RESUMO
Reconstituted high-density lipoproteins (rHDLs) can transport and specifically release drugs and imaging agents, mediated by the Scavenger Receptor Type B1 (SR-B1) present in a wide variety of tumor cells, providing convenient platforms for developing theranostic systems. Usually, phospholipids or Apo-A1 lipoproteins on the particle surfaces are the motifs used to conjugate molecules for the multifunctional purposes of the rHDL nanoparticles. Cholesterol has been less addressed as a region to bind molecules or functional groups to the rHDL surface. To maximize the efficacy and improve the radiolabeling of rHDL theranostic systems, we synthesized compounds with bifunctional agents covalently linked to cholesterol. This strategy means that the radionuclide was bound to the surface, while the therapeutic agent was encapsulated in the lipophilic core. In this research, HYNIC-S-(CH2)3-S-Cholesterol and DOTA-benzene-p-SC-NH-(CH2)2-NH-Cholesterol derivatives were synthesized to prepare nanoparticles (NPs) of HYNIC-rHDL and DOTA-rHDL, which can subsequently be linked to radionuclides for SPECT/PET imaging or targeted radiotherapy. HYNIC is used to complexing 99mTc and DOTA for labeling molecules with 111, 113mIn, 67, 68Ga, 177Lu, 161Tb, 225Ac, and 64Cu, among others. In vitro studies showed that the NPs of HYNIC-rHDL and DOTA-rHDL maintain specific recognition by SR-B1 and the ability to internalize and release, in the cytosol of cancer cells, the molecules carried in their core. The biodistribution in mice showed a similar behavior between rHDL (without surface modification) and HYNIC-rHDL, while DOTA-rHDL exhibited a different biodistribution pattern due to the significant reduction in the lipophilicity of the modified cholesterol molecule. Both systems demonstrated characteristics for the development of suitable theranostic platforms for personalized cancer treatment.
Assuntos
Nanopartículas , Medicina de Precisão , Animais , Camundongos , Distribuição Tecidual , Benzeno , Lipoproteínas HDL/metabolismo , Nanopartículas/uso terapêutico , Colesterol/metabolismo , Lipoproteínas/metabolismo , Radioisótopos , Fosfolipídeos , Receptores Depuradores/metabolismoRESUMO
Cutaneous malakoplakia is a rare infection-related granulomatous disease frequently associated with immunocompromised states. Foamy macrophages containing basophilic granules, called the Michaelis-Gutman bodies, are pathognomonic. We report a case of cutaneous malakoplakia in a 77-year-old male with pyoderma gangrenosum and a 2-year history of a non-healing malleolar ulcer treated successfully with cotrimoxazole.
Assuntos
Hospedeiro Imunocomprometido , Malacoplasia/tratamento farmacológico , Malacoplasia/etiologia , Pioderma Gangrenoso/complicações , Pioderma Gangrenoso/tratamento farmacológico , Administração Cutânea , Idoso , Humanos , Masculino , Resultado do TratamentoRESUMO
Parkinsonia aculeata L. (Caesalpiniaceae) is a traditional ethnomedicine and has been used for the empiric treatment of hyperglycemia, without scientific background. Mechanistic analyses at molecular level from the antioxidant mechanism observed by P. aculeata are required. Herein the effects of the treatment by hydroethanolic extract partitioned with ethyl acetate of P. aculeata aerial parts (HEPa/EtOAc) in mice fed a high-fat diet that share many obesity phenotypes with humans were evaluated. The animals were treated orally with HEPa/EtOAc (125 and 250 mg/kg/day) and pioglitazone (5 mg/kg/day), for 16 days. After the treatment, HEPa/EtOAc reduced fasting serum glucose and insulin levels, as well as homeostasis model assessment for insulin resistance. In addition, an improvement in glucose intolerance was also observed. Indeed, a reduction in the circulating levels of TNF-α and IL-6 was also observed. Furthermore, at molecular level, it was demonstrated that the HEPa/EtOAc treatment was able to improve these physiological parameters, through the activation of peroxisome proliferator-activated receptor γ (PPARγ) per si, as well as the enhancement of antioxidant mechanism by an increase in PPARγ/Cu(2+), Zn(2+)-superoxide dismutase (CuZn-SOD) axis expression in liver and adipose tissue. In sum, P. aculeata is effective to improve insulin resistance in a mouse model of obesity and this effect seems to involve the antioxidant and anti-inflammatory mechanisms through the increase in PPARγ/CuZn-SOD axis expression.
