Apoptosis in the central nervous system of cerebral adrenoleukodystrophy patients.

The childhood cerebral form of adrenoleukodystrophy (ALD) is a fatal demyelinating disease, yet mice deficient in the ALD gene do not show such clinicopathological phenotype. We have therefore investigated in human autopsy tissues whether the ALD gene mutation results in apoptosis of CNS cells. Specimens from telencephalic and brainstem regions of four patients, and three controls were examined for internucleosomal DNA fragmentation, in situ detection of DNA breaks by the TUNEL method, and caspase-3 immunostaining. None of the controls showed significant apoptosis in white matter, while apoptotic nuclei with chromatin alterations were detected in areas of active demyelination in three ALD patients. A large proportion of apoptotic cells were oligodendrocytes and some express activated caspase-3. TUNEL-positive nuclei and/or caspase-3 staining were also detected in perivascular infiltrates and, occasionally, in neurons. We conclude that apoptosis of oligodendrocytes may account, at least in part, for the demyelinating process in the ALD brain.

The neurobiology of X-linked adrenoleukodystrophy, a demyelinating peroxisomal disorder.

Adrenoleukodystrophy (ALD) is caused by mutations in an ATP-binding-cassette transporter located in the peroxisomal membrane, which result in a fatal demyelinating disease in boys and a milder phenotype in men and some heterozygous women. There is no molecular signature to indicate a particular clinical course. The underlying molecular mechanisms of this disease have yet to be targeted clinically. Is the increase in very-long-chain fatty acids (VLCFA) the disease trigger? Why is there no phenotype in ALD null mice that show this increase? Do VLCFA destabilize human myelin, once formed, and lead to the inflammation seen in this genetic disease? Bone-marrow transplantation might save a child by providing normal brain macrophages and allowing myelin regeneration early in disease. The processes that underlie ALD challenge neuroscientists to elucidate peroxisomal transporter functions in the nervous system and to pursue the gene-transfer strategies leading to remyelination until a preventive therapy emerges.

Mutational and protein analysis of patients and heterozygous women with X-linked adrenoleukodystrophy.

X-linked adrenoleukodystrophy (ALD), a neurodegenerative disorder associated with impaired beta-oxidation of very-long-chain fatty acids (VLCFA), is due to mutations in a gene encoding a peroxisomal ATP-binding cassette (ABC) transporter (ALD protein [ALDP]). We analyzed the open reading frame of the ALD gene in 44 French ALD kindred by using SSCP or denaturing gradient-gel electrophoresis and studied the effect of mutations on ALDP by immunocytofluorescence and western blotting of fibroblasts and/or white blood cells. Mutations were detected in 37 of 44 kindreds and were distributed over the whole protein-coding region, with the exception of the C terminus encoded in exon 10. Except for two mutations (delAG1801 and P560L) observed four times each, nearly every ALD family has a different mutation. Twenty-four of 37 mutations were missense mutations leading to amino acid changes located in or close to putative transmembrane segments (TMS 2, 3, 4, and 5), in the EAA-like motif and in the nucleotide fold of the ATP-binding domain of ALDP. Of 38 ALD patients tested, 27 (71%) lacked ALDP immunoreactivity in their fibroblasts and/or white blood cells. More than half of missense mutations studied (11 of 21) resulted in a complete lack of ALDP immunoreactivity, and six missense mutations resulted in decreased ALDP expression. The fibroblasts and/or white blood cells of 15 of 15 heterozygous carrier from ALD kindred with no ALDP showed a mixture of positive- and negative-ALDP immunoreactivity due to X-inactivation. Since 5%-15% of heterozygous women have normal VLCFA levels, the immunodetection of ALDP in white blood cells can be applicable in a majority of ALD kindred, to identify heterozygous women, particularly when the ALD gene mutation has not yet been identified.

Obstructing carcinoma of the left colon: treatment by extended right hemicolectomy.

Obstructing carcinoma of the left side of the colon causes proximal distension of the colon with subsequent thinning of the colonic wall and vascular impairment. Conventional surgical treatment is multi-staged. Each stage carries its own morbidity and mortality. An alternate treatment, extended right hemicolectomy, requires a single surgical procedure. Fifty-six cases of acute obstructing carcinoma of the left colon are presented: 16 in Group I were treated conventionally; 40 in Group II were treated by extended right hemicolectomy. In Group I, four died within one week of surgery. Six survived with a colostomy; all suffered from poor quality of life until death. For the six who received complete treatment, average total hospitalization was 54 days. Group II suffered no peri-operative mortality. Patients were discharged without a colostomy after an average hospitalization of 15.7 days. Advantages of and conditions for treatment by extended right hemicolectomy are discussed.