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1.
Acta Endocrinol (Buchar) ; 17(1): 101-105, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34539916

RESUMO

CONTEXT: Rapidly progressive precocious puberty (RPPP) is a rare condition in Turner syndrome (TS), with no consensus on treatment and follow-up. Only 12 cases have been reported so far. OBJECTIVE: We aimed to evaluate the effects of the GnRH analog (GnRHa) on growth and anti-mullerian hormone (AMH) levels in TS and RPPP. DESIGN: The clinical and laboratory data was recorded at baseline and after treatment. SUBJECTS AND METHODS: An 8.1-year old girl with a karyotype of 45, X/46, XX presented with breast development at Tanner stage-2. Breast development advanced to Tanner stage-3 at the age of 8.7 years. Growth velocity (GV) was 8 cm/year. Bone age was 11 years with a predicted adult height of 152 cm. Luteinizing hormone (LH) was 1.69mIU/mL and estradiol was 33pg/mL, confirming the central puberty. AMH level was 6.33ng/mL. The sizes of ovaries and uterus were compatible with the pubertal stage, with an endometrial thickness of 5 mm. GnRHa was started for RPPP. RESULTS: After three months, GV declined to 0 cm/3 months and AMH level to 50% of the baseline. Growth hormone (GH) treatment was started for insufficient growth. GV improved with GH treatment, as well as a far more decreased AMH level. RESULTS: After three months, GV declined to 0 cm/3 months and AMH level to 50% of the baseline. Growth hormone (GH) treatment was started for insufficient growth. GV improved with GH treatment, as well as a far more decreased AMH level. CONCLUSION: GV usually declines before puberty in patients with TS, even if the mid-parental height is tall. RPPP should be considered if GV is increased. Excessive suppression of growth may be prevented with GH treatment. GnRHa treatment also plays a role in reducing AMH levels in patients with TS.

2.
J Steroid Biochem Mol Biol ; 202: 105730, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32682944

RESUMO

Deficiency in Sphingosine-1-phosphate lyase (S1P lyase) is associated with a multi-systemic disorder incorporating primary adrenal insufficiency (PAI), steroid resistant nephrotic syndrome and neurological dysfunction. Accumulation of sphingolipid intermediates, as seen with loss of function mutations in SGPL1, has been implicated in mitochondrial dysregulation, including alterations in mitochondrial membrane potentials and initiation of mitochondrial apoptosis. For the first time, we investigate the impact of S1P lyase deficiency on mitochondrial morphology and function using patient-derived human dermal fibroblasts and CRISPR engineered SGPL1-knockout HeLa cells. Reduced cortisol output in response to progesterone stimulation was observed in two patient dermal fibroblast cell lines. Mass spectrometric analysis of patient dermal fibroblasts revealed significantly elevated levels of sphingosine-1-phosphate, sphingosine, ceramide species and sphingomyelin when compared to control. Total mitochondrial volume was reduced in both S1P lyase deficient patient and HeLa cell lines. Mitochondrial dynamics and parameters of oxidative phosphorylation were altered when compared to matched controls, though differentially across the cell lines. Mitochondrial dysfunction may represent a major event in the pathogenesis of this disease, associated with severity of phenotype.


Assuntos
Insuficiência Adrenal/metabolismo , Aldeído Liases/deficiência , Mitocôndrias/metabolismo , Doenças Mitocondriais/metabolismo , Insuficiência Adrenal/genética , Aldeído Liases/genética , Respiração Celular , Células Cultivadas , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Hidrocortisona/metabolismo , Doenças Mitocondriais/genética , Fosfoproteínas/genética , Progesterona/farmacologia , Pele/citologia
3.
J Endocrinol Invest ; 43(2): 185-196, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31435881

