RESUMO
BACKGROUND: Vitamin A (VA) deficiency and excess negatively affect development, growth, and bone health. The World Health Organization's standard of care for xerophthalmia due to VA deficiency, is 3 high-dose VA supplements of 50,000-200,000 IU, based on age, which may cause hypervitaminosis A in some individuals. OBJECTIVES: This study measured VA status following 3 VA doses in 2 piglet studies. METHODS: In Study 1, 5 groups of piglets (n = 10/group) were weaned 10 d postbirth to VA-free feed and orally administered 0; 25,000; 50,000; 100,000; or 200,000 IU VA ester on days 0, 1, and 7. On days 14 and 15, the piglets underwent the modified relative dose-response (MRDR) test for VA deficiency, and were killed. Tissues were collected for high-pressure liquid chromatography analysis. Study 2 used the same design in 3 groups (n = 13/group) weaned at 16 d and administered 0; 25,000; and 200,000 IU doses. RESULTS: In Study 1 (final weight: 3.6 ± 0.7 kg), liver VA concentration was hypervitaminotic in 40%, 90%, and 100% of 50,000; 100,000; and 200,000 IU groups, respectively. The 25,000 IU group was 100% adequate, and the placebo group was 40% deficient. In Study 2 (final weight: 8.7 ± 0.8 kg), where 200,000 IU could be prescribed to infants with a similar body weight, 31% of the piglets were hypervitaminotic, the 25,000 IU group was 100% VA adequate, and the placebo group was 100% deficient. The MRDR test measured deficiency in 50% and 70% of the placebo group in each study but had 3 false positives among hypervitaminotic piglets in Study 1. CONCLUSIONS: Repeated high-dose VA may cause hypervitaminosis, indicating dose sizes may need reduction. The MRDR resulted in false positives in a hypervitaminotic state during malnutrition and should be paired with serum retinyl ester evaluation to enhance VA status assessment in populations with overlapping interventions.
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Suplementos Nutricionais , Hipervitaminose A , Vitamina A , Xeroftalmia , Animais , Vitamina A/administração & dosagem , Suínos , Xeroftalmia/tratamento farmacológico , Relação Dose-Resposta a Droga , Doenças dos Suínos/tratamento farmacológico , Deficiência de Vitamina A/tratamento farmacológico , Deficiência de Vitamina A/veterinária , Feminino , Masculino , Fígado/metabolismo , Fígado/efeitos dos fármacosRESUMO
BACKGROUND: Measuring vitamin A (VA) status during lactation is required to inform dietary recommendations. Limited data exist on VA stores in women. OBJECTIVES: Our objective was to assess VA status in lactating Thai women by measuring total body VA stores (TBSs), serum and breast milk retinol concentrations, and dietary intake. METHODS: Lactating women (n = 94), 6-8 wk postpartum, were enrolled from rural (Ayutthaya) and urban (Bangkok) areas. TBSs were measured by the 13C-retinol isotope dilution (RID) technique using 2.0 µmol 13C-retinyl acetate and a single blood sample 14 d post-dose. Natural 13C-enrichment was determined in nonenrolled women (n = 11). Estimated total liver VA reserves (TLRs) were determined using assumptions for lactation. Serum, foremilk, and hindmilk samples were analyzed for retinol by HPLC. Dietary VA intake was assessed by FFQ and 24-h dietary recalls for 3 d. Multiple regression and Pearson correlation were used to evaluate relations. RESULTS: Median VA intakes were 51.8% of 2003 Thai daily recommendations for lactating women, with the majority from animal-source foods. Many women in Ayutthaya consumed liver weekly. Considering TLRs as 50% TBS, 20% and 11% of mothers in Ayutthaya and Bangkok, respectively, showed deficient reserves (≤0.10 µmol retinol/g). Median (quartile 1, quartile 3) serum [1.58 (1.34, 1.91) and 1.52 (1.30, 1.70) µmol/L] and milk [1.88 (1.29, 2.95) and 1.74 (0.96, 2.26) µmol/L] retinol in Ayutthaya and Bangkok, respectively, were normal. Women with deficient TLRs showed low milk retinol concentrations (≤1.0 µmol/L) and consumed less dietary VA, especially from animal-source foods. Breast milk retinol concentrations, especially hindmilk, demonstrated strong correlation with TBSs and TLRs estimated from the RID test. CONCLUSIONS: Approximately 15% of Thai lactating women had deficient TLRs. Breast milk retinol concentrations in conjunction with dietary intake records show potential to screen mothers at risk of VA deficiency to guide interventions.The Thai Clinical Trials Registry number is TCTR20160824001 for the work in Thailand.