Assuntos
Fabaceae/química , Regulação da Expressão Gênica/efeitos dos fármacos , Resistência à Insulina , Obesidade/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , PPAR gama/biossíntese , Extratos Vegetais/farmacologia , Superóxido Dismutase/biossíntese , Animais , Dieta/efeitos adversos , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Obesidade/induzido quimicamente , Obesidade/metabolismo , Obesidade/patologia , Extratos Vegetais/químicaRESUMO
BACKGROUND: Actinic keratosis (AK) lesions have the potential to develop into invasive squamous cell carcinomas (SCCs), and approaches to treatment are evolving to try to reduce the burden of SCC. OBJECTIVE: To present the published clinical research surrounding the use of 0.5% 5-fluorouracil with 10% salicylic acid (low-dose 5-FU/SA) for the treatment of hyperkeratotic AKs. METHOD: A review of published clinical evidence for low-dose 5-FU/SA for the treatment of AKs. The articles were selected following a MEDLINE database search of the combined terms fluorouracil, salicylic acid and actinic keratosis which represent the peer review publications of clinical studies that primarily investigate the use of Actikerall in AK. RESULTS: Combining low-dose 5-FU with keratolytic SA is associated with high rates of histologic clearance, reduction in lesion number/area, and sustained clinical response in clinical study and the clinical practice setting. Low-dose 5-FU/SA has also been evaluated using imaging to detect the progression of subclinical AK lesions through a course of the field-directed treatment. CONCLUSION: Low-dose 5-FU/SA is an effective and well-tolerated treatment option licensed for the lesion-directed treatment of mild-to-moderate hyperkeratotic AK lesions.
Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Fluoruracila/administração & dosagem , Ceratolíticos/administração & dosagem , Ceratose Actínica/tratamento farmacológico , Ácido Salicílico/administração & dosagem , Administração Cutânea , Combinação de Medicamentos , Humanos , SoluçõesRESUMO
Visual inspection may fail to accurately evaluate field cancerisation (subclinical actinic keratoses [AKs]). We aimed to describe field cancerisation by confocal reflectance microscopy and changes induced by the application of 3% diclofenac sodium gel in 2.5% hyaluronic acid. Fourteen male patients, > 50 years old, with AKs on the bald scalp were included. Clinical examination, confocal microscopy and histological study of clinically visible lesions and "normal appearing" adjacent skin before and after treatment was completed. Reflectance confocal microscopy showed a decrease in scaling (p = 0.001) and atypia of the honeycomb pattern (p = 0.001) at 2 weeks of treatment. Changes in parakeratosis, inflammation and dermal collagen remodelling were also observed. Histology correlated with confocal features in AK and subclinical AK. Reflectance confocal microscopy was useful in the evaluation of field cancerisation and monitoring of treatment response. A rapid improvement in epidermal atypia was observed.
Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Diclofenaco/administração & dosagem , Ácido Hialurônico/administração & dosagem , Ceratose Actínica/tratamento farmacológico , Microscopia Confocal/métodos , Microscopia de Interferência/métodos , Dermatoses do Couro Cabeludo/tratamento farmacológico , Couro Cabeludo/efeitos dos fármacos , Neoplasias Cutâneas/tratamento farmacológico , Administração Cutânea , Biópsia , Quimioterapia Combinada , Humanos , Ceratose Actínica/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Couro Cabeludo/patologia , Dermatoses do Couro Cabeludo/patologia , Neoplasias Cutâneas/patologia , Fatores de Tempo , Resultado do TratamentoRESUMO
All cases of MM diagnosed in 23 hospitals in Catalonia, from 2000 to 2007 were recorded and melanoma incidence calculated and adjusted for the European standard population via the direct method. The age standardised rate/100,000 inhabitants varied from 6.74 in 2000 to 8.64 in 2007 for all melanomas and from 4.79 to 5.80 for invasive MMs; the Breslow thickness was stable during the period. The increase in invasive melanoma incidence in the elderly was remarkable, the crude rate/100,000 inhabitants increasing from 11.04 (2000) to 15.49 (2007) in the 60-64 year population, while remaining more stable in the 30-34 year range, from 3.97 in 2000 to 4.55 in 2007, and with a tendency to decrease from 5.1 in 2000 to 2.5 in 2007 for the age range of 25-29 years. These lower age ranges are much more affected by immigration. Despite the large immigrant population (nearly one million immigrants arrived in Catalonia during the study period from countries with a low melanoma incidence), melanoma incidence in our region has risen considerably and this trend is likely to persist in the near future.
