indicadores Básicos de Saúde , Idoso , Composição Corporal , Índice de Massa Corporal , Impedância Elétrica , Feminino , Avaliação Geriátrica/métodos , Humanos , Pessoa de Meia-Idade , Caracteres Sexuais
9.
Biochim Biophys Acta ; 1838(6): 1509-17, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24463068

RESUMO

The synthetic fatty acid 2-hydroxyoleic acid (2OHOA) is an antitumor drug that regulates membrane lipid composition and structure. An important effect of this drug is the restoration of sphingomyelin (SM) levels in cancer cell membranes, where the SM concentration is lower than in non-tumor cells. It is well known that free fatty acid concentration in cell membranes is lower than 5%, and that fatty acid excess is rapidly incorporated into phospholipids. In a recent work, we have considered the effect of free 2OHOA in model membranes in liquid ordered (Lo) and liquid disordered (Ld) phases, by using all-atom molecular dynamics. This study concerns membranes that are modified upon incorporation of 2OHOA into different phospholipids. 2OHOA-containing phospholipids have a permanent effect on lipid membranes, making a Ld membrane surface more compact and less hydrated, whereas the opposite effect is observed in Lo domains. Moreover, the hydroxyl group of fatty acid chains increases the propensity of Ld model membranes to form hexagonal or other non-lamellar structures. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.


Assuntos
Membrana Celular/química , Ácidos Graxos/química , Bicamadas Lipídicas/química , Lipídeos de Membrana/química , Ácidos Oleicos/química , Fosfolipídeos/química , Animais , Humanos , Microdomínios da Membrana
10.
Biochim Biophys Acta ; 1838(6): 1628-37, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24412218

RESUMO

The complex dual mechanism of action of 2-hydroxyoleic acid (2OHOA), a potent anti-tumor compound used in membrane lipid therapy (MLT), has yet to be fully elucidated. It has been demonstrated that 2OHOA increases the sphingomyelin (SM) cell content via SM synthase (SGMS) activation. Its presence in membranes provokes changes in the membrane lipid structure that induce the translocation of PKC to the membrane and the subsequent overexpression of CDK inhibitor proteins (e.g., p21(Cip1)). In addition, 2OHOA also induces the translocation of Ras to the cytoplasm, provoking the silencing of MAPK and its related pathways. These two differential modes of action are triggered by the interactions of 2OHOA with either lipids or proteins. To investigate the molecular basis of the different interactions of 2OHOA with membrane lipids and proteins, we synthesized the R and S enantiomers of this compound. A molecular dynamics study indicated that both enantiomers interact similarly with lipid bilayers, which was further confirmed by X-ray diffraction studies. By contrast, only the S enantiomer was able to activate SMS in human glioma U118 cells. Moreover, the anti-tumor efficacy of the S enantiomer was greater than that of the R enantiomer, as the former can act through both MLT mechanisms. The present study provides additional information on this novel therapeutic approach and on the magnitude of the therapeutic effects of type-1 and type-2 MLT approaches. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.


Assuntos
Membrana Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Bicamadas Lipídicas/química , Lipídeos de Membrana/química , Ácidos Oleicos/farmacologia , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo , Animais , Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Membrana Celular/metabolismo , Fatores de Transcrição Forkhead/fisiologia , Glioma/tratamento farmacológico , Glioma/metabolismo , Glioma/patologia , Humanos , Bicamadas Lipídicas/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Lipídeos de Membrana/metabolismo , Camundongos , Camundongos Nus , Modelos Químicos , Simulação de Dinâmica Molecular , Ácidos Oleicos/química , Transdução de Sinais/efeitos dos fármacos , Estereoisomerismo , Células Tumorais Cultivadas , Difração de Raios X
11.
J Med Virol ; 87(11): 1973-80, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25959607

RESUMO

Integration of HPV16 DNA into the host chromosome usually disrupts the E1 and/or E2 genes. The present study investigated the disruption of E1, E2 genes in a total of eighty four HPV16-positive precancerous and cervical cancer specimens derived from Greek women (seventeen paraffin-embedded cervical biopsies and sixty seven Thin Prep samples). Complete E2 and E1 genes were amplified using three and nine overlapping primer sets respectively, in order to define the sites of disruption. Extensive mapping analysis revealed that disruption/deletion events within E2 gene occurred in high grade and cervical cancer samples (x(2) test, P < 0.01), while no evidence of E2 gene disruption was documented among low grade cervical intraepithelial neoplasias. In addition, disruptions within the E1 gene occur both in high and low grade cervical intraepithelial neoplasia. This leads to the assumption that in low grade cervical intraepithelial neoplasias only E1 gene disruption was involved (Fisher's exact test, P < 0.05), while in high grade malignancies and cervical cancer cases deletions in both E1 and E2 genes occurred. Furthermore, the most prevalent site of disruption of E1 gene was located between nucleotides 1059 and 1323, while the most prevalent deleted region of the E2 gene was located between nucleotides 3172 and 3649 (E2 hinge region). Therefore, it is proposed that each population has its own profile of frequencies and sites of disruptions and extensive mapping analysis of E1 and E2 genes is mandatory in order to determine suitable markers for HPV16 DNA integration analysis in distinct populations.


