Heart transplantation for homozygous familial transthyretin (TTR) V122I cardiac amyloidosis.

Heart failure is the usual cause of death in patients with amyloid cardiomyopathy. The commonest form of hereditary cardiac amyloidosis is associated with the Val122Ile variant of transthyretin (TTR), which is carried by 3-4% of the African American population. Here, we report the outcome of the first cardiac transplantation in a patient with TTR V122I. A 59-year-old Caribbean man presented with biventricular failure. Other than previous bilateral carpel tunnel syndrome, he had been well and had no evidence of extracardiac amyloidosis. An endomyocardial biopsy demonstrated amyloid of TTR type. Sequencing of TTR gene indicated homozygosity for V122I. He underwent cardiac transplantation and 3 years later, remains well with no evidence of allograft or systemic amyloid deposition.

Bone marrow findings correlate with clinical outcome in systemic AL amyloidosis patients.

AIMS: Bone marrow sampling is a key investigation in the work-up of amyloid light chain (AL) amyloidosis, but the relationship between bone marrow findings and the varied phenotype and clinical outcome of AL amyloidosis is unclear. The aim was to determine if bone marrow pathological parameters at diagnosis were related to clinical behaviour in AL amyloidosis patients. METHODS AND RESULTS: Bone marrow findings, clinical features and outcome of 80 patients referred with a diagnosis of systemic AL amyloidosis were evaluated; six patients were subsequently excluded due to re-categorization as other forms of amyloidosis. At latest follow-up (median 66 months), 11 of the 18 patients with no identifiable bone marrow neoplastic cells (61%) versus only seven of the 56 patients with neoplastic plasma cells or non-Hodgkin's lymphoma (13%) were alive (P = 0.0046). However, neither the quantity of the neoplastic cells nor the serum light chain levels were correlated with amyloid burden or patient survival. CONCLUSIONS: Identification of a neoplastic population in the bone marrow of AL amyloidosis patients by histology and immunohistochemistry correlates with poor outcome; however, the neoplastic cell burden is not prognostically significant, suggesting that additional factors are important in determining disease behaviour in AL amyloidosis.

Organ transplantation in hereditary apolipoprotein AI amyloidosis.

Patients with hereditary apolipoprotein AI (apoAI) amyloidosis often have extensive visceral amyloid deposits, and many develop end-stage renal failure as young adults. Solid organ transplantation to replace failing organ function in systemic amyloidosis is controversial due to the multisystem and progressive nature of the disease and the risk of recurrence of amyloid in the graft. We report the outcome of solid organ transplantation, including dual transplants in 4 cases, among 10 patients with apoAI amyloidosis who were followed for a median (range) of 16 (4-28) and 9 (0.2-27) years from diagnosis of amyloidosis and transplantation, respectively. Eight of 10 patients were alive, seven with a functioning graft at censor. Two patients died, one of disseminated cytomegalovirus infection 2 months after renal transplantation and the other of multisystem failure following severe trauma more than 13 years after renal transplantation. The renal transplant of one patient failed due to recurrence of amyloid after 25 years. Amyloid disease progression was very slow and the natural history of the condition was favorably altered in both cases in which the liver was transplanted. Failing organs in hereditary apoAI amyloidosis should be replaced since graft survival is excellent and confers substantial survival benefit.

Cloning and nucleotide sequence of the Butyrivibrio fibrisolvens gene encoding a type III glutamine synthetase.

A Butyrivibrio fibrisolvens glnA gene encoding glutamine synthetase (GS) was cloned on a recombinant plasmid pGS4 which enabled Escherichia coli glnA deletion mutants to utilize (NH4)2SO4 as a sole source of nitrogen. The nucleotide sequence of a 2423 bp DNA segment containing the GS-coding region of B. fibrisolvens was determined and the complete amino acid sequence (701 residues) was deduced. Comparisons of the derived B. fibrisolvens GS protein sequence with the amino acid sequences of GS from other bacteria indicate that it is the second reported example of a type III GS, originally identified in the obligate anaerobe Bacteroides fragilis. The presence of GS in B. fibrisolvens cells and the regulation of the cloned GS in E. coli cells was demonstrated by Western blot analysis.

Molecular analysis of the Bacteroides fragilis recA gene.

The nucleotide sequence of a 2.5-kb DNA segment containing the Bacteroides fragilis recA gene was determined. The coding region of the recA gene specifies a protein of 318 amino acids. The RecA protein of B. fragilis shows significant homology with that of Escherichia coli, Thiobacillus ferrooxidans, Pseudomonas aeruginosa and Proteus mirabilis. No SOS box characteristic of LexA-regulated promoters could be identified in the 5'-noncoding region of the B. fragilis recA gene. Promoter activity of the cloned recA gene in E. coli was located within a 113-bp fragment of the B. fragilis DNA by in vitro construction of operon fusions with a promoterless lacZ gene. The transcription start point for this gene in B. fragilis was determined by primer extension analysis.