Assuntos
Melanoma/epidemiologia , Neoplasias Cutâneas/epidemiologia , Adulto , Distribuição por Idade , Idoso , Emigração e Imigração , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Espanha/epidemiologia , Adulto JovemRESUMO
Acral melanoma, which is not ultraviolet (UV)-associated, is the most common type of melanoma in several low- and middle-income countries including Mexico. Latin American samples are significantly underrepresented in global cancer genomics studies, which directly affects patients in these regions as it is known that cancer risk and incidence may be influenced by ancestry and environmental exposures. To address this, here we characterise the genome and transcriptome of 128 acral melanoma tumours from 96 Mexican patients, a population notable because of its genetic admixture. Compared with other studies of melanoma, we found fewer frequent mutations in classical driver genes such as BRAF, NRAS or NF1. While most patients had predominantly Amerindian genetic ancestry, those with higher European ancestry had increased frequency of BRAF mutations and a lower number of structural variants. These BRAF-mutated tumours have a transcriptional profile similar to cutaneous non-volar melanocytes, suggesting that acral melanomas in these patients may arise from a distinct cell of origin compared to other tumours arising in these locations. KIT mutations were found in a subset of these tumours, and transcriptional profiling defined three expression clusters; these characteristics were associated with overall survival. We highlight novel low-frequency drivers, such as SPHKAP, which correlate with a distinct genomic profile and clinical characteristics. Our study enhances knowledge of this understudied disease and underscores the importance of including samples from diverse ancestries in cancer genomics studies.
RESUMO
Overnutrition caused by overeating is associated with insulin and leptin resistance through IKKbeta activation and endoplasmic reticulum (ER) stress in the hypothalamus. Here we show that physical exercise suppresses hyperphagia and associated hypothalamic IKKbeta/NF-kappaB activation by a mechanism dependent upon the pro-inflammatory cytokine interleukin (IL)-6. The disruption of hypothalamic-specific IL-6 action blocked the beneficial effects of exercise on the re-balance of food intake and insulin and leptin resistance. This molecular mechanism, mediated by physical activity, involves the anti-inflammatory protein IL-10, a core inhibitor of IKKbeta/NF-kappaB signaling and ER stress. We report that exercise and recombinant IL-6 requires IL-10 expression to suppress hyperphagia-related obesity. Moreover, in contrast to control mice, exercise failed to reverse the pharmacological activation of IKKbeta and ER stress in C3H/HeJ mice deficient in hypothalamic IL-6 and IL-10 signaling. Hence, inflammatory signaling in the hypothalamus links beneficial physiological effects of exercise to the central action of insulin and leptin.
Assuntos
Anti-Inflamatórios/metabolismo , Retículo Endoplasmático/patologia , Proteínas I-kappa B/metabolismo , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Condicionamento Físico Animal/fisiologia , Animais , Anti-Inflamatórios/farmacologia , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Metabolismo Energético , Hiperfagia , Hipotálamo/fisiopatologia , Insulina/fisiologia , Interleucina-10/farmacologia , Interleucina-6/farmacologia , Leptina/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Ratos , Ratos WistarRESUMO
INTRODUCTION: The diagnosis of vitiligo is mainly based on clinical findings. However, dermoscopy or reflectance confocal microscopy (RCM) could be useful for assessing its progression (stability, pigmen-tation, or depigmentation). OBJECTIVES: To evaluate the correlation of dermatological findings by dermoscopy and RCM in pediatric vitiligo. METHODS: We conducted a cross-sectional, descriptive, and analytical clinical study. Pediatric patients with vitiligo of both sexes, aged > 1 year and < 18 years, with all spectrums of the disease were includ-ed. Vitiligo lesions were evaluated clinically, by dermoscopy, and microscopy. RESULTS: A total of 40 patients with vitiligo were included. Eight dermoscopic patterns were found: reduced/absent pigment network, perifollicular pigmentation, trichromic, tapioca sago, perifollicular depigmentation, starburst, leukotrichia, and erythema. Skin with a normal pigment network showed complete dermal papillary rings and half-rings. Skin with reduced/absent pigment network also had an absence of papillary rings or only showed half-rings and was more common in unstable vitiligo. The trichrome pattern only showed half-rings. The Tapioca sago pattern showed complete papillary rings and appeared in younger patients. Perifollicular pigmentation showed half-rings and complete rings and did not show associations. The diffuse borders did not present complete papillary structures. It was found that vitiligo duration time of fewer than 24 months (Odds Ratio 4.56, CI 1.09-18.99) and absent papillary rings (OR 2.75, CI 1.01-7.51) are associated with unstable prognosis. CONCLUSIONS: Certain dermatoscopic and microscopic findings, such as the reduction/absence of the pigment network, tapioca sago pattern, and absence of papillary rings, can be used to assess the stabil-ity of the disease and provide insight into the clinical behaviour of vitiligo.
