ROS Scavenger, Ebselen, Has No Preventive Effect in New Hearing Loss Model Using a Cholesterol-Chelating Agent

BACKGROUND AND OBJECTIVES: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. MATERIALS AND METHODS: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. RESULTS: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. CONCLUSIONS: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.

Spectrum of paediatric lysosomal storage disorders in Oman

The aim of this study was to look at the spectrum of paediatric lysosomal disorders in Oman. Lysosomal storage disorders [LSDs] are a heterogeneous group of inherited metabolic diseases. Few studies on the birth prevalence and prevalence of LSDs have been reported from the Arabian Peninsula. We studied 86 children with LSDs diagnosed over a period of nine years, from June 1998 to May 2007. Detailed clinical data, including age of onset, sex, age and mode of first presentation, and presence of consanguinity were collected. Our data showed the combined birth prevalence for all LSDs in Oman to be around 1 in 4,700 live births. Sphingolipidoses was the most common group of disorder encountered [47.7%], followed by neuronal ceroid lipofuscinoses [NCL] [23.2%] and mucopolysaccharidoses [MPS] [23.2%]. The proportion of consanguineous marriages in our series was found to be 87.5%. Conclusion: Our data represent the birth prevalence and clinicalspectrum of such disorders in Oman, one of the highly consanguineous societies in the Middle East

Arsenic induces oxidative stress, sphingolipidosis, depletes proteins and some antioxidants in various regions of rat brain.

OBJECTIVES: To seek an interrelationship, if any, between oxidant stress and neurochemical changes in various rat brain regions after arsenic exposure. MATERIALS AND METHODS: This study was carried out at the Department of Biochemistry, Al Arab Medical University, Benghazi, Libya. Seventy five male Spraque-Dawley rats were divided into three groups: CONTROL GROUP: Rats were administered 2 ml of normal saline solution/kg body weight (b.wt.) daily for 20 days by intraperitoneal (i.p.) route. ARSENIC-TREATED GROUP: Rats received elemental arsenic (as sodium arsenate) 2.0 mg/kg b.wt. daily for 20 days by i.p. route. RECOVERY GROUP: Rats received 2.0 mg/kg b.wt. elemental arsenic daily for 20 days by i.p. route and were allowed to recover for 20 days. Rats were sacrificed and brains were dissected into cerebral cortex, corpus striatum, cerebellum and brain stem. Tissue homogenized in respective mediums. And were analyzed for lipid classes, oxidative stress, concentration of proteins, glutathione and ascorbic acid by utilizing standard colorimetric procedures. RESULTS: Arsenic exposure increased the oxidant stress because lipid peroxidation was enhanced. And decreased the contents of lipid classes, proteins, glutathione and the ascorbic acid in various rat brain regions. However, thins-layer chromatography exhibited regional variations in phospholipids classes. CONCLUSION: These results suggested that arsenic-initiated oxidant stress by increasing lipid peroxidation. The losses of lipid classes, ascorbic acid and glutathione may be attributed to peroxidative damage and binding of arsenic with sulfhydryl groups of enzymes. Recovery of animals showed reversibility in most of studied parameters, but gangliosides and cerebrosides over shooted. And speculated "Sphingolipidosis". It is then likely that repeated exposures of humans to arsenic may result in hampering of cell signalling, apoptosis and mutagenesis.

Correlación clínico-patológica de enfermedades cutáneas de depósito lisosomal (I parte) / Clinico-pathological correlation of lysosomal storage skin diseases (part I)

Las enfermedades de depósito lisosomal corresponden a alteraciones congénitas del metabolismo, las cuales se heredan de forma autosómica recesiva y están caracterizadas por el déficit específico de una hidrolasa lisosomal y por el acúmulo de su sustrato en varios tejidos del organismo. Dependiendo de la naturaleza bioquímica del sustrato acumulado, éstas pueden dividirse en esfingolipidosis, oligosacaridosis, mucolipidosis, mucopolisacaridosis y otras.

Lysosomal storage diseases are autosomal recessive disorders of inborn errors of metabolism, characterized by a deficiency in a specific lysosomal hydrolase and by accumulation of its specific substrate in various body tissues. Depending on the basis of the biochemical nature of the accumulated substrate, they can be divided in sphingolipidoses, oligosaccharidoses, mucolipidoses, mucopolysaccharidoses, and others.

Sphingolipidoses / 한양의대학술지

Sphingolipidoses are a subgroup of lysosomal storage disorders. They are characterized by relentless progressive storage in affected organs and concomitant functional impairments. No overall screening procedure for these disorders is available. Their course and appearance, however, are usually characteristic and, together with relevant technical procedures such as magnetic resonance imaging (MRI), clinical neurophysiology, ophthalmologic examination, etc., a provisional diagnosis can be made, after which enzymatic diagnosis can close the gap in the diagnostic process. Subgroups of sphingolipidoses are grouped together, such as disorders with prominent hepatosplenomegaly (Niemann-Pick A, B and Gaucher disease) and disorders with central and peripheral demyelination (metachromic leukodystrophy and Krabbe disease). Farber disease and Fabry disease are unique in themselves. The last decade has seen hopeful progress in therapeutic strategies, especially for Gaucher disease. Therefore, emphasis of this review has been placed on these new developments.

