Electron Microscopic and Isozyme Study of a Case of Ochronosis

1972 ◽  
Vol 30 ◽  
pp. 88-89
Author(s):  
Jay W. Cha ◽  
Perry J. Melnick
Keyword(s):  
Benzene Ring ◽  
Enzyme System ◽  
Homogentisic Acid ◽  
Degenerative Changes ◽  
Acid Oxidase ◽  
Electron Microscopic ◽  
Tyrosine Metabolism ◽  
Collagenous Tissues

Hereditary ochronosis in very few cases has been examined electron microscopically or histochemically. In this disease homogentisic acid, a normal intermediary of tyrosine metabolism, forms in excessive amounts. This is believed to be due to absence or defective activity of homogentisic acid oxidase, an enzyme system necessary to break the benzene ring and to further break it down to fumaric and acetoacetic acids. Ochronotic pigment, a polymerized form of homogentisic acid, deposits mainly in mesenchymal tissues. There has been a question whether the pigment originates from the collagenous tissues, or deposits passively, where in contrast to melanin it induces degenerative changes.

scholarly journals Skin pigmentation, a window to diagnose Alkaptonuria: a very rare entity

2017 ◽  
Vol 5 (6) ◽  
pp. 2801
Author(s):  
Sandhya Chauhan ◽  
Ashok Garg ◽  
G. R. Tegta ◽  
Kuldeep Thakur
Keyword(s):  
Autosomal Recessive ◽  
Skin Pigmentation ◽  
Clinical Manifestations ◽  
Homogentisic Acid ◽  
Cardiac Complications ◽  
Acid Oxidase ◽  
Urine Examination ◽  
Tyrosine Metabolism ◽  
Oxidase Enzyme ◽  
Rare Inborn Error

Alkaptonuria (AKU) or endogenous ochronosis is a very rare inborn error of tyrosine metabolism inherited by autosomal recessive mode. There is complete absence of homogentisic acid oxidase enzyme which results in accumulation of homogentisic acid in cartilaginous connective tissue thus produces ochronotic clinical manifestations. Here we reported a 36 year old woman with bluish pigmentation of pinnae, index fingers (lateral aspect), nails, teeth and sclera. Detailed clinical and investigative workup was done to diagnose patient. Skin biopsy showed changes of ochronosis and urine examination revealed detectable level of homogentisic acid. Classical ocular findings, ochronosis on clinical and HPE and positive urinary tests for homogentisic acid confirmed the diagnosis of alkaptonuria. The highlight of our case is that an asymptomatic patient was detected early by ochronosis prior to development of musculoskeletal or cardiac complications.

scholarly journals HOMOGENTISIC ACID OXIDASE

1955 ◽  
Vol 212 (2) ◽  
pp. 565-582
Author(s):  
Dana I. Crandall
Keyword(s):  
Homogentisic Acid ◽  
Acid Oxidase

scholarly journals Mutation spectrum of homogentisic acid oxidase (HGD) in alkaptonuria

2009 ◽  
Vol 30 (12) ◽  
pp. 1611-1619 ◽  
Author(s):  
Thierry Vilboux ◽  
Michael Kayser ◽  
Wendy Introne ◽  
Pim Suwannarat ◽  
Isa Bernardini ◽  
...  
Keyword(s):  
Homogentisic Acid ◽  
Mutation Spectrum ◽  
Acid Oxidase

The effects of an antiserum to the contractile proteins of the heart on the developing rat embryo

Development ◽  
1971 ◽  
Vol 25 (2) ◽  
pp. 203-212
Author(s):  
Colin L. Berry
Keyword(s):  
Rat Heart ◽  
Contractile Proteins ◽  
Degenerative Changes ◽  
Foetal Death ◽  
Rat Embryo ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
Specific Reactivity ◽  
Developing Rat ◽  
Isolated Rat

An antiserum with specific reactivity against the contractile proteins of the rat heart has been raised in the rabbit. Fractions of the serum have been shown to enter the isolated rat embryo by electron-microscopic studies with ferritin, where they bind to the myocardium, producing degenerative changes. Both IgG and IgM fractions are toxic, producing foetal death in a large proportion of explanted embryos.