RESUMO

BACKGROUND: Allgrove syndrome (OMIM 231550) is a rare autosomal recessive disease characterized by non-CAH primary adrenal insufficiency (non-CAH PAI), alacrima, and achalasia. It is caused by mutations in the AAAS gene. The syndrome is also associated with variable progressive neurological impairment and dermatological abnormalities. METHODS AND RESULTS: We diagnosed 23 patients from 14 families with Allgrove syndrome, based on the presence of at least two characteristic symptoms, usually adrenal insufficiency and alacrima, between 2008 and 2018. A previously described nonsense variant of AAAS was detected in 19 patients from 12 families at homozygous state. Another novel homozygous mutation (c.394-397delCTGT) in AAAS was detected in four patients from two families. Presenting symptoms were alacrima (23/23; 100%), adrenal insufficiency (18/23; 78%), achalasia (13/23; 57%), short stature/growth retardation (16/23; 70%), hyperreflexia (15/23; 65%), palmoplantar hyperkeratosis (13/23; 57%), hyperpigmentation of the skin (10/23; 43%), hypoglycemia-induced convulsion (7/23; 30%), swallowing difficulty and vomiting (6/23; 26%). Serum DHEAS concentrations were low in all patients (23/23; 100%). CONCLUSIONS: Clinical symptoms vary even among patients carrying the same mutation. Triple A syndrome should be considered in the etiology of non-CAH PAI in Arab populations and in Southeast Turkey. Any child with non-CAH PAI should be evaluated for the presence of alacrima and/or achalasia or family history of alacrima and/or achalasia. Children with alacrima and/or achalasia should also be investigated for adrenal insufficiency. Definitive molecular diagnosis is essential for early diagnosis and management of adrenal insufficiency, neurological symptoms, and growth retardation in patients and early diagnosis of as yet asymptomatic cases in the family, together with genetic counseling.


Assuntos
Insuficiência Adrenal/diagnóstico , Insuficiência Adrenal/genética , Acalasia Esofágica/diagnóstico , Acalasia Esofágica/genética , Adolescente , Insuficiência Adrenal/epidemiologia , Criança , Pré-Escolar , Acalasia Esofágica/epidemiologia , Oftalmopatias Hereditárias/diagnóstico , Oftalmopatias Hereditárias/epidemiologia , Oftalmopatias Hereditárias/genética , Feminino , Humanos , Doenças do Aparelho Lacrimal/diagnóstico , Doenças do Aparelho Lacrimal/epidemiologia , Doenças do Aparelho Lacrimal/genética , Masculino , Mutação/genética , Turquia/epidemiologia
4.
J Endocrinol Invest ; 42(4): 453-470, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30132287

RESUMO

BACKGROUND: Studies regarding genetic and clinical characteristics, gender preference, and gonadal malignancy rates for steroid 5-alpha-reductase type 2 deficiency (5α-RD2) are limited and they were conducted on small number of patients. OBJECTIVE: To present genotype-phenotype correlation, gonadal malignancy risk, gender preference, and diagnostic sensitivity of serum testosterone/dihydrotestosterone (T/DHT) ratio in patients with 5α-RD2. MATERIALS AND METHODS: Patients with variations in the SRD5A2 gene were included in the study. Demographic characteristics, phenotype, gender assignment, hormonal tests, molecular genetic data, and presence of gonadal malignancy were evaluated. RESULTS: A total of 85 patients were included in the study. Abnormality of the external genitalia was the most dominant phenotype (92.9%). Gender assignment was male in 58.8% and female in 29.4% of the patients, while it was uncertain for 11.8%. Fourteen patients underwent bilateral gonadectomy, and no gonadal malignancy was detected. The most frequent pathogenic variants were p.Ala65Pro (30.6%), p.Leu55Gln (16.5%), and p.Gly196Ser (15.3%). The p.Ala65Pro and p.Leu55Gln showed more undervirilization than the p.Gly196Ser. The diagnostic sensitivity of stimulated T/DHT ratio was higher than baseline serum T/DHT ratio, even in pubertal patients. The cut-off values yielding the best sensitivity for stimulated T/DHT ratio were ≥ 8.5 for minipuberty, ≥ 10 for prepuberty, and ≥ 17 for puberty. CONCLUSION: There is no significant genotype-phenotype correlation in 5α-RD2. Gonadal malignancy risk seems to be low. If genetic analysis is not available at the time of diagnosis, stimulated T/DHT ratio can be useful, especially if different cut-off values are utilized in accordance with the pubertal status.