Assuntos
Proteínas de Ligação a DNA/genética , Papillomavirus Humano 16/fisiologia , Proteínas Oncogênicas Virais/genética , Displasia do Colo do Útero/patologia , Neoplasias do Colo do Útero/patologia , Integração Viral , Feminino , Grécia , Papillomavirus Humano 16/genética , Humanos , Deleção de Sequência , Neoplasias do Colo do Útero/virologia , Displasia do Colo do Útero/virologia
12.
Food Chem ; 459: 140314, 2024 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-39024881

RESUMO

The combined impact of initial state, pressure, and freezing on peroxidase denaturation during high-pressure freezing (HPF) processing of enzyme-containing foods remains unclear. This study investigated solid-liquid (initial low/high concentration) biphasic peroxidase using spectroscopic and computer simulation techniques to analyze structural changes affecting peroxidase (POD) activity under HPF. The results indicate that the primary factors determining POD activity during HPF treatment can be ranked as follows: concentration > physical state > pressure > freezing. Higher initial concentrations strengthen protein interactions, leading to a 1% increase in the molecular diameter and a 34% increase in molecular height of HL-POD, thereby increasing aggregation likelihood during crystallization and facilitating structural changes that activate enzymes by 6-17%. The amide I peak proves to be a reliable indicator for monitoring both POD activity and structural alterations. This study offers valuable insights for optimizing HPF technology in food processing.


Assuntos
Congelamento , Peroxidase , Pressão , Peroxidase/química , Peroxidase/metabolismo , Manipulação de Alimentos , Estabilidade Enzimática
13.
Forensic Sci Int ; 360: 112046, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38718526

RESUMO

Research into the recovery of DNA from illicit drug samples has shown it is possible to get forensically useful profiles from such substrates. However, it is not yet known if the different physical states that drugs can be found in influences the quantity and quality of DNA that can be recovered or what is the best sampling method to adopt for powdered samples. This research used acetaminophen in four different states - large crystalline, powder, in solution, or residue - to determine the efficacy of current DNA technology in recovery and analysis of the resulting sample. Five replicates of each were prepared. Human blood was deposited on or mixed with the drug and left for 1 hour. The surface of the drug was sampled by wet/dry swabbing (where appropriate), or the entire sample was deposited in a tube, and the DNA then extracted using DNA-IQ™. The amount of DNA recovered (ng), degradation index, number of PCR cycles (Ct) required for the IPC to reach threshold, number of alleles in the DNA profile and average peak height (APH) were assessed. All samples, irrespective of the physical state they were collected from, returned full DNA profiles that corresponded to the DNA profile of the blood donor, with no degradation or inhibition detected. It was also found the wet/dry swabbing method returned higher levels of DNA than inclusion of the entire sample into the tube for powdered acetaminophen and the appropriate method to use will be dependent on casework circumstances. The findings of this research further develops our understanding of the recovery of DNA from drugs, and supports the need for further investigation to understand under what conditions DNA can be recovered from illicit substances.


Assuntos
Acetaminofen , Impressões Digitais de DNA , DNA , Reação em Cadeia da Polimerase , Manejo de Espécimes , Acetaminofen/sangue , Humanos , DNA/isolamento & purificação , Manejo de Espécimes/métodos , Impressões Digitais de DNA/métodos , Pós , Repetições de Microssatélites , Analgésicos não Narcóticos , Degradação Necrótica do DNA
14.
Biology (Basel) ; 13(2)2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38392296

RESUMO

Human papillomaviruses (HPVs) and, specifically, high-risk HPVs (HR-HPVs) are identified as necessary factors in the development of cancer of the lower genital tract, with CaCU standing out as the most prevalent tumor. This review summarizes ten mechanisms activated by HR-HPVs during cervical carcinogenesis, which are broadly associated with at least seven of the fourteen distinctive physiological capacities of cancer in the newly established model by Hanahan in 2022. These mechanisms involve infection by human papillomavirus, cellular tropism, genetic predisposition to uterine cervical cancer (CaCU), viral load, viral physical state, regulation of epigenetic mechanisms, loss of function of the E2 protein, deregulated expression of E6/E7 oncogenes, regulation of host cell protein function, and acquisition of the mesenchymal phenotype.