RESUMO
Vitiligo is a chronic, acquired autoimmune pigmentary skin disease, most times it can be diagnosed clinically. Dermoscopy can confirm vitiligo in a non-invasive way. It is a diagnostic technique that visualizes sub-macroscopic morphological structures which correspond with specific histological structures. It detects subtle changes in the pigment pattern, evaluates vitiligo activity, attempts of re-pigmentation, leucotrichia, and differentiates it from other hypo pigmentary disorders. Most dermatoscopic clues used to assess vitiligo activity are found at the perifollicular level in the center and edge of the lesion. Perifollicular pigmentation is present in both active lesions and treated pigmented lesions with treatment. However, perifollicular depigmentation represents poor response, in treated lesions, and poor prognosis in untreated ones. The center of the lesion has reduced and/or absent pigment network, in active and stable lesions. If on dermoscopy the center of the lesion shows islands of pigment, erythema, or telangiectasias, re-pigmentation is suggested. At the periphery of the lesion, unstable vitiligo usually shows up as a diffuse border, trichrome pattern, micro-Koebner/comet tail phenomenon, satellite lesions, or a tapioca sago pattern. In stable lesions it is more frequent to find well defined or trichromic border. Pigmented lesions commonly present sharp borders and marginal or perilesional hyperpigmentation.
RESUMO
The gut has been suggested as the first organ to be affected by unbalanced diets contributing to the obesogenic process. This study aimed to test a short time-course exposition model to a known pro- or anti-inflammatory enriched fatty diet to understand the early gut alterations. Male mice were exposed to the chow diet (CT), high-fat (HF) diet, or a high-fat diet partially replaced on flaxseed oil (FS), rich in omega-3 (ω3), for 14 days. HF and FS increased the total body weight mass compared with the CT group, but FS reduced the epididymal fat depot compared to HF. The bioinformatics from mice and human databases showed the Zo1-Ocln-Cldn7 tight junctions as the main protein-triad. In the ileum, the HF diet has increased IL1ß transcript and IL1ß, TNFα, and CD11b proteins, but reduced the tight junctions (Zo1, Ocln, and Cld7) compared to the CT group. Despite the FS diet being partially efficient in protecting the ileum against inflammation, the tight junctions were increased, compared to the HF group. The GPR120 and GPR40 receptors were unaffected by diets, but GPR120 was colocalized on the surface of ileum macrophages. The short period of a high-fat diet was enough to start the obesogenic process, ileum inflammation, and reduce the tight junctions. Flaxseed oil did not protect efficiently against dysmetabolism. Still, it increased the tight junctions, even without alteration on inflammatory parameters, suggesting the protection against gut permeability during early obesity development.
