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1.
Biol Psychol ; 179: 108564, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37061084

RESUMO

Elevated irritability during adolescence predicts mental health issues in adulthood. Social interactions commonly elicit symptoms of irritability. Prior research has traditionally examined neural activity during the anticipation of, and immediate reaction to, social feedback separately in irritable adolescents. However, studies suggest that irritable adolescents demonstrate altered brain activation when anticipating feedback, and these alterations may have downstream effects on the neural activity when actually presented with feedback. Thus, the goal of this study was to characterize the influence of irritability on the relationship between brain function during anticipation and receipt of social feedback. We leveraged the Virtual School task to mimic social interactions using dynamic stimuli. Parallel region of interest (ROI) analyses tested effects of anticipatory bilateral amygdala (or dorsal anterior cingulate cortex; dACC) activation on the dACC (or bilateral amygdala) activation during receipt of peer feedback. Parallel exploratory whole-brain analyses were conducted to identify the effects of anticipatory bilateral amygdala or dACC activation on other regions during receipt of peer feedback. In ROI analyses, more vs. less irritable adolescents showed distinct relationships between anticipatory bilateral amygdala activation and dACC activation when receiving predictably mean feedback. Across both whole-brain analyses, anticipatory bilateral amygdala and dACC activation were separately associated with activation in socioemotional regions of the brain during subsequent feedback. These relationships were modulated by irritability, and the valence and predictability of the feedback. This suggests that irritable adolescents may engage in altered emotion processing and regulation strategies, depending on the valence and predictability of social feedback.


Assuntos
Encéfalo , Humor Irritável , Humanos , Adolescente , Retroalimentação , Humor Irritável/fisiologia , Giro do Cíngulo/fisiologia , Grupo Associado , Imageamento por Ressonância Magnética
2.
J Food Sci Technol ; 59(2): 456-466, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35153304

RESUMO

In the present study, the antimicrobial, rheological, mechanical, barrier and optical properties of Carrageenan and Manihot esculenta (composite) starch biobased edible film incorporated with caraway (Carum carvi L.) essential oil (EO) were investigated. The Minimum Inhibitory Concentration (MIC) of caraway oil against B. cereus, E. coli, P. aeruginosa and S. aureus were found to be 0.6, 1.4, 1.4 and 0.8% respectively. The Gas Chromatography- Mass Spectroscopy (GC-MS) of caraway EO expressed a distinct chromatogram peak for phenolic compounds. Rheological results of Film-Forming Solution (FFS) revealed solid-like viscoelastic behavior. Incorporation of caraway EO in the film caused significant (P < 0.05) increase in moisture, moisture absorption, bio-degradability in terms of film solubility, L value, total color difference (ΔE), haziness and transparency value, however, significantly (P < 0.05) decreased tensile strength and whiteness index were observed. The zone of inhibition of caraway EO incorporated films against all test bacteria were highly significant (P < 0.01) than control whereas antibacterial activity was found more towards gram-positive bacteria than gram-negative bacteria. No significant (P>0.05) changes in thickness, density, water activity, swelling, elongation at break, water vapor transmission rate, a and b value were observed with increasing caraway EO concentration. These results with some good rheological, physic-mechanical, antimicrobial and optical characteristics suggest the application of such active film into a variety of foods with improved food safety and quality. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05028-1.