Assuntos
Deficiência de Vitamina A , Vitamina A , Humanos , Animais , Feminino , Leite Humano/química , Lactação , Tailândia , Exposição Dietética , População do Sudeste Asiático , Fígado/químicaRESUMO
BACKGROUND: Anthocyanins and carotenoids are phytochemicals that may benefit health through provitamin A carotenoid (PAC), antioxidant, and anti-inflammatory activities. These bioactives may mitigate chronic diseases. Consumption of multiple phytochemicals may impact bioactivity in synergistic or antagonistic manners. OBJECTIVES: Two studies in weanling male Mongolian gerbils assessed the relative bioefficacy of ß-carotene equivalents (BCEs) to vitamin A (VA) with simultaneous consumption of the non-PAC lycopene or anthocyanins from multicolored carrots. METHODS: After 3-wk VA depletion, 5-6 gerbils were killed as baseline groups. The remaining gerbils were divided into 4 carrot treatment groups; the positive control group received retinyl acetate and the negative control group was given vehicle soybean oil (n = 10/group; n = 60/study). In the lycopene study, gerbils consumed feed varying in lycopene sourced from red carrots. In the anthocyanin study, gerbils consumed feed varying in anthocyanin content sourced from purple-red carrots, and positive controls received lycopene. Treatment feeds had equalized BCEs: 5.59 ± 0.96 µg/g (lycopene study) and 7.02 ± 0.39 µg/g (anthocyanin study). Controls consumed feeds without pigments. Serum, liver, and lung samples were analyzed for retinol and carotenoid concentrations using HPLC. Data were analyzed by ANOVA and Tukey's studentized range test. RESULTS: In the lycopene study, liver VA did not differ between groups (0.11 ± 0.07 µmol/g) indicating no effect of varying lycopene content. In the anthocyanin study, liver VA concentrations in the medium-to-high (0.22 ± 0.14 µmol/g) and medium-to-low anthocyanin (0.25 ± 0.07 µmol/g) groups were higher than the negative control (0.11 ± 0.07 µmol/g) (P < 0.05). All treatment groups maintained baseline VA concentrations (0.23 ± 0.06 µmol/g). Combining studies, serum retinol had 12% sensitivity to predict VA deficiency, defined as 0.7 µmol/L. CONCLUSIONS: These gerbil studies suggested that simultaneous consumption of carotenoids and anthocyanins does not impact relative BCE bioefficacy. Breeding carrots for enhanced pigments to improve dietary intake should continue.
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Daucus carota , beta Caroteno , Animais , Masculino , Vitamina A , Daucus carota/química , Antocianinas/farmacologia , Licopeno , Gerbillinae , CarotenoidesRESUMO
BACKGROUND: Stable isotope techniques using 13C to assess vitamin A (VA) dietary sources, absorption, and total body VA stores (TBSs) require determination of baseline 13C abundance. 13C-natural abundance is approximately 1.1% total carbon, but varies with foods consumed, supplements taken, and food fortification with synthetic retinyl palmitate. OBJECTIVES: We determined 13C variation from purified serum retinol and the resulting impact on TBSs using pooled data from preschool children in Burkina Faso, Cameroon, Ethiopia, South Africa, Tanzania, and Zambia and Zambian women. METHODS: Seven studies included children (n = 639; 56 ± 25 mo; 48% female) and one in women (n = 138; 29 ± 8.5 y). Serum retinol 13C-natural abundance was determined using GC-C-IRMS. TBSs were available in 7 studies that employed retinol isotope dilution (RID). Serum CRP and α1-acid-glycoprotein (AGP) were available from 6 studies in children. Multivariate mixed models assessed the impact of covariates on retinol 13C. Spearman correlations and Bland-Altman analysis compared serum and milk retinol 13C and evaluated the impact of using study- or global-retinol 13C estimates on calculated TBSs. RESULTS: 13C-natural abundance (%, median [Q1, Q3]) differed among countries (low: Zambia, 1.0744 [1.0736, 1.0753]; high: South Africa, 1.0773 [1.0769, 1.0779]) and was associated with TBSs, CRP, and AGP in children and with TBSs in women. 13C-enrichment from serum and milk retinol were correlated (r = 0.52; P = 0.0001). RID in children and women using study and global estimates had low mean bias (range, -3.7% to 2.2%), but larger 95% limits of agreement (range, -23% to 37%). CONCLUSIONS: 13C-natural abundance is different among human cohorts in Africa. Collecting this information in subgroups is recommended for surveys using RID. When TBSs are needed on individuals in clinical applications, baseline 13C measures are important and should be measured in all enrolled subjects.
