Estudo piloto sobre a eficácia e segurança do uso da cisteamina 5% como terapia de contato por toda noite no tratamento do melasma facial / Efficacy and safety of the 5% cysteamine cream left in overnight for facial melasma: a pilot study

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Not applicable, this is a letter.

Challenges for cysteamine stabilization, quantification, and biological effects improvement / 药物分析学报

The aminothiol cysteamine, derived from coenzyme A degradation in mammalian cells, presents several biological applications. However, the bitter taste and sickening odor, chemical instability, hygroscopicity, and poor pharmacokinetic profile of cysteamine limit its efficacy. The use of encapsulation systems is a good methodology to overcome these undesirable properties and improve the pharmacokinetic behavior of cysteamine. Besides, the conjugation of cysteamine to the surface of nanoparticles is generally pro-posed to improve the intra-oral delivery of cyclodextrin-drug inclusion complexes, as well as to enhance the colorimetric detection of compounds by a gold nanoparticle aggregation method. On the other hand, the detection and quantification of cysteamine is a challenging mission due to the lack of a chromophore in its structure and its susceptibility to oxidation before or during the analysis. Derivatization agents are therefore applied for the quantification of this molecule. To our knowledge, the derivatization techniques and the encapsulation systems used for cysteamine delivery were not reviewed previously. Thus, this review aims to compile all the data on these methods as well as to provide an overview of the various biological applications of cysteamine focusing on its skin application. Cysteamine Detection Encapsulation Skin Stability The aminothiol cysteamine, derived from coenzyme A degradation in mammalian cells, presents several biological applications. However, the bitter taste and sickening odor, chemical instability, hygroscopicity, and poor pharmacokinetic profile of cysteamine limit its efficacy. The use of encapsulation systems is a good methodology to overcome these undesirable properties and improve the pharmacokinetic behavior of cysteamine. Besides, the conjugation of cysteamine to the surface of nanoparticles is generally pro-posed to improve the intra-oral delivery of cyclodextrin-drug inclusion complexes, as well as to enhance the colorimetric detection of compounds by a gold nanoparticle aggregation method. On the other hand, the detection and quantification of cysteamine is a challenging mission due to the lack of a chromophore in its structure and its susceptibility to oxidation before or during the analysis. Derivatization agents are therefore applied for the quantification of this molecule. To our knowledge, the derivatization techniques and the encapsulation systems used for cysteamine delivery were not reviewed previously. Thus, this review aims to compile all the data on these methods as well as to provide an overview of the various biological applications of cysteamine focusing on its skin application.

Nephropathic cystinosis presenting with uveitis: Report of a “Can't See, Can't Pee” situation

Nephropathic cystinosis is a rare autosomal recessive lysosomal disease characterized by accumulation of pathognomonic cystine crystals in renal and other tissues of the body. Cystinosis is caused by mutant cystinosin, the cystine transport protein located in lysosomal membranes, leading to systemic deposits of cystine and resultant end organ damage. Cystinosis is rarer in Asians than Caucasians with only a handful of cases reported from India to date. Due to its extreme rarity and clinically insidious presentation in contrast to the infantile form, the diagnosis of juvenile nephropathic cystinosis is frequently delayed or overlooked. Moreover, routine processing and sectioning of paraffin embedded tissues dissolves cystine crystals, making it difficult to diagnose this condition on light microscopic examination alone, mandating electron microscopic (EM) analysis of renal biopsies for an accurate diagnosis of this condition. We describe a case of juvenile nephropathic cystinosis presenting with uveitis and photophobia in a 17-year-old Indian male, diagnosed after EM examination of the patient's renal biopsy for evaluation of nephrotic syndrome. While highlighting the diagnostic utility of EM, we describe a few histopathologic clues which can prompt inclusion of EM analysis of renal biopsies in this setting.

In vivo confocal microscopy and anterior segment optical coherence tomography follow-up of cysteamine treatment in corneal cystinosis

A 36-year-old female presented initially with photophobia and visual deterioration. After examination and laboratory tests, patient was diagnosed with cystinosis. Cysteamine drops 4 × 1 drops/day was given as treatment for 1 year. During follow-up, in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) was performed. Photophobia was relieved and IVCM obtained the decrease in size and density of corneal crystals 1 year after. Depth of corneal crystals did not change but crystal density score reduced with cysteamine treatment.