Alkaptonuria in an adolescent boy

2021 ◽  
Vol 14 (2) ◽  
pp. e240147
Author(s):  
Geminiganesan Sangeetha ◽  
Senthil Chandran ◽  
Swathi Ganesan ◽  
Jaippreetha Jayaraj
Keyword(s):  
Inborn Errors Of Metabolism ◽  
Genetic Test ◽  
Genetic Disorder ◽  
Homogentisic Acid ◽  
Paediatric Nephrology ◽  
Inborn Errors ◽  
Tyrosine Metabolism ◽  
Ear Cartilage

Alkaptonuria is a rare genetic disorder resulting in abnormality of tyrosine metabolism. It is one of the Garrod’s tetrad of ‘inborn errors of metabolism’ proposed to have Mendelian recessive inheritance. The disorder is characterised by deposition of homogentisic acid leading to ochronosis and ochronotic osteoarthropathy; however, blackish discoloration of urine is the only childhood manifestation. Other manifestations present only after third decade. A 13-year-old boy presented to paediatric nephrology clinic with blackish discolouration of urine since infancy. Examination revealed bluish black discolouration of bilateral sclera and ear cartilage; however, he had no symptoms of ochronotic osteoarthropathy. Genetic test pointed towards alkaptonuria. Currently, he is on regular follow-up and is being treated with vitamin C to delay the progression of the disease. Early diagnosis with appropriate intervention delays the onset of complications and preserves the quality of life of the patient.

scholarly journals Immunocytochemical localization of D-amino acid oxidase in the central clear matrix of rat kidney peroxisomes.

1986 ◽  
Vol 34 (12) ◽  
pp. 1709-1718 ◽  
Author(s):  
N Usuda ◽  
S Yokota ◽  
T Hashimoto ◽  
T Nagata
Keyword(s):  
Amino Acid ◽  
Proximal Tubule ◽  
Rat Kidney ◽  
Protein A ◽  
Immunoblot Analysis ◽  
Acid Oxidase ◽  
Electron Microscopic ◽  
Amino Acid Oxidase ◽  
Thin Sections ◽  
Gold Particles

Light and electron microscopic localizations of D-amino acid oxidase (DAO) in rat kidney was investigated using immunoenzyme and protein A-gold techniques. The enzyme was purified from rat kidney homogenate and its antibody was raised in rabbits. By Ouchterlony double-diffusion analysis and immunoblot analysis with anti-(rat kidney DAO) immunoglobulin, the antibody was confirmed to be monospecific. The tissue sections (200 micron thick) of fixed rat kidney were embedded in Epon or Lowicryl K4M. Semi-thin sections were stained for DAO by the immunoenzyme technique after removal of epoxy resin for LM, and ultra-thin sections of Lowicryl-embedded material were labeled for DAO by the protein A-gold technique for EM. By LM, fine cytoplasmic granules of proximal tubule were stained exclusively. Among three segments of proximal tubules, and S2 and S3 segments were heavily stained but the S1 segment only weakly so. By EM, gold particles indicating the antigenic sites for DAO were exclusively confined to peroxisomes. Within peroxisomes, the gold particles were localized in the central clear matrix but not in the peripheral tubular substructures. The results indicate that D-amino acid oxidase in rat kidney is present exclusively in peroxisomes in the proximal tubule and that within peroxisomes it is found only in central clear matrix and not in the peripheral tubular substructures.

scholarly journals Sequential tendon ruptures in ochronosis: case report

2017 ◽  
Vol 3 (6) ◽  
pp. 1235
Author(s):  
E. G. Mohan Kumar ◽  
G. M. Yathisha Kumar
Keyword(s):  
Connective Tissue ◽  
Case Reports ◽  
Autosomal Recessive Disorder ◽  
Degradation Pathway ◽  
Homogentisic Acid ◽  
The Body ◽  
Acid Oxidase ◽  
Connective Tissues ◽  
Dark Pigmentation ◽  
Tendon Ruptures

<p>Alkaptonuria is a rare autosomal recessive disorder characterised by the absence of homogentisic acid oxidase, due to deficiency of an enzyme that degrades HGA in the tyrosine degradation pathway. Homogentisic acid (HGA) and its metabolites accumulate in the connective tissues leading to dark pigmentation of connective tissue in patients with alkaptonuria. HGA deposits in connective tissue causes weakness of the tendon and subsequent rupture, especially the large tendons in the body. Only few cases are reported in the literature with multiple tendon rupture but many case reports are available with isolated rupture of tendons. We report on a patient with sequential tendon ruptures in a patient. The case is reported for its rarity.</p>

Purification of the homogentisic acid oxidase from mammalian liver

1995 ◽  
Vol 27 (12) ◽  
pp. 1357-1363 ◽  
Author(s):  
Soňa Hudecová ◽  
Zuzana Straková ◽  
Olga Krianova
Keyword(s):  
Homogentisic Acid ◽  
Acid Oxidase ◽  
Mammalian Liver
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