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Deficiência de Vitamina A , Vitamina A , Humanos , Feminino , Pré-Escolar , Masculino , Dieta , Deficiência de Vitamina A/epidemiologia , Suplementos Nutricionais , Isótopos , ZâmbiaRESUMO
BACKGROUND: Vitamin A (VA) assessment is important for targeting public health programs. Retinol isotope dilution (RID) is a sensitive method to estimate total body VA stores (TBSs) and total liver reserves (TLRs), but the impact of subclinical inflammation on RID is unclear. OBJECTIVE: We determined the association between TBSs and TLRs, estimated by RID, and inflammation among preschool children without clinical infection in Burkina Faso, Cameroon, Ethiopia, South Africa, and Tanzania. METHODS: Five studies (n = 532; 47.9 ± 8.3 mo; 49.0% male) included 13C-RID and measurement of inflammation markers, CRP, and α1-acid glycoprotein (AGP). Spearman correlations were used to evaluate TBSs and TLRs with inflammation biomarkers. Wilcoxon and Kruskal-Wallis tests were used to compare TBSs and TLRs by inflammation categories [normal vs. elevated CRP (>5 mg/L) or AGP (>1 g/L)] and inflammation stage [reference, incubation (elevated CRP), early convalescence (elevated CRP and AGP), and late convalescence (elevated AGP)]. RESULTS: Complete data were available for 439 children. Median (Q1, Q3) TLRs ranged from 0.12 (0.07, 0.18) µmol/g in Ethiopia to 1.10 (0.88, 1.38) µmol/g in South Africa. Elevated CRP ranged from 4% in Burkina Faso to 42% in Cameroon, and elevated AGP from 20% in Tanzania to 58% in Cameroon. Pooled analysis (excluding Cameroon) showed a negative correlation between TBSs and AGP (ρ = -0.131, P = 0.01). Children with elevated AGP had higher probability of having lower TBSs (probability = 0.61, P = 0.002). TBSs differed among infection stages (P = 0.020). Correlations between TLRs and CRP or AGP were not significant. CONCLUSIONS: No indication of systematic bias in RID-estimated TLRs was found due to subclinical inflammation among preschool children. The inverse relationship between TBSs and AGP may reflect decreased stores after infection or an effect of inflammation on isotope partitioning. Further research should investigate potential confounding variables to improve TBS-estimate validity.
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Deficiência de Vitamina A , Vitamina A , Humanos , Masculino , Pré-Escolar , Feminino , Convalescença , Inflamação , Biomarcadores , Fígado/química , Isótopos , África do Sul , Orosomucoide/análiseRESUMO
BACKGROUND: Vitamin A (VA) deficiency (VAD) affects â¼19 million pregnant women worldwide. The extent of VAD in Zambian women of reproductive age is unknown owing to lack of survey inclusion or the use of static serum retinol concentrations, a low-sensitivity biomarker. OBJECTIVES: This cross-sectional study employed isotopic techniques to determine VA status with serum and milk among women aged 18-49 y (n = 197) either lactating with infants aged 0-24 mo or nonlactating with or without infants. METHODS: Assistants were trained and piloted data collection. Demographic data, anthropometry, and relevant histories were obtained including malaria and anemia. For retinol isotope dilution (RID), baseline fasting blood and casual breast milk samples were collected before administration of 2.0 µmol 13C2-retinyl acetate and 24-h dietary recalls. On day 14, blood (n = 144) and milk (n = 66) were collected. Prevalence of total liver VA reserves (TLR) ≤0.10 µmol/g was defined as VAD with comparison to the DRI assumption of 0.07 µmol/g as minimally acceptable for North Americans. RESULTS: When a 20% adjustment for dose lost to milk was made in the RID equation for lactation, mean total body VA stores (TBS) for lactating women were 25% lower than for nonlactating women (P < 0.01), which was not the case without adjustment (P = 0.3). Mean ± SD TLR for all women were 0.15 ± 0.11 µmol/g liver. Using retinol purified from breast milk instead of serum for RID analysis yielded similar TBS and TLR, which were highly correlated between methods (P < 0.0001). Serum retinol ≤0.70 µmol/L had 0% sensitivity using either VAD liver cutoff and milk retinol ≤1.0 µmol/L had 42% sensitivity for VAD at 0.10 µmol/g. CONCLUSIONS: Determining accurate VA status among women of reproductive age, especially lactating women, forms a basis for extrapolation to the general population and informing policy development and program implementation.
Assuntos
Leite Humano/química , Deficiência de Vitamina A/sangue , Vitamina A/sangue , Vitamina A/química , Adulto , Biomarcadores , Isótopos de Carbono , Feminino , Humanos , Lactação , Adulto Jovem , ZâmbiaRESUMO
BACKGROUND: Vitamin A (VA) deficiency is a public health problem in some countries. Fortification, supplementation, and increased provitamin A consumption through biofortification are efficacious, but monitoring is needed due to risk of excessive VA intake when interventions overlap. OBJECTIVES: Two studies in 28-36-d-old male Mongolian gerbils simulated exposure to multiple VA interventions to determine the effects of provitamin A carotenoid consumption from biofortified maize and carrots and preformed VA fortificant on status. METHODS: Study 1 was a 2 × 2 × 2 factorial design (n = 85) with high-ß-carotene maize, orange carrots, and VA fortification at 50% estimated gerbil needs, compared with white maize and white carrot controls. Study 2 was a 2 × 3 factorial design (n = 66) evaluating orange carrot and VA consumption through fortification at 100% and 200% estimated needs. Both studies utilized 2-wk VA depletion, baseline evaluation, 9-wk treatments, and liver VA stores by HPLC. Intestinal scavenger receptor class B member 1 (Scarb1), ß-carotene 15,15'-dioxygenase (Bco1), ß-carotene 9',10'-oxygenase (Bco2), intestine-specific homeobox (Isx), and cytochrome P450 26A1 isoform α1 (Cyp26a1) expression was analyzed by qRT-PCR in study 2. RESULTS: In study 1, liver VA concentrations were significantly higher in orange carrot (0.69 ± 0.12 µmol/g) and orange maize groups (0.52 ± 0.21 µmol/g) compared with baseline (0.23 ± 0.069 µmol/g) and controls. Liver VA concentrations from VA fortificant alone (0.11 ± 0.053 µmol/g) did not differ from negative control. In study 2, orange carrot significantly enhanced liver VA concentrations (0.85 ± 0.24 µmol/g) relative to baseline (0.43 ± 0.14 µmol/g), but VA fortificant alone (0.42 ± 0.21 µmol/g) did not. Intestinal Scarb1 and Bco1 were negatively correlated with increasing liver VA concentrations (P < 0.01, r2 = 0.25-0.27). Serum retinol concentrations did not differ. CONCLUSIONS: Biofortified carrots and maize without fortification prevented VA deficiency in gerbils. During adequate provitamin A dietary intake, preformed VA intake resulted in excessive liver stores in gerbils, despite downregulation of carotenoid absorption and cleavage gene expression.