Assuntos
Ácidos Graxos Ômega-3 , Óleo de Semente do Linho , Humanos , Masculino , Animais , Camundongos , Óleo de Semente do Linho/farmacologia , Junções Íntimas/metabolismo , Ácidos Graxos Insaturados , Inflamação/metabolismo , Dieta Hiperlipídica/efeitos adversos , Camundongos Endogâmicos C57BL , Ácidos GraxosRESUMO
Background Melanoma is an aggressive cutaneous cancer. Acral lentiginous melanoma is a melanoma subtype arising on palms, soles, and nail-units. The incidence, prevalence and prognosis differ among populations. The link between expression of major histocompatibility complex Class II alleles and melanoma progression is known. However, available studies report variable results regarding the association of melanoma with specific HLA Class II loci. Aims The aim of the study was to determine HLA Class II allele frequencies in acral lentiginous melanoma patients and healthy Mexican Mestizo individuals. Methods Eighteen patients with acral lentiginous melanoma and 99 healthy controls were recruited. HLA Class II typing was performed based on the sequence-specific oligonucleotide method. Results Three alleles were associated with increased susceptibility to develop acral lentiginous melanoma, namely: HLA-DRB1*13:01; pC = 0.02, odds ratio = 6.1, IC95% = 1.4-25.5, HLA-DQA1*01:03; pC = 0.001, odds ratio = 9.3, IC95% = 2.7-31.3 and HLA-DQB1*02:02; pC = 0.01, odds ratio = 3.7, IC95% = 1.4-10.3. Limitations The small sample size was a major limitation, although it included all acral lentiginous melanoma patients seen at the dermatology department of Dr. Manuel Gea González General Hospital during the study period. Conclusion HLA-DRB1*13:01, HLA-DQB1*02:02 and HLA-DQA*01:03 alleles are associated with increased susceptibility to develop acral lentiginous melanoma in Mexican Mestizo patients.
Assuntos
Melanoma , Alelos , Estudos de Casos e Controles , Cadeias HLA-DRB1 , Haplótipos , Humanos , Melanoma/diagnóstico , Melanoma/epidemiologia , Melanoma/genética , Neoplasias Cutâneas , Melanoma Maligno CutâneoAssuntos
Carcinoma Basocelular/patologia , Dermoscopia/métodos , Neoplasias Fibroepiteliais/patologia , Neoplasias Primárias Múltiplas/patologia , Neoplasias Cutâneas/patologia , Braço , Biópsia por Agulha , Carcinoma Basocelular/diagnóstico , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Fibroepiteliais/diagnóstico , Neoplasias Primárias Múltiplas/diagnóstico , Nevo Pigmentado/diagnóstico , Nevo Pigmentado/patologia , Doenças Raras , Neoplasias Cutâneas/diagnósticoRESUMO
Fibrous dysplasia, including McCune-Albright syndrome, is a genetic, non-inheritable benign bone disorder that may involve a single or multiple bone, typically occurring in the diaphysis or the metaphysis of long bones. In very rare instances polyostotic fibrous dysplasia present involvement of the epiphysis in long bones. Aneurysmal bone cysts are benign, expansile, lytic bone lesions formed by cystic cavities containing blood, that may occur de novo or secondary to other lesions of bone, including fibrous dysplasia. We report a case of an 18-year-old female with polyostotic fibrous dysplasia (McCune-Albright syndrome) with diaphyseal and unusual multiple foci of epiphyseal involvement of long bones as well as in the patella, and a simultaneous aneurysmal bone cyst of the left femoral neck with pathologic fracture. This is the first report of a simultaneous aneurysmal bone cyst in a patient with polyostotic fibrous dysplasia (McCune-Albright syndrome) with involvement of diaphysis and epiphysis of long bones, highlighting that fibrous dysplasia should be included in the differential diagnosis of polyostotic tumors involving the diaphysis as well as the epiphysis. In patients with polyostotic fibrous dysplasia there should be an active search for lesions in the epiphysis.
RESUMO
Obesity and insulin resistance (IR) are well-studied risk factors for systemic cardiovascular disease, but their impact on pulmonary hypertension (PH) is not well clarified. This study aims to investigate if diet-induced obesity induces PH and if peroxisome-proliferator-activated receptor (PPAR-γ) and/or endoplasmic reticulum (ER) stress are involved in this process. Mice were maintained on a high-fat diet (HFD) for 4 months, and IR and PH were confirmed. In a separate group, after 4 months of HFD, mice were treated with pioglitazone (PIO) or 4-phenylbutyric acid for the last month. The results demonstrated that HFD for at least 4 months is able to increase pulmonary artery pressure, which is maintained, and this animal model can be used to investigate the link between IR and PH, without changes in ER stress in the pulmonary artery. There was also a reduction in circulating adiponectin and in perivascular adiponectin expression in the pulmonary artery, associated with a reduction in PPAR-γ expression. Treatment with PIO improved IR and PH and reversed the lower expression of adiponectin and PPAR-γ in the pulmonary artery, highlighting this drug as potential benefit for this poorly recognized complication of obesity.