Assuntos
3-Oxo-5-alfa-Esteroide 4-Desidrogenase/deficiência , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/genética , Di-Hidrotestosterona/sangue , Transtornos do Desenvolvimento Sexual/complicações , Neoplasias dos Genitais Femininos/etiologia , Neoplasias dos Genitais Masculinos/etiologia , Testosterona/sangue , Adolescente , Adulto , Criança , Pré-Escolar , Aberrações Cromossômicas , Transtornos do Desenvolvimento Sexual/metabolismo , Transtornos do Desenvolvimento Sexual/patologia , Feminino , Estudos de Associação Genética , Neoplasias dos Genitais Femininos/metabolismo , Neoplasias dos Genitais Femininos/patologia , Neoplasias dos Genitais Masculinos/metabolismo , Neoplasias dos Genitais Masculinos/patologia , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Maturidade Sexual , Turquia , Adulto Jovem
5.
J Clin Endocrinol Metab ; 101(11): 3959-3967, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27403927

RESUMO

BACKGROUND: In boys with suspected partial androgen insensitivity syndrome (PAIS), systematic evidence that supports the long-term prognostic value of identifying a mutation in the androgen receptor gene (AR) is lacking. OBJECTIVE: To assess the clinical characteristics and long-term outcomes in young men with suspected PAIS in relation to the results of AR analysis. METHODS: Through the International Disorders of Sex Development Registry, clinical information was gathered on young men suspected of having PAIS (n = 52) who presented before the age of 16 years and had genetic analysis of AR. RESULTS: The median ages at presentation and at the time of the study were 1 month (range, 1 day to 16 years) and 22 years (range, 16 to 52 years), respectively. Of the cohort, 29 men (56%) had 20 different AR mutations reported. At diagnosis, the median external masculinization scores were 7 and 6 in cases with and without AR mutation, respectively (P = .9), and median current external masculinization scores were 9 and 10, respectively (P = .28). Thirty-five men (67%) required at least one surgical procedure, and those with a mutation were more likely to require multiple surgeries for hypospadias (P = .004). All cases with an AR mutation had gynecomastia, compared to 9% of those without an AR mutation. Of the six men who had a mastectomy, five (83%) had an AR mutation. CONCLUSIONS: Boys with genetically confirmed PAIS are likely to have a poorer clinical outcome than those with XY DSD, with normal T synthesis, and without an identifiable AR mutation. Routine genetic analysis of AR to confirm PAIS informs long-term prognosis and management.


Assuntos
Envelhecimento , Síndrome de Resistência a Andrógenos/diagnóstico , Síndrome de Resistência a Andrógenos/genética , Mutação , Receptores Androgênicos/genética , Adolescente , Adulto , Síndrome de Resistência a Andrógenos/fisiopatologia , Criança , Pré-Escolar , Estudos de Coortes , Progressão da Doença , Transtorno 46,XY do Desenvolvimento Sexual/diagnóstico , Transtorno 46,XY do Desenvolvimento Sexual/genética , Transtorno 46,XY do Desenvolvimento Sexual/fisiopatologia , Ginecomastia/etiologia , Ginecomastia/cirurgia , Humanos , Hipospadia/etiologia , Hipospadia/cirurgia , Lactente , Recém-Nascido , Agências Internacionais , Masculino , Mastectomia , Pessoa de Meia-Idade , Prognóstico , Puberdade Tardia , Receptores Androgênicos/metabolismo , Sistema de Registros , Estudos Retrospectivos , Índice de Gravidade de Doença , Adulto Jovem
6.
Pediatr Obes ; 11(5): 383-8, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26463004