Thiol/disulfide status regulates the activity of thiol-containing kinases related to energy homeostasis in rat kidney

ABSTRACT Considering that thiol-containing enzymes like kinases are critical for several metabolic pathways and energy homeostasis, we investigated the effects of cystine dimethyl ester and/or cysteamine administration on kinases crucial for energy metabolism in the kidney of Wistar rats. Animals were injected twice a day with 1.6 µmol/g body weight cystine dimethyl ester and/or 0.26 µmol/g body weight cysteamine from the 16th to the 20th postpartum day and euthanized after 12 hours. Pyruvate kinase, adenylate kinase, creatine kinase activities and thiol/disulfide ratio were determined. Cystine dimethyl ester administration reduced thiol/disulfide ratio and inhibited the kinases activities. Cysteamine administration increased the thiol/disulfide ratio and co-administration with cystine dimethyl ester prevented the inhibition of the enzymes. Regression between the thiol/disulfide ratio, and the kinases activities were significant. These results suggest that redox status may regulate energy metabolism in the rat kidney. If thiol-containing enzymes inhibition and oxidative stress occur in patients with cystinosis, it is possible that lysosomal cystine depletion may not be the only beneficial effect of cysteamine administration, but also its antioxidant and thiol-protector effect.

Cistinosis nefropática: caso clínico que ilustra diagnóstico molecular / Nephropatic cystinosis: report of one case

Nephropatic cystinosis (NC) is a rare disease associated with pathogenic variants in the CTNS gene, with a common variant that consists of a 57kb-deletion involving CTNS. Patients with NC that are treated with cysteamine improve their life quality and expectancy. We report a 12-month-old girl with a poor growth rate since the 4th month of life. She was admitted to the Hospital with acute kidney injury, severe dehydration and metabolic acidosis. She was treated with volume restorative and bicarbonate. Proximal tubulopathy and Fanconi's syndrome was diagnosed. Medical treatment improved renal function that was stabilized in stage 4 chronic kidney disease (CKD). Since infantile NC was suspected, CTNS genetic analysis was considered. Genomic DNA was isolated from peripheral blood to perform PCR for exons 3-12 in CTNS gene and for the specific 57kb-deletion PCR. Afterwards, variant segregation analysis was performed in the familiar trio. The genetic analysis showed that the patient was homozygous for the common 57kb-deletion encompassing CTNS that had been inherited from her asymptomatic heterozygous parents. The molecular confirmation allowed genetic counselling for parents and facilitated the access to cysteamine. Oral treatment with cysteamine resulted in improvement of renal function to CKD stage 3. After 16 months of treatment the patient shows metabolic stability and mild recovery of height. Ophthalmologic follow-up detected ocular cystine crystals 12 months after diagnosis, starting cysteamine drops.

Cristales oportunos: cistinosis nefropática. Reporte de caso / Timely cristals: nephropathic cystinosis. Case report

Objetivo: Describir el caso clínico de un paciente con Cistinosis Nefropática diagnosticado a muy temprana edad. Método: Reporte de caso. Resultados: Se reporta el caso de una paciente de 7 meses de edad, quien consulta con poliuria, piolidipsia, glucosuria y bajo peso para la edad. De acuerdo a protocolos de evaluación interdisciplinaria establecidos con el servicio de Pediatría se logra evidenciar hallazgos oculares que orientan al diagnóstico final de la paciente. Conclusión: La Cistinosis es una enfermedad rara, cursa con manifestaciones oculares que podrían orientar un diagnóstico temprano e incluso predecir la severidad de la enfermedad y brindar la posibilidad de un tratamiento temprano. Es importante establecer protocolos interdisciplinarios, de apoyo diagnóstico, ante la sospecha de enfermedades sistémicas con posible compromiso ocular, en lugar de desistir ante la dificultad para valorar a los niños en la consulta de oftalmología, sobre todo en aquellos menores de un año. Se demuestra este caso con fines académicos teniendo en cuenta la baja incidencia de la enfermedad, pero también para destacar la importancia de contar con protocolos de atención interdisciplinaria ante la sospecha de enfermedades metabólicas en todas las edades.

Purpose: To describe a case of an infant with Nephropathic Cystinosis and the ocular fi ndings that leads to the diagnosis. Method: Case report. Results: Th is report describe a prompt and accurate diagnosis of a 7 months old patient, who consults with polyuria, piolidipsia, glucosuria and low weight. According to interdisciplinary evaluation protocols previusly established with Pediatrics services, it was possible to demonstrate ocular fi ndings of the disease, guiding the physician to the fi nal diagnosis. Conclusion: Cystinosis is a rare disease, its clinical presentation has ocular manifestations that could guide diagnosis and even predict its severity, off ering the possibility of an early treatment. When one suspect a systemic disease, It is important to establish interdisciplinary protocol, instead of surrendering to the challenge of an ophthalmological examination of an infant. We choose this case due to its low incidence, but also to highlight the importance of having interdisciplinary care protocols when a metabolic disease is suspected.

