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1.
Transl Vis Sci Technol ; 10(12): 6, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34609477

RESUMO

Purpose: To evaluate a region of interest (ROI) method of analyzing anterior segment optical coherence tomography (AS-OCT) corneal densitometry (CD) in the setting of Descemet membrane endothelial keratoplasty (DMEK) dehiscence. Methods: Retrospective chart review of eyes that underwent (1) DMEK for Fuchs dystrophy (2) between 2018 to 2020 with (3) a partial DMEK dehiscence on AS-OCT, (4) involvement of only one side of the graft, (5) high-quality corneal AS-OCT scan, and (6) location of dehiscence within the central 5.5 mm of the cornea. Image analysis of the ROIs with ImageJ compared the total edematous area, mean stromal CD, and ratio of anterior-to-posterior (A/P) stromal CD for regions of DMEK dehiscence compared to the contralateral side with an attached DMEK graft. Control regions (with no dehiscence) and postdehiscence resolution images were also analyzed. Results: Seventy sectors of the 21 images from 21 eyes with DMEK dehiscence were included. Compared to the contralateral side, regions of DMEK dehiscence had larger total areas (P < 0.0001), lower mean stromal CD (P = 0.0003), and higher A/P stromal CD (P < 0.0001). All control regions and postdehiscence resolution images did not show any significant differences compared to the contralateral sides. Conclusions: This technique to analyze multiple ROIs on AS-OCT can be useful to evaluate CD of specific regions of corneal pathology. Lower mean stromal CD and higher A/P stromal CD may specify corneal edema. Translational Relevance: Analyzing CD via multiple specific ROIs may be more suitable than measuring the CD of the full cornea and has broader applications extending to other corneal pathologies.


Assuntos
Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior , Densitometria , Lâmina Limitante Posterior/diagnóstico por imagem , Estudos Retrospectivos , Tomografia de Coerência Óptica , Acuidade Visual
2.
Int J Mol Sci ; 22(18)2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34576223

RESUMO

Tuberous sclerosis complex (TSC) is a rare, multi-system genetic disease with serious neurological and mental symptoms, including autism. Mutations in the TSC1/TSC2 genes lead to the overactivation of mTOR signalling, which is also linked to nonsyndromic autism. Our aim was to analyse synaptic pathology in a transgenic model of TSC: two-month-old male B6;129S4-Tsc2tm1Djk/J mice with Tsc2 haploinsufficiency. Significant brain-region-dependent alterations in the expression of several synaptic proteins were identified. The most prominent changes were observed in the immunoreactivity of presynaptic VAMP1/2 (ca. 50% increase) and phospho-synapsin-1 (Ser62/67) (ca. 80% increase). Transmission electron microscopy demonstrated serious ultrastructural abnormalities in synapses such as a blurred structure of synaptic density and a significantly increased number of synaptic vesicles. The impairment of synaptic mitochondrial ultrastructure was represented by excessive elongation, swelling, and blurred crista contours. Polyribosomes in the cytoplasm and swollen Golgi apparatus suggest possible impairment of protein metabolism. Moreover, the delamination of myelin and the presence of vacuolar structures in the cell nucleus were observed. We also report that Tsc2+/- mice displayed increased brain weights and sizes. The behavioural analysis demonstrated the impairment of memory function, as established in the novel object recognition test. To summarise, our data indicate serious synaptic impairment in the brains of male Tsc2+/- mice.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Sinapses , Animais , Animais Geneticamente Modificados , Transtorno do Espectro Autista/genética , Comportamento Animal , Encéfalo/fisiologia , Núcleo Celular/metabolismo , Cerebelo/metabolismo , Córtex Cerebral/metabolismo , Densitometria , Haploinsuficiência , Hipocampo/metabolismo , Masculino , Camundongos , Microscopia Eletrônica de Transmissão , Tamanho do Órgão , Fosforilação , RNA Mensageiro/metabolismo , Reconhecimento Psicológico , Transdução de Sinais , Esclerose Tuberosa/metabolismo , Proteína 2 do Complexo Esclerose Tuberosa/genética
3.
J Chromatogr A ; 1655: 462488, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34474191

RESUMO

A densitometry method based on steady-state and time-resolved fluorescence assessments for thioridazine and its photoproducts applied on HPTLC plates has been developed. The excitation source was a picosecond diode laser emitting at 375 nm. This method was used for the analysis of the photoproducts resulted from thioridazine irradiation with 266 nm nanosecond-pulsed laser. The validation of the developed method was performed for thioridazine in terms of linearity, precision, limits of detection and quantification. Furthermore, analysis of the photoproducts of irradiated thioridazine was performed by steady-state and time-resolved fluorescence. The fluorescence spectra and fluorescence lifetime of each photoproduct were obtained and the horizontal chromatograms of fluorescence maxima were generated.