RESUMO

BACKGROUND: Hypothalamic obesity (HyOb) is a common complication of childhood hypothalamic tumours. Patients with HyOb probably have a higher mortality rate than those with other types of obesity due in many cases to obstructive sleep apnoea/hypoventilation. OBJECTIVES: To identify predictive factors for mortality caused by HyOb in children. METHODS: Twenty children with HyOb secondary to hypothalamic tumours that were followed-up for ≥3 years and aged <15 years at diagnosis, and received supraphysiological glucocorticoid treatment for ≤1 month. RESULTS: Mean age at diagnosis was 6.36 ± 3.60 years. Mean body mass index (BMI) Standard deviation of the samples (SDS) increased from 0.77 ± 1.26 to 2.66 ± 1.45 during the first 6 months, but slowed from month 6-12 (2.73 ± 1.35). ΔBMI SDS at 0-6 months was significantly higher in patients aged <6 years at diagnosis than in those aged >6 years at diagnosis (3.71 ± 1.96 vs. 0.83 ± 0.73, P < 0.001). Maximum BMI SDS was also significantly higher in the younger group (3.88 ± 1.39 vs. 2.79 ± 0.64, P < 0.05). In all, four patients died and the mortality rate was significantly higher in the patients with a further increase in BMI SDS > 1 SDS after 6 months of therapy (RR: 8.4, P < 0.05). Both overall mortality and obesity-related mortality rates were higher in the patients aged <6 years at diagnosis (4.5-fold, 7.2-fold higher, respectively, P > 0.05). The mortality rate was also 3.7-fold higher in the patients with a maximum BMI SDS ≥ 3 at any time during the first 3 years after therapy(P > 0.05). CONCLUSIONS: An increase in BMI SDS after 6 months of therapy was observed to be a risk factor for mortality caused by HyOb. In addition, age <6 years at diagnosis and a maximum BMI SDS ≥ 3 were associated with a higher mortality rate, indicating that earlier and more aggressive treatment of obesity is required.


Assuntos
Neoplasias Hipotalâmicas/complicações , Hipotálamo/fisiopatologia , Obesidade/etiologia , Adolescente , Índice de Massa Corporal , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Neoplasias Hipotalâmicas/mortalidade , Lactente , Masculino , Obesidade/diagnóstico , Obesidade/mortalidade , Estudos Retrospectivos , Fatores de Risco
7.
Andrology ; 2(4): 572-8, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24737579

RESUMO

46,XY disorders of sex development (DSD) are caused by disorders of gonadal development, androgen biosynthesis and receptor (AR) defects. Although, clinical/biochemical features help in distinguishing specific aetiologies, there are overlaps which necessitate molecular analyses for the definitive diagnosis. To test precision of our clinical diagnosis of androgen insensitivity (AIS) by analysing AR and then SRD5A2 genes, patients were recruited at Marmara University Hospital and molecular analyses were performed at Vall d'Hebron Research Institute. Among 101 46,XY DSD patients, 46 index and five siblings (nine complete, 42 partial) with clinical/biochemical data suggestive of AIS and stimulated T/DHT ratio <25 were selected. AR and then SRD5A2 genes were sequenced. We detected AR mutations in 11 patients [seven index and four siblings (22% of all and 15% of index patients)] and SRD5A2 mutations in six [five index and one sibling (12% of all and 11% of index)]. AR mutation detection rate was 6/9 in all CAIS and 4/7 in the index (67 and 57% respectively) and 5/42 in all PAIS and 3/40 in the index (12 and 7.5% respectively). The eight mutations detected in the AR gene were as follows: p.Q58L, p.P392S, p.R609K, p.R775H, p.R856H, p.A871A, p.V890M and p.F892L, with p.A871A and p.F892L being novel. Further six patients had SRD5A2 mutations which were as follows: p.L73WfsX59, p.Y91H, p.R171S and p.G196S, the first being novel. Hormonal data in those with AR mutations, SRD5A2 mutations and no mutations were not statistically different. In conclusion, a significant proportion of children with presumptive diagnosis of AIS has a normal AR gene. The less severe the phenotype, the less likely is the chance of demonstrating a mutation. Furthermore, a significant number of children with presumptive diagnosis of AIS have mutations in SRD5A2 gene and are clinically and biochemically indistinguishable from AIS.