Clinical Trials in Mitochondrial Disease: An Update on EPI-743 and RP103

Abstract Mitochondrial dysfunction results in the production of an abnormally high amount of reactive oxygen and nitrogen species, which results in redox imbalance and glutathione deficiency. Therapeutics such as EPI-743 (?-tocotrienol quinone) and RP103 (cysteamine bitartrate) have the theoretical potential to improve redox imbalance by increasing intracellular glutathione and are currently under investigation in multiple clinical trials. This review provides an update on the use of these compounds in clinical trials related to primary and secondary mitochondrial disorders. These clinical trials have not only provided hope to affected patients and their families and caregivers, but also will serve as important stepping stones for further studies as our understanding of mitochondrial disease pathogenesis continues to improve.

The reaction of cinnamaldehyde and cinnam(o)yl derivatives with thiols

Spurred by the alleged relevance of the thia-Michael reaction in the bioactivity of various classes of cinnam(o)yl natural products and by the development of a quick NMR assay to study this reaction, we have carried out a systematic study of the "native" reactivity of these compounds with dodecanethiol and cysteamine as models, respectively, of simple thiols and reactive protein thiols that can benefit from iminium ion catalysis in Michael reactions. Cinnamoyl esters and amides, as well as cinnamyl ketones and oximes, did not show any reactivity with the two probe thiols, while cinnamaldehyde () reacted with cysteamine to afford a mixture of a thiazoline derivative and compounds of multiple addition, and with aliphatic thiols to give a single bis-dithioacetal (). Chalchones and their vinylogous C5-curcuminoid derivatives were the only cinnamoyl derivatives that gave a thia-Michael reaction. From a mechanistic standpoint, loss of conjugation in the adduct might underlie the lack of a native Michael reactivity. This property is restored by the presence of another conjugating group on the carbonyl, as in chalcones and C5-curcuminoids. A critical mechanistic revision of the chemical and biomedical literature on cinnamaldehyde and related compounds seems therefore required.

Endocrine complications during and after adolescence in a patient with cystinosis

Cystinosis is a rare disease characterized by abnormal lysosomal cystine accumulation of cystine due to impaired lysosomal transport. We previously reported the first case of cystinosis in Korea in a 12-year-old boy with short stature, general weakness, and photophobia. The diagnosis was confirmed based on ophthalmic findings and biochemical analyses (serum leukocyte cystine measurement). Major endocrine manifestations at diagnosis included hypothyroidism, growth retardation, and hypogonadism. Despite oral cysteamine administration and renal replacement therapy, multiple complications including both endocrine and nonendocrine disorders developed during and after adolescence. In this report, we review the presenting features and factors related to the long-term complications in a patient with cystinosis.

Preparation of the cysteamine group substitutes of catechin compounds / 国际药学研究杂志

Objective To prepare cysteamine group substitutes of catechin compounds from Weimaining. Methods After thiolased by cysteamine, Weimaining was subjected to the open column chromatography on C18, and subsequently to the semi-preparative high performance liquid chromatograph (HPLC) to prepare the cysteamine group substitutes of catechin compounds. Results Compounds 4β-(2-aminoethylthio)catechin, 4β-(2-aminoethylthio)epicatechin, and 4β-(2-aminoethylthio) epicatechin-3-O-gallate were obtained, and their purities were above 95%. Conclusion The method is simple and easy, and provides a reference for the preparation of the cysteamine group substitutes of catechin compounds.

Preparation of the cysteamine group substitutes of catechin compounds / 国际药学研究杂志

Objective To prepare cysteamine group substitutes of catechin compounds from Weimaining. Methods After thiolased by cysteamine, Weimaining was subjected to the open column chromatography on C18, and subsequently to the semi­preparative high performance liquid chromatograph (HPLC) to prepare the cysteamine group substitutes of catechin compounds. Results Compounds 4β-(2-aminoethylthio)catechin, 4β-(2-aminoethylthio)epicatechin, and 4β-(2-aminoethylthio) epicatechin-3- J-gallate were obtained, and their purities were above 95%. Conclusion The method is simple and easy, and provides a reference for the preparation of the cysteamine group substitutes of catechin compounds.