3.
Mymensingh Med J ; 30(3): 780-788, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34226468

RESUMO

LASER Haemorrhoidoplasty (LH) is a novel procedure in modern medical science. It is a no cut, painless and bloodless clinical procedure with comparatively fewer complications in comparison to Stapler Haemorrhoidopexy (SH) for the treatment of grade III-IV haemorrhoids. It is very applicable surgical procedure at shrinking the terminal branches of haemorrhiodal arteries with fewer complications than Stapler Haemorrhoidopexy (SH). The aim of the study was to compare LASER Haemorrhoidoplasty (LH) with Stapler Haemorrhoidopexy (SH). The comparative study was performed in Bangabandhu Sheikh Mujib Medical University (BSMMU), Anower Khan Modern Medical College and Hospital and Care Medical College and Hospital, Dhaka, Bangladesh from August 2019 to July 2020. A total of 84 patients with grade III-IV haemorrhoids were allocated into two groups: LASER Haemorrhoidoplasty (LH) and Stapler Haemorrhoidopexy (SH) with 42 patients in each group prospectively. Comparative results and post-operative follow up periods were 4 months. The mean operative time was 28.6min (LH) and 36.2min (SH) (p=0.0006). The average blood loss was 6.42ml (LH) and 12.6ml (SH) (p<0.05). The mean hospital stay 18.36 hours (LH) and 28.40 hours (SH) (p<0.05). Mean postoperative pain score (VAS) at 12 hours was 3.8 (LH) and 6.81 (SH) (p<0.05), at 24 hours was 2.6 (LH) and 4.6 (SH) (p<0.05), at 1 week was 0.46 (LH) and 0.88 (SH) (p=0.05) and at 3 months 0.04 (LH) and 0.10 (SH) (p=0.401). Complications were found in (2.4%) patients ≤1 week in the (LH) group 7(16.7%) in the (SH) group which was statistically significant (p<0.05) between the two groups. Patients with haemorrhoids treated with LASER Haemorrhoidoplasty had a better outcome than stapler haemorrhoidopexy in terms of early postoperative pain as well as complications and was associated with a shorter hospital stay and early return to work. LASER Haemorrhoidoplasty was most effective and alternative to the popular stapler Haemorrhoidopexy for grade III-IV haemorrhoids.


Assuntos
Hemorroidas , Bangladesh , Hemorroidas/cirurgia , Humanos , Lasers , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/prevenção & controle , Complicações Pós-Operatórias , Estudos Prospectivos , Grampeamento Cirúrgico , Resultado do Tratamento
4.
Mymensingh Med J ; 30(2): 410-414, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33830121

RESUMO

The aim of the present study was to compare the sensitivity between Alvarado and RIPASA score for the diagnosis of acute appendicitis patients. A comparative study was conducted in the Dhaka National Medical College Hospital, Bangladesh from July 2015 to December 2015. The study was approved by the institutional ethical committee. Most of the appendicitis patients belonged to the between 21-30 years which was 64(32%). Male appendicitis patients (52%) are more than the female patients (48%). Majority of the patients (69%) complains pain occurs in the Right iliac fossa. Sensitivity of Alvarado scores was 81.60%, specificity 74.58%, accuracy 79.35%, positive and negative predictive values were 87.18% and 65.67% respectively. RIPASA score's sensitivity was 85.6%, specificity 69.49%, accuracy 80.40%, positive and negative predictive values were 85.60% and 85.60% respectively. This study reported that RIPASA score is significantly shown higher diagnostic accuracy then that Alvarado score.


Assuntos
Apendicite , Doença Aguda , Apendicectomia , Apendicite/diagnóstico , Bangladesh/epidemiologia , Feminino , Humanos , Masculino , Estudos Prospectivos , Sensibilidade e Especificidade
5.
Hum Exp Toxicol ; 40(10): 1673-1684, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33832332

RESUMO

Hepatotoxicity is a major dose-limiting side effect of CP chemotherapy besides nephrotoxicity and gastrointestinal dysfunction. TQ, a principal Nigella sativa seed oil constituent, has been shown to improve hepatic functions in various in vivo models of acute hepatic injury. In view of this, the present study aimed to evaluate the effect of TQ against CP-induced hepatotoxicity. Rats were divided into four experimental groups; control, CP, CP+TQ and TQ. Animals in CP+TQ and TQ groups were administered TQ (1.5 mg/kg bwt, orally), with or without a single hepatotoxic dose of CP (6 mg/kg bwt, i.p.) respectively, for 14 days before and four days following the CP treatment. CP induced an upsurge in serum ALT and AST activities, indicating liver injury, as also confirmed by the histopathological findings. CP caused significant alterations in the activities of membrane marker enzymes, carbohydrate metabolic enzymes, and the enzymatic and nonenzymatic components of the antioxidant defense system. TQ supplementation ameliorated all these adverse biochemical and histological changes in CP-treated rats. Thus, TQ may have excellent scope for clinical applications in combating CP-induced hepatic pathophysiology.