Assuntos
Lasers , Tioridazina , Cromatografia em Camada Delgada , Densitometria
4.
Transl Vis Sci Technol ; 10(9): 32, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34436543

RESUMO

Purpose: To enhance the current standards of subclinical keratoconus screening based on the statistical modeling of the pixel intensity distribution of Scheimpflug images. Methods: Scheimpflug corneal tomographies corresponding to 25 corneal meridians of 60 participants were retrospectively collected and divided into three groups: controls (20 eyes), subclinical keratoconus (20 eyes), and clinical keratoconus (20 eyes). Only right eyes were selected. After corneal segmentation, pixel intensities of the stromal tissue were statistically modeled using a Weibull probability density function from which parameter α (pixel brightness) was derived. Further, data were transformed to polar coordinates, smoothed, and interpolated to build a map of the corneal α parameter. The discriminative power of the method was analyzed using receiver operating characteristic curves. Results: The proposed platform-independent method achieved a higher performance in discriminating subclinical keratoconus from control eyes (90.0% sensitivity, 95.0% specificity, 0.97 area under the curve [AUC]) than the standard method (Belin-Ambrósio enhanced ectasia display), which uses only corneal morphometry (85.0% sensitivity, 85.0% specificity, 0.80 AUC). Conclusions: Analysis of light backscatter at the cornea successfully discriminates subclinical keratoconus from control eyes, upgrading the results previously reported in the literature. Translational Relevance: The proposed methodology has the potential to support clinicians in the detection of keratoconus before showing clinical signs.


Assuntos
Ceratocone , Córnea/diagnóstico por imagem , Paquimetria Corneana , Topografia da Córnea , Densitometria , Humanos , Ceratocone/diagnóstico , Estudos Retrospectivos , Sensibilidade e Especificidade
5.
Molecules ; 26(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208193

RESUMO

Metronidazole is a drug widely used in the prevention and treatment of bacterial infections. Due to its possibility of the formation of stable metal complexes, it was decided to broaden its activity spectrum by introducing the silver(I) coordination compounds i.e., [Ag(MTZ)2NO3] and [(Ag(MTZ)2)2]SO4, which have significant antibacterial properties. The paper presents a description of a new qualitative and quantitative analysis of metronidazole in bulk and possible pharmaceutical preparations by thin-layer chromatography with densitometric detection. Optimal separation conditions were selected, and the analytical procedure was validated according to the ICH guidelines. The obtained data indicate that the method is sufficiently sensitive, precise, and accurate. The stability of the metronidazole solutions obtained from tablets, pure metronidazole, and its silver(I) complexes was tested. The research was carried out in various environments, at different temperatures, in H2O2 solution, and during exposure to radiation (UV, sunlight). The greatest degradation was found in the alkaline environment and at higher temperatures. The silver(I) complexes exhibited relatively high stability under analyzed conditions that are higher than standard metronidazole solutions and tablets. The observations were confirmed by the kinetic and thermodynamic analysis. The described studies of new metronidazole silver(I) complexes increase the potential for their application in infections both in humans and animals.


Assuntos
Antibacterianos/química , Complexos de Coordenação/química , Peróxido de Hidrogênio/química , Metronidazol/química , Compostos de Prata/química , Animais , Cromatografia em Camada Delgada/métodos , Densitometria/métodos , Estabilidade de Medicamentos , Humanos , Cinética , Comprimidos
6.
Photodiagnosis Photodyn Ther ; 35: 102423, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34197969