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Carotenoides/administração & dosagem , Carotenoides/farmacocinética , Fígado/química , Vitamina A/administração & dosagem , Vitamina A/farmacocinética , Ração Animal , Animais , Biofortificação , Carotenoides/efeitos adversos , Carotenoides/metabolismo , Daucus carota , Relação Dose-Resposta a Droga , Interações Medicamentosas , Gerbillinae , Fígado/metabolismo , Masculino , Vitamina A/efeitos adversos , Zea maysRESUMO
BACKGROUND: Venous congestion is the principle cause of flap failure after microsurgical breast reconstruction. We aim to correlate preoperative computed tomography angiography (CTA) findings with postoperative venous congestion to predict patients at risk of congestion. METHODS: All patients undergoing deep inferior epigastric perforator (DIEP) breast reconstruction between August 2009 and August 2013 underwent preoperative CTA and prospectively entered the study. Patients with postoperative venous congestion were matched with a similar cohort of complication-free patients. Preoperative CTAs were randomized and re-interpreted by a radiologist, blinded to the subsequent clinical outcome. Inter-group comparisons were performed. RESULTS: Two hundred and forty DIEP flaps were performed in 202 patients over the 4-year study. Venous congestion affected 15 flaps (6.3%). Preoperative CTA showed significantly more atypical venous connections between deep and superficial systems in congested flaps compared to controls (66.7% vs. 8%; P < .0001), with a positive predictive value of 83%. Atypical connections were narrow, tortuous, or incomplete. Patients with congestion-free flaps had more normal connections (80% vs. 26.7%; P < .001) and more cranial perforators (P = .02). Similar CTA findings between groups included perforator size and lateral position, superficial inferior epigastric vein size, crossing of midline, and absent connections (P > .05). CONCLUSIONS: Preoperative CTA identifies atypical venous connections between deep and superficial systems that increase the risk of postoperative DIEP congestion five-fold. Identifying atypical venous connections maximizes the chances of flap survival and minimizes complications for patients considering DIEP breast reconstruction.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Angiografia por Tomografia Computadorizada , Hiperemia/etiologia , Mamoplastia/efeitos adversos , Retalho Perfurante , Complicações Pós-Operatórias/etiologia , Adulto , Neoplasias da Mama/cirurgia , Estudos de Coortes , Artérias Epigástricas , Feminino , Humanos , Mastectomia , Pessoa de Meia-Idade , Valor Preditivo dos TestesRESUMO
Abdominal contour deformities are an aesthetic challenge to the plastic surgeon. Patients present with diverse clinical histories, multiple comorbidities, and unique aesthetic demands. Weight loss, previous pregnancy, and aging are 3 principal indications for abdominoplasty. Bariatric surgery has increased demand for body contouring procedures. This heterogeneous patient cohort means a "one-size-fits-all" abdominoplasty is not appropriate. Precise evaluation, evidence-based decision-making, and artistic acumen are required while balancing patient goals with safe, realistic, and long-lasting aesthetic outcomes. This article reviews surgical options for abdominal body contouring, providing an evidence-based treatment algorithm for selecting the appropriate procedure for each patient to maximize clinical and patient reported outcomes.