Assuntos
Antineoplásicos/toxicidade , Benzoquinonas/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Cisplatino/toxicidade , Suplementos Nutricionais , Animais , Humanos , Masculino , Distribuição Aleatória , Ratos , Ratos Wistar
7.
Opt Express ; 27(25): 36846-36854, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31873456

RESUMO

We demonstrate a technique to simultaneously stabilize the frequency and output power of a terahertz quantum-cascade laser (QCL). This technique exploits frequency and power variations upon near-infrared illumination of the QCL with a diode laser. It does not require an external terahertz optical modulator. By locking the frequency to a molecular absorption line, we obtain a long-term (one-hour) linewidth of 260 kHz (full width at half maximum) and a root-mean-square power stability below 0.03%. With respect to the free-running case, this stabilization scheme improves the frequency stability by nearly two orders of magnitude and the power stability by a factor of three.

8.
Opt Express ; 27(4): 5420-5432, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30876146

RESUMO

Near-infrared optical excitation enables wideband frequency tuning of terahertz quantum-cascade lasers. In this work, we demonstrate the feasibility of the approach for molecular laser absorption spectroscopy. We present a physical model which explains the observed frequency tuning characteristics by the optical excitation of an electron-hole plasma. Due to an improved excitation configuration as compared to previous work, we observe a single-mode continuous-wave frequency coverage of as much as 40 GHz for a laser at 3.1 THz. This represents, for the same device, a ten-fold improvement over the usually employed tuning by current. The method can be readily applied to a large class of devices.

9.
Sci Rep ; 9(1): 1334, 2019 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-30718639

RESUMO

Hierarchical twinning, at multiple length scales, was noted in a metastable body-centered cubic (bcc) ß-titanium alloy on tensile deformation. Site-specific characterization within the deformation bands, carried out using EBSD and TEM, revealed {332} <113> type primary bcc twins, containing different variants of secondary and tertiary twins, as well as the formation of stress-induced martensite (α"). Within the primary {332} <113> type twin, "destruction" of the prior quenched-in athermal ω phase was observed, while a stress-induced ω phase reforms within the tertiary twins, revealing the intricate nature of coupling between deformation twinning and displacive ω transformation.

10.
Diabet Med ; 36(3): 383-387, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30307056

RESUMO

AIMS: To assess the impact of social deprivation, demographics and centre on HbA1c outcomes with continuous subcutaneous insulin infusion (CSII) in adults with Type 1 diabetes. METHODS: Demographic data, postcode-derived English Index of Multiple Deprivation data and 12-month average HbA1c (mmol/mol) pre- and post-CSII were collated from three diabetes centres in the north west of England, University Hospital of South Manchester (UHSM), Salford Royal Foundation Hospital (SRFT) and Manchester Royal Infirmary (MRI). Univariable and multivariable regression models explored relationships between demographics, Index of Multiple Deprivation, centre and HbA1c outcomes. RESULTS: Data were available for 693 (78%) individuals (UHSM, n = 90; SRFT, n = 112; and MRI, n = 491) of whom 59% were women. Median age at CSII start was 39 (IQR 29.5-49.0) years and median diabetes duration was 20 (11-29) years. Median Index of Multiple Deprivation was 15 193 (6313-25 727). Overall median HbA1c improved from 69 to 64 mmol/mol (8.5% to 8.0%) within the first year of CSII. In multivariable analysis, higher pre-CSII HbA1c was significantly associated with higher deprivation (P = 0.036), being female (P < 0.001), and centre (MRI; P = 0.005). Following pre-CSII HbA1c adjustment, post-CSII HbA1c or HbA1c change were not related to demographic factors and deprivation, but remained significantly related to the centre; UHSM and SRFT had larger reductions in HbA1c with CSII compared with MRI [median -7.0 (-0.6%) vs. -6.0 (-0.55%) vs. -4.5 (-0.45%) mmol/mol; P = 0.005]. CONCLUSIONS: Higher pre-CSII HbA1c levels were associated with higher deprivation and being female. CSII improves HbA1c irrespective of social deprivation and demographics. Significant differences in HbA1c improvements were observed between centres. Further work is warranted to explain these differences and minimize variation in clinical outcomes with CSII.