RESUMO

BACKGROUND: To compare the optical densitometric changes in the lens of patients with renal transplantation with those of a healthy group using Pentacam HR. METHODS: Twenty-four right eyes of 24 healthy patients (Group 1) were compared with 24 right eyes of 24 kidney transplant recipients. Kidney transplant recipients were evaluated thrice (preoperatively: Group 2a, postoperative 1st month: Group 2b, postoperative 12th month: Group 2c). Corneal endothelial cell count, intraocular pressure, and central corneal thickness of all participants were measured. Lens optical densitometry was measured with Pentacam HR using 3D scanning mode. The optical density of the lens was analyzed by taking the corneal apex as the center and analysing the 12 mm diameter area. (Zone 1: 2.0 mm, Zone 2: 4.0 mm, and Zone 3: 6.0 mm). RESULTS: Corneal endothelial cell count was 2571.2±106.7 cells/mm2 in Group 1 and 2462.8±127.6 cells/mm2 in Group 2a (p=0.001). For lens optical densities, significant differences were observed between the groups in Zone 1 and Zone 3, but the difference in Zone 2 was not significant (p=0.003, p=0.164, p=0.009, respectively). There was a positive correlation between dialysis time and preoperative lens optical densitometry in Zone 1, Zone 2, and Zone 3 (r= 0.496, r= 0.131, r= 0.463, respectively). CONCLUSIONS: Although a decrease in lens transparency was observed after kidney transplantation, steroids may cause an increase in lens transparency in the postoperative period. Patients with renal transplantation should be followed closely for possible lens changes in the post-transplant period.


Assuntos
Transplante de Rim , Fotoquimioterapia , Córnea , Densitometria , Humanos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes , Estudos Prospectivos
7.
PLoS One ; 16(7): e0254370, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34252119

RESUMO

PURPOSE: Lens opacification is a common complication after pars plana vitrectomy (PPV) and knowing its progression would facilitate consulting patients. The purpose of this study was to evaluate a quantitative model for lens-status-monitoring after PPV with C3F8 gas. Our model was evaluated in rhegmatogenous retinal detachment (RRD) patients of various age and lens densitometry (LD). METHODS: Data between March 2018 and March 2020 were evaluated retrospectively. LD measurements of the PentacamHR® Nucleus Staging mode (PNS) were used to quantify lens opacification over time. A mixed-effect regression model was designed, to enable LD predictions at any time postoperatively. Calculations were based on patient's age and baseline LD as dependent variables. Six patients were randomly excluded during model development, to be used for testing its power afterwards. RESULTS: 34 patients (male 19 [55.9%], female 15 [44.1%]) matched the inclusion criteria. Average age was 58.5 years (32-77;±4.3) and average follow-up was 7.2 months (3,4-23.1;±1,8). Mean baseline LD of the treated and fellow eye before surgery were 10.9% (8.7%-14.8%;±0.8) and 10.7% (8.5%-14.1%;±0.6), respectively. Using our prediction model, LD values for the six pre-selected patients closely match the observed data with an average deviation of 1.07%. CONCLUSIONS: Evaluation of age and baseline LD using a mixed-effect regression model might predict cataract progression in RRD patients treated with PPV and C3F8-gas. Such a tool could be considered during cataract surgery consultation in these patients.


Assuntos
Catarata/diagnóstico , Densitometria , Progressão da Doença , Cristalino/patologia , Descolamento Retiniano/cirurgia , Vitrectomia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios , Estatística como Assunto
8.
Optom Vis Sci ; 98(6): 592-596, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34081651

RESUMO

SIGNIFICANCE: Soft contact lens wear may lead to physiological changes in the cornea. Corneal densitometry is a new software tool that may detect these physiological changes by monitoring their effects on corneal transparency. PURPOSE: This study aimed to assess corneal densitometry values and corneal endothelium in patients using soft contact lenses. METHODS: The study included 36 eyes of 36 subjects with soft contact lens use (group 1) and 36 eyes of 36 healthy control subjects (group 2). Anterior segment parameters and corneal densitometry of all subjects were evaluated using Scheimpflug corneal topography (Pentacam; Oculus Inc., Wetzlar, Germany). A total corneal area of 12 mm was divided into four annular zones (0 to 2, 2 to 6, 6 to 10, and 10 to 12 mm) and into three regions as anterior, central, and posterior for densitometry examination. Cell density, cell distribution, and cell morphology (quadrangular, pentagonal, hexagonal, and other cell percentages) of the endothelial layer were examined in both groups using specular microscopy (Nidek CEM 530; Nidek Co., Gamagori, Aichi, Japan). RESULTS: In group 1, the mean duration of contact lens wear was 4.45 ± 2.15 years. The anterior segment parameters were not significantly different between the two groups (P > .05). The anterior 0- to 2- and 2- to 6-mm corneal densitometry values were significantly higher in group 1 compared with group 2 (23.2 ± 4.7 for group 1 and 17.3 ± 5.6 for group 2 [P = .03]; 22.4 ± 6.4 for group 1 and 17.8 ± 1.4 for group 2 [P = .03], respectively). There were no significant differences between the groups for corneal densitometry values between 6 and 12 mm, or for cell density, cell distribution, and cell morphology (P > .05). CONCLUSIONS: Although the cornea remains transparent in soft contact lens wearers, corneal densitometry may increase in the 0- to 6-mm annular zone of the anterior region.