Inborn Errors of Metabolism in Korea

Diseases of inborn errors of metabolism (IEMs) are very rare but the overall prevalence of IEMs is not low, and in the United States, about 5~10% of admitted patients have some genetic predispositions. Clinical manifestations of IEMs are very diverse, but most frequent manifestations are neurological symptoms and signs. IEMs in Korea have been underestimated because of prejudice, underdevelopment of diagnostic tools and ignorance. The Korean Pediatric Society has done a retrospective study in order to know the relative incidence of IEMs in 2001. All hospitals with over 100 beds participated in the study. The most frequent disease was Wilson disease (201 cases for 10 years) followed by phenylketonuria (98 cases for 10 years) and Hunters disease (69 cases for 10 years). Disorders of mineral metabolism were the most frequently diagnosed disease groups (252 cases for 10 years) followed by organic acidopathies (220 cases), aminoacidopathies (139 cases), mucopolysaccharidosis (131 cases), disorders of carbohydrate metabolism (84 cases), sphingolipidosis (69 cases), urea cycle disorders (39 cases), peroxisomal disorders (27 cases), porphyrias (16 cases), disorders of purine and pyrimidine metabolism (14 cases), disorders of membrane transport (13 cases), fatty acid oxidation disorders (9 cases), oligosaccharidosis (2 cases), and mucolipidosis (1 case). Clearly, Koreans are not protected from IEMs and a systematic approach is needed to make diagnosis more easy and accurate.

Manifestações esqueléticas da doença de gaucher / Skeletal manifestations in Gaucher's disease

A doença de Gaucher é manifestação genética causada pela deficiência da enzima glicocerebrosidase, resultando no acúmulo secundário de glicocerebrosídeos nos órgãos do sistema reticuloendotelial. Apresenta-se sob três formas clínicas distintas, podendo ser rapidamente fatal ou crônica com poucos sintomas. O presente trabalho tem o objetivo de analisar os achados da radiografia simples do esqueleto em 32 pacientes comprovadamente portadores da doença, de ambos os sexos e em diferentes faixas etárias. Foram observadas as seguintes alterações: osteopenia difusa em todos os casos, deformidade em "frasco de Erlenmeyer" em 93,7 por cento, alterações articulares em 40,6 por cento, necrose da cabeça do fêmur e lesões líticas em 28,1 por cento, respectivamente, fratura patológica em 9,3 por cento e necrose da cabeça do úmero em 6,2 por cento dos casos. Estes resultados encontram-se de acordo com as descrições da literatura, demonstrando a importância da radiologia convencional como método complementar no diagnóstico desta enfermidade

Gaucher's disease has a genetic background and is characterized by the deficiency of enzyme glucocerebrosidase, resulting in secondary accumulation of glucocerebrosides in the reticuloendothelial organs. The objective of the present study is to evaluate the x-ray findings in the skeleton of a group of 32 male and female patients of different ages, with biochemical diagnosis of Gaucher's disease. The following bone lesions were observed: diffuse osteopenia (100% of the patients), "Erlenmeyer flask" deformities (93.7% of the patients), abnormalities of the joints (40.6% of the patients), necrosis of the femoral head (28.1% of the patients), lytic lesions (28.1% of the patients), pathological fractures (9.3% of the patients) and necrosis of the humeral head (6.2% of the patients). These results are concordant with the literature, and demonstrate the importance of conventional x-ray as a complementary method in the diagnosis of Gaucher's disease.

Doença de Fabry: apresentação de um caso / Fabry disease: a case report

É relatado um caso de Doença de Fabry (Angioceratoma Corporal Diifuso Universal) em uma paciente que na segunda internação no Hospital da Santa Casa de Misericórdia do Pará, em 1995, aos 12 anos de idade, apresentava Encefalopatia Hipertensiva. No transcurso desta de de várias outras internações subsequentes, foram constatadas alterações renais, cardíacas (decorrentes da hipertensão arterial), vasculares de fundo de olho e cutâneas, prepoderando, entretanto, as manifestações renais. O diagnóstico de sua doença básica foi efeetuado por histopatologia de biópsia percutânea renal. Foi instituida a terapêutica com o uso de hipotensores, diuréticos e dieta. A recrudescência do quadro hipertensivo determinou as varias internações, a última em 13.08.1999. A paciente permanece em observação ambulatorial por uma eventual necessidade de transplante renal