Assuntos
3-Oxo-5-alfa-Esteroide 4-Desidrogenase/genética , Síndrome de Resistência a Andrógenos/diagnóstico , Transtorno 46,XY do Desenvolvimento Sexual/genética , Proteínas de Membrana/genética , Receptores Androgênicos/genética , Adolescente , Síndrome de Resistência a Andrógenos/genética , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Mutação , Turquia
8.
Minerva Pediatr ; 63(6): 483-90, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22075803

RESUMO

Childhood obesity is one of the most serious global public health challenges of the 21st century. The prevalence of this problem has increased at an alarming rate in many countries. The main causes of childhood obesity are; sedentary lifestyle, unhealthy eating patterns, genetic factors, socio-economic status, race/ethnicity, media and marketing, and the physical environment. Children are clearly being targeted as a receptive market by the manufacturing industry. Undoubtedly, television provides one of the most powerful media through which products can be advertised. Furthermore, food advertising accounted for the largest percentage of these advertisements in virtually all countries. Detailed nutritional analysis of food advertisements identified that up to 90% of food products have a high fat, sugar or salt content. Therefore TV viewing is recently identified as one of the risk factors contributing to development of childhood obesity by several mechanisms. This review provides some facts and figures about the global trend of rising obesity among children, amount and content of television and especially food advertisements being watched by children and its possible mechanisms how to cause adverse effects on children's health and contribute to childhood obesity.


Assuntos
Publicidade , Indústria Alimentícia , Obesidade/epidemiologia , Pobreza , Televisão , Índice de Massa Corporal , Criança , Proteção da Criança , Alimentos , Saúde Global , Humanos , Necessidades Nutricionais , Obesidade/etiologia , Prevalência , Saúde Pública , Fatores de Risco
10.
J Clin Pharm Ther ; 33(6): 603-11, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19138237

RESUMO

BACKGROUND: To study the effects of inhaled steroid withdrawal on bronchial hyperreactivity, sputum inflammatory markers and neutrophilic apoptosis in children with non-cystic fibrosis (non-CF) bronchiectasis. OBJECTIVES: To evaluate the role of inhaled steroids in the treatment of children with non-CF bronchiectasis with specific emphasis on the bronchial hyperreactivity and neutrophilic apoptosis. METHODS: Twenty-seven children with steady-state non-CF bronchiectasis were evaluated primarily with metacholine challenge tests and apoptotic neutrophil ratios in induced sputum and secondarily with symptom scores, pulmonary function tests and tumour necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8) levels and neutrophil ratios in induced sputum before and after 12-week withdrawal of inhaled steroids. RESULTS: There were 16 girls and 11 boys. Median (interquartile range) age was 11.4 (9.5-13.6) years, follow-up duration was 3.5 (2-6.5) years. Symptom scores (4 vs. 3; P = 0.27), oxygen saturation (95% vs. 97%; P = 0.06), pulmonary function tests (FEV1: 82% predicted vs. 83% predicted; P = 0.73), sputum neutrophil ratios (29.9% vs. 46.8%; P = 0.20), TNF-alpha (58 pg/mL vs. 44.5 pg/mL; P = 0.55) and IL-8 (2.7 ng/mL vs. 2.4 ng/mL; P = 0.82) levels in induced sputum were similar before and after 12-week withdrawal of inhaled steroids. However, the number of patients with bronchial hyperreactivity increased (37% vs. 63% of patients; P = 0.016) and neutrophilic apoptosis in induced sputum decreased (42.8% vs. 20.2%; P = 0.03) after withdrawal. CONCLUSION: In this study, 12 week-withdrawal of inhaled steroid treatment resulted in a significant increase in bronchial hyperreactivity and decrease in neutrophil apoptosis, but no change in sputum inflammatory markers in children with non-CF bronchiectasis was observed.


Assuntos
Bronquiectasia/tratamento farmacológico , Glucocorticoides/administração & dosagem , Síndrome de Abstinência a Substâncias/etiologia , Administração por Inalação , Adolescente , Apoptose/efeitos dos fármacos , Biomarcadores/metabolismo , Hiper-Reatividade Brônquica/etiologia , Criança , Feminino , Humanos , Inflamação/etiologia , Masculino , Cloreto de Metacolina , Neutrófilos/metabolismo , Escarro/metabolismo
11.
Acta Paediatr ; 93(6): 770-4, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15244225