Assuntos
Dieta Hiperlipídica/efeitos adversos , Estresse do Retículo Endoplasmático , Hipertensão Pulmonar/patologia , Resistência à Insulina , Obesidade/complicações , PPAR gama/antagonistas & inibidores , Artéria Pulmonar/patologia , Animais , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , PPAR gama/genética , PPAR gama/metabolismo , Artéria Pulmonar/metabolismoRESUMO
Acral lentiginous melanoma is a histological subtype of cutaneous melanoma that occurs in the glabrous skin of the palms, soles and the nail unit. Although in some countries, particularly in Latin America, Africa and Asia, it represents the most frequently diagnosed subtype of the disease, it only represents a small proportion of melanoma cases in European-descent populations, which is partially why it has not been studied to the same extent as other forms of melanoma. As a result, its unique genomic drivers remain comparatively poorly explored, as well as its causes, with current evidence supporting a UV-independent path to tumorigenesis. In this review, we discuss current knowledge of the aetiology and diagnostic criteria of acral lentiginous melanoma, as well as its epidemiological and histopathological characteristics. We also describe what is known about the genomic landscape of this disease and review the available biological models to explore potential therapeutic targets.
Assuntos
Doenças do Pé/patologia , Melanócitos/patologia , Melanoma/patologia , Doenças da Unha/patologia , Neoplasias Cutâneas/patologia , HumanosRESUMO
OBJECTIVE: Fetal goitrous hypothyroidism is a rare and potentially lethal condition. Consequently, its early diagnosis and treatment improve prognosis. Thyroid hormone measurement in either fetal serum or amniotic fluid implies important risks. Here we present a fetal goiter and the follow-up procedure, both done by the traditional method and by using 3-dimensional power Doppler (3DPD) imaging and virtual organ computer-aided analysis (VOCAL). METHODS: A single well-documented case of fetal goiter was followed weekly from 22 weeks until delivery. Amniocentesis for thyrotropin (TSH) and free thyroxine (T(4)) measurement as well as levothyroxine injections were performed at every control. In addition to amniocentesis, every control involved a sonographic evaluation, which included standard measurements of the gland and the capture of volume image sets in gray scale and 3DPD. Volume calculation of the gland was done using VOCAL software. Vascularization of the gland was evaluated by the vascularization index (VI) included in the software. RESULTS: With treatment, TSH levels decreased progressively until normalization. Free T(4) levels increased toward the end of gestation. Sonographic measurements of the gland volume to estimated fetal weight ratio decreased across treatment as levels of TSH did. The VI clearly depicted the vascular regression of the goiter, decreasing throughout treatment in a consistent way until 24 hours before delivery. CONCLUSIONS: Gray scale and 3DPD evaluations of the thyroid gland have been validated under similar circumstances and might be reliable complements to the invasive methods used in the management of this fetal condition.
Assuntos
Doenças Fetais/diagnóstico por imagem , Bócio/diagnóstico por imagem , Hipotireoidismo/diagnóstico por imagem , Imageamento Tridimensional , Ultrassonografia Pré-Natal/métodos , Adulto , Amniocentese , Biomarcadores/análise , Diagnóstico Diferencial , Feminino , Humanos , Gravidez , Testes de Função TireóideaRESUMO
Light scattering is a fundamental property that can be exploited to create essential devices such as particle analysers. The most common particle size analyser relies on measuring the angle-dependent diffracted light from a sample illuminated by a laser beam. Compared to other non-light-based counterparts, such a laser diffraction scheme offers precision, but it does so at the expense of size, complexity and cost. In this paper, we introduce the concept of a new particle size analyser in a collimated beam configuration using a consumer electronic camera and machine learning. The key novelty is a small form factor angular spatial filter that allows for the collection of light scattered by the particles up to predefined discrete angles. The filter is combined with a light-emitting diode and a complementary metal-oxide-semiconductor image sensor array to acquire angularly resolved scattering images. From these images, a machine learning model predicts the volume median diameter of the particles. To validate the proposed device, glass beads with diameters ranging from 13 to 125 µm were measured in suspension at several concentrations. We were able to correct for multiple scattering effects and predict the particle size with mean absolute percentage errors of 5.09% and 2.5% for the cases without and with concentration as an input parameter, respectively. When only spherical particles were analysed, the former error was significantly reduced (0.72%). Given that it is compact (on the order of ten cm) and built with low-cost consumer electronics, the newly designed particle size analyser has significant potential for use outside a standard laboratory, for example, in online and in-line industrial process monitoring.