Cloning and disruption of the gene encoding an extracellular metalloprotease of Aspergillus fumigatus

Aspergillus fumigatus secretes a serine alkaline protease (ALP) and a metalloprotease (MEP) when the fungus is cultivated in the presence of collagen as sole nitrogen and carbon source. The gene encoding ALP was isolated and characterized previously. We report here the cloning and the sequencing of the gene encoding MEP. Genomic and cDNA clones were isolated from A. fumigatus libraries using synthetic oligonucleotides as probes. Stretches of the deduced amino acid sequence were found to be in agreement with the N-terminal amino acid sequence of MEP and with internal peptide sequences. The amino acid sequence of the enzyme contains a putative active-site sequence HEYTH homologous to the active site of other bacterial and eukaryotic zinc metalloproteases. Sequence analysis reveals that MEP has a pre-proregion consisting of 245 amino acid residues preceding the 388 amino acid residues of the mature region (molecular mass of 42 kDa). An alp mep mutant, deficient in proteolytic activity at neutral pH in vitro, was constructed and tested for pathogenicity in a murine model. No difference in pathogenicity was observed between the wild-type strain and the alp mep double mutant, suggesting that ALP and MEP are not essential for the invasion of the lung tissues by A. fumigatus.     

Cutaneous toxicity following the administration of dactinomycin

The author describes a patient who has a successful coronary artery bypass. Six weeks later, after a physical examination of the chest, she had unbearable sharp, stabbing pain around the incision which was not responding to nerve blocks, analgesics, nonsteroidal anti inflammatory agents, and epidural blocks. The pain was responsive to mexilitine and disappeared after three weeks of treatment.     

High-dose chemotherapy with carboplatin, etoposide and cyclophosphamide followed by a haematopoietic stem cell rescue in patients with high-risk retinoblastoma: a SFOP and SFGM study

This study investigates the role of high-dose chemotherapy with haematopoietic stem cell rescue as consolidation treatment in high-risk retinoblastoma (extraocular disease at diagnosis or relapse or invasion of cut end of optic nerve). 25 patients received high-dose chemotherapy including carboplatin (250 mg/m2/day from day 1 to day 5 for the 6 first patients and 350 mg/m2/day from day 1 to day 5 for the other patients), etoposide (350 mg/m2/day from day 1 to day 5) and cyclophosphamide (1.6 g/m2/day from day 2 to day 5) (CARBOPEC) followed by autologous haematopoietic stem cell rescue. 19 patients received this drug combination for chemosensitive extraocular relapse. The other 6 patients with histological high-risk factors were given this treatment as consolidation after enucleation and conventional chemotherapy. The three year disease-free survival was 67.1%. In 7 of the 9 relapsing patients, the first site of relapse was the central nervous system. All patients with central nervous system disease died except one. The main toxicity was haematological and digestive (mucositis and diarrhoea). 2 of the 13 evaluable patients had grade III and IV ototoxicity. One patient experienced an acute grade I reversible cardiotoxicity. The CARBOPEC regimen seems to be a promising therapeutic strategy in patients with high-risk retinoblastoma, especially those with bone and/or bone marrow involvement. This treatment did not improve the outcome of patients with central nervous system disease.