Assuntos
Lentes de Contato Hidrofílicas , Córnea , Lentes de Contato Hidrofílicas/efeitos adversos , Córnea/diagnóstico por imagem , Topografia da Córnea , Densitometria , Endotélio Corneano , Humanos
9.
Eur J Ophthalmol ; 31(6): 3505-3510, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34058904

RESUMO

OBJECTIVE: Evaluation of central corneal densitometry changes following Ferrara corneal ring segment implantation in patients with keratoconus, especially the correlation between corneal densitometry and keratometry. METHODS: Retrospective, non-comparative, interventional study based on the review of medical records of patients diagnosed with keratoconus who underwent Ferrara corneal ring segment implantation. Pre and post-operative corneal densitometry measurements obtained with Pentacam HR (Oculus, Wetzlar, Germany) were analyzed. The follow-up time was 3 months, and data comparison was made, using specific statistical analysis, with the data of 3 months postoperatively. RESULTS: The study sample consisted of 43 eyes of 36 patients. The mean corrected visual acuity improved from 0.82 LogMAR preoperatively (SD ± 0.33) to 0.19 LogMAR (SD ± 0.13) postoperatively. The mean spherical equivalent varied from -4.63 (SD ± 3.94) preoperatively to -2.16 (SD ± 2.63) postoperatively. Asphericity varied from -0.69 (SD ± 0.32) preoperatively to -0.27 (SD ± 0.31) postoperatively. The mean maximum K was 54.01D (SD ± 3.38) preoperatively and 51.50D (SD ± 2.90) postoperatively. The mean anterior densitometric value was 18.26 (SD ± 2.03) preoperatively and 17.66 (SD ± 1.84) postoperatively. CONCLUSION: Corneal densitometry is an interesting technology that should be studied in keratoconus patients. Our results suggest that the corneal densitometry in the cornea's anterior layer reduces after ICRS implantation and correlates with corneal keratometry. Further studies should be performed to increase the knowledge in this field.


Assuntos
Ceratocone , Córnea/diagnóstico por imagem , Substância Própria/diagnóstico por imagem , Substância Própria/cirurgia , Topografia da Córnea , Densitometria , Humanos , Ceratocone/cirurgia , Próteses e Implantes , Implantação de Prótese , Refração Ocular , Estudos Retrospectivos , Acuidade Visual
10.
Phys Med ; 85: 63-71, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33971530

RESUMO

PURPOSE: To train and validate a predictive model of mortality for hospitalized COVID-19 patients based on lung densitometry. METHODS: Two-hundred-fifty-one patients with respiratory symptoms underwent CT few days after hospitalization. "Aerated" (AV), "consolidated" (CV) and "intermediate" (IV) lung sub-volumes were quantified by an operator-independent method based on individual HU maximum gradient recognition. AV, CV, IV, CV/AV, IV/AV, and HU of the first peak position were extracted. Relevant clinical parameters were prospectively collected. The population was composed by training (n = 166) and validation (n = 85) consecutive cohorts, and backward multi-variate logistic regression was applied on the training group to build a CT_model. Similarly, models including only clinical parameters (CLIN_model) and both CT/clinical parameters (COMB_model) were developed. Model's performances were assessed by goodness-of-fit (H&L-test), calibration and discrimination. Model's performances were tested in the validation group. RESULTS: Forty-three patients died (25/18 in training/validation). CT_model included AVmax (i.e. maximum AV between lungs), CV and CV/AE, while CLIN_model included random glycemia, C-reactive protein and biological drugs (protective). Goodness-of-fit and discrimination were similar (H&L:0.70 vs 0.80; AUC:0.80 vs 0.80). COMB_model including AVmax, CV, CV/AE, random glycemia, biological drugs and active cancer, outperformed both models (H&L:0.91; AUC:0.89, 95%CI:0.82-0.93). All models showed good calibration (R2:0.77-0.97). Despite several patient's characteristics were different between training and validation cohorts, performances in the validation cohort confirmed good calibration (R2:0-70-0.81) and discrimination for CT_model/COMB_model (AUC:0.72/0.76), while CLIN_model performed worse (AUC:0.64). CONCLUSIONS: Few automatically extracted densitometry parameters with clear functional meaning predicted mortality of COVID-19 patients. Combined with clinical features, the resulting predictive model showed higher discrimination/calibration.