Assuntos
Carência Cultural , Diabetes Mellitus Tipo 1 , Hemoglobinas Glicadas/metabolismo , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Sistemas de Infusão de Insulina , Insulina/administração & dosagem , Adulto , Glicemia/metabolismo , Demografia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/epidemiologia , Inglaterra/epidemiologia , Feminino , Geografia , Hemoglobinas Glicadas/análise , Humanos , Infusões Subcutâneas , Masculino , Pessoa de Meia-Idade , Distância Psicológica , Estudos Retrospectivos , Resultado do Tratamento
11.
Opt Express ; 26(6): 6692-6699, 2018 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-29609356

RESUMO

We report on the Doppler-free saturation spectroscopy of a molecular transition at 3.3 THz based on a quantum-cascade laser and an absorption cell in a collinear pump-probe configuration. A Lamb dip with a sub-Doppler linewidth of 170 kHz is observed for a rotational transition of HDO. We found that a certain level of external optical feedback is tolerable as long as the free spectral range of the external cavity is large compared to the width of the absorption line.

12.
Curr Oncol ; 25(1): e90-e94, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29507500

RESUMO

Chemotherapy remains the mainstay of treatment for advanced pancreatic ductal adenocarcinoma (pda). Two randomized trials have demonstrated superiority of the combination regimens folfirinox (5-fluorouracil, leucovorin, oxaliplatin, and irinotecan) and gemcitabine plus nab-paclitaxel over gemcitabine monotherapy as a first-line treatment in adequately fit subjects. Selected pda patients progressing to first-line therapy can receive secondline treatment with moderate clinical benefit. Nevertheless, the optimal algorithm and the role of combination therapy in second-line are still unclear. Published second-line pda clinical trials enrolled patients progressing to gemcitabine-based therapies in use before the approval of nab-paclitaxel and folfirinox. The evolving scenario in second-line may affect the choice of the first-line treatment. For example, nanoliposomal irinotecan plus 5-fluouracil and leucovorin is a novel second-line option which will be suitable only for patients progressing to gemcitabine-based therapy. Therefore, clinical judgement and appropriate patient selection remain key elements in treatment decision. In this review, we aim to illustrate currently available options and define a possible algorithm to guide treatment choice. Future clinical trials taking into account sequential treatment as a new paradigm in pda will help define a standard algorithm.