Assuntos
Abdominoplastia/métodos , Contorno Corporal , Parede Abdominal/anatomia & histologia , Algoritmos , Cirurgia Bariátrica , Humanos , Consentimento Livre e Esclarecido , Tempo de Internação , Lipectomia , Necrose/etiologia , Manejo da Dor , Dor Pós-Operatória/prevenção & controle , Medidas de Resultados Relatados pelo Paciente , Fotografação , Exame Físico , Cuidados Pós-Operatórios , Complicações Pós-Operatórias , Fatores de Risco , Seroma/etiologia , Tromboembolia/etiologiaRESUMO
Background: Retinol isotope dilution (RID) indirectly estimates vitamin A (VA) status. Multicompartment modeling of RID data is used to refine study designs and equations to calculate VA stores. Previous studies suggest that VA in slowly turning over pools is not traced if follow-up is not long enough; however, shorter RID studies are being investigated. Few long-term models have been published. Objective: We determined the effect of time on mathematical models of VA kinetics, model parameters, and outcomes. Methods: In this longitudinal study, women (mean ± SD age: 22 ± 3 y; n = 7) were given 2.0 µmol [14,15]-13C2-retinyl acetate. Blood samples were staggered from 4 h to 152 d; the fraction of dose in serum was modeled with compartmental models. Four model-time categories were created: full models that used all data (median: 137 d; range 97-152 d) and truncated shorter studies of 14, 27, and 52 d (range: 42-62 d). Outcomes included number of compartments to adequately model serum data, kinetic parameters, total traced VA mass, and time-to-dose equilibration. To gain insight into longer follow-up, an additional participant was given 17.5 µmol 13C4-VA, and data were modeled as long as enrichment was above baseline (5 y). Results: Longer follow-up times affected kinetic parameters and outcomes. Compared with the 14-d models, long-term full models required an additional compartment for adequate fit (14.3% compared with 100%; P = 0.0056) and had longer [median (quartile 1, quartile 3)] whole-body half-life [15.0 d (10.5, 72.6 d) compared with 135 d (115, 199 d); P = 0.0006], time-to-dose equilibration [3.40 d (3.14, 6.75 d) compared with 18.9 d (11.2, 25.7 d); P < 0.0001], and total traced mass [166 µmol VA (162, 252 µmol VA) compared with 476 µmol VA (290, 752 µmol VA); P = 0.0031]. Conclusions: Extended RID sampling alters numerous mathematically modeled, time-dependent outcomes in women. Length of study should be considered when using mathematical models for calculating total-body VA stores or kinetic parameters related to VA turnover. This study is registered at www.clinicaltrials.gov as NCT03248700.
Assuntos
Técnicas de Diluição do Indicador , Estado Nutricional , Deficiência de Vitamina A/metabolismo , Vitamina A/metabolismo , Adulto , Isótopos de Carbono/metabolismo , Diterpenos , Feminino , Humanos , Cinética , Estudos Longitudinais , Modelos Biológicos , Modelos Teóricos , Ésteres de Retinil , Fatores de Tempo , Estados Unidos , Vitamina A/análogos & derivados , Vitamina A/sangue , Vitamina A/farmacocinética , Deficiência de Vitamina A/sangue , Deficiência de Vitamina A/diagnóstico , Adulto JovemRESUMO
Background: Neonatal vitamin A (VA) supplementation is being evaluated as a public health policy for preventing infant mortality, but inconsistencies in mortality trials demand mechanistic work to determine biological plausibility.Objectives: We investigated the absorption, distribution, and storage of single large oral VA doses administered shortly after birth.Methods: Fifty pregnant sows (Sus scrofas domesticas) were fed a VA-free diet. Male and female newborn piglets (n = 313) were orally administered 0, 25,000, 50,000, or 200,000 IU VA in oil within 12 h of birth when mean ± SD weight was 1.56 ± 0.25 kg. Blood was drawn to determine absorption and storage 0.5-240 h after administration. Metabolic and postnatal dose-timing substudies were performed. Liver, lung, kidney, spleen, and adrenal VA concentrations were determined 7-240 h after administration.Results: Serum retinol and retinyl ester concentrations responded to treatment (P < 0.0001); however, differences between groups disappeared by 96 h. Liver VA concentrations responded to treatment (P < 0.0001), which persisted for 240 h. Liver VA for control piglets at 10 d (mean ± SD: 0.05 ± 0.02 µmol/g) was ≤0.1 µmol/g (deficiency), whereas groups that received VA maintained concentrations >0.1 µmol/g. Extrahepatic tissue VA concentrations displayed treatment effects (P ≤ 0.0077); groups that received treatments had higher VA concentrations than controls at early time points. Lung, kidney, and spleen VA did not differ between groups by 96 h, whereas adrenal glands did not differ by 240 h. Body weight was affected by treatment (P = 0.0002); VA-deficient piglets weighed 23-29% more than all treated groups 240 h after administration.Conclusions: A high dose of VA administered to newborn piglets was well absorbed, appeared in serum primarily as retinyl esters, and was taken up dose-dependently in all tissues studied; however, enhancement did not persist in sera, lungs, kidneys, spleens, or adrenal glands. Short-term impacts of retinoid signaling on weight gain remain to be elucidated, and longer follow-up studies are needed.