Assuntos
COVID-19 , Densitometria , Humanos , Pulmão , Estudos Retrospectivos , SARS-CoV-2 , Tomografia Computadorizada por Raios X
11.
Biomed Chromatogr ; 35(11): e5154, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33955025

RESUMO

A selective and simple salting-out-assisted thin-layer chromatographic methodology was developed for the simultaneous determination of two oral hypoglycemic drugs, dapagliflozin (DAPA) and metformin (MET) in their pure forms, tablets and spiked human plasma samples. Silica gel 60 F254 plates were used in the separation of the two drugs using a mobile phase consisting of 0.5 m (NH4 )2 SO4 and methanol (3:7, v/v). The plates were scanned in the reflectance mode at λmax = 237 nm. The obtained retardation factor (Rf ) values for DAPA and MET were 0.77 ± 0.02 and 0.25 ± 0.02, respectively. The thin-layer chromatography method was validated according to International Conference on Harmonization guidelines. The peak areas were linearly increased with the increases in concentrations of 45-1,000 and 50-1,500 ng/band for DAPA and MET, respectively. Moreover, the method was applied to estimate the molecular lipophilicity parameters of DAPA and MET via retention data. The suggested method was efficiently utilized for the analysis of DAPA and MET in pharmaceutical tablets and plasma samples with recoveries 98.4-100.4 and RSDs in the ranges of 1.4-2.6 and 2.2-3.0% for DAPA and MET, respectively.


Assuntos
Cromatografia em Camada Delgada/métodos , Hipoglicemiantes/análise , Hipoglicemiantes/química , Compostos Benzidrílicos/análise , Compostos Benzidrílicos/química , Densitometria , Glucosídeos/análise , Glucosídeos/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção , Modelos Lineares , Metformina/análise , Metformina/química , Reprodutibilidade dos Testes , Comprimidos/química
12.
J Chromatogr Sci ; 59(6): 576-583, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-33822903

RESUMO

A high-performance thin-layer chromatographic method was developed and validated for the concurrent determination of simeprevir (SMV) and sofosbuvir (SOF). The chromatographic separation was attained on silica gel 60 F254 as stationary phase and ethyl acetate-hexane-methanol (5.0:4.0:1.0, v/v/v) as developing solvent with UV detection at 273 nm. The RF values were 0.67±0.02 and 0.43±0.02 for SMV and SOF, respectively. The method has been validated in respect to the guidelines of the International Conference on Harmonization. Linearity was maintained between 60-1,000 and 70-1,200 ng/band for SMV and SOF, respectively, with good correlation coefficients (0.9993-0.9997) for both drugs. The suggested method was highly sensitive as the calculated detection limits were 15 and 22 ng/band, while the quantitation limits were 44 and 66 ng/ band for SMV and SOF, respectively. The suggested methodology has been effectively employed for the determination of the mentioned drugs in their pure forms and their pharmaceutical dosage forms as well as human plasma without significant interference of the pharmaceutical excipients or plasma components.


Assuntos
Antivirais/sangue , Cromatografia em Camada Delgada/métodos , Simeprevir/sangue , Sofosbuvir/sangue , Antivirais/análise , Cápsulas , Densitometria/métodos , Hepatite C/tratamento farmacológico , Humanos , Limite de Detecção , Simeprevir/análise , Sofosbuvir/análise
13.
Int J Clin Pract ; 75(7): e14234, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33872447