13.
Diabet Med ; 34(10): 1372-1379, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28636773

RESUMO

AIMS: To compare long-term HbA1c changes associated with different insulin pumps during routine care in a large cohort of adults with Type 1 diabetes representative of other clinic populations. METHODS: Observational, retrospective study of 508 individuals starting pump therapy between 1999 and 2014 (mean age, 40 years; 55% women; diabetes duration, 20 years; 94% Type 1 diabetes; median follow-up, 3.7 years). Mixed linear models compared covariate-adjusted HbA1c changes associated with different pump makes. RESULTS: The pumps compared were: 50% Medtronic, 24% Omnipod, 14% Roche and 12% Animas. Overall HbA1c levels improved and improvements were maintained during a follow-up extending to 10 years (HbA1c : pre-continuous subcutaneous insulin infusion (pre-CSII) vs. 12 months post CSII, 71 (61, 82) vs. 66 (56, 74) mmol/mol; 8.7 (7.7, 9.6) vs. 8.2 (7.3, 8.9)%; P < 0.0001). The percentage of individuals with HbA1c ≥ 64 mmol/mol (8.0%) reduced from a pre-CSII level of 68% to 55%. After adjusting for baseline confounders, there were no between-pump differences in HbA1c lowering (P = 0.44), including a comparison of patch pumps with traditional catheter pumps (P = 0.63). There were no significant (P < 0.05) between-pump differences in HbA1c lowering in pre-specified subgroups stratified by pre-pump HbA1c , age or diabetes duration. HbA1c lowering was positively related to baseline HbA1c (P < 0.001) and diabetes duration (P = 0.017), and negatively related to the number of years of CSII use (P = 0.024). CONCLUSIONS: Under routine care conditions, there were no covariate-adjusted differences in HbA1c lowering when comparing different pump makes, including a comparison of patch pumps vs. traditional catheter pumps. Therefore, the choice of CSII make should not be influenced by the desired degree of HbA1c lowering.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Sistemas de Infusão de Insulina , Insulina/administração & dosagem , Adulto , Instituições de Assistência Ambulatorial , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Atenção Primária à Saúde , Estudos Retrospectivos
14.
Neuroscience ; 318: 84-93, 2016 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-26774051

RESUMO

Prenatal exposure to lipopolysaccharide (LPS) has been exploited to simulate brain disorder in animal model. Prenatal LPS-exposure has shown elevated levels of pro-inflammatory cytokines in the early stages of the postnatal period. This study determines the effect of prenatal LPS-exposure on oxidative stress (OS) in the distinct brain regions in the early postnatal stages. LPS (50 µg/kg, i.p.) and water for injection (100 µl, i.p.) were given to the experimental (n=5) and control (n=5) group of pregnant Swiss albino mice respectively on gestational day (GD)-16 and 17. Animals were decapitated on postnatal day (PnD) - 1, 7, 14 and 21 to assay levels of oxidative markers from 6 distinct brain regions. When compared with the control, prenatal LPS-exposure alters levels of OS markers: (i) on PnD-1, glutathione (GSH) level is raised and superoxide dismutase (SOD) activity is dropped, (ii) on PnD-7, advanced oxidation of protein product (AOPP) level is elevated, (iii) on PnD-14, lipid peroxidation (MDA) and activity of catalase (CAT) are enhanced, (iv) on PnD-21, increased MDA continued. The hippocampus (HC) and cerebellum (CB) were mostly susceptible to OS in the early postnatal development. Levels of MDA and activity of CAT enzyme were increased on PnD-14 in the cortex, HC and CB. Except MDA, all OS markers recovered and returned to the level of control animals on PnD-21. Taken together, these results suggest that prenatal LPS-exposure induces age- and region-specific OS in the early postnatal stage.


Assuntos
Encéfalo/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Envelhecimento , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Gravidez
15.
JNMA J Nepal Med Assoc ; 52(195): 892-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-26982662

RESUMO

INTRODUCTION: Long term physical training has been considered to adversely affect the performance of athletes especially the females. It may be due to the iron depletion caused by hemolysis or hemodilution results from plasma volume expansion. This study aims to assess the effect of heavy exercise on hemoglobin concentration and some other hematological parameters in female athletes. METHODS: This cross sectional study was carried out in the Department of physiology, Dhaka Medical College, Dhaka, from July 2010-June 2011. A total number of 105 females (70 athletes and 35 non athletes) between 15-25 years of age were recruited. The 35 apparently healthy female non athletes were taken as control (Group-A) and 70 female athletes comprise the study group (Group-B). According to sporting category, Group-B was further subdivided as B1:Runners and B2:Cyclists. Hemoglobin percentages (Hb %), red blood cell (RBC) concentration, packed cell volume (PCV), serum iron, serum ferritin and total iron binding capacity (TIBC) were measured in fasting state after two months training. Statistical analysis was done by using SPSS/ win.15.0 for comparison between the groups, using student's unpaired "t" test. RESULTS: Mean Hb%, RBC, PCV, iron and ferritin level were significantly (P<0.001) lower in athletes than those of control group. Within the study groups, runner's serum iron and ferritin level were lower than cyclists. TIBC significantly (P<0.001) rose in Group-B2 in comparison to Group-A. CONCLUSIONS: The current study showed that intense physical exercise leads to early stages of Hb%, RBC, PCV, iron and ferritin depletion which might compromise the health and performance of athletes.