Expression and regulation of a Bacteroides fragilis sucrose utilization system cloned in Escherichia coli.

A Bacteroides fragilis strain isolated from human feces was the source of chromosomal DNA in the construction of plasmid pBS100. The cloned 6-kilobase insert of plasmid pBS100 conferred a sucrose positivity phenotype on transformed cells of Escherichia coli JA221. E. coli JA221(pBS100) cells were able to utilize sucrose as the sole source of carbon because of the presence of sucrase enzyme and sucrose uptake activities. Sucrase activity was inducible in B. fragilis but constitutive in E. coli JA221(pBS100) cells. In sucrose-minimal medium, both B. fragilis and E. coli JA221(pBS100) produced intracellular and extracellular sucrase activities throughout the growth cycle. Osmotic shock experiments performed on E. coli JA221(pBS100) indicated that up to 55% of the sucrase activity was localized in the periplasmic space, 30% was in the cytoplasm, and the remaining 15% was in the cell-free extracellular supernatant fluid. B. fragilis and E. coli JA221(pBS100) actively transported sucrose. Sucrose uptake was induced by sucrose in B. fragilis, whereas the uptake activity in E. coli JA221(pBS100) was constitutive. E. coli JA221(pBS100) appeared to transport sucrose by a phosphotransferase-independent system. B. fragilis transported sucrose only under strictly anaerobic conditions. No uptake activity was detected under aerobic conditions with or without addition of catalase.

Cloning of Bacteroides fragilis plasmid genes affecting metronidazole resistance and ultraviolet survival in Escherichia coli.

Since reduced metronidazole causes DNA damage, resistance to metronidazole was used as a selection method for the cloning of Bacteroides fragilis genes affecting DNA repair mechanisms in Escherichia coli. Genes from B. fragilis Bf-2 were cloned on a recombinant plasmid pMT100 which made E. coli AB1157 and uvrA, B, and C mutant strains more resistant to metronidazole, but more sensitive to far uv irradiation under aerobic conditions. The loci affecting metronidazole resistance and uv sensitivity were linked and located on a 5-kb DNA fragment which originated from the small 6-kb cryptic plasmid pBFC1 present in B. fragilis Bf-2 cells.

Molecular analysis of a novel glutamine synthetase of the anaerobe Bacteroides fragilis.

The nucleotide sequence of a 2777 bp DNA segment containing the Bacteroides fragilis glnA gene was determined. The B. fragilis glnA open reading frame of 2187 bp encoded a glutamine synthetase (GS) subunit of 729 amino acid residues with a calculated Mr of 82,827. The apparent Mr of the GS subunit determined by SDS-PAGE was approximately 75,000. A single mRNA transcription start point was identified upstream of the B. fragilis glnA open reading frame. The B. fragilis GS subunit is approximately 270 and 400 amino acids longer than the GSI and GSII subunits, respectively, of other prokaryotes and eukaryotes. The GSI and GSII holoenzymes are dodecamers and octamers respectively, whereas the GS of B. fragilis is a hexamer. Although GSI and GSII subunits show amino acid similarity in five conserved regions, this similarity is not strongly conserved in the B. fragilis GS. The GS of B. fragilis is not regulated by adenylylation and lacks the adenylylation site. It also lacks the Trp residue associated with the active site in GSI and GSII enzymes from other prokaryotes and eukaryotes.

Cloning and expression in Escherichia coli of a recA-like gene from Bacteroides fragilis.

The recombinant plasmid pHG100, containing a 5.2-kb DNA fragment from Bacteroides fragilis, complemented defects in homologous recombination, DNA repair and prophage induction to various levels in an Escherichia coli recA mutant strain. There was no DNA homology between the cloned B. fragilis recA-like gene and E. coli chromosomal DNA. pHG100 produced two proteins with Mr of approx. 39,000 and 37,000 which cross-reacted with antibodies raised against E. coli RecA protein. The production of these proteins was not increased after UV induction. The cloned B. fragilis recA-like gene product did not enhance the production of native but defective E. coli RecA protein after UV irradiation.

Heat shock stress in Bacteroides fragilis.

The response to heat shock was investigated in the obligate anaerobe Bacteroides fragilis. The cells responded quickly to stress and synthesised seven heat shock proteins immediately upon exposure to heat. The apparent molecular weights of the seven proteins differed from the apparent molecular weights of the proteins induced by UV irradiation, O2 and H2O2. Heat shock did not induce phage reactivation whereas UV irradiation, O2 and H2O2 did induce phage reactivation systems. Ethanol did not elicit the heat shock response. Two heat resistant B. fragilis mutants were isolated. Both mutants lost the ability to synthesise the same two heat shock proteins. It is concluded that the heat shock response and the responses to UV irradiation, O2 and H2O2 represent two independent groups of stress responses in B. fragilis.