RESUMO

PURPOSE: To investigate the corneal topography and densitometry changes in patients with lichen planus (LP). METHODS: Anterior segment parameters and corneal densitometry of patients with LP and age- and gender-matched individuals with healthy eyes were evaluated using Scheimpflug corneal topography. A 12 mm corneal area was divided into 4 annular zones and 3 regions-in-depth anterior, central and posterior-for densitometry evaluation. RESULTS: The study included 45 patients with LP and 50 individuals with healthy eyes. The two groups were similar in age and gender, and they showed no significant differences in anterior segment corneal topography parameters. Schirmer's I test results were significantly lower in the patients with LP than in the control group (P Ë‚ .001). The total corneal densitometry was higher in patients with LP than in the control group (P = .030). The anterior, central and posterior corneal densitometry in the 0-2 mm and 2-6 mm annular zones was higher in the LP group than in the control group. Correlation analysis between disease duration and corneal densitometry values showed a strong positive correlation in the anterior segment and a moderate positive correlation in the central and posterior segments (r = 0.632, P Ë‚ .001; r = 0.572, P Ë‚ .001; and r = 0.562, P Ë‚ .001, respectively). CONCLUSIONS: Corneal densitometry values were higher in patients with LP than in individuals with healthy eyes, even if the patients had a clinically transparent cornea. More studies are needed to evaluate the changes that may occur in corneal transparency in patients with LP and other autoimmune dermatologic diseases that may affect the eye.


Assuntos
Córnea , Líquen Plano , Córnea/diagnóstico por imagem , Topografia da Córnea , Densitometria , Humanos , Líquen Plano/diagnóstico
14.
Nutrients ; 13(4)2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33806245

RESUMO

Whilst the assessment of body composition is routine practice in sport, there remains considerable debate on the best tools available, with the chosen technique often based upon convenience rather than understanding the method and its limitations. The aim of this manuscript was threefold: (1) provide an overview of the common methodologies used within sport to measure body composition, specifically hydro-densitometry, air displacement plethysmography, bioelectrical impedance analysis and spectroscopy, ultra-sound, three-dimensional scanning, dual-energy X-ray absorptiometry (DXA) and skinfold thickness; (2) compare the efficacy of what are widely believed to be the most accurate (DXA) and practical (skinfold thickness) assessment tools and (3) provide a framework to help select the most appropriate assessment in applied sports practice including insights from the authors' experiences working in elite sport. Traditionally, skinfold thickness has been the most popular method of body composition but the use of DXA has increased in recent years, with a wide held belief that it is the criterion standard. When bone mineral content needs to be assessed, and/or when it is necessary to take limb-specific estimations of fat and fat-free mass, then DXA appears to be the preferred method, although it is crucial to be aware of the logistical constraints required to produce reliable data, including controlling food intake, prior exercise and hydration status. However, given the need for simplicity and after considering the evidence across all assessment methods, skinfolds appear to be the least affected by day-to-day variability, leading to the conclusion 'come back skinfolds, all is forgiven'.


Assuntos
Absorciometria de Fóton/métodos , Atletas , Composição Corporal , Pregas Cutâneas , Densitometria , Impedância Elétrica , Humanos , Pletismografia , Reprodutibilidade dos Testes , Análise Espectral , Esportes , Ultrassonografia
15.
Int J Mol Sci ; 22(9)2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33925417

RESUMO

Craniofacial neuropathic pain affects millions of people worldwide and is often difficult to treat. Two key mechanisms underlying this condition are a loss of the negative control exerted by inhibitory interneurons and an early microglial reaction. Basic features of these mechanisms, however, are still poorly understood. Using the chronic constriction injury of the infraorbital nerve (CCI-IoN) model of neuropathic pain in mice, we have examined the changes in the expression of GAD, the synthetic enzyme of GABA, and GlyT2, the membrane transporter of glycine, as well as the microgliosis that occur at early (5 days) and late (21 days) stages post-CCI in the medullary and upper spinal dorsal horn. Our results show that CCI-IoN induces a down-regulation of GAD at both postinjury survival times, uniformly across the superficial laminae. The expression of GlyT2 showed a more discrete and heterogeneous reduction due to the basal presence in lamina III of 'patches' of higher expression, interspersed within a less immunoreactive 'matrix', which showed a more substantial reduction in the expression of GlyT2. These patches coincided with foci lacking any perceptible microglial reaction, which stood out against a more diffuse area of strong microgliosis. These findings may provide clues to better understand the neural mechanisms underlying allodynia in neuropathic pain syndromes.