15.
Mol Nutr Food Res ; : e2400365, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-39388527

RESUMO

SCOPE: Consumption of high-fat meals is associated with increased endotoxemia, inflammation, and atherogenic profiles, with repeated postprandial responses suggested as contributors to chronically elevated risk factors. However, effects of lipid solid versus liquid state specifically have not been investigated. METHODS AND RESULTS: This exploratory randomized crossover study tests the impact of lipid crystallinity on plasma levels of endotoxin transporters (lipopolysaccharide [LPS] binding protein [LBP] and soluble cluster of differentiation 14 [sCD14]) and select proinflammatory and atherogenic markers (tumor necrosis factor-alpha [TNF-α], C-reactive protein [CRP], interleukin-1-beta [IL-1ß], interferon-gamma [IFN-γ], interleukin-6 [IL-6], soluble intercellular adhesion molecule [sICAM], soluble vascular cell adhesion molecule [sVCAM], monocyte chemoattractant protein-1 [MCP-1/CCL2], plasminogen activator inhibitor-1 [PAI-1], and fibrinogen). Fasted healthy men (n = 14, 28 ± 5.5 years, 24.1 ± 2.6 kg m-2) consumed two 50 g palm stearin oil-in-water emulsions tempered to contain either liquid or crystalline lipid droplets at 37 °C on separate occasions with blood sampling at 0, 2-, 4-, and 6-h post-meal. Timepoint data, area under the curve, and peak concentration values are compared. Overall, no treatment effects are seen (p > 0.05). There are significant effects of time, with values decreasing from baseline, for TNF-α, MCP-1/CCL2, PAI-1, and fibrinogen (p < 0.05). CONCLUSION: Responder analysis pointed to differential treatment effects associated with some participant baseline characteristics but, overall, palm-stearin emulsion droplet crystallinity does not acutely affect plasma endotoxin transporters nor select inflammatory and atherogenic markers.

16.
Food Chem ; 428: 136703, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37423103

RESUMO

The synergistic effect of the initial state of the enzyme and pressure level on the denaturation of PPO has not been clear yet, but it significantly affects the application of high hydrostatic pressure (HHP) in the enzyme-containing food processing. Solid (S-) and low/high concentration liquid (LL-/HL-) polyphenol oxidase (PPO) was used as the study object, and the microscopic conformation, molecular morphology and macroscopic activity of PPO under HHP treatments (100-400 MPa, 25 °C/30 min) were investigated by spectroscopic techniques. The results show that the initial state has a significant effect on the activity, structure, active force and substrate channel of PPO under pressure. The effec can be ranked as follows: physical state > concentration > pressure, S-PPO > LL-PPO > HL-PPO. High concentration has a weakening effect on the pressure denaturation of the PPO solution. Under high pressure, the α-helix and concentration factors play a crucial role in stabilizing the structure.


Assuntos
Catecol Oxidase , Manipulação de Alimentos , Catecol Oxidase/química , Manipulação de Alimentos/métodos , Pressão Hidrostática
17.
Pharmaceutics ; 15(2)2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36839712

RESUMO

Mesoporous silica (MPS) carriers are considered as a promising strategy to increase the solubility of poorly soluble drugs and to stabilize the amorphous drug delivery system. The development by the authors of a solvent-free method (milling-assisted loading, MAL) made it possible to manipulate the physical state of the drug within the pores. The present study focuses on the effects of the milling intensity and the pore architecture (chemical surface) on the physical state of the confined drug and its release profile. Ibuprofen (IBP) and SBA-15 were used as the model drug and the MPS carrier, respectively. It was found that decreasing the milling intensity promotes nanocrystallization of confined IBP. Scanning electron microscopy and low-frequency Raman spectroscopy investigations converged into a bimodal description of the size distribution of particles, by decreasing the milling intensity. The chemical modification of the pore surface with 3-aminopropyltriethoxisylane also significantly promoted nanocrystallization, regardless of the milling intensity. Combined analyses of drug release profiles obtained on composites prepared from unmodified and modified SBA-15 with various milling intensities showed that the particle size of composites has the greatest influence on the drug release profile. Tuning drug concentration, milling intensity, and chemical surface make it possible to easily customize drug delivery.