Assuntos
Atletas , Contagem de Eritrócitos/métodos , Hematócrito/métodos , Hemoglobinas , Ferro , Esforço Físico/fisiologia , Adolescente , Adulto , Bangladesh , Estudos Transversais , Feminino , Hemoglobinas/análise , Hemoglobinas/metabolismo , Humanos , Ferro/sangue , Ferro/metabolismo , Esportes/classificação , Esportes/fisiologia
16.
Oral Microbiol Immunol ; 22(6): 381-3, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17949340

RESUMO

BACKGROUND/AIMS: Microorganisms of Peptostreptococcus micros are asaccharolytic, anaerobic gram-positive cocci that are frequently isolated from human oral sites such as periodontal pockets. Preliminary study showed that several amino acids, including serine, enhanced slightly the growth of P. micros. Therefore, we investigated the degradation of serine and serine-containing oligopeptides. METHODS: Metabolic end products were determined with high-performance liquid chromatography. The related enzymatic activities in cell-free extract were also assayed. RESULTS: Washed P. micros degraded serine-tripeptides (Ser-Ser-Ser), and produced formate, pyruvate, acetate, and ammonia. They also degraded serinyl-tyrosine (Ser-Tyr) to the same products. Related enzymatic activities, such as serine dehydratase, pyruvate formate-lyase, formate dehydrogenase, pyruvate oxidoreductase, phosphate acetyltransferase, and acetate kinase, were detected in the cell-free extract, indicating that the organisms produced ATP in the serine metabolism. CONCLUSION: P. micros utilized serine-containing oligopeptides as exogenous metabolic substrates rather than serine itself, and degraded Ser-Ser-Ser and Ser-Tyr to formate, pyruvate, acetate, and ammonia with ATP generation.


Assuntos
Oligopeptídeos/metabolismo , Peptostreptococcus/metabolismo , Serina/metabolismo , Acetato Quinase , Acetatos/metabolismo , Acetiltransferases , Trifosfato de Adenosina/biossíntese , Amônia/metabolismo , Formiato Desidrogenases , Formiatos/metabolismo , Humanos , L-Serina Desidratase/metabolismo , Peptostreptococcus/enzimologia , Fosfato Acetiltransferase , Piruvato Sintase , Ácido Pirúvico/metabolismo , Tirosina/metabolismo
17.
J Magn Reson ; 180(2): 210-21, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16563820

RESUMO

Two-dimensional (1)H-(13)C INEPT MAS NMR experiments utilizing a (1)H-(1)H magnetization exchange mixing period are presented for characterization of lipid systems. The introduction of the exchange period allows for structural information to be obtained via (1)H-(1)H dipolar couplings but with (13)C chemical shift resolution. It is shown that utilizing a RFDR recoupling sequence with short mixing times in place of the more standard NOE cross-relaxation for magnetization exchange during the mixing period allowed for the identification and separation of close (1)H-(1)H dipolar contacts versus longer-range inter-molecular (1)H-(1)H dipolar cross-relaxation. These 2D INEPT experiments were used to address both intra- and inter-molecular contacts in lipid and lipid/cholesterol mixtures.