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Suplementos Nutricionais , Fenômenos Fisiológicos da Nutrição do Lactente , Deficiência de Vitamina A/prevenção & controle , Vitamina A/farmacocinética , Glândulas Suprarrenais/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Animais Recém-Nascidos , Peso Corporal/efeitos dos fármacos , Ésteres/sangue , Feminino , Humanos , Recém-Nascido , Rim/metabolismo , Fígado/metabolismo , Pulmão/metabolismo , Masculino , Baço/metabolismo , Suínos , Distribuição Tecidual , Vitamina A/sangue , Vitamina A/metabolismo , Vitamina A/uso terapêutico , Deficiência de Vitamina A/metabolismoRESUMO
Stem cells and progenitor cells are integral to tissue homeostasis and repair. They contribute to health through their ability to self-renew and commit to specialized effector cells. Recently, defects in a variety of progenitor cell populations have been described in both preclinical and human diabetes. These deficits affect multiple aspects of stem cell biology, including quiescence, renewal, and differentiation, as well as homing, cytokine production, and neovascularization, through mechanisms that are still unclear. More important, stem cell aberrations resulting from diabetes have direct implications on tissue function and seem to persist even after return to normoglycemia. Understanding how diabetes alters stem cell signaling and homeostasis is critical for understanding the complex pathophysiology of many diabetic complications. Moreover, the success of cell-based therapies will depend on a more comprehensive understanding of these deficiencies. This review has three goals: to analyze stem cell pathways dysregulated during diabetes, to highlight the effects of hyperglycemic memory on stem cells, and to define ways of using stem cell therapy to overcome diabetic complications.
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Diferenciação Celular/fisiologia , Terapia Baseada em Transplante de Células e Tecidos , Complicações do Diabetes/terapia , Transplante de Células-Tronco , Células-Tronco/metabolismo , Animais , Complicações do Diabetes/metabolismo , Humanos , Transdução de Sinais/fisiologiaRESUMO
BACKGROUND: Crops such as maize, sorghum, and millet are being biofortified with provitamin A carotenoids to ensure adequate vitamin A (VA) intakes. VA assessment can be challenging because serum retinol concentrations are homeostatically controlled and more sensitive techniques are resource-intensive. OBJECTIVES: We investigated changes in serum retinol relative differences of isotope amount ratios of (13)C/(12)C (δ(13)C) caused by natural (13)C fractionation in C3 compared with C4 plants as a biomarker to detect provitamin A efficacy from biofortified (orange) maize and high-carotene carrots. METHODS: The design was a 2 × 2 × 2 maize (orange compared with white) by carrot (orange compared with white) by a VA fortificant (VA+ compared with VA-) in weanling male Mongolian gerbils (n = 55), which included a 14-d VA depletion period and a 62-d treatment period (1 baseline and 8 treatment groups; n = 5-7/group). Liver VA and serum retinol were quantified, purified by HPLC, and analyzed by GC combustion isotope ratio mass spectrometry for (13)C. RESULTS: Treatments affected liver VA concentrations (0.048 ± 0.039 to 0.79 ± 0.24 µmol/g; P < 0.0001) but not overall serum retinol concentrations (1.38 ± 0.22 µmol/L). Serum retinol and liver VA δ(13)C were significantly correlated (R(2) = 0.92; P < 0.0001). Serum retinol δ(13)C differentiated control groups that consumed white maize and white carrots (-27.1 ± 1.2 δ(13)C) from treated groups that consumed orange maize and white carrots (-21.6 ± 1.4 δ(13)C P < 0.0001) and white maize and orange carrots (-30.6 ± 0.7 δ(13)C P < 0.0001). A prediction model demonstrated the relative contribution of orange maize to total dietary VA for groups that consumed VA from mixed sources. CONCLUSIONS: Provitamin A efficacy and quantitative estimation of the relative contribution to dietary VA were demonstrated with the use of serum retinol δ(13)C. This method could be used for maize efficacy or effectiveness studies and with other C4 crops biofortified with provitamin A carotenoids (e.g., millet, sorghum). Advantages include no extrinsic tracer dose, 1 blood sample, and higher sensitivity than serum retinol concentrations alone.
Assuntos
Carbono/metabolismo , Carotenoides/metabolismo , Provitaminas/metabolismo , Vitamina A/sangue , Zea mays/metabolismo , Animais , Biomarcadores/sangue , Isótopos de Carbono , Carotenoides/química , Daucus carota , Alimentos Fortificados , Gerbillinae , Humanos , Masculino , Plantas Geneticamente Modificadas , Provitaminas/química , Vitamina A/metabolismoRESUMO
INTRODUCTION: Plastic surgery teaching has a limited role in the undergraduate curriculum. We held a 1-day national course in plastic surgery for undergraduates. Our aim was to introduce delegates to plastic surgery and teach basic plastic surgical skills. We assessed change in perceptions of plastic surgery and change in confidence in basic plastic surgical skills. METHOD: The day consisted of consultant-led lectures followed by workshops in aesthetic suturing, local flap design, and tendon repair. A questionnaire divided into 3 sections, namely, (1) career plans, (2) perceptions of plastic surgery, and (3) surgical skills and knowledge, was completed by 39 delegates before and after the course. Results were presented as mean scores and the standard error of the mean used to calculate data spread. Data were analyzed using the Mann-Whitney U test for nonparametric data. RESULTS: Career plans: Interest in pursuing a plastic surgery career significantly increased over the course of the day by 12.5% (P < 0.0005).Perceptions: Statistically significant changes were observed in many categories of plastic surgery, including the perception of the role of plastic surgeons in improving patient quality of life, increased by 18.31% (P = 0.063). Before the course 10% of delegates perceived plastic surgery to be a superficial discipline and 20% perceived that plastic surgeons did not save lives. After completing the course, no delegates held those views.Surgical skills: Confidence to perform subcuticular and deep dermal sutures improved by 53% (P < 0.0001) and 57% (P < 0.0001), respectively. Delegates' subjective understanding of the basic geometry of local flaps improved by 94% (P < 0.0001). Interestingly, before the course, 2.5% of delegates drew an accurate modified Kessler suture compared with 87% of on completion of the course. CONCLUSIONS: A 1-day intensive undergraduate plastic surgery course can significantly increase delegates' desire to pursue a career in plastic surgery, dispel common misconceptions about this field, and increase their confidence in performing the taught skills. The results of this course demonstrate that a 1-day course is an effective means of teaching basic plastic surgery skills to undergraduates and highlights the potential role for local plastic surgery departments in advancing plastic surgery education.