Assuntos
Microglia/metabolismo , Neuralgia/etiologia , Corno Dorsal da Medula Espinal/metabolismo , Animais , Comportamento Animal , Proteínas de Ligação ao Cálcio/metabolismo , Densitometria , Modelos Animais de Doenças , Proteínas da Membrana Plasmática de Transporte de Glicina/metabolismo , Hiperalgesia/etiologia , Masculino , Nervo Maxilar/lesões , Camundongos Endogâmicos C57BL , Proteínas dos Microfilamentos/metabolismo , Microglia/patologia , Corno Dorsal da Medula Espinal/patologia , Núcleo Inferior Caudal do Nervo Trigêmeo/metabolismo , Núcleo Inferior Caudal do Nervo Trigêmeo/patologia
16.
Cornea ; 40(4): 449-452, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33881810

RESUMO

PURPOSE: To determine which baseline characteristics are associated with vision-related quality of life (QOL) after endothelial keratoplasty. METHODS: A patient- and outcome-masked randomized clinical trial. Consecutive patients presenting with isolated endothelial disease requiring endothelial keratoplasty at Oregon Health Sciences University and Stanford University. Study eyes randomized to one of the 2 types of endothelial keratoplasty were given the national eye institute vision function questionnaire 25 at baseline and 12 months. In this prespecified secondary outcome, we assessed the role of recipient and donor characteristics as predictors of the 12-month national eye institute vision function questionnaire 25 change score. RESULTS: The mean vision function questionnaire (VFQ) score was 74 (SD 14) at baseline and increased to 82 (SD 12) at 3 months and 87 (SD 10) at 12 months. We were unable to find a difference in vision-related QOL in study participants who underwent Descemet membrane endothelial keratoplasty compared with ultrathin Descemet stripping endothelial keratoplasty [coef -0.98, 95% confidence interval (CI) -9.27 to 7.31; P = 0.82]. In multivariable analysis, patients who underwent endothelial keratoplasty in 2 eyes had approximately 8 points higher VFQ at 12 months after the second eye than those who had only one eye enrolled (95% CI 0.10-15.72; P = 0.047). Posterior densitometry produced an approximately 1-point increase each in the VFQ change score for each 1 grayscale unit increase at baseline (95% CI 0.26-1.81; P = 0.009). Although the sample size was small, a diagnosis of pseudophakic bullous keratopathy had approximately 19-points more improvement on average compared with Fuchs (95% CI 7.68-30.00; P = 0.001). CONCLUSIONS: Bilateral endothelial keratoplasty resulted in higher vision-related QOL compared with unilateral. Baseline densitometry, objective measure of corneal haze that predicts vision-related QOL, may play a role in monitoring disease progression.


Assuntos
Córnea/fisiopatologia , Distrofias Hereditárias da Córnea/cirurgia , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior/métodos , Qualidade de Vida/psicologia , Visão Ocular/fisiologia , Acuidade Visual/fisiologia , Idoso , Distrofias Hereditárias da Córnea/fisiopatologia , Distrofias Hereditárias da Córnea/psicologia , Aberrações de Frente de Onda da Córnea/fisiopatologia , Densitometria , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Inquéritos e Questionários , Resultado do Tratamento
17.
Int Ophthalmol ; 41(8): 2667-2676, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33754236

RESUMO

AIM: To evaluate corneal and crystalline lens densitometry in patients with vernal keratoconjunctivitis (VKC). METHODS: This is a case-control study. Patients with VKC and age-gender-matched healthy controls underwent a complete ophthalmologic examination with corneal and crystalline lens densitometry measurements. Additionally, the anterior chamber parameters comprise anterior and posterior Kmean and astigmatism, anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), pachymeter, and corneal volume (CV). Patients who had clinically grade 0 or grade 1 VKC and with only tarsal conjunctiva involvement during the conductance of the study were included. The variables were compared statistically. RESULTS: One hundred and nine eyes were included in the study, in which fifty-one were in the VKC group. There were 25 males in the VKC group (26 female) and 22 males in the control group (36 female). A statistically significant difference was found between the groups in terms of posterior corneal astigmatism (p = 0.02). The mean corneal pachymeter, CV, ACD, ACA, and ACV were similar in both groups (p = 0.63, p = 0.26, p = 0.60, p = 0.41, and p = 0.32, respectively). The total mean corneal densitometry in the zones extending from 6 to 10 mm and 10 to 12 mm was increased in the VKC group compared to the control group (p = 0.04 and p = 0.012, respectively). The mean crystalline lens was found to be denser in the VKC group compared to the control group (8.96 ± 1.6 vs. 8.5 ± 0.57, respectively, p = 0.04). CONCLUSION: Posterior corneal astigmatism is increased in VKC cases in comparison with age- and gender-matched controls. The peripheral anterior 6-12 mm annular corneal zone showed increased corneal densitometry in VKC cases compared to the healthy subjects. Additionally, the lens clarity is found to be decreased subclinically in VKC cases compared to control cases.