RESUMO

AIM: Breath-holding spells are common in infancy and early childhood, and patients are frequently referred to paediatric cardiology clinics for exclusion of heart disease. Recent data reveal subsequent development of epilepsy and neurocardiogenic syncope. Autonomic dysregulation and increased vagal stimulation leading to cardiac arrest and cerebral ischaemia is considered as the cause. Iron deficiency anaemia may be associated with these spells. We studied QT dispersion for the assessment of ventricular repolarization in these patients. METHODS: The study group consisted of 19 girls and 24 boys between 3 and 108 mo of age (mean +/- SD = 22.7 +/- 17.7 mo); and the control group consisted of 13 girls and 12 boys between 3 and 57 mo of age (mean +/- SD = 22.9 +/- 15.1 mo). QT interval was measured; corrected QT interval (QTc), QT dispersion (QTd) and QTc dispersion (QTcd) were calculated from 12-lead surface electrocardiograms of the patients and the control group. RESULTS: There was no statistically significant difference in terms of QT and QTc intervals between patient and control groups, while QTd and QTcd values were significantly increased in patients with breath-holding spells compared to the healthy children. QT dispersion was 59.5 +/- 35.9 ms and 44.8 +/- 11.9 ms, respectively, in patients and controls (p < 0.05). QTc dispersion was 102.1 +/- 41.9 ms and 79.6 +/- 24.6 ms, respectively (p < 0.01). The presence of iron deficiency did not effect the QT and QTc dispersion. CONCLUSION: QT dispersion is increased in patients with breath-holding spells, and this finding justifies further investigation for rhythm abnormalities and autonomic dysfunction in this patient group.


Assuntos
Arritmias Cardíacas/etiologia , Choro , Deficiências de Ferro , Respiração , Síncope/etiologia , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/fisiopatologia , Pré-Escolar , Eletrocardiografia , Humanos , Lactente , Síncope/diagnóstico , Síncope/fisiopatologia
12.
Br J Ophthalmol ; 77(4): 233-7, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8494860

RESUMO

Local laser targeted delivery of a platelet aggregating agent to occlude retinal and choroidal vessels was evaluated in rabbits and rats. Liposomes containing adenosine diphosphate (ADP) were administered intravenously and an argon laser was used to lyse the liposomes in main retinal arteries. Control vessels were treated with the same energy of laser without administering ADP. Fluorescein angiography performed 2 weeks later showed that all the control vessels were perfused. Ninety percent of the ADP-treated arteries showed complete or partial occlusion. Successful occlusion increased with the laser energy and decreased with increasing vessel diameter. Histopathology showed that occlusion was achieved in retinal as well as choroidal vessels. The inner retina remained relatively unaffected at the treatment site but the outer retina was thermally damaged. These preliminary results suggest that targeted delivery of a platelet aggregating agent holds promise for occluding vessels in the fundus.


Assuntos
Difosfato de Adenosina/administração & dosagem , Embolização Terapêutica/métodos , Agregação Plaquetária/efeitos dos fármacos , Vasos Retinianos , Animais , Corioide/irrigação sanguínea , Corioide/patologia , Portadores de Fármacos , Angiofluoresceinografia , Lasers , Lipossomos , Coelhos , Ratos , Artéria Retiniana/patologia , Oclusão da Artéria Retiniana/patologia
13.
Invest Ophthalmol Vis Sci ; 32(8): 2351-6, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2071345

RESUMO

A new method was developed to deliver locally a bolus dose of a drug to the retinal vasculature. The targeted delivery system was based on encapsulating the drug in heat-sensitive liposomes, which are injected intravenously and lysed in the retinal vessels by a heat pulse generated by a laser. To test if substances delivered in the vessels could also penetrate into the surrounding tissue, 6-carboxyfluorescein was encapsulated in liposomes and used as a marker for drug penetration. Moderate argon laser pulses were applied to the retinal vessels of Dutch pigmented rabbits to induce breakdown of the blood-retinal barrier (BRB). A suspension of liposomes at a dose of 2 ml/kg body weight, corresponding to a carboxyfluorescein dose of 12 mg/kg, was injected into the ear vein. The dye was released from the liposomes proximal to the damaged portion of the vessel. Fundus fluorescein angiograms were recorded with a video camera and digitized for subsequent image analysis. The penetration of carboxyfluorescein into the retinal tissue was evaluated by comparing the fluorescence intensity of the area around the damaged vessel with that of an adjacent control area. The dye penetration increased with the numbers of laser applications (P less than 0.001). The leakage was localized distally to the released site and was restricted to areas with a disrupted BRB. The mass of carboxyfluorescein that penetrated gradually spread with time. Both veins and arteries could be used for the targeted delivery. These results indicated that this delivery system, which is fully controllable by laser through the pupil, can deliver drugs inside the vasculature and into the retinal tissue wherever the BRB is disrupted.