Assuntos
Escolha da Profissão , Competência Clínica , Educação de Graduação em Medicina/métodos , Estudantes de Medicina/psicologia , Cirurgia Plástica/educação , Feminino , Humanos , Londres , Masculino , Avaliação de Programas e Projetos de Saúde , Procedimentos de Cirurgia Plástica/educação , Inquéritos e QuestionáriosRESUMO
The macula flavae (MF), populated by vitamin A-storing stellate cells (SCs), are believed to play a fundamental role in development, maintenance and repair of the vocal fold (VF) mucosa; however, to date, they have mostly been examined in observational human cadaver studies. Here, we conducted an interspecies comparison of MF and SC phenotype, as well as vitamin A quantification and localization, in human, pig, dog, rabbit and rat VF mucosae. MF containing vitamin A-positive SCs were only identified in human and rat specimens. Pig, dog and rabbit VF mucosae contained no discernable MF, but rather exhibited preferential vitamin A localization to mucous (pig), serous (dog) or mixed (rabbit) glands. This glandular vitamin A storage corresponded to exceedingly high concentrations of retinol in pig and dog mucosae, and retinyl ester in dog mucosa. These findings have significant implications for the presumed role of the MF and SCs in VF biology, the nature of vitamin A storage within the VF mucosa, and the selection of an appropriate animal model for future experimental studies.
Assuntos
Mucosa Laríngea/metabolismo , Vitamina A/metabolismo , Prega Vocal/citologia , Adulto , Animais , Cadáver , Cães , Matriz Extracelular/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Coelhos , Ratos , Especificidade da Espécie , Suínos , Prega Vocal/metabolismoRESUMO
Provitamin A biofortification of staple crops may decrease the prevalence of vitamin A (VA) deficiency if widely adopted in target countries. To assess the impact of processing methods on the VA value of plant foods, the unique bioefficacies of cis-ßC isomers (formed during cooking) compared with all-trans (at) ß-carotene (ßC) must be determined. The bioefficacies of 9-cis (9c)- and 13-cis (13c)-ßC isomers were compared with those of the at-ßC isomer and VA positive (VA+) and negative (VA - ) controls in VA-depleted Mongolian gerbils (Meriones unguiculatus) in two experimental studies (study 1, n 56; study 2, n 57). A 3- or 4-week depletion period was followed by a 3- or 4-week treatment period in which the groups received oral doses of the 9c-, 13c- or at-ßC isomers in cottonseed oil (study 1, 15 nmol/d; study 2, 30 nmol/d). In study 1, the ßC isomers did not maintain baseline liver VA stores in all groups (0.69 (SD 0.20) µmol/liver) except in the VA+group (0.56 (SD 0.10) µmol/liver) (P= 0.0026). The ßC groups were similar to the VA+group, but the 9c- and 13c-ßC groups did not differ from the VA - group (0.39 (SD 0.09) µmol/liver). In study 2, the ßC isomers maintained baseline liver VA stores in all the ßC groups (0.35 (SD 0.13) µmol/liver), and in the VA+group, the VA supplement (0.54 (SD 0.19) µmol/liver) exceeded the baseline VA status (0.38 (SD 0.15) µmol/liver) (P< 0.0001); however, the 9c-ßC group did not differ from the VA - group (0.20 (SD 0.07) µmol/liver). In vivo isomerisation of ßC was confirmed in both experimental studies. Lower VA bioconversion factor values were obtained for the cis-ßC isomers in study 2 when compared with study 1, but higher values were obtained for the at-ßC isomer. Dose and VA status clearly affect bioconversion factors. In conclusion, the cis-ßC isomers yielded similar liver VA stores to the at-ßC isomer in Mongolian gerbils, and liver VA stores of the 9c- and 13c-ßC groups did not differ when the doses were provided at physiological levels over time in two studies.