Effect of Cysteamine on Human Peripheral Blood Mononuclear Cells-Chemically Injured Keratocytes Reaction

PURPOSE: To investigate the effect of cysteamine on mixed peripheral blood mononuclear cells (PBMCs)-chemically injured keratocytes reaction (mixed lymphocyte-keratocyte reaction; MLKR). METHODS: PBMC stimulation assay was performed after keratocytes were chemically injured with 0.05 N NaOH for 60 seconds. MLKR was treated with various concentrations of cysteamine (0-10 mM). Intracellular reactive oxygen species (ROS) formation was measured using the oxidation-sensitive fluorescent probe, 2'7'-dichlorofluorescein diacetate (DCF-DA). Proliferation rate of PBMCs stimulated by NaOH-treated keratocytes and secretion profiles of matrix metalloprotease-9 (MMP-9), transforming growth factor-beta1 (TGF-beta1), interleukin-6 (IL-6), and macrophage migration inhibitory factor (MIF) were determined using the bromodeoxyuridine proliferation assay and enzyme-linked immunosorbent assay, respectively. RESULTS: Proliferation rate of PMBCs was suppressed by cysteamine in a dose-dependent manner (p = 0.019). Fluorescence of DCF-DA decreased depending on cysteamine concentration (p < 0.001). MMP-9, IL-6 and TGF-beta1 levels were suppressed by cysteamine in a dose-dependent manner (p < 0.05), whereas MIF levels increased with cysteamine concentration of 0.5-10 mM (p = 0.008). CONCLUSIONS: These study results indicate that cysteamine induced the ROS-mediated inhibition of inflammatory cytokine release and proliferation of PBMCs stimulated by chemically injured keratocytes. Thus, cysteamine can be used in the treatment of chemical corneal burns.

Analysis of condensed tannins' constituent units by thiolysis with cysteamine hydrochloride and analysis of thiolysis products' HPLC behavior / 国际药学研究杂志

Objective To establish a method of analyzing the structural units of condensed tannins from Chinese patent medicine Wei MaiNing. Methods The ethanol extract of Wei MaiNing capsule was depolymerized in the presence of cysteamine and analyzed by HPLC, and eight major thiolysis products were identified by LC-MS analysis combined with reference sample. Meanwhile, the influence of mobile phases with different pH values on the HPLC behavior of thiolysis products was investgated. Results Eight major thiolysis products were 4β-(2-aminoethylthio)catechin, 4β-(2-aminoethylthio)epicatechin, catechin, 4β-(2-aminoethylthio)epicatechin-3-O-gallate, epicatechin, 4β-(2-aminoethylthio)catechin-3-O-gallate, epicatechin-3-O-gallate and catechin-3-O-gallate. Variation of the pH value had more impact on the retention time of catechins' aminomethylthio derivatives than that of catechins', which led to the changes of chromatographic peaks order. Conclusion The method is simple, reliable, and could be used to determine the structural units of condensed tannins. In order to ensure the stability of derivatives retention time, pH values of mobile phases should be controlled strictly when thiolysis products are analyzed by HPLC.

Inhibition of intimal hyperplasia by local perivascular application of rapamycin and imatinib mesilate after carotid balloon injury / 대한외과학회지

PURPOSE: Inhibition of the intimal hyperplasia after vascular surgery is an important issue. The purpose of this study is to define whether perivascular application of rapamycin, imatinib mesylate or cysteamine can reduce intimal hyperplasia in a carotid balloon injury model. METHODS: Each drug was mixed with 40% pluronic gel solution and was topically applied over the injured carotid artery evenly. Two or four weeks after injury, the arteries were harvested and morphometric analysis was done. RESULTS: The medial areas were not significantly different in each group and a thinning of the media as a toxic drug effect was not observed in any treatment group. The intimal area and intima-to-media (I/M) ratio were significantly reduced in rapamycin-treated group and imatinib-treated group (P < 0.05). But cysteamine-treated group showed a trend of decrease in I/M ratio in 2 weeks, but no difference in 4 weeks. CONCLUSION: Perivascular delivery of imatinib or rapamycin with pluronic gel attenuated the development of intimal hyperplasia. But cysteamine did not. Further studies are needed to refine the optimal drug dosages in large animal models.

Efeito das células do cumulus e cisteamina durante o cultivo de maturação in vitro de oócitos bovinos sobre a maturação nuclear e aquisição da competência para desenvolvimento embrionário / Effects of cumulus cells and cysteamine during bovine oocyte in vitro maturation on meiosis progression and acquisition of developmental competence