Assuntos
Conjuntivite Alérgica , Cristalino , Estudos de Casos e Controles , Conjuntivite Alérgica/complicações , Conjuntivite Alérgica/diagnóstico , Córnea , Densitometria , Feminino , Humanos , Masculino
18.
Int J Biol Macromol ; 177: 221-228, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33609578

RESUMO

The objective of present research was to develop an easy, precise and accurate HPTLC densitometry method for quantification of fructooligosaccharides (FOSs) from inulin hydrolysate. The chromatographic separation of FOSs was performed on pre-coated silica gel (60, F254) TLC plates using a mobile phase (butanol:ethanol:water, 60:24:16), and densitometry evaluation of FOSs was performed at A500. Both kestose and nystose were successfully resolved with Rf value of 0.43 and 0.34, respectively. The accuracy, reliability and reproducibility of developed method was assessed by percent relative standard deviation of kestose and nystose for instrument precision (1.43% and 1.50%), repeatability (1.48% and 1.56%), intra-day precision (1.60% and 1.63%), inter-day precision (1.62% and 1.66%), limit of detection (4.58 ng/spot and 4.58 ng/spot), limit of quantification (13.87 ng/spot and 13.89 ng/spot) and recovery (98.81% and 98.69%). Moreover, overlapping spectra of test sample with standard confirms the specificity of developed method, which was validated as per ICH guidelines.


Assuntos
Densitometria , Inulina/química , Oligossacarídeos/análise
19.
J AOAC Int ; 104(4): 975-982, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-33560299

RESUMO

BACKGROUND: Paracetamol (PC) is one of the most widely used analgesic and antipyretic drugs and has recently been integrated into the supportive therapy of COVID-19. Pharmaceuticals containing methionine (MT) with PC may contribute to avoid hepatotoxicity and eventual PC overdose-dependent death. OBJECTIVE: The current work purposes to develop and validate two chromatographic methods for the simultaneous determination of MT and PC in the presence of two PC impurities (4-nitrophenol [NP] and 4-aminophenol [AP]). METHOD: Two chromatographic methods were established and validated according to the International Conference on Harmonization guidelines. The first one was an RP-HPLC/UV method based on applying a "dual-mode" gradient elution. The separation was realized via varying both the composition of the ternary mobile phase (acetonitrile-methanol-water) and its flow rate. This strategy enabled a relatively rapid analysis with a satisfactory resolution, although the investigated compounds exhibit a significant difference in lipophilicity. The second one relied on TLC-densitometry, where the optimum separation was realized using a quaternary mobile phase system composed of butanol-dioxane-toluene-methanol (8:2.5:3.5:0.3, by volume). Both methods were monitored at 220 nm. RESULTS: The developed methods were proven to be robust, accurate, specific, and appropriate for the routine analysis of PC in its pure form or in pharmaceutical formulations with MT in quality control laboratories. CONCLUSIONS: The corresponding methods are suitable to determine MT and PC in the presence of PC impurities. HIGHLIGHTS: The study achieves the analysis of MT and PC in the presence of PC impurities via the application of HPLC and TLC-densitometry methods.


Assuntos
Acetaminofen , COVID-19 , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Delgada , Densitometria , Humanos , Metionina , Reprodutibilidade dos Testes , SARS-CoV-2
20.
Arch Osteoporos ; 16(1): 23, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33528678

RESUMO

Latin America and the Caribbean region account for 8% of the world's total population. Experts from 18 countries were invited to contribute to this article to provide the best available data on the number, types, and quality of densitometry, DXA experts, the local/national incidence and prevalence of osteoporosis and fragility fractures, and other uses and information on the challenges and opportunities for quality densitometry with examples of local initiatives. Osteoporosis is the primary reason for densitometry in our region, which is not a priority for public health in most countries. Access and quality are major challenges, and there is a clear trend to concentrate on densitometry services in the largest cities. Urgent action is needed to face the rapidly increasing burden of osteoporosis in our region, including robust and up to date epidemiology, access to health professionals, and quality densitometry. Health professionals require better access to training, courses, and other activities at a more local or regional level.


Assuntos
Osteoporose , Região do Caribe , Densitometria , Humanos , Incidência , América Latina/epidemiologia , Osteoporose/diagnóstico por imagem , Osteoporose/epidemiologia
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