Assuntos
Bicamadas Lipídicas/química , Ressonância Magnética Nuclear Biomolecular/métodos , Isótopos de Carbono , Colesterol/química , Lipídeos/química , Modelos Teóricos
18.
Eur J Vasc Endovasc Surg ; 29(3): 269-76, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15694800

RESUMO

An intact vascular endothelium is critical to the maintenance of normal arterial tone and coagulation status. Endothelial injury leading to dysfunction is thought to be a precursor to most if not all vascular disease, and has been implicated as a critical event in atherosclerosis. At present there are several methods available for detection of in vivo endothelial function, and the aim of this study was to critically review these methods. Five distinct methods were identified and studied in detail. These methods are diverse and each assesses a different vascular bed. Importantly there is no uniformity among investigators over choice of method and protocol, making it difficult to compare in vivo enothelial dysfunction between groups. These issues need to be addressed in large scale comparative analyses so that investigators can agree a common approach to endothelial function assessment.


Assuntos
Endotélio Vascular/fisiopatologia , Doenças Vasculares/diagnóstico , Doenças Vasculares/fisiopatologia , Artéria Braquial , Humanos , Iontoforese , Fluxometria por Laser-Doppler , Pletismografia , Pulso Arterial , Fluxo Sanguíneo Regional , Artéria Retiniana , Vasodilatação
19.
J Magn Reson ; 167(1): 161-7, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14987610

RESUMO

The effect of a distribution in the (1)H-(1)H dipolar coupling on (1)H double-quantum (DQ) magic angle spinning (MAS) nuclear magnetic resonance (NMR) spinning sideband patterns is considered. In disordered or amorphous materials a distribution in the magnitude of the (1)H-(1)H dipolar coupling is a realistic possibility. Simulations of the (1)H DQ MAS NMR spinning sideband spectra were performed with the two-spin approximation. These simulations reveal that a dipolar coupling distribution can greatly affect the DQ spectral shape and behavior of the DQ build-up. The spectral line shapes are quantified by measurement of the relative intensities of the DQ sidebands. These variations in the (1)H DQ NMR spectra are evaluated as a function of the width of the dipolar coupling distribution. As an example, the experimental DQ spinning sideband spectrum for a hydrated polyoxoniobate containing 15 H(2)O molecules per hexaniobate cluster, are better simulated with a distribution of dipolar couplings opposed to a single coupling constant.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Modelos Químicos , Modelos Estatísticos , Nióbio/análise , Nióbio/química , Sódio/análise , Sódio/química , Marcadores de Spin , Simulação por Computador , Prótons , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Pharmazie ; 58(3): 173-6, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12685811

RESUMO

Silymarin isolated from Silybum marianum is a mixture of three isomers, silybin (1), silydianin (2) and silychristin (3). Silybin is the most active antihepatotoxic agent, and contains a 1,4-dioxane ring in addition to a flavonoid moiety. Based on the skeleton of silybin, we prepared some flavones and coumarins containing the 1,4-dioxane ring system and evaluated them for antihepatotoxic activity against carbon tetrachloride induced hepatotoxicity in albino rats. The degree of protection was determined by measuring biochemical parameters such as serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvate transaminase (SGPT), alkaline phosphatase (ALKP), total protein (TP) and total albumin (TA). The compounds namely 3',4'(1",4"-dioxino) flavone (4f), and 3',4'(2-hydroxy methyl, 1",4"-dioxino) flavone (4g) were found to exhibit a significant activity comparable to standard drug silymarin (silybon-70). Other compounds also exhibited good activity. The structure activity relationship (SAR) was also studied, and where the flavonoid analogues containing a hydroxy methyl group at position-2" in the dioxane ring exhibited superior antihepatotoxic activity in comparison to coumarin derivatives.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Dioxanos/síntese química , Dioxanos/uso terapêutico , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/uso terapêutico , Animais , Intoxicação por Tetracloreto de Carbono/prevenção & controle , Feminino , Indicadores e Reagentes , Testes de Função Hepática , Espectroscopia de Ressonância Magnética , Masculino , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Ratos , Ratos Wistar , Silimarina/química , Silimarina/farmacologia
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