Complexos cumulus-oócito (COC), oócitos desnudos (DO) e DO cocultivados com células do cumulus em suspensão (DO+CC) foram maturados in vitro (MIV) na presença ou ausência de cisteamina (50mM). Observou-se efeito benéfico da cisteamina durante o cultivo de MIV, pois a maturação nuclear no grupo COC cisteamina foi maior do que a do COC controle (P<0,05). No grupo sem a adição de cisteamina, foi observado que a ausência de CC durante o cultivo de MIV prejudicou a maturação nuclear em DO, em relação ao COC (P<0,05), todavia a cisteamina restaurou a capacidade de progressão da meiose em DO, tornando-os semelhantes aos COC (P>0,05). O acoplamento entre oócitos e CC durante MIV demonstrou ser essencial para aquisição da competência do oócito para suportar o desenvolvimento embrionário inicial, pois COC apresentaram maior porcentagem de blastocistos e eclosão quando comparados a DO e DO+CC (P<0,05). A inclusão de cisteamina no cultivo de MIV não restaurou a aquisição da competência em DO e DO+CC, que permaneceram semelhantes aos do grupo-controle (P>0,05). Conclui-se que a cisteamina no meio de MIV melhora as taxas de maturação nuclear em COC e restaura a capacidade de progressão da meiose em DO. Todavia, na concentração utilizada neste estudo, não promove efeito benéfico no desenvolvimento embrionário.

Cumulus-oocyte complexes (COC), denuded oocytes (DO) and DO co-cultured with cumulus cells in suspension (DO+CC) were in vitro matured (IVM) in the presence or absence of cysteamine (50mM). A beneficial effect of cysteamine was observed during IVM, because the nuclear maturation in the COC cysteamine group was higher than in COC control (P<0.05). In the control group, the absence of CC during IVM impaired nuclear maturation in DO when compared to COC (P<0.05), but cysteamine restored the ability of meiosis progression in DO, making them similar to COC (P>0.05). The coupling between oocytes and CC during IVM proved to be essential for the acquisition of oocyte competence to support early embryonic development, as COC had higher percentages of blastocyst and hatching when compared to DO and DO+DC (P<0.05). However, the inclusion of cysteamine in the IVM culture did not restore the acquisition of competence in DO and DO+DC, which remained similar to the control group (P>0.05). It is concluded that cysteamine in the IVM culture improves the nuclear maturation in COC and restores the progression ability of meiosis in DO. However, in the concentration used in this study, cysteamine does not promote a beneficial effect on embryo development.

Antiulcer activity of Andrographis paniculata (Burm.f.) Wall. against cysteamine-induced duodenal ulcer in rats.

Antiulcer activity of Andrographis paniculata was evaluated by cysteamine induced duodenal ulcer model in rats. Male albino Wistar rats were pre-administered with 200 mg/kg body wt. of hydroalcoholic extact of Andrographis paniculata (HAEAP) orally, for 30 days prior to i.p. administration of 420 mg/kg body wt. of cysteamine as a single dose. Rats pre-administered with 30 mg/kg body wt. of ranitidine served as standard drug. Ulcer index, thiobarbituric acid reactive substances, mucin, glutathione peroxidase and myeloperoxidase activities, reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, glycoproteins and membrane bound enzyme activities were measured in duodenum of experimental animals. The ulcer score and myeloperoxidase activity were significantly minimized in rats treated with HAEAP. Mucin content was found to be preserved in rats treated with the extract. GSH/GSSG ratio and glutathione peroxidase activities were found to be maintained by the HAEAP. Level of lipid peroxidation products was found to be significantly low in HAEAP treated rats compared to ulcer control rats. The basolateral and brush border membrane bound enzyme activities which were depleted significantly in ulcer control rats were found to be maintained in rats pre-treated with the extract. The ulcer preventing effect was comparable to that of ranitidine treated rats. Level of glycoproteins was also found to be preserved in rats treated with the extract. The normal rats treated with the HAEAP did not show any abnormal alterations in the parameters studied. Histopathological observations also showed the ulcer preventing effect of the HAEAP. It is suggested that the ulcer preventing effect may be due to its mucin preserving and antioxidant nature.

Pharmacological efficacy of argemone mexicana plant extract, against cysteamine-induced duodenal ulceration in rats.

Objective: The plant Argemone mexicana is traditionally used as diuretic, anti-inflammatory, antibacterial, antifungal agent, and has wound-healing property. This study was carried out to evaluate the effect of A. mexicana aerial part of the plant (methanolic and aqueous extract p.o.) on duodenal ulceration. Materials and Methods: The study was carried out on the duodenal ulceration model by using cysteamine hydrochloride. Ranitidine (20 mg/kg) was used as standard drug. Results: Both the extracts of the plant A. mexicana produced a significant activity in cysteamine-induced duodenal ulceration. The aqueous extract at the dose-dependent manner showed the potent activity than methanolic extract. Conclusion: The plant A. mexicana Linn. Increased healing of gastric ulceration and prevented the development of experimentally induced duodenal ulceration in rats.