18.
Membranes (Basel) ; 12(9)2022 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-36135842

RESUMO

Bortezomib (BTZ) is a potent proteasome inhibitor currently being used to treat multiple myeloma. However, its high toxicity and resistance to therapy severely limit the treatment outcomes. Drug-membrane interactions have a crucial role in drugs' behavior in vivo, affecting their bioavailability and pharmacological activity. Additionally, drugs' toxicity often occurs due to their effects on the cell membranes. Therefore, studying BTZ's interactions with cell membranes may explain the limitations of its therapy. Due to the cell membranes' complexity, lipid vesicles were proposed here as biomembrane models, focusing on the membrane's main constituents. Two models with distinct composition and complexity were used, one composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and the other containing DMPC, cholesterol (Chol), and sphingomyelin (SM). BTZ's interactions with the models were evaluated regarding the drugs' lipophilicity, preferential location, and effects on the membrane's physical state. The studies were conducted at different pH values (7.4 and 6.5) to mimic the normal blood circulation and the intestinal environment, respectively. BTZ revealed a high affinity for the membranes, which proved to be dependent on the drug-ionization state and the membrane complexity. Furthermore, BTZ's interactions with the cell membranes was proven to induce changes in the membrane fluidity. This may be associated with its resistance to therapy, since the activity of efflux transmembrane proteins is dependent on the membrane's fluidity.

19.
Int J Pharm ; 609: 121145, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34600056

RESUMO

The aim of the study is to investigate the thermal behavior of poloxamer 188 (P188) in binary (P188-water) and ternary (P188-trehalose-water) solutions during freezing and thawing. The thermal behavior of P188 in frozen (binary and ternary) systems was characterized by differential scanning calorimetry (DSC) and low-temperature X-ray powder diffractometry (XPRD) as a complementary technique. The influence of processing conditions (cooling rate, annealing) and a noncrystallizing co-solute (addition of trehalose) on the behavior of P188 was evaluated during freezing as well as thawing. In rapidly cooled (10 °C/min) aqueous binary solutions, P188 (10% w/v) was retained in the amorphous state. At slower cooling rates (0.5-5 °C/min), the extent of crystallization depended on the cooling rate. In ternary P188-trehalose-water systems (P188 4% w/v, trehalose 0-10% w/v), a concentration dependent inhibition of P188 crystallization was observed with increasing trehalose concentration. However, irrespective of trehalose concentration, annealing resulted in P188 crystallization. The presence of trehalose as well as the processing conditions (cooling rate and annealing) influenced the physical state of P188 at different stages of freezing and thawing. As the cooling rate decreased, the extent of P188 crystallization progressively increased. In presence of trehalose (≥4.0% w/v) crystallization of P188 (4.0% w/v) was inhibited and this effect could be reversed by annealing. Depending on the intended application, the physical form of P188 could be modulated, by annealing even in presence of a noncrystallizing solute.


Assuntos
Poloxâmero , Água , Varredura Diferencial de Calorimetria , Cristalização , Liofilização , Congelamento , Soluções , Trealose
20.
Int J Biol Macromol ; 193(Pt A): 847-855, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34740680

RESUMO

Herein, the effects of chitosan (CH) coating with different water-soluble polyphenol extracts (pomegranate peel (PPE), grape seed (GSE) and green tea (GTE)) through vacuum impregnation on the quality retention and microflora of refrigerated grass carp fillets were studied. Generally, the quality degradation of carp fillets was remarkably alleviated using coatings when compared to the control. As suggested by microbial enumeration and high-throughput sequencing, protective coatings were conductive to inhibit bacteria growth, especially spoilage bacteria of Pseudomonas. As a result, the indicator related to bacteria such as total volatile basic nitrogen (TVB-N) and K value had lower levels in coating groups than that in control. In addition, coating also slowed down the deterioration of physical properties of color, texture and water holding capacity in fillets, giving fillets a better edible quality. By contrast, the fillets treated by composite coatings had better quality during storage when compared to chitosan coating alone, and a relatively good synergistic antibacterial effect between chitosan and extracts was also observed, especially for CH-GTE. Overall, the best performance to inhibit quality deterioration was recorded in CH-GTE, with the lowest values of TVB-N, TBARS, K-value and water loss, and highest values of shear force and sensory preference among groups.


Assuntos
Carpas/microbiologia , Quitosana/farmacologia , Conservação de Alimentos/métodos , Armazenamento de Alimentos/métodos , Alimentos Marinhos/microbiologia , Animais , Bactérias/efeitos dos fármacos , Paladar/efeitos dos fármacos
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