Assuntos
Suplementos Nutricionais , Modelos Animais de Doenças , Fígado/metabolismo , Deficiência de Vitamina A/prevenção & controle , Vitamina A/uso terapêutico , beta Caroteno/uso terapêutico , Animais , Biotransformação , Cromatografia Líquida de Alta Pressão , Diterpenos , Gerbillinae , Masculino , Estrutura Molecular , Ésteres de Retinil , Estereoisomerismo , Vitamina A/administração & dosagem , Vitamina A/análogos & derivados , Vitamina A/sangue , Vitamina A/metabolismo , Deficiência de Vitamina A/sangue , Deficiência de Vitamina A/metabolismo , beta Caroteno/administração & dosagem , beta Caroteno/química , beta Caroteno/metabolismoRESUMO
Atopic dermatitis (AD) is a common, chronic relapsing, and remitting inflammatory skin disease that is characterized by erythematous, scaly, and pruritic lesions often located over the flexural surfaces. Treatment goals of AD include the reduction of itching and burning, as well as the reduction of skin changes. Treatment of AD includes emollients and skin care, topical therapies including topical corticosteroids and steroid-sparing therapies, systemic therapies, and phototherapy.
Assuntos
Dermatite Atópica , Humanos , Corticosteroides/uso terapêutico , Corticosteroides/administração & dosagem , Dermatite Atópica/tratamento farmacológico , Dermatite Atópica/terapia , Fármacos Dermatológicos/uso terapêutico , Fármacos Dermatológicos/administração & dosagem , Emolientes/uso terapêutico , Emolientes/administração & dosagem , Fototerapia/métodos , Higiene da Pele/métodosRESUMO
Excessive vitamin A (VA) negatively impacts bone. Interactions between VA and vitamin D (VD) in bone health are not well-understood. This study used a traditional two-by-two factorial design. Pigs were weaned and randomized to four treatments (n = 13/group): -A-D, -A+D, +A-D, and +A+D for 3 and 5 wk. Serum, liver, kidney, adrenal glands, spleen, and lung were analyzed by ultra-performance LC. Growth was evaluated by weight measured weekly and BMD by DXA. Weights were higher in -A+D (18.1 ± 1.0 kg) and +A+D (18.2 ± 2.3 kg) at 5 wk than in -A-D (15.5 ± 2.1 kg) and +A-D (15.8 ± 1.5 kg). Serum retinol concentrations were 0.25 ± 0.023, 0.22 ± 0.10, 0.77 ± 0.12, and 0.84 ± 0.28 µmol/L; and liver VA concentrations were 0.016 ± 0.015, 0.0065 ± 0.0035, 2.97 ± 0.43, 3.05 ± 0.68 µmol/g in -A-D, -A+D, +A-D, and +A+D, respectively. Serum 25(OH)D3 concentrations were 1.5 ± 1.11, 1.8 ± 0.43, 27.7 ± 8.91, and 23.9 ± 6.67 ng/mL in -A-D, +A-D, -A+D, +A+D, respectively, indicating a deficiency in -D and adequacy in +D. BMD was highest in +D (p < 0.001). VA and the interaction had no effect on BMD. Dietary VD influenced weight gain, BMD, and health despite VA status.
Assuntos
Densidade Óssea , Deficiência de Vitamina A , Vitamina A , Vitamina D , Animais , Densidade Óssea/efeitos dos fármacos , Vitamina D/sangue , Suínos , Vitamina A/sangue , Feminino , Masculino , Modelos Animais de Doenças , Fígado/metabolismo , Fígado/efeitos dos fármacos , Suplementos NutricionaisRESUMO
Atopic dermatitis (AD) is a common, chronic relapsing, and remitting inflammatory skin disease that is characterized by erythematous, scaly, and pruritic lesions often located over the flexural surfaces. Treatment goals of AD include the reduction of itching and burning, as well as the reduction of skin changes. Treatment of AD includes emollients and skin care, topical therapies including topical corticosteroids and steroid-sparing therapies, systemic therapies, and phototherapy.
Assuntos
Dermatite Atópica , Humanos , Dermatite Atópica/terapia , Dermatite Atópica/tratamento farmacológico , Pele , Emolientes/uso terapêutico , Glucocorticoides/uso terapêutico , FototerapiaRESUMO
Transmembrane protein 135 (TMEM135) is thought to participate in the cellular response to increased intracellular lipids yet no defined molecular function for TMEM135 in lipid metabolism has been identified. In this study, we performed a lipid analysis of tissues from Tmem135 mutant mice and found striking reductions of docosahexaenoic acid (DHA) across all Tmem135 mutant tissues, indicating a role of TMEM135 in the production of DHA. Since all enzymes required for DHA synthesis remain intact in Tmem135 mutant mice, we hypothesized that TMEM135 is involved in the export of DHA from peroxisomes. The Tmem135 mutation likely leads to the retention of DHA in peroxisomes, causing DHA to be degraded within peroxisomes by their beta-oxidation machinery. This may lead to generation or alteration of ligands required for the activation of peroxisome proliferator-activated receptor a (PPARa) signaling, which in turn could result in increased peroxisomal number and beta-oxidation enzymes observed in Tmem135 mutant mice. We confirmed this effect of PPARa signaling by detecting decreased peroxisomes and their proteins upon genetic ablation of Ppara in Tmem135 mutant mice. Using Tmem135 mutant mice, we also validated the protective effect of increased peroxisomes and peroxisomal beta-oxidation on the metabolic disease phenotypes of leptin mutant mice which has been observed in previous studies. Thus, we conclude that TMEM135 has a role in lipid homeostasis through its function in peroxisomes.