Assuntos
Barreira Hematorretiniana/efeitos dos fármacos , Fluoresceínas/farmacocinética , Lipossomos , Retina/metabolismo , Animais , Barreira Hematorretiniana/efeitos da radiação , Portadores de Fármacos , Angiofluoresceinografia , Fundo de Olho , Temperatura Alta , Processamento de Imagem Assistida por Computador , Terapia a Laser , Lasers/efeitos adversos , Coelhos , Vasos Retinianos/efeitos dos fármacos , Vasos Retinianos/efeitos da radiação
14.
Invest Ophthalmol Vis Sci ; 31(11): 2300-6, 1990 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2242995

RESUMO

A new method designed to allow repeated mapping of retinal hemodynamics on a macro- and microcirculatory level was evaluated in the primate eye. The method, called "targeted dye delivery," consists of encapsulating a fluorescent dye in temperature-sensitive liposomes, injecting the liposomes systemically, and using a light pulse from an argon laser to release a bolus of dye in a targeted retinal vessel. The follow-up of the well-defined dye front thus generated allows calculation of the blood flow and capillary transit time. Evaluation of targeted dye delivery in a monkey indicated that centerline blood velocity and the vessel diameter can be measured with a reproducibility of 10% and 4%, respectively, in vessels that are 40 microns and larger. These measurements yielded flow values that had a reproducibility of 10% on the same day and 13% on different days. The normalization of flow rate by the vessel diameter was consistent with theoretic estimates and promises to be a circulation indicator independent of variations between individual and species. The transit time across capillary beds at different locations was found to be similar, thus indicating that the method could be used to evaluate the local viability of the microcirculation.


Assuntos
Angiofluoresceinografia/métodos , Fluoresceínas , Vasos Retinianos/fisiologia , Animais , Densitometria , Portadores de Fármacos , Fluoresceínas/administração & dosagem , Fundo de Olho , Hemodinâmica/fisiologia , Lasers , Lipossomos , Macaca mulatta , Reprodutibilidade dos Testes
15.
Invest Ophthalmol Vis Sci ; 31(8): 1459-65, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2387679

RESUMO

Although fluorescein angiography has proven to be an important tool in the diagnosis and management of retinal vascular diseases, it is subject to certain limitations, namely the presence of the choroidal background, which usually precludes a detailed examination of the retinal microvasculature. Moreover, the inability to repeat the bolus reduces the chance of obtaining high-quality photographs of early phases, and does not allow for a complete binocular examination or for testing the response to induced physiologic changes. We have developed a method of targeted dye delivery that consists of encapsulating the dye in lipid vesicles, injecting them intravenously, and causing them to release their contents locally when a short heat pulse is induced in a retinal artery by a laser. This method was applied in the rhesus monkey in order to visualize the retinal microvasculature. A well-defined bolus and absence of background fluorescence permitted both following of the dye front through the vasculature and clear imaging of the capillary network over the whole posterior pole. The bolus delivery could be repeated as many as 100 times in 45 min without significant loss of contrast. The comparison of these results with conventional fluorescein angiography illustrated the advantage of the new method. The examination of the safety of the delivery system indicates that there is no major obstacle to the eventual application to humans.


Assuntos
Angiofluoresceinografia/métodos , Fluoresceínas/administração & dosagem , Vasos Retinianos/anatomia & histologia , Animais , Capilares/anatomia & histologia , Portadores de Fármacos , Fundo de Olho , Lasers , Lipossomos , Macaca mulatta
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